Effects of heterogeneous interaction strengths on food web complexity

Oikos (Impact Factor: 3.44). 01/2008; 117(3):336 - 343. DOI: 10.1111/j.2007.0030-1299.16261.x


Using a bioenergetic model we show that the pattern of foraging preferences greatly determines the complexity of the resulting food webs. By complexity we refer to the degree of richness of food-web architecture, measured in terms of some topological indicators (number of persistent species and links, connectance, link density, number of trophic levels, and frequency of weak links). The poorest food-web architecture is found for a mean-field scenario where all foraging preferences are assumed to be the same. Richer food webs appear when foraging preferences depend on the trophic position of species. Food-web complexity increases with the number of basal species. We also find a strong correlation between the complexity of a trophic module and the complexity of entire food webs with the same pattern of foraging preferences.

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Available from: Joan Saldaña
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    • "The ecological literature is replete with references to interacting groups of species within systems, variously termed compartments (May, 1973; Pimm 1982; Prado & Lewinsohn 2004), modules (Olesen et al. 2007; Garcia-Domingo & Salda~ n a, 2008; Dupont & Olesen 2009), cohesive groups (Bascompte et al. 2003; Danieli-Silva et al. 2011; Guimar~ aes, Jordano & Thompson 2011) or simply communities (Fortunato 2010). Their attraction, for ecologists, is that they promise a way to simplify the description and understanding of an ecological system, by representing not each and every species, but aggregating their interactions and energy fluxes into a more manageable set of modules (e.g. "
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    Preview · Article · Dec 2013 · Methods in Ecology and Evolution
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    ABSTRACT: The fundamental building blocks of any ecosystem, the food webs, which are assemblages of species through various interconnections, provide a central concept in ecology. The study of a food web allows abstractions of the complexity and interconnectedness of natural communities that transcend the specific details of the underlying systems. For example, Fig. 1 shows a typical food web, where the species are connected through their feeding relationships. The top predator, Heliaster (starfish) feeds on many gastropods like Hexaplex, Morula, Cantharus, etc., some of whom predate on each other [129]. Interactions between species in a food web can be of many types, such as predation, competition, mutualism, commensalism, and ammensalism (see Section 1.1, Fig. 2).
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