Home – Home – Jornals – Flora and Vegetation of Asian Russia 2023 number 4

For the first time, an algological study of Lake Nogaan-Khol, located in the Todzha basin of the Republic of Tyva, was carried out. The results of phytoplankton, phytobenthos and fouling are presented. A comprehensive study and identification of species composition is relevant not only from the point of view of biodiversity inventory, but for the most efficient use and protection of water bodies. 218 species, varieties and forms of algae were identified in the reservoir, belonging to 94 genera, 52 families and 8 divisions: Cyanoprokaryota (33), Bacillariophyta (124), Chrysophyta (1), Dinophyta (3), Xanthophyta (1), Euglenophyta (2), Chlorophyta (24), Charophyta (30). To assess the role of individual taxa, the frequency of occurrence was calculated. 4 groups were distinguished - especially active (with a frequency of occurrence over 75 %), highly active (74-45 %), inactive (44-15 %) and inactive (less than 15 %). The dominant complex is represented by a small set of species. Fouling groups on various substrates and benthic communities are considered. An ecogeographical analysis was carried out, according to which the algoflora is represented by benthic (33.9 %) and periphytonic (25.2 %) species, with a predominance of indifferent (70.2 %) forms in relation to the halicity and active reaction of the environment (48.2 %). In the studied lake, 152 species-indicators of saprobity were identified. Marked indicators of all zones of saprobity, except for polysaprobic. Inhabitants of very clean (x - xenosaprobe) and highly saprobic (a - mesosaprobe) waters are represented by a small number of taxa - 5 and 6, respectively. Geographically, cosmopolitans (54.1 %) and boreal (26.6 %) species dominated. The purpose of the study was to determine the species composition and ecological state of the waters of the Nogaan-Khol lake.