Assessment of plant ecological variability and heavy metal accumulation potential in naturally growing plant species of Pakhar bauxite mine site, Jharkhand, India

Abstract

Abandoned bauxite mine (ABM) soil generally contains an unacceptable number of heavy metals (HMs), causing several ecological and environmental issues. The present study was conducted with a similar objective to assess the HM accumulation potential of the naturally growing plant species from Pakhar ABM site. Vegetation communities were studied using quadrat methods for plant species at both ABM and the control site (near the ABM site). A total of 21 (9 at the ABM site and 12 at the control site) plant species were recorded in the present study belonging to 10 families. Vegetation study revealed that the dominant plant species were Ammophila arenaria and Lantana camara at ABM site and Lantana camara at the control site. The concentration of HMs in soil at the ABM site, were 66180.00 mg kg^-1 Al, 62.20 mg kg^-1 Cr, 22.60 mg kg^-1 Cu, 346800.00 mg kg^-1 Fe, 780.80 mg kg^-1 Mn, and 39.80 mg kg^-1 Zn while in the soil of site located nearby taken as the control showed 56500.00 mg kg^-1 Al, 4.40 mg kg^-1 Cu, 51120.00 mg kg^-1 Fe, 58.20 mg kg^-1 Mn, 13.00 mg kg^-1 Zn. Ammophila arenaria, Miscanthus sinensis, Acacia drepanolobium and Rumex pulcher exhibited the highest metal accumulation at the ABM site, while Ocimum campechianum, Lantana camara, Panicum virgatum L., Euphorbia hirta and Holcus lanatus, Cerastium glomeratum thuill and Shorea robusta exhibited the highest metal accumulation at control site. Plant Lantana camara showed considerable TF values for Pb, Al and Fe, from the ABM soil while Shorea robusta showed high TF values for Al, Cu, Zn, and Fe from the control soil. The BAF for Cu, Mn and Zn from ABM soil were observed in Acacia drepanolobium whereas Cerastium glomeratum thuill exhibited maximum BAF values for Zn and Cu from control soil.

Keywords: Abandoned bauxite mining; Accumulation; Heavy metal; Vegetation community.