Convergence in temperature sensitivity of soil respiration: Evidence from the Tibetan alpine grasslands
Convergence in temperature sensitivity of soil respiration: Evidence from the Tibetan alpine grasslands
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土壤呼吸温度敏感性的收敛：来自西藏高寒草原的证据
DOI：
10.1016/j.soilbio.2018.04.005
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发表时间：
2018
影响因子：
9.7
通讯作者：
He Jin Sheng
中科院分区：
文献类型：
--
作者：
Wang Yonghui;Song Chao;Yu Lingfei;Mi Zhaorong;Wang Shiping;Zeng Hui;Fang Changming;Li Jingyi;He Jin Sheng
最近的研究提出，在使用奇异谱分析（SSA）或混合效应模型（MEM）方法等新方法消除混杂效应后，土壤呼吸（Rs）的温度敏感性（Q10）趋于收敛。然而，由于SSA仅应用于涡动相关数据来估算q10随气温的变化，这可能导致在气候-碳耦合模式中低估了地下碳循环过程对气候变暖的响应；MEM在单点研究中的适用性尚未得到检验。结果表明，1)rsrs -温度季节关系估计的rsrs的混淆Q10与Rs的季节性正相关，2)使用SSA（平均 = 2.4,95%可信区间（CI）： 2.1-2.7）和MEM（平均 = 3.2,95% CI: 2.3-4.2）估计的rsrs的非混淆Q10与理论亚细胞水平Q10（≈2.4）一致。这些结果支持了rq10的收敛性，并暗示了一个守恒的r -温度关系。这些发现表明，在估计Rs的q10时应消除rsha的季节性，否则估计应该是可疑的。他们还指出，季节性q10及其对变暖的响应不应直接用于碳气候模型，因为它们包含混淆效应。
Recent studies proposed a convergence in the temperature sensitivity (Q10) of soil respiration (Rs) after eliminating confounding effects using novel approaches such as Singular Spectrum Analysis (SSA) or the mixed-effects model (MEM) method. However, SSA has only been applied to eddy covariance data for estimating the Q10with air temperature, which may result in underestimations in responses of below-ground carbon cycling processes to climate warming in coupled climate-carbon models; MEM remains untested for its suitability in single-site studies. To examine the unconfounded Q10of Rs, these two novel methods were combined with directly measured Rsfor 6 years in two Tibetan alpine ecosystems. The results showed that, 1) confounded Q10of Rsestimated from seasonal Rs-temperature relationship positively correlated with the seasonality of Rs, and 2) estimates of unconfounded Q10of Rsusing SSA (mean = 2.4, 95% confidence interval (CI): 2.1–2.7) and MEM (mean = 3.2, 95% CI: 2.3–4.2) were consistent with the theoretical subcellular-level Q10(≈2.4). These results support the convergence in the Q10of Rsand imply a conserved Rs-temperature relationship. These findings indicate that the seasonality of Rshas to be eliminated from estimating the Q10of Rs, otherwise the estimates should be questionable. They also indicate that seasonal Q10and its responses to warming should not be directly used in carbon-climate models as they contain confounding effects.