Education | Forest Function | Global Carbon | Land/Water | Landcover/Land Use | Science in Public Affairs
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Woods Hole Research Center Scientist Furthering Discussion of Temperature, Carbon Decomposition and Feedbacks to Climate ChangeMarch 10, 2006
Significantly more carbon is stored in the world's soils than is present in the atmosphere. In a process called a "positive feedback," global warming may stimulate decomposition of soil organic matter, thus releasing heat-trapping carbon dioxide gas to the atmosphere, possibly causing the rate of global warming to increase further. Disagreement exists, however, regarding the effects of climate change on global soil carbon stocks. Eric Davidson, a senior scientist at the Woods Hole Research Center, has written a review paper that clarifies the issues regarding temperature sensitivity of decomposition within a framework that helps to focus the ensuing debate and research. Co-authored with Ivan Janssens of the University of Antwerpen (Belgium), the study is being published in an upcoming issue of Nature. According to Dr. Davidson, interest in this topic is high because of its importance in the global carbon cycle and potential feedbacks to climate change. “The arctic, in particular, is experiencing very rapid warming, causing permafrost to melt and some peatlands to dry out, thus potentially exposing huge stocks of previously frozen and waterlogged carbon to decomposition. We need to understand how much of this carbon that is stored in soils, peatlands, and permafrost is susceptible to loss in a warmer world. If you unplug your refrigerator, you can demonstrate that your food, which is basically organic matter, spoils more quickly when it is warm. However, because the soil is a complex mixture of minerals and organic matter derived from plant leaves and roots, soil scientists and ecologists have had difficulty teasing out the conditions and types of organic matter that respond significantly to temperature changes.” The review paper by Davidson and Janssens sets forth a description of how both the chemical complexity of carbon molecules and the soil conditions in which they are found determine the rates at which they decompose. While most of the research results that Davidson and Janssens review
come from studies of forests and farms in temperate regions, they conclude
that research on the temperature sensitivity of decomposition should
be broadened to include peatlands, wetlands and permafrost in boreal
and arctic regions, where huge stocks of soil carbon are susceptible
to a rapidly changing climate Davidson’s research on soil carbon has been funded by the Department of Energy, the National Science Foundation, and NASA. Dr. Davidson is an ecologist and soil scientist interested in the role of soil microorganisms as processors of carbon and nitrogen. He has studied the transfer of carbon and nitrogen gases from the soil to the atmosphere, where they contribute to warming of the earth. His research addresses how human management of the land affects this transfer of greenhouse gases. Dr. Davidson has held positions as National Research Council Associate at the NASA Ames Research Center and as Post-Doctoral Research Associate in Soil Microbiology at the University of California, Berkeley. He earned his doctorate in forestry at North Carolina State University. The Woods Hole Research Center is dedicated to science,
education, and public policy for a habitable Earth. We seek to conserve
and sustain the planet's vegetation, soils, water, and climate by clarifying
and communicating their interacting functions in support of human well-being
and by promoting practical approaches to their management in the human
interest. The Center has projects in the Amazon, the Arctic, Africa,
Russia, Alaska, Canada, New England, and the Mid-Atlantic — as
well as integrative efforts at continental to global scale — working
in collaboration with a wide variety of partners ranging from local
NGOs, research centers, and enterprises to national governments and
the United Nations. |
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©Woods Hole Research Center, 2007 |
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