Case Study: Sand Dune Succession

Edexcel A-level BiologyThe Nature of EcosystemsLesson 10 of 39

Sand dune succession is a well-studied example of primary succession, found on coasts such as Studland in Dorset. Dunes further inland are older, so walking away from the sea is like moving forward in time through the seral stages.

1. Embryo dunes. Near the strandline, pioneer plants such as sea rocket and sand couch grass colonise bare sand. They tolerate salt spray, drying out and shifting sand. Their roots trap blown sand, forming small dunes.

2. Yellow dunes. Marram grass becomes dominant. It grows upwards through accumulating sand, and its deep roots and rhizomes bind the sand. Its leaves roll up, reducing water loss. As it dies, humus starts to form, but the sand is still yellow because there is little humus.

More in The Nature of Ecosystems

• Biosphere
• Primary Succession
• Climax Community
• Secondary Succession
• Light
• Temperature
• Wind and Water Currents
• Water Availability

All 39 lessons in The Nature of Ecosystems · All Edexcel A-level Biology topics