Diffusion of forest carabid beetles in hedgerow network landscapes

Summary

Hedgerows interconnected in a network and connected to woods characterize the “bocage”, rural landscapes of western France.

Local populations of forest carabid species are present in hedgerows even far from a source forest. If exchanges of individuals occur between these populations, this would indicate a control at the landscape level, characteristic of the meta-population dynamics. By mark-recapture experiments, we have shown that local populations settle in nodes of the hedgerow network, either small woods or intersections of lanes bordered by parallel hedgerows. We tested the existence of dispersers using hedgerows as corridor by using the same mark-recapture technique all along hedgerows connecting two woods. Preliminary results indicate that individuals living in hedgerows are at low density and show a high intensity of movement compared to individuals living in woods or nodes of the network. Some woods are occupied and some are vacant. We propose a hypothetical representation of population dynamics of forest carabid beetles in the “bocage”.