Psammosere

Movement of sand, due to wind, can build up around an obstacle. (e.g. driftwood)

Hostile environment: - salt
                      - strong winds

Roots stabilise dune so sand builds up

Not as hostile

Marram grass dominant

Plants die => soil forms

Sea Spurge starts to grow

Marram Grass dies so layer of humus forms

Gorse starts to dominate

If below water table, can fill with water

More developed community due to sheltered conditions

No longer gets fresh supply of sand

Forest forms local climate determines type

Oak dominates

Interference: 

• People keep beaches aesthetically pleasing (by removing obstacles) so dunes can't form
  
• Tourism - people walking over dunes displaces veg./sed.

• Intense Weather - strong winds/heavy rain can blow/wash sediment away

Can be 10-30m high

More acidic soil