The interaction between predation and competition
The interaction between predation and competition
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DOI：
10.1038/nature07248
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发表时间：
2008-11-13
期刊：
影响因子：
64.8
通讯作者：
Kuang, Jessica J.
中科院分区：
文献类型：
--
作者：
Chesson, Peter;Kuang, Jessica J.
竞争和捕食是生态学中研究最多的物种相互作用，在物种多样性维持研究中占主导地位。然而，这两种相互作用通常被认为是高度不对称的。对资源的竞争被视为限制多样性的主要相互作用，而捕食会改变竞争的作用(1)，尽管理论模型长期以来支持不同的观点（1-5）。在这里，我们表明，使用一个全面的三营养级模型，竞争和捕食应该被对称地看待：这两种相互作用同样能够限制或促进多样性。多样性维持需要种内密度反馈回路比种间反馈回路更强。我们以一种简单的、可解释的形式量化了捕食和竞争对这些循环的贡献，显示了它们加强或削弱多样性维持的同等潜力。此外，我们发现竞争和捕食可以相互破坏，更强的相互作用倾向于促进或限制多样性。过去未能认识到竞争和捕食的对称效应和相互作用，过度限制了多样性维持的研究。应该采用多营养的观点来研究比过去普遍认为的更多样化的捕食可能产生的影响。保护和管理策略需要更多地关注营养相互作用强度变化的影响。
Competition and predation are the most heavily investigated species interactions in ecology, dominating studies of species diversity maintenance. However, these two interactions are most commonly viewed highly asymmetrically. Competition for resources is seen as the primary interaction limiting diversity, with predation modifying what competition does(1), although theoretical models have long supported diverse views(1-5). Here we show, using a comprehensive three- trophic- level model, that competition and predation should be viewed symmetrically: these two interactions are equally able to either limit or promote diversity. Diversity maintenance requires within- species density feedback loops to be stronger than between- species feedback loops. We quantify the contributions of predation and competition to these loops in a simple, interpretable form, showing their equivalent potential to strengthen or weaken diversity maintenance. Moreover, we show that competition and predation can undermine each other, with the tendency of the stronger interaction to promote or limit diversity prevailing. The past failure to appreciate the symmetrical effects and interactions of competition and predation has unduly restricted diversity maintenance studies. A multitrophic perspective should be adopted to examine a greater variety of possible effects of predation than generally considered in the past. Conservation and management strategies need to be much more concerned with the implications of changes in the strengths of trophic interactions.