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African Journal of Environmental Economics and Management ISSN 2375-0707 Vol. 7 (3), pp. 001-005, March, 
2019. Available online at www.internationalscholarsjournals.org © International Scholars Journals 

 

Author(s) retain the copyright of this article. 
 
 

 

Full Length Research Paper 

 

Ecological study on Uyun Layla in Saudi Arabia 

 
Wafaa Mohammed Al-Ghanem 

 
Department of Botany, Faculty of Science, Princess Nora University,Al-Riyadh- Saudi Arabia. E-mail: 

taia_taxonomy@hotmail.com 
 

Accepted 11 November, 2018 
 
Soil characters and vegetation types have been investigated in the desiccated Uyun Layla lakes from October, 2007 
till May, 2010, except during the summer months. The vegetation in and between the 23 dolines was very poor. 
Twenty xerophytic species were recorded mainly Zygophyllum coccineum, Zygophyllum simplex, Salsola spp., 
Traganum nudatum, Haloxylon salicornicum, Zilla spinosa, Rhanterium epapposum and Gymnocarpos decandrum. 
The importance value (I.V.) of all the species has been calculated and their taxonomic position has been described. 
The soil was sandy, yellowish white and very poor in minerals. In spite of that, the total soluble salts, calcium and 
copper contents were considerably high. The results have been discussed and interpreted according to the 
environmental changes occured in this area. 

 

Key words: Al-Aflag, Uyun Layla, soil characters, vegetation. 

 
INTRODUCTION 

 
Wetlands in Saudi Arabia have been subjected to high 
pressure from both human activities and global warming. 
The report of the IUCN (1984) indicated the destruction of 
the wetlands and change in the habitats in Saudi Arabia. 
Mackey (2007, cited in Taylor and Figiis) predicts an 
interaction between climate change and other drivers of 
biodiversity that will increase extinction risk from what 
occurred in periods of rapid climate change in the past. 
Sambas and Symens (1993) pointed to the great loss of 
the wetlands in the Gulf area. Frazier and Stevenson 
(1999) described the Middle East area as being largely 
semi-arid to arid and they pointed to the lack of 
information in these areas. This is the state of Saudi 
Arabia, but there are some coastal or lowland areas 
receiving great amount of rainfall leaving ponds or 
sometimes lakes behind. Uyun Laila was an example of 
these lakes which originated from severe rainfalls during 
the winter season. These lakes, located 10 km south 
Layla town in Al-Riyadh Province, are a series of small to 
medium sized limestone karst lakes, which were unique 
in the Arabian Peninsula (Newton, 1995). The lakes were 
popular recreational area in the past, given its proximity 
to Riyadh and al Kharj. These lakes have been subjected 
to direct human pumping for cultivation, resulting in the 
current dryness situation. Due to the change in water 
availability, the vegetation and the soil characters have 
been altered. Al-Ghanem (2011) described the vegetation 
in these lakes by being scarce, restricted to few 

 
 
halophytic species. Accordingly, more works are needed 
to investigate the ecological change in this area. For this 
reason, the present study is one of the projects used to 
evaluate the amount of salts and minerals in the soils of 
the dry dolines and the effect it has on the vegetation. 

 
Study area 

 
The site area is about 3,000 ha. it is with an altitude of 
540 m and 330 km. It is located south of Al-Riyadh city, 
the capital of Saudi Arabia. It comprises a total of 23 
doline and sinkhole subsidence craters, of which five are 
shaped irregularly, the largest at about 1,500 by 500 m, 
and the other four ranging in size down to 250 by 75 m. 
The remainders are circular in shape, of which four 
measure between 100 and 175 m in diameter, and four 
are less than 100 m in diameter. Nearly all the craters are 
completely dry. Over-abstraction has caused extreme 
desiccation of the shallower dolines and sediments 
forming the crater walls and surrounding terrain. 
 

 
MATERIALS AND METHODS 

 
Monthly visits were done to the studied area from October, 2007 to 
May, 2010, excluded the summer times, to record the different plant 
species grown in this area. No quadrates have been done, but the 



  
 
 
 
 
 
 
 
 
 
 
 
 

 

1 2 3  
 
 
 
 
 
 
 
 
 

 

4 5 6 
 

Photographs 1 to 6. The different dry dolines. 
 
