The Buckthorn Problem

The Buckthorn Problem
Ryan Polenski
3/17/11
Buckthorn has been known as an invasive species for some time now but how did it get here? Not many people in the younger generations know where it came from. In the early 1800’s it was introduced from Eurasia as an ornamental plant. It was commonly used as a hedge and by the 1900’s it was widespread and naturalized. One thing that we have known for a while is that it invades native plant communities and can take over and dominate the understory in a short period of time. How does it do this? Buckthorn is able to take over an area relatively quickly because of its traits. It’s a species that is fast growing, produces a lot of seeds, starts growth earlier than other species and end growth later and it is tolerant to a wide range of sites and conditions. This makes it capable of becoming established in just about any area that it gets introduced. The fruit are loved by birds which allow it to spread over large distances and because of dense growth it chokes out native plants. It can be easily identified by its Purple to blackish fruit or its grayish lenticel bark. Buckthorn also has sub opposite to alternating branching and its leaves have a venation similar to dogwoods. It can reach twenty to twenty five feet in height and ten inches in diameter. Most commonly however it is found in a large shrub form. The glossy variation is characterized by its glossy leaves. Over the years we have developed many techniques to managing this invasive only to be thwarted by its ability to re-sprout. With any treatment you would want to remove the plants before they begin to seed. We have tried hand pulling Buckthorn but that appears to only be successful in areas were the outbreaks are small and still young. Cutting-girdling is another method used but because of Buckthorns re-sprouting cutting has to be done repeatedly. Chemical treatments have been used with some success but the timing has to be perfect for foliar sprays. There have been some that have combined the chemical treatments and cutting. This has been proven to be more effective and because the chemical can be applied to the stumps it is move selective. Some of the chemicals that have been used are Glyphosate and Triclopyr. These have been in a twenty to twenty five percent mixture for Glyphosate and a twenty to fifty percent mixture for Triclopyr. If it’s applied to the foliage it is done in the fall when other species are dormant using a one and a half percent Glyphosate solution or a two percent Triclopyr solution. Fire is another option but is limited to larger areas away from communities and may need to be repeated several times. What I would like to know is if anyone has any alternative options or would recommend one over the other or a different combination? Also if you agree or disagree with Buckthorns classification as an invasive your comments are welcome.
Resources:
http://dnr.wi.gov/invasives/fact/buckthorn_com.htm
http://www.hort.uconn.edu/cipwg/art_pubs/TNC/pdf/nat_buckglossy.pdf