On the relationships between primary, net community, and export production in subtropical gyres
On the relationships between primary, net community, and export production in subtropical gyres
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DOI：
10.1016/j.dsr2.2006.01.024
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发表时间：
2006-01-01
影响因子：
3
通讯作者：
Bates, Nicholas R.
中科院分区：
文献类型：
--
作者：
Brix, Holger;Gruber, Nicolas;Bates, Nicholas R.
净初级产量（NPP）、净群落产量（NCP）、颗粒有机碳输出（Phi(POC)）及其相互关系受当地环境条件的支配，这些环境条件要么有利于微生物主导的再生循环（Phi（POC）与NPP的低比率），要么有利于具有输出路径特征的大型浮游生物主导的系统（Dpoc与NPP的高比率）。我们分析了来自两个亚热带时间序列站（北太平洋的夏威夷海洋时间序列（HOT）和北大西洋的百慕大大西洋时间序列（BATS））的10多年数据，以调查这种再生循环与出口途径的假设，特别是验证两者之间的转换是由增加的营养物质输入控制的这一观点。在年代际长期均值中，NPP、（Dpoc）和NCP之间的关系揭示了BATS的出口路径特征，而HOT则以再生循环为主。这种差异与BATS更强的季节强迫和由此产生的更高的新养分输入是一致的。然而，这些特征只在一年中的部分时间有效。特别是在BATS，出口通道只存在于春季，系统在夏秋两季恢复到再生循环。这与我们的假设是一致的，因为夏季分层强烈，导致新营养输入水平低。在年际时间尺度上，我们发现很少有证据表明长期平均特征在统计上有显著变化，我们将这一发现归因于有限的强迫强度、数据记录的长度以及可能固有的可预测性的缺乏。我们关于NCP与NPP之比（e-ratio）以及Phi（POC）与NPP之比（pe-ratio）的结果与Laws等[温度对公海出口生产的影响]模型预测结果的比较。[4]张建军，张建军，张建军，等。地球化学与地球化学研究进展。全球生物地球化学循环19 （GB40261）对长期平均值的反映较为一致，但这些模式未能捕捉到这些比值的年际变化。(c) 2006 Elsevier Ltd.版权所有。
It has been proposed that net primary production (NPP), net community production (NCP), particulate organic carbon export (Phi(POC)) and the relationships among them are governed by local environmental conditions that favor either a microbially dominated assemblage leading to a regeneration loop (low ratio of (Phi(POC) to NPP) or a system dominated by large plankton with export pathway characteristics (high ratio of (Dpoc to NPP). We analyze more than 10 years of data from two subtropical time-series stations (Hawaii Ocean Times-series (HOT) in the North Pacific, and Bermuda Atlantic Time-Series (BATS) in the North Atlantic) in order to investigate this regeneration loop versus export pathway hypothesis and in particular to test the idea that the switch between the two is controlled by enhanced input of nutrients. In the decadal long-term mean, the relationships between NPP, (Dpoc and NCP, which we take here as a proxy for export production, reveal export pathway characteristics at BATS, while HOT is dominated by the regeneration loop. This difference is consistent with the stronger seasonal forcing at BATS and the resulting higher new nutrient input. However, these characteristics are only valid for parts of the year. Especially at BATS, the export pathway exists only in spring and the system reverts to a regeneration loop in summer and fall. This is consistent with our hypothesis given the strong summer-time stratification and the resulting low levels of new nutrient input. On interannual time-scales, we find little evidence for statistically significant alterations of the long-term mean characteristics, a finding we ascribe to a combination of limited magnitude of forcing, length of the data records, and possibly an inherent lack of predictability. A comparison of our results for the ratio between NCP and NPP (e-ratio) and the ratio between Phi(POC) and NPP (pe-ratio) with those predicted by the models of Laws et al. [Temperature effects on export production in the open ocean. Global Biogeochemical Cycles 14(4), 1231-1246] and Dunne et al. [Empirical and mechanistic models for particle export ratio. Global Biogeochemical Cycles 19, GB40261 respectively, show reasonable agreement for the long-term mean, but these models fail to capture the observed interannual variability in these ratios. (c) 2006 Elsevier Ltd. All rights reserved.