Identifying important areas for connectivity today and into the future: a spatial synthesis

Abstract Context Promoting landscape connectivity to support species movement has long been a key conservation strategy, one that is increasingly important as species move to track shifting climatic conditions. Connectivity modelers have developed a multitude of methods to identify important areas for providing connectivity in general or connectivity specifically to address climate change, and each resulting map has its own assumptions, uncertainties, and targets. Making decisions and conducting spatial planning with such diverse and often contradictory maps poses a significant challenge. Objectives Our objective was to synthesize both climate-connectivity and non-climate connectivity studies to identify areas of joint importance. Specifically, we 1) identified areas of agreement among climate connectivity maps, 2) identified areas of agreement among non-climate connectivity maps, and 3) identified areas jointly prioritized by both climate- and non-climate connectivity maps that may help species move both in the present and as the climate changes. We also asked secondary questions regarding the spatial distribution of mapping efforts, and whether climate- and non-climate connectivity maps are correlated with patterns of elevation and human modification in the region. Methods We reviewed 103 connectivity maps across far western North America, categorizing them by methodological approach, connectivity target, and whether they addressed climate-driven movements. We generated synthesis maps of these connectivity maps to highlight areas with little coverage, and identify regions of agreement and divergence. We also evaluated the relationship between connectivity, elevation, and human modification. Results Our main results are our synthesis maps, which provide spatially explicit metrics of connectivity modeling effort and agreement across the region. We found large variations in connectivity modeling effort, systematic patterns of agreement and divergence between climate- and non-climate-connectivity analyses, and associations between connectivity scores, elevation, and human modification. Conclusions Our approach helps ecologists and conservation planners draw insights from increasing numbers of connectivity analyses. The areas of agreement we identify suggest places for conservation investments that support connectivity in the present and into a dynamic future.