The vegetation on the ocean-facing edge consequently receives the highest concentrations of salts, but these levels are very weak. The outer edge of vegetation will experience the greatest effects of physical buffeting and salinity from soaking high tides and swells during storm surges. Dry surface sand is mobile. Plants can be damaged by sand blast, roots are sometimes exposed, and shoots frequently are buried by shifting sand, pushed by strong winds. To move sand grains, wind speed must be at least four meters per second.
Beach sand has a low capacitance to retain water and is nutrient-poor, with little organic matter.
Surface sand, which experiences rapid wet-dry episodes, is a stressful environment for plant roots. Deep sands may remain moist, receiving and storing water while the surface sand stays dry much of the time. Roots and rhizomes can penetrate sand rapidly, in comparison with growth within heavy soils having clay. Ecologists have often recognized, and sometimes attempted to name and characterize, zonation of the shoreline sandy habitats for land plants. Obviously, the zones are not sharply defined, because some species appear in both subcommunities.