THE CURRENT STATE OF ANTHROPOGENICALLY DISTURBED MIRES IN THE SOUTH OF THE TOMSK REGION

Abstract

The condition of drained and partially worked-out in 1970-1980 mires of the Tomsk region was comprehensively assessed using the example of three key sites (Tagan, Kargalinskoye, Porotnikovskoye). We evaluated the state and dynamics of vegetation cover, transformation of the hydrophysical properties of peat deposits, and the chemical composition of peat and mire waters. Data from field and laboratory studies conducted in 2023, multi-time satellite images, and archival maps were used. The research has revealed a high degree of vegetation transformation in all of the studied sites, occurring in mire areas directly exposed to drainage and peat extraction as well as in adjacent parts of mires outside the drainage network, and expressed in increasing afforestation of mires, replacement of mire species with forest and meadow ones. The worked-out areas are abandoned lands covered with an open water surface (peat excavation pits) or occupied by thickets of trees and shrubs on a residual layer of peat with low water content, which are therefore characterized by a high fire hazard. An exception is the Tagan mire, where intensive suburban development is currently taking place on one of the worked-out sites. The transformation of the upper layers of the peat deposit is manifested in an increase in ash content, density, and degree of decomposition, and a decrease in water content. The modern accumulation of peatis noted only at the pristine plot of the Porotnikovsky mire. As a result of the decrease in the level of mire waters, thereis noted an increase in N-NH4+ and N-NO3- concentrations in peat, an increase in Fetotal and NH4+ content, and a decreasein NO3– and Corg in mire waters, which is the result of mineralization of the upper layers of the peat deposit.