Benthic phosphorus regeneration, net primary production, and ocean anoxia: A model of the coupled marine biogeochemical cycles of carbon and phosphorus
Benthic phosphorus regeneration, net primary production, and ocean anoxia: A model of the coupled marine biogeochemical cycles of carbon and phosphorus
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DOI：
10.1029/94pa01455
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发表时间：
1994-10
期刊：
影响因子：
--
通讯作者：
P. Cappellen;E. Ingall
中科院分区：
文献类型：
--
作者：
P. Cappellen;E. Ingall
利用碳(C)和磷(P)耦合海洋生物地球化学循环的质量平衡模型，研究了海洋通风、初级生产、水柱缺氧和底栖生物再生之间的关系。元素循环通过海洋浮游植物的Redfield C/P比值和海洋沉积物中保存的有机质的C/P比值耦合。该模型假定，在地质时间尺度上，海洋的净初级生产受到溶解磷上涌到光带的限制。该模型考虑了沉积在水-沉积物界面的颗粒物中营养磷的再生对底水氧合的依赖。来自现代和古代海洋和湖泊环境的证据表明，当底水缺氧-缺氧扩大时，与有机质和铁氧氢氧化物相关的磷的沉积埋藏减少。稳态模拟表明，温盐环流速率的降低或下潜水团含氧量的降低，加剧了水柱缺氧-缺氧，同时增加了地表水的生产力。第一个影响反映了海洋深处氧气供应的减少。第二个效应是由于底栖生物从有机物和铁氧氢氧化物中再生磷的能力增强。另一方面，海洋通气减少促进了有机碳和自生磷酸钙矿物（钙磷矿）的沉积埋藏。根据该模型，全球范围的缺氧-缺氧导致海洋系统中活性磷的更有效回收。因此，即使大陆对海洋的活性磷供应保持不变，也可以实现更高的初级生产和有机碳埋藏率。
We examine the relationships between ocean ventilation, primary production, water column anoxia, and benthic regeneration of phosphorus using a mass balance model of the coupled marine biogeochemical cycles of carbon (C) and phosphorus (P). The elemental cycles are coupled via the Redfield C/P ratio of marine phytoplankton and the C/P ratio of organic matter preserved in marine sediments. The model assumes that on geologic timescales, net primary production in the oceans is limited by the upwelling of dissolved phosphorus to the photic zone. The model incorporates the dependence on bottom water oxygenation of the regeneration of nutrient phosphorus from particulate matter deposited at the water-sediment interface. Evidence from marine and lacustrine settings, modern and ancient, demonstrates that sedimentary burial of phosphorus associated with organic matter and ferric oxyhydroxides decreases when bottom water anoxia-dysoxia expands. Steady state simulations show that a reduction in the rate of thermohaline circulation, or a decrease of the oxygen content of downwelling water masses, intensifies water column anoxia-dysoxia and at the same time increases surface water productivity. The first effect reflects the declining supply of oxygen to the deeper parts of the ocean. The second effect is caused by the enhanced benthic regeneration of phosphorus from organic matter and ferric oxyhydroxides. Sedimentary burial of organic carbon and authigenic calcium phosphate mineral (francolite), on the other hand, is promoted by reduced ocean ventilation. According to the model, global-scale anoxia-dysoxia leads to a more efficient recycling of reactive phosphorus within the ocean system. Consequently, higher rates of primary production and organic carbon burial can be achieved, even when the continental supply of reactive phosphorus to the oceans remains unchanged.