Microbial succession in soils of the Okskii Reserve

The amounts of dry microbial biomass in five biogeocenoses of the Okskii Re serve have been determined. They can be as high as several tens of tons per hectare. The biomass of eukaryotic organisms significantly exceeds the bio mass of prokaryotic organisms. Every soil type is characterized by a certai n pool of microbial biomass and specific patterns of its spatial (in the ve rtical profile of soil) and temporal (seasonal changes) distribution. Soil fungi predominate in the microbial biomass and are represented mostly by my celium and not by spores. The character of seasonal changes in the total po ol of microbial biomass and in the proportions between different groups of microorganisms depends on the soil moisture content and soil texture that p redetermine the water permeability of soils. The number of fungi depends on season. Forest litters and sod horizons of flood-plain soils are character ized by the highest values of microbial biomass and species diversity.