Evaluation of metal uptake factors of native trees colonizing an abandoned copper mine e a quest for phytostabilization

Accumulation and enrichment of heavy metals in the above ground parts of Australian native Acacia pycnantha (Ap) and Eucalyptus camaldulensis (Ec) growing in an abandoned copper mine located in Kapunda, South Australia have been studied. Cu and other metals (Na, Al, K, Ca, Fe, Zn, Cd and Pb) in plants and corresponding soils were analysed to evaluate plant interaction with soils containing heavy metals. As per the total metal analysis of leaf and corresponding soil samples, Ap accumulated 93.6 mg kgˉ¹ of Cu in leaf while the corresponding soil concentration was 1632 mg kgˉ¹. The Ec accumulated 5341 mg kgˉ¹ of Cu in leaf while the concentration of this heavy metal in soil was 65 mg kgˉ¹ in soil. The ESEM spectral analysis also showed a high leaf concentration of Cu in Ec (7%) as against only 0.12% in Ap. The average bioconcentration factor for Cu, Zn,Cd and Pb in Ec wasmuch higher than that of Ap. Similarly, enrichment factor was more in Ec for Cu, Zn and Pb than in Ap. In contrast, translocation factor for only Zn and Cd was high in Ap. This study points out that Ec and Ap have different stabilising potential in remediating heavy metals like Cu in mined soils.