Weeds and Invasive Plants
Last review/updated: May 11, 2004
Invasive
plants are introduced plants that grow, spread and take over a new
habitat beyond their natural range. They are usually introduced by
human activity. These plants threaten the environment, the economy,
and/or society. They include, but are not limited to, what we define
as weeds.
What makes a plant a weed? A weed is a plant that out-competes the native or desired plants in a given area, and because it is introduced, it has no natural enemies to prevent its spread. Weeds and other invasive plants adapt quickly and easily to a wide range of temperature and moisture conditions and soil types. Many start growing early in the spring before native plants. Some have effective methods for spreading seed, and a lot of these seeds survive. Some have built-in protection to avoid being eaten (e.g. thorns). A quote by Doug Larson humorously characterizes weeds as: "A weed is a plant that has mastered every survival skill except for learning how to grow in rows."
What are the impacts of invasive plants? How are we managing them and what are we doing to prevent their spread? These answers as well as additional information on provincial legislation and common examples of invasive plants, can be found at http://www.srd.gov.ab.ca/forests/health/invasiveplants/default.aspx.
