Forest Invasive Species

“Garlic Mustard, Honeysuckle, Buckthorn”──What enticing names! Consider yourself lucky if these woodland invaders are not present on your property. However, if they are, addressing them now rather than later will save you lots of time and money.

Forest exotic invasive species such as garlic mustard, buckthorn, and honeysuckle are spreading at an alarming rate throughout southern Wisconsin. This spread will continue unless immediate action is taken. Forest invasive species are a major environmental concern because they out-compete native vegetation and shade-out native herbaceous plants. This intense competition dramatically reduces natural forest regeneration and leads to drastic changes in the native ecosystem, which are extremely difficult to reverse. Many high-quality woodland understories are so filled with invasives that tree saplings are being shaded out, rendering them unable to replace the mighty oaks, hickories, and maples when they are eventually harvested or die. In addition, a recent study found that sugar maple and other hardwood seedlings grew much slower when the soil came from an area infested with garlic mustard than from a mustard-free area.They found that garlic mustard disrupts the mutualistic associations between the trees and the belowground mycorrhizal fungi.

Forest invasive species also have detrimental impacts on migratory songbirds.  Invasive species will dominate the forest edge and since invasives leaf out much earlier than native trees, forest birds build their nests in these edge areas rather than utilizing the interior of the forest. This leads to nest predation and brood parasitism, which is much less likely to occur in the interior of the forest. Many landowners are unaware of the threat of forest invasive species and few landowners realize that they have invasives in their woodlands. 

The good news is that this is one environmental problem that we can do something about. A little work now can make a tremendous difference in the battle to regain land from invasive species. To help reduce the spread of forestry invasive species and assist landowners with the elimination of these aggressive plants, the Southwest Badger Resource Conservation and Development (RC&D) Council has hired Dan Bohlin to serve as the Invasive Species Specialist for southwest Wisconsin. Dan is available to meet with landowners at no cost to assist with the identification of invasive species, develop eradication plans, and provide technical assistance on the best methods to rid properties of invasives.

For more information

Invasive Species Publications