Microbiological Study of Paleosols Buried under Kurgans in the Desert-Steppe Zone of the Volga-Don Interfluve

摘要

Microbiological studies of paleosols buried under kurgans of the Bronze and Early Iron ages (5000-1600 years BP) and the background light chestnut soil have been conducted.It is found that the microbial bio-mass of buried paleosols varies from 20 to 42 ug C-CO2/g soil,increasing to 59 (j.g C-CO2 in the modern surface soil.The trophic structure of microbial communities in the soils of different historical epochs changes significantly.Thus,the portion of microorganisms utilizing dispersed nutrients varies from 21 to 58%; the portion of microorganisms consuming humic substances,from 18 to 36%; and the portion of microorganisms consuming plant remains,from 23 to 61%.Microbiological,morphological,and chemical data on buried paleosols make it possible to reconstruct the paleoclimatic conditions in the studied area.It is shown that periods of increased climatic moistening took place in the end of the fourth millennium BC and in the fourth century AD; some humidization of the climate also took place in the first quarter of the second millennium BC.