7 Annales Universitatis Paedagogicae Cracoviensis Studia Naturae, 5: 7–24, 2020, ISSN 2543-8832 DOI: 10.24917/25438832.5.1 Yura Drach*, Zvenysvala Mamchur Ivan Franko National University of Lviv, 4, Hrushevskyi St, Lviv 79005, Ukraine; *yuriy.drach@lnu.edu.ua Bryophytes of the upper reaches of the Western Bug River (Lviv Region, Ukraine) Introduction �e upper reaches of the Western Bug River (Lviv Region) are physically and geo- graphically located within the boundaries of Male Polissya, partly Roztochia, and to a minor extent in the Gologoro-Voronyatsky denudo-structural hills. On the territory of Lviv Region, the natural area of Male Polissya lies within the central part of the Western Bug; its geological composition is dominated by marls covered with alluvial sand deposits. Only on the territory of the Batyatytsia remains, Neogene sandstones have been preserved, indicating the presence of a tertiary stratum in this area in the past (Tsys, 1962). Geographers distinguish �ve main geomorphological regions within Male Polis- sya in Lviv Region: the Ratyn gently undulating aquaglacial alluvial denudation plain, the Bug-Styr gently undulating aquaglacial denudation alluvial plain, the Radekhiv undulating denudation plain, the Pidpodilska undulating-residual denudation plain, and the Upper Pobuzhia with aeolian loess ridges and wide valleys between the ridges (Nazaruk et al., 2018). �e area is represented by pine, oak and pine, and occasionally hornbeam and oak forests, as well as �oodplain meadows and swamps (eutrophic and less frequently meso- and oligotrophic). �e latter are represented by a wide range of aquatic vegetation (Didukh, 2003). �e bryophytes of the above-mentioned area have not been studied well. �e �rst scienti�c records of the bryophytes in Lviv Region can be found in the works of J.H. Lobarzewski, a botanist and a professor of the Lviv University who was the �rst to publish data on mosses of Galicia based on his own collection (Lobarzewski, 1847, 1849). Most data on bryophytes were published by J. Krupa: 71 species of liverworts and 225 species of mosses, some of which were collected outside the city of Lviv (Krupa, 1885). We can �nd some data in the work of bryologists such as A. Geheeb Y ur a D ra ch , Z ve ny sv al a M am ch ur 8 (1899), F. Lilienfeldówna (1910, 1911, 1914), A.J. Żmuda (1911), T. Wilczyński in 1912 (Tasenkevich et al., 2013), who completed “Zielnik Wilczyńskiego” – a  collection of bryophytes including those from the outskirts of Lviv and Roztochia, A.T. Wisniewski (1923) and others. However, this information concerns only individual collections from the outskirts of Lviv. In the second half of the twentieth century, Zerov (1964), Slobodyan (1967), Ul- ychna (1978, 1979), Bradis (1969), and bryologists of the Institute of Ecology of the Carpathians (Danylkiv et al., 2002) studied bryophytes of this area. Among modern researchers, the most valuable contributions were made by a  Lviv botanist A. Kuz- yarin, who studied the �oodplain vegetation of the upper reaches of the Western Bug basin and, in addition to vascular plants, collected mosses (Kuzyarin, 2010, 2012, 2013), and M. Ragulina, who studied bryophytes of quarry outcrops of Lviv Region (Ragulina et al., 2012; Ragulina, Kuzyarin, 2014). �e bryo�ora of the Chervonohrad coal basin was studied by Kuzyarin (2013) and Karpinets et al. (2017). I. Danylkiv compiled the �rst annotated list of bryophytes for the Chronicle of nature of the na- tional park “Northern Podillya”. However, this information was not published. Some data on mosses from the upper reaches of the Western Bug River are presented in the collections of �e Moss Flora of the Ukrainian SSR and �e Moss Flora of Ukraine (Bachuryna, Melnychuk, 1987, 1988, 1989, 2003). �is article reports new �ndings on the species composition and distribution of bryophytes, as well as analyses of substrate preferences, ecological groups and life forms of bryophyte species from the upper reaches of the Western Bug River. Materials and methods �e �eld survey was carried out by the route method (Lazarenko, 1955; Ignatov, Igna- tova, 2003) in the period from 2017 to 2019 in the upper reaches of the Western Bug River within Male Polissya and partly on the territory of the Gologoro-Voronyatsky denudo-structural hills (Fig. 1). In the course of the study, 14 sites were surveyed: