Temporal development in the impacts of plant invasions: search for the underlying mechanisms.

Many invasive plants have negative impacts on native populations and communities, but there remains much uncertainty about how these impacts develop over time. In this review, I describe the mechanisms that promote the initial dominance of invaders, the characteristics associated with large negative impacts, and present the processes that contribute to changes in invader abundance and impacts over time. Together with ecological processes such as ecosystem engineering or enemy accumulation, I show that temporal variation in impacts can be linked to evolution in both native and invasive species. I also show that multiple processes operating in the same invasion system can jointly shape long-term impacts. Finally, I present the framework of modern coexistence theory as a tool for predicting the effects of invaders on native populations, and how these effects change with processes ongoing within invaded communities.