Configurational heterogeneity drives songbird diversity at distinct spatial scales in managed boreal forests

Parsing scale-dependent responses of wildlife communities to mosaic landscapes is key to evaluating conservation outcomes of natural resource development.

We evaluate how spatial heterogeneity of harvest plans and oil and gas activity influence local boreal songbird species richness at ecologically relevant spatial extents.

We implemented a multi-scale framework by varying extents at which species richness and landscape configuration metrics are measured. Birds were surveyed with Passive Acoustic Monitoring (PAM) in harvest plots across forested zones of Alberta, Canada, and species richness counted at 13 increasingly broad extents. For five configuration metrics, multiple landscape extents were compared to identify scale of effects unique to each response extent.

Four of five metrics converged on a domain boundary at 11-14 ha. Below this threshold, within-harvest heterogeneity indexing linear features and residual retention-edge density and Shannon diversity-drove species richness. Above it, mosaic configuration metrics (patch size variation, shape complexity) became influential alongside edge density and Shannon diversity. No single landscape extent was associated with species richness across response extents.

Effects of landscape heterogeneity on songbird diversity at within-harvest and mosaic scales can be detected from individual PAM surveys when survey extent is appropriately constrained. Empirically identifying the spatial extents at which community diversity responds to configuration allows forest planners to match monitoring design and management actions to the scale at which they will have the greatest effect.

The online version contains supplementary material available at 10.1007/s10980-026-02341-y.