Data from: Spatial heterogeneity in landscape structure influences dispersal and genetic structure: empirical evidence from a grasshopper in an agricultural landscape

Dispersal may be strongly influenced by landscape and habitat
characteristics that could either enhance or restrict movements of
organisms. Therefore, spatial heterogeneity in landscape structure could
influence gene flow and the spatial structure of populations. In the past
decades, agricultural intensification has led to the reduction in
grassland surfaces, their fragmentation and intensification. As these
changes are not homogeneously distributed in landscapes, they have
resulted in spatial heterogeneity with generally less intensified hedged
farmland areas remaining alongside streams and rivers. In this study, we
assessed spatial pattern of abundance and population genetic structure of
a flightless grasshopper species, Pezotettix giornae, based on the surveys
of 363 grasslands in a 430-km² agricultural landscape of western France.
Data were analysed using geostatistics and landscape genetics based on
microsatellites markers and computer simulations. Results suggested that
small-scale intense dispersal allows this species to survive in intensive
agricultural landscapes. A complex spatial genetic structure related to
landscape and habitat characteristics was also detected. Two P. giornae
genetic clusters bisected by a linear hedged farmland were inferred from
clustering analyses. This linear hedged farmland was characterized by high
hedgerow and grassland density as well as higher grassland temporal
stability that were suspected to slow down dispersal. Computer simulations
demonstrated that a linear-shaped landscape feature limiting dispersal
could be detected as a barrier to gene flow and generate the observed
genetic pattern. This study illustrates the relevance of using computer
simulations to test hypotheses in landscape genetics studies.