Vulnerability of Species to Climate Change in the Southwest: Threatened, Endangered, and At-Risk Species at the Barry M. Goldwater Range, Arizona
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Vulnerability of Species to Climate Change in the United States Southwest: Threatened, Endangered, and At-Risk Department of Agriculture Species at the Barry M. Goldwater Range, Arizona Forest Service Rocky Mountain Research Station Karen E. Bagne and Deborah M. Finch General Technical Report RMRS-GTR-284 August 2012 Bagne, Karen E.; Finch, Deborah M. 2012. Vulnerability of species to climate change in the Southwest: threatened, endangered, and at-risk species at the Barry M. Goldwater Range, Arizona. Gen. Tech. Rep. RMRS-GTR-284. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 139 p. ABSTRACT Future climate change is anticipated to result in ecosystem changes, and consequently, many species are expected to become increasingly vulnerable to extinction. This scenario is of particular concern for threatened, endangered, and at-risk species (TER-S) or other rare species. The response of species to climate change is uncertain and will be the outcome of complex interactions and processes. Nevertheless, a simple flexible strategy is needed to help integrate climate change into management planning and actions. This assessment uses SAVS, an assessment tool based on ecological principals, to rank individual species of interest within the eastern portion of the Barry M. Goldwater Range, Arizona, according to predicted climate change responses and associated population declines balanced with responses expected to incur resilience or population increases. Further, specific areas of vulnerability, research needs, and management implications are identified for each species in detailed species accounts. Based solely on predicted response to climate change, Sonoran pronghorn (Antilocapra americana sonoriensis) and desert tortoise (Gopherus morafkai) are the most vulnerable to population declines. Results also suggest that climate change will make management of some TER-S species more difficult. Several critical management areas are identified that can mitigate negative impacts to benefit multiple species, including fire and fuels, invasive species, natural and artificial waters, and landscape-scale planning. Management planning should be in place that will assist species impacted by extreme events such as prolonged drought, severe wildfires, and/or intense flooding. The assessment process was also used to identify areas where climate change may present opportunities, as opposed to challenges, for species management. Keywords: climate change, vulnerability, Southwest, Arizona, endangered species, SAVS AUTHORS Karen E. Bagne is a Wildlife Ecologist with the USDA Forest Service, Rocky Mountain Research Station. Deborah M. Finch is the Program Manager for the Grassland, Shrubland, and Desert Ecosystem program of the USDA Forest Service, Rocky Mountain Research Station. Cover photo: Barry M. Goldwater Range by R. Whittle. Photos are authorized for this publication only, and any further use requires authorization from the photographers. You may order additional copies of this publication by sending your mailing information in label form through one of the following media. Please specify the publication title and series number. Publishing Services Telephone (970) 498-1392 FAX (970) 498-1122 E-mail [email protected] Website http://www.fs.fed.us/rm/publications Mailing address Publications Distribution Rocky Mountain Research Station 240 West Prospect Road Fort Collins, CO 80526 CONTENTS Introduction ............................................................................................................1 Climate Change Assessment ................................................................................1 Purpose ..........................................................................................................................1 Approach ........................................................................................................................2 Scope .............................................................................................................................3 Projections of Climate, Disturbance, and Biotic Communities .........................4 Current and Future Climate............................................................................................4 Water Sources ...............................................................................................................5 Disturbance ....................................................................................................................5 Biotic Communities ........................................................................................................6 Mexico and Central America ..........................................................................................8 Scoring Results and Discussion ..........................................................................9 Vertebrate Species .........................................................................................................9 Vascular Plants ............................................................................................................13 Management Implications: Using Assessment Results ...................................13 Artificial and Natural Waters .........................................................................................14 Fire, Fuels, and Invasive Species Management ..........................................................15 Anticipating Shifts in Distribution ..................................................................................15 Coping With Physiological Thresholds .........................................................................16 Anticipating Shifts in Timing .........................................................................................17 Prioritization .................................................................................................................17 Landscape-Scale Management and Partners ..............................................................17 Uncertainty ...................................................................................................................18 Next Steps .............................................................................................................18 Literature Cited .....................................................................................................19 Appendix A: Species Accounts ..........................................................................25 Couch’s Spadefoot .......................................................................................................26 Morafkai’s Desert Tortoise ............................................................................................33 Saddled Leaf-nosed Snake ..........................................................................................43 Red-backed Whiptail ....................................................................................................49 Yuman Fringe-toed Lizard ............................................................................................55 American Peregrine Falcom.........................................................................................61 Cactus Ferruginous Pygmy-Owl ..................................................................................67 Gilded Flicker ...............................................................................................................75 Le Conte’s Thrasher .....................................................................................................81 Cave Myotis .................................................................................................................87 California Leaf-nosed Bat.............................................................................................93 Mexican Long-tongued Bat ..........................................................................................99 Lesser Long-nosed Bat ..............................................................................................107 Desert Bighorn Sheep ................................................................................................118 Sonoran Pronghorn ....................................................................................................126 Acuña Cactus .............................................................................................................135 ACKNOWLEDGMENTS This project was funded by the Department of Defense Legacy Resource Management Program (Project 09-433). Additional funding was provided by the USDA Forest Service. Information from the original report (posted on www.denix.osd.mil, August 2010) was updated to create this report. We thank Richard Whittle and Daniel Garcia of Luke Air Force Base for their support. Megan Friggens produced Figure 3 and, along with Sharon Coe, provided review and discussion of climate change topics that improved this assessment. Collaborators that inspired assessment development include: Carolyn Enquist and David Gori of The Nature Conservancy, Lisa Graumlich at the University of Arizona, and Heather Bateman at Arizona State University Polytechnic. Further support and advice was provided by Jack Triepke and Bryce Rickel of USDA Forest Service, Rocky Mountain Region. Mary Bagne provided editing assistance. Introduction A large number of species are imperiled and at risk of extinction if populations continue to decline (Wilcove and Master 2005). Of Federal landholdings, those managed