Mycorrhizal dominance influences on forest tree diversity in Southwest China

Mycorrhizal associations drive plant community diversity and ecosystem functions. Arbuscular mycorrhiza (AM) and ectomycorrhiza (EcM) are two widespread mycorrhizal types and are thought to differentially affect plant diversity and productivity by nutrient acquisition and plant–soil feedback. However, it remains unclear how the mixture of two mycorrhizal types influences tree diversity at large spatial scales. Here, we explored these issues using data from 698 plots (400 m2 for each) across natural forests located in Southwest China. Both AM-dominated and EcM-dominated forests show relatively lower tree species richness, species evenness and Shannon diversity, whereas forests with the mixture of mycorrhizal strategies support more tree diversity. Interestingly, the impacts of EcM dominance depend on climate and soils. Our findings suggest that mycorrhizal dominance influences tree diversity in forest ecosystems.