Changes of soil organic matter stock in meadow ecosystems in the south of Western Siberia

Abstract

The study was conducted on the Baraba plain in the southern part of Western Siberia. Soil samples in meadow ecosystems that are at different stages of succession after drying of the lake bottom were analyzed. The conducted research allowed us to establish that the content of soil organic matter and microbial biomass (the active part of soil organic matter) in successional ecosystems formed in the floodplain of the drying salt lake gradually increases and in the last stages of development reaches the values of zonal chernozem soils. The process of accumulation of carbon stocks of humus and microbial biomass slows down against the background of a high concentration of salts in individual horizons of young soil profiles. This may be the reason for the revealed pattern, according to which the main carbon stock of humus and microbial biomass are concentrated in the upper (0-10 cm) layer of the emerging soils. This is especially noticeable at the very first initial stage of soil development and the next stage of the salicornia community (Salicornia perennans). In the last stages of succession, solonetz and chernozem-meadow soils are formed under meadow ecosystems. The carbon stock of humus and microbial biomass at these stages of soil development significantly increase against the background of active processes of reducing the amount of salts in the profiles of meadow soils. And only at these last stages there is a significant increase in carbon stocks of humus and microbial biomass in a layer of 10-20 cm.