performance of sweet pepper under protective structure international journal of environment issn 2091-2854 iv | p a g e international journal of environment volume-8, issue-2, 2019 issn 2091-2854 guest editorial sustainable marketing – a path to follow as the world sees a depletion of its rare and scarce natural resources, it is of utmost importance not to neglect the various calamities occurring almost simultaneously around different parts of the world, namely the fire in australia/queensland, the floods in mumbai and other parts of india, dorian and its damaging effects in the bahamas. during a short visit in mauritius and madagascar last week, the holy pope placed emphasis on deforestation and its influence on the global climate. these calls for our close attention and such messages coming from several corners and spheres cannot be ignored. sustainability marketing has emerged as an important roadmap and framework to follow to help the world and its population in its global village. sustainable marketing is the adoption of marketing processes to create customer’s satisfaction and generate returns by taking into consideration the ecological and societal needs. sustainability marketing is about the triple bottom line that includes along with profits the benefits to society and the environment in a holistic manner. accordingly, sustainable marketing serves as an immediate solution to contain the consumption of goods and services while taking into consideration the sustainable use of resources and controlled consumption levels that have another set of implications including waste handling plus ecological and environmental concerns. it is noteworthy that some measures are already in place to combat negative consequences of consumptions that arise out of greed instead of need. for example, drastic diminution of fish in our oceans is being addressed through increasing application of aquaculture to raise production of fish and other aquatic resources. solar, wind and other forms of energy are used to complement the use of oils and petrol. increasing contribution of the hybrid and electric vehicles and engines in turn helps to reduce emissions drastically in urban areas as those experienced in for example new delhi in india. such initiatives are to be commended and sustained over time and relentlessly. international journal of environment issn 2091-2854 v | p a g e the contribution of everyone in these endeavors is to be tapped without exceptions. if properly educated and led, poorer areas may be put to contribution as they are resources that are left untapped mostly as a result of little education and poverty. for instance, why not promote agriculture and farming though individual householders like it used to be back in the years – if everyone brings in something the shortage of food and fruits is likely to be bridged. for instance, the government of mauritius have taken the decision to plant 100000 plants around the island following the visit of the holy pope. such examples need to be taken seriously and adopted by every parts of a country that has the capacity to do so one way or the other. initiatives must come from the top in numerous cases and through transformational leadership, the population is very likely to contribute to the cause of sustainable development that by now has convinced many if not all. transformational leaders are no longer rare as many are attending university education in sustainable marketing and related courses, thereby building capacity in areas of priority and they must be tapped to contribute effectively and efficiently. if adopted worldwide and consumption becomes more modest such as increasing use of bicycles and other more efficient modes of transportation, low energy bulbs, hybrid cars, increasing use of solar panels, increasing contribution towards production of food, farm products and fruits, elimination of plastics that cause several harms to the environment, increasing adoption of recycling and use of recycled products, less wastage of clothing and food etc. we can be more confident about the future of the next and future generations towards healthy living and cheerfulness. under these conditions that clearly emerge from sustainable marketing practice, we can expect nature to give something back to us in return and sustain the welfare of every citizen. mehraz mehraz boolaky, ph.d., mba, b. chem engg. cpe, fhea professor of marketing and management university of liverpool/laureate email: mehz51@yahoo.co.uk; mehraz.boolaky@online.liverpool.ac.uk september 17, 2019 doi: http://dx.doi.org/10.3126/ije.v8i2.25654 copyright ©2019 ije this work is licensed under a cc by-nc which permits use, distribution and reproduction in any medium provided the original work is properly cited and is not for commercial purposes mailto:mehz51@yahoo.co.uk mailto:mehraz.boolaky@online.liverpool.ac.uk http://dx.doi.org/10.3126/ije.v8i2.25654 performance of sweet pepper under protective structure international journal of e nvironment issn 2091-2854 109 | p a g e international journal of environment volume-3, issue-4, sep-nov 2014 issn 2091-2854 received:19 october revised:19 november accepted:25 november pollen morphology and palynotaxonomical studies of common garden plants of apocynaceae, in kolkata, west bengal, india reshmi chatterjee 1* , satadip sarkar 2 and g. m. narasimha rao 3 1,2 department of botany, bethune college, kolkata700 006, west bengal. india 3 department of botany, andhra university, visakhapatnam-530 003, andhra pradesh, india * corresponding author: chatterjeeresidence@ gmail.com abstract taxonomy and identification of angiosperms are mainly based on external morphological characters and traits of the plants; however palynological data sets are remotely used for the study. pollen characters are genetically regulated that can be used as an ideal tool for establishing taxonomic groups. this type of integrated study can be useful in redefining the status of families in higher group of plants. apocynaceae, a eurypalynous family exhibits variation in possessing more than one type of pollen grains from simple porate to compound colporate apertures. pollen attributes has been utilized in building a pollen key that would enable us to distinguish genera solely on the basis of pollen characters. keywords: apocynaceae, taxonomy, palynology, pollen, eurypalynous introduction every man is a taxonomist from the cradle to the grave. he is surrounded by plants and trees all around him and therefore they can be considered as the primary companion in the biotic community. classification of the plants can be dated back with the onset of human civilization, when he classified plants under groups based on their economic potential to him. the scientific approach of classification was recognized by a. p. de candolle and he introduced the formal subject of “taxonomy” in his legendary work theorie elementaire de la botanique (candolle, 1813). taxonomic identification of angiosperms is mainly done based on visible morphological aspects and characters of the plants. phenetic system of international journal of e nvironment issn 2091-2854 110 | p a g e classification encompasses characters and data from all available sources including morphology, anatomy, phytochemistry, palynology, cytology and others to establish relationship amongst taxa. the scientific study of pollen grains and spores, both living and fossils make up the subject “palynology”. it was introduced by hyde and williams in the journal of pollen analysis circular (hyde and williams, 1944). the term is derived from the greek word „palunō‟ meaning to sprinkle, fine meal. pollen grain forms the first cell of the male gametophytic generation of the spermatophytic group of plants. it consists of two wall layers: the outer sculptured, ornamented exine and the inner intine. characters of pollen grains are genetically labeled and display unique traits in wall ornamentation, aperture and reticulation. pollen grains are produced in profuse number per anther to ensure successful pollination followed by germination that eventually led to seed-set production (chatterjee et al., 2014). this makes it a potential tool for taxonomic study as it overcomes the major drawback of other features namely, flower, fruits, seed, etc. which are produced in limited number, a necessary handicap with these parameters. study of pollen morphology is highly significant as it can be useful in establishing relationship amongst various taxa, resolving disputed taxonomical problem, building phylogenetic tree, tracing ancestry of a particular clade. besides, this discipline gives us a sound knowledge on pollination ecology, constructing phylogenetic classification as well as in palynotaxonomic studies. in case of angiosperm, pollen grains are produced from the sporogenous tissue of the anther of flower. morphologically angiospermic pollen grains exhibit highest level of variation that can be utilized in plant taxonomy (nair, 1964). they display unique traits of apertural variation right from the simplest inaperturate type recorded from the valanginian of the lower cretaceous of israel (brenner and bickoff, 1992) to the highly advanced echinate form as exhibited by the asteraceae. taxonomists strive to establish evolutionary relationships between plant populations and classify them into particular level of organization. based on the similarity index in pollen characters, various workers have attempted in drawing the evolutionary divergence and history of plant groups (guinet, 1966; tryton, 1986). but attempting in taxonomic identification of plants at generic level based on pollen character is a novel deed that has been attempted in the present work. international journal of e nvironment issn 2091-2854 111 | p a g e pollen characters are constant and are guided by the genetic makeup of the parent plant, hence providing us with very convincing data that can be utilized in building a systematic classification of angiosperms. comparative studies of palynological attributes have revealed that angiospermic families can be broadly categorized into two groups:  stenopalynouswith respect to size, aperture and stratification of exine, characters of pollen grain types is more or less constant within the family level as exemplified by poaceae, crucifeare, asclepediaceae, lamiaceae, etc.  eurypalynouswithin the family level grains shows considerable variation in attributes like size, exine ornamentation, apertures. solanaceae, asteraceae, apocynaceae, rubiaceae, etc are some common examples of this group. apocynaceae or “dogbane family” was instituted by antoine laurent de jussieu (jussieu, 1789). on a global scale, there are c. 5100 species distributed under 357 genera (meve, 2002; meve and liede-schumann, 2007; nazar et al., 2012). the family is represented by 24 genera and 52 species, in india (karthikeyan, 2000). the members have successfully established themselves right from the southern tropical rainforest to the temperate forest of the himalayan foothills. in west bengal, this family is represented by 16 species which are placed under 21 genera (sur, 2004). the members are widely used for their economically important nature; some of them provide us with crude drugs like cardiac glycosides, reserpine, vincristine, vinblastine, etc. from members like rauvolfia serpentina, catharanthus roseus and others. they are also widely used as ornamental plants like nerium, vinca, carissa, allamanda, plumeria, thevetia, mandevilla, etc. apocynaceae family has been considerably studied with respect to their morphological characters of pollen (pichon, 1947; 1948; leeuwenberg, 1988). palynologically apocynaceae depicts eurypalynous nature with variation in apertural characters. the family depicts simple porate aperture to compound colporate one. this palynological variation is helpful in identification of the taxa at the generic level. however this data is yet to be applied for building a pollen key that would be useful for re-categorizing the existing taxonomic position of genera under apocynaceae. the present study has been conducted on seven genera under the apocynaceae family namely; allamanda, alstonia, catharanthus, nerium, plumeria, thevetia and tabernaemontana that are commonly grown as ornamental plants in kolkata, west bengal international journal of e nvironment issn 2091-2854 112 | p a g e (figure 1). the members flowers round the year (except alstonia, a winter bloomer), with pollen output in considerable amount. species level variation is withheld for the time being. mature pollen grains were collected soon after anther dehiscence to get optimized result. pollen grains were collected from freshly opened flower buds preferably of same age to obtain uniformity in result, just before the anthesis stage. mature anthers were surface sterilized in 10% sodium hypochlorite solution. grains were pre-hydrated and arrested prior to germination stage when visibility of the apertures is most prominent. figure 1. map of india showing the study area, kolkata, west bengal to minimise error in measurement at least 20 pollen grains were measured randomly per genera from plants growing at different locality in kolkata. individual grains were measured using standardized stage and ocular micrometer. grains were acetolysed following the standard acetolysis method using acetolysis mixture (9:1 acetic anhydride and concentrated h2so4), followed by several washings with glacial acetic acid and distilled international journal of e nvironment issn 2091-2854 113 | p a g e water (erdtman, 1969). the acetolysed residue was stored in 50% glycerine with a drop of phenol for microscopic observation. temporary slides were prepared; shapes of pollen grains are categorized on the basis of the ratio of polar axis (pa) and equatorial diameter (ed) (erdtman, 1952). individual microphotographs of the grains were taken after preparing „single-grain preparation slides‟ (figure 2). figure 2. morphological variation in pollen grains amongs t the genera under apocynaceae a: alstonia; b: allamanda; c: catharanthus; d: plumeria; e: thevetia; f: plumeria; g: tabernaemontana; h: nerium. (all scale bar = 25 um.) since, palynological knowledge has been very limitedly applied in the taxonomical classification of angiosperms. keeping this view in mind, a pollen-key has been drafted for the seven genera of apocynaceae family that would help for a quick identification of the genera based on the pollen apertural characters. for ease of identification “bracketed key” is prepared with number of lead indicated in parentheses. characters of pollen grains are named following the npc-system of classification (erdtman, 1969). key to the genera: 1. pollen grains monad (single, free). 2. bladders absent. 3. pollen grains aperturate. 4. apertures simple; with pores; porate............................................... (6) international journal of e nvironment issn 2091-2854 114 | p a g e 4. apertures compound; with ora in colpi; colporate........................... (5) 5. pollen grains with pa/ed > ±75.6/71.4 µm.................................... (7) 5. pollen grains with pa/ed < ±75.6/71.4 µm.................................... (6) 6. pollen grain porate; 3-porate............................................................ (7) 6. pollen grain colporate; 3-colporate.................................................. 1. alstonia 7. pollen grain 3-colporate; apertural pore diameter > ±19 µm............ (8) 7. pollen grain porate; apertural pore diameter < ±19 µm...................... (9) 8. pollen grain with pa/ed ~ (±159.6 ±172.2) µm / ~ (±151.2 ±168) µm; exine psilate; grain prolate-spheroidal......................................2. catharanthus 8. pollen grain with pa/ed ~ (±100.8 ±126) µm / ~ (±79.8 ±92.4) µm; exine verrucate; grain sub-prolate................................................. 3.tabernaemontana 8. pollen grain 3-porate; pollen grain with pa/ed ~ (±58.8 ±155) µm / ~ (±50.4 ±138.6) µm........................................................................................ (11) 9. pollen grain 4-porate; pollen grain with pa/ed ~ (±54.6 ±84) µm / ~ (±50.4 ±75.6) µm............................................................................ (10) 9. pollen grain sub-prolate................................................................... 4. nerium 10. pollen grain prolate-spheroidal........................................................ 5. plumeria 10. pollen grain with pa/ed ~ (±134.4 ±155) µm / ~ (±113.4 ±138.6) µm; pore diameter (±29.4 ±42) µm........................................................ 6. thevetia 11. pollen grain with pa/ed ~ (±58.8 ±75.6) µm / ~ (±50.4 ±67.2) µm; pore diameter (±10.5 ±16.8) µm..................................................7. allamanda acknowledgements this research paper is made possible through the help and support from everyone, including: parents, teachers, family, friends, and in essence, all sentient beings. the author(s) expresses sincere appreciation to the unanimous reviewer for his/her critical remarks that helped in improving the quality of paper. references brenner, g.j. and bickoff, i.s., 1992. palynology and age of the cretaceous basal kurnub group from the coastal plain to the northern negev of israel. palynology 16, 137-185. international journal of e nvironment issn 2091-2854 115 | p a g e candolle, a.p. de., 1813. théorie élémentaire de la botanique ou exposition des principes de la classification naturelle et de l‟art de décrire et d‟etudier les végétaux. déterville, paris. chatterjee, r., sarkar, s. and narasimha rao, g. m. 2014. improvised media for in vitro pollen germination of some species of apocynaceae. international journal of environment 3 (3), 146-153. erdtman, g., 1960. the acetolysis method, revised description. svensk botanisk tidskrskrift 54, 561–564. erdtman, g., 1952. pollen morphology and plant taxonomy. angiosperms. almqvist and wiksell, stockholm, pp. 539. erdtman, g., 1969. handbook of palynology an introduction to the study of polllen grains and spores. munksguard, copenhagen, pp. 486. guinet, p., 1966. les caractères du pollen dans le genreleucaena (mimosaceae). pollen & spores 8, 37–48. hyde, h.a. and williams, d.a., 1944. the right word. pollen analysis circul ar 8, 6. jussieu, a.l. de., 1789. genera plantarum. (herissant: paris). karthikeyan, s., 2000. a statistical analysis of flowering plants of india. in: n. p. singh et al. (eds.) flora of india, introductory volume part ii botanical survey of india, calcutta, pp. 201 217. leeuwenberg, a.j.m., 1988. the nerieae (apocynaceaeapocynoideae).monographs in systematic botany from the missouri botanical garden 25, 157-160. meve, u., 2002. species numbers and progress in asclepiad taxonomy. kew bulletin 57, 459-464. meve, u. and liede-schumann, s., 2007. ceropegia (apocynaceae, ceropegieae, stapeliinae): paraphyletic, but still taxonomically sound. annals of the missouri botanical garden 94, 392–406. nair, p.k.k., 1964. advances in palynology. national botanical garden, lucknow, india, pp. 203-204. nazar, n., goyder, d.j., clarkson, j.j., mahmood, t. and chase, m.w., 2013. the taxonomy and systematics of apocynaceae: where we stand in 2012 botanical journal of the linnean society, 171, 482–490. international journal of e nvironment issn 2091-2854 116 | p a g e pichon, m., 1947. classification des apocynacées: v. cerbéroïdées natural systematics (paris) 13, 212-229. pichon, m., 1948. classification des apocynacées. i. carissées et ambelaniées. mémoires du muséum national d'histoire naturelle, séries b, botanique 24, 111–181. sur, p.r., 2004. contribution to the apocynaceae of west bengal. journal of economic and taxonomic botany 28 (3), 562 572. tryton, a.f., 1986. in: pollen and spores (eds.), stasis, diversity and function in spores based on an electron microscope survey of pteridophyta, s. blackmore and i.k. ferguson, academic press, london, pp. 233–249. international journal of environment issn 2091-2854 1 | p a g e international journal of environment volume-1, issue-1, jun-aug 2013 issn 2091-2854 received: 26 may revised: 17 july accepted: 16 august performance of sweet pepper under protective structure in gazipur of bangladesh g. m. a. halim 1 and m. s. islam 2* 1 cso, olericulture division, horticulture research centre, bari, gazipur 2 dr. md. shahidul islam, associate professor, dept. of horticulture, sylhet agricultural university, sylhet *corresponding author: shahidulhrt@gmail.com abstract evaluation of sweet pepper cultivation under different protective structures was made in two consecutive seasons of 2007-08 and 2008-09 at the experimental field of horticulture research center of bari, gazipur. one popular commercial capsicum variety california wonder was included in the study with four protective structures (low height poly tunnel, polytunnel with side open, poly tunnel with side closed and poly house) including control (open field). protective structures had remarkable and significant influence on plant growth and yield of sweet pepper. the plants grown under protective structures had higher plant height compared to that of plants grown in open field. the highest individual fruit weight (65.2g) was recorded form the plants grown under poly house condition while it was the lowest from open field grown plant (3.34 g). more than five fruits were harvested when the plants were grown under poly tunnel (side closed) or poly house. the maximum fruit yield per plant (334.0g) was recorded from poly house, which was 160.4% higher than that of plants grown under open field condition. the second highest yield was recorded from the plants of poly tunnel (212.5) indicating bright scope for sweet pepper cultivation under protective structures. key words: sweet pepper, protective structure, poly tunnel, open field introduction sweet pepper (capsicum annuum l) is one of the most important vegetable crops grown extensively throughout the world especially in the temperate countries. the crop is very sensitive to environmental factors (bhatt et al., 1992). owing to its sensitivity, its yield is affected significantly. capsicum is the most important summer crop of temperate regions but now a days efforts are being made to grow sweet pepper in bangladesh (paul, 2009). some advanced farmers grow capsicum sporadically to meet the demand of the periphery of dhaka city (saha and salam, 2004). its production is in bangladesh is largely affected due high infestation of mite and low night temperature. (anon, 2008). the optimum temperature requirement for sweet pepper growth ranged from 16-25 0 c. high night temperature is more mailto:shahidulhrt@gmail.com international journal of environment issn 2091-2854 2 | p a g e detrimental to fruit set than day temperature (rylski and spigelman, 1982). again night temperature below 16 0 c and day temperature above 32 0 c also causes blossom dropping (boswell, 1964). in bangladesh, from december to january during vegetative and fruiting stage of the crop, night temperature is gradually decreased below 10 0 c or less. in that situation vegetative and reproductive stage of capsicum plants become ceased or stunted, fruit and flower drops may occur. so for proper growth and yield of capsicum at low temperature under netted poly tunnel or poly house may be effective because it protected the plants from pest infestation and from cold injury since night temperature inside poly covers raises higher than outside. however, information regarding use of protective structures for capsicum production in bangladesh is very scanty. therefore, the present investigation was undertaken to study the effect of protective structures on the growth and yield of capsicum. materials and methods the study was conducted at olericulture division, hrc, bari gazipur, during rabi season of two consecutive years of 2006-07 and 2007-08. the study was set up in rcb design with four replications. one popular commercial capsicum variety california wonder was included in the study with four protective structures including control (t1=open field, t2=low height poly tunnel having 2.0 feet height in the middle, t3= polytunnel having 6.0 feet height in the middle in which side of the tunnel remain open, t4=poly tunnel having 6.0 feet height in the middle in which side of the tunnel remain closed by polythene and t5=poly house). photograph of the treatments are presented in figure 1. international journal of environment issn 2091-2854 3 | p a g e the seeds were sown in seedbed on october 17 in both of the year 2006 and 2007. seedlings of 2-3 leaf stage were transplanted to poly bags. thirty five days old seedlings (4-5 true leaf stage) were transplanted in the experimental plots. the unit plot size was 4.0 x 2.0 m and the plants were spaced 50 x 40 cm between plant-to-plant and row-to-row, respectively. the crop was fertilized with cow dung, urea, tsp, mp, gypsum and zno at the rate of 10 ton, 220kg, 330 kg 200 kg 110 kg and 5 kg per hectare, respectively. half of the quantity of cow dung was applied at final land preparation. the remaining cow dung, entire quantity of tsp, zno, t5: poly house t4: poly tunnel (side closed) t1: control t2: low height poly tunnel t3: poly tunnel (side open) figure1. photographs of different treatments t1 t2 international journal of environment issn 2091-2854 4 | p a g e gypsum and one third each of urea and mp were applied during pit preparation. the rest of urea and mp were applied in two equal splits at 25 and 50 days after transplanting in the main field. irrigation, weeding and mulching were done as required. data were recorded on yield and yield attributes and analysed using mstat software for interpretation of results. results and discussion main effect of protective structure significant variation was observed among the different structures for all the parameters studied (table 1). days required to flower was the earliest (59.0days) for the plants when grown in open field conditions. the plants grown under poly tunnel (t4=side closed) required maximum days (65.5 days), which was at par with the plants grown in poly house (64.90 days). the variation in days to first flower between open field and protective structures might be attributed due to the congenial atmosphere prevailed in protective structures which encouraged the plants for more vegetative growth. this statement is clearly reflected in the plant growth when grown in protective structures. the highest plant height was recorded from the plants (51.58cm) when grown under poly house while it was the lowest in open field condition (39.10 cm). low night temperature and other biotic and abiotic stresses in the open field were responsible for low plant growth. boswell (1964) opined that low night temperature is very detrimental for growth of sweet pepper. again the highest number of fruits per plant was recorded from the crop grown under poly house (5.12) followed by side closed polytunnel (5.20). not only that, individual fruit weight, fruit length, and fruit breadth also the highest for the crop when grown under poly house. the heaviest individual fruit weight (65.20 g) was recorded from poly house grown plant while it was only 38.87 g when grown in open field. the highest fruit yield per plant was obtained from the poly house crop (334.6g/plant) where as it was only 128.5 g form the plants of open field. from the above discussion it is clear that protective structure is a prerequisite for successful capsicum production under bangladesh condition. protective structures provide congenial atmospheric conditions and also protected the crops from pests. again structures were found more effective because at night, capsicum plants covered with polythene sheet prevent the crop form cold injury and enhance proper growth and development. table 4 was also supported that the minimum temperature under protective structures was 2-3 0 c higher than that of open field temperature. the increased temperature in protective structure compared to open field favors proper growth of the plant under protective structure condition. specially, the minimum temperature from 15 december to 15 january in protective structure was international journal of environment issn 2091-2854 5 | p a g e around 14 o c while it was around 11 o c in the open field condition (table 4). this temperature variation might be the cause of yield variation between open field and protective structure. not only that shade can improve yield or sweet pepper (el-aidy et al., 1989). wien et al. (1989) concluded that a little shade in the tropics might benefit pepper growth. under this study, protective structures protect the plants from direct sun, which ultimately influence plant growth and yield. interaction between year and protective structures interaction effect between protective structures and year for different parameters was presented in table 2. days to first flower was varied from 60 to 68.5 days. plants those were grown under protective structures exhibited delayed flowering. maximum plant height was also recorded from the plants of protective structures in both of the years (107.2cm and 95.3 cm, respectively). the highest individual fruit weight was observed in 1 st year when plants were grown under poly house (67.33g). similar trend was also observed for the 2 nd year crop when grown under poly tunnel (63.17g). the higher individual fruit weight might be attributed due to better vegetative growth of the plants grown under poly house. the highest number fruits per plant was recorded in first year crop when grown side closed poly tunnel (7.39) closely followed by poly house (6.42). similarly in 2 nd year crop, higher number of fruits was harvested from the plants grown in poly house and side closed poly tunnel. in respect of fruit yield per plant, protective structures like poly house and side closed poly tunnel provided higher amount of fruit per plant. in first year, the highest fruit yield per plant was recorded from the plant of poly house (431.6g) followed by side closed poly tunnel plants (308.0g). in both of the year, the lowest yield was recorded from open field plant. paul (2009) opined that use of poly-shade and shade nets are very much effective for sweet pepper production in bangladesh. again paul (2009) recorded better marketable yield when the crop was provided with partial shading. mean effect of year yearly variation as regard to yield and yield parameters of sweet pepper is presented in table 3. most of parameters were significantly higher for 1 st year crop. fruit yield per plant was much higher in 1 st year (286.42.3) compared to that of 2 nd year crop (136.40). this indicates that sweet pepper is very much sensitive to environment. for two years investigation result suggested that sweet pepper production under bangladesh condition is possible provided the crop is protected from biotic and a biotic international journal of environment issn 2091-2854 6 | p a g e stresses. protection of plants from low night temperature during heavy cold, protraction of the plants from mite and insects are the prime prerequisite for successful capsicum production in bangladesh table 1. yield and yield components of sweet pepper under different protective structures (pooled over means of two years) tre atm ent days to flower days to harvest plant height (cm) fruit length (cm) fruit breadth (cm) individual fruit weight (g) number of fruit/ plant fruit yield/ plant (g) % yield incre ase t1 59.0 c 96.13 c 39.10 d 6.18 b 5.03 c 38.87 d 3.31 b 128.5 c t2 63.08 b 99.08 b 41.10 c 5.36 c 4.66 d 41.73 b 3.80 b 162.0 c 26.0 t3 62.40 b 97.68 b 41.65 bc 5.36 c 5.01 c 42.10 b 3.43 b 150.4 c 16.6 t4 65.65 a 98.08 b 42.73 b 6.18 b 5.17 b 40.03 c 5.20 a 212.5 b 65.0 t5 64.90 a 101.3 a 51.58 a 7.23 a 6.22 a 65.30 a 5.12 a 334.6 a 160.4 ftest ** ** ** ** ** ** ** ** means followed by same letter(s) in a column do not differ significantly by lsd where, t1= control (open), t2= low height poly tunnel, t3=poly tunnel (side open) t4= poly tunnel (side closed), t5=poly house table 2. interaction effect between year and protective structure on yield and yield parameters of sweet pepper treatment days to flower days to harvest plant height (cm) fruit length (cm) fruit bread th (cm) individu al fruit weight (g) numbe r of fruit/ plant fruit yield/ plant (g) year1x t1 58.0 a 102.0 b 36.13 g 6.13 5.06 38.3 g 4.58 cd 173.5 c year1x t2 65.0 b 103.2 b 34.03 h 5.26 5.02 44.13 d 5.18 c 228.2 c year1x t3 62.8 c 102.3 b 40.27 ef 5.39 5.31 48.23 c 4.47 cd 214.7 c year1x t4 68.3 a 102.2 b 38.30 f 6.2 5.44 42.03 e 7.34 a 308.0b year1x t5 68.5 a 107.2 a 49.27 b 7.11 6.3 67.23 a 6.42 b 431.6a year 2x t1 60.0 d 90.2 d 42.07 de 6.23 5.0 39.43 f 2.10 f 83.4 d year 2x t2 61.1 d 95.0 c 48.17 dc 5.45 4.3 39.33 f 2.42 ef 95.8 d international journal of environment issn 2091-2854 7 | p a g e year 2x t3 62.0 c 93.1 c 43.03 d 5.33 4.71 35.97 g 2.39 ef 86.1 d year 2x t4 63.0 c 94.0 c 47.17 c 6.16 4.90 38.02 h 3.06 e 117.1 d year 2x t5 61.3 cd 95.3 c 53.90 a 7.34 6.14 63.17 b 3.83 d 241.94b f-test ** ** ** ns ns ** ** ** **= significant at 1% level of probability, ns= not significant means followed by same letter(s) in a column do not differ significantly by lsd table 3. yearly variation of yield and yield parameter of sweet pepper treatment days to flower days to harvest plant height (cm) fruit length (cm) fruit breadth (cm) individual fruit weight (g) number of fruit/ plant fruit yield/ plant (g) y1 62.52 103.35 39.60 6.02 5.43 48.98 5.59 273.91 y2 61.49 93.54 46.86 6.10 5.01 43.18 2.76 119.17 f-test ** ** ** ** ** ** ** ** table 4.fortnight temperature ( o c) data (outside and inside of protective structures) during cropping period of first and second year crop period 2007-2008 maximum ( o c) minimum ( o c) outside inside outside inside nov 1-15 30.2 32.5 20.8 23.1 nov 16-30 28.8 31.7 17.2 19.8 dec 1-15 26.74 28.9 15.0 18.3 dec 16-30 25.1 26.7 11.6 13.9 jan 1-15 26.2 28.5 11.7 13.8 jan 16-30 22.6 24.35 13.1 14.9 feb 1-15 25.3 26.9 12.9 14.8 feb 16-29 27.5 29.1 14.6 15.9 references anonymous. 2008. annual report-2008 of olericulture division, horticulture research center, bari, gazipur. international journal of environment issn 2091-2854 8 | p a g e bhatt, r. m.; n. k. s. rao and n. anand. 1992.response of bell pepper to irradiance photosynthesis, reproductive attributes and yield. indian j. hort., 56(1):62-66. boswell, v. r. 1964. pepper production. in: spices, vol 1(ed). longman scientific technical, john willy and sons inc. new york :p.331. el-aidy,f., m. el-afry and f. ibrahiem. 1989. the influence of shade nets on the growth and yield of sweet pepper. in: green s. k. (ed.) tomato and pepper production in the tropics. avrdc, taiwan, 345-348. paul t. k. 2009. technology of sweet pepper production in bangladesh. phd theis. dept of horticulture, bsmrau, salna, gazipur. p. 225. ryiski, i and m spigelman. 1982. effects of different diurnal temperature combination on fruit set of sweet pepper. scintia hort., 17: 359-366. saha, s. r. and m. a. salam 2004. modern techniques of sweet pepper cultivation. a booklet published by plant physiology section, hrc, bari, gazipur. wien, h. c., k. e. tripp, a. r. harnandez and a. d. turner. 1989. abscission of reproductive structures in pepper: causes, mechanism and control. in: green s. k. (ed.) tomato and pepper production in the tropics. avrdc, taiwan, 150-165. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 85 | p a g e international journal of environment volume-3, issue-1, dec-feb 2013/14 issn 2091-2854 received:22 december revised:6 january accepted:21 january three new records of jungermannia species (hepaticae, jungermanniales) from nepal nirmala pradhan natural history museum, swayambhu, kathmandu, nepal corresponding author: nir.pradhan1@gmail.com abstract jungermanniaceae is the largest family of the order jungermanniales, which includes three subfamilies viz jamesonielloideae, mylioideae and jungermannideae representing 18 genera and 71 species in nepal. this paper deals with three new records viz. jungermannia exertifolia steph., j. infusca (mitt.) steph. and j. pumila with., which were recorded in the year 2010 and 2011 at different elevations (150 to 1300 m) in chitwan district of central nepal. these species were observed mostly in the mesic habitats of sal (shorea robusta) forest with other tree species like dalbergia sisoo and acacia catechue. jungermannia pumila was recorded in broad leaved deciduous forest at 1275 m of elevation. key words: habitat, jungerminniaceae, new records, nepal, subfamily introduction bryophytes show diverse distribution patterns than the vascular plants, perhaps of their greater dispersal capacity through minute spores. many cosmopolitan species are found over all the continents. the high humidity and predominating rain are the important factors to create suitable environment for the luxuriant growth of bryophytes. the decrease in precipitation is directly associated to the decrease in the growth and distribution. some bryophytes can tolerate high temperature, extreme desiccation and some can survive prolonged freezing under wet or dry conditions (puri, 1973). jungermanniales is one of the largest orders of class hepaticae, having 275 genera and 7000 species in the world. nepal represents the same order with 77 genera, 353 species and 24 families (pradhan and joshi, 2009). jungermanniaceae is the most diverse family representing three subfamilies viz jamesonielloideae, mylioideae and jungermannideae with total of 18 genera and 71 species in nepal. jungermanniais the widely distributed genus of this family. they may be dioecious or paroecious ground flora of varying sizes. shoots are prostrate or erect with lateral branches. rhizoids pale white to brownish arise from the ventral surface. lateral leaves oval with entire margin and succubous in arrangement. innovation arises beneath the perianth. very few literatures are available on nepalese bryophytes which are based mostly on the species diversity of eastern and central nepal. amakawa (1972) in his publications on mailto:nir.pradhan1@gmail.com international journal of environment issn 2091-2854 86 | p a g e asiatic species of jungermanniaceae also has mentioned some species like jungermannia macrocarpa, jungermannia kanaii and jungermannia truncata from eastern nepal. srivastava and singh (1988) made remarkable study which added two more species of jungermannia to the list of himalaya. these were jungermannia fauriana and jungermannia stephanii. likewise, mizutani (1979) compiled a list of 128 species of hepaticae including six species of jungermannia which were recorded from east nepal. long and grolle (1990) in their study on bhutanese hepaticae also has mentioned 13 species of jungermannia from nepal. mizutani et al. (1995) recorded 97 species belonging to 42 genera and 16 families of jungermanniales from the eastern and central nepal. this included a total of 17 species of jungermannia. this was the result of the botanical expedition of national science museum of japan held in 1988. shrestha et al. (2004) in their publication presented a list of 75 species of bryophytes collected in the chitwan district of nepal which also included six jungermannia species. these were collected at different elevations (150-1300 m). hattori (1966) compiled a list of three genera and nine species of jungermanniaceae of the eastern himalaya. of them, jungermannia glauca amak. was mentioned endemic to nepal which was collected at the elevation of 2500-3000 m. materials and methods study area chitwan is the central district of nepal, lies between 27º 21’ to 27º 52’ n and 83º 54’ to 84º 48’ e. major part of this district is incorporated into the national park system where potential floral components are found. this district is mostly dominated by the shorea robusta forest including other tree species like dalbergia sisoo, terminalia alata, bombyx ceiba, acacia catechue, trewia nudiflora, adina cordifolia, etc. common bryophytes of this district are asterella wallichiana, marchantia emarginata, plagichiasma pterospermum, fissidens sylvaticus, bryum coronatum, physcomytrium eurystomum, etc. fig. 1. map of nepal and location of chitwan (star) international journal of environment issn 2091-2854 87 | p a g e the present study was carried out from november to february (2010 – 2011) during sporophytic stage. laboratory knife and a standard wood chisel were used to scrape bryophytes from rocks and tree barks. the identification of bryophytes was done using standard published literature such as arnell (1956), kashyap (1972), so (1995), smith (1996), and zhu and so (1996). brummitt and powell (1992) was consulted to confirm the authority of the species. some of the delicate vegetative thalli of these plants were kept in wet conditions in biology laboratory for further anatomical study. the collected specimens were preserved in clean and sterilized glass bottles using a mixture of 4% formalin, faa solution (5 ml formalin, 5 ml glacial acetic acid , 90 ml of 70 % ethyl alcohol) and 50 % ethanol (manandhar 1982). results family: jungermanniaceae jungermannia l., sp. plant. ed.1: 1131, 1753. 1. jungermannia exertifolia steph., spec. hepat.6: 86, 1971; vana, j. hattori bot. lab.35: 312, 1972; sm., liverworts brit. & ireland: 142, 1996. plants dioecious or paroecious, vary in sizes, yellowish green to brown. shoots prostrate to erect, 5-6 cm long, profusely branches, arise laterally. rhizoids are hyaline to brown or deep red to purple and end to the knob like structure. leaves alternate, obliquely inserted, succubous, reniform, orbicular, broadly ovate to cordate with entire margin and 3x2 mm in size, middle laminal cells hexagonal, 34x17 µm in diameter, thin walled with 5-6 oil bodies and without trigones. underleaves and gemmae are usually lacking. innovations appear underneath the perianth. spores spherical, light brown, 10-24 µm in diameter (fig.2). habitat: wet boulder stones. status: rare specimens examined: c. nepal: chitwan, daughat-phedi forest, 300 m, 20.11.2010, pradhan 235 (nhm). distribution: nepal; british columbia, canada, caucasus, china, europe, greenland, iceland, japan, north italy and south spain. 2. jungermannia infusca (mitt.) steph., spec. hepat.2: 74, 1901. prectocolea infusca mitt., trans. linn. soc. london 2, 3: 196, 1891. nardia infusca (mitt.) steph., bull. herb. boiss. 5: 81, 1897. large patch of velvety bright green plants found intermingle with mosses, generally creeping and overlapping each other. stems usually unbranched, 8-10 mm long, flat with rectangular cells (12x23 µm in diameter). rhizoids pale brown, grow numerous on the ventral surface of the stem. lateral leaves on exposed parts are succubous, large, oval with entire margin and leaves on unexposed stems are little distant, pale brown, oval and 442x430 µm in sizes, laminal cells hexagonal, 34x23 µm in diameter, chlorophyllous and 2-3 oil bodies, trigones feebly developed. capsule spherical, dark purplish to maroon, 0.5 mm in diameter, on smooth location map of study sites in chitwan international journal of environment issn 2091-2854 88 | p a g e hyaline seta. spores spherical, light brown, 20.5 µm in diameter, elaters light brown, double banded with blunt ends (fig. 3). habitat: sandy soil. status: rare. specimens examined: c. nepal: chitwan, jugedi, 250 m, 21.11.2010 pradhan 266 (nhm). distribution: nepal; china, japan, taiwan, and u.s.s.r. 3. jungermannia pumila with., arrang. brit. pl. ed. 3,3: 883, 1796; arnell, moss fl. fennos 1: 106, 1956; amakawa, j. hattori bot. lab.22: 49, 1960; vana, j. hattori bot. lab.35: 315, 1972; sm., liverworts of brit. & ireland: 138-140, 1996. jungermannia zeyheri hubuene, hep. germ. : 89, 1834. jungermannia rostellata hubuene, hep. germ.: 95, 1834. jungermannia clavata hook. f. & tayl., london j. bot. 4: 88, 1845. aplozia pumila (with.) dumort., bull. soc. roy. bot. belgique13: 59, 1874. aplozia pumila var. rivularis schiffn., lotos 48: 326, 1900. plants small, dull green to blackish green. shoots 1-2 cm long and 0.3 mm broad. stems procumbent, apical part of stem ascending. rhizoids hyaline to pale brownish. leaves loosely imbricate, obliquely inserted, more or less uniform, dark green, elliptical to ovate, somewhat concave, erect to erecto-patent and 0.4x0.3 mm in size, margin entire, cells more or less hexagonal, double walled, isodiametric measuring 32x18 µm in diameter, trigones absent, oil bodies oval-spherical usually brown. female bracts resemble stem leaves, male bracts 4-8 in pairs below narrower and fusiforms perianth. spores spherical, small, 16-20 µm in diameter (fig. 4.). specimens examined: c. nepal: chitwan, shaktikhor-upperdang gadi, 1000-1275 m, 15.11.2010, pradhan 186 (nhm). habitat: bank and wet rocks. status: rare. distribution: nepal; china, iceland, ireland, greenland, peninsula, north britain, north fennoscandia, north italy, siberia, tanzania, west russia and yugoslavia. international journal of environment issn 2091-2854 89 | p a g e fig. 2. jungermannia exertifolia steph. (pradhan 235). a. habit, b. the sterile plant enlarged, c. a portion of female branch, d. portion of rhizoid with knob end, e. leaves, f. apical portion of the leaf, g. laminal cell. fig. 3. jungermannia infusca (mitt.) steph. (pradhan 266) a. habit, b. a fertile branch, c. leaves, d. a laminal cell with trigones, e. spores. international journal of environment issn 2091-2854 90 | p a g e fig. 4. jungermannia pumilawith. (pradhan 186). a. habit, b. a sterile plant, c. a fertile shoot, d. leaves, e. a laminal cell discussion the checklist of nepalese bryophytes presents 307 species of liverworts, 766 species of mosses and 8 species of hornworts (pradhan, 2000). the recent database at the natural history museum (nepal) contains 1205 species of bryoflora collected from different geographical regions of nepal (pradhan, 2013). pradhan, (2000) documented 31 species of jungermannia from different elevations of the country. pradhan and joshi (2009) listed 353 species, 77 genera and 24 families of the order jungermanniales of nepal which also included 41 species of jungermannia. grolle(1966) made a remarkable work on the bryophytes of nepal which brought a list of 5 endemic species of jungermannia like jungermannia atrorevoluta amak., j. flagellaris amak., j. poeltii amak., j. raujeana amak. and j. ventroversa grolle. the three newly recorded species differ each other in various respects. jungermannia. exetrtifolia and j. infusca are dioecious whereas j. pumila is paleocious. tyigones in leaf cells are absent in j. exertifolia and j. pumila but feeble developed in j. infusca. the stem leaves of j. exertifolia are quite larger than j. infusca and j. pumila. the narrow fusiform perianth is characteristic of j. pumila. amakawa (1960) and vana (1972) considered it as a subspecies of jungermannia cordifolia hook. it differs from j. cordifolia by its ovate oblong leaves which are cordate at their base. but schuster (1969) stated that both the taxa are conspecific. conclusion jungermanniaceae is the family of the order jungermanniales which is represented by three subfamilies viz jamesonielloideae, mylioideae, jungermannideae in nepal. altogether 18 genera and 71 species of this family have been reported in this country. three species viz jungermannia exertifolia steph., j. infusa (mitt.) steph. and j. pumila with. are the newly international journal of environment issn 2091-2854 91 | p a g e recorded and rare species which were collected within the elevation range of 150 to 1300 m in the mesic habitat of the sal (shorea robusta) forest at chitwan district of central nepal. acknowledgements the author would like to express sincere thanks to prof. dr. bhaiya khanal of natural history museum, nepal, for his valuable suggestions for the present manuscript. the author is also thankful to all colleagues and students, who cooperated during the fieldwork till its tenure. references amakawa, t., 1960. family jungermanniaceae of japan. journ. hattori bot. lab. 22: 1-90. amakawa, t., 1972. new or little known asiatic species of the family jungermanniaceae vii. journ. hattori bot. lab. 35: 382-390. arnell, s., 1956. illustrated moss flora of fennoscandia i. hepaticae. cwk gleerup pubs., london. brummitt, r.k. and powell, c.e., 1992. author’s of plant names. royal botanic garden, kew, uk. grolle, r., 1966. die lebermoose nepals. ergebnisse forschungs-unternehen nepal himalaya. 1(4): 262-298. hattori, s., 1966. bryophyta: anthocerotae and hepaticae in flora of eastern himalaya (eds. hara, h.) i: 501-590. kashyap, s.r., 1972. liverworts of the western himalayas and the punjab plain. part i & ii. research co. pubs, delhi. long, d.g. and grolle, r., 1990. hepaticae of bhutan ii. journ. hattori bot lab. 68: 381440. manandhar, n., 1982. floristic and taxonomic studies on some thalloid bryophytes of kathmandu valley. a dissertation submitted to the central department of botany, tribhuvan university, for the partial fulfilment of master’s science degree in botany. mizutani, m., 1979. hepaticae from eastern nepal collected by himalayan expedition of chiba university. journ. hattori bot. lab. 46: 311-325. mizutani, m., amakawa, t., kitagawa, n., furuki, t.,yamada, k. and higuchi, m., 1995. hepaticae from nepal collected by the botanical expedition of the national science museum, tokyo in 1988. i. jungermanniales (in watanabe, m and hagiwaga, h. eds.) cryoptogamic himalayas. national sci. mus., tsukuba. tsukuba 3: 383-392. international journal of environment issn 2091-2854 92 | p a g e pradhan, n., 2000. materials for a checklist of bryophytes of nepal. the natural history museum, london. pradhan, n. and joshi, s.d., 2009. liverworts and hornworts of nepal: a synopsis. botanical orientalis, journ of plant sci. 6: 69-75. pradhan, n., 2013. diversity and status of bryophytes in panch pokhari region of the northern sindhupalchok district of central nepal. journ. nat. hist. mus.27: 4558. puri, p., 1973. bryophytes: a broad perspective. atma ram and sons, delhi, india, pp 437 schuster, r.m., 1969. studies on hepaticae xviii. the family jungermanniaceae, s. lat.: a reclassification. trans. brit. bryol. soc. 6:86-107. shrestha, k., shrestha, p.k., khanal, b., pradhan n. and shakya, s. 2004. study of the biodiversity of tropical region of nepal, chitwan district. final report, pro natura foundation, japan. shrivastava, s.c. and singh, p., 1988. two species of jungermannia (solenostoma) new to himalaya (india). lindbergia 14(3): 162-166. smith, a.j.e., 1996. the liverworts of britain and ireland. cambridge university press, london. so, m.l., 1995. mosses and liverworts of hong kong. vol.1. heavenly people depot, hong kong. vana, j., 1972. miscellaneous notes on the asiatic jungermannioideae. journ. hattori bot. lab. 35: 312-318. zhu, r.l. and so, m.l., 1996. mosses and liverworts of hong kong. vol.2. heavenly people depot, hong kong. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 55 | p a g e international journal of environment volume-3, issue-2, mar-may 2014 issn 2091-2854 received:18 march revised:25 april accepted:18 may study of myrsine capitellata wall in forest areas of paiyunpata village, baglung, nepal hom nath pathak department of botany p.n. campus, pokhara corresponding author: homnpathak@gmail.com abstract present study focuses on ecology of myrsine capitellata wall. and its rapid decline due to overexploitation in forests of paiyunpata village, baglung district. ecological parameters like importance value, species diversity, etc. have been studied. besides, soil characters and causes and consequences of its deforestation have been discussed. the myrsine capitellata wall. is important forest component of the study area. community diversity is less in north facing slope than in south facing slope. soil is acidic, with high whc value, low moisture content and sandy type of texture. after this study, it is recommended to begin for the extensive plantation and other conservation efforts of myrsine before being extinct. key words: setikath, deforestation, conservation, nepal introduction forest is the natural renewable resource, which provides a sustained economic and social contribution for the development of the country. forest is major factor to environment concern, which provides habitat for wildlife, help in balancing the gaseous cycle of atmosphere and tend to increase local rainfall and water holding capacity of soil. it maintains soil fertility, regulates earth's temperature and water cycle, checks soil erosion, landslides, shifting of sand and reduces the flood havoc. the forests of nepal are the second largest natural resources after water (unep, 2001). however, during the last four decades, rapid forest decline began from 1950s. after nationalization of forest, the forest area has decreased considerably due to uncontrolled use of forests and their products. compared to 6.4 million hectares of forest in 1964, the current forest international journal of environment issn 2091-2854 56 | p a g e area is 4.27 million hectares i.e. 29% of the country's total area (dfrs, 1999). the current annual rate of deforestation is estimated to be 1.7 percent with 2.3 percent in hills (mope, 2000, dhoubhadel, 2001). this is mainly due to fault government policy and illegal logging and forest clearance for agricultural land. uncontrolled but sometimes a well planned clearing of forest for various purposes such as shifting agriculture (khoriya), fire wood, fodder, timber, grazing etc. is known as deforestation, which is the human encroachment on forest. present study is mainly focused on the deforestation of myrsine capitellata wall. belonging to myrsinaceae family and locally known as seti kath. the plant species has been cleared day by day in the study area for firewood, thankra (supports for climbers), muhura (stick for harvesting for cereals), handles of sickle, hammer, spade and axe, and thus the ground cover of the forest is emptied for leaf litter collection. this forest of myrsine is going to be extinct soon if the deforestation trend will further be like this. it will bring the environmental problems too. that is why the plant species is selected for the study. fuel-wood accounts for 78 percent of energy consumption, but not all firewood comes from forest; agro-forestry sector shares some contribution to it. consumption has increased along with population growth (mope, 2001 & unep, 2001). variety of species encountered in a plant community with respect to their relative importance is the species diversity of that community. study of these parameters with soil properties had given clear ecological importance of the myrsine capitellata wall. in the forest of the study area. study area present study was carried out at paiyunpata village of baglung district as shown in figure 1. it lies to the southern part of baglung bazaar. there is narayansthan village to the eastern side of the study area. amalachour village is located to the south and bhakunde village is located in the west of study area while kaligandaki river lies to the northern part. there are 500 households in paiyunpata village. total population is 2705 there (cbs, 2005). main occupation of the people is farming. few people are involved in armed forces, teaching, government jobs and social works. the inhabitants of the study area are mainly brahmin, chhetri, and marginalized social groups called dalits (traditionally called damai, sarki and kami). the dalits are the majority inhabitants in ward no 3, 5 and 8. there are brahmin and chhetri in other wards. international journal of environment issn 2091-2854 57 | p a g e fig 1: schematic map of the study area the main food crops of the area are rice, wheat, maize and millet. animal husbandry is the common agricultural practice of the inhabitants. for last few years only, there is availability of electricity. but it is only for lighting purpose in some of the villages of balewa area. people cannot afford petroleum gases and other energy sources for cooking and heating. paiyunpata village; the southern part of baglung district by the side of kali-gandaki river, lies in sub-tropical belt (chaudhary, 1984) and constitutes the saal forest. at the top of the hills, the forest is mixed with schima-castanopsis type. however, at the higher elevations, coniferous forest consisting pinus roxburghii, tsuga demosa, taxus baccata etc with rhododendron arboreum and quercus species are found in western side of study area. myrsine capitellata wall. is found mixed with schima-castanopsis forest. population growth is the major cause of destruction of myrsine. according to the older generation of the inhabitants of the area, there was a dense forest of this species in this area. as population increased, people encroached upon the forest for cultivation. there was practice of shifting cultivation. later on this agricultural system is followed by other subsistence farming. thus the forest of seti kath has been destroyed for all of these farmlands. methodology 1.sampling as stated in the study area section, the forest area is schima-castanopsis type. however, the sites dominated by myrsine was selected for the study. for vegetation study, stratified international journal of environment issn 2091-2854 58 | p a g e random sampling method was employed in two sites of the forest i.e. one in north facing slope and the other in south facing slope. in each case, 10 quadrats of 10×10m were laid down with convenient sampling. the forest area was 50/ 50 ropani in each slope. vegetation study was focused on tree species only. soil samples were collected by following the methods described by trivedi and goel, 1986. from each vegetational sampling plot, about 1kg of soil up to the depth of 10cm was collected by making four holes and it was collected in polythene bags and mixed homogenously. each of the bags was sealed tightly. for the information related to deforestation, its causes and consequences; semi structured questionnaires were used among 50 inhabitants sampled randomly by lottery system. the persons selected by the people for forest protection (ban pale) and some elderly people were the samples for group discussion. group discussion was focused to support the collection of the information about the myrsine forest at present and past. sampling was done during september/october 2013. 3. data collection i. vegetation survey: individuals of every tree species were recorded from the samples for frequency and density. cover of each tree species (>5%) was estimated. ii. social survey: information related to deforestation along with its causes and consequences was gathered using semi-structured questionnaire from (10%) sampled households. iii. classification: the species enumerated in each quadrat were grouped together to determine frequency, density and coverage. similarly social data were grouped together according to the category. herbarium species of the enumerated species were prepared. they are deposited in the botany department, prithvi narayan campus, pokhara. the plant species were confirmed from the villagers for local names and then identified for botanical names with the help of literatures; manandhar, 2002 and stainton, 1988. 2. data analysis the vegetation data were analyzed quantitatively for density and frequency using mishra (1968). important value index was calculated by adding the values of relative density, relative frequency and relative cover. species diversity was calculated by using following formula (margalef, 1968) as used by pathak, 1999. h = -∑ ni ln ni n n where, h = shannon index of general diversity ni =important value index of each species international journal of environment issn 2091-2854 59 | p a g e n=total ivi of all species. soil ph, the water holding capacity, soil texture, and moisture content were analyzed in two sites of the study area using zobel et al. (1987). result socioeconomic status setikath (myrsine capitellata wall) was recognized by 100% respondents in the study site. setikath forest was a dense forest and it is rare at present. the parts of the plant were used as fuel wood (100%), thankra (supports for climbers , 90%), muhura (sticks for harvesting crops, 90%) and fodder (rarely, 10%), and dry leaves were used as litter for composting. 90% of the respondents said it was best for fuel quality and 10 % told as good quality. regarding chopping quality the wood was 100% best. plantation is nil till today. soil status in average, soil ph was obtained to be 6.06 indicating acidic nature of soil. water holding capacity was about 76.66%. regarding texture, the soil has been found to consist of gravel 17.1%, sand 51.5%, silt 26.2% and clay 2.85%. thus the soil was mostly sandy. moisture content was found to be nearly 16.91%. it is drier soil in habitat of the myrsine forest. important value and species diversity table 1: ivi and species diversity in norh facing slope sn name of the species relative density relative frequency relative coverage ivi (ni) total ivi of all spp ni/n ln ni/n ni/n ln ni/n 1 myrsine capitellata wall. 37.03 16.67 18.18 71.88 299.92 0.23966391 -1.428517711 -0.342364141 2 schima wallichii(dc) korth 14.28 16.67 30.3 61.25 299.92 0.204221126 -1.588551923 -0.324415862 3 dyospyrus kaki thunberg 2.59 5.55 2.01 10.15 299.92 0.033842358 -3.386042067 -0.114591648 4 rhododendron arboretum sm. 9.74 11.11 15.18 36.03 299.92 0.120132035 -2.119163848 -0.254579466 5 castanopsis indica(roxb) miq 3.23 11.11 3.03 17.37 299.92 0.057915444 -2.848771192 -0.164987849 6 engelherdtia spicatalesch. ex blume 4.54 11.11 10.09 25.74 299.92 0.085822886 -2.45546957 -0.210735485 7 eurya cerasifolia(d don ) kob. 12.33 11.11 6.06 29.5 299.92 0.098359563 -2.319125509 -0.228108171 8 melastoma normaled don 14.93 11.11 13.12 39.16 299.92 0.130568152 -2.035859955 -0.265818471 9 fraxinus floribundawall 1.28 5.55 2.01 8.84 299.92 0.029474527 -3.524228896 -0.103874978 10 sapium insigne (royale) benth ex hook. f 0 0 0 0 299.92 0 0 0 299.92 communitsity diversity -2.00947607 international journal of environment issn 2091-2854 60 | p a g e in north facing slope, the importance value index of myrsine was highest i.e. 71.88%. schima wallichii occupied next position (61.25), but sapium insigne was totally absent, however, it was present in south facing slope. fraxinus floribunda (8.84) stands as the least important species. melastoma (39.16), rhododendron (36.03), eurya (29.5), engelherdtia (25.74), castanopsis (17.37) and dyospyrus (10.15) are other important species. table 2: ivi and species diversity in north facing slope sn name of the species relative density relative frequency relative coverage ivi (ni) total ivi of all species (n) ni/n ln ni/n ni/n ln ni/n 1 myrsine capitellata wall 13.63 46.59 31.42 91.64 289.31 0.316753655 1.14963092 0.275526388 2 schima wallichii(dc) korth 13.63 8.61 8.57 30.81 289.31 0.106494763 -2.55344 -0.04170639 3 dyospyrus kakithunberg 4.54 0.43 7.14 12.11 289.31 0.041858214 -2.48259 0.016860704 4 rhododendron arboretum sm. 10.22 7.32 7.14 24.68 289.31 0.085306419 -3.07557 0.027736783 5 castanopsis indica(roxb) miq 13.63 9.04 11.42 34.09 289.31 0.117832083 -2.92237 0.040320727 6 engelherdtia spicatalesch ex blume 13.63 6.04 17.14 36.81 289.31 0.127233763 -1.936 0.065719919 7 eurya cerasifolia(d don )kobuske 10.22 6.89 6.42 23.53 289.31 0.081331444 -2.89968 -0.02804842 8 melastoma normale d don 10.22 7.32 5.0 22.54 289.31 0.077909509 -2.76966 0.028129629 9 fraxinus floribunda wall 6.81 3.44 2.85 13.1 289.31 0.045280149 -2.87201 0.015766014 10 sapium insigne(royale) benth ex hook .f 3.4 1.29 2.85 7.54 289.31 0.02606201 -3.5638 0.007312983 289.31 community diversity 0.547127958 in south facing slope of the myrsine forest, ivi value of myrsine capitellata wall. appears to be highest i.e.91.64. engelherdtia contains ivi value around 36.81, schima 30.81 and dyospyrus had values 12.11. rhododendron, eurya , melastoma, fraxinus, sapium were less important but had values 24.68, 23.53, 22.54,13.1 and 7.54 respectively. the importance value index had the determinant role for species diversity in south facing slope too. discussion myrsine capitellata wall is a medium sized soft wooded tree and has been recognized by 100% respondents. its forest was dense in the past but rare at present. it is used as fuel-wood, supports for climbers, sticks for beating crops during harvesting and rarely as fodder. leaf litter international journal of environment issn 2091-2854 61 | p a g e is good for composting. fuel quality was best and chopping quality was 100%. no plantation of the species was in practice. therefore, both in-situ and ex-situ conservation practice is needed for its conservation. the important feature of this tree is that it becomes dry soon. therefore, its wood catches the fire easily and produces less smoke. so, the local people of area have been destroying or clearing its forest mostly for firewood. in summer, when there is lack of straw and other fodders for cattle, people gather the leaves of myrsine with castanopsis, schima etc. on the other hand, leaf litter on the forest ground is collected by farmers for composting. so, the seedlings also, cannot get nutrients for their development and therefore the regeneration of this species is greatly affected. however, the status of regeneration needs further extensive research to predict about it. small trees of setikath are used as poles for climbers (thankra), because they are light and easy to handle, as wall materials etc. soil type of the habitat of the myrsine is important for its conservation. it is slightly acidic but nearly neutral with high water holding capacity and texture of sandy type (51.5%), much drier with much less moisture content. since the study was carried out in myrsine forest, schima wallichii occupied the second position in both north facing slope but engelherdtia spicata was second in south facing slope. sapium insigne had its presence on south facing slope but absence on north facing slope. conclusion myrsine capitellata wall was dominant in the study area since long past, but due to its use for fuel wood, thankra, muhura, litter and fodder, it is under the threat of destruction. it needs serious conservation efforts. regarding ivi value, myrsine capitellata wall. appears important species even today. species diversity is less in north facing slope than in south facing slope. the soil of the habitat is acidic with high water holding capacity, sandy type of texture and with low moisture content. plantation of myrsine is not common in any part of nepal known so far. with the search of the conservation efforts of this tree species, plantation of the species proves most important step. plantation of the tree with the above mentioned characteristics of soil will be beneficial for conservationists. on the other hand, its conservation should follow the uncontrolled harvesting for good chopping quality, and burning for fire wood should be stopped in the forest areas where it is found, especially in sub tropical and temperate forest of central and western nepal. still the myrsine forest is important regarding species diversity over there. schima wallichii, castanopsis indica, rhododendron arboretum are other important tree species. associated with the forest, sapium insigne are also found in the forest type. acknowledgement the author is indebted to idea wild; an organization located in united states, providing fund for this research work. he is also grateful for suggestions by dr dinesh raj bhuju, central international journal of environment issn 2091-2854 62 | p a g e department of environment, tribhuwan university, kirtipur, kathmnandu, nepal and quick comments on the manuscripts by dr bharat babu shrestha, central department of botany, tu, kirtipur, kathmandu. mr homa nath sharma poudel, department of english, prithvi narayan campus, pokhara, nepal is highly acknowledged for his efforts for language editing. references black, c.a., 1968) soil plant relationship, second edition. willy eastern, new delhi. cbs. 2005. village development committee statistics. central bureau of statistics, nepal. chaudhary, r.p., 1984, vegetation pattern in: nepal nature's paradise, 105-111p, majupuria, tc (ed) white lotus company ltd, bangkok, thailand (pub). dfrs. 1999, forest resources of nepal (1987-1998), kathmandu, hmg, dfrs, nepal. dhoubhadel, s.p., 2001, deforestation in the middle hills of nepal; its cause, consequences and some measures to control it. in: michiganstateuniversity, multidisciplinary studies in nepal.(pub) manandhar, n.p., 2002. plants and people of nepal. timber press, portland, oregon, usa. margalef, r., 1968. perspectives in ecological theories. chicago press, university of chicago. mishra, r., 1968. ecology work book. oxford and ibh publishing company. mope. 2000. state of the environment nepal (agriculture & forests), kathmandu, nepal. his majesty's government of nepal, ministry of population and enviromment, kathamandu, nepal, june 2000. pathak, h.n., 1999. vegetation succession and impacts of socio-economic factors on khoriya cultivation (an ecological study at lwang/ghalel village, acap). a dissertation submitted to central department of botany in the partial fulfillment of the requirement for the master's degree in botany. stainton, a., 1988. flowers of the himalayasa supplement. oxford university press, new delhi, india. trivedy, r. k. and goel, p. k., 1986. chemical and biological methods for water pollution studies, published by environmental publication, karad. unep. 2001. state of the environment in collaboration with mope/hmgn, sacep, icimod. kathmandu. zobel, d.b., behan, m.j., jha, p.k. and yadav, u.k.r., 1987. a practical manual for ecology. ratna book distributors, baagbazaar, kathmandu, nepal (pub.). performance of sweet pepper under protective structure international journal of environment issn 2091-2854 224 | p a g e international journal of environment volume-2, issue-1, sep-nov 2013 issn 2091-2854 received:2 november revised:13 november accepted:13 november effects of land use on the nature and population of microorganisms in the semi-arid region of norht-eastern nigeria bello h. s., isa t., isa m. a.* and akinmuisere k department of microbiology, university of maiduguri, borno state, nigeria *correspondence author: mustafaalhajiisa@gmail.com abstract this study was aim to investigate the effects of land use on the nature and population of microorganisms in soil from five different farms within university of maiduguri, borno state. a total of ten composite samples were obtained and analyzed in the laboratory. the total microbial population was consistently higher in the grazing reserved land with mean of 105x10 4 cfu/g than in cultivated farms with means of 84.5x10 4 cfu/g, 66x10 4 cfu/g and 66x10 4 cfu/g, for cereal (sorghum), beans and tomato farms respectively. the site with the least microbial population was gum-arabic plantation with the mean of 29x10 4 cfu/g. bacteria were the most dominant species at all sites regardless of depths. key words: farming practices, biodiversity, fungi, bacteria and population introduction soil support diverse microbial communities that play important roles in ecosystem level processes such decomposition of organic matter and nutrient cycling(wright and reddy, 2001).one gram of soil in good conditions can contain 600 million bacteria belonging to about 15,000 to 20,000 different species. these values decrease to one million bacteria encompassing from 5000 to 8000 species in desert soil (informativocapebe, 2010).one cubic meter of soil may house many hundreds of species of bacteria, actinomycetes, fungi, and algae. there may be 1.5 million species of fungi but only five percent have been described (tilak, 2000).the richness, abundance and activity of the microbial community is vulnerable to influence by soil physical and chemical properties such as ph, moisture, organic matter content, and nutrient availability. alterations in the physical and chemical nature of the soil may lead to shifts in microbial community, composition and changes in microbial function. agricultural practices such as fertilization and tillage influence soil chemical properties and nutrient dynamics throughout the soil profile (gesch et al., 2007; wright et al., 2007). although several studies indicate that cultivation increases the population and diversity of soil biota, there has been few report of increased population under minimum tillage with residue incorporation as compared to conventional tillage (linn and doran, 1984).in general, cultivated soils have greater diversity than fallow lands (kennedy and smith, 1995). in a comprehensive study in alfisols and vertisols in pennisular, india international journal of environment issn 2091-2854 225 | p a g e (venkateswarlu, 2000) observed a considerable decline in population and diversity as a result of top soil erosion. application of nitrogen fertilizers like ammonium sulfate increases the fungal population whereas fym and npk application increased the population of fungi, bacteria and actinomycetes (sharma et al., 1983). certain species of microorganisms like azobacter are very sensitive to soil acidity while others like nitrosomonas and nitrobacter are more sensitive to erosion of top soil (venkateswarlu, 2000). chemical fertilizers in particular are sometimes responsible for soil acidity (barak et al., 1998) and a decrease of microbiological activities in fertilized soils compared to those in natural habitat (monkiedje et al., 2006). it is known that addition of charred plant materials to soil accelerates breakdown of simple carbohydrates (hamer et al., 2004), and that microbial community activity and metabolic efficiency increases linearly with the addition of charcoal to soils(steiner et al., 2008).the application of animal manures, sewage sludge and compost have the potential not only to increase soil organic matter stock, but also to increase the size(anderson and domsch, 1989; guerrero et al. ,2007), activity (bolton et al., 1987) and diversity (hassink et al., 1991) of the soil microbial community. the abundances of biomarkers from gram-negative bacteria are normally increased in soil receiving application of farmyard manures (peacock et al., 2001; bohme et al., 2005; bossio et al., 1998). application of inorganic nitrogen (peacock et al., 2001)or compost (bossio et al., 1998), are however associated with increased abundance of gram positive biomarkers. without changes to upstream animal husbandry and waste management, greater use of manures and allied materials within a more sustainable form of conventional agriculture has the potential to produce substantial, long live-changes to soil microbial community composition through the introduction of metals and antibiotics/other veterinary medicines(abaye et al., 2005).in a dry hot climate, the humidity and soil salinity are the most stressful factors for the soil microbial flora and frequently occur simultaneously (batra and manna, 1997; zahran, 1997; rietz and haynes, 2003; sardinha et al., 2003). the effect is always more pronounced in the rhizosphere according to the increase in water absorption by plants due to transpiration. fungi have been reported to be more sensitive to osmotic stress than bacteria (pankhurst et al., 2001; sardinha et al., 2003; wichern et al., 2006).there is a significant reduction in the total fungal count in soil salinized with different concentrations of sodium chloride. the populations and biomass levels of major groups of organisms in a typical soil profile (0-25cm) has already been described by miller (1990). in terms of biomass, fungi dominate in the soil followed by bacteria and actinomycetes. the total populations and live biomass are only reflections of the status of the soil at a given point of time, but do not give a clear picture of the living diversity as influenced by different land use practices over time. this research work aims to determine the effects of different farming practices and its functional significance on the soil biota with reference to university of maiduguri farms. materials and method study area the research was conducted at university of maiduguri, borno state, nigeria. maiduguri is located in the semi-arid region of northeastern nigeria, it is known for its dryness with semiarid climate, savannah or tropical grasslands vegetation, light annual rainfall of above 300 to 500mm and the average daily temperature ranging from 22 to 35 degree centigrade, with international journal of environment issn 2091-2854 226 | p a g e mean of the daily maximum temperature exceeding 40 degree centigrade between march and june. it has mainly sandy loam soils (arku et al., 2011).the university of maiduguri farms were divided into five namely; cereal vegetable, and legume farms, grazing land, and gumarabic plantation. collection of soil samples the soil samples were collected at two depths: 0-15cm and 15-30cm, using screw-auger. five samples were taken randomly from each site and mixed thoroughly to form composite samples. the soils were put into plastic bags, labeled and immediately transported to the laboratory for analysis (subra, 2001; okonkwo, 2010). a total of 10 composite samples were used in the study. soil analysis the soil samples were sieved through a 2mm sieve. one gram of each sample was mixed with 10ml of deionized water in a screw-capped bottle. the soil solutions were then serially diluted down to five steps. one ml of each sample was pipetted into a petri dish in 3 replications, and was then mixed with nutrient agar (subra, 2001; jackie, 2013).the mixtures in the petri dishes were allowed to solidify and were incubated at 28˚c for 48 hours. the petri dishes were then removed from the incubator and the colonies enumerated using the plate count method (julia et al., 2005; jackie, 2013) results table 1: numbers and distribution of microorganisms present in the soils of different land use system sites soil depths bacterial counts cfu/g fungal counts cfu/g total microbial counts cfu/g cereal (sorghum) farm 0-15cm 15-30cm 80.5x10 4 74x10 4 4.0x10 4 5.5x10 4 84.5x10 4 79.5x10 4 grass (reserved) land 0-15cm 15-30cm 95x10 4 82x10 4 10x10 4 6x10 4 105x10 4 88x10 4 gum-arabic plantation 0-15cm 15-30cm 28x10 4 64x10 4 1x10 4 5.5x10 4 29x10 4 50.5x10 4 harvested beans farm 0-15cm 15-30cm 64x10 4 64x10 4 2x10x 4 2.5x10 4 66x10 4 66.5x10 4 tomato farm 0-15cm 15-30cm 57x10 4 46x10 4 9x10 4s 3.5x10 4 66x10 4 49.5x10 4 table 1 above shows the numbers and distribution of microorganisms present in the soil samples of different land use system. the result indicated that the numbers of international journal of environment issn 2091-2854 227 | p a g e microorganisms were influenced by soil depths. as shown in the table, grass land has the highest microbial diversity of 105x10 4 cfu/g at the depth of 0-15cm while, gum-arabic plantation has the lowest microbial counts of 50.5x10 5 cfu/g. at the soil depth of 15-30cm, grass reserved land has the highest microbial counts of 88x10 4 cfu/g, while tomato farm has the lowest. fungal populations increased in the grass reserved land and cereal farm and were more at the top (0-15cm). regardless of depth, bacteria tend to outnumber the fungi. discussion the main aim of the study was to determine the effects of land use on the nature and population of microorganisms in university of maiduguri farms. soil microbial communities are susceptible to changes with different agricultural practices and land use management. in this study, soil dilution and plates counts method was used for the enumeration and isolation of the biota in soil samples from land under grazing, plantation and cultivation. the results from the table above shows that all cultivated lands and the grass land soils show consistently higher microbial populations than soil samples from land planted with gum-arabic trees. the number of microorganisms was influenced by soil depths. in all the soil samples tested, the distribution of microbes was higher at the soil depth of 0-15cm, with the exception of soil samples from gumarabic plantation which shows higher microbial counts at the depth of 15-30cm,and the harvested beans farm which shows relatively higher microbial populations also at same depth of 15-30cm. however, the higher diversity of microbes may be influenced by the abundance of leaves and grass residue that are dropped on the soil surface, which soil biota used as food source. amendment of soil surface with manure, sewage sludges, compost, and other chemical fertilizers may increases organic matter contents which may increases the size of the soil microbial community. the result of this study is contrary to the work of ekelund et al. (2001) who reported that, a bacterial peak has been observed at a 42.5cm depth in the peat profile of a spruce (piceaabies) and birch (betula pubescens) forest in denmark, caused by partial anaerobic conditions, higher water contents, and higher organic matter content deeper in the soil. it also contrary to the result of wuczkowski et al. (2003) who reported that in agricultural soils with conventional farming the higher diversity was recorded at a depth of 30-35cm caused by agricultural practices. the bacterial counts of soil samples studied were generally higher than the fungal counts. fungi populations increased in the grass land and tomato farm and were even more in the top soil (0-15cm).the abundance of fungi in the two land use systems may be attributed to their ability to proliferate at acidic soil. this corresponds with the work of okonkwo (2010) who reported that the abundance of fungi on the top soil (0-15cm) may be attributed to the fact that fungi are strict aerobes and exhibit selection preference for various depths of the soil. it also agreed with the report of wuczkowski et al. (2003) that the highest diversity of cultivable microfungi and yeasts in autsria was found in the top layer of the forest soil (0-15cm) without temporal flooding. the total microbial counts varied with the different farming systems, with sample from grass land generally having the highest counts ranged from 105 x 10 4 cfu/g to 88 x 10 4 cfu/g. gum-arabic plantation was the least, ranged from 29 x 10 4 cfu/g to 50.5 x 10 4 cfu/g. the variations in the distribution of microorganisms may be influenced by plant residues that covers the soil surface, also protect the soil from sealing and crusting by international journal of environment issn 2091-2854 228 | p a g e raindrop impact, thereby enhancing the proliferation and activity of microorganisms. also, heavy application of organic materials in the soil surface, such as human waste, and animal dropping during grazing may provide carbon to the soil organisms, and also helps to balance the micronutrients contents of the soil, hence increases their population and diversity. the lower microbial counts at the soil surface of gum-arabic trees may be resulted from the lack of leaf litter which may expose the soil to erosion. this study corresponds with the work of vertakeswarlu (2000), who observed a considerable declined in populations and diversity of as a result of top soil erosion. an even distribution of microorganisms without a decrease in their number with depth was found in a cryogenic weakly solidized loamy-sandy pale soil of yakutia (inovano, et al., 2008).this finding was similar or slightly similar with our result on the total microbial counts of harvested beans farm, which equal distributions of microbes at both depths, with ranged from 66 x 10 4 cfu/g to 66.5 x 10 4 cfu/g. it could be concluded that increase in microbial activity and diversity is influenced by soil depths. also, grass land and cultivated lands support the growth and survival of soil biota. references abaye d. a., lawlor k, and hirsch p.j. (2005) changes in the microbial community of an arable soil caused by long-term metal contamination.eur.j.soil sci. 56:93-102. anderson t. h. and domsch k.h. (1989) ratios of microbial biomass carbon to total organic carbon in arable soils.soil biol.biochem.21:471-479. arku a. y., musa s.m., mofoke a.l.e and dibal j.m. 2011.re-examining raw effluents from nigerian bottling company maiduguri for crop irrigation.j.applphytotechnol. environ.sanit. 1 (1):43-49. barak p., jobe b. o., krueger a., peterson l. a. and laird d. a., 1998. effects of long-term soil acidification due to agricultural inputs in wisconsin. plant soil, 197, 61-69. batra, l. & manna, m.c. (1997). dehydrogenase activity and microbial biomass carbon in salt affected soils of semiarid and arid regions. arid soil research and rehabilitation, vol. 11, no 3, (available online: january, 2009), pp. 295–303, issn 0890-3069. bohme l., langer u. and bohme f. (2005) microbial biomass,enzyme activities and microbial community structure in two european long-term field experiments.agricecosyst.environ 109:141-152. bolton h. j., elliott l. f. andpapendick r. i. (1985) soil microbial biomass and selected soil enzyme activities:effects of fertilization and cropping practices.soilbiol.biochem 17:297-302. bossio d. a., scow k.m.,andgunapala n.,(1989) determinants of soil microbial communities:effects of agricultural management,season,and soil type on phospholipid fatty acid profiles.microb. ecol. 36:1-2. ekelund f., ronnr. and christensen s. 2001. distribution with depth of protozoa,bacteria and fungi in soil profile from three danish forest sites.soil biol. biochem. 33:475481. international journal of environment issn 2091-2854 229 | p a g e gesch, r. w., d. c. reicosky,r. a. gilbert, and d. r. morris.2007. influence of tillage and plant residue management on respiration of a florida everglades histosol.soil and tillage research 92:156-166. guerrero c,moralr,and gomez i.,(2007) microbial biomass and activity of an agricultural amended with the solid phase of pig slurries.bioresourtechnol 98:3259-3264. hamer u., marschner b. and bradowski s. (2004) interactive priming of black carbon and glucose mineralization. org. geochem. 35:823-830. hassink j., voshaar j. h. and nijhus e. h. (1991) dynamics of microbial populations of a reclaimed-polder soil under a reduced-input farming system.soil biol. biochem 23:515-524. informativo capebe 06/12/2010 um patrimôniochamado solo. disponívelem >http://www.capebe.org.br/informativo.php?id=355>acessoem 13 de junho de 2011. ivanova t. i., kuzmina n.p., chevychelov a.p.,2008.the number of microorganisms and the microbiological activity of human modified crogenic pale soils of yakutia.eurasian soil sci.41:1213-1220. jackie, r. (2013). serial dilution protocols.kent state university, kent , oh. julia f. and jackie, a. (2005). monitoring and assessing soil bioremediation(enumeration of soil microorganisms).publisher:springer berlin heidelberg.soil biology volume 5,pp 261-280. kennedy a.c. and smith, k.l. (1995). soil microbial diversity and the sustainability of agricultural soils. plant and soil 170:75-86. linn d. m. and doran, j.w. (1984). aerobic and anaerobic microbial populations in no-till and ploughed soils.soil. sci. soc. am. j. 48:794-799. miller r. h. (1990). soil microbiological inputs for sustainable agricultural systems in: sustainable agriculture systems: c.a. edwards, r.p. madden, r. h. miller (eds.), gar house, 614623. monkiedje a., spiteller, d. fotio, and p. sukul. (2006).the effects of land use on soil health indicator in peri-urban agriculture in the humid forest zone of southern cameroon. journal of environmental quality 35:2402-2409. okonkwo c. i. (2010) effects of burning and cultivation on soil properties and microbial population of four different land use systems in abaliki.research journal of agriculture and biological science 6(6): 1007-1014. 2010. pankhurst, c. e., yu, s., hawke, b. g. & harch, b. d. (2001). capacity of fatty acid profiles and substrate utilization patters to describe differences in soil microbial communities associated with increased salinity or alkalinity at three locations in south australia. biology and fertility of soils, vol. 33, no 3, (march, 2001), pp. 204–217, issn: 01782762. peacock a.d., mullen m.d.,andringelberg d.b.,(2001b) soil microbial community responses to dairy manure or ammonium nitrate applications.soil biol.biochem.33:1011-1019. rietz d.n., haynes, r.j., 2003. effects of irrigation induced salinity and sodicity on soil microbial activity. soil biology & biochemistry, vol. 35, no 6, (june, 2003), pp. 845– 854, issn 0038-0717. international journal of environment issn 2091-2854 230 | p a g e sardinha m.; muller, t.; schmeisky, h. &joergensen, r.g. (2003). microbial performance in soils along a salinity gradient under acidic conditions. applied soil ecology, vol. 23, no 3, (july, 2003), pp. 237–244, issn: 0929-1393. sharma n., srivastava, l.l and mishra,b. 1983. studies on microbial changes in soil as a result of continuous application of fertilizers, farmyard manure and lime. j. indian. soc. soil. sci. 31:202-206. steiner c, das k.c.,garciam.,et al.,(2008) charcoal and smoke extract stimulate the soil microbial community in a highly weathered xanthicferralsol.pedobiologia 51:359-366. subra, r., (2001).soil microbiology (fourth edition of soil microorganisms and plant growth).p.o.box, 699s, enfiela, new hampshire 03748.united state of america. tilak, k.v.b.r. 2000. conservation and utilization of microbial diversity for natural resource management, in: international conference on managing natural resources for sustainable agricultural production in the 21st century (ed. yadav, j.s.p. et al .), new delhi , india . pp. 76-78 venkateswarlu, b. 2000. soil microbial diversity in rainfed ecosystems as influenced by erosion and conservation practices. in: international conference on managing natural resources for sustainable agricultural production in the 21 st century (ed. yadav.j.s.p. et al ), new delhi , india . pp.717-718 wichern, j.; wichern, f. &joergensen, r.g. (2006). impacto of salinity on soil microbial communities and the decomposition of maize in acidic soils. geoderma, vol. 137, no 1-2, (december, 2006), pp. 100-108, issn: 0016-7061. wright, a.l. and k.r.reddy, 2001.phosophrus loading effects on extracellular activity in everglades’s wetland soil.soil science society of america journal 65:588-595. wright, a. l.,and f. dou, and f. m .hons. 2007. crop species and tillage effects on carbon sequestration in subsurface soil.soil science 172:124-131. wuczkowski m., sterflinger k., kraus g .f., klug b. and prillinger h. 2003. diversity of microfungi and yeasts and their diversity in soils of the alluvial zone national park along the river danube downstream of vienna, austria (‘nationalparkdonauauen”). die bodenkultur 54:109-117. zahran, z. (1997). diversity, adaptation and activity of the bacterial flora in saline environments. biology and fertility of soils, vol. 25, no 3, (september, 2007), pp. 211– 223, issn: 0178-2762. