With any topic regarding the environment, there appears to be a proportional amount of misconception circulating around it. You guessed it, the topic of invasive species is no exception to that trend.
Myth #1: The movement of invasive species to new areas is a natural process.
To some extent, this statement does provide a valuable argument. It is true that glaciation events in the Earth’s history have accounted for the distribution of many plant and animal species beyond their previously-natural ranges. However, the establishment of new habitats by these displaced species occurred over thousands of years, following changes in the climate.
The problem we are currently experiencing with invasive species is caused by unnatural, human-assisted movement of species at a much greater pace and scale than ever before. Human activity is the primary driving force behind the introduction of invasive species into Canada. From the beginning of international trade and especially in the past century, humans have intentionally and accidentally introduced species into new environments.
Myth #2: Invasive species increase diversity
In a normal situation (or perhaps a perfect world), the addition of a new species would mean the number of different species in a given area would increase, therefore increasing diversity. However, when invasive species are involved, that is not the case. The fast-growing and spreading nature of invasive species allows them to quickly invade natural areas and outcompete the native species. This means they can reduce the amount of water, nutrients and space available for other plants and form dense monocultures that shade out native plants, resulting in a loss of biodiversity.
Myth #3: It’s fine to grow an invasive plant if it’s an indoor houseplant
Most people repot their houseplants at least once and where is that usually done? Outside. It may seem harmless to repot your English Ivy on your back deck, and then brush away any spilled soil onto your yard. This is where you’ve gone wrong: it is common for invasive plants to only require small root fragments, often present in discarded soil, to propagate and form a new plant.
There are also many ways seeds or regenerative plant fragments could travel outside:
- maybe the plant is sitting next to an open window and a gust of wind carries away some seeds, or
- your dog brushes against the plant and gets seeds stuck in its fur, or
- you stick plant houseplant clippings into the compost after pruning a houseplant.
In any case, growing invasive plants indoors is not a risk we are willing to take!
Myth #4: Harmful herbicide is the only way to get rid of invasive species
SSISC, like many other organizations in British Columbia, works closely with landowners and managers. SSISC’s actions are being guided by an integrated pest management plan. This means that invasive plants are controlled using manual, chemical and biological control. You can learn more about SSISC’s integrated pest management approach on this page.
Many invasive species in the Sea to Sky can be effectively controlled using manual control methods such as hand-pulling, cutting or digging etc. Manual control is our preferred control method, wherever possible and feasible.
Another option is using biological controls, which play into interspecific interactions between the invasive plant and its natural pests. For instance, parasites, predators and pathogens could be used to reduce another organism’s density to a lower level. In BC, the biological control is managed by the Province of BC’s Biocontrol program.
When these two control methods are not feasible or possible for the treatment of an invasive plant at a given site, then herbicides may be used. Extremely aggressive and destructive invasives, such as Japanese Knotweed, require chemical control as it is the only effective method of management and eradication.
All herbicide control work done by SSISC is completed by Certified Pesticide Applicators, under our Pesticide Use License.
Photo credit: B. Brett
Links
Links mentioned in the article
- English Ivy Species Profile Page
- Knotweeds Species Profile Page
- Invasive Plant Management
- Biological control (Province of BC’s site)
- Pesticide certification and training (Province of BC’s site)
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