Naturalisation (biology)

Naturalisation (or naturalization) is the ecological process by which a species, taxon, or population of exotic—as opposed to native—origin becomes integrated into a given ecosystem. Through this process, the organism establishes self-sustaining populations, becoming capable of reproducing, growing, and disseminating spontaneously without continued human assistance. In some cases, a species’ presence in an ecosystem is so ancient that it becomes impossible to determine with certainty whether it is native or the result of a historical introduction. Such taxa may be regarded as naturalised when their origin cannot be conclusively established.

Generally, any introduced species may (in the wild) either go extinct or naturalise in its new environment.

Some populations do not sustain themselves reproductively, but exist because of continued influx from elsewhere. Such a non-sustaining population, or the individuals within it, are said to be adventive. Cultivated plants, sometimes called nativars, are a major source of adventive populations.