sand dunes

Question 1

when do sand dunes occur? therefore what does the formation of sand dunes require?

Answer 1

prevailing winds blow sediment to the back of the beach

therefore formation requires large quantities of sand and a large tidal range

Question 2

the sand dunes develop as a process of what? and explain this

Answer 2

process of vegetation succession

Pioneer species such as sea rocket are resistant and able to survive in the salty sand, with its roots helping to bind the dunes together

Decaying organic matter adds nutrients and humus to the soil allowing marram grass to grow

Larger plants are able to colonise the area and the climatic climax occurs when trees are
able to colonise the area

Question 3

what are the five types of dunes?

Answer 3

embryo
yellow
grey
dune slack
heath and woodland

Question 4

what is an embryo dune?

Answer 4

upper beach area where sand starts to accumulate around a small obstacle (eg driftwood, wooden peg or ridge of shingle)

Question 5

what is a yellow dune?

Answer 5

more sand accumulates
dune grows
vegetation develops on the upper and back dune surfaces
stabilising it
its the tallest of all dune successions

Question 5

what is dune slack?

Answer 5

water table rises closer to the table
allowing the development of moisture loving plants

Question 6

what is a grey dune?

Answer 6

sand develops into the soil with lots of moisture and nutrients
vegetation dies enabling more varied plant growth

Question 7

what is heath and woodland sand dunes?

Answer 7

sandy soils develop as there is a greater nutrients content
allows for less brackish plants to thrive
trees also grow