The resilience of plant communities to invasion by exotic species may depend on the extent to which native and exotic plant performance are mediated by abiotic and biotic components of the soil. In a recent study published in AoB PLANTS by Shivega and Aldrich-Wolfe, two native tallgrass prairie species and an exotic invasive exhibited strong differences in performance between soils with and without native microbes and with differing nitrogen availability in a greenhouse experiment. Increased nitrogen availability benefitted only the exotic, while native microbes benefitted only the natives. The microbial benefit to native plant growth disappeared under high soil nitrogen, while the negative effect of elevated nitrogen on survival of one of the natives was ameliorated by the presence of the exotic. Nitrogen and soil microbes thus interact to affect the strength of competition in plant invasions.
