Despite a rich history of theoretical and empirical work showing that increasing biodiversity results in higher ecosystem function, this research has not made a commensurate impact on the reclamation of degraded lands, where enhancing ecosystem function is of primary importance. In this study, we manipulated plant diversity on heavily degraded mine lands and showed that increasing plant diversity greatly enhanced the reclamation of these lands. We found that high‐diversity assemblages were often associated with more biomass, higher stability and less toxic foliage than low diversity treatments, although the monocultures of Miscanthus sinensis (the most productive species) performed equally well as some of the polycultures. Our results showed that species composition and richness explained most of the total variation in biomass yield of the experimental plots, indicating that both the selection and complementarity effects influenced the positive diversity effects observed in this study. Miscanthus sinensis and legumes (as a functional group) were found to be the main contributors to the selection effect. The plots with M. sinensis tended to harbour fewer soil fungal pathogens than those without it and a similar pattern was observed for the legumes, indicating a poorly known plant–soil fungal pathogen feedback for these plants. This kind of feedback appeared to play an important role also in shaping the positive plant species richness–ecosystem function relationships recorded in the degraded mine land. More importantly, we provide the first evidence that the observed plant–soil fungal pathogen feedbacks were likely mediated by chitinolytic bacteria that release anti‐fungal enzymes. Cellulose‐degrading bacteria that aid in plant decomposition and nutrient cycling also attained higher abundances in plots with higher plant diversity, suggesting the contribution of another kind of plant–soil feedback to the positive diversity effects. Synthesis and applications. Our findings reveal that highly diverse plant assemblages are better able to spur plant–soil feedbacks and that increasing plant diversity is an important strategy to enhance land reclamation efficiency after contamination. Meanwhile, our results also indicate that some plants such as Miscanthus sinensis and legumes should be preferentially used to establish diverse plant communities for rapid reclamation of degraded lands.

A wide-spread subtropical tree species, Schima superba (Theaceae), 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. Schima 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.

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In this study, we developed a novel selective method for copper quantification based on gold nanoclusters (GNCs) and DNAzyme.

Heavy metal contamination of minesoils is a widespread problem in China. In Pingle manganese mineland in Guangxi (south China), heavy metal concentrations in soils and dominant plants were determined, and soil contamination was assessed with pollution index (Pi) and index of geoaccumulation (I-geo). Pi showed the minesoil was heavily polluted by Cd and slightly polluted by Cr. I-geo showed a severer pollution for all metals (except for Mn) than Pi because I-geo tended to overestimate the real pollution effect of minesoil. Fresh tailings dam had both the highest Pi and I-geo among the four sites indicating a high metal contamination. All the "bio-available" fractions of the studied metals were below 5% of the totals. Dominant plants tended to accumulate higher Cd and Cr, and showed higher Mn translocation to aboveground parts. Besides the agricultural reclamation, more diverse restoration goals with lower environmental risks should be considered for the Mn mine wastelands in South China.

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We present a study of the effect of gold nanoparticles (Au NPs) on TiO 2 on charge generation and trapping during illumination with photons of energy larger than the substrate band gap. We used a novel characterization technique, photoassisted Kelvin probe force microscopy, to study the process at the single Au NP level. We found that the photoinduced electron transfer from TiO 2 to the Au NP increases logarithmically with light intensity due to the combined contribution of electron–hole pair generation in the space charge region in the TiO 2 –air interface and in the metal–semiconductor junction. Our measurements on single particles provide direct evidence for electron trapping that hinders electron–hole recombination, a key factor in the enhancement of photo(electro)catalytic activity.

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