Prior predation alters community resistance to an extreme climate disturbance

Abstract

Short-term physical disturbances occur amid a backdrop of longer-term biotic interactions, including predation, which shape communities. Effects of consumer interactions typically begin in early stages of assembly and continue throughout post-disturbance recovery. Despite decades of predation and disturbance research, few studies examine how consumer interactions during these different time periods may affect community responses to disturbance. Here we use replicate communities of tropical, sessile invertebrates to ask whether fish predation during initial assembly (before) and recovery (after) influences community resistance to a hurricane-level low-salinity event. Results revealed that pre-event predation determined whether communities shifted in biomass and community structure following disturbance. Communities that assembled without predators responded to the low-salinity event strongly, with large shifts in community composition and a mean loss of 54% of pre-disturbance biomass after a one-month recovery period. In contrast, those that experienced predation during initial assembly were strikingly resistant to disturbance, which had no effect on species composition or biomass. Results were driven by predator removal of a dominant competitor, which gave rise to more disturbance-resistant communities. These findings highlight the potential for past trophic interactions to shape community stability in the face of physical disturbances predicted to escalate with global change.