Warren P H, Lawton J H
Department of Biology, University of York, YO1 5DD, Heslington, York, UK.
Oecologia. 1987 Dec;74(2):231-235. doi: 10.1007/BF00379364.
It has been suggested by Cohen and Newman (1985) that many of the patterns in published food webs can be derived from a stochastic model in which the species are arranged in a trophic hierarchy (the 'cascade model'). We suggest that, if predators are larger than their prey, a trophic hierarchy can be generated on the basis of body size Empirical evidence from the literature shows that there is a positive relationship between predator and prey size for a range of invertebrates and that predators are usually larger than their prey. Using experimental data on an aquatic food web we show that body size can lead to the type of trophic hierarchy used in the cascade model, suggesting that many food web patterns may be a product of body size. This conclusion is discussed with respect to the limitations of the food web data and the relationship between 'static' and 'dynamic' models of web structure.
科恩和纽曼（1985年）曾提出，已发表的食物网中的许多模式可从一个随机模型推导得出，在该模型中，物种按营养级层次排列（“级联模型”）。我们认为，如果捕食者比其猎物体型大，那么基于体型就可以生成一个营养级层次。文献中的实证证据表明，一系列无脊椎动物的捕食者与猎物大小之间存在正相关关系，而且捕食者通常比其猎物体型大。利用一个水生食物网的实验数据，我们表明体型能够导致级联模型中所使用的那种营养级层次类型，这表明许多食物网模式可能是体型的产物。本文针对食物网数据的局限性以及食物网结构的“静态”和“动态”模型之间的关系对这一结论进行了讨论。
