Trace metal accumulation and natural mycorrhizal colonisation in an afforested coalmine overburden dump: a case study from India

In India, coalmine overburden (OB) dumps are reclaimed by forestry reclamation approach (FRA), thus selection of appropriate tree species is essential for the reclamation success. In the present study, screening of tree species was done based on natural mycorrhizal association, metal tolerance, and amelioration of minesoil properties. The study showed that tree plantation improves the moisture content, bulk density, pH, and the overall nutrient contents of minesoils. Trees possessing high levels of mycorrhiza colonisation (Dalbergia sissoo, Acacia auriculiformis and Cassia seamea) were found to be most suitable for FRA. The study infers that the stress condition of minesoils encourages higher mycorrhizal colonisation than natural soil. Acidic pH in minesoils increases the bioavailability of metals but their concentrations were found within toxic limits. The results of this study underscore the need for close monitoring of trace elements in reclaimed OB dumps.