YARMOUTH — Maine is turning to crowdsourcing to chronicle the invasive plants that plague some of its natural areas.

The state is gathering the data through its iMapInvasives website, which launched a year ago. The online tool allows residents to send photos of invasive plants they encounter on public or private land.

Some 224 users have submitted more than 2,800 observations of about 40 nonnative plant species through the tool, said state invasive plant biologist Nancy Olmstead. The state is using the data to improve the way it manages public lands and to inform private landowners of how they can stamp out invasive species, she said.

“The problem with these plants is that they overrun native habitats and crowd native species,” Olmstead said. “A better understanding of these plants will be helpful as we get a better idea of their distribution.”

Invasive plants in the state include buckthorn, Japanese barberry, Morrow’s honeysuckle and dozens of others. They are found all over the state – one, autumn olive, is found along a 40-mile stretch of Interstate 295 from Yarmouth to Gardiner.

The plants can interfere with native plants and animals, disrupt ecosystems and the food chain, and potentially bring dangers to humans. One, giant hogweed, has toxic properties that can cause pain and permanent injuries. Others provide good habitat for mice that harbor the ticks that carry Lyme disease and other tick-borne diseases, Olmstead said.


In the longer term, the plants can impact the biological diversity of the state’s forests, where some of them grow so densely that they impact the regeneration of trees, Olmstead said. That can alter the complexion of the state’s beloved natural areas, which draw thousands of tourists every year.

Many of the plants arrived in Maine as ornamental plants through the horticultural trade, said Ann Gibbs, the state horticulturist. Others came in by accident, such as purple loosestrife, which arrived on the ballast of a ship, she said.

“Often these plants are more prevalent in the southern two-thirds of the state,” Gibbs said. “The invasive plant issue is often tied to development, and where we’ve got more people living.”

Invasive plants are an especially big problem in Acadia National Park, one of the most visited natural areas in the state. More than 1,000 species of plants have been recorded on Mount Desert Island, where the park is located, and about a quarter of them are not native, said Judy Hazen Connery, the park’s vegetation program director. About 30 of those are considered threatening to the park’s ecosystem, she said.

Mapping invasive plants can give environmental managers tools to be better stewards, Hazen Connery said.

“It’s really important because trying to determine what is feasible and what’s prudent really involves determining what is it, how long has it been there, what’s its density,” she said. “It also helps educate the public about it – it helps get the word out about exotic, invasive plants.”

Managing the plants is daunting and costly, Olmstead said. The state is working with land trusts and conservation commissions to develop strategies to prioritize and manage the plants, Olmstead said.

Users currently access the map through their Web browser, though a smartphone application is in development, Olmstead said. It is designed to record information from users who submit their location via points on a map, she said.

The map cost about $2,500 to launch and requires about $5,000 in annual maintenance, not including the cost of paying staff to support it, Olmstead said. At least eight other states and one Canadian province also use the mapping tool to track invasive species.

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