Hydrobiological parameters of tributaries of the Vychegda river basin in different units of landscape division

The diversity of natural conditions of landscape complexes, differences in the geological structure and relief of the catchment areas of the Vychegda river basin are the basis for the formation of the main hydrobiological characteristics of its tributaries. To differentiate small and medium-sized tributaries of the Vychegda River, it was proposed to use zoning based on differences in the structure of the geological foundation, geomorphology, modern relief, soil-forming rocks and vegetation cover. The results of segmentation of Landsat image mosaic were used to analyze the distribution features of dominant terrestrial ecosystems within the basin. The results of hydrobiological and hydrochemical observations on 59 small and medium-sized rivers within the selected landscape complexes of the Luzhsko-Vychegodsky and Vychegodsko-Mezensky plains and the Timansky ridge were presented. A review of the results of long-term hydrobiological observations on watercourses of the Vychegda River basin with hydrochemical and biological characteristics of plankton and bottom communities was given. It was stated that the landscape confinement of small and medium-sized tributaries of the Vychegda River determined the characteristics of water communities. Ordination of the results of measurements of the number and mass of benthos by the method of multidimensional non-metric scaling (NMDS) showed the presence and formation of polar cores in terms of total population and biomass for the Vychegodsko-Mezensky and Timansky landscape areas. An intermediate position is occupied by the group of the Luzsko-Vychegodsky plain. The variety of environmental conditions of small and medium-sized watercourses caused mutual "penetrations" and the blurred nature of the selected groups. There was no pronounced differentiation found for the zooplankton characteristics.