Teacher Resource 7 – Sand dune
succession
Correct order:Bare ground is colonized by pioneer species such as marram grass that can tolerate the dry,
salty conditions.
Marram grass stabilizes the sand due to its dense roots.
As the marram grass decays it makes the sand less hostile, adding humus and improving
water retention.
This allows other plants to grow such as grasses, ragwort and restharrow.
As plants build up, and then decay, soil depth and quality improve further allowing taller
plants to establish – firstly small shrubs and then trees.
This greater variety increases biodiversity encouraging the presence of insects and birds.
Eventually a stable woodland may develop.
Damage to dunes by rising sea levels, storms or trampling may reverse succession. These
are deflecting factors.
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Photosynthesis, food production and populations
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© OCR 2016