[Effect of emissions from a copper-nickel plant on soil microbial communities in forest biogeocenoses of the Kola Peninsula].

The effect of industrial pollution with emissions from the Severonikel Copper-Nickel Plant (SCNP) on soil microbial communities of forest biogeocenoses has been studied taking into account their relative location under tree crowns (near the stem, in the undercrown area, or under gaps in the canopy). The results show that increasing technogenic pollution results in a significant decrease in the microbial biomass, basal respiration, and maximum specific growth rate, as well as in dominance of K-strategists in the microbial communities of polluted soils. The effect of location under the crown, compared to the intercrown area, manifests itself in dominance of rapidly growing microorganisms with the r-strategy.

[Microbial biomass and growth kinetics of microorganisms in chernozem soils under different farm land use modes].

The carbon content of microbial biomass and the kinetic characteristics of microbial respiration response to substrate introduction have been estimated for chernozem soils of different farm lands: arable lands used for 10, 46, and 76 years, mowed fallow land, non-mowed fallow land, and woodland. Microbial biomass and the content of microbial carbon in humus (Cmic/Corg) decreased in the following order: soils under forest cenoses-mowed fallow land-10-year arable land-46- and 75-year arable land. The amount of microbial carbon in the long-plowed horizon was 40% of its content in the upper horizon of non-mowed fallow land.

[The antibiotic-aided separation of fungal and bacterial substrate-induced respiration in various soil ecosystems].

Fungal and bacterial substrate-induced respiratory activities have been distinguished in gray forest and chestnut soils in various ecosystems (forest, grassland, tillage, unused land, and shelterbelt) using the antibiotics cycloheximide and streptomycin. The optimal inhibitory concentrations of the antibiotics, added separately and in combination; the preincubation time of the antibiotics with the soil before glucose addition; and the mass of added inert material (talc) have been determined. Based on the results obtained, the inhibitor additivity ratio (IAR) has been calculated for the antibiotics.

[Ecological strategies of soil microbial communities under plants of meadow ecosystems].

Dominant growth strategies of soil microbial communities of mown and unmown meadows were assessed with respect to the constants of saturation and maximal specific growth rate of microorganisms. The microbial community of mown-meadow soil was characterized by a greater biomass and activity due to prevalence of microorganisms with the r strategy, compared to the microbial community of unmown-meadow soil. In contrast to nonrhizosphere soil, rhizosphere soil was dominated by rapidly growing microorganisms with the r strategy.