National Park Service U.S. Department of the Interior Natural Resource Program Center Invasive Plant Species Early Detection in the San Francisco Bay Area Network 2007 Annual Report Natural Resource Report NPS/PWR/SFAN/NRTR—2008/135 ON THE COVER Golden Gate National Parks Conservancy employee Elizabeth Speith gathers data Photograph by: Marcus Koenen, NPS Invasive Plant Species Early Detection in the San Francisco Bay Area Network 2007 Annual Report Natural Resource Report NPS/PWR/SFAN/NRTR—2008/135 Andrea Williams and Elizabeth Speith National Park Service San Francisco Bay Area Network Fort Cronkhite Building 1063 San Francisco, CA 94965 July 2008 U.S. Department of the Interior National Park Service Natural Resource Program Center Fort Collins, Colorado The Natural Resource Publication series addresses natural resource topics that are of interest and applicability to a broad readership in the National Park Service and to others in the management of natural resources, including the scientific community, the public, and the NPS conservation and environmental constituencies. Manuscripts are peer-reviewed to ensure that the information is scientifically credible, technically accurate, appropriately written for the intended audience, and is designed and published in a professional manner. The Natural Resources Technical Reports series is used to disseminate the peer-reviewed results of scientific studies in the physical, biological, and social sciences for both the advancement of science and the achievement of the National Park Service’s mission. The reports provide contributors with a forum for displaying comprehensive data that are often deleted from journals because of page limitations. Current examples of such reports include the results of research that addresses natural resource management issues; natural resource inventory and monitoring activities; resource assessment reports; scientific literature reviews; and peer reviewed proceedings of technical workshops, conferences, or symposia . Views, statements, findings, conclusions, recommendations and data in this report are solely those of the author(s) and do not necessarily reflect views and policies of the U.S. Department of the Interior, NPS. Mention of trade names or commercial products does not constitute endorsement or recommendation for use by the National Park Service. Printed copies of reports in these series may be produced in a limited quantity and they are only available as long as the supply lasts. This report is also available from the San Francisco Area I&M Network website ( http://www.nature.nps.gov/im/units/SFAN ) or the Natural Resource Publications Management website (http://www.nature.nps.gov/publications/NRPM ) on the internet, or by sending a request to the address on the back cover. Please cite this publication as: Williams, A. E. and E. Speith. 2008. Invasive plant species early detection in the San Francisco Bay Area Network: 2007 annual report. Natural Resource Technical Report NPS/PWR/SFAN/NRTR—2008/135. National Park Service, Fort Collins, Colorado. NPS D-44, November 2008 ii Contents Page List of Figures................................................................................................................................. v List of Tables .................................................................................................................................. v List of Appendixes........................................................................................................................ vii Executive Summary....................................................................................................................... ix Acknowledgements........................................................................................................................ xi 1.0 Introduction............................................................................................................................... 1 1.1 Background........................................................................................................................... 1 1.2 Objectives ............................................................................................................................. 2 2.0 Methods..................................................................................................................................... 3 2.1 Prioritization ......................................................................................................................... 3 2.1.1 Species ........................................................................................................................... 3 2.1.2 Areas .............................................................................................................................. 3 2.2 Search Areas ......................................................................................................................... 4 2.3 Field Methods ....................................................................................................................... 4 2.4 Trainings ............................................................................................................................... 5 2.5 Analyses/GIS Manipulations ................................................................................................ 6 2.6 Species List Revisions .......................................................................................................... 6 3.0 Results....................................................................................................................................... 7 3.1 Search Effort ......................................................................................................................... 7 3.2 Species Found ....................................................................................................................... 7 3.3 Species List Revisions .......................................................................................................... 8 3.4 Outreach.............................................................................................................................. 14 4.0 Discussion............................................................................................................................... 15 4.1 Collaboration....................................................................................................................... 15 iii Contents (continued Page 6.0 Literature Cited ....................................................................................................................... 17 7.0 Glossary .................................................................................................................................. 19 iv Figures Page Figure 1. Tiered levels of data collection........................................................................................ 4 Tables Page Table 1. Number of occurrences and species list revisions for GOGA based largely on 2006- 2007 field results. Percentages based on 66 subwatersheds searched. Changes in bold. ............... 9 v Appendixes Page Appendix A. Maps showing prioritized subwatersheds. .............................................................. 21 Appendix B: List of priority invasive species by park (2007)...................................................... 25 Golden Gate, Muir Woods, Presidio and Fort Point: Priority 1 Species .................................. 25 Golden Gate, Muir Woods, Presidio and Fort Point: Priority 2 Species .................................. 26 Golden Gate, Muir Woods, Presidio and Fort Point: Priority 3 Species .................................. 27 Golden Gate, Muir Woods, Presidio and Fort Point: Priority 4 Species .................................. 28 Golden Gate, Muir Woods, Presidio and Fort Point: Priority 5 Species .................................. 29 Appendix C. Maps showing survey results................................................................................... 31 vii Executive Summary Parks need to know where incipient populations of highly invasive plants are becoming established, and protect the most critical areas from invasion. This year was the first full field season of testing the early detection protocol. The methods detailed in this report focus on surveying road- and trail-side in priority areas using volunteers, and is based on the SFAN I&M Network’s Early Detection Monitoring of Invasive Plant Species in the San Francisco Bay Area Network: A Volunteer-Based Approach (Williams et al. 2008 in review). The Golden Gate National Recreation Area (GOGA) contains 38 subwatersheds deemed at high risk of invasion and/or harm to significant biological resources, of which 33 subwatershed were within the boundaries actively managed by the park. Searches were conducted by teams of two or three along the prioritized trails and roads in these subwatersheds looking for up to 83 plant species ranked as having the greatest risk for invasion in these areas. One thousand and one high- priority plant populations were mapped in the park. Of 66 subwatersheds searched, 45 were found to contain the highest priority species. Twenty-eight of these subwatersheds were deemed at high risk for invasion. Maps were created of all areas surveyed in the GOGA and priority plant species found. Based on results, the species list was modified to better reflect actual population levels within the park. Volunteers played a pivotal role in the implementation