About Invasive Species

Invasive species are those which occur outside their natural range and can have significant ecological, social and/or economic impacts once established.

These species have been introduced to BC without their natural predators and pathogens that would otherwise keep their populations in check in their countries of origin, giving them a competitive advantage over native species.

Why Should We Care?

Environmental Impacts  

Often, invasive species form complete monocultures, dominating ecosystems and excluding other species. Most of invasive plants provide very low habitat value (food and/or shelter) for our native wildlife, so native species are displaced from their natural habitat. Invasive plants have impacts on aquatic ecosystems, choking out water ways, shading and depleting them of oxygen, and making them impassible. Invasive species are also a significant threat to species at risk.

Economic Impacts

Invasive species indirectly impact a number of British Columbian industries including forestry, fishing, tourism, horticulture and recreation. Invasive plants compete with crops and reduce agriculture yields. Hectares of land can quickly become wastelands with no grazing value whatsoever. Some invasive plants are toxic to livestock.

There are also direct costs associated with managing and controlling invasive species. All levels of governments and some business and local residents are burdened with the cost of restoring or protecting infrastructure, managing invasive species their property, and educating the public.

Health and Safety Impacts

Invasive plants pose a number of health and safety risks to the public. Some invasive plants are toxic to humans (ingested or topical), reduce visibility on roadways, cause erosion, create fire hazards or compromise infrastructure (foundations and roads).

Why are invasive plants so successful?  

Growth Strategy: Invasive plants grow quickly and aggressively. It is this quality that helps them to easily outcompete native vegetation. Some species have been noted to grow up to 4 cm per day!

Reproductive Strategy: Many of these plants reproduce by seed, rhizomes, plant parts or any combination of these. Some plants have unique abilities to disperse their seeds including shooting, self sowing, floating, and attaching to animals. Invasive plants often produce seeds prolifically or multiple times a year, with some species releasing over a million seeds per plant.

Living Conditions: Many of these plants can live where native species cannot. Most can thrive in disturbed and poor conditions that native plants cannot tolerate. Many invasive plant species also exhibit a tremendous ability to adapt to a number of different types of living conditions.

Invasive Animals

Why are invasive animals so successful?

Growth Strategy: Invasive animals have the ability to grow quickly and disperse easily.

Reproductive Strategy: Many of these animals are able to reproduce quickly and are capable of producing a large amount of offspring at a time.  

Living Conditions: Invasive animals are often highly adaptable, meaning they can adjust to their current environment and are tolerant of a wide variety of environmental conditions. Many of these species have a generalist diet, which helps them be more adaptable.

How You Can Stop The Spread

Understanding where invasive species come from can help us to stop their introduction and spread. There are many ways that invasive species can be introduced and spread, either intentionally or unintentionally:

  • Through garden ornamentals and seed packages (invasive plants continue to be sold in many nurseries and stories in our region)
  • Escape from people's gardens
  • Seed spread by wind, water and birds
  • Plant parts and/or seeds catch a ride on an animal, hiking boot, ATV, or machinery
  • Contaminated soil gets moved from one part of the region to another
  • Insects and other small animals can be moved on plants, food, or in wood