Abstract:
Objective To Screen appropriate plants for facilitating the ecological restoration of degraded antimony mines.
Method Four native plant species, including Coriaria napalensis, Cryptomeria fortunei, Betula luminifera, and Plantago asiatica, were grown in antimony mineral soil (MS), and the effects of MS on the plant biomass production, photosynthetic capacity, nutrient concentrations (carbon C, nitrogen N, and phosphorous P), and antimony (Sb), arsenic (As) accumulation were explored. Non-mineral soil (NMS) was treated as the control.
Result The plant biomass and photosynthesis rate of B. luminifera and P. asiatica were insignificantly affected by MS compared to the control, suggesting the high tolerance to Sb with tolerance indices (TI) values of 92.12% and 123.57%, respectively. In contrast, C. napalensis and C. fortunei in MS significantly decreased in plant growth and photosynthesis under MS than that in control, with TI values of 67.54% and 45.49%. The N concentrations in the leaves, stems, and roots of C. fortunei, and the N concentration in the leaves of C. napalensis, were significantly lower under MS than those under the control treatment. Conversely, B. luminifera remained constant concentrations of C and N, as well as stoichiometric ratios in leaves, stems, and roots between MS treatment and control. P. asiatica demonstrated significantly higher C and N concentrations in leaves and higher N concentrations in roots under MS treatment compared to the control. For all four species, the P concentrations in leaves and roots were higher under MS treatment than those in control. The bioconcentration factors (BAF) of Sb and As in four species were all more than 1, and the BAF of Sb in C. napalensis, C. fortunei, B. luminifera, P. asiatica were 30.79, 9.85, 36.98 and 24.02 under MS treatment, respectively.
Conclusion P. asiatica and B. luminifera have high nutrient balance, high tolerance and accumulation to Sb pollution; thus, they can be used as potential plant materials for ecological restoration in antimony mining areas.