Trade-off escape as a framework for understanding plant invasions

Trade-offs are a central organizing principle in ecology and evolution, defining feasible phenotypic combinations that shape life histories, species interactions, and community assembly. But what if introduced species do not play by the same rules as the natives they displace? Many invasion frameworks assume invaders succeed by shifting toward one extreme of established trade-off axes (e.g., rapid growth) at the expense of another (e.g., stress tolerance). Yet, evidence is accumulating that some successful plant invaders achieve unusually high performance on both sides of classic trade-offs. We present a ‘trade-off escape' framework to distinguish invaders that simply shift along trade-off surfaces from those that circumvent constraints limiting native species, and to guide questions needed to evaluate when and why escape occurs.