ИСТИНА

Digital map of organic carbon stock in 30-cm soil layer of Russia was created for GSOC-17 FAO project. Our objective was developing and testing algorithms for soil organic carbon (SOC) mapping on the basis of information accumulated in the Information System “Soil-Geographic Database of Russia”, i.e. vectorized different-scale soil maps, analytical characteristics of reference profiles and attribute data from regular monitoring surveys. Calculation of main SOC map performed in the form of synthesis of two types of source data: a map of the entire territory of the Russian Federation based on the Soil Map of RSFSR (ed. V.M. Fridland, 1988) at the scale of 1:2.5 M combined with sparse and irregular grid of about 2000 soil profiles and maps of separate agricultural areas based on the large- and medium-scale soil maps and a dense grid of regular soil observations. Both maps were merged into one grid. The SOC map for litter is calculated on the base of previously published map adapted to the GSOC17 requirements. The SOC map for duff and peaty litter horizons of semi-hydromorphic soils was calculated by using the averaged expert estimations of bulk density values. The final version of the SOC map of Russia is a per pixel sum of above maps. Our calculations indicate that the total carbon stock in 30-cm soil layer of Russia is about 150 Pg, and nearly half of these stocks (45%) are concentrated in organogenic horizons.