Community assembly of plant, soil bacteria, and fungi vary during the restoration of an ecosystem threatened by desertification

Purpose The restoration of degraded ecosystems is an important issue in applied ecology. Understanding community assembly during restoration can help facilitate ecological restoration. Aerial seeding is a widely used method to restore degraded ecosystems threatened by desertification. However, there is limited understanding of how aerial seeding affects community assembly processes and the driving factors of plants, soil bacteria, and fungi during ecosystem restoration. Methods This study analyzed the community composition, β-diversity (community difference degree), community assembly processes, and influencing factors of plants, soil bacteria, and fungi using aerial seeding restoration chronosequences from 1983 to 2017 in Mu Us sandy land, China. Results Our results showed that plant biomass and relative abundances of beneficial flora in soil bacterial and fungal communities all increased since restoration commenced. β-Diversity of plant communities first decreased and then increased with increasing restoration time. Community assembly 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 (soil total nitrogen, soil total organic carbon, and mean annual precipitation) influenced stochastic and deterministic processes in plant communities, respectively. The β-diversity of soil bacteria continuously decreased, and community assembly was almost entirely driven by stochastic processes in the entire chronosequences. Homogenizing dispersal was the key factor driving community assembly. We found no significant changes in soil fungal β-diversity. Deterministic and stochastic processes simultaneously drove soil fungal community assembly. Both environmental filtering (soil total organic carbon and mean annual precipitation) and dispersal limitation affected the community assembly. Conclusion We confirmed the effectiveness of aerial seeding restoration by studying the community composition of plants, soil bacteria, and fungi. Our study highlights that the community assembly processes and driving factors varied for plants, soil bacteria, and fungi during restoration chronosequences. It is necessary to carry out research simultaneously on the community assembly of aboveground plants and underground soil microorganisms.