The Mobile Coast II

1st December 2007, Saturday

If any picture sums up the changeable face of the Dungeness Coast (yes I said Dungeness as in the shingle beach) it is this one, taken on the north-east edge of the Dungeness National Nature Reserve today.

Marram Grass on Greatstone Beach

Ten years ago this was vegetated shingle. Over the past ten winters increasing quantities of sand have blown onto the shingle and now marram grass Ammophila arenaria is well established. The dunes are likely to start building upwards quickly if this trend continues, as they have done to the north of the Romney Sands car park.

There is nothing new in the dynamic relationship between dune and shingle, Hundreds of years ago along the east coast of Dungeness there was a similar transition from shingle to sand. You can view the remains today, at the entrance to London Ashford Airport, behind the tall Airport sign. It is now over 2km inland but the vegetation is a mix of shingle beach and sand dune. I am never sure if it is sandy shingle or shingly sand! Marram grass and sand sedge Carex arenaria, both dune species, still grow here on the old coastline’s ridges.

So why is it happening at Greatstone? At Dungeness the sea is deep, the wave energy consequently strong, and any sand is washed away, leaving only the heavier shingle. 6km up the coast, in the shelter of Dungeness Point sand has accumulated to form a shallow sandy bay. At low tide it dries out and blows onto the shingle, allowing marram grass to colonise and start the process of dune creation. The photo below shows the coastal sand flats, the old shingle beach, and the embryo dunes forming above the shingle. It just goes to show how dynamic this stretch of coast is – nothing stays the same.

Greatstone Beach