Trophic cascades in 3D: network analysis reveals how apex predators structure ecosystems
Trophic cascades in 3D: network analysis reveals how apex predators structure ecosystems
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DOI：
10.1111/2041-210x.12663
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发表时间：
2017-01
影响因子：
6.6
通讯作者：
Arian D. Wallach;A. Dekker;M. Lurgi;J. Montoya;Damien A. Fordham;E. Ritchie
中科院分区：
文献类型：
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作者：
Arian D. Wallach;A. Dekker;M. Lurgi;J. Montoya;Damien A. Fordham;E. Ritchie
营养级联理论预测，顶端捕食者结构生态系统的调节mesopredator和草食动物的丰度和行为。对营养级联的研究通常集中在物种相互作用的短线性链上。需要一个框架，整合更现实和复杂的相互作用，使更广泛的预测生态系统结构。网络分析用于研究食物网和其他类型的物种相互作用网络。这些通常包括大量的物种，但很少考虑多种相互作用类型和强度。在这里，我们开发了一个中间复杂性的理论框架，允许规范的多种相互作用类型和强度的研究营养级联。该生态网络旨在适应通常来自实地研究的数据。营养级联网络包含的节点比食物网少，但提供了半加权方向链接，使不同类型的相互作用可以包含在一个模型中。我们使用这个营养级联网络模型，探讨如何在澳大利亚干旱的生态系统顶端捕食者形状的生态系统结构。我们比较了两个网络，对比在一个顶点捕食者的优势，野狗（犬野狗），使用已发表的结果排名的方向和强度的关键相互作用。节点和链路动态地相互作用，形成这些网络。我们研究了顶端捕食者种群的变化如何影响生态系统结构，通过其直接和间接的影响，这个生态群落的不同组成部分。在较强的顶端捕食者影响下，网络结构更加密集、复杂、均匀、自上而下驱动，野狗捕食和土壤同化作用形成了更为密集的交互模块。弱的顶点捕食者的影响下（例如，反映捕食者控制），由此产生的网络结构磨损，与mesopredator捕食和放牧形成模块。我们的研究表明，中等复杂性的网络可以提供一个强大的工具，用于阐明顶端捕食者的潜在生态系统影响，并预测管理干预的后果，如捕食者控制。将营养级联及其一系列复杂的相互作用与生态网络的三维结构相结合，有可能揭示出两者都不能单独捕获的“生态结构”。
Trophic cascade theory predicts that apex predators structure ecosystems by regulating mesopredator and herbivore abundance and behaviour. Studies on trophic cascades have typically focused on short linear chains of species interactions. A framework that integrates more realistic and complex interactions is needed to make broader predictions on ecosystem structuring. Network analysis is used to study food webs and other types of species interaction networks. These often comprise large numbers of species but rarely account for multiple interaction types and strengths. Here, we develop an intermediate complexity theoretical framework that allows specification of multiple interaction types and strengths for the study of trophic cascades. This ecological network is designed to suit data typically derived from field‐based studies. The trophic cascade network contains fewer nodes than food webs, but provides semi‐weighted directional links that enable different types of interactions to be included in a single model. We use this trophic cascade network model to explore how an apex predator shapes ecosystem structure in an Australian arid ecosystem. We compared two networks that contrasted in the dominance of an apex predator, the dingo (Canis dingo), using published results ranking the direction and strength of key interactions. Nodes and links interacted dynamically to shape these networks. We examined how changes to an apex predator population affect ecosystem structure through their direct and indirect influences on different components of this ecological community. Under strong apex predator influence, the network structure was denser and more complex, even and top‐down driven; and dingo predation and soil commensalism formed denser interactive modules. Under weak apex predator influence (e.g. reflecting predator control), the resulting network structure was frayed, with mesopredator predation and grazing forming modules. Our study demonstrates that networks of intermediate complexity can provide a powerful tool for elucidating potential ecosystem‐wide effects of apex predators and predicting the consequences of management interventions such as predator control. Integrating trophic cascades, with their array of complex interactions, with the three‐dimensional structure of ecological networks, has the potential to reveal ‘ecological architecture’ that neither captures on its own.