Dispersal is crucial in structuring species distribution, population structure and species ranges at large geographical scales or within local patchily distributed populations. The knowledge of dispersal evolution, motivation, its effect on metapopulation dynamics and species distribution at multiple scales is poorly understood and many questions remain unsolved or require empirical verification. In this thesis we contribute to the knowledge of dispersal, by studying both ecological and evolutionary aspects of spider dispersal in fragmented grey dunes. Studies were performed at the individual, population and assemblage level and indicate that behavioural traits narrowly linked to dispersal, considerably show [adaptive] variation in function of habitat quality and geometry. Dispersal also determines spider distribution patterns and metapopulation dynamics. Consequently, our results stress the need to integrate knowledge on behavioural ecology within the study of ecological landscapes.