Where the Land Is Wet
Wetland environments are any flooded or water-soaked
area with a covering of water plants. A wetland is classified by the plant
species that live in it. What types of plants grow depend on how fast the water
in the wetland flows. Some wetlands are like a swiftly flowing river, while
others are like a thick sponge. The world’s major wetlands are located
in southern Africa, North America, central South America, and Asia. The largest
wetlands in the world are the bogs of the Siberian lowlands in Russia. They
cover 600,000km2.
That’s three times the size of Great Britain. All the world’s wetlands,
even the large Siberian bogs, are endangered environments.
Wetlands are an important habitat for many bird species.Some of these species
live year-round in wetlands. Others use several different wetlands along
their migration route when traveling between their winter and summer grounds.
©G.Ellis/GLOBIO.org Bogs, Marshes, and Swamps, Oh My!
Wetlands are found in nearly every region
of the world. Types of wetlands include swamps, bogs, marshes, estuaries, and
fens. In different areas, they may have different local names. For example,
bogs are located in colder, temperate climates. You’ll find bogs in Finland,
northern Germany, Scotland, Denmark, Estonia, and the Falkland Islands. Canada
has bogs, too, but Canadians call them muskegs. In the southeastern United
States, swamps are called bayous.
Keep That Water Clean
About one-third of all the water that evaporates from the ocean falls on the
land as rain and snow. This is the water that fills rivers, lakes, swamps,
marshes, and other wetlands. Wetlands filter and maintain much of the freshwater
humans and other animals depend on. This makes wetlands one of the most important
environments.
Only Soggy Sometimes
Not all wetlands are wet all year. The pantanal in southern Brazil is a large
flat wetland. It is covered by 1m of
water part of the year and is dry and spongy the rest of the year. Plants and
animals in the wetlands must be able to adapt to
seasonal changes.
Cormorants are sea birds that often fish in estuaries, which are salty wetlands
found close to oceans.
©M.Wilhelm/GLOBIO.org
Wetlands With a Dash of Salt
Another type of wetland is an estuary or salt marsh.These wetlands are where
freshwater and seawater mix. The plants and animals living here must adapt
to many changes to survive. Estuaries are places where four conditions meet – freshwater,
seawater, land, and air. These conditions allow for a great diversity of plant
and animal life. This biodiversity is
equal to or greater than that found in a tropicalrainforest. The unique habitat
of an estuary makes a great home for animals that spend part of their lives
in salt water and part of their lives in freshwater, like the salmon. Chesapeake
Bay on the east coast of the USA is the largest estuary in the world.
Where Did the Dinosaurs Roam? Ancient Wetlands!
Alligators and crocodiles are found in warmer, more tropical wetland areas
on several continents. Animals like these spend time in water and on land.
They are responsible for carrying plants and their seeds to new areas where
they can grow and spread.
©G.Ellis/GLOBIO.org
Wetlands have been an important part of life
on Earth for millions of years. Many dinosaur species depended on wetlands
and the plants growing there for food and safety. Today, scientists find some
of the best-preserved dinosaur fossils in
ancient wetlands. A few dinosaur relatives still live in tropical wetlands.
These include crocodiles, caimans, and alligators.
Layers of a Wetland
Wetlands are really interesting places. They
are rich in diversity and are where land and water environments meet and mix.
Discover more about what makes a wetland interesting by clicking below.
A Great Place to Call Home
Wetlands provide habitat for
a great number of water and land species. They are also an important environment
to many migratory bird species.
These birds use them on their way to and from their winter and summer grounds.
Almost half of all threatened and endangered species in North America rely
on wetlands.
Who Lives in a Wetland?
Fish,
frogs, water birds, and insects are found in wetlands on every continent. There
are also some fascinating creatures that live only in specific wetlands. In
South America, capybara, the world’s largest rodents, are found in wetlands.
In Africa, flamingoes, hippos, lechwe antelope, fish eagles, and Nile crocodiles
all need wetlands. In the South Pacific, wetlands are home to reptiles like
snake necked and pig nosed turtles and freshwater crocodiles. American
beavers help create and maintain North American wetlands used by ducks, bald
eagles, and moose. Wetlands in the grasslands are critical habitat for
millions of geese, ducks, and wading birds such as herons. In the southeast
USA, swamps are home to alligators, anhingas, and endangered Florida panthers.
Different species of ducks are found in most wetlands around the world.
Ducks have webbed feet that make them great swimmers. They also have special
sieve-like bills for pushing water out of their mouths while keeping little
plants and arthropods in.
©M.Wilhelm/GLOBIO.org
Arthropods at the Beginning
Arthropods are some of the wetlands’ most important creatures. They
take advantage of the many different niches a
wetland environment creates. Arthropods are also at the beginning of the food
chain. This means they help support all kinds of other life, from fishes and
frogs to birds and crocodiles.
Wetlands and People
Very few people live in wetlands. In Iraq,
the Ma’dan, or Marsh Arabs, learned to build mudhif - distinctive
cathedral-shaped reed houses. They fished and lived in the large wetlands east
of An Nasiriyah. But the Ma’dan, who inhabited these areas for thousands
of years, no longer live there. Habitat destruction poses serious threats not
only to native peoples but also to the area's wildlife populations. New conservation
projects are working to restore the marsh for the Ma’dan and the wildlife.
Wetlands Are Not Wastelands
People once viewed wetlands as wasted land.
For most of the past one hundred years, people have been draining the water
from wetlands and filling them in. They then build houses, cities, and roads
where the wetlands used to be. Thousands of areas have been drained and converted
to farms, too. Pollution from
chemicals, fertilizers, and other sources poses another threat to wetlands.
Some scientists estimate that the world may have lost up to 50% of all wetlands
since 1900. The remaining wetlands are in danger of degradation or are currently degraded.
Almost all wetlands are degraded or in danger of becoming degraded. Air
and water pollution damage many wetland areas, especially those near factories
and industrial plants. Many wetlands have also been drained and destroyed
in order to build houses and cities. Wetlands are not only homes for millions
of species, but they also help keep the world’s water clean.
©G.Ellis/GLOBIO.org Protect Them!
Fortunately, people are discovering how important
wetlands are to the health of the environment that surrounds the wetland. Many
countries now have laws to protect wetlands, and they are working to protect
even more. The Ramsar Convention is an international treaty that has been signed
by 146 parties for the wise use of wetlands and their resources. The Convention
has been critical to the protection of wetlands for migrating water birds.
There are many plant species that have special adaptations for living in
wetland environments. These plants are very good at living where the ground
is soaked with water. Many of them have adapted to taking in nutrients from
the water, which keeps them healthy and the water clean.
©G.Ellis/GLOBIO.org