Diversity is the spice of life. Nowhere is this more apparent than where land and water meet. The blending of terrestrial and aquatic environments creates a wetland, an ecosystem that often supports more life than either the land or water alone.
When thinking of wetlands, many people envision the marshes found mainly along the shore of the Chesapeake Bay and tidal portions of rivers. They recognize the value of these wetlands as spawning and nursery grounds for fish, shellfish and crabs. Waterfowl and wading birds nest and feed here.
The meandering flow of water provides opportunities for boating, crabbing and bird watching. Low-lying marshes also store floodwaters, minimizing erosion. As this water is slowly released it has essentially been cleansed: The nutrients are processed by the grasses and shrubs, and pollutants and sediments are intercepted and trapped.
The importance of another type of wetland, the forested wetland, is often overlooked. Many forested wetlands have standing water only on a seasonal or temporary basis. These “saturated” wetlands provide the same benefits as marshes although it may not be apparent.
As with all wetland types, the hydrology, or the movement of water, drives the saturated forested wetland system. The hydrologic cycle has a wet and a dry phase that is affected by local weather, climate changes and activities by people.
From early summer to late fall, precipitation within the Chesapeake Bay watershed becomes less frequent. Vegetation, particularly trees, use large amounts of water to grow. As a result, the groundwater in saturated forested wetlands may drop to a foot or more below the surface. This is the dry phase, and a casual observer would scarcely recognize the habitat as a wetland.
The wet phase begins in late fall through spring. Nourished by thaws, spring rains and dormant vegetation, groundwater levels rise, often covering the surface of the wetland. The wetland habitat is strikingly apparent. This alternating dry-wet cycle influences the diversity of plant life, which in turn influences the types of wildlife found here.
Many species of trees are found in saturated wetlands, including red maple, sweet gum, black gum, American holly, willow oak and loblolly pine. Highbush blueberry, spicebush and sweet pepperbush are some of the common shrubs. The forest floor explodes with a variety of flowering plants, ferns and vines.
Spring moisture and warming temperatures promote a literal rebirth for some species. Small saturated areas and temporary pools are critical to amphibians like frogs, toads and salamanders. They gather here to mate and lay eggs. These then become nurseries for green frogs, wood frogs, spring peepers, red-spotted newts and spotted salamanders, just to name a few.
Bird watchers can appreciate the importance of saturated forested wetlands, which provide breeding and nesting habitat for both migratory as well as year-round resident birds. Common yellowthroat, black-and-white warbler, Kentucky warbler, ovenbirds, tufted titmouse and wood thrush are a few of the birds whose songs can be heard here. Dead hollow trees, known as snags, provide prime nest sites for cavity-nesting birds like wood ducks and many species of woodpeckers and owls. Although one may only spy their tracks, black bear, white-tailed deer, raccoon, opossum, river otter are just a few of the larger mammals who call these forested wetlands their home.
Just like marshes, forested wetlands are great places to hunt, fish, watch wildlife or explore.
Saturated forested wetlands literally breathe life into the ecosystem. They support a huge diversity of plants from tiny mosses to humongous trees. A multitude of animals use these areas for mating, spawning, nesting and rearing their young. They help protect property and clean waterways.
These often overlooked and underappreciated swampy lands preserve the biodiversity and healthy functioning of our planet.
By Kathy Reshetiloff
Bay Journal News Service