Physical and biological controls of vertical gradients in phytoplankton
Physical and biological controls of vertical gradients in phytoplankton
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DOI：
10.1215/21573698-1267403
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发表时间：
2011-04
影响因子：
4.5
通讯作者：
J. Prairie;P. Franks;J. Jaffe;M. Doubell;H. Yamazaki
中科院分区：
文献类型：
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作者：
J. Prairie;P. Franks;J. Jaffe;M. Doubell;H. Yamazaki
浮游植物分布的小尺度垂直异质性在沿海沃茨中很常见，可能是影响浮游系统营养耦合的一个重要特征。在这里，我们开发了一个模型来研究控制浮游植物丰度垂直梯度的生物和物理动力学。该模型包括浮游植物层的形成和层的破坏，通过混合和预测，当地最大规模的浮游植物梯度控制这些动态的相对强度。我们比较了这个模型的预测，以高分辨率的配置文件的浮游植物浓度和荧光收集使用自由落体平面激光成像荧光计（FIDO-F）和湍流微观结构轮廓仪数据（TurboMAP-L）。从这些配置文件中，我们估计模型参数：层形成的最大速率和最小可能的层厚度。层形成的最大速率范围从0.46至0.94天21，这是最大的报告中发现在我们的样品中最常见的浮游植物类群的增长率相媲美。从我们的数据估计的最小层厚度表明，持久性浮游植物层薄于约0.5米可能是罕见的沿海沃茨。这项研究提供了一个机械的解释，一些基本的动力学浮游植物层的形成，维护和破坏，并将使我们能够更好地预测这些生态重要的结构在该领域的规模和发生。
Small-scale vertical heterogeneity in phytoplankton distributions is common in coastal waters and may be a critical feature influencing trophic coupling in planktonic systems. Here we develop a model to investigate the biological and physical dynamics that control vertical gradients in phytoplankton abundance. The model includes phytoplankton layer formation and layer destruction through mixing and predicts that the local maximum scaled phytoplankton gradient is controlled by the relative strengths of these dynamics. We compare the predictions of this model to highly resolved profiles of phytoplankton concentration and fluorescence collected using a free-falling planar laser imaging fluorometer (FIDO-F) and turbulence microstructure profiler data (TurboMAP-L). From these profiles, we estimate the model parameters: the maximum rate of layer formation and minimum possible layer thickness. The maximum rate of layer formation ranged from 0.46 to 0.94d 21 , which is comparable to maximum reported growth rates of the most common phytoplankton taxa found in our samples. The minimum layer thickness estimated from our data suggests that persistent phytoplankton layers thinner than approximately 0.5m may be rare in coastal waters. This study provides a mechanistic explanation for some of the underlying dynamics governing phytoplankton layer formation, maintenance, and destruction and will allow us to better predict the magnitude and occurrence of these ecologically important structures in the field.