Foredune psammophilous communities and coastal erosion in a stretch of the Ligurian sea (Tuscany, Italy)

Italy sandy coasts are characterised by a great diversity of habitats and, at the same time, many of these coastal stretches are in erosive condition. Therefore, it is important to understand, in areas where marine erosion is particularly strong, which are the most vulnerable and most threatened habitats. The paper sets out data from the survey of foredune habitats (annual vegetation of drift lines, embryonic dunes, mediterranean white dunes, sensu Directive 92/43/EEC) in the San Rossore Estate sandy coast (Northern Tuscany, Italy) strongly subjected to erosion. The surveys, in addition to updating the information collected, aim to point out the arrangement of these habitats in relation to coastal retrogradation and foredune erosion, in order to identify appropriate management tools for mitigating disturbance factors. The surveys, conducted in the field and by photo-interpretation, revealed the presence of foredune plant communities hardly referable, from the phytosociological point of view, to known associations of neighboring coasts. The Cakile maritima plant communities of annual vegetation of drift lines, the Elymus farctus/ Othantus maritimus phytocoenosis of embryonic dune and the Ammophila arenaria/Euphorbia paralias communities of white dunes, are markedly altered in their floristic composition; the coverage and distribution of the different plant communities are in a highly differentiated manner according to erosion gradients. The understanding of dynamics of alteration of psammophilous plant communities in relation to coastal erosion may suggest potential aid in the management actions aimed at containing the transformations or and/or useful for the restoration of the same habitats