Effects of between-site variation in soil microbial communities and plant-soil feedbacks on the productivity and composition of plant communities

A critical challenge in the science and practice of restoration ecology is to understand the drivers of variation in restoration outcomes. Soil microbial communities may have a role in explaining this variation due to both site-to-site variation in the composition of soil microbial communities and due to variation that can arise due to plant-soil feedbacks. We tested the relative importance of between-site variation in soil microbial community composition and plant-soil feedbacks in shaping plant community composition and ecosystem function. We used a standard two-phase plant-soil feedback design. Soil inoculum was collected from four tallgrass prairie sites. Then, soils were conditioned separately with nine plant species, and conditioned soils were used to inoculate prairie community mesocosms. In a separate experiment using soil from an additional site we tested conditioned soil samples for the abundance of arbuscular mycorrhizal fungi (AMF) and rhizobia. Site of soil origin and...