Wetland

Wetlands are special places where the ground is covered or soaked with water. They are between dry land and water bodies, like lakes or rivers. The plants and animals in wetlands have adapted to live in these watery conditions. Because of this, wetlands are very alive and full of many different kinds of plants and animals.

You can find wetlands all over the world, except in Antarctica. They can have fresh, salty, or a mix of both kinds of water. There are many types of wetlands, such as marshes, which have tall grasses and reeds, and swamps, which have trees and shrubs. Other types include mangrove forests near the ocean and bogs, which get their water from rain.

Wetlands are very important for people and the planet. They help clean water, protect shorelines from storms, and control flooding. They also help fight climate change by storing carbon. However, many wetlands are under threat from human activities like building and pollution. Protecting wetlands is important for keeping both nature and people safe and healthy.

Definitions and terminology

Main article: Classification of wetlands

A wetland is a place where the land is often covered with water. This water may be on top of the ground or just below it, and it stays there for some of the year. Wetlands are special because they are a mix of dry land and water bodies. The plants and animals in wetlands have learned to live in these wet places.

Wetlands can be found everywhere, in hot, cold, or mild climates. Some wetlands are always wet, while others are only wet for a short time. There are many kinds of wetlands, such as marshes, swamps, bogs, and fens. Each type has its own special plants and animals.

Processes

Wetlands can look very different depending on where they are. Things that change wetlands include the shape of the land, how water moves, and what plants grow there. When dead plants build up in waterlogged soil, special wetlands called bogs and fens form.

The biggest thing that creates wetlands is water flooding the land or keeping the soil very wet for long periods. This flooding decides what kinds of plants grow there. Other factors that matter include soil richness, natural disturbances, and animals eating plants. Water gets into wetlands mainly from rain, rivers, and water underground. Water leaves wetlands through evaporation, flowing over the land, and moving underground. How water moves through a wetland changes how much water stays there. The land's shape and what lives there affect how water behaves. The amount of oxygen and carbon dioxide in wetland water depends on temperature and mixing with outside air. Wetlands usually get water that contains materials from the soil, except for special bogs that get water only from rain. Bogs get most of their water from rain, so their water has few minerals. Other wetlands get water from underground or tides, so they have more nutrients and minerals. Fens get water from both rain and underground sources.

Biology

Wetlands are special places where plants, animals, and tiny organisms like bacteria and fungi live. The most important thing about wetlands is how long they stay filled with water. Other things, like how rich the soil is or how salty the water is, also matter. Plants and animals in wetlands can change with the seasons or depending on how often the area floods.

Wetlands have four main types of plants. Some plants grow completely underwater, like seagrasses and eelgrass, and they help give food and homes to small creatures. Other plants float on the water's surface, such as duckweeds. Plants like cattails and sedges grow up out of the water. When trees and shrubs grow in wet soil, the area is called a swamp. Swamps can have just one type of tree, like silver maple swamps, or many different kinds of trees, like in the Amazon basin.

Ecosystem services

Further information: Ecosystem service

Wetlands give many benefits to people and nature. They help stop floods by holding extra water. They clean water by catching pollution. They give homes to many animals and plants. Wetlands also help with fishing, farming, and even give materials for building and medicine.

Wetlands are important because they save money. Instead of building costly dams or water treatment plants, healthy wetlands do these jobs naturally. They protect coastlines from big waves and storms. They refill underground water supplies and help stop soil erosion. Without wetlands, it would cost much more to keep our water clean and our lands safe.

Disturbances and human impacts

Wetlands can be affected by changes from nature and from people. These changes can include things like too much rain or not enough rain, or humans building things, taking too many fish, or polluting the water. These changes can hurt the plants and animals that live in wetlands.

Some big problems for wetlands include pollution that makes the water too rich in nutrients, harmful chemicals, and too much dirt. When wetlands are turned into dry land for farming or building, it can hurt the environment. Building walls to hold back water can also cause more flooding later. Taking too many fish from wetlands can also be a big problem.

Conservation

Wetlands have sometimes been drained for building or farming, and other times flooded to make lakes or produce power. Many important farms were once wetlands. But since the 1970s, people have worked harder to protect wetlands because they are important for nature. To keep wetlands healthy, we need to reduce changes that harm them.

Wetlands are important for the people who live near them. Research in places like Malawi and Zambia shows that we can farm in wet areas called dambos without hurting them. These projects helped grow lots of food, taught better farming ways, and found smart ways to manage water for watering crops.

Main articles: Ramsar Convention and List of Ramsar wetlands of international importance

The Ramsar Convention is an agreement between countries to help protect important wetlands all around the world. Its goals are to list these special wetlands and make sure they are used wisely. This means sometimes limiting who can visit and teaching people why wetlands are valuable, not empty land. The convention works with groups like Birdlife International, the IUCN, the International Water Management Institute, Wetlands International, and the World Wide Fund for Nature to share knowledge, study wetlands, and support protection efforts.

Restoration

Restoration helps bring wetlands back to their natural state after they have been disturbed. Scientists use different ways to help them heal. One way is to stop more harm and let the wetland recover on its own. Another way adds soil or plants to help it grow back. The biggest way is building a whole new wetland, often in cities to help with water and wildlife. Local communities can share their knowledge to help guide the restoration.

Main article: Constructed wetland

Climate change aspects

Wetlands are important for our planet's climate. When wetlands like peat swamp forests are damaged, stored carbon is released into the air as carbon dioxide. This can help cause climate change. This often happens in Southeast Asia, where peatlands are drained and burned.

Restoring wetlands can help fight climate change. Wetlands can trap carbon from the air and store it. They also help protect coastlines and control water levels. This is important because climate change can cause more extreme weather like floods and droughts.

Valuation

Wetlands are important to communities because they provide many useful services. People map where wetlands are located and study what they do, like cleaning water or giving animals homes. This helps decide which wetlands need protection.

There are quick ways to check how healthy a wetland is. These methods use simple questions and checklists to give a score. This helps people know which wetlands are most important. Scientists also watch wetlands over time to see if they are staying healthy or getting worse. They use tools like satellites and maps to keep an eye on them from far away.

Legislation

Each country has rules to protect wetlands. In the United States, wetlands are areas that stay wet and support special plants. These rules help protect wetlands under laws like the Clean Water Act. Some states, like Massachusetts and New York, have their own rules.

In Canada, there are also policies to protect wetlands. Each province and territory has its own guidelines to keep these areas safe.

Examples

See also: List of Ramsar Wetlands of International Importance, Mediterranean wetlands, List of Ramsar wetland sites in Pakistan, and List of Ramsar sites in Australia

Some of the largest wetlands in the world are the swamp forests in the Amazon River basin, the peatlands on the West Siberian Plain, the Pantanal in South America, and the Sundarbans in the Ganges-Brahmaputra delta. These places are important homes for many plants and animals because they are often flooded or very wet.