Reinvasion Is Not Invasion Again

Biological invasions are a major driver of global environmental change, and there is well-developed theory for predicting invasion success. Managing the impacts of established invasive species is expensive and hugely problematic, but this ongoing challenge is largely about managing reinvasion-defined here as the reestablishment of a nonindigenous species in a location after control. We review conceptual and theoretical frameworks developed to understand initial invasions and identify how reinvasion differs because of three factors: (1) changes in the invader, (2) changes in the invaded environment, and (3) interactions among invaders and with local taxa. We find a distinct lack of theory about the processes involved in reinvasion, but theory is needed to develop systematic research to optimally manage reinvaders. We detail the circumstances under which reinvasion is fundamentally different from initial invasion, address management issues specific to understanding and managing reinvasion, and highlight promising opportunities for future research.