Abstract: Global change is altering ecological communities and the food webs they support via a process dubbed ‘food web rewiring’. Better understanding 1) how existing trophic relationships might change and 2) how new ones will establish during this rewiring process is essential for forecasting population and community level stability. While a variety of features likely impact the dynamics of impacted food webs, the relative importance of intrinsic factors (i.e. characteristics of the food web itself) and extrinsic factors (i.e. the type of perturbation experienced) is still unclear. We use a dynamical trait-based food web model to investigate how the distribution of species richness and the distribution of biomass across trophic levels, affect food web dynamics. We also investigate how three types of perturbations (pulse, press, and periodic pulse) affect food webs. We show that the type of perturbation affects food webs dynamics in both short and long time-scales. The interaction between food web shape and perturbation type also structures how network metrics such as connectance and modularity change over time, but not how persistence of species changes. Our trait-based approach also allows us to understand how body size and other important species traits correlate under different perturbation types. These findings can be useful when forecasting how communities of interest (such as fisheries) react to various types of perturbations that affect the system differently - such as climate change and harvest.
