It is the habitat of the first embryonic dunes, it forms further inside habitat 1210, where the action of winter storms is less severe. the wind accumulates sand behind the tufts of vegetation forming small embryonic dunes, but its strength and the scarcity of vegetation lead to the movement of the accumulations.
Due to the lack of sand supply during bora storms (dry wind blowing from the NE) due to the presence of the port mouth, high dunes do not form in San Nicolò and this means that the habitat of the embryonic dunes does not come into contact with the usual habitat of the white dunes of Ammophila (Ammophila arenaria), but extends to the retrodune habitats of the sileno-vulpieto and the tortulo-scabioseto. Due to an insufficient supply of sand, ammophila is found only with a few isolated tufts, while its place is increasingly taken by spartina (Spartina versicolor), which forms pure and compact populations even on flat soils and in the absence of sand supply.