An Assessment of Climate Change and the Vulnerability of Wildlife in the Sky Islands of the Southwest Sharon J. Coe, Deborah M. Finch, Megan M. Friggens United States Department of Agriculture / Forest Service Rocky Mountain Research Station General Technical Report RMRS-GTR-273 April 2012 Coe, Sharon J.; Deborah M. Finch; Megan M. Friggens. 2012. An assessment of climate change and the vulnerability of wildlife in the Sky Islands of the Southwest. Gen. Tech. Rep. RMRS-GTR-273. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 208 p. ABSTRACT We evaluated the historical and projected trends in climate and vegetation relevant to the Coronado National Forest in southeast Arizona, USA. We then applied this information in an assessment of the vulnerability of 30 species of terrestrial vertebrates on the Coronado National Forest to the potential effects of future climate change. We used a pilot version of a decision-support tool developed by the U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station that produces scores that represent relative measures of vulnerability to climate change as related to habitat, physiology, phenology, and biotic interactions. Over the next ~100 years, increased temperature and aridity are projected for the region, as well as a reduction in forested areas. All 30 species were considered vulnerable with respect to at least some criteria comprising the decision-support tool. The elegant trogon (Trogon elegans) and Tarahumara frog (Rana tarahumarae) were tied for the largest vulnerability score. The Slevin’s bunchgrass lizard (Sceloporus slevini) had the smallest vulnerability score. While species varied in their expected responses to climate change, most appeared to be vulnerable relative to one or more expected negative impacts to their habitat, such as an overall reduction in suitable habitat. The assessment results can be used by USFS managers in climate change adaptation planning for these species and their habitats by helping to identify goals for adaptation planning. Keywords: climate change, vulnerability assessment, wildlife management, Coronado National Forest, decision-support tool AUTHORS Sharon J. Coe is a Postdoctoral Researcher with the USFS Rocky Mountain Research Station in Albuquerque, New Mexico, in collaboration with the University of Arizona. She holds both a Ph.D. and an M.Sc. degree in Biology from the University of California, Riverside. She is researching the vulnerability of wildlife to climate change and the effects on wildlife from vegetation treatments to reduce fire risk. Deborah M. Finch is the Program Manager for the Grassland, Shrubland, and Desert Ecosystems Program at USFS Rocky Mountain Research Station in Albuquerque, New Mexico. She received her B.S. degree in Wildlife Management from Humboldt State University, her M.S. degree in Zoology and Physiology from Arizona State University, and her Ph.D. in Zoology and Range Science from University of Wyoming, Laramie. Megan M. Friggens is a Research Ecologist with the USFS Rocky Mountain Research Station in Albuquerque, New Mexico, where she has worked on the development and application of tools and assessments regarding the vulnerability of species to climate change. She obtained a B.S. and M.S. degree in Biology from the University of New Mexico and a Ph.D. in Forest Science from Northern Arizona University. She is researching disturbance (fire, drought, land conversion, and climate change), impacts on wildlife species, and wildlife disease ecology. Cover photos—top: Chiricahua Mountains, © Larry Jones; bottom You may order additional copies of this publication by sending your left: elegant trogon (Trogon elegans), mailing information in label form through one of the following media. Dominic Sherony (Wikimedia Please specify the publication title and series number. Commons); bottom right: bighorn Publishing Services sheep (Ovis canadensis), Terry L. Spivey, Terry Spivey Photography, Telephone (970) 498-1392 Bugwood.org. Photos are authorized FAX (970) 498-1122 for this publication only, and any E-mail [email protected] further use requires authorization from Website http://www.fs.fed.us/rm/publications the photographers. Mailing address Publications Distribution Rocky Mountain Research Station 240 West Prospect Road Fort Collins, CO 80526 PREFACE The success and persistence of plants and animals in their natural environments is inextricably linked to climate. While species in North America have experienced historical variation in climate, a relatively rapid increase in global temperature has the potential to create unique environmental conditions for plant and animal species relative to their recent evolutionary past. Mean global surface temperature has increased over the last 157 years (i.e., over the instrumental record; Trenberth and others 2007). The global average temperature increased 0.35 °C from the 1910s to the 1940s and then 0.55 °C from the 1970s to the end of 2006. Temperatures are projected to increase in the United States, overall, and in the Southwest specifically, according to a variety of climate change models. There is substantial support for a projected increase in surface-air temperatures in the United States of 2 °C during the next century on an annual-mean basis; some models predict temperature increases exceeding 4 °C (Christensen and others 2007). How to manage for the effects of climate change on plant and animal species has become an increasing concern for resource managers and others whose goal it is to maintain species viability into the future. The U.S. Forest Service (USFS) has identified climate change as an important force that puts ecosystems at risk. USFS (2011a) identifies the need for “science-based assessments of the relative vulnerability of key ecosystem components” to address risks and vulnerabilities of national resources. It also states the need to identify knowledge gaps and management outcomes under climate change. Each National Forest and National Grassland is required to meet standards in 11 areas related to climate change planning, and each is evaluated annually for achievement using a “scorecard” system (USFS 2011b). One criterion is education of all employees on the causes and impacts of climate change. Another criterion measures the extent to which information about the vulnerability of key resources and ecosystem elements to climate change is used in decision-making. The Coronado National Forest (CNF) is located in southeastern Arizona and includes the Peloncillo Mountains that extend into southwestern New Mexico (Fig.1.1). The National Forest encompasses large areas of a group of high-elevation mountains called the Sky Islands. In this report, we provide information about climate change and a vulnerability assessment of 30 species on the CNF based on the possible effects of climate change over the next ~100 years. Vulnerability assessments are discussed in more detail in Chapter 2, but overall, they can be used to help set management priorities and to develop strategies for responding to climate change (“adaptation strategies;” Glick and others 2011). Assessing vulnerability to climate change requires knowledge of possible changes in temperature, precipitation, and vegetation. We review these potential changes in Chapter 1, which is used as a basis for the species vulnerability assessment presented in Chapter 2. Readers who are interested primarily in a review of climate and potential climate-related changes in the Southwest (here, mainly Arizona and New Mexico) will find that information within Chapter 1. Readers who are interested primarily in the evaluation of species vulnerability, and not specifically the evaluation of climate, can proceed directly to Chapter 2. REFERENCES Bagne, K.E., M.M. Friggens, and D.M. Finch. 2011. A system for assessing vulnerability of species (SAVS) to climate change. Gen. Tech. Rep. RMRS-GTR-257. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 28 p. Christensen, J.H., B. Hewitson, A. Busuioc, [and others]. 2007. Regional climate projections. In: Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor, and H.L. Miller, eds. Climate Change 2007. The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, United Kingdom: Cambridge University Press. Glick, P., B.A. Stein, and N.A. Edelson, eds. 2011. Scanning the Conservation Horizon: A Guide to Climate Change Vulnerability Assessment. Washington, DC: National Wildlife Federation. Available: www.nwf.org/vulnerabilityguide. Trenberth, K.E., P.D. Jones, P. Ambenje, [and others]. 2007. Observations: Surface and atmospheric climate change. In: Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller, eds. Climate Change 2007: The Physical i Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, United Kingdom: Cambridge University Press. U.S. Forest Service [USFS]. 2011a. National roadmap for responding to climate change. FS-957b. Washington, DC: U.S. Department of Agriculture, Forest Service. Available: http://www.fs.fed.us/climatechange/pdf/Roadmapfinal.pdf. U.S. Forest Service [USFS]. 2011b. Navigating the climate change performance scorecard. Washington, DC: U.S. Department of Agriculture, Forest Service. Available: http://fsweb.