Ecological Strategies of Soil Microbial Communities under Plants of Meadow Ecosystems

Abstract

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. The dependence of the dominant ecological strategy of rhizosphere microbial community on vegetation stage of plants has been traced. The effect of plant species on the growth strategies of rhizosphere microorganisms was studied. It was found that the features of the K strategy are manifested more strongly in the series of rhizosphere microbial communities of grasses at the same stage of development: r strategy--Bromopsis inermis L.--Poa pratensis L., P. compressa L.--Dactylis glomerata L.--Festuca pratensis L.--K strategy. In the absence of limitation by climatic factors, the growth strategies of rhizosphere microorganisms are determined by the competition between microorganisms and plants for substrate.