Used through U.S. Fish and Wildlife Service

One typically used group system because that wetlands was arisen by Cowardin and also is described in Classification that Wetlands and Deepwater Habitats the the unified States. The Cowardin device is supplied by the U.S. Fish and Wildlife business for the nationwide Wetlands Inventory. In this system, wetlands space classified by see position, vegetation cover and hydrologic regime. The Cowardin system has five significant wetland types: marine, tidal, lacustrine, palustrine and also riverine.

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Used through U.S. Military Corps the Engineers

Another usual wetland classification system, used by the U.S. Military Corps that Engineers, was arisen by Brinson and is described in A Hydrogeomorphic classification for Wetlands. Together the location implies, wetlands room classified by their geomorphic setting, dominant water source (e.g. Precipitation, underground water or surface ar water) and hydrodynamics. The hydrogeomorphic (HGM) includes five major wetland types: riverine, slope depressional, flat and also fringe.

Types of Wetlands


Description that Marshes

Marshes are identified as wetlands commonly or continuous inundated with water, identified by emergent soft-stemmed vegetation adjusted to saturated soil conditions. There are numerous different type of marshes, varying from the prairie potholes to the Everglades, coastal to inland, freshwater to saltwater. All types receive many of your water from surface ar water, and also many marshes are likewise fed by groundwater. Nutrients room plentiful and also the pH is commonly neutral top to an abundance of plant and also animal life. We have split marshes right into two primary categories: non-tidal and tidal.


Functions & values of Marshes

Marshes recharge groundwater supplies and moderate streamflow by providing water to streams. This is an especially important function during durations of drought. The presence of marshes in a watershed help to reduce damages caused by floods through slowing and storing overwhelming water. Together water moves gradually through a marsh, sediment and also other pollutants resolve to the substrate or floor the the marsh. Swamp vegetation and also microorganisms additionally use excess nutrient for development that have the right to otherwise pollute surface water such together nitrogen and also phosphorus native fertilizer.

Non-Tidal Marshes



Non-tidal marshes are the most prevalent and widely distributed wetlands in north America. Lock are largely freshwater marshes, back some are brackish or alkaline. They frequently occur follow me streams in poorly drained depressions and also in the shallow water along the limits of lakes, ponds and also rivers. Water level in these wetlands typically vary native a couple of inches to two or three feet, and also some marshes, like prairie potholes, may periodically dry out completely.

Highly organic, mineral rich soils the sand, silt, and clay underlie these wetlands, while lily pads, cattails (see photo), reeds and bulrushes carry out excellent habitat for waterfowl and other small mammals, such together Red-winged Blackbirds, an excellent Blue Herons, otters and muskrats. Instances of non-tidal marshes are: Prairie potholes, playa lakes, vernal pools and also wet meadows.

Functions & Values

Due to their high levels of nutrients, freshwater marshes are one of the most fertile ecosystems ~ above earth. They have the right to sustain a vast array the plant communities that subsequently support a wide range of wildlife within this an essential wetland ecosystem. Together a result, marshes sustain a diversity that life the is disproportionate with their size. In addition to their substantial habitat value, non-tidal marshes serve to alleviate flood damage and also filter excess nutrients from surface runoff.



Pickerelweed (Pontederia cordata). Status

Unfortunately, like countless other wetland ecosystems, freshwater marshes have suffered major acreage casualty to human development. Some have actually been degraded by excessive deposits of nutrients and sediment native construction and farming. Significant flooding and nutrient deposition to downstream waters have actually often followed marsh destruction and also degradation. Such environmental difficulties prove the an important roles these wetlands play. This realization has spurred amplified protection and restoration of swamp ecosystems, such together the prairie potholes and also the Everglades.

Tidal Marshes


Tidal marshes deserve to be discovered along protected coastlines in middle and high latitudes worldwide. They are many prevalent in the United says on the eastern coastline from Maine come Florida and also continuing on to Louisiana and also Texas follow me the Gulf the Mexico. Some space freshwater marshes, others room brackish (somewhat salty), and also still others room saline (salty), yet they space all affected by the movement of ocean tides. Tidal marshes are generally categorized into two distinct zones, the reduced or intertidal marsh and the upper or high marsh.

