Temperature sensitivity of soil carbon decomposition and feedbacks to climate change

• Published in: Nature Vol. 440; no. 7081; pp. 165 - 173
• Main Authors: Davidson, E.A, Janssens, I.A
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 09.03.2006; Nature Publishing; Nature Publishing Group
• Subjects: air temperature; Atmosphere; biodegradation; biogeochemical cycles; Carbon; Carbon - metabolism; Carbon Dioxide - metabolism; Climate change; Climate effects; Decomposition; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; Freshwater; Greenhouse Effect; Humanities and Social Sciences; literature reviews; multidisciplinary; Organic compounds; Peatlands; Permafrost; Plants - metabolism; Pollution, environment geology; review-article; Science; Science (multidisciplinary); Soil - analysis; soil organic carbon; soil organic matter; Soil sciences; soil temperature; Soils; Surficial geology; Temperature; Temperature effects; Wetlands; wetlands; climate modification; permafrost; carbon; peat bogs; substrates; temperature; organic compounds; kinetics; soils; peat
• ISSN: 0028-0836; 1476-4687; 1476-4687; 1476-4679
• DOI: 10.1038/nature04514

Significantly more carbon is stored in the world's soils-including peatlands, wetlands and permafrost-than is present in the atmosphere. Disagreement exists, however, regarding the effects of climate change on global soil carbon stocks. If carbon stored belowground is transferred to the atmosphere by a warming-induced acceleration of its decomposition, a positive feedback to climate change would occur. Conversely, if increases of plant-derived carbon inputs to soils exceed increases in decomposition, the feedback would be negative. Despite much research, a consensus has not yet emerged on the temperature sensitivity of soil carbon decomposition. Unravelling the feedback effect is particularly difficult, because the diverse soil organic compounds exhibit a wide range of kinetic properties, which determine the intrinsic temperature sensitivity of their decomposition. Moreover, several environmental constraints obscure the intrinsic temperature sensitivity of substrate decomposition, causing lower observed 'apparent' temperature sensitivity, and these constraints may, themselves, be sensitive to climate.