Wetlands in National Parks

We would like to thank Naaman Horn, Park Ranger, at Lassen Volcanic National Park and the National Park Service for information provided for this and other pages on our website.

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Coastal Lowlands can be created by flooding in protected areas. They can also be formed when silt is carried down-river and deposited when it reaches the sea. Plants take root and hold the soil deposits firm.

 

River Floodplains are formed through erosion and through the depositing of sediment on adjacent lands when flooding occurs. They also form when flooding or high water tables provide enough moisture. They are susceptible to change as rivers and streams form new channels and when floods occur.

 

Glaciers formed wetlands when they dammed rivers, scoured valleys, and reworked floodplains. Large blocks of ice left by receding glaciers formed pits and depressions, which were later filled by water.

 

Beavers form smaller inland wetlands by damming rivers and streams.

 

Other Forces of Nature include wind action in sand hills which form depressions, many of which become wetlands. They may also form in sink holes. Earthquakes can create them by damming streams or causing land to drop down near the water table. Waterfalls often have lush wetland areas under and around them. These are sustained by the spray.

 

People help form some wetlands when highway and dam construction, irrigation projects, or other activities change drainage patterns or hold back water. Conservation groups and individuals have intentionally created and restored wetlands.

Peatlands are inland wetlands containing thick deposits of slowly decaying plant material, peat. Two types are bogs and fens. Such plants as sphagnum moss, pitcher plants, sundews, Venus flytraps, and some orchids grow in the nutrient-poor, acidic bogs. Sedges, willows, and grasses grow in the nutrient-richer and less acidic fens.

 

Southern Deepwater Swamps are wetlands of the southeastern US that have standing water for most or all of the growing season. Such trees as bald cypress tupelo gum, and water oak grow in these swamps.

 

Inland Freshwater Swamps is a variety of this type. They may be isolated depressions, fringes around ponds and lakes, nearly flat expanses of emergent wetlands, or high elevation wet mountain meadows. Grasses, rushes, cattails, and water lilies grow in these marshes.

 

Riparian Wetlands form on the floodplains of rivers and streams, and may be dry for part of the growing season. Bottomland hardwood forests are common vegetation. In arid regions, they contrast with the surrounding upland vegetation.

Tidal Salt Marshes form near river mouths, behind barrier islands, or in other areas affected by tides and protected from the full force of the waves. Grasses and other plants adapted to salt water grow along steep shorelines and flat expanses.

 

Mangrove Swamps replace tidal salt marshes in subtropical and tropical regions. Salt-tolerant trees grow in these wetlands.

 

Tidal Fresh Marshes form farther inland from the salt marshes and the mangrove swamps, along bays, inlets, and tidal rivers, but are affected by the tides. Grasses and floating-leaved aquatic plants grow here.

Environmental Quality act as natural water purifiers, filtering sediment, and absorbing many pollutants in surface waters. The vegetation acts as a buffer against shoeline and riverbank erosion by absorbing the energy of storm waves and slowing water currents. Plants provide erosion control by binding the soil and slowing the downstream movement of sediment.

 

Plants, Fish, and Wildlife are provided for through wetland habitats. Wetlands provide habitat for many species of amphibians, reptiles, birds, and mammals. Upland wildlife often use wetlands for food and shelter. Freshwater and marine fish use wetlands for food, cover, spawning, and nursery grounds. About one-third of all plants and animals listed as threatened or endangered species in the US depend on wetlands for survival. Many plant species can survive only in wetlands. Nutrients and plant materials flushed from some of these systems during storms provide food for plants, fish, and wildlife in estuaries and other downstream ecosystems.

Socio-Economic Functions and Values – Coastal wetlands help to reduce flooding, erosion, and property damage during major storms. Many wetlands contain a diversity of plants and animals that provide places for sightseeing, hiking, fishing, hunting, boating, birdwatching, and photography. Some provide clean, plentiful water supplies in aquifers. They also provide many opportunities for environmental education and public awareness programmes.