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 1 | p a g e international journal of environment volume-2, issue-1, sep-nov 2013 issn 2091-2854 received:6 august revised:30 august accepted:29 september influence of calcium on water relation of two cultivars of wheat under salt stress nahid akhtar 1* , f. hossain 2 and a. karim 3 1, 2 plant physiology and biochemistry laboratory, department of botany, jahangirnagar university, savar, dhaka-1342, bangladesh tel: 88-01754996573 and fax: 88-02-7791052 3 bangabandhu sheikh mujibur rahman agricultural university, salna, gazipur * corresponding author: nahid_akhtar98@yahoo.com abstract the purpose of the present investigation was to study the effects of ca 2+ on water relation of two wheat cultivars (akbar and kanchan) under salt stress. the two wheat cultivars were grown in pots with 0 and 150 mm nacl salinity. calcium was applied in the form of gypsum in 0.12, 0.24 and 0.36g pot -1 (that is 20, 40 and 60 kg ha -1 ) respectively. salinity decreased rwc, wrc, exudation rate and ψleaf, while increased wsd and wuc. application of increased levels of ca improved the plant water status in both cultivars. the results obtained in the present study suggest that elevated ca 2+ increases salt tolerance by improving the plant water status. keywords: calcium, plant water relation, salt stress, wheat, cultivar introduction salinity is an important environmental factor that can severely inhibit plant growth and agricultural productivity. salt accumulation in irrigated soil is one of the main factors that diminish crop productivity, since most of the plants are not halophytic (hoshida et al., 2000). salinity disturbs the plant’s water relations due to decreased availability of water from soil solution as a result of lowered osmotic potential (munns, 2005), thus making it difficult for roots to extract water from their surrounding media (mittler, 2002). crop improvement for saline conditions requires an understanding of the mechanisms enabling salt tolerance. mechanisms of salt tolerance, not yet clear, can be to some extent explained by stress-adaptation effectors that mediate ion homeostasis, osmolyte biosynthesis, toxic radical scavenging, water transport and long distance response coordination (neill et al., 2002). chemical treatment and agronomical crop management practices have been tried to alleviate the salt stress, but the application of calcium to stressed plants attracted little attention. supplementing the medium with ca 2+ alleviates growth inhibition by salt in plants (imlay, 2003). ca 2+ sustains k + transport and k + /na + selectivity in na + challenged plants. the interaction of na + and ca 2+ on plant growth and ion relations is well established (jaleel et al., 2007). the purpose of this study was to investigate the ameliorative effects of supplemental ca 2+ on water relation of two cultivars of wheat under saline condition which is associated with salt tolerance. mailto:nahid_akhtar98@yahoo.com international journal of environment issn 2091-2854 2 | p a g e materials and methods plant material two wheat cultivars, namely akbar (tolerant) and kanchan (susceptible) were selected as plant materials. the seeds were obtained from bangladesh agricultural research institute, gazipur. analysis of soil the soil for the experiment was collected from the botanical garden of jahangirnagar university, savar, dhaka. the soil samples used in the pots were dried, powdered and mixed thoroughly. the physical and chemical properties of the soil were analyzed in the laboratory of soil resources development institute (srdi). treatments saline water was prepared artificially by dissolving calculated amount of commercially available salt (nacl) with tap water to make 150 mm nacl solution. tap water was used as control. levels of calcium three levels of calcium were applied in the form of gypsum. low (ca1) = 20 kg ha -1 (0.12g pot -1 ), which is 50% of the recommended dose. optimum (ca2) = 40 kg ha -1 (0.24g pot -1 ), which is 100% of the recommended does. high (ca3) = 60 kg ha -1 (0.36g pot -1 ), which is 150% of the recommended dose. nitrogen, potassium and phosphorus were applied in the form of urea, mp and tsp as their recommended does, 180, 110, 140 kg ha -1 , (1.08g pot -1 , 0.66 pot -1 and 0.84g pot -1 ), respectively. methods of cultivation each pot was filled up with 12kg air-dried soil. the respective amount of nutrients was incorporated with the soil before seed sowing. the compost was 1/4 th of the soil by volume. the pots were kept under natural sunshine. the seeds were surface sterilized by soaking the seeds with 0.1% sodium hypochloride for three minutes followed by washing 7 to 8 times with tap water and three times with distilled water. seeds of uniform size were directly sown on 12 november, 2006. tap water was applied in all pots up to the emergence of seedling. after seedling establishment tap water in control pots and 12.5mm nacl solution were applied in salt treatment. when the first leaf appeared i.e. ten days after emergence (dae) actual amount of nacl solutions were applied. seedling in control group was irrigated with tap water. measurement of plant water status leaf (lamina) of same size and age of five seedlings from each treatment was collected and fresh weight of the leaf was taken immediately. the leaf was kept immersed in distilled water for 24 hour at room temperature in the dark. the turgid weight of the leaves was then measured. afterwards the leaves were oven-dried at 80˚c for 72 hour in order to take dry weight. the fresh, turgid and dry weights of the leaves were used to determine the following parameters (sangakkara et al., 1996): relative water content (rwc) = 100 dry weight weight turgid dry weight -ht fresh weig  international journal of environment issn 2091-2854 3 | p a g e water saturation deficit (wsd) = 100 rwc water retention capacity (wrc) = dry weight weightturgid water uptake capacity (wuc) = dry weight htfresh weig weight turgid measurement of exudation rate exudation rate was measured at 5 cm above from the base of the stem. at first, dry cotton was weighed. a slanting cut on stem was made with a sharp knife. then the weighed cotton was placed on the cut surface. the exudation of sap was collected from the stem for 1 hour at normal temperature. the final weight of the cotton with sap was taken. the exudation rate was measured by deducting cotton weight from the sap containing cotton weight and expressed in mg per hour as follows: (h) time cotton ofweight sap)cotton of(weight rate exudation   measurement of leaf water potential leaf water potential was measured at 6am by pressure-bomb technique (tyree and hammel, 1972). results relative water content: salinity decreased rwc. rwc increased with the application of ca from ca1 to ca3 levels both under control and saline conditions of the two varieties of wheat (table 1). water saturation deficit: salinity increased wsd at all levels of ca (ca1, ca2 and ca3) compared to those of corresponding levels of ca under control condition. the wsd showed a decreasing tendency due to application of higher level of ca (table 1). water retention capacity: salinity reduced wrc significantly compared to that of control at all levels of calcium. however, application of ca increased wrc both in control and salt treated plants of the two varieties of wheat (table 1). water uptake capacity: salinity increased wuc compared to that of control. application of calcium decreased wuc in both control and saline condition (table 1). exudation rate and leaf water potential: salinity decreased exudation rate drastically. application of increased level of ca from ca1 to ca3 increased the exudation rate significantly both under control and saline condition (table 2). leaf water potential (ψleaf) decreased with the salinity. the ψleaf showed an increasing tendency with the increasing levels of ca application (table 2). discussion the relative water content (rwc) signifies the water contents of plants. the relative water content was decreased by salinity (table 1). application of increased level of ca from ca1 to ca3 increased the relative water content significantly both under control and saline condition (table 1). reduction in rwc due to salinity was reported in different crops by many workers (ghoulam et al., 2002 in sugar beet; sayed and gadallah, 2002 in sunflower). it is well known that salinity decreases soil water potential and thus reduces the water uptake by plant that reflect in the lower rwc. the results of this study imply that application of ca exerted international journal of environment issn 2091-2854 4 | p a g e beneficial effect of water uptake which was reflected with the higher rwc. similar effect was reported by francisco et al. (2004) in pepper plant. water saturation deficit (wsd) showed an inverse trend of rwc. water saturation deficit indicates the degree of water deficit in plants. as expected salinity increased wsd at all levels of ca (ca1, ca2 and ca3) compared to those of corresponding levels of ca under control condition. the wsd showed a decreasing tendency due to application of higher level of ca (table 1). under saline condition plants suffered from water deficit especially at high salt concentration (orcutt and nilsen, 2000), though information on ca-induced change in wsd under saline condition is scarce. the result of the present study agrees well with that of cheeseman (1988). water retention capacity (wrc) illustrates the capacity of plant cell to retain water. water retention capacity is determined by cell structure. plant grown under a high moisture regime maintains a higher ratio that could be due to the lower destruction of plant tissues by moisture deficit (sangakkara et al., 1996). islam (2001b) showed in bushbean that plants grown under a high soil moisture regime had a higher ratio than that of the plants grown under mild stress and severe stress conditions. salinity reduced the wrc significantly compared to that of control at all levels of calcium. however, application of ca increased this ratio both in control and salt treated plants of the two cultivars of wheat (table 1).under saline condition the highest ratio was observed at the highest level of calcium indicating that the capacity of plant to absorb moisture increased with the increased level of calcium. similar result was reported by cramer et al. (1989) in barley. the water uptake capacity (wuc) quantifies the ability of a plant to absorb water per unit dry weight in relation to turgid weight. a higher water uptake capacity under saline condition means a plant is subjected to water stress at a greater degree, because the plant would absorb more water to reach turgidity than a plant under control condition (islam, 2001b). salinity resulted in an increase in the water uptake capacity compared to that of control. application of calcium decreased wuc in both control and saline condition. therefore, calcium exerted a positive role to maintain better water relation under both control and saline condition. similar effect was reported by grieve and fujiyama (1987) in rice and francisco et al. (2004) in pepper plant. under normal condition exudation rate is higher than that of under stress condition. exudation can thus be used as an indicator to measure the severity of stress. salt stress decreased exudation rate drastically. application of increased level of ca from ca1 to ca3 increased the exudation rate significantly both under control and saline condition (table 2). the highest exudation rate (264.301 mg/h in akbar and 248.062 mg/h in kanchan) was observed under control condition applied with ca3 and the lowest (83.521 mg/h in akbar and 68.430 mg/h in kanchan) was under saline conditions with ca1. therefore, greater amount of ca had a positive role on the maintenance of water relation of the two varieties of wheat under saline condition. a significant positive correlation (r 2 =0.9647 in akbar and r 2 =0.9983 in kanchan at control and r 2 =0.9603 in akbar and r 2 =0.9967 in kanchan at 150 mm; significant at 1% level) between levels of ca and exudation rate was noticed (fig.1 and 2). the lower exudation due to salinity indicated that the plant was subjected to water stress (sangakkara et al., 1996). exudation rates directly related with the flow of transpiration stream. increased exudation rate means a plant can absorb more water from the soil solution international journal of environment issn 2091-2854 5 | p a g e than a plant with lower exudation rate. however, it is not clear from this study how higher levels of ca increased the exudation rate. further study is needed to elucidate the mechanisms of ca induced enhancement of exudation in wheat. table 1: effect of salinity and calcium levels on relative water content, water saturation deficit, water retention capacity and water uptake capacity of cv. akbar and kanchan table 2: effect of salinity and calcium levels on exudation rate and leaf water potential of var. akbar and kanchan salinity levels (mm) calcium levels (kg/h a) relative water content (%) water saturation deficit (%) water retention capacity (tw/dw) water uptake capacity akbar kancha n akbar kanc han akbar kancha n akbar kanchan 0 20 40 60 75.15 77.30 79.48 78.04 79.08 80.02 14.78 13.54 12.18 14.98 13.88 12.50 4.20 4.98 5.50 4.85 5.10 5.75 0.50 0.36 0.30 0.56 0.52 0.36 150 20 40 60 50.44 52.72 59.22 42.58 44.20 50.05 35.00 25.45 16.32 40.02 28.08 18.12 3.60 4.06 4.98 3.15 4.06 4.40 1.66 1.38 1.08 2.02 1.84 1.18 lsd (5%) cv (%) 1.78 19.90 1.36 29.70 0.83 45.60 1.82 50.60 0.92 15.60 0.56 19.80 0.07 65.30 0.05 66.40 salinity levels (mm) calcium levels (kg/ha) exudation rate (mg/h) leaf water potential (mpa) akbar kanchan akbar kanchan 0 20 40 60 232.500 243.135 264.301 224.062 235.203 248.062 -0.564 -0.546 -0.504 -0.520 -0.500 -0.458 150 20 40 60 83.521 89.527 102.063 68.430 79.520 88.605 -0.815 -0.725 -.0720 -0.798 -0.710 -0.638 lsd (5%) cv (%) 10.19 50.70 8.23 55.00 0.042 -47.80 0.051 -22.10 international journal of environment issn 2091-2854 6 | p a g e leaf water potential (ψleaf) decreased with the salinity (table 2). the ψleaf showed an fig. 1 relationship between calcium levels and exudation rate of akbar under saline conditions. bars indicate ± se . ca 1 ca 2 ca 3 0 50 100 150 200 250 300 0 20 40 60 calcium level e x u d a ti o n r a te ( m g /h ) 0 150 y = 73.162 + 0.4635x r 2 = 0.9603 y = 214.84 + 0.795x r 2 = 0.9647 fig. 2 relationship between calcium levels and exudation rate of kanchan under saline conditions. bars indicate ± se . ca 1 ca 2 ca 3 0 50 100 150 200 250 300 0 20 40 60 calcium level e xu d at io n r at e (m g /h ) 0 150 y = 58.677 + 0.5044x r 2 = 0.9967 y = 211.78 + 0.6x r 2 = 0.9983 fig. 3 relationship between calcium levels and leaf water potential of akbar under saline conditions. bars indicate ± se. ca 1 ca 2 ca 3 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0 20 40 60 calcium level l e a f w a te r p o te n ti a l (m p a ) 0 150 y = 0.0015x 0.598 r 2 = 0.9494 y = 0.0024x 0.8483 r 2 = 0.7894 fig. 4 relationship between calcium levels and leaf water potential of kanchan under saline conditions. bars indicate ± se. ca1 ca2 ca3 -1 -0.9 -0.8 -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0 0 20 40 60 calcium level l e a f w a te r p o te n ti a l (m p a ) 0 150 y = 0.5547 + 0.0016x r 2 = 0.9597 y = 0.8753 + 0.004x r 2 = 0.9967 international journal of environment issn 2091-2854 7 | p a g e increasing tendency with the increasing levels of ca application. the highest ψleaf (-0.504 in akbar and -0.458 mpa in kanchan) was recorded from ca3 applied under control conditions and the lowest (-0.815 in akbar and -0.798 mpa in kanchan)) was from ca1 under saline conditions. a positive correlation (r2=0.9494 in akbar and r2=0.9597 in kanchan at control and r2=0.7894 in akbar and r2=0.9967 in kanchan at 150 mm; significant at 1% level) between ψleaf and levels of ca was found (fig.3 and 4). the decreased ψleaf due to salinity was reported by many workers for different crops (nandwal et al., 2000; carvajal et al., 1999). kramer (1988) found that with the increase in ca, ψleaf increased under saline condition in barley. plant synthesizes different metabolites across the tonoplast to maintain turgor. however, the plants need to spend substantial energy to maintain turgor under water deficit conditions (munns and termaat, 1986). higher ψleaf in optimal and high ca salinized plant might suggest a mechanism of osmotic adjustment or an increase in cell wall elasticity. conclusion from these results, it can be concluded that the addition of calcium to salt (nacl) stressed wheat has a significant role in partial alleviation of salinity stress by improving the plant water status. acknowledgements the authors wish to thank jahangirnagar university for a research grant in support of this project. references carvajal, m., v. martinez and a. cerda. 1999. influence of magnesium and salinity on tomato plant grown in hydroponics culture. journal of plant nutrition 22, 177-190. cheeseman, j. m. 1988. mechanisms of salinity tolerance in plants. plant physiology 87, 547 – 550. cramer, g.r., e. epstein and a. lauchli. 1989. na-ca interactions in barley seedlings: relationship to ion transport and growth. plant, cell and environment 12, 551-558. francisco, j. c., v. martinez and m.carvajal. 2004. does calcium determine water uptake under saline conditions in pepper plants, or is it water flux which determines calcium uptake? plant science166, 443-450. ghoulam, c., a. foursy and k. fares. 2002. effect of salt stress on growth, inorganic ions and proline accumulation in relation to osmotic adjustment in five sugar beet cultivars. environmental and experimental botany 47, 39-50. grieve, c.m. and fujiyama h. 1987. the response of two rice cultivars to external na/ca ratio. plant and soil 103, 245-250. hasegawa, p.m., r.a. bressan, j.k. zhu and h.j. bohnert, 2000. plant cellular and molecular responses to high salinity, annual review of plant physiology and plant molecular biology 51, 463-499. hoshida, h., y. tanaka, t. hibino, y. hayashi, a. tanaka and t. takabe, 2000. enhanced tolerance to salt stress in transgenic rice that over expresses chloroplast glutamine synthetase. plant molecular biology 43, 103-111. imlay, j.a., 2003. pathways of oxidative damage, annu. rev. microbiol., 57: 395-418. islam, m.s. 2001b. morpho-physiology of blackgram and mungbean as influenced by salinity. an m.s. thesis. dept. of agronomy. bangabandhu sheikh mujibur rahman agricultural university, salna, gazipur. international journal of environment issn 2091-2854 8 | p a g e jaleel, c.a., r. gopi, p. manivannan and r. panneerselvam, 2007. antioxidative potentials as a protective mechanism in catharanthus roseus (l.) plants under salinity stress. turkish journal of botany 31, 245-251. kramer, p.j. 1988. changing concepts regarding plant water relations. plant, cell and environment 11, 565-568. mittler, r., 2002. oxidative stress, antioxidants and stress tolerance. trends in plant science 7, 405-410. munns, r. 2005. genes and salt tolerance: bringing them together.new phytologist 167, 645– 663. munns, s.r. and a. termaat. 1986. whole plant response to salinity. australian journal of plant physiology 13, 143-160. nandwal, a.s., m. godara, d.v. kamboj, b.s. kundu, a. mann, b. kumar and s.k. sharma. 2000. nodule functioning in trifoliate and pentafoliate mungbean genotypes as infleunced by salinity. biologia plantarum 43, 459-462. neill, s., r. desikan, a. clarke, r.d. hurst and j.t. hancock, 2002. hydrogen peroxide and nitric oxide as signaling molecules in plants, journal of experimental botany 53, 1237-1247. orcutt, d. m. and e. t. nilsen. 2000. the physiology of plants under stress. john wily & sons, inc., 605 third avenue, new york, ny. 10158-0012, usa. pp. 177-235. sangakkara, u.r., u.a. hartwig and j. nosberger. 1996. responses of root branching and shoot water potentials of french bean (phaseolus vulgaris l.) of soil mositure and fertilizer potassium. journal of agronomy and crop sciences 177, 165-173. sayed, s.a. and m.a.a. gadallah. 2002. effects of shoot and root application of thiamin on salt-streesed sunflower plants. plant growth regulators 36, 71-80. tyree, m.t. and h. t. hammel. 1972. the measurement of the turgor pressure and the water relation of plants by the pressure-bomb technique. journal of experimental botany 23, 267-282. performance of sweet pepper under protective structure international journal of e nvironment issn 2091-2854 154 | p a g e international journal of environment volume-3, issue-3, jun-aug 2014 issn 2091-2854 received:7 july revised:24 july accepted:20 august performance of different pearl millet genotypes under irrigated conditions jamal ishaq 1 * silvestro meseka 2 1 agricultural research corporation, p.o. box 126, wad medani, sudan 2 current address international institute of tropical agriculture, pmb 5320, oyo road, ibadan, nigeria corresponding author: jamalellden@ gmail.com abstract thirty four genotypes of pearl millet( pennisetum glaucum (l.) r. br) were evaluated at sudan. including two released varieties, ugandi and ashana at gezira research farm (grf) and rahad research farm(rrs) in the autumn of 2009. the experiment was arranged in randomized complete block design with three replications. grain yield and some yield components including number of productive tillers and panicle length , varied significantly among the thirty four genotypes. mean of grain yield for all genotypes across sites was 1.3 t/ ha-. sadag togo had the highest grain yield (1.7 ha-1 )followed by okashana-3 (1.6 t/ha-1 ),while ip 19745 had lowest grain yield (0.8 t/ha-1 )across tow site.okashana-3 out yielded the best than check (ashana). the combined result for genotypic coefficient of variability and broad sense heritability estimates grain yield and head weight varied significantly among the thirty four genotypes. keywords: pennisetum glaucum, irrigated farm, performance, yield components, sudan. mailto:jamalellden@gmail.com international journal of e nvironment issn 2091-2854 155 | p a g e introduction pearl millet [pennisetum glaucum (l.) r. br.] belongs to the genus pennisetum, of the poaceae family and the paniceae tribe. it ranks sixth after wheat, rice, maize, barley and sorghum in importance in terms of contribution to global cereal supply. pearl millet comprises of about 120 to 130 species grown principally for grain in the tropical and subtropical areas of africa, yielding approximately 10 million tons of grain, about 70% of it being produced in west africa. the important species are pearl millet, finger millet, porso millet, and foxtail millet (payne, 1997). ninety-four percent of the world’s millet production is grown in developing countries (gill and turton, 2001). the grains of pearl millet cultivars are of different coolers (grey, pale yellow white or slightly bluish in some types) and protrude from the floral scales. pearl millet species is grown on 40 million ha around the world for both forage and grain yields (fao, 1986; hanna et al., 1998). it is found mainly in the tropics and sub-tropics and to a lesser extent in warm temperate areas. (gill and turton, 2001). the major pearl millet producing countries in west africa are nigeria, niger, brukinafaso, chad, mali, mauritania and senegal. in eastern africa, it is grown commercially in sudan and uganda. in southern africa, the commercialization of agriculture has resulted in maize partially or completely displacing this traditional food crop (pearl millet). in sudan, pearl millet is grown mainly for human consumption. it is a staple food for the vast majority of poor farmers in western sudan. thus it remains an important component of the diets in western sudan; its use is reflected in many traditional dishes (vogel and graham, 1979). pearl millet production in sudan is concentrated in the warm and drier regions of western sudan (darfur and kordofan), with little in the central clay plains of the sudan gezira. (icrisat, 1985). most of the varieties being grown by farmers are mostly farmers’ selection of landraces or introductions from west african states of niger and nigeria. many researchers focused their attention on characterization and multiplication and of west and central african pearl millet land races (haussamann et al., 2006).the objectives of this study were to identify genotypes with high grain yield in pearl millet germplasm under irrigated condition in agriculture research condition sudan. international journal of e nvironment issn 2091-2854 156 | p a g e material and method experiment site was during main season at gezira research farm (grf), gezira state and at rahad research station (rrs)the genetic materials used in this study were thirty four pearl millet genotypes from different genetic background these genotypes were introduced from international crops research institute for the semiarid tropic (icrisat),agricultural research corporation (sudan) and west african and are presented in table 1. table 1: name and origin of thirty four pearl millet genotypes used for variability study carried out at gezira and rahad research stations in 2009 s/n genotype origin s/n genotype origin 1 sadc long w. africa 18 sdmv 95030 icrisat 2 ugandi icrisat 19 sudan ii sudan 3 sdmv 95032 icrisat 20 dahabya sudan 4 ip 19745 icrisat 21 baladi white sudan 5 sadc togo w. africa 22 okashana-3 icrisat 6 bauda sudan 23 okshana-1 icrisat 7 icmv 221 icrisat 24 isc ii icrisat 8 ip 19706 icrisat 25 ashana icrisat 9 mcnelc icrisat 26 sudan i sudan 10 icmv 155 icrisat 27 mcsrc icrisat 11 baladi yellow sudan 28 icmv155 brish icrisat 12 isc iii icrisat 29 icmv155 white icrisat 13 ip 19854 icrisat 30 dembi yellow sudan 14 umgarfa sudan 31 icmv 91059 icrisat 15 top cross pollinator icrisat 32 sudan iii sudan 16 ip 19743 icrisat 33 sosat-c8 icrisat 17 gb8735 icrisat 34 ip 19827 icrisat two released varieties, ugandi and ashana, were used as check and were arranged in a randomized complete block design (rcbd) with three replications for each site. each entry was planted on a two row plot, five meters long with inter-row spacing kept at 75 cm and between hills at 50 cm apart. all plots were thinned to 2 plants per hill three weeks after crop emergence. the exact sowing dates for the two sites were 9 august and 25 july 2009 at grf and rrs, respectively. the first irrigation were given on same days of planting and later given at irrigation intervals between 10 to 15 days according weather conditions. all recommended cultural practices for pearl millet followed from crop growth till harvest. all data were collated on 2 rows in each plot, days to 50% flowering plant height (cm),panicle length(cm),productive international journal of e nvironment issn 2091-2854 157 | p a g e tillers(no),head weight (kg plot-1),grain yield (t ha-1) and 1000seed weight(g). relationships between grain yield and yield components and contributions of each component to total variation were analyzed using the statistical analysis software sas. data were analyzed for each location separately and combined according to standard (anova) methods and using statistical analysis for system (sas, 1997). results and discussion analysis across two sites revealed wide range of variation significant differences among the thirty four pearl millet genotypes for grain yield, tsw, days to 50% flowering, panicle length and productive tillers are presented in table (table 2). the combined analysis of variance showed significant differences for genotypes and genotypes × site interaction for most of the character, panicle length , productive tillers, grain yield and tsw this variation could be attributed to genetic and environmental effects as well as their interaction . substantial variations in pearl millet have been reported by abdelrahman et al.(2002) general of mean performance of the thirty four pearl millet genotypes at grf and rrs are shown in (table 3). the results of trial revealed significant differences for panicle length, number of productive tillers, grain yield and 100 seed weight in terms of maturity, the mean for days to 50% flowering for all genotypes was 56. ashana was relatively early and attained 50% flowering at 54 days followed by mcsrc , while dembi yellow attained 50% flowering after 61 days. dembi yellow was a late maturity genotype and similar to ugandi which demonstrated flowering pattern in a similar manner 50% flowering at 60 days after planting. sadac togo and baladi white attained 50% flowering at 56 days indicating that they are intermediate yielding genotypes and would do well under marginal as well as favorable growing conditions. similar results have been reported by muhammed et al.( 2002) .mean plant height of all genotypes was 170 cm; with dembi yellow expressing short plant statue(158cm) and icmv 155 bristol was the tallest (180cm). ashana and ugandi had plant height of 173 and 159, respectively. baladi white (173cm) and okashana-3 (175cm) had similar to ashana but both were taller than sadac togo (165cm). the results are supported by findings of naeem et al. (2007).the panicle length and head weight of most genotypes were similar. the overall panicle length and head weight of most genotypes was 24.0 cm; ip19743 had the longest panicle length (28.2cm) followed by dembi yellow (27cm), while icmv91059 had the shortest panicle length (20.4cm). regarding head international journal of e nvironment issn 2091-2854 158 | p a g e weight, the overall mean head weight was 2.3kg. okashana-3 and sudan 1 had the heaviest head weight (2.7kg), while ip19745 had the lightest head weight (1.7kg). ashana (2.3kg) and ugandi (2.2kg) had relatively similar head weight. considering the mean grain yield across sites the over all mean grain yield 34 pearl millet genotypes was 1.3 (t/ha) . genotype sadag togo had the highest grain yield (1.7 t/ ha-1 ) followed by okashana -3 (1.6 t/ha-1 ), while ip19745 had the lowest grain yield (0.8 t/ha-1 ). the check varieties, ashana and ugandi had grain yields of 1.4 and 1.3 t/ha-1, respectively (table3). sadag togo had yield over the best check, ashana. the results suggest that sadag togo and okashana-3 can further be tested in multilocation trails to confirm their yield potential for a possible release in their own rights. these results agree with the findings of vanoosteron et al. (2002) who reported that the number of productive tillers is associated with grain yield and changes with plant population. grain yield potential and differences in pearl millet performance are associated with kernel number, panicle length, number of productive tillers and kernel weight. evans and wardlaw (1976) urge that environmental factors such as temperature and available water may influence yield components. potential for yield compensation occurs early in plant life cycle through adjustment in the number of panicles per square meter and kernels per panicle. estimates of genotypic, phenotypic coefficient of variations and broad sense heritability genotypes coefficient of variability was relatively high for grain yield and head weight only at grf. heritability estimates for these traits were also high at grf (table 4). these results indicate variability among thirty four pearl millet genotypes for grain yield, days to 50% flowering, panicle length, tsw and productive tillers. the yield components (panicle length, tsw and productive tillers) determine grain in pearl millet . these results increased the probability of isolating superior genotype for obtaining higher yielding genotype, since direct selection for grain yield alone could be misleading (islam and rasul, 1998). international journal of e nvironment issn 2091-2854 159 | p a g e table 2: genotypic, phenotypic variances and heritability estimates of 34 pearl millet genotypes tested at grf and rrs in 2009 *, **, *** significant at 0.05, 0.01 and 0.001 probability levels, respective sov df days 50% flowering plant height panicle length productive tillers head weight grain yield 1000seed weight (day) (cm) (cm) (no.) (kgplot1 ) (t/ ha-1) (g) site 1 60.4** 5917.4** 637.1*** 37.7** 2.4** 5.4*** 13.6** rep x site 4 11.4 800.4** 28.1** 3.8 2.3*** 1.4*** 3.1** genotype 33 23.1*** 192.4 16.7** 4.9* 0.4 0.3* 1.4** genotype ×site 33 0.9 184.5 12.7* 5.6** 0.4 0.7** 1.2* error 132 6.9 129.5 7.4 3.1 0.4 0.2 0.7 mean 56.4 169.8 24 6.1 2.3 1.3 9.5 c.v. 4.7 6.7 11.3 28.8 26 20.5 8.7 international journal of e nvironment issn 2091-2854 160 | p a g e table 3: me an pe rformance of 34 pe arl mille t ge notype s acros s grf and rrs during the rainy s e as on in 2009 *, **, *** significant at 0.05, 0.01 and 0.001 probability levels, respectively ns = not significant at p>0.05 probability level genoty p e 50%flowering plant height panicle length productive tiller head weight grain y ield 1000seed weight (day ) (cm) (cm) (no.) (kg p lot-1) (t ha-1) (g) sadc long 59.5 169.6 24.1 5.5 2.2 1.5 9.5 sdm v95032 58.0 164.7 24.1 6.2 2.1 1.1 9.6 ip19745 56.2 166.7 25.2 6.7 1.7 0.8 9.1 s adc togo 56.3 165.0 26.9 5.0 2.6 1.7 9.9 bauda 57.5 166.5 23.6 7.0 2.3 1.4 9.4 icm v221 55.0 167.9 25.8 6.3 2.5 1.4 9.7 ip19706 55.2 179.3 23.6 5.9 2.2 1.3 9.3 m cnelc 55.5 167.0 25.8 6.1 2.1 1.2 8.6 icm v155 54.8 175.5 24.3 7.8 2.6 1.2 9.3 baladi yellow 55.8 175.1 22.6 4.7 2.5 1.4 10.0 isc iii 56.2 166.6 24.5 5.4 1.8 1.1 9.9 ip19854 58.7 168.8 25.3 5.8 2.4 1.5 10.2 um garfa 57.5 175.3 25.4 7.1 2.0 1.1 9.7 top cross p oll. 57.7 170.4 24.3 8.5 2.5 1.4 9.1 ip19743 58.5 177.4 28.2 5.2 2.1 1.1 9.1 gb8735 52.0 164.2 23.8 5.1 2.0 1.2 9.8 sdm v95030 55.0 171.1 23.5 6.8 2.3 1.3 9.1 sudan ii 55.3 179.0 23.3 5.5 2.7 1.5 9.4 dahbaya 54.5 171.5 22.6 5.7 2.3 1.3 9.8 balabi white 56.3 173.1 25.6 6.2 2.1 1.3 9.8 okashana-3 54.2 174.5 23.4 6.2 2.7 1.6 9.2 okashana-1 56.7 175.9 25.3 5.2 2.4 1.5 9.6 isc ii 56.2 167.0 24.6 4.6 2.0 1.2 9.3 sudan i 58.0 166.3 21.5 7.7 2.7 1.4 9.6 m csrc 54.0 172.5 24.5 6.2 2.6 1.5 9.9 icm v155 bris. 54.8 179.7 22.7 6.3 2.1 1.2 9.4 icm v155 white 54.8 168.2 21.7 6.4 2.2 1.3 8.2 dem bi yellow 60.7 157.6 23.9 6.4 2.5 1.3 9.7 icm v91059 55.8 160.3 20.4 6.8 2.1 1.2 8.8 sudan iii 55.8 166.5 24.5 5.5 2.2 1.3 10.1 sosat c-8 59.7 173.2 25.9 4.9 2.0 1.2 10.4 ip19827 58.2 164.8 22.0 6.3 2.3 1.4 8.9 as hana 53.8 173.1 21.0 5.9 2.3 1.4 10.2 ugandi 59.7 159.4 23.3 5.2 2.2 1.3 10.0 m ean 56.4 169.8 24.0 6.1 2.3 1.3 9.5 se± 2.63*** 11.38 2.71** 1.75* 0.59 0.40* 0.82** prob.< g x l ns ns * ** ns * * international journal of e nvironment issn 2091-2854 161 | p a g e table 4: genotypic, phenotypic variances and heritability estimates of 34 pearl millet genotypes tested at grf and rrs in 2009 *significant at 0.05 probability level character genotypic coefficient of variation phenotypic coefficient of variation broad sense heritability (h2 b) grf rrs across grf rrs across grf rrs across 50% flowering (day) 2.9 2.3 4.1 5.1 5.2 6.2 33 19 43.8 plant height (cm) 2.7 2.4 2.7 6.6 7.8 7.2 18 10 13.9 panicle length (cm) 3.5 8.0 7.3 13.7 12.4 13.5 7 42 29.7 productive tillers/hill (no.) 3.2 18.4 13.0 22.2 37.7 31.6 2 24 16.9 head weight (kg plot-1) 9.1* 11.4 3.9 28.6 25.9 26.3 12* 19 2.2 grain yield (t ha-1) 6.6* 10.5 6.4 28.9 31.8 30.9 05* 11 4.2 thousand grain weight (g) 4.6 5.2 5.2 8.8 11.1 10.1 28 22 26.4 international journal of e nvironment issn 2091-2854 162 | p a g e conclusion this study has demonstrated performance within thirty four pearl millet genotypes with different genetic backgrounds and origin. the significant differences were observed in panicle length, number of productive tillers, grain yield and 100 seed weight among the thirty four genotypes ashana was the earliest variety to 50% flowering (54 days) followed by mcsrc, dembi yellow was the short variety (158 cm) while bristol was the tallest (180 cm) and okashana-3 (175 cm) had similar to ashana. the grain yield of all genotypes across sites was 1.3 t/ ha-1. sadag togo had the highest grain yield (1.7 ha-1) followed by okashana-3(1.6 ha-1 ),while ip 19745 had lowest grain yield (0.8 ha-1 )across tow site. these yield components contributed positively to grain yield as demonstrated broad sense heritability estimates grain yield and head weight varied significantly among the genotypes. analysis of variance at each site and across sites showed significant variability among the genotypes for grain yield days to50% flowering, panicle length, number of productive tillers and tsw. also significant differences were observed for genotypes and genotypes × site interaction for panicle length, productive tillers, grain yield and tsw. this evaluation would help in selection of parents for use in conventional breeding and contribution of the stability of different pearl mille characters under a rang of environments and irrigated conditions. acknowledgment the authors are thankful to dr. s.k. meseka and his technicians for their support in the design and implementation of this study. the study was funded by the agricultural research corporation (arc) sudan, project pearl millet program. references abdelrahman, s.h. and abdalla, a.h., 2002. stability analysis in some upland (gossypium hirsutum l) genotype. university of khartoum journal of agriculture science 14 (2) : 326-342. evans, l.t. and wardlaw, i.f., 1976. aspects of the comparative physiology of the grain yield in the cereals. adv. agron. 28:301-359. international journal of e nvironment issn 2091-2854 163 | p a g e fao, 1986. production yearbook. vol. 40. fao, united nations, rome. kassam, a.h. and j.m. kowal. 1975. water use, energy balance and growth of gero millet at samaru, northern nigeria. agr. met. 15:333-342. gill, g.j. and turton, c., 2001. pearl millet in developing countries. international sorghum and millets newsletter 42:1-7. hanna, w.w., 1998. pearl millet, pp 332-343 . in: banga, s.s., and banga, s.k.(eds). hybrid cultivar development. narosa publishing house, new dalhi, india. sorghum and millets newsletter 42:1-7. haussmann, b.i.g., boureima, s.s. and bidinger, f.r., 2006. evaluation of medium maturity, high-tillering pearl millet population diallel in niger. international sorghum and millets newsletter 47:126-128 icrisat, 1985. international crop research institute for semi-arid and tropics annual report, pp: 130 131. patancheru, andhra pradesh, india. islam, m.s. rasul . 1998. genetic parameters, correlations and path coefficient analysis in groundnut. bangla.j. sai. indus. res., 33:250-254. naeem, m., shahid, m.s. and khan, a.h., 2007. performance of pearl millet genotypes for forage under irrigated conditions. journal agricultural reseach institute, faisalabad, pakistan, 45(3). muhammad, m.n., 2002. performance of different pearl millet varieties under rainfed condition. pakistan j. agric. res. vol. 17 no.4. payne, w.a., 1997. managing yield and water use for pearl millet in the sahel.agronomy journal, 89 (3), 481490.vol 171. sas institute, 1997. sas/stat user’s guide version 6, fourth ed. sas inst., cary, nc. van oosterom, e.j., o´leary, g.j., carberry, p.s. and craufurd, p.q., 2002. simulating growth, development, and yield of tillering pearl millet. iii. biomass accumulation and partitioning. field crops res.79:85-106. van oosterom, e.j., o´leary, g.j., carberry, p.s. and craufurd, p.q., 2002. simulating growth, development, and yield of tillering pearl millet. iii. biomass accumulation and partitioning. field crops res.79:85-106. vogel, s. and graham, m., 1979. sorghum and millet: food production and use. report of a workshop held in nairobi, kenya, 4-7 july 1979. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 1 | p a g e international journal of environment volume-12, issue-1, 2023 issn 2091-2854 received: 1 august 2022 revised: 7 january 2023 accepted: 8 january 2023 adult emergence and morphometrics of chinese citrus fly, bactrocera minax (enderlein) (diptera: tephritidae) in nepal bhawana regmi1 *, sundar tiwari1, arvind srivastava1, hom nath lamsal2, januka pandit2, shruti shrestha1, shailesh pandit3 and debraj adhikari1, 2 1agriculture and forestry university, chitwan, nepal 2ministry of agriculture and livestock development, kathmandu, nepal 3south dakota state university, brookings, south dakota, u.s. *corresponding author: rbhawana1027@gmail.com abstract chinese citrus fly, bactrocera minax is a destructive and univoltine pest of citrus fruits. geographical altitudinal gradients as well as prevailing climate affect the biology and ecology of insect. hence, this study aimed to ascertain the effect of altitude on the adult emergence and morphological variations in various ecological settings of ramechhap district of nepal from february to june 2021 in citrus orchard. six altitude ranges were selected in 50 m distance from 1200 to 1500 m above sea level (masl), ranging from 1201-1250 masl, 1251-1300 masl, 1301-1350 masl, 1351-1400 masl, 1401-1450 masl and 1451-1500 masl. the peak adult emergence periods were the 2nd, 3rd, 4th week of april in 1201-1250 masl, 1251-1300 masl, 1301-1350 masl, respectively, followed by 1st, 2nd and 3rd week of may in 1351-1400 masl, 1401-1450 masl, 1451-1500 masl, respectively. morphometrics of chinese citrus fly such as weight, length and width of pupa and adult were almost similar to the species collected in various altitudes. the average body length of male chinese citrus fly adult was 11.58± 0.112 mm while female was 15.57± 0.076 mm. the average wingspan of male was 20.71± 0.285 mm while that of female was 23.14± 0.156 mm. the longevity of adult chinese citrus fly species increased with increase in altitude. this information could be useful to design an appropriate management plan of chinese citrus fly in various altitudinal gradients of nepal. keywords: adult emergence, length, longevity, peak period, sweet orange doi: https://doi.org/10.3126/ije.v12i1.52437 copyright ©2023 ije this work is licensed under a cc by-nc which permits use, distribution and reproduction in any medium provided the original work is properly cited and is not for commercial purposes mailto:rbhawana1027@gmail.com https://doi.org/10.3126/ije.v12i1.52437 https://orcid.org/0000-0003-0540-6395 international journal of environment issn 2091-2854 2 | p a g e introduction sweet orange, citrus sinensis (l.) osbeck is a high-value fruit having huge potential for area expansion in nepal (pun and thakur, 2018). it ranks second among the citrus fruit species in terms of area and production after mandarin in nepal (parajulee et al., 2021). the geographic position and climate of ramechhap district resembles with the mid-hills of nepal that favors all citrus crops including sweet orange production (acharya and shrestha, 2021). insect pest and diseases are the major production threat in citrus fruits in nepal. fruit flies (diptera: tephritidae) are among the most destructive agricultural pests that induce significant losses in production (bhattacharya et al., 2013). the distribution of fruit flies is cosmopolitan and distributed in tropical, subtropical and temperate regions (agrawal and sueyoshi, 2005). this pest can cause direct damage to fruits and vegetables by laying their eggs inside the fruits that lead to yield loss ranges from 90-100% depending on the various geographical, potential host and climatic conditions (kumar et al., 2011). sixteen economically important fruit fly species are recorded in nepal among them seven fruit fly species are reported from citrus orchards of sindhuli (adhikari et al., 2019). chinese citrus fly, bactrocera minax (enderlein) (diptera: tephritidae) is an economic insect pests which attacks fruits of citrus species (sharma et al., 2015). in nepal, this pest is distributed exclusively from eastern to central hilly areas of nepal (bhandari et al., 2017). chinese citrus fly was first reported in 2007 in sweet orange at paripatle, dhankuta, district of nepal (adhikari et al., 2020). this insect species are oligophagous, feeding exclusively on the fruits of citrus species and is univoltine unlike other tephritid flies, with adults emerging during april to may and overwintering as pupae (xia et al., 2019). the pest can cause up to 100% damage to the sweet orange fruit in severe condition (huang et al., 2007). fruit fly life stages are affected differently with respect to the altitude due and prevailing climatic conditions (dominiak et al., 2006). the assessment of adult emergence period of chinese citrus fly is felt necessary for adoption of suitable management strategy in sweet orange orchards (acharya and shrestha, 2021). assessment of adult emergence period and its behavior are the most fundamental requirement for successful pest management. it is equally important to ascertain pest identity and obtain knowledge on its habitat and behavior before applying any pest management strategies. specifically, knowledge about the morphometrics of pupa and adult of the chinese citrus fly can help sweet orange growers to manage the pest by making the identification easier and the implementation of control measures effective (adhikari et al., 2022). this study was carried out to know the adult emergence time at various elevations and document morphometrics of pupa and adult chinese citrus fly in ramechhap district. international journal of environment issn 2091-2854 3 | p a g e materials and methods research site this study was conducted in sunapati rural municipality and ramechhap municipality of ramechhap district of nepal. study consisted of two major parts: study of adult emergence in various altitudes and morphometrics study of pupa and adult chinese citrus fly. the experiment was conducted in randomized complete block design with six treatments (different altitudinal ranges) replicated four times. table 1. location detail of adult emergence study in ramechhap, 2021 locations altitudes (masl) latitudes (°n) longitudes (°e) kartike 1201-1250 27.3312 86.0779 babiyakharka 1251-1300 27.3338 86.0689 dharapani 1301-1350 27.3335 86.0681 bhangeri 1351-1400 27.3413 86.0614 tallo hileypani 1401-1450 27.3190 86.1074 mathillo hileypani 1451-1500 27.3185 86.1114 figure 1. map showing study site in ramechhap district of nepal international journal of environment issn 2091-2854 4 | p a g e assessment of adult emergence period pupae of chinese citrus fly were collected from the sweet orange orchard of respective elevations on 10th of february, 2021. five plastic containers (height 15.6 cm, length 9.4 cm and diameter 7.4 cm) were taken for each treatment. each plastic container was filled with 40 g sandy loam soil from the respective orchard to its one-third portion. in each plastic container twenty chinese citrus fly pupae were kept and then it was covered with sandy loam soil. in total, there were 80 similar size pupae for each treatment. each plastic container was covered with 1.2 mm mesh size nylon net in order to prevent the escape of adult after its emergence. the soil was replaced with the respective orchards soil at an interval of one week in each container in order to assure similar field moisture inside the plastic container (size same as above). the adult emergence of individual chinese citrus fly from its pupae in the plastic container was recorded in its respective location. for this, the number of adult emergence was counted from among all the pupae of plastic container separately at its respective elevation. the date of adult emergence was recorded precisely. then the period of adult emergence from eighty pupae each at its respective elevation was recorded which was further analyzed by using spss (v20) for the peak period of its adult emergence from pupae at their respective orchard. morphometrics of pupa and adult chinese citrus fly for assessment of morphometrics of pupa and adult of chinese citrus fly, single pupa was kept in each plastic container and each container was filled with soil from respective orchard following the same procedure as for study of adult emergence period. weight of pupae and adult were recorded using weighing balance (cocinaco sf-400 c electronic compact scale). length and width of pupae were measured with the help of vernier caliper (dasqua 150 mm measuring stainless) before keeping it inside the plastic container. the mortality of individual adult in each container was recorded daily. body length and the expanded wingspan of both male and female adult chinese citrus flies were measured with the help of measuring ruler (starrett c636me 150 mm steel ruler). the sex ratio of adult in each replication was noted as per the formula: sex ratio = total number of female emerged total number of male emerged (wei, 2010) statistical analysis data was analyzed by rstudio (v2021). one-way anova was used to check if the treatments were statistically different from one another. square-root transformation was performed for data normalization. mean comparison was done by using duncan’s multiple range test (dmrt) at 5% level of significance. international journal of environment issn 2091-2854 5 | p a g e results and discussion adult emergence period the highest frequencies (22) of adult chinese citrus fly emergence were observed during second week of april at the altitude of 1201-1250 masl (figure 2). in the altitude range of 1251-1300 masl, the maximum frequency (28) of adult emergence was observed during the third week of april. maximum frequency (26) of adult emergence was observed during the last week of april in an altitude range of 1301-1350 masl. the maximum frequency (31) of adult emergence was observed during the first week of may in the altitude range of 1351-1400 masl. at an altitude of 1401-1450 masl, the highest frequency (30) of adult chinese citrus fly emergence was observed in the second week of may. similarly, altitude range of 1451-1500 masl, the maximum frequency (27) of adult emergence was observed during the third week of may. from the multiple line mean, it can be assumed that adult emergence of chinese citrus flies have been shifted forward at weekly intervals with increase in altitude. similar results were observed by gautam et al. (2020) where in the early emergence of the chinese citrus fly has been observed at lower altitude. in the higher altitude, longer pupal stage of chinese citrus fly was observed by wang and luo (1995) which support the late adult emergence at higher altitude. figure 2. frequency of adult emergence of chinese citrus fly in ramechhap from 4th week of march to 4th week of may, 2021. international journal of environment issn 2091-2854 6 | p a g e adult longevity and adult sex ratio there was non-significant effect of altitude on the sex ratio of adult chinese citrus fly (table 2). however, it was observed that sex ratio of chinese citrus fly was similar regardless of variation of differences in the altitude. similar result was observed in adult of queensland fruit fly where the interaction between latitude and sex was non-significant in the analysis of covariance (ancova) (dominiak et al., 2006). female population was greater than male population. there was a significant effect of altitudinal variation on the longevity of adult chinese citrus fly. adult longevity was similar in altitudes of 1201-1250 masl, 1251-1300 masl, 1301-1350 masl, 1351-1400 masl, and 1401-1450 masl. similarly, it was observed that longevity of adult chinese citrus flies was found to increase with increase in altitude, highest being at 1451-1500 masl followed by 1401-1450 masl, 1351-1400 masl, 1301-1350 masl, 1251-1300 masl and 1201-1250 masl, respectively. similar finding was observed in ceratitis fruit fly by duyck et al. (2010). such variations can be affected by temperature (danjuma et al., 2014). table 2. effect of different altitudes on longevity and sex ratio characteristics of adult of chinese citrus fly in ramechhap, 2021. altitude (masl) characteristics of adult longevity (days) sex ratio (female: male) 1201-1250 2.05b 2.54 1251-1300 2.35b 1.09 1301-1350 2.45b 2.23 13511400 2.45b 1.92 14011450 2.45b 2.54 14511500 2.95a 1.29 lsd (0.05) 0.393** ns sem (±) 0.073 0.28 p value <0.01 >0.05 c.v.% 10.79 74.84 grand mean 2.45 1.94 sem: standard error of means; lsd: least significant difference; c.v.: coefficient of variation; ns= nonsignificant, **= significant at 1% probability morphometrics of pupa and adult of chinese citrus fly table 3 shows the effect of different altitude on morphometrics measurement such as weight, length and width of pupa and adult of chinese citrus fly in ramechhap. no significant effect was observed between different altitude and morphometrics of pupa and adult of chinese citrus fly (table 3). since there was no significant difference between morphometrics of pupa and adult, it was observed that morphometrics measurement such international journal of environment issn 2091-2854 7 | p a g e as weight, length and width of pupa and adult of chinese citrus fly was found to be similar regardless of variation of difference in the altitude. thus site specific population differentiation of chinese citrus fly is not strongly supported by this data. similar result was observed by gomez, et al. (2014) where wing size was reported to be similar among populations of anopheles albimanus (culicidae: diptera) with no significant differences between eco-regions. table 3. effect of different altitudes on morphometrics of pupa and adult of chinese citrus fly in ramechhap, 2021. altitude (masl) morphometrics of pupa (n=120) morphometrics of adult (n=120) weight (g) length (mm) width (mm) weight (g) length (mm) wing span (mm) 1201-1250 0.07 10.00 4.26 0.016 14.19 22.62 1251-1300 0.08 10.04 4.34 0.017 13.39 21.54 1301-1350 0.06 9.89 4.37 0.016 13.81 22.30 13511400 0.07 9.84 4.15 0.018 14.03 21.74 14011450 0.08 9.94 4.13 0.015 14.18 22.38 14511500 0.07 9.75 4.07 0.016 14.07 22.30 lsd (0.05) ns ns ns ns ns ns sem (±) 0.001 0.04 0.04 0.0004 0.18 0.17 p value >0.05 >0.05 >0.05 >0.05 >0.05 >0.05 c.v.% 9.05 1.85 1.69 12.18 6.89 16.51 grand mean 0.07 9.9 4.22 0.016 13.94 22.15 sem: standard error of means; lsd: least significant difference; c.v.: coefficient of variation; ns= nonsignificant figure 3. pupa of chinese citrus fly collected from sweet orange orchard in ramechap district. international journal of environment issn 2091-2854 8 | p a g e figure 4. adult of chinese citrus fly (bactrocera minax) (left: female, right: male). morphometrics variation among male and female the length of male adult chinese citrus fly was found in the range of 9 to 12.5 mm while that of female was 13.0 to 16.6 mm (table 4). similar findings were observed by adhikari et al. (2022) where length of male adult chinese citrus fly was reported 9.47 to 14.45 mm and that of female ranged from 11.6 to 16.10 mm. likewise, the wingspan of male adult chinese citrus fly was 16.0 to 24.4 mm while that of female was ranges from 18.0 to 26.0 mm. adults body length and wingspan was longer in females than male adult chinese citrus flies. the length of male was smaller than the female which was similar with the findings of sharma and tiwari (2020). the female-biased body size dimorphism is well explained by the studies on caribbean fruit flies indicating that the female had a longer developmental period or faster growth rates than males (sivinski and calkins, 1990). similarly, smaller body size of male is believed to provide a high level of easy flight movement while mating as observed by sivinski and dodson (1992). based on this finding, it can be suggested that chinese citrus flies with longer wingspan and length are generally female. similar findings were also reported by adhikari et al. (2022). such information is helpful to sweet orange growers in distinguishing adult chinese citrus flies. table 4. morphometrics of adult of chinese citrus fly in ramechhap, 2021 (n= 80). sex of adult length (mm) wingspan (mm) mean ± se range mean ± se range male (with expanded wings) 11.58 ± 0.112 9.00 – 12.5 20.71 ± 0.285 16.00 – 24.40 female (with expanded wings) 15.57 ± 0.076 13.00 – 16.6 23.14 ± 0.156 18.00 – 26.00 conclusions in lower altitudes, the adult flies emerge earlier than in higher altitudes. adult emergence period was shifted one week later with every 50 m rise in altitude. these findings clearly show that the life cycle of chinese citrus fly is related to the location which is crucial in determining the timing to adopt the management strategy. the longevity of adult chinese citrus flies increased with increase in altitude. thus these results suggested that international journal of environment issn 2091-2854 9 | p a g e citurs orchard should be established at an altitude lower than 1450 masl. pupal length and adult’s wingspan of male were smaller than female. this information can suggest for designing an appropriate management strategy of chinese citrus fly in various altitudes. authorship contribution as, da and br have conceived and planned the experiment. br and ss carried out the experiments. st and hnl were involved in planning and supervising the work. br performed the analysis. st, da, jp and sp worked on the manuscript. all authors have read and agreed to the published version of the manuscript. conflict of interest the authors declare that there is no conflict of interest regarding the publication of this paper. acknowledgements the authors are thankful to prime minister agriculture modernization project and agriculture and forestry university, rampur, chitwan for support to conduct this research. references acharya, u., and shrestha, h., 2021. opportunity and challenges of sweet orange (citrus sinensis l. osbeck) production in sindhuli and ramechhap districts. nepal horticulture, 15, 89-96. doi:https://doi.org/10.3126/nh.v15i0.36685 adhikari, d., joshi, s., thapa, r., du, j., sharma, d., and gc, y., 2019. status and management of fruit fly in nepal. proceedings of the national plant protection workshop. lazimpat, kathmandu. adhikari, d., thapa, r., joshi, s., and du, j., 2022. morphometrics of adult chinese citrus fly bactrocera minax (enderlein) (diptera: tephritidae) in nepal. journal of the plant protection society, 7(01), 7885. doi:https://doi.org/10.3126/jpps.v7i01.47291 adhikari, d., thapa, r., joshi, s., du, j., and acharya, u., 2020. receded sweet orange losses from chinese citrus fly, bactrocera minax (enderlein) in sindhuli citrus orchards: lesson from area wide control program. proceeding of national horticulture seminar. kirtipur, kathmandu: nepal horticulture society. agrawal, m., and sueyoshi, m., 2005. catalogue of indian fruit flies (diptera: tephritidae). oriental insects, 39(1), 371-433. international journal of environment issn 2091-2854 10 | p a g e bhandari, k., ansari, a., joshi, s., subedi, h., & thakur, m., 2017. fruit fly (diptera: tephritidae) diversity in citrus fruits in eastern hills of nepal. preceedings of the ninth national horticulture workshop. bhattacharya, k. k., halder, s., and banerjee, d., 2013. new records of fruit flies (diptera: tephritidae) from renuka wetland and wildlife sanctuary, himachal pradesh. zool. surv. india, 113, 145-149. danjuma, s., thaochan, n., permkam, s., and satasook, c., 2014. effect of temperature on the development and survival of immature stages of the carambola fruit fly, bactrocera carabolae, and the asian papaya fruit fly, bactrocera papayae, reared on guava diet. journal of insect science, 14(126), 116. dominiak, b., mavi, h., and nicol, h., 2006. effect of town microclimate on the queensland fruit fly bactrocera tryoni. australian journal of experimental agriculture, 46, 1239-1249. doi:10.1071/ea04217 duyck, p., kouloussis, n., papadopoulos, n., quilici, s., wang, j., jiang, c., and carey, j., 2010. lifespan of a ceratitis fruit fly increases with higher altitude. biological journal of the linnean society, 101(2), 345-350. doi:10.1111/j.1095-8312.2010.01497.x gautam, e., srivastava, a., singh, l., karki, s., adhikari, d., acharya, u., and thapa, r., 2020. survey and monitoring of chinese citrus fly (bactrocera minaxenderlein) in sweet orange orchards of sindhuli, nepal. nepalese horticulture, 14, 56-62. doi: https://doi.org/10.3126/nh.v14i1.30161 gomez, g.f., marquez, e.j., gutierrez, l.a., conn, j.e., and correa, m.m., 2014. geometric morphometric analysis of colombian anopheles albimanus (diptera: culicidae) reveals significant effect of environmental factors on wing traits and presence of a metapopulation. acta tropica, 135, 75-85. doi: 10.1016/j.actatropica.2014.03.020 huang, d., xiao, g., yang, z., and wen, j., 2007. the damage and control technology of bactrocera (tetradacus) minax enderlein in taoyuan county. plant quarantine, 4, 233-235. kumar, p., almalinda, a., ketelaar, j., and shanmugam, v., 2011. field exercise guide on fruit flies integrated pest management. bangkok, thailand: area-wide integrated pest management of fruit flies in south and southeast asia. parajulee, d., kandel, a., panta, s., and devkota, k., 2021. economic analysis of sweet orange in sindhuli district of nepal. international journal of social sciences and management, 8(3), 396-400. doi:https://doi.org/10.3126/ijssm.v8i3.38504 international journal of environment issn 2091-2854 11 | p a g e pun, a., and thakur, m., 2018. performance of exotic sweet orange genotypes at dhankuta, nepal. international journal of applied sciences and biotechnology, 6(4), 308-312. doi:10.3126/ijasbt.v6i4.16023 sharma, d., adhikari, d., and tiwari, d., 2015. fruit fly surveillance in nepal. agricultural and biological sciences journal, 1(3), 121-125. sharma, s., & tiwari, s., 2020. biology of pumpkin fruit fly, zeugodacus tau walker (diptera: tephritidae) in cucumber in kathmandu, nepal. j. plant proct. soc., 6. sivinski, j., and calkins, c., 1990. sexually dimorphic developmental rates in the caribbean fruit fly (diptera: tephritidae). environ. entomol., 19, 1491-1495. sivinski, j., and dodson, g., 1992. sexual dimorphism inanastrepha suspensa (loew) and other tephritid fruit flies (diptera: tephritidae): possible roles of developmental rate, fecundity, and dispersal. j. insect behav., 5, 491-506. wang, x., and luo, y., 1995. advanced study on bactrocera minax. chinese bulletin of entomology, 32, 310-315. wei, y., 2010. sex ratio of nysius huttoni white (hemiptera: lygaeidae) in field and laboratory populations. new zealand journal of zoology, 19-28. doi:10.1080/03014220809510100 xia, y., huang, j.-h., jiang, f., he, j.-y., pan, x.-b., lin, x.-j., and ouyang, g.c., 2019. the effectiveness of fruit bagging and culling for risk mitigation of fruit flies affecting citrus in china: a preliminary report. florida entomologist, 102(1), 79-84. doi:10.1653/024.102.0112 international journal of environment issn 2091-2854 20 | p a g e international journal of environment volume-1, issue-1, jun-aug 2013 issn 2091-2854 received: 14 june revised: 8 july accepted: 10 july physico chemical characteristics of lakhna devi temple water tank, lakhna, bakewar, etawah, u.p. with reference to cyanobacterial diversity omesh bajpai 1 *, sujata mishra 1 , narendra mohan 2 , jitendra mohan 2 and rajan k. gupta 3 1 csir-national botanical research institute, lucknow, india 2 environment research unit, department of botany, d. a-v. p.g. college, kanpur, india 3 department of botany, pt.l.m.s govt. p.g college, rishikesh, dehradun, india *corresponding author: omeshbajpai@gmail.com abstract fresh water bodies in populated plains of tropical countries face various disturbances in the form of pollutant and nutrient inflow, heavy metal and elemental precipitation (wet or dry) and constant silt inflow (natural or anthropogenic). the physico-chemical characteristics are very much important for any water body. in lentic water bodies these characteristics shows very much variation because in summer they have less and in rains large amount of water. these adverse constrain effectively influence the algal assemblage and can be a good indicator of overall health of the water body. in the study different physico-chemical characteristics and algal diversity were monthly observed for one year duration (jun. 2008 to may 2009). some of 31 species of cyanobacteria recorded from the study site viz. microcystis aerughinosa, m. flos-aquae, m. robusta, chroococcus minor, c.minutes, gloeocapsa magma, aphanocapsa littoralis, aphanothece microscopis, coelosphaerium kuetzingianum, merismopedia glauca, m. tenuissima, arthrospira spriulinoides, spirulina gigantean, s. major, oscillatoria formosa, o. subuliformis, o. princeps, phormidium ambiguum, p. fragile, p. lucidum, lyngbya contorta, o. epiphytica, o.majuscule, cylindrospermum minutissimum, nostoc commune, n. punctiforme, anabaena oscillarioides, a. oryzae, calothrix gloeocola, rivularia aquatic and gloeotrichia pisum. keywords: lakhna devi temple, physico-chemical characteristics, cyanobacterial diversity introduction now a day the demands on lakes, reservoirs, ponds and rivers is increasing for the drinking water and many other uses, but due to speedy industrialization the pollution is rising up (ghose and basu, 1968; patil and tijare, 2001; singh and mathur, 2005). there is an interesting side of lakes, reservoirs and ponds is the characteristic change due to seasonal mailto:omeshbajpai@gmail.com international journal of environment issn 2091-2854 21 | p a g e variations which results change in water volume, salt concentration, dissolved substances, gases & organic matters and as a result affects the plant life. therefore the annual monitoring of water bodies by checking out the algal diversity and the physico-chemical characteristics provides a scientific way to manage such type of water bodies. fresh water bodies in populated plains of tropical countries face various disturbances in the form of pollutant and nutrient inflow, heavy metal and elemental precipitation (wet or dry), industrial and municipal wastes. this affects the physic-chemical quality as well as the aquatic flora and fauna (dwivedi and pandey, 2002). the algae have a major role in oxygen enrichment of water, binding and removal of certain toxic substances. these algal and specially the blue green algae (bga) contributions are very crucial for water quality improvement. the aquatic environment supports hydrophytic vegetation with abundant growth of algae. considerable amount of work has been done about systematic survey, distribution and periodicity of algae in different habitats of india (pandey, 1973; kumar, et al., 1974; prasad and saxena, 1980; sukuman, 1980; suseela & toppo, 2004; dwivedi et al., 2005; sridhar et. al., 2006; tiwari & chauhan, 2006; sultana & gupta, 2009; suseela & toppo, 2010a, 2010b; suresh et al., 2012). several important works dealing with the ecological distribution of cyanophyceae have been done (rao, 1955; singh, 1960; venkateshwarlu, 1969; mohan et al., 1989; swaranlatha & rao, 1998; mohan et al., 2007). the qualitative abundance of cyanobacteria has also been recorded (gupta, 1957; singh, 1961; shukla, 1971). however, numbers of species are not constant within fresh water environments (morrison & fair, 1966). the study site lakhna devi temple water tank, lakhna, bakewar, etawah, u.p. was selected because it represents a developing town from upper gangetic plain of india. the water tank of the temple is a cemented pond with religious faith. to check the cyanobacterial diversity and to generate some physico-chemical properties of the water body the study was carried out. identification of the effect of these variables on algal assembling and the potential factors influencing the algal growth in the site was also done. materials and methods study site: the town is an area with population of ca. 10,470 with moderate to low level of anthropogenic pressure (anonymous, 2001). the water body selected for the study is situated international journal of environment issn 2091-2854 22 | p a g e east-south to the lakhana town at 26°38’57.35” n, 79°09’03.91” e and at the elevation of 150 m. figure 1. location of study site, etawah, uttar pradesh sampling of data and analysis: sampling was done from each selected spots in the study sites. the water samples were collected at 30 days interval from the fixed spots around 10:00 am. the samples were collected in wide mouth glass bottle (1.0 litter) and all the samples were brought to the laboratory and stored at 4°c in a refrigerator till the analysis was completed. the details of sampling procedure and analysis of water samples were same as per standard methods (apha, awwa, wef, 1998). the sampling of algal flora was done from the study sites once in a month at the same day of water sampling. the collected samples were preserved in 4% formalin and deposited in the herbarium of environment research unit, department of botany, d.a-v. p.g.college, kanpur, uttar pradesh, india. the preserved algal samples were examined and identified with the help of desikachary (1959), prescott (1964, 1976), whitford & schumacher (1973), anand (1998). results and discussion the results of physico-chemical characteristics of water are given in table 1. as such algae have not only marvelous significance as bio-indicators but intrinsic value in biology of international journal of environment issn 2091-2854 23 | p a g e environments. cross pollution of water can be studied on both physico-chemical and biological characteristics. table 1. annual variations of physico-chemical characteristics. w.l.d. = water level depth (cm), t.h. = total hardness (m.eq.l -1 ), t.s. = total solids (mg.l -1 ), d.o. = dissolved oxygen (mg.l -1 ), bod = biological oxygen demand (mg.l -1 ), f.a. = free ammonia (m.eq.l 1 ), carb. = carbonate (m.eq.l -1 ), bicarb. = bicarbonate (m.eq.l -1 ), t.alka. = total alkanity (m.eq.l -1 ), chlori. = chloride (m.eq.l -1 ), w. tem. = water temperature ( 0 c) and trans. = transparency (cm). months w.l.d. t.h. t.s. d.o. bod f.a. ph carb. bicarb. t.alka. chlori. w.tem. trans. jun.08 220 149 568 1.9 19 1.23 7.98 61 21 82 20 37 9 jul. 08 300 123 563 2.1 17 1.25 7.90 51 16 67 17 28 8 aug.08 320 113 584 2.2 13 1.35 7.73 47 12 59 16 26 10 sep.08 290 95 602 2.7 14 1.68 7.43 45 11 56 17 24 13 oct.08 210 124 624 2.8 15 1.85 7.35 49 14 63 14 23 15 nov.08 170 130 640 3.2 18 2.03 7.28 52 16 68 19 18 17 dec.08 160 133 659 3.5 16 2.11 7.38 54 18 72 21 9 20 jan.09 140 177 588 3.1 10 2.08 7.64 65 45 110 24 9 18 feb.09 130 176 584 2.8 9 1.82 7.91 67 42 109 25 17 17 mar.09 120 170 633 2.7 14 1.80 7.88 68 44 112 28 25 12 apr.09 118 169 643 2.4 16 1.76 8.22 70 46 116 27 30 11 may.09 100 160 632 2.2 18 1.81 8.06 67 40 107 25 36 10 the occurrence and periodicity of algal samples studied are given in table 2. the distribution of algae found in aquatic system showed 31 species belonging to class cyanophyceae in a year. microcystis aerughinosa was the only species, collected from the water body in every month during the study period. the cold winters have been found the most favorable period for their growth, when 25 species (beside gloeotrichia pissum,lyngbya contora, l. epiphytica, l. majuscule, merismopedia glaucaand rivularia aquatic) were collected from the study site where as only 18 species (beside anabaena oryzae,aphanocapsa littoralis,coelosphaerium kuetzingianum, gloeocapsa magma, merismopedia tenuissima,microcystis flos-aquae,m. robusta,nostoc commune, n. punctiforme, oscillatoria formosa, o. princeps, phormidium ambiguum, p. lucidum) were collected in hot summers. international journal of environment issn 2091-2854 24 | p a g e table 2. annual variations of distribution of algal diversity (1 = present and 0 = absent). algal spp. (year 2008-09) jun. jul. aug. sep. oct. nov. dec. jan feb. mar. apr. may. microcystis aerughinosa 1 1 1 1 1 1 1 1 1 1 1 1 microcystis flosaquae 0 0 1 1 1 0 1 1 1 1 0 0 microcystis robusta 0 0 0 0 0 0 1 1 1 0 0 0 chroococcus minor 1 1 1 0 0 0 0 1 1 1 1 1 chroococcus minutes 0 0 0 0 1 1 1 1 1 1 1 0 gloeocapsa magma 0 0 0 0 0 1 1 1 1 0 0 0 aphanocapsa littoralis 0 0 0 0 1 1 1 1 1 1 0 0 aphanothece microscopic 0 0 0 0 0 0 0 1 1 1 1 1 coelosphaerium kuetzingianum 0 0 0 0 0 0 1 1 1 1 0 0 merismopedia glauca 1 1 1 0 0 0 0 0 1 1 1 1 merismopedia tenuissima 1 1 0 0 1 0 1 1 1 1 0 0 arthrospira spriulinoides 1 0 0 0 0 0 1 1 1 1 1 1 spirulina gigantea 0 0 0 0 0 1 1 1 1 1 1 0 spirulina major 0 0 1 1 1 1 1 1 1 1 1 0 oscillatoria formosa 0 0 0 0 1 1 1 1 1 1 0 0 oscillatoria subuliformis 0 0 0 1 1 1 1 1 1 1 1 1 oscillatoria princeps 0 0 0 0 0 1 1 1 1 1 0 0 phormidium ambiguum 0 0 0 0 1 1 1 1 1 1 0 0 phormidium fragile 1 1 0 0 0 0 1 1 0 0 0 1 phormidium lucidum 0 0 0 0 0 0 0 1 1 0 0 0 lyngbya contorta 1 1 0 0 0 0 0 0 0 1 1 1 lyngbya epiphytica 0 0 0 0 0 0 0 0 1 1 1 0 lyngbya 1 1 0 0 0 0 0 0 1 1 0 1 international journal of environment issn 2091-2854 25 | p a g e majuscule cylindrospermum minutissimum 0 0 0 0 1 1 1 1 1 1 1 0 nostoc commune 0 0 0 1 1 1 1 1 1 0 0 0 nostoc punctiforme 0 0 1 1 1 1 1 1 0 0 0 0 anabaena oscillarioides 1 1 0 0 0 0 1 1 1 1 1 0 anabaena oryzae 0 0 0 1 1 1 1 1 1 1 0 0 calothrix gloeocola 0 0 0 1 1 1 1 1 1 1 1 0 rivularia aquatic 0 0 1 1 0 0 0 0 0 0 1 1 gloeotrichia pisum 0 0 1 1 1 0 0 0 0 0 1 1 the biological oxygen demand (bod) has been found higher (17.5 ± 1.3 mg.l -1 ) in the summers (jun., jul. in 2008 and apr., may in 2009), when the lesser cyanobacterial diversity was observed in the study site whereas the lower (13.6 ± 3.9 mg.l -1 ) value of bod was observed in the winters (oct. dec. 2008 and jan., feb. 2009) with greater diversity. the dissolved oxygen (d.o.) & free ammonia (f.a.) fallow the inverse pattern and found higher (3.08 ± 0.29 mg.l -1 & 1.98 ± 0.13 m.eq.l -1 ) in the winters while lower (2.15 ± 0.21 mg.l 1 & 1.51 ± 0.32 m.eq.l -1 ) in the summers respectively. the bod, d.o. and f.a. are the major physico-chemical which may be characterized the pollution level of a water body. the presence of higher f.a. (i.e. more polluted water) gives higher d.o. and lower bod due to the presence of higher bga diversity. this supports the view that algae and specially cyanobacteria could be of greatest benefits in making the water clean from inorganic pollutants which get bound up in them along with oxygenation of water and attributes of microbe profile prospects. the study found that rivularia aquatic, gloeotrichia pisum and lyngbya contorta may be used as indicator species to identify the presence of higher f.a. due to their escaping behavior at the higher level of the f.a.the study gives an idea about the periodic behavior of species in the defined area. the allergenic algae such as anabaena, microcystis and oscillatoria were observed in the study site, thus it has been suggested to avoid bath and intake of this religious water body. aspects of present investigation appear proves to be of both academic and applied significance. international journal of environment issn 2091-2854 26 | p a g e acknowledgements it is a part of m. phil. thesis of the corresponding author. the authors are sincerely grateful to the director, csir-national botanical research institute, lucknow and principal, d.a-v. p.g.college, kanpur, india for facilities. the thanks are also due to the dr. l. b. chaudhary principal scientist at csir-national botanical research institute, lucknow and prof. jitendra pandey from banaras hindu university, varanasi, india for their encouragement. references anand, n., 1998. indian freshwater microalgae. bishen shigh mahendra pal singh publication, dehra dun, india. anonymous, 2001. office of the registrar general and census commissioner (web), delimitation commission of india (web). apha, awwa, wef, 1998. standard methods for the examination of water and wastewater (20 th edn.). american public health association, washington, usa. desikachary, t.v., 1959. cyanophyta, monograph on blue green algae. i.c.a.r., new delhi, india, pp. 1-689. dwivedi, b.k. & pandey, g.c. 2002. physico-chemical factors and algal diversity of two ponds, (girija kund and maqubara pond), faizabad. pollution research 21, 361-371. dwivedi, s., misra, p.k., tripathi, r.d., rai, u.n., dwivedi, c.p., baghal, v.s., suseela, m.r. & srivastava, m.n., 2005. systematic and ecological studies on chlorophyceae of north india and their relationship with water quality. journal of environmental biology 26, 495-505. fritsch, f.e., 1935. the structure and reproduction of the algae. vol. 1. cambridge university press, uk. fritsch, f.e., 1945. the structure and reproduction of the algae. vol. 2. cambridge university press, uk. ghose, b.b. & basu, a.k. 1968. observation on estuarine pollution of the hooghly by effluents from a chemical factory complex at reshasa, west bengal. environment and health 10, 209-218. gupta, a.b., 1957. the algal flora of some paddy fields and its importance in soil economy. journal of research 3(1), 1-24. international journal of environment issn 2091-2854 27 | p a g e kumar, h.d., bisaria, g.p., bhandri, l.m., rand, b.g. & sharma, v., 1974. ecological studies of algae isolated from effluent a refinery fertilizer factor and a brewery. indian journal of environment and health16(3), 247-265. mohan, j., narain, s., kumar, h. & mohan, n., 2007. diversity of blue green algae in allen forest lake, zoological park, kanpur, mixing with campus sewage. indian hydrobiology 10 (1), 123-127. mohan, n., kumar, n. & mohan, j., 1989. algal flora of alcohol distillery effluent: a sample survey. advanced and applied phycology 2, 207-211. morrison, s.m. & fair, j.f., 1966. influence of environment on stream microbial dynamics. hydrology no. 13. colorado state univ. fort collins colorado. pandey, s.n. 1973. studies on distribution periodicity and some ecological aspects of phytoplankton of kanpur. advanced and applied phycology 2, 70-73. patil, d.b. & tijara, r.v. 2001. studies on water quality of godchiroli lake. pollution research 20, 257-259. prasad, b.n. & saxena, m., 1980. ecological study of blue green algae in the river gomti. indian journal of environment and health 22(2), 151-168. prescott, g.w., 1964. the fresh water algae. brown company publishers, dubuque, lowa. prescott, g.w., 1976. how to know the fresh water algae. brown company publishers, dubuque, lowa. rao, c.b., 1955. on the distribution of six small ponds ii algal periodicity. journal of ecology 43, 291-308. shukla, a.c., 1971. systematic description of algae from panki rice fields. revue algologique10(3), 257-270. singh, r.n., 1961. role of blue green algae in nitrogen economy of indian agriculture. i.c.a.r., new delhi. singh, r.p. & mathur, p. 2005. investigation of variations in physico-chemical characteristics of a fresh water reservoir of ajmer city, rajasthan. indian journal of environmental science 9, 57-61. singh, v.p., 1960. phytoplankton ecology of inland waters of uttar pradesh. in proceeding of symposium on algology. i.c.a.r., new delhi. pp. 243-271. sridhar, r., thangaradjou, t., kumar, s.s. & kannan, l., 2006. water quality and phytoplankton characteristics in the palk bay, south-east cost of india. journal of environmental biology 27, 561-566. international journal of environment issn 2091-2854 28 | p a g e sukunan, v.v., 1980. seasonal fluctuations of plankton of nagarjuna sagar reservoir, andhra pradesh, india. indian journal of fisheries society india 12, 79-91. sultana, l.h. & gupta, s., 2009. phytoplankton diversity and dynamics of chatla floodplain lake, barak valley, assam, north-east india – a seasonal study. journal of environmental biology 30, 1007-1012. suresh, a., kumar, r.p., dhanasekaran, d. & thajuddin, n., 2012. biodiversity of microalgae in western and eastern ghats, india. journal of biological sciences 15(19): 919-928. suseela, m.r. & toppo, k., 2004. fresh water algae of changu lake of sikkim himalayas, india. phytotaxonomy 4, 100-103. suseela, m.r. & toppo, k., 2010. algae flora of katarniyaghat wildlife sanctuary, district bahraich in uttar pradesh, india. indian journal of forestry 33(2), 217-220. suseela, m.r. & toppo, k., 2010. fresh water algae of amarkantak biosphere, madhya pradesh, india. journal of economic and taxonomic botany 34(1), 37-41. swaranlatha, n. & rao, a.n. 1998. ecological studies of banjara lake with reference to water pollution. journal of environmental biology 19, 179-189. tiwari, a. & chauhan, s.v.s., 2006. seasonal planktonic diversity of kitham lake, agra. journal of environmental biology 27, 35-38. venkateswarlu, v., 1969. an ecological study of the algae of the mossi river, hyderabad (india) with special reference to water pollution part ii .factor influencing the distribution of algae. hydrobiology 33, 352-363. whitford, l.a. & schumacher, g.j., 1973. a manual of freshwater algae. spark press, raleigh. ole_link1 ole_link2 international journal of environment issn 2091-2854 9 | p a g e international journal of environment volume-1, issue-1, jun-aug 2013 issn 2091-2854 received: 9 june revised: 14 august accepted: 16 august method for estimation of calcium carbonate in soils from iraq jabbar k. kassim department of soil and water science, faculty of agriculture sciences, university of sulaimani, kurdistan, iraq corresponding author: jabbar_50@yahoo.com abstract attempts have been made to evaluate four methods of quantitative determination of soil carbonates. calcium carbonates equivalent were determined by the acid neutralization, calcimeter and acetic acid methods. also, it obtains by the fourth methods when the acid neutralization method is corrected against proton adsorption. the acid neutralization method gave significantly higher estimates of total carbonates and different from each of the others. the calcimeter method gave the lower estimates of caco3 equivalent. the results showed that the corrected values of caco3 equivalent did not differ significantly from other three methods but the overall mean tended to be higher than the acetic acid and calcimeter methods. it may be concluded that the acetic acid method is simple, can reasonably estimate the carbonate content and requires only a ph meter. it can be used for routine determination of soil carbonate. keywords: calcium carbonate equivalent, calcimeter, acid neutralization, acetic acid introduction carbonate is a natural constituent of many soils occurring as sparingly soluble, alkaline earth carbonate, chiefly as calcite and dolomite. most carbonate minerals found in local soils are calcite and account 90% of total soil carbonates (al-kasyi,1989). soil properties play a major role in planning land use activities such as agriculture, erosion control, environmental protection and nature conservation. the determination of total carbonate such as caco3 in soil is of great interest on account of high usefulness for diagnosing soil status in terms of structure, texture, biological activity or nutrient content. in calcareous soils carbonates exert a major influence on the chemical properties. also carbonate content is used as a differentiating criterion for some classes at the family level of soil taxonomy (soil survey staff, 2006). few attempts have been made to evaluate methods of quantitative determination of carbonates in arid and semiarid soils. so, numerous methods mailto:jabbar_50@yahoo.com international journal of environment issn 2091-2854 10 | p a g e have been used for quantitative determination of soil carbonates (u.s. salinity laboratory staff, 1954; derimains, 1962; hassan and altawil, 1973; bullok, 1975; loeppert et al., 1974; nelson, 1982, el mahi et al.,1987, moore et al.,1987 and ashworth, 1977). the most commonly used procedures involve dissolution of the solid phase carbonates by reaction with acid. quantitation is commonly achieved by measurement of evolved co2 volumetrically, gravimetrically, manometrically, titrimetrically. also, it may be achieved quantitatively by measurement of acid consumed during the neutralization reaction. a fourier transform infrared spectrometer, is employed to determine automatically the total inorganic carbonate in solid and waters based on active photoacoustic absorption of infrared light by carbon dioxide (wenxin et al., 1999). on the other hand, zougagh et al., (2005) used two methods for determination of total carbonate soils by continuous flow piezoelectric detection. several of the specific procedures are outlined below .the acid neutralization procedure, is probably the most commonly used, due to its simplicity which involves addition of excess acid and back titration with standard base (u.s. salinity laboratory staff ,1954 ).another widely used method is quantitative volumetric procedure, in which volume of co2 is determined fallowing addition of excess hcl (derimains,1962 and bullock,1974).the pressure-calcimeter in which increase in pressure is measured atconstant temperature and volume following addition of excess acid (martin and reeve, 1955; hassan and altawil,1973 and presley,1975) provides an alternative procedure for determination of soil carbonate. it is applicable in straight forward manner to soils in low organic matter and containing no dolomite and no appreciable quantity of mno the calcimeter method is widely used locally to determine soil carbonates. another proposed procedure was used to determine soil carbonate which is based on the following reaction: caco3 + 2hc2 h2 o2 → ca +2c2 h2 o2 +h2 o +co2 the neutralization of acetic acid expressed in the reaction hc2 h2 o2 → h + + c2 h2 o2 it was based on that a known quantity of acetic acid was added to a known quantity of soils. then the ph of reaction mixture was determined fallowing complete dissolution of caco3 and equilibrium (loeppert et al., 1974). also, el mahi et al., (1987) reported that the values of carbonate equivalent estimated by acid neutralization were corrected as: caco3 equivalent = acid neutralization % caco3 0.05 cec. international journal of environment issn 2091-2854 11 | p a g e the objective of this investigation is to evaluate and compare the common available procedure for quantitative determination of local soil carbonate with the objective of finding a rapid method that is reasonably accurate and simple. materials and methods the studied soil samples were collected from different profile horizon of different parts of iraq. soils were air – dried, ground by hand and sieved through a 2 mm sieve. the lime content (caco3 equivalent) was determined by dissolution of carbonate with 0.5 m hcl and titration of excess acid with 0.2 mnaoh as described by allison and moodie (1965). in addition to the calcimeter method described by bullock (1975) the carbonate was determined by procedure proposed by loeppert et al., (1974). it was based on adding a known quantity of 0.4 m acetic acid to a known quantity of soil samples (<2 mm fraction). then the ph of the mixtures was experimentally determined. 2.000 g samples were weight into 50 ml polypropylene centrifuge tubes and 25 ml aliquot of 0.400 m acetic acid was added to each tube. tubes were shaken for 8 h and the samples were allowed to sit overnight with cap loosed to allow escape of co2 produce during the dissolution of caco3. tubes were centrifuged and then ph of the superannuate was accurately determined + 0.01 ph units with a combination ph electrode which was allowed to equilibrate for exactly 5 min before recording the value. also, some tubes were allowed to sit over a period of 7 days. kaolinite and bentonite (smectite group) deposit from al – anbar province was initially fractionated to obtain the > 2 mm particle size separated and was casaturated by titration to ph 8.0 with ca(oh)2 . calcium carbonate (0.25, 0.50, 1.0 and 1.50 g of ca saturated kaolinite and / or smectite. the ph of the solution was determined and experimental caco3 contents calculated as previously described for soil samples. precaution was taken to ensure that all soil samples were treated identically during ph determination. results and discussion the soils were selected from a collection of calcareous soils of different parts of iraq, to give a wide range in carbonate (30 to 4967 g caco3 kg soils. these soils were very low in organic matter (5.45 to 27.85 g organic matter kg soil) and free fe – oxides and oxyhydroxide (1.13 to 9.57 g kg soil ) content ( kassim et al., 1993 ). the soils and their classification were given in table (1). international journal of environment issn 2091-2854 12 | p a g e table 1. location and classification of 21 soils profiles used in the study. ---------------------------------------------------------------------------------------------- profile numbers location classification p1,p2 al-nassriah typic fluvaqents p3,p4 al-nassriah vertic fluvaqents p5,p6 tikrit cambic gypsiorthids p7 mosul cambic gypsiorthid p8,p9 tikrit calcic gypsiorthids p10 rabiah calcic gypsiorthids p11 south of mosul calcic gypsiorthid p12,p13 tikrit typic torripsammen p14,p15 rabiah typic calciorthids p16,p17 rabiah typic calcixerolls p19,20 rabiah calcixerollic xerochrepts p20 mosul calcixerollic xerochrepts p21 aski kalaic mollic calciorthids eight two -soil samples were taken from different depths from 21 profiles. all samples were analyzed for lime (caco3equivalent) using three different methods. these methods were acid neutralization (hcl), calcimeter and acetic acid reaction (us salinity laboratory staff, 1954, allison and moodie, 1965 and loeppert et al 1974). in case of acetic acid method, an addition of a known amount of pure calcite (caco3) was added to excess quantity of acetic acid and the ph of the reaction was experimentally determined. the ph vs. initial caco3 weight is plotted and shown in fig (1). the results indicated that the ph rang is 2.98 to 5.74 and the relative change in ph was great at low caco3, generally when it was > 75 mg caco3. the standard curve for soil samples was obtained by the procedure proposed by loeppert et al., (1974). a plot of ph vs. log [mgcaco3/ (t – mg caco3)] was obtained to serve as standard curve for soil samples and was approximately linear with an r =0.996 (fig 2). fig 1: the effect of pure calcium carbonate on ph international journal of environment issn 2091-2854 13 | p a g e in case of acetic acid method, the relative change in ph was great at low caco3 levels and it was sensitive to small changes in caco3 content. the errors due to consumption of protons by ion exchange complex were very high at low carbonate levels. it may be reduced by manipulating condition to result in an increase final equilibrium ph. it may be accomplishes by increasing soil sample size and /or reducing concentration or volume of acid reactant. however, it was preferred increasing soil samples to reduce the error. also, the soils under investigation showed that only few soil samples where low in carbonate content (fig 3). fig 2: the relationship between the log amount of pure calcium carbonate and ph the major sources of error in the procedure for determination of soil carbonates were clay minerals, organic matter, incomplete dissolution of caco3 and error in ph determination. addition of acetic acid to different quantity of caco3 in the presences of different levels of clay minerals, the caco3level was experimentally determined. the results were shown in table ( 2). it was indicated that the levels of experimentally determined caco3 were higher in presences of clay minerals especially at lower added caco3. upon addition of 25 ml of 0.40 m acetic acid to 25.0 of pure caco3 in presence of 0.250, 0.500, 1.00 and 1.50 g of kaolinite or smectite, the experimentally determined caco3 levels were approximately 26,26, 28, and 29; 26,28,30 and 32 respectively (table 2). table 2influence of ca-saturated clay on determination of caco3 equivalent by acetic acid actual kaolinite experimentaly bentonite experimentaly caco3 determined (smectite) determined caco3 caco3 mg mg mg mg mg 250 26 250 26 500 26 500 27 25 1000 28 1000 39 international journal of environment issn 2091-2854 14 | p a g e 1500 29 1500 31 ----------------------------------------------------------------- 250 50 250 51 500 52 500 53 50 1000 52 1000 53 1500 53 1500 56 ------------------------------------------------------------------ 250 100 250 101 500 102 500 104 100 1000 102 1000 106 1500 107 1500 107 ------------------------------------------------------------------ 250 150 250 150 500 154 500 156 150 1000 155 1000 158 1500 153 1500 158 --------------------------------------------------------------------- 250 200 250 200 500 203 500 206 200 1000 204 1000 207 1500 204 1500 207 also, the experimentally determined caco3 was higher in the presence of smectite than kaolinite. therefore it is evident that the clay mineral consumed protons predominantly via a mechanism of ion exchange onto the clay surface or interlayer. so, it could be concluded that relative experimental or actual error generally increased as the clay contents were increased for a given caco3 level. for example with actual caco3 quantity of 25, 50,100 and 200 mg, relative percentage errors in presence of 1.50 g of kaolinite were 16, 6, 4.7,3 and 2 respectively. but the relative percentage errors in the presence of 1.50 of smectite were 24, 13, 7, 5.3 and 3.5 respectively. it was well known that the dissolution of caco3, ca +2 was released into the reaction mixture. the proportion of h +1 on the exchange complex was controlled largely by ca +2 / h +1 exchange equilibrium relationships. the amount of adsorbedh +1 being influenced by the quantity and cation exchange capacity of the clay. therefore, at low carbonate levels and high clay levels, errors due to retention of h +1 on the exchange complex were greatest especially in presence of smectite. the relative errors may be reduced by manipulating conditions to results in an increase in final equilibrium ph. increasing soil sample size and /or reducing concentration or volume of acetic acid reactant could be accomplished this. also, the errors in experimentally determination of actual caco3 in presence of kaolinite and smectite by the two other methods (acid – base titration and calcimeter methods). the results in table (3) showed that the relative percentage errors were the highest in acid base titration than the other methods. for example with actual caco3 quantity of 25,50,100 and 200 mg the relative percentage errors in presence international journal of environment issn 2091-2854 15 | p a g e of 1.5 g of kaolinite or smectite were 24,16,13,6.6 and 4.5 for kaolinite and 40,28,18,12 and 8 for smectite respectively in acid base titration method. but they were negligible in the calcimeter method even in the presence of high percentage of clays. so, it is evident that the clay consumed protons predominantly via mechanism of ion exchange on the clay surface. also, it could be due to decomposition of the clay mineral especially in acid base titration methods. generally, the relative experimental error increased as the clay content was increased for a given caco3 level. another error may be due to presence of organic matter especially at high organic matter (martin, 1955), which may be attributed to large number of potential proton binding sites. but these errors could be negligible simply because the studied soils were very low in organic matter content (al – janbi et al., 1989 a,b and kassim et al.,1989 ). these results are in agreement with the results reported by hassan and al – tawil (1973) that organic matter could not be considered are limiting factor for application especially for calcimeter methods. table 3 influence of ca-saturated clay on determination of caco3 ------------------------------------------------------------------------------------------------------------------------------------- acid titration calcimeter actual kaolinite experimentaly bentonite experimentaly kaolinite experimentaly bentonite experimentaly caco3 determined (smectite) determined determined (smectite) determined caco3 caco3 caco3 caco3 mg mg mg mg mg mg mg mg mg 250 27 250 27 250 25 250 26 500 27 500 29 500 25 500 26 25 1000 31 1000 35 1000 26 1000 26 1500 32 1500 36 1500 26 1500 27 --------------------------------------------------------------------------------------------------------------------------- 250 54 250 57 250 50 250 50 500 56 500 60 500 50 500 52 50 1000 56 1000 63 1000 51 1000 52 1500 58 1500 64 1500 51 1500 52 --------------------------------------------------------------------------------------------------------------------------- 250 103 250 108 250 100 250 100 500 104 500 109 500 100 500 100 100 1000 109 1000 116 1000 101 1000 102 1500 113 1500 119 1500 101 1500 103 --------------------------------------------------------------------------------------------------------------------------- 250 152 250 153 250 150 250 150 500 154 500 155 500 150 500 150 150 1000 157 1000 166 1000 150 1000 151 1500 160 1500 168 1500 151 1500 151 ------------------------------------------------------------------------------------------------------------------------- 250 201 250 204 250 200 250 200 500 202 500 208 500 200 500 201 international journal of environment issn 2091-2854 16 | p a g e 200 1000 207 1000 212 1000 201 1000 202 1500 209 1500 216 1500 201 1500 202 the soils under investigation were high in carbonate content and the results were shown in fig (3). the histograms showed that more than 80% of these soils were high in carbonate exceed 200 g caco3kg soil. it had been found that the rate of reaction of caco3 was linearly and inversely related to ph within the range 3.00 to 5.00 (berner and morse, 1974). the condition employed in these experiments i.e. addition of 25 ml of 0.40 m acetic acid to 2.0 g soil samples. it has been found that the maximum working limit is 200 g caco3 kg soil, which results in final equilibrium ph of approximately 4.85. so, if the soil carbonate minerals (kassim and haba, 1989), it would not be preferred increasing the acid concentration especially with soil containing readily decomposable minerals example soil chlorite may be subjected to severe errors due to decomposition of soil components. on the other hand, contact time must be sufficient to allow for complete dissolution of solid phase caco3. the distribution of soil carbonate contents are summarized in fig 3 and present values of caco3 equivalents determined by three methods. the acid neutralization method gave significantly higher estimates of total carbonate (p 0.001) than the other methods. but the calcimeter method gave the lowest estimates value of total carbonate. also, it is interesting to note that the 5% caco3 equivalent as the lower limit for calcareousness (hodgson, 1976) only 7 out of the 82 soil samples could not be classified as than 5% caco3 equivalent. on the other hand, the acid neutralization was the only method calcareous soil by the calcimeter method, while none of the other methods gave values less gave values 40% caco3 equivalent and 25 soils samples were caco3 values above 350 mg caco3 kg soil. the acetic acid and / or calcimeter methods gave only 7 and 3 soils have values of 350 mg caco3 kg soil respectively. the results showed that the majority of soil samples were within the range of 200 to 300 mg caco3 kg soil. the mean caco3 content for all soil samples studied were 209, 246, and 287 mg caco3 kg soil estimated by calcimeter, acetic acid and acid neutralization methods respectively. the mean values indicated that the results of acid neutralization method were significantly different from each other and gave the highest mean values for caco3content. this could be attributed to the fact that the acid neutralization method suffers from the reaction of acid with soil constituents other than carbonate and the consumption by the exchange complex that lead to overestimate of carbonate. these results were in agreement international journal of environment issn 2091-2854 17 | p a g e with results found by many workers (bundy and bremmer, 1972; nelson and summer, 1982; loeppert et al., 1984 and el mahi et al., 1987). the acid neutralization method suffers from the reaction of the acid with soil constituent other than carbonates and the consumption of protons by the exchange complex. the latter error was corrected by assuming that protons occupied the entire exchange complex (el mahi et al.,1987). the corrected values of caco3 equivalent using acid neutralization did not differ significantly from the other three methods. on the other hand, the overall mean values (272 mg caco3 kg ) were higher than those of the others, suggesting that the acid may be reacted with noncarbonated soil minerals. fig 3: frequency distribution of carbonate in soils determined by the calcimeter, acetic acids and hydrochloric acids generally, it may be concluded that the calcimeter method gave the lowest caco3equivalent estimate while the acid neutralization method gave the highest caco3 equivalent content. the results in table (4) shown that there were highly significant correlation between the methods. the acetic acid method was higher correlated with the calcimeter method (r = 95.1). also, the acetic acid method may be reasonably used to determine caco3 equivalent in the local soils of arid and semiarid. in addition to its simplicity, it required only a ph meter. international journal of environment issn 2091-2854 18 | p a g e table 4. simple correlation coefficients(r values) between different methods of estimation of caco3 equivalent ------------------------------------------------------------- methods calcimeter acetic acid ------------------------------------------------------------- acetic acid 0.975 acid neutralization 0.963 0.974 corrected 0.963 0.973 ------------------------------------------------------------ a further investigation will needed to developed methods for evaluating the particle size distribution and reactivity of soil carbonate. also, it is important to study carbonate mineralogy to quantify carbonate minerals phases present in local soils. references al-janabi, k.z.,alkubiasy,j.k.kassim and l.k.mohmmad-ali (1989 b).some soils in jezira area : properties and classification. 5 th sci. conf. sci. rec.council (iraq, baghdad)vol.1 part 1: 138-149. al-janabi,k.z,j.k.kassim,a.m.al-kubiasy and l.k.mohmmad-ali(1989 a). some rangeland soils in salah aldeen province: characteristics and classification.j. agric. water reso. vol. 8 no. 2: 341-354. allison,l.e. and j.w. morse,1965.carbonate.inc.a. black et al.(ed)methods of soil analysis, part 2.agronomy 9:1379-1400. al-kayo,s.(1989).effect of wetting – drying cycles of soils on carbonate and phosphorus adsorption. 1physical and chemical properties of carbonate .5 th sci. conf. sci.res. council(iraq, baghdad).vol.1 part 2:29-36 ashworth j.(1997) improvement to two rotine methods for calcium carbonate determination in soils. comm. in soil sci. plant anal. 28: 11, 841 – 848. berner,r.a. and j.w. morse,1974. dissolution kinetics of calcium carbonate in sea water.am.j.sci. 274:108-134. bundy l.g. and j.m.bremner,1972.a simple titrimetric method for determination of in organic carbon in soils. soil sci.soc. am. proc.39:273-275. dreimanis,a. 1962.quantitalive gasometric determination of calcite and dolomite by using chittickapparatus.j.sediment petrol.32:520-529. international journal of environment issn 2091-2854 19 | p a g e el mahi,y.,i.s.ibrahim,h.m.abdelmajid and a.m.eltilib,1987. a simple method for determination of calcium and magnesium carbonate in soils soil sci. soc.am.j.51:1152-1155. hassan,n.a.k. and b.h.al-tawil,1973. astudy on lime status of iraqi soils 1amanometricmethod for the determination of lime in soil.tech.bull.46.sci.res.foundation min.of higher educ. and sci. res. baghdad, iraq. hodgson,j.h.1976. soil survey field handbooks.describing and sampling soil profiles tech. monogr.no 5 harpendon,herts,england. kassim,j.k. and j.haba 1989.identification of soil chlorite.5 th sci.conf.sci.rec. council.