Invasive species are impacting British Columbia in the following ways:
|Spotted Knapweed infestation. Photo: Barb Stewart|
|Globally, invasive alien species are one of the five most important direct drivers of biodiversity loss and change in ecosystem services. —Millennium Ecosystem Assessment, 2005|
The economic impact of invasive species in Canada is significant. According to Environment Canada:
The extent of economic costs of invasive species in BC is currently unknown and requires further research. In BC, invasive plants (not including other species) cause:
|Purple loosestrife is an aquatic invasive plant that can produce 2.5 million seeds annually, displacing native species and threatening wildlife habitat.|
Invasive species can alter habitats and disrupt essential ecosystem functions. Invasive plants specifically displace native vegetation through competition for water, nutrients, and space. Once established, invasive plants can:
Invasive species threaten biodiversity and many rare and endangered species are at risk from extinction from non-native invasions of invasive plants and other species. Invasive species can disrupt the natural migrations of wildlife since their habitat, without prevention or intense and costly management, can be damaged or destroyed – with the impacts often irreversible to the local ecosystem. Prevention is key to any effective management plan!
|Himalayan balsam infestation on private property. Photo: J. Hallworth|
|As native plant communities are replaced by invasive plant infestations, biodiversity declines and habitats change. These impacts are often irreversible and restoration can be extremely difficult, if not impossible; therefore, preventing their establishment and spread is key!|
When established in crops or natural areas, invasive plants and/or species can result in:
Invasive plants also impact human health and safety by obstructing sightlines and road signs along transportation corridors, causing skin burns and dermatitis, and increasing allergies. For example:
The impacts of invasive species requires further study in BC. Problems with invasive rabbits on Vancouver Island in metropolitan areas and their destruction to infrastructure, and the American Bull-frog and Grey Squirrel populations competing for resources with their native counterparts in the Lower Mainland are just some examples of invasive species causing damage in BC. Visit the Most “Unwanted” Invasive Organisms section to learn more.