Diatoms of surface bottom sediments of lakes in Mongolia

Abstract

This paper presents data on lake sediments that were selected from 5 lakes in Mongolia (10 points); the lakes are located at different absolute elevations above sea level. The purpose of this work is to study diatoms from surface bottom sediments (0-2 cm). In addition, the morphometric and physicochemical characteristics of the water in these lakes were studied. The water of the studied lakes was mainly ultra-fresh (40% of the lakes), the remaining 60% had fresh, slightly fresh and salt water (20% each). Such morphometric parameters as the area of the water surface, the length and width of the lake, the average width, the maximum depth and others were studied. As a result of studying the composition of diatoms, 111 species were identified that belong to 3 classes of Bacillariophyta. In terms of the number of species discovered, Lake Boon-Tsagan-Nuur turned out to be the richest. 10 species are classified as dominants, among them Staurosira venter can be distinguished; among the common species, Pseudostaurosira brevistriata stands out, which is dominant and subdominant in 5 samples; Stephanocyclus meneghinianus, Lindavia radiosa - dominants and subdominants in 4 samples. The diatom flora of the studied reservoirs shows that bottom forms predominate in the lakes.