Ecosystem services of soil microorganisms and microbiological component condition assessment of the quarry Pechurki.

Abstract

The obligatory component of any biogeocenosis is soil microorganisms, which perform a number of cruical metabolic and ecophysiological functions. They participate in plant cover recovery and in circulation of elements, promote maintaining of soil fertility and regulate parts of humification. The prime role of soil biota in a root delivery of plants consists in returning nutrients to their mineral forms, which plants can take up again. Soil microorganisms are shown to influence acid-base balance stabilization and transformation of root exudates. The decrease of toxic substances negative consequences level on biogeocenoses components was also established. Soil formation criterion is the biological soils condition which is estimated on microbiological activity. In stability maintaining of communities and ecosystems development an important role is played by a condition of replantozem microbiocenoses though it has not been studied. It is relevant to study the microbiological component condition at the technogenic habitats. The aim of this research was to assess the quantitative maintenance of a microbial component and its activity in the quarry Pechurki. The microbial biomass content varied from 0,98 to 4,6 microg C/g of the soil, values increase with overgrowing term. In Cmik value the studied samples can be arranged in this row: underlay> organomineral horizon> rock. Values of the microbial metabolic coefficient was not higher than 0,021 microg СO2–С/mg Сmic per hour, what is showing an instable functioning of microbial societies. Thus the restitution of microbiological activity of disturbed lands is slowed down considerably and does not depend on the type of substrate and the plant community. The received results shown the low stability of microbial societies and the ineffectiveness of using the organic substrate, especially in the first stage of quarry overgrowing. In order to analyze succession of soil microbial communities investigation of metagenomics of soil samples has been conducted. Taxonomic analysis of communities at the phyla level did not reveal differences between different age dumps. In all cases, the largest phyla was the Proteobacteria (55.7%), Actinobacteria (17.0%), Bacteroidetes (10.3%), Acidobacteria (6.4%), and Chloroflexi (3.8%). The dominant taxa in young dumps were Acinetobacter (8.8% of the total community), Micrococcaceae (8%) and Pseudomonas (6%). In the middle-aged dumps, representatives of Micrococcaceae (4.5%) and Sphingomonadaceae (1.4%) prevailed. Old age dumps showed a high proportion of representatives of Bradyrhizobiaceae (5%), Chitinophagaceae (2.9%) and Hyphomicrobiaceae (2.5%) in the community. This work was supported by Russian Scientific Foundation, project № 17-16-01030 “Soil biota dynamics in chronoseries of posttechnogenic landscapes: analyses of soil-ecological effectiveness of ecosystems restoration”