Invasive Species Overview

Whether you live in an urban area or in a rural setting, invasive species can be lurking in your backyard.

What is an invasive species?

Invasive species are species (a plant, insect, disease, animal, bacteria etc.) that are introduced to an area outside of their native range and threaten the environmental, economic and social health of that area. Invasives generally have an advantage, as the natural predators or pathogens found in their native range are not present to keep them in check.

Why invasive species a problem?

They can negatively impact the environment:

    • Loss of biodiversity (second only to habitat loss) - outcompete native species for space, light and the resources needed for growth
    • Alter habitat - change soil chemistry, reduce beneficial soil organisms, displace food and habitat for wildlife
    • Compete and displace native species, compete with endangered or at risk species

    They can have a negative economic impact - cause losses for industry:

    • Forestry - loss of wood, cause quarantines the prevent the movement of wood, can increase fire hazards, decrease regeneration of the forest, increase erosion and sedimentation and more.
    • Agriculture - reduce crop yield and quality, reduce pasture quality for foraging livestock, increase herbicide usage, diseases and insects may "piggyback" on imported plants and animals causing new infestations
    • Fisheries - decrease yields, increase handling and sanitation, negatively affect infrastructure, are difficult to manage in an aquatic environment.

    They can have a negative social impact:

    • Human health - can contain toxins, can cause rashes or skin burns, impede recreational activities such as boating or swimming, create problems in gardens, block viewscapes, access points or pathways.

    Why are we concerned about invasive species in the City?



    • Some invasive species threaten our urban forest such as: Dutch elm disease that kills elm trees, emerald ash borer that kills all true ash tree species, Oriental bittersweet that climbs up, covers and kills trees that it grows on.
    • Invasive plants such as purple loosestrife and Himalayan balsam prefer moist areas so can thrive in and take over riparian zones and wetlands that exist in our green spaces and “natural areas” in the City.
    • Urban areas are one of the most likely pathways for the introduction of invasive species. There are so many people and so much of goods in and out of a city that it is more likely that in invasive will be introduced become established in an urban area.
    • Invasives in a urban area can easily be moved to rural areas where they can threaten PEI’s forest and natural areas.

     “How wonderful it is that nobody need wait a single moment before starting to improve the world” ~ Anne Frank