A wide-spread subtropical tree species, <I>Schima superba (Theaceae)</I>, occurring in a Mn mine wasteland, was found to contain unusually high Mn content in the leaf tissues. A pot growth experiment with different Mn treatments was conducted to further illustrate its Mn tolerance, accumulation and relocation capacity. <I>Schima</I> saplings grew well and showed no symptoms of Mn toxicity with Mn supply below 60 mmol/l. Total plant biomass decreased with the increase of Mn supply, but Mn contents in tissues increased significantly, and peaked (62 412.3 mg/kg) in stem at 150 mmol/l treatment. Under all treatments, Mn concentrations in the aboveground tissues were constantly greater than those in roots. When the external Mn supply was over 40 mmol/l, the Mn levels in the leaves and stems all exceeded 10 000 mg/kg, the suggested value for Mn hyperaccumulation. Most of the Mn taken from the substrates were transported to the aboveground tissues, e.g. over 86% accumulated in the aboveground parts at 150 mmol/l treatment. These findings confirmed that Schima superba is a Mn hyperaccumulator.
Selenium tolerance, accumulation, localization and speciation in a Cardamine hyperaccumulator and a non-hyperaccumulator
