Why are invasive plants a problem?
- They outcompete and displace native plants that wildlife depend on.
- They can alter water flow and lead to erosion and/or less available water.
- They can create an increased fire hazard.
- Some contain substances that are toxic to people and animals.
- Each year, hundreds of thousands of dollars are spent controlling invasive plants.
Why should we care about invasive plants?
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
- 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
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
- Destruction of infrastructure (foundations and roads)
- In natural ecosystems, invasive plants displace or destroy native plant populations.
- Many rare and endangered native plants are also at risk from extinction from non-native plant invasion.
- By removing the natural wildlife, invasive plants also reduce wildlife habitat.
Aquatic & Riparian
- Shallow root systems can increase erosion, causing higher surface runoff, which increases stream sediment and reduces water quality.
- Riparian invasive plants often grow in dense monocultures, resulting in negative impacts to nesting, cover and breeding habitat for fish and wildlife.
- Infestations can change wetland structure by trapping sediments, creating higher, drier land that favours tree and shrub species rather than wetland species.
- Invasive plants outcompete with existing forage and are often unpalatable to livestock, reducing overall levels of grazing.
- They also compete with agricultural crops and reduce overall crop yield and quality.
- Invasive plants require costly, long-term strategies to control and manage their spread.
- Dense infestations of weeds increase the risk of wildfire because they are a source of fuel as they mature.
- Noxious weed infestations compete with new tree seedlings for soil nutrients, light and moisture. This results in increased costs for silviculture.
- Invasive plants degrade the natural beauty biodiversity of the landscapes.
- Invasive plants can limit access for recreationalists (i.e. Gorse and Himalayan blackberry).