Multidimensional Statistical Analysis of the Structure of Plankton and Bottom Communities of Mineralized Rivers of the Lake Elton Basin

Abstract
The paper presents the results of our comprehensive studies of the saline rivers of the arid Prieltonie region based on hydrobiological surveys of plankton and bottom communities. We have compared two tables of the specific structure according to the results of observations at 13 river sites in 2013 and 2018, which included the numbers of hydrobionts of 94 different taxonomic groups of macrozoobenthos, meiobenthos and zooplankton. Using the method of joint inertia analysis, we have revealed a high statistical consistency of the data matrices, due to objective laws of the spatial distribution of aquatic organisms. A randomization test of the Procrustean correlation coefficient showed the statistical significance (p = 0.00026) of the conjugacy of both specific structures in the space of latent variables. At the same time, a certain trend was noted in the changes in the taxonomic composition of communities at individual stations over time under the conditions of dynamic abiotic factors. We have analyzed the dependence of the taxonomic structure of hydrobionts on a set of 30 abiotic environmental factors obtained during hydrobiological and hydrochemical monitoring of the studied river sections. Using canonical correlation analysis and the projection method on latent structures, a set of ordination diagrams was plotted to allow revealing peculiar “ecological niches” for each group of species with a certain set of characteristics of their biotopes. The plankton and bottom communities were shown to correlate quite well with each other, which indicates a close relationship between them, due to both biotic interactions and a mutually agreed response to changes in aquatic factors.