Evidence that decomposition rates of organic carbon in mineral soil do not vary with temperature
Evidence that decomposition rates of organic carbon in mineral soil do not vary with temperature
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DOI：
10.1038/35009076
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发表时间：
2000-04-20
期刊：
影响因子：
64.8
通讯作者：
Ryan, MG
中科院分区：
文献类型：
--
作者：
Giardina, CP;Ryan, MG
有人认为，温度的升高会加速森林矿物土壤中所含有机碳（C-s）的分解，因此，全球变暖会增加土壤有机碳向大气的释放（1-6）。然而，这些预测假设，衰减常数可以准确地从短期的实验室培养的土壤或新鲜的凋落物原位培养准确地代表C-S分解的温度敏感性。但是，我们对控制碳硫分解速率的生物物理因素的有限理解，以及在长期森林土壤加热实验（7-12）和碳硫分解速率的纬度比较（13-15）中观察到碳硫分解速率随温度仅略有增加，使这些预测受到质疑。在这里，我们收集了来自五大洲82个地点的C-S分解数据。我们发现，C-S分解率是显着恒定的全球尺度梯度的年平均温度。这些数据表明，森林土壤的C-S分解速率不受温度对微生物活性的限制的控制，并且单独增加温度不会刺激矿物土壤中森林来源的碳的分解。
It has been suggested that increases in temperature can accelerate the decomposition of organic carbon contained in forest mineral soil (C-s), and, therefore, that global warming should increase the release of soil organic carbon to the atmosphere(1-6). These predictions assume, however, that decay constants can be accurately derived from short-term laboratory incubations of soil or that in situ incubations of fresh litter accurately represent the temperature sensitivity of C-s decomposition. But our limited understanding of the biophysical factors that control C-s decomposition rates, and observations of only minor increases in C-s decomposition rate with temperature in longer-term forest soil heating experiments(7-12) and in latitudinal comparisons of C-s decomposition rates(13-15) bring these predictions into question. Here we have compiled C-s decomposition data from 82 sites on five continents. We found that C-s decomposition rates were remarkably constant across a global-scale gradient in mean annual temperature. These data suggest that C-s decomposition rates for forest soils are not controlled by temperature limitations to microbial activity, and that increased temperature alone will not stimulate the decomposition of forest-derived carbon in mineral soil.