title: Static and dynamic explanations for patterns in food webs.
abstract: Ten interesting patterns can be discerned in compendia of published food webs, and are not all easily dismissed as artefacts of poor data. A variety of theoretical explanations have been put forward to explain one, or more, of these patterns; for example, five reasons have been advanced for why food chains are short. Two bodies of theory each satisfactorily account for a majority (but not all) of the patterns, but draw on very different assumptions. One group of theoretical explanations is based on dynamic interactions between species, modelled by Lotka-Volterra equations. The other takes a static view of food web assembly, and assumes a trophic cascade, or hierarchy of feeding links, in which species body sizes appear to play a crucial role. On present evidence, it is not possible to distinguish between the relative contributions of either of these possibilities in the creation of structure in real food webs.
authors.affiliation: Department of Biology, University of York, York Y01 5DD, UK.
authors.forename: J H
authors.initials: JH
authors.lastname: Lawton
authors.forename: P H
authors.initials: PH
authors.lastname: Warren