Robustness to secondary extinctions: Comparing trait-based sequential deletions in static and dynamic food webs
Robustness to secondary extinctions: Comparing trait-based sequential deletions in static and dynamic food webs
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DOI：
10.1016/j.baae.2011.09.008
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发表时间：
2011-01-01
影响因子：
3.8
通讯作者：
Rall, Bjoern C.
中科院分区：
文献类型：
--
作者：
Curtsdotter, Alva;Binzer, Amrei;Rall, Bjoern C.
生态群落物种的丧失可能引发一连串的次生物种灭绝，其风险和程度可能取决于从群落中丧失的物种的特征。为了识别对物种丧失的食物网稳健性有最大影响的物种特征，我们在这里基于物种的连通性、一般性、易损性或体重对异速测量的动态食物网模型进行了几个缺失序列。此外，为了评估动力学对拓扑效应的相对重要性，我们比较了动态模型和纯拓扑模型的稳健性。这种比较表明，拓扑方法高估了总体上的稳健性，特别是对于某些序列。在拓扑分析中，自顶向下定向序列对稳健性没有影响或影响很小，而动态分析表明，它们可能与高影响的自底向上定向序列一样重要。此外，在动力学方法中，没有平均导致没有或很少二次灭绝的缺失序列。相反，动态方法中危害最小的序列产生类似于拓扑法中最有害(非基本)缺失序列的平均稳健性。因此，拓扑分析可能导致关于不同物种性状对稳健性的相对和绝对重要性的错误结论。动态顺序缺失分析表明，食物网对具有多个营养连接或占据低营养水平的物种的损失最不稳健。与以前的研究相反，我们可以推断，尽管是间接的，次级物种灭绝是由自下而上和自上而下的级联引发的。
The loss of species from ecological communities can unleash a cascade of secondary extinctions, the risk and extent of which are likely to depend on the traits of the species that are lost from the community. To identify species traits that have the greatest impact on food web robustness to species loss we here subject allometrically scaled, dynamical food web models to several deletion sequences based on species' connectivity, generality, vulnerability or body mass. Further, to evaluate the relative importance of dynamical to topological effects we compare robustness between dynamical and purely topological models. This comparison reveals that the topological approach overestimates robustness in general and for certain sequences in particular. Top-down directed sequences have no or very low impact on robustness in topological analyses, while the dynamical analysis reveals that they may be as important as high-impact bottom-up directed sequences. Moreover, there are no deletion sequences that result, on average, in no or very few secondary extinctions in the dynamical approach. Instead, the least detrimental sequence in the dynamical approach yields an average robustness similar to the most detrimental (non-basal) deletion sequence in the topological approach. Hence, a topological analysis may lead to erroneous conclusions concerning both the relative and the absolute importance of different species traits for robustness. The dynamical sequential deletion analysis shows that food webs are least robust to the loss of species that have many trophic links or that occupy low trophic levels. In contrast to previous studies we can infer, albeit indirectly, that secondary extinctions were triggered by both bottom-up and top-down cascades.