Research On The Assembly Of Plant And Soil Microbial Communities Along The Restoration Sequences Of Aerial Seeding In Mu Us Sandy Land

Ecosystem degradation will cause a range of environmental problems and seriously obstruct the sustainable development of human society.Therefore,restoring degraded ecosystems has become a hot issue in current applied ecology research.Understanding community assembly during restoration can provide theoretical value for ecological restoration and help facilitate ecological restoration.The Mu Us sandy land has long been threatened by severe desertification as an ecologically fragile area.In response to desertification,various ecological restoration projects have been implemented in the Mu Us sandy land,among which aerial seeding is an effective measure of restoration.However,there is limited understanding of community assembly processes,and driving factors in plants,soil bacteria,and soil fungi along aerial seeding restoration sequences.This study relied on the aerial seeding restoration sequences of the Mu Us sandy land from 1983 to 2017,and 29 sites of different aerial seeding years were selected for investigation.Combined with plant community surveys and biomass data,highthroughput sequencing data of soil bacteria and fungi,environmental factors(climate and soil factors)and spatial factor data,the community composition and structure,?diversity(community differences),community assembly processes and driving factors of plants,soil bacteria,and fungi were analyzed respectively.The main results are as follows:(1)With the increase of recovery time,the number of families,genera,species of plants,and the number of phyla and genera of soil bacteria and soil fungi increased continuously,and the kind of three biological groups was continuously enriched.Aerial seeding restoration significantly increased the ?-diversity of three biological groups.In addition,the community composition of plants,soil bacteria,and soil fungi changed,and plant biomass and the relative abundance of beneficial bacteria and fungi increased.(2)Linear regression analysis showed that with the increase in recovery time,the?-diversity of plant communities first decreased and then increased.The community similarity of plants increased first and then decreased.The ?-diversity of soil bacterial communities decreased significantly,and community similarity increased continuously.The ?-diversity soil fungal communities showed no significant changes.(3)The community assembly and driving factors of plants,soil bacteria,and fungi varied.Community assembly of plant communities was dominated by stochastic processes in early stages of restoration,deterministic processes in middle stages,and stochastic processes in later stages.Dispersal limitation and environmental filtering(total nitrogen)are influencing factors that lead to stochastic and deterministic processes in plant communities.(4)Soil bacterial community assembly was driven by stochastic processes and transient deterministic processes.Homogenizing dispersal and environmental filtering(total nitrogen)influenced the soil bacterial community assembly.(5)Both deterministic and stochastic processes simultaneously drove soil fungal community assembly.Environmental filtering(total nitrogen)and dispersal limitation affected community assembly.The above results indicated that the community ?-diversity and composition of plants,soil bacteria,and soil fungi would change during the restoration of aerial seeding in Mu Us sandy land.Aerial seeding restoration is beneficial to the increase of the biomass and ?-diversity of plant species and the emergence of beneficial flora in soil bacteria and fungi.The study also revealed the different community assembly patterns of the three biological groups during the restoration of sandy land.The research results provide theoretical support for the restoration effect of the Mu Us sandy land and emphasize the necessity of simultaneously researching the assembly of aboveground plant communities and underground soil microbial communities.