Soil Carbon and Nitrogen, and Characteristics of Soil Active Layer in Siberian Permafrost Region

Abstract

Permafrost region of Siberia is mostly covered with larch forest or forest tundra. The permafrost-affected soils were generally classified as Cambisols (moderately developed soils) on plain topography and Leptosols (shallow and high gravel content soils) in mountainous topography (FAO 1993). The latest revision of soil classification systems of both USDA and FAO adopted permafrost as a diagnostic horizon, and created a new “soil order” (USDA) or a “main soil” (FAO) for permafrost-affected soils: Gelisols in the USDA classification system (Soil Survey Staff 1998), Cryosols in the FAO system (ISSS Working Group RB 1998), and Cryozems in the Russian system (V. V. Dokuchaev Soil Science Institute 2001; Naumov Ye 2004; Sokolov et al. 2004). There had been a few soil survey expeditions to the permafrost region of Siberia (e.g., Ivanova 1969), but most studies in the former Soviet Union focused on examination of podzolisation and humus chemistry. The results were published nearly exclusively in Russian language and were expressed in organic matter concentrations, not in carbon contents. No map coordinate data were generally available for the survey points in the literature. Though Alexeyev and Birdsey (1998) compiled soil carbon storage data for administrative unit of Russia, there were still uncertainties in soil bulk density, rock fragment ratio, fine earth content, etc. These are disadvantages of the available information if they are to be used in discussions of carbon or nutrient storage and dynamics.