the Volytsky Botanical Reserve of national importance, the Romaniv Landscape Reserve of local importance, the Storonybaby Nature Reserve of local importance, the Pid- lyska Hill (Shashkevych Hill) complex natural monument of local importance, the Zhovkivska botanical natural monument of local importance, the Ivan Franko Park in Busk, a railway track outside the village of Zakomarya, a �oodplain of the Solotvyna River, the outskirts of the villages of Kulychkiv, Zarvanytsia, Poltva, Zavady, Pidlyssia, Romaniv and Shopky. Various types of ecotopes were examined: swamps, swampy forests, �oodplains of rivers, oak, pine, beech and mixed forests, urban ecosystems, railway tracks, etc. B ryophytes of the upper reaches of the W estern B ug R iver (Lviv R egion, U kraine) 9 Tab. 1. Information on localities of the study area within the upper reaches of the Western Bug River No. Place Coordinates Date 1. the Volytsky Botanical Reserve 50°17ʹ25.2ʺN, 23°57ʹ57.6ʺE 16.05.2018 29.04.2018 2. swampy mixed forests near the village of Kulychkiv 50°16ʹ50.3ʺN, 24°06ʹ33.3ʺE 22.07.2018 3. Ivan Franko Park in Busk 49°57ʹ59.9ʺN, 24°36ʹ30.3ʺE 28.03.2018 4. �oodplain of the Solotvyna River 49°56ʹ55.0ʺN, 24°47U48.2ʺE 25.03.2017 5. railway track near the village of Zakomarya 49°57ʹ00.0ʺN, 24°45ʹ30.2ʺE 28.03.2018 6. the Storonybaby Nature Reserve 49°56ʹ37.6ʺN, 24°39ʹ44.9ʺE 03.09.2017 7. swampy meadow near the village of Zarvanytsia 49°46ʹ16.9ʺN, 24°59ʹ36.0ʺE 17.07.2018 8. mixed forest near the village of Zarvanytsia 49°45ʹ21.8ʺN, 24°58ʹ26.8ʺE 19.07.2018 9. the outskirts of the village of Poltva 49°52ʹ34.0ʺN, 24°30ʹ47.4ʺE 24.09.2019 10. the outskirts of the village of Romaniv and the Romaniv Landscape Reserve 49°41ʹ57.4ʺN, 24°21ʹ26.6ʺE 23.03.2018 11. the outskirts of the village of Zavady and the Zhovkivska botanical natural monu- ment of local importance 50°03ʹ00.5ʺN, 23°54ʹ25.2ʺE 28.08.2017 12. the outskirts of the village of Pidlyssia and the Pidlyska Hill (Shashkevych Hill) com- plex natural monument of local importance 49°55ʹ58.4ʺN, 24°51ʹ06.0ʺE 16.04.2018 13. the outskirts of the village of Shopky 49°44ʹ51.7ʺN, 24°31ʹ41.7ʺE 09.06.2018 14. the outskirts of the village of Novyi Yarychiv 49°52ʹ43.9ʺN 24°17ʹ44.8ʺE 29.09.2019 Fig. 1. Map of the study area within the upper reaches of the Western Bug River (Numbers of research areas correspond to those in table 1 and table 2 – Appendix 1) Y ur a D ra ch , Z ve ny sv al a M am ch ur 10 Sample collection and identi�cation was conducted by methods of bright-�eld mi- croscopy. Latin names of taxa are given according to the checklists by Boіko (2014) and Mosyakin, Fedoronchuk (1999). Sozological assessment is given according to Boiko (2010) and Hodgetts et al. (2019). �e following substrate types on which the species grew were noted: RO – rocks; StA – arti�cial stone; SG – soil with gravel or sand; SO – soil; SV – soil among grass or leaf litter; WR – rotten wood; WL – living wood; AM – aqueous medium. Ecological groups and life forms of are given according to Hill et al. (2007) and Ellenberg, Leuschner (2010). Results Based on our survey, 165 species belonging to 92 genera, 41 families, and 18 orders were identi�ed (Tab. 2 – Appendix 1). Out of the recorded taxa, 151 species were moss- es (Bryophyta), 13 species were liverworts (Marchantiophyta) and one was a hornwort (Anthocerotophyta). Families with the highest numbers of recorded species, which comprise 66.7% of all identi�ed species, are: Brachytheciaceae (12.1%), Pottiaceae (11.5%), Amblystegiaceae (8.5%), Mniaceae (7.3%), Orthotrichaceae (6.1%), Hypn- aceae (4.8%), Bryaceae (4.8%), Sphagnaceae (4.2%), Polytrichaceae (3.6%), Dicran- aceae (3.6%). Among the found species, three are on the list of species o�cially recognised as rare – Alleniella besseri, Campyliadelphus elodes, Tomenthypnum nitens and 16 are recognised as regionally rare – Aloina rigida, Aulacomnium androgynum, Calliergon giganteum, Dicranum �agellare, Didymodon tophaceus, Encalypta streptocarpa, Porella platyphylla, Rhodobryum ontariense, Sciurohypnum plumosum, S. re�exum, Sphagnum cuspidatum, S. fallax, S. �mbriatum, Straminergon stramineum, Syntrichia papillosa, Taxiphyllum wissgrillii. Substrate preferences By substrate preference, most of the identi�ed species were epigean (116 species, 70.3%). �ey are dominated by bryophytes that grow on bare soil or