Global arbuscular mycorrhizal fungal diversity and abundance decreases with soil available phosphorus.

Aim: Arbuscular mycorrhizal fungi (AMF) are widely distributed soil organisms that play critical roles in ecosystem functions. However, little is known about their global distribution and the underlying mechanisms. Here, we aimed to explore distribution pattern and key predictors of AMF diversity and abundance at the global scale. Location: Global. Time Period: 1987–2022. Major Taxa Studied: Arbuscular mycorrhizal fungi. Methods: We investigated the distribution pattern and key predictors of AMF diversity and abundance at the global scale by compiling 654 field studies. Results: We found that cold climate zones had relatively low AMF diversity. At the ecosystem level, grassland tended to have higher AMF diversity and abundance. Soil available phosphorus (P) and latitude were the most important predictors of AMF diversity. AMF richness and Shannon index decreased with increasing soil available P and latitude. Soil available P and soil pH were the main predictors for global distribution of AMF abundance. AMF colonization rate and spore abundance declined with soil available P and increased with soil pH. Mean annual precipitation was also an important, positive correlate of spore abundance. Main Conclusions: Our findings highlight soil available P as an important predictor affecting the distribution of AMF diversity and abundance, advancing our understanding of the mechanisms underlying the distribution patterns of mycorrhizal fungal diversity and abundance at the global scale. [ABSTRACT FROM AUTHOR]