Полнотекстовый поиск:
Где искать:
только в названии
только в тексте
слова в тексте
только заголовок

Рекомендуем ознакомиться

Остальные работы->Реферат
Edgar Allan Poe was born in Boston, Massachusetts; He was orphaned as a child and raised by John Allan, a successful businessman of Richmond, Virginia...полностью>>
Остальные работы->Реферат
Looking back in time, it is evident man has mastered his resources in an effort to increase his technology. This technology has had a measurable effec...полностью>>
Остальные работы->Реферат
Moll Flanders: A woman in the 17th century who was born in Newgate ( a prison) and spent twelve years as a whore, twelve years as a thief, was married...полностью>>
Остальные работы->Реферат
his name. His company wants to be with you in your office, your car, and even your kitchen. His name is Bill Gates. There is a lot more to Bill Gates ...полностью>>

Главная > Реферат >Остальные работы

Сохрани ссылку в одной из сетей:

Preservation of Wetlands

Wetlands are in danger. We must try to help them because they are very important to us. They provide habitat and food for a variety of animals. They also provide the unique growing conditions needed to grow certain kinds of plants. The survival of many species depends on wetlands.

A wetland is an ecosystem in which land meets water or a piece of land that is covered with a thin layer of water at least part of the year ( Lisowski 1). Most wetlands in the Continental U.S. are in the upper Midwest, the southern Gulf coast, and along the Northeastern coastal states ( Liptak ). Wetlands are found all over the planet. Over half of Alaska is made up of wetlands and five percent of the lower 48 states are wetlands( Arem 347). Wetlands cover six percent of the Earth’s total land mass, yet they are among the World’s liveliest places. More animals depend on wetlands than any other ecosystem, except for the ocean (Staub 10). Wetlands collect water from rain, snow, and runoff from flooded rivers, lakes, and higher surfaces. They may also collect ground water from below ( Arem 346). Wetlands need woodlands and meadows nearby. The plants trap pollutants that would have gone into the water. Some birds roost in the trees and feed in the wetlands (Hirschi ix). There is very little oxygen in water or watery soil. Many plants get oxygen from tiny openings on their leaves above water. Others have openings in bark or roots for oxygen (Arem 347).

Wetlands are major breeding grounds and migrating stopovers for waterfowl- ducks, geese and swans- and other birds. A magnificent array of wading and shore birds- herons, egrets, and ibis- need the wetlands. Rails, coots, and many song birds also need the wetlands. Some amphibians and many reptiles rely on the wetlands as well as mammals. The wetlands are also shared with many insects, clams, snails, and crabs (Liptak ). Animals have many ways of getting around wetlands. Fish and frogs swim, ducks and beavers have webbed feet to paddle, and insects have shaped bodies that allow them to float or walk on the water (Arem 347).

There are mainly two types of wetlands. There is freshwater, which marshes, swamps, and bogs belong to, and saltwater, which is comprised of salt marshes and mangrove swamps

One type of freshwater wetland is a marsh. Over 90% of all wetlands are marshes. Marshes contain a few inches to a few feet of water (Arem 348). Ducks depend on marshes for food, nesting, habitat, and shelter. They make their nests among the thick marsh plants lining small ponds or lakes. Ducks have suffered losses in population because of the destruction of wetlands. Whooping cranes are extremely endangered. There were as few as 29 left on the face of the planet in 1973. Thankfully their population has risen to 131 today. They need marshes to survive ( Hirschi 6-10). Small birds, such as blackbirds, sparrows, and warblers, feed and nest in marshes. Wading birds, like herons, rails, and bitterns, walk the marsh in search of food. Most marsh plants are soft stemmed and non-woody grasses or grass-like plants, such as cat tails, bulrushes, and sedges. Marsh plants provide food for muskrats, beavers, mink, fox, moose, deer, frogs, turtles, dragonflies, spiders, skunks, snakes, and many others ( Arem 348 )

There is a special type of marsh called a prairie pothole. The prairie pothole region covers part of the northern U.S. and Canada. Potholes are depressions in the land that have filled up with water and have turned into marshes. 7,000,000 ducks visit the potholes to feed and nest in these marshes. Because of this, the pothole region has been nicknamed North America’s “Duck Factory” (Arem 348).

