Jelena BLA@EN^I]

THE OHRID LAKE – AN IMPORTANT CENTRE OF CHAROPHYTA DIVERSITY

Jelena BLA@EN^I]

Institute of Botany and Botanical Garden „Jevremovac“, Faculty of Biology, University of Belgrade, Serbia e-mail: jblaz@ Eunet. yu

ABSTRACT

Bla`en~i} J. (2004). The Ohrid Lake-an important centre of Chraophyta diversity. Proceedings of the 2nd Congress of Ecologists of the Republic of Macedonia with International Participation, 25-29.10.2003, Ohrid. Special issues of Macedonian Ecological Society, Vol. 6, Skopje. There are 24 charophyta taxa recorded in the Ohrid Lake, the oldest lake in Europe and one the oldest ones in the world, located in the south-west part of Macedonia. These 24 taxa are at the levels of species (15) and forms (nine), belonging to the genera of Chara (10 species), Nitella (four species) and Tolypella (one species). The Ohrid Lake is a locus clasicus for the endemic Chara ohridana. When we compare the number of the existing species in various lakes, the Ohrid Lake becomes one of the richest charophyta localities in the Balkan Peninsula and together with the Skadar Lake in Montenegro and the Bacinska lakes in Croatia makes the three most important centres of the charophyta diversity in the Balkans.

Introduction charophyta in the Balkans is applied, we can conclude that the Ohrid Lake’s charophyta flora is more The Ohrid Lake, like few others in the world (the diversified than such flora of other Balkan countries Baikal Lake, the LakeTanganyika and the Lake (Blazencic et al. 2003). Nyasa), was created in the very early days of the New data about the charophyta of the Ohrid Lake are planet, in the period before the Ice Age. It is the oldest very limited (Talevska et al. 2002, Trajanovska 2002) lake in Europe and is a locality for the living world and the majority of our knowledge about their flora bearing specific, very endemic and relict and distribution, their basic phytocenologic and characteristics. (STANKOVIC 1957, 1960). It is ecologic elements dates back to 1936. (Jakovljevic located in the south-western part of Macedonia, at 1936, Kostic 1936)! This paper is aimed at gathering the altitude of 695 metres. Apart from being the oldest, and analysing available knowledge about the Ohrid it is also one of the largest and deepest lakes in Europe. Lake charophyta, at giving an estimate of their It covers the space of 348 square metres and its vulnerability level and at inspiring an all- maximum depth is 286 metres. By its origin, it belongs encompassing study of the charophyta in this unique to the tectonic lakes. living milieu with a special accent put on the studies Macrophyte vegetation of the Ohrid Lake shows very of the endemic species Chara ohridana. zonal distribution (Stankovic 1957, 1960; Talevska et al. 2002, Trajanovska 2002). Although we could Material and methods find the charophyta in all three vegetation zones, they are achieving their maximum development in the Data on flora of the Lake Ohrid charophyta that are greater depths of the lake and are building a belt in presented in this paper come from the published the lithoral zone of the lake, at the lower borderline papers, wet and dry collections of the charophyta kept of the macrophyta vegetation distribution. The at the Institute of the Botany and Botanical Garden importance and power of this zone was pointed out in Jevremovac (BEOU). the classical work of Stankovic (1957, 1960) „The Balkan Lake Ohrid and its Living World and Identification of species was made according to a Trajanovski et al. (2002). slightly modified Key for Determination of R. Corillion (1957, 1975). A very diversified chrarophyta flora with well- developed vegetation characterises the Ohrid Lake. Categorization of the degree of threat to specific It also includes some rare and endemic representatives species follows the principles and criteria stipulated like - Chara kokeilii, Chara ohridana. When by the International Union for the Conservation of comparative analyses of biological diversity of Nature (IUCN 1994). 378 Zbornik na trudovi od 2-ot Kongres na ekolozite na Makedonija The Ohrid Lake-an important centre of Chraophyta diversity

