The Change Of Microbial Community Structure In Biological Soil Crusts Of Tailings,Tongling

The wasteland of copper mine tailings is a man-made protogenesis bare land. The ecosystem development on the tailings wastelands is a primary succession. Biological soil crust is an early stage in the process of the ecological system succession, it widely distributed in tailings wastelands surface. The object of this study is biological soil crust and the subcutaneous layers tailings on Yangshanchong and Tongguanshan copper mine tailings, we investigated the algae diversity and the dominant taxa in biological soil crusts by conventional cultivation, and using the method of molecular biology, while taking advantage of statistical methods, to study the change of microbial community structure in biological soil crusts of different vegetation types. The results showed that:1. Different succession stages and vegetation types of biological soil subepidermal tailings have different physicochemical properties, Tongguanshan tailing has higher nutrient content than Yangshanchong tailing; The results also showed that organic matter, total nitrogen and total phosphorus content of different vegetation types of tailings to be higher than bare land, but there were no significant difference of pH; The physicochemical property of tailings is different along with the change of season.Heavy metal content determination showed that As, Cd, Cu and Zn are lower than Yangshanchong tailing, however, Fe and Pb are significantly higher than Yang shanchong tailing; The total heavy metal distribution rule of different succession stages and different types of vegetation appears as Fe> Cu> As> Zn> Pb> Cd, and along with the change of season, the distribution law without change.From the relevant analysis can be seen, there are different degree of positive and negative significant correlation between physicochemical properties and heavy metals of tailings sample, this suggests that the heavy metal content of tailings has important influence on nutrient cycling.2. Microscopic observation showed that the algae mainly including Cyanophyta, Chlorophyta, Bacillariophyta, Zooxanthellae and Euglenophyta, dominant Cyanophyta including Microcoleus, Leptolyngbya, Microcystis, Oscillatoria, Planktolyngbya subtilis and Chroococcus; dominant Chlorophyta is Chlorella vulgaris, other algae relatively less, and most species in individual communities only. Different samples showed different species composition.3. According to RFLP analysis and sequencing result, it could be found that bacteria species composition including Proteobacteria, Cyanobacteria, Bacteroidetes, Acidobacteria, Planctomycetes, Chloroflexi, Actinobacteria, Gemmatimonadetes, Firmicutes and Verrucomicrobia. Bacteria species composition is various in different vegetation and season, but the absolute advantage groups unchanged.4. The research of different succession stages showed that Tongguanshan has higher bacterial diversity than Yangshangchong tailings, but there have no significant change in advantage groups.5. The correlation analysis of statistics showed that the main influence factors of microbial diversity including physicochemical, heavy metal, nutrient content and vegetation types.