From range retraction to population cycling: How spatially-explicit demographic models can inform climate change vulnerability

English Abstract:

Adaptation to climate change requires understanding species vulnerabilities in terms of demographic sensitivity and exposure to climatic and other environmental factors across full life cycles and in diverse landscapes. As part of an ongoing project, we present findings from two case studies using spatially-explicit demographic modeling to assess the vulnerability of Eastern Massasauga Rattlesnake (Sistrurus catenatus) and Ruffed Grouse (Bonasa umbellus) to climate change in the upper Midwest and Great Lakes region of the United States. Results from multiple survival and reproductive success studies were used to identify demographic sensitivities to several climatic and land use factors. We then used these relationships to parameterize demographic simulations with dynamic climate and land use from 1960 to 2012, and evaluated the resulting population models by comparison to long-term and spatially extensive monitoring datasets. Our modeling framework is implemented in a region showing marked variation in habitat connectivity and climatic conditions; allowing for a quantitative assessment of the relative influence of these factors on long-term population dynamics and geographic distributions. We highlight several important findings demonstrating the role of climate and land use on long-term range contraction in massasauga rattlesnakes and altered dynamics of population cycling in ruffed grouse. Both analyses are critical examples of the role of variation in temperature and precipitation extremes, synergistic effect of climate and land use change, and the importance of considering the full life cycle of vulnerable species. Climate change vulnerability assessment provides a framework for linking demographic and distributional dynamics to environmental change, and can provide unique information for conservation planning.