What happens to terrestrial organic matter in the ocean?
What happens to terrestrial organic matter in the ocean?
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DOI：
10.1016/s0146-6380(97)00066-1
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发表时间：
1997-10-01
影响因子：
3
通讯作者：
Benner, R
中科院分区：
文献类型：
--
作者：
Hedges, JI;Keil, RG;Benner, R
每年河流从大陆向海洋输送约0.25 × 10（15）克溶解有机碳（< 0.5 μ m）和0.15 × 10（15）克颗粒有机碳（0.5 μ m）。仅河流DOC的全球排放就足以维持整个溶解在海水中的有机碳池的周转。同样，河流输入的陆地POC足以供应海洋沉积物中埋藏的所有有机碳。因为河流中的有机物是由高度降解的、缺乏氮的陆生生物遗骸组成的，所以它们在海洋中可能只会受到最小的呼吸作用。因此，全球碳循环中最大的谜团之一是，溶解在海水中并保存在海洋沉积物中的有机物质中，似乎只有一小部分来自陆地。要么是我们的全球预算和分布估计有很大的误差，要么是陆地来源的溶解有机物和颗粒有机物在海洋中都遭受了迅速和非常广泛的再矿化。尽管仍有许多不确定因素，但最近的研究提供了越来越多的证据，证明海洋中溶解的和颗粒状的陆地有机物都遭到了破坏。这些大量的有机物质在排放后如此迅速地被氧化的机制在很大程度上是未知的。本报告的重点是海洋中陆源有机物的运输和转化，重点介绍了最近对所涉及的模式和过程的研究。1997爱思唯尔科学有限公司版权所有。
Each year rivers transport approximately 0.25 x 10(15) g of dissolved (< 0.5 mu m) organic carbon (DOG) and 0.15 x 10(15) g of particulate (> 0.5 mu m) organic carbon (POC) from continents to the ocean. Global discharge of riverine DOC is sufficient alone to sustain turnover of the entire pool of organic carbon dissolved in seawater. Similarly, the input of terrestrial POC by rivers is adequate to supply all the organic carbon buried in marine sediments. Because riverine organic matter consists of highly degraded, nitrogen-poor remains of terrestrial organisms, it might be expected to suffer minimal respiration in the ocean. One of the biggest mysteries in the global carbon cycle, therefore, is that only a small fraction of the organic matter dissolved in seawater and preserved in marine sediments appears to be land-derived. Either our global budgets and distribution estimates are greatly in error, or both dissolved and particulate organic matter of terrestrial origin suffer rapid and remarkably extensive remineralization at sea. Although many uncertainties remain, recent studies provide growing evidence for destruction of both dissolved and particulate terrestrial organic matter in the ocean. The mechanisms by which these huge masses of organic materials might be so rapidly oxidized following discharge are largely unknown. This report focuses on the transport and transformations of land-derived organic matter in the ocean, highlighting recent research on the patterns and processes involved. (C) 1997 Elsevier Science Ltd. All rights reserved.