Variability of inorganic and organic phosphorus turnover rates in the coastal ocean
Variability of inorganic and organic phosphorus turnover rates in the coastal ocean
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DOI：
10.1038/19061
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发表时间：
1999-04-08
期刊：
影响因子：
64.8
通讯作者：
Buesseler, KO
中科院分区：
文献类型：
--
作者：
Benitez-Nelson, CR;Buesseler, KO
磷是远洋海洋生态系统中的一种基本营养素。然而，人们对上层海洋中的磷循环知之甚少，很少有研究直接调查这种必需元素的生物利用情况（1-4）。在这里，我们已经确定了在沿海海洋环境中的原位磷周转率，通过测量活动的两个宇宙成因的放射性核素（P-32和P-33，半衰期分别为14.3和25.3天）在溶解无机，溶解有机和总颗粒磷池在一个季节性周期。溶解和颗粒池内的磷周转率是快速的，并随季节的时间尺度而变化，这表明低磷浓度可以支持相对较高的初级生产。此外，微微型浮游生物（例如细菌）似乎优先利用某些溶解的有机磷化合物来获得其他相关营养物质，例如碳和氮。似乎溶解的无机磷和有机磷在支持初级生产中的作用的重要性，因此，CO2吸收和颗粒有机碳的输出，迄今为止一直被低估。
Phosphorus is an essential nutrient in pelagic marine ecosystems. Phosphorus cycling in the upper ocean is, however, poorly understood, and few studies have directly investigated the biological utilization of this essential element(1-4). Here, we have determined in situ phosphorus-turnover rates in a coastal marine environment by measuring the activities of two cosmogenic radionuclides (P-32 and P-33, with half lives of 14.3 and 25.3 days, respectively) in dissolved inorganic, dissolved organic and total particulate phosphorus pools over a seasonal cycle. Phosphorus turnover rates within dissolved and particulate pools are rapid and vary over seasonal timescales, suggesting that low phosphorus concentrations can support relatively high primary production. Furthermore, picoplankton, such as bacteria, appear preferentially to utilize certain dissolved organic phosphorus compounds to obtain other associated nutrients, such as carbon and nitrogen. It seems that the significance of the roles of both dissolved inorganic and organic phosphorus in supporting primary production-and, hence, CO2 uptake and particulate organic carbon export-has been hitherto underestimated.