This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
Accurate predictions of community and ecosystem responses to climate change will require identifying not only the direct effects of altered climate on species, but also the indirect effects that occur through biotic interactions or as a result of species impacts on the environment. Those indirect effects may be particularly important for species that modify physical habitat structure. For plants, microbial symbionts have strong potential to mediate plant responses to climate change. This project will compare the relative importance of abiotic and biotic controls on the ways that Ammophila breviligulata (American beach grass) modifies its environment in Great Lakes dune systems. Ammophila breviligulata stabilizes moving sand through prolific root production during the early stages of dune succession, and thus is considered an important ecosystem engineer. Increased summer droughts resulting from climate change may reduce the capacity of A. breviligulata to bind sand and stabilize dunes. However, A. breviligulata hosts a symbiotic fungal endophyte in its leaves and arbuscular mycorrhizal fungi in its roots, which may improve tolerance to drought, alter root architecture, and thus enhance soil stability. Using a combination of lab and field experiments and broad geographic surveys, this study will test whether a microbial symbiosis can mediate effects of climate change on the functioning of an ecosystem engineer. This work will increase knowledge of non-agronomic plant symbionts, with direct application for improving dune restorations in the Great Lakes and Atlantic Coast, as well as for managing invasive populations of A. breviligulata on the West Coast. Underrepresented minorities will be recruited through the NSF AGEP program, providing research experiences for economically disadvantaged students in an EPSCoR state. K-12 education will also be enhanced by providing high school student research opportunities and a national teacher workshop.