Loverens Mill Cedar Swamp: Antrim’s Globally Rare Ecosystem

A boardwalk leads hikers into the cedar swamp.

Of all the ecosystems here in our region -- from hemlock forests to peatland bogs -- few are really rare.


But a swamp in the northern part of Antrim is globally rare.

Loverens Mill Cedar Swamp is a great example of what ecologists describe as an “inland Atlantic white cedar swamp.”

Because of its excellent condition, size and exemplary nature, The Nature Conservancy protected this place in 1999. In 2006, the Conservancy acquired an additional 635 acres that helped protect the swamp’s watershed.

Now, the Conservancy’s 1,200-acre Loverens Mill Cedar Swamp Preserve lies within a conserved landscape of some 15,000 acres, protected by the Society for the Protection of New Hampshire Forests and other partner organizations.

Thanks to volunteers and staff of The Nature Conservancy, a trail and boardwalk leads into a piece of this strange and quiet place. From the boardwalk, you can see that it’s really a type of forested wetland; dark, cool and damp. Nothing like any other place in the region.

New Hampshire’s Rare Wetlands

Of New Hampshire’s 500,000 acres of wetlands, only 1 percent are Atlantic cedar swamps. Most of them are small and near the coast. Some of those cedar swamps, like one in Kingston, is quite open in nature, with trees spaced far apart in bright sunlight.

Another good example is in Manchester -- also protected by The Nature Conservancy -- and is 42 acres. The Manchester swamp is a bit different from Loverens Mill. Manchester Cedar Swamp. It hosts ancient black gum (some 400-plus years old) and giant rhododendron, which flower in early summer.

At nearly 50 acres, Loverens Mill Cedar Swamp is New Hampshire’s second largest. And it has a few traits that give it a northern (or boreal) flavor. Surrounded by hills, the swamp sits in the bottom of a  bowl -- at 1,040 feet in elevation -- where cold air collects and influences the plants that grow here. You’ll see northern species like tamarack, black spruce, balsam fir and Labrador tea, among others.

Atlantic white cedars -- which are found along the Eastern coast from Mississippi to Maine -- grow extremely slowly. Botanists have found some Atlantic white cedars less than 1 foot tall that are over 200 years old. The old cedars in Antrim are a respectable 130 years old.

While Atlantic white cedars can grow on little hummocks in swamps, their collective success can hinge on the wetlands themselves. If drained or flooded, for example, cedars can die in the wetlands and the ecosystem would peter out. That’s what has happened throughout New Hampshire where cedar swamps were once more abundant.

The water levels at Antrim’s Loverens Mill Cedar Swamp has probably been fairly consistent for hundreds or more years. In fact, a study of pollen cored from the depths of the Antrim swamp show that cedar has been here for more than 4,000 years. That is quite a testament to this system’s resilience.

Guided Tour of Loverens Mill Cedar Swamp Feb. 25
On Saturday, Feb. 25, join botanist Nur Ritter and The Nature Conservancy’s Eric Aldrich for a tour of Loverens Mill Cedar Swamp. Meet at 9 a.m. at the preserve entrance, Loverens Mill Road, off Route 9 in Antrim. Hike wraps up by noon; co-sponsored by the Harris Center for Conservation Education.

Eric Aldrich writes from his home in Hancock.