Exploring the UK's wetlands

Wetlands are areas of the land that are covered by water for most of the time. They can form naturally or be man-made.

Wetlands are areas that are filled or soaked with either freshwater, saltwater or brackish water, a mixture of the two. They are neither dry land or underwater; they are somewhere in between.

Wetlands form when water cannot drain away from the area, so it builds up and floods it.

The water in wetlands can come from:

• sea

• rivers and lakes when they flood

• estuaries, where river water mixes with water from the sea

• rain

The amount of water in the soil, and the type of water determine which plants and animals can be found in wetlands.

There are different types of wetlands. The four main ones in the UK are:

Marshes

In marshes, the water covers the area for long periods of time.

Marshes form near rivers and along seacoasts and can have either fresh or salty water.

Salt marshes can be found along coasts particularly around estuaries.

There are no trees in marshes. They are home to a variety of birds, such as herons, and other animals, including otters and newts.

Swamps

Both swamps and marshes have soil rich in minerals, but swamps usually have trees. Like marshes, swamps can have either salty or fresh water. Fresh water swamps can be found in the Scottish uplands and saltwater swamps form near coastlines. Swamps are rich in wildlife, and are home to animals including fish, birds and frogs.

Bogs

Bogs are more common in colder areas, and they often form in places where glaciers once eroded the ground and left behind a freshwater lake.

The lake fills up with roots of dead plants, leaves and stems. As it becomes shallower, moss starts extending into the lake from its edges and soon, the whole lake is filled with plants.

The oldest, rotten plants at the bottom of the bog form a thick, spongy mat called peat, which can be used as fuel. Only certain types of plants can grow in bogs, because the soil is not very rich in nutrients so many plants must find nutrients from sources other than the soil. Mosses and heaths are common here.

Fens

Fens are in the lowlands of the UK that are always full of groundwater. Because they are always water-logged, plant material can't rot away and it builds up to form peat. Peat doesn't have many nutrients and so only certain plants - such as mosses and sedges can grow in it.

Bog and fens are both waterlogged areas of land - bogs by rainfall and fens by groundwater.

Wetlands are incredibly important for the planet and environment:

• They are home to a wide variety of animals and plants.

• They absorb water during heavy rain. This can help to protect people’s homes from flooding.

• They protect coasts from erosion caused by storms, wave action and rising sea levels. They help keep the shoreline stable.

• They are a popular place for recreational activities such as canoeing, hunting and birdwatching.

• They act as a water filter: the plants in the wetlands can filter the pollution and make the water cleaner by absorbing the chemicals.

• They also act as carbon sinks, as the plants absorb carbon dioxide from the air.

For centuries, people have added water to wetlands and drained water from them. Many of the areas have been drained to provide land for agriculture, roads, houses and factories.

In some places, bogs have been destroyed to use peat as fuel. Logging has removed many of the trees found in wetlands.

However, there are now laws that protect wetlands and help them return to their original state. New wetlands are constructed to act as natural water filters.