Peatlands and Global Warming

Global peatlands store large amounts of carbon within a few meters of the atmosphere, and the peatland-atmosphere carbon exchange is of major interest to global change scientists, including Zicheng Yu.

Yu takes an interdisciplinary approach to his research, which centers on the late Quaternary paleoecology and paleoclimatology. He uses information stored in peatlands and lake sediments to study the dynamics of vegetation, climate, hydrology and carbon cycle and their connections.

Yu is breaking ground with his research. Working this summer on Alaska’s North Slope, Yu and his team extracted soil core samples, each up to a few meters deep.

Scientists want to know what will happen in the underlying layers of peat as the climate gets warmer.  The approach is to examine geo-historical records and make observations and understand how peatland carbon responded to warming climate in the past, which can be used to infer what will happen in the future.

“We’ve found that peatlands are happier when it’s warmer,” he says. “They accumulate carbon rapidly under a warmer climate, but they need to be wet, as the warming may make the climate drier and the peat bogs suffer.”

 Yu speculates that peatlands will expand in a warmer climate, despite they are suffering along the southern edge of northern peatlands due to a drier climate. The challenge is to determine the overall balance for the next 100 years as some peatlands release carbon while others capture more carbon from the atmosphere.

Beyond his work in Alaska, Yu has conducted research in the Tibetan Plateau, Patagonia, and Kamchatka. Yu’s work last summer in Kamchatka, Russia developed the first carbon accumulation record of peatlands there. Along with collaborators at University of Hawaii, Bowdoin College, Lehigh postdoctoral fellow Julie Loisel and others, he is synthesizing data across the Arctic to create a detailed view of how carbon responded to past warming periods, as far as 10,000 years.  Funded also by the National Science Foundation, Yu will travel to Antarctica in February to examine how peat responds to climate change. 

By using paleoecological information resulting from lake and wetland sediments, he is reconstructing past changes and determining environmental influences on upland and wetland vegetation. Reconstructed change from these paleoecological records, together with independent information on climate from oxygen isotopes and on soil/ landscape development, provides valuable data in discussing past ecosystem processes related to climate-soil-vegetation interactions.