Post-pyrogenic changes in the properties of grey forest podzolic soils of ecogeosystems of pine forests under conditions of anthropogenicloading

Abstract

This article presents the analysis of results of experimental data of postpyrogenic change of soils of ecological systems of pine forests.Ground fires transform the surface organogenic horizons of soils. The negative influence of low-intensity fires of different intensity on the change of humus stock, qualitative fractional composition of organogenic soil horizons and their chemical composition is shown.Post-pyrogenic transformations of physical and chemical soil characteristics are found, which are not simply their corresponding reaction to the pyrogenic effect, but a clear signal reflecting the state of the soil immediately after the fire, taking into account its strength and intensity, and after a certain period of time. There is a certain dependence of the degree of pyrogenicity on the duration of the effect of fire on the soil. The recent influence of a medium intensity fire on the soil is marked by a clear reaction of the complex of its properties.Physical and chemical properties of soils after fires deteriorate: humus burns, the content of nitrate nitrogen decreases.Forest fires sharply change the morphological state of the upper part of the soil profile. The nature of the surface horizons of soils changes, a new pyrogenic horizon is formed, which differs from natural analogues in terms of physical and chemical properties and the content of ash elements. Under the influence of fire there are changes in such properties as: pH, content of exchange cations, gross and moving forms of nitrogen, etc.The heavy metal concentration in surface horizons increases several times and exceeds the background values due to the mineralization of forest litter and herbaceous vegetation from the combustion and subsequent migration of chemical elements , which presents an environmental hazard.The change in the chemical composition of soils can create conditions for the impossibility of the existence of a root ecosystem, its death, and development, after a certain time, of another modified ecogeosystem.