Poster #21

Mechanisms of invasion-induced shifts in plant-fungal associations
V. INFANTE, S. R. FUQUA, L. PARSONS, R. GALLERY
School of Natural Resources and the Environment, University of Arizona, Environment and Natural Resources 2 N582, 1064 E Lowell St, Tucson, AZ 85719, USA

Plant invasions can disrupt species interactions such as associations between plants and root endophytic fungi. In previous work, we found that coastal dunes invaded by European beachgrass (Ammophila arenaria) hosted higher abundances of arbuscular mycorrhizal fungi in the soil compared to native habitats. Beachgrass invasion was also accompanied by changes to soil chemistry, suggesting a potential mechanism for invasion-induced shifts in soil communities. In this study, our goals were to 1) compare plant-fungal associations across native and invaded habitats and 2) untangle the mechanistic drivers of fungal community shifts following invasion. We established plots across a gradient of beachgrass invasion in California coastal dunes. In each plot, we quantified plant community composition and soil chemistry, and collected root samples from a subset of plant individuals. We used a subset of the root samples to quantify endophytic fungal colonization under a microscope. We surface-sterilized the remaining samples and characterized endophytic fungi using amplicon sequencing of the ITS1 region. We used these data in structural equation models (SEM) to look for mechanisms underlying fungal community shifts. We found evidence of invasion-induced shifts in plant-fungal associations, which has implications for native dune community recovery.