Sensitivity of organic matter decomposition to warming varies with its quality

作者：Richard T. Conant, Rhae A. Drijber, Michelle L. Haddix, William J. Parton, Eldor A. Paul, Alain F. Plante, Johan Six, J. Megan Steinweg · 发表于：Global Change Biology · 年份：2008 · DOI：10.1111/j.1365-2486.2008.01541.x · 被引用次数：463 · 研究领域：Soil Carbon and Nitrogen Dynamics、Soil and Water Nutrient Dynamics、Peatlands and Wetlands Ecology

Abstract The relationship between organic matter (OM) lability and temperature sensitivity is disputed, with recent observations suggesting that responses of relatively more resistant OM to increased temperature could be greater than, equivalent to, or less than responses of relatively more labile OM. This lack of clear understanding limits the ability to forecast carbon (C) cycle responses to temperature changes. Here, we derive a novel approach (denoted Q 10− q ) that accounts for changes in OM quality during decomposition and use it to analyze data from three independent sources. Results from new laboratory soil incubations (labile Q 10− q =2.1 ± 0.2; more resistant Q 10− q =3.8 ± 0.3) and reanalysis of data from other soil incubations reported in the literature (labile Q 10− q =2.3; more resistant Q 10− q =3.3) demonstrate that temperature sensitivity of soil OM decomposition increases with decreasing soil OM lability. Analysis of data from a cross‐site, field litter bag decomposition study (labile Q 10− q =3.3 ± 0.2; resistant Q 10− q =4.9 ± 0.2) shows that litter OM follows the same pattern, with greater temperature sensitivity for more resistant litter OM. Furthermore, the initial response of cultivated soils, presumably containing less labile soil OM ( Q 10− q =2.4 ± 0.3) was greater than that for undisturbed grassland soils ( Q 10− q =1.7 ± 0.1). Soil C losses estimated using this approach will differ from previous estimates as a function of the magnitude of the temp...