Physical disturbances occur amid ongoing biotic interactions including predation, which shape communities and may influence how they respond to acute disturbance. Predation typically begins in early stages of assembly and continues throughout post-disturbance recovery. Despite decades of disturbance and stability research, the ways that predation may act across these different time periods to impact community resistance remains largely unexplored. We take as a model system replicate communities of tropical, sessile invertebrates, combining field and laboratory experiments to ask whether predation during initial assembly and/or post-disturbance recovery affects the extent that communities resist shifts in species richness, composition, and biomass following a hurricane-level low-salinity event.
Results/Conclusions
We found that predation during assembly—but not recovery—drove differences in resistance, determining how, and whether, biomass and species composition changed after the disturbance. Communities assembled without predators responded to the low-salinity event strongly, with large compositional shifts and an average 54% loss of pre-disturbance biomass after a one-month recovery period. In contrast, those open to predators during assembly were strikingly resistant to disturbance, which had no effect on community composition or biomass. Effects were not mediated by diversity per se, as neither predation nor disturbance affected richness. Rather, differences in disturbance resistance were driven by predator control of a high-biomass competitive dominant. Our findings highlight the potential for past trophic interactions, and current declines in consumers, to shape community stability in the face of physical disturbances, which appear to be escalating with global change.