Sand dunes - along the Northumberland Coast

We had promised to talk about how the dunes are created and how they come to be associated with different colours.

Strandline and embryo dunes

Imagine seaweed left stranded at the highest point of the beach. See it drying out and the sparse nutrients leaching into the sandy soil. Eventually some hardy plants will take advantage of this source of nutrients and sea rocket or maybe sea sandwort will start to grow. As these plants expand they will trap and stabilise the sand.

Yellow or white dunes.

Higher up than the strongest tides will reach you have an environment where the sand is still mobile but there is enough nutrient to support marram grass. This gras sbrings improved stability and this allows ragwort, sand sedge, fescues and hawkweed to grow between the clumps of marram grass.

Grey or fixed dunes.

Further back and over time mosses and lichens start to appear and they give this area a grey colour on the sand. And at last we get the Bloody Cranesbill.....the county flower of Northumberland.

Remember that when you are strolling along the beach at Bamburgh that there is much more here than people usually see.

Sand Dunes and wildlife - Bamburgh, Seahouses and the coast

So many times we have parked our car just south of Bamburgh and crossed the sand dunes to the beach. In our eagerness to reach the beautiful beach we don't really stop and consider the dunes and what they represent.

So this post is dedicated to the sand dunes of the north east beaches.

First off is the question of the underlying rock which is usually the Whin Sill. This andesitic rock produces poor quality acidic soils. The east facing slopes are generally dipping and typically have shallow lime rich and draught prone soils.If you then add in the harsh maritime conditions you get a very distinct environment with some unique plants.

Most of the Northumberland dunes are calcareous due to their high shell content. This soil supports a colourful flower rich ecosystem during the hot summer months with the low levels of nitrogen discouraging some of the more vigorous plants found in the area.

Most of the coastal dunes were formed 200 to 300 years ago. There are older ones, especially around Lindisfarne, but these are more acidic due the calcareous remains of shells having been leached out of them over time. These more acidic and older dunes typically have more heath type grasses and plants.

Our next post on the dunes will talk about the different colours and how they develop.