Concentrations of soil rare earth elements and their accumulation characteristics in plants in recovered mining wastelands in Fujian Province, South China

Based on filed sampling and laboratory analysis, this paper studied the concentration, distribution, and migration of rare earth elements (REEs) in the soils and dominant plants in recovered mining wastelands in Changting County of Fujian Province. Due to the serious destruction of the soils, their nutrient contents were lower, but the REEs concentrations ranged from 507.40 to 841.37 mg·kg^-1, being higher than those of the control. The REEs in the soils were mainly in exchangeable form, accounting for 61%-98% of total. The soil REEs were transformed from single exchangeable form to a variety of fractions, and the concentration of organic fractions increased significantly. The REEs concentrations in plant root, stem, and leaf were 40.27 - 986.01, 5.14-206.58, and 6.81-2364.51 mg·kg^-1, respectively. Except that the REEs concentrations in Dicranopteris pedata organs were in the order of leaf > stem > root, those in the other plants organs were in the order of root > leaf > stem. According to the REEs concentrations in shoot and root, the plants could be classified into two types. Dicranopteris pedata was accumulator plant, whereas Eucalyptus spp., Paspalum wettsteinii, Schima superba, and Camellia sasanqua were root-compartment plants.