What defines an invasive species?

An invasive species is defined predominantly as a species that causes economic, environmental, or health harm. This definition emphasizes the impact that these species can have when they establish themselves outside their native range and proliferate in new environments. Invasive species often disrupt local ecosystems, outcompete native species for resources, and can lead to significant changes in habitat structure and function.

When an invasive species is introduced to an area, it can alter food webs, reduce biodiversity, and contribute to the decline of native species. This can result in substantial economic costs associated with control measures, loss of agricultural productivity, and the need for expensive restoration efforts for damaged ecosystems. Additionally, invasive species can pose health risks to humans and animals, often facilitating the spread of diseases.

Other choices do not accurately capture the essence of what makes a species invasive. A species being native to its ecosystem does not justify its invasiveness, nor does ease of control indicate whether a species is invasive. Similarly, a species benefiting the local ecosystem contradicts the definition of an invasive species, which is characterized by negative impacts.