With peatlands reducing the greenhouse gas carbon dioxide by absorbing carbon like hyper-efficient sponges, Dr. Michael Philben of the Hope College faculty is seeking to learn how much climate change might affect how well they work.
He recently received major support for the research through a $508,000, five-year grant from the Faculty Early Career Development Program (CAREER) of the National Science Foundation. The NSF program recognizes early-career faculty who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization.
“Peatlands are wetland ecosystems that naturally store carbon due to very slow decomposition of plant material, and now store a massive amount of carbon as organic matter. The fate of the carbon in these ecosystems is a key uncertainty in predicting future changes in our climate,” said Philben, an assistant professor of geological and environmental science and chemistry who joined the Hope faculty in 2019. “This project will establish a climate transect of peatlands to help predict how future warming will affect the carbon stored in these ecosystems.”
It’s research for which being based in Michigan serves well. The state is not only home to a number of peatlands, but, Philben explained, provides a distinct enough difference in temperature from south to north that the impact can already be measured. Philben and his team of student researchers will be collecting data from seven locations — from as far south as Portage in the Lower Peninsula to as far north as Newberry in the Upper Peninsula, which as the crow flies are nearly 300 miles apart.
“The sites span 5 degrees Celsius in average temperature, which is similar to the warming expected over the next century,” Philben said. “The project will exploit these natural differences in temperature to determine how carbon cycle processes in peatlands will change with warming.”
Philben plans to uncover how the changes in temperature affect peatlands via the rate of both plant growth, which increases the amount of carbon in the peatlands, and decomposition of the organic matter contained in the wetlands, which decreases the peatlands’ carbon content. “Predicting future changes in the carbon balance has proved difficult because both of these fluxes are expected to increase with warming,” he said.
“Changes in carbon inputs via plant growth will be mediated by nitrogen availability, due to the strong nitrogen limitation of peatland ecosystems,” he said. “Carbon losses will be evaluated by measuring carbon dioxide and methane emissions from the soil, and using litter bag decomposition experiments.”
He will also examine the impact of the overall 1-degree Celsius increase in temperature that has happened since 1900. “The long-term accumulation rate will be compared to the recent accumulation rate, using computer modeling to account for organic matter included in the recent rate that is still undergoing aerobic decomposition,” Philben said.
Hope students will work collaboratively with Philben on the research during both the school year and summer. In addition, he will develop a new course for freshmen that will be centered around a field trip to the project’s peatland sites during the week before the start of classes.
The NSF CAREER grant builds on Philben’s ongoing research interest on the relationship between climate change and the carbon and nitrogen cycles, particularly in ecosystems such as peat bogs and Artic tundra. Prior to starting at Hope, he worked as a postdoctoral researcher at Memorial University in Canada and at Oak Ridge National Laboratory in Tennessee. He has conducted field work in the boreal forests of Newfoundland and Labrador, Canada, and the tundra near Nome, Alaska. His publications include several articles about his research in referred scientific journals.
He graduated from Northwestern University in 2010 with a bachelor’s degree in earth and planetary science, and from the University of South Carolina in 2014 with a doctorate in marine science.