Canadian Forest Service Publications
Maintaining animal species assemblages through single-species management: the case of threatened caribou in boreal forest. 2016. Bichet, O.; Dupuch, A.; Hébert, C.; LeBorgne, H.; Fortin, D. Ecol. Appl. 26:612-623.
Issued by: Laurentian Forestry Centre
Catalog ID: 36213
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With the intensification of human activities, preserving animal populations is a contemporary challenge of critical importance. In this context, the umbrella species concept is appealing because preserving a single species should result in the protection of multiple co-occurring species. Practitioners, though, face the task of having to find suitable umbrellas to develop single-species management guidelines. In North America, boreal forests must be managed to facilitate the recovery of the threatened boreal caribou (Rangifer tarandus). Yet, the effect of caribou conservation on co-occurring animal species remains poorly documented. We tested if boreal caribou can constitute an effective umbrella for boreal fauna. Birds, small mammals, and insects were sampled along gradients of post-harvest and post-fire forest succession. Predictive models of occupancy were developed from the responses of 95 species to characteristics of forest stands and their surroundings. We then assessed the similarity of species occupancy expected between simulated harvested landscapes and a 90 000-km2 uncut landscape. Managed landscapes were simulated based on three levels of disturbance, two timber-harvest rotation cycles, and dispersed or aggregated cut-blocks. We found that management guidelines that were more likely to maintain caribou populations should also better preserve animal assemblages. Relative to fragmentation or harvest cycle, we detected a stronger effect of habitat loss on species assemblages. Disturbing 22%, 35%, and 45% of the landscape should result, respectively, in 80%, 60%, and 40% probability for caribou populations to be sustainable; in turn, this should result in regional species assemblages with Jaccard similarity indices of 0.86, 0.79, and 0.74, respectively, relative to the uncut landscape. Our study thus demonstrates the value of single-species management for animal conservation. Our quantitative approach allows for the evaluation of management guidelines prior to implementation, thereby providing a tool for establishing suitable compromises between economic and environmental sustainability of human activities.
Plain Language Summary
This study tested the “umbrella species” concept whereby one sensitive species is protected in order to protect hundreds of other species. To do so, the researchers studied how the implementation of the woodland caribou recovery plan in the boreal forest could protect all of the animal communities.
They found that a management plan for maintaining caribou herds effectively preserved animal communities and thus the integrity of the boreal forest. By extending the tree cutting interval (cutting cycle) and decreasing the removal rate (percentage of logged area), it is possible to maintain animal communities more effectively.
The researchers collected samples of bird, insect and small mammal species in forests of various ages originating from fire or logging. They created an area occupancy model for 95 animal species within a landscape of 90,000 km2. They also measured resemblances between animal communities following the implementation of various forest logging scenarios based on the caribou recovery plan.