A swamp is a freshwater wetland where trees and shrubs grow. Swamps form along, lakes, rivers, and in low lying areas. They contain a few inches to a few feet of water. Swamps usually flood during growing season and may dry up during late summer or remain year round. Swamps tend to be dark and still and are patterned with floating plants and shadows from the tall mossy trees above. Swamps exist in both the northern and southern states. In the north common trees are the red maple, the black willow, the white cedar, and the cottonwood. In the south the water oak, the tupelo, and the bald cypress tree’s are common. Swamps may host, depending on their location, such exotic animals as

panthers, alligators, and black bears. Swamps shelter ducks and wading birds which paddle or pick their way through the shallows in search of fish and snails. Cottonmouth snakes and snapping turtles are in the water while pileated woodpeckers drill the trees. One special type of swamp is a shrub swamp. Shrub swamps have mostly shrubs and no trees. This type of swamp is found near lakes, marshes, streams, and next to regular swamps. Common swamp shrubs are the pussy willow, the bottom bush, and the leather leaf (Arem 349).

Bogs are freshwater wetlands that form in cool areas where little water flows in and out and where the soil is low in oxygen. Most bogs were formed thousands of years ago. The combination of coolness, poor drainage and low oxygen levels create unique conditions. Dead plants and animals decay slowly and over time layers of dead plant matter build up and pack together to form an acidic material called peat. Bogs are visited by many animals but few live there. Some of the visitors may include moose, deer, bears, and cranes. Oxygen and food are in short supply in bogs. Only a few specially adapted plants and animals can live there. The black spruce is commonly found in bogs because it has special roots that pull in extra oxygen. The bog plants grow on the peat or spread across the open water. Most common plants are tiny, carpet-like plants called sphagnum moss. Networks of tiny water plants weave with the moss which forms a floating mat. As the mat thickens, it can support larger plants and even trees. Orchids, which have beautiful, showy flowers grow in bogs as do cranberries. Some carnivorous plants which grow here are the floating bladderwort, sundew, and pitcher plant) also grow in bogs (Arem 350).

The salt marsh is a saltwater wetland. Salt marshes develop in bays, coves, inlets, and estuaries. All of these places are protected from the full force of the tides. They are places where grasses have been able to take root and grow. Salt marshes cover nearly 10,000 sq. miles of the U.S. coastline. Almost half of them are found between Maine and Florida. Salt marshes are in tune with the tides. Twice daily the ocean rises and falls. The marsh environment changes as the water washes in and out. Salt marshes receive salty water from the ocean and freshwater from rivers. This is to their benefit because the saltier the water, the fewer the number of plants and animals that can live there. Most salt marsh

plants are tall, hardy grasses. A few of these include pickle weed, cord grass, spike grass, and salt grass (Arem 351).

Most animals that live in salt marshes are strongly affected by the tides. Some parts are always covered by water and others are rarely underwater. Some creatures have adapted to live in this rapidly changing environment. Fiddler crabs find food at low tide. When the water rises, they race into their holes. A waxy looking plant called glasswort anchors itself in the squishy mud. When the tide is out, mussels lie in the mud, attached to the plant. When it comes in, they open up to feed. When it goes back out they close up again to keep from drying out. Salt marshes have food for many creatures. Most animals live on the surface or in tubes or shallow burrows. Small animals become food for larger animals. Snowy egrets catch fish, and clapper rails eat fiddler crabs, snails, insects, and seeds. Tidal flats often form between salt marshes and open ocean waters. Here the force of the incoming and outgoing waves and tides are very strong, which means that plants cannot grow. The flats are exposed during low tide and covered with water during high. Not far from shore the marsh may be brackish, containing a mix of salt and fresh water. More plants are often able to grow here (Arem 351).

Mangrove swamps, the other kind of saltwater wetland, are known for mangrove trees. They are found in the warm tropical and subtropical regions of the planet. In the U.S., mangrove swamps line parts of the coast along southern Florida. Mangrove trees send tough, finger like roots into the mud. The roots hold the tree in place and keep the trunk above water. Some species of mangroves pull in extra oxygen through their roots. Oysters attach themselves to the mangrove roots. Sea horses may be found hanging by their tails. Blue crabs, fish, and shrimp climb and swim along the roots. Green backed herons live in the roots as do spiders, snakes frogs and crabs (Arem 354).