(baghdad, iraq).vol.1 part 2 37-47. kassim,j.k,.k.z.al-janabi and a.m.al-kubaisy,1993. distribution of different forms of iron oxides in soils of al-jezera and western desert regions of iraq.meso.j.agri.vol.25:19-27. loeppert, r.m.,c.t.hallmark and m.m. koshy 1974.routine procedure for rapid determination of soil carbonate. soil sci. soc. am. j.48:1030-1033. martine,a.e. and r.reeve,1955.a rapid manometric method for determining soil carbonate. soil sci. 70:187-197. moore,t.j., r.h.loeppert, l.t.west and c.t. hallmark.1987.rotine method for calcium carbonate equivalent of soil. comm.soil sci. plant anal.18:265 – 277. nelson,d.w. and l.e.sommers,1982.total carbon organic carbon and organic matter.in a. l. page et al.(ed).methods of soil analysis part 2 2 nd ed. agronomy 9 : 539-560. nelson,r.e. 1982. carbonate and gypsum .in a.l.page et al.(ed).agronomy 9 : 181-197. soil survey staff. 1999. soil taxonomya basic system of soil classification for making and interpreting soil surveys. usda-scs agric. handb.436.u.s.government printing office, washington dc. u.s.salinity laboratory saff, 1954.diagnosis and improvement usda –scs handb. 60 u.s.government printing office, washington dc. zougagh, m., a.rios and m.valcarcel (2005). direct determination of total carbonate salts in soil samples by continuous – flow piezoelectric detection. talanta j. 65: 29 -35. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 263 | p a g e international journal of environment volume-3, issue-2, mar-may 2014 issn 2091-2854 received:20 may revised:25 may accepted:27 may morphotaxonomy of three rare terricolous taxa of jungermanniales occurring in nilgiri hills (western ghats) india afroz alam department of bioscience and biotechnology, banasthali vidyapith, rajasthan corresponding author: afrozalamsafvi@gmail.com abstract nilgiri hills being a part of biodiversity hot spot, is a home of colossal life forms including bryophytes. bryophytes have a great diversity in nilgiri hills which includes both terricolous and corticolous forms. this study deals with morphotaxonomy of three extremely infrequent terricolous taxa of order jungermanniales, viz., gottschelia schizopleura (spruce) grolle, lethocolea javanica (schiffn.) grolle and jackiella javanica var. cordifolia schiffn, occurring in nilgiri hills. these taxa were located to a few restricted pockets and facing high risk of habitat loss which need urgent/immediate conservation management. key words: bryophyta, jungermanniales, nilgiri hills, morphotaxonomy, habitat loss, conservation management introduction jungermanniales is the largest order in hepaticae and comprises 82-85% of the total hepatic vegetation on earth, distributed equally in tropical and temperate parts of the world (pradhan, 2014). schuster (1984) classified jungermanniales in 15 suborders of which 13 have been reported from india represented by 27 families, 97 (+ 3) genera and 520-600 species (chopra, 1938a, 1938b, 1943; kashyap, 1929, 1932; parihar et al, 1994; mitten, 1861; stephani, 1917-1924; udar, 1976; srivastava, 1998; sharma and srivastava, 2003). in nilgiri hills the class hepaticae is represented by, 29 families and 55 genera with 164 species. of these 90 mailto:afrozalamsafvi@gmail.com international journal of environment issn 2091-2854 264 | p a g e species in 24 genera are epiphytic and remaining strictly terrestrial (alam and srivastava, 2012; verma et al., 2013). the terrestrial liverworts are more vulnerable to disappear than the corticolous forms due to habitat loss. habitat loss is the major biotic threat to the terrestrial liverworts in india mainly due to rapid urbanization, industrialization, change in land use pattern, demand on forest products, etc. beside these catastrophic activities and biological imparities are natural causes of decline in terrestrial liverwort diversity (bhattacharyya, 2011). as a result, several of the previously reported taxa in nilgiri become extinct. it all happened due to rapid habitat loss (alam, 2009; 2011; alam et al., 2009; 2012). in present study efforts have been made to provide morphotaxonomic account of three such terrestrial taxa which presume rare in their occurrence in nilgiri. these three taxa are gottschelia schizopleura (spruce) grolle, jackiella javanica var. cordiofolia schiffn., and lethocolea javanica (schiffn.) mitt. materials and methods study area the blue mountain of nilgiri is due to the predominant and verdant blue bloom of angiosperm – strobilanthus kunthianus (acanthaceae), is an ancient land mass that thrust upwards at the junction of two major mountain ranges near the southern end of india some 70 million years ago. situated at 10º1’-11º45’ n latitude, 76º-77º15’ e longitude, and about 12002500 m altitude spread over an expanse of 2600 km 2 it forms the center of diversification in the india’s oldest ‘biosphere reserve’, the nilgiri biosphere reserve (nbr), of tamil nadu. geographically the region is located between moyar gap and palghat gap which creates a natural barrier for the migration and diversification of taxa (fig. 1). the geography and climate of the region make the area an important centre for diversification of the species. recently few taxa reported new to the region (alam, 2008). international journal of environment issn 2091-2854 265 | p a g e figure 1. map of tamil nadu showing study area the present study was carried out from january 2001 to june 2009. several collections were made during this period and on the basis of collection and field observations these three taxa are found to be very rare. collections have been made according to standard field methods. the identification has been made by comparing type material and consulting relevant literature international journal of environment issn 2091-2854 266 | p a g e (udar and kumar, 1981b; 1982; 1986). nomenclature is updated following brummitt and powell (1992). observations 1. gottschelia schizopleura (spruce) grolle gottschelia schizopleura (spruce) grolle. jour. hatt. bot. lab. 31: 16 (1968); udar et kumar, j. indian bot. soc. 61: 250 (1982);-jungermannia schizopleura spruce, trans. proc. bot. soc. edinberg 15: 577 (1885); -anastrophyllum cucullifolium st., spec. hepat. 6: 104 (1917); jamesoniella microphylla (nees) schiffn., in pande and singh, bull. bot. soc. univ. saugar 11: 1 (1959). plants robust, reddish, rigid, suberect, up to 30-35 mm long. stem 112-176 µm in diameter, cortical region 2-3 cell layered thick, deep brown, cells 9.2-15.2 x 9.2-17.5 µm, thick walled, medullary cells hyaline, occasionally light yellow, 11.2-22.4 x 11.2-26.6 µm, thin walled, branches rare. leaves contiguous, entire, succubus, ovate to oblong, 0.91-1.3 mm long, 0.76-0.89 mm broad, concave, more or less transversely inserted, interlocking dorsally, apex obtuse, margin incurved, marginal cells 19.2-30.4 x 15.2-26.4 µm, middle and basal cells 19.2-38.4 x 11.2-26.4 µm, thin to thick walled with prominent bulging to confluent trigones, more prominent in posterior part of the leaves, sometimes with intermediate nodular thickening in cell walls. oil bodies not seen. underleaves absent. dioicous. male inflorescence terminal becoming intercalary, male bracts similar to leaves; one antheridium per bract; antheridia globose, stalked. female inflorescence terminal on main shoot, female bracts in 1 pair, comparatively larger than vegetative leaves, oblong, strongly concave, with entire, incurved margin, apex obtuse, occasionally retuse to bilobed, sometimes with abaxial fold on apex, bracteoles absent, perianth largely exserted, cylindrical. perianth contracted and 5-plicate toward apex. sporophyte immature (fig. 2). type locality: madagascar (boswell) as jungermannia schizopleura (bonner, 1965). sexuality: dioicous. ecology: terricolous, grows on moist and shady soil surface. global distribution: africae. africa, madagascar, asiachina, celebes, india, indonesia (borneo, java, sumatra) malaysia (malaya), philippines, sri lanka (ceylon), norfolk island, papua new guinea, west iran. distribution in india: south india: tamil nadunilgiri hills [ootacamund (avalanche, dodabetta, governorsholai), palni hills: shembaganur, kodaikanal, madura]. specimens examined: south india: tamil nadu: avalanche, ca. 2439 m, 02.01.1972 r. udar and party, det.: r. udar and a. kumar, 55 s /1972 (lwu). palni hills, ca. 2000 m, 07.10.2000, s. c. srivastava and party, 12337/2000 (lwu); nilgiri hills – avalanche ca. 1950 m, 09.10.2000, s. c. srivastava and party, 12538-12543/2000, 12555/2000 (lwu); ootacamund (dodabetta), ca. 2400 m, 26.03.2001, p.k. verma and afroz alam, 13474/2001, 13494/2001 international journal of environment issn 2091-2854 267 | p a g e (lwu); ootacamund (governorsholai), ca. 2200 m, 10.04.2002, p. k. verma, afroz alam and n. sahu, 15447/2002, 15466/2002, 15469/2002, 15491/2002 (lwu). characteristics of species: 1. plants robust, reddish up to 35 mm long, 2. leaves entire, ovate to oblong, 3. female bracts oblong with entire margin; apical part of the perianth smooth. note: this species was instituted as jungermannia schizopleura spr. by spruce (1884-85) and later described under the name of anastrophyllum cucullifolium st. (stephani, 1917), and as jamesoniella microphylla (nees) schiffn. (pande and singh, 1959). grolle (1968) described it as gottschelia schizopleura. 2. lethocolea javanica (schiffn.) grolle lethocolea javanica (schiffn.) grolle, bot. mag. tokyo 78: 93 (1965);symphyomitra javanica shiffn. denkschr. math. nat. class. kais akad. wiss. wien 67: 193 (1898); udar & kumar, lindbergia 12: 103.f.1-14 (1986). plants prostrate, up to 3.55.0 mm long, green to brownish, stem 0.95 x 1.0 mm in diam., 8-10 cells across, cortical and medullary region indistinct, cells thin walled, 7.5-12.5 x 5.0-12.5µm. rhizoids numerous, scattered on ventral surface of axis, simple, sinuate, hyaline. leaves succubous, sub quadrateovate, entire, slightly oblong, 800-1200 x 7601040 µm, marginal cells recurved, slightly decurrent dorsally, 30.4-45.6 x 19.0-34.0 µm, median cells 34.2-49.7 x 30.4-57.0 µm, basal cells 45.6-91.2 x 26.6-49.4 µm in size, apex obtuse-rotundate, thin walled, without or with incipient trigones. oil bodies not seen. underleaves absent. androecia not seen; gynoecia not seen. marsupium terminal up to 3.68 mm long, cylindrical, pendent, rhizoidous, 5-7 cells thick, inner surface with numerous mucilaginous cells (fig. 3). type locality: java (udar and kumar, 1986). ecology: terrestrial, grows on moist soil and soil covered rocks along with jungermannia sp., cephaloziella sp., asterella sp. and mosses. distribution in india: india: south indiakerala (mannar) and tamil nadu: nilgiri hills (mukhurthy) (udar and kumar, 1986), coonoor (aruvankadu, droog), gudulur (cherambadi, yellamalai, wilson plantation). global distribution: india and java (udar and kumar, 1986). specimens examined: india-south india : tamil nadu-nilgiri hillsmukhurthy, ca. 2000m, 23.09.1983, r. udar and party, 5769/1983, 5770/1983(lwu); ootacamund (glenmorgan), ca. 1900 m, 01.12.2001, p. k. verma and a. alam, 14681/2001(lwu); coonoor (aruvankadu), ca. 1800m, 03.12.2001, p. k. verma and a. alam, 14802/2001, 14807/2001(lwu); gudulur (cherambadi), ca. 1200 m, 28.09.2002, p. k. verma and a. alam, 16088-90/2002(lwu); gudulur (yellamalai), ca. 1200m, 29.09.2002, p. k. verma and a. alam, 16148/2002(lwu); gudulur road (wilson international journal of environment issn 2091-2854 268 | p a g e plantation), ca. 1600-1800m, 30.09.2002, p. k. verma and a. alam, 16156/2002(lwu); coonoor (droog), ca. 1800m, 05.10.2002, p. k. verma and a. alam, 16550/2002 (lwu). characteristics of species: 1. plants prostrate, leaves succubous, sub quadrateovate, margin recurved, apex obtuse, rotundate, 2. oil bodies 1(-2) in each leaf cell, 3. underleaf absent, 4. perianth absent; marsupium terminal, cylindrical pendent, rhizoidous, 5-6 cells thick, 5. asexual reproduction by tuberous tip of marsupium or by discoid gemmae. note: this is the second time that this genus is being reported from india after its original discovery therefore, it can be consider as rare taxon in india. 3. jackiella javanica var. cordifolia schiffn. jackiella javanica var. cordifolia schiffn., denscher. mat.nat. cl. kais akad. wiss. wien 70: 217 (1900); udar et ad. kumar, j. indian bot. soc. 60: 107.f. 1-36 (1981); jackiella brunnea (horik.) hatt., bull. tokyo sci. mus. 11: 48 (1944). plants prostrate to suberect, delicate, upto 2.0 to 3.0 cm long, light green, occasionally yellowish brown, with ascending shoot apices, in dense mat. stem 114-201 µm in diameter upto 6-7 cells across, cortical region 1(-2) cell layered thick, cells thick walled; light to deep brown, isodiametric, 19.0-26.6 x 11.2-15.2 µm, medullary cells light brown to yellowish brown, thick to intercalary, small, ascending, light green. leaves contiguous, somewhat distant, entire, succubous, ovate to cordate or sub quadrate to slightly oblong, usually longer than broad or as long as broad or occasionally broader than long, 0.68-0.75 mm long, 0.58-0.68 mm broad at middle, 0.54-0.68 mm long 0.64-0.63 mm broad at apex, light green to light brown, sub opposite, insertion oblique, apex obtuse, occasionally slightly retuse, margin entire (to wavy), not decurrent, marginal cells 19.2-26.6 x 19.2-27.0µm, middle and basal cells 22.6-38.0 x 15.2-31.5 µm, wall thin, trigones prominently bulging, oil bodies not seen. underleaves reduced, upto 4-5 cells long, 4-5 cells broad, 53.2-95.0 x 38.0-63.2µm, bifid, lobes uniseriate, margin dentate, connate at base with leaves of one side, cell wall thin, trigones feebly developed. rhizoids numerous on prostrate axis, particularly near the base of underleaves, with swollen tips harboring mycorrhiza. asexual reproduction by 1-2 celled gemmae, arising from the marginal cells of the leaves. dioicous. fertile plants not seen (fig. 4). type locality: java. sexuality: dioicous (udar and kumar, 1982). habitat: grows on soil and rock surface in dense mats at moist places in association with jungermannia sp., notoscyphus sp. and pogonatum sp. global distribution: india and java (udar and kumar, 1982). distribution in india: south india: karnataka abbi fall in mercara, agumbe; kerala lakkidi in wynad; tamil nadu nilgiri hills: ootacamund (dodabetta), coonoor (wellington), gudalur (yellamalai, nellakota). international journal of environment issn 2091-2854 269 | p a g e specimens examined: india: south indiatamil nadu: nilgiri hillscoonoor (wellington), ca. 1350 m, 31.12.1971, r. udar and party, 375/1971 (lwu); gudulur (nellakota); ca. 1600 m; 04.04.2002; p. k. verma and a. alam; 14912/2002 (lwu); gudulur (yellamalai), ca. 1900 m, 29.09.2002, p. k. verma and afroz alam, 16146/2002 (lwu). characteristics of species: 1. plants prostrate to sub erect, with ascending apex or ascending branches, 2.leaves with or without curved margins, longer than broad, flat, hardly decurrent and comparatively smaller at the middle of axis, 3. rhizoids numerous on prostrate axis, particularly near the base of underleaves, 4. asexual reproduction by 1-2 celled gemmae. note: jackiella javanica var. cordifolia was instituted by schiffner (1900) from java. after 2002, this species could not be collected in following explorations to nilgiri hills hence considered rare. international journal of environment issn 2091-2854 270 | p a g e figure 2. gottschelia schizopleura (spruce) grolle: 1-11. 1. habit of plant, 2. male plant, 3. female plant, 4. t. s. of axis, 5. a leaf, 6. marginal cells of leaf, 7. median cells of leaf, 8. basal cells of leaf, 9-10. male bracts, 11. antheridium (figures drawn from lwu-12555/2000). international journal of environment issn 2091-2854 271 | p a g e figure 3. lethocolea javanica (schiffn.) grolle: 1-14. 1. plant in dorsal view, 2. plant with marsupium (lateral view), 3. cross section of axis, 4-10. leaves, 11. apical cells of leaf, 12. median cells of leaf, 13. basal cells of leaf, 14. t. s. of marsupium. (figures drawn from lwu-14802/2001). international journal of environment issn 2091-2854 272 | p a g e figure 4. jackiella javanica var. cordifolia schiffn.: 1-22. 1. a plant (dorso-lateral view), 2. t. s. of axis, 34. rhizoids, 5-11. leaves with gemmae, 12-15. gemmae, 16. marginal cells with gemmae, 17. apical cells of leaf, 18. median cells of leaf, 19. basal cells of leaf, 20-22. underleaves (magnified) (figures drawn from lwu-14912/2002). international journal of environment issn 2091-2854 273 | p a g e discussion as far as the terricolous taxa are concerned, nilgiri hills hosting 74 taxa distributed in 3 suborders, 21 families and 30 genera. the polymorphic order jungermanniales is the most diversified with 14 genera and 30 species (alam and srivastava, 2012). in comparison to epiphytic forms terrestrial jungermanniales always come under greater risk of extinction due to various biotic and natural activities mainly consequential in the form of habitat loss (alam, 2009). in present study, taxa like gottschelia schizopleura, jackiella javanica var. cordifolia and lethocolea javanica have been reported for the second time after their original discovery strengthen this fact, and revealed the uncongenial surroundings which do not seem supporting the growth and development of these species consequently they become confined only to particular ecological niche. conclusion the infrequent occurrence of these three taxa explains that various factors contribute the loss of terricolous diversity of these liverworts such as habitat loss and fragmentation, pollution, introduction of exotic species, over exploitation, intensive agricultural and forestry. however, the main threat to diversity may be attributed to habitat destruction through expanding human population. fragmentation of habitats results in destruction of complex ecological interaction among species resulting in ecological catastrophes. natural disturbance and degradation are some of the usual causes of habitat destruction resulting excessive loss of habitat in a very short period. therefore, some very serious attentions and efforts are required to save valuable gene pool for future. acknowledgements the author is grateful to professor s. c. srivastava, former head department of botany, lucknow university and former collaborator of the all india coordinated project on taxonomy (aicoptax) for facilities and encouragement during the study and the ministry of environment and forests (new delhi) for financial assistance under aicoptax. thanks are also due to professor aditya shastri, vice-chancellor, banasthali vidyapith (rajasthan) for providing basic support. references alam, a. and srivastava, s. c., 2012. hepaticae of nilgiri hills, western ghats india (india), vol. iterrestrial diversity, pp.1-400. lap-lambert academic publishing, germany. alam, a., 2008. new additions to the bryoflora of nilgiri hills (tamil nadu), south india. geophytology 38 (1 2), 41-44. alam, a., 2009. rare and endangered terricolous liverworts of nilgiri and palni hills, tamil nadu. journal of indian botanical society 88 (3 &4), 236-238. international journal of environment issn 2091-2854 274 | p a g e alam, a., 2011. diversity and distribution of terricolous liverworts (hepaticae) in nilgiri hills, tamil nadu, india. proceedings of the national academy of sciences (biological section). 81 b (ii), 206-217. alam, a., kumar, a. and srivastava, s. c., 2009. jungermannia (plectocolea) nilgiriensis sp. nov. from nilgiri hills (western ghats) india. bulletin botanical survey of india 49(14), 219-224. alam, a., sharma, d. and yadav, s., 2012. solenostoma tetragonum (lindb.) r. m. schust. ex vana et d. g. long var. kodaikanaleinsis var. nov. from palni hills, tamil nadu. phytotaxonomy 12, 68-71. bhattacharyya, s. d., 2011. threats and conservation of liverworts in india: an overview. assam university journal of science & technology: biological and environmental sciences 7 (1), 168-172. bonner, c. e. b., 1965. index hepaticarum. pars v. j. cramer, weinheim, germany. brummitt, r. k. and powell, c. e., 1992. author’s of plant names. royal botanic garden, kew, uk. chopra, r. s., 1938a. notes on indian hepaticae. i. south india. proceedings of the indian academy of science b 7, 239 – 251. chopra, r. s., 1938b. notes on indian hepaticae. ii. sikkm himalaya. proceedings indian academy of science b 8: 427 – 439. chopra, r. s., 1943. a census of indian hepatics. journal of indian botanical society 22, 237259. grolle, r., 1968. gottscheliaeine new jungermanniales gottung der palaotropis. journal of hattori botanical laboratory. 31: 13-39. kashyap, s. r., 1929. liverworts of the western himalayas and the panjab plains. part i – lahore. kashyap, s. r., 1932. liverworts of the western himalayas and the panjab plains. part ii – lahore. mitten, w., 1861. hepaticae indiae orientalis: an enumeration of the hepaticae of the eastindies. journal of the proceedings of the linnean society. botany 5, 385 – 392. pande, s. k. and singh, v. b., 1959. on jamesoniella microphylla (nees) schiffn.new to indian bryoflora. bulletin botanical society, university of saugar 11, 1-2 parihar, n. s., katiyar, n. and lal, b., 1994. hepaticae and anthocerotae of india. a new annotated checklist, pp.1-106. central book depot, allahabad. pradhan, n., 2014. three new records of jungermannia species (hepaticae, jungermanniales) from nepal. international journal of environment 3(1), 85-92. schiffner, f.,1900. die hepaticae der flora vont buitenzorg (leiden: e.j. brill.) 1-110. schuster, r. m., 1984. evolution, phylogeny and classification of the hepaticae. new manual of bryology vol. ii (ed. schuster, r. m.) pp. 760-1070. the hattori botanical laboratory nichinan, miyazaki japan. international journal of environment issn 2091-2854 275 | p a g e sharma, d. and srivastava s. c., 2003. jungermanniales (hepaticae) in indiaan overview. abstract: pii. 4. national conference on biodiversity and applied biology of plants, oct. 8-10, 2003. department of botany. lucknow university, lucknow. pp.61. spruce, r., 1884-85. hepaticae of the amazon and the andes of peru and ecuador. transactions and proceedings of the botanical society of edinburgh 15, 1-11, 1-308 (1884), 309-588 (1885). srivastava, s. c., 1998. distribution of hepaticae and anthocerotae in india. in: topics in bryology. (ed. chopra, r.n.) allied publishers ltd. pp. 53 – 85. stephani, f., 1917 – 1924. species hepaticarum 6: 1-763 (1917: 1-128; 1918: 129-176; 1921: 177-240; 1922 241-368; 1923: 369-432; 1924: 433-763). geneve. udar, r. and kumar, a., 1981b. studies in indian jungermanniaceae-i gottschelia schizopleura (spruce) grollea rare taxon. journal of indian botanical society 61, 250-253. udar, r. and kumar, a., 1982. genus jackeilla in south india. proceedings of indian academy of science (plant sci.) 91(2), 131-137. udar, r. and kumar, a., 1986. the genus lethocolea mitt. in india. lindbergia 12, 103-105. udar, r., 1976. bryology in india. pp. 1-200. new delhi. verma, p. k., alam, a. and rawat, k. k., 2013. assessment of liverworts and hornworts flora of nilgiri hills, western ghats (india). polish botanical journal 58(2), 525-537. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 1 | p a g e international journal of environment volume-3, issue-2, mar-may 2014 issn 2091-2854 received:10 january revised:11 april accepted: 8 may use of the universal soil-loss equation to determine water erosion with the semi-circular bund water-harvesting technique in the syrian steppe mahmoud al, hamdan 1* , issam al, khouri 2 , awadis arslan 3 1 homs center the general commission for scientific agricultural research 2 al.baath university, homs, syria 3 the general commission for scientific agricultural research, damascus, syria * corresponding author: alhamdan1978@hotmail.com abstract this research was conducted through the rain season 2009 -2010, in mehasseh research center at (al qaryatein), the area is characterized by a hot and dry climate in summer and cold in winter with an annual average rainfall of 114 mm. three slopes (8%, 6%, 4%) were used in semicircular bunds water -harvesting techniques with bunds parallel to the contours lines at flow distance of 18, 12 and 6 m. the bunds were planted with atriplex halimus seedlings. graded metal rulers were planted inside the bunds to determine soil loss and sedimentation associated with the surface runoff, and metallic tanks were placed at the end of the flow paths to determine agricultural soil loss from water runoff. a rain intensity gauge was placed near the experiment site to determine the rainfall intensity that produced runoff. the treatments were done in three replications. the amount of soil erosion (in tons per hectare per year) increased with increasing of the slope, the highest recorded value was 38.66 at slope of 8% and the lowest 0.05 at 4% slope. the amount of soil erosion also increased with increasing of water run distance, which was 38.66 t.ha -1 .yr -1 at 18 m and 0.05 t.ha -1 .yr -1 at 6 m . bunds with different diameter of water harvesting reduced soil erosion by about 65% at slope of 8%, 55% at 6%, and 46% at 4%. the input parameters of universal soilloss equation were found to be suitable for determining soil erosion in this arid and semi-arid region. key words: bunds, runoff distances, universal soil -loss equation, water harvesting techniques mailto:alhamdan1978@hotmail.com international journal of environment issn 2091-2854 2 | p a g e introduction water is considered the main limiting factor for agricultural production in arid and semiarid area, rainfall is the only source of water in such regions, because, as there areas no permanent sources of water such as lakes, river, streams; rain falls irregularly but heavily during the rainy season. many seasons of drought lead to the degradation of natural resources such as soil, water, and vegetation. natural resources in rangeland must therefore be managed by water harvesting to ensure adequate production of livestock feed throughout the season and to reduce soil erosion. water harvesting is the chemical, physical, and morphological process for concentrating and gathering the runoff of rainfall water for use when necessary to irrigate plants or for drinking water for livestock (somme et al., 2001). various techniques are used to collect rainwater from natural terrains or modified areas and to concentrate it for use at smaller sites or on cultivated fields to ensure economic crop yields. collected runoff is stored in the soil behind dams, terraces, cisterns or gullies or used to recharge aquifers (oweis, 2004). in the syrian arab republic, water harvesting is seldom used by farmers, mainly because they are not aware of this traditional system, which is widely adopted in other dry areas, including in egypt, pakistan, tunisia and yemen. furthermore, the agricultural research and extension support services in the country lack specific, systematic knowledge about potential areas and suitable locations for water harvesting (de pauw et al., 2004). erosion is the physical process that destroys soil production ability, and runoff leads to loss of organic matter and the entire content of soil. erosion comprises processes by which earth materials are entrained and transported across a surface, while soil loss is the material actually removed from a particular hill slope or segment. soil loss may be less than erosion because of on-site deposition in micro-topographic depressions on a hill slope. the sediment yield from a surface is the sum of soil losses minus deposition in macro-topographic depressions, at the toe of a hill slope, along field boundaries or in terraces and channels sculpted into the slope (terrence and foster, 1998). during the past few decades, scientists have devised mathematical models for calculating water erosion of soil. the models include the factors that affect the amount of soil erosion and are used to reduce damage to the soil. the universal soil-loss equation (usle) is considered to be one of the most significant developments in soil and water conservation in the 20th century and is used on every continent in places where soil erosion caused by water is a problem. it is an empirical equation based on the work of many individuals that has evolved over the past 60 years and is still being revised(laften and moldenhauer, 2003).the equation first published in agriculture handbook no. 537 of the united states department of agriculture (wischmeier and smith, 1978) is: se= r*k*ls*c*p where se is the long-term average annual soil loss (usually expressed in t.ha -1 .yr -1 ),r is rainfall erosion potential in j.ha -1 , k is soil erosion susceptibility in t.ha -1 , ls is the dimensionless impact of slope length and steepness, and c and p are the dimensionless impacts of cropping and management systems and of erosion control practices. the usle has become the standard tool for predicting soil erosion by water throughout the world (meyer, 1984). the objective of this study was to use the usle to determine the effectiveness of semi-circular bunds of different diameters (18, 12, 6m) in reducing soil erosion, the influence of runoff distances of 18, 12 and 6 m in reducing soil erosion and to determine all the factors international journal of environment issn 2091-2854 3 | p a g e that affect the usle in order to find a suitable form for calculating soil erosion in arid and semi-arid areas. material and methods site: the site studied is located in the syrian steppe 120 km northeast of damascus. it covers about 7000 ha and is at 850–950 m altitude, 37.20 º longitudes, and 34.08º latitude, with a rainfall of 114 mm.yr -1 (figure 1). figure 1. site of the experiment (qaryatien) the area is considered to be arid to semi-arid area. it is very hot in summer and very cold in winter, with low rainfall (an annual average of 114 mm) and an evaporation rate of 1750 mm. climate characteristics are recorded tan electronic climate station (table 1). table 1. climatic characteristics of studied site annual dec. nov. oct. sept. aug. jul. jun. may apr. mar. feb. jan climatic element 96.4 4.5 0 4.4 0.3 0.0 0.0 0.0 1 18.5 26 14 27.7 rainfall (mm) 11.89 rainfall density mm.h -1 )) 15.9 6.9 12.1 17.6 23 25.1 26.2 23.9 21.4 13.2 8.9 6.4 6.5 air temperature (ºc) 23.0 13 18.2 25.4 31 33.9 34.1 32.7 28.9 22.1 14.1 12.5 10.3 max. temperature (ºc) 8.1 1.3 6.1 7.9 13.3 16.7 17.2 14.3 11.5 6.4 2.1 -0.2 0.65 min. temperature (ºc) 55.1 73.1 68 50.3 48.7 49.1 45.3 44.2 35 51.4 57.9 64.2 74.1 relative humidity (%) 4.05 4.5 3.1 3.2 3.6 4.4 6 4.6 4.3 4.1 3.6 3.8 3.4 wind speed (m.s -1 ) 1671 41 80 143 196 224 217 222 223 136 86 61 42 evapotransportation(mm) international journal of environment issn 2091-2854 4 | p a g e the chemical properties of the soil were the same on the three slopes. the average proportion of total carbonates was very high (41.96%); the ph was7.69, and the organic matter content was 0.534% (table 2).the percentages of sand, silt and clay and the bulk density differed by slope; however, the real density was the same (table 2) table 2. chemical and physical properties of soil according to slope physical properties chemical properties slope (%) sand (%) silt (%) clay (%) bulk density g.cm -3 real density g.cm -3 total carbonates (%) ph organic matter (%) 37 5 22 8221 22.5 40.26 32.5 42550 1 .6 88 24 8221 22.5 08201 323. 42513 . 34 88 86 8221 22.5 0826. 32.1 420.2 0 field structure the study was conducted on three slopes (8%, 6%, 4%), which were chosen with a nevo device. contour lines were drawn on the three slopes at 18, 12 and 6 m to serve as runoff distances. then, semi-circular bunds with diameters of 18, 12 and 6m were dug on the contour line. a control system had the same diameter contours (18, 12, 6 m) but no bunds. the bunds and the blanks were planted with the livestock feeding shrub atriplex halimus. all treatments were distributed randomly on three replicates for each slope (figure 2). the rainfall during the season studied was recorded at an electronic climate station installed at the site. rainfall gauges were used to measure the amount of rainfall, and graded pins and metal tanks were planted in the water catchment area to measure accumulated and eroded soil with the usle (united states department of agriculture, 2008). a rain intensity gauge was placed near the site to determine the rainfall intensity that produced runoff. international journal of environment issn 2091-2854 5 | p a g e 3.4 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 01 /01 /20 10 02 /01 /20 10 03 /01 /20 10 04 /01 /20 10 05 /01 /20 10 06 /01 /20 10 07 /01 /20 10 08 /01 /20 10 09 /01 /20 10 10 /01 /20 10 11 /01 /20 10 12 /01 /20 10 13 /01 /20 10 14 /01 /20 10 15 /01 /20 10 16 /01 /20 10 17 /01 /20 10 18 /01 /20 10 19 /01 /20 10 20 /01 /20 10 21 /01 /20 10 22 /01 /20 10 23 /01 /20 10 24 /01 /20 10 25 /01 /20 10 26 /01 /20 10 27 /01 /20 10 28 /01 /20 10 29 /01 /20 10 30 /01 /20 10 31 /01 /20 10 days of the month r ai nf al l (m m ) rainfall(mm) figure 2.position of treatments in the experiment (one replication) result and discussion the highest rainfall during the rainy season was27.7mm in december 2009, with a rainfall density during that month of 11.89 mm.h -1 (table 1). the runoff of rainwater in this season was compared with erosion of the agricultural soil on the three slopes and at the three runoff distances. soil erosion was calculated for r, k, ls, c and p of the usle. the r coefficient represents rainfall and is determined from the amount of rainfall and the quantity of runoff. its value is therefore related to rainfall density, which can be calculated from: r (j.ha -1 ) =∑ei30 where, e = (118.9+87.3)log 10 /i30, and i is the highest rainfall intensity during half an hour during a rain storm. i is calculated by plotting the amount of rainfall during1 month (figure 3). figure 3. value of i in the usle blan k شاهد blan k blan k blan k blan k blan k شاهد blan k semi circle (18m )m) semi circle (12m ) أقواس يدوية قطر متر 6 slope 4% slope 6% slope 8% c o n to u r e d g e 18 m 12m 18 m 6 m 6m 12 m semi circle (18m m) semi circle (12m ) متر semi circle (12m ) متر semi circle (18m m) semi circle (12m ) متر أقواس يدوية قطر متر 6 semi circle (18) m) semi circle (12m ) متر semi circle (18m m) semi circle (12m ) ) semi circle (18m m) semi circle (12m ) متر أقواس يدوية قطر متر 6 semi circle (18m m) semi circle (12m ) متر semi circle (12m ) متر semi circle (6m) c o n t o u r lin e b la n k b la n k semi circle (6m) semi circle (6m) semi circle (6m) semi circle (6m) semi circle (6m) semi circle (18m m) semi circle (6m) semi circle (6m) semi circle (6m) semi circle (18m m) c o n to u r e d g e c o n t o u r lin e 12m 18 m 6m international journal of environment issn 2091-2854 6 | p a g e the k coefficient is calculated (fredrrich et al., 2003) as follows: k= {(2.1 × 10 -4 )* (12-om) m 1.14 +3.25(s-2) +2.5(p-3)}/100 where om is the soil content of organic matter (%), m is{(silt+sand)*(silt + fine sand)}, s is the coefficient of the class of soil texture, related to the diameter of the soil aggregates(table 3) and p is the infiltration of soil in cm.day -1 (table 4). table 3.value of coefficient s in calculating k in the usle s feeiciffe c mitsfef e io tee fetef )ss) 8 8 > 2 8–2 7 2–84 0 8 < table 4. value of coefficient p in calculating k in the usle after calculating the coefficients of the equation for the k factor in the usle, we determined the erosion potential of the soil due to water runoff (table 5). the value of k was < 0.09, which is in agreement with the results of ferreira et al., (1995),who found a value of 0.09 when the organic matter content of soil was less than 2%. table 5. calculated k coefficient in the usle k infiltration (cm.day -1 ) coefficient of soil texture(s) sand (%) silt (%) total organic matter % runoff distance(m) slope (%) 0.043 6 1 0.525 0.20 1.623 18 0.08 0.043 6 1 0.525 0.20 0.913 12 0.08 0.043 6 1 0.525 0.20 0.71 6 0.08 0.018 4.8 1 0.500 0.25 0.403 18 0.06 0.018 4.8 1 0.500 0.25 0.71 12 0.06 0.018 4.8 1 0.500 0.25 0.913 6 0.06 0.018 3.6 1 0.525 0.20 0.811 18 0.04 0.018 3.6 1 0.525 0.20 0.51 12 0.04 0.018 3.6 1 0.525 0.20 0.51 6 0.04 infiltration of soil (cm.day -1 ) p < 1 8 1–10 2 10–40 7 40–100 0 100–300 5 > 300 . international journal of environment issn 2091-2854 7 | p a g e the ls coefficient of the usle represents the length, slope and shape of the catchment area (troeh et al., 2004). we first determined the coarseness of the surface by accurately surveying the surface of the catchment area and recording topographic elements such as boulders, cobbles, gravel (fine, medium and coarse) and plant roots on the three slopes. we then calculated the average percentage of each topographic element per square of catchment area, to derive the coarseness of the land (table 6). table 6. coarseness of study site coarseness (%) roots (%) fine gravel (%) medium gravel (%) coarse gravel (%) catchment area (m 2 ) length (m) slope (%) 0.0875 3 5 12 15 127.17 18 8 0.0564 1.85 2 8.7 10 56.52 12 8 0.0397 0.8 5 5.5 4.6 14.13 6 8 0.0610 2 4.9 8 9.5 127.17 18 6 0.0545 1 4.6 8 8.2 56.52 12 6 0.0465 0.6 4.5 7 6.5 14.13 6 6 0.0420 1 4.5 4.5 6.8 127.17 18 4 0.0295 1 2.5 2.5 5.8 56.52 12 4 0.0243 1 2.3 2.2 4.2 14.13 6 4 we determined the ls coefficient in the usle by multiplying the value for coarseness by the length of the catchment area (18, 12, 6 m) and by the slope (8,6,4%)(table 7).the value of ls was < 1, which is in agreement with the results of stone(2000). table 7. calculated ls coefficient in the usle ls length(m) slope (%) coarseness (%) 0.126 18 0.08 0.0875 0.054 12 0.08 0.0564 0.019 6 0.08 0.0397 0.066 18 0.06 0.0610 0.039 12 0.06 0.0545 0.023 6 0.06 0.0465 0.060 18 0.04 0.0420 0.0141 12 0.04 0.0295 0.0058 6 0.04 0.0243 the c coefficient corresponds to the vegetation cover in the catchment and target area. vegetation plays an important role in fixing the soil and thus reducing soil erosion by rainfall. the value of this coefficient is affected by the percentage of planted shrub cover. international journal of environment issn 2091-2854 8 | p a g e the coefficient is calculated from: c= (area of vegetation * percentage of successful shrubs) / catchment area in this study, c increased with increasing slope and increasing diameter of the water harvesting bunds (table 8). the vegetation cover in the bunds was greater than in the controls on all three slopes. the value of this coefficient in the usle was < 1, in agreement with the results of foster (2000), who found values of 0.02–0.04on pastureland. table 8.calculated c coefficient in the usle c catchment area (m 2 ) successful shrubs (%) dimensions of shrubs diameter (m) slope (%) treatment width (m) length (m) plant coverage (m 2 ) 0.0416 127.17 3425. 0.25 0.30 0.075 18 8 bund 0.0029 127.17 86222 0.12 0.16 0.019 8 blank 0.0335 56.52 5225. 0.18 0.20 0.036 12 8 bund 0.0044 56.52 86242 0.11 0.12 0.013 8 blank 0.0213 14.13 732.. 0.08 0.10 0.008 6 8 bund 0.0001 14.13 81265 0.01 0.01 0.000 8 blank 0.0284 127.17 .5235 0.22 0.25 0.055 18 6 bund 0.0020 127.17 86282 0.10 0.11 0.011 6 blank 0.0300 56.52 0625. 0.18 0.19 0.034 12 6 bund 0.0037 56.52 86242 0.10 0.11 0.011 6 blank 0.0310 14.13 7722. 0.11 0.12 0.013 6 6 bund 0.0013 14.13 81231 0.10 0.11 0.011 6 blank 0.0075 127.17 72264 0.16 0.18 0.029 18 4 bund 0.0017 127.17 86284 0.10 0.11 0.011 4 blank 0.0062 56.52 26276 0.10 0.12 0.012 12 4 bund 0.0031 56.52 81211 0.1 0.11 0.011 4 blank 0.0041 14.13 26285 0.04 0.05 0.002 6 4 bund 0.0013 14.13 81235 0.10 0.10 0.001 4 blank the p coefficient represents the ability of the water-harvesting technique to reduce soil erosion. we determined p by measuring the amount of erosion inside the metal tanks at runoff distances of 18, 12 and 6m on the three slopes. we determined the accumulated soil behind the bunds after taking readings from the metal pins and obtained p by dividing the amount of erosion by the accumulated soil and multiplying the result by 100. the results (table 9) agreed with those of renard et al.(1997), who found values of 40–70% in farmland with the contour line technique. international journal of environment issn 2091-2854 9 | p a g e table 9. calculated p coefficient in the usle p(%) runoff distance (m) soil erosion (t.ha -1 .yr -1 ) treatment slope (%) 65.028 18 80.7 accumulated pins 8 124.1 erosion tank 61.735 12 33.8 accumulated pins 54.8 erosion tank 61.370 6 22.4 accumulated pins 36.5 erosion tank 55.005 18 60.2 accumulated pins 6 109.5 erosion tank 54.110 12 23.7 accumulated pins 43.8 erosion tank 52.249 6 17.7 accumulated pins 33.8 erosion tank 46.069 18 25.2 accumulated pins 4 54.8 erosion tank 44.337 12 17.8 accumulated pins 40.2 erosion tank 42.009 6 4.6 accumulated pins 11.00 erosion tank having determined all the coefficients of the usle, we estimated the amount of soil erosion on the three slopes (table 10). the amount of soil erosion on slope 8%at a runoff distance of 18 m was greater than that with the other treatments. table 10.amount of soil erosion obtained with the usle soil erosion bulk density g.cm -3 p c ls k r runoff distance m slope % t. h a -1 .y r -1 m 3 .h a -1 38.66 1.06 1.28 0.650 0.0416 0.126 0.043 72.29 18 8 12.66 0.35 1.28 0.617 0.0335 0.054 0.043 72.29 12 3.04 0.08 1.28 0.613 0.0230 0.019 0.043 72.29 6 4.90 0.13 1.28 0.550 0.0284 0.066 0.018 72.29 18 6 3.01 0.08 1.28 0.541 0.0300 0.039 0.018 72.29 12 0.99 0.03 1.28 0.522 0.0310 0.023 0.018 72.29 6 0.98 0.03 1.28 0.460 0.0075 0.060 0.018 72.29 18 4 0.18 0.01 1.28 0.443 0.0062 0.014 0.018 72.29 12 0.05 0.00 1.28 0.420 0.0041 0.006 0.018 72.29 6 international journal of environment issn 2091-2854 10 | p a g e conclusion the amount of soil erosion increased with increasing slope, with the highest value on the 8% slope (38.66 t.ha -1 .yr -1 ) and the lowest on the 4% slope (0.05 t.ha -1 .yr -1 ).the amount of soil erosion increased with increasing water runoff, reaching 38.66 t.ha -1 .yr -1 at 18 m, while it was only 0.05 t.ha -1 .yr -1 at the shortest distance (6 m). use of water harvesting bunds with different diameters led to reductions in soil erosion of 65% at a 8%slope, 55% at a 6%slope and 46% at a 4% slope. for the first time in the region, the input parameters for the usle have been determined, and a suitable means for calculating soil erosion in this arid and semi-arid region has been obtained. references de pauw, e., oberle, a., and zobiesch, m., 2004. land cover and land use in syria an overview. jointly published asian institute of technology(ait), icarda and world association of soil and water conservation ( waswc). 47pp. ferreira, v.a., g.a. weesies, d.c. yoder, g.r. foster, and k.g. renard., 1995. the site and condition specific nature of sensitivity analysis. j. soil and water conserve. 50(5):493-497. foster, g.r., d.c. yoder, d.k. mccool, g.a. weesies, t.j. toy, and l.e. wagner., 2000. developing databases for national application of rusle. presented at the 8th annual isco conference: soil and water conservation challenges and opportunities, december 4-8, 1994, new delhi, india. fredrrich, r., troeh, s., arthur, hobbs, r. and danahue, l., 2003. soil and water conservation for productivity and environmental protection, united states. laften, j. m., .and moldenhauer, w.c., 2003. pioneering soil erosion prediction, world association of soil and water conservation (waswc), special publication no.1. meyer, l.d., 1984. evolution of the universal soil loss equation. j. soil water conserve. 39:99-104. oweis, t., 2004. rainwater harvesting for alleviating water scarcity in the drier environments in west asia and north africa paper presented at the international workshop on water harvesting and sustainable agriculture, september 7th, 2004, moscow, russia. renard, k. g., g.r. foster, g.a. weesies, d.k. mccool, and yoder, d.c., 1997. predicting soil erosion by water: a guide to conservation planning with the revised universal soil loss equation. u.s. department of agriculture, agriculture handbook 703. 384pp. somme, g., akhter, a., theib, o., abduial, a., burrgeman, a. (1996-2001): micro catchment water harvesting for improved vegetative cover in syrian baddia. stone, r.p., 2000. universal soil loss equation, soil management/omafra; don hilborn p05/00. terrence, j. and foster, r., 1998.use of the revised universal soil loss equation(rusle) on mined lands, construction sites, and reclaimed lands, august, 186p. international journal of environment issn 2091-2854 11 | p a g e troeh, f.r., j.a. hobbs and donahue, r.l., 2004. soil and water conservation for productivity and environmental protection, us, 656 pages. usda(united state department of agriculture). 2008. water erosion project, soil erosion research, texas university. wischmeier, w.h. and smith, d.d., 1978. predicting rainfall erosion losses: a guide to conservation planning. agriculture handbook no. 537, us dept. of agric., washington, dc. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 60 | p a g e international journal of environment volume-2, issue-1, sep-nov 2013 issn 2091-2854 received:12 september revised:5 october accepted:10 october human threat on phenological cycle of selected dry deciduous tree species in north gujarat region (ngr), gujarat, india rajendra kumar 1* and s. kalavathy 2 1 professor, science and humanities, mookambigai college of engineering, srinivasa nagar, kalamavur, pudukottai, tamil nadu 622 502, india 2 associate professor, botany department, bishop heber college, tiruchirappalli, tamil nadu 620 017, india * corresponding author: meen_rajendrakumar@yahoo.co.in abstract phenological observations were taken for 13 woody species for two years (jan 2006 dec 2007) in dry deciduous forest of north gujarat. the phenological behavior of most of the woody species was almost similar in two different years. leaf initiation started in the month of march with peak april – may before pre-monsoon showers and leaf fall began in october with a peak in november and december. flowering in most of the woody species was observed in the month of february continued till may, fruit appearance for these species from march, with a peak of august. in july and august 69% of woody species appeared in fruit ripening stage. while monsoon begins same duration, that allow to the optimal germination of tree species. an observing human impact on selected species facing seasonal threats, more number of species faced cutting during leaf fall period or before on setting of flowers. key words: dry deciduous, human impact, cutting, woody species, leaf fall introduction phenology is the relationship between climatic factors and periodic phenomena in organisms. plant phenologies are the result of interactions of biotic and climatic factors with plant species that through natural selection, determine the most efficient timing for growth and reproduction (van schaik et al., 1993). biotic factors include morphological and physiological adaptations of plants (borchert, 1983) and climatic factors include photoperiod (wright and van schaik, 1994), temperature (arroyo et al., 1981) and rainfall (opler et al., 1976). the plant species within communities may share phenological patterns at varying degrees for a variety of reasons, for example, being subject to the same climatic regimes. the plant species may also share phenologial patterns independently of their morphological and physiological adaptations. on the other hand different species may show similar patterns in phenology because of close phylogeny (wright and calderon, 1995). hence, the study on phenology provide knowledge about the pattern of plant growth, relationship with mailto:meen_rajendrakumar@yahoo.co.in international journal of environment issn 2091-2854 61 | p a g e environment and selective pressure on flowering and fruiting behaviors of a particular region or vegetation type (zhang et al., 2006). the ngr is dominated by dry deciduous forest, falls under agro-climatic zones and hot semiarid type. the study area in ngr experiences three prominent seasons: summer, winter and monsoon. the summer season covers the months between march and june, while the monsoon starts in the month of july and lasts till the end of october. winter season stars in november and ends in february. the average rainfall was of 913mm during the period of 2001 – 2007, with the minimum of 373 mm in 2002 and maximum of 1483mm in 2006. the temperature ranged from 5 0 (winter) – 46 0 (summer). above said climatic conditions provides an ideal environment for the occurrence and abundance of diverse flora and the richness of this forest. in additions, the presence of biotic, abiotic and threat factors of diverse habitats also give selective pressure on plants, which might change the pattern of plant growth and reproduction (joshua et al., 2007). further, tree species in this habitat are used by local people for constructing house, furniture, fuel wood and fodder for cattle has added to the degradation. as a result, significant numbers of woody species have lost their regeneration capacity. the present study on phenology of selected dry deciduous tree species was comprises, vegetative and reproductive status of plants, mainly flowering and fruiting patterns and human pressure on phenological cycles of tree species. an outcome of this study provides information on factors which exactly affects the reproduction potential of tree species. also, the study results reflect the changes in phenological patterns of tree species by on-going human threats in long-term. materials and methods: study area the ngr lies between 23 o 35’ 13.0” to 24 o 30’ 57.0” n and 72 o 10’ 28.0” to 73 o 24’ 47.0” e and falls under three administrative districts viz. banaskantha, sabarkantha and meshsana. it extends to about 8.7% (1638 km 2 ) of the total forest cover of gujarat state (18,868.28 km 2 ) and includes protected areas viz. jessore sloth bear wildlife sanctuary (jsbws), balaram ambaji wildlife sanctuary (baws), taranga hill and vijaynagar forest (map 1). forest was the most predominant land use type of the study area covering 1638 km 2 , followed by agriculture land use largely in the valleys. third major land use is rocky barren surface, while mining areas cover over 15 km 2 . only 8 km 2 areas are in the form of water bodies or wetlands (joshua et al., 2007). although major forest types are found in the study area, they have been classified into two major sub-groups viz. 5a southern tropical dry deciduous forest and 6b northern tropical thorn forest (champion and seth, 1968). the dominant soil of this region is classified as alluvial sandy soil mixture of sandy and coarse particles. further, sandy loam and black soil are distributed in banaskantha and sabarkantha districts. in meshana, 90% of the area is covered by light sandy soil and at some patches where sandy soil is mixed with black soil, the cultivation is possible. the pure sandy soil usually distributed in the forest region of meshana districts, mainly taranga hill and abarkantha forest, have good natural thorn forest (chavan and lal, 1984). international journal of environment issn 2091-2854 62 | p a g e map 1: location of study area field study to study the phenology, 13 dominant dry deciduous species were selected and 10 individuals of each were marked and studied during the period of jan 2006 to dec 2007. these species were checked once in every 15 days (twice in a month, n=48) (marques et al., 2004). phenological study included various stages of vegetative phases (sprouting leaves (spl), young leaves (yl), matured leaves (ml), dead leaves or yellow leaves (dl/yel) and no leaves (nil) and reproductive phases (flowering and fruiting stage). flowering stage was further divided into flower bud (flb), young flower (yfl), and matured flower (mfl), while the fruiting stage was divided into young fruit (yfr), matured fruit (mfr), and dry fruit (dfr). availability of different stages was given in percentage with both vegetative and reproductive phases accounting for 100% each. human interference on phenology was recorded by cutting and lopping signs on selected trees species. data analysis the variation of phenology were examined and classified into (1) flushing (2) leaf fall (3) flowering and (4) fruiting. flushing is defined to be the interval between the beginnings of leaf bud opening to the appearance new leaves to at least 75% of their final size. this was calculated from the proposition of spl, yl, and ml. leaf fall is defined as when <50% of the leaves on the plant showed dl, yel and nl or fallen leaves were on the ground. flowering was the presence of the one or more open flowers in the phase of flb, yfl and mfl. similarly fruiting was the presence of one or more fruit in the phases of yfr, mfr and dfr. intervals between phases were also examined. further, month wise cutting activities were concurrent with phenology of plant species. international journal of environment issn 2091-2854 63 | p a g e results leaf flushing: leaf initiation started in the month march. the flushing was continued till the month of july august, with a peak in may – june before the onset of monsoon (figure 1). out of the 13 species studied, butea monosperma and diospyros melanoxylon showed leaf initiation in march 2006 followed by aegle marmelos, anogeissus latifolia, feronia limonia, holarrhena pubscens, lannea coromandelica, miliusa tomentosa, mitragyna parvifolia, terminalia bellirica in april and boswellia serrata, cassia fistula, wrightia tinctoria in may. but in 2007, 11 species, (about 85%) showed leaf initiation in april followed by may (table 1). table 1: flushing, leaf fall, flowering and fruiting pattern of woody species in three different forest types of north gujarat region sl. no scientific name flushing leaf fall flowering fruiting 2006 2007 2006 2007 2006 2007 2006 2007 1 aegle marmelos (l.) corr. apr apr nov nov mar mar apr apr 2 anogeissus latifolia (roxb. ex dc.) wall. ex guill. & perr. apr apr dec nov oct sep nov nov 3 boswellia serrata roxb. ex cocls. may may nov nov feb feb apr apr 4 butea monosperma (lam.) taub. mar apr nov nov feb jan apr apr 5 cassia fistula l. may apr nov nov apr apr may may 6 diospyros melanoxylon roxb. mar apr nov nov apr apr jun jun 7 feronia limonia (l.) swingle apr apr nov nov may apr jun may 8 holarrhena pubscens (buch. ham.) wall. ex g. don apr apr nov nov mar mar may may 9 lannea coromandelica (houtt.) merrill apr apr nov oct feb feb apr apr 10 miliusa tomentosa (roxb.) j. sinclair apr apr nov oct mar mar may may 11 mitragyna parvifolia (roxb.) korth. apr apr nov nov apr mar may may 12 terminalia bellirica (gaertn.) roxb. apr apr nov nov mar mar may may 13 wrightia tinctoria (roxb.) r. br. may may nov nov mar mar may apr leaf fall: leaf shedding began in the month of october with peaks in november and december (figure 1). the earliest leaf shedding was also observed in lannea coromandelica and miliusa tomentosa. flowering: flowering activity of selected woody species is in the month of february continued till may. when aegle marmelos, boswellia serrata, butea monosperma, cassia fistula, diospyros melanoxylon, feronia limonia, holarrhena pubscens, lannea coromandelica, miliusa tomentosa, mitragyna parvifolia, terminalia bellirica, wrightia tinctoria flowering pattern were observed (figure 1 and table 1). fruiting: the initial fruiting activity was observed in the month of march. all the selected species had attained the fruiting stage in april and may continued till november, with a peak in august (figure 1). during this period 69% of the woody species (aegle marmelos, international journal of environment issn 2091-2854 64 | p a g e boswellia serrata, butea monosperma, cassia fistula, holarrhena pubscens, miliusa tomentosa, mitragyna parvifolia, terminalia bellirica, wrightia tinctoria) appered to be in fruiting stage. rest of the species attained fruiting stage in june (table 1). figure 1: phenological pattern of selected dry deciduous species in north gujarat region human interface on phenological cycle: two years of phenological observation showed all studied species faced threat in the form of cutting. month wise cutting activities of 13 species are given figure 2. it revealed that, more numbers of species faced cutting during winter (dec feb) or before the winter seasons starts (sep nov) and, 80% species faced threats during the summer (may – jun). rest of the months the plant faced minimal threats further, the cutting activities were correlated with phenological cycle. out of 13 species 11 species (except holarrhena pubscens and lannea coromandelica) faced cutting, in the month of may – jun during the leaf initiation stage. whereas sep – nov, dec – feb all the tree species faced high incidence cutting, that falls leaf fall stage. but anogeissus latifolia and lannea coromandelica were in reproductive stage. figure 2: month wise human interface on phonological cycle of selected dry deciduous species in north gujarat region discussion leaf flushing: leaf initiation peak in may may be attributed to the triggering effect of the rising temperature and increase in the length of photoperiods as suggested by njoku (1964), lawton and akpan (1968) and walter (1968). leaf production during the dry seasons and before rains has already been observed by several researchers (frankie et al., 1974; shukla international journal of environment issn 2091-2854 65 | p a g e and ramakrishnan, 1982; sundriyal, 1990; singh and singh, 1992; kikim and yadava, 2001; singh and kushwaha, 2005a and b; yadav and yadav, 2008). borchert and rivera (2001) also suggested that in dry summer season, the vegetative buds of spring flushing stem succulent species are in a state of endo-induced dormancy and terminated by declining and increasing photoperiod, respectively. the role of photoperiod has been confirmed by rivera et al (2002) who reported that spring flushing in tropical semi-deciduous trees is induced by an increase in photoperiod of 30 minutes or less. they further supported that production of new foliage shortly before the rainy season is likely to optimize synthetic gain in tropical forests with relatively short growing season. this is also approved by elliot et al (2006) and kushwaha and singh (2005). leaf fall: the leaf fall was concentrated in cool winter months of the year i.e. from october to december. prasad and hegde (1986) observed similar pattern of leaf fall in tropical deciduous forests in the bandipur tiger reserve, south india. the results are also in conformity with singh and singh (1992) who reported that initiation of leaf fall coincides with the onset of the post-monsoon, low temperature, dry period and can be a mechanism maintaining turgidity of shoots. however, borchert and rivera (2001) and borchert et al (2002) suggested that in argentina forest, leaf shedding of several species before time is probably caused by a combination of increasing leaf age and declining photoperiod rather than increasing drought. further, morellato et al (1989) suggested that, flushing and leaf fall are often correlated in intensity and timing in which flushing follows leaf fall. flowering: as majority of the species produced flowers during flushing or leaf-fewer phases, flowering and flushing may overlap in some species. the same meristems that produce buds also produce the flowers (borchert, 1983). synchronization of flowering and leaf flushing seems to be related to moisture, temperature and day length, which is in conformity with observations made by others workers (boojh and ramakrishnan, 1981; murali and sukumar, 1994). borchert (1994) also suggested that the stored water buffers the impact of seasonal drought and enables flowering and flushing during the dry season. further, the flowering activity was observed in drier (february to may) periods are due to synchronous flowering in a particular time may be due to seasonally active pollinators, or because several species share the same set of pollinators. the asynchronous flowering (delayed or earlier flowering activity) may reduce competition for pollinators (rathcke and lacey, 1985; van schaik et al., 1993), which also favors the wind pollinators (singh and singh, 1992). fruiting: the peak of fruiting follows that of flowering. in several species fruit ripening begins in monsoon period that may be due to the difference in fruit maturation activity (kikim and yadava, 2001). thus fruit dehiscence of tree species coincides with the monsoon to allow optimal germination (frankie et al., 1974; primack, 1987; singh and kushwaha, 2006; singh and singh, 1992). human interface on phenological cycle: the recorded phenological cycle of selected tree species showed leaf initiation – mar – may; leaf fall – oct – dec; flowering – feb – may; fruiting – mar – aug. similarly threat on tree species are in two peaks 1. leaf initiation period; 2. before attaining flowering and fruiting (leaf fall period). the degradation caused by human being upon the trees, is called as “seasonal threats”. international journal of environment issn 2091-2854 66 | p a g e this seasonal threat affects the flowering and fruiting pattern of tree species, mainly delaying or absence of flowering and fruiting at a particular time, leads to low manifestation of reproduction. extensive wood cutting in the species or individual, result shifts in switch of vegetative and reproductive phase (bernier, 1988), affects the phenological cycle (like, time of fruit ripening, fruit maturation and fruit dehiscence are shunt) and a process of maturation (rajvansh and goutam, 1990), changes in canopy structure (longman and jenik, 1974), and ecosystem functions (picket et al., 1989). the cut tree does not maintain a maximum structure and therefore the rates or magnitude of the interaction between the physical components of that tree are impaired in companion to certain (uncut) trees (rykicl, 1985). naturally the system of reproduction is getting disturbed or restorative effective of tree species is less has resulted in the environmental maladies of most of the tree species (khoshoo, 1988). conclusion  tree species exhibited inconsiderable variation in leaf initiation and leaf fall.  as majority of tree species produced flowers during flushing or leaf-fewer phases, exception in anogeissus latifolia  similarity in all species fruiting follows that of flowering  fruit ripening begins in monsoon period, to allow optimal germination of tree species  all selected tree species facing “seasonal threats” in the form of cutting, results early losses of tree branches, affects the flowering and fruiting pattern of ngr. implications for conservation genuine efforts to minimize the human pressure are essential for the survival of forest in ngr, since the tribal, dependence on forest for fuel wood and timber, is almost inevitable, there is urgent need for strategic planned to save the forest  creating awareness on rotational cutting, educating people about the value of forest and species usage.  enhancing the fuel wood through afforestation program with species having high calorific values  encourage fuel wood plantation in degraded lands  long term study on impact of cutting on plant phenology  also, detailed research on human activities in forest with relation to the plant phenology  understanding the impact of cutting pressure on regeneration potential of crucial woody species through long term research acknowledgement the authors wish to acknowledge the constant encouragement, supports and facilities provided by gujarat institute of desert ecology (guide), bhuj, kachchh and foundation for ecological security (fes), anand, gujarat for successful completion of this work. many thanks are due to dr. v. gokula, m.sc., m. phil., ph.d., associate professor, department of international journal of environment issn 2091-2854 67 | p a g e zoology, national college, tiruchirappalli for the valuable suggestions and the review of this paper. references arroyo, m.t.k., j.j. armesto & c. villagran (1981). plant phenological patterns in the high andean cordillera of central chile. journal of ecology 69: 205-223. bernier, g. (1988). the control of floral evocation and morphogenesis. journal of annuals review of plant physiology and plant molecular biology 39: 275-219. boojh, r & p.s. ramakrishnan (1981). phenology of tree in subtropical evergreen montane forest in north east india. geo. eco. trop 5: 189-209. borchert, r & g. rivera (2001). photoperiods control of seasonal development and dormancy in tropical stem-succulent trees. tree physiology 21: 213-221. borchert, r (1983). phenology and control of flowering in tropical trees. biotropica 15: 8189. borchert, r (1994). soil and stem water storage determine phenology and distribution of tropical dry forest trees. ecology 75: 1437-1449. borchert, r., g. rivera & w. hagnauer (2002). modification of vegetative phenology in a tropical semi-deciduous forest by abnormal drought and rain. biotropica 34: 27-39. champion, h.g & s.k. seth (1968). revised forest types of india. government of india publications, new delhi. chavan, s.a & b. lal (1984). biodiversity status of important ecosystems of gujarat. pp.66-107. in: kotwal, p.c banerjee, s. (ed.) managed forests and protected areas, agro botanic publications and distributors, bikanar, rajasthan, india. elliott, s., p.j. baker & r. borchert (2006). leaf flushing during the dry season: the paradox of asian monsoon forests. global ecology and biogeography 15: 248-257. frankie, g.w., h.g. baker & p.a. opler (1974). comparative phenological studies of trees in tropical wet and dry forests in the low lands of costa rica. journal of ecology 62: 881-919. joshua, j., s.f.w. sunderraj, s. rajendrakumar, h.k.p. kala, p. manojkumar & l. muthuandavan (2007). assessment of biodiversity and preparation of conservation plan for the forest of north gujarat region. a final report prepared by gujarat institute of desert ecology, bhuj, kachchh, gujarat. 206pp. kikim, a & p.s. yadava (2001). phenology of tree species in subtropical forests of manipur in north eastern india. topical ecology. 42: 269-276. khoshoo, t.n (1988). environmental concerns and strategies. ashish publishing house, new delhi. kushwaha, c.p & k.p. singh (2005). diversity of leaf phenology in a tropical deciduous forest in india, ecology 21: 47-56. lawton, j.r.s & e.e.j. akpan (1968). periodicity in plumeria. nature 218: 384-386. longman. k.a & a. jenik (1974). tropical forest and its environment. longman, londaon 196pp. marques, m., j. ropper & b. salvalaggio (2004). phenological pattern among plant lifeform in a subtropical forest in southern brazil. plant ecology 173: 203-213. morellato, l.p.c., r.r. rodrigues, h.f. leitao-filho & c.a. joly (1989). estudo comparative da fenologia de species arboreas de floresta de altitude e floresta international journal of environment issn 2091-2854 68 | p a g e mesofila semidecidua na serra do japi, jundia. sao paulo. revista brasileria de botanica. 12: 85-98. murali, k.s. & r. sukumar (1994). reproductive phenology of a tropical dry forest in mudumala, southern india. ecology 82: 759-767. njoku, e (1964). seasonal periodicity in the growth and development of some forest trees in nigeria. ii. observations on seedlings. ecology 2: 19-26. opler, p.a., g.w. frankie & h.g. baker (1976). rainfall as a factor in the release, timing and synchronization of anthesis by tropical trees and shrubs. biogeography 3: 231239. picket, s.t.a., j. kolsa, j. armesto & s.l. colins (1989). the ecological concept of disturbance and its expression at various hierachial levels. oikos 54: 129-136. prasad, s.n & m. hedge (1986). phenology and seasonality in the tropical deciduous forest of bandipur, south india. proceedings of indian academy of sciences (plant sciences). 96: 121-133. primack, r.b (1987). relationship among flowers, fruits and seeds. annual review of ecology and systematics 18: 409-430. rajvansh, a & p. goutam (1990). pole cutting pressure in bastar forest in central india and their ecological impacts. indian journal of forestry 13(2): 92-96. rathcke, b & e.p. lacey (1985). phenological patterns of terrestrial plants. annual review of ecology and systematics 16: 179-214. rivera, g., s. elliott, l.s. caldas, g. nicolossai, v.t.r. coradin & r. borchert (2002). increasing day length induces spring flushing of tropical dry forest trees in the absence of rain. trees. 16: 445-456. rykicl, e.j (1980). towards a definition of ecological disturbance. australian journal ecology 10: 361-365. shukla, j.s & p.s. ramakrishnan (1982). phenology of trees in a sub-tropical humid forest in north-eastern india. vegetatio 49: 103-109. singh, j.s & v.k. singh (1992). phenology of seasonally dry forest. current science 63: 103-109. singh, k.p & c.p. kushwaha (2005a). paradox of leaf phenology: shorea robusta is a semi-evergreen species in tropical dry deciduous forest in india. current science 88: 1820-1824. singh, k.p & c.p. kushwaha (2006). diversity of flowering and fruiting phenology of trees in a tropical deciduous forest in india. annals of botany. 97: 265-276. singh, k.p & c.p. kushwaha (2005b). emerging paradigms of tree phenology in dry tropics. current science 89: 964-975. sundriyal, r.c (1990). phenology of some temperate woody species of the garhwal himalaya. international journal of ecology and environmental sciences 6: 107117. van schaik, c.p., j.w. terborgh & s.j. wright (1993). the phenology of tropical forest: adaptive significance and consequences for primary consumers. annual review of ecology and systematics 24: 353-377. walter, h (1968). die vegetation der erde in oeko physiological conditions. springer, verlag, new york. international journal of environment issn 2091-2854 69 | p a g e wright, s.j & c.p. van schaik (1994). light and the phenology of tropical trees. naturalist. 143: 192-199. wright, s.j & o. calderon (1995). phylogenetic patterns among tropical flowering phenologies. ecology 83: 937-948. yadav, r.k & a.s. yadav (2008). phenology of selected woody species in a tropical dry deciduous foret in rajasthan, india. tropical ecology 49(1): 25-34. zhang, g., q. song & s. yang, (2006). phenology of ficus racemosa in xishuangbanna, southwest china. journal of biotropica. 38: 334-341. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 1 | p a g e international journal of environment volume-3, issue-1, dec-feb 2013/14 issn 2091-2854 received:10 december revised:6 january accepted:21 january growth and chlorophyll fluorescence under salinity stress in sugar beet (beta vulgaris l.) fadi abbas 1 *,entessar al-jbawi 2 and mohammed ibrahim 3 1 department of field crops. scientific agriculture research center of homs .general commission for scientific agricultural research (gcsar)-syria 2 general commission for scientific agricultural research (gcsar). crops research administration, sugar beet research department. douma, p.o.box 113, damascus, syria 3 department of plant protection.scientific agriculture research center of hama.general commission for scientific agricultural research (gcsar)-syria *corresponding author: fadiab77@gmail.com abstract this study was carried out in the general commission for scientific agricultural research (gcsar), syria, at der ezzour agricultural research center, from 2008-2010, to examine the effect of salt conditions on some growth attributes and chlorophyll fluorescence in 10 sugar beet (beta vulgaris l.) genotypes under salinity stress. sugar beet plants were irrigated with saline water, having electrical conductivity ranged from 8.6-10 ds.m -1 during first year and 8.4-10.4 ds.m -1 during second year. a randomized completely block design with three replicates was used. the results showed that all studied growth attributes, leaf area, leaf number, relative growth rate, and net assimilation rate were decreased in salinity stress conditions compared to the controlled state. the findings indicated that salinity caused a decrement of light utilizing through increased values of fluorescence origin (fo), decreased values of fluorescence maximum (fm), and maximum yield of quantum in photosystem-ii (fv/fm). genotypes differed significantly in all studied attributes except in leaf number. under salt conditions, brigitta (monogerm) achieved an increase in net assimilation rate, while kawimera (multigerm) achieved the lowest decrement in quantum yield in photosystem-ii. further studies are necessary to correlate the yield with yield components under similar conditions to determine the most tolerant genotype. key words: growth, chlorophyll fluorescence, salinity stress, sugar beet (beta vulgaris l.). introduction salinity is considered as a global environmental challenge, affecting crop production on over 800 million hectares, or a quarter to third of all agricultural land on earth (rengasamy, 2010). the 21 st century is marked by global scarcity of water resources, international journal of environment issn 2091-2854 2 | p a g e environmental pollution, and increased salinity of soils and waters (djilianov et al., 2005). the problem is particularly severe in irrigated areas (zhu, 2001), where as much as one-third of global food production occur (zhang et al., 2010), and also where infiltration of highly saline sea water observed (flowers, 2004). however, salinity is also increased in dry land agriculture in many parts of the world (rengasamy, 2006). development of crops with improved salt tolerance is proposed as part of solution to this problem (zhu, 2001). plants follow different behaviors to combat salinity. detailed reviews about salinity tolerance mechanisms in different species are presented by ashraf (2004) and sairam and tyagi (2004). sugar beet (beta vulgaris l., family; chenopodiaceae), has halophytes ancestors. its tolerance threshold to salinity is high (7 ds m -1 ) (katerji et al., 1997). it is a salt sensitive species during seed germination period and seedling emergence, and a salt tolerant with variations in its genotypes (sadeghian et al., 2000; ghoulam et al., 2002, abbas et al., 2009). sugar beet plant has a good ability in modifying its osmotic potential as a response to salt stress (abbas et al., 2012). salinity decrease growth and net photosynthesis of higher plants (long and baker, 1986), which may open the possibility of using photosynthetic parameters in salt-tolerance screening. the rationale for the view that changes in leaf photosynthetic parameters may be used to carry out screening of stress-resistant cultivars is that such parameters would reflect any constraint acting on the photosynthetic processes. therefore, more stress-tolerant cultivars are expected to exhibit photosynthetic parameters during stress periods (belkhodja et al., 1994). chlorophyll fluorescence could be an excellent tool for screening, since it is easy to measure and may allow the screening of large numbers of genotypes in a short time span. this approach was used in screening several sugar beet genotypes for drought and salinity tolerance (abbas, 2011), to characterize the changes in the efficiency of photosynthetic energy conversion occurring in fe-deficient sugar beet plants (morales et al., 1991). the technique is also used to study the changes in quantum yield under sulfur spray on sugar beet foliage (abbas and seedo, 2010), and zinc sulfate application (abbas, 2012). results of abbas and seedo (2010) and abbas (2012) showed that foliar application of sulfur and zinc sulfate accelerated the yield of quantum in photosystem-ii. the purpose of the present study is to study the effect of salinity stress on some growth parameters and chlorophyll fluorescence in 10 sugar beet genotypes. materials and methods two field trials were tested on 7 th and 9 th august during (2008-2009, 2009-2010) growing seasons. the experiments were carried out in the general commission for scientific agricultural research (gcsar) at der ezzour agricultural research center, syria. the area is dry with an irrigation facilities for the sugar beet production. the aim of these trials was to evaluate the response of ten sugar beet genotypes (five monogerms and five multigerm) (table 1) under salinity stress and control conditions. the investigated genotypes were obtained from different breeding companies. nitrogen fertilization was added at the rate of 446 kg ha -1 . phosphorous at a rate of 180 kg p2o5 and potassium at a rate of 185 kg k2o were added during sowing and after thinning. mechanical and chemical analysis of the soil at the experimental site was carried out (table 2). international journal of environment issn 2091-2854 3 | p a g e plants were irrigated with saline water under saline stress conditions, having electrical conductivity ranged from 8.6 to 10 ds.m -1 (first year) and 8.4 to 10.4 ds.m -1 (second year). it is also important to mention that the first three emergent were irrigated with pure water, and the same plants were fed with saline water during growing season. for this, randomized completely block design with three replicates was used. the size of each plot was 24 m 2 , consisted of 6 ridges (8m long, 50cm wide) and hills were 20 cm apart from each block. table 1. source, germity and salt tolerance of sugar beet genotypes no genotype source germity poloidy type salt tolerance * 1 dita belgium monogerm diploid n tolerant 2 brigitta germany monogerm diploid nz tolerant 3 progress usa monogerm diploid n mid-tolerant 4 rifle belgium monogerm diploid n sensitive 5 concept usa monogerm diploid ne sensitive 6 tigris denmark multigerm polyploid n sensitive 7 montebaldo germany multigerm triploid n tolerant 8 prestibel belgium multigerm polyploid ne mid-sensitive 9 waed germany multigerm diploid n tolerant 10 kawimera germany multigerm triploid n tolerant * abbas et al. (2011) table 2. soil properties of study area soil sample season particle size distribution chemical analysis of soil paste extraction sand silt clay caco3 ec (mmhos/cm) (25 0 c) ph % % % % 2008-2009 33.3 36.4 30.3 19.4 1.8 8.1 2009-2010 29.3 40.7 29.6 20.7 1.9 8.2 two samples were selected during the growth period i.e. 120 and 150 days during sowing period. five guarded plants were chosen at random from each sub-plot to determine: leaf area index (la) (cm 2. plant -1 ): the disk method was followed using 10 disks of 0.91 cm. diameter according (watson, 1958). leaf number (ln) only number of green leaves with a lamina length greater than 6 cm was considered (rinaldi, 2003). relative growth rate (rgr) in (g.g -1 .day -1 ) (watson, 1958) 12 12 loglog tt ww rgr e    net assimilation rate (nar) (gm -2 day -1 )(radfords, 1967) ))(( )log)(log( 1212 1212 aatt aaww nar ee    where w1,w2 and a2 refer to dry weight to plant, and leaf area at time t1 and t2, respectively. -chlorophyll fluorescence was measured in middle-aged leaves after 150 days from sowing time. the fast phase of chlorophyll a fluorescence variation was determined by plant efficiency analyzer (pea, handsatech instruments ltd., king’s lynn,norfolk pe32 ijl england). leaves were exposed to dark state for 30 minutes before measurements, international journal of environment issn 2091-2854 4 | p a g e as dark phase stimulates reaction centers of photosystem ii to rest (not involved in any photosynthetic reactions (lavorel and etienne, 1977). dark adaptation was inducted by a clip having a sliding opening. measurements were taken from 11 am till 2 pm after 30 minutes of dark state. measurements included: fo (fluorescence origin): dark adapted initial minimum fluorescence. fm (fluorescence maximum): maximal fluorescence measured during first saturation pulse after dark adaptation. fv/fm = (fm – fo) / fm.the dark adapted test used to determine maximum quantum yield. this ratio is an estimate of maximum portion of absorbed quanta used in ps-ii reaction centers. data for each treatment were statistically analyzed and presented as anova. the combined analysis for four evaluated planting dates was done for each season (gomez and gomez, 1984). treatment means were compared using the least significant difference (lsd) method. results leaf area (la) and leaf number (ln) under salinity stress, leaf area (la) in all genotypes decreased by 8.94% as compared to control after 120 days from sowing period. indeed, the genotypes differed significantly in this trait (p<0.01). the decrement in la ranged from 4.87% in montebaldo and 17.67% in tigris. leaf numbers per plant decreased (0.94-6.79%) but the decrements were not significant under saline conditions. however, the mean decrement in all genotypes was 2.37% compared to control. the results depicted that leaf number was less affected than leaf area by salinity (table 3). table 3. leaf area (cm 2 .plant -1 ) and leaf number (leaf/plant) for 10 sugar beet genotypes under control and salinity stress conditions leaf number (150 days) leaf area (120 days) genotype comparison with control (±%) salt conditions control comparison with control (±%) salt conditions control -0.94 34.33 34.67 -6.47 4239 4352 dita -2.47 32.67 33.50 -5.93 4692 4987 brigitta -3.05 31.83 32.83 -8.54 4459 4878 progress -3.45 32.00 33.17 -14.12 3957 4610 rifle -4.46 31.67 33.17 -15.21 3991 4708 concept -6.79 31.83 34.17 -17.67 3805 4620 tigris -0.98 34.50 34.83 -4.87 4849 5101 montebaldo -4.64 30.83 32.33 -8.44 4040 4413 prestibel -3.02 32.00 33.00 -3.31 4344 4493 waed -2.37 34.17 35.00 -4.88 5000 5257 kawimera -3.22 32.58 33.67 -8.94 4338 4742 mean leaf area (lsd0.01=442.3 **), leaf number (ns) international journal of environment issn 2091-2854 5 | p a g e relative growth rate (rgr) rgr decreased in all genotypes by an average of 34.85% as compared to control. the decrement ranged from 8.14% in brigitta and 78.35% in tigris (table 4). net assimilation rate (nar) nar decreased also in all genotypes by an average of 26.47% as compared to control, which was increased in brigitta by 2%. the decrement ranged between 1.81% in dita and 73.49% in tigris (table 4). table 4. rgr (g.g -1 .day -1 ), and nar(g.m -2 .day -1 ) for 10 sugar beet genotypes under salinity stress conditions during (120-150) days period after sowing genotype rgr nar control salt condition comparison with control (±%) control salt condition comparison with control (±%) dita 0.015 0.013 -13.23 5.57 5.45 -1.81 brigitta 0.014 0.012 -8.14 4.77 4.86 +2 progress 0.014 0.01 -26.69 4.63 3.49 -24.1 rifle 0.013 0.005 -61.66 4.58 1.93 -57.67 concept 0.014 0.006 -58.82 4.92 2.41 -51.3 tigris 0.014 0.003 -78.35 4.79 1.26 -73.49 montebaldo 0.015 0.012 -21.65 5.35 5.09 -4.51 prestibel 0.015 0.009 -38.07 5.69 4.19 -25.63 waed 0.014 0.011 -20.85 5.59 4.75 -14.42 kawimera 0.014 0.011 -21.09 4.98 4.28 -13.72 mean 0.014 0.009 -34.85 5.09 3.77 -26.47 rgr (lsd0.01=0.003**), nar (lsd0.05=0.679 **) chlorophyll fluorescence chlorophyll a fluorescence as measured by fo, fm, and fv/fm ratio at 150 days after sowing is the stress and non-stress conditions are presented in table 5.fo was increased under salt stress condition in all genotypes by an average of 30.25% compared to control, but fm decreased in all genotypes by 23.54%, so the ratio fv/fm also decreased by 15.62%. the differences among genotypes were significant. table 5.fo, fm,fv/fm for 10 sugar beet genotypes under salinity stress conditions fv/fm fm fo genotype comparison with control (±%) salt condition control comparison with control (±%) salt condition control comparison with control (±%) salt condition control -10.66 0.729 0.816 -18.08 2934 3585 20.82 794 659 dita -9.45 0.752 0.831 -21.51 2957 3773 14.63 731 639 brigitta -12.34 0.712 0.812 -17.78 2939 3575 26.28 844 670 progress -24.76 0.622 0.827 -26.33 2518 3426 61.77 951 591 rifle -22.94 0.642 0.833 -35.1 2494 3844 39.54 891 640 concept -30.46 0.58 0.835 -37.72 2202 3586 57.09 920 589 tigris -9.61 0.746 0.825 -18.4 2982 3671 18.12 755 640 montebaldo international journal of environment issn 2091-2854 6 | p a g e -21.08 0.655 0.83 -31.87 2590 3806 38.21 886 644 prestibel -8.72 0.743 0.804 -19.2 2841 3513 9.76 755 688 waed -6.23 0.769 0.82 -9.49 3308 3671 16.23 764 661 kawimera -15.62 0.694 0.823 -23.54 2776 3645 30.25 829 642 mean fo (lsd0.01=74.96 **), fm (lsd0.01=339.5 **), fv/fm (lsd0.01=0.026 **) disscussion the leaf number was less affected than leaf area by salinity. it is suggested that most of the reduction in plant leaf area was caused by the inhibition of leaf expansion. this is consistent with the results of previous researches, which showed that high levels of salinity decreased the leaf area due to combination of decrease in cell number and cell size (deherralde et al., 1998; dadkhah and grrifiths, 2006). munns and termaat (1986) demonstrated that for a given amount of nacl transport to the shoot, reduction in leaf expansion results in the same proportional increase in the leaf nacl concentration. salt stressed barley plants produced smaller leaf areas, which caused a higher na + accumulation in specific leaf area (munns, 1985). witkwski and lamont (1991) reported that plants might reduce water loss by reducing their evaporation surface. therefore, leaves tend to be smaller and thicker under saline conditions. halophytes tolerate the saline conditions and show a resistance to higher salt concentrations with a reduction in growth rate. different cultivars of the same plant had different behavior toward salt tolerance (flowers and hajibagheri, 2001; qadir et al., 2001). our results indicated that rgr and nar of all genotypes decreased significantly under salt condition. the decreased biomass weights of plants under saline conditions are correlated with the reduced leaf area, which results in decreases of photosynthetic area (yang et al., 2008). it is thought that a decreased photosynthesis under stress could have reduced the shoot growth and development, leading to lower biomass production compared to control (campbell and nishio, 2000). greenway and munns (1980) reported that the effect of salinity on leaf area was greater than dry weight, as salt accumulation in the shoot occurs via transpiration stream, which is highest in old leaves killing them. this proves that brigitta genotype showed an increase in net assimilation rate under salinity stress. many studies have concluded that reduction in photosynthesis in response to salinity reduce stomatal conductance and consequently restrict the availability of co2 for carboxylation (everard et al., 1994). in control plant, there is no significant difference in chlorophyll fluorescence measurement, but in the presence of salinity the significant differences represented the differences in the efficiency of photosystem ii in sugar beet cultivars. the fluorescence suggested that the rate of energy translocation or light capture might be limited by salinity (long and hallgern, 1993). we suggested that 10 genotypes experienced some degree of photo inhibition. moreover, lower fv/fm was observed in salt-stressed conditions compared to control plants, which indicated that rubp(ribulose-1,5-bisphosphate) regeneration, which needs adequate electron translocation from photosystem ii to electron acceptors, might be disturbed by salinity. international journal of environment issn 2091-2854 7 | p a g e in terms of genotype tolerance, the genotypes differed significantly in all studied attributes except for ln. under salt conditions, brigitta (monogerm) achieved an increasing in (nar), while kawimera (multigerm) achieved the lowest decrement in (fv/fm). tigris (monogerm) shows the highest reduction in all parameters, so, we consider tigris the most non-tolerant genotype. and further studies must be done in future to study the correlations with yield and yield components of these genotypes under the same conditions to determine the most tolerant genotype. conclusion the foregoing discussion showed that all studied growth attributes, leaf area, leaf number, relative growth rate, and net assimilation rate was decreased in salinity stress conditions compared to the controlled state, we think these could be returned to the decrement of light utilizing through increased values of fluorescence origin (fo), decreased values of fluorescence maximum (fm), and maximum yield of quantum in photosystem-ii (fv/fm). genotypes differed significantly in all studied attributes except in leaf numbers. under salt conditions, brigitta (monogerm) achieved an increase in net assimilation rate, while kawimera (multigerm) achieved the lowest decrement in quantum in photosystem-ii. tigris (monogerm) shows the highest reduction in all parameters, so, it considered the most non-tolerant genotype. references abbas, f., 2011.response of some sugar beet (beta vulgaris l.) genotypes to drought and salinity stresses, and the genotype x environment interaction assessment for some yield and quality traits.phd thesis.al-bath university.faculty of agriculture. 196p. abbas, f., 2012. study of the photochemical processes and its correlation with yield in sugar beet,beta vulgaris l., under effect of zinc application. persian gulf crop protection (pgcp). 1 (2): 41-48. (in arabic). abbas, f., mohanna, a., allahham, g., al-jbawi, e., 2012. osmotic adjustment in sugar beet plant under salinity stress.journal of sugar beet. sugar beet seed institute (sbsi), karaj ,iran. 28 (1): 67-80 (in persian). abbas, f., mohanna, a., allahham, g., al-jbawi, e., al-jasem, z., 2011.evaluation the response of some sugar beet (beta vulgaris l.) genotypes under saline water irrigation conditions. the arab journal for arid environments 4 (1): 93-105. abbas, f.,seedo, m., 2010. study of the assimilation activity in sugar beet,beta vulgaris l., maximum yield of quantum in photosystem-ii , and yield under effect of sulfur application. proceedings of the 10 th conference of general commission for scientific agricultural research. damascus, douma. 29-30/9/2010.p.43. ashraf, m., 2004.some important physiological selection criteria for salt tolerance in plants. flora, 199: 361-376. campbell, s.a., nishio, j.n., 2000. iron deficiency studies of sugar beet using an improved sodium bicarbonate-buffered hydroponics growth system. j plant nutr 23:741-757. dadkhah, a.r., grrifiths, h., 2006. the effect of salinity on growth, inorganic ions and dry matter partitioning in sugar beet cultivars. j. agric. sci. technol. (2006). 8: 199-210. international journal of environment issn 2091-2854 8 | p a g e de-herralde, f., biel, c., save, r., morales, m.a., torrecillas, a., alarcon, j.j., 1998. effect of water and salt stresses on the growth, gas exchange and water relations in argyranthemumcoronopiflium.plants. crop sci., 139: 9-17. djilianov, d., georgieva, t., moyankova, d., atanassov, a., shinozaki, k., smeeken,scm.,verma, dps., murata, n., 2005. improved abiotic stress tolerance in plants by accumulation of osmoprotectantsgene transport approach.20th anniversary agro bio institutebiotechnol.andbiotechnol. eq. 19/2005. special issue.63-71. everard, j.d., gucci, r., kang, s.c., flore, j.a., leoscher, w.h., 1994. gas exchange and carbon partitioning in the leaves of celery (apiumgraviolens l.) at various levels of root zone salinity. plant physiol., 106: 281-292. flowers, t.j., 1985.physiology of halophytes. plant soil, 89: 41-56. flowers, t.j., hajibagheri, m.a., 2001. salinity tolerance in hordeumvulgare: ion concentration in root cell of cultivars differing in salt tolerance. plant soil.1-9. ghoulam, c., foursy, a., fares, k., 2002. effect of salt stress on growth, inorganic ions and proline accumulation in relation of osmotic adjustment in five sugar beet cultivars. journal of environment and experimental botany. 47: 39-50. gomez, k.a., gomez, a.a., 1984. statistical procedures for agricultural research. john wiley and sons, inc., new york. pp: 680. greenway, h., munns, r., 1980.mechanisms of salt tolerance in nonhalophytes.annu.rev.plant physiol., 31: 149-190. hester, m.w., mendelssohn, i.a., mckee, k.l., 2001. species and population variation to salinity stress in panicumhemitomon, spartina patens, and spartinaalterniflora: morphological and physiological constraints. environ. exp. bot., 46: 277-297. katerji, n., van-hoorn, j.w., hamdy, a., mastroili, m., 1997.osmotic adjustment of sugar beet in response to soil salinity and its influence on stomatal conductance, growth and yield.journal of agriculture and water management., 34: 557-569. koyro, h.w., 2006. effect of salinity on growth, photosynthesis, water relations and solute composition of the potential cash crop halophyte plantagocoronopus (l.). environ. exp. bot., 56: 136-146. lavorel, j., etienne, a.l., 1977. in vitro chlorophyll fluorescence. in: primary processes of photosynthesis (ed. j. barber). elsevier/north holland biomedical press, amsterdam, new york, pp: 203-268. long, s., baker, n., 1986. saline terrestrial environments. in n baker, s long, eds, photosynthesis in contrasting environments. elsevier, new york, pp: 63-102. long,s.p., hallgern, j.e., 1993.measurement of co2 assimilation by plants in the field and the laboratory. in: "photosynthesis and production in a changing environment", (eds.): hall, d. o., scurlock, j. m. o., bolhar-nordenkampf, h. r., leegood, r. c. and long, s. p..chapman and hall, london, pp. 129-167. morales, f., anunciacion, a., abadia, j., 1991. chlorophyll fluorescence and photon yield of oxygen evolution in iron-deficient sugar beet (beta vulgaris l.) leaves. plant physiol. 97: 886-893. munns, r., 1985. na+, k+ and clin xylem sap flowing to shoots of nacl treated barley. j. exp.bot., 36: 1032-1042. international journal of environment issn 2091-2854 9 | p a g e munns, r., termaat, a., 1986. whole-plant responses to salinity. aust. j. plant physiol., 13: 143-160. qadir, m., ghafoor, a., murata, g., 2001. amelioration strategies for saline-sodic soils: a review, land degrad. and develop. 12: 357-386. radfords, p.j., 1967. growth analysis formulae, their use and abuse. crop sci., 7: 171-175. ramzi, b., fermin, m., abadia, a., joaquin, c.a., abadia, j., 1994.chlorophyll fluorescence as a possible tool for salinity tolerance screening in barley (hordeumvulgarel.). plant physiol. 104: 667-673. rengasamy, p., 2006. world salinization with emphasis on australia. journal of experimental botany 57: 1017–1023. rengasamy, p., 2010. soil processes affecting crop production in salt affected soils. functional plant biology 37: 613–620. rinaldi, m., 2003. variation of specific leaf area for sugar beet depending on sowing date and irrigation . ital. j. agron., 71: 23-32. sadeghian, s.y., fazli, h., mohammadian, r., taleghani, d.f., mesbah, m., 2000.genetic variation for drought stress in sugar beet. journal of sugar research., 37: 35-77. sairam, r.k., tyagi, a., 2004. physiology and molecular biology of salinity stress tolerance in plants. journal of current science., 86: 407-421. watson, d.j., 1958. the dependence of net assimilation rate on leaf area index. ann bot. lond. n.s., 22: 37-54. witkowski,etf., lamont, b.b., 1991. leaf specific mass confounds leaf density and thickness. oecologia, 88: 486-490. yang, c., jianaer, a., li, c., shi, c., wang, d., 2008 comparison of the effects of salt-stress and alkali-stress on the photosynthetic production and energy storage of an alkaliresistant halophyte chlorisvirgata. photosynthetica 46(2):273278. zhang, j.l., flowers, t.j., wang, s.m., 2010. mechanisms of sodium uptake by roots of higher plants. plant and soil 326: 45–60. zhu, j.k., 2001. plant salt tolerance.trends in plant science. 6: 66–71. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 86 | p a g e international journal of environment volume-8, issue-2, 2019 issn 2091-2854 received: 14 july 2019 revised: 9 aug 2019 accepted: 10 aug 2019 feeding habits of different fish species in negombo lagoon neetha punchihewa* and m.p.c. silva department of zoology, the open university of sri lanka nawala, nugegoda, sri lanka *corresponding author: neetha_punchihewa@yahoo.co.nz abstract to investigate the feeding habits of different fish species in negombo lagoon, fish species were collected from kadolkele and liyanagemulla sites during february 2015 to july 2015 using a drag net. collected specimens were preserved in 5% formalin. later, the fish specimens were dissected, and stomach contents were mixed with water to make a suspension. one ml of suspension was added to the sedgewick rafter cell, and examined under the light microscope. the occurrence %, volume %, numbers %, and the relative importance values (riv) were calculated. the gut contents of 62 samples from 12 fish species were analyzed; 11 species were found to feed on mangroves, 10 on seagrasses, and 8 on filamentous algae. 