Sand Dunes

Mobile (yellow)or Fore Dunes.

When sand has built up above the height of the highest spring tides (EHWS) marram grass (Ammophila arenaria) dominates; it quickly encourages substantial accretion and this overwhelms the typical embryo dune species.

This marram-dominated stage of sand dune succession is the most widespread, extensive colonising community on mobile coastal sands all around the British coast.

Although the influence of the sea is waning, the mobile nature of the substrate makes this a difficult habitat for many species to cope with. Scour, dehydration and nutrient and temperature stresses are still important abiotic factors here. There is still a lot of bare sand at this stage, which is why this type of dune is sometimes referred to as a yellow dune.

On the plus side marram stabilises the dunes, nutrients and organic matter begin to accumulate. Rabbits may graze the site and their droppings will input nutrients into the system.