Invasive species and their consequences

In short: Invasive species are plants or animals introduced by human activity into ecosystems where they don’t naturally occur and can cause considerable damage there. They are among the biggest drivers of species extinction worldwide.

In more detail: Without natural enemies or competitors, invasive species can often reproduce uncontrollably and displace native species.

In detail

• Introduction pathways: Global trade, shipping, and the ornamental plant trade are among the most common ways species unintentionally reach new areas.
• Lack of natural control: In their new environment, invasive species often encounter no natural predators that would limit their population.
• Displacement of native species: Invasive species often successfully compete with native species for food, habitat, and breeding opportunities.
• Economic damage: Invasive pests and plants cause substantial costs worldwide in agriculture, forestry, and infrastructure.
• Ecosystem changes: Some invasive species fundamentally alter entire ecosystems, for example through changes to soil composition or water balance.
• Control measures: Mechanical removal, biological control through natural adversaries, and strict import controls are common countermeasures.
• Prevention: Preventing introduction is considered significantly more effective and cheaper than subsequently combating already-established invasive populations (artensterben-und-biodiversitaet, nahrungskette-und-oekosystem).