Warming mineralises young and old soil carbon equally
Warming mineralises young and old soil carbon equally
复制标题
DOI：
10.5194/bg-3-515-2006
复制
发表时间：
2006-01-01
期刊：
影响因子：
4.9
通讯作者：
Alewell, C.
中科院分区：
文献类型：
--
作者：
Conen, F.;Leifeld, J.;Alewell, C.
土壤有机碳分解的温度敏感性对预测未来气候变化至关重要，因为土壤储存的碳量是大气碳量的2-3倍。特别有争议的问题是，年轻的或不稳定的碳库与年老的或更稳定的碳库之间的温度敏感性是否不同。迄今为止，实验方法的模糊性限制了对任何特定假设的确证。在这里，我们以一种明确的方法表明，年轻碳和老碳之间的温度敏感性差异可以忽略不计。利用C3到C4植被过渡系统中稳定成分的变化，我们能够直接区分出年龄相差几十年的碳的温度敏感性。与之前的方法相比，这种方法有几个优点。它可以识别更古老的碳的释放，避免长期孵育的非自然条件，并且不需要有争议的曲线拟合。研究结果表明，碳循环对气候变化的反馈是由年轻和年老土壤有机碳共同驱动的。
The temperature sensitivity of soil organic carbon decomposition is critical for predicting future climate change because soils store 2-3 times the amount of atmospheric carbon. Of particular controversy is the question, whether temperature sensitivity differs between young or labile and old or more stable carbon pools. Ambiguities in experimental methodology have so far limited corroboration of any particular hypothesis. Here, we show in a clear-cut approach that differences in temperature sensitivity between young and old carbon are negligible. Using the change in stable composition in transitional systems from C3 to C4 vegetation, we were able to directly distinguish the temperature sensitivity of carbon differing several decades in age. This method had several advantages over previously followed approaches. It allowed to identify release of much older carbon, avoided un-natural conditions of long-term incubations and did not require arguable curve-fitting. Our results demonstrate that feedbacks of the carbon cycle on climate change are driven equally by young and old soil organic carbon.