The Relationship Between Different Dominant Plant Communities And Soil Microbial Diversity In Alpine Meadow

Under natural conditions,the alpine meadow presents a “Mosaic” landscape occupied by different dominant plant communities and closely “Mosaic” together.The differences of various plant communities composed of the “Mosaic” are not only reflected in the dominant plants,but also different soil microbial diversity and composition.However,little is known about the coupling or decoupling relationship between plant community attributes and function and soil microbial diversity,including the mixed effects of plant and soil feedbacks and environmental factors,and how to synergically maintain biodiversity and function of landscape level plant communities.Here,we determined the plant community attributes,plant community traits,edaphic factors,soil bacterial and fungal community diversity and composition of the communities with different plant as dominant species(Typical-community,Sedges-dominated,Grassesdominated,Forbs-dominated,Legumes-dominated)in the same alpine meadow environment.We examined the difference in plant and soil microbial diversity between distinct communities using generalized linear models and assessed the relationships between plants,soil microbes,and edaphic factors using canonical discriminant analysis and generalized partial regression.The mainly results are as follows:(1)There were significant differences in the diversity of soil bacteria and fungi in the communities with different plant as dominant species in the same alpine meadow;Soil bacterial diversity was significantly higher in the communities with sedges-and grasses than in the typical communities,and soil fungal diversity was significantly higher in the communities with sedges-and legumes-than in the typical communities.The distribution of dominant phyla,families and genera of soil bacteria and fungi in different communities was not significantly different,and the composition of soil microbial community was not significantly different among different communities.(2)Changes in plant community attributes and edaphic factors could explain 52-66% of the variation in soil bacterial diversity.Soil bacterial diversity was positively correlated with plant species diversity,standing biomass and soil available phosphorus,and negatively correlated with soil p H and soil available nitrogen.Changes in plant community properties and edaphic factors accounted for 18-23% of the variation in soil fungal diversity,while soil fungal diversity had no significant correlation with plant community properties and edaphic factors.(3)Changes in community-weighted mean of plant could explain 13-24% of the variation in soil bacterial diversity,but there was no significant correlation between soil fungal diversity and community-weighted mean of plant.Changes in community-weighted mean of plant could explain 18-19% of the variation of soil bacterial diversity,but there was no significant correlation between soil fungal diversity and community-weighted mean of plant.(4)Changes in diversity of plant functional traits could explain 30-44% of the variation of soil bacterial diversity,and soil bacterial diversity was positively correlated with diversity of plant height and leaf dry matter content,and negatively correlated with diversity of leaf specific leaf area and phosphorus content.Changes in diversity of plant functional traits could explain27-40% of the variation of soil fungal diversity,and soil fungal diversity was significantly negatively correlated with diversity of leaf area,leaf nitrogen content and leaf phosphorus content.In summary,there are significant differences in plant,soil microbiota,and edaphic factors between different dominant plant in alpine meadows.Our results also reveal that the diversity of soil microbiota is closely coupled with the availability of soil phosphorus in the complex interactions among plants,soil,and microbe.At the plot scale,there is weak correlation between functional traits of plant communities and changes in diversity of soil microbial,but diversity of plant height can well explain the variation in soil microbial.This study provides more perspectives for understanding the formation and maintenance of diversity of soil microbial and plant communities in alpine meadows.