Climate change will likely cause shifts in species interactions that might impact plant population declines. One such interaction is the plant-soil feedback (PSF) that occurs when plant species influence the composition of microbes in the plant rhizosphere, which in affect the plant’s growth. Reduced survival and growth in a species’ own soil suggest negative feedback, likely via accumulation of belowground enemies. Species experiencing positive PSFs might accumulate enemies more slowly or benefit from increased decomposition or interactions with symbionts such as mycorrhizal fungi. However, we know little about PSFs under climate change or their role in plant population declines. We used historical data from 60-80-year-old botanical surveys combined with field and greenhouse experiments to investigate the combined effects of plant-soil feedbacks and climate warming on the growth of locally extinct (here defined as species that have disappeared from a particular area) vs. extant prairie species. Using an experimental warming array, we compared the strength of plant-soil feedbacks in 4 pairs of locally extinct and extant prairie species when they are grown in soil collected from ambient and warmed (+3°C) experimental plots in a simulated global warming array.
Results/Conclusions
Extinct species tend to demonstrate lower growth in warmed soil than in ambient soil, while extant species’ growth did not shift between ambient and warmed soil (status x soil temperature Χ2=3.26, p=0.07). This suggests that plant performance is affected by temperature-mediated shifts in microbial communities. This study will help to inform predictions of future extinction risk of threatened species and improve our understanding of PSFs under climate change.