Plants are central to the formation, growth and character of sand dunes. Plants that have adapted to salty coastal conditions are known as halophytes.
Coastal sand dunes form where a beach is large enough to allow the sand to dry out and where winds can blow the sand landward. Here the sand is then trapped by dune grasses which grow through layers of sand. Within the sand dunes there is little organic matter meaning few nutrients available for the plant species that grow there. In some cases plants have adapted to store nitrogen in their root structure. Sand dune vegetation varies widely and it can depend greatly on when the sand is deposited. One of the first plants to colonise a sand dune system is usually Marram grass (Ammophila arenaria). This incredible grass has a deep root system which allows it to cope when sand is deposited on top of it. Over time other plant species begin to colonise the dunes and help improve the sandy soil structure. Today many sand dunes are threatened from coastal erosion, climate change, residential development and invasive species. This highlights how important is is to protect and conserve these valuable ecosystems that support important plant and animal life.