The future of midwestern tallgrass prairies: Soil pathogen community response to environmental change

Soil pathogens are an important and often overlooked component of plant communities. Though they are harmful to individual plants, they positively contribute to the overall diversity and composition of plant communities. While beneficial symbiont communities in prairie ecosystems have been extensively studied, little is known about how pathogenic soil microbes are affected by global climate change and human land use in these systems. Therefore, in this study, we examine the impact of human disturbance and global change on soil pathogen community structure. To study these soil pathogens, we looked at paired sites of remnant prairies, those undisturbed by human activity, and disturbed prairies across a precipitation and temperature gradient in the Midwestern US. Oomycete and fungal DNA was sequenced from extracted soil and run through two custom pipelines. We then used statistical tests to examine differences in community composition and OTU richness across these environmental and human use gradients. Ultimately, we find that different groups of soil microbes react similarly to human land use disturbance across environmental gradients: environmental gradients are important in driving community responses in remnant, but not disturbed, prairies. These results illuminate how microbial pathogens react to their environmental factors, and has implications for restoration success, remnant stability after restoration, and potential invasion by non-native plants.