13 food items were identified. most of the analysed fish were categorized as omnivores and opportunistic feeders. the juvenile fish mainly feed on a combination of mangroves, seagrasses and filamentous algae. apart from plant matter, the juvenile fish were found to feed upon cyclops sp. and mysids. although hemirhamphus marginatus is an omnivore, it specially fed on mangroves, seagrasses and filamentous algae. furthermore, h. marginatus consumed common food items in both habitats except mangroves and molluscs, and the shifting of its diet was depended on the availability of food. the broadest niche breadth was recorded by h. marginatus and the shortest niche breadth by the herbivorous fish species, siganus vermiculatus and liza macrolepis. caranx sexfasciatus exhibited an ontogenetic shift in their diet. the smaller c. sexfasciatus was a carnivore and the larger individuals of the same species were herbivores. key words: feeding habits, juvenile fish, mangroves, seagrasses, negombo lagoon. doi: http://dx.doi.org/10.3126/ije.v8i2.25522 copyright ©2019 ije this work is licensed under a cc by-nc which permits use, distribution and reproduction in any medium provided the original work is properly cited and is not for commercial purposes http://dx.doi.org/10.3126/ije.v8i2.25522 https://orcid.org/0000-0002-9122-3212 international journal of environment issn 2091-2854 87 | p a g e introduction estuaries and lagoons are among the most productive ecosystems in the world. negombo lagoon is a highly productive ecosystem in sri lanka. mangroves are the main vegetation type bordering the negombo lagoon and seagrasses are submerged in it. these ecosystems provide diverse habitats for commercially important fish and crustaceans. many species of fish utilize mangrove and seagrass areas as feeding or nursery sites (sasekumar, 1984; pinto and punchihewa, 1996) and this vegetation constantly supplies the coastal waters with nutrients. however, estuaries and lagoon are highly dynamic ecosystems that are very vulnerable both to natural and anthropogenic disturbances. the food and feeding habits of fish species are closely associated with their ecological environment. stomach content analysis of fish provides important details about their feeding patterns and this allows us to understand their feeding strategy (lagler, 1949). however, it is difficult to identify all the contents in the stomach and clearly separate the organisms into prey categories for quantification due to the presence of unidentifiable and inseparable partially digested material (baker, 2014). generalized food preferences were often associated with early growth stages but as the fish matured, various populations were more specialized in their feeding habits (livingston, 1982). a study of cross river estuary, nigeria showed that feeding habits of fish species vary with age and the stage of development (ajah, 2012). both juvenile and sub adult stages of citharinus latus fed on phytoplankton with the diet of the adult stage being planktonic. ethmalosa fimbriata was omnivorous at the juvenile stage, monophagus (phytoplanktonic) at the sub-adult stage and planktonic at adult stage (ajah, 2012). however, hepsetus odoe was found to be carnivorous at both the juvenile and adult stages but tilted towards omnivory at sub adult stage. trichiurus lepturus was carnivorous at all three stages (ajah, 2012). morphologically similar closely related species in a fish community utilize the same food resources and habitats for their co-existence (costa and fernando, 1967). the gut content of mullet species valamugil buchanani and liza subviridis from merbok estuary in malaysia, showed that both species fed on plant and animal materials (kaniz, et al, 2013). however, plant materials were the most abundant food items of both fish species. the gut analysis of 34 fish species collected from mangrove and seagrass areas in the negombo lagoon, revealed that feeding habits vary among them, with the ratio of herbivore: carnivore: omnivore being 4:9:21 (pinto and punchihewa, 1996). most of the cohabitating fish species in the negombo lagoon feed on different food items, resulting in ecological segregation (shirantha and wijeyaratne, 2002). however, the food items of 10 species of fish showed that amongst them a high dietary overlap was evident. the study on the food and feeding habits of scatophagus argus in cochin estuary, india (sivan and radhakrishnan, 2011), revealed that algae and detritus dominated the diet. furthermore, it was evident that the flexibility in their feeding ecology and food selection was based on the relative abundance of prey and also an ontogenetic shift in diet. international journal of environment issn 2091-2854 88 | p a g e the high ecological productivity of mangroves provides facilities for the continuation of food chains throughout brackish water ecosystems (saenger et al., 1983). furthermore, it is estimated that up to 80 % of the global fish catch is directly or indirectly dependent on mangroves. in negombo lagoon, mangroves are fast disappearing due to human population expansion, development projects and industrial pressure. the purpose of this study is to provide detailed information on the feeding relationships of fish species living in two different areas, a mangrove area and an area cleared of mangrove. therefore, considering the economic and ecological significance of fish in brackish waters, present investigation would further advance the understanding of their feeding relationships with respect to their habitats. the main objective of this study is to determine the type of food consumed by different fish species and their corresponding habitat relationships. the study further aims to determine whether diet variations occur within the same species with different age groups or fish lengths. methodology fish specimens were collected from two different sites kadolkele and liyanagemulla, in negombo lagoon (fig. 1). the kadolkele site is a mangrove area located in the upper part of the lagoon and the other site, liyanagemulla is without mangrove vegetation and is located in the mid lagoon area close to katunayake highway. figure 1: study sites, negombo lagoon fish samples were collected using a drag net of mesh size 0.9 cm, in each month, starting from february to july 2015. the net was dragged along 100 m length. samples were preserved immediately in 5 % formalin to inhibit the enzymatic activities of the gut contents to prevent any further digestion. the length of each individual of fish specimen was measured using a standard measuring tape. by dissecting each fish specimen, the gut contents were taken out carefully and mixed with 10 ml water to prepare a suspension. 1 ml of suspension was added to the sedgewick rafter cell and examined under the light microscope using the eyepiece micrometer. the sample of the gut contents were observed in 20 squares. three replicates were international journal of environment issn 2091-2854 89 | p a g e trialed up to sixty squares per specimen. percentage occurrence (f %), percentage volume (v %), percentage of numbers (n %), and finally relative importance values (riv) (hyslop, 1980) were calculated for each fish species where more than two individuals were captured. percentage of occurrence = the number of stomachs which a given food item is found × 100 % (f %) the number of stomachs examined percentage of number = the number of stomachs which a given food item is found × 100 % (n %) the number of total food item in all specimens percentage of volume = the volume of one food item found in all specimens × 100 % (v %) the volume of all food items in all specimens relative importance value (riv) = (n% + v %) x f% the niche breadth of each species was calculated based on levins measure of niche breadth, levins index (b), where pi is the proportion of food items. the counts of the number of food items used by each individual of fish species was considered. results among the 12 different species of fish, liza dussumier, leiognathos brevirostis and eleotris fusca were recorded with only one individual from the mangrove site. due to a fewer number of individuals, their gut content analyses were calculated as percentage volume of food items present in the gut (table 1). accordingly, l. brevirostis and e. fusca mainly fed on cyclops sp. (42 % & 48 % respectively), while l. dussumier fed mainly on animal matter. all of them fed on mangroves and seagrass with the exception of e. fusca which fed on mangroves but not seagrass. all three species seem to be omnivorous. table 1: the percentage volume of food items contained in the stomachs of some fish species. sg = sea grass, mg =mangroves, fa =filamentous algae, cy =cyclops, uap =unidentified animal parts, dt =detritus, my =mysids, dp= daphnia sp. atherinomorus duodecimalis and oryzias melastigma were captured only from a mangrove area, and were found to feed upon seven different food types (table 2). they commonly feed on plant matter (mangroves, sea grasses and filamentous algae), cyclops sp. and detritus. all individuals (f %) of a. duodecimalis, depend species length (cm) percentage volume of food items sg mg fa cy uap dt my dp liza dussumier 4.25 13 4 18 45 11 9 leiognathos brevirostis 4.80 38 8 42 4 8 eleotris fusca 4.30 15 48 11 11 15 b = 1 / ∑pi 2 ∑ p i 2 ∑ p i 2 _ international journal of environment issn 2091-2854 90 | p a g e mainly on cyclops sp., mangroves and mysids. cyclops sp. had the highest importance value (riv), followed by mangroves and mysids. all ten individuals of o. melastigma fed on detritus and eight fed on cyclops sp. and seagrasses (f %). however, cyclops sp. was the most important (ri value) food item, followed by seagrasses and detritus. both species showed omnivorous feeding habits. table 2: gut content analysis of a. duodecimalis and o. melastigma atherinomorus duodecimalis (n =10, length 1.2-1.7cm) oryzias melastigma (n=10, length 2.25-3.05cm) food type f % n % v % riv f % n % v % riv seagrasses 40 42.85 8.64 2060 80 50 41.56 7325 mangroves 100 71.42 36.65 10807 20 12.5 6.48 380 cyclops sp. 100 71.42 52.29 12371 80 50 23.33 5866 filamentous algae 20 14.28 1.16 309 40 25 2.93 1117 detritus 40 42.85 6.64 1980 100 2.5 45.50 4800 diatoms 60 37.5 18 3330 molluscs 20 12.5 0.002 250 unidentified animal parts 40 57.14 3.59 2429 mysid 100 71.42 6.34 7776 f% -percentage occurrence, n% -percentage number, v% -percentage volume, riv -index of relative importance, n -number of individuals parambassis dayi and ambassis urotaenia were captured only from the mangrove area and fed on both plant and animal matter (table 3), therefore appearing to be omnivores. however, the most important food items of a. urotaenia (ri value) were mangroves, filamentous algae and seagrasses, and only one individual recorded animal matter. therefore, their diet showed preference towards herbivory while p. dayi showed a greater dietary emphasis towards animal matter. table 3: gut content analysis of p. dayi and a. urotaenia. parambassis dayi (n=6) ambassis urotaenia (n=3) food type f % n % v % riv f % n % v % riv cyclops sp. 100.00 85.71 99.00 18471.00 33.33 20 0.056 668.46 diaptomus sp. 83.33 71.42 2.27 6140.58 daphnia sp. 50.00 42.85 0.09 2174.00 diaphanosoma sp. 16.66 14.28 14.28 475.80 seagrasses 33.33 28.75 0.03 959.23 66.66 40 29.42 4627.53 mangroves 33.33 28.75 0.05 959.90 66.66 40 99.37 9290.40 detritus 33.33 28.75 0.49 959.87 filamentous algae 100.00 60 0.14 6004.00 unidentified animal parts 33.33 20 0.12 666.99 f% -percentage occurrence, n% -percentage number, v% -percentage volume, riv -index of relative importance, n -number of individuals siganus vermiculatus and l. macrolepis fed on plant matter (seagrasses, filamentous algae and mangroves) and detritus, therefore appearing to be herbivores. all individuals of both species fed on seagrasses and detritus (f %). the most important food items (riv) of s. vermiculatus were seagrasses, detritus and mangroves while l. macrolepis showed a international journal of environment issn 2091-2854 91 | p a g e similar importance but instead of mangroves, the filamentous algae showed more importance (table 4). both species were captured only from the mangrove area. table 4: gut content analysis of s. vermiculatus and l. macrolepis. siganus vermiculatus 2.1-2.7(n=4) liza macrolepis 3.4-5.3 (n=3) food type f % n % v % riv f % n % v % riv seagrasses 100 100 98.63 19863 100 75 74.73 14974 filamentous algae 25 25 0.02 626 66.66 50 1.66 3444 detritus 100 100 0.6 10060 100 75 20.97 9599 mangroves 25 25 0.75 2518 33.33 25 2.26 909 f% -percentage occurrence, n% -percentage number, v% -percentage volume , riv relative importance value, n -number of individuals analysis of individuals captured from different areas hemirhamphus marginatus was the only fish species captured from both areas. the individuals collected from the mangrove site fed on a variety of food items; seagrasses, mangroves, molluscs, cyclops sp., daphnia sp., diaphanosoma sp., filamentous algae, diatoms (t. nitzschioides & c. pelagica) and mysids (table 5). all individuals from the mangrove site fed on filamentous algae, mangroves, and cyclops (f %) and the most important (riv) food items were seagrasses, mangroves and cyclops. the individuals collected from the mangrove cleared site fed on same food items (as the mangrove site) except on mangroves and molluscs. among the 10 individuals, nine fed on diatoms and detritus, eight fed on cyclops sp., diatoms and mysids; revealing the most important food items (iri) to be cyclops sp., seagrasses and detritus. the results of both sites showed that h. marginatus is an omnivore (table 5). table 5: gut content analysis of h. marginatus collected from mangrove site, and mangroves cleared site. mangrove site (n=5) mangrove cleared site (n=10) food type f% n% v % riv f % n % v % riv seagrasses 80 40 88.59 10287.25 70 77.77 98.95 12370.49 mangroves 100 100 0.79 10079.48 filamentous algae 100 50 1.59 5159.66 70 77.77 .0009 5443.95 cyclops sp. 100 50 0.99 5099.23 80 88.88 0.02 7112.00 daphnia sp. 80 40 3.57 3486.26 30 33.33 0.05 1001.64 diaphanosoma sp. 80 40 3.77 3501.66 20 22.22 0.01 444.63 diatom(t. nitzschioides) 80 40 0.19 3215.87 80 88.88 0.05 7114.40 diatom (c. pelagica) 40 20 0.47 818.85 90 100 0.10 9009.13 molluscs 20 10 0.49 209.92 mysids 20 10 0.01 200.24 80 88.88 0.06 7115.11 detritus 90 100.00 0.76 9060.86 f% -percentage occurrence, n% -percentage number, v% -percentage volume, riv -index of relative importance, n -number of individuals analysis of different size (length) of fish hemirhamphus marginatus individuals that were captured from the mangrove cleared site were categorized under different length ranges; 5.5-6.9 cm (as small) and 12.05-16.05 cm (as large). analysis revealed that small fish depend on seven different food types while large fish depend on nine food types (table 6). among international journal of environment issn 2091-2854 92 | p a g e them, the common food types are seagrasses, cyclops sp., diatoms, mysids, filamentous algae and detritus. the large fish fed on daphnia sp. and diaphanosoma sp. but the small fish did not consume these food items, which are the main difference in food items between them. the majority of small fish consumed the diatom cerataulina pelagica and detritus, while all large fish fed on thalassionema nitzschioides, cyclops sp., filamentous algae and detritus. the most important food item (riv) for small fish was c. pelagica while for large fish, it was seagrasses. all individuals showed a common omnivorous food habit. table 6: gut content analysis of h. marginatus with different length ranges captured from mangrove cleared area. f% -percentage occurrence, n% -percentage number, v% -percentage volume, riv -index of relative importance, n -number of individuals zenarchopterus dispar was collected only from the mangrove site with differing sizes of individuals being clearly observed. the smaller z. dispar depends on a variety of food items; mainly all fed on detritus, seagrasses, mangroves, cyclops sp., daphnia sp. and filamentous algae. detritus had the highest importance value (iri) followed by seagrasses. the adult individuals mainly consumed detritus and seagrass (table 7). both the adult and smaller fishes commonly fed on plant matter (filamentous algae & seagrass), animal matter (cyclops sp. & daphnia sp.) and detritus. therefore, both the adult and juvenile z. dispar are omnivores. table 7: gut content analysis of juvenile and adult z. dispar length of small fish 3.45 cm, 4.25 cm, 4.95 cm (n = 3), adult fish length 16.15 cm (n = 1) food type f% n% v% riv percentage volume of food item seagrasses 100.00 33.33 11.67 4500.00 18.85 mangroves 100.00 33.33 6.50 3983.00 cyclops sp. 100.00 33.33 8.81 4221.00 4.59 daphnia sp. 100.00 33.33 10.44 4377.00 1.47 diaptomus sp. 33.33 11.11 2.25 445,28 mysids 66.66 22.22 11.04 2217.11 detritus 100.00 33.33 49.55 8288.00 63.28 filamentous algae 100.00 33.33 5.79 3912.00 7.75 unidentified animal parts 100.00 33.33 8.53 4186.00 4.56 f% -percentage occurrence, n% -percentage number, v% -percentage volume, iri -index of relative importance, n -number of individuals food type small size (5.50-6.10cm), (n=4) large size (16.70-14.90cm), (n=6) f % n % v % riv f % n % v % riv seagrasses 50 28.57 7.12 1784.84 83.33 55.55 96.86 12700.1 cyclops sp. 50 28.57 3.70 1598.90 100 66.66 0.07 6672.95 diatom (t. nitzschioides) 50 28.27 0.02 1414.61 100 66.66 0.004 6666.40 diatom (c. pelagica) 100 57.14 5.29 6243.51 50 33.33 0.089 1670.94 mysids 25 14.28 4.60 472.03 16.66 11.11 0.003 185.13 filamentous algae 25 14.28 0.14 360.70 100 66.66 0.004 6666.44 detritus 100 57.14 9.15 6629.00 100 66.66 0.759 6741.92 daphnia sp. 50 33.33 0.012 1667.10 diphasoma 50 33.33 0.017 1667.36 international journal of environment issn 2091-2854 93 | p a g e two individuals of caranx sexfasciatus were captured from mangrove area and showed two different lengths (4.95 cm & 10.05 cm). due to fewer numbers of individuals, their gut content analysis was performed according to percentage volume of the food items. both commonly fed on detritus (table 8). other than that, the small fish fed on cyclops sp. and mysids, and the larger fish fed on mangroves and seagrasses. the smaller fish highly depend on mysids while larger fish highly depend on detritus. according to the analysis smaller c. sexfasciatus is a carnivore and the larger individual is a herbivore. table 8: the percentage volume of food items contained in the guts of caranx sexfasciatus food type percentage volume of food items small individual ( 4.95 cm) large individual ( 10 .05 cm) seagrasses 9.63 mangroves 10.53 filamentous algae 20.24 detritus 11.41 59.59 cyclops sp. 11.96 mysids 76.63 figure 2: niche breadth of fish species (levins index) according to niche breadth of fish species (fig. 2), the broadest niche breadth was achieved by h. marginatus that were captured from mangroves and fed on ten food items; z. dispar and a. duodecimalis fed on nine food items and achieved the second broadest niche breadth. the herbivorous fishes, s. vermiculatus and l. macrolepis were recorded to have the shortest niche breadth. international journal of environment issn 2091-2854 94 | p a g e discussion the gut contents of 60 samples from 12 different fish species were analyzed with 13 food items being identified: plant materials (detritus, mangroves and seagrasses), phytoplankton (filamentous algae, diatom), molluscs and crustaceans (cyclops sp., daphnia sp., daptomus sp., diphanosoma sp. and mysids). most of the species depend on plant matter: mangroves (11 species), seagrasses (10 species), and filamentous algae (9 species). among the 12 species recorded from the mangrove areas, e. fusca and a. urotaenia did not feed on seagrasses while l. dussumieri did not feed on mangroves. eleotris fusca, l. brevirostis and p. dayi did not feed on filamentous algae. hemirhamphus marginatus is the only fish species that fed on diatoms (t. nitzschioides and c. pelagica). ten fish species fed on detritus with the exception of l. dussumieri and a. urotaenia. results indicated that mangroves, seagrasses and filamentous algae have a higher importance as food items in numerous fish species. similarly, v. buchanani and l. subviridis in malaysia fed on plant and animal matter (kaniz et al., 2013), and their most abundant food items were recorded to be plant matter. furthermore, the ten fish species in the present study depend on animal matter. most of them depend on cylops sp. (ten species) and mysids (six species). only four species fed on daphnia sp. and daptomus sp. while two species fed on diphanosoma sp. and molluscs. this suggest that apart from plant matter, the next most important food items for juvenile fish are cyclops and mysids. most of the fish analyzed (l. dussumieri, l. brevirostis, e. fusca, h. marginatus, z. dispar, o. melastigma, and a. duodecimalis) are omnivores and a high dietary overlap was evident among them. these results agree with previous similar studies from the negombo lagoon (pinto and punchihewa, 1996; shirantha and wijeyaratne, 2002). accordingly, more omnivorous fish are seem to inhabit this lagoon. the omnivorous fish found in this lagoon might be opportunistic feeders, who feed on different food items, depending on their availability. the present study found that, s. vermiculatus and l. macrolepis are strict herbivores. although, a. urotaenia and p. dayi feed on both animal and plant matter, the main food items for a. urotaenia skewed towards herbivory and p. dayi showed more importance towards carnivory. similarly, pinto and punchihewa (1996) recorded s. vermiculatus as a herbivore and p. dayi as a carnivore in a study from the same lagoon. according to present findings that younger (4.95 cm) c. sexfasciatus is a carnivore and the older (10.05 cm) one is a herbivore. pinto and punchihewa (1996), also recorded c. sexfasciatus (length range 3.8-6.3cm) as a carnivore. considering the size of fish in both studies, it is obvious that the younger ones are carnivores and the larger ones are herbivores. it is evident that the feeding habits of c. sexfasciatus vary with its age. feeding habits of h. marginatus do not vary with age, both young and elderly were found to be omnivores. however, when considering the food types, there is a difference in diatom species they consumed. small individuals consumed mainly the diatom c. pelagica while larger fish fed on the diatom t. nitzschioides. this showed that the food items and feeding habits of some fish species vary with their age and stage of their international journal of environment issn 2091-2854 95 | p a g e development. this is supported by ajah (2012), in which both the juvenile and sub adult stages of cithcarinus latus were phytoplankton and the adult stage was planktonic and trichiurus lepturus was carnivorous at all three stages. fish species analysed from the mangrove area (l. dussumieri, l. brevirostis, e. fusca, a. uroteenia, h. marginatus, z. dispar, o. melastigma, a. duodecimalis, s. vermiculatus. parambassis dayi and l. macrolepis) were directly dependent on mangroves as a source of food. hemirhamphus marginatus found from both areas mainly fed on common food items. however, h. marginatus captured from the mangrove area fed specially on mangroves, filamentous algae and seagrasses whereas h. marginatus from mangrove cleared area fed specially on seagrasses and filamentous algae and did not consume mangroves or molluscs. according to these findings, h. marginatus is a selective feeder, however the shifting of diet may occur depending on the habitat. among the 12 species, the broadest niche breadth was achieved by h. marginatus and the second broadest niche breadth was evidenced in z. dispar and a. duodecimalis. shorter niche bread was recorded by herbivorous fish. although most of the analyzed fish are omnivores, the juvenile fish mainly feed on mangroves and seagrasses. acknowledgement this project was funded by the faculty of natural science, the open university of sri lanka. references ajah, p.o., 2012. food and feeding habits of four selected fish species in cross river estuary, nigeria. tropical freshwater biology, 21 (2): 25 40. baker, r., 2014. fish gut content analysis: robust measures of diet composition. fish and fisheries, 15, 170 177. costa, h.h. and fernando, e.c.m., 1967. the food and feeding relationship of common meso and macro fauna of the maha oya, small mountain stream at ceylon. ceylon journal of sciences (bio.sci.), 7, 74 90. hyslop, e.j., 1980. stomach content analysis-a review of methods and their application. journal of fish biology. 17, 411429. kaniz, f., wan, m., wan, o. and mansor, m., 2013. identification of food and feeding habits of mullet fish, liza subviridis (valenciennes, 1836), valamugil buchanani (bleeker, 1853) from merbok estuary, kedah, malaysia. journal of life sciences and technologies, 1(1), 47-50. lagler, k.f., 1949. studies in freshwater biology. ann arbor press, chelsea, michigan, pp: 119. livingston, r. j., 1982. trophic organization of fishes in a coastal seagrass system, marine ecology progress series, 7, 1-12. pinto, l. and punchihewa, n., 1996. utilisation of mangroves and seagrasses by fishes in the negombo estuary, sri lanka. marine biology, 126(2), 333-345. international journal of environment issn 2091-2854 96 | p a g e saenger, p., hegerl, e.j. and davy, j.d.s. 1983. global status of mangrove ecosystems. the environmentalist, 3, 1 88. sasekumar, a., ong, t.l. and through, k.l., 1984. predation of mangrove fauna by marine fishes. pro. as symp mangr, env. res. & manag, 378 -384. shirantha r.r.a.r. and wijeyaratne, m.j.s., 2002. diurnal variations in food resource partitioning among some co-occurring fishes in the negombo estuary of sri lanka. ceylon journal of sciences (bio.sci.), 29, 25-38. sivan, g. and radhakrishnan, c.k., 2011. food, feeding habits and biochemical composition of scatophagus argus. turkish journal of fisheries and aquatic sciences, 11, 603-608. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 10 | p a g e international journal of environment volume-3, issue-1, dec-feb 2013/14 issn 2091-2854 received:10 december revised:23 december accepted: 21 january flood forecasting in blue nile basin using a process-based hydrological model osama r. abdel-aziz department of hydraulic and irrigation structures, faculty of engineering, alexandria university, alexandria, egypt corresponding author: osamaragab24@gmail.com abstract predictions of variations in global and regional hydrological cycles and their response to changes in climate and the environment are key problems for future human life. therefore, basin-scale hydrological forecasts, along with predictions regarding future climate change, are needed in areas with high flood potential. this study forecasts hydrological process scenarios in blue nile basin using a distributed hydrological model (dhm) and predicted scenarios of precipitation from two general circulation models, ccsm3 model and miroc3.2hires. firstly, river discharge was simulated by the dhm using the observed rainfall from 1976 to 1979 and then, simulating future precipitations from 2011 to 2040, discharge scenarios were predicted. keywords: blue nile basin, distributed hydrological model, flood forecast, ccsm3, miroc3.2 introduction the intergovernmental panel on climate change (ipcc) had been created by the united nations environment program and the world meteorological organization to oversee and report the current understanding of climate change and its potential impacts (ipcc, 2007). the ipcc has released four assessment reports on the understanding of climate change as well as numerous other special reports and technical reports. the ipcc researchers use sophisticated general circulation models (gcms) to simulate atmospheric, land and sea interactions as a result of probable emissions scenarios. the emission scenarios used in these models are very detailed and consider multiple factors of climate change. the earth`s climate has changed many times during the planet`s history, with events ranging from ice ages to long period of warmth. climate changes have visible impacts on the natural systems. however their impact will be significant with the hydrological cycle. climate change is expected to aggravate current stress on water resources availability from population growth, urbanization and land-use change (ipcc, 2007). international journal of environment issn 2091-2854 11 | p a g e scientists agreed that changes in the earth`s climate will hit developing countries like ethiopia first and hardest because their economics are strongly dependent on crude forms of natural resources and their economic structure is less flexible to adjust to such drastic changes (nmsa, 2001). in recent years, a large part of the scientific community has made efforts analyzing the impact of projected climate change on water resources and proposing adaptation strategies (e.g. loaiciga et al., 1996; hattermann et al., 2008; wilby et al., 2008; allamano et al., 2009; goulden et al., 2009). the usual framework of this type of study can be seen in elshamy et al, 2009. this approach has become very popular as it potentially allows the quantification of changes in floods, flow duration curves, and whatever part of the hydrological cycle (bloschl et al, 2010). different studies have been conducted to assess the impact of climate change on hydrology in different parts of the world (abdo et al., 2009). many of these studies indicated water resource variability associated with climate change. it is noted that a few studies quantified the combined effects of future climate and land use changes on hydrology (van roosmalen et al., 2009) which is a key study area for the future. recently, a number of studies analyzed the effects of climate change on the hydrology of the nile river basin (nrb), the world`s longest river. in fact, the nrb could be vulnerable to water stress under climate change because of the limited water availability and the increasing demand for water from different sectors (bates et al., 2008). in addition, there is a serious concern about the fact that sea level rise could adversely impact on people living in nile delta and other coastal areas. nevertheless, conway (2005) found that there is no clear indication of how nile river flow would be affected by climate change, because of the uncertainty in projected rainfall patterns in various parts of the basin and the influence of complex water management (and water governance structures). more recently, githui et al. (2008) used a technique of adjustment (the so-called delta change method) of historical time series to project gcm impacts on flood risks in the nzoia river, one of the major river systems draining into lake victoria. in addition, elshamy et al. (2009) analyzed climate effects on the main nile at dongola and the blue nile at diem, using a spatio-temporal statistical downscaling technique for various gcms and showed varying trends depending on the gcm used. furthermore, soliman et al. (2009) investigated climate change effects on the blue nile catchment using the regional climate model regcm3 to downscale the results of the echam5 general circulation model (max planck institute, hamburg, germany). these studies demonstrate a large diversity in the use of ipcc scenario, climate models and downscaling techniques (time series adjustments, statistical and physically-based methods). these different techniques may lead to opposing trends and contradicting recommendations for policy makers. as ethiopia is following agricultural based industrialization which is strongly tied with climate and a large part of the country is arid and semi-arid, climate change should be a concern. studies done by many researchers indicated that the water resources are sensitive to climate change. however, most of the studies made so far are mainly at the catchment level. as a catchment encompasses different climatic zones, it might be difficult to identify the exact impact of the climate change so as to take adaptive measures. therefore it is advisable to study the impact of climate change in sub-basin level. hence, this study was targeted to address the effect of climate change on sub-basin and basin level in blue nile river. this study focused on blue nile basin which is among sub-basins of nile river. blue nile basin international journal of environment issn 2091-2854 12 | p a g e and atbara basin are the largest basins feeding main nile river, the biggest river in africa. blue nile is the key socio-economic focal point in the area. it is used for hydropower generation, irrigation, recreation, fishing and navigation. however, due to climate variability and change, the water level in the basin fluctuates. on the other hand, water level drop is also observed in some periods of the year. hence, this study will have a paramount importance in giving an insight on the vulnerability of blue nile to climate change. in this research, dhm using two general circulations model (gcm) outputs as forcing. first step is validating the dhm using the observed rain gauge precipitation. next, predicting stream flow scenarios over the next 40 years using the gcm outputs is done. finally, predicting observational records of hydrological data, such as precipitation and river discharge, and critically examine the trends to be suitable in water resource management in the future. study area the nile river encompasses ten countries. the blue nile basin, which is selected as the study area, is located in the high steep mountainous region of the upper nile river (fig. 1) on the ethiopian plateau, which is concentrated at elevations of 2000-3000m, with several peaks up to 4000 m or more. the plateau country is not flat but very broken and hilly, with grassy uplands, swamp valleys and scattered trees. there are occasional rocky peaks, some of which are of volcanic origin. the curious course of the river may follow the original drainage pattern radiating from such volcanic centers. the basin is cut by deep ravines or canyons in which the blue nile and other rivers flow. the whole area is intersected by streams, most of which are highly seasonal in their flow. the catchment area of the blue nile basin lying upstream of the khartoum hydrological station is 325000 km 2 . the average annual rainfall over the blue nile basin is about 1600 mm. it increases from about 1000mm near the sudan border to about 1400-1800 mm over parts of the upper basin, in particular in the loop of the blue nile below lake tana, and above 1800 mm in the south within the disessa basin (conway 2000). past changes (precipitation and discharge data) on the bnb precipitation rainfall in the blue nile basin shows various modes of seasonality within the annual cycle and inter-annual variability depending on the location of the specific sub-catchment with respect to the equator and moist advection wind regimes. the blue nile area (consisting of ethiopian highlands and sudan) shows a uniform distribution, with the main wet season spanning the period june–september. according to sutcliffe & parks (1999), the annual rainfall amount varies from less than 50 mm/year (over the lower or main nile) in northern sudan and southern egypt to more than 1200 mm/year over the ethiopian part of the nile. while there is generally no significant change detected in the annual rainfall in most of the nile sub-basins, there appears to be decreasing in some key watersheds of the upper nile in ethiopia such as the southern blue nile (wing et al., 2008). referring to the longer term, e.g. the period 1905–1984, sayed et al. (2004) provided evidence that the bnb has shown a slightly increasing trend in rainfall over the observation period of 1905–1965, followed by a prolonged decline reaching its minimum in 1984. the rainfall is recovered significantly during the 1990s as the explanation of precipitation trend presented in ipcc technical paper international journal of environment issn 2091-2854 13 | p a g e vi (bates et al., 2008). however, the scientific literature does not provide clear indications on the trend in the occurrence of extreme rainfall events. river discharge observational studies over the blue nile confirm that the seasonal and inter-annual variability is more significant than any long-term trend (awulachew et al., 2008). this is consistent with the variability of precipitation over the region. however, the variability of flow in the bnb appears to behave similarly in their temporal patterns of fluctuation (awulachew et al., 2008).the variability in rainfall plays a significant role in the modelling of the basin level. based on the review of the publications on the climate variability of the bnb, conway (2005) showed that climate variability of ethiopian highlands is primarily manifested by rainfall fluctuations. figure 1. study area data availability the basin topography was simulated by a digital elevation model having 1 km resolution. the original elevation data were obtained from hydro1k. land cover information was collected from a 1996 usgs global land use map (global land cover characteristics data base version 2.0). this map classifies land use into 31 types; the dominant land use types in the study area were savanna (58%) and agricultural land (18%). information on the soil water properties was collected from fao soil databases based on the food and agricultural organization (fao)/unesco soil map of the world. the spatial reference for both land cover and soil types is 1 km. for discharge calibration, observed discharge data from ministry of water resources and irrigation (nile water sector-nile control department) were collected in the study period from 2001 to 2002. meteorological data were obtained from the nile basin capacity database. according to the data quality, the daily rainfall data of 4 years (1976 to 1979) at 35 gauges were selected for the calibration of hydrological model. future rainfall scenario was taken from future gcm experiments: miroc3.2_hires and ccsm3. as climate scenario special report on emission scenarios (sres) a1b indicating in the high economic growth rate was chosen. the distribution of the available rainfall data is shown in fig.2. all of the collected meteorological data were international journal of environment issn 2091-2854 14 | p a g e adjusted to 1km resolution for the computation units. the thiessen polygon method was used to obtain weighted average rainfall by determination of the distance between each pair of rain gauge points. methodology a distributed hydrological model, gbhm was calibrated and validated. the downscaled climate outputs were used as an input to gbhm model and used to assess the impact of climate change on the blue nile basin. the climate projection analysis was done for each year in the coming 40 years. the period 2001-2002 was taken as baseline period against which comparison was made. hydrological model set up to simulate the current and long-term discharge dynamics for the river basin, the dhm geomorphology-based hydrological model (gbhm) is used. this model’s features were physically based on hydrological processes. that is, the water budget at each computational unit was simulated by a hill-slope module, and the lateral inflow was routed downstream by a kinematic wave module. the discharge at each gauge point was obtained. a 4-km grid is chosen as computational units. each computational unit is viewed as a rectangular inclined plane with a defined length and unit width. the inclination angle was given by the surface slope, and the bedrock was assumed to be parallel to the surface. the hill-slope element introduced by yang et al (2002) is used. the hill-slope module is applied in computational units having this feature. the module is divided into four parts: storage of precipitation in the soil; precipitation storage in the canopy; water exchange between the saturated layer, unsaturated layer, and the surface; and evapotranspiration from the canopy and the soil. richard’s equation is used to calculate the water exchange between the saturated and unsaturated layers (van dam et al., 2000). darcy’s law is used to calculate the water flow in the saturated zone (manning, 1997). to simulate transpiration, the normalized difference vegetation index (ndvi) from advanced very high resolution radiometer (avhrr) is used to obtain the canopy cover ratio in each computational unit. the land use type and soil type from the usgs and fao data determined each parameter of each hill-slope equation, and each parameter is calibrated for each type of soil and land use. the simulated discharge flowing from each computational unit is accumulated into interval flows, which were identified according to the pfafstetter basin numbering system. the accumulated discharge is routed from the upper to the lower basin according to the pfafstetter numbering scheme by using the kinematic wave module. thus, the discharge at each control point was obtained. international journal of environment issn 2091-2854 15 | p a g e figure 2. spatial distribution of rainfall and discharge points model calibration calibration of the parameters mentioned in the previous section is done by comparing the discharge simulated using rain gauge data and the observed discharge at the outlet of the basin in khartoum station from 1976 to 1979. the simulation time step was 1h. because only daily precipitation observations were available, they were transformed to hourly data on the basis of the average time distribution in one day. to include the effect of the rosieres dam in the simulation, the released flow was assumed to be the same as the observed discharge at p.1 located downstream raisers dam (fig.2). on the other hand, the effect of sennar dam is neglected due to the small size of the dam. evaluation of gcm outputs daily future precipitation determined by the gcms was compared against the average of the available daily rainfall ground data from 1971 to 1982. the timing of base flow and peak flow was studied in this comparison. we should be aware that each future climate by gcm simulations does not necessarily show similar characteristics of climate condition of observed climate in short time scale, since scenario simulation by gcms reflect their own internal climate systems, resulting from different time series of dry and flood season and other seasonal to annual climate oscillations. the monthly average precipitation from rain gauge and two modified gcm outputs is shown from 2001 to 2010 in fig.3. this figure shows that gcm outputs could capture the main events such as low density and high density of rainfall along the year in blue nile basin. then, gcm outputs have an accepted quality that can be considered for future prediction. international journal of environment issn 2091-2854 16 | p a g e scenarios of future river discharge we obtained simulated discharge from 2011 to 2040 with gcm outputs. since simulated discharge using gcm outputs cannot be forecasted within short training period, our analysis is based on the highest and average peak discharge within six five years groups. results and discussion calibration of dhm model the simulated discharge calculated using rain gauge data at khartoum station is shown in fig.4. the hydrological data (daily data) from 1976 to 1979 are used for calibrating the model parameters in order to well detect the observed discharge in these years. the discharge calculated using rain gauge data was close to the observed discharge at khartoum station. the deviation of runoff volumes (dv) and nash-sutcliffe coefficient (nr) of the discharge simulated using rain gauge data versus the observed discharge was equal to 13.6%, 0.92 respectively. where the nr can range from -∞ to 1; improved model performance is indicated as the nr approaches 1, while a value of zero indicates that simulated values are no better than the mean of observed values. on the other hand, the dv can take on values between -100% and 100%, with negative values indicating under-prediction and positive values indicating over-prediction. the value obtained is an indicator of the degree of error in the predictions. generally, the lower this error is, the better the performance is, thus values close to zero indicate a good model performance. future hydrological scenarios simulated discharge from 2001 to 2002 at khartoum station with two precipitation patterns from gcms are shown in fig.5. this graph is shown to evaluate the annual seasonality. the simulated tend of discharge was underestimated than observation using ccsm3-ncar scenario and overestimated than observation using miroc hires3.2 scenario. focusing on seasonality, the months with the highest peak discharge simulated are between july and september. future hydrographs from 2011 to 2040 were simulated at khartoum as shown in fig. 6. in the part of this figure, hyetograph from miroc output can be seen. a consistent response of the hydrological model in dotted line using miroc data can be noticed. particularly, it is evident for years 2016, 2021, and 2036. then, we calculated the annual mean and highest discharge in seven year groups (2011-2015, 2016-2020, 20212025, 2026-2030, 2031-2035, and 2036-2040) at the khartoum station as shown in fig.7 and fig.8. from fig.7, the mean annual discharge at each group does not show a high variation. on the other hand, fig.8 shows the annual highest discharge seems to increase for future groups, especially from 2026 to 2030 using ccsm3-ncar output and from 2036 to 2040 using miroc hires3.3 output. actually, simulations with miroc output predict higher flood peaks. on the other hand, calculated discharges with ccsm3 ncar output predict lower flood peaks. international journal of environment issn 2091-2854 17 | p a g e fig. 3. average precipitation of entire target basin using gcm models comparing with average precipitation using ground data fig. 4. discharge simulation at khartoum station using rain gauge data months m o n th ly r a in fa ll (m m /m o n th ) ccsm3-ncar rainfall values average monthly precipitation from 2001 to 2010 months m o n th ly r a in fa ll (m m /m o n th ) miroc hires 3.2 rainfall values average monthly precipitation from 2001 to 2010 months m o n th ly r a in fa ll (m m /m o n th ) ground data rainfall values average monthly precipitation from 1971 to 1995 international journal of environment issn 2091-2854 18 | p a g e fig. 5. discharge simulation at khartoum station with gcm outputs in 2001-2002 fig. 6. future hyetographs at khartoum station using ccsm3-ncar and miroc hires3.2 d is ch a rg e ( m 3 /s e c) months simulation with ccsm3-ncar simulation with miroc-hires3.2 observation values d is c h a r g e ( m 3 /s e c ) months rainfall (mm/month) discharge(m3/sec)-ncar discharge (m3/sec)-miroc hires3.2 international journal of environment issn 2091-2854 19 | p a g e fig.7. average of highest discharge at each group fig. 8. mean annual discharge at each group conclusion in this paper, a distributed hydrological model and the data simulated by modified gcm are applied to blue nile basin. the overall performance of the dhm model using observed precipitation showed acceptable agreement with observed river discharge. future river discharge patterns are predicted forcing the dhm model using two modified gcms. the results suggest that the mean highest peak discharge might increase within the future seven year groups. in addition, the higher flood peaks seems to be more concentrated in august in the simulated basin. in the future, more appropriate bias correction of the gcm output to the river basin is necessary in order to project future hydrology. hence, long-term comparisons of in situ data and this models’ output are essential. all of this information might be helpful for watershed management in blue nile basin by controlling dams according to the knowledge of higher and lower peaks and mean flow in the future groups. mean of highest discharge-ncar mean of highest discharge-miroc group mean annual discharge-ncar mean annual discharge-miroc group international journal of environment issn 2091-2854 20 | p a g e references abdo, k.s., fiseha, b.m., rientjes, thm., gieske, asm., haile, a.t. , 2009. assessment of climate change impacts on the hydrology of gilgel abay catchment in lake tana basin. ethiopia 23:3661-3669. allamano, p., laio, f. & claps, p., 2009. global warming increases flood risk in mountainous areas. geophys. res. lett. 36(24), l24404. awulachew, s.b., mccartney, m., steenhuis, t.s. & ahmed, a.a., 2008. a review of hydrology, sediment and water resource use in the blue nile basin. colombo, sri lanka: international water management institute, iwmi working pape131. bates, b.c., kundzewicz, z.w., wu, s. & palutikof, j.p. (eds), 2008. climate change and water. geneva: intergovernmental panel on climate change secretariat, technical paper. blöschl, g., ardoin-bardin, s., bonell, m., dorninger, m., goodrich, d., gutknecht, d., matamoros, d., merz, b., shand, p. & szolgay, j., 2010. at what scales do climate variability and land cover change impact on flooding and low flows? hydrol. processes 21, 1241–1247. conway, d., 2000. the climate and hydrology of the upper blue nile river. the geogr. j. 166, 49–62. conway, d., 2005. from headwater tributaries to international river basin: adaptation to climate variability and change in the river nile basin. global environ. change 25, 127-151. elshamy, m.e., sayed, m.a. & badawy, b., 2009. impacts of climate change on nile flows at dongola using statistically downscaled gcm scenarios. nile water science & engineering magazine, special issue on water and climate 2, 1–14. goulden, m., conway, d. & persechino, a., 2009. adaptation to climate change in international river basins in africa: a review. hydrol. sci. j. 54(5), 805–828. hattermann, f., krysanova, v., post, j., dworak, th., wrobel, m., kadner, s. & leipprand, a., 2008. understanding consequences of climate change for water resources and water-related sectors in europe. in: the adaptiveness of iwrm, analysing european iwrm research (j. g. timmerman, c. pahl-wostl & j. moltgen, eds), 89–112. london: iwa publishing. ipcc (intergovernmental panel on climate change), 2007. ipcc fourth assessment report: climate change 2007 (ar4). core writing team (r. k. pachauri & a. reisinger, eds). geneva: ipcc. loaiciga, h., valdes, j. b., vogel, r. & garvey, j., 1996. global warming and the hydrologic cycle. j. hydrol. 174, 83–127. manning, j.c., 1997. applied principles of hydrology, p. 276. prentice hall, third edition. nmsa (national meteorological services agency), 2001. initial national communication of ethiopia to the uunited nations framework convention on \climate change (unfccc). addis ababa, ethiopia. soliman, e.s.a., sayed, m.a. & jeuland, m., 2009. impact assessment of future climate change for the blue nile basin using a rcm nested in a gcm. nile water science & engineering special issue on water and climate 2, 31–38. international journal of environment issn 2091-2854 21 | p a g e sutcliffe, j. and parks, y. p., 1999. the hydrology of the nile, iahs special publication no. 5, iahs press, institute of hydrology, wallingford , oxford shire ox10 8bb, uk, p. 33, and 57 87 . van dam, g.c., wosten, j.h.m. and nemas, a., 2000. unsaturated soil water movement in hysteretic and water repel field soils. journal of hydrology, 184 (3/4), 153-173. van roosmalen, l., sonnenborg, t.o., jensen, k.h., 2009. impact of climate and land use change on the hydrology of a large-scale agricultural catchment. water resour res 45: w00a15, doi: 10.1029/2007wr006760. wilby, r.l., beven, k.j. & reynard, n.s., 2008. climate change and fluvial flood risk in the uk: more of the same? hydrol. processes 22, 2511–2523. wing, h., cheung, a., gabriel, b.s. & singh, a., 2008. trends and spatial distribution of annual and seasonal rainfall in ethiopia. int. j. climatol. 28(13), 1723-1734. yang. d., oki, t., herath, s. & mtisiake k., 2002. a geomorphology-based hydrological model and its applications. in: mathematical models of small watershed hydrology and applications (ed. by v. p. singh & d. k. frevert). water resources publications! littleton, colorado, usa. chapter 9, 259-300. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 122 | p a g e international journal of environment volume-3, issue-1, dec-feb 2013/14 issn 2091-2854 received: 10 january revised: 17 january accepted: 21 january tree resources of katerniaghat wildlife sanctuary, uttar pradesh, india with especial emphasis on conservation status, phenology and economic values lal babu chaudhary 1* , anoop kumar 2 , ashish k. mishra 3 , nayan sahu 4 , jitendra pandey 5 , soumit k. behera 6 and omesh bajpai 7 1,2,3,4,6,7 plant diversity, systematics and herbarium division, csir-national botanical research institute, rana pratap marg, lucknow, uttar pradesh-226 001, india 5,7 centre of advanced study in botany, banaras hindu university, varanasi, uttar pradesh221 005, india *corresponding author: dr_lbchaudhary@rediffmail.com abstract uttar pradesh, one of the most populated states of india along international border of nepal, contributes only about 3% of total forest & tree cover of the country as the major parts of the area is covered by agriculture lands and human populations. the forests are quite fragmented and facing severe anthropogenic pressure in many parts. to protect the existing biodiversity, several forest covers have been declared as national parks and wildlife sanctuaries. in the present study, katerniaghat wildlife sanctuary (kws) has been selected to assess tree diversity, their phenology and economic values as the trees are the major constituent of any forest and more fascinating among all plant groups. the sanctuary consists of tropical moist deciduous type of vegetation and situated along the indo-nepal boarder in bahraich district of uttar pradesh, india. after, thorough assessment of the area, a list of 141 tree species belonging to 101 genera and 38 families have been prepared. the family fabaceae exhibits highest generic and species diversity with 14 genera and 23 species. the genus ficus of moraceae has been found the largest with 11 species. maximum trees with about 51 species have been found to flower in post winter season (february to march) in the forest. about 62 trees are used as medicinal for various purposes, 50 as ornamental & avenue trees, 37 as timber wood, 36 as edible, 16 as fire wood and 12 as fodder. since the sanctuary area has been surrounded by several villages and facing anthropogenic pressure, the public awareness program related with biodiversity conservation and sustainable uses is highly needed to protect the forest covers. keywords: diversity, tree, phenology, economic uses, katerniaghat wildlife sanctuary, uttar pradesh, india. mailto:dr_lbchaudhary@rediffmail.com international journal of environment issn 2091-2854 123 | p a g e introduction the biodiversity existing on our planet earth is a precious gift of the nature. sustainable management of biodiversity is very important because of its known and unknown implication and also due to its rapid rate of depletion in the present era (iclei, 2009; cooney, 2004). the assessment of the biodiversity is the first step towards formulating its management plans by documenting them. such type of documentation of the plants with their phenology and economic benefits provides the basic knowledge of the plant wealth of the area which will be used in climate change assessment, sustainable uses and conservation programmes. in india, uttar pradesh is one of the largest states which cover a geographical area of about 2,40,9288 km 2 (anonymous, 2005). most of the land of the state is used for agricultural activities and accumulation of human population whereas only 16,583 km 2 area is covered by the forests (anonymous, 2005). most of the forests of the state have been conserved by declaring them wildlife sanctuaries and national parks to protect its biodiversity. the forest of katerniaghat declared as wildlife sanctuary in 1976 is situated in bahraich district of uttar pradesh in india along the indo-nepal international border between 27 ° 41' 27 ° 56' n and 81 ° 48'81 ° 56' e at 116 to 165 m elevations (figure 1). figure 1. location map of katerniaghat wildlife sanctuary, uttar pradesh, india the sanctuary covers an area of 551.64 km 2 which has been divided into six forest ranges (i.e. katerniaghat, nishangarah, dharmapur, murthia, kakraha and motipur). the forest of the sanctuary comes under the tropical moist deciduous forest of the himalayan terai-bhabar international journal of environment issn 2091-2854 124 | p a g e region (champion & seth, 1968; rodgers & panwar, 1988). the entire area of the forest has been classified into four forest types (i) sal forest, (ii) teak plantation, (iii) miscellaneous forest and (iv) savannah grassland (behera et al., 2012). the rivers kaudiyala and saryu and its tributaries flowing adjacent to the sanctuary provide alluvial soil to the area. although, the scattered information on the plant diversity of the sanctuary area is available in different publications (duthie, 1903; panigrahi et al., 1969; saini, 2005a, b; maliya & datt, 2010; kumar et al., 2011; maliya, 2011; mishra et al., 2013), however, a separate account exclusively on all tree species of the area including their phenology and economic values has not been dealt so far. since trees are major constituent of the forest and play important role in ecological and climate change studies, in addition to their high economic values, the present study assess the tree diversity of entire area after critical evaluation of existing literature, examination of herbarium specimens housed at bsa, bsip, cdri, lwg and extensive field surveys. the phenological data and economic importance of all tree species occurring within the study area have also been provided for all species. the main aim of the present study is to bring out a checklist of trees of the study area with their phenology, conservation status and economic importance. the checklist will provide a base line data for flora writing and diversity assessment of the area. the phenological information provided here may be used to compare the effect of climate change on the sexual behavior of the species in the future. the data provided on the conservation status will also help in the management of some of the rare and highly economically important tree species on priority basis by the forest department. materials and methods climate the monsoon climate is presented throughout the area. the area witnesses three distinct seasonal variations: winter (november to february), summer (april to june) and warm-rainy (july to september). the mean minimum and maximum temperature varies from 8 °c to 22 °c in january and to 27 °c to 40 °c in may june. the annual rainfall varies from 36 to 142 mm in winter, 34 to 662 mm in summer and 1294 to 1689 mm in warm-rainy seasons (bajpai et al., 2012a). vegetation the forest of the sanctuary comes under the tropical moist deciduous type of vegetation (champion & seth, 1968; rodgers & panwar, 1988). the entire area is chiefly dominated by sal forest, miscellaneous forest and teak plantation (bajpai et al., 2012b). the savannah grasslands are also present in some pockets in the forest area (behera et al., 2012). the upper stratum of the forest is represented by shorea robusta gaertn. f., tectona grandis l. f., terminalia elliptica willd., madhuca longifolia (l.) macbr. var. latifolia (roxb.) chev., ficus benghalensis l., ficus racemosa l., bombax ceiba l., sterculia villosa roxb. ex sm. a. rees, lannea coromandelica (houtt.) merr., haldina cordifolia (roxb.) ridsdale etc., while the middle stratum is represented by hymenodictyon orixense (roxb.) mabberley, syzygium cumini (l.) skeels, mitragyna parvifolia (roxb.) korth., ehretia laevis roxb., lagerstroemia parviflora roxb., diospyros exsculpta buch.-ham., schleichera oleosa (lour.) merr., aegle marmelos (l.) correa, dalbergia sissoo roxb. ex dc. mabberley, mallotus nudiflorus (l.) kulju & welzen etc. and the lower stratum is chiefly consists of international journal of environment issn 2091-2854 125 | p a g e mallotus philippensis (lamk.) muell.-arg., ficus hispida l. f., bridelia retusa (l.) a. juss., streblus asper lour., murraya koenigii (l.) spreng. etc. data collection and diversity assessment during last three years from 2010 2012 the entire study area has been thoroughly explored in different seasons to collect and document the tree diversity. the plants were randomly collected from all kinds of habitats and vegetation and prepare the herbarium specimens following standard herbarium techniques (lawrence, 1951; jain & rao, 1977). these specimens have been deposited at lwg for future record. all species have been correctly identified with the help of flora, revision and published work and compared with the earlier authentic collections housed at bsa, bsip, cdri and lwg. the correct nomenclature has been provided after consulting large number of recent regional and national floras, literature and different websites like grin, ipni, ildis, the plant list, wikipedia etc. the phenology of the species has been recorded based on our field visits under taken in different seasons. an abundance scale has also been used to know the conservation status of the species in the area following palmer et al. (1996). the information related with the economic values of the trees has been collected by interviewing the local tribal persons as well as from published work from the area. all species recorded here have been provided alphabetically in table 1 along with their conservation status, family, phenology and economic values. table 1. alphabetical list of tree species with their conservation status, family, phenology and economic values s.no. plants name conservation status family phenology economic values 1 acacia auriculiformis a. cunn. ex benth. cultivated fabaceae (mimosoideae) sep. mar. ornamental & avenue tree 2 acacia catechu (l. f.) willd. abundant fabaceae (mimosoideae) jul. feb. fodder, firewood 3 acacia nilotica (l.) willd. ex delile planted fabaceae (mimosoideae) aug. apr. hedge tree, fodder, medicinal 4 aegle marmelos (l.) correa abundant rutaceae mar. jul. fruits edible 5 ailanthus excelsa roxb. abundant simaroubaceae feb. jun. low grade timber 6 alangium salvifolium (l. f.) wang. frequent cornaceae feb. aug. medicinal 7 albizia chinensis (osbeck) merr. frequent fabaceae (mimosoideae) mar. jan. ornamental & avenue tree, fodder 8 albizia lebbeck (l.) benth. planted fabaceae (mimosoideae) apr. mar. ornamental & avenue tree, medicinal 9 albizia odoratissima (l. f.) benth. planted fabaceae (mimosoideae) apr. feb. ornamental & avenue tree 10 albizia procera (roxb.) benth. planted fabaceae (mimosoideae) may feb. ornamental & avenue tree, medicinal 11 alstonia scholaris (l.) r. br. planted apocynaceae nov. jun. ornamental & avenue tree, medicinal 12 annona squamosa l. cultivated annonaceae apr. jan. fruits edible 13 anogeissus acuminata (roxb. ex dc.) planted combretaceae mar. dec. household timber international journal of environment issn 2091-2854 126 | p a g e wall. ex guill. & perr. wood 14 antidesma acidum retz. rare phyllanthaceae may nov. timber wood, medicinal 15 antidesma ghaesembilla gaertn. abundant phyllanthaceae jun. dec. fruits edible 16 artocarpus heterophyllus lamk. cultivated moraceae feb. sep. fruits edible as vegetable 17 artocarpus lakoocha roxb. cultivated moraceae jan. nov. fruits edible 18 averrhoa carambola l. cultivated oxalidaceae jun. oct. fruits edible 19 azadirachta indica a. juss. cultivated meliaceae mar. jul. timber wood, medicinal 20 barringtonia acutangula (l.) gaertn. abundant lecythidaceae apr. nov. ornamental tree, medicinal 21 bauhinia acuminata l. cultivated fabaceae (caesalpinioideae) jul. jan. ornamental tree 22 bauhinia malabarica roxb. cultivated fabaceae (caesalpinioideae) aug. mar. ornamental tree, medicinal 23 bauhinia purpurea l. abundant fabaceae (caesalpinioideae) sep. apr. ornamental tree, medicinal 24 bauhinia racemosa lamk. frequent fabaceae (caesalpinioideae) mar. dec. religious, ornamental tree 25 bombax ceiba l. abundant malvaceae jan. may silviculture, match industry 26 breynia vitis-idaea (burm. f.) c.e.c. fisch. abundant phyllanthaceae apr. nov. medicinal 27 bridelia retusa (l.) a. juss. abundant phyllanthaceae may dec. medicinal 28 broussonetia papyrifera (l.) l„h‟er ex vent. cultivated moraceae mar. oct. timber wood 29 buchanania cochinchinensis (lour.) almeida occasional anacardiaceae feb. may seed edible 30 butea monosperma (lamk.) taub. planted fabaceae (papilionoideae) mar. jun. dye, tannin, timber wood, medicinal 31 callistemon citrinus (curtis) skeels planted myrtaceae mar. jun. ornamental & avenue tree 32 calotropis gigantea (l.) r. br. abundant apocynaceae dec. aug. religious, medicinal, fiber 33 careya arborea roxb. abundant lecythidaceae mar. jul. local timber wood, medicinal 34 cascabela thevetia (l.) lippold planted apocynaceae most part of the year ornamental tree, medicinal 35 cassia fistula l. planted fabaceae (caesalpinioideae) mar. dec. ornamental tree 36 casuarina equisetifolia l. cultivated casuarinaceae mar. jul. ornamental tree 37 catunaregam spinosa (thunb.) trivengadum abundant rubiaceae mar. dec. firewood, medicinal 38 celtis tetrandra roxb. abundant cannabaceae feb. nov. firewood, medicinal 39 citrus aurantiifolia (christm.) swingle cultivated rutaceae apr. jan. fruits edible, medicinal 40 citrus medica l. cultivated rutaceae apr. jan. fruits edible, medicinal 41 cordia dichotoma g. forst. frequent boraginaceae mar. jul. fruits edible 42 cordia grandis roxb. cultivated boraginaceae mar. sep. fruits edible 43 dalbergia latifolia roxb. abundant fabaceae (papilionoideae) apr. nov. timber wood international journal of environment issn 2091-2854 127 | p a g e 44 dalbergia sissoo roxb. ex dc. abundant fabaceae (papilionoideae) mar. aug. timber wood 45 delonix regia (bojer ex hook.) raf. cultivated fabaceae (caesalpinioideae) apr. mar. ornamental tree 46 desmodium oojeinense (roxb.) h. ohashi abundant fabaceae (papilionoideae) mar. may medicinal 47 dillenia indica l. abundant dilleniaceae may feb. firewood, local timber wood 48 dillenia pentagyna roxb. abundant dilleniaceae mar. may local timber wood, medicinal 49 diospyros exsculpta buch.-ham. abundant ebenaceae apr. oct. timber wood, medicinal 50 ehretia acuminata r. br. abundant boraginaceae sep. apr. ornamental & avenue tree 51 ehretia laevis roxb. abundant boraginaceae jan. aug. ornamental & avenue tree 52 erythrina arborescens roxb. cultivated fabaceae (papilionoideae) jul. feb. ornamental tree, local timber 53 eucalyptus tereticornis sm. planted myrtaceae feb. oct. quality timber wood 54 ficus benghalensis l. abundant moraceae jun. mar. religious, medicinal 55 ficus elastica roxb. cultivated moraceae not seen ornamental tree 56 ficus hispida l. f. abundant moraceae aug. dec. fodder 57 ficus microcarpa l. f. rare moraceae aug. feb. ornamental tree 58 ficus palmata forssk. subsp. virgata (roxb.) browicz abundant moraceae jun. oct. figs edible 59 ficus racemosa l. abundant moraceae apr. jul. figs edible 60 ficus religiosa l. abundant moraceae apr. sep. religious, medicinal 61 ficus retusa var. nitida (thunb.) miq. rare moraceae most part of the year ornamental tree 62 ficus rumphii blume abundant moraceae apr. jul. fodder 63 ficus semicordata buch.-ham. ex j. e. sm. abundant moraceae may oct. figs edible 64 ficus squamosa roxb. occasional moraceae apr. jan. fodder 65 firmiana colorata (roxb.) r. br. rare malvaceae feb. jun. ornamental tree 66 flacourtia indica (burm. f.) merr. abundant salicaceae feb. may firewood, fruit edible, medicinal 67 garuga pinnata roxb. abundant burseraceae mar. oct. fruits edible, medicinal 68 grewia asiatica l. abundant malvaceae apr. jul. fruits edible, medicinal 69 grewia multiflora juss. frequent malvaceae aug. jan. fruits edible 70 grewia optiva dumm. ex burret. frequent malvaceae aug. sep. timber wood, fruits edible 71 grewia tillifolia vahl rare in wild malvaceae apr. sep. fruits edible, medicinal 72 guazuma ulmifolia lamk. cultivated malvaceae feb. jul. religious, medicinal 73 guidonia tomentosa (roxb.) kurz abundant salicaceae feb. aug. firewood, fodder 74 haldina cordifolia (roxb.) ridsdale abundant rubiaceae jun. mar. timber wood 75 helicteres isora l. abundant malvaceae jul. dec. medicinal 76 heynea trijuga roxb. ex sims abundant meliaceae feb. oct. ornamental tree international journal of environment issn 2091-2854 128 | p a g e 77 hibiscus rosa-sinensis l. cultivated malvaceae most part of the year ornamental tree 78 holarrhena pubescens (buch.-ham.) wall. ex g. don abundant apocynaceae may feb. firewood, medicinal 79 holoptelea integrifolia (roxb.) planch. frequent ulmaceae feb. jul. low grade timber wood 80 hymenodictyon orixense (roxb.) mabberley abundant rubiaceae may jan. firewood, medicinal 81 jacaranda mimosifolia d. don cultivated bignoniaceae mar. oct. ornamental tree 82 jatropha curcas l. planted euphorbiaceae apr. nov. hedge tree, seeds for bio-diesel 83 kavalama urens (roxb.) raf. frequent malvaceae jan. apr. gum production 84 kydia calycina roxb. frequent malvaceae jul. may medicinal, fiber 85 lagerstroemia parviflora roxb. abundant lythraceae apr. jan. ornamental tree 86 lagerstroemia speciosa (l. ex murray) pers. frequent lythraceae may nov. ornamental tree 87 lannea coromandelica (houtt.) merr. planted anacardiaceae mar. jun. local timber wood, medicinal 88 lepisanthes rubiginosa (roxb.) leenh. rare sapindaceae apr. jul. timber & firewood, medicinal 89 leucaena leucocephala (lamk.) de wit. planted fabaceae (mimosoideae) jun. nov. fodder 90 litsea glutinosa (lour.) rob. occasional lauraceae apr. jan. seeds for essential oils, medicinal 91 litsea monopetala (roxb.) pers. frequent lauraceae mar. nov. timber wood, fodder, medicinal 92 madhuca longifolia (l.) macbr. var. latifolia (roxb.) chev. frequent sapotaceae mar. jul. petals edible, seed for vegetable oil 93 mallotus philippensis (lamk.) muell.arg. abundant euphorbiaceae sep. may tannin or dyes, medicinal, fodder 94 mallotus nudiflorus (l.) kulju & welzen frequent euphorbiaceae feb. oct. timber wood, fodder, medicinal 95 mangifera indica l. cultivated anacardiaceae feb. jul. fruits edible, timber wood 96 manilkara hexandra (roxb.) dub. planted sapotaceae oct. feb. fruits edible, timber wood 97 melia azedarach l. cultivated meliaceae mar. jun. timber wood, medicinal 98 miliusa tomentosa (roxb.) sinclair abundant annonaceae apr. jul. fruits edible, medicinal 99 miliusa velutina (dunal.) hook. f. & thoms. abundant annonaceae mar. aug. fruits edible, local timber wood 100 mitragyna parvifolia (roxb.) korth. abundant rubiaceae may dec. timber wood, medicinal 101 moringa concanensis nimmo ex dalz. & gibb. cultivated moringaceae nov. feb. medicinal, firewood, low grade timber wood 102 moringa oleifera lamk. cultivated moringaceae feb. jul. fruits edible, medicinal, firewood 103 morus alba l. cultivated moraceae feb. jun. fruits edible 104 murraya koenigii (l.) spreng. abundant rutaceae feb. oct. medicinal, leaf as spices 105 neolamarckia cadamba (roxb.) bosser planted rubiaceae may oct. ornamental & avenue tree international journal of environment issn 2091-2854 129 | p a g e 106 nyctanthes arbor-tristis l. cultivated oleaceae sep. mar. ornamental tree, medicinal 107 olax zeylanica l. rare olacaceae may jun. firewood 108 oroxylum indicum (l.) vent. occasional bignoniaceae may dec. medicinal, firewood 109 parkinsonia aculeata l. cultivated fabaceae (caesalpinioideae) oct. may hedge tree 110 phyllanthus emblica l. cultivated phyllanthaceae feb. dec. fruits edible, medicinal 111 polyalthia longifolia (sonn.) thw. cultivated annonaceae apr. sep. ornamental tree, medicinal 112 polyalthia suberosa (roxb.) thwaites cultivated annonaceae apr. sep. ornamental tree, medicinal 113 pongamia pinnata (l.) pierr. frequent fabaceae (papilionoideae) apr. jul. avenue tree, seeds for bio-diesel 114 psidium guajava l. cultivated myrtaceae sep. aug. fruits edible 115 putranjiva roxburghii wall. planted putranjivaceae mar. jan. ornamental & avenue tree 116 salix tetrasperma roxb. abundant salicaceae jan. jul. timber & firewood 117 schleichera oleosa (lour.) merr. abundant sapindaceae mar. nov. avenue tree, firewood 118 semecarpus anacardium l. f. frequent anacardiaceae apr. oct. timber wood, medicinal 119 senna siamea (lamk.) irwin & barneby planted fabaceae (caesalpinioideae) jul. feb. fruits edible, medicinal, fodder 120 shorea robusta gaertn. f. abundant dipterocarpaceae mar. jun. quality timber wood 121 sterculia foetida l. abundant malvaceae feb. aug. ornamental tree, medicinal 122 sterculia villosa roxb. ex sm. a. rees abundant malvaceae feb. oct. ornamental tree, medicinal 123 stereospermum chelonoides (l. f.) dc. rare bignoniaceae apr. dec. timber wood, medicinal 124 streblus asper lour. abundant moraceae jan. jul. firewood, medicinal 125 syzygium cumini (l.) skeels frequent myrtaceae apr. aug. fruits edible, timber wood, avenue tree 126 syzygium nervosum a. cunn. ex dc. occasional myrtaceae apr. aug. fruits edible, timber wood 127 syzygium salicifolium (wight) j. graham abundant myrtaceae mar. aug. fruits edible, timber wood 128 tamarindus indica l. occasional fabaceae (caesalpinioideae) jul. mar. fruits edible, avenue tree, medicinal 129 tamarix gallica l. var. indica (willd.) ehrenb. occasional tamaricaceae most part of the year ornamental tree 130 tamilnadia uliginosa (retz.) tirveng. & sastre. occasional rubiaceae may dec. ornamental tree 131 tecoma stans (l.) juss. ex kunth cultivated bignoniaceae jul. jun. ornamental tree 132 tectona grandis l. f. planted lamiaceae jul. dec. quality timber wood 133 terminalia arjuna (roxb. ex dc.) wight & arn. planted combretaceae apr. mar. avenue tree, medicinal 134 terminalia bellirica (gaertn.) roxb. frequent combretaceae mar. sep. avenue tree, medicinal international journal of environment issn 2091-2854 130 | p a g e 135 terminalia elliptica willd. abundant combretaceae may mar. timber wood, medicinal 136 toona ciliata m. roem. frequent meliaceae mar. jul. timber wood 137 wendlandia heynei (roem. & schult.) santapau & merchant frequent rubiaceae mar. aug. ornamental tree 138 wrightia arborea (dennst.) mabberley frequent apocynaceae apr. dec. ornamental tree, medicinal 139 xylosma longifolia clos frequent salicaceae oct. apr. hedge tree 140 ziziphus mauritiana lamk. abundant rhamnaceae sep. mar. fruits edible 141 ziziphus xylopyrus (retz.) willd. rare rhamnaceae apr. jul. fruits edible results and discussion the analysis of data reveals that the entire area consists of 141 tree species under 101 genera and 38 families. the family fabaceae has been found to exhibit the highest generic and species diversity with 14 genera and 23 species (figure 2). species per genus ratio has been observed maximum in moraceae (3.2) due to the presence of higher number of species (i.e. 16) than genera (i.e. 5). nineteen families (i.e. burseraceae, cannabaceae, casurinaceae, cornaceae, dilleniaceae, dipterocarpaceae, ebenaceae, lamiaceae, lauraceae, lythraceae, moringaceae, olacaceae, oleaceae, oxalidaceae, putranjivaceae, rhamnaceae, simaroubaceae, tamariacaceae and ulmaceae) are represented by single genus out of which 14 families (i.e. burseraceae, cannabaceae, casurinaceae, cornaceae, dipterocarpaceae, ebenaceae, lamiaceae, olacaceae, oleaceae, oxalidaceae, putranjivaceae, simaroubaceae, tamariacaceae and ulmaceae) consist of only solitary species. the genus ficus of moraceae has been observed the largest genus with 11 tree species. figure 2. diversity amongst the larger families (number of species, genera and species per genus ratio) on the abundance scale (palmer et al., 1996) about 52 tree species have been found distributed abundantly and 21 as frequently in the sanctuary area. due to the ornamental and other purposes about 31 trees have been grown in the fringes of the forest. in addition, about 20 trees have also been planted to fill up the open lands or as an avenue trees in the sanctuary. the eight species have been found occasionally and nine species rarely only with few individuals in the sanctuary area (figure 3). international journal of environment issn 2091-2854 131 | p a g e figure 3. number of abundant, frequent, cultivated, planted, occasional and rare trees the phenological observation reveals that the maximum tree species (about 51spp.) flower in post winter season during february to march with the rise of ambient temperature and matured fruits are noticed on majority of the trees during rainy season (i.e. jun.-sep.) (figure 4). the maximum germinations of seeds in the forest bed take place in post monsoon season. on an average about 11.3 ± 3.8 tree species have been observed in fruiting condition throughout the year which is considered good for the survival of faunal diversity available in the sanctuary. figure 4. number of flowering trees in different months of the year about 44% (i.e. 62 spp.) of the total tree species of the sanctuary have been found useful for various medicinal purposes, 35.5% (i.e. 50 spp.) for ornamental, 26.2% (i.e. 37 spp.) for timber wood, 25.5% (i.e. 36 spp.) as edible, 11.4% (i.e. 16 spp.) for firewood and 8.5% (i.e. international journal of environment issn 2091-2854 132 | p a g e 12 spp.) for fodder (figure 5). figure 5. number of species used for different aspects conclusion almost all tree species recorded here from the sanctuary area, directly or indirectly are in the use of human beings to meet their daily needs. therefore, there is a heavy anthropogenic pressure on the forest by local people. this may leads to the gradual decrease of the species from the natural habitats. hence, the awareness programme regarding the importance of the plant species for the survival of human beings on the planet earth and their sustainable uses and conservation of biodiversity among local people is the need of hour. the area also contains many plant families represented by solitary genus and solitary species and some rare species which require special attention and conservation measures to protect their gene pool in the sanctuary area. acknowledgement the authors are sincerely grateful to the director, csir-national botanical research institute, lucknow, india for providing facilities and financial support under csirnetworking project nwp-020. the thanks are also due to the in-charge of herbaria mentioned in the work for granting permission for herbarium consultation. the pccf (wildlife), uttar pradesh and forest field staffs are highly acknowledged for their hospitality and assistance provided during the field work. references anonymous, 2005. annual report. ministry of environment and forest, govt. of india. new delhi. bajpai, o., kumar, a., mishra, a.k., sahu, n., behera, s.k. & chaudhary, l.b., 2012a. phenological study of two dominant tree species in tropical moist deciduous forest from the northern india. international journal of botany 8(2), 66-72. international journal of environment issn 2091-2854 133 | p a g e bajpai, o., kumar, a., mishra, a.k., sahu, n., pandey, j., behera, s.k. & chaudhary, l.b., 2012b. recongregation of tree species of katerniaghat wildlife sanctuary, uttar pradesh, india. journal of biodiversity and environmental sciences 2(12), 24-40. behera, s.k., mishra, a.k., sahu, n., kumar, a., singh, n., kumar, a., bajpai, o., chaudhary, l.b., khare, p.b. & tuli, r. 2012. the study of microclimate in response to different plant community association in tropical moist deciduous forest from northern india. biodiversity and conservation 21(5), 1159-1176. champion, h.g. & seth, s.k., 1968. a revised survey of the forest types of india. publication division, govt. of india, new delhi. cooney, r., 2004. the precautionary principle in biodiversity conservation and natural resource management: an issues paper for policy-makers, researchers and practitioners. iucn policy and global change series. no. 2. iucn. duthie, j.f., 1903. flora of upper gangetic plains and of the adjacent siwalik & subhimalayan tracts. botanical survey of india, calcutta. iclei local action for biodiversity, 2009. lab perspectives #1. “nature and biodiversity: perceptions, importance, and the urban context.” jain, s.k., rao, r.r., 1977. a handbook of field and herbarium methods. today & tomorrow‟s printers & publishers. new delhi. kumar, a., bajpai, o., mishra, a.k., sahu, n., behera, s.k. & chaudhary, l.b., 2011. assessment of diversity in the genus ficus l. (moraceae) of katerniaghat wildlife sanctuary, uttar pradesh, india. american journal of plant sciences 2, 78-92. lawrence, g.h.m., 1951. taxonomy of vascular plants. oxford ibh publishing co. pvt. ltd. new delhi. maliya, s.d. & datt, b., 2010. a contribution to the flora of katarniyaghat wildlife sanctuary, bahraich district, uttar pradesh. journal of economic and taxonomic botany 34(1), 42-68. maliya, s.d., 2011. new or less known uses of some ethnomedicinal plants of wildlife sanctuary katarniyaghat of bahraich uttar pradesh. journal of economic and taxonomic botany 35(1), 35-38. mishra, a.k., bajpai, o., sahu, n., kumar, a., behera, s.k., mishra, r.m. & chaudhary, l.b., 2013. study of plant regeneration potential in tropical moist deciduous forest in northern india. international journal of environment 2(1), 153-163. palmer, m.w., wade, g.l. & neal, p., 1996. professional biologist: standard for the writing of flora. bioscience 45(5), 339-345. panigrahi, g., singh, a.n. & misra, o.p., 1969. contribution to the botany of the tarai forests of the bahraich district of uttar pradesh. bulletin of botanical survey of india 11(1 & 2), 89-114. rodgers, w.a. & panwar, h.s., 1988. planning a protected area network in india. vol i & ii. the report wildlife institute of india, dehradun, india. saini, d.c., 2005a. flora of bahraich district, uttar pradesh i-iv. journal of economic and taxonomic botany 29(3), 528-636. saini, d.c., 2005b. flora of bahraich district, uttar pradesh v-vi. journal of economic and taxonomic botany 29(4), 843-920. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 47 | p a g e international journal of environment volume-12, issue-1, 2023 issn 2091-2854 received: 19 october 2022 revised: 26 december 2022 accepted: 7 january 2023 controlled burning and its effects on shorea robusta (sal) regeneration in dhansar block forest, rautahat badri prasad dhungana1, 2 *, balram bhatta 2, sundar sharma3, vivek thapa chhetri4 1division forest office, rasuwa, bagmati, nepal. 2agriculture and forestry university, faculty of forestry, hetauda, nepal. 3undrr-regional south asia wildland fire network. 4institute of forestry, tribhuvan university, pokhara, nepal. *corresponding author: bpstona2090@gmail.com abstract fire is used as a management tool to administer a wide range of ecosystems worldwide. forest fires in shorea robusta (sal-dominated) forests take the form of ground fires and mostly affect regeneration. we investigated the effect of forest fire on sal regeneration in 42 sample plots, of which 21 were subjected to controlled burning. the results showed that species richness decreased from fire-unaffected (19) to fire-affected (10). the total density of sal seedlings in the fire-affected sites was 3829 seedlings ha-1, while in the fire-unaffected sites were 1779 seedlings ha-1 representing an increased species dominance of sal species in the post-fire condition. the total density of sal saplings in the fire-affected sites was 343 seedlings ha-1, while in the fireunaffected sites was 571 seedlings ha-1. a significant difference with a large effect size (cohen’s d=0.97) was observed in the seedling regeneration of sal, while no significant difference was observed in the sapling regeneration of sal in the post-fire condition. the increment of sal seedlings may be due to the fire-hardy silvicultural characteristics of shorea robusta and the decline of sal saplings may be due to stem mortality in the small diameter classes. we conclude that fire is a beneficial tool for seedling regeneration but not for plant establishment. future research studies regarding the impact of fire intensities, soil moisture, biological disturbances, temperature, light intensity, etc. on regeneration are recommended. keywords: disturbance, diversity, dominance, post-fire, wildfire doi: https://doi.org/10.3126/ije.v12i1.52442 copyright ©2023 ije this work is licensed under a cc by-nc which permits use, distribution and reproduction in any medium provided the original work is properly cited and is not for commercial purposes mailto:bpstona2090@gmail.com https://doi.org/10.3126/ije.v12i1.52442 https://orcid.org/0000-0002-6044-3036 international journal of environment issn 2091-2854 48 | p a g e introduction fire is one of the most significant eco-events that can have varied ecological effects (keane et al., 2002; whelan, 1995). forest fire has influenced the earth's surface for more than 350 million years, and human societies have coexisted with it since its origin (doerr and santín, 2016). forest fire is one of the main contributors to forest degradation around the world (fao, 2020), and several countries have suffered a significant loss in the primary productivity of forests (weisse and goldman, 2020). forest fires destroy timber and non-timber forest products, reduce biological diversity, and degrade soil, inducing soil erosion, and risks of floods and landslides (parajuli et al., 2015). fire is ubiquitous as it may play an important role in the management of landscapes (verma et al., 2017). natural regeneration is an indicator of forest ecosystem health (tyagi et al., 2011). a healthy regeneration of species maintains species diversity and density in any ecosystem (bargali et al., 2022). plant communities are strongly affected by forest fires (danthu et al., 2003), which influence regeneration potential and plant mortality (de luis et al., 2005). fire plays an important role in the removal of competition from surviving species. in addition to suppressing certain species, forest fires also encourage other species, leading to changes in vegetation structure (walters et al., 2004). fire-tolerant plant species generally increased in abundance at the expense of those killed by fire (fire-sensitive plants) due to a considerable reduction in competition and possibly due to alternations in other conditions (gallagher et al., 2022). regeneration of post-fire trees depends on a variety of factors, from climate suitability to the characteristics of the microsite (wooten et al., 2022). a successful reestablishment post-fire may be influenced by seed source, climate, competition or facilitation, and micro-climates (stevens-rumann and morgan, 2019). there are regular occurrences of forest fires during the long and intense dry season, which have serious impacts both on ecosystem degradation, and the deterioration of vulnerable social and economic conditions, especially in fragile himalayan ecosystems in nepal (wang et al., 2021). however, no systematic collection of fire impacts on wildlife, medicinal plants, health, weather and climate from brown clouds have been studied in nepal. this scenario is also similar in south asia as a whole (lelieveld et al., 2019). regeneration, dominance, and diversity of woody species are connected to the overall disturbance regime, including intensity, frequency, and scale (zhu et al., 2007). a forest fire reduces the floral production, alters regeneration rates, and threatens endemic and endangered species (bargali et al., 2022). a forest fire has a significant impact on species composition, structure, and diversity in tropical forests (kittur et al., 2014). it is crucial to understand how vegetation responds to fire to gain insight into changes in fuel availability, landscape flammability, and wildlife habitat (belcher, 2013). the environmental impacts of fire have drawn the interest of researchers in recent years (martin et al., 2002). considering the changing fire regime, forests are expected to take a longer time to recover, affecting on regeneration and species composition (verma et al., 2017). international journal of environment issn 2091-2854 49 | p a g e commonly, forest fires occur every year in nepal, particularly in the forests of the terai and churia hills. community forests and leasehold forests are less affected as compared to protected forests and governmentmanaged forests in nepal (acharya, 2008). an average of 200,000 hectares of forests are burned during the fire season from november to may in nepal (bajracharya, 2002; ndrrma, 2022). nepal witnessed severe wildfire incidents from september 2019 to september 2020 (figure 1). the forest fire occurrences are increasing as a consequence of regional warming and extended dry spells (sharma and goldammer, 2011), growing aridity, and hydrological changes (ncvst, 2009), nevertheless, the national capability to deal with these wildfires is insufficient in nepal. shorea robusta-dominated natural deciduous broadleaved forests are the major forests of the terai region of nepal (sharma, 1996a; sapkota et al., 2009). it can yield a large number of seedlings in a good seed year, but only a minority of them survive and establish (chapagain et al., 2021). the effects of fire on vegetation, soil properties, and biomass have been studied across the globe over the last few decades (verma and jayakumar, 2012). the impact of disturbance regimes on s. robusta regeneration has been researched (belbase et al., 2020; gautam et al., 2016; gautam and mandal, 2018; bhuyan et al., 2003). limited research has focused on the factors affecting tropical forests and no studies have focused on the post-fire regeneration of s. robusta in nepal. hence, this study aimed to understand the post-fire effects on the regeneration density of s. robusta compared to the recorded other plant species in the dhansar block forest representing the terai region of nepal as a case study. investigating the post-fire changes in the sal regeneration helps in the forest management planning in the tropical sal forests in nepal. figure 1: modisc6 image of nepal from 2019 september to 2020 september. international journal of environment issn 2091-2854 50 | p a g e material and methods study area the research site was dhansar block forest, rautahat district, nepal, which is situated in the north-west part of rautahat district, nepal (latitude: 27008’59’’ to 27012’05’’ n, longitude: 85014’28’’ to 85016’30’’ e, and elevation: 155 m to 180 m msl). the whole forest area is 1050 ha (excluding the river bank of the dhansar river), which is divided into three compartments and 24 sub-compartments. an irregular shelterwood system was applied, which is an intensive silvicultural system for the management of forests for production purposes. shorea robusta, terminalia alata, adina cordifolia, etc., are the main floral species, and asparagus racemosus, terminalia chebula, terminalia bellirica, etc. are the main ntfps of the forest. poaching is the main cause of the wildfires that spread through this block forest. fire line construction, leaf litter collection, and burning before the fire season are the main activities to control the fire listed in the management scheme in the dhansar block forest. the dhansar block forest of rautahat district was selected with due consideration that the forest is frequently affected due to high human disturbances owing to the disturbed forest. figure 2: study area map of the dhansar block forest. international journal of environment issn 2091-2854 51 | p a g e data collection experimental design this study was conducted in 2020 within 3 months (april-august) research duration in the dhansar block forest. the controlled burning (low-intensity fire) was set in 3 ha of the forest during april. the measurements were taken after 3 months in august. the total sampling area of the whole forest was 6 ha and divided into two strata i.e. fire affected and unaffected. a total of 42 sampling plots (21 for fire affected and 21 for unaffected areas) were assessed. stratified random sampling was used to lay out the sample plots in each stratum. for seedlings, 1*1 m subplots were laid on one corner of the 5*5 m plot, whereas saplings were measured in the 5*5 m plot size. the number of regeneration (seedlings and saplings) of all the recorded species during sampling was considered. the seedlings were considered as heights between 30 cm to 100 cm. the saplings were considered a height of more than 100 cm and dbh up to 9.9 cm (government of nepal/mfsc, 2004). data analysis the analyses were made on the basis of shorea robusta and other species found in the field survey (table 1). species other than s. robusta were considered other species. regeneration density (no/ha) under fire-affected and fire-unaffected sites was calculated, analyzed, and investigated for making statistical inferences using ibm spss statistics 23. a two-tailed t-test with a 5 % level of significance (p) was used to test the significant difference between two independent sample means (fire affected and fire unaffected) of variation in regeneration (seedling and sapling). the null hypothesis for the study was that i) there is no significant variation in post-fire conditions due to fire on the regeneration of s. robusta and other species, whereas the alternate hypothesis was that there is a significant variation in post-fire conditions due to fire on regeneration. results effect of controlled burning on regeneration the pattern of forest fires on species regeneration and diversity revealed a decrease in species richness in the fire-affected sites (10) than in the fire-unaffected sites (19) (table 1). international journal of environment issn 2091-2854 52 | p a g e table 1: regeneration of species during fire affected and fire unaffected condition fire fire species affected unaffected shorea robusta gaertn. + + lagerstroemia parviflora roxb. + + albizia chinensis (osbeck) merr. + + terminalia bellirica (gaertn.) roxb. + + toona ciliata m. roem. + terminalia chebula retz. + + bixa orellana l. + + lagerstroemia indica l. + + cleistocalyx operculatus (roxb.) merr. & l.m. perry + + hydrangea aspera d. don + + holarrhena pubescens wall. ex g. don + + carthamus tinctorius l. + murraya koenigii (l.) spreng. + bridelia retusa (l.) a. juss. + dysoxylum gobara (buch.-ham.) merr. + cassia fistula l. + cornus oblonga wall. + sapium insigne (royle) benth. & hook. f. + schima wallichii (dc.) korth. + + indicates the presence of the species whereas – indicates the absence of the species the density of seedlings (number/ha) of the shorea robusta was higher in the fire-affected site (3829) than in the fire-unaffected site (1771). similarly, other species’ seedlings’ density was higher in the unaffected site (2514) than in the fire-affected site (2000) (figure 3). international journal of environment issn 2091-2854 53 | p a g e figure 3: seedling density under fire-affected and fire-unaffected sites the density of saplings (number/ha) of the s. robusta were higher in the fire-unaffected site (571) than in the fire-affected sites. similarly, saplings of other species were also higher in the fire-unaffected site (629) than in the fire-affected site (229) (figure 4). figure 4: sapling density under fire-affected and fire-unaffected sites the results revealed a significant mean difference in s. robusta seedlings with t=3.166, p=0.003. findings showed that fire-affected sites were found 2.16 times higher on s. robusta seedlings (m=9.57, sd=5.60) compared to the fire-unaffected sites (m=4.43, sd=4.89). the value of cohen’s d was 0.97 (> 0.8) which indicates a large effect size (table 2). 