Does the biogeographic origin of species matter? Ecological effects of native and non-native species and the use of origin to guide management

1. The introduction and success of non-native species are both a consequence and a cause of rapid global change. Humans have created novel ecosystems through environmental modification and mass movements of organisms around the planet. 2. It has been argued that species biogeographic origin cannot explain or predict ecological impacts and the origin of a species should not influence ecosystem management. This rejection of 'origin' is overly simplistic. Origin effects can arise through biased sampling of the types of species transported, the environmental and evolutionary context of their source environments and the communities and environments to which they are introduced. Differences in co-evolutionary histories between source and recipient environments, and adaptation of introduced species to modified environmental conditions, can also shape origin effects. 3. The high rates and long distances of human-mediated dispersal have increased the sizes of regional species pools. In addition, human transported, non-native species can change the function of recipient ecosystems through changes to community composition. We outline how origin effects can cascade through to ecological impact at population, community and ecosystem levels. 4. Synthesis. Non-native species can have predictable and preventable effects on recipient communities. We identify multiple sources of origin effects and describe the ecological and evolutionary pathways through which origin effects lead to impacts. This functional understanding of origin effects must include human actions. However, species origin should not, on its own, be used as a shortcut for management decisions; origin effects should instead feed into a process whereby ecologists work together with managers, policymakers and broader society to guide decisions on how to respond to the effects of non-native species.