What is an invasive plant?

An invasive plant is a non-native species whose interaction causes economic harm, harm to human health and/or environmental harm. Invasive plants are often likened to "super-bugs". These "super-weeds" have abilities to reproduce and survive that far exceed their native counterparts. Invasive plants quickly displace native vegetation and completely take over sensitive ecosystems as they have no natural predators (i.e. diseases, fungi, insects) in their non-native environment.

What makes invasive plants so successful?

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 pants that produce seed often make seed prolifically, some species having over a million seeds per plant.

Living Conditions

Many of these plants can live where native species cannot. Most can thrive in nutrient deficient, acidic conditions. Many invasive plant species also exhibit a tremdous ability to adapt to a number of different types of living conditions.

Growth Strategy

Invasive plants grow quickly and agressively. 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!

Why should we care about invasive plants?

Economic Impacts

Economic impacts of invasive plants are much less direct in our region of the province than in others. In regions with rangeland, farmers feel the impacts of invasive plants much more directly as these plants can quickly decrease available forage for livestock. Hectares of land can quickly become waste lands with no grazing value whatsoever. In our region, economic impacts are more indirect and in some cases have been slower to develop. Our economic impacts are:

• Costs associated with managing/controling invasive plants by all levels of government and private land owners
• Damage to infrastructure (i.e. roads, foundations)
• Impacts on recreation and tourism (i.e. trails becoming impassable, loss of wildlife in infested areas
• Reduction in agricultural yield
• Impacts on fisheries from damaged riparian zones

Ecological Impacts

Often, invasive species form complete monocultures in sensitive habitat creating what is called a "biodesert". Most of these plants have very low habitat value (food and/or shelter) for our native species of insects, birds and animals so these native species are displaced from their natural habitat. Monocultures of invasive plants also have impacts on our fish as these riparian species quickly choke out water ways, deplete them of oxygen, make them impassable and shade them out.

Health and Safety Impacts

Invasive plants pose a number of health and safety risks to the public. These include:

• Exposure to toxins (ingested or topical)
• Reduced visibility on road ways
• Fire hazard
• Erosion
• Destruction of infrastructure (foundations and roads)