Eating Like a Bird: NSF Grant Keeps Tabs on Geese Herbivory and Carbon in the Yukon

The Earth’s carbon can be stored in trees and plants, in the ocean, in fossil fuels deep underground, and in the soil directly beneath our feet. It is pulled from these natural stockpiles when plants decay, when humans burn coal for energy, when wildfires burn across a landscape … and in western Alaska when millions of migratory geese have dinner. 

In the Yukon-Kuskokwim Delta, a high latitude Alaskan wetland and one of the largest river deltas in the world, migratory geese are a key driver of greenhouse gas fluctuation. As they graze on native grasses and sedges, these birds are pulling strings in a complex web of ecological interactions that release large amounts of carbon into the atmosphere. And now, with a three-year, $1.4 million grant from the National Science Foundation Polar Programs, USU Watershed Sciences and Ecology Center assistant professor Trisha Atwood and her team can further explore the specific relationship between geese herbivory, plant communities and carbon storage—research that could have major implications for understanding the unpredictable carbon balance in the region over the next century.

Plant-eating birds strongly influence the carbon cycle in far-north ecosystems, by impacting factors both above the ground (eating plants) and below it (altering microbial communities), said Atwood. In the Yukon-Kuskokwim Delta, researchers know that migratory geese are a key component in the system, but can’t yet detail specifically how they impact the carbon cycle. And to exacerbate the issue, migratory patterns for geese are shifting under climate change, creating unpredictable consequences for carbon balance across the entire ecosystem, she said.

“Our goal as a team is to define the working relationship between grass-eating geese, native plants, and the soil microbial communities that are making changes in carbon cycling,” said Bonnie Waring, co-PI on the grant and USU professor of biology. “Understanding exactly how these factors interact on the ground will help us to predict how much carbon will be in the system as geese populations continue to change.”

The team doesn’t plan to leave their research findings on paper. They are partnering with schools in the Lower Kuskokwim school district to develop a program describing the relationship between herbivores, the microbial soil community and carbon cycling, which will be incorporated into the high school curriculum. Native Alaskan students will be trained as technicians on the field projects, and a multimedia story about the research will be produced and disseminated across local channels. 

“This is such a great opportunity … both to better understand an important part of Alaska’s ecosystem and the carbon cycling system that affects the entire planet, and also to share this story with people who have a deep stake in keeping this ecosystem resilient and healthy,” said Karen Beard, co-PI on the grant and USU professor in wildland resources.