Evaluating connectivity metrics for biodiversity conservation

Habitat fragmentation threatens biodiversity by disrupting ecological connectivity. To support conservation planning, we evaluate which spatial connectivity metrics best predict species occurrence. We do so by comparing six common connectivity metrics as predictors of occurrence patterns of three red-listed species in the Dutch River Area. Our results show that simple metrics, and particularly total habitat area, outperform more complex metrics like graph-based indices. Notably, woody linear elements such as hedgerows, which are central to current Dutch policies aiming for 10% ‘green-blue connectivity’, show no consistent effect. These findings suggest that conservation efforts should likely prioritize increasing habitat area, while reconsidering connectivity metrics that show limited ecological effect.