BioND — Dynamics of Biological Networks

A general consumer-resource population model

Kevin Lafferty, Giulio DeLeo, Cheryl J. Briggs, Andrew P. Dobson, Thilo Gross, and Armand M. Kuris
Science 349(6250), 854-857, 2015.



Food-web dynamics arise from predator-prey, parasite-host, and herbivore-plant interactions. Models for such interactions include up to three consumer activity states (questing, attacking, consuming) and up to four resource response states (susceptible, exposed, ingested, resistant). Articulating these states into a general model allows for dissecting, comparing, and deriving consumer-resource models. We specify this general model for 11 generic consumer strategies that group mathematically into predators, parasites, and micropredators and then derive conditions for consumer success, including a universal saturating functional response. We further show how to use this framework to create simple models with a common mathematical lineage and transparent assumptions. Underlying assumptions, missing elements, and composite parameters are revealed when classic consumer-resource models are derived from the general model.

Media Coverage

Kevin Knudson, Forbes, 2015-10-15
Scientists love unifying theories – a single equation (or set of equations) that explains everything in the discipline. Physicists have been searching for theirs for decades, running into difficulty unifying quantum theory with relativity. Economists work very hard at trying to model the global economy via complicated regression models. Until recently, however, ecologists thought that different food webs operated under distinct conditions. That is, the dynamics of foxes and squirrels must be different from those of parasites eating hosts.

Just Cebrian, Science Magazines, 2015-09-04
All organisms in an ecosystem can be placed on a trophic level, depending on whether they are producers or consumers of energy within the food chain (see the photo). Ecologists have long debated what regulates the trophic structure and dynamics of ecosystems (1). This is important because trophic structure and dynamics regulate many of the goods and services that ecosystems provide to wildlife and humankind, such as the production of harvestable food and energy, carbon sequestration and modulation of climate change, and nutrient uptake and control of global biogeochemical cycles (2). A study by Hatton et al. on page 1070 of this issue (3) and a recent report by Lafferty et al. (4) represent important advances toward a unified theory of trophic structure that captures observed trends across all ecosystems.


Supporting Material