Plant–soil feedbacks: connecting ecosystem ecology and evolution

Summary While an appreciation of plant–soil feedbacks (PSF) continues to expand for community and ecosystem ecology, the eco-evolutionary mechanisms and consequences of such feedbacks remain largely unknown or untested. Determining the cause and effect of plant phenotypes is central for understanding these eco-evolutionary dynamics since phenotypes respond to soil selective gradients that are, in turn, modified by plant traits. Genetic variation in plant phenotypes can change soil processes and biotic communities; oppositely, soil gradients and microbial communities can influence the expression and evolution of plant phenotypes. Although these processes represent the two halves of genetic based PSF, research in these areas has developed independently from one another. Greater connectivity between research on ecosystem consequences of plant genetic variation and soil selective gradients that drive plant phenotypic evolution will create novel and important opportunities to link ecology and evolution in natural systems. Papers in this special feature build on the inherent ecological and evolutionary processes involved in PSF, outlining many ways to identify and test mechanisms that connect ecosystem ecology and evolution.