VEGETATION OF MOTORWAY VERGES - INFLUENCE OF EXTENSIVE MANAGEMENT ANDADJACENT HABITATS

In order to assess the functional relations between a linear and artif icial structure - motorways and adjacent habitats, species richness an d plant communities of motorway verges were compared to three differen t habitats. Motorway verges are managed extensively in order to favour spontaneous dynamics of vegetation. Species richness of motorway verg es is independent of adjacent habitat richness and is positively corre lated with width. Verges are more diversified than adjacent habitat wh en the latter is impoverished by human use. In all cases studied, verg es are colonized by native vegetation, which seems favourable to the c onnectedness of verges (disrupted at the building) with adjacent habit ats. Nevertheless some differences in flora existed, especially becaus e of verge management (mowing regime) and structure, identical in all sites. It seems possible to manage motorway verges in order to maintai n or restore ecological functions in a landscape, like corridor or hab itat, which will have to be verified with data on fauna.