Potential carbon emissions dominated by carbon dioxide from thawed permafrost soils
Potential carbon emissions dominated by carbon dioxide from thawed permafrost soils
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DOI：
10.1038/nclimate3054
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发表时间：
2016-10
影响因子：
30.7
通讯作者：
C. Schädel;M. Bader;E. Schuur;C. Biasi;R. Bracho;P. Čapek;S. Baets;K. Diáková;J. Ernakovich
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文献类型：
--
作者：
C. Schädel;M. Bader;E. Schuur;C. Biasi;R. Bracho;P. Čapek;S. Baets;K. Diáková;J. Ernakovich
北方高纬度地区气温的升高正在导致永久冻土融化，使大量先前冻结的有机物容易受到微生物分解的影响。永冻层融化也创造了干燥和潮湿土壤条件的碎片化景观，决定了释放到大气中的碳（C）的数量和形式（二氧化碳（CO2）或甲烷（CH4））。碳释放的速率和形式控制着冻土碳反馈的大小，因此它们对气候变暖的相对贡献仍不清楚。我们量化的影响，温度升高和变化从有氧到厌氧的土壤条件下，使用25个土壤培养研究，从冻土区。在这里，我们使用两个独立的荟萃分析表明，孵育温度增加10 °C，碳释放增加了2.0倍（95%置信区间（CI），1.8至2.2）。在有氧培养条件下，土壤释放的碳比厌氧条件下多3.4倍（95%CI，2.2至5.2）。即使当占较高的热捕获能力的甲烷，土壤释放2.3（95% CI，1.5至3.4）倍以上的C有氧条件下。这些结果表明，在一定的碳含量下，冻土生态系统在有氧条件下融化并释放CO2比在淹水条件下释放CO2和CH4更能加强冻土碳反馈。
Increasing temperatures in northern high latitudes are causing permafrost to thaw, making large amounts of previously frozen organic matter vulnerable to microbial decomposition. Permafrost thaw also creates a fragmented landscape of drier and wetter soil conditions,that determine the amount and form (carbon dioxide (CO2), or methane (CH4)) of carbon (C) released to the atmosphere. The rate and form of C release control the magnitude of the permafrost C feedback, so their relative contribution with a warming climate remains unclear,. We quantified the effect of increasing temperature and changes from aerobic to anaerobic soil conditions using 25 soil incubation studies from the permafrost zone. Here we show, using two separate meta-analyses, that a 10 °C increase in incubation temperature increased C release by a factor of 2.0 (95% confidence interval (CI), 1.8 to 2.2). Under aerobic incubation conditions, soils released 3.4 (95% CI, 2.2 to 5.2) times more C than under anaerobic conditions. Even when accounting for the higher heat trapping capacity of CH4, soils released 2.3 (95% CI, 1.5 to 3.4) times more C under aerobic conditions. These results imply that permafrost ecosystems thawing under aerobic conditions and releasing CO2will strengthen the permafrost C feedback more than waterlogged systems releasing CO2and CH4for a given amount of C.