invasive

Invasive is an adjective used to describe a species, organism, or process that spreads rapidly outside its native range and causes harm to ecosystems, economies, or human health. In ecology, invasive species are non-native to the ecosystem under consideration and tend to become established and spread, often due to traits such as rapid reproduction, broad environmental tolerance, and a lack of natural predators. Not all non-native species are invasive; many fail to establish or cause minimal impact.

Invasive species typically disrupt native communities by competing with or preying upon native species, altering habitat structure, and changing food webs. They can reduce biodiversity, alter ecosystem services such as water quality and soil stability, and impose economic costs in agriculture, forestry, infrastructure, and recreation. Some invasives also introduce diseases or hybridize with native species, further altering ecosystems.

Common pathways for introduction include international trade, transportation, horticulture, aquaculture, and human movement. Globalization and climate change can increase the likelihood of invasives establishing in new regions by expanding suitable habitats and creating new corridors for spread.

Management of invasive organisms emphasizes prevention, early detection, rapid response, and long-term control. Strategies range from physical removal and chemical controls to biological control and habitat restoration. Effectiveness varies by context and often requires an integrated approach, ongoing monitoring, and coordination among agencies, land managers, and communities.

The term invasive is also used outside ecology, for example in medicine to describe cells, tissues, or procedures that spread or invade surrounding areas beyond their normal boundaries; however, the ecological use is the most common reference.