Sand Dune Formation

Question 1

General Overview

Answer 1

• Dunes initially develop from debris trapping sand at the back of a beach.
• Vegetation helps stabilise it.
• Over a period of several hundred years, it is known as sand dune succession.

Question 2

Stage I

Answer 2

• First colonising plants are the ‘pioneer species’, which are able to cope in very dry and salty conditions (e.g sea rocket, couch grass).
• When they die, the organic mass adds to the developing soil.

Question 3

Stage II

Answer 3

• As ‘pioneer species’ take hold, they bind sand together, forming low sand dunes called ‘fore dunes’
• Marram Grass is a typical species here (it has long roots for finding water)
• Marram growth is stimulated by burial and it’s roots help bind sand.

Question 4

Stage III

Answer 4

• As the environment changes, different species colonise the sand dunes, reaching stability.
• The final community in this development of landscape is known as the’ climactic climax community’.

Question 5

Sand Dune Life Cycle

Answer 5

• Embryo dunes are first to develop.
• These grow into bigger fore dunes.
• Depressions between dunes form into dune slacks, where the ground is close to the water table.