Plateau zokor disturbances transform the stability and functional characteristics of soil fungal communities

Abstract

As crucial regulators of the ecosystem functions, soil microbes are facing a range of challenges including ecological degradation caused by small mammal disturbances. These disturbances not only threaten biodiversity but also affect the healthy functioning of ecosystems. Effects of plateau zokor (Eospalax baileyi) disturbances on the complexity, stability and assembly processes of belowground microbial networks remain unclear. In this study, we employed ITS rRNA gene amplicon sequencing to systematically investigate fungal network properties, assembly mechanisms, functional potential, and the links to plant-soil functions in soil fungal communities through various stages of zokor mound succession: (i) new mounds (NM), (ii) semi-new mounds (SM), (iii) old mounds (OM) and (iv) pristine grassland (CK), as a control. The results demonstrated that zokor disturbances significantly altered plant species diversity and soil properties, simultaneously affecting the composition and structure of soil fungal communities. Disturbances increased the complexity of fungal community networks but decreased their stability. Moreover, dispersal limitation and homogeneous selection were identified as the primary mechanisms that shape fungal community structure. Functional potential analysis revealed that zokor disturbances led to a decline in the relative abundance of lichenized fungi and plant saprotrophs. Multiple environmental factors, including soil pH, soil organic carbon (SOC), and total phosphorus (TP) were identified as pivotal in driving changes in soil fungal communities. These results deepen our comprehension of the impacts of small mammal disturbances on fungal community characteristics in the Tibetan Plateau grassland ecosystem and provide valuable insights into the potential mechanisms sustaining fungal diversity in extreme environments.