with minor in- clusion of grasses (SO – 98 species, 59.4%). Species that grow on soil among grass (SV – 33 species, 20%) and on sandy or gravelly soil (SG – 31 species, 18.8%) also constitute a  signi�cant share. �e most frequent are typical forest species: Atrichum undulatum, Dicranella heteromalla, Fissidens taxifolius, Polytrichum commune, Pseu- doscleropodium purum, Rhytidiadelphus squarrosus, Eurhynchium angustirete. Species Cratoneuron �licinum, Drepanocladus aduncus, Kindbergia praelonga, Leptodictyum riparium, Oxyrrhynchium speciosum and Sciurohypnum plumosum grow along the banks of rivers. B ryophytes of the upper reaches of the W estern B ug R iver (Lviv R egion, U kraine) 11 A group of epiphytes (46 species, 27.9%) is signi�cantly represented by forest species: Anomodon attenuatus, Homalia trichomanoides, Leucodon sciuroides, Metzgeria furca- ta, Porella platyphylla, Radula complanate. �ese species are most commonly found in mixed forests on the bark of trees such as Acer platanoides, A. pseudoplatanus, Alnus glutinosa, Fraxinus excelsior, Quercus robur, occasionally Fagus sylvatica and others. Due to the signi�cant presence of wood at di�erent stages of decomposition in moist fairly intact mixed forests, epixile species are quite common in the study area (WR – 56 species, 33.9%). Among the obligate epixiles, relatively rare species were found: Dicranum �agellare, Lepidozia reptans, Nowellia curvifolia, Ptilidium pulcher- rimum, Riccardia latifrons and Tetraphis pellucida. Polysubstrate species also inhabit decaying wood; they include: Brachythecium salebrosum, Callicladium haldanianum, Dicranum montanum, D. polysetum, Herzogiella seligeri, Hypnum cupressiforme, Platy- gyrium repens, Sciurohypnum populeum and others. �e fourth most numerous bryophyte group is composed of epilithic species – 43 species (29.6%). Among them, 28 species (17.0%) grow on arti�cial rocky substrate (StA) and 23 species (13.9%) on natural stone or rock outcrops (RO). Seven species (4.2%) were found on both types of rocky substrates. �e group is represented by both typical obligate epiliths (Alleniella besseri, Didymodon rigidulus, Homalothecium lutescens, Orthotrichum anomalum, Rhynchostegium murale, Tortula muralis) and fac- ultative ones (Amblystegium serpens, Ceratodon purpureus, Brachythecium rutabulum, Leskea polycarpa, Plagiomnium cuspidatum). �e lowest number of identi�ed species belong to a group of bryophytes that are completely or partially submerged in water (22 species, 13.3%). �ese are species that grow in swamps, ditches and other wetland areas – Brachythecium mildeanum, Cal- liergon cordifolium, C. giganteum, Calliergonella cuspidata, Campyliadelphus elodes, Campylium stellatum, Cratoneuron �licinum, Leptodictyum riparium, Drepanocladus aduncus, Hygroamblystegium tenax, Fissidens adianthoides, Ptychostomum pseudotri- quetrum, Scorpidium cossonii and Warnstor�a �uitans. Ecological groups Although the substrate plays an important role in the life of the bryophytes, envi- ronmental conditions are no less important, since factors such as humidity, light and temperature play a decisive role for them. �us, within the spectrum of heliomorphs, dominate the species that inhabit both moderately shaded and illuminated places – subheliophytes (51 species, 30.9%) and hemisciophytes (51 species, 30.9%). Slightly fewer of the identi�ed species belong to the group of bryophytes adapted to a habitat with a very intensive insolation – heliophytes (24 species, 14.5%) and ultraheliophytes (14 species, 8.5%). A small number (19 species, 11.5%) of the identi�ed bryophytes – Y ur a D ra ch , Z ve ny sv al a M am ch ur 12 sciophytes, prefer well-shaded ecotypes. Six species (3.6%) are indi�erent to light or the indicator has not been established. �e distribution of hydromorphs indicates the predominance of species with inter- mediate characteristics in relation to moisture among the studied bryophytes – meso- phytes (49 species, 29.7%), hygromesophytes (35 species, 21.2%) and xeromesophytes (32 species, 19.4%). Signi�cantly fewer species represent the groups of drought-toler- ant species (xerophytes – 20 species, 12.1% and ultraxerophytes – 4 species, 2.4%) and species that inhabit wet and humid places (hygrophytes – 25 species, 15.2%). In terms of temperature regime, more than half of the bryophytes are cold-tolerant (98 species, 59.4%). Signi�cantly fewer moderately heat-tolerant (29 species, 17.6%) and heat-tolerant (6 species, 3.6%) species were found. Almost one-��h of the species are indi�erent or demonstrate no speci�c characteristics in relation to temperature. By pH preference dominate neutrophils (83 species, 50.3 %) followed by acido- philes – species growing on acidic substrates (34 species, 20.6 %) and extreme aci- dophiles (2 species, 1.2 %). �e smallest number of the detected species (19 species, 11.5 %) belong to sub-basophils and basophils (3 species, 1.8 %) that grow on sub- strates with free calcium carbonate, mainly chalk and limestone. Life forms In terms of the structure of life forms of the bryophytes distinguishes two groups of bryophytes: shoots that are not part of an organised colony and shoots that form a part Fig. 2. �e range of life forms of bryophytes in the upper reaches of the Western Bug River: Fa – fan, We – we�, Mt – thalloid mat, Ms – smooth mat, Mr – rough mat, De – dendroid, Cu – cushion, Tu� – loose cushion, Tf – turf, Ts – scattered turf, St – solitary thalloid, Sc – solitary creeping shoots B ryophytes of the upper reaches of the W estern B ug R iver (Lviv R egion, U kraine) 13 of an organised colony. In terms of the structure of life forms of the bryophytes (Fig. 2), in the study area, the �rst group was represented by only 5 species (2.9%): Stramin- ergon stramineum – solitary creeping shoots (Sc), Riccia glauca and Anthoceros agrestis – solitary thalloid (St), Aloina rigida and Phascum piliferum – scattered turf (Ts). �e second group is dominated by species forming turfs (Tf ) – 50 species (30.3%), loose cushions (Tu�) – 17 species (10.3%). Next come species with a mat life form: rough mat (Mr – 30 species, 18.2%), smooth mat (Ms – 16 species, 9.7%), thalloid mat (Mt – 4 species, 2.4%). �e third place is occupied by species that form tightly intertwined turf – we� (We) – 25 species (15.2%). �e cushion life form (Cu) is characteristic of 13 species (7.9%) – these are mainly epiliths and epiphytes (Orthotrichum spp., Dicranum montanum, Grimmia pulvinata and others). �e least numerous is dendroid (De) – 2 species (1.2%) and fans (Fa) – 3 species (1.8%). Discussion �e upper reaches of the Western Bug River (Lviv Region) are distinguished by rich species diversity, a wide range of ecomorphs and substrate groups of the bryophytes due to heterogeneity of the relief, a  considerable diversity of ecotopes (pine, oak and mixed forests, open and forest bogs, river �oodplains, areas a�ected by anthro- pogenic transformations, etc.), as well as a  signi�cant number of protected areas (the Roztochia nature reserve, the Yavorivsky National Park, the Northern Podil- lya National Park, the Volytsky botanical reserve of national importance, the Ro- maniv landscape reserve of local importance, the Storonybaby nature reserve, the Pidlyska Hill (Shashkevych Hill) complex natural monument of local importance, the Zhovkivska botanical natural monument of local importance, the Hryada forest reserve and others). �e following nine species are reported for the �rst time for Lviv Region: Orth- otrichum patens, Palustriella falcata, Pedinophyllum interruptum, Ptychostomum tor- quescens, Rhodobryum ontariense, Sphagnum angustifolium, S. inundatum, Taxiphyl- lum wissgrillii, Tortella humilis (Zerov, 1964; Bachuryna, Melnychuk, 1987, 1988, 1989, 2003; Boiko, 2014). We have also con�rmed the presence of Campyliadelphus elodes on the outskirts of the village of Zarvanytsia (Kuzarin, 2012), which was found in a swampy reclamation canal. �is is the third locality of the distribution of this species in Ukraine (Bachuryna, Melnychuk, 2003). Pedinophyllum interruptum, which was found on soil in the wood on the outskirts of the village of Zarvanytsia, is reported for the �rst time not only for Lviv Region but also for the whole plain territory of Ukraine. Previous �ndings of this species were reported from the territory of the Ukrainian Carpathians (Zerov, 1964; Boiko, 2014). �e families Brachytheciaceae and Pottiaceae typically dominate on most of the plains Y ur a D ra ch , Z ve ny sv al a M am ch ur 14 of Lviv Region as well as the upper reaches of the Western Bug River (Kuzyarin, 2010, 2013; Mamchur et al., 2017a, b, 2018; Rahulina, Kuzyarin, 2014). �e bryo�ora of this territory is represented by a  