OOS 18

Plant-Soil Feedbacks and Plant Coexistence: Integrating Theoretical Models and Empirical Approaches

Feedback between plants and soils are increasingly recognized as a key component of plant community assembly and diversity. Plant-soil feedbacks are often strongly negative, which could enhance coexistence between plant species and thus increase diversity. Across ecosystems, feedback can vary between plant functional groups and with abiotic conditions, such as soil nutrients and climate. At the local scale, feedback strengths are often correlated with natural relative abundances of co-occurring plant species in a community. While recent work suggests that plant-soil feedback could be a strong driver in plant species coexistence, a mechanistic understanding of this process across taxonomic and spatial scales is lacking. Evaluating the relative importance of plant-soil feedback compared to other community drivers in facilitating plant community coexistence and diversity is now one of the new frontiers of ecological research, largely aided by the rapid development of molecular tools to study microbial communities. However, the generality of the magnitude and drivers of plant-soil feedback across ecosystems is unknown. As with any emerging field, there is a diversity of empirical approaches and wide-ranging theoretical extensions that could benefit from integration. This session aims to bring together early-career and established scientists in the area to exchange cutting-edge results, spark new dialogue, and facilitate effective experimental design to test theory, as well as evidence-informed development of new theoretical directions. This session is organized to present perspectives linking a variety of mechanisms through which plant-soil feedbacks mediate plant species coexistence and community diversity. These perspectives first investigate basic coexistence criteria such as mutual invasibility and intra/interspecific competition and explore mechanisms driving these patterns. The session then extends this perspective to implications for above-belowground interactions, within and between species variation, and exotic plant invasions. Finally, the influence of climate on plant soil feedback is addressed. Overall, this session will link cutting edge empirical and theoretical research on both the biotic and abiotic drivers of plant-soil feedback with plant coexistence across ecosystems.