Vulnerability of Lower-Elevation Aspen Forests to Altered Fire and Climate Dynamics: Assessing Risks and Developing Actionable Science

Aspen forests are considered keystone ecosystems, meaning that loss of aspen habitat would result in negative impacts to numerous plant and animal species. Aspen also provide important economic and social benefits, including drawing tourists, serving as potential fire breaks, improving local economies, and providing forage for wildlife and livestock. Ecologically-valuable aspen forests are considered at risk in many areas of the western U.S., but especially in lower-elevation areas. Risks to aspen include climate-change and past land use. The effects of drought and browsing animals (that eat young aspen) are often more severe for lower-elevation aspen and can threaten aspen forest health and long-term persistence. In the northern Great Basin, lower-elevation aspen often grow as small, isolated patches within sagebrush-dominated landscapes. These sagebrush shrublands are increasingly being transformed into grasslands that are composed of exotic, fire-prone plant species not native to North America. Although aspen is a fire-adapted species, if fire is too frequent at low elevations it could negatively affect aspen survival, especially when combined with impacts from exotic plants, worsening droughts, or other stresses, such as insects and disease.  

The intent of this research is to investigate how these changing disturbance and climate conditions, like drought, are affecting lower-elevation aspen forests in the northern Great Basin. To accomplish this, the research team will use a combination of field sampling, geographic analysis, remote sensing, and statistical modeling. The primary outcomes of this project will be a regional assessment of where and under what conditions lower-elevation aspen are most vulnerable to undesirable ecological change, like potential decline in forest health. The tools and information from this research will have direct and timely uses for land managers working to conserve aspen forests in the Great Basin and surrounding regions.