The abbreviations used in the tables read as follows: thuilleri are the species recorded from the Nitellaceae EX - extinct, CR - critically endangered, EN- family and one not identified species of the genus endangered, VU - vulnerable, LR - lower risk. Tolypella was also recorded.. The Characeae family The endemic species of the Ohrid Lake, mentioned is represented by: Chara aspera (Deth.) Willd., Chara here, have both the symbol representing the degree of braunii Gmelin, Chara golubolaris Thuill. (as Ch. the threat and the symbol GLOB next to their names fragilis Desv. in Lois.) Chara vulgaris L. (as since their extinction from this locality or the status Ch.foetida A.Br.), Ch. vulgaris f. subgymnophylla of being critically endangered in this region would Mig., Chara vulgaris var. gymnophylla f. submunda also mean the same status globally. The endangered (A.Br.) Hy. (as Ch. gymnophylla A.Br. f. submunda species only in the region of the Balkan peninsula have Mig.), Chara hispida L., Chara imperfecta A.Br., the symbol representing the degree of the threat and Chara kokeilii A.Br. f. gymnophylla Kostic, Chara the abbreviation BALK next to their name. ohridana (Kostic) Krause (as Ch. dissluta A. Br. var. ohridana Kostic), Chara tenuispina A.Br., Ch. tenuispina f. major Mig., Ch. tenuispina f. Results and discussion subgymnophylla Kostic, Ch. tenuispina f. longifolia Kostic and Chara tomentosa L. (Tab.1). Floristic and taxonomic analyses Comparative floristic analyses of the charophyta of Nitella hyalina (DC) Ag. Macedonia and the recorded species in the Ohrid Lake (Tab. 1) shows that out of the total of the recorded The Nitella hyalina species of the Ohrid Lake was species in Macedonia, 15 exist in the Ohrid Lake. Nine described first by KRAUSE (1997), and a more precise of these species are recorded only in the Ohrid Lake description of the locality and the exact points where (Tab. 1). Apart from 15 species, nine forms have also it was recorded were given by KOSTIC (1936). The been recorded in the Ohrid Lake and three of them - samples were taken at the Strusko hunting point IV, f. gymnophylla Kostic of the speciec Chara kokeilii, Kalisko hunting points II and III, Radozda (western f. subgymnophylla Kostic and f. longifolia Kostic of shore) and Gumisce. Nitella hyalina grows as a bush the Ch. tenuispina species are new to the science. at the depth of 0.8 to 5.0 m. As KOSTIC (1936) (Stankovic 1957, 1960, Jakovljevic 1936, Kostic describes it, it fructificates at 0.8 to 2.0 m deep water, 1936, Blazencic et al. 1991, 1999, Krause 1997 ). at the temperature between 20.2 and 21.0 ºC, in The recorded representatives of the Charales belong August and September. It grows on the light brown to two families of the recent charophyta: Nitellacea and brown mud. and Characeae. Nitella hyalina (DC) Ag., Nitella mucronata A.Br., N. mucronata f. heteromorfa A.Br., Nitella mucronata A.Br. N. mucronata f. robustior A.Br.. Nitella opaca (Bruz.) Nitella mucronata of the Ohrid Lake has been Ag., Nitella syncarpa (Thuil.) Kütz., N. syncarpa f. recorded in two forms - f. heteromorpha A.Br. and f.

