Unit 5 - Health of the Forest Ecosystem

Lesson 6: Invasive Weeds


Invasive weeds are a non-native species that originate in another region or country; they adapt quickly and aggressively to the Alberta landscape causing lasting damage.



These invasive weeds are introduced into the forest ecosystem either intentionally or accidentally.

They are typically more aggressive and adaptable than native species, invasive weeds often win the competition for light and nutrients.

The common toadflax, to the left, is pretty but invasive.


The negative effects of invasive weeds include:

  • choking out the local species which results in decreased biodiversity within the forest
  • interfering with natural ecological succession patterns
  • changing the structure and composition of the biological community
  • suppressing the growth of native seedlings which interferes with forest development
  • reducing property values for residents and agricultural producers
  • increasing land management expenses for counties, municipalities, businesses and property owners

Below are eight weeds that are of concern in Alberta. Their invasiveness and/or their noxious nature make them an extreme nuisance.




                 

              Digging Deeper

Do you like to garden?  If so,  download this pamphlet to know which plants to avoid.  


For some fun activities on invasive plants, download this Activity Book.      


These publications are courtesy of The Alberta Invasive Species Council.