Using landscape graphs to assess the ecological relevance of biodiversity conservation plans for forest habitat networks

Conservation measures integrated into planning documents are designed for the protection and management of natural habitats. They are part of planning strategies for maintaining biodiversity and the functional connectivity of habitat networks. However, spatial planning strategies need to consider a wide range of socio-economic requirements in addition to biodiversity issues. This leads to a mismatch between the planning documents emerging from stakeholders’ discussions and the most ecologically relevant conservation strategies for habitat networks. Here, we use a generic spatial modelling approach based on landscape graphs to model forest habitat networks in four areas matching the boundaries of French inter-municipal planning instruments (SCoTs). This enables us to consistently compare our modelling outputs with the habitat networks defined in the corresponding planning documents, for a representative set of ecological profiles. Independently, we assess ecological connectivity using metrics focusing on several key components of habitat connectivity, i.e., habitat patch area, inter-patch dispersal, and network traversability. Our results reveal both similarities and differences among SCoTs in the way they map and conserve habitat networks for different species profiles. The SCoTs differed particularly in the importance accorded to each component of habitat connectivity, although the metric related to habitat area was overall well accounted for. Our connectivity modelling framework provides a testing ground to support decision-making when mapping spatial habitat networks for biodiversity conservation and land-use planning.