Validation of ecological connectivity model predictions in urban areas: replicated landscape genetic study on the land snail Cornu aspersum
Résumé
Dispersal plays a major role in many ecological and evolutionary processes. Facilitating dispersal movements, by promoting ecological connectivity (the degree to which the land-scape facilitates or impedes movement among resource patches) is considered as a major
conservation issue, notably in urban landscapes (expanding strongly impervious and characterized by extreme fragmentation degrees). Functional connectivity can be predicted by modelling techniques such as least-cost path analysis and circuit theory based on resistance
maps reecting the cost to move for an organism though di erent habitat types. We propose to validate predictions of these two methods with analysis of population genetic structure which reects the movement of genes or individuals among populations.
The studied species is the land snail, Cornu aspersum, common in urban landscape and characterized by spatially-restricted dispersal. The energetic cost of movement being extremely high in terrestrial molluscs, we hypothesize that functional connectivity (integrating habitat
type suitability) will be a good predictor of genetic distances between populations.