In saline tidal marshes, the lower marsh is typically covered and also exposed everyday by the tide. It is mostly covered through the tall form of Smooth Cordgrass (Spartina alterniflora). The saline marsh is spanned by water only sporadically and also is characterized by quick Smooth Cordgrass, Spike Grass and also Saltmeadow rush (Juncus gerardii). Saline marshes assistance a highly devoted set that life adapted for saline conditions.

Functions & Values

Tidal marshes serve many important functions. Lock buffer stormy seas, slow coastline erosion and are able come absorb overfill nutrients before they reach oceans and also estuaries. Tidal marshes additionally provide an essential food and habitat because that clams, crabs and juvenile fish, and also offering shelter and nesting sites because that several types of migratory waterfowl.


Pressure to to fill in these wetlands for seaside development has led to far-reaching and proceeding losses of tidal marshes, particularly along the Atlantic coast. Pollution, specifically near urban areas, likewise remains a major threat to this ecosystems. Fortunately, most states have actually enacted special laws to protect tidal marshes, however diligence is necessary to assure that this protective procedures are actively enforced.


Skunk Cabbage (Symplocarpus foetidus) sprouts an extremely early in the spring, melt the bordering snow. The insects that pollinate it room attracted by its odor, which resembles decaying flesh.

Description the Swamps

A swamp is any kind of wetland dominated by woody plants. There are plenty of different type of swamps, varying from the forested Red Maple, (Acer rubrum), swamps the the Northeast to the comprehensive bottomland hardwood forests uncovered along the sluggish rivers the the Southeast. Swamps are characterized by saturated soils during the growing season and standing water during details times of the year. The highly organic soils the swamps type a thick, black, nutrient-rich setting for the growth of water-tolerant tree such together Cypress (Taxodium spp.), Atlantic White Cedar (Chamaecyparis thyoides), and also Tupelo (Nyssa aquatica). Part swamps are overcame by shrubs, such together Buttonbush or Smooth Alder. Plants, birds, fish, and invertebrates such together freshwater shrimp, crayfish, and clams call for the habitats provided by swamps. Plenty of rare species, such together the intimidated American Crocodile, rely on these ecosystems as well. Swamps may be split into two significant classes, depending upon the type of vegetation present: shrub swamps and also forested swamps.

Functions & worths of Swamps

Swamps serve an essential roles in overwhelming protection and nutrient removal. Floodplain woodlands are particularly high in productivity and species diversity because of the rich deposits of alluvial soil from floods. Numerous upland creatures depend on the diversity of food discovered in the lowland swamps, and an important timber have the right to be sustainably harvest to carry out building materials for people.


Due to the nutrient-rich soils present in swamps, plenty of of these productive woodlands have been drained and also cleared for agriculture and various other development. Historically, swamps have actually been illustrated as frightening no-man"s-lands. This perception brought about the large devastation of enormous tracts the swampland over the previous 200 years, such together the destruction of an ext than half of the legendary great Dismal Swamp that southeastern Virginia.

Swamps generally support highly varied vegetation since of the countless layers that vegetation present: shrubs, saplings, and also herbaceous plants.

Forested swamps are discovered throughout the united States. Castle are regularly inundated with floodwater from nearby rivers and also streams. Sometimes, they are covered by countless feet of an extremely slowly moving or was standing water. In really dry year they might represent the only shallow water because that miles and also their visibility is critical to the survive of wetland-dependent varieties like wood Ducks (Aix sponsa), river Otters (Lutra canadensis) and also Cottonmouth snake (Agkistrodon piscivorus). Several of the common types of trees uncovered in these wetlands are Red Maple and also Pin Oak (Quercus palustris) in the northern United States, Overcup Oak (Quercus lyrata) and also Cypress in the South, and also Willows (Salix spp.) and also Western Hemlock (Tsuga sp.) in the Northwest. Bottomland hardwood swamp is a name generally given come forested swamps in the south main United States.

