Strategies for identifying priority areas for songbird conservation in Canada’s boreal forest

摘要

Canada’s boreal forest region is among the most extensive and largely intact ecosystems on earth, but has experienced rapid industrial development in the last half-century. Calls for urgent conservation action have been prompted by the increasing pace of development and declines in biodiversity, including songbirds. To assist conservation decision making, we introduce a framework to facilitate selection of the highest priority areas for a given conservation objective. We varied six key decision points representing possible constraints or a priori conservation factors: (1) prioritization metric (species representation vs. diversity), (2) geographic stratification, (3) degree of anthropogenic disturbance, (4) species’ conservation status, (5) species’ ecological association, and (6) climate-change and uncertainty discounting. Using the Zonation conservation planning tool, we evaluated landbird conservation priorities across 128 scenarios for 63 passerine species based on current and projected future density predictions. We compared Zonation land rankings across scenarios with respect to consistency, efficiency (additive and proportional conservation value per unit area), and the relative contributions of each of the six factors of interest. We found large differences between solutions depending on constraints and conservation objectives, and relatively low conservation efficiency overall, with the largest gains in overall conservation value observed in areas ranging from 0.31–0.56 of the study region. This reflects the large range of conservation opportunities still present in the Canadian boreal region, and the widely dispersed nature of landbird distributions, which results in high substitutability among similar areas. However, we did find increasing consistency among solutions as multiple constraints were considered. In particular, stratifying solutions geographically resulted in more consistent priorities, although at the expense of efficiency. Other constraints, including climate change, disturbance- and uncertainty-discounting, and the selection and weighting of species, helped to further focus priorities. Although no single scenario can be viewed as prescriptive, we provide a roadmap for prioritizing boreal songbird conservation efforts across multiple conservation objectives.