Active exploitation of coal deposits in the Rostov region was resulted in formation of more than 600 waste heaps that are of serious ecological danger. The main species for recultivation of heaps is black locust (Robinia pseudoacacia L.). The aim of study is to examine the state and growth of black locust on reclaimed waste heaps of Donetsk Ridge, accumulation of humus-like substance in primitive soil under plantings. It is found that the productivity of locust plantings depends on sulfate content in waste heap substrate. According to this index all examined waste heaps were divided into three categories: with high (> 0.16 mg/kg), medium (0.15-0.16 mg/kg), and low (< 0.15 mg/kg) content of sulfates in substrate. Locust plantings on waste heaps of Donetsk Ridge are characterized by the following indices: height of the trees at the age of 30 years old varies from 8.9 m (under high content of sulfates in substrate) to 10.6 m (under low content), diameter at the same age is from 7.5 to 13.5 cm respectively. The stock of plantings changes from 16.7 to 45.25 m³/ha (maximum meaning corresponds to conditions with low content of sulfates in substrate). Locust plantings on waste heaps have the average mark of life state that is from 3.1 to 2.6 and are characterized as medium damaged. Under locust plantings, the formation of primitive soils takes place. The thickness of this soil layer is from 2 to 3 cm, and the content of humus-like substance is from 4.38 to 7.3 %.
Keywords: black locust, sulfate content, waste heap, reclamation, Donetsk Ridge.