Shrub Swamps

Shrub swamps are similar to forested swamps except that shrubby vegetation such as Buttonbush, Willow, Dogwood (Cornus sp.) and Swamp climbed (Rosa palustris) predominates. In fact, forested and shrub swamps are frequently found nearby to one another. The floor is often water logged for lot of the year and covered at times by as much as a few feet of water because this type of swamp is found along slow relocating streams and also in floodplains. Mangrove swamps are a form of shrub swamp overcame by mangroves the covers vast expanses of southerly Florida.


This eastern Mud Salamander (Pseudotriton montanus) is resting on sphagnum moss. Sphagnum create bogs by hold water and creating acidic conditions. Sphagnum itself may be up to 70 percent water.

Description that Bogs

Bogs are among North America"s most distinctive type of wetlands. They are characterized by spongy peat deposits, acidic waters and also a floor covered by a special carpet that sphagnum moss. Bogs obtain all or many of their water indigenous precipitation quite than native runoff, groundwater or streams. As a result, bogs are low in the nutrients required for plant growth, a condition that is enhanced by acid creating peat mosses.

There space two main ways that a bog can develop: bogs can kind as sphagnum moss grows over a lake or pond and also slowly filling it (terrestrialization), or bogs can type as sphagnum moss blankets dried land and prevents water native leaving the surface ar (paludification). End time, numerous feet that acidic peat deposits develop up in bogs of one of two people origin. The unique and also demanding physical and also chemical characteristics of bogs result in the presence of plant and animal neighborhoods that demonstrate plenty of special adaptations to short nutrient levels, waterlogged conditions, and acidic waters, such as carnivorous plants.

Carlisle Bog in Alaska. Uneven the remainder of the joined States, Alaska still has most the its wetlands.

Functions & worths of Bogs

Bogs serve critical ecological duty in preventing downstream flooding by soaking up precipitation. Bogs support several of the most amazing plants in the United states (like the carnivorous Sundew) and provide habitat to pets threatened by human encroachment.

Status of Bogs

Bogs in the United claims are mostly found in the glaciated northeast and good Lakes regions (northern bogs) but likewise in the south-east (pocosins). Your acreage declined historically together they to be drained to be offered as cropland and mined for your peat, which was supplied as a fuel and also a soil conditioner. Recently, bogs have been recognized for their function in regulating the an international climate by storing big amounts that carbon in peat deposits. Bogs room unique neighborhoods that deserve to be damaged in a issue of days yet require hundreds, if not thousands, of years to form naturally.

Northern Bogs

This bog in Nova Scotia, Canada is conquered by ericaceous dwarf-shrubs, a common family of tree in the peat bogs of the Northeast.
The north Pitcher plant (Sarracenia purpurea) overcomes the nutrient deficiencies of bog life by capturing insects in pools of water in that is leaves and also digesting them through the assist of some regional bacteria. The north Pitcher Plant"s flower looks much like the Sweet Pitcher Plant"s (see below).

Northern bogs space generally associated with short temperatures and also short farming seasons whereby ample precipitation and high humidity reason excessive humidity to accumulate. Therefore, most bogs in the United states are discovered in the northern states. North bogs often kind in old glacial lakes. Castle may have actually either considerable quantities of open up water surrounding by floating vegetation or vegetation may have totally filled the lake (terrestrialization).

The sphagnum peats of northern bogs reason especially acidic waters. The an outcome is a swamp ecosystem v a very dedicated and distinct flora and fauna that can thrive in these problems called acidophiles. Nevertheless, bogs assistance a number of species of plants in enhancement to the characteristics Sphagnum Moss, including Cotton Grass, Cranberry, Blueberry, Pine, Labrador Tea and also Tamarack. Moose, deer, and also lynx room a couple of of the animals that deserve to be found in north bogs. The higher Sandhill Crane, the Sora Rail, and also the great Gray Owl depend on bogs for survival.


Pocosins space densely vegetated through trees and also shrubs. They are subjected come fire around every 10 to 30 year (Photo through Dr. Curtis Richardson/Duke wetland Center). Description

The native pocosin originates from the Algonquin aboriginal American word for "swamp top top a hill." this evergreen shrub and tree dominated landscapes are found on the Atlantic coastal Plain indigenous Virginia to north Florida; though, most are uncovered in phibìc Carolina. Usually, over there is no standing water current in pocosins, yet a shallow water table pipeline the soil saturated for lot of the year.They variety in dimension from less than an acre to numerous thousand acres situated between and also isolated native old or existing stream systems in most instances.

