03C1

C. Inland waters

Charophyte communities in stagnant waters

Relationships with habitat classifications. EUNIS: C1.14 Submerged charophyte carpets in oligotrophic water bodies, C1.25 Submerged charophyte carpets in mesotrophic water bodies, C1.512 Submerged charophyte carpets in inland saline or hypersaline water bodies; PAL. CLASS.: 22.44 Chandalier algae submerged carpets, 23.12 Salt basin charophyte carpets; HD 92/43: 3140 Hard oligo-mesotrophic waters with benthic vegetation of Chara formation.

Conservation status. BDA, HD.

Category. Endangered [EN – A1, 2 C1 D3 E2 F2 G2 H2 I L1].

General characteristics. The submerged charophyte “carpets” include the following charophyte genera: Chara, Lamprothamnium, Nitellopsis, Nitella and Tolypella. They partly or completely cover the bottom of standing (including brackish and saline ones) water bodies. The coenoses develop on muddy bottom at 0–2 m (rarely 5 m) depth, covering relatively small areas. Sometimes they partly or completely disappear due to drying up but have good restoration potential when the water bodies or the wetlands are restored, even after a long period of time. The abiotic conditions in the water bodies can vary: different degree of eutrophication (from oligotrophic to eutrophic), pH (from neutral with pH=7 to highly alkaline  with pH>8,5), salinity (fresh water, brackish to saline water bodies), temperature, etc. The following subtypes can be identified:

1. Charophyte coenoses in stagnant fresh water bodies. Submerged charophyte “carpets” from the following genera: Chara, Lamprothamnium, Nitella and Tolypella, Nitellopsis in fresh, oligo-mezotrophic lakes, dams, microdams, swamps, flooded riverside areas, mires and bogs. They occur mainly in calcareous or karst areas. Together with the Chara species some macroalgae species from the genera  Cladophora and Vaucheria occur,together with many vascular plants: Alisma plantago-aquatica, Butomus umbellatus, Carex acuta, C. riparia, Ceratophyllum demersum, Eleocharis palustris, Iris pseudacorus, Lemna minor, L. trisulca, Mentha aquatica, Myriophyllum spicatum, M. verticillatum, Najas marina, Phragmites australis, Potamogeton crispus, P. lucens, P. natans, P. pectinatus, Ranunculus aquatilis, Sagittaria sagittifolia, Salvinia natans, Scirpus lacustris (= Schoenoplectus lacustris), Scirpus litoralis (= Schoenoplectus litoralis), Sparganium erectum, Typha angustifolia, T. latifolia, T. laxmannii, Utricularia vulgaris, Wolffia arrhiza, Zannichellia palustris etc.

2. Charophyte communities in stagnant inland brackish and saline water bodies. Submerged charophyte “carpets” from the genus Chara that can endure high salinity – C. aspera, C. canescens, C. connivens, C. hispida var. major, C. kokeilii, C. tomentosa,and C. vulgaris. These coenoses occur in water ponds and on the bottom of seaside oligo- to hypersaline lakes, swamps, lagoons and estuaries with slowly flating water – Shabla lake, Shablenska Tuzla and Nanevska Tuzla localities, Varna, Beloslav and Pomoriisko lakes, the Devil’s Swamp and estuary of Silistar river. Some macroalgae species from the genera Vaucheria, Cladophora, Enteromorpha,and many vascular plants: Bolboschoenus maritimus, Ceratophyllum demersum, Juncus maritimus, Lemna minor, L. trisulca, Najas marina, N. minor, Phragmites australis, Potamogeton lucens, P. pectinatus, Scirpus lacustris, S. triqueter (= Schoenoplectus triqueter), Typha angustifolia, T. latifolia etc. occur in these coenoses.

Characteristic taxa.

Distribution in Bulgaria. Etropole dam, Vrachanska Mts. – Pecheniyski Lokvi swamps, near Varshets town, Gabrovski Balkan Mts., above Ribaritsa village, near Gotse Delchev, Razlog, Velingrad, and Assenovgrad towns, North Black Sea coast – Shabla lake, South Black Sea coast – Atanasovsko Lake near Burgas town, Devil’s swamp near Primorsko, estuary of Silistar river, Strandzha Mts. – along Rezvaya River near Malko Tarnovo town, Danubian Plain – between Svistov and Belene towns; NE Bulgaria – between Devnya lakes and Razdelna village, Forebalkan – Rabisha and Doirentsi dams, the microdam near Goran village, Kamenets dam, Devetashko plateau, Yovkovtsi dam (near Elena town), near Draganovo village, near Levski, and Lovech town; East Balkan Range the bottom of the water bodies – Ovcharovo and Ticha dams, near Sliven town; Sofia region – Aldomirovsko swamp, Dragomansko swamp, Lyulin Mts. above Dragichevo village, near Radomir and Slivnitsa towns, Thracian Lowland – near Novo Selo village, the valley of Struma river – near Kocherinov railway station; East Rhodopi Mts. – Kardzhali dam and the surroundings; at 0–1500 m alt.

Conservation importance. The charophyte submerged “carpets” used to be widely distributed in the past throughout Bulgaria. Nowadays they have limited distribution and in most cases cover small areas. There is a risk of extinction for many of these localities.

Threats. Draining of swamps, filling up of the water bodies, construction of dykes, changes in the hydrological regime, management of the water level and the macrophyte vegetation, pollution of the water bodies. Natural processes such as congestion, drying up, eutrophication, accumulation of organic material, transition of the aquatic ecosystems into  terrestrial ones.

Conservation measures taken. The habitat is included in Annex № 1 of BDA. Some of the localities are within protected areas and in sites from the European Ecological Network NATURA 2000.

Conservation measures needed. Partial to complete restoration of the natural conditions in the places where the habitat used to occur in the past; prohibition of activities that can have, even minimal, negative impact on the localities; monitoring of the existing localities, information signs to mark them in the field, raising public awareness on the protection of aquatic habitats; proclamation of new protected areas.

References. Blaženčić & Temniskova 2002; Kochev & Jordanov, 1981; Petkoff 1914; Petkoff 1913, 1922, 1925, 1929, 1934, 1938, 1943; Temniskova et al. 2006; Vodenicharov et al. 1971; Wodenitscharow 1963; J. Blaženčić, D. Temniskova, P. Ivanov unpublished data.

Authors: Plamen Ivanov, Dobrina Temniskova


Charophyte communities in stagnant water bodies (distribution map)