Camargue is separated from the sea by a first protective cordon of front beach mobile dunes. They are covered with fragile vegetation of marram grass (Ammophila arenaria), a perennial plant of the Poaceae family which stabilizes the sandy soils thanks to a very deep root system. The older interior dunes of Camargue present more bushy and more wooded plant covers composed of Phillyrea, mastic trees, alaternas, tamarisks, or pines.