United States Department of Agriculture Climate Change Vulnerability and Adaptation in the Intermountain Region Part 2 Forest Rocky Mountain General Technical Report Service Research Station RMRS-GTR-375 April 2018 Halofsky, Jessica E.; Peterson, David L.; Ho, Joanne J.; Little, Natalie, J.; Joyce, Linda A., eds. 2018. Climate change vulnerability and adaptation in the Intermountain Region. Gen. Tech. Rep. RMRS-GTR-375. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. Part 2. pp. 199–513. Abstract The Intermountain Adaptation Partnership (IAP) identified climate change issues relevant to resource management on Federal lands in Nevada, Utah, southern Idaho, eastern California and western Wyoming, and developed solutions intended to minimize negative effects of climate change and facilitate transition of diverse ecosystems to a warmer climate. U.S. Department of Agriculture Forest Service scientists, Federal resource managers, and stakeholders collaborated over a 2-year period to conduct a state-of-science climate change vulnerability assessment and develop adaptation options for Federal lands. The vulnerability assessment emphasized key resource areas—water, fisheries, vegetation and disturbance, wildlife, recreation, infrastructure, cultural heritage, and ecosystem services—regarded as the most important for ecosystems and human communities. The earliest and most profound effects of climate change are expected for water resources, the result of declining snowpacks causing higher peak winter streamflows, lower summer flows, and higher stream temperatures.These changes will in turn reduce fish habitat for cold-water fish species, negatively fectaf riparian vegetation and wildlife, damage roads and other infrastructure, and reduce reliable water supplies for communities. Increased frequency and magnitude of disturbances (drought, insect outbreaks, wildfire) will reduce the area of mature forest, affect wildlife populations (some positively, some negatively), damage infrastructure and cultural resources, degrade the quality of municipal water supplies, and reduce carbon sequestration. Climate change effects on recreation, a major economic driver in the IAP region, will be positive for warm-weather activities and negative for snow-based activities. IAP participants developed adaptation options that can be implemented in planning, project management, monitoring, and restoration as climate-smart responses to altered resource conditions. Keywords: adaptation, climate change, ecological disturbance, Intermountain Adaptation Partnership, resilience, science-management partnership, vulnerability assessment Front cover photo: top: Hiking trail near Lake Mary dam and reservoir, Uinta-Wasatch-Cache National Forest, photo U.S. Forest Service. All Rocky Mountain Research Station publications are published by U.S. Forest Service employees and are in the public domain and available at no cost. Even though U.S. Forest Service publications are not copyrighted, they are formatted according to U.S. Department of Agriculture standards and research findings and formatting cannot be altered in reprints. Altering content or formatting, including the cover and title page, is strictly prohibited. Editors Jessica E. Halofsky is a Research Ecologist with the University of Washington, College of the Environment, School of Environmental and Forest Sciences in Seattle, Washington. David L. Peterson was a Senior Research Biologist Scientist with the U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station in Seattle, Washington. Joanne J. Ho is a Research Environmental Economist with the University of Washington, College of the Environment, School of Environmental and Forest Sciences in Seattle, Washington. Natalie J. Little is the Regional Sustainability and Climate Coordinator, U.S. Department of Agriculture, Forest Service, Intermountain Region in Ogden, Utah. Linda A. Joyce is a Research Ecologist with the U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Human Dimensions Research Program in Fort Collins, Colorado. Acknowledgments We thank leadership and resource managers of the U.S. Forest Service Intermountain Region and National Park Service for their support of the Intermountain Adaptation Partnership. We greatly appreciate the enthusiasm and contributions of all participants in the vulnerability assessment and adaptation workshops. We appreciated the help of Gary Eickhorst, DuWayne Kimball, and Tosha Wixom in logistical assistance with the workshops, and the facilitation of the webinar series by Karen Dante-Wood. The following peer reviewers provided insightful comments that greatly improved this publication: Seth Arens, Robert Al-Chokhachy, Sarah Baker, Dale Blahna, Kristie