Invasive species of plants and animals have made major changes in neighborhoods and natural areas across the United States. In Illinois, May has been designated as Invasive Species Awareness Month. The Morton Arboretum and other organizations across the state work together during May to raise public awareness of this large but often unseen problem.
What is an invasive species? It is a plant or animal species that, when it travels far from its native place and does harm to the local plants, animals, or communities elsewhere by infesting or outcompeting the plants and animals that belong there.
The emerald ash borer (EAB) is an example of an invasive species. This insect traveled from China, most likely in wood packing materials, and continues to destroy ash trees all over the northeastern, central and now western United States. Several species of Asian carp, which were brought to the Mississippi River region for fish farming, are invasive species that now threaten not only that river and its tributaries but the Great Lakes. Another example is zebra mussels, which escaped from ballast water to permanently change the ecosystem of Lake Michigan.
Many species of plants that were brought from around the world to adorn gardens, such as purple loosestrife, phragmites reed, and buckthorn, have escaped into the wild and are now considered invasive species that pose an enormous threat to natural areas. Plants that are useful and ornamental in gardens can become invasive when they reproduce too freely and choke out native trees, shrubs, and wildflowers.
Invasive species are a major concern to everyone, including gardeners, who may inadvertently introduce them to the environment; municipal officials, who must stretch budgets to replace trees killed by EAB, cope with invasive zebra mussels in water intakes, or remove choking phragmites reed from ponds in public parks; foresters, who must battle sprouting buckthorn saplings so they don’t rob other trees of water and nutrients; and natural areas managers, who fight a wide range of native plants in order to save or restore native ecosystems.
What can you do?
- Invasive insects often make their homes in piles of firewood. Avoid moving logs whenever possible to curb the spread of these pests.
- Volunteer to remove invasive plants in the Arboretum's natural areas. Learn more
- Become a woodland steward. Learn more
- Spot invasive plants and remove them from your landscape so they don't crowd out native plants in natural areas. Learn more
Discover more about Illinois Invasive Species Awareness Month.