Sand Dunes And Psammosere

Question 1

Where are sand dunes formed?

Answer 1

Formation begins in back of foreshore in upper beach

Question 2

Give a brief description of the formation of sand dunes

Answer 2

1. Strong onshore winds
2. Wide foreshore area exposed at low tide - sand dries out and is transported beyond mean high tide by onshore winds
3. Trap on the back shore needed to encourage accumulation e.g. Driftwood

Question 3

Define ecosystem

Answer 3

Interaction between living things and their non-living environment

Question 4

Define succession

Answer 4

Long term change in a plant community as it develops

Question 5

Define sere

Answer 5

Individual stage in the process of succession

Question 6

Define pioneer species

Answer 6

First species to colonise a bare inorganic surface

Question 7

Define climatic climax community

Answer 7

End of succession where the ecosystem is in equilibrium with its environment

Question 8

Give an example of a pioneer species

Answer 8

Sea couch

Question 9

State the reasons why the conditions are so ‘harsh’

Answer 9

• Saline environment
• Dynamic sediment
• Submerged (High tides and storm waves)
• Low nutrient content

Question 11

Give 3 ways in which pioneer species adapt to cope with ‘harsh’ conditions

Answer 11

• Waxy cuticle (Reduces water loss)
• Small leaves (Less surface area means less evaporation)
• Wide, shallow roots (Act as anchor)

Question 12

State the stages of sand dunes giving a form of vegetation found at each stage

Answer 12

1. Embryo dunes (Lyme grass)
2. Fore dunes (Marram grass)
3. Yellow dunes (Marram grass)
4. Feet dunes (Marram grass)
5. Dune slack (Willow)
6. Dune heath (Bracken)
7. Climatic climax (Oak)