| Two waste piles hills in the north and south of Shengxiong coal mine area of Muli coalfield in Qinghai Province were selected as the research objects to investigate the target background values of surrounding natural mountain,the control experiments of different planting years and different restoration treatments.The characteristics of vegetation community and soil physical and chemical properties were analyzied.The diversity of bacterial and fungal communities was determined by Illumina Genome Analyzer IIx.The effects of artificial restored vegetation on microbial communities in the mine area were discussed.The results showed that:(1)The physical and chemical properties of soil in the unrestored area of the waste pile.The dominant genera of microorganism are Gemmatimonas,GP6,Gibberella and unidentified genera.Soil nutrients in natural mountains were lost a litle due to grazing,and that in wetlands surrounding the waste piles was better.The dominant genera in wetlands were GP6 and GP16.The number of OTU of microorganisms in the waste piles was higher by 9.8%than that in wetlands and higher by 21.8%than that in the natural mountains.The diversity of bacteria in the marsh wetlands was higher comparing with natural mountains and waste piles,while that of fungi in the wetlands was lower than that in the unrestored area.(2)With the increase of planting years,the vegetation height and germination rate increased first and then decreased,but the vegetation coverage and biomass increased,and reproductive branch number decreased.The physical and chemical properties of the soil,the number of soil microbial OTU,and the diversity and richness of bacterial microorganisms all increased.The sphingomycetes,GP6 and Preussia were the dominant genera in bacteria.With the increase of recovery years,OTUs increased and approached natural mountains.Relashionship between the fungal microorganisms and those of soil water content,available N and fast-acting fungi.Available K content was significantly correlated(P<0.05).(3)The vegetation height,biomass and the number of reproductive branches on the south and east-facing slope were significantly higher than those on the north-facing slope.The contents of N,P and K in surface soil were the highest in south and east-facing slopes,while the content of organic matter in surface soil was significantly lower than that in north-facing slope(P<0.05).Bacterial OTU quantity,diversity and Chao index among all slopes were the highest in the south-facing slope,the lowest in the east-facing slope.Gemmatimonas accounted for a larger proportion in the south-facing slope than in the north and east-facing slopes.Ustilago was high in the north-facing slope.The dominant microorganisms were positively correlated with soil available N and water content(P<0.05).(4)Sowing date experiments had no significant effects on aboveground and underground organisms(P>0.05).The effects of different sowing rates on vegetation growth were small,and there was no significant change(P>0.05).Soil bacterial and microbial OTUs were the largest in the sowing experiments 3(100%)and 4(150%),while fungal OTUs were the largest in the sowing experiment 5(200%).However,there were no significant changes in microbial diversity,evenness and chaol index at different sowing rates(P>0.05).(5)Vegetation height and coverage were the largest in fertilizer experiment3(450kg/hm~2).Soil available N and K contents were the highest in fertilizer experiment 4(675kg/hm~2),and fine sand content was the highest in fertilizer experiment 2(225kg/hm~2).The number of OTUs and Shannon index of bacteria were the highest in fertilizer experiment 4,and the Shannon index and chaol index of fungi were the highest in fertilizer experiment 1(0kg/hm~2).Bacillus,GP6,sphingomycetes were slightly higher than other three treatments in fertilizer experiment 2.Candida and Powdery Mildew had the lowest proportion in fertilizer experiment 4.Total N,total P and pH in soil were positively correlated with dominant groups at generic level(P<0.05).The aboveground biomass and coverage of vegetation increased with the increase of topsoil replacementcover thicknesses of 5,10 and 15 cm,and the contents of available N and organic matter increased.With the three topsoil replacement treatments,the number of bacterial OTU in the treatment 3(15 cm)and the number of fungal OTU in the treatment 2(10 cm)were the highest among all treatments.Arthrobacter in the treatment 3(15 cm)increased significantly,and it was positively correlated with available N and K(P<0.05).In conclusion,the artificial planting measures of coal waste pile can promote the restoration of soil microbial community,and help to stabilize the relationship among between soil microorganisms,vegetation and soil.They play a positive role on the ecological restoration of the permafrost mine region. |
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