Food webs are assemblies of species that exist as a web of consumer-resource interactions. They can be simply visualized as a set of dots (individual species) connected by consumer resource links. While considerable work has focused on the network structure of foodwebs, the structure of the links that join these dots together have been adumbrated by Lotka-Volterra or Yodzis predator-prey equations. In 2015, a group of us suggested a more general form for the structure of links in food webs (Lafferty et al. 2015). The full model can be used for any food web link as it has the vital property that it can always be collapsed down to a different well-studied form of consumer-resource relationship: host-parasite, predator-prey, plant herbivore.
Results/Conclusions
In this talk I will attempt to use these models to examine the structure of the main species in the Yellowstone National Park food web. In particular, I will use the model to examine the conditions for a trophic cascade to operate in Yellowstone. Where possible, I will attempt to parameterize the model for the links coupling the major species in Yellowstone: elk, wolves, bison, grizzlies, and several aggregated types of vegetation. A central theme of the talk will be how much detail do we need to model food webs for large and relatively undisturbed natural ecosystems.
Lafferty, Kevin D., Giulio DeLeo, Cheryl J. Briggs, Andrew P. Dobson, Thilo Gross, and Armand M. Kuris. 2015. "A general consumer-resource population model." Science 349 (6250):854-857. doi: 10.1126/science.aaa6224.