TYPES OF WETLANDS
TYPES OF WETLANDS
Each Wetland differs due to variations in soils, landscape, climate, water regime and chemistry, vegetation, and human disturbance. Here are brief descriptions of the major types of wetlands found in our area organized into four general categories: Marshes, swamps, bogs, and fens.
1. Marshes are periodically saturated, flooded or ponded with water and characterized by herbaceous (non-woody) vegetation adapted to wet soil conditions. Marshes are further characterized as tidal marshes (along coastlines) and non-tidal marshes.
a. Non-tidal (inland) marshes: dominated by herbaceous plants and frequently occur in poorly drained depressions, floodplains, and shallow wataer areas along the edges of lakes and rivers.
b. Freshwater marshes: characterized by periodic or permanent shallow water, little or no peat deposition, and mineral soils. They typically derive most of their water from surface water, including floodwater and runoff, but do receive ground water inputs.
c. Wet Meadows: Commonly occur in poorly drained areas such as shallow lake basins, low-lying depressions, and the land between shallow marshes and upland areas. Precipitation serves as their primary water supply, so they are often dry in summer.
d. Wet Prairies: similar to wet meadows but remain saturated longer. May receive water from intermittent streams as well as ground water and precipitation.
e. Vernal Pools: have either bedrock or a hard clay layer in the soil that helps keep water in the pool. They are covered by shallow water for variable periods from winter to spring, but may be completely dry for most of the summer and fall. Several endangered species such as the mole salamanders, wood frogs, fingernail clams, fairy shrimp, etc. need these areas for laying their eggs.
2. Swamps are fed primarily by surface water inputs and are dominated by trees and shrubs. Swamps occur in either freshwater or saltwater floodplains. They are characterized by very wet solid during the growing season and standing water during certain times of the year. Swamps are classified as forested, shrub or mangrove.
a. Forested swamps: are found in broad floodplains of the northeast, southeast and south central U.S. and receive floodwater from nearby rivers and streams. Common deciduous trees found in these areas include cypress, water tupelo, swamp white oak, and red maple.
b. Shrub Swamps: are similar to forested swamps except that shrubby species like buttonbush and swamp rose.
3. Bogs are freshwater wetlands characterized by spongy peat deposits, a growth of evergreen trees and shrubs, and a floor covered by a thick carpet of sphagnum moss. These systems, whose only water source is rainwater, are usually found in glaciated areas of the northern U.S.
4. Fens are ground water-fed peat-forming wetlands covered by grasses, sedges, reed and wildflowers. Willow and birches are also common. Fens, like bogs, tend to occur in glaciated areas of the northern U.S. Fenway Park of Boston, home of the Red Sox, was named for the fens that were filled to create this field.