The Distribution Of Soil Microbial Ommunities Among Different Topography Following Implementation Of The 'Grain-to-green Program' On The Loess-plateau

On the Loess Plateau,because of the special topography,the influence of environmental factors and the way of land use change,soil and water loss and soil erosion were serious.Different topography went through different levels of wind and water soil erosion,which could lead to change of soil physicochemical properties,soil microbial activities and microbial communities among different slope positions and aspects.This study chose Yunwu mountains' natural protected area located in Ningxia province as the research region and elucidated the distinct of soil physicochemical properties,soil microbial activities and microbial communities among different topography.This study also selected three restoration years(30 years,20 years and 5 years)and two soil layers(topsoil(0 ~ 20 cm)and subsoil soil(20-40 cm))to compare the change rule among different topography and took advantage of high-throughput sequencing and multivariate statistical analysis to explore the condition of grassland area conversion from the perspective of soil quality and microbial communities comprehensively.The main conclusions were as follows:(1)Soil physicochemical properties and microbial activities had no same trend among different slope positions and aspects in each year and soil layer,however,they had significant differences among distinct topography and increased along with succession of restoration years,soil water content played important role specially.(2)The distinct of soil microbial community composition among different topography increased along with succession of restoration years,in 30 year of restoration,soil microbiome was clearly divided by different slope position and asepct.Soil microbiome of two soil layers had significant differences in three restoration years.Soil microbial activities was more sensitive and had more effects on soil microbial communities than soil physicochemical properties.There were habitat-specific that different environmental factors affect microbiome in distinct area.(3)There were various significantly different bacterial species and the co-occruence patterns of bactrial communties in 30 year was different among distinct topography.The key stone species were adapted to the sepcial environment conditions.In general,under the background of the loess plateau,this study overall revealed the distinct of soil microbial communities among different slope positions and aspects,as well driving-mechanism from external environment factors,which provided adequate theoretical basis for precision governance of various topography on the Loess Plateau.