Colorado State Researchers to Evaluate Whether Arctic Soil Microbes are Key Factor in Climate Change

The behavior of trillions of tiny microorganisms in the cold, dark soils of the Arctic may tell scientists how climate change will impact the fragile soils of this vast region.

Two Colorado State University scientists in separate colleges – Matthew Wallenstein in the Warner College of Natural Resources and Ken Reardon in the College of Engineering – are working with Josh Schimel from the University of California-Santa Barbara and Michael Weintraub from the University of Toledo on the research, which is funded by the National Science Foundation. As part of the $904,623 grant, the Colorado State scientists will study proteins in the cells of the soil’s microorganisms – a brand-new field of research known as soil proteomics.

The research is funded as part of the 4th International Polar Year, a global effort to support a wide array of scientific investigations of the Arctic, which appears to be experiencing effects of rapid climate change.

"The distribution of plants in the Arctic is changing because of global warming and that is having an impact on microorganisms," said Reardon, a professor of chemical and biological engineering. "We want to look at how the constant process of freezing and thawing affects the functioning of these microbes and ultimately impacts the whole Arctic ecosystem."

Wallenstein, a research scientist in ecology, along with fellow research scientist Heidi Steltzer, leave in October for the U.S. Air Force base in Thule, Greenland; Reardon plans to visit in the spring. Wallenstein’s graduate student, Jessica Ernakovich, plans to join the team from the University of California and the University of Toledo on a sampling trip to Alaska later this fall.

"We will study tundra systems in low Arctic of Toolik Lake in northern Alaska, and the high Arctic of western Greenland because between them, they cover the full latitude and climate range within the terrestrial Arctic and, as a result, cover most of the dominant arctic plant communities," said Wallenstein, who is the principal investigator on the Colorado State portion of the research. "We now know that soil microbes are not dormant in frozen soils. The activity of microbes during the arctic winter is an important aspect of nutrient cycling, and this activity has strong impacts on the plants that live in these cold environments, and has the potential to affect the concentration of carbon dioxide in our atmosphere.

"We’re taking a multidisciplinary approach – it’s ecology, it’s biochemistry, microbiology and biological engineering."

The goal of proteomics is to look at all the proteins in a cell or tissue simultaneously, whereas other approaches only consider one protein at a time. Reardon’s group was among the first to apply these techniques to complex communities that contain thousands of bacterial species, such as those found in soils. This study will apply these cutting-edge techniques to address fundamental questions in biology that are especially important to understand the rapidly changing planet.

They’ll take samples in the field and bring them back to their Colorado State laboratories where they will detect the proteins that the soil microbes use to survive in freezing conditions, and when soils are repeatedly frozen and thawed. On the tundra, the top layers of the soil can undergo repeated cycles of freezing and thawing as they warm in the daytime sun and freeze at night. This can lead to the release of carbon dioxide from the soil, which is a contributor to climate change.

Using chemical and biological engineering, scientists can study all the proteins in the cells of microorganisms to determine how those cells survive in extreme conditions.

"This research will give us a basic understanding of these processes so we can better predict the future effects of climate change on these important ecosystems," Wallenstein said.

Reardon and his research group in engineering have been studying the biological breakdown of pollutants for 18 years and have been using proteomics for the past 12 years on bacteria involved in bioremediation and other environmental processes.

Wallenstein joined the Natural Resource Ecology Laboratory at Colorado State in May 2006. His research interests include arctic microbial ecology, soil microbial responses to climate change, and environmental proteomics.

Reardon and Wallenstein are among a group of Colorado State scientists who are involved in International Polar Year research. For more information, visit