Multiyear increases in dissolved organic matter inventories at station ALOHA in the North Pacific Subtropical Gyre
Multiyear increases in dissolved organic matter inventories at station ALOHA in the North Pacific Subtropical Gyre
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DOI：
10.4319/lo.2002.47.1.0001
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发表时间：
2002-01-01
影响因子：
4.5
通讯作者：
Karl, DM
中科院分区：
文献类型：
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作者：
Church, MJ;Ducklow, HW;Karl, DM
ALOHA 站地表水中溶解有机物 (DOM) 的库存和动态是根据 1989-1999 年期间的夏威夷海洋时间序列 (HOT) 数据集进行分析的。透光区、溶解有机碳 (DOC)、氮 (DON) 和磷 (DOP) 的深度积分 (0-175 m) 浓度随时间变化。特别是1993-1999年期间，DOC和DON的浓度增加，而DOP的库存量保持不变。 DOC 库存增加了 303 mmol C m(-2) yr(-1)，该值相当于该地点测得的初级产量（C-14 方法）的约 2%。 DON 在 11 mmol N m(-2) yr(-1) 时增加，导致累积 DOM 的平均 DOC : DON 摩尔比为 27.5。 DOC 和 DON 的积累，而没有相应的 DOP 积累，导致大量有机物 C:N:P 化学计量发生变化；散装 DOC : DOP 比率增加 16%，DON: DOP 比率增加 17%。这些结果表明，每年产生的有机物中的一小部分在数月至数年的时间尺度上逃脱了生物利用。更重要的是，相对于 P，累积的 DOM 库存逐渐富集在 C 和 N 中。北太平洋副热带环流 (NPSG) 栖息地的根本变化似乎改变了调节有机物通量的微生物过程。综合考虑，DOC 和 DON 库存的长期增加与之前的观察结果一致，表明最近浮游生物群落动态的重组可能改变了该生态系统中的有机物循环。
The inventories and dynamics of dissolved organic matter (DOM) in the surface water at Station ALOHA were analyzed from the Hawaii Ocean Time-series (HOT) data set for the period 1989-1999. Euphotic zone, depth-integrated (0-175 m) concentrations of dissolved organic carbon (DOC), nitrogen (DON), and phosphorus (DOP) were temporally variable. In particular, during the period 1993-1999, concentrations of DOC and DON increased while inventories of DOP remained unchanged. DOC inventories increased by 303 mmol C m(-2) yr(-1), a value equivalent to approximately 2% of measured primary production (C-14 method) at this site. DON increased at 11 mmol N m(-2) yr(-1), resulting in a mean molar DOC : DON ratio of 27.5 for the accumulated DOM. Accumulation of DOC and DON without corresponding accumulation of DOP resulted in changes to the bulk organic C : N : P stoichiometry; bulk DOC : DOP ratios increased 16% and DON: DOP ratios increased by 17%. These results indicate that a small fraction of the annually produced organic matter escaped biological utilization on time scales of months to years. More importantly, the accumulated DOM inventories grew progressively enriched in C and N relative to P. Fundamental changes in the North Pacific Subtropical Gyre (NPSG) habitat appear to have altered microbial processes that regulate organic matter fluxes. Considered together, the long-term increases in DOC and DON inventories are consistent with previous observations, indicating that a recent reorganization of plankton community dynamics may have altered organic matter cycling in this ecosystem.