Tab. 1. The list of the distribution of the charophytes in Macedonia

Proceedings of the 2nd Congress of Ecologists of Macedonia 379 Jelena BLA@EN^I] robustior A.Br. N. mucronata f. heteromorpha was in the Ohrid Lake. It was recorded at numerous recorded at the Railway station Podmolje between localities: Pestani, bay Sv. Stevan, close to the Ohrid and Struga towns, and f. robustior was recorded Hydrobiological Institute and the marina in Ohrid, at close to Gorica. Both forms of this species grow in the exit of the Crni Drim, at the Monastery of Sv. shallow waters (from 1.0 to 60.0 cm), on the light or Bogorodica, before the villages of Radozde, Struga, dark brown mud. The samples of f. heteromorpha Gorica, Gumiste and Sv. Naum (Jakovljevic 1936, were collected in September 1936 (Kostic, 1936) from Kostic 1936). Most often, it was found at the depth of a boggy meadow, at the temperature of 17ºC. Talus 2.5 to 6.2 m, and sometimes also at the deeper waters parts were forming a thick carpet in the water at the but no deeper than 8.0 m (Kostic 1936). It grows on depth of up to 5 cm. This form of Nitella mucronata the sandy and muddy bottom in thick groups or in a was recorded also in the canal next to the meadow in mosaic like shapes of bushes with Chara tomentosa, somewhat deeper water, (60 cm). The plants were or, more rarely with Ch. imperfecta, Ch. vulgaris, fructificating, like those of the f. robustior sample Nitella opaca Zannichellia palustris L., Myriophyllum collected in October in the water at about 30 cm. spicatum, Potamogeton pectinatus L., P. lucens L. (Jakovljevic 1936). The Southern borderline of the Nitella opaca (Bruz.) Ag. area covered by this species in Europe is going through the Ohrid Lake. (Krause 1997) According to Jakovljevic (1936) this species could be found only at locations in the Ohrid Lake lithoral: to the left of the marina in Ohrid, where it grows at Chara braunii Gmelin the depth of 4.5 to 5.85 m, close to the Kaneo place at Chara braunii was recorded in the stream next to the the depth of 4.5 m and in front of the Ohrid beach at Crni Drim (Moruniste - Dobovljani) under the name the depth of 3.6 to 6.5 m. At these locations it was of Chara coronata Ziz. The samples were collected, found in different combinations with Chara aspera, in September, in the shallow waters (10 cm) at the Ch. tomentosa, Ch. imperfecta, Ch. vulgaris, temperature of 16ºC. It develops in bushes and it Potamogeton perfoliatus L,, and rarely with also fructificates (Kostic 1936). Myriophyllum spicatum L., Ceratophyllum demersum L. and Valisneria spiralis. L. Krause (1997) mentioned the Ohrid Lake while he was talking about this plant’s Chara globularis Thuill. diversity in Europe. Chara globularis (as Ch. fragilis Desv.) was found at the depths between 6.4 and 8.0 m at the Kaneo, in front of the beach in Ohrid, in front of the Sv. Nitella syncarpa (Thuill.) Kütz. Bogorodica Monastery (Jakovljevic 1936) and at Nitella syncarpa f. thuilleri A.Br. was recorded at Rotina (fishermen’s name for a place on the eastern Struga near the exit of the Crni Drim river, at Radozde, side shore between Pestan and Trpezice) and Rajac, Gumisca, Pestan and Rajac. It grows at the depth (KOSTIC 1936). It grows together with Chara between 0.8 and 8.0 m, on the greyish white or brown tomentosa, Ch. imperfecta, Najas major, Potamogeton mud, and at Rajac it also grows on the sand bottom perfoliatus, Ceratophyllum demersum, Myriophyllum and detritus among some bigger stones. In the shallow spicatum, Zannichelia palustris (Jakovljevic 1936) waters it forms a thick carpet, whereas in the deeper Apart from the locality at the Lake, there are canals waters it grows in a mosaic like form on the lake and other places near the Lake that were also inhabited bottom. The samples were taken between August and by this species, especially the shallow waters (10 do October of 1936 (Kostic 1936). According to this 30 cm), muddy or sandy bottoms of these places. Such source, the richest localities of this charophyta were places include canals close to Gorica, Podmolje, found at the depth of 7.5 m at Gumisce and at the village Tasmoruniste and the river of Crni Drim water temperature of 20.4ºC. Except for the plants (Kostic 1936). found at 8.0 m, on all the other plants there were gametangia or oospores. Krause (1997) also mentions the Ohrid Lake as the locality of these plants. Chara vulgaris L. Chara vulgaris (like Chara foetida A.Br.) was Tolypella sp. recorded sporadically in the deeper waters of the Ohrid Lake (between 5.7 and 17.6 m of depth!) where it Stankovic (1929) was mentioning the genus Tolypella was building monospecies communities Charetum sp when he was writing about the zonal distribution vulgaris Corillion 1957, or mixed communities with of the vegetation in the Ohrid Lake. Chara aspera, Ch. tomentosa, Ch. imperfecta, Nitella opaca, Potamogeton pectinatus, Myriophyllum Chara aspera (Deth.) Willd. spicatu (Jakovljevic 1936). Chara aspera is, according to Jakovljevic (1936), after Chara vulgaris f. subgymnophylla Mig. (as Chara Chara tomentosa, the most abundant species found foetida f. subgymnophylla Mig.) was recorded in the

