Assessment of the Ecological Status of Technogenic Ecotopes of Dumps in Donbass Coal Mines

The aim of this work is to assess the current ecological status of Technosols on dumps of the Donbass coal mines. Their physical, chemical, and biological properties and the content of heavy metals have been studied. Data on the properties of dumps on the hilltops and slopes of various aspects prior to the mining and biological rehabilitation stages of the 1970s and 50 years later are presented. Fine sand and coarse silt fractions predominate in the dumps, and the top of the Tsentral’no-Zavodskaya coal mine dump is characterized by the smallest amount of physical clay and by the relatively coarse texture: the content of fine sand fraction exceeds 40%. The enzymatic activity at the studied dumps varies depending on the slope aspect and relief features. The mean concentrations of the studied metals decrease in the sequence: Mn > Zn > Pb > Ni ≥ Cu > Cd. Taking into account that they exceed the MPC and belong to the class of hazardous heavy metals, Pb, Zn, and Cd are the priority soil pollutants in the studied area, while Mn, Ni, and Cu are less dangerous pollutants. Technosols of the Tsentral’no-Zavodskaya mine dump are characterized by an excess of the content of heavy metals by 1.1–3.7 times and of their mobile forms by 1.4–8.4 times as compared to the Technosols of mine dump 5–6. In combination with the coarse texture and high hydrolytic acidity of soils of the Tsentral’no-Zavodskaya mine dump, this may indicate unfavorable ecological conditions for the formation of a stable vegetation cover.