ABSTRACT. - Les espèces introduites et envahissantes au canada : état des lieux des risques et impacts environnementaux et propositions pour leur gestion. Invasive alien species represent a severe risk to Canada's environment and economy, disturbing biodiversity, ecosystem functioning, agriculture, economic activities, and human health and well-being. In 2005, the Government of Canada started to implement An Invasive Alien Species Strategy for Canada. Firstly, based on examples of three key invasive animal species in Canada, namely the European starling (Sturnus vulgaris), the House sparrow (Passer domesticus), and the Asian Longhorned Beetle (Anoplophora glabripennis), this paper characterizes and analyses the risk and impacts on native species. Secondly, this paper illustrates and analyses the problems resulting from invasive plant species on wetland, forest and aquatic ecology and ecosystems by focusing on three key invasive plant species in Canada, namely the Eurasian water milfoil (Myriophyllum spicatum), the Common buckthorn (Rhamnus frangula), and the Common reed (Phragmites australis). The paper then reviews efforts that are underway for controlling invasive species, and finally it provides propositions for action to better understand and addressing the invasive plant problem in Canada.
Key-words: invasive alien species; Myriophyllum spicatum; Rhamnus frangula; Fragmites australis; wetland, aquatic and forest conservation; competition; biological control; Canada