Pyotr Alexandrovich Kozhevin

The possibility of using microbiological indicators of soil «health» to assess the soils. The fundamental possibility of quantitative characterization of the functional potential of the microbial system with the assessment of «ecological services» is shown. Th ermodynamic criteria of natural microbial system (exergy and specifi c exergy) allow to carry out diagnostics of soil condition with direct estimation of degradation and damage. System characteristics of soil microbiota allow to approach the solution of many topical problems of functional soil science.

Despite the significant role of the black garden ant (Lasius niger) in soil formation processes, the seasonal dynamics of microbial biomass in its nests and adjacent urban soils remains poorly understood. The relevance of this study is related to the need to assess the contribution of L. niger to the biological activity of soils under anthropogenic stress. The study is aimed at analyzing the dynamics of microbial biomass and its activity in the nests of L. niger ants and the surrounding urban soils during the growing season. In this work, methods of luminescent microscopy were used to estimate the total number of microorganisms and the dynamics of its changes during the growing season, as well as the method of multisubstrate testing to determine the functional diversity of microbial communities and methods of mathematical statistics. In the studied urban soils, there was a significant decrease in the proportion of fungal and an increase in the proportion of bacterial components in microbial biomass compared to zonal soils. The predominance of fungal cells (spores and yeast cells) was recorded in the fungal biomass, while their maximum number and minimum biomass of fungal mycelium were noted at the end of the growing season. The effect of L. niger ants on the composition of microbial biomass in the soil was manifested in an increase in the length of the fungal mycelium and bacterial biomass reserves compared with the control. The influence of anthropogenic stress on the structure of microbial biomass in anthills is more pronounced than in control soils. The nesting activity of ants had a significant impact on the functional parameters of microbial communities formed in the soil. The material of the anthills showed a change in the spectrum of organic substrates consumed by the microbial complex and the rate of their consumption compared to the control soils. It was found that microbial communities less climactic than in the soil form in anthills in areas with the lowest anthropogenic load, which may be due to a more intense foraging activity of insects in these areas. It should be noted that the stability index (d) of microbial complexes in anthills showed less variability during the growing season than in the same indicator in soils.