Department of Environmental Sciences, University of Virginia, PO Box 400123, Charlottesville, Virginia 24151, USA.
Nature. 2012 Sep 27;489(7417):550-3. doi: 10.1038/nature11440.
About half of annual marine carbon burial takes place in shallow water ecosystems where geomorphic and ecological stability is driven by interactions between the flow of water, vegetation growth and sediment transport. Although the sensitivity of terrestrial and deep marine carbon pools to climate change has been studied for decades, there is little understanding of how coastal carbon accumulation rates will change and potentially feed back on climate. Here we develop a numerical model of salt marsh evolution, informed by recent measurements of productivity and decomposition, and demonstrate that competition between mineral sediment deposition and organic-matter accumulation determines the net impact of climate change on carbon accumulation in intertidal wetlands. We find that the direct impact of warming on soil carbon accumulation rates is more subtle than the impact of warming-driven sea level rise, although the impact of warming increases with increasing rates of sea level rise. Our simulations suggest that the net impact of climate change will be to increase carbon burial rates in the first half of the twenty-first century, but that carbon-climate feedbacks are likely to diminish over time.
大约有一半的年度海洋碳埋存量发生在浅海生态系统中，这些生态系统的地貌和生态稳定性是由水的流动、植被生长和沉积物输运之间的相互作用驱动的。尽管陆地和深海碳库对气候变化的敏感性已经研究了几十年，但人们对沿海碳积累率将如何变化以及对气候可能产生的潜在反馈仍知之甚少。在这里，我们开发了一个盐沼演化的数值模型，该模型是基于最近对生产力和分解的测量结果得出的，并证明了矿物质沉积物沉积和有机物质积累之间的竞争决定了气候变化对潮间带湿地碳积累的净影响。我们发现，变暖对土壤碳积累速率的直接影响比由海平面上升驱动的变暖影响更为微妙，尽管变暖的影响随着海平面上升速率的增加而增加。我们的模拟表明，在二十一世纪的前半叶，气候变化的净影响将增加碳埋藏率，但随着时间的推移，碳-气候反馈可能会减弱。
