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 (Ea), an index of temperature sensitivity, was as great at the landscape scale as has been observed at the continental scale. Ea was lower for soils with more labile C, consistent with the ‘Carbon quality-temperature’ hypothesis. Soil pH explained 67% of the variation in Ea. Although there are strong environmental correlates with the Ea 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.