Changing Soil Microbial Community Stability and Its Influencing Factors During the Restoration of Degraded Alpine Meadow

Abstract

The alpine meadows on the Qinghai-Tibet Plateau have been severely degraded, forming a large number of bare patches (BP). The recovery and succession of these BP may lead to changes in the stability of soil microbial communities in the meadow ecosystem. Currently, it is unclear how microbial community characteristics and stability respond to the recovery and succession of the BP. We selected four types of patches, including BP, initial-term recovery patches, long-term recovery patches, and healthy alpine meadows, and different succession stages of the patchily degraded alpine meadow were analyzed to determine the properties of their plants, soil, and soil microbial communities. The results showed that during the recovery and succession of the patchily degraded alpine meadow, belowground biomass (BGB), plant community diversity index, soil moisture, and soil electrical conductivity, as well as the contents of soil organic carbon, STN, ammonium nitrogen, leucine aminopeptidase and alkaline phosphatase, and the composition and niche breadth of soil bacteria all increased. The stability of soil microbial network was enhanced. The stability of soil bacterial resistance and resilience stability showed an increasing trend with recovery length, whereas soil fungi showed a decreasing trend. The main environmental factors affecting the stability of soil microbial communities were identified as BGB, Shannon–Wiener index of soil fungi, ammonium nitrogen content, and soil electrical conductivity. Soil physical properties directly or indirectly affected vegetation characteristics, soil nutrients, soil enzyme activities, and soil microbial diversity, all of which, in turn, affected the stability of soil microbial communities.