The role of natural vegetation in the analysis of the spatio-temporal changes of coastal dune system: a case study in Sicily

The coastal dunes of the Mediterranean area are among the most vulnerable and seriously threatened ecosystems due to human activities. Habitat fragmentation is generally considered as one of the most influential factors in biodiversity loss. In this paper, we investigated the temporal and spatial changes in the floristic composition and abundance in sand dunes along a coastal strip of Sicily (Italy). Six transects perpendicular to the coastal line were selected in southern Sicily. For each transect, the floristic composition and cover of the species were determined using standard relev, methods. A total of 186 plots were collected. The plots data was analyzed using classification (UPGMA, Chord coefficient) and ordination methods (Detrended Correspondence Analysis). A total of 14 plant communities with specific floristic composition were established, belonging mainly to six habitats. To evaluate the reduction of the habitats of the complex dune system in the last 70 years, aerial photos from 1938 to 2007 have been used and elaborated with ArcGis 10.3. The cartographic analysis shows a radical transformation of the Macconi dune system with a reduction of the dune habitats. In particular, the results show a strong reduction/loss of habitats (2250, 2210 and 2120 EU code) as well as a strong alteration of the ecological succession of the psammophilous vegetation. Moreover, floristic richness and diversity index showed an increased trend from the coastal line towards inner dunal zone.