Zooplankton grazing and egestion shifts particle size distribution in natural communities
Zooplankton grazing and egestion shifts particle size distribution in natural communities
复制标题
浮游动物的放牧和排泄改变了自然群落中的颗粒尺寸分布
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
A. Pershing
中科院分区：
文献类型：
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作者：
K. Stamieszkin;N. Poulton;A. Pershing
：海洋浮游生物群落可以从其大小结构而不是其分类组成来看待，揭示了异速生长关系如何影响群落的功能。海洋颗粒尺寸光谱可用于解释和预测碳输出效率的变化，因为大颗粒通常比小颗粒下沉得更快。由于浮游生物的营养相互作用会影响海洋表面的颗粒尺寸，因此这种尺寸结构视图对于连接浮游生物生态学与生物地球化学是有用的简化。我们进行了一系列放牧实验，以检验这样的假设：中型浮游动物通过放牧和排泄粪便颗粒，以可预测的方式将粒径谱转向较大的颗粒，从而反映其群落大小结构。这些实验进行了几个月，并使用了在缅因湾沿海收集的中型浮游生物及其微型浮游生物猎物的自然群落。孵化后，我们分析了样品以确定尺寸分布和分类信息。我们的结果表明，中型浮游生物放牧对微型浮游生物的影响与其丰度成正比。在个体水平上建立的浮游生物捕食者和猎物之间的体型关系并不能线性地转化为群落水平。此外，虽然放牧本身不会显着改变颗粒尺寸谱，但将猎物重新包装成中型浮游动物粪便颗粒会使颗粒尺寸谱向更大的颗粒移动。
: Marine plankton communities can be viewed in terms of their size structure rather than their taxonomic composition, revealing how allometric relationships affect the functioning of the community. Oceanic particle size spectra can be used to explain and predict variability in carbon export efficiency, because large particles generally sink faster than small particles. Since plankton trophic interactions impact particle size in the surface ocean, this size-structured view is a useful simplification for connecting plankton ecology with biogeochemistry. We conducted a series of grazing experiments to test the hypothesis that mesozooplankton shift particle size spectra toward larger particles, in a predictable manner that reflects their community size structure, through grazing and egestion of fecal pellets. These experiments were carried out over several months, and used natural communities of mesozooplankton and their microplankton prey collected in the coastal Gulf of Maine. After incubation, we analyzed the samples to determine size distribution and taxonomic information. Our results show that mesozooplankton grazing impacts microplankton in proportion to their abundance. Size relationships between plankton predators and prey that have been established at the individual level do not linearly translate to the community level. Further, while grazing itself does not significantly alter the particle size spectrum, repackaging of prey into mesozooplankton fecal pellets shifts particle size spectra toward larger particles.