Freshwater wetlands provide good examples of watershed areas having a strong interaction with other parts of a larger watershed system. The Environmental Protection Agency lists the following freshwater wetland benefits.
FRESHWATER WETLANDS:
The freshwater wetlands of Acadia National Park and Mount Desert Island are living communities that are still in the process of formation. In a hundred years, many of them will look different than they do today. The Tarn and Aunt Betty's Pond, for instance, are filling in and emergent wetland plants such as arrowhead, bayonet grass, and pickerelweed make the two ponds look like green meadows in late summer.
These wetlands got their start after the last glacier receded some 12,000 years ago, leaving deposits of sand, clay, and till that in many places blocked or reduced the free flow of runoff and streams. As the climate warmed, plants repopulated the region, and within 2,000 years, a succession of forest trees was reintroduced, including birch, white pine, hemlock, and by the time European settlers appeared on the scene, the prevalent spruce-fir forest we see around us today.
Forested wetlands are one type of freshwater wetland. In Acadia, the dominant species include Northern white cedar, red spruce, and black spruce, together with subordinate species such as larch, red maple, quaking aspen, and white birch. Shrubs include serviceberry, winterberry, speckled alder, green alder, highbush blueberry, wild raisin, meadowsweet, mountain holly, sheep laurel, blueberry, sweetgale, black huckleberry, Labrador tea, and leatherleaf. Ground cover species include skunk cabbage, bunchberry, Canada mayflower, starflower, twinflower, goldthread, swamp dewberry, creeping snowberry, large-leaved cranberry, three-seeded sedge, cinnamon fern, and sphagnum moss. Many of these species are found in the watershed study plots illustrated elsewhere on FLOW: THE WATER CYCLE (click on "Site map" above, then "Plots").
Reflecting their need for water during the growing season, certain species of plants serve as indicators to the availability of water in the freshwater wetlands in which they thrive.
INDICATOR SPECIES IN ACADIA'S FRESHWATER WETLANDS
Freshwater wetlands provide habitat for three groups of plants and wildlife: (1) upland species that can tolerate wetland conditions including white pine, white-tailed deer, garter snakes, as well as frog and salamander species that breed in flooded wetlands in spring; (2) aquatic species including mummichogs, snapping turtles, otters, and water striders that can survive in wetland pools; and (3) species that live predominantly in wetlands including cattails, muskrat, beaver, and pickerel frogs.
Learn more about Acadia's water resource program.
