Decomposition of particulate organic matter is more sensitive to temperature than the mineral associated organic matter
Decomposition of particulate organic matter is more sensitive to temperature than the mineral associated organic matter
复制标题
DOI：
10.1016/j.soilbio.2013.12.032
复制
发表时间：
2014-03-01
影响因子：
9.7
通讯作者：
Brar, Kiranvir
中科院分区：
文献类型：
--
作者：
Benbi, D. K.;Boparai, A. K.;Brar, Kiranvir
土壤有机质分解的温度敏感性对于确定土壤在未来气候变化中的作用具有重要意义。我们分离出粗粒和细粒有机质(CPOM和fPOM)和矿质伴生有机质(MinOM)，分别代表不稳定的、相对不稳定的和稳定的土壤有机质池(SUM)，并在四个不同的温度下培养每个有机质，以确定分解的温度敏感性。土壤有机C(SOC)库最小的粗颗粒有机C最易分解，占SOC一半以上的矿质伴生有机C最不分解。在所有温度下，碳矿化速率的大小顺序为CPOM>；=fPOM>；全土>；MinOM。在15~45℃温度范围内，CPOM与其他两种总和和全土矿化速率的差异随着温度的升高而扩大，表明不稳定的总和比稳定的总和对温度更敏感。Arrhenius、Llyod和Taylor以及Gauss模型很好地描述了有机质分解的温度依赖性，但不同模型的温度响应曲线形状差别很大。对于不同的总和和整个土壤，Gauss模型的分解Q(10)最高，Arrhenius模型的Q(10)最低。在低于25℃的温度下，分离的总和组分的分解温度响应主要不同，超过25℃，反应趋于收敛，这表明不稳定和稳定的池对温度的差异响应在温度低于25℃时最明显，超过25℃的影响将很小，对于不同稳定性的总和池的影响也是相似的。受全球变暖影响，CPOM组分的分解受影响最大，MinOM受影响最小。(C)2014爱思唯尔有限公司。保留所有权利。
Temperature sensitivity of soil organic matter decomposition is important in determining the role of soils in future climate change. We isolated coarse and fine particulate organic matter (cPOM and fPOM) and mineral associated organic matter (MinOM) to represent labile, relatively less labile and stable pools of soil organic matter (SUM), respectively and incubated each at four different temperatures to determine temperature sensitivity of decomposition. The coarse particulate organic C, which comprised the smallest pool of soil organic C (SOC) was most decomposable and the mineral associated organic C that accounted for more than half of the SOC was least decomposable. At all the temperatures, the C mineralization rate followed the order cPOM >= fPOM > whole soil > MinOM. The disparity in the mineralization rates between cPOM and the other two SUM fractions and the whole soil widened with increase in temperature from 15 degrees to 45 degrees C indicating that the labile pools of SUM were more sensitive to temperature than the stable pool. The Arrhenius, the Llyod and Taylor and the Gaussian models well-described the temperature dependence of organic matter decomposition, but the shape of the temperature response curve for different models varied considerably. Gaussian model yielded the highest decomposition Q(10) and the Arrhenius model the lowest Q(10) for different SUM fractions and whole soil. The decomposition temperature response of isolated SUM fractions mainly differed at temperatures below 25 degrees C beyond which the response tended to converge suggesting that the differential response of labile and stable pools to temperature will be foremost at temperatures below 25 degrees C beyond which the effect will be small and similar for SUM pools of different lability. The decomposition of cPOM fraction is likely to be influenced to the greatest extent and the MinOM at the least as a result of global warming. (C) 2014 Elsevier Ltd. All rights reserved.