What defines an invasive species?

An invasive species is specifically defined as a non-native species that spreads and disrupts local ecosystems. This definition is crucial because invasive species often outcompete native species for resources, such as food, space, and light, leading to declines or even extinction of native populations. They can alter habitat structure and ecosystem functions, significantly impacting biodiversity and the health of ecosystems.

The distinction lies in the non-native status of these species; they have been introduced to a new environment, either intentionally or accidentally, and thrive due to a lack of natural predators or competitors. This allows them to proliferate unchecked in their new surroundings, resulting in ecological imbalances.

In contrast, native species that thrive in diverse habitats do not fit this definition, nor do endangered species, as they belong to habitats where they are originally found. Beneficial species that enhance biodiversity are also not considered invasive, as they typically support and stabilize ecosystems rather than disrupt them. Therefore, the defining characteristic of an invasive species is its non-native origin combined with its negative ecological impact on local environments.