Understanding the effects of above- and belowground linkages on carbon cycling in a high latitude, coastal wetland

Utah State University, Logan UT

Investigators

Abstract

The Yukon-Kuskokwim Delta of western Alaska is one of the largest river deltas in the world and the summer home to millions of migratory birds. Although grazing birds strongly affect the plant communities in river deltas, little is known about how changing waterfowl populations in the Arctic affect the release from soils of greenhouse gases like carbon dioxide and methane. This project is examining relationships among grazing birds, plant communities, soil microbes, and ecosystem carbon cycling in the Yukon-Kuskokwim Delta to predict how these ecosystems may change in the future. This project will produce on-line learning modules about the relationships among geese, plants, microbes, and greenhouse gases and disseminate them to middle school students in the local Alaskan school district. Local students will also be trained in and produce local radio stories about the research. Finally, the research will be broadcasted through on-line media outlets and local TV channels. This project is using a combination of field experiments, lab experiments, and biogeochemical models to provide a mechanistic understanding of the effects of grazing on greenhouse gas dynamics in a high latitude coastal wetland. This project is quantifying the independent and combined effects of grazing, trampling, and feces deposition by geese on microbial communities, soil microclimate, and carbon dynamics using a two-year field experiment. A laboratory experiment is being used to quantify how herbivore-mediated changes in the quantity and quality of soil carbon inputs affect microbial community structure and carbon dynamics. Finally, results from these experiments are being used to parameterize a biogeochemical simulation model to predict how changes in herbivory will affect carbon dynamics in subarctic wet sedge under future climates. By examining the effects of herbivory with this holistic view, the predictive power of ecosystem models will be increased, especially for high-latitude systems where herbivory is a prevalent driver of primary production and plant community composition. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.