Food web assembly in oak forest canopies: integrating ecology and evolution

Oak trees harbour the most species-rich canopy arthropod communities in the Western Palearctic. At all trophic levels within this system the resource is represented by a living, evolving set of organisms. My aim is to understand how this evolution interacts with contemporary ecological dynamics to affect the assembly and structure of these multitrophic communities. To do this I have studied bark-dwelling mites, a suite of herbivores including leaf chewers (caterpillars and beetles), sap suckers (true bugs) and gall-inducers (oak gall wasps), omnivores (true bugs) and natural enemies (more true bugs, parasitoid wasps, and birds) in a series of large-scale field studies. I will outline how the results shed light on the influences of (1) phenotypic evolution and niche availability, (2) shared evolutionary and geographic history, (3) relative host abundances, and (4) dispersal limitation, on the ecological dynamics of multitrophic food web assembly, and on the potential for future diversification at multiple trophic levels.