foredunes

Foredunes are the first dune ridge adjacent to the beach, forming the landward edge of a dune system. They develop where wind-blown sand from the shore accumulates behind the foreshore and becomes stabilized by vegetation, creating a dynamic barrier between the sea and inland areas. Foredunes act as a protective buffer against storm surge and coastal erosion, reduce inland flooding, and trap sand that can be reworked to build higher dunes behind them. They often support specialized plant communities, typically grasses such as marram grass (Ammophila spp.), which stabilize the sand with their extensive root systems, along with other shrubs and forbs depending on climate and region.

Formation and dynamics: Sediment supply, wind direction, and vegetation establishment govern foredune growth. Their height and extent vary with coastal conditions and disturbances; during storms foredunes can be eroded, while periods of calm weather and sand supply allow vegetation to stabilize and rebuild them. Overwash and wind redeposition can create features that feed back into dune development behind the foredune.

Ecology and habitat: Foredunes provide habitat for invertebrates and various bird species and contribute to the overall biodiversity of coastal dune systems. Changes in erosion, sediment supply, or vegetation cover influence habitat quality and resilience.

Human impacts and management: Trampling, coastal development, sand extraction, and invasive plants can degrade foredunes. Restoration approaches include re-vegetation with native dune grasses, installation of sand fencing to trap sand, and careful sand nourishment to restore sediment supply while maintaining natural dynamics.