Coastal areas get very heavy use by people, but they are important for wildlife and vegetation too.
Salt marshes are areas of periodically flooded low-lying coastal wetlands. They are often rich in plants, birds and animals.
A salt marsh begins its life as an accumulation of mud and silt in a sheltered part of the coastline, e.g. in the lee of a spit or bar. As more deposition takes place, the mud begins to break the surface to form mudflats. Salt tolerant plants such as Cordgrass soon start to colonise the mudflats. These early colonizers are called pioneer plants. Cordgrass is tolerant of the saltwater and its long roots prevent it from being swept away by the waves and the tides. Its tangle of roots also helps to trap sediment and stabilise the mud.
As the level of the mud rises, it is less frequently covered by water. The conditions become less harsh as rainwater begins to wash out some of the salt and decomposing plant matter improves the soil. New plant species start to colonise the area and gradually, over hundreds of years, a succession of plants develops.
This is known as a vegetation succession
The power of waves is one of the most significant forces of coastal change. Waves are created by wind blowing over the surface of the sea. As the wind blows over the surface of the sea, friction is created - producing a swell in the water.
The size and energy of a wave is influenced by:
· the length of time that the wind has been blowing
· the strength of the wind
· how far the wave has travelled (called the fetch)
Waves can be destructive or constructive.
· are created from big, strong waves when the wind is…