Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Soil Microbial Community and Diversity in Hexi Corridor Desert Response to the Environment

Auteur : 王福祥

Grade : Master 2022

Université : Lanzhou University of Technology

Résumé partiel
The natural ecosystem of the Hexi Corridor is fragile and the soil desertification is serious,but the habitat contains abundant microbial resources.The survival and adaptation mechanism of microorganisms in desert soil and their ecosystem functions are of great significance for revealing the process of material transformation in arid areas.In this paper,16 transects were set up along the natural precipitation gradient from the southeast to the northwest of the Hexi Corridor.Through field transect setting,survey sampling,indoor soil physical and chemical property testing,and data collection and processing,the climatic characteristics（precipitation,average Air temperature,surface pressure,wind speed,evapotranspiration）,vegetation community structure（number of species,height,cover,aboveground biomass）,soil mechanical composition（gravel,sand,silt,clay）and soil physicochemical properties（p H,conductivity,soil moisture,alkaline nitrogen,available potassium,available phosphorus,total potassium,total nitrogen,total phosphorus,organic matter）and other factors,and one-way analysis of variance was used to explore the spatial differences in the levels of environmental factors ;high-throughput Sequencing technology explores the diversity characteristics of soil bacteria and fungi ;Pearson correlation analysis and redundancy analysis explore the correlation between climate characteristics,vegetation community characteristics,soil physicochemical properties and microbial community structure and diversity.The main findings and conclusions of the study are as follows :（1）The soil mechanical composition shows that the sand content of the three transects in the east of the Hexi Corridor is greater than 90%,indicating that the eastern region is dominated by sandy deserts,and the silt content of the central transect is more than 10%,indicating that The central region is a loamy desert,and the gravel content of the western transect is greater than 10%,and the silt and clay content is greater than10%,indicating that the gravel desert and loamy desert in the western region are crossdistributed.The soil p H value is between 8.39 and 9.40,indicating that the desert soil of Hexi Corridor is alkaline,and the contents of soil organic matter（SOM）,total phosphorus（TP）,total nitrogen（TN）,and total potassium（TK）indicate that its abundance is low.or very low,the content of available phosphorus（AP）was extremely high,and the content of AP in the central region was significantly higher than that in the eastern and western regions（P＜0.05）.The vegetation characteristics study found that the number of dominant species of vegetation in the 16 transects of the Hexi Corridor desert was between 2 and 5,and the vegetation was scarce ;the vegetation height was between 23.20 and 68.43 cm,mainly shrubs and herbs ;the Margalef index indicated that the central region Species richness is higher than that of east and west,Shannon index indicates that the index of species diversity of east and middle is higher than that of west,the species of 16 transects are extremely dissimilar,and the replacement rate of plant species along the precipitation gradient changes irregularly

Mots clés : Hexi Corridor ;soil microorganisms ;high-throughput sequencing ;environmental factors ;redundancy analysis ;

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