Jesse Wheeler, vegetation project manager of Acadia National Park, identifies the invasive glossy buckthorn among the wide variety of plants in the Great Meadow, the park’s largest freshwater wetland, fed by run off from Dorr Mountain and Huguenot Head.

Wading through waist-high grasses swaying in the breeze, Jesse Wheeler looks both concerned and delighted by the variety of plants around him. Acadia National Park’s vegetation project manager ticks off sweet gale, leather leaf, meadow sweet and other shrubs and bushes. He is not enthused to see one large, shiny-leafed shrub. It’s the infamous glossy buckthorn.

“I appreciate all plants, some of them just frustrate me” the biologist said.

The purple berry-bearing plant is invasive to Acadia National Park and more specifically, the Great Meadow Wetland, a marshland fed by water runoff from Dorr and Champlain mountains.

Wild oyster mushrooms stand out along the Jesup Path that leads into Great Meadow.

The Great Meadow is wonderland for birds such as warblers, vireos and barred owls. It also is favored by beavers for building dams. The vast wetland is an alternative walk for visitors and local residents who prefer flat terrain to traverse. The 100-acre wetland, stretching on the outskirts of Bar Harbor, is part of the Cromwell Brook watershed. It is near Sieur de Monts Spring and was made part of the Sieur de Monts National Monument by U.S. President Woodrow Wilson in 1916. The monument was renamed Lafayette National Park and became Acadia National Park in 1929.

More than a century later, Acadia’s hydrologists, biologists and resource management specialists are seeking to create a “climate-smart” future for this treasure-trove of wildlife in the heart of the national park. Along with their partners at Friends of Acadia and Schoodic Institute and funding from the federal government, the team aims to revamp drainage, eradicate invasives and enhance exploration.

“How does land-use history affect what we are seeing now?” is a question that Jesse Wheeler often asks himself while working in this area. One answer may be that while George B. Dorr had the best of intentions when he chose Sieur De Monts Spring as a hub for the park, Acadia’s first superintendent did not realize the impact his developments eventually would have on the health of the low-lying land. Put in 100 years ago, roads and ditches now impede natural waterflow and, ultimately, plant life within the Great Meadow.

Under Acadia’s Park Loop Road, this culvert will be widened to provide sufficient drainage and help prevent flooding in Great Meadow.

Jesup Path, home to a wide, winding, raised boardwalk with informational waysides for rest and observation, is an example of a “stream-smart” trail that allows for water and organisms to freely travel below. With rising annual rainfall due to climate change, Cromwell Brook continuously floods the valley, overwhelming the small culvert outlet under the busy Park Loop Road at the north end of the wetland. Expanding the culvert into a bridge, filling the old ditches and eliminating unused roadways is an initiative currently in the works to continue this trend of watershed revitalization.

Less frequent flooding in the wetland will also help to discourage opportunist invasive plants that thrive in disturbed soils. Along with readjusting waterflow, trail crews will reseed native shrubs and grasses in place of the pesty interlopers in order to ensure a healthy variety of plant life.

“Maintaining biodiversity will ultimately increase visitor enjoyment,” says Wheeler. It is a group effort that requires the anticipation of climate changes to come.

From Richmond, Va., Whitney and Jonathan Richman with their children, Arley and Cole, enjoy walking through stands of white birch and hemlock along the Jesup Path.

To take the 2-mile Great Meadow Loop, get directions at mainetrailfinder.com. Friends of Acadia offers opportunities for stewardship volunteers to take part in their efforts on Tuesday, Thursday and Saturday mornings through October. Whether it’s posting photos of witch’s butter mushrooms on iNaturalist to add to data collection, volunteering or just making a conscious effort to have less impact on the fragile peat soil, Acadia’s Great Meadow welcomes visitors’ and local residents’ assistance. Learn more at www.nps.gov or at www.friendsofacadia.org.