Impact of degradation and restoration on soil fungi and extracellular enzyme activity in alpine rangelands on the Tibetan Plateau

Degradation and enclosure can change plant composition and soil properties, thereby alter soil microbial community, diversity and activity. This study used high-throughput sequencing and microplate fluorometric to determine the patterns of soil fungal community and extracellular enzyme activity (EEA) under degradation and restoration on the Tibetan Plateau. Three degradation (including: non-degraded, DN; moderately degraded, DM; and severely degraded, DS) and three enclosure (including: 5 years, EI; 10 years, EII; and 15 years, EIII) treatments were set up. DM and DS increased the species richness of fungi compared with DN. EI decreased the fungal diversity compared with DS while EII significantly increased it. DM significantly increased EEA while DS had no significant effect on any EEA compared to DN. EI decreased EEA (significant for βX), EII increased EEA (significant for βG) compared with DS while EIII had no significant effect. This variation of EEA among different degradation and enclosure treatments could be partially explained by soil properties and fungal community but had no relation with plant properties. The degradation could change soil fungi and extracellular enzyme activity and may adversely affect vegetation health in the alpine ecosystem. Enclosure could partially reverse these changes, but long-term field experiments are still needed.