Introduction to Invasive Species

What are Non-native and Invasive species?

Non-native species refer to species that have been introduced through human action outside of their natural distribution. Alien, exotic, introduced, non-indigenous and non-native are all synonyms and frequently used interchangeably.

Invasive species are a subset of these. Invasive species are species whose introduction and/or spread by human action outside their natural distribution threatens biological diversity, food security, and human health and well-being. “Invasive” means tending to expand into and modify ecosystems to which it has been introduced. Invasive Non-native Species, Invasive Alien Species and Invasive Non-Indigenous Species are all considered synonymous terms. To help accessibility of language, we will normally use the term “Invasive Species”.

Many species may be non-native without being invasive. Indeed, our economies depend on many non-native species (e.g. agricultural crops).
Some native species can cause economic or other problems within their native range, however, these species are not in the scope of this website.