Microbial Diversity And Correlation With Environmental Factors In The Permafrost Soil Of The Greater Hinggan Mountains

In order to explore the correlation between soil vertical spatial microbial community structure and environmental factors in the permafrost region of Greater Hinggan Mountains,soil sediments of different depths were collected and environmental factors of soil samples were determined in August 2016.The bacterial community structure and diversity were analyzed by 16s rDNA sequencing technology,fromthe active layer and permafrost were discussed.The soil bacterial community structure and its correlation with soil environmental factors provided basic information for the protection and sustainable development of ecological environment in permafrost region of Greater Hinggan Mountains.The spatial distribution characteristics of soil environmental factors were as follows:the average value of pH was 6.66,showing the soil was acidic;the mean content of SWC%was 25.82%;the mean content of TOC was 5.53 g/kg;the mean content of DOC was 408.62 mg/kg;the mean content of NH₄⁺-N was 8.68 mg/kg;the mean content of NO₃^--N was 0.18 mg/kg;the mean content of TN was 109 mg/kg;the mean content of TP was 423.68 mg/kg;and the mean content of C/N was 62.68.The TOC content in soil was the highest,DOC,while TN and TP content was relatively higher.The results suggested that TOC?TP?SWC%?NO₃^--N?C/N content and value were affected by the depth of soil layer;TN?pH?NH₄⁺-N values were affected by the depth of soil layer,possessing the characteristics of vertical increase to a certain extent.Meanwhile,the DOC content distribution in soil vertical section has no significant change.We analyzed the microbial community composition,diversity and its correlation with soil environmental factors and found that 9 high-throughput sequencing results in639459 effective sequences and 3231 OTUs acteria which belong to 20 phyla and 29genus respectively.The microbial community composition of each genus in the vertical space of soil was quite different.RB41,11-24 and Solidbacte were dominant in the microbial community composition of soil active layer.Oryzihumus,Gaiella and Rhizobium were widely distributed in permafrost layer.In addition,the results showed that the Ace index,Chao1 index,Shannon index were different,the Simpson index was smaller,and the soil active layer had higher microbial diversity,which was more stable than the permafrost microbial community structure.The correlation analysis of microbial community composition,diversity and soil environment showed that soil depth was the main environmental factor affecting microbial community composition,distribution and diversity.The microbial community composition in vertical soil space was affected by the interaction of various environmental factors.TOC,C/N and TN were the main environmental factors affecting the microbial community structure in soil active layer.SWC%and DOC are the main environmental factors affecting the microbial community structure in permafrost layer.The influence of microbial diversity was driven by multiple of environmental factors.TOC was the key environmental factor affecting microbial diversity.