Genetic monitoring of connectivity, diversity and adaptive potential

In a rapidly changing world, adaptation to novel conditions is necessary to ensure population persistence. To ensure conservation of insects and the ecosystem services they supply, maintaining their adaptive potential is pivotal. Within-population genetic variation is the substrate for adaptation. However, we know little of how loss of genetic variation and adaptive potential is affected by on-going fragmentation of landscapes. It has been suggested that green infrastructure may alleviate fragmentation problem, but how it actually affects dispersal and thus gene flow between habitat patches is poorly known. For instance, rare long-distance dispersal may be critical for maintaining genetic variation, but is hard to monitor without genetic techniques. Here we apply genetic approaches to investigate under what conditions genetic variation is eroded, using butterflies dependent on seminatural grasslands as a study system, focussing on the Polyommatini clade including both common and threatened species. We use landscapes where semi-natural grasslands are fragmented to different degrees. Landscape genetic analyses are used to address how functional distance, reflecting separation taking the differences in matrix permeability into account, affects isolation. The overall aims are 1) to evaluate the effect of green infrastructure in the habitat matrix on butterfly genetic diversity, and 2) to develop guidelines for investigating reductions in genetic diversity in insect species.