Warming increases the proportion of primary production emitted as methane from freshwater mesocosms
Warming increases the proportion of primary production emitted as methane from freshwater mesocosms
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DOI：
10.1111/j.1365-2486.2010.02289.x
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发表时间：
2011-02
影响因子：
11.6
通讯作者：
G. Yvon‐Durocher;J. Montoya;G. Woodward;J. I. Jones;M. Trimmer
中科院分区：
文献类型：
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作者：
G. Yvon‐Durocher;J. Montoya;G. Woodward;J. I. Jones;M. Trimmer
甲烷(CH4)和二氧化碳(CO2)是有机碳再矿化的主要气态最终产物，也是人为温室效应的两大贡献者。在淡水中游实验中，我们研究了气候变暖是否改变了CH4流出相对于初级生产力(GPP)和生态系统呼吸(ER)的平衡。整个生态系统的CH4排放与温度密切相关，表观活化能为0.85 eV。此外，随着温度的升高，CH4流出比ER或GPP增加得更快，三个过程的活化能都依次较低。升温4℃时，GPP以CH4形式流出的比例增加了20%，ER以CH4形式流出的比例增加了9%，与各自活化能的偏移量一致。由于甲烷作为一种温室气体的效力是二氧化碳的21倍，这些结果表明，淡水生态系统可能会在变暖和碳循环之间推动一种以前未知的正反馈。
Methane (CH4) and carbon dioxide (CO2) are the dominant gaseous end products of the remineralization of organic carbon and also the two largest contributors to the anthropogenic greenhouse effect. We investigated whether warming altered the balance of CH4 efflux relative to gross primary production (GPP) and ecosystem respiration (ER) in a freshwater mesocosm experiment. Whole ecosystem CH4 efflux was strongly related to temperature with an apparent activation energy of 0.85 eV. Furthermore, CH4 efflux increased faster than ER or GPP with temperature, with all three processes having sequentially lower activation energies. Warming of 4 °C increased the fraction of GPP effluxing as CH4 by 20% and the fraction of ER as CH4 by 9%, in line with the offset in their respective activation energies. Because CH4 is 21 times more potent as a greenhouse gas, relative to CO2, these results suggest freshwater ecosystems could drive a previously unknown positive feedback between warming and the carbon cycle.