Consistent temperature dependence of respiration across ecosystems contrasting in thermal history
Consistent temperature dependence of respiration across ecosystems contrasting in thermal history
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DOI：
10.1111/j.1365-2486.2011.02597.x
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发表时间：
2012-04-01
影响因子：
11.6
通讯作者：
Woodward, Guy
中科院分区：
文献类型：
--
作者：
Perkins, Daniel M.;Yvon-Durocher, Gabriel;Woodward, Guy
生态系统呼吸是碳循环的主要组成部分，了解决定其温度依赖性的机制对于预测碳排放率如何应对全球变暖至关重要。我们使用了一个罕见的模型系统，包括一个地热加热的流网络，温度范围从5类似摄氏度到25类似摄氏度，探索呼吸和温度之间的关系的性质。使用这个自然的实验，我们测试了是否纳塔尔热制度的流社区影响呼吸的温度依赖性在没有其他潜在的混淆变量。13个流的经验调查表明，整个流呼吸的温度依赖性相当于呼吸复合物的平均活化能（0.60.7类似于eV）。这一观察结果也与原地底栖呼吸一致。实验室实验，孵育生物膜从四个流在整个温度梯度范围内，揭示了呼吸的活化能和Q10是非常一致的跨流，尽管显着的差异，在其热历史和显着的营业额在物种组成。此外，在标准化温度下的绝对呼吸速率也与环境流温度无关，但强烈反映了生物膜生物量的差异。总之，我们的研究结果表明，核心生物化学，驱动氧化呼吸代谢的动力学，可以很好地保存在不同的类群和环境中，呼吸对温度的内在敏感性不受周围环境温度的影响。
Ecosystem respiration is a primary component of the carbon cycle and understanding the mechanisms that determine its temperature dependence will be important for predicting how rates of carbon efflux might respond to global warming. We used a rare model system, comprising a network of geothermally heated streams ranging in temperature from 5 similar to degrees C to 25 similar to degrees C, to explore the nature of the relationship between respiration and temperature. Using this natural experiment, we tested whether the natal thermal regime of stream communities influenced the temperature dependence of respiration in the absence of other potentially confounding variables. An empirical survey of 13 streams across the thermal gradient revealed that the temperature dependence of whole-stream respiration was equivalent to the average activation energy of the respiratory complex (0.60.7 similar to eV). This observation was also consistent for in-situ benthic respiration. Laboratory experiments, incubating biofilms from four streams across the thermal gradient at a range of temperatures, revealed that the activation energy and Q10 of respiration were remarkably consistent across streams, despite marked differences in their thermal history and significant turnover in species composition. Furthermore, absolute rates of respiration at standardised temperature were also unrelated to ambient stream temperature, but strongly reflected differences in biofilm biomass. Together, our results suggest that the core biochemistry, which drives the kinetics of oxidative respiratory metabolism, may be well conserved among diverse taxa and environments, and that the intrinsic sensitivity of respiration to temperature is not influenced by ambient environmental temperature.