Abstract
The proposition that the migration of organisms between habitat patches could be enhanced by corridors has been much discussed among conservation biologists. But the few experimental studies supporting the usefulness of corridors have all concerned animal species. We investigated the role of corridors in seed dispersal, studying population genetic and demographic structure in metapopulations of the rare, pond‐dwelling, autogamous plant species Ranunculus nodiflorus L. in the Fontainebleau Forest ( France ). Differentiation on three polymorphic isozyme markers was strong among local populations ( ponds ) within metapopulations ( sites ) and moderate among metapopulations. Partial Mantel tests revealed that the connection of ponds through temporarily flooded natural corridors, facilitating seed migration, had a strong negative effect on genetic differentiation between local populations and that a pond was more likely to be colonized when connected by corridors to other occupied ponds. Thus, corridors are probably a key element of landscape structure for metapopulation dynamics in R. nodiflorus. From a conservation perspective, our results suggest that corridors could increase the chance of persistence of plant species living in fragmented habitats by promoting seed dispersal between habitat patches.