Primary succession of plants of technogenic dumps of the Kabardino-Balkarian Republic

Abstract

The article presents data on the regularities of the flow of primary succession on the terraces of the tailing dump of the Tyrnyauz tungsten-molybdenum combined plant. In the accumulative ecotope of old-age terraces of the lower level of the dump, grass-wormwood and herb-wormwood communities dominate with a projective cover of up to 60 %. In the transeluvial ecotope of middle-aged terraces, there are ruderal-natural grass-forb grass communities with a projective cover of 37 %. In the eluvial ecotope of young terraces of the upper level, there are monodominant explent communities with a projective cover of 13 %. Old age terraces have the greatest similarity with the zonal flora and have characterics of relatively high species richness and saturation. With an increase of succession length, there are changes in the dominant life forms (from terophytes to hemicryptophytes), a decrease in the proportion of species with wide ranges (pluriregional, holarctic, and palaearctic), an increase in the number of stenobionts and hemistenobionts. A number of species growing in extreme conditions of ecotopes of middle and upper terraces are characterized by the absence of deviations from ecological regimes and indifference to elevated concentrations of Mo and W. High toxicity of the substrate constrains the speed of transition from initial to subsequent stages of primary succession. To restore vegetation, it is necessary to carry out both biological and technical remediation.