Photosynthetic activity of plankton in saline lakes under climatic fluctuations conditions

Abstract

Climate change causes the alternation of high-water and low-water years, which is reflected in morphometric characteristics of lakes. Changes in the depth and volume of water bodies affect the structural and functional activity of the ecosystem, including the growth and development of primary producers. The photosynthetic activity of water body plankton was shown on the example of Dabasa-nor lake and Kudzhertai lake located in the steppe territory of the South-Eastern Transbaikalia. The studied lakes differ in their hydrochemical composition. The content of chlorophyllain Dabasa-nor lake is lower than in Kudzhertai lake. Degraded form of chlorophylla- pheophytin is present only in Dabasa-nor lake, which currently has the least depth of its filling. Carotenoids, as more stable forms of pigments, dominate in the pigment diversity of lake plankton. Chlorophyllcwas not detected in any of the plankton of both lakes. Factor analysis of the main components showed the interdependence of a number of abiotic agents with the pigment characteristic of phytoplankton. Thus, under the current conditions of the period of lake water availability recovery after a long dry period, the photosynthetic activity of the water body ecosystem is experiencing certain difficulties.