Invasive Species in FSU’s Arboretum

Frostburg’s arboretum is a sanctuary for the campus community. It offers a small portion of nature on campus to admire and learn about the biodiversity of the Appalachian Mountains. The beauty of Appalachia comes from the wide assortment of specimens it contains. Recently, however, this beauty has been under threat from a variety of invasive species, the most aggressive of which has been the Japanese knotweed. This plant, amongst others, threaten to ruin the natural beauty of the arboretum. The Bottom Line sat down with Theodore Hoxie, a board member of Frostburg’s Wildlife Society, to talk about the current situation and the consequences if proper action is not taken.

TBL: What can you tell the campus about the arboretum?

“The arboretum is an area of the campus set aside, kind of like a park, as a natural learning area. It’s a good place for students to go relax and destress in nature. The creek that runs through campus runs right through the arboretum. You can sit along the creek-side and relax. It is a haven for biodiversity in the otherwise built-up campus environment. Every year, hundreds of migrator birds flock to the arboretum. Mourning doves and other migrator songbirds make a seasonal stop using the arboretum to rest and replenish their fat stores. ”

TBL: What about the biodiversity of the arboretum?

“The natural biodiversity of the Appalachian Mountain region is incredibly high. This area is one of the more biodiverse areas of the whole country. Especially one of the more biodiverse regions in Maryland. This is due to the changes in elevation. When the glaciers receded at the end of the last ice age, lots of species like blue spruces trees were left behind on the tops of mountains in the Appalachian region. Where everywhere else, the blue spruce moved back up north to areas like upstate New York, Maine, and Pennsylvania. There are all these remnant species and an endangered species of salamanders in the upstream of the creek that runs through campus. There are native brook trout. Trout Unlimited has put a lot of work into making it a more viable habitat for native brook trout. Maybe in the future, we can once again have a viable population this far downstream. There are still occasional brook trout that are both caught and electroshocked in the stream. They still come down here.”

TBL: What invasive species are in the arboretum?

“There’s a multitude of invasive species on campus. There is bush honeysuckle, autumn olive, and Japanese knotweed. Those are the main species I’ve seen in the arboretum. Japanese knotweed is the worst. It forms very dense monoculture stands, shading out all the native plants. It even has the ability to prevent forest regeneration. If it grows in the understory as the overstory trees die out, the understory trees are not replaced. Because the thick stand of knotweed will choke everything else out, decreasing overall biodiversity and ecosystem function. It’s been on campus for over a decade. In recent years, it’s gotten worse because of reduced management efforts. As far as I can tell, the college has not completely given up but, in part, given up because it is so difficult to remove. It can spread by both the seeds and rhizomes. The roots will spread underground and pop up. When it gets established in an area, it’s very difficult to get rid of because you have to get rid of the roots and the soil. It grows as an annual. It can reach maturity in one growing season. It can grow from a seed to producing seeds in one growing season. It reproduces incredibly fast. The native shrubs, wildflowers, bushes, and grasses have no way to compete. There are no natural predators. Deer prefer to browse on native vegetation instead of Japanese knotweed, which makes it especially pervasive. The deer selectively harvest the native versus the invasive. This only adds to the problem. In the past, there have been organized efforts to remove Japanese knotweed. But, unfortunately, it comes back. Efforts have been relatively successful. It’s mainly on the football stadium side of the stream, but it’s starting to spread to the other side. If they are not dealt with Japanese knotweed has the potential to take over the entire arboretum. That’s the worst-case scenario. Japanese knotweed has the potential to out-compete for overstory trees which are vital to the recovery of the brook trout recovery efforts because the overstory trees provide shade to prevent the stream from overheating to the point where brook trout populations are no longer viable.”

TBL: What are the consequences of the Japanese knotweed taking over the entire arboretum?

“The biodiversity and wildlife potential would decrease greatly over time. Most of the plant life would be reduced until it was mainly Japanese knotweed. To remove it, you can pull it by hand. This is difficult because you have to get all the roots out which grow deep. Even if you remove all the knotweed, it’s going to grow back because there are seeds in the soil. You can use herbicides, but that also harms the native vegetation in the area. Once again, it still has the potential to regrow if the applications are not done on a yearly basis and followed-up work isn’t done. It’s a constant process. You have to pull and poison the entire area and continually monitor every year. If no management is done, it will continue to decrease the incredible biodiversity of the Appalachian mountain region. Luckily, we have thousands of students on campus. Japanese knotweed removal projects are a great way for students to get involved with environmental stewardship and community service.”

TBL: Is there anything you would like to say to the student body?

“As a community, we need to work towards not only increasing our human diversity but increasing the biodiversity on campus.”