The role of the Ob-Irtysh valley in the dynamics and evolution of the soil-earth materials factor of taiga-plain landscape is considered. The study demonstrates the mechanisms of operation of the soil-earth materials factor that is responsible for the formation of zonal forest facies along the valley which undergo swamping at the final stage of their functioning. The progressive development of this regional process leads to marked changes of the biogeochemical situation, and to a deterioration of habitat quality. The problem is complicated by technogenic impacts on the landscape sphere of the oil and gas production complex of Western Siberia.