3829 2000 1771 2514 0 500 1000 1500 2000 2500 3000 3500 4000 4500 shorea robusta other species n u m b e r/ .h a seedlings fire affected site fire unaffected site 343 229 571 629 0 100 200 300 400 500 600 700 shorea robusta other species n u m b e r/ h a saplings fire affected site fire unaffected site international journal of environment issn 2091-2854 54 | p a g e table 2: mean comparison of fire-affected and fire-unaffected sites in s. robusta seedlings fire affected fire unaffected variables m sd m sd t p cohen’s d s. robusta seedlings 9.57 5.60 4.43 4.89 3.166 0.003 0.97 the results revealed a non-significant mean difference in the other species’ seedlings with t= -1.416, p=0.165. findings showed that fire-unaffected sites were found higher in the rest species’ seedlings (m=6.29, sd=2.77) compared to the fire-affected sites (m=5, sd=3.098). the value of cohen’s d was 0.43 (<0.5) which indicates a small effect size (table 3). table 3: mean comparison of fire-affected and fire-unaffected sites in other species seedlings fire affected fire unaffected variables m sd m sd t p cohen’s d other species seedlings 5 3.098 6.29 2.77 -1.416 0.165 0.43 the results revealed a non-significant mean difference in the s. robusta saplings with t= -0.710, p=0.482. findings showed that fire-unaffected sites were found higher in the s. robusta saplings (m=1.43, sd=3.58) compared to the fire-affected sites (m=0.86, sd=0.85). the value of cohen’s d was 0.21 (<0.5) which indicates a small effect size (table 4). table 4: mean comparison of fire-affected and fire-unaffected sites in s. robusta saplings fire affected fire unaffected variables m sd m sd t p cohen’s d s. robusta saplings 0.86 0.85 1.43 3.58 -0.710 0.482 0.21 the results revealed a non-significant mean difference in the saplings of other species with t= -1.42, p=0.163. findings showed that fire-unaffected sites were found higher in the rest species saplings (m=1.57, sd=3.18) compared to the fire-affected sites (m=0.57, sd=0.50). the value of cohen’s d was 0.43 (<0.5) which indicates a small effect size (table 5). international journal of environment issn 2091-2854 55 | p a g e table 5: mean comparison of fire-affected and fire-unaffected sites in other species saplings fire affected fire unaffected variables m sd m sd t p cohen’s d other species saplings 0.57 0.50 1.57 3.18 -1.42 0.163 0.43 discussion tropical forests used to experience very few fires, leaving plenty of time for regeneration (slik et al., 2008). nevertheless, tropical forest fires have increased in frequency and on a larger scale in the last few decades than in the past (dickson et al., 2006; stephens et al., 2015). the extent of the damage depends upon the frequency and intensity of fires, forest types, the availability of fuel, and local climatic factors. results showed that species richness decreased and species dominance of certain fire-resistant species i.e. density of shorea robusta species increased in the post-fire condition which aligns with the study (bargali et al., 2022; kittur et al., 2014; verma et al., 2017). the increased species density of s. robusta may be due to fire-resistant characteristics (gautam and devoe, 2006). the decrease in species richness in post-fire conditions may be due to the proliferation of root sprouts (saha and howe, 2003). gautam et al. (2016) found a negative relationship between disturbance and regeneration (both seedlings and saplings), while sapkota et al. (2009) concluded that moderate disturbances promote regeneration. the seedling density of shorea robusta was found significantly higher in the fire-affected sites which are supported by the previous research of gould et al. (2002) and mondal and sukumar (2015). forest fires in s. robusta forests take the form of ground fires and mostly affect the regeneration and the ground flora which normally recovers during the monsoons (kovacic, 1998). s. robusta was a successful survivor after the fire and became an important component of the post-fire community in uttaranchal, india (chandra et al., 2015). the enhanced number of seedlings of s. robusta could be caused by increased nutrient availability, reduced pathogen population, and breaking of seed dormancy (verma et al., 2017). nevertheless, the seedling density of other species was found lower in the fire-affected sites which is consistent with the findings of (kittur et al., 2014). specifically, in burned areas, seedling establishment and survival may differ from unburned areas (petrie et al., 2016). thus, regeneration patterns during the first few years after fire likely affect the trajectory of the ecosystem (turner et al., 2016). however, the interaction of various potential influencing factors is complex, and climate variables may not adequately explain the germination and survival processes in post-fire environments (stevens-rumann and morgan, 2019). fire occurred through natural or manmade factors that reduce vegetation growth and change forest structure (spanos et al., 2010). our study found increased sal seedlings but reduced saplings in the low-intensity international journal of environment issn 2091-2854 56 | p a g e controlled burning. however, similar to our results, keyser et al. (2008) found sites with high burn severity had lower regeneration than those with low to moderate burn severity. in contrast, the highest tree regeneration densities were found in high-severity burn plots by coop et al. (2010) and shive et al. (2013). many have also found that tree regeneration varies with distance from the seed source, but not with burn severity (coop and schoettle, 2009). forest fire management is an important aspect of sustainable forest management ensuring the health of forest ecosystems, where negative impacts of fire are minimized and positive impacts are maximized. these research findings help to address the issue of the post-fire effect on sal regeneration for the effective forest management of sal-dominated forests in the terai region of nepal. the research duration was short for the in-depth study so effective factors for variation such as rainfall quantity, soil moisture, biological disturbance, intensity, temperature, canopy, etc., in regeneration pattern are further recommended for future study. conclusions this study examined the post-fire effects of controlled burning in regeneration density. the reduction of species richness and species dominance of shorea robusta in the post-fire conditions induces favorable conditions for regeneration, thereby reducing the survival competition. a significant difference with a large effect size due to post-fire conditions in the seedling regeneration of s. robusta indicates fire as a positive catalyst tool for seedling regeneration and seedling production of s. robusta. the variation of the sapling regeneration of s. robusta and other species was found to be lower in the fire-affected areas, i.e., fire is a beneficial tool for regeneration but not for plant establishment. hence, fire is not recommended for the sapling establishment period or after the seedling regeneration. this study provides baseline data for the regeneration management of s. robusta in the terai region of nepal. this study has the limitation of short duration effect, hence, future studies might focus on the long-term studies considering different fire intensities effects on regeneration. authorship contribution statement conceptualization, b.p.d., and v.t.c.; methodology, b.b.; s.s.; b.p.d, and v.t.c.; validation, b.b.; s.s.; b.p.d, and v.t.c.; formal analysis, b.p.d., and v.t.c.; data collection, b.p.d.; writing—original draft, b.p.d.; writing—review and editing, b.b.; s.s.; b.p.d, and v.t.c. we agree that the published version of the manuscript is accurate and complete. conflict of interest statement no conflict of interest is declared by the authors. international journal of environment issn 2091-2854 57 | p a g e acknowledgments we would like to thank division forest office, rautahat for granting us permission to conduct this study. we would like to acknowledge mr. jeetendra gautam for his supervision. we are thankful to mr. gandiv kafle, mr. shiva kumar wagle, mr. ashok parajuli and mr. kamal acharya for providing technical guidance to conduct this research. the first author thanks the redd implementation centre, babarmahal, kathmandu for providing the financial support for the master level research. references acharya, k. p., 2008. forest fire management plan. makawanpur district forest office amatya, s. m., shrestha, k. r., cedamon, e., 2016. nepal forestry handbook. nepal foresters association. bajracharya, k.m., 2002. forest fire situation in nepal. (iffn no. 26 – january 2002, p. 84-86): https://gfmc.online/iffn/country/np/np_2.html bargali, h., calderon, l. p. p., sundriyal, r. c. & bhatt, d., 2022. impact of forest fire frequency on floristic diversity in the forests of uttarakhand, western himalaya. trees, forests and people, 9(march), 100300. https://doi.org/10.1016/j.tfp.2022.100300 belbase, k., poudel, a. s. & chhetri, s. g., 2020. comparison of forest stand condition between thinned and unthinned blocks under collaborative forest management of western lowlands of nepal. research square, 1–14. belcher, c. m., 2013. understanding fire regimes and the ecological effects of fire. fire phenomena and the earth system: an interdisciplinary guide to fire science, 97–124. bhuyan, p., khan, m. l. & tripathi, r. s., 2003. tree diversity and population structure in undisturbed and human-impacted stands of tropical wet evergreen forest in. biodiversity and conservation, 12, 1753– 1773. chandra, k., bhardwaj, a. k., chandra, k. k. & kumar bhardwaj, a., 2015. incidence of forest fire in india and its effect on terrestrial ecosystem dynamics, nutrient and microbial status of soil. researchgate.net, 5(2), 69–78. https://doi.org/10.5923/j.ijaf.20150502.01 chapagain, u., chapagain, b. p., nepal, s. & manthey, m., 2021. impact of disturbances on species diversity and regeneration of nepalese sal (shorea robusta) forests managed under different management regimes. earth, 2(4), 826–844. https://doi.org/10.3390/earth2040049 coop, j. d. & schoettle, a. w., 2009. regeneration of rocky mountain bristlecone pine (pinus aristata) and limber pine (pinus flexilis) three decades after stand-replacing fires. forest ecology and management, 257(3), 893-903. coop, j. d., massatti, r. t. & schoettle, a. w., 2010. subalpine vegetation pattern three decades after stand‐ https://gfmc.online/iffn/country/np/np_2.html international journal of environment issn 2091-2854 58 | p a g e replacing fire: effects of landscape context and topography on plant community composition, tree regeneration, and diversity. journal of vegetation science, 21(3), 472-487. dickson, b. g., prather, j. w., xu, y., hampton, h. m., aumack, e. n. & sisk, t. d., 2006. mapping the probability of large fire occurrence in northern arizona, usa. landscape ecology, 21(5), 747–761. https://doi.org/10.1007/s10980-005-5475-x doerr, s. h. & santín, c., 2016. global trends in wildfire and its impacts: perceptions versus realities in a changing world. philosophical transactions of the royal society b: biological sciences, 371(1696). https://doi.org/10.1098/rstb.2015.0345 gallagher, m. r., kreye, j. k., machtinger, e. t., everland, a., schmidt, n. & skowronski, n. s., 2022. can restoration of fire‐ dependent ecosystems reduce ticks and tick‐ borne disease prevalence in the eastern united states?. ecological applications, 32(7), e2637. gautam, k. h. & devoe, n. n., 2006. ecological and anthropogenic niches of sal (shorea robusta gaertn. f.) forest and prospects for multiple-product forest management a review. forestry, 79(1 spec. iss.), 81–101. https://doi.org/10.1093/forestry/cpi063 gautam, m. k., manhas, r. k. & tripathi, a. k., 2016. patterns of diversity and regeneration in unmanaged moist deciduous forests in response to disturbance in shiwalik himalayas, india. journal of asiapacific biodiversity, 9(2), 144–151. https://doi.org/10.1016/j.japb.2016.01.004 gautam, t. p. & mandal, t. n., 2018. effect of disturbance on plant species diversity in moist tropical forest of eastern nepal. our nature, 16(1), 1–7. https://doi.org/10.3126/on.v16i1.21558 gould, k. a., fredericksen, t. s., morales, f., kennard, d., putz, f. e., mostacedo, b. & toledo, m., 2002. post-fire tree regeneration in lowland bolivia: implications for fire management. forest ecology and management, 165(1–3), 225–234. https://doi.org/10.1016/s0378-1127(01)00620-x government of nepal/mfsc., 2004. cf inventory guideline 2004. ministry of forest and soil conservation, kathmandu, nepal. keyser, t. l., lentile, l. b., smith, f. w. & shepperd, w. d., 2008. changes in forest structure after a large, mixed-severity wildfire in ponderosa pine forests of the black hills, south dakota, usa. forest science, 54(3), 328-338. kittur, b., jhariya, m. k. & lal, c., 2014. is the forest fire can affect the regeneration and species diversity. ecology, environment and conservation, 20(3), 989–994. lelieveld, j., klingmüller, k., pozzer, a., burnett, r. t., haines, a. & ramanathan, v., 2019. effects of fossil fuel and total anthropogenic emission removal on public health and climate. proceedings of the national academy of sciences of the united states of america, 116(15), 7192–7197. https://doi.org/10.1073/pnas.1819989116 international journal of environment issn 2091-2854 59 | p a g e martin, d., tomida, m. & meacham, b., 2002. environmental impact of fmd. veterinary record, 150(11), 327. https://doi.org/10.1186/s40038-016-0014-1 mondal, n. & sukumar, r., 2015. regeneration of juvenile woody plants after fire in a seasonally dry tropical forest of southern india. biotropica, 47(3), 330–338. https://doi.org/10.1111/btp.12219 parajuli, a., chand, d. b., rayamajhi, b. k. & khanal, r., 2015. spatial and temporal distribution of forest fires in nepal invasion of alien plant species and their impact on different ecosystems of panchase area, nepal view project. xiv world forestry congress, september, 7–11. petrie, m. d., wildeman, a. m., bradford, j. b., hubbard, r. m. & lauenroth, w. k., 2016. a review of precipitation and temperature control on seedling emergence and establishment for ponderosa and lodgepole pine forest regeneration. forest ecology and management, 361, 328–338. https://doi.org/10.1016/j.foreco.2015.11.028 saha, s. & howe, h. f., 2003. species composition and fire in a dry deciduous forest. ecology, 84(12), 3118– 3123. https://doi.org/10.1890/02-3051 sapkota, i. p., tigabu, m. & odén, p. c., 2009. spatial distribution, advanced regeneration and stand structure of nepalese sal (shorea robusta) forests subject to disturbances of different intensities. forest ecology and management, 257(9), 1966–1975. https://doi.org/10.1016/j.foreco.2009.02.008 shive, k. l., sieg, c. h. & fulé, p. z., 2013. pre-wildfire management treatments interact with fire severity to have lasting effects on post-wildfire vegetation response. forest ecology and management, 297, 75-83. slik, j. w. f., bernard, c. s., van beek, m., breman, f. c. & eichhorn, k. a. o., 2008. tree diversity, composition, forest structure and aboveground biomass dynamics after single and repeated fire in a bornean rain forest. oecologia, 158(3), 579–588. https://doi.org/10.1007/s00442-008-1163-2 spanos, i., ganatsas, p. & tsakaldimi, m., 2010. evaluation of postfire restoration in suburban forest of thessaloniki, northern greece. global nest j, 12, 390-400. stephens, s. l., north, m. p. & collins, b. m., 2015. large wildfires in forests: what can be done? stevens-rumann, c. s. & morgan, p., 2019. tree regeneration following wildfires in the western us: a review. fire ecology, 15(1), 1–17. https://doi.org/10.1186/s42408-019-0032-1 turner, m. g., whitby, t. g., tinker, d. b. & romme, w. h., 2016. twenty-four years after the yellowstone fires: are postfire lodgepole pine stands converging in structure and function? ecology, 97(5), 1260– 1273. https://doi.org/10.1890/15-1585.1 tyagi, j. v., kumar, r., srivastava, s. l. & singh, r. d., 2011. effect of micro-environmental factors on natural regeneration of sal (shorea robusta). journal of forestry research, 22(4), 543–550. https://doi.org/10.1007/s11676-011-0197-1 international journal of environment issn 2091-2854 60 | p a g e verma, s., singh, d., mani, s. & jayakumar, s., 2017. effect of forest fire on tree diversity and regeneration potential in a tropical dry deciduous forest of mudumalai tiger reserve, western ghats, india. ecological processes, 6(1), 4–11. https://doi.org/10.1186/s13717-017-0098-0 wang, s. w., lim, c. h. & lee, w. k., 2021. a review of forest fire and policy response for resilient adaptation under changing climate in the eastern himalayan region. forest science and technology, 17(4), 180–188. https://doi.org/10.1080/21580103.2021.1979108 wooten, j. t., stevens-rumann, c. s., schapira, z. h. & rocca, m. e., 2022. microenvironment characteristics and early regeneration after the 2018 spring creek wildfire and post-fire logging in colorado, usa. fire ecology, 18(1). https://doi.org/10.1186/s42408-022-00133-8 zhu, j., mao, z., hu, l. & zhang, j., 2007. plant diversity of secondary forests in response to anthropogenic disturbance levels in montane regions of northeastern china. journal of forest research, 12(6), 403– 416. https://doi.org/10.1007/s10310-007-0033-9 performance of sweet pepper under protective structure international journal of environment issn 2091-2854 32 | p a g e international journal of environment volume-3, issue-1, dec-feb 2013/14 issn 2091-2854 received:13 december revised:30 december accepted: 21 january allelopathic interaction of pepper (capsicum annuum) and pearl millet (pennisetum glaucum) intercropped leila radhouane 1* and thouraya rhim 2 national tunisian institute for agriculture research (inrat) hédi karray avenueariana 2049-tunisia * corresponding author: radhouane.leila@iresa.agrinet.tn abstract intercropping is common practice in many regions of tunisia, particularly in cap-bon where different crops such as tomato, pepper, cucumber, peanut, corn, pearl millet and sorghum are grown together in the same field and at the same time for self-sufficiency. a number of these crops and vegetables are known for their allelopathic activities. the interaction between plants could be within the individuals of the same species (intraspecific interaction or autotoxicity) or between different species (interspecific interaction or teletotoxicity). little is known about allelopathic interaction of some of these intercropped plants in mixed farming systems in our local conditions. therefore, the objectives of the present investigation are to evaluate, under laboratory condition, the allelopathic effect of mixed crops, which interacted positively or negatively when cultivated together in the same field. two plant species were used to study the effects of their aqueous extract on germination and growth of each other (pepper and pearl millet). the results suggested that aqueous extracts from shoots and roots significantly inhibited germination and seedling growth and the inhibitory effects were increased proportionally with the extract concentration. the shoot and root aqueous extract also exhibited intraspecific and interspecific allelopathy. generally, it was observed that roots were more toxic than shoots. for root extract, the highest inhibition percentage was gained from the effect of pearl millet on pepper (40%) and highest autotoxicity was observed from pearl millet (36%). the effect of shoot extract on germination indicated that the highest reduction (55%) was obtained from pepper shoot extract on pearl millet and highest autotoxicity was observed from pepper which reached (45%). in most cases autotoxicity appeared to be more severe than teletotoxicity, on seed germination of the two intercropped plant species. keywords: allelopathy, pearl millet, pepper, aqueous extract, germination. international journal of environment issn 2091-2854 33 | p a g e introduction allelopathy has been increasingly recognized as an important ecological mechanism that plays an appreciable role in plants dominance, plant succession, formation of communities and climax vegetation and crop productivity (chou, 1999). allelopathy is the interaction of plants as influenced by the chemical substances that they release into the environment (machado, 2007) and (dayan et al., 2009). allelopathy can enhance the competitive success of the invader plants, since the release of phytotoxins in the environment may affect the growth and life processes of other community species (callaway et al., 2002). the world is still in search of and in the process of developing farming techniques, which are sustainable for environment, crop production and protection as well as socio-economic points of view. integrated weed management is one of such approaches where allelopathy can play its eco-friendly role in weed management (hussain et al., 2007). the allelopathic properties of plants can be exploited successfully as tool for pathogens and weed reduction (xaun et al., 2005). in fact, allelochemicals have been shown to be less toxic, environmentally safer, conserve the resources and also their potential biodegradability would nullify the problems raised by synthetic chemicals (rizvi et al.,1992). allelopathic crops, when used as cover crops, mulch, smother crops, intercrops or green manures, or grown in rotational sequences, can combat biotic stresses such as weed infestation, insect pests and disease pathogens (khanh et al., 2005) and additionally build up fertility and organic matter status of soil, thereby reducing soil erosion, and improve farm yields (jabran et al., 2007). nevertheless, damaging consequences of an allelopathic crop in rotation have also been observed. in fact, in some rotation, allelochemicals exuded from some crops affected the development of the subsequent crop (roth et al., 2000). the toxic effects of these allelochemicals are species specific and dependent on stage of plant, growth conditions, mass added into the soil, their movement and their persistence in soil (inderjit, 2001). the allelochemicals may be produced by any part of plant although stems and leaves are most important source of allelochemicals (rice, 1984). several crops are known for their allelopathic activities such as alfalfa (miller, 1983), corn (almezori, 1996), rice (ebana et al., 2001), tomato (saied and saied, 2001), sorghum (cheema et al., 2004), ficus (rsaissi et al., 2013) and many of which have been chemically characterized (pereda-miranda et al., 1993) and (inderjit, 1996). the idea of exploiting these compounds as natural herbicides is therefore very attractive (weston, 1996) and (duke et al., 2000). many researchers investigated the effect of plant extracts on the germination and growth of other plants (ben hammouda et al., 2001) and (saied, 2004). these aspects become particularly interesting when plants are intercropped. in fact, intercropping is common practice in many regions of tunisia, particularly in cap-bon where different crops such as tomato, pepper, cucumber, peanut, corn, pearl millet and sorghum are grown together in the same field and at the same time for self-sufficiency. a number of these crops and vegetables are known for their allelopathic activities. the interaction between plants could be within the individuals of the same species (intraspecific interaction or autotoxicity) or between different species (interspecific interaction or teletotoxicity). however, little is known about allelopathic interaction of some of these intercropped plants in mixed farming systems in our local conditions. therefore, the objectives of the present investigation are to evaluate, under laboratory condition, the allelopathic effect of mixed crops, which interacted positively or negatively when international journal of environment issn 2091-2854 34 | p a g e cultivated together in the same field. two plant species were used to study the effects of their aqueous extract on germination and growth of each other (pepper and pearl millet). materials and methods in field conditions, the problem of toxicity arises with rains or irrigations; therefore, only aqueous extracts of pearl millet and pepper roots and shoots were taken. the root and shoot residues were collected after harvest, from tunisian research institute. a study has been undertaken on the effect of aqueous extracts of autochthonous pearl millet ecotype (ks) and local variety of pepper on seed germination and on plant growth of pearl millet and pepper. preparation of aqueous extracts of pearl millet and pepper roots and shoots of ks pearl millet ecotype and pepper were separated, cleaned, dried at (80°c) for 48 hours and mixed with warm distilled water for 3 days. the mixtures were passed through cheesecloth and filtered by filter paper. the concentrations of aqueous extract used were respectively 3% for roots and 10% for shoot. effect of aqueous extracts of pearl millet and pepper on seed germination 5 ml of the extracts were added to each petri dish planted with 25 seeds. 4 replicates of each treatment were randomly distributed in a growth germinator at 30°c. the germination percentages were recorded after 7 days of cultivation. it corresponded at the maximum number of seedlings that germinated during the experiment. effect of aqueous extracts of pearl millet and pepper on plant growth experiment was carried out in plastic pots. each pot was planted with 4 seeds and 50 ml of extracts were added to each pot. throughout the duration of the experiment, the pots were alternatively irrigated with equal quantities of nutrient solution and aqueous extracts. the pots were distributed randomly in a green house, in three replications. after two months, the length of root and shoot system was recorded, then dried at 80°c for 48 h. statistics analyse average counts for each of replicates were pooled and subjected to standard statistical analysis. data were statistically analyzed using analysis of variance techniques appropriate for randomized complete block design. main and interaction effects were separated by lsd test at 0.05 level of probability, if the f-values were significant results effect on germination for root extract (table 1), the highest inhibition percentage was gained from the effect of pearl millet on pepper (40%) and highest autotoxicity was observed from pearl millet (36%). table 1. effect of root aqueous extract of pearl millet and pepper on pepper and on pearl millet germination plant type concentration (%) pepper germination (%) pearl millet germination (%) pepper 0 100 a 100 a international journal of environment issn 2091-2854 35 | p a g e 3 84 b 96 a (%) inhibition 16 4 pearl millet 0 3 100 a 60 b 100 a 64 b (%) inhibition 40 36 means with different letters in a column differed significantly (5% level). the effect of shoot extract on germination (table 2) indicated that the highest reduction (55%) was obtained from pearl millet shoot extract on pepper and highest autotoxicity was observed from pepper which reached (45%). in most cases autotoxicity appeared to be more severe than teletotoxicity, on seed germination of the two intercropped plant species. generally, it was observed that roots were more toxic than shoots. indeed, with a lesser concentration (3% vs 10%), effect of root on germination reductions was greater or equal than those obtained with shoot aqueous extract. table 2. effect of shoot aqueous extract of pearl millet and pepper on pepper and on pearl millet germination plant type concentration (%) pepper germination (%) pearl millet germination (%) pepper 0 10 100 a 55 b 100 a 90 b (%) inhibition 45 10 pearl millet 0 10 100 a 45 b 100 a 92 b (%) inhibition 55 8 means with different letters in a column differed significantly (5% level). effect on seedling growth aqueous extract of pepper shoot on pepper growth caused reduction only in shoot, root and intact plant dry weights (table 3).the influence of shoot extracts on lengths of different plant types was, however, not significant. for pearl millet, application of 10 % of pepper shoot extract concentrations resulted in decrease in lengths and weight of all parameters except for root dry weight. the reduction is more important for total length (76%) than total dry weight (25%). table 3. the effect of pepper shoot aqueous extract on the growth and dry weight of pearl millet and pepper plant type concentration (%) shoot length (cm) root length (cm) intact plant length (cm) shoot dry weight (mg/plant) root dry weight (mg/plant) intact plant dry weight (mg/plant) pepper 0 10 9 a 10 a 11 a 8 a 20 a 18 a 95 a 65 b 95 a 65 b 190 a 130 b international journal of environment issn 2091-2854 36 | p a g e pearl millet 0 10 28 a 5 b 23 a 7 b 51 a 12 b 190 a 130 b 130 a 110 a 320 a 240 b means with different letters in a column differed significantly (5% level). shoot extract of pearl millet decreased significantly the root and intact plant lengths of pearl millet and also diminished shoot and intact plant dry weights (table 4). instead, pearl millet shoot extract has only a low effect on length and dry weight of pepper. table 4. the effect of ks pearl millet ecotype shoot aqueous extract on the growth and dry weight of pearl millet and pepper plant type concentration (%) shoot length (cm) root length (cm) intact plant length (cm) shoot dry weight (mg/plant) root dry weight (mg/plant) intact plant dry weight (mg/plant) pepper 0 10 9 a 9 a 10 a 9 a 19 a 18 a 90 a 90 a 90 a 80 b 180 a 170 b pearl millet 0 10 27 a 27 a 22 a 16 b 49 a 43 b 183 a 120 b 130 a 125 a 313 a 245 b means with different letters in a column differed significantly (5% level). the effect of root extract of pepper was not significant on root, shoot and intact plant lengths of pepper, while significant differences were obtained from root, shoot and intact plant lengths and weights of pearl millet (table 5). table 5. the effect of pepper root aqueous extract on the growth and dry weight of pearl millet and pepper plant type concentration (%) shoot length (cm) root length (cm) intact plant length (cm) shoot dry weight (mg/plant) root dry weight (mg/plant) intact plant dry weight (mg/plant) pepper 0 3 9 a 10 a 10 a 6 a 19 a 16 a 90 a 60 b 90 a 60 b 180 a 120 b pearl millet 0 3 27 a 6 b 22 a 6 b 50 a 12 b 180 a 130 b 130 a 100 b 310 a 230 b means with different letters in a column differed significantly (5% level). root extract of pearl millet significantly affected lengths and weights of different parts of the plant of pearl millet. whereas the same extract had not effect on pepper. pearl millet appeared more susceptible than pepper (table 6). autotoxicity appeared to be more severe than teletotoxicity. table 6. the effect of ks pearl millet ecotype root aqueous extract on the growth and dry weight of pearl millet and pepper plant type concentration (%) shoot length (cm) root length (cm) intact plant length (cm) shoot dry weight (mg/plant) root dry weight (mg/plant) intact plant dry weight (mg/plant) pepper 0 9 a 10 a 19 a 90 a 90 a 180 a international journal of environment issn 2091-2854 37 | p a g e 3 8 a 12 a 20 a 80 a 80 a 160 a pearl millet 0 3 27 a 23 b 22 a 21 a 49 a 44 b 183 a 123 b 129 a 125 a 312 a 248 b means with different letters in a column differed significantly (5% level). discussion some crop and weed plants are able to release some exudates into the environment, suppressing the growth of plants of their own kind, other plants or weeds. this is called the allelopathic effect (narwall and willis, 2006). allelopathy plays an eminent role in the intraspecific and interspecific competition and may determine the type of interspecific association. mixed cropping is practiced particularly in cap-bon and in kairouan where different vegetables and other crops are cultivated together in the same field at the same time. among these crops, particular attention is given for pepper and pearl millet intercropped and for allelopathic effect of mixed crops. the results of seed germination indicated that autotoxicity is present for the two species. this suggests that pearl millet and pepper are allelopathic plants, which are capable of suppressing their own germination and growth. allelopathic pepper effects is supported by several authors such siddiqui and uzzaman (2005), zhongqun et al. (2012), valcheva and popov (2013). for pearl millet, the capability of p. glaucum to release allelopathic substances through water is cited by many authors (saxena et al. (1996) and radhouane (2012). allelophathic effects depended upon the parts assayed, test species and physiological process involved (reigosa et al., 1999). in fact, inhibition effect is more severe for pepper under pepper shoot aqueous extract (45%) than under pepper root extract (16%). these data suggest that stimulatory and inhibitory effects of a given plant extract are a function of concentration (saxena et al. 1996) and (hussain and ilahi, 2009). that difference was present between shoot and root extracts of the same plant concerning their effect on others (ben-hamouda et al., 2001). this can be explained by the differences of plant parts in accumulation of phytotoxin (gonzalez et al., 1997). further higher concentrations of aqueous extracts bioassayed caused decline in total dry matter per seedling. the results suggest that the growth inhibition due to an autotoxic principle contained in the root and shoot tissue of both plants is concentration–dependent. it implies that the phytotoxic compounds will have to accumulate in sufficient quantity in the soil to cause autotoxicity. inderjit and duke (2003) stated that plants release phytochemicals from dead tissues, and their incorporation to the soil could be accelerated by leaching thus facilitating their harmful effects in the field. the mode of action of allelochemicals spans over a wide range of actions including cell lysis, blistering or growth inhibition (wu et al., 2003). the allelochemicals present in the two plants root and shoot aqueous extracts might have inhibited root growth by at least two mechanisms. the first possible target is cell division in roots (bhowmik and doll, 1982). phenolics represent one of the largest groups of allelochemicals and avers and goodwin (1956) have shown that various phenolic http://www.scialert.net/fulltext/?doi=ijbc.2009.56.70 international journal of environment issn 2091-2854 38 | p a g e compounds inhibited cell division. it is also possible that the cell elongation was affected by extracts of plants residues. tomaszewski and thimann (1966) found many allelochemicals inhibited gibberellin and indole acetic acid-induced growth. su and fang (1981) and hegde and miller (1992) also reported the adverse effects of phytotoxins from crop residues on the seedling growth of succeeding crops. this study leads us to avoid practicing intercropping pepper with pearl millet and also to avoid monoculture. this study also shows the importance of crop rotation in improving crop yields. conclusion autochthonous pearl millet ecotype and local pepper have strong allelopathic potentials in mixed cropping. but, in most cases autotoxicity appeared to be more severe than teletotoxicity, on seed germination of the two intercropped plant species. so, they might be candidates for biological control of weeds and insects. they may be used in different ways to influence weeds such as surface mulch, incorporation in to the soil, spray of aqueous extracts, rotation, smothering or mix cropping. however, further studies are required to see their allelopathic behavior under field condition against others species and to identify the toxic principle, their quantification and their efficacy in the soil. references almezori, h.a.m., 1996. studies on the allelopathic potential of (zea mays l.). ph.d. thesis baghdad university, iraq. 150 pp. avers, c.j. and goodwln, r.h., 1956. studies on roots. iv. effects of coumarin and scopoletin on the standard root growth pattern of phleumpratense. american journal of botany 43, 612-620. ben hammouda, m., ghorbal, h., kremer, r.j. and oueslati, o., 2001. allelopathic effects of barley extracts on germination and seedlings growth of bread and durum wheats. agronomie 21, 65-71. bhowmik, p.c. and doll, j.d., 1982. corn and soybean response to allelopathic effects of crop and weed residues. agronomy journal 74, 601-606. callaway, r.m., nadkarni, n.m. and mahall, b.e., 2002. facilitation and interference of quercus douglasii on understory productivity in central california. ecology 72, 1484-1499. cheema, z.a., khaliq, a. and saeed, s., 2004. weed control in maize (zeamays l.) through sorghum allelopathy. journal of sustainable agriculture 23, 73-86. chou, c.h., 1999. methodologies for allelopathy research: from fields to laboratory. recent advances in allelopathy. vol.i. a science for the future 1, 3-24. dayan, f.e., cantrell, c.l. and duke, s.o., 2009. natural products in crop protection. bioorganic and medicinal chemistry 17, 4022–4034. duke, s.o., romagni, j.g. and dayan, f.e., 2000. natural products as sources for new mechanisms of herbicidal action. crop protection 19, 583-589. international journal of environment issn 2091-2854 39 | p a g e ebena, k., yan, w., dilday, r.h., namai, h. and okuno, k., 2001. variation in the allelopathic effect of rice with water soluble extracts. agronomy journal 93(1), 12-16. gonzalez, l., souto, x.c. and reigosa, m.j., 1997. weed control by capsicum annuum. allelopathy journal 4, 101-110. hegde, r.s. and miller, d.a., 1992. concentration dependency and stage of crop growth in alfalfa autotoxicity. agronomy journal 84, 940-946. hussain, s., siddiqui, s.u., khalid, s., jamal, a., qayyum, a. and ahmad, z., 2007. allelopathic potential of senna (cassia angustifolia vahl.) on germination and seedling characters of some major cereal crops and their associated grassy weeds. pakistan journal of botany 39(4), 1145-1153. hussain, f. and ilahi, i., 2009. allelopathic potential of cenchrus ciliaris l., and bothriochloa pertusa (l.). journal of science & technology 33, 47-55. inderjit, i., 1996. plant phenolics in allelopathy. botanical revue 62, 186-202. indrejit, i., 2001. environnemental effects on allelochemical activity. agronomy journal 93(1), 79-84. inderjit, k.l. and duke, s.o., 2003. ecophysiological aspects of allelopathy. planta 217: 529-539. jabran, k., cheema, z.a., farooq, m. and khaliq, a., 2007. evaluation of fertigation and foliar application of some fertilizers alone and in combination with allelopathic water extracts in wheat. proc international workshop on allelopathy – current trends and future applications 24, 18–21 khanh, t.d., chung, m.i., xuan, t.d. and tawata, s., 2005. the exploitation of crop allelopathy in sustainable agricultural production. journal of agronomy and crop sciences 191, 172–184. machado, s., 2007. allelopathic potential of various plant species on downy brome: implications for weed control in wheat production. agronomy journal 99, 127-132. miller, d.a., 1983. allelopathic effect of alfalfa. journal of chemical ecology 9, 1059-1071. narwall, s.s. and willis, r.j., 2006. 100 years allelopathy bibliography. htpp://www.allelopathy-journal.com. pereda-miranda, r., mata, r., anaya, a.l., pezzuto, j.m., wickramaratne, d.b.m., kinghorn, a.d. and tricolorin, a., 1993. major phytogrowth-inhibitor from ipomoea tricolor. journal of natural products 56, 571-582. radhouane, l., 2012. allelopathic effects of pearl millet (pennisetum glaucum(l.)r.br.) on seed germination and seedling growth. 1 st biotechnology world congress. united arab emirates, dubai: 14-15 february 2012. reigosa, m.j., souto, x.c. and gonzalez, l., 1999. effect of phenolic compounds on the germination of six weeds species. plant growth regulation 28(2), 83-88. rice, e.l., 1984. allelopathy. academic press, orlando, 350 pp. rizvi, s.j.h., haque, h., singh, v.k. and rizvi, v., 1992. a discipline called allelopathy, in allelopathy: basic and applied aspects, ed. by rizvi sjh and rizvi v. chapman and hall, london, uk, pp. 1–10. roth, c.m., shroyer, j.p. and paulsen, g.m., 2000. allelopathy of sorghum on wheat under several tillage systems. agronomy journal 92, 885–860. international journal of environment issn 2091-2854 40 | p a g e rsaissi, n., bouhache, m. and bencharki, b., 2013. allelopathic potential of barbary fig « opuntia ficus-indica" on the germination and growth of wild jujube « ziziphus lotus" international journal of innovation and applied studies 3(1), 205-214. saied, s.m. and saied, j.a., 2001. the effect of rice and tomato residues on the growth and some of the yield component of some wheat cultivars triticum aestivum l. al rafedain science journal 13, 1-44. saied, j.a., 2004. the response of some durum wheat cultivars to the allelopathic effect of barley hordeum distichum l. iraqi journal of agricultural sciences 5(3), 1-3. saxena, a., singha, d.v. and joshi, n.l., 1996. autotoxic effects of pearl millet aqueous extracts on seed germination and seedling growth. journal of arid environments 33 (1), 255 260. siddiqui, z.s. and uzzaman, a., 2005. effects of capsicum leachates on germination, seedling growth and chlorophyll accumulation in vigna radiata seedlings. pakistan journal of botany 37(4), 941-947. su, s.m. and fang, v.l., 1981. the effect of stubble lands of different crops on following crops. acta agronomica sinica 7, 123–128. tomaszewski, m. and thimann, k.v., 1966. interaction of phenolic acids, metallic ions and chelating agents on auxin induced growth. plant physiology 41, 1443–1454. valcheva, e. and popov, v., 2013. role of the allelopathy in mixed vegetable crops in the organic farming. series a. agronomy (lvi), 422-425. waller, g.r., 1987. allelopathic compounds in soil from no tillage vs conventional tillage in wheat production. plant soil 98, 5–15. weston, l.a., 1996. utilization of allelopathy for weed management in agroecosystems. allelopathy in cropping systems. agronomy journal 88, 860-866. wu, x., heflin, m.b., ivins, e.r., argus, d.f. and webb, f.h., 2003. large-scale global surface mass variations inferred from gps measurements of load-induced deformation. geophysics research letter 30, 17421758. xuan, t.d., shinkichi, t., khanh, t.d. and chung, i.m., 2005. biological control of weeds and plant pathogens in paddy rice by exploiting plant allelopathy: an overview. crop protection 24(3), 197-206. zhongqun, h., junan, z., haoru, t. and zhi, h., 2012. different vegetables crops in response to allelopathic of hot pepper root exudates. world applied sciences journal 19(9), 1289-1294. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 62 | p a g e international journal of environment volume-4, issue-4, sep-nov 2015 issn 2091-2854 received:13 august revised:8 september accepted:2 november perception, trends and impacts of climate change in kailali district, far west nepal lal b thapa 1* , himanchal thapa 2 , bimala gharti magar 3 1,2 central department of botany, tribhuvan university, kirtipur, kathmandu, nepal 3 central department of anthropology, tribhuvan univeristy, kirtipur, kathmandu, nepal *corresponding author: lal_thapa25@yahoo.com abstract perception and place-based studies give useful information on climate change in context of nepal due to having its wide geographical, climatic, biological and cultural diversity. a household survey and focus group discussions were carried out in this study to document local people’s perceptions on climate change in kailali district of nepal. most of respondents in the study area have perceived that temperature and fog are increased; and rainfall and hail are decreased with severe fluctuation. trend of temperature supports local people’s perception. people have noticed impacts of these changes in vegetation, plant phenology and agriculture. fundamentally, they have observed that certain plant species are decreasing, increasing and showing changes in flowering and fruiting time. this information could have significance for future research to identify climate change sensitive or indicator plants. keywords: climate change, peoples’ perception, temperature, rainfall, vegetation international journal of environment issn 2091-2854 63 | p a g e introduction climate change has become a global challenging issue since few decades. there are several consequences of climate change such as floods, droughts, storms, spreading of infectious diseases and extinction of species (parry et al., 2005). global trend of surface temperature is consistently increasing since about 1950 (solomon et al., 2007) and in the high mountain areas the changes are likely to increase more (shrestha et al., 1999). along with temperature, precipitation is another climatic factor showing changes in amount and pattern. global land precipitation has increased by about 9 mm over the twentieth century (new et al., 2001). the trend of temperature in nepal are similar to the global trend but concerning precipitation, a significant variability have been observed in the country (shrestha et al., 1999, 2000; tiwari et al., 2010). most of perception based studies show that local peoples’ perception matches with these trends of temperature and precipitation (eg. timilsina -parajuli et al., 2013; devkota, 2014). however; change in climatic factors, its impacts and perception at different regions are still remained to be documented (shrestha et al., 2012) which are fundamental to identify local and global contexts, and for constructing generalized theory around how people response towards changing environment and associated risks (crona et al., 2013). inhabitants of rural areas are still not known about climate change and its impacts on various aspects but they perceive unexpected events to their surroundings (chaudhary and bawa, 2011). people are good observers of their local environment who can identify and interpret changes occurring in their surroundings, which can play a key role in shaping collective response to climate change (byg and salick, 2009). as there is much to learn from community-based approaches in different geographical locations about climate change, we have carried out this study to document local people’s perception, trend of temperature and rainfall and changing events in vegetation, phenology and agriculture in kailali district of far west nepal. methods study area the study was carried in kailali district of far western development region, nepal. it is part of tropical tarai and churiya region having warm climate throughout the year except short winter. the district lies between 28°34'n and 80°34'e and covers an area of 2742 square kilometers with population 142480 (cbs nepal, 2012). the landscape altitude ranges from 179 m to 1957 m above sea level. this study was concentrated in two vdcs (shahajpur and pandoun) located at subtropical churiya range and two municipalities (dhangadhi and tikapur) located at tropical tarai region (fig. 1). international journal of environment issn 2091-2854 64 | p a g e fig. 1 study sites; (a) nepal, (b) kailali district and vdcs household survey and interview a purposive sampling method was used to capture experienced local people’s knowledge and their views on climate change. respondents were selected from a total of 120 households (30 from each study vdc and municipality). the survey focused koltadi, khimadi and kunthapaani villages in paundaun vdc; bayala, belghari and lakhi villages in sahajpur vdc; badhara and chatakpur villages in dhangadhi municipality and bangaun and kerabari villages in tikapur municipality. among the total respondents majority of them were farmers (59.16%) and others were businesspersons (22.50%) and jobholders (18.33%). t he people of age forty years and above were included in interview. a questionnaire for interview was prepared prior to the fieldwork. in each study site focus group (5-10 people) discussions were conducted. the participants were asked to enumerate all the information, which they have international journal of environment issn 2091-2854 65 | p a g e perceived mainly to identify changes in climate and impacts of such changes particularly on vegetation, agriculture and livelihood. direct observation and transect walk survey was also done to observe and identify vegetation types, individual plants and agricultural fields. the plant species (recently appearing/increasing or decreasing) as noticed by local people were collected and identified in the field. the survey was carried out during october 2012 to february 2013. temperature data recorded by tikapur and godawari stations and rainfall data recorded by tikapur, sadepani and godawari stations of kailali district were obtained from department of hydrology and meteorology (dhm), government of nepal, ministry of science, technology & environment, kathmandu, nepal. results people’s perception on climatic factors four options viz. increasing, decreasing, same and don’t know were given to the respondents to express their perception on climatic factors (temperature, rainfall, fog, storm and hail). opinion of 83% respondents was on ‘increasing’ for temperature while 9% said that there is no change in temperature (fig 2a). concerning rainfall, 77.50% had opinion towards decreasing rainfall and 11% noticed that there is no decrease in rainfall (fig 2b). fig. 2 respondent’s perception on temperature (a) and rainfall (b) local people have experienced irregular pattern of rainfall different from previous rainfalls in the area. seventy six percent respondents said that the rainfall occurs lately in present days (fig 3a). similarly, majority of the respondents (58%) gave opinion that fog is increasing and opinion of 24% respondents was it is decreasing (fig 3b). based on people’s experience, the fog moves from low land (tarai) to uplands (subtropical range) in winter. the people of uplands had no experience of such event about 15 -20 years ago. variation in percentage of respondents about perception on hail was low i.e. 49% gave opinion of decreasing hail and 32% had agreement with there is no change in hail. (fig 3c). in case of storm, majority of respondents (48%) perceived that storm is increasing wherea s 28% respondents had experience of decreasing storm. nearly to the second opinion, 21% respondents said that pattern of storm is same (fig 3d). international journal of environment issn 2091-2854 66 | p a g e fig. 3 respondent’s perception on pattern of rainfall (a), fog (b), hail (c) and storm (d) climate change impact on vegetation and phenology most of the respondents (85%) had opinion towards changing vegetation (fig. 4a). the people’s argument was that there is important role of community people to destroy natural vegetation due to population pressure and lack of awareness, but the people have noticed changes in composition of vegetation by appearance and increasing of certain new species or decreasing of certain native species population in the nature. the respondents enumerated a total of 13 plant species decreased in surrounding and 9 plant species increased surprisingly around natural habitats since 2-3 decades (table 1 and table 2). the decreasing species are classified according to respondents’ opinion into rare (r) and extremely rare (er) (table 1). local people’s important notice was on plant phenology i.e. flowering and fruiting time has been changed according to 56% respondents. the plants showing phonological changes enumerated by them were myrica esculenta buch.-ham ex d.don (kafal, myricaceae), rhododendron (gurans, ericaceae), ficus hispida l.f. (tote, moraceae), psidium guajava l. (amba, myrtaceae), mangifera indica wall (anp, anacardiaceae), punica granatum l. (darim, punicaceae), ficus auriculata lour. (timila, moraceae), berberis (chutro, berberidaceae) and prunus persica (l.) batsch (aru, rosaceae). they have noticed that the flowering time of rhododendron, p. guajava, and m. indica has been shifted 15 days to 1 month before than 20-30 years ago. similarly, fruit-ripening time of p. persica, m. esculenta, international journal of environment issn 2091-2854 67 | p a g e f. hispida, p. guajava, m. indica and berberis also has been shifted by same pattern. they also have shown that the flowers of p. granatum and fruits of f. auriculata in off seasons and sometimes throughout year since recent 5 -7 years. other respondents (36%) said that they have not noticed phenological changes in these plants (fig 4b). fig. 4 respondent’s perception on vegetation (a) and phonological changes in plants listed by respondents (b) table 1: list of plants decreased in natural habitat sn name of plants local name family remarks 1 calotropis gigantea (l.) dryand. ank asclepiadaceae er 2 artemisia indica willd. titepati asteraceae r 3 anaphalis busua (buch.-ham. ex d. don) dc buki asteraceae er 4 cannabis sativa l. bhang cannabaceae er 5 cuscuta reflexa roxb. akas beli convolvulaceae er 6 asparagus racemosus willd. kurilo asparagaceae r 7 smilax sp. kukurdaino smilacaceae er 8 viscum album l. hadchur loranthaceae er 9 thysanolaena maxima (roxb.) o. kuntze amriso poaceae r 10 cynodon dactylon (l.) pers dubo poaceae r 11 imperata cylindrica (l.) p. beauv siru poaceae r 12 urtica dioica l. sisnoo urticaceae r 13 tinospora cordifolia (willd.) miers. gurgo menispermaceae r note: r; rare, er; extremely rare international journal of environment issn 2091-2854 68 | p a g e table 2: list of plants increased in natural habitat sn name of plants local name family problematic area 1 ageratum conyzoides l. gandhe asteraceae oa, f, cl 2 ageratina adenophora (sprengel) king and rob. banmara asteraceae oa, f 3 spilanthes calva dc. marathi asteraceae oa, cl 4 parthenium hysterophorus l. badmas jhar asteraceae oa, f 5 cyperus rotundus l. mothe cyperaceae oa, f, cl 6 cyperus iria l. chhatare cyperaceae oa, f, cl 7 cassia tora l chhinchhine fabaceae oa, f 8 argemone mexicana l. thakalikada papaveraceae oa, cl 9 lantana camara l kuri verbenaceae oa, f note: oa; open area, f; forest, cl; crop land climate change impacts on agriculture according to 72% respondents the agricultural practices are different from earlier practices as they know (fig. 5a). fluctuation of planting time, unexpected drought and rainfall since last 15 to 20 years is becoming major problem in agriculture. this has been affecting sometimes positive and frequently negative in crop production. all the respondents of both municipalities said that they have been using chemical fertilizers and pesticides since many years. the respondents of both vdcs also said that they have started using chemical fertilizers due to less production of compost fertilizer with decreasing number of cattle and also pesticides has become common since last 10 to 15 years. respondents (63%) have perceived that pests and pathogens are increased and the people have no option of using pesticides to control crop diseases. some respondents (22%) said that there is no increase of crop diseases because they have started using modern pesticides (fig. 5b). common crops of study areas are cereals (maize, wheat and rice), pulses (gram and lentil) and oil crop (mustard). regarding productivity of these crops, the perception difference did not vary greatly, only 42% respondents agreed in ‘decreasing’ for all crops and 37% said ‘increasing’ while no change was perceived in productivity by 17% respondents (fig. 6). nowdays productivity depends on fertilizers and pesticides used and irrigation from local kulo or tube well water. respondents said that they also have started changing crop varieties due to frequent impacts of changing environment on agriculture. local cereal crops (maize, wheat, rice) and vegetables (potato, brinjal, tomato, chilly, gourds) are replaced by hybrid ones in both vdcs and municipalities. in addition, the local people have abandoned traditional seed storage practice because hybrid varieties are available in local market from where they can buy when needed but the local people of pandaun vdc still have not changed traditional practices. international journal of environment issn 2091-2854 69 | p a g e fig. 5 respondents’ perception on changing agriculture practice (a) and crop diseases (b) fig. 6 people’s perception on productivity (cereal crops, pulses and mustard) trend of changing rainfall and temperature observed trend of yearly rainfall in different parts of kailali district of last 30 years was fluctuating between 967.1 mm to 2313 mm (total rainfall per year). the trend was decreasing from 1982 to 1997 in all three parts (tikapur, sadepani and godawari) and after that each five years mean of total annual rainfall/year shows either increasing or decreasing trends (table 3). fig. 7 shows the trend of rainfall of all three stations (tikapur, sadepani and godawari) of kailali district. international journal of environment issn 2091-2854 70 | p a g e table 3. difference in rainfall amount (5 years mean of total rainfall/year from 1982 to 2011) year total rainfall/year (mm) tikapur station difference sadepani station difference godawari station difference 1982-1986 1896.16 … 2099.2 … 2405.46 … 1987-1991 1706.52 -189.64 1974.1 -125.1 2306.36 -99.1 1992-1997 1377.7 -328.82 1663.38 -310.72 2229.06 -77.3 1997-2001 1863.1 485.4 2117.28 453.9 2537.4 308.34 2002-2006 1481.56 -381.54 1669.38 -447.9 1910.46 -626.94 2007-2011 1776.18 294.62 2244.66 575.28 2550.74 640.28 note: raw data obtained from tikapur, sadepani and godawari stations ( source: dhm) fig. 7. trend of rainfall in kailali district (total rainfall/year, source: dhm) regarding temperature, tikapur had experienced annual maximum temperature fluctuating between 28.75°c to 31.69 °c and minimum temperature between 12.17°c to 18.88°c during the period of last 30 years (1982 – 2011). whereas the record of godawari station near to dhangadhi and sahajpur shows that, the average annual maximum temperature was fluctuated between 27.8°c to 32.4 °c and minimum temperature between 16.5°c to 20.7°c. trend of average annual temperature of both stations showed increasing pattern from 1982 to 2001 while it was opposite since 2002 to 2011. five years mean temperature of 1987-1991 was greatly differed from the mean of 1982-1986 (1.11⁰c) in tikapur while decreasing differences are lesser than the increased difference (table 4). similarly, record of godawari station shows greater differences in five years mean between 1997-2001 and 1992-1996 international journal of environment issn 2091-2854 71 | p a g e (0.34⁰c) while decreasing difference was higher than the increased difference in 2002-2006 (table 4, fig. 8). comparison between the mean of 1982-1986 and 2007-2011 confirms that the temperature had been increased by 1.5⁰c in tikapur and 0.21⁰c in godawari. fig. 8 shows the trend of both maximum and minimum temperature in two stations (godawari and tikapur) of kailali district. table 4. difference in temperature (5 years mean of average temperature/year from 1982 to 2011) year tikapur station (temperature ⁰c) godawari station (temperature ⁰c) max min mean difference max min mean difference 1982-1986 29.80 15.46 22.63 … 29.59 19.80 24.70 … 1987-1991 30.24 17.25 23.74 1.11 30.01 19.59 24.80 0.11 1992-1996 30.52 17.46 23.99 0.25 30.48 19.72 25.10 0.29 1997-2001 30.28 18.02 24.15 0.16 30.89 19.98 25.44 0.34 2002-2006 30.54 17.77 24.15 0.00 30.20 19.67 24.94 -0.50 2007-2011 31.12 17.14 24.13 -0.02 30.87 18.95 24.91 -0.03 note: temperature (⁰ c); raw data obtained from tikapur and godawari stations (source: dhm) fig. 7. trend of temperature in kailali district (average temperature/year, max = maximum; min = minimum; source: dhm) file:///d:/lbt/nepal/research/nast%20final%20report/final%20report%20submitted/kaiali%20data%20(autosaved).xlsx%23sheet4!a50 file:///d:/lbt/nepal/research/nast%20final%20report/final%20report%20submitted/kaiali%20data%20(autosaved).xlsx%23sheet4!a50 international journal of environment issn 2091-2854 72 | p a g e discussion according to the results, most of respondents in the study area have noticed changes in climatic factors in comparison to past 2-3 decades. meteorological data of temperature before 2001 supports opinion of local people. still people perceived increasing trend of temperature might be due to access of modern facilities with extension of electricity in the villages. the data shows that rainfall was decreased since 1982 to 1997, which can coincide with respondents’ perception, but the fluctuating trend is shown from 1998-2011 which differ from peoples’ perception. similar trends of temperature and rainfall, and perceptions of local people were observed in various districts of nepal eg. in chitawan, rampur (paudel et al. 2014), banke and dang (devkota, 2014), kaski (timilsina-parajuli et al., 2014), doti and surkhet (bhandari, 2013), rupandehi (dahal et al., 2015); shankarpur vdc of kanchanpur and gadariya vdc of kailali (maharjan et al., 2011). the trend of temperature in whole country was increasing from 1975 to 2006 by 1.8⁰c and rainfall pattern was more erratic in the nepal (malla, 2008). in addition, peoples’ perception on other factors such as fog, hail and storm was not much conflicting. peoples’ perception and the trend of both temperature and rainfall in kailali district indicate that the district is also one of the vulnerable districts of nepal to climate change and climate change impacts on various sectors. peoples are wondering on decreasing natural vegetation, change in vegetation composit ion with decreasing or increasing certain plant species in their surrounding and natural habitats (table 1 and 2). the people accept that anthropogenic disturbances could be one important causes of decreasing vegetation but the disturbances have been contr olled since 10-15 years before and they have conserved forests as community forest with strict rules and regulations, however, they have not noticed reformation of vegetation with composition as it was in the past. it confirms that the changing climatic factors have influenced and altered vegetation composition. invasive alien species can be introduced intentionally or unintentionally and they have wide range of capabilities to spread and colonize novel habitats, which includes fast growth, self-compatibility, many seeds, and general habitat requirements etc (baker and stebbins, 1965; bates et al., 2013). the relationship of alien invasion and climate change is complex; even though, increased co2, temperature, and precipitation pattern help alien species to introduce to exotic range (dukes and mooney, 1999; bradley et al., 2010). invasive alien species, then affect native biota, genetic diversity, ecosystem process, crops and human health (didham et al., 2005; charles and dukes, 2007). the report of certain alien species such as a. adenophora, p. hysterophorus, l. camara, a. mexicana in the study area may create various problems in local environment and ecosystems. further studies are necessary to confirm the relationship of increasing alien species (table 2) or decreasing native species (table 1) with climate change. people’s perception on plant phenology could have great significance for future research and provide basis to find out climate change sensitive plant species through scientific investigations. local people observe closely the local environment, they can identify and interpret changes occurring in their surroundings as well as this knowledge can play a key role in shaping collective response to climate change (byg and salick, 2009). use of wild international journal of environment issn 2091-2854 73 | p a g e fruits by local people is common practices in the villages ( cunningham, 2001; shrestha and dhillion, 2006; thapa et al. 2014) and therefore the people every year get chance to observe flowering and fruiting events. it cannot be neglected that the introduced hybrid fruits might have changed peoples’ perception on phenology in comparison to local varieties but respondents claim that the local varieties have been showing changed phenological behavior since few decades. they suspect that the unexpected trend of climatic factors might have brought these changes in vegetation pattern and composition including plant phenology, and usually they discuss together in community level and conclude that these are common events of ‘kaliyug (age of demon)’. some previous studies also have reported similar shifting phenology in plants due to climate change around the world (hughes, 2000; hulme, 2005; parmesan, 2006; cleland et al., 2007; walther, 2010). the yield of cereal crops is correlated with the seasonal rainfall (bha ndari, 2014). the people’s agreement on changing agricultural practice in the study area such as fluctuation of planting time of crops due to unexpected drought and rainfall indicates that the farmers have achieved frequently negative and rarely positive benefits on crop production. similar to our study dahal et al. (2015) also reported that climate change decreases agricultural production in rupandehi district of nepal. in spite of peoples’ awareness on effect of chemical fertilizers and pesticides, they have no alternate of using chemical fertilizers and pesticides in agricultural lands as they have felt that the soil quality is reduced and, pests and diseases are increased. local people, especially indigenous communities have adopted indigenous knowledge and traditional means to cope with climate change impacts but this study shows people’s dependency on modern practices in the study sites. use of chemical fertilizers and pesticides without proper knowledge and awareness would increase risk of changing soi l quality and health hazards. the governmental bodies should implement programs such as training, awareness and education as well as monitoring and control pesticide trade, use and practice (tilahun and hussen, 2014). in conclusion, most of respondents in the study area have perceived increasing temperature, fog and storm as well as reduced and fluctuating rainfall and hail. the temperature has been increased by 0.21 to 1.5⁰c in comparison to past 25 year’s data which supports local people’s perception. changes in climatic factors have impacts on local vegetation, agriculture and people’s livelihood. increasing or decreasing certain plant species has increased risk of alien species invasion and endangerment or extinction of native species. peoples’ opinion indicates that there is relationship of increasing alien species and decreasing native species with climate change. in addition, change in phenology of some fruit plants is important sign of climate change. these findings have significance for future research and provide basis to find out climate change sensitive plant species through scientific investigations. acknowledgement nepal academy of science & technology (nast), khumaltar, lalitpur, nepal is acknowledged for financial support and we are grateful to prof. dr. p. k. jha, head, central department of botany, tribhuvan university, kathmandu, nepal for encouragement. international journal of environment issn 2091-2854 74 | p a g e references baker, h.g. and stebbins, g.l., 1965. the genetics of colonizing species: proceedings of the first international union of biological sciences symposia on general biology. academic press. 588 pp. bates, a.e., mckelvie, c.m., sorte, c.j., morley, s.a., jones, n.a., mondon, j.a, bird, t.j. and quinn, g., 2013. geographical range, heat tolerance and invasion success in aquatic species. proceedings of the royal society of london b: biological sciences, 280(1772), 20131958. doi: 10.1098/rspb.2013.1958 bhandari, g., 2013. trends in seasonal precipitation and temperature-a review in doti and surkhet districts of nepal. international journal of environment, 2(1), 269-279. doi: 10.3126/ije.v2i1.9227 bhandari, g., 2014. effect of rainfall on the yield of major cereals in darchula district of nepal. international journal of environment, 3(1), 205-213. bradley, b.a., blumenthal, d.m., wilcove, d.s. and ziska, l.h., 2010. predicting plant invasions in an era of global change. trends in ecology & evolution, 25(5), 310-318. doi: 10.1016/j.tree.2009.12.003. byg, a. and salick, j., 2009. local perspectives on a global phenomenon -climate change in eastern tibetan villages. global environmental change, 19(2), 156-166. doi: 10.1016/j.gloenvcha.2009.01.010. cbs, nepal, 2012. national population and housing census 2011. national report. thapathali, kathmandu, nepal. vol. 01, 262 pp. chaudhary, p. and bawa, k.s., 2011. local perceptions of climate change validated by scientific evidence in the himalayas. biology letters, rsbl20110269. cleland, e.e., chuine, i., menzel, a., mooney, h.a. and schwartz, m.d., 2007. shifting plant phenology in response to global change. trends in ecology & evolution, 22(7), 357-365. doi: 10.1016/j.tree.2007.04.003. crona, b., wutich, a., brewis, a. and gartin, m., 2013. perceptions of climate change: linking local and global perceptions through a cultural knowledge approach. climatic change, 119(2), 519-531. doi: 10.1007/s10584-013-0708-5. cunningham, a.b., 2001. applied ethnobotany: people, wild plant use and conservation. earthscan publications ltd, london and sterling, verginia, usa. xviii + 300 pp. dahal, k.r., manandhar, m. and sharma, c.m., 2015. people’s perception on impact of climate change in paschim amawa and tikuligadh village development committee (vdc) of rupandehi district, nepal. international journal of environment, 4(1), 141160. doi: 10.3126/ije.v4i1.12185 devkota, r.p., 2014. climate change: trends and people’s perception in nepal. journal of environmental protection, 5(4), 255-265. doi: 10.4236/jep.2014.54029. didham, r.k., tylianakis, j.m., hutchison, m.a., ewers, r.m. and gemmell, n.j., 2005. are invasive species the drivers of ecological change? trends in ecology & evolution, 20(9), 470-474. doi: 10.1016/j.tree.2005.07.006. dukes, j.s. and mooney, h.a., 1999. does global change increase the success of biological invaders?. trends in ecology & evolution, 14(4), 135-139. doi: 10.1016/s01695347(98)01554-7. international journal of environment issn 2091-2854 75 | p a g e hughes, l., 2000. biological consequences of global warming: is the signal already apparent?. trends in ecology & evolution, 15(2), 56-61. doi: http://dx.doi.org/10.1016/s0169-5347(99)01764-4. hulme, p.e., 2005. adapting to climate change: is there scope for ecological management in the face of a global threat?. journal of applied ecology, 42(5), 784-794. doi: 10.1111/j.1365-2664.2005.01082.x. maharjan, s.k., sigdel, e.r., sthapit, b.r. and regmi, b.r., 2011. tharu community's perception on climate changes and their adaptive initiations to withstand its impacts in western terai of nepal. international ngo journal 6(2), 035-042. doi: 10.5897/ngo10.003. malla, g., 2009. climate change and its impact on nepalese agriculture. journal of agriculture and environment, 9, 62-71. doi: http://dx.doi.org/10.3126/aej.v9i0.2119 new, m., todd, m., hulme, m. and jones, p., 2001. precipitation measurements and trends in the twentieth century. international journal of climatology, 21(15), 1889-1922. doi: 10.1002/joc.680. parmesan, c., 2006. ecological and evolutionary responses to recent climate change. annual review of ecology, evolution, and systematics, 637-669. paudel, b., acharya, b.s., ghimire, r., dahal, k.r., and bista, p., 2014. adapting agriculture to climate change and variability in chitwan: long-term trends and farmers’ perceptions. agricultural research, 3(2), 165-174. doi: 10.1007/s40003-014-0103-0. perry, a.l., low, p.j., ellis, j.r. and reynolds, j.d., 2005. climate change and distribution shifts in marine fishes. science, 308(5730), 1912-1915. doi: 10.1126/science.1111322. shrestha, a.b., wake, c.p., mayewski, p.a. and dibb, j.e., 1999. maximum temperature trends in the himalaya and its vicinity: an analysis based on temperature records from nepal for the period 1971-94. journal of climate, 12(9), 2775-2786. doi: 10.1175/15200442(1999)012 shrestha, p. m. & dhillion, s. s. 2006. diversity and traditional knowledge concerning wild food species in a locally managed forest in nepal. agroforestry systems, 66(1), 55-63. doi: 10.1007/s10457-005-6642-4. shrestha, u.b., gautam, s. and bawa, k.s., 2012. widespread climate change in the himalayas and associated changes in local ecosystems. plos one, 7(5), e36741. doi: 10.1371/journal.pone.0036741. solomon, s., qin, d., manning, m., chen, z., marquis, m., averyt, k.b., tignor, m. and miller, h.l., 2007. climate change 2007: working group i: the physical science basis. cambridge, uk: cambridge university press. 996 pp. thapa, l.b., dhakal, t.m. and chaudhary, r., 2014. wild edible plants used by endangered & indigenous raji tribe in western nepal. international journal of applied sciences and biotechnology, 2(3), 243-252. doi: http://dx.doi.org/10.3126/ijasbt.v2i3.10969. tilahun, b. and hussen, a., 2014. assessment of pesticide use, practice and risk in gedeo and borena zones; ethiopia. international journal of environment, 3(3), 201-209. timilsina-parajuli, l., timilsina, y. and parajuli, r., 2014. climate change and community forestry in nepal: local people’s perception. american journal of environmental protection, 2(1), 1-6. doi: 10.12691/env-2-1-1. http://dx.doi.org/10.1016/s0169-5347(99)01764-4 http://dx.doi.org/10.3126/ijasbt.v2i3.10969 international journal of environment issn 2091-2854 76 | p a g e tiwari, k.r., awasthi, k.d., balla, m.k. and sitaula, b.k., 2010. local people’s perception on climate change, its impact and adaptation practices in himalaya to terai regions of nepal. himalayan journal of development and democracy, nepal study center, the university of mexico, us 5: pp 56-63. walther, g.r., 2010. community and ecosystem responses to recent climate change. philosophical transactions of the royal society of london b: biological sciences, 365(1549): 2019-2024. doi: 10.1098/rstb.2010.0021. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 41 | p a g e international journal of environment volume-3, issue-1, dec-feb 2013/14 issn 2091-2854 received:14 december revised:24 january accepted: 28 january fluoranthene induced changes in photosynthetic pigments, biochemical compounds and enzymatic activities in two microalgal species: chlorella vulgaris beijerinck and desmodesmus subspicatus chodat miral patel¹*, nirmal kumar j.i.² and k.k.tiwari 3 1,3 sophisticated instrumentation center for applied research and testing (sicart), vallabh vidya nagar, gujarat india388 120 2 p.g. department of environmental science and technology, institute of science and technology for advanced studies and research (istar), vallabh vidya nagar, gujarat india388 120 *corresponding author: miral24@gmail.com abstract the photosynthetic pigments, biochemical and enzymatic activities in two freshwater microalgal species, chlorella vulgaris and desmodesmus subspicatus at different fluoranthene concentrations were compared with the control conditions. during 16-days of incubation period when treated with fluoranthene, both microalgal species exhibited variable amount of photosynthetic pigment, biochemical compounds and enzymatic activities. the addition of fluoranthene at concentrations ranged from 1.5 mg l¯¹ to 10 mg l¯¹ to microalgal cultures led to changes in all different metabolites but the patterns varied from species to species. among the two species tested, pigment, biochemical and enzymatic contents were remarkably declined from 7 % to 95% in c. vulgaris. moreover, all metabolites in d. subspicatus also diminishing significantly by 3% to 88% of fluoranthene doses (10ppm). these results suggest that fluoranthene-induced changes of pigments, biochemical and enzymatic variations in test microalgae, d. subspicatus and c. vulgaris, might reveal its resistance and ability to metabolize pahs. at the same time, the pah impact changes on different metabolic activities were higher at 12 and 16 days than at 4 and 8 days in treated microalgae. keywords: fluorathene, microalgae, pigments, biochemical compounds, enzymes. mailto:miral24@gmail.com international journal of environment issn 2091-2854 42 | p a g e introduction diversity of indigenous microorganisms capable of degrading pollutants such as crude oil, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in different environments (kanaly et al., 2003; kasai et al., 2001) was taken into consideration recently. pahs are acting as carcinogens, mutagens, and endocrine disruptors to a variety of aquatic organisms, (pittinger et al., 1987; hellou et al., 2006). identification of the key organisms that play a role in pollutant degradation processes is relevant to the development of optimal in situ bioremediation strategies. contamination of pahs in the environment is a serious public health problem and is of increasing concern. most pahs in aquatic systems are associated with natural particulate and dissolved organic matter (wakeham and farrington, 1980). the major sources of pahs are derived anthropogenically from pyrolysis and combustion processes and spillage of petroleum hydrocarbons (kennish, 1998). microalgae are essential constituents of aquatic ecosystem since they are the first trophic level in the food chains and the major organism providing oxygen and organic substances to other life forms. algae are essential components of the aquatic ecosystems and their contribution to the degradation and detoxification of recalcitrant pahs and their potential mutagenic intermediates must be considered. the remediation of pahs contaminated water using microalgae has received great attention in last few decades. during the degradation processes of pahs , the response of photosynthetic pigment, biochemical and enzymatic activities of microalgal species towards pahs treatments have not been investigated yet, therefore, in the present study , authors focused light on flouranthene induced changes on photosynthetic pigments, biochemical and enzymatic activities of two microalgal species: chlorella vulgaris beijerinck and desmodesmus subspicatus chodat which are dominant and widely distributed algal species in freshwater environments. material and method strain selection the axenic cultures of microalgae chlorella vulgaris beijerinck and desmodesmus subspicatus chodat were obtained from the central marine and salt research institute, bhavnagar, india. the growth media selected for microalgae c. vulgaris was develop in zarrouks (1996) medium and for d. subspicatus slight modified bg 11 media (rippika,1988) under controlled illumination of 40μem-2s-1 at 27±1°c in aerobic and static conditions. as this species is non-heterocyst forming algae, nitrogen source was supplemented artificially to bg 11 media. all inoculations were carried out under aseptic conditions and the cultures were periodically checked for any contamination. polycyclic aromatic hydrocarbon-fluoranthene fluoranthene is a polycyclic aromatic hydrocarbon (pah) consisting of naphthalene and a benzene unit connected by a five-membered ring. its name is derived from its fluorescence under uv light. fluoranthene is found in many combustion products, along with other pahs. its presence is an indicator of less efficient or lower-temperature combustion, since nonalternant pahs are less preferred in formation than alternant pahs. fluoranthene has been classified by the international agency for research on cancer as a group 3 carcinogen, "not classifiable as to its carcinogenicity to humans, however it was found to possess carcinogenic international journal of environment issn 2091-2854 43 | p a g e properties in case of newborn mice according to short-term lung tumor assay (busby et al., 1989). dose selection and inoculation on the basis of a series of experiments for lc50, the effective doses were resulted in table i. table i: lc50 values species lower lc50 lc50 higher lc50 c. vulgaris 1.25ppm 2.5ppm 5.0ppm d. subspicatus 2.5ppm 5.0ppm 10ppm fluoranthene stock solution of 200 µg mlˉ¹ was prepared in hplc grade acetone. exponentially growing 2.0ml of the culture was inoculated to each effective dose and made up to 20.0 ml. for each experiment, the solution of fluoranthene was prepared fresh. all solvents and chemical used in this experiment were hi-media and merck made. milli-q water was used throughout the whole experiment. all the spectrophotometer readings were taken in uv-vis spectrophotometer, made perkin elmer, model lambda 19. samples were taken at every four days interval up to 16 days with the set of three replicates. photosynthetic pigments measurement: chlorophyll a, b and carotenoids were extracted in 80% acetone and determined spectrophotometrically by measuring the absorbance at 663, 645, 630 and 480 nm, respectively (jeffrey and humphrey, 1975; parsons and strickland, 1963). phycobillin protein content was extracted in 50mm potassium phosphate buffer (ph 7.0) after repeated freezing and thawing and measured at 562, 615 and 652 nm, respectively (bennett and bogorad, 1973). biochemical compounds estimation: the total carbohydrates, proteins, amino acids and phenols were extracted in 80% ethanol. carbohydrates were estimated by the method of hedge and hofreitte (1991), protein estimation was done by lowry et al (1951), the total amino acids was performed by measured by lee and takahanshin, (1966) and phenols estimation was carried out as per malick and singh (1980). enzyme assays: nitrate reductase enzyme was extracted using cysteine buffer (ph 8.8). the enzyme activity was assayed spectrophotometrically given by sempruch et al, (2008). glutamine synthetase enzyme was extracted in tris hcl buffer (ph 7.5). the enzyme assay was determined by a slight modification of the method described by yuan et al, (2001) and spectrophotometrically read at 540nm. the estimation of in-vivo succinate dehydrogenase (sdh) activity was measured by the method of kun and abood (1949). results the ability to reduce the high molecular weight hydrocarbon by microalgae, chlorophyll has been identified as key compound in order to evaluate the growth capability in presence of pahs (fluoranthene). total chlorophyll concentrations (chlorophyll a and b) reduction showed a little effect in all treatments over the early days of experiment (fig.1). a loss of chlorophyll-a in c. vulgaris was observed on 8 th day by 15%, 22% and 25% for 1.5ppm, 3ppm and 6ppm respectively and was consistently decreased upto 16 th day by 78%, 81% and 86%. whereas chlorophyll b followed the similar trend which shown that the inhibitory rates were reached the maximum value on day 16 th day to all three doses of the high molecular weight fluoranthrene. international journal of environment issn 2091-2854 44 | p a g e moreover, inhibitory effect of d.subspicatus by fluoranthene increased from the first and then continued through the time of experiment. the doseresponse on chlorophyll-a content declined by 18% at 2.5ppm followed by 27% at 5ppm and ceased to by 48% at 10 ppm on 8 th day as compared to control. chlorophyll-b content in d.subspicatus also reduced by 0.0069±0.00075 mg ml⁻²⁰ on 4 th day to 0.0049±0.00056 mg ml⁻²⁰ on 16 th day. the utmost drop in chlorophyll-a content was recorded in d.subspicatus by 78% at 10 ppm, pursued by c.vulgari by 86% at 6 ppm at the end of 16th day. fig. 1 (a and b) response on chlorophyll (a,b and total) content of c. vulgaris and d. subspicatus to fluoranthene. (data were the mean values and standard deviations of three replicates.) international journal of environment issn 2091-2854 45 | p a g e fig. 2 (a and b) response on carotenoids content of c. vulgaris and d. subspicatus to fluoranthene. (data were the mean values and standard deviations of three replicates.) fig. 3 and 4 (a) response on phycocyanin content of c. vulgaris and d. subspicatus to fluoranthene. (data were the mean values and standard deviations of three replicates.) international journal of environment issn 2091-2854 46 | p a g e fig. 3 and 4 (b) response on allophycocyanin content of c. vulgaris and d. subspicatus to fluoranthene. (data were the mean values and standard deviations of three replicates.) fig. 3 and 4 (c) response on phycoerythrene content of c. vulgaris and d. subspicatus to fluoranthene. (data were the mean values and standard deviations of three replicates.) carotenoids decreased significantly over 16 days of the experiment in pahs treatments (fig.2a and 2b) the carotenoids reduced by 16%, 19% and 24% in the treatments of 1.5, 3 and 6 ppm on 4 th day in c. vulgaris, whereas it declined by 8%, 16%, and 22% at the doses of 2.5 ppm, 5 ppm and 10 ppm in d. subspicatus. the c. vulgaris continued to reduced and reached maximum value of 0.050±0.0040 mg ml⁻²⁰ on 16 th day. while in d. subspicatus the fall of carotenoids reached to 0.016±0.005 mg ml⁻²⁰ at 16 th day by 98% at 10ppm than percentage decrease in c. vulgaris by 86% in 6ppm. the decline in the phycobilliprotein in response to increasing exposure periods (days) was more conspicuous and highly significant at higher doses as compared with lower doses. the phycobiliproteins (phycocyanin, allophycocyanin, and phycoerythrin) of the organism dropped continuously with increasing pahs concentrations. the percentage reductions at the highest fluoranthene concentration (10 ppm) in c. vulgaris (6 ppm) were 93%, 95% and 91% by the end of 16 days (fig.3a,3b and 3c), on the other hand, in d. subspicatus (fig 4a, 4b and 4c) percentage international journal of environment issn 2091-2854 47 | p a g e reductions were reclined by 92%, 93% and 61% in phycocyanin, allophycocyanin, and phycoerythrin, respectively. the total carbohydrate contents of d. subspicatus cultures were gradually started to decrease, when the algal cultures subjected to lower level (2.5 and 5 µg ml⁻¹) to a higher dose of the pahs (fig 5a and 5b). under high pahs concentration, in 4 th day c. vulgaris at 6 ppm reduced the carbohydrate content to 0.74±0.055 mg/ml⁻²⁰ whereas d. subpicatus showed declined value of 0.48±0.062 mg ml⁻²ᴼ at 10 ppm. the values recorder after 16 days showed a great reduction in carbohydrate content. the carbohydrate contents were depressed by 86% at 10 ppm in d. subspicatus followed by 91% in c. vulgaris at 6 ppm. the protein contents showed significant effect with the escalation of pahs levels in the medium cultures at initial stage among both the algal species (fig 6a and 6b). between 4 and 8 days, percentage decline of protein from c. vulgaris was 61% to 83% at 6ppm and for d. subspicatus, reduction was 33% to 66% at 10 ppm respectively. at later stage of the experiment, the protein content was 0.0434± 0.0059 mg ml⁻²⁰ at 6 ppm in c. vulgaris, where d. subpicatus showed reduction value of 0.0284±0.0041 mg ml⁻²⁰ at 10ppm. fig. 5 a and b response on carbohydrate content of c. vulgaris and d. subspicatus by fluoranthene. (data were the mean values and standard deviations of three replicates). fig. 6 a and b response on protein content of c. vulgaris and d. subspicatus by fluoranthene. (data were the mean values and standard deviations of three replicates.) international journal of environment issn 2091-2854 48 | p a g e fig.7a and b response on amino acid content of c. vulgaris and d. subspicatus by fluoranthene. (data were the mean values and standard deviations of three replicates.) fig. 8 a and b response on phenol content of c. vulgaris and d. subspicatus by fluoranthene. (data were the mean values and standard deviations of three replicates.) the total amino acid reduction from both algae was determined by the difference between the control and the different pahs doses. c. vulgaris showed no such significant amount of reduction in amino acid content. the amino acid value at initial stage in c. vulgaris was 0.690±0.060, 0.657±0.037 and 0.627±0.047 mg/ml⁻²⁰ (day 4) with different lc50 values, while in d. subspicatus , it showed lightly raised by 0.54±0.047, 0.44±0.046 and 0.36±0.055 mg ml⁻²ᴼ respectively. at 12th day, c. vulgaris showed immense decrease in amino acid by 58%, 68% and 79% and continued the suppressed at 16 th day with 80%, 85% and 89% (fig. 8a and 8b). same as in d. subspicatus, amino acid reduction at 16 th day by 90%, 94% and 95% with respective doses. phenol content in respective to treated cells of c. vulgaris and d. subspicatus as compared to the control increased from 8th day onwards with respect to higher concentrations of the fluoranthene as well as exposure periods (fig. 8a and 8b). phenol content in the two species, c. vulgaris (95%) and d. subspicatus (98%) exhibited a relative increase at 16 th day at 6 μg ml⁻¹ and 1.5 μg ml⁻¹ concentrations of the pahs. international journal of environment issn 2091-2854 49 | p a g e an incubation period of up to 16 days, the enzymatic assay was constant showing decreasing linearity. at the preliminary stage nitrate reductase of c. vulgaris showed 0.70±0.071 mg ml⁻²⁰ by 7% decrease and 0.34±0.047 mg ml⁻²⁰ by 3% in d. subspicatus at 1.5ppm and 2.5ppm respectively compared to other doses. maximal nr reduction was observed at 16 th day by 88% in d. subspicatus and 93% in c. vulgaris at 6 µg ml⁻¹ and 10 µg ml⁻¹ respectively (fig 9a and 9b). glutamine synthetase (gs) enzyme showed a sharp reduction by 38% and 68% in c. vulgaris and d. subspicatus respectively after 4th day. the reduction percentage increased by 87%, 88%, and 89% at the end of 16 th day in d. subspicatus on the other hand c. vulgaris showed fall of gs avtivity by 83%, 91% and 92% at 1.5, 3.0 and 6.0 ppm respectively. the treatment of these pahs lowered the sdh activities of d. subspicatus by 59, 67, and 75 % at 16 days while in disparity in c. vulgaris showed a reduction of 70%, 76% and 83% at 1.5, 3.0 and 6 ppm after 16days (fig 11a and 11b). fig. 9 a and b response on nitrate reductase activity of c. vulgaris and d. subspicatus by fluoranthene. (data were the mean values and standard deviations of three replicates.) fig. 10 a and b response on glutamine synthetase activity of c. vulgaris and d. subspicatus by fluoranthene (data were the mean values and standard deviations of three replicates.) international journal of environment issn 2091-2854 50 | p a g e fig. 11 a and b response on succinate dehydrogenas activity of c. vulgaris and d. subspicatus by fluoranthene (data were the mean values and standard deviations of three replicates.) discussion the effect of two pahs on microalgal populations has been considered to be inhibitory at high doses (panigrahi et al., 2003). data obtained in the present investigation revealed that both the strains were more susceptible to pahs. in present study, the effect has been considered to be inhibitory at higher doses to both the microlagal species. soto et al. (1975) reported that high percentages of chlamydomonas angulosa, a green microalgal species, inoculated in a medium saturated with naphthalene were killed but the remaining live cells could restore their growth when naphthalene in the medium gradually reduced through evaporation. according to moradi and ismail (2007), reduced chlorophyll contents at higher salinities are due to decrease in photosynthetic rate because of salt osmotic and toxic ionic stress. bricker and newman, (1982) also stated the decline in chlorophyll might be attributed to the earlier structural loss of photosystem i as compared to photosystem ii). bidwell (1979) reported that chlorophyll-b is formed due to oxidation of the methyl group ring ii to the aldehydes from chlorophyll-a, this could be the reason that chlorophyll b content more than chlorophyll a. the results are also in consonance with the deleterious effects of clotrimazole fungicides on chlrophyll-a, carotenoids, and phycobiliproteins within marine microalgal communities (porsbring et al., 2009). the phycocyanin content in fluoranthene treated cultures was more adversely affected than chlorophyll. mostafa and helling, (2002) suggested that decrease in chlorophyll-a, carotenoid and phycobiliprotein contents might be ascribed to the inhibition of pigment synthesis directly by the insecticide or accelerated degradation of pigments due to increased active oxygen species (aos ) formation at various sites of the photosynthetic electron transport chain during stress. the retardation in the carbohydrate content might be due to interference of chemicals with photosynthesis process (padhy, 1985). nirmal kumar (1991) reported the inhibition of sugar contents of the algae by accelerating doses of substituted urea herbicide n-(4-isopopylphenyl) n, n-dimethyl urea and stated that this retardation might be due to the interference of chemicals during photosynthetic process, which ultimately lapse the production of net gain of carbohydrates. thiel (1990) emphasized that decrease in protein content in anabaena variabilis was observed in starved cells. it could be suggested that accumulation of protein at low pahs international journal of environment issn 2091-2854 51 | p a g e concentrations may be one of the ways through which the algae can abolish their toxic effects, or to increase respiration leading to the utilization of carbohydrate in favor of protein accumulation. similar observations were recorded by nirmal kumar et al. (2008) on treatment of tolypothrix tenuis with fertilizer industrial effluents. mallick and rai (1994) stated that increase in phenols could be due to the possible conversion of primary metabolites into phenols as well as accumulation of detoxicants of fungicide during stress conditions. similar observations were also made by nirmal kumar et al (2010) using fungicide. the decrease in the nitrate reductase enzyme also simultaneously indicated a fall in the nitrogen fixing ability of anabaena sp. (nirmal kumar et al., 2009). glutamine synthetase (gs) activity also expressed a concentration dependent inhibition when treated with the fluoranthene (fig 10a and 10b) which has also been further supported by rajendran et al. (2007) expressing a remarkable decrease in the gs activity to different pesticide concentrarions. succinate dehydrogenase (sdh) enzyme is a major respiratory enzyme responsible for conversion of succinate to fumarate in the tricarboxylic acid cycle (tca). similar inhibition of the enzyme succinate dehydrogenase activity was observed in the cultures of four gram(+) bacteria, rhodococcus sp. ak 1, bacillus cereus frankland & frankland, bacillus subtilis (ehrenberg) cohn, nocardia asteroides and a gram(-) bacterium, rhizobium leguminosarum when treated with the fungicide tridenmorph by kalam and banerjee (1995). statistical analysis anova: all the parameters found to be nonsignificant (p>0.05) between the pigments, metabolites, enzymatic activities and concentrations applied (table 1). correlation matrix: a noteworthy positive correlation between pigments (r =0.711 to 0.988), metabolites [r = (-562) to 0.972] and enzymes [ r = (-0.735) to r = 0.981] were recorded in c. vulgaris, moreover, in case of d. subspicatus also a positive correlation was recorded between pigments(r = 0.876 to r = 0.981), metabolites[r = (-0.572) to r = 0.992)] and enzymes [r = (0.623) to r = 0.971] except with phenol content after 16th day exposure to fluoranthene (table 2 and 3). table ii: one way analysis of variance (anova) of c. vulgaris and d. subspicatus with reference to biochemical parameters (pigments, metabolites and enzymes) of control and three graded concentrations of fluoranthene after 16 days of incubation parameters chlorella vulgaris desmodesmus subspicatus f(cal) p(f<=f(cal)) f(0.05) f(cal) p(f<=f(cal)) f(0.05) total chlorophyll 1.071 n.s. (p>0.05) 0.397 0.655 n.s. (p>0.05) 0.595 carotenoids 0.059 n.s. (p>0.05) 0.980 0.079 n.s. (p>0.05) 0.969 phycobilliproteins 6.328 *** (p<=0.001) 1.073 1.331 n.s. (p>0.05) 0.247 carbohydrate 0.756 n.s. (p>0.05) 0.539 0.321 n.s. (p>0.05) 0.809 protein 0.124 n.s. (p>0.05) 0.943 0.145 n.s. (p>0.05) 0.930 amino acid 2.179 n.s. (p>0.05) 0.1433 0.050 n.s. (p>0.05) 0.984 phenol 2.760 n.s. (p>0.05) 0.088 2.199 n.s. (p>0.05) 0.140 nitrate reductase 0.042 n.s. (p>0.05) 0.987 0.051 n.s. (p>0.05) 0.983 international journal of environment issn 2091-2854 52 | p a g e succinate dehydrogenase 0.510 n.s. (p>0.05) 0.682 0.359 n.s. (p>0.05) 0.783 glutamine synthetase 2.519 n.s. (p>0.05) 0.107 0.138 n.s. (p>0.05) 0.935 table iii corellation matrix of chlorella vulgaris with defferent compounds *chlo=total chlorophyll, car=carotenoids, pc=phycocyanin, apc=allophycocyanin, pe=phyceorythrene, cho=carbohydrate, aa=amino acid, nr=nitrate reductase, sd=succinate dehydrogenase, gs=glutamine synthetase chlo car pc apc pe cho protein aa phenol nr sd gs chlo 1 car 0.892612 1 pc 0.826677 0.916496 1 apc 0.839677 0.933013 0.985596 1 pe 0.752849 0.907148 0.711557 0.732952 1 cho 0.856418 0.938338 0.972132 0.965088 0.777127 1 protein 0.792245 0.953932 0.855616 0.873669 0.944586 0.893836 1 aa 0.860097 0.862236 0.942148 0.92117 0.645042 0.954895 0.74878 1 phenol -0.90021 -0.80587 -0.86913 -0.85739 -0.56271 -0.87041 -0.65105 -0.94663 1 nr 0.821364 0.959203 0.912787 0.913544 0.85276 0.904061 0.943101 0.791296 -0.73526 1 sd 0.877926 0.926813 0.981303 0.978719 0.734845 0.969741 0.874038 0.923815 -0.88461 0.927083 1 gs 0.882959 0.812147 0.876034 0.849734 0.583623 0.864421 0.668184 0.944186 -0.95832 0.734058 0.86785 1 table iv corellation matrix of desmodesmu subspicatus with defferent compounds *chlo=total chlorophyll, car=carotenoids, pc=phycocyanin, apc=allophycocyanin, pe=phycoerythrene, cho=carbohydrate, aa=amino acid, nr=nitrate reductase, sd=succinate dehydrogenase, gs=glutamine synthetase parameters chlo car pc apc pe cho protein aa phenol nr sd gs chlo 1 car 0.876753 1 pc 0.897879 0.933408 1 apc 0.896522 0.93435 0.999957 1 pe 0.981346 0.919847 0.916782 0.915735 1 cho 0.967489 0.941449 0.930945 0.92996 0.991047 1 protein 0.803417 0.984423 0.908303 0.910361 0.855397 0.880401 1 aa 0.887022 0.992979 0.944453 0.945649 0.9206 0.936847 0.983096 1 phenol -0.84993 -0.66695 -0.66543 -0.6639 -0.81004 -0.78519 -0.572 -0.68233 1 nr 0.901991 0.971545 0.957174 0.958232 0.933569 0.947587 0.959891 0.971853 -0.66815 1 sd 0.967931 0.832488 0.917096 0.916289 0.938747 0.92369 0.770467 0.853995 -0.79495 0.888501 1 gs 0.914563 0.884914 0.956369 0.955023 0.919934 0.931163 0.839193 0.881641 -0.62338 0.928818 0.927875 1 conclusion experiments were conducted with a view to determining the deleterious and differential effects of fluoranthene on the photosynthetic pigments, metabolic and enzymatic activities of microalgea. the results suggest that desmodesmus subspicatus was the most international journal of environment issn 2091-2854 53 | p a g e susceptible organism to fluoranthene studied. the order of pah tolerance of each organism towards the fluoranthene can be described as d. subspicatus being more tolerant than c. vulgaris. the present results also suggest that pigments, metabolites and enzymes are positively correlated with each other but not with phenolic content of both the microalgae. acknowledgement authors are highly acknowledge sicart for providing instrumentation as well as laboratory facility to carry reserch work. references bennett, a. and bogorad, l., 1973. complementary chromatic adaptation in a filamentous blue-green alga. j. cell biol. 58:419-435. bidwell, r. g. s., 1979. plant physiology (2nd ed.). macmillan, london. botany,53: 109-117. bricker, t. m., newman, d. w., 1982. changes in the chlorophyll protein and electron transport activities of soybean cotyledon chloroplast during senescence. photosynthesis, 16: 239–244. busby, w.f.j., 1989. comparative lung tumorigenicity of parent and mononitro-polynuclear aromatic hydrocarbons in the blu:ha newborn mouse assay. toxicology and applied pharmacology, 99: 555–563. mostafa, f.i., and helling, c.s., 2002. impact of four pesticides on the growth and metabolic activities of two photosynthetic algae. j. environ. sci. health.,vol. 37, pp. 417444. hedge, j. e. and hofreitte, b. t., 1991. carbohydrate chemistry. in sadasivam, s & manickam, a. (eds), biochemical methods for agriculture sciences. wiley estern ltd. pub, pp. 8. hellou, j., leonard, j., collier, t. k., ariese, f., 2006. assessing pah exposure in feral finfish from the northwest atlantic. marine pollution bulletin, 52 (4), 433-441. jeffrey, s. w. and humphrey, g.f., 1975. new spectrophotometric equations for determining chlorophylls a, b, c1 and c2 in higher plants, algae and natural populations. biochem. physiol. pflanzen. 