On aquatic macrophytes in the ultracontinental climate conditions of the Upper Indigirka River

Abstract

The first results of the study of aquatic macrophytes of the Upper Indigirka River area are presented. The species composition includes ~84 species (~74 vascular plants and more than 10 cryptogamous macrophytes). 47 water bodies of different age, size and origin (tectonic, glacial, river, thermokarst and artificial) were studied. For each type of water bodies, the main ecological characteristics, features of the species composition and vegetation cover are given. The most common type of water bodies of the territory is thermokarst, and the greatest floristic diversity (54 species of macrophytes) is found here. There are 40 species in tectonic lakes, 37 - in rivers lakes, 35 - in glacial lakes, the lowest diversity was for small artificial waterbodies. For the Oimyakon District, new records of protected species are reported: macroalga Tolypella canadensis, vascular plants Isoetes echinospora, Nuphar pumila, Nymphaea tetragona (common and its rare pink-flowered form) and Subularia aquatica. Possible consequences for aquatic ecosystems while maintaining current trends in climate change (increase in average annual temperature, shift to earlier periods of spring warmth, changes in the amount and distribution of precipitation, depth of seasonal thawing of soils) leading to degradation of permafrost and their impact on the biodiversity of aquatic macrophytes in the region are discussed. The most vulnerable aquatic ecosystems of the Oimyakon Highlands are the mature thermokarst lakes.