large number of boreal and nemoral species as well as typical arid species characterised by a  signi�cant level of synanthropisation (Lazarenko, 1956; Boiko, 1999). Relative to light tolerance, the spectrum of ecomorphs is dominated by hemiscio- phytes and subheliophytes, in relation to humidity – by mesophytes, and in terms of temperature regime – by cold-tolerant species, by substrate preference – by neutro- phils. A wide diversity in the life forms of bryophytes in the study area is also due to the variety of growth conditions. However, turf, rough mat, we�, tu� and smooth mat forms prevail. Apparently, the dominance of turfs is due the signi�cant environmen- tal tolerance of this life form, in particular, the species that represent it are capable of withstanding high levels of solar radiation. Such life forms as mat and we� are characteristic of the species with perennial life strategies and consequently are more widely distributed (During, 1979, 1992; Batista et. al., 2018). �e bryophytes grow on a variety of substrates of both natural and anthropogenic origin. Among the variety of substrates, the bryophytes most o�en give preference to bare soil, or soil with a slight inclusion of grasses. In terms of moisture conditions, epigean bryophytes usually oc- cur in turfs, mats or even we�s, which is characteristic of species of both natural and anthropogenically a�ected ecosystems (Mamchur et al., 2017b). �e epixile group is well represented due to the availability of wood at di�erent stages of decomposition in the natural ecosystems. �e most common life forms are rough mat, smooth mat, we�, tu� and turf. �e epilithic species grow on di�erent types of rocky substrates, of both natural and arti�cial origin. An increase in the number of anthropogenic rocky ecotopes con- tributes to an increase in the proportion of epilithic species (Mamchur et al., 2018). �e predominant life forms of epiliths are rough mats, turfs, tu�s and cushions. �e species that grow on natural rocks are dominated by rough mat, turf and we�, while those growing on arti�cial rock are mainly represented by rough mat, turf, tu� and cushion. Among the bryophytes that are partially or completely submerged in water, the most common life forms are turf, we� and rough mat. �e life form of rough mat is the most common in the group of polysubstrate species, as it is suitable for bryophytes with various substrate preferences. In general, the species composition of the bryophytes occurring in habitats under anthropogenic impact is relatively insigni�cant. It is mainly represented by synan- thropic species distinguished by a  considerable environmental plasticity: Amblyste- gium serpens, Brachytheciastrum velutinum, Brachythecium glareosum, B. rutabulum, Bryoerythrophyllum recurvirostrum, Bryum argenteum, B. caespiticium, Ceratodon B ryophytes of the upper reaches of the W estern B ug R iver (Lviv R egion, U kraine) 15 purpureus, Fissidens taxifolius, Funaria hygrometrica, Hypnum cupressiforme, Plagiom- nium cuspidatum, P. rostratum, Pohlia nutans, Syntrichia ruralis (Ochyra,1983; Wolski, Fudali, 2013; Maslovsky, 2012; Godovičová, 2019; Szűcs, 2020). Anthropotolerant epiphytes in the upper reaches of the Western Bug River are dominated by Leskea polycarpa, Platygyrium repens, Pseudoleskeella nervosa, Ptychos- tomum moravicum, Pylaisia polyantha, Syntrichia papillosa (Fudali, 2012; Marka, 2017; Mamchur et al., 2018; Szűcs, 2020). In terms of life forms, epiphytes are mainly represented by rough and smooth mats, much less frequently by cushions or turfs. On the contrary, a considerable diversity of species is typical of various types of ar- eas under protection. It was on those sites that the o�cially and regionally recognised rare species of the bryophytes were found. In particular, such species as Alleniella bes- seri, Aloina rigida, Encalypta streptocarpa, Porella platyphylla, Taxiphyllum wissgrillii were found on the territory of the Romaniv Landscape Reserve of local importance; Tomenthypnum nitens, Calliergon giganteum, Sphagnum cuspidatum, S. fallaх, S. �m- briatum, Straminergon stramineum, Syntrichia papillosa – in the Volytsky Botanical Reserve of national importance; Didymodon tophaceus, Rhodobryum ontariense – on the territory of the Pidlyska Hill (Shashkevych Hill) complex natural monument of local importance; Aulacomnium