Native = natural, and neither are useful concepts for conservation 

We argue that the concept of “native” is essentially synonymous with the concept of “natural” and therefore subject to all the critiques of incoherency that have been leveled against naturalness. The term “native” implies that for every place, there are a list of species that are native to it and for every species there is a geographic area that it is native to. In practice, however, Invasion Biology is focused on introduced species, and so the category of “native” is typically defined as “not introduced by humans.” Contentions that there are fundamental biological or ecological differences between newly arrived species and long-established species have not been empirically demonstrated, leaving Invasion Biologists largely reliant on historical evidence of introductions. Sudden policy changes when the status of a species changes and the welcoming reaction to new species that arrive "naturally," such as the barn owl in New Zealand, show that it isn’t the effects of these species that are ultimately justifying how they are being valued and managed, but rather the presence or absence of the human touch.Thus, to be native is to be natural. However, humans are animals and not outside of “nature.” Despite the incoherence of naturalness, it might be argued that the concept of nativeness is nevertheless useful to conservation because it identifies species likely to have unwanted effects. Yet it is a universally accepted tenet of Invasion Biology that only a small percentage of introduced species become “problematic.” To identify which will become problematic, one has to wait for unwanted effects to manifest. Given that “native” species not infrequently also create unwanted effects (e.g. white-tailed deer, bracken fern, bark beetle, crown-of-thorns starfish), it seems that the useful indicator is in fact the unwanted effects themselves, not the organism’s status as “introduced.” Understanding ecological history is crucial if we hope to manage ecosystems wisely–but the concept of nativeness creates an oversimplified understanding of a system–one with unambiguous heroes and villains–which can unhelpfully lead managers to skip the important step of clarifying goals and values.