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Bacterial And Fungal Communities Along An Elevational Gradient On Taibai Mountain And Their Response To Labile Carbon Addition

Posted on:2020-10-10Degree:MasterType:Thesis
Country:ChinaCandidate:Y N TangFull Text:PDF
GTID:2370330578483915Subject:Ecology
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Soil microorganism is an important part of forest ecosystem,these roles of microorganisms in soil are often influenced by community structure and functional groups,so exploring the structure and diversity of soil microbial community can help us understand the important role of soil microbial community.In the context of global climate change,the increase of atmospheric CO2 concentration and temperature will lead to the storage of more carbon by vegetation,and thus increase the input of vegetation litters and root exudate.The increase of carbon input causes the transformation of microbial community to regulate the process of soil carbon balance,and many studies have proved that the structure of soil microbial community changes after the addition of exogenous carbon.Therefore,it is helpful for us to better understand the regulation process of soil microorganisms on soil carbon balance by identifying the specific types of microbial groups that are changing.In this study,soil samples were collected from the Taibai Mountain.We chose five altitude gradients,representing five typical vegetation types.The changes of soil physical and chemical properties at different altitudes and different soil layers were investigated,and the differences of soil microbial community structure at different altitudes and different soil layers were emphatically analyzed,as well as the changes of soil microbial community structure after the addition of exogenous carbon.The following conclusions are mainly drawn:Shannon index and observed OTUs of soil bacterial community changed with elevation gradient or soil layer,and significantly correlated with SOC,TN,AP and bulk density.NMDS analysis of soil bacterial community structure showed that there were significant differences in the bacterial community structure between elevation gradient and soil depth,which were mainly related to soil pH,SOC,TN and bulk density.Shannon index of soil fungi community was not significantly different at different altitudes or between different soil layers.However,the observed OTU number of topsoil is affected by elevation gradient.NMDS analysis of soil true community structure showed that the fungal community structure was only significantly different in elevation gradient,which was mainly related to soil pH,powder content and sand content.After the addition of labile carbon,the structure of soil microbial community also changed,and the surface soil and deep soil of QW showed the same change trend,the relative proportion ofproteobacteria and actinobacteria increased.LC surface soil and deep soil have the same change trend,the relative proportion of proteobacteria and actinobacteria is increased and then decreased,and the relative proportion of acidobacteria is decreased and then increased.According to the above results,soil microbial community structure and its diversity change with altitude and soil depth,which is significantly related to soil physical and chemical properties.After the addition of labile carbon,the microorganism community structure also changes in order to regulate the soil carbon balance.
Keywords/Search Tags:elevation gradient, soil layer, soil microbial community, labile carbon addition, soil physical and chemical properties
PDF Full Text Request
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