Forest Invasive Alien Species (FIAS)

List of species
Established
in Canada

List of species
Undesired
in Canada

Databases
on FIAS

FIAS Document
Library

Alien species (insects, micro-organisms and plants) are species found outside of their natural range. They can be pests, diseases, insects or weeds. Other alien species are competitors of indigenous species rather than pests. They do not cause damage to trees and plants, but they do change the natural biological diversity of local ecosystems by crowding out indigenous species. These species are termed invasive if they are able to modify indigenous ecosystems either as pests or competitors. The introduction of alien pests into a new environment, sometimes far away from their original environment, is most often accidental. Some plants introduced for horticultural or ornamental reasons become invasive weeds that invade and threaten natural ecosystems if allowed to grow wild. More...