Long-term effects of predator arrival timing on prey community succession.

The stochastic arrival of competing species and their subsequent interactions have been highlighted as principal forces underlying biotic historical effects in community assembly. However, despite the widely recognized effect of predation on prey communities, the effects that the stochastic arrival of predators may have on assembling communities are poorly understood. We used a microbial microcosm experiment to investigate whether the timing of predator arrival to a prey community undergoing naturalistic succession affected species abundances and community diversity. Predator arrival timing affected the long-term abundance of a prey species that was persistent throughout succession in the absence of predators. Our data indicate that this timing effect occurred indirectly via transient interactions between early-successional prey species and predators. Specifically, we suggest that transient early-successional prey species served as a springboard for early-arriving (but not late-arriving) predators, allowing the exploiting predators to increase their abundances and subsequently alter long-term community dynamics. These results show that the history of predator arrival can have lasting consequences for community structure in ecological succession.