167: 191-194. kalam, a. and banerjee, a.k., 1995. action of the fungicide tridemorph on the glucose, lactate and succinate dehydrogenase activities of some tridemorph-sensitive and -resistant bacteria. pest sci 43(1): 41-45. kanaly, r. a., bartha, r., watanabe, k. and harayama, s., 2000. rapid mineralization of benzo[a] pyrene by a microbial consortium growing on diesel fuel. appl. environ. microbiol. 66:4205–4211. kasai, y., kishira, h., syutsubo, k., and harayama, s., 2001. molecular detection of marine bacterial populations on beaches contaminated by the nakhodka tanker oil-spill accident. environ. microbiol. 3:246–255. kennish, m.j. (ed.), 1998. pollution impacts on marine biotic communities, crc press, boca raton, p. 310. international journal of environment issn 2091-2854 54 | p a g e kun, e., abood, l.g., 1949. colorimetric estimation of succinic dehydrogenase by triphenyl tetrazolium chloride. science, 109 (2824):144-146. lee, y . and takahanshin, t., 1966. an imported colorimetric determination of amino acids with the use of ninhydrin. anal biochem., 14, 71-77. lowry ,o h., rosenbrough, n h., farr, a l. & randall, r j., 1951. protein measurements with folinphenol reagent. j. biol. chem., 193, 265-275. malick, c p. & singh, m. b, 1980. plant enzymology and histo enzymology. kalyani publishers, new delhi, pp. 286. mallick, n. and rai, l c., 1994. kinetic studies of mineral uptake and enzyme activities of microbial population changes during bioremediation of an experimental oil spill. appl. environ. microbiol. 65:3566–3574. moradi, m. and ismail, a.m., 2007. responses of photosynthesis, chlorophyll fluorescence and ros – scavenging systems to salt stress. during seedling and reproductive stages of rice. ann. botany 99:1161-1173. mostafa, f.i, and helling, c.s., 2002. impact of four pesticides on the growth and metabolic activities of two photosynthetic algae. j environ sci health 37: 417-444. nirmal kumar j.i., kumar rita n., bora anubhuti and manmeet kaur amb., 2009. photosynthetic, biochemical and enzymatic investigation of anabaena fertilissima in response to an insecticide-hexachloro-hexahydromethano-benzodioxathiepineoxide. journal of stress physiology & biochemistry, vol. 5, no. 3, pp. 4-12 issn 1997-0838. nirmal kumar j.i., rita kumar n., ira bhatt., 2008. metabolic response and nutrient removal by tolypothrix tenuis (kutz.) from fertilizer industrial effluent. jr. of industrial poll. control 24 (1) 69-74. nirmal kumar j.i., 1991. response of anabaena sp. 310 to isoproturon. j ind bol soc 70: 277280. nirmal kumar, j. i., anubhuti bora, and manmeet kaur amb., 2010. chronic toxicity of the triazole fungicide tebuconazole on a heterocystous, nitrogen-fixing rice paddy field cyanobacterium, westiellopsis prolific janet j. microbiol. biotechnol. 20(7), 1134–1139. padhy, r.n., 1985. cyanobacteria and pesticides. residue rev. 95:1–44. panigrahi, s., padhy, s., padhy, r. n., 2003. toxicity of parathion-methyl to cells, akinetes and heterocysts of the cyanobacterium cylindrospermum sp. and the probit analysis of toxicity. annu. appl. biol. 143:195–199. parsons, t.r. and strickland, j.d., 1963. discussion of spectrophotometric determination of marine plant pigments with revised equations for ascertaining chlorophylls and carotenoids. j. mar. res. 21: 155-163. pittinger, c. a., buikema, a. l., falkinham, j.o., 1987. in situ variations in oyster mutagenicity and tissue concentrations of polycyclic aromatic hydrocarbons. environmental toxicology and chemistry, 6, 51-60. porsbring, t., blanck, h., tjellström, h., and backhaus, t., 2009. toxicity of the pharmaceutical clotrimazole to marine microalgal communities. aquat. toxicol. 91: 203-211. international journal of environment issn 2091-2854 55 | p a g e rajendran, u.m., kathirvel, e., narayanaswamy, a., 2007. effects of a fungicide, an insecticide, and a biopesticide on tolypothrix scytonemoides. pesticide biochemistry and physiology, 87(2), 164-171. rippka r., 1988. isolation and purification of cyanobacteria, methods enzymol, 167, pp. 3–27. sempruch, c., ciepiela, a. p., sprawka,i., chrzanowski, g., 2008. purification and some physicochemical properties of nitrate reductase isolated from winter triticale seedlings. electronic journal of polish agricultural universities, 11(1) soto, c., hellebust, j. a., hutchinson, t. c., 1975. effect of naphthalene and aqueous crude oil extracts on the green flagellate chlamydomonas angulosa. i. growth. canadian journal of botany, 53: 109–117. thiel t., 1990. protein turn over and heterocyst differentiation in the cyanobacterium anabaena variabilis-under condition of starvation. j.phycol., 26(1), 50-54. wakeham, s.g., farrington, j.w. in: baker, r.a. (ed.), contaminants and sediments, vol. 1, ann arbor science, mi. yuan, h.f., min-wang, c., kung, h.w., 2001. purification and characterization of glutamine synthetase from unicellular cyanobacterium synechococcus rf-1. bot. bull. aca. sin.,42,23-33. zarrouk, c., 1966. contribution à l’étude d’une cyanophycée. influence de divers’ facteurs physiques et chimiques sur la croissance et la photosynthèse de spirulina maxima. ph.d. thesis, université de paris, paris. international journal of environment issn 2091-2854 29 | p a g e international journal of environment volume-1, issue-1, jun-aug 2013 issn 2091-2854 received: 15 july revised: 27 july accepted: 29 july artisanal fisheries in zimbabwe: options for effective management wilson mhlanga 1* and lindah mhlanga 2 1 department of environmental science, bindura university of science education zimbabwe 2 lindah mhlanga, department of biological sciences, university of zimbabwe zimbabwe *corresponding author: wmhlanga63@gmail.com abstract the small-scale (artisanal) fisheries in zimbabwe play an important role in incomegeneration and food security at the household level. this sector has the potential to significantly increase its contribution to household income and food security if more effective fisheries management strategies are put in place. historically, fisheries management has adopted a centralised “top-down” approach. this approach has had very limited effectiveness. over the last decade, efforts have been made to implement co-management in the fisheries sector. several factors have hampered the success of fisheries co-management in the artisanal fishery. these factors have been institutional, ecological, human and financial. this paper discusses these factors and proposes possible solutions. a more innovative and effective fisheries management approach is also proposed. key words: fisheries management, zimbabwe, co-management, artisanal fisheries, sustainability introduction zimbabwe is endowed with a number of major rivers but there are no natural reservoirs. in order to harness the nation’s water resources, dams have been built throughout the country. while most of these dams have been built for irrigation, mining, industry and domestic (potable) water supply, a few dams such as lake kariba have been created for hydro-electric power generation. according to nugent (2007) there are over 10,000 dams in more than 60 district council jurisdictions, around 2,000 of which are in communal areas. table 1 shows the numbers by province and net capacity of the major dams in zimbabwe. most of these major dams have a net capacity of more than 1,000,000 m 3 . mailto:wmhlanga63@gmail.com international journal of environment issn 2091-2854 30 | p a g e table 1: distribution of major dams by province. (source: zimbabwe national water authority) province number of dams net capacity (x 10 6 m 3 ) mashonaland west 13 (excluding kariba) 1,380.049 mashonaland east 13 66.555 mashonaland central 15 236.394 manicaland 13 657.913 midlands 20 519.844 matebeleland north 10 52.698 matebeleland south 24 732.064 masvingo 28 2,519.997 total 136 6,165.997 note: kariba dam has a net capacity of 64,800 x 10 6 m 3 these dams have given rise to fisheries activities of varying scales. on lake kariba there is a commercial (industrial) fishery based on the introduced tanganyika sardine (limnothrissa miodon) which is known locally as kapenta. apart from lake kariba, most of the other dams in the country have small-scale (artisanal) fisheries. these artisanal fisheries are important because they provide a livelihood for the fishers and the fish traders who act as middlemen between the producers and the market. the artisanal fisheries are also important in that they are a source of comparatively cheap animal protein. the price of fresh fish is lower than that of chicken and beef. for example, the price of fresh fish can be as low as us$2 per kilogram, while beef usually costs more than us$5 per kilogram. while statistics on the number of fishers in the whole country are not readily available, the figures from lake kariba serve to illustrate the important role of fisheries in terms of livelihoods (e.g. employment). on the zimbabwean side of lake kariba there are about 1,154 artisanal fishers in 41 fishing villages/camps (zimbabwe lake kariba fisheries frame survey report, 2011) while on the zambian side, mbewe et al. (2011) reported that there were about 4,653 artisanal fishers in 63 permanent fishing villages. in terms of catches on the zimbabwean side, karenge and kolding (1995) noted that production from the artisanal fishery was about 5,000 tons per year. for lake kariba, diffey (2012) observed that it is necessary to build capacity for monitoring and surveillance in the artisanal fishery. he international journal of environment issn 2091-2854 31 | p a g e also recommended that support should be provided for strengthening community based enforcement. the potential of most of these dams to support artisanal fisheries has not yet been fully exploited. the development of artisanal fisheries on these dams is important for several reasons. these dams can provide a livelihood option for those communities around the dams as well as fish traders who may come to buy the fish. this will boost household income as well as contribute to meeting the protein needs at household level. where fish production exceeds household protein requirements, the surplus fish will be sold and hence boost the national fish production. the increased fish production will result in increased fish protein intake at the household level. currently, the bulk of the fish being sold on the domestic market is from commercial fish farming (aquaculture) with very little coming from the artisanal fishery. the development of the fish production potential of the dams should include both the harvesting of the fish from the wild (capture fisheries) in the short term as well as the development of small-scale fish farming (aquaculture) using appropriate technologies in the medium to long term. this paper focuses on capture fisheries management as this can be implemented without substantial infrastructure inputs. aquaculture development requires significant capacity-building as well as major initial capital investment (for example pond construction or manufacture of fish cages). the dams in zimbabwe can be classified into two broad categories, namely those within the zimbabwe parks and wildlife management authority (zpwma) estate, and those outside the parks and wildlife estate. the dams within the parks and wildlife estate are designated as recreational parks (according to the parks and wildlife act chapter 20:14). these include lake kariba, chivero, manyame, mutirikwi (kyle), sebakwe, osborne, manjirenji, bangala as well as the dams in rhodes matobo and rhodes nyanga recreational parks. current annual fish production from the artisanal fisheries on the dams in zimbabwe is well below the potential levels. one of the major reasons for this low production is the absence of effective fisheries management. this paper highlights the options that are available to improve artisanal fisheries management so as to increase annual fish production from the sector. international journal of environment issn 2091-2854 32 | p a g e current fisheries management fisheries management on dams in parks estate fisheries management in the dams/lakes within the parks estate is centralised and entry into the fishery is controlled. there are dams where artisanal fishing is carried out using mainly gill-nets (e.g. chivero, manjirenji and kariba), while for other dams such as those in rhodes nyanga estate, only recreational fishing using rod and line is carried out. entry into the fishery is regulated through a licensing system. annual gill-net fishing licences are issued by the zimbabwe parks and wildlife management authority (zpwma). the gill-net fishers pay a licence fee to parks (zpwma). resource monitoring (data collection and analysis) is carried out by parks personnel. law enforcement is also carried out by parks personnel. for most of the dams, annual statistics from fish production in the artisanal fishery are not readily available mainly due to manpower constraints. it is therefore necessary to come up with new strategies for data collection that include other key stakeholders in order to address the current bottleneck created by manpower constraints. law enforcement efforts also need to be supported by other stakeholders, especially the fishers, in order to curb illegal fishing (poaching). this calls for a new fisheries management approach. this will ensure that the small-scale fisheries do not become de facto open access resources. fisheries management outside parks estate the parks and wildlife act mandates the authority (zpwma) to issue fishing licences in consultation with the relevant local authorities (rural district councils) as well as the ministry of agriculture, mechanization and irrigation development (through the fisheries unit in the department of livestock production and development). the fisheries unit plays a pivotal role in recommending the number of fishers that can be licensed for any particular dam (i.e. fishing effort). the licenced fishers have to pay a levy (fishing licence fee) to the local authority (e.g. on a quarterly basis). the fishers do not play any significant role in the management of the fishery. consequently, fisheries management is still centralised (i.e. “top-down” approach). given the large number of dams in the country and the manpower available in both parks and the fisheries unit, there are human resource and financial constraints to ensure effective coverage of all dams in the country. consequently, in order to effectively address these constraints, it is essential to come up with a more inclusive management approach. this management approach should be based on fisheries co-management. fisheries cointernational journal of environment issn 2091-2854 33 | p a g e management is not a new approach in zimbabwe. this approach was implemented in the artisanal fishery on the zimbabwean side of lake kariba. on the zambian side, the fisheries co-management approach encompassed both the artisanal fishers and the kapenta fishers. while the co-management approach has been fairly successful on the zambian side, the approach has not progressed very well on the zimbabwean side due to several factors. these factors are discussed later in this paper. rationale for fisheries co-management viswanath et al. (2003) observed that implementation of fisheries co-management is premised on the fact that both traditional fisheries management and “modern” fisheries management institutions have failed to address governance issues. they argue that the “modern” fisheries management focuses on objectives relating to the fish resources and is based exclusively on formal biological science. viswanath et al. (2003) concluded that modern fisheries management fails to address the core concerns of fishing communities, is insensitive to local conditions, lacks backing from fishing communities and is even inefficient in achieving its own objectives (i.e. sustainability of the resource). it is generally accepted that this approach, which was developed in industrialised societies is increasingly being questioned in the societies it was developed and attempts to introduce such management in other environments have generally failed. due to these challenges, the need for institutional reforms in the structures for fisheries management has been widely accepted. consequently, there have been efforts to introduce fisheries comanagement in several countries all over the world. co-management is widely recognised as a promising option for reform of governance institutions (ibid). according to viswanath et al. (2003), governance of fisheries involves 3 main components, 1. setting management objectives, 2. defining and providing the knowledge base for management and, 3. ensuring implementation of management decisions. in most international journal of environment issn 2091-2854 34 | p a g e countries, fishery resources are state property and hence government plays an important role in governing these resources. figure 1 shows the 2 types of co-management and modern management in relation to the 3 main components of fisheries governance. figure 1. types of fisheries management (source: viswanath et al. 2003) modern management in this approach, the government is responsible for (1) setting management objectives, (2) defining and providing the knowledge base for management, and (3) ensuring implementation of management decisions. the fishing communities have no role in governance. this has been the common approach for most of the fishery resources in zimbabwe. instrumental co-management in this approach the government still sets management objectives as well as defines and provides the knowledge base for management. thus the practical adaptation of the comanagement approach is limited to involving communities in the implementation process only. the co-management on lake kariba (zimbabwean side) can be regarded as being in this category although the communities did play a part in providing the knowledge base (through the resource monitors). modern management instrumental co-management empowering co-management 1. setting management objectives. 2. defining and providing knowledge base for management. 3. ensuring implementation of management decisions. a government fishing communities 1 2 3 b government fishing communities 1 2 3 c government fishing communities 1 2 3 international journal of environment issn 2091-2854 35 | p a g e empowering co-management in this approach the fishing communities play an active role in 1. setting management objectives, 2. defining and providing the knowledge base and 3. ensuring implementation of management decisions. five major requirements of the empowering co-management were identified. these are: i. a rethink of the logic for management and subsequently a change in the knowledge base for management. ii. a major restructuring of the institutional and organisational arrangements supporting management. iii. a substantial change in attitudes from both governments and fishing communities towards their role in such arrangements. iv. aspiration from fishing communities and government to proceed along this avenue. v. capacity-building at several levels both within governments and fishing communities. a major feature of the empowering co-management concept is that it is a learning process for all the parties involved. therefore an adaptive approach to management has to be implemented. sen and nielsen (1996) noted that fisheries co-management is considered to be one solution to the growing problems of resource over-exploitation. they defined fisheries comanagement as “an arrangement where responsibility for resource management is shared between government and user-groups.” co-management differs from community based natural resources management (cbnrm) in that government is also involved in the decision-making process concerning management of the fishery. international journal of environment issn 2091-2854 36 | p a g e government based management user group based management informative advisory cooperative consultative instructive government management user group management sen and nielsen (1996) conducted a comparative analysis of case studies on fisheries comanagement arrangements that were documented in fisheries management literature. based on these case studies, they identified five broad categories of fisheries co-management. these categories were dependent on the role played by government and users (figure 2). figure 2: spectrum of co-management arrangements (source: sen and nielsen, 1996) type a – instructive there is only minimal exchange of information between government and users. this type of management is only different from centralised (“modern”) management in the sense that mechanisms exist for dialogue with users, but the process itself tends to be that of government informing users on the decisions they plan to make. type b – consultative mechanisms exist for government to consult with users but all decisions are taken by government. type c – co-operative government and users co-operate as equal partners in decision-making. for some authors, this is the definition of co-management. type d – advisory users advise government of decisions to be taken and government endorses these decisions. international journal of environment issn 2091-2854 37 | p a g e type einformative in this approach, government would have delegated authority for decision-making to user groups that are responsible for informing government of these decisions. these categories are meant to simplify a very complex concept/process. the 22 case studies that were reviewed were in different categories as shown in table 2. table 2: categories of case studies that were reviewed typology number of case studies instructive 2 consultative 5 co-operative 6 advisory 4 informative 5 (source: sen and nielsen, 1996) based on the review of 22 case studies, the authors concluded that co-management covered a broad spectrum of possible collaborative decision-making between government and usergroups. this encompasses; (a) the roles of government and user groups in decision-making. (b) the types of management tasks that can and want to be co-managed by user groups and government, and (c) the stage in the management process when co-management is introduced (i.e. planning, implementation, evaluation). in an assessment of fisheries co-management on lake malawi, donda (2006) identified three key factors for the sustainability of co-management arrangements. firstly, the malawi department of fisheries’ (dof) understanding of the socio-economic and cultural factors of fishing communities. these factors were important for the department of fisheries in the assessment of potentials (opportunities) and constraints of fishing communities that enable them to participate in fisheries co-management. knowledge of local institutions and how they affect people’s behaviour are essential in planning effectively on how to approach and involve fishing communities in co-management. secondly, the department of fisheries’ institutionalisation of appropriate property rights over the lake and fish resources. this provides for the rights of exclusion and instils a sense of ownership over the resources. international journal of environment issn 2091-2854 38 | p a g e thirdly, capacity-building for both the department of fisheries and communities. capacity building among the communities would include aspects such as legal empowerment, financial empowerment and training of fishers in concepts relating to co-management. fisheries co-management on lake kariba – lessons learnt several factors have negatively impacted on the implementation of the fisheries comanagement approach in the artisanal fishery on the zimbabwean side of lake kariba. these factors can be broadly classified as institutional, ecological, human and financial. institutional factors in zimbabwe, the mandate for fisheries management is within the zimbabwe parks and wildlife management authority. this authority is under the ministry of environment and natural resources management. thus, the authority is responsible for both wildlife (terrestrial) and fisheries management. consequently, wildlife issues tend to overshadow fisheries issues. the principal legislation (i.e. parks and wildlife act) governing fisheries management is skewed more towards wildlife issues than fisheries issues. consequently, there is more focus on wildlife issues than on fisheries issues. in the medium-term, it will be essential to revise the parks and wildlife act so that it has enhanced coverage of fisheries issues. in countries where fisheries have a significant institutional profile (such as zambia and malawi), the fisheries co-management approach has recorded significant progress. the organisational restructuring that occurred in the zimbabwe parks and wildlife management authority during the implementation of the co-management programme resulted in significant staff changes (transfers and staff turnover). this negatively impacted implementation as there was no smooth transition (hand-over) of the programme. in order to improve implementation of the co-management programme on lake kariba, it is essential for parks (zpwma) to implement a management approach that incorporates the key stakeholders. these key stakeholders are the artisanal fishers, the kapenta operators, the fisheries unit in the department of livestock production and development (dlpd), through the agricultural extension officers/workers who are in the lake kariba area, the rural district councils (rdcs), namely nyaminyami and binga rural district councils). these stakeholders can be involved in activities such as resource monitoring (catch and effort data collection), law enforcement as well as fisheries management meetings. international journal of environment issn 2091-2854 39 | p a g e incentives for the fisheries resource monitors should be re-introduced for effective and sustainable data collection. capacity building (training) of the fishers, extension personnel as well as rdc staff will be a prerequisite that will facilitate meaningful participation in management. ecological-social factors fish productivity in the designated fishing areas is much lower than in the closed (non-fished) areas. for some of the fishers this factor resulted in loss of enthusiasm towards the programme as they continued to increase their fishing effort (number of nets) above those stipulated in the fishing permit. this behaviour was driven mainly by the licenced fishers’ lack of security of tenure. the inclusion of the fishers in management will pave the way for allaying the fears/perceptions relating to lack of security of tenure. as fishers become part of the stewards of the resource their support for the co-management approach will be strengthened. in the medium to long-term, small-scale fish farming ventures should be promoted in order to reduce the pressure on capture fisheries. the experiences of countries such as uganda, kenya, nigeria and ghana would be useful in this intervention. human resources factors human resource constraints also impacted negatively on the co-management programme. the number of personnel available for activity implementation fell short of the requirements for a lake such as kariba with about 41 fishing camps/villages distributed along the shoreline of the lake that is 300 km long as reported by kenmuir (1983). the involvement of other stakeholders should also address the problem of human resources constraints. apart from the fishers, rdcs and extension staff (dlpd), other stakeholders such as universities and non-governmental organisations (ngos) could also assist in addressing human resource constraints. the universities could play a pivotal role in data capture and analysis, as well as in capacity building. the ngos could also assist in capacity building as well as the development of small-scale aquaculture ventures. financial resources factors implementation of the co-management programme was funded largely through development assistance (donor funding) as a project. no mechanism for the self-financing of international journal of environment issn 2091-2854 40 | p a g e the programme had been developed at the time the project came to an end. consequently, the programme could not be sustained in the post-project phase. the economic challenges that the nation was going through in the last decade (2000 to 2010) also worsened the financial constraints. a key factor of success for the co-management programme is a sustainable financing mechanism. while development assistance can play an important role in “kick-starting” the programme, it is essential that effective financing mechanisms be put in place for long term financing of the co-management. thus the key stakeholders (parks, fishers, rdcs and dlpd) should set aside funds for the participation of their respective personnel in this programme. a percentage of the licence (fish permit) fees could be set aside for convening of relevant meetings as well as hosting of the secretariat for the co-management programme. proposed fisheries management fisheries management in parks estate the shift from centralised fisheries management to fisheries co-management will ensure that figure 3. shows the proposed fisheries management arrangements on lake kariba artisanal fisheries management (lake kariba) artisanal fishers' associations/ committees universities– (natural and social scientists) dlpd and fisheries unit (extension staff) parks (zpwma) rdcs nyami-nyami binga ngos kapenta fishers operators (associations) exofficio? international journal of environment issn 2091-2854 41 | p a g e resource users play a more significant role in all aspects of fisheries management including resource monitoring, law enforcement, fisheries policy and strategy development and implementation. through lake kariba fisheries research institute (lkfri) the parks authorities (zpwma) would be the co-ordinating institution. the fishers themselves would be key stakeholders. their participation would be through representation. the sub-area fishers’ associations and district fishers associations that were established in earlier interventions should be resuscitated. other major stakeholders would be the 2 rdcs that have jurisdiction over the communal areas that are on the shoreline of the lake (i.e. nyaminyami and binga). the fisheries unit in the dlpd would also be a primary stakeholder mainly through the extension staff stationed along the lake’s shoreline (e.g. in gache gache and binga). the kapenta fishers (through their associations), universities and ngos would be secondary stakeholders. the kapenta operators’ representatives would provide a link between the artisanal fisheries management and the commercial (pelagic) fisheries management. universities would play a supportive role. university personnel (both social scientists and natural scientists/fisheries biologists) would be able to provide their skills in the fisheries management process as well as assist in capacity building. the mode of collaboration between the secondary stakeholders (i.e. universities and ngos) and the primary stakeholders could be formalised through mous (memoranda of understanding). the ngos with expertise in capacity-building would play a key role in training of the fishers in aspects such as financial management and later fish-farming.figure 4 shows the proposed management arrangements for the other dams/lakes within the parks estate. in these dams, the primary stakeholders would be parks (zpwma) and the fishers. universities and ngos would be the secondary stakeholders as in the case with lake kariba. international journal of environment issn 2091-2854 42 | p a g e figure 4: proposed fisheries management arrangements on dams/lakes within parks estate fisheries management outside parks estate for all other dams/lakes outside the parks estate, it is proposed that a two-tier management approach be implemented (figure 5). artisanal fisheries management (recreational parks / parks dams) artisanal fishers (dam/lake committee) universities parks zpwma ngos international journal of environment issn 2091-2854 43 | p a g e figure 5: fisheries management arrangements on dams outside parks estate the first tier would be at the national level where a co-ordinating unit would be housed (figure 5). this co-ordinating unit would have the fisheries unit (dlpd) and parks (zpwma) as the primary stakeholders and universities as the secondary stakeholders. parks would continue to be responsible for licencing of fishers as well as providing advisory support to the dam level management structures whenever necessary. parks would also be responsible for housing a national fisheries database. the database would include information on production (catch and fishing effort) as well as data on the fishers (e.g. number of fishers, fisheries management outside parks estate (at national level) licencing fisheries database advisory technical support dam surveys (natural and social scientists) catch/effort data collection capacity building fisheries management outside parks estate (at dam level) capacity building advisory role parks zpwma ma fisheries unit (dlpd) universities rdc fisheries unit (co-ordinates) fishers (representatives) ngos universities international journal of environment issn 2091-2854 44 | p a g e and number of fishing gear). the fisheries unit (dlpd) would continue with the responsibility of conducting dam surveys as well as co-ordinating data collection at dam level. the universities would provide technical support whenever required. they could also assist in providing manpower through student industrial attachment. the second tier would be the management arrangements at site (dam) level. the primary stakeholders would be the fisheries unit (through the agricultural extension officer/worker based near the dam), the rdc(s) for the area where the dam is located and the licenced fishers. the ngos and universities would be secondary stakeholders providing mainly advisory, research and capacity-building support. conclusion and recommendations the fish resources in zimbabwe’s dams have the potential to contribute significantly to increased household income and food security, especially among the riparian communities. the absence of a robust fisheries management system is a major constraint to increased fish production from the artisanal fisheries sector. given the financial and human resource constraints that are faced by fisheries managers, it is imperative for stakeholders from different institutions to collaborate with the resource users (fishers) in the management of the fishery resource. this paper presents proposals for fisheries co-management. these proposals should be viewed as a contribution to the discourse on the development of a fisheries comanagement approach in the artisanal fisheries sector in zimbabwe. in implementing fisheries co-management arrangements, the lessons learnt from previous artisanal fisheries projects in zimbabwe should be used to inform the new arrangements. these lessons include previous projects on small water bodies (nyikahadzoi, 2005; nugent 2007). information on lessons learnt in other artisanal fisheries in southern african countries should also guide this process. references diffey, s. j. (2012). artisanal fisheries, income diversification study, eco-tourism and recreational fisheries. programme for the implementation of a regional strategy for the eastern and southern africa and indian ocean region. smartfish. fs/2012/17. 69p. international journal of environment issn 2091-2854 45 | p a g e donda, s. (2006). governance and institutional changes in malawi fisheries: impact on poverty reduction and environmental integrity. ins.v.siar, m. ahmed, u kanagaratnam, & j. muir. (eds). governance and institutional changes in fisheries: issues and priorities for research. worldfish center discussion series no. 3. karenge, l. & kolding j. (1995). on the relationship between hydrology and fisheries in man-made lake kariba central africa. fisheries research 22: 205-226. kenmuir, d. (1983). fishes of kariba. mardon printers. harare. zimbabwe. mbewe, m., mweemba, c., habulembe, i. &silwimba, e. (2011). lake kariba frame survey report. nugent, c. (2007). strengthening fish production through improved management of small water bodies and dams in zimbabwe. fao. tcp/zim/3003. nyikahadzoi, k. (2005). fish enhancement through improved management and restocking of small water bodies in zimbabwe: problems, constraints and opportunities. fao/tcp/3003. sen, s. & nielsen, j.r. (1996). fisheries co-management: a comparative analysis. marine policy 20(5):405 – 418. viswanath, k. k., nielsen, j.r., degnbol, p., ahmed m., hara, m. & raja abdulla, n. m. (2003). fisheries co-management policy brief: findings from a worldwide study. worldfish center policy brief 2. 26p. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 14 | p a g e international journal of environment volume-5, issue-1, dec-feb 2015/16 issn 2091-2854 received:21 september 2015 revised:06 october 2015 accepted:06 december 2015 co-composting of organic solid waste and sewage sludge – a waste management option for university campus bernard fei-baffoe 1 *, kenneth osei 2 , eric appiah agyapong 3 and eugene atta nyankson 4 1,2,3,4 department of environmental science, kwame nkrumah university of science and technology, kumasi, ghana *corresponding author: feibaffoe@yahoo.com abstract co-composting organic solid waste with dewatered sewage sludge was carried out to determine its suitability for managing waste on a university campus. windrow composting method was employed in which dewatered sewage sludge and organic solid waste were mixed at volume ratios: 1:1, 1:2, 1:3, 0:1 and 1:0 sludge/organic solid waste. parameters such as ph, percentage n, c, p, k, ca, mg, organic matter, ash content and c/n ratio were determined weekly. total and faecal coliform population were measured biweekly with pb and cd levels determined at the beginning and end of the composting. with the exception of ratio 1:0 sludge/organic solid waste, all other ratios attained a favourable carbon to nitrogen (c/n) ratio both at the start and end of the composting process. levels of major nutrients measured were found to be favourable for use as organic fertilizer. there was a general decline in carbon and organic matter in all the compost piles except the sewage sludge pile (1:0). apart from the compost ratio 1:0 sludge/organic solid waste, all other ratios attained a temperature of 55 o c within 8 days of composting. generally the compost ratios 1:2, 1:3 and 0:1 (sludge/organic solid waste) were found to be the most suitable for use as organic fertilizer. keywords: co-composting, organic solid waste, sewage sludge, compost quality, waste management option. mailto:feibaffoe@yahoo.com international journal of environment issn 2091-2854 15 | p a g e introduction effective handling of waste is a major challenge for municipalities in most countries with increasing population, prosperity and urbanization. developing countries are the most disadvantaged due to inadequate facilities and lack of adequate technology required for waste management (fei-baffoe et al., 2014). ghana as a developing country produces a lot of refuse especially in the cities as a result of growth in population, rapid urbanization and industrialization. however, there hasn‟t been a commensurate increase in essential infrastructure, human resource and logistics for effective and efficient waste management services to be delivered across the country. this often creates an unhealthy environment which eventually results in serious incidence of diseases. kwame nkrumah university of science and technology (knust), one of the government assisted universities in ghana has experienced an increase in student population over the years. this has resulted in a corresponding increase in waste generation with more than 50% of the waste classified as decomposable (pare et al., 1999). the main method of disposal is by landfilling. this method is more expensive to operate and maintain. there is also the problem of land acquisition which is popularly referred to as nimby syndrome. landfilling of waste has the potential of polluting soil and water resources as a result of the release of leachate. this occurs particularly from landfills that are poorly constructed and operated. the release of a greenhouse gas like methane from landfills is also an environmental concern for the current state of the globe where climate change has become a big problem to contend with (mensah and larbi, 2005). the case of ghana is a cause for concern because most landfills are primarily open dumps without leachate or gas recovery systems, a number of them located in ecological or hydrologically sensitive areas, thus, posing a significant threat to public health especially for those living close to the landfill sites (mensah and larbi, 2005). composting, another means of handling waste has been an ancient technology for agricultural purposes (richard, 1997). it is a well-established method of producing manure by decomposition and stabilization of organic waste through microbial activities. different methods of composting especially of municipal organic solid waste have been advocated as a n environmentally friendly, less expensive to operate and maintain, and sustainable means of recycling waste when used as fertilizers and soil conditioners. sewage sludge is a product of waste water treatment and is very rich in nutrient and trace element which can be reused as fertilizer (tiquia et al., 2002). however, its high odour international journal of environment issn 2091-2854 16 | p a g e emission, high level of heavy metal and toxic compounds and the presence of pathogenic micro-organisms demand pre-treatment of sewage sludge before application in agriculture (tiquia et al., 2002). the usage of sludge for agricultural purposes is considered the most appropriate alternative if pollutants in the sludge are found within the acceptable guideline values. nevertheless, lack of acceptance from the public makes it difficult to use. better means of sludge handling for agricultural use to promote patronage include drying, composting and co-composting with other materials (hultman and levlin, 1998; strauss et al., 2003). co-composting is the controlled aerobic degradation of organics, using more than one feedstock (faecal sludge and organic solid waste) to provide a sustainable and cost effective disposal/re-use method for the co-composted material (strauss et al., 2003). good quality compost can be obtained by co-composting organic solid waste which is rich in fibre with sewage sludge which is also rich in nitrogen. high temperature should be attained duri ng the composting process to destroy pathogens and weed seed that may occur in the sludge (kraus and wilke, 1997). the study therefore aims to assess the quality of compost produced from cocomposting organic solid waste and dewatered sewage sludge, as a case study for the management of organic waste on university campus in ghana. materials and methods study area the study was undertaken during the dry season between the months of november and february at the premises of the sewage treatment plant of knust. the main university campus is about 11 square miles in area and is located about 5 km to the east of kumasi, which is the capital of the ashanti region of ghana. collection and preparation of composting material solid waste was collected from waste receptors at the halls of residence on the university campus and their canteens. a grab amount of the waste was collected using shovel into empty sacks for characterization into decomposable and non-decomposable fractions at site. characterization was done manually by separating the waste into decomposable fractions which mainly composed of food left over, fruit wastes and vegetable wastes and nondecomposable portions such as, plastics and metal cans and others as shown in figure 1. international journal of environment issn 2091-2854 17 | p a g e figure 1: waste composition of campus solid waste decomposable fraction of waste was then shredded and mixed to obtain a uniform mixture using cutlass and shovel respectively. the dewatered sludge was taken directly from the sludge drying beds of the sewage treatment plant of knust. characteristics and composition of composting material a preliminary analysis was conducted to determine the characteristics of the feedstock (organic solid waste and dewatered sewage sludge) including the c/n ratios and moisture (table 1) so that different proportions of the materials could be mixed to achieve favourable c/n ratios (20 -30) and moisture (55 65%) necessary for effective composting. the most widely used parameter for composting is the c/n ratio of the initial composting material; high initial c/n ratio will cause a slower beginning of the process and the required composting time to be longer than usual while low initial c/n ratio results in high emission of nh3 (ogunwande et al., 2008). it is also important to maintain the water content of the composting material at a proper level to avoid undesirable factors like longer composting period from arising. it is also reported that with too little water, the heat required for proper composting wi ll not be attained while anaerobic conditions may set in with too much water (ogunwande et al., 2008). therefore, the preliminary analysis provided the basis for mixing the dewatered sewage sludge and organic solid waste at ratios of 1:1, 1:2, 1:3, 0:1 and 1:0 (v/v) respectively. 0 10 20 30 40 50 60 70 organic paper plastic glass metal textile inert other 65 % 6% 3.5% 3% 2.5% 1.7% 17.1% 1.2% c o m p o si ti o n ( % ) fraction international journal of environment issn 2091-2854 18 | p a g e table 1: characteristics of the composting material parameter sewage sludge organic solid waste moisture 72.6±1.8 61.3±0.6 ts (%) 27.4±1.8 38.7±0.6 c/n 11.65 ±0.86 25.93±0.17 composition analysis of the various ratios (sewage sludge/organic waste) before composting is summarized in table 2. moisture content (mc) and c/n of the initial composting mixture was adjusted based on the results of the initial analyses shown in table 1. the c/n ratio of the sewage sludge was raised to 22±2.0, 23.8±0.7 and 23.1±0.1 (1:1, 1:2, 1:3 sewage sludge / organic solid waste respectively) through the addition of organic solid waste (rynk et al., 1992; ogunwande et al., 2008). the mc of all the composting material was adjusted to (50-60 %) (wet basis) at the beginning of the composting process by the method given by rynk et al. (1992). table 2: composition analysis of the composting material at the start of the process parameter ratios (sewage/organic solid waste) 1:1 1:2 1:3 0:1 1:0 c (%) 45±1.0 47.1±0.3 47.3±1.5 49.4±06 40.9±0.8 n (%) 2.2±0.1 2.13±0.07 2.2±0.07 1.84±0.2 3.92±0.08 c/n 22±2.0 23.8±0.7 23.1±0.1 26.85±3.2 10.43±0.1 p (%) 0.64±0.08 0.42±0.11 0.39±0.06 0.25±0.07 0.84±0.05 k (%) 0.52±0.2 0.41±0.07 0.54±0.07 0.78±0.01 0.75±0.07 ash (%) 22.6±1.7 19±0.5 18.7±2.6 15±1.0 29.7±1.3 om (%) 77.4±1.7 81± 0.5 81.3± 2.6 85±1.0 70.3±1.3 ph 6.8±014 7.1±0.28 7.25±0.21 7.4±0.28 6.3±0.14 ca (%) 1.2±0.08 1.03±0.13 1.06±0.18 0.6±0.12 0.82±0.2 mg (%) 0.9±0.2 0.74±0.09 0.7±0.20 0.42±0.09 1.01±0.09 tc (mpn/g) 9.5± x 10 11 9.5± x 10 10 6.4± x10 10 7.5 ±x 10 10 2.4 ±x 10 14 fc( mpn/g ) 2.1± x 10 11 6.4 ±x 10 8 1.5 ±x 10 8 2.4 ±x 10 8 2.9± x 10 13 cd (mg / kg) 3.3±0.01 4.8±0.10 2.25±0.03 2.1±0.5 2.4±0.7 pb (mg/kg) 56.4±2.1 59.6±1.4 37.8±2.0 49.2±0.09 34.8±1.03 international journal of environment issn 2091-2854 19 | p a g e composting the open windrow pile method was adopted with each heap measuring 1 metre high and 1.5 metres wide. each compost pile was manually mixed with a shovel for about 10 minutes to turn the pile and provide better aeration. the turning of the compost piles were done every 3 days for the first 21 days. the turning of compost piles continued once every week until the compost piles reached maturity. each pile was watered at each time of turning to keep the moisture content at an appreciable level (50-60%) required for effective composting. the moisture content was determined at regular intervals by the oven drying method. the ambient temperature and the temperature within each pile at a depth of 15 cm from the surface of the piles were determined using a thermometer. a thermometer attached to a rod of about 60 cm long was inserted into each pile, in the middle and at both edges of each pile. the temperatures were recorded and the averages calculated. temperature measurements including the ambient were taken three (3) times daily for the entire composting period. sampling and analysis a 50 grams sample was taken from each compost pile by collecting sub samples at different depths and points in the piles and homogenised. each compost sample was air dried, milled and sieved for physicochemical analysis. moisture content and total solids were determined using the gravimetric method. loss on ignition at a temperature of 550 o c was used to measure total organic matter, carbon and ash content (motsara and roy, 2008). ph was determined using the ph meter. total nitrogen was analysed using microkjedahl method. spectrophotometric vanadium phosphomolybdate method was employed to measure total phosphorus whiles magnesium, calcium, cadmium, potassium and lead content were determined using atomic absorption spectrophotometry (levinson, 1998; motsara and roy, 2008). with the exception of cadmium and lead which were determined at the beginning and end of composting all other physicochemical analysis were done weekly. for the microbiological determination, 10 grams sample each was also taken from all compost piles and analysed for total and faecal coliforms using the most probable number method (anon, 1994). this was done biweekly throughout the composting period. all analysis were done in triplicates to reduce variation in results. single factor anova was used to make international journal of environment issn 2091-2854 20 | p a g e comparisons among the means of parameters measured in different compost ratios at 95% confidence limit. results and discussion the main physicochemical and microbiological characteristics of the feedstock and their ratios before and after composting are summarised in this section. ph there was gradual decline in ph in all the compost heaps (1:1, 1:2, 1:3, 0:1 and 1:0 sewage sludge/organic solid waste) during the initial composting phase (fig. 2). this was likely caused by mineralization of organic acid by acid forming bacteria. these findings are in sync with those of beck-friis et al. (2003) and lim et al., (2009). after 21 days of composting until maturity, the ph increased in all compost piles except the pile 1:0 (sewage sludge/organic solid waste). the increased ph could be attributed to intense proteolysis and rapid metabolic degradation of organic acid which must have liberated alkaline ammonia compound due to protein degradation. nattinpong and alissara (2006) made similar observations during composting of cassava pulp with swine manure. figure 2: mean weekly ph of compost (sewage sludge / organic solid waste) near neutral ph (5.2 – 8.0) was recorded throughout the composting period. this must have enhanced efficient microbial activity that promoted effective degradation of the compost mass. in the maturity phase, as observed from the sixth week, the ph was almost neutral and stabilized; this was due to the buffering nature of humic substances as indicated by lim et al. (2009). four of the compost piles (i.e., 1:1, 1:2, 1:3 and 0:1 ratios) reached maturity by the sixt h week (fig. 2). ph time (weeks) 1:1 1:2 1:3 0:1 1:0 international journal of environment issn 2091-2854 21 | p a g e the heap that consisted of only sludge (i.e.,1:0 ratio), however recorded low ph by the eighth week, an indication that the process of decomposition and production of organic acids was still ongoing (fig. 2). organic matter, carbon, ash content and c/n ratio initial compost piles had high amount of organic matter and carbon. these parameters were highest in the compost pile that contained only organic solid waste (i.e., the 0:1 ratio). the lowest levels of these parameters were recorded in the compost pile that contained only sewage sludge (i.e., the 1:0 ratio) (table 3). percentage organic matter and carbon were found to have decreased rapidly within the first 21 days of composting pointing to high rate of degradation of the organic materials resulting in an increase in temperature from mesophilic to thermophilic phase of the composting process. decomposition was however slower in compost pile 1:0 (sewage sludge/organic. solid waste). decomposition during composting is associated with the conversion of biodegradable organic matter into volatile co2 and h2o which are removed from the compost into the atmosphere (edriss et al., 2006). a decrease in the rate of organic matter and carbon degradation was recorded over time which is an indication of gradual stabilization of the organic matter and carbon forming humic compounds during the composting process. cedric et al. (2005) reported a similar trend after 20 days of composting, which was attributed to the presence of organic substances that were recalcitrant to degradation. percentage reduction in both organic matter and carbon content, which indicated the extent of degradation of the compost mass was highest in the compost pile 0:1 (sewage sludge/organic solid waste) at 49.5% and lowest in the pile 1:0 (sewage sludge/organic solid waste) containing only sewage sludge (19.3%). the difference in organic matter and carbon content in the final compost amongst the heaps was statistically significant (p <0.05). ash content in the compost was found to be inversely related to organic matter. thus high amount of ash which is the inorganic fraction was an indication of the extent of composting in the various heaps. mahdi et al. (2007) argued that the amount of ash in compost reflects microbial decomposition of organic matter and stabilization during composting. this was highest in pile 0:1 (sewage sludge/organic solid waste). differences in the compost piles were also statistically significant (p < 0.05). auldry et al. (2009) identified an increase in ash content and humic acid due to a decrease in organic matter content over the composting period caused by mineralization and humification. international journal of environment issn 2091-2854 22 | p a g e all compost piles except pile 1:0 (sewage sludge/organic solid waste) had initial carbon/nitrogen ratio suitable for effective composting (table 3), which is in agreement with studies conducted by eldridge (1995) and korner et al. (2003). low initial c/n ratio in compost pile 1:0 was realized possibly due to relatively low carbon with corresponding high nitrogen content contained in the sludge (table 3). low c/n ratio in compost has the potential of slowing down decomposition with associated loss of nitrogen through ammonia volatilization (ogunwande et al., 2008). a significant reduction in carbon/nitrogen ratio over the composting period probably caused by carbon consumption was observed in all compost piles throughout the composting period. this is a reflection of microbial decomposition and stabilization of organic matter, a phenomenon also observed by mahdi et al. (2007). c/n ratio is a factor that is used to indicate compost maturation. according to nattinpong and alissara (2006), compost with c/n ratio of 20 or less could be accepted as matured. this enhances net mineralization of nitrogen in the soil for plant use if used as fertilizer. c/n ratios recorded in the various compost piles were near stable after the fourth week which is a probable indication that they had entered the maturation phase. each of the compost piles attained a final c/n ratio below 20 (table 3). decline in c/n ratio in the various compost piles over the composting period was found to be significant (p <0.05). table 3: values of organic matter, carbon, ash and c/n ratio at the start and end of composting parameter ratios (sewage/organic solid waste) initial final 1.1 1.2 1.3 0.1 1.0 1.1 1.2 1.3 0.1 1.0 om (%) 77.4±1.7 81± 0.5 81.3±2.6 85±1.0 70.3±1.3 47.8±2.6 47.2±0.5 46.7±2.3 42.9±2.8 56.7±0.9 ash (%) 22.6±1.7 19±0.5 18.7±2.6 15±1.0 29.7±1.3 52.2±2.3 52.8±0.5 53.3±2.6 57.1±2.8 43.3±0.9 c (%) 45±1.0 47.1±0.3 47.3±1.5 49.4±0.6 40.9±0.8 27.8±1.3 27.4±0.3 27.2±1.3 24.9±1.6 33±0.8 c/n 22±2.0 23.8±0.7 23.1±0.1 26.85±3.2 10.43±0.1 9.86±0.4 10.15±1.4 9.48±0.7 11.58±0.3 9.35±0.5 macro-nutrients changes in macro-nutrients during composting are mainly due to mineralization which results from microbial activities. total nitrogen increased slightly in the finished compost in all piles except pile 1:0 (sewage sludge/organic solid waste (table 4). nitrogen is needed by decomposing microorganisms for protein formation and body building to enhance degradation of international journal of environment issn 2091-2854 23 | p a g e the compost mass. this was realized at the initial stage of composting, which saw a slight reduction in nitrogen in each compost pile. however, an increase was realized later, which could be attributed to a decrease in compost mass due to degradation of organic carbon. ajay and kazmi (2007) and auldry et al. (2009), measured increase in total nitrogen during the composting process and attributed it to the decrease in substrate carbon resulting from the loss of co2 (due to the decomposition of the organic matter which is chemically bound with nitrogen). analysis of variance (anova) showed a significant difference between nitrogen content in the final compost amongst the piles (p< 0.05). table 4: values of macro-nutrients at the start and end of composting parameter ratios (sewage/org. solid waste) initial final 1.1 1.2 1.3 0.1 1.0 1.1 1.2 1.3 0.1 1.0 n (%) 2.2±0.1 2.13±0.07 2.2±0.07 1.84±0.2 3.92±0.08 2.82±0.04 2.7±0.3 2.87±0.1 2.15±0.1 3.53±0.3 p 0.64±0.08 0.42±0.11 0.39±0.06 0.25±0.07 0.84±0.05 1.06±0.04 0.99±0.02 0.73±0.08 0.49±0.01 1.7±0.08 k (%) 0.52±0.2 0.41±0.07 0.54±0.07 0.78±0.01 0.75±0.07 0.51±0.02 0.73±0.03 0.7±0.06 1.1±0.42 0.15±0.07 mg (%) 0.9±0.2 0.74±0.09 0.7±0.20 0.42±0.09 1.01±0.09 0.59±0.09 0.58±0.01 0.56±0.08 1.54±0.01 0.82±0.04 ca (%) 1.2±0.08 1.03±0.13 1.06±0.18 0.6±0.12 0.82±0.2 2.35±0.02 2.29±0.45 1.95±0.21 1.38±0.11 2.21±0.13 total phosphorus and potassium increased over the composting period following a similar trend as recorded for nitrogen (table 4). this increase could be caused by organic matter decomposition leading to the net loss of dry mass, which might have concentrated the phosphorus and potassium in the compost piles. nattinpong and alissara (2006) and ajay and kazmi (2007), share similar views. slight decrease in phosphorus and potassium along the composting period probably resulted from the mineralization and consumption by microbes as stated by ajay and kazmi (2007). percentage phosphorus was highest in pile 1:0 (sewage sludge/organic solid waste) and lowest in pile 0:1 (sewage sludge/organic solid waste). compost ratios that contained relatively higher proportion of sewage sludge recorded higher percentage phosphorus in the order; 1:0, 1:1, 1:2, 1:3, and 0:1 (sewage sludge/organic solid waste). this is an indication that the sewage sludge was rich in phosphorus. nattinpong and alissara (2006) recorded lower amount of total phosphorus in compost piles that had lower amount of swine manure as compared to other piles. this was related to high release of phosphorus from the swine manure. potassium however international journal of environment issn 2091-2854 24 | p a g e showed a reverse trend where compost ratios containing higher proportion of organic solid waste measured higher percentage of potassium, an indication that the organic solid waste was rich in potassium. both phosphorus and potassium levels in all compost piles exceeded the minimum level required for land application (p2o5 ≥ 0.3%), (k2o ≥ 0.5%) as stated by strauss et al. (2003) and nattinpong and alissara (2006), respectively. difference in mean values in phosphorus measured in the various ratios over the composting period was significant (p < 0.05). however that of potassium was not significant (p> 0.05). calcium content increased significantly over composting period. this could be attributed to calcium mineralization during decomposition and reduction in compost volume. it is also an indication that the composting materials were rich in calcium. the final compost product however decreased in magnesium content compared to the initial material prior to composting except pile 0:1 (sewage sludge/organic solid waste) which contained only organic solid waste (table 4). lim et al. (2009) identified increased amount of p, k, ca and mg during windrow co-composting process of oil palm mesocarp fibre and palm oil mill effluent anaerobic sludge and described the resulting compost to be of high quality. temperature rapid decomposition of readily degradable organic matter, which was recorded especially in the initial stages of composting amongst the piles, was associated with heat generation which must have stemmed from the release of energy from the biochemical reaction of microorganisms. rapid heat generation raised the temperature of compost piles, which caused the process to move from mesophilic phase (10 to 40ºc) to thermophilic phase (higher than 40ºc) where high rate of organic matter degradation was experienced (fig. 3). this is in sync with the findings of nelson et al. (2006). an initial temperature of 30 o c was recorded in all compost piles. however, temperature of 55 o c and above required for pathogenic destruction was attained in the 4 th , 6 th , 7 th , and 8 th days for compost ratios 0:1, 1:2, 1:3 and 1:1 (sludge / organic solid waste) respectively. this was probably due to high amount of organic carbon in the piles coupled with good aeration. compost ratio 1:0 (sewage sludge / organic solid waste) however, could only attain a maximum temperature of 44 o c, probably due to relatively low amount of readily degradable carbon and less aeration. by usepa (1994) standards, windrows or piles must be exposed to a temperature of 55 o c for 15 days to maximize sanitation in the finished compost. from the study, the compost ratios 1:2, 1:3 and 0:1 (sludge / organic solid waste) could maintain the temperature of 55 o c for more international journal of environment issn 2091-2854 25 | p a g e than 15 days (1:2 and 1:3 – 18 days) and (0:1 16 days) thus having the potential to sanitize the compost (fig. 3). pile 1:1 (sludge / organic solid waste) could maintain the recommended temperature of 55 o c for 11 days with pile 1:0 not attaining this temperature at all. a maximum temperature of 64 o c was measured in pile 3 (1:3) and this was maintained for 4 days. the ambient temperature ranged from 28 – 30 o c. the core temperature in the piles after being retained for some days as mentioned above reduced gradually to the ambient temperature. tiquia et al. (2002) reported that compost material could be considered matured when the temperature in the compost reached the ambient temperature. thus compost ratios 0:1, 1:3, 1:1 and 1:2 could be said to have reached maturity by 35 th , 40 th , 41 st and 47 th days, respectively (figure 3). nelson et al. (2006), argued that a sustained drop in temperature of windrow composting where there is the failure of a cooled compost windrow to reheat after turning indicates that decomposition has slowed enough for the compost to be cured. piles of sewage sludge and sawdust co-composting were considered to have reached maturity within 35-38 days of composting (edriss et al., 2006). nattinpong and alissara (2006) also established compost maturity after 40 days in the composting of swine manure with cassava pulp. figure 3: temperature variation over composting period (sewage sludge / organic solid waste) coliforms ajay and kazmi (2007) explained that, the presence of coliform bacteria is used as an indicator for the overall sanitary quality of compost. standards set by usepa (1994) for hygienization of compost recommend that faecal coliforms should be less than 1000 mpn / g. by the fourth week of composting, both total and faecal coliforms had reduced international journal of environment issn 2091-2854 26 | p a g e considerably in numbers. faecal coliforms in piles 1:2, 1:3 and 0:1 (sewage sludge / organic solid waste) had attained the recommended standard (640, 430 and 930 mpn/g respectively), thus the finished compost can be considered safe for use as organic fertilizer (table 5). the drastic drop in numbers of both total and faecal coliform could be attributed t o thermophilic temperatures in those piles that could be sustained for at least 15 days as recomme nded by usepa (1994) (fig. 3). ajay and kazmi (2007) reported a considerable reduction in faecal coliforms, from 7.5 × 10 8 to 7.5 × 10 2 and 9.3 × 10 10 to 2.5 × 10 5 mpn/g in two separate piles in composting food waste and cattle manure. pile 1:1 although experienced high thermophilic temperatures, it had values above the recommended standard for sanitary compost (1.6 x10 3 ). pile 1:0, however, recorded less reduction in total and faecal coliform population by the eighth week, an indication of poor thermophilic conditions recorded in the pile throughout the composting period (table 5). table 5: values of total coliforms (tc), faecal coliforms (fc), cadmium (cd) and lead (pb) at the start and end of composting heavy metals according to hsu and lo (2000), the composting process may increase the concentration of heavy metals due to reduction in volume of the compost mass. however, hammadi et al. (2007), recorded lower levels of copper and cadmium in matured sludge compost as compared to their respective concentrations in activated sludge. results obtained after the composting process revealed highly significant decrease in both lead and cadmium levels as compared to levels measured in the piles before composting (p < 0.05) (table 5). reduction in metal levels may have resulted from complexing actions of the newly formed humic parameter ratios (sewage/org. solid waste) initial final 1.1 1.2 1.3 0.1 1.0 1.1 1.2 1.3 0.1 1.0 tc (mpn/g) 9.5 x 10 11 9.5 x 10 10 6.4 x10 10 7.5 x 10 10 2.4 x 10 14 9.3 x 10 4 2.1x 10 4 2.3 x 10 3 2.4 x 10 4 1.2 x 10 7 fc (mpn/g) 2.1 x 10 11 6.4 x10 8 1.5 x 10 8 2.4 x 10 8 2.9 x 10 13 1.6 x 10 3 7.5 x 10 2 6.4 x 10 2 7.5 x 10 2 1.6 x 10 8 cd (mg /kg) 3.3±0.01 4.8±0.10 2.25±0.03 2.1±0.5 2.4±0.7 0.27±0.13 0.45±0.04 1.32±0.01 1.14±0.14 1.65±0.23 pb (mg/kg) 56.4±2.1 59.6±1.4 37.8±2.0 49.2±0.09 34.8±1.03 21.9±0.91 13.2±1.05 15.3±0.41 9.1±2.1 6.6±1.7 international journal of environment issn 2091-2854 27 | p a g e compounds to this metallic micro pollutant as indicated by pare et al. (1999). hogarh et al. (2008) ascribed low levels in cd and pb detected in household compost to the absence of contaminants such as plastics, printed materials and metals. both lead and cadmium concentrations found in each compost pile at the end of composting were below maximum levels specified by the canadian council of ministers of the environment that gave a maximum concentration of 3 mg/kg and 150 mg/kg for cadmium and lead, respectively in composts approved for use as fertilizer for food crops (nova scotia, 2006). conclusion co-composting dewatered sewage sludge and organic solid waste produced ideal compost with sufficient nutrient levels required for use as fertilizer. this was reflected in the compost pile ratios; 1:3, 1:2, 0:1 and 1:1 (sewage sludge/organic solid waste), (nb. arranged in order of compost quality). the compost pile 1:2, 1:3, and 0:1 (sewage sludge/organic solid waste) recorded the appropriate temperature and prolonged thermophilic stage necessary for the inactivation/destruction of coliform bacteria per the usepa (1994) threshold set for sanitary compost (< 1000 mpn/g). composting sewage sludge (1:0) alone showed a slow rate of decomposition and also failed to attain the temperature required for pathogenic destruction. compost produced from the, 1:2 1:3 and 0:1 ratios could be considered most safe for use as organic fertilizer because of low levels of heavy metals, faecal coliforms, and high levels of nutrient for plant growth. the overall composting experiment as shown in the result of the study was a success. this therefore indicates that the large quantities of organic waste and dewatered sewage sludge generated on the university‟s campus can be used to produce high quality compost which can be used at the university‟s greenhouse and for other agr icultural activities on campus. this will help the university achieve its aim of providing environmentally sound, economically viable and sustainable waste management. it can therefore be concluded that co-composting sewage sludge and organic solid waste offers a better option for waste management across universities in ghana and the world at large. international journal of environment issn 2091-2854 28 | p a g e acknowledgments the authors appreciate the logistic and technical support provided by the department of environmental science at the kwame nkrumah university of science and technology, ghana, during the research and manuscript preparation. references ajay, s. k. and kazmi, a. a., 2007. rotary drum composting of mixed organic waste based on different c/n ratios. proceedings of the international conference on sustainable solid waste management, chennai, india. pp. 258-265. anon, 1994. centres for disease control and prevention. food borne outbreaks of enterotoxigenic escherichia coli. rhode island and new hampshire, mmwr. 43:8189. auldry, c. p., osumanu, h. a., abd majid, n. m., hassan, m. n., make, j. a nd michael, g. b., 2009. chemical characteristics of compost and humic acid from sago waste. american journal of applied sciences. 6 (11): 1880-1884. beckfriis, b., smars, s., jonsson, h., eklind, y. and kirchmann, h. , 2003. composting of source separated household organics at different oxygen levels: gaining and understanding of the emission dynamics. compost science and utilization. 11: 41-50. cedric, f., maelenn, p. and sabine, h., 2005. stabilization of organic matter during composting: influence of process and feedstock. compost science and utilization. 13 (1): 72-83. edriss, b., zazouli, a .m., javad, b. and anoushirvan, m. b., 2006. evaluation of microbiological and chemical parameters during wastewater sludge and sawdust cocomposting. j. appl. sci. environ and mgt. vol. 10 (2): 115 – 119. eldridge, r., 1995. development of a composting recipe for swine. soil conservation service northeast, department of biological systems engineering, us department of agriculture. engineering service, cooperative extension, ithaka, new york. pp. 1-20 fei-baffoe, b., nyankson, e.a., and gorkeh-miah, j., 2014. municipal solid waste management in sekonditakoradi metropolis, ghana. journal of waste management 2014: 1-9. international journal of environment issn 2091-2854 29 | p a g e hammadi, m. a. e., trabelsi, m., jrad, a. and hanchi, b., 2007. analysis and comparison of toxicants between tunisian activated sludge and produced compost. research journal of environmental sciences. 1 (3): 122-126. hogarh, j.n., fobil, j.n., ofosu-budu, g.k., carboo, d., ankrah, n.a. and nyarko, a., 2008. assessment of heavy metal contamination and macro-nutrient content of composts for environmental pollution control in ghana. global journal of environmental research. 2 (3): 133-139. hu, s.w. and shy, s.m., 2001. health effects of waste incineration: a review of epidemiological studies. j. air waste management association. 51: 1100-1109. hultman, b. and levlin, e., 1998. sustainable sludge handling. division of water resources engineering. royal institute of technology (kth) s100 44, stockholm, sweden, pp. 1 12 hsu, j.h. and lo, s.l., 2000. effect of composting on characterization and leaching of copper, manganese and zinc from swine manure. journal environmental pollution. 114: 119-127. korner, i., braukmeier, j., herrenklage, j., leikam, k., ritzkowski, m., schlegelmilch, m. and stegmann, r., 2003. investigation and optimization of composting processes-test systems and practical examples. j. waste management. 23: 17–26. kraus, p. and wilke, m., 1997. schadstoffe in bioabfallkompost. (contaminants in biocompost) mull und abfall. 211-219. levinson, a.a., 1998. analytical methods for atomic absorption spectrometry. perkinelmer corp., norwalk, connecticut, usa. pp. 3-30. lim, s. h., azhari, s. b., mohd, n. a., umi, k. m., nor, s., aini, a. r., suraini, a., mohd, a. h. and yoshihito, s., 2009. physicochemical changes in windrow cocomposting process of oil palm mesocarp fiber and palm oil mill effluent anaerobic sludge. australian journal of basic and applied sciences, 3 (3): 28092816. mahdi, a., azni, i. and syed, o., 2007. physicochemical characterization of compost of the industrial tannery sludge. journal of engineering science and technology, 2 (1): 8194. international journal of environment issn 2091-2854 30 | p a g e mensah, a. and larbi, e., 2005. „solid waste disposal in ghana‟ well factsheet-regional annex. available at http://www.lboro.ac.uk/well/resources/factsheets/fact -sheetshtm/rsa%20solid%20waste.htm. (accessed on 18/04/2015). motsara, m.r. and roy, r.n., 2008. guide to laboratory establishment for plant nutrient analysis. fao fertilizer and plant nutrition bulletin 19. food and agriculture organisation of the united nations. rome, pp. 42-88 nattinpong, k. and alissara, r., 2006. effect of c/n ratio on the composting of cassava pulp with swine manure. journal of water and environment technology. 4 (1): 9-32 nelson, v.l., crowe, t.g., shah, m.a. and watson, l.g., 2006. temperature and turning energy of composting feedlot manure at different moisture content in southern alberta. canadian biosystems engineering., 48: 31–37. nova scotia, 2006. composting facility guidelines. nova scotia environment and labour . pp. 1 22 nsaful, f., diewuo, f. and qauye, t. n. a., 2006. assessing the recycling potential and treatment option of waste streams of municipal solid waste generated on the knust campus. m.sc thesis, knust, kumasi. pp. 1-88. ogunwande, g. a., osunade, j. a. and ogunjimi, l. a. o., 2008. “effects of carbon to nitrogen ratio and turning frequency on composting of chicken litter in turnedwindrow piles”. agricultural engineering international: the cigr ejournal. manuscript ee 07 016. vol. x: 1-16 pare, t., dinel, h. and schnitzer, m., 1999. extractibility of trace metals during cocomposting of biosolids and municipal solid wastes. biol fertil soils. 29: 31-37. richard, st. j., 1997. on-farm manure composting techniques understanding nitrogen and carbon conservation coesa report no.: res/man-003/97 ecologistics limited 490 dutton drive, suite a1 waterloo, ontario n2l 6h7. pp. 1 -137. rynk, r., van de kamp, m., wilson, g.b., singley, m.e., richard, t.l., kolega, j.j., gouin, f.r., laliberty, l., kay, jr.d., murphy, d.w., hoitink h.a.j. and brinton, w.f., 1992. on farm composting. northeast regional agricultural engineering services, ithaca, new york, pp. 186. strauss, m., montangero, a., zurbrügg, c., drescher, s., olufunke, c. and drechsel, p., 2003 composting of faecal sludge and solid waste. a literature and state-of-knowledge international journal of environment issn 2091-2854 31 | p a g e review. eawag-sandec/iwni (ghana)/ french ministry of foreign affairs project report. duebendorf, switzerland. pp. 1 – 44. tiquia, s.m., wan, j.h.c. and tam, n.f.y., 2002. microbial population dynamics and enzyme activity during composting. compost science and utilization. 10: 150 – 161. tiquia, s.m., tam, n.f.y. and hodgkiss, i.j., 1997. effects of turning frequency on compost of spent-pig manure. pp. 37-42. united states environmental protection agency, 1994. a plain english guide to the epa part 503 biosolids rule. washington, d.c: office of wastewater management. u.s. environmental protection agency. epa/832-b-93-005, pp. 144. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 70 | p a g e international journal of environment volume-8, issue-2, 2019 issn 2091-2854 received: 29 jun 2019 revised: 9 aug 2019 accepted: 10 aug 2019 investigation of hematological and biochemical profiles of tannery workers exposed to chromium in hazaribagh, bangladesh adua rahman, md. fahimur rahman, jobaida akther, a. h. m. nurun nabi, laila n. islam* department of biochemistry and molecular biology, university of dhaka, dhaka-1000, bangladesh *corresponding author: laila@du.ac.bd abstract occupational exposure to chromium used in mineral tanning processes cause adverse health effects on workers of leather tanning industries. this study aimed to evaluate the hematological and biochemical profiles in tannery workers of hazaribagh, bangladesh compared with a control group. a total of 225 participants, 121 tannery workers and 104 controls, were enrolled. all subjects completed interviewer-administered questionnaires; their physical health was examined, blood samples were collected and the hematological and biochemical parameters were analyzed. the tannery workers had mean duration of work exposure at tanneries for 13.1±9.7 years, and working hours per day of 10.7±2.3 which were significantly higher than 7.6±2.2 of the controls. previous results showed long-term exposed tannery workers had significantly higher serum chromium concentrations than controls. the tanners had dermatological problems, infections on body surfaces, and respiratory ailments, among other complaints. the red blood cell count, hematocrit (48.91 %) and mean corpuscular hemoglobin concentration (29.39 g/dl) were lower in tannery workers but hemoglobin (14.58±1.30 g/dl) was significantly lower than in the controls (15.96±0.88 g/dl). the tanners had significantly lower neutrophil (51.31 %), higher lymphocyte (41.82 %), monocyte (2.44 %) and eosinophil (4.17 %) counts. their mean creatinine and alkaline phosphatase values were normal but markers of liver damage, alanine transaminase (42.7±39.3 u/l) and aspartate transaminase (44.3±20.5 u/l), and liver dysfunction marker bilirubin (1.04±0.85 mg/dl) levels were significantly higher. these findings suggest that exposure to chromium poses serious threats to the health of tannery workers who are at risk of toxicity related liver damage and hematological disorders. keywords: tannery workers, chromium, liver damage, hematological disorders, bangladesh doi: http://dx.doi.org/10.3126/ije.v8i2.25521 copyright ©2019 ije this work is licensed under a cc by-nc which permits use, distribution and reproduction in any medium provided the original work is properly cited and is not for commercial purposes mailto:laila@du.ac.bd http://dx.doi.org/10.3126/ije.v8i2.25521 http://orcid.org/0000-0001-8832-8737 international journal of environment issn 2091-2854 71 | p a g e abbreviations alkaline phosphatase (alp); alanine transaminase (alt); aspartate transaminase (ast); chromium (cr); mean corpuscular hemoglobin concentration (mchc); mean corpuscular volume (mcv); ethylene diamine tetra acetic acid (edta). introduction hazaribagh, the largest tanning industrial area in bangladesh which is situated on the south-western part of the capital city of dhaka on the bank of the buriganga river, has around 300 tanning units (mohanta et al., 2010). tannery industries use chemicals containing known or suspected carcinogens including hexavalent chromium (cr(vi)) salts, arsenic, organic solvents such as benzene, formaldehyde, butyl acetate, ethanol, acetoacetate, toluene and acetone (stern et al., 1987). occupational workers in the tanneries are often challenged to chemical exposure due to poor maintenance, safety, hygiene, and ignorance about the hazards (mohanta et al., 2012; biswas and rahman, 2013). despite its usefulness as an essential trace element required for normal energy metabolism, chromium poses a threat to mankind due to its toxic effects. there are two major forms of chromium of which cr(vi) is about 1000 times more toxic than trivalent chromium (cr(iii)) (zhang and jin, 2006). cr(iii) is not very soluble and is immobilized by precipitation as hydroxides while cr(vi) is toxic, soluble and easily transported to water resources (kamaludeen et al., 2003). occupational exposures often include mixed exposure to both cr(iii) and cr(vi). cr(vi) is structurally similar to sulfate and phosphate and thus highly absorbed through active transportation compared to cr(iii) (costa, 1997). the general population is exposed to cr by inhaling ambient air, ingesting food, and drinking water containing chromium. tannery workers are primarily exposed to chromium through the airways and skin contacts (de flora et al., 1995). cr(vi) salts used for leather preservation often bind with skin protein of the workers and cause hypersensitivity (shahzad et al., 2006). industrial exposure to cr and its relation with increased mortality from respiratory cancer has been reported for decades (atsdr, 2000). cr exposure in tanning industry is attributed as possible reasons for impaired hepatic and renal functions among workers because of oxidative stress on body system (khan et al., 2013). oral cr ingestion and poisoning may lead to hepatomegaly (michie et al., 1991) and hepatic failure (loubières et al., 1999). following entry into the blood stream, cr(vi) ions are rapidly taken up by red blood cells (rbcs) and trapped through reduction inside the cell (atsdr, 2000; dayan and paine, 2001). this may harm cellular integrity as cr(vi) can induce rbc membrane scrambling through increasing ca2+ ion entry and depletion of atp concentration leading to the process eryptosis (lupescu et al., 2011). there are clinical histories related to ingestion of cr compounds which adversely affect the hematological status because of intravascular international journal of environment issn 2091-2854 72 | p a g e hemolysis (sharma et al., 1978). evidence of anemia and thrombocytopenia is also found (loubières et al., 1999). acute dermal exposure of cr in an electroplating worker showed alerting situation of leukocytosis and reduced hemoglobin (lin et al., 2009). cr accumulation in tannery workers also adversely affects iron metabolism (kornhauser et al., 2002). the occupational workers at tanneries are the worse suffers of toxic fumes and chemicals including cr, and many kinds of microbes that enter their bodies from the putrefied animal hides. cr(iii) has been found to accumulate in the hair of the tannery workers (randall and gibson, 1989). studies with the tannery workers of kanpur in india and hazaribagh in bangladesh showed various health effects like respiratory and gastrointestinal tract problems and skin complaints (rastogi et al., 2008; islam et al., 2019). the tannery workers of sialkot, pakistan have been found highly exposed to cr and showed hematological, hepatic and renal function impairment (khan et al., 2013). a previous work reported prevalence of allergic diseases and elevated levels of serum immunoglobulin e in the tannery workers of hazaribagh (hossain and islam, 2016). cr exposure can affect certain biochemical parameters including glucose intolerance and lipid metabolism (štupar et al., 1999). in view of inadequate data on health parameters of these workers, this study was undertaken to investigate the hematological and biochemical profiles of tannery workers exposed to chromium in hazaribagh, bangladesh. materials and methods study subjects all the subjects included in this cross-sectional study were males; the female workers were excluded as they had very short duration of work exposure (<6 months). the tannery workers, working in 27 leather tanning industries of hazaribagh, dhaka, were enrolled in this study. a map of the study area had been shown elsewhere (islam et al., 2015). a total of 121 tannery workers with at least 6 months of work exposure, and 104 unexposed subjects (non-tannery workers, not age-matched) volunteered to participate in this study as control subjects. they were academic and non-academic staffs of the university departments, gardeners, guards, cleaners and canteen staffs of student’s dormitory. exclusion criteria included those suffering from impaired renal and liver functions and any other chronic conditions. data collection from studied subjects this study was conducted from july 2013 to august 2015. the general information of the studied subjects including age, level of education, number of family members, height, weight, waist to hip ratio, international journal of environment issn 2091-2854 73 | p a g e duration of work exposure, working hour per day, types of work, blood pressure etc. were recorded on a preformed questionnaire form. their physical health conditions were examined by an expert physician. ethical approval this study was approved by the ethical review committee (erc) of the faculty of biological sciences, university of dhaka, bangladesh. before enrollment, each individual was informed about the objectives and significance of the study. only the full consenting volunteers were included in the study. simple random and availability sampling was applied to collect samples. the guidelines of the erc were followed during physical health examination, interviewing of the participants and peripheral blood sample collection. collection of blood samples about 6 ml of peripheral blood was collected from each participant, 3 ml was transferred in a purple capped vacuum tube containing di-potassium edta and the remainder was allowed to clot in a glass tube. aliquots of fresh blood samples were used for the complete blood count. following centrifugation, serum and plasma were collected in eppendorf tubes and stored at -20oc until analyzed. determination of hematological parameters hemoglobin was determined by the cyanmethemoglobin method after oxidizing the hemoglobin content of blood by adding potassium ferricyanide reagent (randox laboratories ltd., united kingdom) and taking optical density readings in a genesys 20 spectrophotometer (thermo scientific); the red blood cells (rbc) and white blood cells (wbc) were counted using hemocytometer; differential wbc counts were done by staining a smear of blood with giemsa’s stain and counting at least 200 cells under the high power optics of an olympus (ch-30rf200, japan) microscope; the hematocrit (v/v), mean corpuscular hemoglobin concentration (mchc), and mean corpuscular volume (mcv) were determined by calculations using hemoglobin, hematocrit and rbc data. reagents all reagents used for the determination of glucose, and bilirubin were purchased from randox laboratories ltd., uk; the creatinine assay kit was obtained from chemelex, s.a., spain; and alp, alt and ast assay kits were from emapol, poland. all reagents used in this study were of analytical grade. determination of plasma glucose, creatinine and bilirubin glucose was determined after enzymatic oxidation of a plasma sample by glucose oxidase enzyme, and the concentration was determined from a standard graph constructed with known amounts of glucose. for the assay of creatinine, 100 µl of sample was mixed with 1000 µl of the working reagent consisting of equal volumes of picric acid (17.5 mmol/l) and sodium hydroxide (0.29 mol/l) and the value was determined by kinetic method, as described in the protocol. the albumin-bound bilirubin present in 100 µl of plasma international journal of environment issn 2091-2854 74 | p a g e sample was released by reaction with 1000 µl of dca reagent [2,4-dichloroaniline (3.0 mmol/l), hydrochloric acid (80 mmol/l), and a detergent (60 g/l) mixed with equal volume sodium nitrite, 3.0 mmol/l] to form a colored azobilirubin that was measured at 546 nm against the sample blank. the bilirubin concentration in the sample was determined according to the manufacturer’s protocol. determination of alp, alt and ast activities for the determination of alkaline phosphatase (alp) activity in serum, 20 µl of the sample was added to 1000 µl of the working buffered substrate consisting of p-nitrophenyl-phosphate (53 mmol/l) in diethanolamine buffer (1 mol/l, ph 9.8), mixed well, and then absorbance was taken at 405 nm by using a shimadzu uv-vis spectrophotometer at 0, 1, 2, and 3 minutes. alp activity was calculated as the mean absorbance change per min multiplied by correction factor 2760 and expressed in u/l. for the determination of alanine transaminase (alt) activity, 100 µl of serum was added with 1000 µl of the working buffered substrate consisting of l-alanine in tris buffer mixed with enzyme/coenzyme/α-oxoglutarate and the initial absorbance was taken against air after 1 min at 365 nm by using a shimadzu uv-vis spectrophotometer and then after 2 and 3 min interval. the mean absorbance change per min was used to calculate alt activity in the sample and was expressed in u/l. aspartate transaminase (ast) activity was determined by adding 100 µl of serum sample with 1000 µl of the working buffered substrate consisting of l-aspartate in tris buffer mixed with enzyme/coenzyme/α-oxoglutarate and then following the same procedure as described for alt. statistical analyses data analyses were carried out using the statistical package for social sciences (version 17.0 for windows, spss inc., chicago, usa). all results were expressed as mean±standard deviation. the student’s t-test was used to compare demographic characteristics, hematological and biochemical profiles among the tannery workers and controls, and categorical data was compared by chi square test. the results were considered significant when the value of p≤0.05. results demographic data of the studied participants the demographic data of the studied subjects including bmi, waist to hip ratio (whr), number of family members, working hour per day, literacy, blood pressure etc. are compared in table 1. the age of the tannery workers ranged from 15 to 65 years and that of the control subjects ranged from 19 to 60 years. the tanners had mean work duration at tanneries for 13.1±9.7 years ranging from 0.5 to 47 years. the body mass index (bmi, kg/m2) of the tanners varied from 15.7 to 28.9 while that of the control subjects ranged from 14.6 to 29.4. about 15% of the tannery workers were underweight (malnourished, bmi: <18.5) compared to 5% of the controls (p<0.05, χ2 test), 18% were overweight (bmi: ≥25.0) compared to 21% of the controls, and international journal of environment issn 2091-2854 75 | p a g e the remaining 67% of tanners were within the healthy range of bmi (18.5 to 24.99) compared to 74% of the controls. the level of education of the tanners was as follows: primary (54%), secondary (30%), higher secondary (3%), and the remaining 13% had no education. on the other hand, all control subjects received secondary education, some with higher degrees. table 1. demographic characteristics of tannery workers and control subjects parameters tested tannery workers, n=121 control subjects, n=104 age (yrs) 32.1±10.7 30.4±8.9 body mass index (bmi, kg/m2) 22.2±2.9 23.0±2.9 waist to hip ratio (whr) 0.91±0.06 0.89±0.05 no. of family members 4.32±1.48 4.25±1.27 working hrs per day 10.7±2.3* 7.6±2.2 sbp (mmhg) 121.6±9.0 118.7±12.4 dbp (mmhg) 78.1±5.5 79.5±5.6 pulse rate (beats per min) 76.6±4.8 81.3±13.5 literacy (%)a 87** 100 *: p<0.05; **: p<0.01; a : chi-square test. types of work of the tanners out of the total 121 tannery workers, 98 were directly working in the main tanning and finishing sections where they were being directly exposed to various corrosive chemicals including cr salts used for tanning; of the remaining tanners, 13 were working inside the tanning units as machine operators and 10 were supervisors and other staffs who had indirect exposure to chromium salts (table 2). table 2. type of job category of the tannery workers health examination of the tannery workers about half of the tannery workers (49%) had rough skin along with itch and rash (dermatitis) on both limbs, 24% had decolorized skin which was clearly evident in workers exposed for as little as 0.5 yrs. a total of 9% of the tanners had reported food allergy, 15% had pain in different parts of the body, 14% had fungal job category of tannery workers no. of workers (n=121) wet blue section 26 drum section 20 lime and other chemical treatment of raw hide 18 leather shaving, splitting and spot removing 15 machine operator 13 color spray and washing 10 supervisor and other staff 10 vacuum drying, finishing, and buyer section 09 international journal of environment issn 2091-2854 76 | p a g e and bacterial infections on body surfaces, 13% reported respiratory problems while 6% had general weaknesses and 9% were anemic by their eye examination. evaluation of hematological parameters of the studied subjects the blood samples of 80 tanners and 60 control subjects were analyzed for these parameters. the results are shown in table 3. it was found that hemoglobin concentrations in the tannery workers varied from 11.33 to 16.73 g/dl and the mean value was significantly lower (p<0.01) than in the control subjects with values ranging from 14.16 to 16.91 g/dl. the rbc count in the tannery workers and control subjects varied from 3.28-5.68×109 cells/ml and 3.92-5.60×109 cells/ml, respectively. their hematocrit ranged from about 43 to 58% compared to 45.8 to 58.3% in the control subjects; the mchc was also lower but mcv was higher. the blood samples of 100 tannery workers and 80 control subjects were investigated for the total and differential wbc counts. the mean total wbc count of the study groups was within the normal range (4.0×106 cells/ml-11.0×106 cells/ml) but the differential counts showed 40% of the tanners had neutropenia (having <50% neutrophils) and 64% had lymphocytosis (having >40% lymphocytes). the mean neutrophil to lymphocyte ratio was 1.3 in the tanners compared to 1.9 in the controls. the percentages of lymphocytes, monocytes and eosinophils were significantly higher while neutrophils were significantly lower in the tannery workers than in the controls (table 3). table 3. evaluation of hematological profiles of the tannery workers and control subjects parameters control subjects, n=60 tannery workers, n=80 hemoglobin (g/dl) 15.96±0.88 14.58±1.30** rbc count (10⁹ per ml) 4.59±0.53 4.53±0.69 hematocrit (%) 52.30±2.89 48.91±8.09 mcv (fl) 113.58±12.55 119.80±23.97 mchc (g/dl) 30.02±1.66 29.39±3.69 wbc count (10⁶ per ml)a 7.36±1.06 7.41±1.79 neutrophils (%) 62.03±6.40 51.31±7.04*** lymphocytes (%) 32.68±6.20 41.82±6.88*** monocytes (%) 2.11±0.61 2.44±1.04** eosinophils (%) 2.96±0.85 4.17±2.84*** basophils (%) 0.18±0.30 0.12±0.27 **: