Two members of Acadia’s invasive plants management team attack a patch of privet on Bar Island. ISLANDER PHOTO BY DICK BROOM

Acadia battling invasive ‘aliens’

ACADIA NAT’L PARK — The park is under attack.

The invaders are nonnative plants that, once they take root, try to take over.

Among the biggest threats to native species are woody shrubs such as glossy buckthorn, bush honeysuckle, European privet and barberry.

Acadia has a team of four people that spend about nine months a year working to control and, if possible, eradicate invasive species. Their work is important for several reasons, according to Judy Hazen Connery, the park’s natural resource specialist.

“In many instances, the invasive plants displace native plants, especially in high-value wildlife habitats like wetlands,” she said. “Also, recent research has found that a lot of different animals are affected by invasive plants. For example, European buckthorn can emit a chemical that retards the development of amphibians in wetlands.”

As for barberry, Connery said, “There’s really good science that shows that it enhances the number of ticks. It’s not the plants themselves that cause that, but they create the habitat for ticks.”

Connery said only about 25 of the roughly 250 exotic or nonnative plant species in the park are a serious concern; they are primarily the ones that spread rapidly and change the environment.

Acadia’s invasive plants originated in a number of places and came here in a variety of ways, Connery said.

“In many instances, they are plants that were imported for horticultural use before people really knew what the impacts were going to be.”

She said that because of the warming climate, some invasive plants that used to be found no father north than southern New England are now in southern Maine and are probably spreading this way.

“Burning bush is one that we have our eyes open for,” Connery said. “It has brilliant red foliage in the fall and is really popular in horticultural use. There are places in Connecticut where the forest floor is covered with it.”

Acadia’s invasive plants management team uses several control methods including cutting, uprooting and spraying herbicide.

“For each species, we have a comprehensive attack plan that uses the method that is the least toxic but most effective so that we can be efficient in the way we go about it,” Connery said.

Purple loosestrife, a fast-spreading invasive species that was prevalent in parts of the park just a few years ago, has been virtually eliminated.

“We’ve also put a big dent in Oriental bittersweet, Japanese knotweed and a few other species,” Connery said.

She said the park staff tries to educate people in the surrounding communities about invasive species so they can be on the lookout for them and discourage their importation and sale.

Dick Broom

Dick Broom

Reporter at Mount Desert Islander
Dick Broom covers the towns of Mount Desert and Southwest Harbor, Mount Desert Island High School and the school system board and superintendent's office. He enjoys hiking with his golden retriever and finding new places for her to swim. [email protected]

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