CHANGE IN BIOLOGICAL ACTIVITY OF SOIL IN THE PROCESS OF PINERY NATURAL REGENERATION

Abstract

Introduction. The use of biological activity of soil as an indicator of environmental control is relevant when addressing general theoretical and practical tasks: mechanism of forest biogeo-cenosis recovery as related to the new edaphic conditions and optimisation of soil microbiota. The work aims to research into the changes of biological activity of soil in the process of the natural recovery of the forest community. Materials and methods. The research was carried out in the buffer zone of Kivach State Nature Reserve located in middle subzone of European taiga in Karelia. Within a long-term model experiment we researched into the biological activity of soil, developed as a result of natural pine-wood regeneration (30% sampling followed by clear cutting). Environmental control was imposed on undisturbed 65 year old myrtillus pinery. Soil was represented by illuvial ferriferous sandy podzol formed on glacial silts. Soil evaluation on transformed forest ecosystems was carried out based on the analysis of structural and functional organization of microbiota. Evaluation of microbial abundance of various functional groups as well as trophic and taxonomic structure of microbiota was carried out by means of laboratory-based seeding method in selective nutrient medium as well as by field application. Results. As a result of research we defined the changes in quantity and contents of microorganisms pertaining to important environmental-trophic groups, soil enzyme activity (catalase, urease, protease) exposed to various degree of clear-felling. In the model field experiment we revealed velocity variations of cellulose bed mineralization in soil. Sensitivity and information capacity of microbiological indicators as related to anthropogenic impact can be used as a biological indicator of the natural environment condition. It is deemed necessary to establish a system for continuous microbiological monitoring of anthropogenically disturbed soil at different stages of forest regeneration.