androgynum, Dicranum �agellare, Calliergon gigan- teum, Sphagnum cuspidatum, S. fallax and S. �mbriatum – in the mixed forest on the outskirts of the village of Kulychkiv. �is fact proves the signi�cant role of protected areas for the preservation of the biodiversity of species, particularly the bryophytes (Virchenko, Orlov, 2009; Virchenko, 2014; Barsukov, 2015). �e study area is also distinguished by a  signi�cant number of species growing in wetlands. Given the large areas of drained land in Lviv Region, rare species are of particular value. Swamps and water bodies are among the most endangered habi- tats of the bryophytes in Europe, primarily due to drainage of wetlands (Hodgetts et al., 2019). �erefore, the preservation of the o�cially and regionally recognised rare species of the bryophytes in the upper reaches of the Western Bug River (19 species altogether) is particularly important, especially wetland species such as Aulacomnium androgynum, Calliergon giganteum, Campyliadelphus elodes, Sphagnum cuspidatum, S. fallax, S. �mbriatum, Straminergon stramineum and Tomenthypnum nitens. In phytocenoses, the bryophytes are particularly sensitive components that re- spond to minor changes in the environmental conditions. In ecosystems, the bryo- phyte component plays a signi�cant role in the nitrogen, carbon, biomass, and water balance cycles (Turetsky, 2003). In accordance with the Development Strategy of Lviv Region by 2027, the preservation of biodiversity, the protection of valuable natural areas and expansion of nature reserves are top priority issues (Development strategy of Lviv Region, 2019). Given that, inventory and further study of the bryo�ora are highly important. Y ur a D ra ch , Z ve ny sv al a M am ch ur 16 Acknowledgements �e authors would like to thank the anonymous Reviewers for their valuable comments and suggestions to improve the quality of the paper. Con�ict of interest �e author declares no con�ict of interest related to this article. References Bachuryna, H.F., Melnychuk, V.M. (1987). Флора мохів Української РСР (Moss Flora of the Ukrainian SSR). Kyiv: Naukova Dumka. [In Ukrainian] Bachuryna, H.F., Melnychuk, V.M. (1988). Флора мохів Української РСР. Вип. 2. (Moss Flora of the Ukrainian SSR. Vol. 2.). Kyiv: Naukova Dumka. [In Ukrainian] Bachuryna, H.F., Melnychuk, V.M. (1989). Флора мохів Української РСР. Вип. 3. 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Porella platyphylla RO, WL 3, 10 11. Ptilidium pulcherrimum WR 2 12. Radula complanata WR, WL 3, 4, 6, 8, 14 13. Riccardia latifrons WR 2 14. Riccia glauca SO 14 Bryophyta 15. Abietinella abietina RO, SG, SO, SV 1, 2, 8, 9, 10, 11, 12 16. Alleniella besseri RO 10 17. Aloina rigida SG 10 18. Amblystegium serpens RO, StA, SG, SO, SV, WR, WL 1, 2, 3, 4, 5, 6, 8, 10, 11, 12, 14 19. Anomodon attenuatus SO, WR, WL 4, 8 20. Anomodon longifolius WR, WL 4, 8 21. Anomodon viticulosus RO 10 22. Atrichum undulatum SG, SO, WR 6, 10, 11 23. Aulacomnium androgynum SO 2 24. Aulacomnium palustre SO, SV, AM 1, 2 25. Barbula convoluta RO, SG 5, 12 26. Barbula unguiculata RO, StA, SG 2, 4, 8, 10, 11 27. Brachytheciastrum velutinum RO, SO, WR, WL 2, 6, 8, 10, 11, 12 28. Brachythecium albicans StA, SG 1, 5, 11 29. Brachythecium campestre SO, WR 1, 2, 6 30. Brachythecium glareosum RO, StA, SG, SO, SV, WR, WL 4, 5, 8, 9, 10, 11, 12 31. Brachythecium mildeanum AM 1 32. Brachythecium rutabulum StA, SG, SO, SV, WR, WL 1, 2, 3, 4, 5, 6, 8, 9, 11, 14 33. Brachythecium salebrosum RO, StA, SG, SO, WR, WL 3, 5, 6, 8, 10, 14 34. Bryoerythrophyllum recurvirostrum SO 2 35. Bryum argenteum StA, SG 1, 2, 3, 4, 8, 10, 11 B ryophytes of the upper reaches of the W estern B ug R iver (Lviv R egion, U kraine) 21 36. Bryum caespiticium RO, StA, SG 1, 5, 11, 12, 13, 14, 37. Bryum elegans SO 10 38. Callicladium haldanianum WR, WL 2, 6, 9 39. Calliergon cordifolium SG, SO, WR, AM 1, 2 40. Calliergon giganteum SV, AM 1, 2, 7 41. Calliergonella cuspidata SG, SO, SV, WR, AM 1, 2, 8, 9, 11 42. Campyliadelphus chrysophyllus RO, SO, SV 1, 10, 12, 13 43. Campyliadelphus elodes AM 7 44. Campylium sommerfeltii SG, SO 8 45. Campylium stellatum SO, SV, AM 1, 2, 7 46. Ceratodon purpureus StA, SG, SO, SV, WR, WL 1, 2, 3, 4, 5, 7, 9, 10, 11 47. Climacium dendroides SO, SV, AM 1, 10 48. Cratoneuron �licinum RO, AM 7, 12 49. Ctenidium molluscum RO, AM 7, 12 50. Dicranella heteromalla