| Shanxi Pingshuo Antaibao coal mine is the large opencast coal mining,where the ecological environment in mining area has been seriously destroied because of the large-scale coal exploitation,especially the loss of topsoil stripping and vegetation.The land self-rehabilitation rate is low due to the lack of mellow soil in mining substrate and poor nutrient.Therefore,it is necessary to create an environment conducive to vegetation growth to promote ecological restoration of mining areas.Soil microbes play important roles in the improvement of soil structure,soil fertility,nutrient cycling,and plant growth.The present study most foucused on vegetation community succession and soil physical and chemical properties after vegetation reclamation,but soil microorganism which plays an important role in the reclamation process is little studied.In this project,we studied soil microbial community succession with the reclamation process.There were 12 study sites with different reclamation years(1,2,4,5,6,8,10,15,18,20,22 and 25 years respectively)of Pinus tabulaeformis platations in Antaibao Opencast Coal Mine.The soil physical and chemical properties were determined,and the structure and relative abundance of microbes were determinated through high-throughput sequencing technology,the functional diversity of microbe were measured using Biolog method.We analysis the succession of soil physical and chemical properties,and microbial community composition and functional diversity,in order to explored the dynamics of plant and microbe succession.The main results are as follows:(1)Soil pH from all study sites were weakly alkaline(7.06-8.15),and there were not significant differences among sites.Soil total nitrogen and total carbon content improved with reclaimed years,and the significantly high content were found in long-time reclaimed palatations.Soil water holding capability also increased with reclaimed process.(2)Soil bacterial,archaeal and fungal communities were assessed by tag-encoded 454 pyrosequencing.The number of operational taxonomic units for three domains microbe increased with reclaimed process,and the significant differences were found in bacterial and archaeal ones.Bacterial and archaeal diversity indices demonstrated significant improvement with reclaimed years,however,there were no significant increase in fungal diversity indices.Classified archaeal sequences were Crenarchaeota and Euryarchaeota,and Crenarchaeota accounted for the majority.There were 20 rarefied bacterial phyla presenting sequences abundances above 1%.The highest relative abundant sequences were Proteobacteria and Acidobacteria.The relative abundances of 7 fungal phyla were above 1%,and the dominant fungal phyla were Asco,mycota and Basidiomycota.(3)The results of canonical correspondence analysis(CCA)revealed that soil pH and water content significant factors for archaeal communities.Soil water content significantly affected Euryarchaeota.Soil total nitrogen significantly influenced bacterial and fungal communities' compositions.In addition,soil total nitrogen significantly correlated with fungal diversity.(4)The biolog-ECO micro plate was used to determine the capacity of using carbon sources for microbes.The value of AWCD for microbes increased during the initial incubation period,and then arrived to the stable state.Both the maximum AWCD and the variation rate showed an increasing trend with the reclamation years.These indicated that soil enzyme activities improved with the reclamation years,and utilization of carbon sources were different among study sites.There were 6 carbon sources demonstrated increasing trend with the culture time.The source of esters was easy to be used by microbes among all sites,but the carbohydrate was recalcitrant fro microbes.The highest utilization ratio of carbohydrates,amino acids,esters,alcohols and acids were in found in 25-year reclaimed plantation.Both abiotic and biotic characteristics indicted that soil quality would improve reclaimed time. |
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