Invasive trees, shrubs, and woody vines pose a serious threat to natural areas in the Great Lakes region, out-competing native plants and damaging wildlife habitat. Invasive woody species can also encroach on farm fields and pastures, prevent the regeneration of trees in timber stands, and restrict outdoor recreation by growing over trails and access points. Additionally, some woody invaders provide ideal conditions for ticks that transmit diseases to people. While every region of North America has invasive species problems, the Great Lakes region’s status as a global transportation hub leaves it vulnerable to a larger number of invaders (U.S. Fish and Wildlife Service).
The Woody Invasives of the Great Lakes (WIGL) Collaborative brings interested partners together to consolidate information on woody invasive plant species. Our goal is to provide residents from all walks of life with the information they need to manage invasive woody plants and restore habitat for native plants and wildlife around the Great Lakes.
We’re happy to announce the WIGL Summit, November 5 & 6, 2020, in conjunction with the Upper Midwest Invasive Species Conference. Our two-day online summit will feature talks on the cutting edge of woody invasive species research and control. Registration is closed. If you are signed up, join the meeting here!
*New Oct 2020*:
- The WIGL Summit has been accredited for CFEs through the Society of American Foresters – 1.5 credits per session, 10.5 for the whole event
- The WIGL Summit has been accredited for Certified Applicator credits by Michigan Dept. of Ag and Rural Development – 2 credits per session.
- Click here to download the final WIGL Summit program
We encourage you to use our website to learn more about the woody plants you notice growing in your area and build the knowledge that will help you to be part of the solution! Here are just a few examples of how this website can be used:
Learners & Educators:
- Learn to identify the invasive trees, shrubs, and vines in your neighborhood and the surrounding area and report them in EDDMapS. This website is a resource for woody invasive species in the midwest
Every region of the United States has invasive species problems, but the Great Lakes has larger numbers because it is a transportation hub.
(U.S. Fish and Wildlife Service)
Of the approximately 50,000 non-native species in the U.S. today, less than 10 percent are considered invasive species.
(United States Fish and Wildlife Service)
Several woody invasive species are still popular as landscape plants and are readily available through nurseries and garden centers.
75% of the species evaluated by the WIGL Collaborative produce seeds that are moved over long distances by birds that eat the fruit.
Killing an invasive woody plant is not easy! All of the species evaluated by the WIGL Collaborative frequently sprout from the roots and/or the old stump if only the above-ground portion of the plant is treated (e.g., by one-time cutting, burning, mowing, or grazing).
Some woody plants, such as black locust (Robinia pseudoacacia), are native to North America but become invasive when introduced to new areas far beyond their historic native ranges.
All but two of the species evaluated by the WIGL Collaborative (93%) were purposefully introduced to North America for their horticultural usefulness. Many were introduced by early colonists hundreds of years ago.
The woody invasive species common barberry (Berberis vulgaris) was the target of a massive eradication program in the U.S. lead by the USDA and the departments of agriculture of 17 states because it is a host of the crop disease black stem rust. Between 1918 and 1981, over 400 million common barberry shrubs were destroyed. (United States Department of Agriculture)
Photo Credit: The Great Lakes region is home to many unique ecosystems that are vulnerable to invasive woody plants, including dunes, forests, wetlands, savannahs and prairies (Photo: National Park Service)