Strong latitudinal patterns in the elemental ratios of marine plankton and organic matter
Strong latitudinal patterns in the elemental ratios of marine plankton and organic matter
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DOI：
10.1038/ngeo1757
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发表时间：
2013-04-01
影响因子：
18.3
通讯作者：
Lomas, Michael W.
中科院分区：
文献类型：
--
作者：
Martiny, Adam C.;Pham, Chau T. A.;Lomas, Michael W.
大约 75 年前，Alfred C. Redfield 观察到海洋表层海洋浮游生物的元素组成与海洋内部溶解的营养物质之间存在相似性(1)。这种化学计量学（称为雷德菲尔德比率）仍然是海洋生物地球化学的核心原则，并用于推断各种生态系统过程，例如浮游植物生产力以及固氮和损失速率(2-4)。模型、实地和实验室研究表明，不同的机制可以解释海洋浮游生物群落中碳与氮和磷的恒定和可变比率。海洋中 C/N/P 比率的范围及其可预测性是许多活跃研究的主题(5-12)。在这里，我们利用广泛纬度范围内已发表和未发表的颗粒磷、氮和碳的观测结果，并辅以表层浮游生物种群的元素数据，评估了上层海洋浮游植物和颗粒有机物元素组成的全球模式。我们表明，海洋有机物的元素比率表现出很大的空间变化，全球平均值与典型的雷德菲尔德比率有很大不同。然而，元素比率表现出明显的纬度趋势。具体来说，我们观察到，在温暖的营养贫乏的低纬度环流中，这一比例为195:28:1；在温暖、营养丰富的上升流区域，这一比例为137:18:1；在寒冷、营养丰富的高纬度地区，这一比例为78:13:1。我们认为，海洋碳、氮和磷循环之间的耦合可能因生态系统而系统地变化。
Nearly 75 years ago, Alfred C. Redfield observed a similarity between the elemental composition of marine plankton in the surface ocean and dissolved nutrients in the ocean interior(1). This stoichiometry, referred to as the Redfield ratio, continues to be a central tenet in ocean biogeochemistry, and is used to infer a variety of ecosystem processes, such as phytoplankton productivity and rates of nitrogen fixation and loss(2-4). Model, field and laboratory studies have shown that different mechanisms can explain both constant and variable ratios of carbon to nitrogen and phosphorus among ocean plankton communities. The range of C/N/P ratios in the ocean, and their predictability, are the subject of much active research(5-12). Here we assess global patterns in the elemental composition of phytoplankton and particulate organic matter in the upper ocean, using published and unpublished observations of particulate phosphorus, nitrogen and carbon from a broad latitudinal range, supplemented with elemental data for surface plankton populations. We show that the elemental ratios of marine organic matter exhibit large spatial variations, with a global average that differs substantially from the canonical Redfield ratio. However, elemental ratios exhibit a clear latitudinal trend. Specifically, we observed a ratio of 195: 28: 1 in the warm nutrient-depleted low-latitude gyres, 137: 18: 1 in warm, nutrient-rich upwelling zones, and 78: 13: 1 in cold, nutrient-rich high-latitude regions. We suggest that the coupling between oceanic carbon, nitrogen and phosphorus cycles may vary systematically by ecosystem.