On ecosystem functions of the technozem humusogenic layer in the remote period of soiling of coal mining waste dumps in Siberia

Abstract

People strove for creating productive soils to increase the yield of cultivated crops since prehistoric times. Currently, restoration of soil properties is relevant for areas affected by mining. In Siberia, long-term coal mining has led to significant destruction of the soil cover, accumulation of overburden and host rocks on the daytime surface. This initiated the search for resource-saving technologies to compensate for soil losses, including methods of formation of artificial soil-like bodies with a deposited fertile layer for subsequent agricultural use. This article presents the results of a study of physicochemical and microbiological properties of the humus-accumulative layer after 40 years of man-made wasteland soiling in three natural zones (sub-taiga, forest-steppe, dry-steppe) in order to characterize the ecosystem functions that ensure fertility. It was established that the humus layer of perennial technogenic soils (technozems) has ecosystem functions of background soils, however, in the forest-steppe and dry-steppe zones it shows signs of decreased resistance to elevated pH, increased ecotoxicants, reduced organic carbon reserves and a pool of metabolic active nitrogen-fixing bacteria. In arid conditions, the greatest biogenic depletion of technozems is diagnosed, the manifestation of an inertial mutation of bacterial populations, ensuring their dissociation and preservation in extreme habitats. The information can be used to characterize ecosystem functions and ecosystem services of long-term technozems, in forecasts of the effectiveness of man-made wasteland management in different natural zones, and taken into account in the development of nature-like technologies.