Pocosins provide big tracks of undisturbed land necessary by black Bears (Ursus americanus).

Because pocosins are discovered in broad, flat, upland areas far from huge streams, they space ombrotrophic like northern bogs, meaning rain provides most of their water. Additionally like the bogs the the far north, pocosins are uncovered on waterlogged, nutrient bad and acid soils. The soil itself is a mixture that peat and also sand containing large amounts of charcoal from routine burnings. These natural fires occur because pocosins regular become really dry in the feather or summer. The fires room ecologically important due to the fact that they increase the diversity the shrub species in pocosins.

The most usual plants space evergreen tree (Loblolly Bay, Red Bay and also Sweet Bay), and also evergreen shrubs (titi, fetterbush and also zenobia). Pocosins administer important habitat for many animals, including some endangered types like the red-cockaded woodpecker. Lock are particularly important together the critical refuge for black color Bears in coastal Virginia and also North Carolina and also the Red Wolf has recently been reintroduced in phibìc Carolina pocosins.

Functions & Values

Habitat is the most valuable function of Pocosins. Some pocosins room very large and an overwhelming to develop, and also so lock remain mostly undisturbed. Together a result, they space a haven for varieties adapted to living in unaltered forests. As an ext and much more land is occurred in the Eastern unified States, pocosins are coming to be ever more valuable refuges for wildlife.

The Sweet Pitcher plant (Sarracenia rubra) is among the carnivorous plants found in pocosins.

The slow movement of water with the thick organic matter in pocosins gets rid of excess nutrients deposited by rainwater. The very same organic matter additionally acidifies the water. This really pure water is slowly released to estuaries, wherein it helps to maintain the suitable salinity, nutrients and also acidity. This process is crucial to aid maintain healthy fish populations crucial to both commerce and also recreation. Pocosins are additionally sources of valuable timber and fuel, but these provides can injury or damage pocosins if they room not carried out responsibly.


Historically, pocosins were mostly threatened by agriculture. Today, lumber harvesting, peat mining, and phosphate mining join agriculture as the biggest threats to the continuing to be undisturbed pocosins.


Description that Fens

Fens, are peat-forming wetlands that obtain nutrients indigenous sources various other than precipitation: usually from upslope sources through drainage from neighboring mineral soils and from groundwater movement. Fens differ from bogs since they are less acidic and have greater nutrient levels. Therefore, they are able to support a much an ext diverse plant and animal community. These systems are regularly covered by grasses, sedges, rushes and also wildflowers. Part fens are characterized by parallel ridges the vegetation be sstclairdrake.netrated by less fertile hollows. The ridges of this patterned fens kind perpendicular come the downslope direction that water movement. Over time, peat may construct up and also sstclairdrake.netrate the fen from its groundwater supply. As soon as this happens, the fen receives fewer nutrients and may come to be a bog.

Like bogs, fens are largely a north hemisphere phenomenon -- occurring in the northeastern unified States, the great Lakes region, the Rocky Mountains and also much of Canada -- and also are generally associated with short temperatures and short growing seasons, wherein ample precipitation and also high humidity cause excessive humidity to accumulate.

Functions & worths of Fens

Fens, prefer bogs, carry out important services in a watershed, including preventing or reducing the threat of floods, boosting water quality and also providing habitat for distinct plant and animal communities.

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Fens may be overcame by woody or herbaceous vegetation. In this photograph, trees room invading one herbaceous fen.

Status of Fens

Like most peatlands, fens competent a decrease in acreage at a rate of about eight percent indigenous 1950 come 1970, mainly from mining and draining because that cropland, fuel and also fertilizer. Due to the fact that of the large historical lose of this ecosystem type, remaining fens room that much much more rare, and also it is an essential to defend them. It is necessary to acknowledge that while mining and also draining this ecosystems provide resources for people, up to 10,000 year are compelled to type a fen naturally.

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