380 Zbornik na trudovi od 2-ot Kongres na ekolozite na Makedonija The Ohrid Lake-an important centre of Chraophyta diversity shallow waters (4 to 10 cm deep) of the streams and way down to the greater depths of the lake (over 9 m) canals next to the Ohrid Lake. At these places, it was where it often forms almost monospecies growing in the bushes and at the time of collecting – communities. It was recorded at the following October – it was fructificating. localities: Radozda, Struga, Ohrid, Gorica, Gumnisce, Chara vulgaris var. gymnophylla f. submunda (like Rotina, Rajac, Sv. Naum. Ch. gymnophylla A.Br. f. submunda Mig..) was recorded in the shallow waters (5-25 cm) of the Chara tenuispina A.Br. streams, dumps and other places next to the Lake’s Chara tenuispina was recorded at the localities near shore at the localities of the Sv. Stefan, Moruniste - the Ohrid Lake, in the canals where it was determined Dobovljani, Sv. Erazam - Podmolje i and close to the as f..major Mig. (Sv.Erazam - Podmolje, near the road village Openac (Kostic 1936). It grows in a mosaic Ohrid Struga), f. longifolia Kostic (in the canal near like shaped forms on light brown or black mud. Gorice) and f. subgymnophylla Kostic (around the road near Struga). Chara tenuispina grows in the Chara hispida L. shallow waters (20 - 30 cm) on the muddy bottom, which it covers in a thick layer. According to Jakovljevic (1936), Chara hispida was recorded near Pestani at 14.5 m deep water, close to the Hydrobiological station at the depth of 5 m and at Chara tomentosa L. the marina in Ohrid at the depth of 6.5 m and 13.5 m. Chara tomentosa covers large spaces in the lithoral It grows on the sandy bottom in the clean communities zone of the Ohrid lake, according to the researches (Pestani, at the Hydrobiological station) or with Chara (Jakovljevic 1936, Kostic 1936, Talevska et al. 2002, tomentosa (at the marina in Ohrid). Trajanovska 2002, Talevski et al. 2002). It grows at the depths of 4.0 to 13.0 m around the whole lake. Chara imperfecta A.Br. Extremely abundant meadows are at the depths of 6.0 According to the data provided by Jakovljevic (1936) to 12.0 m. At these depths, it builds almost clean Chara imperfecta could be recorded only at certain communities Charetum tomentosae (Sauer 1937) localities in the Ohrid Lake. It is growing at different Corillion 1957. This species was mentioned by Krause depths between 1.7 and 10.5 m. It was found together (1997), too, in relation to the Ohrid Lake. with Chara tomentosa, Ch. aspera, Ch. vulgaris, Nitella opaca, Myriophyllum spicatum and An Overview of the Degree of the Vulnerability and Potamogeton pectinatus at the localities Sv. Naum, the categorization of the species close to the marina in Ohrid, in front of the beach in It was in respect to the increased vulnerability of the Ohrid and in the vicinity of the exit of the Crni Drim. living world by the ever more aggressive behaviour of the human beings towards the natural balance of Chara kokeilii A.Br. the basic living conditions and to the increased The species of Chara kokeilii was related to the Ohrid sensibility of the aquatic ecosystems in this regard, that the analyses of the degree of the vulnerability Lake by KRAUSE (1997), and was described as a new was deemed necessary for the Ohrid Lake form to the science, f. gymnophylla Kostic, KOSTIC (1936). This new taxon was determined from the charophytes. Categorization was performed in localities in Struga - Strusko hunting point in August accordance with the principles and criteria IUCN of 1936. The sample was collected at the water (Vasic 1995, Stevanovic 1999), and the results are shown in the table 2. temperature of 20.2ºC, from the muddy bottom at the depth of 80 cm (Kostic 1936). We suspect that the species Chara imperfecta is extinct (EX BALK) since its locality in the Ohrid Lake was the only known locality in the Balkan Peninsula and Chara ohridana (Kostic) Krause since 1936, the species has not been recorded. The Chara ohridana is an endemic species, so far recorded Balkan’s endemic Chara ohridana and a rare species only in the lakes of Ohrid and Prespa and the localities of Chara kokeilii are globally endangered species (EN near the Dojran Lake (Kostic 1936, Krause 1997, GLOB), since they are faced with high risk of Blazencic et al. 1999). Formerly determined as Chara extinction as a result of pollution (A1e), their dissoluta var. ohridana Kostic 1936, under the name fragmented population (B1) and the shrinking number of Chara ohridana it was mentioned in 1997 in the of the localities where they have been found (B2d). ambitious monography about charophytes by Krause According to the most recent data from the Dojran (1997). Lake, Chara ohridana is already extinct. The similar In the vegetation belt of the submerged plants in the fate awaits Chara tenuispina and Nitella syncarpa, Ohrid Lake, Chara ohridana is organized in the shape the only difference being that they are endangered in of individual bushes or in the mixed populations with the Balkans only (EN BALK), not globally. Chara other charophytes and other plants. It grows all the hispida, Nitella mucronata and Chara tomentosa are

Proceedings of the 2nd Congress of Ecologists of Macedonia 381 Jelena BLA@EN^I]

Tab. 2. Categorization of degree of threat of charophytes of Lake Ohrid.

