Transformation of the soil organic matter under the extreme pollution by emissions of the Severonikel smelter

The direct impact of the long-term extreme pollution by emissions of the Severonikel copper-nickel processing plant per se is not capable of inhibiting the organic matter transformation even within the local zone of this enterprise. However, a great number of indirect pollution factors can affect the organic matter content and the composition of the soils in the local zone. The destruction of the vegetation and the changes in the amount and botanical composition of the falloff influence the soil humus status to the greatest extent. As fresh falloff is absent, the old (formerly accumulated) organic matter of the soils is gradually mineralized, and its content decreases. In the most damaged ecosystems of the local zone, the soils have lost almost all their organic matter, and their properties are returning to those of the initial parent rock. The disturbance of the water regime of some ecosystems and of the whole landscape intensifies the migration of substances within the soil profiles and in the whole landscape. This is the second by significance factor affecting the humus status of the soils in the local zone. The transformation of the organic soil profiles under the influence of the indirect factors is sufficient to change their taxonomic position at the level of subtypes or type.