Cartographic Estimation of the Structure of Organic Carbon Stocks in Soils of Russia

New spatially distributed estimations of background (potential) organic carbon stocks in the 30-, 50-, and 100-cm layers of Russian soils (total and individual for mineral and organic horizons) are obtained. The maps are calculated, using a developed software package that operates within the Information System “Soil-Geographical Database of Russia” and enables the calculation of carbon stocks in a soil layer of a specified thickness for real profiles, which represent the complete natural diversity of Russian soils. The algorithm for mapping different soil organic carbon pools has been developed with the account of the soil cover composition of polygons on the Soil Map of Russia. Carbon stocks in the 30-, 50-, and 100-cm soil layers are estimated at 186, 251, and 348 Gt, and the proportions of organic horizons with the organic matter content more than 15% comprise 50, 44, and 42% of them, respectively. Carbon stocks calculated, using the dominant soil of a map polygon or taking into account associated soils, differ only by a few percent for the entire territory of Russia. The consideration of associated soils in particular areas may result in a decrease in estimates by 10–45% (primarily in mountainous regions) or in their increase by 10–100% (usually in swampy plains). The account of the soil cover composition in the calculations results in the change in estimates in almost a half (45%) of the area of Russia. The verification of spatially distributed estimates of the structure of organic carbon stocks in the soil cover enables us to consider regional characteristics in strategic planning of the area development.