Past selection impacts the strength of an aquatic trophic cascade
Past selection impacts the strength of an aquatic trophic cascade
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过去的选择影响水生营养级联的强度
DOI：
10.1111/1365-2435.13102
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发表时间：
2018
影响因子：
5.2
通讯作者：
A. Siepielski
中科院分区：
文献类型：
--
作者：
B. H. Ousterhout;Savannah R. Graham;A. Hasik;M. Serrano;A. Siepielski
1.在复杂的食物网中，不同营养级物种间的相互作用可以产生级联的间接效应，将顶级捕食者与初级生产者耦合起来，从而影响生态系统的功能。顶级掠食者对中级掠食者的自然选择可能在塑造这些营养级联的强度方面发挥作用，但这一猜想在很大程度上尚未得到验证。2.为了确定自然选择对营养级联强度的影响，我们在四级水生营养系统中进行了一个由两部分组成的实验，涉及顶级捕食者（鱼）、中间捕食者（豆娘）、食草动物（动物园）-浮游生物）和初级生产者（藻类）。我们首先量化了鱼的捕食如何在控制表型可塑性后产生对豆娘活动水平的选择。然后，我们测量了这种选择对初级生产（浮游植物生物量）的间接影响。在这两个实验中，我们改变了捕食者的密度，使我们能够阐明性状介导和密度介导的间接效应。3.我们发现，随着鱼类密度的增加，豆娘的生存率下降，这产生了自然选择，有利于不太活跃的豆娘。这些结果是强大的考虑到潜在的影响可塑性鱼类捕食线索后。幸存的豆娘可能是
1. In complex food webs, interactions among species in different trophic levels can generate cascading indirect effects that couple top predators with primary pro -ducers, thereby affecting ecosystem functioning. Natural selection imposed by top predators on intermediate predators may play a role in shaping the strength of these trophic cascades, but this conjecture remains largely untested. 2. To determine the effects of natural selection on the strength of trophic cascades, we conducted a two-part experiment in a four-level aquatic trophic system involv ing a top predator (fish), an intermediate predator (damselflies), herbivores (zoo -plankton) and primary producers (algae). We first quantified how predation by fish generated selection on damselfly activity levels after controlling for phenotypic plasticity. We then measured the indirect effects of this selection on primary pro duction (phytoplankton biomass). In both experiments, we varied the density of predators, allowing us to elucidate both trait-mediated and density-mediated indi rect effects. 3. We found that as fish density increased, damselfly survivorship declined, which generated natural selection favouring less active damselflies. These results are robust after taking into account latent effects of plasticity in response to fish predator cues. The surviving damselflies likely foraged
影响因子：
8.8
作者：
Byrnes, J;Stachowicz, JJ;Thornber, CS
通讯作者：
Thornber, CS