Controlling Japanese Knotweed in the Wapizagonke-Nord Area of La Mauricie National Park

Japanese Knotweed (Reynoutria japonica), an invasive alien species, is a threat to the ecological integrity of La Mauricie National Park. This plant has a remarkable ability to compete with indigenous species, take up space and affect the natural landscape and biodiversity, and eradication and control methods are limited and complex. Efforts to control colonies must be intensive and sustained over a long period to be effective.
Japanese Knotweed colonies can be found in developed areas of Lac Gabet and the Wapizagonke-Nord area. Some are established along the Parkway while others are near water and within designated critical habitat for the at-risk Wood Turtle (Glyptemys insculpta). 
In light of the growing effort to tackle this invader, the challenges associated with the various control methods and the long-term monitoring required to fight the spread of the species, the colony tarping method was selected as the most effective and efficient technique for controlling the species. 
The proposed project is to spread geomembrane tarps over previously cleared surfaces inhabited by colonies, in early spring 2022, to deprive the stems and their root systems of exposure to the sun, reduce water supply and promote plant death and decomposition. These membranes must be inspected regularly and kept in place for a minimum of 10 years.
This method will be used to control the species and prevent escalation to new outbreaks throughout the water system and the Wapizagonke Lake watershed, a major component of critical Wood Turtle habitat. Invasive plants, such as Japanese Knotweed, are a potential threat to the species and its habitat according to the 2020 recovery strategy.

Latest update

June 10, 2022 – The public comment period on the project is closed. Parks Canada is considering comments received to help inform its determination on whether the carrying out of the project is likely to cause significant adverse environmental effects.


Key documents

Key documents
Document Number Document Title File Date
1 New project being assessed by Parks Canada - Public comments invited from May 11 to June 10, 2022 - May 11, 2022


La Mauricie National Park
702, 5e rue de la Pointe
Shawinigan, Quebec G9N 1E9
Telephone: 819-538-3232 or 1-888-773-8888
Fax: 819-536-3661

  • Location

    • La Mauricie National Park (Quebec)
  • Nature of Activity

    • Remediation and conservation
  • Assessment Status

    In progress
  • Start Date

  • Proponent

    Parks Canada
  • Authorities

    • Parks Canada Agency
  • Assessment Type

    Project on federal lands
  • Reference Number


This map is for illustrative purposes. The markers represent the approximate locations based on available data. More than one marker may be identified for a given assessment.


Nearby assessments

...within 200 kilometres
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