Spatial Distribution Of Soil Fungal Community And Its Influencing Factors In The Alpine Meadow Invaded By Stellera Chamaejasme L.

Stellera chamaejasme L.(Stellera)is one of the most serious weed in Qinhai-Tibetan,the rapid expansion of which exerts an increasing effects on the alpine meadow ecosystem.Soil microorganisms are an important part of grassland ecosystems,and are biologically active factors that are extremely sensitive to environmental changes.Their community composition and diversity can better indicate the variation process and degree of grassland ecosystems.Soil fungi,as the main members of soil microbes,also play an significant roles in the process of decomposition of plant litter,soil nutrient cycling,and symbiosis with host plants.Therefore,it is of graet significance to study the soil fungal community characteristics and its spatial distribution invaded by Stellera chamaejasme L.in the alpine grassland.In this paper,taking the degraded alpine meadow in Qilian Mountain as the study area.with high-throughput sequencing technology and geostatistics,from a regional perspective,the spatial heterogeneity and distribution of the composition and diversity of soil fungal communities in Stellera area and non-Stellera area were analyzed,the effect of Stellera invasion on the spatial distribution of soil fungal communities were explored,and further studied the main enviromental influnencing factors of soil fungal community composition and diversity.The results included:(1)Compared to no-Stellera area,the soil fungal species richness in Stellera area,the dominance increased,the community evenness decreased,the community diversity decreased,and the ?-diversity reduced.The difference of fungal species composition and ?-diversity increased significantly.The two area harbored same composition of fungal species and dominnant,but the relative abundance of each fungal group is different.This shows that the invasion of Stellera altered the diversity and structure of soil fungal community.(2)The spatial heterogeneity degree of soil fungal diversity and dominant phylum in Stellera area are lower than those in no-Stellera area,which is more affected by random factors,but the fungal class is the oppsite.The spatial patches of each elemnet in Stellera area are smaller,and the spatial structure is more complicated.The spatial interpolation results show that the soil fungal diversity index,dominant phylum and class in Stellera area are higher fragmentation,its spatial heterogeneity is obviously enhanced,and spatial stability of soil fungal community characteristics decreased,indicating that the spatial pettern of soil fungal communities was affected by the invasion of Stellera.(3)The correlation between soil fungal community and environmental factors in Stellera area and no-Stellera area was significantly different.The soil fungal diversity index and main dominant phylum in Stellera area have more obvious influences on environmental factors,while the fungal class is the opposite.Especially,soil fungal ?-diversity in Stellera area is sensitive to soil total potassium and vegetation coverage,and the main dominant phylums in Stellera area are sensitive to soil main nutrients(OM,TN)and vegetation.Although Stellera coverage had not a direct correlation with soil fungal community characteristics,it may indirectly affect the spatial distribution of soil fungal communities by changing the soil physical and chemical properties.