Wetlands are of extremely high value, yet they are disappearing. As the human population grows and cities expand, wetlands are covered to make room for homes, offices, factories and shopping centers. Many wetlands in the U.S. are endangered. These include the prairie pothole (Duck Factory) region in the Midwest, the lower Mississippi

flood plain in Louisiana, Mississippi, and Arkansas, and the Kissimmee river, lake Okeechobee, and Everglades system in South Florida. Every time a wetland vanishes, we lose another natural resource with the wildlife it supports (Liptak ). When the Europeans first arrived in North America, the wetlands covered more than 200 million acres. Today over 1/2, some 100 million acres have been lost. We lose about half a million acres of wetlands each year. Many of them have been cleared for farm land, and others are drained to make room for homes and industrial complexes. Wetlands have also been cleared to build channels for navigation and levees (Liptak ). Wetlands are continually plowed and dumped into with fewer restrictions than just a few years ago (Hirschi 2). Natural causes, like erosion and storms, also destroy wetlands (Liptak ).

We need the wetlands. They are the most productive natural ecosystem on earth. Wetlands produce great quantities of plants, some that can grow nowhere else. Many of these plants provide food, shelter, and nesting areas for wetland animals (Liptak ). Some fishermen depend on wetlands because their particular fish begins it’s life there. If the fish don’t have the wetlands, they will die out, which means the fishermen are in trouble (Staub 8). Whooping cranes, crocodiles and other species must have wetland habitat to survive (Hirschi, 14). Water going into wetlands is usually contaminated with something else. When the water flows into a wetland, it slows down. The pollutants settle to the bottom and collect around roots and stems. Thus, the water leaves the wetland cleaner than it entered (Arem 355). Over 1/2 of the seafood caught in the U.S. comes from wetlands, Peat is collected from bogs and sold as a burning material, wild rice grows in wetlands, and some people make their living by growing and selling cranberries, which grow in bogs (Arem 355). According to the Environmental Protection Agency (EPA) 45% of all animals and 26% of all plants on the federal endangered or threatened list depend on wetlands (Hirschi 2). Peat is released from wetlands during dry spells, which benefits any land downhill. Marshes store water which seeps down into the earth where it forms into large pools called aquifers. Aquifers provide a great deal of our drinking water (Hirschi 1,2). So many potholes have been converted into farmland that many ducks face great danger. Food is scarce in ditched potholes, and when the marshes are too dry, fires can start in

them, killing both eggs and ducklings. Because of this, species like the redhead and canvasback ducks are seriously endangered (Liptak 43).

In 1986 the U.S. and Canada adopted the North American Waterfowl Management Plan. The main goal of this is to restore wetland conditions and duck numbers to what they were in the early 1970’s (Liptak ).

In short we need to save the wetlands in order to save ourselves. Remember this next time you drink cranberry juice, eat fish, or drink a glass of water.

Загрузить файл

Похожие страницы:

  1. Wetlands Essay Research Paper Wetlands Policy ProposalIntroductionEvery

    Реферат >> Остальные работы
    Wetlands Essay, Research Paper Wetlands Policy Proposal Introduction Every year our nations wetlands have ... wetlands consist of. There are four major types of wetlands which are: isolated wetlands, bogs of ... only way to preserve our nation wetlands is to stop ...
  2. Location Of Landfills Essay Research Paper Location

    Реферат >> Остальные работы
    Location Of Landfills Essay, Research Paper Location Of Landfills The Issue Landfill, as ... be located within earthquake zones, wetlands, floodplains, or near airports. (Hall ... in landfills, as well as preserving sources of nonrenewable raw materials. (Smith ...
  3. Wetlands Essay Research Paper Environmental Science 101Kim

    Реферат >> Остальные работы
    ... increases turbidity and degradation of wetlands. Pollutants released from boats ... downstream, because of the excess water. Therefore, dams and preservation techniques must ... the Unknown Landscape : A History of. Wetlands. Boston: Greenwood, 1993 Irwan, Samuel ...
  4. Wetland Policy Essay Research Paper IntroductionThe issue

    Реферат >> Остальные работы
    Wetland Policy Essay, Research Paper Introduction The issue of wetland conservation and ... a local economy. The preservation of wetlands near densely populated areas creates ... towards further preservation of wilderness areas, namely wetlands (Schiller and ...
  5. Property Rights Essay Research Paper CONTENTSSUMMARYI Some

    Реферат >> Остальные работы
    Property Rights Essay, Research Paper CONTENTSSUMMARYI. Some Basics A. Public Goals ... 1989 of an expansive definition of wetlands (since abandoned) and the designation of the ... found that application of New York City’s historic preservation ordinance so as ...

Хочу больше похожих работ...

Generated in 0.0022988319396973