Résumé
Aim: A common pattern in biogeography is the scale-dependent effect of
environmental variables on the spatial distribution of species. We tested
the role of climatic and land cover variables in structuring the
distribution of genetic variation in the grey long-eared bat, Plecotus
austriacus, across spatial scales. Although landscape genetics has been
widely used to describe spatial patterns of gene flow in a variety of
taxa, volant animals have generally been neglected because of their
perceived high dispersal potential.Location: England and Europe. Methods:
We used a multiscale integrated approach, combining population genetics
with species distribution modelling and geographical information under a
causal modelling framework, to identify landscape barriers to gene flow
and their effect on population structure and conservation status.
Genotyping involved 23 polymorphic microsatellites and 259 samples from
across the species' range. Results: We identified distinct population
structure shaped by geographical barriers and evidence of population
fragmentation at the northern edge of the range. Habitat suitability (as
captured by species distribution models, SDMs) was the most important
landscape variable affecting genetic connectivity at the broad spatial
scale, while at the fine scale, lowland unimproved grasslands, the main
foraging habitat of P. austriacus, played a pivotal role in promoting
genetic connectivity. Main conclusions: The importance of lowland
unimproved grasslands in determining the biogeography and genetic
connectivity in P. austriacus highlights the importance of their
conservation as part of a wider landscape management for fragmented edge
populations. This study illustrates the value of using SDMs in landscape
genetics and highlights the need for multiscale approaches when studying
genetic connectivity in volant animals or taxa with similar dispersal
abilities.