DEVELOPMENT OF FLOATING KARST MIRES IN THE NORTH-EASTERN PART OF THE MIDDLE RUSSIAN UPLAND, AND CARBON ACCUMULATION IN PEAT DEPOSITS

Abstract

The floating karst mires are unique natural ecosystems of the Middle Russian Upland, since they are habitats of rare species and communities in the region with low paludification (0.5%), and also participate in the deposition of atmospheric carbon. The study of the genesis of the floating karst mires will allow to develop approaches to their conservation. The purpose of this work is to identify the features of development and to estimate the intensity of carbon accumulation in the peat deposits of the floating mires of the Middle Russian Upland. The objects of the study were the mires Glavnoe and Kochaki-1, located in the north-eastern part of the Middle Russian Upland. To identify the genesis of the mires, the peat deposits were drilled and the botanical composition of peat was studied. The carbon content (%) was determined in peat samples and the rate of carbon accumulation by mire paleocenoses was calculated. The conducted studies have revealed different types of paludification in karst depressions, accompanied by the formation of a float, depending on a hydrological regime. It is shown that the most active vertical growth of peat deposits occurs in conditions of high moisture content of mire biotopes. This contributes to the maximum accumulation of atmospheric carbon by mire paleocommunities (up to 79.3–125 gC/m2/year). The highest carbon deposition rates are characteristic of the sphagnum and herb-sphagnum paleocenoses (up to 151–305 gC/m2/year) formed on the floats in the second half of the Subatlantic Holocene period. The results obtained indicate the diversity of the genesis of the floating mires and characterize these ecosystems as a “depot” of atmospheric carbon.