Global rates of marine sulfate reduction and implications for sub-sea-floor metabolic activities
Global rates of marine sulfate reduction and implications for sub-sea-floor metabolic activities
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DOI：
10.1126/science.1249213
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发表时间：
2014-05-23
期刊：
影响因子：
56.9
通讯作者：
Hinrichs, Kai-Uwe
中科院分区：
文献类型：
--
作者：
Bowles, Marshall W.;Mogollon, Jose M.;Hinrichs, Kai-Uwe
硫酸盐还原是海洋沉积物中全球重要的氧化还原过程，但全球速率却很难量化。我们开发了一个人工神经网络训练199硫酸盐配置文件，约束地貌和地球化学地图，以估计全球硫酸盐还原率分布。在全球范围内，每年减少11.3太摩尔的硫酸盐（与先前估计的15%相似），占氧化到海底有机碳通量的12%至29%。结合全球细胞在海洋沉积物中的分布，这些结果表明，在海底下的原核生物栖息地的强烈对比：在大陆边缘，硫酸盐耗尽的沉积物中的全球细胞数量超过那些在覆盖的含硫酸盐沉积物的数量级，而在深渊，大多数生命发生在氧化和/或硫酸盐还原沉积物。
Sulfate reduction is a globally important redox process in marine sediments, yet global rates are poorly quantified. We developed an artificial neural network trained with 199 sulfate profiles, constrained with geomorphological and geochemical maps to estimate global sulfate-reduction rate distributions. Globally, 11.3 teramoles of sulfate are reduced yearly (similar to 15% of previous estimates), accounting for the oxidation of 12 to 29% of the organic carbon flux to the sea floor. Combined with global cell distributions in marine sediments, these results indicate a strong contrast in sub-sea-floor prokaryote habitats: In continental margins, global cell numbers in sulfate-depleted sediment exceed those in the overlying sulfate-bearing sediment by one order of magnitude, whereas in the abyss, most life occurs in oxic and/or sulfate-reducing sediments.