BEF-China

Mycorrhizae are symbiotic associations between terrestrial plants and fungi in which fungi obtain nutrients in exchange for plant photosynthates. However, it remains unclear how different types of mycorrhizae affect their host interactions and productivity. Utilizing a long-term experiment with a diversity gradient of arbuscular (AM) - and ectomycorrhizal (EcM) trees, here we show that the type of mycorrhizae critically controls the effect of diversity on productivity. With increasing diversity, net primary production (NPP) of AM trees increased but EcM trees decreased, largely because AM trees are more effective in acquiring nitrogen and phosphorous. Specifically, with diversity increase, AM trees enhance both nutrient resorption and litter decomposition, while there is a tradeoff between litter decomposability and nutrient resorption in EcM trees. These results provide a mechanistic understanding of why and how AM trees dominate in vast tropical and subtropical forests, which would enable better prediction of ecosystem productivity in changing climates.