Coastal dunes are very dynamic systems offering a wide variety of habitats with different physical and biotic conditions, and this allows for the existence of species with very diverse life-history traits. They can be visualized as a permanently changing environment with distinct degrees of stabilization that is closely correlated with topography, the disturbance produced by sand movement, and distance to the sea. Dune habitats can be classified into three types: (1) those where sand movement dominates, sea spray is sometimes important, and nutritionally poor soils prevail (they are formed by the sandy beach, embryo or incipient dunes, foredunes, blowouts, and active dunes); (2) humid and wet slacks or depressions, that is, those habitats which become inundated during the rainy season when the water table rises and they sometimes may even form dune lakes with wetland vegetation; (3) stabilized habitats, which show no sand movement, conditions are less stressful, and there is more organic matter in the soil. Vegetation cover is more continuous - grasslands, thickets, woodlands, and tropical forests.
Figure 2 shows a beach and dune topographic profile as well as the intensity of some of the abiotic factors mentioned and the areas where they affect the dune system.
Was this article helpful?