The biomass of microbial communities in different types of alluvial soils in the upper reaches of the Selenga River delta

The biomass of several groups of microbial communities occurring in three types of alluvial soils in the upper reaches of the Selenga River delta near the village of Murzino, Kabanskii district, Buryat Republic was studied. The general tendency in the dynamics of the biomass of the dominant groups of microorganisms in drought summer-autumn period of 2005 was revealed. The bacterial complex predominated at the beginning of July; actinomycete and spore-fungal complexes, at the end of August; and spore-fungal and actinomycete complexes, at the beginning of October. In the alluvial sod soil, the actinomycete mycelium biomass was dominant in July, which was caused by more droughty conditions in this facies because it is located at a higher elevation above the river level than other facies.