What is the difference between the plants that grow on primary dunes and secondary dunes?

Primary dunes, located closest to the ocean, typically support hardy plants adapted to harsh conditions, such as high salinity, strong winds, and shifting sands. These plants, like beach grasses, have deep root systems that stabilize the dunes. In contrast, secondary dunes, found further inland, often have more nutrient-rich soils and a more diverse plant community, including shrubs and other vegetation that can tolerate slightly less extreme conditions. This variation in plant life reflects the differences in environmental stresses and soil composition between the two dune types.