categorized as vulnerable in the Balkan Peninsula References (VU BALK), because their population is fragmented (B1), developed on the small areas, at few localities, Blazencic, J., Blazencic, Z. 1999. Doiran lake and are sensitive to the negative anthropogenic Charophytes. - God. zb. Biol., 52: 83-92. Skopje. influence which could lead to the status of these Blazencic, J. & Blazencic, Z. (2003). An overview of species being changed to the category of extremely the existing data on living charophytes (Charales) endangered (D2). Species Nitella opaca, Chara on the Balkan peninsula. - Acta aspera, Ch. braunii, Ch. globularis and Ch. vulgaris micropaleontologica Sinica. 20 (2):103-110. are categorized as a group of low risk of vulnerability Blazencic, J., Blazencic, Z., Cvijan, M & Stevanovic, (LR), they do not need special protection regime B. (1990). Systematic and Biogeographyc studies although they are close to the category of the sensitive of Charophytes in Yugoslavia.- Criptogamie, ones (2nt). Algol. 11 (4): 249-256. Paris. In the Balkan Peninsula 44 species of charophytes Corillion, R. (1957). Les Charophycées de France et have been recorded (Blazencic et al. 2003). Since there d, Europe occidentale. -Bull. Soc. Sci. Bretagne. are some 49 -54 charophytes known in Europe (Krause 32, fasc.h.s., 499 p. 1997), the assumption is that the Balkan Peninsula Corillion, R. 1(975). Flore des Charophytes hosts between 81.4 percent and 89.7 percent of the (Characées) Massif Armoricain et des contrées known charophytes species of Europe. voisines d' Europe occidentale.- Flore et The analyses of the regional distribution of the vegetation du Massif Armoricain Tome IV. Paris. charophytes in the Balkan Peninsula shows that 20 214 p. species of the charophytes have been recorded in IUCN Species Survival Commission (1994): IUCN th Macedonia which makes 47.7 percent of the known Red List Categories - 40 Meeting of the IUCN charophytes in Balkan Peninsula. Out of this number, Council, Gland. 15 species (Chara 10 species, Nitella 4 and Tolypella Jakovljevic, S. (1936). Makrofitska vegetacija sp.) have been recorded in the Ohrid Lake, which Ohridskog jezera. - Arhiv Ministarstva makes 34 percent of the known charophytes in the poljoprivrede, III (5):3 - 31.Beograd. Balkans. Nine of them have been recorded solely in Krause, W. (1997). Charales (Charophyceae) .In : Ettl, the Ohrid Lake (Tab.1). Higher floristic diversity H, Gärtner, G., Heynig, H & Mollenhauer (eds.): within the Balkans, we have found only in the Skadar In: Süßwasserflora von Mitteleuropa. Band 18. Lake (24 species), whereas a similar variety of Gustav Fischer, Jena; Stuttgart; Lübeck. pp 202. charophyta is recorded in the Bacinska lakes in Croatia Stankovic, S.(1957). The Lake of Ohrid and its Live (four genera with 12 species). When comparative World - „Kultura“ Skopje, p.381. (in Serbian). analyses of biological diversity of charophytes in the Stankovic, S.(1960). The Balkan Lake Ohrid and its Balkans is applied, we can conclude that the Ohrid Living world. Monographie Biologicae 9. den Lake’s charophyta flora is more diversified than such Hag. flora in Slovenia (12 species), Bosnia and Stevanovic,V. (1999). Principi rada i primena IUCN Herzegovina (13 species) and Albania (14 species). kategorija ugrozenosti. U: Stevanovic, V. (ed.) : We can conclude that the Skadar Lake, the Ohrid Lake Crvena knjiga flore Srbije 1. Iscezli i krajnje and the Bacinska lakes are three most important ugrozeni taksoni. Beograd. 19-30. centres of charophyta diversity in the Balkans. Talevska . M. & Trajanovska, S. (2002). Lake Ohrid macrophyte vegetation. Macrophyte species list and distribution Phragmites and Chara. Heavy

382 Zbornik na trudovi od 2-ot Kongres na ekolozite na Makedonija The Ohrid Lake-an important centre of Chraophyta diversity

metals in macrophytes. - Limnological ezero.- Zbornik na rabotite 35 (1): 109-118. Ohrid. investigations of Lake Ohrid, Vol. 1&2:97-108. Vasic, V. (1995). Medjunarodni sporazumi, standardi, Hidrobiological Institute Ohrid. kriterijumi i programi od znacaja za ocuvanje, Trajanovska, S. (2002). Distribucija i površina na odrzavanje i trajno odrzivo koriscenje pojasot na hara (Chara spp.) vo Ohridskoto ezero.- biodiverziteta. U: Stevanovic, V. & Vasic, V. (eds.) Zbornik na rabotite 35 (1): 99-108. Ohrid. : Biodiverzitet Jugoslavije sa pregledom vrsta od Trajanovski, S., Krstanovski, Z., Trajanovski, S. & medjunarodnog znacaja. Bioloski fakultet i Budžakovska, B. (2002). Makroinvertebratni Ecolibri, Beograd. 43-57. zaednici vo pojasot na Charophyta vo ohridskoto

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