AMHERST — Microbiologist Kristen DeAngelis at the University of Massachusetts recently was awarded two grants totaling about $2.5 million from the U.S. Department of Energy to help advance understanding of the role of soil microbes in feeding carbon into the atmosphere and contributing to global warming.
Soils are the largest repository of organic carbon in the terrestrial biosphere and represent an important source of carbon dioxide to the atmosphere, DeAngelis says. “Our results could lead to new ideas for curbing the effects of climate change, and one of the implications of this research could be remediating soil to improve its ability to store carbon.”
The first grant is a three-year, $1.9 million study on microbial feedbacks to climate in a warming world, to investigate microbial control over soil carbon dynamics. The second, a two-year, $600,000 study is designed to resolve conflicting physical and biochemical feedbacks to climate in response to long-term warming.
Soils perform an important ecosystem service by storing carbon, preventing its release as greenhouse gases into the atmosphere. DeAngelis, a microbial ecologist, says both projects will focus on research plots at Harvard Forest, a research station in Petersham, to address the question of how climate change affects soil carbon, and both will examine carbon-use efficiency as a possible source of climate-altered feedbacks to warming. CUE refers to the difference between carbon assimilated into microbial products versus carbon lost to the atmosphere as CO2, creating a positive feedback to climate.
The studies take advantage of long-term soil-warming experiments already in place at the research forest, where heating coils similar to those used to keep football and soccer fields from freezing are buried about 4 inches deep in several plots. They keep the soil surface exactly 5 degrees Celsius warmer than the ambient temperature, creating an outdoor laboratory of artificial climate change. The three patches have been kept warm for as long as 25 years, with research suggesting that long-term trends are not linear.
One goal is new information to estimate how much the planet will warm but which do not account for the microbial contributions, a major contribution to global carbon cycling.