CHANGES IN MACROPHYTE MYCODESTRUCTOR COMPLEXES IN URBAN WATER BODY (YAROSLAVL, RUSSIA)

The results of mycodestructors on dead fragments of common reeds and river horsetail study in a small lake-type reservoir in 1998–1999 and 2021–2022 are presented. The method of accumulative culture in 1998–1999 recorded 18 species on reeds (8 Ascomycota teleomorphs, 6 mitospore, 4 Oomycota), 12 species on horsetails (1 Blastocladiomycota, 1 Ascomycota teleomorphs, 3 mitospore, 7 Oomycota). True aquatic (Hymenoscyphus albidus, Massarina fluviatilis, M. phragmiticola, Mollisia hydrophila) and capable of developing teleomorphs and anamorphs of ascomycetes in water have been identified. Mycobiota corresponded to the mesotrophic type of reservoir. In 2021–2022, 4 species were recorded on the reed, 5 – on the horsetail. Fungi-like oomycetes dominated, from genera Pythium and Saprolegnia, they are able to develop in reservoirs with a high concentration of dissolved organic matter and with stand a contaminated environment. Over two decades, according to mycological indicators, the lake changed the trophic status of mesotrophic to eutrophic, which corresponds to eutrophic type of overgrown reservoir with antropogenic pollution.