THE EFFECT OF DRYING-MOISTENING AND FREEZING-THAWING ON SOIL MICROBIAL COMMUNITIES RESILIENCE

The effect of drying-moistening and freezing-thawing on the microbiolo gical activity of gray forest soil under three cenoses (forest, meadow , and plowland) was investigated. The following indices of activity we re studied: rates of basal (V-b) and substratum-induced respiration (V -SIR), and coefficient of microbial respiration (Q(R); Q(R) = V-b/V-SI R). It was shown that the coefficient of microbial respiration display ed rather high sensitivity, and could be used to quantify the resilien ce of the microbial community. Thawing of the frozen soil induced a st ronger effect on the stability of microbial communities than moistenin g of the dry soil.