Microbial communities in the paleosols of archaeological monuments in the desert-steppe zone

Microbial communities in modern soils of solonetzic complex and in the paleosols under burial mounds were studied in the Ergeni Upland (the desert-steppe part of the Volga-Don Interfluve). The total biomass of microorganisms, their respiration activity, the proportions between the microorganisms of different trophic groups, and the number of fungal CFU were determined in the profiles of buried light chestnut soil (K1) and solonetz (Sn) developed in the region in the 4th century AD. After soil burying (1650 years BP), significant changes in microbiological parameters took place in the Al horizon (for KI and Sn) and B1 horizon (for K1). Diagenetic changes in the B2 horizon of studied paleosols were minimal. The biomass and, as a rule, the respiration activity of buried paleosols were found to be approximately equal to those in modern soils. The proportions between populations of microorganisms from different trophic groups significantly differed in B2 horizons of modern and buried soils. For the first time, the possibility of using soil microbiological parameters to reconstruct paleoenvironmental conditions was proved. The end of the Late Sarmatian time (the 4th century AD) was found to have better environmental conditions compared to the present time.