 

 
plant species grown in each doline have been recorded throughout 
the time of study. The importance value (I.V.) for each species was 
calculated as follows: 

 
I.V.= Relative Frequency+ Relative density+ Relative cover. 

 
Soil samples from the 10 selected dolines have been taken from 25 
cm depth of the dolines for chemical analyses. Soil chemical 
analyses were done using X-ray method. Photographs of selected 
doline have been taken. The different species have been identified 
and put in its systematic position in the faculty herbarium for further 
investigation. 
 

 

RESULTS AND DISCUSSION 

 

Succulent perennial species mainly xerophytes are 
dominating in and around the desiccated lakes. Twenty 
perennial species were recorded during the studied 
period. These species are Zygophyllum coccineum, 
Zygophyllum simplex, Aeluropus lagopoides, Cressa 
cretica, Limonium axillare, Pennisetum divisum, Lasiurus 
scindicus, Ochradenus baccatus and Fagonia bruguieri 
scattered in these dolines. While salsola spp., Traganum  
nudatum, Haloxylon salicornicum and Haloxylon 
persicum are widely distributed at the flat bottom of the 
lakes. Meanwhile Artemisia spp., Zilla spinosa,  
Rhanterium epapposum, Astragalus spinosus,  
Gymnocarpos decandrum, Achillea fragrantissima, 
Halothamnus bottae, Tephrosia apollinea are found as 
scattered individuals at the sloping edges of the 
desiccated lakes (Photographs 1 to 15). Not all of these 
species were found during all the studied period, but they 
were recorded during the whole period. The abundant 

 
 
 
 
 

 

species were Z. coccineum, Z. simplex, salsola spp., T. 
nudatum, H. salicornicum, Z. spinosa, R. epapposum and 
G. decandrum. The taxonomic position according to 
Cronquist (1981) and the importance values (I.V.) of 
these species are listed in Table 1. Generally speaking 
the vegetation was poor during all the studied period, it 
was scarce and restricted to few xerophytic species. The 
soil at the bottom of the dolines was loose, sandy and 
yellowish white, while the wall was calcareous and 
grayish white (Photographs 1 to 15). Analysis of the 
chemical contents of the soil listed in Table 2 and 
illustrated in Figures 1 - 4 shows that the soil is alkaline 
with high amount of total salt and calcium ions (Figures 1 
and 2). The amount of the investigated cations and 
anions is very low in all the analyzed dolines (Figure 2 
and 3). The soil was poor in phosphorous as its maximum 
amount was 2.9. Meanwhile the copper content was 
considerably high reaching up to 15.4 (Table 2 and 
Figures 1 and 3).  

This data coincide with that obtained by Jackson 
(1958), Daubenmire (1959), Al-Sheikh and Yousef (1981) 
and Al-Ghanem (2002). They found that the soil in the 
deserts is poor, alkaline with high soluble salt contents 

due to the rarity in rainfall. While the amount of Cl
-
 and S

-

is in reverse proportion where the increase in Cl
-
 and 

decrease in S
-
 is expected in the deserts as found by Al-

Moneyeri et al. (1986). The phosphorous content was 
very low due to the poor vegetation in this area as shown 
by Al-Homaid et al. (1990 b). The high contents of copper 
have its poisonous effect on plant growth (Al-Haish, 
1985). This increase in copper contents may be due to 
the pollution from urbanization and human activities in the 
area. 



  
 
 
 
 
 
 
 
 
 
 

 
7 8 9  

 
 
 
 
 
 
 
 

 
10 11 12  

 
 
 
 
 
 
 
 

 
13 14 15 

 
Photographs 7 to 15. The poor vegetation and the sandy calcareous soil. 

 

 
Table 1. Species recorded and their taxonomic position and I.V.  