SO, SV 1, 6, 9, 11 51. Dicranella varia SO 4 52. Dicranum bonjeanii SO 1 53. Dicranum �agellare WR 2 54. Dicranum montanum SO, WR, WL 1, 2, 9, 10 55. Dicranum polysetum SO, WR 1, 9 56. Dicranum scoparium SO, WR 1, 2 57. Didymodon acutus SO 13 58. Didymodon fallax SO, WL 4, 10 59. Didymodon rigidulus StA, SG, SV 1, 2, 10 60. Didymodon tophaceus RO 12 61. Drepanocladus aduncus SV 1, 9 62. Drepanocladus polygamus SO, SV, WR 1 63. Encalypta streptocarpa SO, SV 7, 10, 13 64. Eurhynchium angustirete SO, WR, WL 2, 4, 6, 8, 65. Eurhynchium striatum SO, SV, WL 1, 6, 8 66. Fissidens adianthoides StA, SV, AM 1, 2, 7 67. Fissidens bryoides SO 6 68. Fissidens dubius SO 13 69. Fissidens taxifolius SO, AM 1, 3, 4, 6, 14 70. Funaria hygrometrica StA, SG 12, 13 71. Grimmia pulvinata SO 10 72. Herzogiella seligeri SO, WR 1, 9, 10 73. Homalia trichomanoides WR, WL 3, 4, 6, 8, 74. Homalothecium lutescens RO, SG 10 75. Hygroamblystegium tenax AM 7 76. Hygroamblystegium varium WL 6, 8 77. Hylocomium splendens SO 2 78. Hypnum cupressiforme SG, SO, SV, WR, WL 1, 2, 3, 4, 5, 6, 8, 9, 10, 12 79. Hypnum fertile WR 12 80. Hypnum pallescens WR, WL 1, 2, 11 Y ur a D ra ch , Z ve ny sv al a M am ch ur 22 81. Isothecium alopecuroides WL 8, 10 82. Kindbergia praelonga SO 4 83. Leptodictyum riparium StA, SG, SV, WR, AM 1, 3, 4, 11 84. Leskea polycarpa StA, SO, WR, WL 3, 4, 6, 8, 10 85. Leucobryum glaucum SO 2 86. Leucodon sciuroides WR, WL 12 87. Mnium marginatum SO 8 88. Mnium spinosum WL 4 89. Mnium stellare RO 10 90. Nyholmiella obtusifolia WR, WL 3, 6, 8 91. Orthotrichum a�ne WL 4, 8 92. Orthotrichum anomalum RO, StA, SG 2, 10, 12 93. Orthotrichum cupulatum WR 12 94. Orthotrichum diaphanum StA, WL 1, 3, 4 95. Orthotrichum pallens WL 4, 6, 8 96. Orthotrichum patens WL 8 97. Orthotrichum pumilum StA, WL 1, 14 98. Orthotrichum speciosum StA, WL 3, 4, 6, 8, 11, 14 99. Orthotrichum stramineum WR 4 100. Oxyrrhynchium hians SO, SV, WR, WL 3, 4, 6, 8, 101. Oxyrrhynchium speciosum SO, WR 4 102. Palustriella falcata AM 7 103. Phascum piliferum SO 4 104. Plagiomnium a�ne SO 1, 8 105. Plagiomnium cuspidatum RO, StA, SG, SO, SV, WR, WL 1, 2, 4, 5, 6, 8, 10, 14 106. Plagiomnium elatum SO, AM 1, 2, 8, 14 107. Plagiomnium ellipticum SO, SV 1, 2, 9 108. Plagiomnium rostratum RO, SG, SO, WR 4, 10, 11, 12 109. Plagiomnium undulatum SO, SV 4, 6, 8, 12 110. Plagiothecium cavifolium SO, WL 8 111. Plagiothecium denticulatum SO, WL 1, 8 112. Plagiothecium laetum SO, WR, WL 1, 8, 10 113. Plagiothecium nemorale SO, WR, WL 4, 6, 10 114. Platygyrium repens SV, WR, WL 1, 2, 3, 4, 6 115. Pleurozium schreberi SO, SV, WR 2, 8, 9 116. Pohlia nutans StA, SO, WR, WL 1, 2, 4, 8, 9 117. Pohlia wahlenbergii SO 10 118. Polytrichum commune SO, SV, AM 1, 2, 11 119. Polytrichum formosum SO 1, 10 120. Polytrichum juniperinum SG, SO 1, 2, 9 121. Polytrichum longisetum SO, WL 1 122. Polytrichum piliferum SG, SO 1, 11 123. Pseudoamblystegium subtile WR 8 124. Pseudoleskeella nervosa WR, WL 3, 4, 8, 10 125. Pseudoscleropodium purum SO 2, 9, 11 B ryophytes of the upper reaches of the W estern B ug R iver (Lviv R egion, U kraine) 23 126. Ptilium crista-castrensis WR 2 127. Ptychostomum moravicum StA, SG, WR, WL 1, 2, 3, 6, 8, 12 128. Ptychostomum pallens SO 4 129. Ptychostomum pseudotriquetrum SG, SV, WR, AM 1, 7, 11 130. Ptychostomum torquescens SO 4 131. Pylaisia polyantha WR, WL 2, 3, 4, 6, 8, 9, 12, 14 132. Rhizomnium punctatum SO 4 133. Rhodobryum ontariense SO 12 134. Rhynchostegium murale StA 3 135. Rhytidiadelphus squarrosus SO 2, 9 136. Rhytidiadelphus triquetrus SO, SV 8 137. Schistidium crassipilum StA, SG 1, 10 138. Sciurohypnum plumosum StA 3 139. Sciurohypnum populeum SO, SV, WR 4, 6, 12 140. Sciurohypnum re�exum SO 4 141. Scorpidium cossonii AM 1, 7 142. Sphagnum angustifolium SO 2 143. Sphagnum cuspidatum SO 1, 2 144. Sphagnum fallax SO, SV 1, 2 145. Sphagnum. �mbriatum SO 1, 2 146. Sphagnum girgensohnii SO 1 147. Sphagnum inundatum SO, AM 11 148. Sphagnum palustre SO, SV 1, 2 149. Straminergon stramineum SO 1 150. Syntrichia papillosa StA, WR, WL 1, 3, 6 151. Syntrichia ruraliformis SO 4 152. Syntrichia ruralis StA, SG, SO, WL 1, 2, 12, 13 153. Taxiphyllum wissgrillii RO 10 154. Tetraphis pellucida WR 1, 2, 4 155. �uidium assimile. SO, SV 2, 4, 8, 10, 12 156. �uidium delicatulum SO 1 157. Tomenthypnum nitens SO 1 158. Tortella humilis SO 12 159. Tortella