Keeping Maples in Cape Cod's Red Maple Swamp

By Charlotte Hohman, National Park Service.

The Red Maple Swamp at Cape Cod National Seashore, in the town of Eastham, is a fine place to walk at almost any time of year. A 0.8-mile trail, partly on boardwalk, winds through its heart under towering red maples that give shade in summer and turn brilliant orange and red in fall.

The current range of the red maple in the eastern United States. U.S. Geological Survey.

The area has long been a swamp dominated by red maple (Acer rubrum), a hardwood found throughout the eastern United States that is adapted to many environments, including swamps. Swamps are forested wetlands with standing water for much of the year. They soak up excess water, preventing floods, and protect coastlines from storms.

Drained to fight mosquitoes

Mosquitoes lay their eggs in standing water. When homes went up around the edge of the swamp, residents soon complained about the mosquitoes, and before Cape Cod National Seashore was created in 1961, ditches were dug through the swamp to drain it. Standing water dropped sharply.

Some standing water remains, but far less than before the swamp was ditched. NPS photo by John DeFoe.

That exposed rich wetland soil that was now drier, and understory shrubs, mostly native but some not, thrived in it. Today they form impenetrable thickets with no room or light for young red maples. If nothing is done, there may be no new trees to replace the adult maples as they die. The swamp cannot simply be restored to its original state, because closing or removing the ditches would flood private property.

Thickets of native and non-native plants leave no space for red maple seedlings. NPS photo by Charlotte Hohman.

Clearing space for seedlings

Over the years, park natural resource staff noticed red maple seedlings coming up in cleared strips along the boardwalk. To test whether clearing would help inside the swamp, in 2023 park scientists had chainsaw crews cut 10-by-10-meter plots of brush down to the ground.

AmeriCorps crews cleared patches of thicket to give red maple seedlings a fighting chance. NPS photo by Stephen Smith.

It worked. Many red maples sprouted soon after, some growing up to six inches before going dormant for the winter. Staff hope many will survive the cold and keep growing when spring returns, and have also considered transplanting seedlings into the clearings if needed. The plots, visible beside the trail, may be the key to keeping the Red Maple Swamp full of maples for generations.

Red maple seedlings in a cleared plot, showing the trees can still thrive in the swamp when given space and resources. NPS photo by Stephen Smith.

Sources

• Charlotte Hohman, "Keeping Maples in the Red Maple Swamp," National Park Service, Cape Cod National Seashore. https://www.nps.gov/articles/000/keeping-maples-in-the-red-maple-swamp.htm
• A boardwalk photograph by Jesse Mechling on the Park Service's page is not reproduced here.