p<0.01; ***: p<0.001; a: n=100 for tanners, and 80 for controls for the total and differential wbc data. international journal of environment issn 2091-2854 77 | p a g e levels of plasma glucose, creatinine and bilirubin in the studied subjects the random plasma glucose level of 75.6% of the tannery workers was normal (normal range: 70140 mg/dl), 16.7% was lower (<70 mg/dl), and 7.7% was higher compared to only 7.6% of the controls with lower level of plasma glucose. in the tannery workers, the mean level of plasma creatinine, which is a measure of kidney function, was within the normal range (table 4). on the other hand, the total plasma bilirubin level, which is a measure of liver function, varied widely from 0.11-4.89 mg/dl in the tannery workers compared to 0.03-0.92 mg/dl in the control subjects (reference range: 0.1-1.2 mg/dl). it was found that about 31% of the tannery workers had abnormally high level of total bilirubin, and the mean value of the population was significantly higher than the control subjects (table 4). activity of serum alp, alt and ast in the studied subjects about 99% of the tannery workers had normal serum alp activity (normal range: 20-140 u/l) and only 1% showed higher activity. on the other hand, all of the control subjects showed normal alp activity. in the case of alt, which is an important liver function test, about 36% of the tannery workers showed abnormally high serum alt activity (normal value: ≤ 41 u/l). the mean alt activity of the tanners was significantly higher than the control subjects. similarly, 61% of the tannery workers had abnormally high serum ast activity (normal value: ≤ 37 u/l); the mean ast activity of the tannery workers was significantly higher than the controls. activities of all these clinically important enzymes are compared in table 4. table 4. comparison of plasma glucose, creatinine and bilirubin levels, and activities of serum enzymes alp, alt and ast in tannery workers and control subjects parameters tested tannery workers, n=80 control subjects, n=60 glucose (mg/dl) 99.6±24.3*** 120.4±24.9 creatinine (mg/dl) 1.03±0.25 0.94±0.22 bilirubin (mg/dl) 1.04±0.85*** 0.41±0.24 alp (u/l) 52.8±22.9 53.5±25.9 alt (u/l) 42.7±39.3*** 25.1±20.0 ast (u/l) 44.3±20.5*** 24.5±7.7 ***: p≤0.001. international journal of environment issn 2091-2854 78 | p a g e discussion this study was conducted to evaluate certain hematological and biochemical functions of occupationally exposed tannery workers of hazaribagh. the tanners, exposed to cr salts used in mineral tanning processes, had duration of work exposure for 13.1±9.7 years with a mean working time per day of 10.7±2.3 hrs including overtime which had increased the risk of adverse health effects upon them. the nutritional status of the tannery workers, as assessed by bmi and waist to hip ratio, and family size was similar to that of the control population. although the mean age of the tanners was slightly higher than the controls (p>0.05), the parameters investigated in this study did not vary much among the controls of different age. a study conducted on the tannery workers of slovenia showed that the total cr content in tannery air (1-54 µg/m3) was higher in comparison to ambient air (4-6 ng/m3). as a result of accumulation, the tanners were showing elevated levels of cr in different tissues and body fluids (štupar et al., 1999). our recent study revealed that the long-term exposed tannery workers of hazaribagh had significantly higher serum cr concentrations than the control subjects (islam et al., 2019). however, in that study the levels of cr in the tanners (≈27 µg/dl) and controls (≈7.4 µg/dl) were much higher than the maximum permissible level in blood, which was 3.0 µg/dl (atsdr, 2008). higher level of plasma cr has been reported in a study conducted on the tannery workers of kasur, pakistan (ahsan et al., 2006). it has been reported that the tannery solid wastes containing high amount of cr are converted to protein-concentrate, which is used as poultry feed, fish feed, and in the production of organic fertilizers in bangladesh, and this extremely hazardous practice has become a common phenomenon in the hazaribagh tannery area of dhaka city (hossain et al., 2007). there could be an accumulation of larger amount of cr in the ecosystem which could give a higher value in serum since the control subjects enrolled in this study were also from the dhaka city. it may be mentioned here that due to increased concern over the health effects of cr exposure and environmental pollution caused by tannery wastes, most of the tanneries of hazaribagh have recently been relocated to a newly built leather industrial estate in savar. one study reported that a large number of workers at the tanneries of hazaribagh suffered from gastrointestinal (58%), dermatological (31%) and other diseases that could be related to pollution at work place and that 90% of them died before the age of 50 years (maurice, 2001). study conducted on the tannery workers of sialkot, pakistan showed that the workers suffer from skin rash, chronic bronchitis, gastritis and conjunctivitis (khan et al., 2013). the tannery workers of kanpur, india also have been reported to suffer from significantly higher low back pain, asthma, chronic bronchitis and dermatitis (öry et al., 2011). in agreement with a recent study on the tannery workers of hazaribagh (islam et al., 2019), the present study international journal of environment issn 2091-2854 79 | p a g e also found a large number of tanners had dermatological problems including dermatitis and decolorized skin on limbs, body pain, microbial infections on body surfaces, and respiratory problems. the prevalence of respiratory problems (asthma) was also found in the tannery workers of karachi, pakistan (shahzad et al., 2006). the present study found significantly lower hemoglobin content in the tannery workers while their rbc count, hematocrit and mchc values were lower than the controls. however, their mean mcv 119.8±23.97 fl (normal value: 80-100 fl) although was not significantly higher than controls but suggested signs of macrocytic anemia. during physical health examination, 9% of the tanners showed signs of anemia while 6% reported weakness which was consistent with laboratory findings of lower hemoglobin contents. however, a previous study found significantly lower rbc count in the tanners (ramzan et al., 2011), which could be due to toxic effect of cr. it has been suggested that cr competes with plasma iron for binding with apo-transferrin and hampers cellular uptake of iron which may affect related parameters such as hemoglobin and hematocrit levels (moshtaghie et al., 1992). the present study found lower neutrophil to lymphocyte ratio in the tannery workers which could be due to loss of neutrophils while fighting with infections on body surface caused by toxic effect of cr exposure. a study on the action of leukocytes following uptake of radiolabelled cr showed both eosinophils and neutrophils caused rapid release of cr from erythrocytes following phagocytosis (sanderson and thomas, 1978). overwhelming infections of the tannery workers from putrefied fleshing and inhalation of fungal spores and hyphae from the raw hide may cause rapid usage of neutrophils for phagocytosis followed by destruction which leads to neutropenia. lymphocytosis may be associated with conditions like increased viral, bacterial and fungal infections. eosinophilia occurs in parasitic and fungal infections, food allergies, and skin disorders. in this study, 14% of the tannery workers were suffering from different types of bacterial and fungal infections on body surfaces, which could lead to adverse health conditions. in agreement with a previous study showing plasma glucose lowering ability of cr (anderson, 1998), the present study found 16.7% of the tanners with less than 70 mg/dl of random glucose compared to 7.6% of the control subjects, and the whole population of tanners showed significantly lower plasma glucose. however, this finding differed with another study conducted on the tannery workers in kasur (ahsan et al., 2006). in the present study the plasma creatinine level of the tannery workers was not significantly different from the control population, suggesting no direct effect of cr on kidney function. this study observed that although kidney disease is often cited as one of the adverse effects of cr, chronic renal disease due to occupational or environmental exposure to cr has not been found, as reported earlier by wedeen and qian international journal of environment issn 2091-2854 80 | p a g e (1991). however, cr-induced early changes in renal function were found among ferrochromium-producing workers (wang et al., 1994). the present study found no significant change in alp activity between the tanners and controls although one study showed significant decrease in alp activity in the men tannery workers while women workers showed an increase in alp (ahsan et al., 2006). a report on inhibition of acid phosphatase, adenosine triphosphatase and succinic dehydrogenase after administration of cr(iii) and cr(iv) was known (behari et al., 1978). on the other hand, significant increase in alp activity after lead intoxication was observed (nehru and kaushal, 1993). however, these discrepancies in different studies could be due to variation in duration and level of cr (or pb) exposure. there are conflicting reports on the effect of cr on liver function, which is assessed by the release of liver specific enzymes alt and ast in the circulation, and elevated bilirubin levels. an old study reported that alt and ast enzymatic activities were higher in tannery workers compared to workers in the shoe factory (bavazzano et al., 1981); another study found no significant differences in alt and ast values of the tannery workers and controls (uyanik, 2001). the study by ahsan et al. (2006) showed variable patterns in alt and ast activities in the tannery workers, with an overall significant increase in all age and gender groups when compared with the control population but the values remained well within the normal range. in the current study, the liver enzymes alt and ast showed significantly higher activities in serum which might be associated with possible liver damage as 61% and 36% of the tannery workers had higher ast and alt activities, respectively. increased alt activity may be associated with possible liver cell damage while increased ast activity may indicate liver function impairment as well as cardiovascular problems. the most important finding of the present study was 31% of the tanners with higher levels of total bilirubin in plasma (>1.2 mg/dl), which indicated excess bilirubin not cleared by liver. collectively, these findings confirmed liver function impairment in the tannery workers. conclusion chromium, an important health risk factor for the occupationally exposed tannery workers of hazaribagh, caused gastrointestinal, dermatological, and respiratory problems, among others, and significantly lowered hemoglobin content in blood while affecting other hematological parameters. chronic exposure to chromium significantly elevated bilirubin level, as well as activities of liver enzymes alt and ast in the circulation, suggesting liver function impairment of the tannery workers. international journal of environment issn 2091-2854 81 | p a g e acknowledgements the authors acknowledge the cooperation received from ms. irin rahman, ms. kamrun nahar sharmin, dr. mohammad mohasin and dr. mahmud hossain in collecting information from the study participants. the authors express sincere thanks and indebtedness to the tannery workers and control subjects who have participated in this study program. funding this study was supported by a research grant (awarded to lni) provided by the ministry of science and technology (most), government of the people’s republic of bangladesh. adua rahman and jobaida akther were awarded nst fellowships by the most. authors’ contribution lni conceived the idea and designed the study, provided expertise and supervised the whole work, wrote and contributed to the critical revision of the manuscript and intellectual contents. ar and mfr are the investigators of the work who helped in writing and critical revision of the manuscript and were involved in data collection of the study. ahmnn contributed to the critical discussion of the results and participated in data collection and analysis. ja was involved in data collection, processing of blood samples and verified the laboratory results. all authors read and approved the final manuscript. disclosure statement: the authors declare no potential conflict of interest. references agency for toxic substances and disease registry (atsdr), 2000. toxicological profile for chromium. agency for toxic substances and disease registry (atsdr), 2008. chromium (cr) toxicity: clinical assessment. pp 43. ahsan, m.m., shakoori f.r. and shakoori, a.r., 2006. biochemical and haematological abnormalities in factory workers exposed to hexavalent chromium in tanneries of kasur district. pakistan journal of zoology, 38(3), 239-253. anderson, r.a., 1998. chromium, glucose intolerance and diabetes. journal of the american college of nutrition, 17, 548-555. pmid: 9853533. international journal of environment issn 2091-2854 82 | p a g e bavazzano, p., benassi, s., forzieri, r. and petrioli, g., 1981. [levels of aspartate aminotransferase and alanine aminotransferase in two factories with various hepato-toxic risks]. quaderni sclavo di diagnostica clinica e di laboratorio, 17(4), 407-420. pmid: 7347821. behari, j., chandra, s.v. and tandon, s.k., 1978. comparative toxicity of trivalent and hexavalent chromium to rabbits. iii. biochemical and histological changes in testicular tissue. acta biologica et medica germanica, 37(3), 463-468. pmid: 153692. biswas, s. and rahman, t., 2013. the effect of working place on worker’s health in a tannery in bangladesh. advances in anthropology, 3(1), 46-53. doi: 10.4236/aa.2013.31007 costa, m., 1997. toxicity and carcinogenicity of cr(vi) in animal models and humans. critical reviews in toxicology, 27(5), 431-42. doi.org/10.3109/10408449709078442 dayan, a.d. and paine, a.j., 2001. mechanisms of chromium toxicity, carcinogenicity and allergenicity: review of the literature from 1985 to 2000. human & experimental toxicology, 20(9), 439-451. doi.org/10.1191/096032701682693062 de flora, s., camoirano, a., bagnasco, m. and zanacchi, p., 1995. chromium and carcinogenesis. in: handbook on metal ligand interactions in biological fluids. berthon, g. (ed.), crc press, bioinorganic medicine, 2, 1020-1036. hossain, m.a. and islam, l.n., 2016. effect of occupational exposure on allergic diseases and relationship with serum ige levels in the tannery workers in bangladesh. bioresearch communications, 2(1), 158163. hossain, a.m.m., monir, t., rezwan ul-haque, a.m., kazi, m.a.i., islam m.s. and elahi, s.f., 2007. heavy metal concentration in tannery solid wastes used as poultry feed and the ecotoxicological consequences. bangladesh journal of scientific and industrial research, 42(4), 397-416. doi: 10.3329/bjsir.v42i4.748 islam, l.n., rahman, a., mahmud, z., nabi, a.h.m.n., hossain, m. and mohasin, m., 2015. assessment of physicochemical and biochemical qualities of tannery effluents of hazaribagh, dhaka, and comparison with non-tannery water samples. international journal of environment, 4, 68-81. doi: 10.3126/ije.v4i1.12179 islam, l.n., rahman, m.f. and hossain, m.a., 2019. serum immunoglobulin levels and complement function of tannery workers in bangladesh. journal of health and pollution, 9.21, 190308. doi: 10.5696/2156-9614-9.21.190308 http://www.ncbi.nlm.nih.gov/pubmed/?term=bavazzano%20p%5bauthor%5d&cauthor=true&cauthor_uid=7347821 http://www.ncbi.nlm.nih.gov/pubmed/?term=benassi%20s%5bauthor%5d&cauthor=true&cauthor_uid=7347821 http://www.ncbi.nlm.nih.gov/pubmed/?term=forzieri%20r%5bauthor%5d&cauthor=true&cauthor_uid=7347821 http://www.ncbi.nlm.nih.gov/pubmed/?term=petrioli%20g%5bauthor%5d&cauthor=true&cauthor_uid=7347821 http://www.ncbi.nlm.nih.gov/pubmed/7347821 http://www.ncbi.nlm.nih.gov/pubmed/7347821 http://www.ncbi.nlm.nih.gov/pubmed/?term=behari%20j%5bauthor%5d&cauthor=true&cauthor_uid=153692 http://www.ncbi.nlm.nih.gov/pubmed/?term=chandra%20sv%5bauthor%5d&cauthor=true&cauthor_uid=153692 http://www.ncbi.nlm.nih.gov/pubmed/?term=tandon%20sk%5bauthor%5d&cauthor=true&cauthor_uid=153692 http://www.ncbi.nlm.nih.gov/pubmed/153692 http://www.ncbi.nlm.nih.gov/pubmed/153692 https://doi.org/10.3109/10408449709078442 https://dx.doi.org/10.5696%2f2156-9614-9.21.190308 international journal of environment issn 2091-2854 83 | p a g e kamaludeen, s.p., megharaj, m., juhasz, a.l., sethunathan, n. and naidu, r., 2003. chromium microorganism interactions in soils: remediation implications. reviews of environmental contamination and toxicology, 178, 93-164. doi: 10.1007/0-387-21728-2_4 khan, d.a., mushtaq, s., khan, f.a. and khan, m.q.a., 2013. toxic effects of chromium on tannery workers at sialkot (pakistan). toxicology and industrial health, 29(20), 209-215. doi.org/10.1177/0748233711430974 kornhauser, c., wróbel, k., wróbel, k., malacara, j.m., nava, l.e., gómez, l. and gonzález, r., 2002. possible adverse effect of chromium in occupational exposure of tannery workers. industrial health, 40(2), 207-13. doi.org/10.2486/indhealth.40.207 lin, c.c., wu, m.l., yang, c.c., ger, j., tsai, w.j. and deng, j.f., 2009. acute severe chromium poisoning after dermal exposure to hexavalent chromium. journal of chinese medical association, 72(4), 219221. doi.org/10.1016/s1726-4901(09)70059-0 loubières, y., de lassence, a., bernier, m., vieillard-baron, a., schmitt, j.m., page, b. and jardin, f., 1999. acute, fatal, oral chromic acid poisoning. journal of toxicology: clinical toxicology, 37(3), 333336. doi.org/10.1081/ clt-100102431 lupescu, a., jilani, k., zelenak, c., zbidah, m., qadri, s.m. and lang, f., 2011. hexavalent chromium induced erythrocyte membrane phospholipid asymmetry. biometals, 25(2), 309-318. doi: 10.1007/s10534-011-9507-5 maurice, j., 2001. tannery pollution threatens health of half-million bangladesh residents. bulletin of the world health organization, 79(1), 78-79. doi: 10.1590/s0042-96862001000100018 michie, c.a., hayhurst, m., knobel, g.j., stokol, j.m. and hensley, b., 1991. poisoning with a traditional remedy containing potassium dichromate. human & experimental toxicology, 10(2), 129-131. doi.org/10.1177/096032719101000207 mohanta, m.k., salam, m.a., saha, a.k., hasan, a. and roy, a.k., 2010. effects of tannery effluents on survival and histopathological changes in different organs of channa punctatus. asian journal of experimental biological sciences, 1(2), 294-302. mohanta m.k., saha, a.k. and hasan, m.a., 2012. prevalence and determination of occupational diseases of leather tannery workers. university journal of zoology, rajshahi university, 31, 79-82. http://tih.sagepub.com/search?author1=dilshad+ahmed+khan&sortspec=date&submit=submit http://tih.sagepub.com/search?author1=shahida+mushtaq&sortspec=date&submit=submit https://doi.org/10.2486/indhealth.40.207 http://www.ncbi.nlm.nih.gov/pubmed/?term=michie%20ca%5bauthor%5d&cauthor=true&cauthor_uid=1675104 http://www.ncbi.nlm.nih.gov/pubmed/?term=hayhurst%20m%5bauthor%5d&cauthor=true&cauthor_uid=1675104 http://www.ncbi.nlm.nih.gov/pubmed/?term=knobel%20gj%5bauthor%5d&cauthor=true&cauthor_uid=1675104 http://www.ncbi.nlm.nih.gov/pubmed/?term=hensley%20b%5bauthor%5d&cauthor=true&cauthor_uid=1675104 http://www.ncbi.nlm.nih.gov/pubmed/?term=hensley%20b%5bauthor%5d&cauthor=true&cauthor_uid=1675104 http://www.ncbi.nlm.nih.gov/pubmed/?term=hensley%20b%5bauthor%5d&cauthor=true&cauthor_uid=1675104 international journal of environment issn 2091-2854 84 | p a g e moshtaghie, a.a., ani, m. and bazrafshan, m.r., 1992. comparative binding study of aluminum and chromium to human transferrin effect of iron. biological trace element research, 32(1), 39-46. doi: 10.1007/bf02784585 nehru, b. and kaushal, s., 1993. alterations in the hepatic enzymes following experimental lead poisoning. biological trace element research, 38(1), 27-34. doi: 10.1007/bf02783979 öry, f.g., rahman, f.u., katagade, v., shukla, a. and burdorf, a., 2011. respiratory disorders, skin complaints, and low-back trouble among tannery workers in kanpur, india. american industrial hygiene association journal, 1, 740-746. doi.org/10.1080/15428119791012397 ramzan, m., malik, m.a., iqbal, z., arshad, n., khan, s.y. and arshad, m., 2011. study of hematological indices in tannery workers exposed to chromium in sheikhupura (pakistan). toxicology and industrial health, 27(9), 857-864. doi.org/10.1177/ 0748233711399316 randall, j.a. and gibson, r.s., 1989. hair chromium as an index of chromium exposure of tannery workers. british journal of industrial medicine, 46(3), 171-175. doi: 10.1136/oem.46.3.171 rastogi, s.k., pandey, a. and tripathi, s., 2008. occupational health risks among the workers employed in leather tanneries at kanpur. indian journal of occupational and environmental medicine, 12(3), 132-135. doi: 10.4103/0019-5278.44695 sanderson, c.j. and thomas, j.a., 1978. a comparison of the cytotoxic activity of eosinophils and other cells by 51chromium release and time lapse microcinematography. immunology, 34(4), 771-780. pmid: 721138 shahzad, k., akhtar, s. and mahmud, s., 2006. prevalence and determinants of asthma in adult male leather tannery workers in karachi, pakistan: a cross sectional study. bmc public health, 6(1), 292. doi: 10.1186/1471-2458-6-292 sharma, b.k., singhal, p.c. and chugh, k.s., 1978. intravascular haemolysis and acute renal failure following potassium dichromate poisoning. postgraduate medical journal, 54(632), 414-415. doi.org/10.1136/pgmj.54.632.414 stern, f.b., beaumont, j.j., halperin, w.e., murthy, l.i., hills, b.w. and fajen, j.m., 1987. mortality of chrome leather tannery workers and chemical exposures in tanneries. scandinavian journal of work environment & health, 13(2), 108-117. doi: 10.5271/sjweh.2073 štupar, j., vrtovec, m., kocijančič, a. and gantar, a., 1999. chromium status of tannery workers in relation to metabolic disorders. journal of applied toxicology, 19(6), 437-446. pmid: 10547626 https://doi.org/10.1007/bf02784585 http://www.ncbi.nlm.nih.gov/pubmed/?term=nehru%20b%5bauthor%5d&cauthor=true&cauthor_uid=7691129 http://www.ncbi.nlm.nih.gov/pubmed/?term=kaushal%20s%5bauthor%5d&cauthor=true&cauthor_uid=7691129 http://www.ncbi.nlm.nih.gov/pubmed/7691129 https://doi.org/10.1007/bf02783979 http://www.tandfonline.com/author/%c3%96ry%2c+f+g http://www.tandfonline.com/author/rahman%2c+f+u http://www.tandfonline.com/author/katagade%2c+v http://www.tandfonline.com/author/shukla%2c+a http://www.tandfonline.com/author/burdorf%2c+a http://www.ncbi.nlm.nih.gov/pubmed/?term=rastogi%20sk%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=sanderson%20cj%5bauthor%5d&cauthor=true&cauthor_uid=721138 http://www.ncbi.nlm.nih.gov/pubmed/?term=thomas%20ja%5bauthor%5d&cauthor=true&cauthor_uid=721138 http://www.ncbi.nlm.nih.gov/pubmed/721138 https://www.ncbi.nlm.nih.gov/pubmed/721138 http://onlinelibrary.wiley.com/doi/10.1002/%28sici%291099-1263%28199911/12%2919:6%3c%3e1.0.co;2-5/issuetoc international journal of environment issn 2091-2854 85 | p a g e uyanik, f., 2001. the effects of dietary chromium supplementation on some blood parameters in sheep. biological trace element research, 84(1-3), 93-101. doi: 10.1385/bter:84:1-3:093 wang., x., qin, q., xu, x., xu, j., wang, j., zhou, j., huang, s., zhai, w., zhou, h. and chen, j., 1994. chromium-induced early changes in renal function among ferrochromium-producing workers. toxicology, 90(1-2), 93-101. doi.org/10.1016/0300-483x(94)90208-9 wedeen, r.p. and qian, l.f., 1991. chromium-induced kidney disease. environmental health perspectives, 92, 71-74. doi: 10.2307/3431139 zhang, g.s. and jin, y.l., 2006. studies on the nephrotoxicity of chromium compounds. journal of hygiene research, 35, 659-662. pmid: 17086728 http://www.ncbi.nlm.nih.gov/pubmed/?term=uyanik%20f%5bauthor%5d&cauthor=true&cauthor_uid=11817699 https://doi.org/10.1385/bter:84:1-3:093 http://www.ncbi.nlm.nih.gov/pubmed/?term=wang%20x%5bauthor%5d&cauthor=true&cauthor_uid=7912862 http://www.ncbi.nlm.nih.gov/pubmed/?term=qin%20q%5bauthor%5d&cauthor=true&cauthor_uid=7912862 http://www.ncbi.nlm.nih.gov/pubmed/?term=xu%20x%5bauthor%5d&cauthor=true&cauthor_uid=7912862 http://www.ncbi.nlm.nih.gov/pubmed/?term=xu%20j%5bauthor%5d&cauthor=true&cauthor_uid=7912862 http://www.ncbi.nlm.nih.gov/pubmed/?term=wang%20j%5bauthor%5d&cauthor=true&cauthor_uid=7912862 http://www.ncbi.nlm.nih.gov/pubmed/?term=zhou%20j%5bauthor%5d&cauthor=true&cauthor_uid=7912862 http://www.ncbi.nlm.nih.gov/pubmed/?term=huang%20s%5bauthor%5d&cauthor=true&cauthor_uid=7912862 http://www.ncbi.nlm.nih.gov/pubmed/?term=zhai%20w%5bauthor%5d&cauthor=true&cauthor_uid=7912862 http://www.ncbi.nlm.nih.gov/pubmed/?term=zhou%20h%5bauthor%5d&cauthor=true&cauthor_uid=7912862 http://www.ncbi.nlm.nih.gov/pubmed/?term=chen%20j%5bauthor%5d&cauthor=true&cauthor_uid=7912862 http://www.ncbi.nlm.nih.gov/pubmed/7912862 https://doi.org/10.1016/0300-483x(94)90208-9 performance of sweet pepper under protective structure international journal of environment issn 2091-2854 12 | p a g e international journal of environment volume-12, issue-1, 2023 issn 2091-2854 received: 19 august 2022 revised: 12 january 2023 accepted: 13 january 2023 regeneration status and population structure in terai community forest: evidence from kalyankot community forest, kapilvastu district, nepal vivek thapa chhetri1, susmita shrestha1 *, shweta parajuli1 and pabitra jha1 1tribhuvan university, institute of forestry, pokhara campus, pokhara 33700, nepal *corresponding author: susmitashrestha141@gmail.com abstract the regeneration status of a forest is an essential metrics to assess the regeneration potential and population structure of forests. in emerging nations like nepal, however, human dependency on forests has had a negative influence on forest diversity and sustainability. this paper analyzes the regeneration status and its link with bio-physical aspects and human disturbances. the data were collected using a systematic random sampling method and sample plots were established using the fishnet tool in arcgis. an inventory survey of 96 plots was carried out with nested circular sample plots with a main radius of 1261 cm. the overall regeneration condition of the forest was found to be in good condition according to community forestry inventory guideline, 2004. the majority of the tree species were determined to have a sound quality and medium (ii) grades in this study. in terms of the diameter class distribution, lower diameter classes (21-60 cm) comprised more adults than the upper diameter classes (61-120 cm). this study found no significant variations in the effects of biophysical factors, such as slope and aspect, on species regeneration. the study concludes the inadequate silvicultural management interventions in the forest. this information can be useful to devise systematic plans to promote good-quality regeneration and manage the factors that are likely to affect the overall regeneration. further research focusing on other biophysical factors as well as social factors and their influence on regeneration including its management techniques is recommended. keywords: biophysical variable, diameter class distribution, disturbances, inventory, seedlings mailto:susmitashrestha141@gmail.com https://orcid.org/0000-0002-6265-0303 international journal of environment issn 2091-2854 13 | p a g e doi: https://doi.org/10.3126/ije.v12i1.52439 copyright ©2023 ije this work is licensed under a cc by-nc which permits use, distribution and reproduction in any medium provided the original work is properly cited and is not for commercial purposes introduction a forest area is comprised of different stages of species composition i.e. seedling, sapling, and tree. the seedling and sapling number in a forest indicates the regeneration status of that forest (karyati et al., 2013). enough number of tree species present in the forest indicates successful and satisfactory behavior (pala et al., 2013) and reflects the productive characteristics of the forest (chauhan et al., 2008). natural regeneration is fundamental for forest ecosystem management as well as sustainability (tesfaye et al., 2010) which is essential for preserving and maintaining global biodiversity (rahman et al., 2011). species diversity and forest structure are primarily determined by the regeneration of species over time and space as well as natural and anthropogenic disturbances (munesh kumar and rajwar, 2009). the seedling and sapling population of the species determines the regeneration potential of the forest (negi and nautiyal, 2005). enhancing natural regeneration in forest stands may also be the most economical strategy to create a diverse, productive stand (pradhan et al., 2019). the study of the regeneration potential and growth status of a species is essential to determine ecosystem stability in the long run (malik and bhatt, 2016). most of the rural populations highly depend on forest resources which leads to forest degradation through the activities like harvesting timber and non-timber forest products, fodder and firewood collection, and domestic grazing (chapagain et al., 2021). in developing countries like nepal, human dependency on forest resources challenges biodiversity conservation (mishra et al., 2004). a healthy forest possesses good regeneration status and predicts good future regenerations (poudel and devkota, 2021). however, natural as well as humaninduced activities may alter the species diversity, population structure, and composition of the forest ecosystems (dutta and devi, 2013). human disturbances, crown cover, geographical features (slope, aspect, and altitude), soil quality, and climatic condition of the area are the most influential factors to affect the population structure of a forest (bose et al., 2016; sapkota et al., 2009a). successful natural regeneration can be an achievement for long-term forest management and its sustainability (malik and bhatt, 2016; saikia and khan, 2013). regeneration along with species richness and diversity is important for the assessment of forests for sustainability, conservation of the species, ecological significance, and policy formation (kacholi, 2014; r. s. tripathi and khan, 2007). though natural regeneration is a slow https://doi.org/10.3126/ije.v12i1.52439 international journal of environment issn 2091-2854 14 | p a g e process, it has a significant role in maintaining a stable age structure in forests (mwavu and witkowski, 2009), and its improvement is the most cost-effective way in achieving a productive stand with rich species (liira et al., 2011). hence, the study of the diverse characteristics of the forest affecting natural regeneration is essential (mousavi et al., 2011). an understanding of the age distribution of a forest population explains its reproductive potential and predicts its future (thakur et al., 2021). community forestry inventory guideline 2004 is a common policy tool for assessing regeneration and yield regulation which is mainly focused on sustainable management of the community forest in nepal (sharma, 2017). in forest management, regeneration studies show not only the current state of the forest but also clues about future changes in forest composition. nepal's forest is a habitat for several species thus improvement of regeneration status is vital to improve the status of degraded forests (chikanbanjar et al., 2020). as the lowland forests of nepal are comprised of diverse wild flora and fauna (paudel and bhattarai, 2011), sustainable management plan to improve the regeneration is very important. the literature review reveals that there are very limited studies related to the regeneration status in lowland terai forests. kapilvastu as a district representing lowland terai forest of nepal and situated in the terai arc landscape (tal) of nepal has no such study carried out to date. thus, a study related to an assessment of population structure reflecting regeneration condition of the forest is very essential that can indicate the entire lowland terai forests of nepal. hence, this study was carried out with the objectives to (i) assess the overall population structure (ii) analyze the current regeneration status and (iii) analyze the factors affecting the regeneration. the results of this study are expected to be useful to the wider policy groups for developing essential plans and procedures to improve the regeneration status as well as the overall forest condition in the lowland forests of nepal. therefore, research and studies on regeneration provide insights into its current structure and composition contributing further forest management planning and conservation strategies such as seedling and sapling manipulation through minimization of grazing and crown cover regulation. materials and methods study area kalyankot community forest is situated in the southern part of the kapilvastu district of nepal (figure 1). the district lies between latitude 27°32′n and longitude 83°3′e at an altitudinal range of 93 to 1491 masl. geographically, it has plain low lands of terai and low chure hills with a humid, subtropical climate. its average annual temperature ranges from 25°c to-19°c with a maximum of 43°c in the summer to a minimum of 4.5°c in the winter. the community forest goes up to 240m from the mean sea level and is surrounded by the chirai river in the east; gangate river in the west; kalyankot (chure area) in the north and indreni community forest in the south. kalyankot is rich in wild flora and fauna. shorea robusta (sal), international journal of environment issn 2091-2854 15 | p a g e anogeissus latifolia (banjhi), terminalia tomentosa (sajh), dalbergia latifolia (satisal), tectona grandis (teak), eucalyptus camuldensis (safeda), madhuca longifolia (mahuwa) are the dominant tree species in the forest. figure 1: map of the study area data collection sampling the data were collected using a systematic random sampling method. sample plots were distributed systematically using the fishnet tool in the arc toolbox function of arcgis 10. 8. if the fishnet was created beyond the boundary, a clipping tool was used to locate the sample plots within the forest boundary and the gps coordinates of the sample plots were extracted. each plot was located in the field with the help of a garmin etrex 10 device. the sampling intensity of 1% was taken for inventory. the total number of sample plots and plot-to-plot distance was calculated as per the community forest inventory guidelines, 2004 using the following formulae: 𝑁 = (𝐴 ∗ 𝑆𝐼% ∗ 10000)/𝑃 where, n= no of sample plots a= area of forest international journal of environment issn 2091-2854 16 | p a g e si= sampling intensity p= plot size 𝐷 = √𝐴 ∗ 10000/(𝑁 + 1) where, d= plot to plot distance a= area of forest n= no of sample plots the circular plots were established for forest inventory. trees were measured in 500 m2 (r= 12.61m) and poles were measured in 100 m2 (r= 5.64m) plots. the established regeneration (saplings) was measured in the nested concentric circular plot of 25 m2 (r= 2.82 m) and the young regeneration (seedlings) was measured in the nested concentric circular plots of size 10 m2 (r= 1.78 m). forest inventory the inventory data were collected in the field from 14th to 21st january 2022. the extracted gps coordinates of the sample plots were inserted in the garmin gps and each plot was located in the field. a total of 95 sample plots were surveyed with a 225 m distance between each sample plot. the plots were laid in a concentric and nested way in the field. measurements (counting the number of individuals of each species) were made in the order of seedlings, saplings, and adults (trees/poles). the young regenerations (seedlings) were considered plants with a height between 30 cm to 100 cm height. the established regenerations (saplings) were considered as plants of height> 100 cm and dbh up to 9.9 cm. poles and trees were considered as the plants with dbh 10 cm to 29.9 cm and ≥ 30cm from 1.3 m above the ground level. in addition, canopy cover, aspect, slope, and human disturbances were recorded to find out the relationship between regeneration status and plot variables. the canopy cover (%) for each plot was estimated visually from the center of the plot following zobel et al. (1987). the disturbance parameters such as grazing, trampling, forest fire, exposed ground, etc. were observed in and around the plot to determine the disturbances following (haq et al., 2019). data analysis a regression analysis was performed by spss 25 to determine the relationship between regeneration and plot variables. based on extrapolation per ha basis, the density of adults, seedlings, and saplings were computed international journal of environment issn 2091-2854 17 | p a g e for the whole forest. densities (numbers per hectare) of seedlings and saplings of each species were also analyzed to determine the regeneration status of the forest following the community forestry inventory guideline. as per the community forestry inventory guidelines 2004 (department of forest, 2004), the forest condition can be regarded as: (i) 'good' if the numbers of seedlings and saplings per hectare exceed 5,000 and 2,000 respectively, (ii) 'medium' if the numbers of seedlings and saplings per hectare lie between 2,000−5,000 and 800−2,000 respectively, and (iii) 'poor' if the numbers of seedlings and saplings per hectare lie below 2,000 and 800 respectively. the regeneration category of the species was assessed using (tiwari et al., 2019) as: (a) ‘good’ if seedling > sapling> adults, (b) ‘fair’ if seedling > sapling ≤ adults, (c) ‘poor’ if a species survives only in the sapling stage but not as seedlings, (d) ‘none’ if a species has no seedlings and saplings, and (e) ‘new’ if the species has only seedlings and saplings. therefore, the regeneration potential of each category was assessed by counting the total number of species in each category of regeneration and dividing by the total number of species representing a value as a percentage of the total species for each forest regeneration category. 𝑅𝑒𝑔𝑒𝑛𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝑝𝑜𝑡𝑒𝑛𝑡𝑖𝑎𝑙 = 𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑠𝑝𝑒𝑐𝑖𝑒𝑠 𝑖𝑛 𝑒𝑎𝑐ℎ 𝑟𝑒𝑔𝑒𝑛𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝑐𝑎𝑡𝑒𝑔𝑜𝑟𝑦 𝑇𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑠𝑝𝑒𝑐𝑖𝑒𝑠 ∗ 100 (pradhan et al., 2019) the tree quality was coded for tree state as: s: sound tree, dd: dead and dying, d: diseased, tc: top cut, l: leaning and tree grade as: i: generally straight and clear bole that can potentially yield at least 3 logs of 6 feet length, ii: generally straight bole that can yield at least 2 logs of 6 feet length, and iii: generally branched, crooked with/out hollow inside, and cannot yield any logs of commercial value. results adult quality the highest percentage (81%) of the tree population i.e. 314 individuals were found to be in a sound state (without any damage to the tree), whereas 8% of trees were dead and dying, 5% were leaning trees, 4% were top cut and 2% were found diseased (figure 2). international journal of environment issn 2091-2854 18 | p a g e figure 2: different tree quality present inside the forest adult grade figure 3 shows the wood quality of the tree expressed in tree grades i.e. good (i), medium (ii), and poor (iii). maximum numbers (44%) of the species were found to be of medium (ii) grade followed by 33% of good (i) grade and 23% of poor (iii) grade. figure 3: wood quality of trees in terms of tree grade dbh classes for adults a total of 637 tree individuals were recorded with various dbh classes. the overall population structure of tree species concerning dbh classes exhibited the tree individuals from lowest (10-20 cm) to highest (110120 cm) dbh class. the highest number (177) of tree individuals were recorded in the dbh class of 2030cm and the lowest (5) number of tree individuals were recorded in the dbh class of 10-20cm. the dbh class of 60-70cm and 70-80cm shared an equal (49) frequency of adults, whereas overall tree population structure varied with dbh classes (figure 4). dd: dead and dying 8% diseased 2% l:leaning 5% s: sound tree 81% tc:top cut 4% dd: dead and dying diseased l:leaning s: sound tree tc:top cut 33% 44% 23% good medium poor international journal of environment issn 2091-2854 19 | p a g e figure 4: distribution of individual trees in different dbh classes regeneration status of kalyankot forest in the entire sample plot of the community forest, the density of seedlings, saplings, and adults were 12756.69, 3063.95, and 305.65 individuals per ha, respectively (table 1). the overall regeneration condition of the forest was found to be in good condition according to cf inventory guideline 2004, as the density of seedlings and saplings exceeded 5000 and 2000, respectively. shorea robusta, bauhinia purpurea, mallotus philippensis, syzygium cumini, and bauhinia variegata were major species with a greater number of seedlings/ha. the major species with a greater number of saplings per hectare were shorea robusta, bauhinia purpurea, mallotus philippensis, terminalia alata, and bauhinia variegate respectively. shorea robusta, anogeissus latifolius, buchanania latifolia, mallotus philippensis, and terminalia alata were 5 major species with a greater density of adult/ha (table 1). table 1: regeneration status of the kalyankot community forest scientific name common name family seedlings/h a saplings/h a adults/h a regeneratio n status category senegalia catechu (l. f.) p. j.h. hurter & mabb. khayar fabaceae 0 0 0.25 none adina cordifolia (willd. ex roxb.) benth. karam rubiaceae 12.50 5 0 new aegle marmelos (l.) correa bel rutaceae 0 0 0.50 none anogeissus latifolius (roxb. ex dc.) bedd. banjhi combrataceae 46.13 35 41.83 fair bauhinia purpurea l. tanki, maluka leguminosae 1756.25 678.33 0 new 5 177 79 125 73 49 49 35 17 18 10 0 20 40 60 80 100 120 140 160 180 200 f re q u e n c y o f a d u lt s dbh classes (cm) international journal of environment issn 2091-2854 20 | p a g e bauhinia variegata l. koiralo, kachnar leguminosae 1059.23 71.67 0 new buchanania latifolia roxb. pyar, piyari anacardiaceae 268.75 48.33 37.03 good careya herbacea roxb. kumbhi lecythidaceae 43.75 0 2.38 fair casearia graveolens dalzell badkaule salicaceae 0 0 1.25 none cassia fistula l. rajbriksh a leguminosae 200.3 59.05 4.52 good citrus limon (l.) burm. f. nibuwa rutaceae 0 6.67 0 poor colebrookea oppositifolia sm. dhursule lamiaceae 62.5 25 0 new dalbergia latifolia roxb.* satisal leguminosae 16.67 5 0.5 good dillenia pentagyna roxb. agai dilleniaceae 0 0 1.25 none diospyrus tomentosa roxb. bidi pat ebenaceae 191.37 45.71 1.67 good diploknema butyracea (roxb.) h.j. lam chyuree sapotaceae 0 0 0.25 none dysoxylum binectariferum (roxb.) hook. dhamina meliaceae 12.5 5 1 good ehretia laevis roxb. datrung ehretiaceae 12.5 5 0 new eucalyptus camaldulensis dehn. masala, safeda myrtaceae 25 16.67 0 new ficus benghalensis linn. bar moraceae 0 0 0.25 none ficus hispida l. kharseto moraceae 66.67 17.50 0 new ficus neriifolia sm. dudhilo moraceae 45.83 5 9.58 fair ficus religiosa l. pipal moraceae 0 5 0 poor garuga pinnata roxb. hook. f. ex brandis dabdabe burseraceae 0 0 10.77 none lagerstroemia parviflora roxb. bot dhaiyaro lythraceae 0 3.33 6.55 poor leucaena leucocephala lam.) de wit ipil ipil leguminosae 20.96 8.33 0 new litsea monopetala (roxb.) pers. kutmero lauraceae 10.42 4.17 0 new madhuca longifolia (koeing) macbride mahuwa sapotaceae 105.06 10 4.25 good international journal of environment issn 2091-2854 21 | p a g e mallotus philippensis (lam.) mull.arg. rohini, sindur euphorbiaceae 1335.42 536.67 28.24 good phyllanthus emblica linn. amala euphorbiaceae 0 4.17 2.29 poor schleichera oleosa (lour.) oken kusum sapindaceae 146.73 16.43 4.25 good semecarpus anacardium l.f bhalayo anacardiaceae 29.17 34.17 13.90 poor shorea robusta gaertn. sal dipterocarpace ae 5246.13 1163.1 90.92 good syzygium cumini (l.) skeels jamun myrtaceae 1145.83 18.1 3.46 good tectona grandis l.f. teak, sagawan verbenaceae 50 30 3.57 good terminalia alata b. heyne ex roth saj combretaceae 750.89 180.95 18.57 good terminalia bellirica gaertn.) roxb. barro combretaceae 44.64 13.10 13.83 fair terminalia chebula retz. harro combretaceae 32.74 4.17 2.79 good vitis lanata roxb. mahur vitaceae 0 3.33 0 poor woodfordia fruticosa (l.) kurz dhayaro lythraceae 18.75 0 0 new total 12756.69 3063.95 305.65 mean 319 77 8 sd 899 221.75 16.74 regeneration potential among 40 species observed at the site, 13 species showed good regeneration status, 4 species with fair regeneration, and 6 species showed poor regeneration. among the remaining species, 10 of them showed new regeneration status while 7 species had no regeneration at all. the regeneration potential for the species under the category good, fair, poor, new, and none was 32%, 10%, 15%, 25%, and 18%, respectively (figure 5). international journal of environment issn 2091-2854 22 | p a g e figure 5: regeneration status of species inside forest effect of biophysical variables on the regeneration the majority of the crown cover range was of 0-30% (1744) followed by 30-60% (443) and least of the above 60% (221). similarly, the highest number of plots were situated in the northern aspect (48) followed by southern (32), western (10) and the least in the eastern aspect (5). furthermore, the majority of the regeneration were found in the disturbance-free plots from anthropogenic factors (1848) followed by human disturbance plots (560). the regression analysis of the number of regeneration and two biophysical variables i.e. slope (figure 6) and aspect were found not to be significant (p>0.05). figure 6: linear regression between the number of regeneration and slope (in degree) good 32% fair 10% poor 15% new 25% none 18% good fair poor new none y = 0.3711x + 21.338 r² = 0.0121 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 n o . o f re g e n e ra ti o n slope (degree) no. of regeneration linear (no. of regeneration) international journal of environment issn 2091-2854 23 | p a g e simple linear regression was used to test if human disturbance predicted the regeneration frequency where, regeneration frequency = 27.58-7.58 (human disturbance). to confirm the level of their relationship, a t-test was performed for regeneration number and human disturbance which indicates that the human disturbance influences the number of regeneration but the effect is not very significant. table 2error! reference source not found. shows that the overall regression was found statistically insignificant (r2= 0.02, p > 0.10). table 2: regression between human disturbance and number of regeneration regression statistics multiple r 0.15 r square 0.02 adjusted r square 0.01 standard error 21.70 observations 95 anova df ss ms f significance f regression 1 1135.23 1135.23 2.40 0.12 residual 93 43808.29 471.05 total 94 44943.53 coefficients standard error t stat p-value intercept 27.58 2.65 10.40 2.90018e-17 human disturbance -7.58 4.88 -1.55 0.12 discussion our study found the mean of the seedlings, saplings and adults to be 319, 77 and 8 indicating the high presence of seedlings in the forest which is suitable from the forest sustainability. the results showed a high number of individuals in the lower dbh classes and a low number of individuals in the upper dbh classes which is similar to the finding of khamyong et al. (2004). higher frequency in the lower diameter class may be due to the restriction on felling of small-sized trees and prevailing appropriate environmental conditions, while the extraction of large-sized trees may be the reason for lower frequency in the higher diameter class (sapkota et al., 2009b; sarkar and devi, 2014). high frequency in the lower diameter class represents the sustainable, stable, and good regeneration condition of the forest (awasthi et al., 2015; manna and mishra, 2017) having a high resource utilization capacity (naidu and kumar, 2016). the majority of the tree species offered sound quality and the maximum numbers of the species were found to be of medium (ii) grade, representing the productive forest which may be supported due to suitable environmental conditions and minimum disturbance factors (sapkota et al., 2009a). the presence of shorea robusta, bauhinia purpurea, mallotus philippensis, syzygium cumini, bauhinia variegate as dominant seedling species suggested a good ability for regeneration, which reflected the international journal of environment issn 2091-2854 24 | p a g e existing favorable environmental conditions. the study showed a greater number of seedlings per hectare than saplings which aligned with the finding of (chikanbanjar et al., 2020) that might be due to the presence of appropriate environmental attributes suitable for seedling establishment. our results showed a higher regeneration potential of shorea robusta which is consistent with the result of joshi et al. (2019). likewise, s. robusta was found to be the dominating tree species in the community forest which is similar to the finding of the inventory (department of forest research and survey/forest resource assessment, 2014). the community forest's total capacity for regeneration was considered to be satisfactory, indicating high regeneration status; nevertheless, the unsatisfactory rate of 18% regeneration may have an impact on future population trends. the regeneration potential of the forest is found highest in the good condition along with substantive poor and no regeneration potential. tripathi and shankar (2014) reported that sal is always found to be a dominating species in the place of its existence to which our study agrees. there is a high number of seedlings, saplings, and poles of sal in the forest. moreover, some species such as garuga pinnata, ficus benghalensis, diploknema butyracea, dillenia pentagyna, casearia graveolens, aegle marmelos, and senegalia catechu had no seedlings and saplings indicating the least regeneration potential. this could be because of insufficient microclimatic conditions within the forest cover, which in turn will affect tree species' ability to regenerate by seed. the composition of the species with no regeneration will also affect species composition of the forest in the future (pradhan et al., 2019). low or inconsistent seed supply, a lack of suitable micro-sites, and/or variables affecting early seedling growth and survival might be the contributing factor to the absence of regeneration (gärtner et al., 2011). many studies have assessed the effects of environmental variables in the regeneration of the tree species. the regeneration of the species may vary due to climatic, edaphic, topographic, biological and anthropogenic factors. however, nepali et al. (2021) explained no significance of the slope and aspect on species richness which commensurate to our finding as the number of regeneration did not vary significantly with the change in slope and aspect. shah and shah (2016) established a relationship between slope and the number of regeneration and concluded that rolling slopes had a higher number of regeneration than regular and steep slopes. in contrast, our study did not find any significance of slope on the number of regeneration. in general, anthropogenic factors and natural phenomena affect the regeneration of species (poudel and devkota, 2021). minimal openings in the canopy cover allow higher light transitivity on the forest floor favoring the lightdemanding species for the seedling recruitment process (webb and sah, 2003). an open canopy is favorable for abundant growth of the seedlings and saplings of light-demanding species like sal (gautam and devoe, 2006). so, it is concluded that thinning activities should be conducted regularly for the proper growth of the seedlings and saplings. similarly, the effect of human disturbances in the regeneration of the species was found international journal of environment issn 2091-2854 25 | p a g e statistically insignificant which may be due to sampling bias of the study. furthermore, this study includes the limitation of smaller sample sizes for the study of effect of biophysical variables and anthropogenic factors which should be addressed by further in-depth studies for the scientific validation. however, the current research findings will help researchers to develop insights into the effects of plot variables in regeneration and assist in developing future management strategies for the community forest. conclusions this study represents the overall regeneration condition of the forest to be in a good condition. the forest was found to have a higher seedling density, indicating that the population may be sustained if there is no adverse impact of potential increased human interferences in future. the total number of species observed in the forest was 40. the greater species count represents the more number of undesirable species prevalent in the forest changing the vegetation ecology which may be due to insufficient tending operations such as thinning and pruning. thus, it is recommended to follow tending operations to increase forest productivity. this study helps policymakers about current population structure of lowland terai forests. this study prompts the decision makers to adopt silviculture system based sustainable forest management model to reap forest benefits in a sustainable way without changing vegetation ecology. further research focusing on other biophysical and social parameters and their effects on regeneration including ways of improving regeneration quality and management techniques should be carried out. authorship contribution statement v.t. chhetri, s. shrestha, and s. parajuli collected field data, reviewed the literature, and prepared a draft manuscript. p. jha conducted data analysis, edited and reviewed the manuscript for finalization. conflicts of interest: the authors declare no conflict of interest. acknowledgment: we would like to acknowledge the institute of forestry, pokhara campus for the field inventory arrangement. we would also like to thank mr. mahendra singh thapa and mr. dhruba bijay gc for guidance during field inventory. we thank division forest office, kapilvastu, and kalynakot community forest for accommodation during the field inventory. we thank our colleagues ms. swastika acharya, mr. prabin adhikari, mr. rajan pun magar, mr. manish poudel, and mr. mission shrestha for their fieldwork assistance. international journal of environment issn 2091-2854 26 | p a g e references awasthi, n., bhandari, s. k., khanal, y., 2015. does scientific forest management promote plant species diversity and regeneration in sal (shorea robusta) forest? a case study from lumbini collaborative forest, rupandehi, nepal. banko janakari, 25(1): 20-29. bose, a. k., weiskittel, a., wagner, r. g., kuehne, c., 2016. assessing the factors influencing natural regeneration patterns in the diverse, multi-cohort, and managed forests of maine, usa. journal of vegetation science, 27(6): 1140–1150. https://doi.org/10.1111/jvs.12433 chapagain, u., chapagain, b. p., nepal, s., manthey, m., 2021. impact of disturbances on species diversity and regeneration of nepalese sal (shorea robusta) forests managed under different management regimes. earth, 2(4): 826–844. https://doi.org/10.3390/earth2040049 chikanbanjar, r., baniya, b., dhamala, m. k., 2020. an assessment of forest structure, regeneration status and the impact of human disturbance in panchase protected forest, nepal. forestry: journal of institute of forestry, nepal, 17(17): 42–66. https://doi.org/10.3126/forestry.v17i0.33621 department of forest, 2004. community forestry inventory guidelines. department of forest research and survey/forest resource assessment, 2014. terai forests of nepal. dutta, g., devi, a., 2013. plant diversity, population structure, and regeneration status in disturbed tropical forests in assam, northeast india. journal of forestry research, 24(4): 715–720. https://doi.org/10.1007/s11676-013-0409-y gärtner, s. m., lleffers, v. j., macdonald, s. e., 2011. ecology and management of natural regeneration of white spruce in the boreal forest. environmental reviews, 19(1): 461–478. https://doi.org/10.1139/a11017 gautam, k. h., devoe, n. n., 2006. ecological and anthropogenic niches of sal (shorea robusta gaertn. f.) forest and prospects for multiple-product forest management–a review. forestry, 79(1): 81-101. haq, s. m., rashid, i., khuroo, a. a., malik, z. a., malik, a. h., 2019. anthropogenic disturbances alter community structure in the forests of kashmir himalaya. tropical ecology, 60(1): 6–15. https://doi.org/10.1007/s42965-019-00001-8 joshi, r., chhetri, r., yadav, k., 2019. vegetation analysis in community forests of terai region, nepal. international journal of environment, 8(3): 68–82. https://doi.org/https://doi.org/10.3126/ije.v8i3.26667 kacholi, d. s., 2014. analysis of structure and diversity of the kilengwe forest in the morogoro region, tanzania. international journal of biodiversity, 1–8. https://doi.org/10.1155/2014/516840 karyati., ipor, ib., jusoh, i., wasli, me., seman, ia., 2013. composition and diversity of plant seedlings and saplings at early secondary succession of fallow lands in sabal, sarawak. acta biologica malaysiana, international journal of environment issn 2091-2854 27 | p a g e 2(3): 85-94. khamyong, s., lykke, a. m., seramethakun, d., barfod, a. s., 2003. species composition and vegetation structure of an upper montane forest at the summit of mt. doi inthanon, thailand. nordic journal of botany, 23(1): 83–97. https://doi.org/10.1111/j.1756-1051.2003.tb00371.x munesh kumar, c. m. s., rajwar, g. s., 2009. the effects of disturbance on forest structure and diversity at different altitudes in garhwal himalaya. ecology, 28(3), 424r432. liira, j., sepp, t., kohv, k., 2011. the ecology of tree regeneration in mature and old forests: combined knowledge for sustainable forest management. journal of forest research, 16(3): 184–193. https://doi.org/10.1007/s10310-011-0257-6 malik, z. a., bhatt, a. b., 2016. regeneration status of tree species and survival of their seedlings in kedarnath wildlife sanctuary and its adjoining areas in western himalaya, india. tropical ecology, 57(4): 677– 690. manna, s. s., mishra, s. p., 2017. diversity, population structure and regeneration of tree species in lalgarh forest range of west bengal, india. international journal of botany studies, 2: 191-195. mishra, b. p., tripathi, o. p., tripathi, r. s., pandey, h. n., 2004. effects of anthropogenic disturbance on plant diversity and community structure of a sacred grove in meghalaya, northeast india. biodiversity and conservation, 13(2): 421–436. https://doi.org/10.1023/b:bioc.0000006509.31571.a0 mousavi, k. s. a., ali roshani, g., jalali, s. g., shahrdami, a., 2011. the effects of cover crown, percentage and slope aspect on the quantitative distribution of the alder’s saplings in forests of north of iran. african journal of agricultural research, 6(16): 3817–3821. https://doi.org/10.5923/j.re.20120201.02 mwavu, e. n., witkowski, e. t. f., 2009. population structure and regeneration of multiple-use tree species in a semi-deciduous african tropical rainforest: implications for primate conservation. forest ecology and management, 258(5): 840–849. https://doi.org/10.1016/j.foreco.2009.03.019 naidu, m. t., kumar, o. a., 2016. tree diversity, stand structure, and community composition of tropical forests in eastern ghats of andhra pradesh, india. journal of asia-pacific biodiversity, 9(3): 328–334. https://doi.org/10.1016/j.japb.2016.03.019 negi, c. s., nautiyal, s., 2005. phyto-sociological studies of a traditional reserve forestthal ke dhar , pithoragarh, central himalayas (india). indian forester, 519–534. nepali, b. r., skartveit, j., baniya, c. b., 2021. impacts of slope aspects on altitudinal species richness and species composition of narapani-masina landscape, arghakhanchi, west nepal. journal of asiapacific biodiversity, 14(3): 415–424. https://doi.org/10.1016/j.japb.2021.04.005 pala, n. a., negi, a. k., gokhale, y., todaria, n. p., 2013. tree regeneration status of sacred and protected landscapes in garhwal himalaya, india. journal of sustainable forestry, 32(3): 230-246. international journal of environment issn 2091-2854 28 | p a g e paudel, p. k., bhattarai, b. p., kindlmann, p., 2012. an overview of the biodiversity in nepal. himalayan biodiversity in the changing world, 1-40. poudel, p., devkota, a., 2021. regeneration status of sal (shorea robusta gaertn.) in community managed forests, tanahun district, nepal. journal of institute of science and technology, 26(2): 23–30. https://doi.org/10.3126/jist.v26i2.41297 pradhan, a., ormsby, a., behera, n., 2019. diversity, population structure, and regeneration potential of tree species in five sacred forests of western odisha, india. ecoscience, 26(1): 85–97. https://doi.org/10.1080/11956860.2018.1522148 rahman, m. h., khan, m. a. s. a., roy, b., fardusi, m. j., 2011. assessment of natural regeneration status and diversity of tree species in the biodiversity conservation areas of northeastern bangladesh. journal of forestry research, 22(4): 551–559. https://doi.org/10.1007/s11676-011-0198-0 saikia, p., khan, m. l., 2013. population structure and regeneration status of aquilaria malaccensis lam. in homegardens of upper assam, northeast india. tropical ecology, 54(1): 1–13. sapkota, i. p., tigabu, m., oden, p. c., 2009a. tree diversity and regeneration of community-managed bhabar lowland and hill sal forests in central region of nepal. bois et forets des tropiques, 300(2): 57–68. sapkota, i. p., tigabu, m., odén, p. c., 2009b. spatial distribution, advanced regeneration and stand structure of nepalese sal (shorea robusta) forests subject to disturbances of different intensities. forest ecology and management, 257(9): 1966–1975. https://doi.org/10.1016/j.foreco.2009.02.008 sarkar, m., devi, a., 2014. assessment of diversity, population structure and regeneration status of tree species in hollongapar gibbon wildlife sanctuary, assam, northeast india. tropical plant reaearch, 1(2): 26–36. shah, s. a. a., shah, w., 2016. impact of terrain slopes and aspect on the natural regeneration of the coniferous forest in the northern pakistan-a case study of ayubia national park: natural regeneration of the coniferous forest in the northern pakistan. proceedings of the pakistan academy of sciences: b. life and environmental sciences, 53(1): 57-64. sharma, s. p., 2017. ignored forest management issues in community forestry inventory guideline 2004 in context of scientific and sustainable forest management. in first national silviculture workshop, 213219. tesfaye, g., teketay, d., fetene, m., beck, e., 2010. regeneration of seven indigenous tree species in a dry afromontane forest, southern ethiopia. flora: morphology, distribution, functional ecology of plants, 205(2): 135–143. https://doi.org/10.1016/j.flora.2008.12.006 thakur, u., bisth, n. s., kumar, a., kumar, m., sahoo, u. k., 2021. regeneration potential of forest international journal of environment issn 2091-2854 29 | p a g e vegetation of churdhar wildlife sanctuary of india: implication for forest management. water, air, and soil pollution, 232(9). https://doi.org/10.1007/s11270-021-05315-9 tiwari, o. p., sharma, c. m., rana, y. s., krishan, r., 2019. disturbance, diversity, regeneration and composition in temperate forests of western himalaya, india. journal of forest and environmental science, 35(1): 6-24. tripathi, a. k., shankar, u., 2014. patterns of species dominance, diversity and dispersion in ‘khasi hill sal’ forest ecosystem in northeast india. forest ecosystems, 1(1): 1–20. https://doi.org/10.1186/s40663-0140023-2 tripathi, r. s., khan, m. l., 2007. regeneration dynamics of natural forestsa review. proceedings of the indian national science academy, 167–195. webb, e. l., sah, r. n., 2003. structure and diversity of natural and managed sal (shorea robusta gaertn.f.) forest in the terai of nepal. forest ecology and management, 176(1–3): 337–353. https://doi.org/10.1016/s0378-1127(02)00272-4 zobel, d. b., jha, p. k., behan, m. j., yadav, u. k. r., 1987. a practical manual for ecology. ratna book distributors, kathmandu, nepal, 149. performance of sweet pepper under protective structure international journal of environment issn 2091-2854 141 | p a g e international journal of environment volume-3, issue-1, dec-feb 2013/14 issn 2091-2854 received:17 january revised:11february accepted:17feburary inventory of threatened plants of bangladesh and their conservation management m. harun-ur-rashid, m. enamur rashid and m. atiqur rahman* department of botany, university of chittagong chittagong 4331, bangladesh *corresponding author: atiquerahman125@hotmail.com abstract the study aimed at inventorying of threatened plant species of bangladesh to determine their status of occurrence for emphasizing the setting-up of national conservation strategies and sustainable management. complete inventory of two families, the apocynaceae and vitaceae, has been made and recognized 28 threatened species facing environmental threats, and need sustainable conservation management. the study was based on long-term field investigation, survey of relevant floristic literature and examination of herbarium specimens. an enumeration of threatened taxa is prepared with updated field data on conservation status to include into red data book of bangladesh. key words: inventory, threatened plant species, conservation, management, bangladesh. introduction global biodiversity is depleting at an alarming rate due to human interferences and environmental degradation, causing high risk of extinction. human impact on nature has reached at such a high proportion that the world is today witnessing an unprecedented rate of species loss. many more species are disappearing from the nature before their discovery and determination. the 1997 iucn red list of threatened plants revealed that 12.5% or c.34,000 of the world’s vascular plant species are at risk of extinction, including 7% of family international journal of environment issn 2091-2854 142 | p a g e apocynaceae and 5% of vitaceae (walter & gillett, 1998). later, the 2004 iucn red list includes 11,824 species of plants, of which 8,321 are threatened. however, only about 4% of the described plant species were evaluated so far, of which about 3% are threatened (baillie et al., 2004). the iucn’s threatened plants unit at the royal botanic gardens, kew, has produced a global data of 50,000 plant species, of which around 20,000 species fall under threatened categories. a conservative estimate of iucn’s threatened plants unit shows that about 60,000 plant species (25%) would become either extinct or nearly extinct by the year 2050 (uberoi, 2010). around 50% of world’s flora might be threatened at risk of extinction, if an appropriate assessment is made following iucn’s criteria (pitman and jorgensen, 2002). in the current wave of multiple threats, humans are unable to predict the impact and consequences of plant extinctions. according to usda (1993), extinction of even a single plant species may result in the disappearance of 30 associated species of plants and wildlife. hence, biodiversity conservation has become a global concern, and almost all developed countries have adopted and implemented national conservation strategies. bangladesh is enriched with high plant diversity, since it lies in a transition of two megabiodiversity hot spots, viz, indo-himalayas and indo-chinese. historically, bangladesh forests are highly vulnerable to anthropogenic disturbances and climate change (khan, 2003). it has been estimated that out of c.5000 angiosperm species, at least 8-10% are facing threats to extinction due to habitat loss, population pressure and over-exploitation of natural resources in bangladesh (khan, 1991; rahman et al., 2010). nevertheless, there have been no concrete steps taken to arrest the process (khan et al. 2001). it has been, therefore emphasized by khan et al. (2001) and rahman et al. (2010) that the first and foremost step in this direction is to make complete inventory of the threatened species with assessment of their conservation status in the flora in order to produce red data book of bangladesh for framing and implementing national conservation strategies. the subject of threatened plants in bangladesh with their importance of inventory was first highlighted by khan (1991) with a tentative list of 12 threatened vascular plants in bangladesh. later, iucn red list of threatened plants included 24 vascular plant species (iucn, 1997). khan et al. (2001) produced red data book of vascular plants of bangladesh with 106 threatened plants. later, rahman (2003) reported 18 threatened plants, and thereafter rahman et al. (2010) reported 58 species as threatened in the wild with different iucn-categories. the inventory of threatened taxa for production of red data book is in progress. in connection with this, the present report endowed with 28 threatened species into two families, apocynaceae and vitaceae, which have been inventoried with 46 and 29 species respectively, to be included in the flora of bangladesh (rahman, 2008, 2009). materials and methods in this study, family apocynaceae and vitaceae were considered to make an inventory of threatened plants of bangladesh. in order to determine the threatened species, major iucn threatened categories viz., vulnerable (vu), endangered (en), critically endangered (cr) and extinct (ex) (iucn, 1994) were considered. the assessment of distribution, abundance and status of occurrence of each species has been made through field investigations, literature survey, and consultation of herbarium specimens preserved in regional, national and international herbaria. international journal of environment issn 2091-2854 143 | p a g e field investigation: investigations for collection and assessment of status of occurrence of plant species of apocynaceae and vitaceae families have been made through repeated field surveys throughout the year in different seasons by an expert team of au-cu biodiversity link project since 1997. fertile specimens were collected, identified, characterized, and preserved at herbarium of chittagong university (hcu). conservation status of individual plant species were assessed based on their abundance and distribution. literature survey: relevant literature, such as hook. f. (1872-1897), prain (1903), heinig (1925), cowan (1926), raizada (1941), sinclair (1956), huq and khan (1984), khan (1991), khan et al. (1994), rashid and rahman (1996), iucn (1997), rahman and uddin (1997), uddin et al. (1998), uddin and rahman (1999), rahman et al. (2000), rashid et al. (2000), khan et al. (2001), rahman et al. (2001), khan (2003), rahman (2003), uddin and hassan (2004), rahman (2008, 2009), tutul et al. (2009, 2010), rahman et al. (2010), uddin and hassan (2010), arefin et al. (2011), uddin and hassan (2012), rashid and chowdhury (2013), and uddin et al. (2013) etc. were consulted for confirmation of occurrence and distribution of these plant species in the flora of bangaldesh. herbaria consulted: in order to study the preserved specimens of the members of apocynaceae and vitaceae of bangladesh, various herbaria were visited like herbarium of botanical survey of india, eastern regional centre, shillong (assam), bangladesh council for science and industrial herbarium at chittagong (bcsirh), bangladesh forest research institute herbarium at chittagong (bfrih), central national herbarium, howrah (cal), bangladesh national herbarium, dhaka (dacb), dhaka university salar khan herbarium (dush), royal botanic garden edinburgh herbarium (e), herbarium of chittagong university (hcu) and kew herbarium, london (k) following rahman et al. (2010). the plant specimens were examined, identified and documented along with collection localities. enumeration: the threatened plant species belonging to the family apocynaceae and vitaceae have been enumerated. under each family, genera and species are arranged alphabetically. each species is cited with current nomenclature, basionym, synonyms, local names, habitat, potential values, botanical identification, flowering and fruiting time, status of occurrence, threats to the species, conservation status, occurrence in bangladesh, global distribution, conservation measures taken, conservation measures proposed, and citation of representative specimens. results and discussion the present study reveals that out of 75 total species of the apocynacee and vitaceae, 28 are threatened under different iucn categories which is about 37%. individually, about 50% species are found to be threatened in the family vitaceae while in the apocynaceae it is about 31% (table 1). the species which have no reports of occurrence after their first collection from the area of bangladesh for about 80 to 200 years were presumed extinct (ex). extinction rate is found much higher (21%) in the vitaceae than that of the apocynaceae (4%). in vitaceae, six species were found extinct (ex), these are: ampelopsis rubifolia international journal of environment issn 2091-2854 144 | p a g e (wall.) planch, cissus verticillata (l.) nicolson & c.e. jarvis, c. vitiginea l., cyphostemma auriculatum (roxb.) singh & shetty, tetrastigma rumicispermum (laws.) planch., and vitis flexuosa thunb. on the other hand, only two apocynads were found extinct (ex) and these are: chonemorpha verrucosa (blume) middleton and urceola micrantha (wall. ex g. don) middleton. it is found that extinction rate is much higher in the vitaceae (21%) than that of the apocynaceae (4%). table 1 also revealed that 11 species are endangered in the apocynaceae and 4 in the vitaceae which represents 22% and 14% respectively. all these species, as stated in the enumeration are found to be very potential resources of the flora in both economically and environmentally and hence to be emphasized for taking and implementing appropriate conservation management by the concerned department of the government. 10 species (5 in each family) are recognized as medicinally important, which represents about 13% of total species of which, cissus verticillata (l.) nicolson & c. e. jarvis of the family vitaceae has already beenextinct (ex), and willoughbeia edulis roxb. of the family apocynaceae is in vulnerable (vu) condition. another 8 species are found to be endangered (en) in the wild. table 1. summary of the inventory of plants of apocynaceae and vitaceae family no. of specie s no. of ts % of ts iucn categories potential values ex en cr v u others md t m fe others apocynacea e 46 14 30.4 3 2 11 1 5 5 1 9 vitaceae 29 14 48.2 8 6 4 4 5 6 7 total 75 28 37 8 14 1 5 7 1 3 16 ts = threatened species; ex= extinct; en= endangered; cr = critically endangered; vu= vulnerable; md= medicinal; tm= timber; fe= fruits edible conclusion it has been determined that the flora of bangladesh is extremely under environmental threat and barge of extinction. the data of these two families indicate that the flora is depleting at a very alarming rate which conforms the report of rahman (2013) on the family asclepiadaceae, which is represented in the flora by 51% threatened taxa including 19 extinct (ex) species. it is revealed that the extinction rate is 28% in the asclepiadaceae followed by the vitaceae with 21%. on the other hand, the rate of extinction is much less in the family apocynaceae (4%). the study also revealed that 10 medicinally important species of these two families representing about 13% of total species are facing threats in various categories. cissus verticillata (l.) nicolson & c. e. jarvis belong to the family vitaceae has already been extinct (ex), willoughbeia edulis roxb. of the family apocynaceae which is in vulnerable (vu) condition and other are in endangered. it is, therefore, an urgent need to make complete inventory of threatened species of the flora, and production of red data book of the country for taking and implementing national conservation strategies (ncs) and international journal of environment issn 2091-2854 145 | p a g e sustainable management of the environment. furthermore, public awareness should be created to stop over-exploitation and habitat destruction. enumeration of threatened plant taxa family: apocynaceae 1. aganosma marginata (roxb.) g. don, gen hist. 4: 77 (1837). fig. 5 basionym: echites marginata roxb. (1832). synonym: echites acuminata roxb. (1832). local name(s): bara-kaoringia, chhoto kuruz. habit: twining shrub. habitat: rain forests. potential value: ornamental plant. botanical identification: a large evergreen twining shrub. leaves linear-oblong, oblong lanceolate, bluntly acuminate, glabrous above, obscurely puberulous beneath. cymes axillary, lax, puberulous. flowers white; calyx lobes lanceolate, acuminate. follicles 2. flowering and fruiting: june-january. status of occurrence: endangered (en). threats to the species: deforestation and habitat destruction. conservation status: although it had been collected from about ten localities of chittagong, cox’s bazar and sylhet districts, the present field investigation showed that due to deforestation and felling of old trees, the plant is disappearing from its collection sites. occurrence in bangladesh: chittagong (sitakunda, deyang hill); cox’s bazar (himchari, bara inani, mehergona, upper rezu) and sylhet (jafflong, singla). global distributions: bangladesh, java, myanmar, sumatra and the philippine islands. conservation measures taken: none. conservation measures proposed: in-situ conservation management should be taken immediately. herbarium specimens: chittagong: deyang hill, 24.03.1996, rahman 146 & 150 (hcu); harbang, 09.06.11979, khan et al. 10298, k.5460 (dacb), cox’s bazar: himchari national park, 27.08.1996, rahman 283b (hcu); goalmara, 04.08.1990, khan et al. k.8432 (dacb); chakaria, khan et al. k.5589 (dacb); bara inani, 22.12.1996, rahman 607 (hcu); mehergona, 24.02.1997, rahman 778 (hcu); sylhet: jafflong, huq & mia h.7912 (dacb), khan et al. k.3326 (dacb), huq et al. h.5103, h.6363 (dacb); singla, kanjilal 4909 (assam). 2. alstonia neriifolia d. don, prodr.: 131 (1825). fig. 1 synonym: blaberopus neriifolius a. dc. (1844). local name(s): chhatim, chaitan. habit: small tree. habitat: moist evergreen forests. potential value: timber and medicinal. botanical identification: a small tree. leaves a few in a whorl, coriaceous, pubescent beneath. cymes sub-umbellate. flowers small; calyx lobes tri-angular-ovate, acute. follicles long, up to 18 cm long. flowering and fruiting: not known. international journal of environment issn 2091-2854 146 | p a g e status of occurrence: endangered (en). threats to species: habitat destruction and fire wood collection. conservation status: its occurrence is very rare in a few localities of the forests of chittagong (hazarikhil) and moulvi bazar (lawachara national park) with rapid decrease of population. occurrence in bangladesh: chittagong (hazarikhil), moulvi bazar (lawachara national park). global distributions: bangladesh, bhutan, india including tropical himalaya and nepal. conservation measures taken: none. conservation measures proposed: both in-situ and ex-situ conservation management to be taken immediately. herbarium specimen: moulvi bazar, lawachara forest, 18.06.2009, rahman et al. s.n. (hcu). 3. beaumontia grandiflora wall., tent. fl. nepal 1: 15 t. 7 (1824). fig. 2 synonym: echites grandiflora roxb. (1820). local name: not available. habit: large woody climber. habitat: evergreen forests. potential value: ornamental. botanical identification: large woody climber. leaves ovate, oblong or elliptic-oblong, acuminate, sparsely tomentose beneath; lateral nerves 15-20 pairs, sub parallel. cymes terminal, pedicels pubescent. flowers white, fragrant, very large. stamens included, adnate at the mouth of the tube. follicles divaricate, oblong. flowering and fruiting: june-january. status of occurrence: endangered (en). threats to species: deforestation and habitat destruction. conservation status: it was first recorded from sylhet and chittagong by hook. f. (1882) without citing any locality. it has been rediscovered from kaptai rampahar forest of rangamati by rahman et al. in 2011. no locality in chittagong and sylhet districts could be traced yet. occurrence in bangladesh: chittagong (lnk), rangamati (kaptai rampahar) and sylhet (lnk). global distributions: bangladesh, india, myanmar, nepal, china and vietnam. conservation measures taken: none. conservation measures proposed: both in-situ and ex-situ conservation management should be taken immediately. herbarium specimen: rangamati, kaptai rampahar forest, 04.05.2011, rahman et al. 8480 (hcu). 4. chonemorpha assamensis furtado in gard. bull. str. settlements 9: 115 (1935). fig. 6 synonym: not available. local name: not available. habit: climbing shrub. habitat: evergreen forests. potential value: bark fibre. international journal of environment issn 2091-2854 147 | p a g e botanical identification: a large woody climbing shrub. leaves opposite, broadly obovateoblong, acute, base cuneate, rounded. cymes axillary or sub-terminal. flowers showy, white, fragrant. follicles 2, divaricate, glabrous. flowering and fruiting: june-january. status of occurrence: endangered (en). threats to species: deforestation and habitat destruction. conservation status: it has been located to only two localities in the forests of cox’s bazar and rangamati. no collection after rahman et al. from shublong area of rangamati in 1999, is available. occurrence in bangladesh: cox’s bazar (paner chara) and rangamati (shubalong). global distributions: bangladesh and india. conservation measures taken: none. conservation measures proposed: both in-situ and ex-situ conservation management to be taken immediately. herbarium specimens: cox’s bazar: paner chara, 15.10.1998, rahman et al. 3843 (hcu). rangamati: shubalong, 05.09.1999, rahman et al. 5668 (hcu). 5. chonemorpha griffithii hook. f., fl. brit. india 3: 662 (1882). fig. 7 synonym: not available. local name: not available. habit: woody climber. habitat: evergreen forests. potential value: wildlife supporting plant. botanical identification: a large woody climber. leaves coriaceous; ovate, orbicular, obtuse, base rounded or sub-cordate, glabrous above. cymes terminal, trichotomously branched, pubescent. flowers large, white, fragrant. follicles 2, recurved. flowering and fruiting: august-january. status of occurrence: endangered (en). threats to species: habitat destruction. conservation status: it has been located to sadhanpur area of chittagong, whykeong forest of cox’s bazar and kaptai sitapahar forest of rangamati. no collection could be made after rahman et al. from kaptai sitapahar in 1999. occurrence in bangladesh: chittagong (sadhanpur), cox’s bazar (whykeong) and rangamati (kaptai sitapahar). global distributions: bangladesh and india. conservation measures taken: none. conservation measures proposed: both in-situ and ex-situ conservation management to be taken immediately. herbarium specimens: chittagong: sadhanpur, 24.05.1996, rahman 230 (hcu); cox’s bazar: whykeong, 25.12.1996, rahman 627, 629 (hcu); rangamati: sitapahar, 23.02.1999, rahman et al. 4351 (hcu). 6. chonemorpha verrucosa (blume) middleton in novon 3: 455 (1993). fig. 3 basionym: tabernaemontana verrocosa blume (1826). synonym: echites elliptica wall. (1829). local name(s): not available. international journal of environment issn 2091-2854 148 | p a g e habit: twining shrub. habitat: evergreen forests. potential value: bark fibre. botanical identification: a large woody twining shrub with profound milky latex. leaves opposite or alternate, coriaceous, glabrous; elliptic-ovate or elliptic-oblong, acuminate or acute, base cuneate or rounded. cymes axillary or sub-terminal, lax, panicle, puberulous. flowers showy, white. follicles 2, pendulous. flowering and fruiting: may-january. status of occurrence: extinct (ex). threats to species: habitat loss; specimens not collected. conservation status: it was reported to occur in sylhet (wall. 1830) and chittagong but no locality is traced yet. occurrence in bangladesh: chittagong (lnk) and sylhet (lnk). global distributions: bangladesh, bhutan, china, india, indonesia laos, malaysia, myanmar, thailand and vietnam. conservation measures taken: none. conservation measures proposed: the plant is to be traced in its collection locality for insitu or ex-situ conservation management as appropriate. herbarium specimen: no specimen is available at any herbaria consulted. 7. melodinus khasianus hook. f., fl. brit. india 3: 629 (1882). fig. 11 synonym: not available. local name: not available. habit: climbing shrub. habitat: hilly evergreen forests. potential value: wildlife supporting plant. botanical identification: a large climbing shrub with milky latex. leaves narrowly elliptic, apex short acuminate, base cuneate. cymes short, few flowered. flowers small, corolla white, corolla lobes orbicular, tube very short. flowering and fruiting: may-june. status of occurrence: endangered (en). threats to species: habitat loss; specimens not collected. conservation status: alam (1988) recorded its distribution in sylhet without citing any locality. no other report of its collection from elsewhere in bangladesh is available. occurrence in bangladesh: sylhet (lnk). global distribution: bangladesh, china and india. conservation measures taken: none. conservation measures proposed: location of occurrence is to be determined and then insitu or ex-situ conservation management to be taken as appropriate. herbarium specimen: no specimen is available at any herbaria consulted. 8. melodinus monogynus roxb., fl. ind. 2: 56 (1832). fig. 12 synonyms: nerium piscidium roxb. (1832). local name(s): not available. habit: climbing shrub. habitat: hilly evergreen forests. potential value: wildlife supporting plant. international journal of environment issn 2091-2854 149 | p a g e botanical identification: a large climbing shrub with milky latex. leaves opposite, ellipticoblong or ovate-oblong, acuminate, base cuneate or rounded. cymes terminal, trichotomously branched, panicle. flowers white. fruits berry, globose with hard or leathery pericarp, orange red, smooth. flowering and fruiting: april-january. status of occurrence: endangered (en). threats to species: deforestation and habitat loss. conservation status: its location has been traced to a few areas of the forests of chittagong and cox’s bazar. no collection could be made after rahman et al. from ramu upper rezu reserve forest of cox’s bazar in 1997. occurrence in bangladesh: chittagong (deyang hill, baraidhala) & cox’s bazar (ramu upper rezu reserve forest). global distributions: bangladesh and india. conservation measures taken: none. conservation measures proposed: both in-situ and ex-situ conservation management to be taken immediately. herbarium specimens: chittagong: deyang hill, march-june, 1996, rahman 152, 172 & 253 (hcu); baraidhala, 23.06.1993, mia et al. m.3255 (dacb); cox’s bazar: upper rezu reserve forest, 13.06.1997, rahman et al. 1367 (hcu). 9. rauvolfia serpentina (l.) benth. ex kurz, forest fl. burma 2: 171 (1877). fig. 4 basionym: ophioxylon serpentinum l. (1753). synonyms: ophioxylon trifoliatum gaertn. (1791); tabernaemontana cylindracea wall. (1829). local name(s): sarpagnadha, chandra, choto chand. habit: herb to small shrub. habitat: mixed forests, plains and foot hills. potential value: medicinal. botanical identification: a perennial herb to small shrub. leaves whorled, ellipticlanceolate or obovate-lanceolateacute to acuminate, base tapering. cymes compact, axillary or terminal. flowers white. drupes crimson to black when ripen. flowering and fruiting: april-october. status of occurrence: endangered (en). threats to species: habitat destruction and over exploitation. conservation status: it is located to a number of localities in several forested areas with one or two individuals in each site. this species is facing threats to high risk of extinction due to habitat destruction and over exploitation. occurrence in bangladesh: chittagong (faiz lake, mireswari, sitakund), cox’s bazar (gorak ghata, inani), bandarban (dudpukoria reserve forest), rangamati (gagra) & khagrachari (manikchari), dinajpur (singra), mymenshingh (gazni), moulavibazar (lawachara). global distributions: bangladesh and india. conservation measures taken: ex-situ conservation has been made in various gardens. international journal of environment issn 2091-2854 150 | p a g e conservation measures proposed: both in-situ and ex-situ conservation management to be taken immediately. herbarium specimens: chittagong: hazarikhil, 21.06.1979, mia & rahman m 63 (dacb); faiz lake, 29.09.1989, mostafiz 71 (hcu); sitakund, chandranath hill, 13.09.1993, rahman et al. 151(hcu, dacb); cox’s bazar: gorak ghata, 10.09.1992, rahman et al. 19 (hcu, dacb); inani range, boro inani block, 04.06.2000, khan et al. k 10597 (dacb). bandarban: loc. non cit., 22.08.1987, m. k. alam 5421 (bfrih); dudpukoria reserve forest, 17.09.1993, rashid & yusuf 161 (hcu, dacb). rangamati: gagra, 25.04.1994, rashid 195 (hcu, dacb). khagrachari: manikchari, 07.04.1994, rashid et al. 170 (hcu, dacb). mymenshingh: gazni, 19.04.1964, d. k. das s. n. (bfrih). dinajpur: singra, 14.05.1965, d. k. das s. n. (bfrih). moulavibazar: lawachara, 06.04.1988, mahfuz et al. mz 86 (dacb). sylhet: jaintapur, near rajbari, khan & mia k5668 (dacb). netrokona: banagra, 25.04.1974, yusuf 126 (dacb). kurigram: bhuringamari, 23.05.1990, huq et al. h 9585 (dacb). kushtia: munshiganj, alamdanga, 10.06.1974, khan & huq k3895 (dacb). chuadanga: darshana, 13.12.1988, huq et al. h 8920 (dacb). note: this species, rauvolfia serpentina benth. ex kurz, of the family apocyanaceae has already been included in the red data book of bangladesh (khan et al. 2001) as lr (cd). 10. urceola micrantha (wall. ex g. don) middleton in novon 4: 151 (1994). fig. 9 basionym: echites micrantha wall. ex g. don (1837). synonyms: ecdysanthera micrantha (wall. ex g.don) a. dc. (1844); parabarium micranthum (wall. ex g. don) pierre (1905). local name: not available. habit: woody climber. habitat: hilly evergreen forests. potential value: wildlife supporting plant. botanical identification: a large woody climber with milky latex. leaves ovate-oblong or oblong-lanceolate, apex acuminate, base acute or cuneate. cymes trichotomously branched, paniculate. flowers small, yellow; calyx pubescent, corolla urceolate, glabrous. follicles 2, divaricate. flowering and fruiting: april-december. status of occurrence: possibly extinct (ex). threats to species: habitat loss; specimens not collected. conservation status: wallich collected it from sylhet in 1830. since then it has not been reported from elsewhere in bangladesh. occurrence in bangladesh: sylhet (lnk). global distributions: bangladesh, bhutan, nepal, india, myanmar, thailand, laos, vietnam, indonesia, malaysia, china and japan. conservation measures taken: none. conservation measures proposed: both in-situ and ex-situ conservation management to be taken as appropriate. herbarium specimens: sylhet: loc. non cit., wall. cat. 1667 (k-w). no specimen is available at dacb, bfrih, and bcsirh. 11. vallaris solanacea (roth) o. kuntze, rev. gen. pl. 2: 417 (1891). fig. 14 basionym: peltanthera solanacea roth (1821). synonym: echites dichotoma roxb. (1832). international journal of environment issn 2091-2854 151 | p a g e local name(s): hadpur, mali, hapormali, agarmoni. habit: scandent shrub. habitat: scrubs or secondary forests. potential value: medicinal. botanical identification: a large, scandent shrub with milky latex. leaves opposite, glabrous, elliptic, oblong-lanceolate, acute or acuminate, base cuneate. cymes axillary. flowers white, pubescent, calyx tube short, acuminate or acute, corolla-tube narrow, cylindrical. fruits 10-15 cm long, beaked. flowering and fruiting: december-april. status of occurrence: endangered (en). threats to species: deforestation and habitat destruction. conservation status: it has been collected from only hazarikhil forest of chittagong in 1995 and sasupahar area of khulna in 2006. since then no locality of its occurrence could be traced yet. occurrence in bangladesh: chittagong (hazarikhil) and khulna (sasupahar). global distributions: bangladesh, india, myanmar, pakistan and vietnam. conservation measures taken: none. conservation measures proposed: location of this species is to be traced for taking conservation management immediately. herbarium specimens: chittagong: hazarikhil, 03.05.1995, rahman 173 (hcu); khulna: sasupahar, 09.04.2006, amina khatun, s.n. (dacb). 12. willoughbeia edulis roxb., pl. corom. 3:77. t. 280 (1820). fig. 8 synonym: willoughbeia martabanica wall. (1832). local name(s): lata aam, lati aam. habit: climbing shrub. habitat: evergreen forests. potential value: fruits edible and medicinal. botanical identification: a large climbing shrub. leaves coriaceous, glabrous, oblong or ovate-oblong, acuminate, reddish brown beneath. cymes axillary. flowers fragrant, yellowish. fruits pyriform. flowering and fruiting: may-december. status of occurrence: vulnerable (vu). threats to species: habitat destruction. conservation status: it occurs sporadically in some forests of chittagong, cox’s bazar, rangamati and greater sylhet. its population is decreasing rapidly due to destruction of habitat. occurrence in bangladesh: chittagong (bariadhala, hazarikhil); cox’s bazar (ramu upper rezu reserve forest, ukhia madhur chara), rangamati (rampahar, sitapahar) and habigonj (satchari). global distributions: bangladesh, cambodia, india, laos, malaysia, myanmar and thailand. conservation measures taken: none. conservation measures proposed: both in-situ and ex-situ conservation management required. international journal of environment issn 2091-2854 152 | p a g e herbarium specimens: chittagong: bariadhala, 16.10.1997, rahman et al. 1980 (hcu), chunati, huq & mia 10324 (dacb). cox’s bazar: ukhia madhur chara, 23.12.1996, rahman 614 (hcu); ramu upper rezu, huq & mia 10576 (dacb) and 08.10.1997, rahman et al. s.n. (hcu). habigonj: satchari, 02.04.2009, arefin et al. ka.76 (dush). rangamati: kaptai rampahar/sitapahar, may-august, 1999, rahman et al. 4893 & 5566 (hcu). dhaka: balda garden, rezia rk.248 (dacb). 13. wrightia arborea (dennst.) mabb., in taxon 26:533 (1977). fig. 10 basionym: periploca arborea dennst. (1818). synonyms: wrightia tomentosa roem. & schult. (1819); w. pubescens roth (1821). local name: not available. habit: medium sized tree. habitat: evergreen forests. potential value: leaves are cooked as vegetable and medicinal. botanical identification: a medium sized deciduous tree with profound milky latex. leaves tomentose on both surfaces, elliptic or ovate, elliptic-lanceolate, acuminate, base cuneate, margins thickly undulate. cymes terminal, corymbose, tomentose. flowers white turning yellow with unpleasant odour. fruits cylindrical, pendulous. flowering and fruiting: mayjanuary. status of occurrence: endangered (en). threats to species: deforestation and habitat destruction. conservation status: it occurs sporadically in some forested areas of bandarban, chittagong, khagrachari, mymensingh, rangamati and sherpur with a fewer number of individuals. occurrence in bangladesh: bandarban (near boga lake, ruma), chittagong (hazarikhil), khagrachari (ramghar), mymensingh (modupur national park) and sherpur (gajni forest). global distributions: bangladesh, china, india, myanmar, sri lanka and thailand. conservation measures taken: none. conservation measures proposed: both in-situ and ex-situ conservation management required immediately. herbarium specimens: bandarban: ruma, near boga lake, 28.02.2011, rahman et al. 8020 (hcu). chittagong: hazarikhil, 06.10.1997, rahman et al. 1980 (hcu). mymensingh: modupur national park, huq et al. h.5727 (dacb). sherpur: gajni forest, khan et al. k.7056 (dacb), huq h.7676 (dacb). 