What is an invasive species?
An invasive species is a plant, fungus, or animal species that is not native to a specific location (an introduced species), and which has a tendency to spread to a degree believed to cause damage to the environment, human economy or human health.

The GRCA has been very actively involved in the invasive species issue.  This has included public information walks and activities, providing informative presentations to public groups, advising landowners about control methods and undertaking control of some species on our own properties, and working with municipal partners on projects and strategies.

How did they get here?
European settlers not only sought new homes but brought things with them. This included invasive species, while some were because they wanted a reminder of home, others hitched a ride and were unintentionally introduced.

It still happens today! There are many ways we are still spreading invasive species.

  • Between lakes and rivers when boats and ships dump ballast water (used to balance ships in rough water) or when small critters including zebra mussels or aquatic plants hitch a ride on a recreational boats.
  • Anglers and the baitfish industry may dump unwanted bait into waterbodies.
  • Local nurseries may sell invasive plants that have not been regulated.
  • The importation of wood products or other shipping materials can bring unnoticed pests such as emerald ash borer or Asian long-horned beetle.
  • Seeds from invasive plants can get caught on hikers or bikers boots, clothing, and gear as they explore the outdoors.

Why are invasive species a concern?
The rapid spread of invasive species has become a major concern worldwide. From an ecological perspective, there is concern about:

  • The displacement of diverse native species
  • Impacts on species that rely on native plants for food, and habitat
  • Reduced genetic diversity
  • The loss of native species can be associated with financial losses.

Some common terrestrial invasive species that are found within the GRCA jurisdiction are below.

Emerald Ash Borer
Emerald Ash Borer
  1. Jewel beetle native to north-east Asia.
  2. Impact: Attacks both stressed and healthy Ash trees. Once infested, mortality of Ash trees is nearly 100%.
  3. GRCA’s Actions: Removal of infested and dead Ash trees throughout our conservation areas.
Phragmites
Phragmites
  1. Perennial wetland grass found particularly in marshes
  2. Impacts: species grows to height of 5 metres and spreads both by seed and by root.  Phragmites is salt tolerant and is most often found in roadside ditches.  Creates dense stands, crowding native vegetation and providing little value for wildlife.
  3. GRCA’s Actions: Chemical treatment at the Millennium Trail Conservation Area. Intensive roadside inventory.
Dog Strangling Vine
Gog Strangling Vine
  1. DSV is a perennial plant of the milkweed family that originated from eastern Europe.
  2. DSV infestations can be so dense as to prevent all other ground cover plants from growing, and can smother small trees. Uses the wind to spread seeds
  3. GRCA’s Actions: Active management in the Ganaraska Forest
Giant Hogweed
Giant Hogweed
  1. Is an invasive toxic plant from Eurasia that can grow to height of 5 metres or more.
  2. Impacts: Human health risk: sap causes severe skin burns when exposed to sunlight. Creates monocultures in wet communities.
  3. GRCA’s Actions:  Distribution mapping and reporting in partnership with Ganaraska Conservation and the Municipality of Clarington.
Garlic Mustard
Garlic Mustard
  1. Is a biennial herbaceous plant that was introduced as a medicinal herb
  2. Impacts: Outcompetes native forest wildflower. Is spread on animal fur, clothing, and in mud on boots and tires.
  3. GRCA’s Actions: Physical removal at the Millennium Trial Conservation Area.
Common Buckthorn
Common Buckthorn
  1. Is a shrub that was introduced from Europe primarily as a windbreak for hedgerows.
  2. Impacts: Produces massive quantities of berries that act as a laxative and are spread throughout the landscape by birds.  It invades forests, sometimes completely taking over the understory.
  3. GRCA’s Action: Physical removal in the tall grass demonstration plot at the Ganaraska Forest Center.
Wild Parsnip
Wild Parsnip
  1. Is a tall perennial plant originally from Eurasia.
  2. Impacts: Human health risk: sap causes severe skin burns when exposed to sunlight. It can grow in large numbers, displacing native plants.
  3. GRCA’s Impacts:  Physical removal and follow up monitoring along trails.
LDD Moth
LDD Moth
  1. A moth that is native to Europe and Asia.
  2. Impacts: Defoliates large amounts of trees, affecting their health. Coniferous trees are less tolerant to defoliation and may die after one season of complete defoliation.
  3. GRCA’s Impacts: Informally monitoring the population throughout the Ganaraska Forest.
Sea Lamprey
Sea Lamprey
  1. Invaded the Great Lakes in the early 20th century.
  2. Impacts: They attach themselves to the body of a fish and suck the fish’s blood. Fish that survive the attack are left with a large open wound that can become infected and often leads to death. Attacks have resulted in reduced stocks of Lake Trout, Salmon, Whitefish, Cisco, and Burbot in the Great Lakes.
  3. GRCA’s Impact: GRCA works with DFO to control the Sea Lamprey population on Cobourg Creek.

 

 

In the Know About Invasive Species
An invasive species is a plant, fungus, or animal species that is not native to a specific location (an introduced species), and which has a tendency to spread to a degree believed to cause damage to the environment, human economy or human health.

Some common terrestrial invasive species that are found within the GRCA jurisdiction are below:

  • Emerald Ash Borer
  • Phragmites
  • LDD Moth
  • Dog-strangling Vine
  • Giant Hogweed
  • Garlic Mustard
  • Common Buckthorn

What you can do

  • Plant Native Species
  • Know your terrestrial invasive species.
  • Report invasive species it to EDDMapS Ontario or contact the Invading Species Hotline at 1-800-563-7711.
  • Stay on the trails. By remaining on the designated trails and keep pets on leashes it will reduce the amount of disturbed area and reduce your chances of being a vector and transporting their seeds to a new location.
  • Clean your footwear, all equipment and your pets before you go from one natural area to another. Equipment can include bikes, ATVs, walking sticks, skis, snowmobiles, snowshoes or anything that can potentially carry invasive species to a new location.
  • Remember to Clean, Drain and Dry your equipment and gear to reduce the transport of invasive species to a new location.
  • Manage you own properties by following Specific Best Management Practices and Land Management Guides.
  • Learn more about invasive species with additional resources available by the Ontario Invasive Plant council and Invasive Species Centre.

Clean your footwear, all equipment and your pets before you go from one natural area to another. Equipment can include bikes, ATVs, walking sticks, skis, snowmobiles, snowshoes or anything that can potentially carry invasive species to a new location.

Manage your own properties by following Specific Best Management Practices and Land Management Guides.