Landscape-level variation in temperature sensitivity of soil organic carbon decomposition

We examined landscape-level variation in temperature sensitivity of labile SOC across 71 sites at a central North American grassland. The observed range in activation energy of decomposition (E-a), an index of temperature sensitivity, was as great at the landscape scale as has been observed at the continental scale. E-a was lower for soils with more labile C, consistent with the 'Carbon quality-temperature' hypothesis. Soil pH explained 67% of the variation in E-a. Although there are strong environmental correlates with the E-a of SOC decomposition at landscape scales, the amount of variation within landscapes could confound regional-to global-scale predictions of the response of soil C to warming. (C) 2009 Elsevier Ltd. All rights reserved.