Beach meadows at the Wadden Sea

The salt marsh is a special habitat type         

A salt marsh is a special habitat type located close to the coast. It is an area of low vegetation that has been affected by sea salt from flooding or from the air. The term meadow is linked to human use of the area in question. And it is only a meadow as long as the vegetation is kept down by grazing animals or haymaking. If the meadow is not utilised, it develops into a bog, swamp or scrub.

Dynamic landscape

In the Wadden Sea, salt affects salt marshes more than on the eastern coasts of Denmark. There is also generally more dynamics here. The tides and storms cause new salt marshes to form, while others erode away at a rate not seen elsewhere in the country. The salt impact is greatest in the outermost part of the salt marsh, while it tends to decrease further up the terrain. After a flood, small isolated lakes - so-called salt pans - can form further inland. When the water evaporates from these pools, a concentrated amount of salt is left behind. The salt pans are actually so salty that nothing can grow in them, but vegetation grows along the edges. If the meadow is heavily affected by salt, many plant species cannot grow here and the vegetation will consist solely of characteristic salt meadow plants.

Grazing ensures diversity

To ensure an open meadow with low vegetation, it may be necessary to release grazing animals such as cows or sheep. Grazing provides light for a wide range of low-growing plants and the insects that depend on low-growing plants. The many insects in the grazed meadows also provide food for typical meadow birds such as lapwing and oystercatcher. In addition, the mere presence of the animals helps to create greater diversity. The animals' trampling constantly creates small niches in the soil where specialised species find room to grow. Read more about this here. 

The plants of the salt marshes

There are a number of plants that have adapted to the salty environment of the salt meadow in different ways. Each plant must be able to accumulate a higher concentration of salt in its cells than in the surrounding soil. Otherwise, water would migrate from the plant into the soil to restore the salt balance and the plant would dry out. But if the salt concentration becomes too high, the plant can be poisoned. The beautiful beach aster solves this problem by collecting the salt in older leaves, which then die and fall off. Plants such as the marsh marigold and wadden grass get rid of the salt through glands on the underside of the leaves.

Fotos: John Frikke, Wasabi Film, Tandrup Naturfilm