Where is wetlands

In drier areas of the swamp, palms and grasses grow. Insects such as bees build hives in the trees. In fact, harvesting honey has been a major economic activity in the Sundarbans for centuries. Bees and other insects are one of the main food sources for tropical birds in the area.

Storks, ibises, and herons nest in the high branches of mangrove and palm trees. Smaller birds such as kingfishers and pigeons roost in shrubs. Many reptiles and amphibians live in and around the swamp, including frogs, toads, turtles, and snakes. Some of the snakes of the Sundarbans, such as the Indian python, regularly grow up to 3 meters 10 feet long.

Monitor lizards and crocodiles, also native to the Sundarbans, are even larger. The large reptiles of the Sundarbans regularly prey on mammals such as deer, boar, mongooses, and monkeys. However, the most famous predator of the Sundarbans is the Bengal tiger, an endangered species. Bengal tigers are apex predator s—human beings are their only natural predator. In the Sundarbans, Bengal tigers swim in the swampy water and climb trees. The cats, which can grow to kilograms pounds , have been known to attack people in the swamp.

Scientists and honey collectors are especially at risk. Marshes North and south of the tropics, swamps give way to marshes. These wetlands form a flat, grassy fringe near river mouths, in bays, and along coastlines. Many are alternately flooded and exposed by the movement of tides. Like swamps, marshes are often divided into freshwater and saltwater categories.

Freshwater Marshes Freshwater marshes, often found hundreds of kilometers from the coast, are dominated by grasses and aquatic plants. These marshes often develop around lakes and streams.

Many freshwater marshes lie in the prairie pothole region of North America, the heart of which extends from central Canada through the northern Midwest of the United States. Prairie potholes are bowl-shaped depressions left by chunks of glacial ice buried in the soil during the most recent ice age.

When the ice melted, muddy water filled the potholes. Fertile soil and a temperate climate make these marshes some of the richest in the world.

For this reason, many prairie potholes have been drained and the land used for agriculture. Thousands of migratory birds depend on the remaining prairie potholes as they travel from the Arctic to more temperate climates every year. Farther south, freshwater marshes form much of the Everglades, a huge wetland region in southern Florida. Water from Lake Okeechobee flows slowly through the Everglades on its way to the ocean.

Sawgrass, cypress, and mangroves grow along its path. The muddy, slow-moving water is also home to rare types of orchid. The Everglades are known for their diversity of wildlife. This marsh contains hundreds of species of wading birds, each of which is adapted to feed on insects, fish, clams, shrimp, or even rodents such as mice. Alligators make their nests in the dense sawgrass, and swim in the murky water. Dominated by grasses, they provide food and shelter for algae, fungi, shellfish, fish, amphibians, and reptiles.

Wading birds and other animals feed on the vegetation and abundant insects. The warm saltwater marshes of northern Australia are influenced by the tides of the Indian and Pacific oceans. They often overlap with the freshwater marshes of rivers, such as the Jardine. A few mangrove trees may dot saltwater marshes, but they are dominated by grasses and a layer of algae called an algal mat. This algal mat is home to many insects and amphibians.

Some of these birds nest in the shrubs and prey on insects and fish in the area. Others are migratory, only visiting the marsh when their home ranges become too cold or dry to support life.

These enormous reptiles often spend the wet season in freshwater swamps and rivers, and migrate to saltwater marshes in the dry season. Many Australian beaches have strict warnings to swimmers during certain seasons, because saltwater crocodiles are a threat to people as well. Bogs Swamps and marshes are generally found in warm climates. They also exist at high altitudes in warmer regions, such as the Sierra Nevada in the United States. Bogs are often called moors or fens in Europe, and muskegs in Canada.

Like many wetlands, bogs develop in areas where the water table, or the upper surface of underground water, is high. They often begin in glacial depressions called kettle lake s, which are deeper than prairie potholes.

A bog forms as a kettle lake gradually fills with plant debris. Leaves, roots, and stems of large plants accumulate on the bed of the lake. As the lake becomes shallower, mosses and other plants growing along the edges of the lake extend into the water. Eventually, these plants are followed by water-loving grasses and sedges. Soon, the water is choked with vegetation. The oldest, partially decayed vegetation at the bottom of the bog forms a thick, spongy mat called peat.

Peat is a valuable fuel in many parts of the world. It is often the first step in the creation of coal , a fossil fuel. The fossils in coal are wetland plants. Some people living near bogs cut and dry squares of peat.

It is burned for heating and cooking, or used to insulate buildings. Bogs preserve more than the remains of plants, however. The bodies of dozens of prehistoric people have been found in bogs in Europe and Asia. Bog bodies are in such excellent condition that anthropologist s can examine clothes, tattoos, and hair color, and even investigate a cause of death.

