Bioaccumulation of Heavy Metals by Dominant Plants Growing in an Abandoned Manganese Mine in Guangxi, South China

According to recent vegetation survey, in the Lipu manganese mine there were 32 species of higher plants that belong to 31 genera and 18 families, including 9 dominant species: Digitaria sanguinalis, Pteridium aquilinum, Imperata cylindrical, Pteris multifida, Malvastrum coromandelinum, Phytolacca acinosa, Erigeron canadensis, Osmanthus fordii and Castanea henryi. The analytical results of Fe, Mn, Cd, Pd and Cu in soils and plants indicated that the highest concentrations of Fe and Mn in soils were 140221 mg/kg and 12114 mg/kg respectively. Different dominant species were found to colonize on the soils with different Fe and Mn concentrations. Pteris multifida grew in the soil with the highest Mn concentration, Urena lobara in the soil with the highest Fe concentration, and Imperata cylindrica in the soil with the lowest Mn and Fe concentrations. The bioaccumulation character of Fe and Mn by different dominant species showed a great diversity. E.canadensis and D.sanguinalis are the possible pioneer plants for the revegetation in manganese mining wastelands because of their rapid growing and strong resistance to Mn contamination. P. acinosa and C.henryi can be used as potential species for phytoremediation of Mn-contaminated soils due to their high capability of enriching Mn.