Canopy cover has divergent effects on movement of closely related bumble bees in managed conifer forest landscapes

Abstract Context Functional connectivity—the degree to which landscape features facilitate or impede movement among resource patches—affects animal survival, health, and ability to cope with environmental changes. This is particularly important in heterogeneous landscapes prone to rapid change, such as intensively managed forests. Objectives We aimed to quantify the effects of forest canopy cover and roads on foraging movement of two closely related bumble bee species ( Bombus vosnesenskii and Bombus caliginosus ) in coniferous forest landscapes intensively managed for timber. We also assessed whether early seral forest configuration predicted site-level colony abundance for each species. Methods We sampled bumble bees and surveyed floral resources in 75 sites in three study landscapes in the central Oregon Coast Range. We modeled the effects of forest canopy cover and secondary road cover on foraging range using a genetic capture-recapture approach and modeled colony abundance as a function of site-level structural connectivity of early seral forest. Results We found evidence that canopy cover impeded foraging movement of B. vosnesenskii but not of B. caliginosus . Roads had neutral or inhibitory effects on B. vosnesenskii movement depending on the landscape but only inhibitory effects on B. caliginosus movement. Colony abundance was not related to site-level connectivity for either species. Conclusions Our study demonstrates that landscape features can have divergent effects on space use of even closely related taxa and that site-level response variables may not always reflect functional connectivity. Management of early seral forest habitats should consider not only patch quality but also configuration and species-specific permeability of matrix features.