Most people found in bogs were killed, though historians and anthropologists debate whether they were murdered or sacrifice d as part of a religious ritual. They are called quaking bogs because the surface quakes when a person walks on the spongy peat.

The island of Ireland, with its cool, wet climate, has hundreds of quaking bogs. Unlike other wetlands, bogs usually are not agriculturally fertile. The amount of acid in the soil and water is generally higher than that in swamps or marshes. The supply of nutrient s, especially nitrogen, is low. Only certain kinds of plants can grow in bogs. Some of the few plants harvested in the wet, acidic soil of bogs are cranberries and blueberries.

Plants are autotroph s, meaning they are able to create their own food from air, water, and sunlight. Many bog plants have adapted to the poor nutrients in the soil and water by expanding their food source. Pitcher plants and sundew, common in bogs, are carnivorous: They trap and consume insects. Because of the limited species of plants, bogs do not have the biodiversity common in other types of wetlands. Insects, common in all wetlands, include butterflies and dragonflies.

These insects feed on the nectar in bog flowers. Ireland has dozens of native butterflies found in bogs. Birds, such as geese and pheasant, also make their homes in the bog, although it is unusual to find larger animals. In North America, moose are one of the few large animals that thrive in bog habitats. Moose, the largest species of deer, consume aquatic plants such as pond lilies. Vital Ecosystems Wetlands are some of the most valuable ecosystems on Earth.

They act like giant sponges or reservoirs. During heavy rains, wetlands absorb excess water, limiting the effects of flooding. Wetlands also protect coastal areas from storm surge s that can wash away fragile beaches and coastal communities. Saltwater swamps and tidal salt marshes help secure coastal soil and sand. Wetland ecosystems also act as water-treatment facilities. The plants, fungi, and algae of a wetland filter wastes and purify water.

Nitrate s and other runoff chemicals often wash into wetlands from urban area s and farm s. As fishing grounds, they sustain hundreds of millions of livelihoods, many of them directly dependent on wetland services. Coastal wetlands such as mangrove forests also provide vital protection from storms, floods and salt water intrusion and in some cases even seal level rise.

Rivers originate as rain on high ground that flows downhill into creeks and streams. They connect to major wetland systems and deltas, which are found on the lower reaches of rivers, where the flow of water slows down and spreads out into expanses of wetlands and shallow water. Rivers and lakes are critical in arid and semi-arid areas, where wetlands are characterised by seasonal rainfall and wetlands that retain water long after the rest of the landscape has dried out.

These wetlands include rivers, swamps, and lakes and springs that dry up for portions of the year. Rivers and lakes serve as important sources of drinking water, food and irrigation for crops. River waters also recharge lakes and transport fertile sediments that enrich floodplains and marshes. Rivers also play an essential role as highways for transportation and commerce and as sources of energy. Rivers and lakes provide critical habitat for fish and other freshwater animals such as amphibians and shellfish.

High altitude wetlands store water from rain and glacial melt, feed groundwater stores, trap sediments and recycle nutrients, enhancing both the quantity and quality of water. High latitude wetlands are important stopping points for migratory birds and breeding grounds for birds, fish and amphibians. Their ability to promote vegetation growth lessens soil erosion and buffers water flow, providing a steady flow of water downstream while reducing the severity of disasters such as landslides, floods and droughts.

Arctic wetlands store enormous amounts of greenhouse gases and are critical for global biodiversity. They are also the main source of livelihoods for local indigenous peoples. Arctic wetlands offer unique habitats to both plants and animals. For many migratory species the Arctic provides indispensable breeding and feeding areas. In addition to this, over four million people, including more than 30 different indigenous groups, live in the Arctic.

Mangrove swamps, with salt-loving shrubs or trees, are common in tropical climates, such as in southern Florida and Puerto Rico. Some tidal freshwater wetlands form beyond the upper edges of tidal salt marshes where the influence of salt water ends. Inland wetlands include marshes and wet meadows dominated by herbaceous plants, swamps dominated by shrubs, and wooded swamps dominated by trees.

Certain types of inland wetlands are common to particular regions of the country. For more information, see Wetland Classifications and Types for a full list. Many of these wetlands are seasonal they are dry one or more seasons every year , and, particularly in the arid and semiarid West, may be wet only periodically.

The quantity of water present and the timing of its presence in part determine the functions of a wetland and its role in the environment. Even wetlands that appear dry at times for significant parts of the year -- such as vernal pools-- often provide critical habitat for wildlife adapted to breeding exclusively in these areas. For more information about wetlands, please visit our Wetland Factsheet Series. Skip to main content.