Features of microorganism distribution in the Al-Fe-humus podzol of the northern-taiga spruce forests: natural and technogenic aspects

Abstract

Natural and anthropogenically induced seasonal variations in the abundance and biomass of various groups of microorganisms in the Al-Fe-humus podzols of boreal spruce forests were analyzed. The fungal biomass in these soils was found to be considerably higher than the bacterial biomass. Microbial population was mainly concentrated in a thin surface layer (10-15 cm in thickness), which included the forest litter and the upper mineral root-inhabited soil horizon and greatly differed from other soil horizons in morphology and other properties. This layer was found to be optimal with respect to hydrothermal and nutritional conditions and was characterized by profound seasonal variations in the abundance and biomass of microbiota. The high acidity, typical of the Al-Fe-humus podzols, resulted from the metabolism of their microbial communities. In the polluted podzols, the population of prokaryotes increased and that of eukaryotes decreased.