 
Species I.V. Order Family Phylla 

 

Zilla spinosa 38.9 
Capparales 

Brassicaseae  
 

Ochradenus baccatus 11.7 Resedaceae 
 

 

  
 

Zygophyllum coccineum 107.3    
 

Zygophyllum simplex 112.5 Geraniales Zygophyllaceae  
 

Fagonia bruguieri 6.89    
 

Halothamnus bottae 7.4    
 

Haloxylon salicornicum 89.5    
 

Haloxylon persicum 11.7 
Caryophyllales 

Amaranthaceae s.l.  
 

salsola spp. 109.4 
  

 

  
Magnolophyta  

Traganum nudatum 84.2 
  

 

   
 

Gymnocarpos decandrum 20.4  Caryophyllaceae  
 

Astragalus spinosus 5.8 
Fabales Fabaceae s.l. 

 
 

Tephrosia apollinea 3.8 
 

 

   
 

Limonium axillare 5.7 Plumbaginales Plumbaginaceae  
 

Cressa cretica 1.8 Solanales Convolvulaceae  
 

Rhanterium epapposum 22.6 
Campanulales Asteraceae 

 
 

Achillea fragrantissima 8.2 
 

 

   
 

Aeluropus lagopoides 5.8    
 

Lasiurus scindicus 7.2 Poales Poaceae Liliophyta 
 

Pennisetum divisum 10.4    
 



 
 
 

 
Table 2. Mineral contents of the soil from 25 cm depth of 10 dolines.  

 
 Dolines 

1 
 

2 3 4 5 
 

6 7 8 
 

9 
  

10 Used materials  

 
Min. 

     
 

                            
 

 Mg 4.9  7.0 8.8 7.8 4.4  3.3 8.5 5.9  3.4  5.2 MgO 
 

 Si 6.2  6.9 8.4 8.9 6.2  6.1 8.4 6.4  5.8  6.2 Quartz 
 

 P 2. 8  2.1 1.7 2.1 2.2  1.9 2.9 2.0  2.1  2.2 GaP 
 

 S 4.0  2.6 3.2 2.9 2.4  2.6 3.8 3.8  4.1  2.8 FeS2 
 

 Cl
-
 9.4  10.4 9.5 9.2 8.1  7.5 10.2 9.2  10.4 10.1 KCl 

 

 K+ 10.4  9.2 10.1 9.8 8.6  8.2 10.3 6.7  10.2 8.8 MAD 
 

 Ca
++

 35.6  36.6 41,6 44.2 52.0  60.2 54.3 52.1  41.6 39.2 Wollas 
 

 Cu 15.4  13.4 6.4 7.9 7.2  6.1 5.2 7.1  10.8 15.3 Cu 
 

 Zn 11.3  11.8 10.3 7.2 8.9  4.1 7.3 6.8  11.6 10.2 Zn 
 

 Sum 100  100 100 100 100  100 100 100  100  100  
 

                             
 

                             
 

                             
 

                             
 

                             
 

                             
 

                             
 

                             
 

                             
 

                             
 

                             
 

                             
 

                             
 

                             
 

                             
 

                             
  

 
Figure 1. Show the element contents Mg, Si and P in 10 dolines.  

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 

Figure 2. Show the element contents S, Cl
-
 and K

+
 in 10 dolines. 



  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 

Figure 3. Show the element contents of Ca
++

, Cu and Zn 
+
  in 10 

dolines.     
 

800     
 

600    ESC(mlmos/ 
 

    
 

    cm) 
 

400     
 

200     
 

0     
 

1 3 5 7 9 
 

Figure 4. The total soluble contents. 
  

 
 

 

The vegetation in and between these desiccated 
dolines is greatly affected by the soil characters and 
environmental changes that were happening in this area. 
According to Kent and Coker (1992) the main purpose of 
studying the vegetation is to know the dynamic and to 
develop strategies to protect the threaten species. In the 
studied area, we recorded twenty perennial xerophytic 
species only, with low I.V. This can be due to soil 
characters, dryness and climatic stress as found by 
Shaltout et al. (1997). Meanwhile the absence of annual 
species can be due to the sandy soil which cannot hold 
sufficient rain water in the surface area, in spite of the 
elevation of the sea level in Najd plateau, where Uyun 
Layla located.  

