The Study Of Soil Microbial PLFA Community Structure And The Environmental Influencing Factors In China Typical Mountain Ecosystems

Soil microorganism is an important component in the soil and it is found in various terrestrial ecosystems.Understanding soil microbial community structure is not only of theoretical value,but also of economic significance.China has a large land area and a wide latitude span,which provides favorable conditions for the study of soil microbial community structure.The elevation gradient of the mountain itself will produce changes in climate and biological cycle,and different elevations will cause changes in biological and abiotic factors.In this paper,four mountains(Xiao bai mountain in the cold temperate zone、Chang bai mountain in the temperate zone、Xiao wutai mountain in the warm temperate zone、Wuyi mountain in the subtropical zone)in the typical temperature zone are used as research areas.The structure of soil microbial communities at different elevations in the four mountains regions is studied by using the method of Phosphatide fatty acid marker(PLFA).The changing trend of soil microbial community structure is discussed from soil factors,elevation gradient and latitude gradient.The purpose is to understand the microbial community structure in typical mountain soils in China,and to explore the relationship between soil microbial community structure and environmental factors.The main findings of this study are as follows:In the four mountain research areas,the content of phosphate fatty acids more than 5 % are mainly include eight kinds: i15:0;a15:0;16:00;16:1ω6,7c;18:1ω7c;18:1ω9c;18:2ω6,9c/18:0 ante;10Me16:0.The distribution patterns of soil microbial community structure are as follows: bacteria is the most distributed,followed by fungi and actinomycetes,and protozoa is the least distributed.The distribution of soil microorganisms has a certain degree of zonality.The distribution of bacteria in the subtropical Wuyi Mountain and the Xiao wutai Mountain in the warm temperate zone are significantly higher than that Xiao bai Mountain in the cold temperate and Chang bai Mountain in the middle temperate zone.Among them,the distribution of Gram’s negative bacteria in the subtropical Wuyi Mountain was significantly higher than that of Chang bai Mountain in the temperate zone.The distribution of fungi in the subtropical Wuyi Mountain was significantly higher than that in the cold temperate area,Xiao bai mountain,Chang bai Mountain in the middle temperate zone,and Xiao wutai Mountain in the warm temperate zone.Correlation analysis showed that there was significant positive correlation between soil p H and total amount of Gram-positive bacteria,Gram-negative bacteria,bacteria,actinomycetes,protozoa and all PLFAs.Soil C: N ratios were significantly negatively correlated with Gram-positive bacteria,Gram-negative bacteria,bacteria,actinomycetes and all PLFAs,while elevation was significantly positive related to these phospholipid fatty acids.There was significant negative correlation between latitude and fungus.The mean annual temperature was positively correlated with fungi.There was a significant positive correlation between soil total phosphorus content and actinomycetes.RDA analysis shows that environmental factors have different degrees of influence on the community structure of microorganisms in different mountain soils.Altitude、annual precipitation、average annual temperature、soil water content,soil C:N ratios,Olsen phosphorus,total phosphorus,p H and latitude are the main environmental factors that explain the differentiation of soil microbial community structures.