Why Dungeness vegetation comes in stripes

17th February 2008, Sunday

One of the first impressions of Dungeness is that the vegetation is stripey. This unusual phenomenon can be viewed on the early false-oat-grass grassland and is fixed as the vegetation ages. Why?

It is all down to the action of the waves. As well as throwing up the shingle in characteristic ridges the gravel is sorted into bands of coarse and fine shingle

 Wave-sorted shingle

This can be observed in the photograph above, with fine pea beach on the right and coarser stones to the left. This is not the only wave sorting that goes on, however. As you travel up the coast from Lydd on Sea to Greatstone the stones get larger and larger. Greatstone is well named.

This sorting is fundamental for the vegetation. Coarse gravel is harder to colonise – seeds drop down through the stones, but probably more important is that the fine gravel traps just enough moisture to allow seedlings to survive. So, on much of Dungeness the result is a natural pattern of stripes – a feature that can be viewed very well from the top of the old lighthouse by the way. Meanwhile, at the northern end of the shingle beach the gravel, composed of predominantly large stones, is naturally almost bare, either because vegetation just cannot establish, or if it does the substrate is unable to support plants with any degree of trampling pressure.