Boatner, Michael Bowker, Polly Buotte, C. Alina Cansler, Caty Clifton, Molly Cross, Dan Dauwalter, Chris Fettig, Nick Glidden, Gordon Grant, Ed Grumbine, Sean Harwood, Justin Humble, Morris Johnson, Gordon Keller, Sarah Leahy, Susan Leslie, Maia London, Jeff Lukas, Danielle Malesky, Anne Marsh, John McCann, Toni Lyn Morelli, Nick Neverisky, Mary O’Brien, Andrew Orlemann, Troy Osborne, Kristen Pelz, Holly Prendeville, Ben Rasmussen, Bryce Richardson, Marcy Rockman, Rema Sadak, Steve Scheid, Nikola Smith, Casey Watson, Jim Winfrey, and Caleb Zurstadt. Paige Eagle provided valuable website design and support. Jeff Bruggink, Robert Norheim, and Teresa Rhoades provided support with geospatial analysis and cartography. Kit Mullen provided valuable input throughout the process. We thank Mark Bethke for his vision, solutions, and leadership. Funding was provided by the U.S. Forest Service Office of Sustainability and Climate, Intermountain Regional Office, and Pacific Northwest and Rocky Mountain Research Stations. Our hope is that the Intermountain Adaptation Partnership will maintain an ongoing dialogue about climate change in the years ahead, catalyzing activities that promote sustainability in the remarkable ecosystems of the Intermountain Adaptation Partnership region. Summary The Intermountain Adaptation Partnership (IAP) is a science-management partnership with a wide variety of participants across the U.S. Department of Agriculture, Forest Service Intermountain Region, which spans Nevada, Utah, southern Idaho, eastern California, and western Wyoming. The partnership includes the Forest Service Intermountain Region, and Pacific Northwest and Rocky Mountain Research Stations; National Park Service Climate Change Response Program; North Central Climate Science Center; Desert, Great Basin, Great Northern, and Southern Rockies Landscape Conservation Cooperatives; the University of Washington; Native American tribes; and dozens of other stakeholder organizations. These organizations and other IAP participants worked together over 2 years to identify climate change issues relevant to resource management on Forest Service and National Park Service lands in the IAP region, and to find solutions that could help to minimize the negative effects of climate change and facilitate the transition of ecosystems to a warmer climate. The IAP provided education, conducted a climate change vulnerability assessment, and developed adaptation options for managing resources of the 12 national forests (Ashley, Boise, Bridger-Teton, Caribou-Targhee, Dixie, Fishlake, Humboldt-Toiyabe, Manti-La Sal, Payette, Salmon-Challis, Sawtooth, Uinta-Wasatch-Cache [plus Curlew National Grassland]) and 22 National Park Service units in the IAP region. The IAP region is characterized by high ecological diversity. Vegetation types include mixed conifer forest, dry ponderosa pine forest, subalpine forest, sagebrush, grasslands, alpine tundra, and wetlands. Ecosystems in the IAP region produce water, fish, timber, wildlife, recreation opportunities, livestock grazing, and other ecosystem services, providing a socioeconomic foundation based on natural resources. The geographic and ecological diversity of the region, especially on Federal lands, contributes significantly to the economic sustainability of human communities, linking Federal resource management with local livelihoods. The effects of climate change on each resource area in the IAP region are synthesized from the available scientific literature and analyses and are based on available climate change projections (Chapter 3). Highlights of the vulnerability assessment and adaptation options for each resource area are summarized next. Water and Soil Resources Climate Change Effects Lower snowpack and increased drought will result in lower base flows, reduced soil moisture, wetland loss, riparian area reduction or loss, and more frequent and possibly more severe wildfire.April 1 snow water equivalent and mean snow residence time are sensitive to temperature and precipitation variations. Warmer (usually lower elevation) snowpacks are more sensitive to temperature variations, whereas colder (usually higher elevation) snowpacks are more sensitive to precipitation. Warmer locations will experience more runoff in winter months and early spring, whereas colder locations will experience more runoff in late spring and early summer. In both cases, future peakflows will be higher and more frequent. Lower snowpacks will cause significantly lower streamflow in summer, and reduce the rate of recharge of water supply in some basins. Annual water yields, which are affected by annual precipitation totals (heavily influenced by winter and spring precipitation in the western