Abstract
Plant–soil feedback (PSF), regulated by both mycorrhizae and soil
pathogens, is a primary mechanism maintaining high tree diversity in the
tropics. But how warming may affect PSF is not well understood. We
conducted warming experiments on seedling survival of a
rhizobia-associated species (Ormosia semicastrata) carrying
coevolved host-specific soil-borne pathogens and an ectomycorrhizal
fungi-associated species (Cyclobalanopsis patelliormis) immune to
soil-borne pathogens. We found elevated temperature lowered seedling
mortality of O. semicastrata, but had no detectable effect on
C. patelliormis seedlings. This indicates that warming weakened
the negative PSF on O. semicastrata but did not affect the
positive PSF on C. patelliormis. The differential warming effects
on seedling mortality of species with different microbial associations
imply that global warming could lead to change in tropical tree
composition. Our study also predicts that global warming would undermine
the role of the JC effect in maintaining tree species diversity in the
tropics.