Extant species are more responsive than locally extinct species to warming effects on soil communities

Purpose: Climate change may alter interactions between plants and their associated soil microbial communities, including microbe-mediated plant-soil feedbacks (PSF). If PSF influence plant performance and abundance in natural communities, climate-induced changes in soil communities might affect local extinction. Here, we examine whether warming-induced shifts in plant-soil interactions are associated with local species loss in tallgrass prairie. Methods: We conducted a traditional two-phase PSF experiment. In phase 1, phylogenetic pairs of locally extinct and extant prairie species were grown under ambient or elevated temperature conditions in the field. In phase 2, soil microbial communities were collected from below those plants and inoculated onto conspecific and heterospecific seedlings grown in the greenhouse. We compared warming effects on plant performance in soil conditioned by locally extinct and extant species as well as net-pairwise PSF between phylogenetic pairs. Results: Locally extinct prairie species were more sensitive to soil biota than extant species, generally performing better when grown in soils cultivated by certain extant species. Meanwhile, extant species were more responsive to warming effects on soil communities than locally extinct species, although the direction and magnitude of temperature effects varied across species. We detected no significant overall effects of warming on net-pairwise PSF. Conclusion: These findings suggest that soil biota might have affected historical plant species losses via negative effects of locally extinct species’ soil on their own growth. Warming-induced shifts in soil communities might influence extant prairie species’ performance under climate change, indicating a need to consider plant–microbe interactions in future prairie conservation efforts.