Precipitation exerts a strong influence on arbuscular mycorrhizal fungi community and network complexity in a semiarid steppe ecosystem

Abstract Arbuscular mycorrhizal fungi (AMF) play a crucial role in ecosystem functioning in terrestrial ecosystems. However, we know little about how AMF communities shift in response to key climatic changes. To test whether precipitation is a driving force in shaping AMF community structure, we conducted a 3-year field experiment to investigate the impacts of increased and decreased precipitation on the AMF community and the co-occurrence network of AMF communities in a temperate steppe of northern China. By combining Illumina Miseq sequencing with bioinformatics analyses, a total of 181 AMF operational taxonomic units (OTUs) were identified under three precipitation manipulation experiments. Based on our results, precipitation significantly affected the community structure of AMF, whereas AMF diversity was not affected by precipitation. Based on the results of redundancy analysis, precipitation indirectly influences the AMF communities via in changes soil pH. Co-occurrence network analysis revealed that increased precipitation increased the complexity of AMF communities, suggesting that precipitation can change the interactions between AMF communities. Our results prove the transformation of AMF communities along key environmental gradients, which would help us to better predict ecosystem-level responses of vegetation to climatic changes.