Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, USA.
Ecology. 2010 Oct;91(10):2941-51. doi: 10.1890/09-1175.1.
The response of an ecosystem to perturbations is mediated by both antagonistic and facilitative interactions between species. It is thought that a community's resilience depends crucially on the food web--the network of trophic interactions--and on the food web's degree of compartmentalization. Despite its ecological importance, compartmentalization and the mechanisms that give rise to it remain poorly understood. Here we investigate several definitions of compartments, propose ways to understand the ecological meaning of these definitions, and quantify the degree of compartmentalization of empirical food webs. We find that the compartmentalization observed in empirical food webs can be accounted for solely by the niche organization of species and their diets. By uncovering connections between compartmentalization and species' diet contiguity, our findings help us understand which perturbations can result in fragmentation of the food web and which can lead to catastrophic effects. Additionally, we show that the composition of compartments can be used to address the long-standing question of what determines the ecological niche of a species.
生态系统对干扰的反应受到物种间拮抗和促进相互作用的调节。人们认为，群落的恢复力在很大程度上取决于食物网——营养关系网络——以及食物网的分隔程度。尽管它具有生态重要性，但分隔和导致分隔的机制仍知之甚少。在这里，我们研究了几种隔室的定义，提出了理解这些定义的生态意义的方法，并量化了经验食物网的分隔程度。我们发现，经验食物网中观察到的分隔仅可以通过物种及其饮食的生态位组织来解释。通过揭示分隔化与物种饮食连续性之间的联系，我们的研究结果帮助我们了解哪些干扰会导致食物网的碎片化，哪些干扰会导致灾难性的后果。此外，我们表明，隔室的组成可以用来解决长期存在的问题，即是什么决定了一个物种的生态位。
