Ecosystem approach to the assessment of land reclamation on the example of Zaporizhzhskiy manganese ore quarry

Abstract

Mining industry is the one of the powerful factors leading to the degradation of native ecosystems. Disturbed ecosystems developed instead the native may be remediated using certain reclamation techniques. The purpose of this work was assessment of the remediation quality within Ordzhonikidze Ore Mining and Processing Integrated Plant on the possibility of their economic use and suitability for the existence of soil biota, as well as providing recommendations for further rational economic use. Technical remediation of the surveyed area included such stages as removal of topsoil with gross method, followed by its storage in piles; reformation and levelling of overburden above-ore dump disposed in the exhaust space of career by gross way; keeping of levelled rocks up to 3 years with the purpose of their subsidence; surface repair after subsidence; application of humic layer; ploughing of reclaimed lands. Assessment of soil quality was carried out by comparing a quality score of reclaimed soils with a quality score of zonal soil. Data collection and processing were carried out on values of humus layer thickness; humus content in filling top layer; content of physical clay in topsoil and subsoil; granulometric composition of one-meter thick fill layer; topsoil and subsoil salinity; composition and properties of underlying rocks. As a result of mining operations, topsoil of remediated soil is depleted in chemical elements necessary for plant growth; as a result, the soil becomes more calcareous, and contains humus 1,5–2 times less than that in topsoil of undisturbed soil. Topsoil thickness is on average 58 cm. Humus content in the filled layer on average is 2.2%. Mechanical composition of the arable layer is middle loamy. The soil is compacted below the plow pan. Mechanical composition of the underlying rock is fine-textured. Salinization with water-soluble salts above the toxicity threshold in the arable layer of the studied soils was not found. Before agricultural use of reclaimed lands, it is essential to repair it with the techniques of biological reclamation. This is achieved through cultivation of salt-resistant perennial grasses for 3–5 years.