Linkage of vegetation and abiotic attributes to grazing effects on biogeographical patterns of arbuscular mycorrhizal fungal communities in temperate grasslands

Purpose Grazing is a traditional way of grassland management in Inner Mongolia of China. Despite important roles of arbuscular mycorrhizal fungal (AMF) communities in grassland ecosystems, few studies have specifically focused on the effects of grazing on AMF communities in grassland, particularly at regional level. Methods High-throughput sequencing technology was used to evaluate the effects of grazing on AMF communities along a 700-km transect that was characterized by a precipitation gradient and comprised of 10 pairs of ungrazed and grazed sites in temperate grasslands along the China-Mongolia border. Results Grazing significantly altered α and β diversity of AMF community along the precipitation gradient from southwest to northeast. α diversity of AMF community was positively correlated with plant species richness and percentage cover. Furthermore, α diversity of AMF community displayed a positive correlation with soil moisture and organic carbon but a negative correlation with pH. The response ratio of α diversity of AMF community displayed positive correlation with the response ratio of percentage cover. Analyses by db-RDA (distance-based redundancy analysis) and VPA (variance partitioning analysis) revealed that both vegetation and abiotic properties were involved in the grazing-induced changes in AMF communities. Conclusions AMF communities exhibited distinct biogeographical patterns across a precipitation gradient from southwest to northeast in northern China. Grazing led to significant changes in the diversity of AMF communities at regional level. Both vegetation and abiotic attributes were linked to grazing-induced changes in AMF community of the temperate steppes.