inclinata RO 12, 13 160. Tortula aestiva StA 1 161. Tortula caucasica SO 4 162. Tortula muralis StA, SG 1, 3, 10, 12 163. Tortula subulata WR 8 164. Tortula truncata SO 4 165. Warnstor�a �uitans SV 1 Y ur a D ra ch , Z ve ny sv al a M am ch ur 24 Abstract In the article, the bryophytes of the upper reaches of the Western Bug River (Ukraine), which is physically and geographically located within Male Polissya, partly Roztochia, and to a minor extent in the Gologoro-Vo- ronyatsky denudo-structural hills, have been studied. Based on our survey, a list of the bryophytes has been compiled for the �rst time. Ecological features, substrate preferences and life forms of the bryophytes have been analysed. According to the ecological features, subheliophytes (30.9%) and hemisciophytes (30.9%) predomi- nate in the spectrum of heliomorphs; mesophytes (29.7%), hygromesophytes (21.2%) and xeromesophytes – in the spectrum of hydromorphs (19.4%); cold-tolerant species (59.4%) – in the spectrum of thermomorphs. Based on the analysis of the substrate preferences of the bryophytes, the following groups were identi�ed: epi- geans (116 species), epixils (56 species), epiphytes (46 species), epiliths (43 species), aquatic (22 species). �e prevailing life forms are turf (30.3%), rough mat (18.2%), we� (15.2%), tu� (10.3%) and smooth mat (9.7%). 3 species that are o�cially recognised as rare and 16 species that are recognised as regionally rare have been found. In the group of bryophytes associated with wetland ecosystems, 2 o�cially rare and 6 regionally rare species were found in the study area. Given the large areas of drained land in Lviv Region, these species are of particular value, especially in the context of conservation of the biodiversity and protection of the valuable natural areas in accordance with the Development Strategy of Lviv Region by 2027. Key words: rare bryophytes, ecomorphs, life forms, ecological groups Received: [2020.08.06] Accepted: [2020.10.13] Mszaki górnego biegu zachodniego Bugu (obwód lwowski, Ukraina) Streszczenie W artykule przedstawiono wyniki badań, dotyczących mszaków górnego biegu Zachodniego Bugu (Ukraina). Teren ten �zycznie i geogra�cznie położony jest w obrębie Małego Polesia, częściowo Roztochii oraz w nie- wielkim stopniu na wzgórzach Gołogóro-Woronieckich. Na podstawie badań terenowych, po raz pierwszy zestawiono listę mszaków tego obszaru. Przeanalizowano cechy ekologiczne, preferencje podłoża i formy ży- ciowe stwierdzonych tu mszaków. Według cech ekologicznych w spektrum heliomorfów dominują subhelio- �ty (30,9%) i  hemiscio�ty (30,9%); mezo�ty (29,7%), higromezo�ty (21,2%) i kseromezo�ty – w spektrum hydromorfów (19,4%); gatunki tolerujące zimno (59,4%) – w spektrum termomorfów. Na podstawie analizy preferencji substratowych, zidenty�kowano następujące grupy mszaków: epigeity (116 gatunków), epiksylity (56 gatunków), epi�ty (46 gatunków), epility (43 gatunki), hydro�ty (całkowicie lub częściowo zanurzone) (22 gatunki). Dominującymi formami życiowymi są formy darniowe (30,3%), tworzące szorstkie maty (18,2%), wełniste (15,2%), kępkowe (10,3%) oraz tworzące gładkie maty (9,7%). Znaleziono 3 gatunki w  skali ogól- nej uznane za rzadkie oraz 16 gatunków uznanych za rzadkie regionalnie. W  grupie mszaków związanych z ekosystemami wodno-błotnymi, stwierdzono 2 gatunki ogólnie rzadkie i 6 gatunków rzadkich regionalnie. Ze względu na duże powierzchnie odwodnionych terenów w obwodzie lwowskim, gatunki te są szczególnie cenne, zwłaszcza w kontekście zachowania różnorodności biologicznej i ochrony ważnych przyrodniczo ob- szarów, zgodnie ze Strategią Rozwoju Obwodu Lwowskiego do 2027 roku. Słowa kluczowe: mszaki rzadkie, ekomorfy, formy życiowe, grupy ekologiczne Information about authors Yura Drach https://orcid.org/0000-0002-6497-5638 His currently works at the Department of Ecology (Head of department), Ivan Franko National Univer- sity of Lviv Research is connected with ecology and biodiversity of bryophytes of the Western Bug River and the Ukrainian Carpathians. Zvenysvala Mamchur https://orcid.org/0000-0003-0527-5639 Zvenyslava Mamchur currently works at the Department of Ecology (Head of department), of Ivan Franko National University of Lviv. She does research in Ecology and Botany. Her current projects are “Ecological features of synanthropic �ora of Lviv”, “Bryophyta”.