Sand Dunes

• Dunes are based on plant succession- how a community of plants change overtime as environmental conditions change
• When pioneer plants die they provide nutrients for new plants. Xerophytic plants require little water, an example of a adapted plant.
• Dunes need a large supply of sand and a wide beach which allows sand to dry and be moved by the wind. As sand is blown more inland it gets stuck behind obstacles creating an embryo dunes. Than plants colonise them (sea couch/rocket).
• Plants stabilise, add nutrients, humus (dead plants) and increase water retention.
• Yellow dunes and tallest ridge, at the front of the system is still active and isn't fully covered by plants, yellow.
• Further inland, dunes are shorter and fixed as they aren't collecting more sand, more humus and heather creates a black/grey colour. These can support more plants and animals.
• Troughs between these grey/heather dunes may have water (dune slacks).
• The further back and older dunes have more biodiversity, and the climax community- plants/animals remain stable and exist in balance.
• Plants on embryo/foredunes are sea rocket and sea crouch. Yellow dunes tend to be colonised by marram grass. Both have deep roots and can tolerate high concentrations of salt.