The number of microorganisms and the microbiological activity of human-modified cryogenic pale soils of Yakutia

Abstract

Specific features of the microbial population—the high number of all the groups of microorganisms (1.6 × 103–3.5 × 107) similar to their abundance in steppe soils of the Transbaikal region and the distribution of microorganisms along the soil profile (without a decrease in their number with depth)—were revealed in a cryogenic weakly solodized loamy sandy pale soil. Unlike the soils of the Transbaikal region and central Russia, where bacteria, as a rule, are accumulated in the litter and upper soil horizons, in the undisturbed and weakly disturbed soils of Yakutia, the number of microorganisms is rather high within the whole soil profile. In the strongly disturbed agropale soil of croplands, the distribution of microorganisms is the same as in the soils of the Transbaikal region and European Russia. In the cryogenic soils studied, actinomycetes predominated, and their number varied from 47 000 to 35 000 000 CFU/g of soil. The number of microorganisms positively (r = 1) correlated with the soil moisture.