The Meaning of a Meadow: Acadia's Great Meadow and Gilmore Meadow

Made by ice and sea

Between Acadia's mountains lie valleys, where the last great glacier ground away softer ground and lobes of ice lingered. As the ice went, a rising sea rushed in, drowning the low-lying land and laying down marine silt and clay. Relieved of a mile-thick ice sheet, the land eventually rose out of the sea. Some deeper basins lost their salt, filled with fresh water and became lakes. Shallower flats became wetlands, and some wetlands became meadows: Fresh Meadow, New Mill Meadow, Oak Meadow, Gilmore Meadow, Little Meadow and Great Meadow.

What a meadow is

Plant ecologists call them emergent marshes or graminoid wetlands, for the sedges, rushes and grasses that thrive in their meandering water. Melted ice, snow and rain move ever so slowly down almost imperceptible slopes, gathering into streams and brooks.

• Along the banks: perhaps alder, swamp maple, meadow willow and meadowsweet.
• Wildlife: perhaps beavers and muskrats, meadow voles and meadow jumping mice, swamp sparrows and meadowhawk dragonflies.
• Downstream: streams leaving the meadows carry nitrogen, carbon and other nutrients to the ocean, sustaining coastal food webs.

Too much water, too fast

Ice, sea and rain shaped Acadia, and still do: rain falling on the ice-rounded summits still runs downhill. But the balance of power is shifting. Too much rain washes out stream channels or floods the meadows too fast. Meadows are made for this — their sticky soils and the roots of thirsty plants soak up water — but even meadows can be overwhelmed.

In recent decades the Great Meadow has suffered damaging floods, as more frequent and intense rain falls on a landscape altered by historical logging, ditching, excavation, road-building and damming.

How the Great Meadow was changed

• A dam: much of the change came from Acadia co-founder George Dorr. He built a dam upstream of the Great Meadow, flooding what had been Little Meadow and its small pool into a larger pond he named The Tarn. His relationship with the land and water differed from that of the Wabanaki people, whose ancestors understood the seasonal flows in the meadows and in the brook linking them — an inland water route between what are now Cromwell Cove and Otter Creek. The dam, and Dorr's network of roads, bridges and trails, interrupted that flow.
• Lost soil: in the 1930s, Civilian Conservation Corps crews dug up parts of the Great Meadow and carried its rich loam to new trails being built along Ocean Drive.
• A small culvert: the culvert carrying Cromwell Brook under the Park Loop Road is too small, and clogs quickly in heavy rainstorms.

So the Great Meadow, Acadia's largest meadow, doesn't work like a meadow. Without deep organic soil it can't absorb extra water, which backs up into the Wild Gardens and the Sieur de Monts area. Once the culvert is cleared — usually by park staff — the water drains fast through the straightened channel and old ditches. Draining so quickly, the meadow generally holds less water and dries out fast in drought, says Kate Miller of the National Park Service.

Miller, who regularly monitors 50 wetland sites in Acadia, says Great Meadow's plants — such as lake sedge (Carex lacustris), Canada bluejoint (Calamagrostis canadensis), willows and other shrubs — tolerate these extremes. Some, such as glossy buckthorn (Rhamnus frangula), are invasive and quickly take over the forest edges if left unmanaged.

A meadow less disturbed

Compare Gilmore Meadow, a similar wetland linked to Aunt Betty Pond and Richardson Brook in the shadow of Sargent Mountain. Its surrounding forests were logged in the 1880s and a carriage road borders one edge, but it escaped the disturbance the Great Meadow suffered. As a result it drains more slowly. It has a thick layer of springy soil, fewer shrubs, and more wetland obligate species: wire grass (Carex lasiocarpa), Northwest Territory sedge (Carex utriculata) and tussock sedge (Carex stricta).

The sedges shimmer in the sun and ripple in the wind like waves — an echo of the ocean that once covered the land that became both meadows. You can still see that ancient sea if you imagine the foot of the surrounding hills as a shoreline, or dig down to the dense blue-gray mud the meadows rest on. The deep past also suggests how they might survive the future.

Ready for restoration

Next to Gilmore and other Acadia wetlands, the Great Meadow is impaired. But its water is clean, and the park's vegetation crews, led by Jesse Wheeler, have been vigilant in removing invasive plants. That leaves the Great Meadow primed for restoration — it has not strayed too far from what a meadow means.

Sources

Based on "The Meaning of a Meadow," Acadia National Park, National Park Service; a work of the United States government in the public domain. Its photographs, credited to the Schoodic Institute, are not reproduced.