How do we know when invasive species control strategies work?

Controlling invasive species is costly and difficult but can have major ecological, economic, and health benefits. Researchers commonly compare the efficacy of specific control methods. However, invasive species control programs vary greatly in overarching goals and often occur over large areas, long timeframes, and varied environmental and social contexts. The success of these programs likely hinges on factors including organizational structures, concurrent restoration activities, geographic and temporal scope of control, and the invasive species' biology. To enable assessment of the relative influence of these common features, we propose clearer definitions of success in invasive species control and explicit comparisons among control programs. Post hoc assessment of existing programs' success will complement system-specific studies to guide strategies that work in real-world situations.