Projecting the Effects of Climate Change on Aspen in the Central and Northern Rocky Mountains Completed

Aspen is an environmentally, economically, and socially important species in the western U.S. It is typically the most abundant deciduous tree species in mountainous landscapes of the western U.S., providing food and habitat for a variety of wildlife, including black bear, deer, elk, moose, and numerous bird species. Aspen woodlands also provide high quality forage for livestock and draw tourists to the region to view the golden vistas that form in the fall.

 

However, aspen is currently declining across large portions of the West and it’s estimated that approximately 40% of western aspen will be without suitable climate conditions within 50 years. In the northern and central Rocky Mountains, it’s thought that reduced soil moisture and changing fire patterns in particular could affect the trees. Yet understanding the future of aspen in the region is currently challenged by a lack of information on how changes in fire and soil moisture interact to impact aspen growth, survival, and distribution. For example, in some places aspen may thrive following fire if soil moisture is adequate, while they may decline in areas where soil moisture is too low.



The goal of this work was to project the likely effects of altered moisture and fire regimes on aspen under climate change. Based on the results, researchers sought to develop maps of future aspen distribution in the northern and central Rocky Mountains and identify areas that could be suitable for aspen restoration. Additionally, researchers aimed to project how climate change and aspen mortality might alter streamflow in watersheds that have large amounts of snow redistribution, in order to help small-scale irrigators adapt to future conditions. The results of this project were expected to help land managers prioritize areas for aspen protection and restoration and proactively plan for the effects of climate change on this important species.