Ecological performances of exotic and native woody species on coal mine spoil in Indian dry tropical region

Abstract

Coal extraction by opencast mining involves the dumping of overburden or mine spoil as large heaps. These large heaps of overburdened materials can act as a serious threat to ecological integrity and, therefore, overall societal well-being. Plantations are often employed to establish revegetation and management of mine spoil, thus mitigating the effects of mining on the environment. However, the performance of plant species can be highly variable due to environmental and species-specific effects. Therefore, the present paper's primary objective is to compare exotic (Acacia auriculiformis, Cassia siamea, Casuarina equisetifolia and Grevillea pteridifolia) and native (Albizia lebbeck, Albizia procera, Dendrocalamus strictus and Tectona grandis) species' performance on the coal mine spoils. Previous studies on the Singrauli coalfields allowed us to compare the growth performance, standing biomass, and net primary production (NPP) of four exotic and four native species plantations. Our results showed that native species have significantly higher survival, stem diameter, biomass, and NPP than exotic woody plantations. Thus, exotic species might not be useful in mine spoil rehabilitation than the native species. Overall, this study suggests that native species are useful for mine spoil rehabilitation despite the faster growth of exotic species.