METHANE CONCENTRATION AND EMISSION IN VARIOUS TYPES OF SOILS OF THE ROSTOV REGION
The results of measurements of methane concentrations in various types of soils of the Rostov region and their flows into the atmosphere are analyzed. The rate of methane emission from the soil surface varied in the range of 0.000-0.136 mg CH4 m-2h-1 and was closely correlated with its concentrations in soils (r = 0.85). The maximum speeds of methane flows are characteristic of periodically flooded soils sampled in reed beds in the floodplain of the Tsimlyansk reservoir, and for man-made soils in the landfills of mines. The methane flow into the atmosphere on chestnut soils of arable land was absent, and its minimal concentration was recorded (0.005 µg/g). In descending order of the average velocity of methane flows into the atmosphere, the studied soiltypes are arranged as follows: alluvial (floodplain) soils periodically flooded with water (0.134 mg CH4 m-2h-1), > ordinary chernozem (0.055 mg CH4 m-2h-1) > alluvial meadow-chernozem soils (0.037 mg CH4 m-2h-1) > chestnut soils (0.033 mg CH4 m-2h-1). According to approximate estimates, the total methane emission from the soil surface of the Rostov region ranges from 46.1 to 193.6 tons per day or from 9675 to 40663 tons per year, which indicates their significant contribution (from 3.0 to 12.7 %) to the total methane emission by natural and anthropogenic sources of the Rostov region.