The return of the trophic chain: fundamental vs realized interactions in a simple arthropod food web

Our research hypothesis is that increasing the number of species that are known to interact when no alternative food is available will increase the number of realized links in the more complex community. To address this question, we explore how pairwise trophic interactions between species are modified by the inclusion of other species in a simple community. We found that increasing the number of potential interactions did not result in more complex realized community modules. Instead, all communities were reduced to one or two linear trophic chains. Our results show that trophic links assumed to occur when species are assembled in pairs do not necessarily occur when other components of the community are present.