How Are Invasive Plants Introduced into Canada?
The way a plant is introduced into a new region is called a pathway. In Canada, the main pathway has been deliberate introduction: of the 245 invasive alien plant species for which there is some information on the pathway of introduction, it is estimated that 141 (or 58%) were introduced intentionally (see Figure 3). These include plants introduced as agricultural crops, landscape plants, ornamentals, and plants for medicinal and research purposes. An estimated 120 (49%) were introduced unintentionally, such as weed seeds mixed in with imported soil or crop seeds. The total adds up to more than 245, and more than 100%, because some species are introduced by more than one pathway. Diffuse knapweed (Centaurea diffusa) Cindy Roche www.bugwood.
