Long-term warming and decreased precipitation regulated microbial community structure and potential function through...

Global climate change can shape the interactions among soil microbes and, in turn, mediate ecosystem functions. However, how these interactions were regulated remains to be investigated. This study utilized 16S rRNA, ITS, and 18S rRNA high-throughput sequencing to investigate the effects of simulated warming and precipitation changes on the major components of soil micro-food webs in the Qinghai-Tibetan Plateau through a field experiment. Adonis and non-metric multidimensional scaling (NMDS) analyses showed that compositions of bacteria, fungi and protists were all affected by changes in temperature and precipitation. Correlation and cross-trophic network analyses revealed that warming and decreased precipitation, both separately and together, enhanced the relationships between bacteria and protists, especially protistan predators. We found that the modified stochasticity ratio of the bacterial community assembly was best predicted by protists. The potential functional structures of bacteria were positively correlated with protistan predators under warming and decreased precipitation condition, suggesting enhanced predator-prey relationships between protists and bacteria might further influence the potential functional characteristics of bacterial communities. Our study indicated that climate change altered bacterial compositional and functional structure via enhanced predator-prey interactions. Therefore, in the context of global climate change, broader and more comprehensive studies on protist-regulated soil bacterial and fungal communities are imperative.