GASTROPOD COMMUNITIES, VEGETATION DYNAMICS AND LANDSCAPE CHANGES ALONG AN OLD-FIELD SUCCESSION IN PROVENCE, FRANCE

Studies about the relationships between land snail communities and landscape are scarce. The abandonment of many cultivated lands in Provence since the end of the last century gives us the opportunity of an analysis of the organisation pattern of gastropod communities in relation to the recent history and the present day structure of a Mediterranean landscape. The dynamics of a 40 ha landscape, mapped on a raster mode, was studied using cadaster data for seven periods between 1890 and 1990. These data were computed using MCA and PCA. Both floristic and malacological releves were made at a scale of one grid cell. At the stand level, the patterns of gastropod communities are strongly correlated with the vegetation structure and composition. At the landscape level, the analysis of gastropod communities permits a very good perception of the present day landscape structure, as well as insight into the recent landscape history. However, even if the fits obtained are good, they should be improved in order to take into account scale dependences of snail communities.