From this study we can conclude that, pumping of 
water from Uyun Layla has led to a severe damage to the 
ecological conditions in this area. This change caused 
desertification, and alteration in soil characters and 
vegetation type. It is therefore an urgent task to develop 
plans to sustain the wild life in this area and improve the 
habitats in this area. 

 
 
 
 

 
REFERENCES 
 
Al-Ayesh FM (1985). The effect of copper and cadmium pollution on the 

growth and productivity of Zea mays. M.Sc. thesis, King Abdul Aziz 
Univ. Fac. Sci. Biol. Dept., Jeddah, K.S.A.  

Al-Ghanem WM (2002). Comparative ecological studies on the natural 
vegetation of three different transects within Al-Riyadh region. Ph.D. 
thesis, Girls College of Education, Al-Riyadh, K.S.A.  

Al-Ghanem WM (2011). Ecological report on the vegetation of Uyun 
Layla in Saudi Arabia. Alex. Sci. Exchang. J., 32(2): Under 
publication.  

Al-Homaid N, Khan MH, Sadik M (1990). Ecology and some desert 
plant communities of the eastern province in Saudi Arabia. Arid Soil 
Res. Rehab., 4(4): 253-260.  

Al-Monayeri MO, Khafagi OA, Ahmed AM, Al-Tantawy HE (1986). 
Contribution to the chemical composition of plants belonging to 
various ecological groups in the Red Sea area. Bull. Desert Inst., 36: 
405-430. 

 
Al-Sheikh AM, Yousef M (1981). Halophytic and xerophytic vegetation 

near Al Kharj springs. J. Coll. Sci. Univ. Al-Riyadh, 12(1): 5-21.  
Cronquist A (1981). An integrated system of classification of flowering 

plants. Columbia University Press, New York, New York, USA.  
Daubenmire RF (1959). Plants and Environment. A text book of plant 

autecology. John Willey and Sons Inc.  
Frazier S, Stevenson NJ (1999). Review of wetland inventory 

information in the Middle East. In Global Review of Wetland 
Resources and Priorities for Wetland Inventory, eds Finlayson CM, 
Spiers AG, Supervising Scientist Report, Canberra, Australia.  

IUCN/MEPA (1984). Report on the distribution of habitats and species 
in the Saudi Arabian Red Sea: Part 1. Saudi Arabia Marine 
Conservation Programme, Report No. 4. IUCN, Gland, Switzerland, 
and Meteorology and Environmental Protection Administration, 
Jeddah, Kingdom of Saudi Arabia. Cited in World Mangrove Atlas, 
eds Spalding M, Blasco F, Field CC 1997, International Society for 
Mangrove Ecosystems, Okinawa, Japan.  

Jackson  ML  (1958).  Soil  Chemical  Analysis.  Constable  and  Co.  Ltd.  
London.  

Kent M, Coker P (1992). Vegetation description and analysis. A 
practical approach. CRC Press, Boca Raton, Ann Arbor, Belhaven 
Press, London, 363 p.  

Mackey B (2007). Protected Areas: buffering nature against climate 
change. In Taylor, M., Figgis, P. eds. Proceedings of a WWF and 
IUCN World Commission on protected Areas symposium, Canberra, 
18-19 June. Sydney: WWF-Australia, pp. 90-96.  

Newton SF (1995). Kingdom of Saudi Arabia. In A Directory of 
Wetlands in the Middle East, ed DA Scott, IUCN, Gland, Switzerland 
and IWRB, Slimbridge, United Kingdom.  

Sambas A, Symens P (1993). Developing a conservation plan for 
wetlands in Saudi Arabia: The NCWCD system plan for protected 
areas. In Wetland and Waterfowl Conservation in South and West 
Asia, Proceedings of an International Symposium, Karachi, Pakistan 
14–20 December 1991, eds Moser M, Van Vessem J, IWRB Special 
Publication No. 25, AWB Publication No. 85, IWRB, Slimbridge, 
United Kingdom, and AWB, Kuala Lumpur, Malaysia, pp. 109–112.  

Shaltout KH, Al-Halawany EF, Al-Garawany MM (1997). Coastal 
lowland vegetation of Eastern Saudi Arabia. Biodiv. Conserv., 6: 
1027-1040. 


