Why Protect Wetlands? Benefits and Diversity.....
Wetland Functions and Values
The physical, chemical, and biological properties of the Commonwealth’s wetlands work in concert to perform “wetland functions.” Wetland functions may include: storage of water, ground water recharge, sediment trapping, transformation of nutrients, and wildlife habitat. Wetlands are some of the most productive habitats on earth, providing nursery grounds for shellfish, fish and other vertebrate wildlife.
Links to learn more about Wetland Functions and Values
The benefits society derives from wetlands functions are often referred to as wetland values. Some widely applicable wetland values include: flood attenuation, water purification, and wildlife habitat. When wetlands store water along a larger water body, they often serve to attenuate periodic flood waters. The process of storing water also slows water to trap sediment and pollutants caused by over land or upstream water flow. As wildlife habitat, wetlands provide hunting and fishing opportunities.
Virginia Wetland Diversity, Virginia Landscape Diversity
An exceptional diversity of wetlands is found across the Virginia landscape. Swamps, tidal marshes, wet meadows, bogs, pocosins and sinkhole wetlands are some of the many types of wetlands found here. The Commonwealth has five physiographic regions
each with specific elevation, geologic, and hydrologic influences. Extending from the eastern coast to the western state-line, and exhibiting increasing elevation, Virginia’s physiographic regions are the Coastal Plan, Piedmont, Blue Ridge Mountains, Valley and Ridge, and Appalachian Plateau. In the Coastal Plain, wetlands are predominantly tidal marshes and tidal forests. In the Piedmont region, isolated or stream-side freshwater forests are the dominant wetland type. In the Blue Ridge Mountains, Valley and Ridge, and Appalachian Plateau; most wetland forests or marshes are associated with streams.
Virginia’s landscape also is commonly categorized by seven ecoregions
. According to the U.S. EPA, “Ecoregions reflect areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources, they are designed to serve as a spatial framework for the research, assessment, management, and monitoring of ecosystems and ecosystem components” (Woods et al. 2003
). The seven ecoregions in Virginia
include: Piedmont, Middle Atlantic Coastal Plan, Northern Piedmont, Southeastern Plains, Blue Ridge, Ridge and Valley, and Central Appalachian. Each ecoregion contains a characteristic, geographically distinct assemblage of natural communities and species. The biodiversity of flora, fauna, and ecosystems that characterize an ecoregion tend to be distinct from that of other ecoregions.
Lesser Known Wetlands of Virginia
Sinkhole or Karst Depressional Wetlands.
In Virginia, the karst, or swiss cheese topography of eastern Augusta, Rockingham, and Page counties in the central Shenandoah Valley exhibit ancient sinkhole wetlands. Sinkhole wetlands are a type of Montane Depression Wetland.
Because they are largely impermeable, many sinkhole wetlands store rainwater long into the drier seasons. Karst regions contain caves and other openings formed from the dissolution of rock such as limestone. They provide unique wildlife habitat and are often linked to aquifers capable of holding large volumes of groundwater.
As the name suggests vernal pools are areas that are accumulate water during the spring months. They provide safe breeding habitats for frogs and salamanders. Because they become completely dry in the fall, they lack predators such as fish and bullfrogs. During drier seasons, vernal pools may be difficult to identify as a wetlands making them very vulnerable to development. Vernal pools are found throughout the state in forests and meadows. Coastal Plain Depression Wetlands
are one type of vernal pool described by the The Natural Communities of Virginia
Found in the southeastern coastal plain, pocosins typically sit on hillside plateaus and accumulate acidic peat like northern bogs. Pocosins experience occasional fires and therefore exhibit a diversity of shrubby evergreens. Like so many wetlands in the Coastal Plain, pocosins serve as important migratory and over-wintering habitat for birds. Pond Pine Woodlands and Pocosins, and Streamhead Pocosins are differentiated in The Natural Communities of Virginia