02C1
Charophytic vegetation in oligotrophic lime-rich running water
Relationships with habitat classifications. EUNIS: C2.19 Lime-rich oligotrophic vegetation of spring brooks, C2.26 Lime-rich oligotrophic vegetation of fast-flowing streams; PAL. CLASS.: 24.42 Lime-rich oligotrophic river vegetation; HD 92/43: 3140 Hard oligo-mesotrophic waters with benthic vegetation of Chara formation.
Conservation status. BDA, HD.
Category. Endangered [EN – A1, 2 C2 D3 E3 F3 G3 H2 I L1].
General characteristics. Habitat of Chara algae, in oligotrophic, calcareous, running waters – springs, streams, upper and middle river flows. They prevail in calcareous and karst areas (low to high alkaline waters, pH>7,5) and in warm, calcareous, mineral springs (so called “toplitsi”). They develop on the muddy-sandy bottom of the water bodies, can form dense tufts and cover relatively small areas.
Characteristic taxa.
- Plants: algae – Chara braunii, C. contraria, C. globularis, C. vulgaris, C. vulgaris var. gymnophilla.
Distribution in Bulgaria. West Balkan Range (near Vratza town, Proboynitsa river above Lakatnik railway station), Central Balkan Range (Uzana locality, Etropole and Elena mountains), East Balkan Range (Emine cape), Rhodopi Mts. (near Chepelare town, Malko Belovo village, Kardzhali dam, Byala river), Strandzha Mts. (Fakiyska river near Golyamo Bukovo village, Elenitsa river, rivulets near Tzarevo and Ahtopol towns and Varvara village), NE Bulgaria (Devnya springs, Provadiyska river), Forebalkan (Panezhka river near Veliko Tarnovo town), Lyulin Mts. (springs above Dragitchevo village), Thracian Lowlands (near Krumovo village); at 50–1300 m alt.
Conservation importance. The underground meadows of Chara algae were poorly distributed in springs, streams and rivers in the past. Today their distribution is extremely restricted on very small territories. There is a great risk of extinction for most of them.
Threats. Water catchment and redirection of streams, river beds, changes in the hydrological regime, improper management of water levels and the water vegetation, pollution of water bodies; natural processes – drying-up, accumulation of organic material, transformation of the water ecosystems into terrestrial ones.
Conservation measures taken. The habitat is included in Annex № 1 of the national Biodiversity Act. Part of the localities are within protected areas – Central Balkan National Park, Strandzha Nature Park, etc., and in sites of the European Ecological Network NATURA 2000 in Bulgaria.
Conservation measures needed. When possible, restoration of the natural conditions in all places where the habitat existed in the past and became extinct as a consequence of the changes in the hydrological regime in the upper and middle streams of the rivers – the open streams beside the warm, mineral springs, that are completely captured nowadays. Chara algae have good reproductive capacity when the water bodies and wet areas are restored even after many years. It is necessary to prohibit activities in close proximity to the existing localities when there is risk for negative impact. Monitoring of the existing localities, their marking in the field (with signs and tables), popularization of the needs for the protection of water habitats. Inclusion of all existing habitats of that type in protected areas or protected sites from NATURA 2000 network.
References. Blaženčić & Temniskova 2002; Kovachev & Jordanov 1981; Petkoff 1913, 1929, 1934, 1938, 943; Vodenicharov et al. 1971; Wodenitscharow 1963; E. Blaženčić, D. Temniskova, & P. Ivanov unpublished data.
Authors: Plamen Ivanov, Dobrina Temniskova
