FLORA AND VEGETATION OF BRACKISH WATERBODIES OF THE NATURE RESERVE "GOLUBYE OZERA" (MIDDLE VOLGA REGION)
The results of studying species and phytocenotic diversity of macrophytes in brackish lakes and streams of the nature reserve “Golubye Ozera” (Middle Volga region) during the vegetation period of 2017 and 2018 are presented. The list of revealed species includes 43 species from 34 genera and 23 families, among them there are macroalgae (9 species), mosses (6) and flowering plants (28). 19 plant species were noted for the first time for the nature reserve. The representatives of 5 ecotypes are present in the flora structure, 16 species of which (37%) are true aquatic plants (hydrophytes). 18 associations from 13 formations are distinguished in the syntaxonomic structure of aquatic and semiaquatic plants. The class of aquatic vegetation is the most various (8 formations with a coenotic saturation of ~1.5 ass./formation) and exceeds semiaquatic (1.33 ass./formation) and riparian, near-water (1.0 ass./formation) classes. The communities of macroscopic algae are predominant in the lake vegetation cover. Their share in the overgrowing of water reaches from 30 to 70% with the degree of overgrowing from 38 to 81%. Among them, the leading role belongs to Charophyteta (Chara contraria) and Chlorophyteta the green filamentous algae (Cladophora glomerata, Spirogyra sp.). In all lakes it is noted the appearance of cenoses Spirogyra sp., that was not registered early. A comparative analysis of the vegetation cover dynamics of Bol'shoye Goluboye Lake indicates a decrease in the share of flowering plant communities in overgrowing of the lakes and their replacement with algal cenoses during the 80-year period.