An alien species is a plant, animal, or other species that has been intentionally or unintentionally introduced by humans outside its natural range. With the help of humans, an alien species has crossed a natural barrier to dispersal, such as the mainland, the sea, or the mountains. Alien species that threaten biodiversity, cause damage to wild organisms, or pose a risk to health or safety have been designated as invasive alien species (Decree on Invasive Alien Species 2014 and National Alien Species Act 2015).
Terminology and references
On this page, you will find explanations of the most commonly used terms and a list of references used in the Tampere Biodiversity Programme.