Climate change and ocean acidification impacts on lower trophic levels and the export of organic carbon to the deep ocean
Climate change and ocean acidification impacts on lower trophic levels and the export of organic carbon to the deep ocean
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气候变化和海洋酸化对低营养层和有机碳向深海出口的影响
DOI：
10.5194/bg-10-5831-2013
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发表时间：
2013
期刊：
影响因子：
4.9
通讯作者：
T. R. Anderson
中科院分区：
文献类型：
--
作者：
A. Yool;E. Popova;A. Coward;D. Bernie;T. R. Anderson
大多数未来预测预测21世纪将发生重大且持续的气候变化，但影响的严重程度取决于限制或重组人类活动以限制二氧化碳排放的努力。世界海洋是大气二氧化碳的主要汇，也是生物资源的主要来源，人们普遍预计，作为这些排放的直接和间接结果，世界海洋将经历深刻的物理变化和通过海洋酸化产生的化学变化。考虑到强烈的生物物理耦合，海洋生物群预计也将经历强烈的变化，以响应这种人为强迫。在这里，我们使用一个中等复杂性的全球生态系统模型Medusa-2.0，研究了21世纪典型浓度路径(RCPs)2.6和8.5期间海洋生物地球化学对气候和酸化影响的大尺度响应。未来变化的主要影响在于分层导致表层水中关键营养物质的可获得性下降，这反过来又导致全球海洋生产力(1990年代与2020年代)下降(−6.3%)。这一影响对以MEDUSA-2.0(−5.8%)为模型的低营养级生物地球化学因素的丰度产生了连锁反应，预计这些因素也将同样影响较高营养级元素，如渔业。在有机物质向海底群落的通量(1000米处−为40.7%)和海洋亚缺氧区的体积(+12.5%)中发现了相关的影响。去除酸化对钙化反馈的敏感性分析发现，这一过程的变化显著影响底栖生物群落，这表明更好地了解钙化生物对OA的敏感性，以及它们在压载有机碳中的作用，可能会显著改善对这些生态系统的预测。对于所有的过程，变化都有地理上的差异--例如，大西洋的生产率下降了21%，北极的生产率上升了59%--在RCP8.5下的变化比RCP2.6下的变化要明显得多。
Most future projections forecast significant and ongoing climate change during the 21st century, but with the severity of impacts dependent on efforts to restrain or reorganise human activity to limit carbon dioxide (CO 2 ) emissions. A major sink for atmospheric CO 2 , and a key source of biological resources, the World Ocean is widely anticipated to undergo profound physical and – via ocean acidification – chemical changes as direct and indirect results of these emissions. Given strong biophysical coupling, the marine biota is also expected to experience strong changes in response to this anthropogenic forcing. Here we examine the large-scale response of ocean biogeochemistry to climate and acidification impacts during the 21st century for Representative Concentration Pathways (RCPs) 2.6 and 8.5 using an intermediate complexity global ecosystem model, MEDUSA-2.0. The primary impact of future change lies in stratification-led declines in the availability of key nutrients in surface waters, which in turn leads to a global decrease (1990s vs. 2090s) in ocean productivity (−6.3%). This impact has knock-on consequences for the abundance of the low trophic level biogeochemical actors modelled by MEDUSA-2.0 (−5.8%), and these would be expected to similarly impact higher trophic level elements such as fisheries. Related impacts are found in the flux of organic material to seafloor communities (−40.7% at 1000 m), and in the volume of ocean suboxic zones (+12.5%). A sensitivity analysis removing an acidification feedback on calcification finds that change in this process significantly impacts benthic communities, suggesting that a~better understanding of the OA-sensitivity of calcifying organisms, and their role in ballasting sinking organic carbon, may significantly improve forecasting of these ecosystems. For all processes, there is geographical variability in change – for instance, productivity declines −21% in the Atlantic and increases +59% in the Arctic – and changes are much more pronounced under RCP 8.5 than the RCP 2.6 scenario.
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影响因子：
5.2
作者：
Jamie D. Wilson;S. Barker;A. Ridgwell
通讯作者：
Jamie D. Wilson;S. Barker;A. Ridgwell
影响因子：
5.1
作者：
Jones, C. D.;Hughes, J. K.;Zerroukat, M.
通讯作者：
Zerroukat, M.
影响因子：
4.9
作者：
Popova E
通讯作者：
Popova E
影响因子：
3.6
作者：
Meijers, A. J. S.;Shuckburgh, E.;Wang, Z.
通讯作者：
Wang, Z.
影响因子：
5.2
作者：
Henson, Stephanie A.;Sanders, Richard;Madsen, Esben
通讯作者：
Madsen, Esben