Abstract
Human actions have led to large-scale shifts in the distributions of species, which have accelerated over recent decades. Two contributing factors include the introduction of non-native species to new regions, and more recently, the shift of species into new ranges to track a human-altered climate. While the context of these species redistributions is different, we argue here that scientists studying the effects of either invasion or range shifting are interested in the same underlying mechanistic questions: (1) What traits make a species likely to survive in a new location? and (2) Which recipient ecosystems are likely to support a newly arrived species? A survey of the theoretical literature surrounding these topics demonstrates the usefulness of this comparison and highlights key differences between range shifting and invasion in factors including genetic diversity, climatic tolerance, local adaptation, and coevolutionary history. This review does not support the blanket application of an invasion framework to climate change-induced range shifts. However, we suggest the use of modified invasion theories, experimental designs, and risk assessments could aid in predicting outcomes and prioritizing management resources for climate-threatened species.