Common Buckthorn

Common Buckthorn- (Rhamnus cathartica)
This invasive species was brought to this area from Europe in the mid-1800’s. It was used to grow hedges around properties but was soon found to be quite invasive. It is classified as a shrub or small tree that can grow to be 22 feet high. It is found in open oak woods, deadfall openings in woodlands, woods edges, prairie and open fields. This species is a problem because it out-competes native plants, degrades the wildlife habitat it is found in, is a host to diseases for several other plants (including oats) and contributes to soil erosion by shading out other plants that grow on the forest floor. It is an almost impenetrable layer of vegetation once established and has no natural controls here (insects or disease) that would restrict its growth.

Options for controlling this invasive species include burning (through prescribed fire) though the nature of the plant makes many areas it inhabits unsuitable for frequent burning. There are herbicides that have been found to be effective in the right doses and when applied at the right times.
For more information, please see:
MN DNR- Common Buckthorn
Plant Conservation Alliance- Common Buckthorn
Wikipedia- Common Buckthorn