As the usage of plant protection products increases in agricultural systems, there are growing concerns for how these products may alter the state of contaminated off-target systems. Midwestern prairie systems represent one such environment that can become contaminated with pesticides via drift and run-off. Yet, the indirect effects that these pesticides have on plant fitness by modulating important plant microbial symbionts are not well understood. For instance, fungicides decrease the diversity and richness of fungal endophytes in soybean crops and alter the diversity and enzymatic activity of soil microbes, but few studies have shown how this shift in microbial communities impacts the plant host. Few studies have also characterized the function of endophytic communities and have instead focused on either studying the impact that single isolates or the co-inoculation of multiple cultivable isolates have on host fitness. Thus, there is a severe lack in knowledge about how endophytic symbionts modulate plant hosts when co-inoculated with other naturally occurring taxa, both cultivable and uncultivable. Lastly, a study that links the function between these aboveground and belowground plant microbial communities is crucial to fully understand how multipartite interactions mediate plant hosts’ fitness. GEMS trainee Noah Brown will utilize an experimental prairie in Urbana, IL called the Philips Tract (PT) to answer these questions about how pesticide-mediated shifts in microbial communities affect the inhabiting plants’ fitness.