These dunes are smaller in size and their sides aren't as steep. Dunes constantly change if there is nothing to prevent the wind from moving the sand around. The wind doesn't stop moving sand once a dune is formed. If no plants grow on the primary dune, then the wind will remove the sand and deposit it onto the secondary dune until pretty soon there is nothing left of the primary dune. When nothing hold the dune system in place, the dunes move or migrate toward the land.
Plants are the primary way dunes are stabilized.
Vegetation, such as beach grass, dusty miller, beach peas, and seaside goldenrod keeps the sand in place with their extensive root systems. The roots hold the sand together and the sand on the surface builds up around the plants themselves.