Connectivity of grassland habitats and rodent outbreaks

The common vole is a grassland rodent whose populations exhibit periodic population booms. Habitat connectivity - in the case of a species whose overabundance poses a problem - and the spatial mechanisms involved were studied by modelling the landscape using graph theory, as part of the Graphab project on the impact of major infrastructure on habitat connectivity. The landscape graph consists of grassland patches to which specific data - in this case, rodent density derived from field surveys - have been incorporated. The links between patches are described in various ways. Groups of patches that are spatially connected and exhibit demographic synchrony were identified, and could be linked to the areas where outbreaks originate and spread; however, this did not allow for precise zoning of local authorities, which would have made monitoring outbreaks more effective. This document is intended for biologists and ecologists, as well as geographers and researchers in network modelling, whether ecological or in any other field.