Cryosols are widespread in the northern and central regions of western Siberia, from 73°30′ to 62° N latitude, where they formed under a vast spectrum of conditions, from tundra to taiga, including swampy areas (Figure 2.8.1). Between 62° and 60° N latitude, these soils occur only within the coldest ecotopes of forest areas. The features, diversity, and geography of Cryosols depend on both recent and paleoclimatic factors that control the presence and properties of permafrost (temperature, content of ice, depth, and water and heat regimes of the active layer).