High biolability of ancient permafrost carbon upon thaw
High biolability of ancient permafrost carbon upon thaw
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DOI：
10.1002/grl.50348
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发表时间：
2013-06
影响因子：
5.2
通讯作者：
J. Vonk;P. Mann;S. Davydov;A. Davydova;R. Spencer;J. Schade;W. V. Sobczak;N. Zimov;S. Zimov;E. Bulygina;T. Eglinton;R. Max Holmes
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文献类型：
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作者：
J. Vonk;P. Mann;S. Davydov;A. Davydova;R. Spencer;J. Schade;W. V. Sobczak;N. Zimov;S. Zimov;E. Bulygina;T. Eglinton;R. Max Holmes
北极持续的气候变暖将融化永久冻土，并重新动员大量的陆地有机碳(OC)池。北部永久冻土约四分之一的有机碳存在于西伯利亚的耶多玛沉积物中，这是永久冻土中最古老的碳形式。然而，我们对这种古老的有机碳在海岸和河流环境中的退化和命运的了解仍然是初步的。在这里，我们展示了古代溶解的有机碳(DOC，>；21,000(14)C年)，这是迄今报道的最古老的DOC，是在排干伊多玛露头的溪水中被动员的。此外，这种DOC具有高度的生物稳定性：在周围河流温度下，在黑暗、充氧的条件下培养14天，34+/-0.8%的损失。与主干河流和海洋水体的混合，模拟原位混合过程，也显示出较高的DOC损失(14天；17+/-0.8%至33+/-1.0%)。这表明，这个异常古老的DOC是之前报道的北极当代河流或溪流中最具生物适宜性的DOC之一。
Ongoing climate warming in the Arctic will thaw permafrost and remobilize substantial terrestrial organic carbon (OC) pools. Around a quarter of northern permafrost OC resides in Siberian Yedoma deposits, the oldest form of permafrost carbon. However, our understanding of the degradation and fate of this ancient OC in coastal and fluvial environments still remains rudimentary. Here, we show that ancient dissolved OC (DOC, >21,000 (14)Cyears), the oldest DOC ever reported, is mobilized in stream waters draining Yedoma outcrops. Furthermore, this DOC is highly biolabile: 34 +/- 0.8% was lost during a 14 day incubation under dark, oxygenated conditions at ambient river temperatures. Mixtures of Yedoma stream DOC with mainstem river and ocean waters, mimicking in situ mixing processes, also showed high DOC losses (14 days; 17 +/- 0.8% to 33 +/- 1.0%). This suggests that this exceptionally old DOC is among the most biolabile DOC in any previously reported contemporary river or stream in the Arctic.