invasive alien species

A species introduced outside its natural past or present distribution whose introduction and/or spread threaten biological diversity.

Species whose introduction and/or spread by human action outside their natural distribution threatens biological diversity, food security, and human health and well-being. Alien refers to the species' having been introduced outside its natural distribution (exotic, non-native and non-indigenous are synonyms for alien). Invasive means tending to expand into and modify ecosystems to which it has been introduced. Thus, a species may be alien without being invasive, or, in the case of a species native to a region, it may increase and become invasive, without actually being an alien species.

animals, plants or other organisms introduced directly or indirectly by people into places out of their natural range of distribution, where they have become established and dispersed, and generating an impact on local ecosystems and species (IPBES, 2016); see Chapter 1 for further discussion). Invasive alien species are a subset of established alien species that have negative impacts.

A species that, once it has been introduced outside its native distributional range, has a tendency to spread over space without direct human assistance.

See Invasive alien species.