Poster, IBS 2015 - 7th International Conference of the International Biogeography Society, University of Bayreuth: 08.01.2015 - 12.01.2015
Corynephorus canescens is a short-lived grass species, specialised on scattered and disturbance-dependent sandy habitats. Its distribution includes Atlantic regions of Western and Central Europe, but not the two other classical European glacial refuge regions (Appenine and Balkan Peninsulas). Decreasing genetic diversity from SW to NE and distinct gene pool clustering (AFLP variation among 49 populations) imply glacial refugia on the Iberian Peninsula and in western France and post-glacial range expansion towards NE Europe. High genetic diversity within and moderate differentiation among populations, and a significant isolation-by-distance pattern indicate a gene flow-drift-equilibrium within C. canescens, probably due to its restriction to scattered and dynamic habitats and limited dispersal distances. These features and the re-colonisation history significantly affected genetic diversity gradients from central to marginal populations, emphasizing the need for including the specific ecology and species histories into such analyses. To account for discontinuous distributions, new indices of marginality were tested for their suitability for studies of centre-periphery gradients.