Patterns of formation and functioning of geosystems of Stebnyk tailings dam

Abstract

The specifics of the landscape structure within the first section of the Stebnyk tailings dam are considered. Two landscape terrains (of natural and anthropogenic genesis), 3 separate landscape belts, 8 types of landscape tracts, and 30 types of landscape sub-tracts have been identified. Geosystems are dominated by flat sloping surfaces of the tailings dam, the external embanked of which forms closed drainless areas requiring systematic regulation of the level of the final reservoir. Features of filling the tailings surfaces played an important relief-forming role. At the same time, there were raised areas (0.5‒2.5 m) confined to the southern and south-western parts of it. Actually, conditions for the formation of tree-bush and meadow-marsh vegetation of different stages of succession were created in these areas. Spatial-temporal regularities of the occurrence and development of plant communities within the first section of the Stebnyk tailings dam were determined based on the decryption of space images for 2006‒2018. Primary meadow-marsh, bush-meadow, and tree-bush communities on surfaces with different levels of salinization were distinguished. In fact, these communities form the primary succession series in the formation of vegetation cover of post-mining geosystems. To decipher the boundaries of plant communities, 16 space images were obtained from the publicly available Google Earth Pro program. The tendencies of changes in the number and area of the plots occupied by different plant groups have been determined. Currently, the area of tree-bush communities is 5.59 hectares (7.87 % of the total area). Bush-meadow and meadow-marsh communities recorded an intensive increase in areas by 2014, followed by a rapid decrease caused by salinization of areas due to significant elevations of the reservoir’s level. In 2014, maximum areas of plant communities (37.55 ha) were identified, covering more than half of the study area (52.84 %), and in 2018 they occupied 21.71 ha (30.55 %). The gradual differentiation of phytocoenoses by moisture gradients and soil salinization continues. To maintain the rate of overgrowth of the first section of the Stebnyk tailings dam, it is necessary to reduce the level of brines regularly.

Keywords

• geosystem
• tailings dam
• functioning
• plant communities