Effects Of Enclosure On Soil Microbial Diversity Of Different Plant Communities In Desert Steppe

Soil microorganisms are the most diverse and abundant species in the world.The soil is the most abundant "bacterial resource pool" and is also a huge "gene resource bank"".It is important for the conservation and utilization of microbial diversity resources to reveal the formation regularity and spatiotemporal distribution pattern of soil microbial species and nuclear gene diversity.Inthis paper four communities in Ningxia desert steppe of Yanchi County were explored,whichwas inside and outside the fence soil of Agropyron mongolicum Keng community,Stipa breviflora Griseb community,Espedeza bicolor Turcz.Community,Sophora alopecuroides L.community,andthe soil physical and chemical properties,soil enzyme activities were analyzed,as well assoil microbial community composition and diversity by high throughput sequencing,in order to reveal the enclosure on desert steppe soil microbial ecological distribution,gene polymorphism and region specific effects.Theresultswereshowed:1.Enclosure on desert steppe in four communities of soil physicochemical properties,soil biological activity showed different exclosure significantly increased the total phosphorus content,organic matter,soil community of Agropyron mongolicum Keng community and Stipa breviflora Griseb community community available phosphorus content,Stipa breviflora Griseb community community total salt content,espedeza bicolor Turcz.community water content,while significantly reduce the four plant communities of soil total nitrogen and available potassium content;pH nitrogen did not change significantly.Fencing to a certain extent,not only to improve the soil conditions,but also increased the microbial biomass carbon,microbial biomass of Lespedeza in desert steppe community in Agropyron mongolicum Keng community and Stipa breviflora Griseb communities.Has the close relationship between different plant communities soil enzyme activity and soil nutrient,soil total nitrogen,available potassium,organic matter,total phosphorus and available phosphorus are important factors affecting soil enzyme activity,can be used to indicate the grassland degradation and recovery.2.Fencing has a significant change in four communities of soil bacterial communities,ecological distribution,community composition and diversity,enclosure significantly increased the relative abundance of four dominant species in Ningxia desert steppe soil bacteria community Proteobacteria,but also reduces the relative abundance of Stipa breviflora Griseb communities and dominant branches of espedeza bicolor Turcz.actinomycete the door;Proteobacteria and Actinobacteria are the dominant bacteria research area,including Proteobacteria in different plant communities in abundance in the highest proportion;common bacteria for odd fungus door,Acidobacteria,Bacteriodetes,Gemmatimonadetes,Firmicutes,Chloroflexi door,thermomicrobia;verrucomicrobia rare flora.Exclosure significantly increased soil bacterial community composition of Sophora alopecuroides L.community,also significantly improve the community and community Espedeza bicolor Turcz.alopecuroides soil bacterial community diversity,but also significantly reduce the Agropyron mongolicum Keng community and Stipa breviflora Griseb communities of soil bacterial community diversity;plant community between Sophora alopecuroides L.community structure and bacteria inside and outside the fence the other three kinds of plant communities in the lowest similarity,high similarity of Agropyron mongolicum Keng community and Stipa breviflora Griseb community bacterial community structure.3.Fencing has a significant change in four plant communities soil archaeal community ecological distribution,community composition and diversity,exclosure significantly increased the relative abundance of different plant communities in Ningxia desert steppe dominant bacteria and Thaumarchaeota,while reducing the relative abundance of dominant bacteria Bacteroidetes,including odd bacteria the door of 56.85%-78.12%,Bacteroidetes bacteria accounted for 14.47%-37.99%,armored door 2.88%-4.91%,the dominant groups were the highest relative abundance of odd,armored bacterial flora was the lowest;the common bacteria,Bacteroides,odd armored bacteria;Euryarchaeota;Proteobacteria,Actinobacteria,Acidobacteria,Gemmatimonadetes,Chloroflexi,planctomycetes for rare flora.The fenced decreased significantly in four communities of ancient flora diversity,but also inhibited the Sophora alopecuroides.L community and Espedeza bicolor Turcz.,the most significant change of Sophora alopecuroides L.community,Agropyron mongolicum Keng community and Stipa breviflora Griseb communities and Lesopdeza bicolor Turcz;communities did not change significantly;the changes of ancient the community structure of bacteria community of Sophora alopecuroides L and other three kinds of plant communities were the greatest difference between inside and outside the fence,archaea community structure of Sophora alopecuroides Land other three kinds of plant communities in the lowest similarity;the other three archaeal community structure community soil did not change significantly.4.Through the correlation analysis of different plant communities in bacteria and environmental factors of soil available phosphorus,nitrogen,alkaline phosphatase,total nitrogen and available potassium is the most influential environmental factors of bacterial community,and with the Agropyron mongolicum Keng between bacterial community and Stipa breviflora Griseb communities,and Sophora alopecuroides L.community,Stipa breviflora Griseb community fenced area minimum correlation.Four kinds of plant communities in ancient flora diversity and main environmental factors of soil nitrogen,alkaline phosphatase,total nitrogen and available potassium were highly correlated with the first axis and the first axis to explain 75.23%;further analysis of soil nitrogen,alkaline phosphatase,total nitrogen and available potassium is the main environmental effects of soil ancient flora diversity factor.