CUMBERLAND — Town employees have been fighting two types of particularly aggressive invasive species in an effort to save the Town Forest from becoming completely infested.

According to Mike Schwindt, chairperson of the Lands and Conservation Commission, about 30 acres of the 100-acre forest – one-third – are covered in invasive plants that include honeysuckle, bittersweet and Japanese knotweed or “American bamboo.” 

Buckthorn and phragmites have been particularly pervasive, according to town officials. Buckthorn inhibits the growth of other plants due to the chemicals present in its roots, leaves and fruit, hindering the necessary diversity for a healthy forest that other plants and animals rely on.

About five acres of buckthorn are being ground down to the forest floor. According to Town Manager William Shane, some areas of the Town Forest are so thick with buckthorn that visitors struggle to walk through it.

Buckthorn is the most common invasive species invading the Town Forest, according to Town Manager William Shane, but not the most aggressive. Contributed / Cumberland Lands and Conservation Commission

Shane said that once the plants have been cut down, the town will have herbicide sprayers come in late August or early September to apply a commercial version of Roundup. The plants will then be starting to take in nutrients and store them in their roots, so the herbicide will also get absorbed into their roots and kill them.  

Phragmites, or “common reed,” looks similar to marsh grass and flourishes in wet areas, particularly adjacent to the capped landfill in the Town Forest. The town cut down and sprayed about 10 acres of phragmites two years ago, of which most is now dead, Shane said. It will be cut down and sprayed once more to ensure it doesn’t get a chance to regrow.

Phragmites’ aggressive underground stem systems squeeze out other plants and create a monoculture. Its dense placement displaces short grass nesters and aquatic birds, and their dead stems are a fire hazard.

“The cutting and spraying might have to happen at least one or two more times before we can get a hold on it,” Shane said, adding it could take up to five years. Once the invasive species are successfully removed, the town will begin replanting species that will coexist in the forest instead of overrunning it.

“The bittersweet will choke the bigger trees off; the knotweed takes over,” Schwindt said. “Basically the new trees and vegetation that you want to have in there won’t grow because the invasive species are growing so fast and so thick that the desirable trees don’t have a chance to get started.”

According to the town, honeysuckle is a shrub with red, orange or yellow berries and bittersweet is a woody vine with red berries in yellow capsules. Knotweed is recognizable because of its bamboo-like stems that can grow up to 10 feet in height.

Responding to community concerns about spraying herbicides, Shane says they’ve found it to be the more effective, both in terms of cost and getting the job done.

“That trail gets a lot of use and we do see a lot of people going through there with families and kids and dogs and there’s wildlife in there as well,” Schwindt said. “We’re going to do this as best we can with the least adverse impact. We’ll be watching what goes on to make sure we don’t cause unintended consequences.” 

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