How dispersal promotes biodiversity in the face of global change

Romain Lorrillière (1), Luc Doyen (2) and Frédéric Jiguet (1)


1 CESCO, UMR 7204 MNHN-CNRS-UPMC, 55 Rue Buffon, 75005 Paris,

2 CNRS-GREThA, University of Bordeaux, avenue Léon Duguit, Pessac,

1 CESCO, UMR 7204 MNHN-CNRS-UPMC, 55 Rue Buffon, 75005 Paris,

Global change induce biodiversity modifications, including polewards range shifts and declines in abundance, particularly for specialist species. We investigated how dispersal rates influence species viability. We proposed a multi-species (37 bird species; farmland species and generalist species) and meta-population model (French scale). For each species, this model estimated the values of dispersal rates. The inclusion of these species with the abundances of neighbouring populations significantly improved the model in comparison with models that only included environmental variables. We found a trade-off between the risk of failing to find a suitable habitat and the need to disperse to these habitats. In terms of meta- population trends, an important consequence of this trade-off was that the dispersal rate had no influence on specialists’ population trends, whereas there was a positive correlation for generalists. Using large-scale empirical data, this original study showed how dispersal promoted species viability, and how specialization restricted this capacity.

Keyword:    Biodiversity,    Land-use,    climate,    meta-population,    dispersal,    viability, specialization, birds