Climate Change Vulnerability Assessment for Rare Plants of the San Juan Region of Colorado May 2014 CNHP’s mission is to preserve the natural diversity of life by contributing the essential scientific foundation that leads to lasting conservation of Colorado's biological wealth. Colorado Natural Heritage Program Warner College of Natural Resources Colorado State University 1475 Campus Delivery Fort Collins, CO 80523 (970) 491-7331 Report Prepared for: Tres Rios Bureau of Land Management & San Juan U.S. Forest Service Recommended Citation: J. Handwerk, B. Kuhn, R. Rondeau, and L. Grunau. 2014. Climate Change Vulnerability Assessment for Rare Plants of the San Juan Region of Colorado. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado. Front Cover from the top: Triteleia grandiflora, © Bob Dorn; Amsonia jonesii, © Joe Leahy; Eriophorum chamissonis, © Delia Malone; Drosera anglica, © Sara Brinton; Mimulus eastwoodiae, © Lori Brummer Climate Change Vulnerability Assessment for Rare Plants of the San Juan Region of Colorado Jill Handwerk, Bernadette Kuhn, Renée Rondeau, and Lee Grunau Colorado Natural Heritage Program Warner College of Natural Resources Colorado State University Fort Collins, Colorado 80523 May 2014 ABSTRACT The 5 million-acre San Juan Region lies in southwest Colorado and is considered part of the Four Corners area. The Colorado Natural Heritage Program tracks 122 plant species within this region. Recently published climate models for the Southern San Juan Region project a median decrease in May precipitation across southwestern Colorado and a 4.3 F increase in average annual temperatures, suggesting drought may become problematic for these species in the future (Lukas et al. 2014). As of 2014, we have conducted Climate Change V⁰ulnerability Assessments using methodology developed by NatureServe for 60 of the tracked plant species known from the region, primarily focused on federally listed or agency sensitive species. Our results indicate that nearly 60% (36 species) of these plant species are extremely vulnerable to climate change. The most vulnerable species were from alpine, cliff and canyon, barrens, and groundwater dependent wetland habitats. Spruce-fir and ponderosa pine forests, and montane grasslands had the least amont of vulnerable species. Of the 60 species assesed, 37% (22 species) are endemic to the Four Corners region and most (19 species) are extremely vulnerable. Barrens support the highest number of endemic species of any habitat (7), and all but one barrens species is extremely vulnerable. We recommend developing climate adaptation strategies for extremely and highly vulnerable species and as time permits, assessing additional rare species. ACKNOWLEDGEMENTS The authors would like to acknowledge Gretchen Fitzgerald (San Juan National Forest) and Bradd Dodd (BLM) for their financial support and encouragement of this project. Special recognition goes to Gay Austin (BLM) and CNHP staff members Denise Culver, Dee Malone, and Peggy Lyon for reviewing the CCVI scores, and to Sierra Crumbaker and Alyssa Meier for assistance with report formatting and fact checking. San Juan Rare Plant Climate Change Vulnerability Assessment i TABLE OF CONTENTS Abstract .........................................................................................................................................................................................i Acknowledgements .................................................................................................................................................................. i Background ................................................................................................................................................................................ 1 Methods ....................................................................................................................................................................................... 2 NatureServe Climate Change Vulnerability Index – Overview .......................................................................... 2 Scoring Factors in the CCVI ............................................................................................................................................ 3 Target Selection .................................................................................................................................................................... 5 Application of the CCVI for Species in the San Juan Region ................................................................................ 6 Results .......................................................................................................................................................................................... 7 References ................................................................................................................................................................................18 Appendix A: List of Rare Plant Species in the San Juan Region with no Climate Change Vulnerability Assessment ...............................................................................................................................................................................22 Appendix B: San Juan Region Rare Plant Species Vulnerability Scores and Profiles................................. 24 Appendix C: Climate Change Vulnerability Index Scoring Categories .......................................................... 144 Appendix D: San Juan Region Rare Plant Species Climate Change Vulnerability Scores ...................... 161 TABLE OF FIGURES Figure 1. Map of San Juan/Tres Rios study area with surface ownership ....................................................... 1 Figure 2. San Juan rare plant species vulnerability by habitat ............................................................................. 8 Figure 3. Number of San Juan rare plant species with CCVIs by habitat .......................................................... 8 Figure 4. Map of San Juan rare plant species distribution by vulnerability score ........................................ 9 Figure 5. San Juan endemic plant species vulnerability and their habitats ................................................... 10 TABLE OF TABLES Table 1. Surface ownership/management in study area ........................................................................................ 1 Table 2. Additional species assessed for this report ................................................................................................. 5 Table 3. Summary of vulnerability assessment results for species by Index Score ..................................... 7 Table 4. Summary of vulnerability assessment results for species by habitat .............................................. 7 ii Colorado Natural Heritage Program © 2014 Table 5. Summary of vulnerability assessment results for species by rarity rank. ..................................... 9 Table 6. Climate change vulnerability scores for rare plants of the San Juan Region alphabetically by habitat ........................................................................................................................................................................................13 San Juan Rare Plant Climate Change Vulnerability Assessment iii BACKGROUND Table 1. Surface ownership/management in study area. The San Juan / Tres Rios study area includes portions of Owner/Manager Acres nine counties covering nearly 5 million acres in USFS 1,865,332 southwestern Colorado. The area represents the Colorado BLM 674,123 portion of the San Juan River, and the southern half of the NPS 53,937 Upper Colorado-Dolores Rivers HUC4 basins. State 86,174 Tribal 769,510 Primary population centers include Durango (pop. 16,887), Other (incl. private) 1,477,914 Cortez (pop. 8,482), Bayfield (pop. 2,333) Pagosa Springs Total 4,926,990 (pop. 1,727), and Mancos (pop. 1,336). The majority of the area’s population lives in smaller towns or in unincorporated areas. Surface ownership (Figure 1, Table 1) is dominated by federal, state, and tribal entities, which account for about 70% of acreage within the study area. Primary economic activities in the area are farming/ranching, logging, energy resource extraction, recreation, and tourism. Figure 1. Map of San Juan/Tres Rios study area with surface ownership. San Juan Rare Plant Climate Change Vulnerability Assessment 1 METHODS We used the NatureServe Climate Change Vulnerability Index (CCVI; Young et al. 2011) to assess vulnerability of rare plant species that occur in the San Juan region of Colorado. Our objectives were to identify: 1. Species most likely to be affected by climate change, and 2. Life history factors that are most sensitive to climate change. This project builds on previous work to assess the vulnerability of rare plant species across Colorado (CNHP 2011) and in the Gunnison Basin (Neely et al. 2011). This document describes detailed methods applied for the species assessed specifically for the San Juan region. We have also included results for species that occur in the region but were previously assessed for different geographic study areas (refer to Appendix D). NatureServe Climate Change Vulnerability Index – Overview This overview has been synthesized and reprinted, with permission, from Young et al. (2011). The Climate Change Vulnerability Index (CCVI), developed by NatureServe, is a Microsoft Excel-based tool that facilitates