††Universidade Federal do Rio

This paper describes the vegetation zonation and its relationship with dune local morphology through the application of a randomization test on some sandy ecosystems of the Italian Mediterranean coast. We postulate that the slope and the aspect of sand dunes are essential variables in the analysis of a correct plant community position along the sea–inland vegetation gradient. This study presents an analysis of coastal vegetation zonation in some of the best preserved sites of the Lazio coast (central Italy). Analysis of variance with randomization testing was performed in order to establish whether community differences are related to slope and aspect. Results from vegetation transects showed that complete community sequence is lacking in the study area. Although some community types are very common and widespread, others are rare and only restricted to areas with well-preserved dune ridges. Regarding slope/aspect, the randomization test shows that only community types located in both extremes of the vegetation zonation revealed significant differences while no differences were found for rare or heavily disturbed communities