14. wrightia coccinea sims. in bot. mag. 53. t. 2696 (1826). fig. 13 synonym: nerium coccineum roxb. (1832). local name(s): dudhi, pallam. habit: medium sized tree. habitat: evergreen forests. potential value: ornamental plant. botanical identification: a medium sized tree, bark whitish grey outside. leaves opposite, superposed; elliptic to ovate-obovate, apex caudate-acuminate, base obtuse to acute. cymes terminal, few flowered. flowers showy, orange red. follicles linear with silky coma at the base. flowering and fruiting: may-january. international journal of environment issn 2091-2854 153 | p a g e status of occurrence: endangered (en). threats to species: habitat destruction. conservation status: it has been located to some forests of chittagong, moulvi bazar, rangamati and sylhet, its occurrence is decreasing rapidly due to habitat destruction. occurrence in bangladesh: chittagong (keochia), dhaka (ramna park), moulvi bazar (biyani bazar), rangamati (sitapahar, belai chari) and sylhet (jaintapur, jafflong, patherkandi, loobah lake). global distributions: bangladesh, china, india, myanmar, pakistan and thailand. conservation measures taken: none. conservation measures proposed: in-situ conservation management to be taken immediately. herbarium specimens: chittagong: keochia, das 6245 (bfrih); dhaka: ramna park, momtaz begum 212 (dacb); moulvi bazar: biani bazar, mujibur rahman 6614 (bfrih) and alam 5808 (bfrih); rangamati: belai chari, rahman et al. 4547 (hcu); sylhet: jaintapur, huq et al. h.6203, h.7858 (dacb); jafflong, huq & mia h.6297 (dacb); patherkandi, gupta 7835 (assam); loobah lake, kanjilal 4680 (assam). family: vitaceae 15. ampelopsis glandulosa (wall. ex roxb.) momiy. in bull. univ. mus. univ. tokyo 2: 78 (1971). fig. 17 basionym: vitis glandulosa wall. ex roxb. (1824). synonym: cissus glandulosa roxb. (1814 num. nud.). local names: jangli boroi. habit: climber. habitat: on the hill slopes. potential value: wildlife supporting plant, fruits edible. botanical identification: a slender branched climber. tendril 2-3 branched. leaves simple, pentagular, cordate-ovate, crenate, often 3-5 lobed. flowers in small dichotomous corymbose cymes, shorter than the leaves. fruit a berry, small, globose, dark purple. seed narrowly elliptic. flowering and fruiting: may-september. status of occurrence: endangered (en). threats to species: habitat destruction. conservation status: only one specimen was collected from sherpur (runctia sal forest) in 2009 by mr. ershad tutul of dhaka university after roxburgh from chittagong in 1832. no other location of its occurrence is traced yet. occurrence in bangladesh: chittagong (lnk) and sherpur (runctia sal forest). global distributions: bangladesh, china, india, myanmar, nepal, taiwan and the philippines. conservation measures taken: none. conservation measures proposed: location of its occurrence is to be traced and then in-situ and ex-situ conservation measures are to be taken as appropriate. herbarium specimen: sherpur: runctia sal forest, gazni, 31. 10. 2009, tutul 444 (dush). 16. ampelopsis rubifolia (wall.) planch. in dc., monogr. phan. 5(2): 463 (1887). fig. 15 basionym: vitis rubifolia wall. (1824). international journal of environment issn 2091-2854 154 | p a g e local name: not available. habit: climbing shrub. habitat: over bushes and scrub jungles of the foot hills. potential value: wildlife supporting plant. botanical identification: a large climbing shrub with 4-angled slender stem and branches. leaves 1 or 2 pinnate, usually 3-foliolate, leaflets ovate-elliptic or ovate. inflorescences umbellate cymes. flowers small, greenish, anthers elliptic, styles conical. fruits berry, globose red, turning black when fully ripen. flowering and fruiting: august-december. status of occurrence: possibly extinct (ex). threats to species: habitat loss; specimens not collected. conservation status: no report since hook.f. (1875) recorded from sylhet without citing any locality. occurrence in bangladesh: sylhet (lnk). global distributions: bangladesh, china, india and japan. conservation measures taken: none. conservation measures proposed: location of occurrence is to be traced and both in-situ and ex-situ conservation management to be taken as appropriate. herbarium specimens: no specimen is available at any herbaria consulted. 17. cayratia pedata (lam.) juss. ex gagnep., notul. syst. (paris) 1: 346 (1911). fig. 16 basionym: cissus pedata lam. (1783). synonym: vitis pedata wall. ex wight & arn. (1834). local names: gwali-lata, goali-kata. habit: woody climber. habitat: rainy forest areas. potential value: medicinal and wildlife supporting plant. botanical identification: a woody climber. leaves pedately 5 foliolate, ovate-elliptic, base rounded, subcordate. inflorescences corymbose. flowers hermaphrodite, usually 4-merous, very small, greenish. fruit a berry, depressed globular. flowering and fruiting: apriloctober. status of occurrence: near threatened (nt). threats to species: habitat destruction. conservation status: although it occurs in few localities but with a very poor number of individuals and likely to be decreasing. occurrence in bangladesh: chittagong (sitakunda, bariadhala), cox’s bazar (himchari national park), dhaka (mirpur) and sylhet (lnk). global distributions: bangladesh, cambodia, india, indonesia, sri lanka, malaysia, myanmar, thailand and vietnam. conservation measures taken: none. conservation measures proposed: both in-situ and ex-situ conservation management to be taken immediately. herbarium specimens: chittagong: sitakunda, bariadhala, 15.11.1998, rahman & rashid 3945 (hcu); sitakunda, 24.06.1979, mia & rahman m.142 (dacb). cox’s bazar: teknaf, international journal of environment issn 2091-2854 155 | p a g e himchari national park, 29.06.1997, rahman & uddin 1432 (hcu); dhaka: mirpur, 15.07.1961, zaman d.83 (dush). 18. cayratia tenuifolia (wight & arn.) gagnep., notul. syst. (paris) 1: 349 (1911). fig. 18 basionym: vitis tenuifolia wight & arn. (1834). synonyms: cissus japonica willd. (1824) (later homonym); c. tenuifolia (wight & arn.) planch. (1887); c. cymosa steud. (1841). local name: not available. habit: climber. habitat: rain forests. potential value: medicinal and wildlife supporting plant. botanical identification: herbaceous climber. leaves pedate, ovate to elliptic or oblong, base acute to cuneate, apex acute. disc of flower yellow at anthesis, becoming white after anthesis. fruit depressed, obpyriform. flowering and fruiting: may-october. status of occurrence: near threatened (nt). threats to species: habitat destruction. conservation status: although it occurs in few localities with a very poor number of individuals and likely to be decreasing. occurrence in bangladesh: bandarban (alikadam), chittagong (garjania), cox’s bazar (teknaf) and rangamati (kaptai, sitapahar). global distributions: bangladesh, india, indonesia, japan, malaysia, nepal and taiwan. conservation measures taken: none. conservation measures proposed: both in-situ and ex-situ conservation management to be taken immediately. herbarium specimens: bandarban: alikadam, guishapjiri, 03.05.1998, rahman et al. 2881 (hcu); chittagong division: garjania, 06.1920, cowan 717 (e); cox’s bazar: teknaf, 23.10.1963, khan 710 (dush); rangamati: kaptai, 03.10.1982, das & alam 4487 (bfrih); sitapahar, 08.10.1998, rahman et al. 3552 (hcu). 19. cissus pentagona roxb., fl. ind. 1: 408 (1820). fig. 23 synonym: vitis pentagona buch.-ham. ex wall. (1831-1832). local name: sona-tola. habit: woody climber. habitat: climbing over bushes and small trees in the hilly forest areas only. potential value: medicinal. botanical identification: a large woody climber with 5-angled stem. leaves simple, cordate or cordate-ovate or ovate, inflorescences cymes, peduncle long. flowers yellowish-red. flowering and fruiting: september-march. status of occurrence: near threatened (nt). threats to species: habitat destruction. conservation status: it occurs sporadically with a fewer number of individuals in degraded forests of chittagong, cox’s bazar and moulvi bazar districts. occurrence in bangladesh: chittagong (sitakunda, hazarikhil), cox’s bazar (whykong, himchari national park, chakaria sundarban, shilkhali), moulvi bazar (lowachara), (kengal chari, rampahar, sitapahar). international journal of environment issn 2091-2854 156 | p a g e global distributions: bangladesh, india and myanmar. conservation measures taken: none. conservation measures proposed: both in-situ and ex-situ conservation management to be taken immediately. herbarium specimens: chittagong: sitakunda, chandranath hill, 11.10.1998, rahamn et al. 3684 (hcu); hazarikhil, 8.11.1998, rahman et al. 513 (hcu). cox’s bazar: teknaf, whykong, 15.10.1998, rahman et al. 2130 (hcu); himchari national park, 15.10.1998, rahman & uddin 3863 (hcu); chakaria sundarban, 25.02.1997, rahman & uddin 802 (hcu); shilkhali, 26.12.1996, m. a. rahman 644 (hcu); panerchara, 12.09.1999, rahman et al. 5944 (hcu). rangamati: kengal chari, 30.05.1998, rahman et al. 2960 (hcu); kaptai, rampahar, 29.10.2011, rahman et al. 7586a (hcu); sitapahar, 20.10.2003, uddin n.2155 (dacb). moulvi bazar: srimongal, lowachara, 17.03.1984, alam 4873 (bfrih). 20. cissus verticillata (l.) nicolson & c. e. jarvis, taxon 33(4): 727 (1984). fig. 19 basionym: viscum verticillatum l. (1753). synonyms: cissus sicyoides l. (1759); c. glauca thw. (1858); vitis sicyoides (l.) miq. (1857). local name: not available. habit: climber. habitat: primary forests. potential value: medicinal, wildlife supporting plant, fruits edible. botanical identification: evergreen perennial vine. leaves typically large, simple, alternate, glabrous, and succulent. inflorescences densely flowered cymes, extended from the leaf axils. flowers yellow-green, calyx light green, cup-shaped and forms a rim around the ovary. fruit a berry, black or purple which is similar to a small grape. flowering and fruiting: julydecember. status of occurrence: extinct (ex). threats to species: habitat loss; specimens not collected. conservation status: no report after roxb. (1832) from chittagong citing without any locality. occurrence in bangladesh: chittagong (lnk). global distributions: argentina, bangladesh, bolivia, brazil, caribbean, central america, chile, colombia, costa rica, ecuador, el salvador, french guiana, guatemala honduras, guyana, india, maxico, nicaragua, panama, peru, suriname, u. s. a. and venezuela. conservation measures taken: none. conservation measures proposed: location of occurrence is to be traced and both in-situ and ex-situ conservation management to be taken as appropriate. herbarium specimens: no specimen is available at any herbaria consulted. 21. cissus vitiginea l., sp. pl.: 117 (1753). fig. 24 synonyms: cissus latifolia lam. (1783); c. glauca roxb. (1820); vitis glauca (roxb.) wight & arn. (1834). local name: guali-lata. habit: climber. habitat: primary rain forests. potential value: not known. international journal of environment issn 2091-2854 157 | p a g e botanical identification: a large climber. leaves 5-angled or lobed, cordate-ovate on main shoots. inflorescences umbellate cyme, leaf-opposed. flowers whitish-green, copular. fruit a berry, ovoid. flowering and fruiting: july-december. status of occurrence: extinct (ex). threats to species: habitat loss; specimens not collected. conservation status: no report after roxb. (1832) from chittagong without citing any locality. occurrence in bangladesh: chittagong (lnk). global distributions: bangladesh, india, myanmar, sri lanka and thailand. conservation measures taken: none. conservation measures proposed: location of occurrence is to be traced, if exists, appropriate conservation management to be taken. herbarium specimens: no specimen is available at any herbaria consulted. 22. cyphostemma auriculatum (roxb.) singh & shetty, taxon 35 (3): 596 (1986). fig. 20 basionym: cissus auriculata roxb. (1824). synonym: vitis auriculata (roxb.) wall. (1831). local name: not available. habit: climber. habitat: evergreen forests. potential value: fruits edible, wildlife supporting plant. botanical identification: a large climber with succulent stem. leaves palmately 5-foliolate, ovate-elliptic, acuminate, base rounded. inflorescences pseudo-axillary or terminal cyme, corolla constricted in bud, pubescent. fruit a globose berry. flowering and fruiting: apriljune. status of occurrence: possibly extinct (ex). threats to species: habitat loss; specimens not collected. conservation status: no report after heinig (1925) from chittagong is available. no locality in chittagong and sylhet could be traced yet. occurrence in bangladesh: chittagong (lnk) and sylhet (lnk). global distributions: africa, bangladesh, india, madagascar and myanmar. conservation measures taken: none. conservation measures proposed: intensive search is to be made to locate this plant, if exists, appropriate conservation management to be taken. herbarium specimens: no specimen is available at any herbaria consulted. 23. parthenocissus semicordata (wall. ex roxb.) planch. in dc., monogr. phan. 5: 451 (1887). fig. 25 basionym: vitis semicordata wall. ex roxb. (1824). synonyms: ampelopsis himalayana royle (1835); cissus himalayana walp. (1842); parthenocissus himalayana (royle) planch. (1887). local name: not available. habit: climber. habitat: hill slopes over bushes. potential value: not known. international journal of environment issn 2091-2854 158 | p a g e botanical identification: a large climber with terete branchlets, sparsely pilose when young, becoming glabrescent; lea ves 3-foliolate, usually nearly sessile, apex mucronate. cymes up to 3 cm long, compact. flowers 4-merous. fruits berry. flowering and fruiting: januaryjune status of occurrence: near threatened (nt). threats to species: habitat destruction. conservation status: it occurs sporadically with a fewer number of individuals in degraded forests of chittagong, cox’s bazar, moulvi bazar and rangamati districts. occurrence in bangladesh: chittagong (deyang hill), cox’s bazar (himchari national park), moulvi bazar (samanbagh beat), rangamati, kaptai (rampahar, sitapahar). global distributions: bangladesh, bhutan, china, india, indonesia, malaysia, myanmar, nepal, north america, pakistan, thailand, vietnam. conservation measures taken: none. conservation measures proposed: both in-situ and ex-situ conservation management to be taken immediately. herbarium specimens: chittagong: deyang hill, 07.06.1996, rahman et al. 254a (hcu). cox’s bazar: bhangamura, himchari national park, 21.03.1997, rahman & uddin 336 (hcu); 30.03.1997, uddin & rashid 2717 (hcu). moulvi bazar: samanbagh beat, 25.04.1987, das & alam 5799 (bfrih). rangamati: kaptai, rampahar, 12.06.2010, rahman et al. 6399 (hcu); sitapahar, 26.02.1965, khan 1198 (dush); 12.05.1996, alam 7622 (bfrih). 24. tetrastigma dubium (laws.) planch. in dc., monogr. phan. 5(2): 437 (1887). fig. 26 basionym: vitis dubia laws. (1875). synonym: vitis oxyphylla wall. ex prain (1903). local name(s): kuanria. habit: climber. habitat: hilly forests. potential value: medicinal, fruits edible. botanical identification: a large sub-woody climber. leaves 5-foliolate, ovate or elliptic or lanceolate, acuminate, base rounded. inflorescences axillary cymes, compact, corymbose. flowers 4 mm across. fruits berry, oblong. flowering and fruiting: march-august. status of occurrence: endangered (en). threats to species: habitat destruction. conservation status: the last collection of this species has been made from chunati of chittagong by ms khan in 1997 after deke from chhatak of sylhet district in 1941. the first collection of it was made from kaptai of rangamati by lace in 1880. no locality could be traced yet. occurrence in bangladesh: chittagong (chunati), rangamati (kaptai) and sylhet (chhatak). global distributions: bangladesh, bhutan, china, india and nepal. conservation measures taken: none. conservation measures proposed: it is to be located to its collection sites for taking ex-situ conservation management immediately. international journal of environment issn 2091-2854 159 | p a g e herbarium specimens: chittagong: chunati, 25.09.1997, khan et al. s.n. (dacb); rangamati: kaptai, 11.03.1880, lace 2179 (e). sylhet: chhatak, 09.02.1941, deka 20542 (assam). 25. tetrastigma rumicispermum (laws.) planch. in dc., monogr. phan. 5(2): 429 (1887). fig. 27 basionym: vitis rumicisperma laws. (1875). synonym: vitis tuberculata wall. (1831). local name: not available. habit: climber. habitat: evergreen forests. potential value: not known. botanical identification: woody lianas. branchlets terete. leaves pedately 5-foliolate, leaflet complex, central leaflet obovate-elliptic, inflorescences axillary or leaf-opposed on lateral branches, umbelliform; calyx shallow, saucer-shaped, glabrous, anthers yellow. fruits berry, globose. flowering and fruiting: april-november. status of occurrence: possibly extinct (ex). threats to species: habitat loss; specimens not collected. conservation status: it was collected once from patharia forest of sylhet by g. mann in 1828. since then no other location of occurrence could be traced yet. occurrence in bangladesh: sylhet (patharia forest). global distributions: bangladesh, bhutan, china, india, laos, nepal, thailand and vietnam. conservation measures taken: none. conservation measures proposed: location of occurrence is to be traced, if exists, ex-situ or as appropriate conservation management to be taken. herbarium specimens: sylhet: patharia forest, 07.1828, mann 1073 (assam). 26. tetrastigma serrulatum (roxb.) planch. in dc., monogr. phan. 5(2):432 (1887). fig. 28 basionym: cissus serrulatum roxb. (1820). synonyms: c. nepalensis dc. (1824); vitis capriolata d. don (1826); v. serrulata (roxb.) wall. (1831). local name: not available. habit: climbing shrub. habitat: rain forests. potential value: fruits edible. botanical identification: an evergreen climbing shrub. plant dioecious. leaves pedately 5foliolate, obovate or elliptic or lanceolate, cuspidate-acuminate, inflorescences umbellate cymes. flowers 4-merous, yellow-green. fruit a berry, globose, reddish-brown when ripen. flowering and fruiting: may-november. status of occurrence: endangered (en). threats to species: habitat destruction. conservation status: it has been collected from teknaf of cox’s bazar in 1997 after sinclair from signal hill in 1943. it was also collected from dhaka city area in 1970. international journal of environment issn 2091-2854 160 | p a g e occurrence in bangladesh: cox’s bazar (teknaf, signal hill) and dhaka (second capital area). global distributions: bangladesh, bhutan, china, india, myanmar, nepal and thailand. conservation measures taken: none. conservation measures proposed: both in-situ and ex-situ conservation management required immediately. herbarium specimens: cox’s bazar: teknaf, 24.10.1997, rahman et al. 2124 (hcu); signal hill, 14.08.1943, sinclair 3142 (e); dhaka: second capital area, 17.05.1970, rahman 100 (dush). 27. vitis flexuosa thunb. in trans. linn. soc. london 2: 103, 332 (1794). fig. 21 synonyms: vitis parvifolia roxb. (1820); v. purani buch.-ham. ex d. don (1825); v. wallichii kurz (1872). local name: not available. habit: climbing shrub. habitat: evergreen forests. potential value: not known. botanical identification: a large climbing glabrous shrub. leaves simple, cordate, sometimes 3-lobed, crenate-serrate, apex somewhat alternate. flowers minute, green, calyx obscurely 5-lobed, corolla lobes 5, cohering. flowering and fruiting: february-may. status of occurrence: possibly extinct (ex). threats to species: habitat loss; specimens not collected. conservation status: hook. f. (1875) reported this plant from eastern part of bengal without citing any locality. since then no report of collection of it from elsewhere in bangladesh is available. occurrence in bangladesh: eastern bengal (lnk). global distribution: bangladesh, china, india, japan, korea, laos, malayesia, north-west himalayas, nepal, pakistan, taiwan, thailand, the philippines and vietnam. conservation measures taken: none. conservation measures proposed: location of occurrence is to be traced, if exists, conservation management to be taken as appropriate. herbarium specimens: no specimen is available at any herbaria consulted. 28. vitis heyneana roem. & schult., syst. veg., ed. 15 bis 5: 318 (1819). fig. 22 synonym(s): vitis lanata roxb. (1814, 1824); cissus vitiginea roxb. (1832); c. heyneana (wall. ex wight & arn.) planch. (1887); vitis heyneana wall. ex wight & arn. (1834); v. indica hook. & arn. (1838). local name: gode lata. habit: climbing shrub. habitat: thickets of foot hills. potential value: fruits edible. botanical identification: a large climbing shrub with corky bark. leaves simple, cordateovate or broadly ovate, apex shortly acuminate, base cordate. inflorescences paniculate http://ipni.org/ipni/idplantnamesearch.do?id=68789-1&back_page=%2fipni%2feditsimpleplantnamesearch.do%3ffind_wholename%3dvitis%2bindica%2b%26output_format%3dnormal international journal of environment issn 2091-2854 161 | p a g e cymes. flowers small, green, unisexual, calyx minute, corolla lobes cohering at the apex. fruits berry, globose, blackish. flowering and fruiting: may-october. status of occurrence: endangered (en). threats to species: habitat destruction. conservation status: it was collected by das in 1964 from gazni of mymensingh and again in 1995 from kaptai sitapahar of rangamati by das & akram. since then no other collection from any locality could be found. occurrence in bangladesh: chittagong (lnk), mymensingh (gazni), rangamati (sitapahar). global distributions: bangladesh, china to the himalayas and myanmar. conservation measures taken: none. conservation measures proposed: both in-situ and ex-situ conservation measures to be taken immediately. herbarium specimens: mymensingh: gazni, 10.04.1964, das s.n. (bfrih). rangamati: kaptai sitapahar, 17.07.1981, das & akram 4150 and 18.06.1995, alam & basak 7432 (bfrih). note: no species of the family vitaceae has been included in the red data book of bangladesh (khan et al., 2001). references arefin, m. k., rahman, m. m., uddin, m. z., and hassan, m. a., 2011. angiosperm flora of satchari national park, habiganj, bangladesh. bangladesh j. plant taxon. 18(2): 117-140. baillie, j. e. m., hilton-taylor, c. and stuart, s. n., (eds.) 2004. 2004 iucn red list of threatened species. a global species assessment. iucn, gland, switzerland and cambridge, uk. pp. xxiv + 1191. cbd (convention on biological diversity)., 2010. cop 10 outcomes. <http://www.cbd.int/nagoya/outcomes/>. retrieved on 10 december 2013. cowan, j. n., 1926. the flora of chakaria sundarbans. rec. bot. surv. ind.1292: 197-225. heinig, r. l., 1925. list of plants of chittagong collectorate and hill tracts. darjeeling, pp. 1-84. hooker, j. d., 1872-1897 (reprint 1978). the flora of british india vols. 1-7. bishen singh mahendra pal singh, dehr dun, india. huq, a. m. and khan, m.s., 1984. a preliminary taxonomic report on the angiospermic flora of moheskhali isalnd 1(dicotyledons). dacca univ. stud. part b, 32(2): 19-31. irfanullah, h. m., 2011. conserving threatened plants of bangladesh: miles to go before we start? bangladesh j. plant taxon. 18(1): 81-91. iucn red list 2010. iucn red list version 2010.4: table 5. threatened species in each country (totals by taxonomic group). http://www.iucnredlist.org/documents/summarystatistics/2010_4rl_stats_table_5.pdf. international union for conservation of nature and natural resources. retrieved on 10 december 2013. khan, m. s., 1991. towards sustainable development: conservation of genetic resources of bangladesh. ministry of environment and forests and national conservation strategy of bangladesh, agricultural research council. dhaka, bangladesh. pp. 35. international journal of environment issn 2091-2854 162 | p a g e khan, m. s., 2003. flora. in: islam, s., miah, s., ahmed, w., chowdhury, a. m., rahman, s. m. m., siddiqui, k. and kabir, s. m. h. (eds), banglapedia: national encyclopedia of bangladesh. vol. 4: 171-177. asiatic society of bangladesh, dhaka. khan, m. s. and huq, a. m., 2001. the vascular flora of chunati wildlife sanctuary in south chittagong, bangladesh. bangladesh j. plant taxon. 8(1): 47-64. khan, m. s., rahman, m. m. and ali, m. a. (eds). 2001. red data book of vascular plants of bangladesh. bangladesh national herbarium, dhaka. pp. 1-179. khan, m. s., rahman, m. m., huq, a. m., mia, m. m. k. and hassan, m.a., 1994. assessment of biodiversity of teknaf game reserve in bangladesh focusing on economically and ecologically important plants species. bangladesh j. plant. taxon. 1(1): 21-33. pitman, n. c. a. and p. m. jorgersen., 2002. estimating the size of the world's threatened flora. science, 298 (5595): 989. prin, d., 1903 (reprint 1963). bengal plants. vols. 1 and 2. bishen singh mahendra pal singh, dehr dun, india. rahman, m.a., 2003. some threatened forest species: iucn red list categories. biodiversity newsletter bangladesh 7(1 & 2): 1-2. rahman, m.a., 2008. apocynaceae. in: ahmed, z.u., begum, z.n.t., hassan, m.a., khondker, m., kabir, s.m.h., ahmad, m., ahmed, a.t.a., rahman, a.k.a. and haque, e.u. (eds). encyclopedia of flora and fauna of bangladesh, vol. 6. angiosperms: dicotyledons (acanthaceae – asteraceae). asiatic society of bangladesh, dhaka. pp. 168-201. rahman, m.a., 2009. vitaceae. in: ahmed, z.u., hassan, m.a., begum, z.n.t., khondker, m., kabir, s.m.h., ahmad, m., and ahmed, a.t.a. (eds). encyclopedia of flora and fauna of bangladesh, vol. 6. angiosperms: dicotyledons (ranunculaceae – zygophyllaceae). asiatic society of bangladesh, dhaka. pp. 492-511. rahman, m.a., 2013. inventory of threatened vascular plants of bangladesh for conservation and production of a red data book. a report submitted to the ministry of education, government of bangladesh. rahman, m.a., das, s. c. and rashid, m.e., 2010. the iucn red list categories of angiosperm plants of bangladesh and their conservation. j. taxon. biodiv. res. 4: 1734. rahman, m.a. rashid, m. h., and wilcock, c.c., 2000. diversity, ecology, distribution and ethnobotany of the apocynaceae of bangladesh. bangladesh j. plant taxon. 7(2): 5976. rahman, m. m., rashid, m. h. and rashid, s.h., 2001. study on the plant diversity of the sand dune ecosystem of cox’s bazar to teknaf coast. bangladesh j. plant taxon. 8(1): 27-45. rahman, m. a. and uddin, s.b., 1997. angiospermic flora of sitakund in chittagong, bangladesh. bangladesh j. plant taxon. 4(1): 17-36. raizada, m. b., 1941. on the flora of chitagong. indian for.67: 245-254. rashid, m. h. and chowdhury, m. a. i., 2013. additions to the angiosperm flora in the sitapahar reserve forest of kaptai, rangamati, bangladesh. bangladesh j. plant taxon. 20(2): 255-257. international journal of environment issn 2091-2854 163 | p a g e rashid, m. h. and rahman, m. a., 1996. an annotated list of apocynad taxa occurring in the southeastern flora of bangladesh. bangladesh j. bot. 25(1): 37-43. rashid, m. h., rahman, e. and rahman, m.a., 2000. additions to the angiospermic flora of moheskhali island. bangladesh j. plant taxon. 7(1): 43-63. sinclair, j., 1956. the flora of cox’s bazar, east pakistan. bull. bot. soc. bengal 9(2): 84118. tutul, e., uddin, m. z., rahman, m. o. and hassan, m. a., 2009. angiospermic flora of runctia sal forest, bangladesh. i. liliopsida (monocots). bangladesh j. plant taxon. 16(1): 83-90. tutul, e., uddin, m. z., rahman, m.o. and hassan, m.a., 2010. angiospermic flora of runctia sal forest, bangladesh. ii. magnoliopsida (dicots). bangladesh j. plant taxon. 17(1): 33-53. uberoi, n. k., 2010. environmental studies (2 nd edition). excel books pvt. ltd, new delhi, india. pp. 1-202. uddin, m. z. and hassan, m. a., 2004. flora of rema-kalenga wildlife sanctuary. iucn bangladesh country office, dhaka, bangladesh, pp 120. uddin, m. z. and hassan, m. a., 2010. angiosperm diversity of lawachara national park (bangladesh): a preliminary assessment. bangladesh j. plant taxon. 17 (1): 9-22. uddin, m. z., alam, m. f., and hassan, m. a., 2013. diversity in angiosperm flora of teknaf wildlife sanctuary, bangladesh. bangladesh j. plant taxon. 20(2): 145-162. uddin, s. b. and rahman, m. a., 1999. angiospermic flora of himchari national park, cox’s bazar, bangladesh j. plant taxon. 6(1): 31-68. uddin, s. n. and hassan, m. a., 2012. angiosperm flora of rampahar reserve forest under rangamati district in bangladesh. i. liliopsida (monocots). bangladesh j. plant taxon. 19(1): 37-44. uddin, s. n., kahn, m.s., hassan, m. a. and alam, m.k., 1998. an annotated checklist of angiospermic flora of sita pahar at kaptai in bangladesh. bangladesh j. plant taxon. 5(1): 13-46. usda forest service., 1993. every species counts: conserving biological diversity. program aid 1499. usda forest service, washington dc. walter, k. s. and gillett, h. j. (eds) 1998. 1997 iucn red list of threatened plants. compiled by the world conservation monitoring centre. lucn the world conservation union, gland, switzerland and cambridge, uk. ixiv + 862pp. international journal of environment issn 2091-2854 164 | p a g e figures 1-7. threatened species of the flora of bangladesh. 1. alstonia neriifolia d. don.; 2. beaumontia grandiflora wall.; 3. chonemorpha verrucosa (blume) middleton; 4. rauvolfia serpentina (l.) benth. ex kurz; 5. aganosma marginata (roxb.) g. don.; 6. chonemorpha assamensis furtado; 7. chonemorpha griffithii hook. f. 1 2 3 4 5 6 7 international journal of environment issn 2091-2854 165 | p a g e figures 8-16. threatened species of the flora of bangladesh (contd.). 8. willoughbeia edulis roxb.; 9. urceola micrantha (wall. ex g. don) middleton; 10. wrightia arborea (dennst.) mabb.; 11. melodinus khasianus hook. f.; 12. melodinus monogynus roxb.; 13. wrightia coccinea sims.; 14. vallaris solanacea (roth) o. kuntze; 15. ampelopsis rubifolia (wall.) planch.; 16. cayratia pedata (lam.) juss. ex gagnep. 15 16 10 11 12 13 14 8 9 international journal of environment issn 2091-2854 166 | p a g e figures 17-22. threatened species of the flora of bangladesh (contd.). 17. ampelopsis glandulosa (wall. ex roxb.) momiyama; 18. cayratia tenuifolia (wight & arn.) gagnep.; 19. cissus verticillata (l.) nicolson & c.e. jarvis; 20. cyphostemma auriculatum (roxb.) singh & shetty; 21. vitis flexuosa thunb.; 22. vitis heyneana roem. & schult. 17 18 19 20 21 22 international journal of environment issn 2091-2854 167 | p a g e figures 23-28. threatened species of the flora of bangladesh (contd.). 23. cissus pentagona roxb.; 24. cissus vitiginea l.; 25. parthenocissus semicordata (wall. ex roxb.) planch.; 26. tetrastigma dubium (laws.) planch.; 27. t. rumicispermum (laws.) planch.; 28. t. serrulatum (roxb.) planch 23 24 25 27 28 26 performance of sweet pepper under protective structure international journal of environment issn 2091-2854 79 | p a g e international journal of environment volume-12, issue-1, 2023 issn 2091-2854 received: 16 november 2022 revised: 26 january 2023 accepted: 11 february 2023 understanding the phyllanthus and terminalia chebula species population change, dependency and sustainability: a study in malai mahadeshwara hills wildlife sanctuary, southern india harisha r.p1 *, siddappa setty r1, ravikanth g2 1centre for environment and development 2centre for biodiversity and conservation, ashoka trust for research in ecology and the environment, royal enclave, srirampura, jakkur post, bangalore 560 064, india *corresponding author: hari@atree.org abstract non-timber forest products (ntfps) are vital sources of livelihood for forest-dependent communities across the globe. this study examined the ntfps species (phyllanthus emblica, p. indofischeri, and terminalia chebula) population change determined by the dependency, disturbances, and accessibility in the dry tropical forest of malai mahadeshwara (mm) hills wildlife sanctuary. the long-term monitoring population data were analyzed across three time periods; 2000-01, 2010-11, and 2020-21. the participatory research methods were used to assess the dependency and accessibility which influence the population structure. the multifactor linkage approach was used to identify the significant drivers of population decline. the results indicated that grazing, fire, hemi-parasite infection, and lantana invasion influenced the tree population structure and regeneration of study species. this study has also indicated variations and changes in the interrelationship among factors that have a significant role in shaping ntfps species population structure. multiple factor analysis determined that grazing, fire, and lantana have significant impacts on population structures, regeneration, and fruit production of ntfps species. the study recommended that forest managers should consider a site-specific adaptive approach and multiple factors models and inclusive management tools provisioned in recent policies like the biological diversity act -2002 and forest rights act-2006 would hold great potential for developing sustainable use and co-management practices. keywords: community; dependency; forest resources; sustainability doi: https://doi.org/10.3126/ije.v12i1.52444 copyright ©2023 ije this work is licensed under a cc by-nc which permits use, distribution and reproduction in any medium provided the original work is properly cited and is not for commercial purposes mailto:hari@atree.org https://doi.org/10.3126/ije.v12i1.52444 https://orcid.org/0000-0001-8836-4383 international journal of environment issn 2091-2854 80 | p a g e 1. introduction forests provide a range of socio-economic and environmental benefits that are essential for human life (millennium ecosystem assessment, 2005; food and agriculture organization, 2014). globally, more than a billion people depend directly on ntfps for their livelihoods (mea, 2005). another three billion people indirectly depend on ntfps for many economic and social benefits (agrawal et al., 2013). thus, ntfps are found to be a vital source of livelihood for people from forest fringe communities across the world. many studies revealed that ntfps realize various functions in enhancing human well-being and rural livelihoods, and it was widely acknowledged globally (angelsen et al., 2014; shackleton et al., 2015; shackleton and pullanikkatil, 2018). in india, ntfps species contribute 2.7 billion usd per year and provide 55% of the total employment in the forestry sector (fao, 2014). these ntfps are harvested for food, medicines, and handicrafts apart from subsistence use and as a source of cash income. past studies have reported that fruit harvesting alone does not have a significant impact on the ntfps population, site-specific multiple factors could change the population structure (ticktin, 2004; brummitt and bachman, 2010; scoles et al., 2012). shaanker et al. (2004a), identified that dependency, degradation, and disturbance factors could contribute to the depletion of ntfps resources in tropical forest settings. however, intermittent extraction of ntfps has influenced stability in the population structure of ntfps species (kodandapani et al., 2004; shackleton et al., 2005; varghese et al., 2015). moreover, resource accessibility changes dependency on ntfps and related livelihoods (marshall et al., 2006). these changes in local context and livelihoods might have influenced or contributed to changes in the ntfps population structure (endamana et al., 2016). it is also apparent that the contribution of ntfps to income varies across ecological settings, seasons, and income levels (marshall et al., 2006). considering the importance of ntfps in the livelihoods of local communities needs more attention on developing appropriate policies and evolving strategies for the better management of ntfps. several attempts have been made to understand the dynamics of the ntfps species population and identify sustainable harvesting practices (gaoue and ticktin, 2010; ravikanth and setty, 2017). most of the ntfps studies have exclusively focused on assessing the impacts of harvesting and other anthropogenic factors on regeneration, productivity, and population structure as well as on genetic diversity (murali et al., 1996; padmini et al., 2001; ganesan and setty, 2004; sinha et al., 2005; ramesha et al., 2007; ravikanth et al., 2009). further, studies also recommended developing effective conservation strategies, sustaining the livelihoods of dependent communities and ecology of ntfps species using anthropogenic factors at multiple scales, times, disciplines, and linkages (peres et al., 2003; schmidt et al., 2011; ticktin et al., 2012). the international journal of environment issn 2091-2854 81 | p a g e attributes such as harvest practices, dependency dynamics, and species response patterns are crucial to evolve an ecologically sustainable practice (ticktin and shackleton, 2011). this study is intended to contribute to the knowledge of understanding the interrelationship between the dependencies; accessibility change and derived disturbance which influenced the species' response toward developing sustainable practices. it helps in developing strategies for finding nature-based solutions to address and manage forest resources. henceforth, this study formulates the hypothesis that a combination of fruit harvest frequency, derived disturbances and accessibility play a crucial role in reshaping the population structure, recruitment rate, and fruit productivity. 2. materials and methods 2.1. study site the study was conducted in malai mahadeshwara (mm) hills which is located in the chamarajanagara district of karnataka in south india. it lies between latitudes 11 ̊55˚n and 12 ̊13˚n, and longitudes 77 ̊30 ̊ and 77 ̊47˚e with cauvery wildlife sanctuary to its north-east and the biligiri rangaswamy temple tiger reserve (brt) to its south-west (figure 1). the sanctuary covers an area of 906 km², hills and valleys are roofed with extensive forests with a chain of continuous mountain peaks (elevations ranging from 600-1380 m) and mosaic habitat. the climate of mm hills is moderate throughout the year, hot summer and cold winter. it receives rain from the southwest monsoon between may-august and from the northeast monsoon between september-november with a pronounced dry period between january and march. the mean annual temperature is 35.3˚c and varies between 24˚c in winter to 42˚c in summer (shaanker et al., 2004a). the forest harbors rich fauna and flora used by local people in traditional healthcare, cultural, and religious systems. it has unlike forest types such as dry deciduous (64.34%), scrub woodland (20.50%), and scattered patches of moist deciduous and riparian forest (2.47%) (aravind et al., 2010). the sanctuary has been invaded by lantana camara which brought significant change to local biodiversity and livelihoods. since the 1990s, the ntfps has played a critical role in the livelihoods of local communities in this region as there has been an increased demand for forest products in the local markets (shaanker et al., 2004b). phyllanthus emblica, p. indofischeri, and terminalia chebula are common ntfps species and fruits have been harvested as a source of income (rist et al., 2008; shaanker et al., 2004a). phyllanthus species are widely known as indian gooseberry, and amla (in hindi). phyllanthus fruits have been used extensively to make pickles, jams, and herbal drinks; in ayurvedic medicine and cosmetics. terminalia chebula is commonly known as black myrobalan and it is also extensively used in ayurveda medicine and cosmetics industries. the populations of t. chebula and p. emblica overlap in forest habitats. however, the populations of phyllanthus species are spatially segregated; p. indofischeri occurs at lower elevations (<900m), in scrub international journal of environment issn 2091-2854 82 | p a g e forests, and p. emblica occurs at higher elevations (>800m) in dry deciduous forests (setty et al., 2008). t.chebula is slow-growing shade-tolerant species and has poor seed germination capacity in natural conditions (anitha et al., 2010). there are 31 settlements (villages) scattered within and periphery of mm hills forest. about eight villages constitute a homogenous community called soligas; whereas another 23 villages are constituted heterogeneous communities called soligas and bedagampana. soligas are the indigenous tribes living in mm hills forest for centuries and they have historically been engaged in hunting, ntfp collection, and shifting cultivation for their livelihood (harisha et al., 2015). shifting cultivation and hunting were banned in 1972 under the wildlife protection act, following which the soligas sedentarized in settlements called 'podu' and continued settled agriculture (murali et al., 1996). most of the villages were notified as revenue villages in 1913. they received titles to their cultivable land ranging in size from 0.5 to 2 hectares under forest rights act 2006. figure 1: location of the study area, mm hills, karnataka, india 2.2. assessment of population structure and regeneration the regeneration capacity of a species is reflected in the population sizeclass distribution; as the assessment of population structure is convenient and provides information on species population status. twenty transects measuring 10m x 100m sample plots were laid for each species in the m m hills forests in 2000-01 and monitored annually till the year 2020-21. sample plots were used to estimate the population structure of p. international journal of environment issn 2091-2854 83 | p a g e emblica, p. indofischeri, and t. chebula. sample plot locations are marked based on ntfps resource maps developed by harvesters during participatory resource appraisal (pra) exercises. all the individuals of the study species in the sample plots were tagged permanently with aluminium tags bearing a unique number (seedlings to adult trees). the diameter at breast height (dbh) of each tree/sapling (measuring above 1 cm dbh) was recorded at 1.3 meters height. the density of lantana camara was estimated by counting the number of individual clumps in five sample quadrates measuring 5mx5m within each of the 20 plots. similarly, grazing intensity was assessed by counting the dung and pellets within the belt transect measuring two-meter wide and 100 meters long, within each of the 20 plots. the forest fire incidents were recorded during the study periods and the extent of the area burned was also mapped in all the plots. 2.3. assessment of fruit productivity and extraction all reproductive adults >5cm dbh stem in the transect were identified and estimated fruit production before harvest to understand the stock of fruits and after harvest to understand the level of extraction. one month before the fruit harvest, the number of fruits was estimated. the fruit production of the tree was estimated visually by counting five fruiting branches which were selected randomly out of the total fruiting branches from each tree and also the number of fruiting branches was estimated. later average fruits per branch were calculated for five selected branches and multiplied by the total fruiting branches. . it has been repeated during the post-harvest to understand the level of fruit extraction by the community. the number of hemi-parasiteinfected branches was counted and branch cut was also recorded before and after the fruit harvest to understand the level of the tree getting damaged while harvesting the fruits. 2.4. assessment of dependency and accessibility the dependency and accessibility of the local community have been assessed by conducting a socioeconomic survey in 2000-01, 2010-11, and 2020-21. the four forest villagers who have traditionally been involved in ntfps collection were selected based on proximity to the road (to the transect points) and the number of people harvesting ntfps based on the frequency of harvest. semi-structured interviews were conducted for 92 households from four villages which were 10% of the total households per village. villages such as anehoa(228 hh), kumbudukki(232), gorasane(242), and kokkubare(218) were located close to the sample plots and were selected for the household interview. the systematic sampling methods were used to select households for the interview by considering the family size (number of people in their family) and based on their occupation (ntfps collection, farming, daily wage, and others) to draw reliable information. both men and women participated in the household survey. the household survey was conducted from october to november, before fruit harvest, and after harvest from april to may. the interviews were 1-3 hours long in the local language (kannada) and information was international journal of environment issn 2091-2854 84 | p a g e validated by revisiting the households. the household survey captured the socio-economic profile, source of income, and livelihood change. the community perception of the present status of ntfps resources, dependency, and accessibility change under the forest protection regime was also documented. 2.5. focus group discussion most of the participants were ntfps harvesters and were members of the cooperative society called large scale adivasimulti-purpose societies (lamps). the community leaders who have been involved in the forest rights act (fra) 2006 implementation, and served as forest department employees for a long time in the study area have also participated. during the fgd, participants prepared resource maps and harvesting timelines for the ntfps species. they also shared the constraints involved in ntfps collection, the impacts of policy change on resources, and their livelihoods. annual fruit harvest estimate accessed from lamps for the past 20 years (from 2000-01 to 2020-21). lamps are the nodal agency for marketing, monitoring, and management of ntfps resources. it consists of a management committee and an executive committee formed by soliga community representatives and forest department officials. 2.6. data analysis we categorized the data collected across three study periods into; indicators of population structure (population density, regeneration rate, and annual fruit yield); disturbance variables (grazing intensity, lantana density, fire frequency, branch cut, and hemi-parasite infection); dependency variables (lamps data on the quantity of fruit collected and income from ntfps-which is a direct indicator of dependency); accessibility change (tenure, policy change and community perceptions on forest regime which had a significant impact on ntfps accessibility). understanding the variation of variables across study periods: the population structure of study species that recruit regularly was characterized by reverse j curves (lykke, 1998; wright et al., 2003). the size class distribution was estimated for the study species by using population monitoring data obtained from three study periods. repeated measure manova statistics was used to evaluate the variance of mean values of population structure, disturbance, and dependency indicators across study periods. determine the relationship between indicators and variables: we used multiple regression analysis to determine the relationship between population structure, disturbance, dependency, and accessibility variables. the data was also used to determine the significant relationship between and within variables. the study used population density, recruitment rate, and fruit yield as response variables to determine the impact of disturbances, dependency, and accessibility. international journal of environment issn 2091-2854 85 | p a g e characterizing the variables which determine the population structure data on variables of dependency, disturbance, accessibility, and indicators of population structure were averaged across sampled points. the binomial distribution model was employed for seedling density and fruit production to check the distribution of data points. a generalized linear model (glm) was employed to explore the link to disturbance, dependency, and indicators of the population structure of the study species. the glm was employed for three study periods separately. the analysis started with an initial model of eight variables to reduce the co-linearity. the variables used were lantana density, grazing intensity, fire frequency, hemi-parasite infection, branch cut, and extraction rate versus population density, regeneration, and fruit production. to assess the overall effect of each predictor variable on population structure and productivity, we have calculated aicc (second-order akaike information criteria, used for small sample size), differences in aicc, and aicc weights for each model in the two model sets (t. chebula and phyllanthus spp.) using the r package aicc moving. we calculated the mean and 95% confidence interval for the regression coefficient of each predictor variable by averaging coefficients across all models, weighted by the aicc weight of each model. a backward selection based on the akaike information criterion (aic) was operated to determine the best combination of factors that have a significant impact on population density, regeneration, and fruit production. data analyses have been carried out using microsoft excel and r (version 3.3.1). 3. results 3.1. understanding the factors across study periods 3.1.1 indicators of population structure size class distribution: the population (>5cm dbh.) density of species varied across the study periods. in 2000-01(p.emblica-20.8/ha.; p. indofischeri -16.9/ha.; t.chebula-43.2/ha.); in 2010-11 (p.emblica18.4/ha.; p.indofischeri-15.5/ha.; t.chebula-41.2/ha.); and in 2020-21 (p.emblica-20.1/ha.; p. indofischeri 16.2/ha.; t.chebula-42.6/ha.). all three species (p. emblica and p. indofischeri and t. chebula) showed three different size-class distributions (including seedlings, saplings, and adults) across the study period. in the year 2000-01, for all three species, the relative frequency of seedlings and saplings was lower than in 2010-11 and 2020-21 resulting in an unstable population structure. however, in 2010-11, all three species showed a sporadic size-class distribution. in 2020-21 all three species showed a reverse j-shaped curve (stable, selfmaintaining population) which indicates that the population is stable compared to previous study periods (fig. 2). international journal of environment issn 2091-2854 86 | p a g e figure 2: size class distributions of species across study periods regeneration: the seedling density of phyllanthus species was lower in 2000-01(89/ha.) compared to 201011 (114/ha.) and (205/ha.) in 2020-21. similarly, the percentage of seedling survival rate increased from 1.8, 2.1, and 8.9 in 2000-01, 2010-11, and 2020-21 respectively. the seedling density of t. chebula was43/ha., 64/ha. and 104/ha.in 2000-01, 2010-11, and 2020-21 respectively. the percentage of seedling survival rate increased from 1.3, 1.8, and 6.3 in 2000-01, and 2010-11 to 2020-21 respectively. fruit production: the percentage of fruiting trees across study periods was 35.6% for p. emblica, 31% for p. indofischeri, and 54.6% for t. chebula. there were no significant differences in the percentage of fruiting trees for all the species across the study periods. similarly, the annual fruit production for p. emblica was 135.5 kg./ha., 158kg./ha., and 206.72 kg/ha in 2000-01, 2010-11, and 2020-21 respectively; similarly for p. indofischeri, it was 115.5 kg./ ha., 114kg./ha., and 161.72 kg/ha., in 2000-01, 2010-11 and 2020-21 respectively; in case of t. chebula it was 235.5 kg./ha., 260.4 kg./ha. and 270.72 kg/ha. in 2000-01, 2010-11, and 2020-21 respectively. 3.1.2. dependency variables annual fruit harvesting: lamps is a tribal co-operative society constituted by a cooperative and the forest department that purchases fruits/ntfps buy fruits from harvesters and sells them in the open market with or without value addition. the fruit harvested by the harvesters in 2000-01 was 67.5 tons, which decreased to 0.00 20.00 40.00 60.00 5 15 25 35 45 r e la ti v e f re q u e n cy (% ) size class(dbh in cm.) phyllanthus indofischeri 2000-01 2010-11 2020-21 0 20 40 60 80 5 15 25 35 45 >50 r e la ti v e f re q u e n cy (% ) size class(dbh in cm.) phyllanthus emblica 2000-01 2010-11 2020-21 0 20 40 60 5 15 25 35 45 >50 r e la ti v e f re q u e n cy (% ) size class(dbh in cm.) terminalia chebula 2000-01 2010-11 2020-21 international journal of environment issn 2091-2854 87 | p a g e 4.1 tons in 2020-21 in the case of phyllanthus. in the case of t. chebula, fruit collection was 13.7 tons in 200001 and it reduced to 3.1 tons in 2020-21 (fig. 3). figure 3: phyllanthus and terminalia fruit harvested (source: lamps) ntfps dependency and income change: fruit collection season is from november to february, soliga community from 31 villages in and around forest area collect and sell them to lamps. the number of households involved in harvesting from each village ranged from 30% to 55% and usually, both men and women participated in fruit harvest. the percentage of income from fruit/ntfps collection in 2000-01 was 43 % per household per capita, whereas in 2010-11 it reduced to 21% and it further reduced to 13 % in 2020-21. fruit harvesting was mainly determined by availability, accessibility, and market linkage. the younger generation has been migrating to nearby towns for jobs and migratory income has increased by two fold in recent years. the percentage of people migration increased from 18% to 51% in 20 years that’s very significant (fig. 4). figure 4: ntfps dependency and income change from the past two decades. r² = 0.5755 r² = 0.3211 0 10 20 30 40 50 60 70 80 f ru it h a rv e st e d ( t o n s) amla arale expon. (amla) expon. (arale) international journal of environment issn 2091-2854 88 | p a g e 3.1.3. disturbance variables grazing intensity: the forest area was wide open for grazing until the year 2013 when the forest department declared mm hills as a wildlife sanctuary. there were 19 cattle sheds spread across the mm hills forest area before being declared a wildlife sanctuary. the forest department put a restriction on cattle grazing and banned cattle sheds inside the wildlife sanctuary. the grazing intensity (the number of cattle and goats) inside the forest reduced drastically from 2013 onwards. it was indicated indirectly in terms of pellet density change which was recorded during the study periods. similarly, the cattle and goat populations in the forest villages were also reduced. according to the official record, the cattle population reduced from 6500 (in 2000-01) to 3400 (in 2020-21), and the goat population from 4900 (in 2000-01) to 2750 (in 2020-21). lantana density: there has been a major change in forest structure due to the invasion of l. camara. this species spread in the landscape after the mass bamboo felling in the 1970s and development activities in the region. in the first period (2000-01) the density of lantana was very high (6342/ha.) compared to 2010-11 (4850/ha.) and 2020-21 (3930/ha.). local people started harvesting lantana from the forest in 2003-04 to make furniture and utility products, which resulted in a gradual decrease in lantana density. fire frequency: incidents of forest fire got reduced after the declaration of the wildlife sanctuary. in 2000-01, thirteen sample plots were partially burnt whereas in 2010-11 only six sampled plots were partially burnt and in 2020-21 only three sampled plots got burned. the incidents of fire reduced across forest areas in general. in 2000-01, 1.25 hectares of forest area got burned, it was reduced to 0 .84 hectares in 2010-11, and in 202021 it was only 0.38 hectare got burned. branch cut and hemi-parasite infection: branch cut and hemi-parasite infection were found only in phyllanthus species. in t. chebula no hemi-parasite infection but branch cuttings were recorded. therefore, we considered phyllanthus species (p.emblica and p.indofischeri) for the analysis. branch cutting was much more common in 2000-01 and 2010-11. it is because of open access to use resources in the forest, grazing livestock, and harvesting fruits. the rate of the branch cut correlated with hemi-parasite infection. fruit harvesters have been removing hemi-parasite-infected branches during fruit harvest to check the further spread of hemi-parasite and grazers to feed their goats. in 2000-01 the frequency of branch cutting was 63% for p.embica and 59.3% for p.indofischeri. whereas in 2020-21 branch cutting was less (11% for p.embica and 6.1% for p.indofischeri). similarly, hemi-parasite infection was very high in 2000-01(36% for p.embica and 9.3% for p.indofischeri compared to 2020-21 (23.3% for p.embica and 4.6 % for p.indofischeri. 3.1.4. tenure and accessibility change since 2013 the mm hills forest was a reserve forest that offered open access to resource use and collection of ntfps in the landscape. also, the forest opened to cattle sheds inside the forest and another livestock grazing international journal of environment issn 2091-2854 89 | p a g e in 2013, mm hills became a wildlife sanctuary which resulted in a ban on grazing, restriction on ntfps collection, and other produce collected by the community from the forest (table 1). also, the forest department initiated strict patrolling and improved management practices (for example, issuing ntfps collection passes, and timings), which reduced incidents of forest fire, a reduction in grazing, and a significant reduction in fruit collection. table 1: showing changes in tenure rights across study periods attributes 2000-01 2010-11 2020-21 forest protection status reserve reserve wildlife sanctuary using forest for grazing, firewood etc. open open ban accessibility fruit harvest no restriction no restriction regularised forest right act 2006 implementation no policy exist started claiming rights rights over ntfps collection received 3.2. variables and indicators variations across study periods the study hypothesized that variables such as population structure, disturbance, dependency, and accessibility change significantly vary across study periods (2000-01, 2010-11, and 2020-21). the analysis of variance (anova) between study periods revealed that variables such as population density and percentage of fruiting trees had not changed significantly. whereas, regeneration (f=18.52, p=>0.01 for phyllanthus and f=7.47, p=>0.01 for t. chebula) rate, fruit production (f=5.52, p=>0.05 phyllanthus and f=6.37, p=>0.05 for t. chebula) have seen significant change. disturbance variables such as grazing intensity observed significant change (measured indirectly by counting pellets and dung) (f=12.52, p=>0.01 for pellets and f=9.43, p=>0.01 for dung). similarly, lantana density (f=8.45, p=>0.05) and fire frequency (f=8.43, p=>0.05) have changed significantly between study periods (appendix 1). 3.3. understanding the variable's relationship with indicators of population structure. listed variables such as fruit extraction, hemi-parasite infection, branch cut, lantana density, grazing intensity, fire frequency, the quantity of fruit harvest, and income were used for multiple regression analysis. dependent variables such as tree density, regeneration rate, and fruit productivity were tested with variables to evaluate the relationship and characterize the impacts on population structure. in 2000-01 grazing intensity, hemi-parasite infection, branch cut, and forest fire had significant negative impacts on the population density of phyllanthus species, in the case of t. chebula, grazing intensity and fire frequency had significant negative impacts on tree population density. similar trends were seen in 2010-11 as well for all three species (appendix 2). whereas, in 2020-21 all of the variables had a significant positive relationship with the population density of phyllanthus species and t. chebula. international journal of environment issn 2091-2854 90 | p a g e the regeneration rate was negatively affected by grazing and forest fire for all the species during 2000-01 and 2010-11. whereas in 2020-21 fruit productivity had a significant positive impact on the regeneration rate (supplementary file 1). in 2000-01 and 2010-11, the fruit productivity of phyllanthus species was negatively affected by hemi-parasite, branch cut, and grazing, in the case of t. chebula grazing had significant negative impacts (appendix 2). fruit production in the case of t. chebula factors such as grazing (r² =-0.561, p=<0.05) had a significant negative impact on fruit production. whereas, adult tree density (r²=0.403, p=<0.05) has a positive relationship with fruit production. while branch cut showed a significant negative impact on p. indofischeri fruit production, in the case of p. emblica, hemi-parasite infection significantly affected fruit productivity. adult tree density (r²=0.413, p=<0.05) also had a positive relationship with fruit production in both the species of phyllanthus (appendix 2). the branch cut reduced fruit production for phyllanthus species. 3.4. characterizing the roles of the variable on indicators of population structure the model selection was based on coefficient value, associated standard error, and corresponding p-value of the covariates in the model that influence species population density, regeneration, and fruit productivity. based on theoretical as well as field knowledge, there were seven models with different combinations of variables/covariates were used to test against the population density, regeneration, and fruit productivity. the detailed model selection procedure for covariates which influenced population density, regeneration, and fruit production for all three species across the study periods was provided in (appendix 3a,3b,3c). in the supplementary file three best models with covariates influencing population density, regeneration, and fruit production of study species was listed. population density: in 2000-01 and 2010-11 the variables such as grazing, fire, and hemi-parasite had a significantly negative influence on the population density of p.emblica. in 2020-21, lantana density and hemiparasite had a significant negative influence on population density. similarly, the p.indoficheri population structure had a significant negative association with variables such as branch cut; grazing, and fire in 2000-01 and 2010-11. but in 2020-21 lantana density and forest fire had a significant negative influence on population density. in the case of t. chebula, grazing and fire had a significant negative role in shaping population structure in 2000-01, whereas in 2010-11 variables like grazing, lantana density, and fire had a significant impact on population density. but in 2020-21 only lantana density and fire had a significant impact on the population density of t. chebula (table 2). international journal of environment issn 2091-2854 91 | p a g e table 2: summary of the best model with covariates that influence population density of the study species. species year covariates wi aic aicc δ aicc k coefficients se p pe 2000-01 hp+gi+ff 0.92 108.72 106.83 0.16 4 hp:-0.064 gi: -0.299 ff:-0.183 0.005 0.008 0.064 <0.05* <0.05* <0.05* 2010-11 hp+gi+ff 0.91 112.43 108.32 0.01 4 hp:-0.064 gi: -0.299 ff:-0.192 0.008 0.069 0.031 <0.05* >0.05 >0.05 2020-21 hp+ld 0.83 102.41 103.16 0.06 3 hp:-0.064 ld:-0.076 0.041 0.231 <0.05* <0.05* pi 2000-01 bc+gi+ff 0.89 117.86 113.91 0.12 5 bc:-0.001 gi: -0.258 ff: -0.076 0.006 0.064 0.008 >0.05 <0.05* <0.05* 2010-11 bc+gi+ff 0.79 111.92 106.03 0.04 4 bc:-0.064 gi: -0.103 ff:-0.214 0.086 0.067 0.041 <0.05* >0.05 <0.05* 2020-21 ld+bc 0.86 105.32 105.89 0.05 3 ld:-0.319 bc:-0.031 0.031 0.072 <0.05* >0.05 tc 2000-01 gi+ff 0.94 104.14 102.65 0.10 4 gi: -0.010 ff: -0.038 0.004 0.007 <0.05* <0.05* 2010-11 gi+ ld+ ff 0.86 119.82 114.68 0.23 4 gi:0.062 ld: -0.246 ff:-0.031 0.013 0.092 0.021 <0.05 <0.05* <0.05* 2020-21 ld+ff 0.91 102.34 104.31 0.04 3 ld:-0.049 ff:-0.031 0.012 0.031 <0.05* >0.05 tc=terminalia chebula; pe=phyllanthus emblica; pi=p.indofischeri; ld=lantana density; gi=grazing intensity; ff=fire frequency; td=tree density; ft=fruiting trees; bc=branch cuts; aic=akaike information criterion; aicc= aic corrected for small-sample bias; δ aicc= difference in aicc values between each model and the model with the lowest aicc; wi=aicc model weight; k=number of parameters estimated by the model; se=standar error. regeneration: hemi-parasite, branch cut, and lantana have affected the regeneration of p.emblica. similarly, the regeneration of p.indoficheri is affected by grazing, fire, and lantana. in the case of t. chebula variables like grazing, fire, and lantana had a significant impact on both seedlings and saplings across international journal of environment issn 2091-2854 92 | p a g e study periods (table 3). this indicated that seedlings and saplings were more sensitive to grazing and fire during drought years which caused high mortality in seedlings and saplings. lantana density had a positive association with seedling density but the sapling survival rate was poor across study periods and species. it is shown that lantana influences regeneration by controlling soil erosion and increasing soil moisture and nutrition. but transforming from seedling to sapling differed between vegetation type and presence and absence of l. camara. the positive association between lantana and seedling density in the dry deciduous forest for all the study species was observed. it indicated that unregulated disturbance other than fruit harvest in the forest had greater impacts on population structure. dry tropical tree species are more prone to physical damage by branch cut, grazing, and fire during drought years (2000-01 and 2007-08). table 3: summary of the best model with covariates that influence regeneration of the study species. species year covariates wi aic aicc δ aicc k coefficients se p-value pe 2000-01 gi+ff 0.94 102.15 101.5 0.06 3 gi: -0.299 ff:-0.021 0.064 0.041 <0.05* <0.05 2010-11 gi+ff 0.91 108.43 105.91 0.13 3 gi: -0.113 ff: -0.057 rf: 0.021 0.008 0.069 0.031 <0.05* >0.05 >0.05 2020-21 ff+ld 0.89 119.82 114.68 0.23 3 rf: 0.031 ld: 0.311 0.013 0.092 <0.05* >0.05 pi 2000-01 gi+ff+ld 0.93 123.81 120.41 1.62 4 gi: -0.001 ff:-0.051 ld: 0.258 0.006 0.064 0.052 >0.05 <0.05* >0.05* 2010-11 gi+ld+ff 0.97 113.92 108.31 0.61 4 gi: -0.064 ld: 0.103 ff:-0.031 rf: 0.052 0.086 0.067 0.030 0.051 <0.05* >0.05 <0.05* >0.05 2020-21 ff+ld 0.88 117.41 114.81 0.41 3 rf: 0.031 ld: 0.046 0.431 0.836 <0.05* >0.05 tc 2000-01 gi+ff 0.94 104.14 107.32 0.061 3 gi: -0.010 ff: -0.038 0.004 0.007 <0.05* <0.05* 2010-11 gi+ff 0.86 116.82 119.45 0.089 3 gi:0.062 ff:0.246 rf: 0.062 0.013 0.092 0.032 <0.05* <0.05* <0.05* 2020-21 ff+ld 0.91 109.56 113.84 0.082 3 rf: 0.021 ld: 0.039 0.084 0.073 <0.05* >0.05 tc=terminalia chebula; pe=phyllanthus emblica; pi=p.indofischeri; ld=lantana density; gi=grazing intensity; ff=fire frequency; td=tree density; ft=fruiting trees; bc=branch cuts; aic=akaike international journal of environment issn 2091-2854 93 | p a g e information criterion; aicc= aic corrected for small-sample bias; δ aicc= difference in aicc values between each model and the model with the lowest aicc; wi=aicc model weight; k=number of parameters estimated by the model; se=standard error fruit productivity: hemi-parasite and branch cuts have affected the fruit productivity of p.emblica. similarly, the fruit production of p.indoficheri is affected by grazing, and branch cutting. in the case of t.chebula variables like grazing, branch cut, and density of fruiting trees had a significant impact on fruit production (table 4). table 4: summary of the best model with covariates that influence fruit productivity of the study species. species year covariates wi aic aicc δ aicc k coefficients se p-value pe 2000-01 hp+bc 0.92 102.53 104.32 0.14 3 hp: -0.064 bc: -0.076 rf: -0.299 0.005 0.008 0.064 <0.05* <0.05* <0.05* 2010-11 hp+bc 0.91 118.31 119.69 0.01 3 hp: 0.113 bc: 0.057 rf: 0.142 0.008 0.069 0.042 <0.05* >0.05 <0.05* 2020-21 hp 0.95 111.83 112.19 0.31 2 hp: 0.041 rf: 0.524 0.052 0.034 <0.05* <0.05* 2000-01 bc+gi 0.89 121.04 121.89 0.51 3 bc: -0.001 rf: -0.258 gi: -0.076 0.006 0.064 0.008 >0.05 <0.05* <0.05* 2010-11 bc+gi 0.97 106.32 107.82 0.02 3 bc: 0.064 rf: 0.103 gi: 0.210 0.086 0.067 0.083 <0.05* >0.05 <0.05* 2020-21 rf+ft 0.88 114.02 115.19 0.43 3 rf: 0.412 rd: 0.023 ft: 0.028 0.042 0.039 0.105 <0.05 >0.05* <0.05* tc 2000-01 gi+bc 0.94 104.14 106.43 0.08 3 gi: -0.010 rf: -0.038 0.004 0.007 <0.05* <0.05 2010-11 gi+bc 0.86 112.82 114.94 0.21 3 gi: 0.062 rf: 0.246 0.013 0.092 <0.05* <0.05 2020-21 ft 0.93 108.5 109.43 0.05 2 rf: 0.531 rd: 0.217 ft: 0.071 0.712 0.372 0.619 >0.05* >0.05 <0.05 tc=terminalia chebula; pe=phyllanthus emblica; pi=p.indofischeri; hp=hemi parasite; gi=grazing intensity; ff=fire frequency; bc= branch cut; rf= rainfall; rd= rainy days; ft=fruiting trees; bc=branch cuts; aic=akaike information criterion; aicc= aic corrected for small-sample bias; δ aicc= international journal of environment issn 2091-2854 94 | p a g e difference in aicc values between each model and the model with the lowest aicc; wi=aicc model weight; k=number of parameters estimated by the model; se=standard error. 4. discussion 4.1. understanding the indicators across the study period the life strategy of a species largely depends on adding more new individuals to its population. long-term monitoring of the regeneration history (the frequency and abundance of seedling establishment) was one of the methods used across the globe to understand population change (charles,1998). results demonstrate that the size class distribution of the study species was stable (reverse ‘j’ shaped curve) in 2020-21 compared to previous years. a significant decrease in disturbances, low human dependency, and restrictions on fruit harvest improved regeneration and reduced mortality in 2020-21. in contrast, in 2000-01 and 2010-11 species population showed very poor seedling and sampling establishment and the distribution curve reflects that regeneration is severely limited. grazing, fire, and branch cut were high in 2000-01 and 2010-11 compared to 2020-21. frequent drought and high accessibility (open to access resource) during the period from 2000-01 to 2010-11 in the forest were practiced. these findings were consistent with population studies elsewhere in the tropical deciduous forest (kodandapani et al., 2004; mandle et al., 2012; varghese et al., 2015). results suggest that grazing, branch cut, and the fire was the main contributors to decreased population density and poor regeneration. these drivers were common across tropical forests with similar forest habitats and climatic conditions like in india (sinha et al., 2005; ticktin et al., 2012). the study suggests that fruit harvest alone did not have a significant impact on population structure, regeneration, and fruit production. similarly, fruit productivity was low in 2000-01 and 2010-11 compared to 2020-21, which indicates that combined effects of disturbance factors such as hemi-parasite infection, branch cut, and grazing resulted in low fruit productivity in phyllanthus species. 4.2. evaluating the relationship between the indicators the study found a significant relationship between changes in size class distribution and variables. the population structure of phyllanthus species was shaped by hemi-parasite, grazing, and fire, in the mm hills forest. hemi-parasite is impacting mainly the tree population and significantly increases tree mortality. grazing and fire had affected the seedling establishment and sampling transformation into an adult. a high rate of seedling and sapling mortality was happening in areas where the high intensity of grazing and frequent fire occurred. several studies have reported similar impacts in many tropical forest studies elsewhere in india (kodandapani et al., 2004; tiktin et al., 2012). international journal of environment issn 2091-2854 95 | p a g e in the case of t. chebula, rainfall, grazing, and fire played a role in seedlings and saplings development. t.chebula also has significant constraints in the fruit set due to predation apart from microclimatic conditions that were vital for seed germination (varghese et al., 2015). lantana density alone does not have a significant impact on the tree density of phyllanthus and t.chebula. however, in fire-prone areas, lantana density had a significant impact on the seedling and sapling density of both phyllanthus and t. chebula species. high grazing usually had low lantana density, which also had a low chance of fire but poor regeneration of seedlings and a low rate of sapling establishment for both species. the areas such as lowgrazing, medium lantana density, and less fire-prone areas showed good regeneration of seedlings and a high rate of sapling establishment for both species. areas with high-density lantana with low grazing were prone to high fire and had poor regeneration and sapling establishment. these patterns revealed that in tropical forests elsewhere in india, south asia, and africa (shackleton et al., 2005; mea, 2005). during drought years, grazing in fire-prone areas was subjected to a major change in population structure as recorded during study periods 2000-01 and 2007-08. on the contrary, the low-grazing, less frequent fire, and medium lantana density have supported the regeneration, seedling, and sapling density in 2014-15 for both phyllanthus and t. chebula species. the change in fruit productivity was determined by rainfall, rainy days and hemi-parasite, and branch cut in the case of phyllanthus species. in the case of t. chebula, rainfall and rainy days, and grazing determined fruit productivity. these findings were consistent with fruit productivity surveys elsewhere in the western ghats (murali et al., 1996; mandle et al., 2012). the disturbance factors such as grazing and branch cut were the common factors that limited fruit production across study species. the infestation by hemi-parasite was an additional factor that played a significant role in limiting fruit production in the case of phyllanthus species. previous studies reported significant impacts of hemiparasites on fruit production (shaanker et al., 2004b; setty et al., 2008; mandle et al., 2012). the adult tree density and the number of fruiting trees were the sources of stocks for fruit productivity for most of the ntfps species. several studies have shown that fruit harvest had a less significant impact on fruit productivity (murali et al., 1996; mandle et al., 2012; varghese et al., 2015) similar to our study results. fruit harvest had less impact on the flowering and fruiting phenology of woody species unless populations were subjected to other stressors like continuous drought, hemi-parasite, fire, grazing, and lantana invasion. 4.3. dependency and harvester’s perspective the change in fruit productivity and regeneration was discussed during the focused group discussions with harvesters. the harvesters observed a high rate of adult mortality due to hemi-parasite infection, prominent in the case of p. emblica. they had been practicing branch cutting to avoid further infection of hemi-parasite during fruit harvest (rist et al., 2008). they also observed a high rate of fruit abortion and fruit predation in international journal of environment issn 2091-2854 96 | p a g e the case of t. chebula. research studies also reported that the low fruit set rate is due to poor pollination and a high rate of immature fruit abscission (varghese et al., 2015). all three species had high fruit predation and were severely affected by grazing and fire and lantana invasion (shaanker et al., 2004a; ticktin et al., 2012). the focus group discussion revealed that their dependency on ntfps species had reduced drastically since the last decade. the reasons for the reduction in dependency were; a) change in resource accessibility and imposition of rules and regulations which inhibit people from ntfps collection b) migration to nearby towns and cities to work as laborers facilitated by increased transportation facilities c) volatile markets for fruits harvested from forest and d) socio-economic welfare schemes from the government such as mnrega, public distribution systems, etc. these reasons were drivers of livelihood change among forest-dependent communities across india (gadgil et al., 1995; lele and rao, 1996; rajindra, 2015). the combination of fruit abortion, fruit predation, hemi-parasite, fire, grazing, lantana invasion, and drought has played a significant role in shaping the population structure of study species. harvesters also mentioned that hemi-parasite infections have increased over the years. usually, the harvesters remove the hemiparasites on phyllanthus trees during fruit harvesting. the fruit harvesting decrease in recent years led to high infestation and increased mortality of trees. 4.4. accessibility the community also revealed that more than 80% of people, below the age of 35 migrate as laborers to granite quarries and cities for construction work. around 45% of the women migrate seasonally to work in the coffee estates. about 60% of people, above the age of 50 years do farming and local labor work. the ntfps cooperative societies (lamps) and forest department staff played an important role in the collection of ntfps (lele and rao, 1996). lack of accessibility and a volatile market also influenced the reduction of ntfps collection. the people's perceptions of policy implications, livelihoods, and resource accessibility in the forest have been recorded. about 82.6% of people perceived that wildlife sanctuary status largely affected their livelihoods and resource accessibility compared to other conservation policies in the region (lele and rao, 1996). similarly, 62% of people felt that the wildlife protection act of 1972 impacted their livelihoods. however, 96.7% of people mentioned that the forest rights act 2006 would positively affect their livelihood (roshni et al., 2019). about 86% were disappointed with the delay in implementation, especially for ntfps accessibility rights (community forest rights). the declaration of wildlife sanctuary resulted in the banning of ntfps harvest, increased patrolling, and fire preventive measures restriction on human activity (grazing, fuelwood collection, and ntfps collection) inside the wildlife sanctuary. international journal of environment issn 2091-2854 97 | p a g e 4.5. characterizing the potential indicators the ntfps species in the tropical forest are subject to multiple disturbances, and the magnitude of individual and combined effects had been poorly studied. our results illustrate that untangling the effects of common drivers was critical for developing effective management strategies. the mix and match between indicators played a significant role in shaping the population structure, regeneration, and fruit production of the study species. as previous studies suggest translating as many indicators/drivers as possible into models using a multi-model inference-based approach which would be more helpful for understanding the population structure. in this study, we used disturbance, dependency, and accessibility variables in general linear model (glm) analysis along with population structure variables. moreover, akaike information criterion (aic) was used to determine the combination of factors, which might have had an impact on the population structure. this would provide useful insights for developing management and conservation strategies for ntfps species. the combination of the availability of adult trees and an increase in fruit trees would lead to higher regeneration. similar patterns were observed across the country with similar climatic and habitat conditions (sundaram, 2011; varghese et al., 2015). during the study period, fire intensity was recorded from 2000 to 2020. fire season was correlated with drought year generally; dry deciduous forests, sites close to villages, and cattle camps were identified as fire-prone areas. because of intensive grazing and frequent fire, consecutive droughts from 2001 to 2003 and in 2012 and 2013 resulted in poor regeneration and low seedling establishment for the species, in general. specifically, hemi-parasite control is essential as it harms the tree population of phyllanthus species and increases adult mortality (rist et al., 2008). moreover, the decline of the phyllanthus species population from 2000-01 to 2010-11 was unable to explain by the invasion of lantana camara alone (sundaram, 2011). instead, hemi-parasite, fire, and grazing along continuous drought could be impacted. the causes of this mortality are consistent across plots and other parts of the forest (ganesan and setty, 2004). moreover, the long-term monitoring revealed the indirect effects of lantana on the ntfps population (sundaram, 2011). recent studies suggest that the population dynamics of fruit harvesting species may be perplexed with other drivers, but these indicators have not been considered (schmidt et al., 2011 sundaram, 2011; gooden et al., 2009). for instance, effective management requires addressing the drivers affecting most of the population's decline. as studies revealed low regeneration even in low lantana density areas (schmidt et al., 2011). similarly, hemi-parasite was found to be a major threat to phyllanthus species in both brt and mm hills forest and it affected other species as well (rist et al., 2008; setty et al., 2008; shaanker et al., 2004a). the pattern of regeneration in t. chebula was determined by the low level of genetic diversity, due to high levels of inbreeding (ravikanth and setty, 2017; shaanker et al., 2004b; anitha et al., 2010). in addition, a international journal of environment issn 2091-2854 98 | p a g e low level of germination and a high proportion of seeds with a lack of embryos and pollinator deficiency has been proposed as possible contributors to low regeneration in the case of t. chebula (varghese et al., 2015) however, these need a further vigorous investigation. 4.6. implications for forest management and conservation the sustainability of ntfps species in tropical forests subjected to multiple stressors and the importance of identifying potential factors which have a greater impact on the population is yet to be answered clearly. however, fruit harvest was blamed for observed declines in the study species and state policy imposed a ban on fruit harvest in protected areas. prohibiting the fruit harvest was ineffective and would not improve the status of these populations; instead, it resulted in negative economic repercussions for harvesters (sandemose, 2009). therefore, it is necessary to direct inclusive conservation policies to frame action plans to reduce the disturbance identified. for example, effective control of grazing, and monitoring the distribution of invasive species like lantana could aid the regeneration of the species. moreover, effective control strategies for hemi-parasite infection and branch-cut could be the participatory monitoring and adaptive management strategy. it was emphasized in the forest rights act 2006 to ensure the sustainable use of resources and the regeneration of the study species (roshni et al., 2019). promoting indigenous control methods for hemi-parasite infection, controlled grazing, and an enterprise-based lantana craft center(lcc) model would help in the management of lantana invasion and better management. lantana density could be a prime factor in reducing fire intensity and grazing during drought years. a better understanding of the interrelationships between disturbances, dependency, and accessibility could shape the population structure, regeneration, and fruit production and develop effective forest management policy. the use of a long-term, multidisciplinary and inclusive approach allowed us to determine the combination of factors/indicators that should be the focus that could help in developing management strategies. it is important to assume that unpredictable climatic factors could change the whole scenario and affect the population structure. moreover, forest fire and developmental activities in and around natural forests could impact the health of the forest and the stability of the ntfps species population. the poor implementation of inclusive policies such as the forest rights act 2006 could affect the resource sustainability in the forests. 5. conclusions the study found that the impact of disturbances, dependency, and accessibility on shaping the ntfps species population was very significant. our results suggested that invasion of l. camara, grazing, hemi-parasite, and branch cuts are major drivers impacting the population structure of both phyllanthus species and terminalia chebula. the cumulative effect of hemi-parasite infection, grazing, and branch cut had a significant negative impact on fruit production and regeneration of study species. however, with changes in dependency, international journal of environment issn 2091-2854 99 | p a g e accessibility, and disturbance due to protected area status, the adult tree density, and fruiting trees would have a significant positive impact on regeneration. control of grazing, hemi-parasite spread, and reduction in branch cut would be the better strategy to retain a stable tree population and regeneration. the multi-factor linkage would evolve to identify drivers of population decline and formulate effective conservation policy. ntfps species and the population are at risk due to multiple disturbances, and it is essential to have inclusive management strategies and practices. moreover, site-based adaptive management and participatory resource monitoring approach as provisioned in the recent forest rights act-2006 would hold great potential for developing sustainable use and comanagement practices in the study area. authorship contribution rph and ssr contributed to the study conception, design, conceptualization, methodology, software, investigation, and data curation. the first draft of the manuscript was written by rph. material preparation, data collection, and analysis were performed by rph. rph, ssr, and rkg supervised and validated the work. all authors commented on previous versions of the manuscript, and read and approved the final manuscript. declaration the authors declare that they have no conflict of interest. acknowledgment this work was supported by ford foundation and dorabji tata trust grants to atree and by nsf grant oise03-52827 to tt. the work was partly supported by usaid and dbt, india. we thank the soliga community, t. ganesh, c. trauernicht, and k.s. bawa for their contributions; the karnataka state forest department for granting permission for this research; and o. gaoue, l. mandle, i. schmidt, and two anonymous reviewers for valuable comments on previous drafts. references agrawal, a., cashore, b., hardin, r., shepherd, g., benson, c. and miller, d., 2013. economic contributions of the forest. background paper prepared for the united nations forum on forests. aheg-2 meeting in vienna, austria, january 13-17, 2013. new york, united nations. http://www.un.org/esa/forests/pdf/session_documents/unff10/ecocontrforests.pdf http://www.un.org/esa/forests/pdf/session_documents/unff10/ecocontrforests.pdf international journal of environment issn 2091-2854 100 | p a g e angelsen, a., jagger, p., babigumira, r., belcher, b., hogarth, n. j. and bauch, s., 2014. environmental income and rural livelihoods: a global-comparative analysis. world dev. 64, s12–s28. doi: 10.1016/j.worlddev.2014.03.006 anitha, k., joseph, s., chandran, r.j., ramasamy, e.v. and prasad, sn., 2010. tree species diversity and community composition in a human-dominated tropical forest of western ghats biodiversity hotspot, india. ecological complexity. 7(2): 217–224. elsevier b.v. aravind, n.a., rao, d., ganeshiah, k.n., shaankar, u. and poulsens, j.g., 2010. impact of the invasive plant, lantana camara, on bird assemblages at male mahadeshwara reserve forest, south india, tropical ecology, and 51:325-338. brummitt, n. and bachman, s., 2010. plants under pressurea global assessment: the first report of the iucn sampled red list index for plants. kew, uk: royal botanical gardens. charles, m. p., 1998. sustainable harvest of non-timber plant resources in the tropical moist forest: an ecological premier. the biodiversity support program c/o world wildlife fund, 1250 24th street, nw, washington, dc, usa 20037. endamana, d., angu, k.a., akwah, g.n., shepherd, g., ntumwel, b.c., 2016. contribution of non-timber forest products to cash and non-cash income of remote forest communities in central africa. international forestry review 18(3):280–295 fao., 2014. state of the world's forests. food and agriculture organization of the united nations, rome. available on http://www.fao.org/3/a-i3710e.pdf gadgil, m. and guha, r. 1995. ecology and equity: the use and abuse of nature in contemporary india. london and new york: routledge. ganesan, r. and setty, s. 2004. regeneration of phyllanthus, an important non-timber forest product from southern india. conservation and society, 2, 365-375 gaoue, o.g. and ticktin, t., 2010. effects of harvest on non-timber forest products and ecological differences between sites on the demography of african mahogany. conservation biology, 24 605-614. gooden, b., french, k. and turner, p. j., 2009. invasion and management of a woody plant, lantana camara l., alters vegetation diversity within wet sclerophyll forest in southeastern australia. forest ecology and management 257: 960–967 harisha, r.p., padmavathy, s., nagaraja, b.c., 2015 . traditional ecological knowledge (tek) and its importance in south india: perspective from local communities. applied ecology and environmental research 14(1):311-326. http://www.fao.org/3/a-i3710e.pdf international journal of environment issn 2091-2854 101 | p a g e kodandapani, n., cochrane, m.a. and sukumar, r., 2004. a comparative analysis of spatial, temporal, and ecological characteristics of forest fires in seasonally dry tropical ecosystems in the western ghats, india. forest ecology management. 256: 607–617. kutty, r., kodiveri, a., lele, s. and setty, s., 2019. india’s forest rights act, 2006 stuck in a maze of bureaucratic interpretations? the indian journal of social work. 80 (4). doi: 10.32444/ijsw.2019.80.4.439-460 https://journals.tlss.edu/ljsw/lndex.php/ljs lele, s.r. and rao, j., 1996. whose cooperatives and whose produce? the case of lamps in karnataka in r. rajagopalan. rediscovering cooperation, institute of rural management anand, gujarat, pp.53-91 lykke, a.m., 1998. assessment of species composition change in savanna vegetation by means of woody plants’ size class distributions and local information. biodivers conserv. 7: 1261–1275. mandle, l. and ticktin, t., 2012. interactions among fire, grazing, harvest and abiotic conditions shape palm demographic responses to disturbance. journal of ecology. 100:997-1008. marshall, e., schreckenberg, k. and newton, a.c., 2006. commercialization of non-timber forest products: factors influencing success. lessons learned from mexico and bolivia and policy implications for decision-makers (unep-wcmc biodiversity series, 23), cambridge, gb. united nations environment programme: world conservation monitoring centre, pp.136. millennium ecosystem assessment (mea)., 2005. ecosystems and human well-being: synthesis. washington, dc: island press. murali, k.s., shaanker, u., ganeshaiah, k.n. and bawa, k.s., 1996. extraction of non-timber forest products in the forests of biligiri rangan hills, india. 2. impact of ntfps extraction on regeneration, population structure, and species composition. economic botany. 50:252-269. padmini, s., rao, m.n., ganeshaiah, k.n. and shaanker, u., 2001. genetic diversity of phyllanthus emblica in tropical forests of south india: impact of anthropogenic pressures. journal of tropical forest science. 13: 297-310. peres, c.a., baider, c., zuidema, p.a., wadt, l.h.o., kainer, k.a. and gomes, s., 2003. demographic threats to the sustainability of brazil nut exploitation. science. 302, 2112-2114. rajindra, k. p., 2015. the uniqueness of every day: herders and invasive species in india, anthropology and climate change science pp. 248-272. ramesha, b.t., ravikanth, g., rao, m.n., ganeshaiah, k.n. and shaanker, u., 2007. genetic structure of rattan, calamusthwaitesii in the core, and buffer and peripheral regions of three protected areas at the central western ghats, india: do protected areas serve as refugia for genetic resources of economically important plants? journal of genetics86 (1): 9. https://journals.tlss.edu/ljsw/lndex.php/ljs international journal of environment issn 2091-2854 102 | p a g e ravikanth, g. and setty, s., 2017. shrinking harvest: genetic consequences and challenges for sustainable harvesting of non-timber forest products. in: transcending boundaries: reflecting on twenty years of action and research at atree. edited by a. j. hiremath, n d. rai and a. siddhartha. bangalore: ashoka trust for research in ecology and the environment. ravikanth, g., rao, m. n., ganeshaiah, k.n. and shaanker, u., 2009. genetic diversity of ntfps species: issues and implications. pp.53-64 in: non-timber forest products conservation, management and policies. u. shaanker, a. j. hiremath, g c. joseph and n.d. rai(eds). published by ashoka trust for research in ecology and environment, bangalore and forestry research support program for asia and the pacific, food and agriculture organization, bangkok. rist, l., shaanker, u., milner, g.e.j. and ghazoul, j. 2008. managing mistletoes: the value of local practices for non-timber forest resources. forest ecology and management, 255, 1684-1691. sandemose, p., 2009. the ban of ntfps collection for commercial use and effects on cash incomes and livelihoods of the soligas in br hills, india. ms thesis, norwegian institute of life sciences. schmidt, i., mandle, l., ticktin, t. and gaoue, o., 2011. what do matrix population models reveal about the sustainability of harvesting non-timber forest products(ntfps)? journal of applied ecology, 48, 815826. scoles, r. and gribel, r., 2012. the regeneration of brazil nut trees in relation to nu harvest intensity in the trombetas river valley of northern amazonia, brazil. for ecology management. 265: 71-81. setty, r.s., bawa, k,. ticktin ,t., gowda, c.m., 2008. evaluation of a participatory resource monitoring system for non-timber forest products: the case of amla (phyllanthus spp.) fruit harvest by soligas in south india. ecol soc. 13: 19. shaanker, r.u., ganeshaiah, k.n., rao, m.n., aravind, n.a., 2004b. ecological consequences of forest use: from genes to ecosystem=a case study in the biligiri rangaswamy temple wildlife sanctuary, south india. conservation and society. 2:347-363. shaanker, u., ganeshaiah, k.n., krishnan, s., ramya, r. and meera et al., 2004a. livelihood gains and ecological costs of non-timber forest product dependence: assessing the roles of dependence, ecological knowledge and market structure in three contrasting human and ecological settings in south india, environmental conservation, 31(3) 242–253. shackleton, c. m. and pullanikkatil, d., 2018. “considering the links between non-timber forest products and poverty alleviation,” in moving out of poverty through using forest products: personal stories, eds d. pullanikkatil and c. m. shackleton. (heidelberg: springer), 15–28. doi: 10.1007/978-3-319-755809_2 international journal of environment issn 2091-2854 103 | p a g e shackleton, c.m., guthrie, g. and main., r., 2005. estimating the potential role of commercial overharvesting in resources viability: a case study of five useful tree species in south africa. land degradation & development, 6: 273–286. shackleton, c.m., pandey, a.k. and ticktin, t., 2015. ecological sustainablity for non-timber forset products: dynamics and case studies of harvesting. routledge, new york, usa., pages 280. sinha, a. and brault, s., 2005. assessing the sustainability of non-timber forest product extractions: how fire affects sustainability. biodiversity and conservation, 14, 3537-3563. sundaram, b., 2011. patterns and processes of lantana camara persistence in south indian tropical dry forests. manipal university, india: ph.d. thesis. ticktin, t., 2004. the ecological implications of harvesting non-timber forest products. j appl ecol. 41:11– 21. ticktin, t., ganesan, r., paramesha, m., setty, s., 2012. disentangling the effects of multiple anthropogenic drivers on the decline of two tropical dry forest trees. j. appl. ecol. pmid: 23539634 ticktin, t., shackleton, c., 2011. harvesting non-timber forest products sustainably: opportunities and challenges. in: shackleton, s., shackleton, c., shanley, p. (eds) non-timber forest products in the global context. tropical forestry, vol 7. springer, berlin, heidelberg. https://doi.org/10.1007/978-3642-17983-9_7 varghese, a., ticktin, t., mandle, l. and nath., s., 2015. assessing the effects of multiple stressors on the recruitment of fruit harvested trees in a tropical dry forest, western ghats india, plos one 10(3): e0119634. doi:10.1371/journal.pone.0119634. wright, s.j., muller-landau, h.c., condit, r., hubbell, s.p., 2003. gap-dependent recruitment realized vital rates and size distributions of tropical trees. ecology. 84: 3174–3185. https://doi.org/10.1007/978-3-642-17983-9_7 https://doi.org/10.1007/978-3-642-17983-9_7