Finding a middle-ground: The native/non-native debate

Throughout the history of invasion biology, there has been long-standing and sometimes fierce debate on the perception and management of non-native species. Some argue that non-native species are universally undesirable for their unpredictability and their ability to at times dramatically disrupt native species and systems. Others argue for an approach that weighs a species' impact and role in a system before determining its desirability, irrespective of its identity. We suggest a middle-ground approach, one that does add extra caution about the desirability of non-native species relative to native species, but also bases perception and management decisions on the population stage of the non-native species and in relation to a wider range of conservation goals. In initial stages of introduction and establishment, we argue that a cautious approach is most prudent, one assuming the potential dangers of the new species in systems. In later stages of established populations, we argue that impact assessments will provide the soundest and more efficient management information, with origin and other available data included as part of the subsequent decision-making process. We explore and expand on these suggestions, and hope that the perspective presented respectfully contributes to finding a common ground in a long and polarized debate. © 2012 Elsevier Ltd.