2.4 The sandy shore
The sandy coastline is a flat expanse of rock grains and broken minerals (FIG1_SES2.4), made of cordons of dunes apparently with no life.
In reality, this kind of environment is teeming with vegetation able to survive in dry
conditions and organisms hidden in the sand, from which they only emerge to breath and get food.
The coastal environment is a dynamic ecosystem in which natural processes and anthropic ones interact modifying their geomorphological, physical and biological characteristics, so the sandy coasts are the most vulnerable territories. The continuous movement of sediments by the sea (currents, tides, waves, storms) changes coastal territories and bring to new settlements of the shore line. The action of the sea is opposed by the river supply of detrital material, reused for the natural reconsolidation of sandy coasts. Coastal areas are the territories most occupied by urban settlements and economic and productive human activities; in the lasts decades the high density of population and activity has increased the coastal evolutionary processes, for example erosive ones.
The sandy shore (FIG2_SES2.4) is an “extreme environment.” The wind carries small droplets of sea water and large quantities of tiny grains of sand creating an “aerosol” that covers all that meets, such as the branches and the leaves of the plants. In addition to this, there is the loss of rainwater and the mineral nutrients that are not retained by the sand and the intense evaporation caused by the sun and the wind, so the sandy soil and subsoil are very dry.