Human impact is often over-simplified in paleoenvironmental studies related to the Holocene period. Several contradictions can be highlighted in the Mediterranean area. For instance: a great density of archaeological sites on one hand and a reversible and moderate human impact at least until Antiquity on another hand; or a discrepancy between simple paleoecological models and complex current ecosystems. In order to better characterize this human impact during the Holocene period in southern France (where human impact is ancient and vegetation very sensitive to disturbances), the indicator chosen for this study is land snail assemblages. Land-snails are theoretically good indicators of human impact because they are dependent on the structure of vegetation and landscape, both of which are affected by human activities (farming and pasture). The reliability of land snail assemblages to reconstruct human impact was tested by the observation of current landscapes: 1) on a spatial scale, assemblages have a fine resolution and they precisely characterize vegetation changes. It is thus possible to record local environmental variations; 2) on a temporal scale, they correctly record human disturbances; the buried land snail assemblages are well stratified in soil. They show that, during the Holocene, the landscapes of calcareous Provence and Eastern Languedoc were influenced early by human impact. The local variations related to particular land-use changes from one site to another are more important than the linear change in landscape structure. Human presence is also largely responsible for expansion of Mediterranean species. Land snails are not relevant to detect climatic variations during the Holocene period because climatic impacts on vegetation structure are smaller than those related to human activites.
