Simple trophic modules for complex food webs

There are two common approaches to food webs. On the one hand, empirical studies have described aggregate statistical measures of many-species food webs. On the other hand, theoretical studies have explored the dynamic properties of simple tri-trophic food chains (i.e., trophic modules). The question remains to what extent results based on simple modules are relevant for whole food webs. Here we bridge between these two independent research agendas by exploring the relative frequency of different trophic modules in the five most resolved food webs. While apparent competition and intraguild predation are overrepresented when compared to a suite of null models, the frequency of omnivory highly varies across communities. Inferences about the representation of modules may also depend on the null model used for statistical significance.