Reduce Invasive Species

What are Invasive Species?

Invasive species are plants and animals that are not native to the ecosystem they inhabit. They can cause environmental, economic, and/or human harm. Invasive species often outcompete the native species as invasives lack predators, grow faster, and reproduce quicker.

Wisconsin's invasive species rule, NR-40, makes it illegal to possess certain invasive species. These are separated between restricted and prohibited species. Restricted species are established in Wisconsin and are encouraged to be removed. Prohibited species are either not in Wisconsin or have small populations and the goal is to contain them anywhere they are found.

How Invasives Impact Forests

Invasive species can often outcompete other native plants in your forest. This means that the invasive species are able to grow and crowd out other native species. This can include many different types of plants, such as wildflowers, grasses, shrubs, and trees. These invasive plants then create a monoculture, allowing nothing else to grow around them, impacting forest succession. Infestation of invasive species can impact foraging and habitat for animals, diminish land value, decrease forest productivity, increase soil degradation, diminish recreation, and more.

How to Control Invasives on Your Own

Manual

Manual control involves physical activities to manage invasive species, such as hand pulling or digging plants. This can be done with many herbaceous plants and woody invasive seedlings.

Mechanical

Mechanical control is using machinery to remove invasives species by mowing, tilling, chopping, etc. This is often useful for areas that manual control is not effective.

Chemical

Chemical control is the use of herbicides to manage invasive plants. Chemical control is often done in combination with these other forms of control.

How TIP & WHIP Can Help

Timberland Invasives Partnership and Wisconsin Headwaters Invasive Partnership can help in many ways. TIP and WHIP can help identify invasive plants, guide landowners on best management practices, control invasive species, and more.

TIP and WHIP are Cooperative Invasive Species Management Areas (CISMAs) that provide resources and education on invasives species across our 9-county area. TIP can help in Langlade, Menominee, Oconto, and Shawano Counties. WHIP can help Lincoln, Oneida, and Vilas Counties. We are able to provide these resources in Northern Wisconsin at no cost to the landowner thanks to the USFS GLRI LSR grant funding received.

Invasive Plant Identification

Landowners and concerned citizens are often the first line of defense for reporting invasive species.

Take some time to learn common invasives in Northern Wisconsin.

Priority Management:

Common and Glossy Buckthorn are invasive shrubs/trees that have gray to brown bark with white lenticels. Buckthorn has oval leaves with curving veins and dark purple fruits. The most common identifiers for buckthorn reveals yellow and orange wood when cut and twigs ending in spines.
Garlic Mustard is an herbaceous biennial with first year plants forming rosettes. Second year plants produce flowering stems. Leaves are heart or kidney-shaped with rounded teeth on leaf edges. The flowers are small and white. Garlic Mustard often smells like garlic when crushed.
Invasive Knotweeds are herbaceous perennials that form hollow canes, resembling bamboo. Knotweeds have large leaves that are heart shaped or squared off at the base. Small white flowers form upright in clusters. Knotweed often forms large colonies and are known to hybridize.
Phragmites is a wetland perennial grass that has hollow stems. Phragmites can reach twenty feet tall and forms dense patches. Leaves are smooth and narrow with bases that sheath around the stem. Flowers form as large feathery heads that can persist year-round.
Bush Honeysuckles are multi-stemmed shrubs that have peeling bark. Honeysuckle have leaves that are oval and untoothed with red, orange, or yellow fruits. The easiest identifier is that invasive honeysuckle has hollow stems when cut.
Invasive Barberry is a dense, spiny shrub that has spatula-shaped leaves. Leaves turn red to purple in the fall. Red-oblong berries hang from branches and can be seen throughout the winter.
Thistles are herbaceous perennials that grow in basal rosette for the first year. The second year, a flower stalk forms purple flowers with bracts. Leaves form in a rosette and along the length of the flower stalk.
Spotted Knapweed is an herbaceous perennial plant that begins as a rosette in its first year with deeply lobed leaves. In the second year, it bolts with multiple flowering stems and leaves with few to no lobes. The flowers are pink to purple with stiff, black-tipped bracts.
Wild Parsnip is an herbaceous perennial that grows as a rosette for one year before forming stout flowering stems. Rosette leaves are broad and oblong and stem leaves are sharply toothed. Small yellow flowers form in flat clusters. Wild Parsnip sap can cause reactions.

Click to view Invasive Images

More Resources on Invasives

WHIP Priority Invasive Species List

WDNR Invasives Identification

Pathways of Prevention Guides

The Pathways of Prevention Guide focuses on the ways invasive species spread and are transported throughout the environment. The guide is broken up into "user groups" to reflect the outdoor activities, recreational and industrial, that are enjoyed in the Upper Midwest. These include:

Gardeners, Anglers, Boaters, ATV riders, Campers, Cyclists, Paddlers, Hunters, Snowmobile riders, Construction crews, Road crews, Farmers, Foresters, and Plant growers.

Each user group section contains invasive plants to watch for and simple action steps to protect our lands and waters from non-native species that might cause harm.

If you are interested in obtaining a Pathways Guide contact Timberland Invasives Partnership at (715) 799-5710 ext. 3 or Wisconsin Headwaters Invasive Partnership at (313) 590-4419.