Sand Dunes

Many coasts have developed sand dune formations.

The source of the sand may be ancient offshore deposits or material eroded from local cliffs.

In order for sand dunes to develop, you need an abundant supply of fine sand, a prevailing onshore wind and then something to trap and retain the sand.

Seaweed and beach debris may initially trigger a small embryo dune.

Once the pioneer plant species such as lyme grass take root, more sand accumulates and the dune grows.

Marram grass is the main coloniser and stabiliser of sand more mature yellow and grey dunes.

Eventually other plants, which are less salt tolerant will colonise the dunes, leading ultimately to a climatic climax woodland ecosystem.

In low-lying areas or slacks, marsh plants such as juncus will colonise.

If the dune vegetation cover is broken by human activity or rabbit burrowing, blow-outs may result with large amounts of sand being removed from the damaged dune.