Structure of food webs

Variation in network structure among food webs

Food webs

Ecosystems, whether they are forests, lakes or coral reefs, consist of a diverse range of species that interact with each other in many ways. As ecologists we want to understand how these complex systems function as a whole and how they respond to human impacts such as harvesting and environmental change. A mechanistic understanding of the underlying biological processes will allow us to predic...

Quantitative analysis of the local structure of food webs.

We analyze the local structure of model and empirical food webs through the statistics of three-node subgraphs. We study analytically and numerically the number of appearances of each subgraph for a simple model of food web topology, the so-called generalized cascade model, and compare them with 17 empirical community food webs from a variety of environments, including aquatic, estuarine, and t...

Food webs: reconciling the structure and function of biodiversity.

The global biodiversity crisis concerns not only unprecedented loss of species within communities, but also related consequences for ecosystem function. Community ecology focuses on patterns of species richness and community composition, whereas ecosystem ecology focuses on fluxes of energy and materials. Food webs provide a quantitative framework to combine these approaches and unify the study...

Rescaling the trophic structure of marine food webs

Measures of trophic position (TP) are critical for understanding food web interactions and human-mediated ecosystem disturbance. Nitrogen stable isotopes (δ(15) N) provide a powerful tool to estimate TP but are limited by a pragmatic assumption that isotope discrimination is constant (change in δ(15) N between predator and prey, Δ(15) N = 3.4‰), resulting in an additive framework that omits kno...