Joint model inference to support RAD-based decision making for aspen management in a changing climate

Quaking aspen is a keystone species in the U.S. Rocky Mountains, and maintaining or increasing aspen cover has been identified as a management priority throughout the region. Management efforts may benefit from knowledge of when and where treatments aimed at reducing conifer competition may promote aspen persistence in the context of ongoing climate change, and where post-treatment climate will limit long-term treatment effectiveness. We use a joint modeling approach to model the covarying canopy cover of aspen and conifers across the Greys River Ranger District in the Greater Yellowstone Ecosystem. We then project cover under future climate, both including and excluding a potential conifer competitor. We apply the resist-accept-direct framework in a modeling context to inform aspen treatment prioritization. Results suggest that warming winter temperatures have the potential to reduce aspen extent and cover, yet resist approaches (e.g., conifer removal) may support aspen persistence in select portions of the landscape. Model projections indicate the potential for aspen to migrate upslope as climate warming progresses, providing opportunities to implement direct approaches to facilitate this shift. Acceptance of aspen loss may be inevitable in areas projected to become climatically unsuitable, but uncertainty in long-term forecasts will require flexible and adaptive management.