Grassland irrigation and grazing prohibition have significantly affected vegetation and microbial diversity by changing soil temperature and moisture, evidences from a 6 years experiment of typical temperate grassland

Abstract

Grasslands are characterized by high primary productivity and offer a diverse array of ecosystem services that contribute to human well-being. The dynamic balance between vegetation-soil in grassland ecosystems is being affected by anthropogenic activities and climate change, in which soil microbial communities play a critical regulating role. However, how microbial biodiversity interacts with vegetation-soil and responds to environmental change remains unclear. We conducted a six-year field experiment in the grasslands of Inner Mongolia to study the effects of grazing and altered precipitation on major vegetation types (or species), soil properties, and microbial community composition. The results showed that increased precipitation influenced positive associations within microbial communities, which helped to increase vegetation diversity. The biomass of Stipa.sareptana increased by 0.054 % under reduced precipitation, while it significantly increased by 2.07 % under the combination of grazing ban and reduced precipitation. Grazing prohibition had a significant negative effect on bacterial diversity and Shannon's index, but a significant positive effect on fungal diversity and abundance. Increasing precipitation had no significant effect on bacterial diversity under grazing conditions, while decreasing precipitation significantly reduced the Shannon index of bacteria. Fungal communities were very sensitive to changes in precipitation, and both increasing and decreasing precipitation significantly affected the structure of fungal communities. In summary, our results highlight how grassland irrigation and moderate grazing can be employed as a management strategy to promote plant diversity and thereby improve ecosystem functioning and resilience.