Dynamics of Chemical and Microbiological Soil Properties in the Desert–Steppe Zone of the Southeast Russian Plain during the Second Part of the Holocene (4000 BC–XIII century AC)

Abstract

The results of studies of the chemical and microbiological properties of the soils buried under the barrows of the Eneolithic, Bronze, and Middle Ages periods of the southeast of the Russian Plain are presented. It was shown that the climate of the region in the Eneolithic period (4200–4100 BC) and in the Middle Ages (700 years ago) was more humid in comparison to the present time. The third millennium BC was characterized by a gradual increase of the climate aridity. Its peak was at the end of the III millennium BC. The number and biomass of microbial cells was maximal in soils buried in periods of high atmospheric humidity (4200–4100 and 3000–2800 BC) and sharply decreased during the aridization period in the second half of the III millennium BC. In general, the variability of indicators of microbocenosis conditions of desert–steppe buried soils of all ages from the burial mounds correlated with the centuries-old dynamics of the climate.