Invasive species

An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native species that become harmful to their native environment after human alterations to its food web. Since the 20th century, invasive species have become serious economic, social, and environmental threats worldwide.

Invasion of long-established ecosystems by organisms is a natural phenomenon, but human-facilitated introductions have greatly increased the rate, scale, and geographic range of invasion. For millennia, humans have served as both accidental and deliberate dispersal agents, beginning with their earliest migrations, accelerating in the Age of Discovery, and accelerating again with the spread of international trade. Notable invasive plant species include the kudzu vine, giant hogweed (Heracleum mantegazzianum), Japanese knotweed (Reynoutria japonica), and yellow starthistle (Centaurea solstitialis). Notable invasive animals include European rabbits (Oryctolagus cuniculus), domestic cats (Felis catus), and carp (family Cyprinidae).