Density estimation of plankton size spectra: a reanalysis of IronEx II data
Density estimation of plankton size spectra: a reanalysis of IronEx II data
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浮游生物大小谱的密度估计：IronEx II 数据的重新分析
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
R. Armstrong
中科院分区：
文献类型：
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作者：
M. Schartau;M. Landry;R. Armstrong
生态系统功能的许多关键过程，包括捕食者和猎物之间的营养关系以及光合作用和生长的最大速率，都是由大小决定的。因此，尺寸光谱数据对于模型师来说是宝贵的，因为它们可以约束对尺寸相关过程的模型预测。在这里，我们展示了一种基于对IronEx II实验中浮游生物大小数据的重新分析来创建大小光谱的多步骤统计方法，在IronEx II实验中，将铁添加到一块明显的水域中，并跟踪生产力和群落结构的变化。首先，应用自助法对原始尺寸测量和细胞计数进行重采样。然后使用核密度估计来提供密度与大小之间的非参数描述。最后，使用参数分布来获得更容易应用于模型的参数估计。这种方法的一个主要优点是它提供了密度分布的置信度包络。我们的分析提出了三种基本的分布模式，即细胞浓度与等值球径的对数的关系。异养生物和光自养生物的复合大小密度揭示了原生生物放牧和浮游植物群落之间耦合的重要方面。
Many critical processes of ecosystem function, including trophic relationships between predators and prey and maximum rates of photosynthesis and growth, are size-dependent. Size spectral data are therefore precious to modellers because they can constrain model predictions of size-dependent processes. Here we illustrate a multi-step statistical approach to create size spectra based on a reanalysis of plankton size data from the IronEx II experiment, where iron was added to a marked patch of water and changes in productivity and community structure were followed. First, bootstrapping was applied to resample original size measurements and cell counts. Kernel density estimation was then used to provide nonparametric descriptions of density versus size. Finally, parametric distributions were used to obtain parameter estimates that can more easily be applied in models. A major advantage of this approach is that it provides confidence envelopes for the density distributions. Our analyses suggest three basic distributional patterns of cell concentration versus logarithm of equivalent spherical diameter for individual taxa. Composite size-densities of heterotrophs and photoautotrophs reveal important aspects of the coupling between protist grazing and the phytoplankton community.