National Park Service U.S. Department of the Interior Natural Resource Stewardship and Science San Juan Island National Historical Park Vegetation Classification and Mapping Project Report Natural Resource Report NPS/NCCN/NRR—2012/603 ON THE COVER Red fescue (Festuca rubra) grassland association at American Camp, San Juan Island National Historical Park. Photograph by: Joe Rocchio San Juan Island National Historical Park Vegetation Classification and Mapping Project Report Natural Resource Report NPS/NCCN/NRR—2012/603 F. Joseph Rocchio and Rex C. Crawford Natural Heritage Program Washington Department of Natural Resources 1111 Washington Street SE Olympia, Washington 98504-7014 Catharine Copass National Park Service North Coast and Cascades Network Olympic National Park 600 E. Park Ave. Port Angeles, Washington 98362 . December 2012 U.S. Department of the Interior National Park Service Natural Resource Stewardship and Science Fort Collins, Colorado The National Park Service, Natural Resource Stewardship and Science office in Fort Collins, Colorado, publishes a range of reports that address natural resource topics. These reports are of interest and applicability to a broad audience in the National Park Service and others in natural resource management, including scientists, conservation and environmental constituencies, and the public. The Natural Resource Report Series is used to disseminate high-priority, current natural resource management information with managerial application. The series targets a general, diverse audience, and may contain NPS policy considerations or address sensitive issues of management applicability. All manuscripts in the series receive the appropriate level of peer review to ensure that the information is scientifically credible, technically accurate, appropriately written for the intended audience, and designed and published in a professional manner. This report received informal peer review by subject-matter experts who were not directly involved in the collection, analysis, or reporting of the data. Data in this report were collected and analyzed using methods based on established, peer-reviewed protocols and were analyzed and interpreted within the guidelines of the protocols. Views, statements, findings, conclusions, recommendations, and data in this report do not necessarily reflect views and policies of the National Park Service, U.S. Department of the Interior. Mention of trade names or commercial products does not constitute endorsement or recommendation for use by the U.S. Government. This report is available from the North Coast and Cascades Network Inventory and Monitoring website (http://science.nature.nps.gov/im/units/nccn/reportpubs.cfm) and the Natural Resource Publications Management website (http://www.nature.nps.gov/publications/nrpm). Please cite this publication as: Rocchio, F. J., R. C. Crawford, and C. Copass. 2012. San Juan Island National Historical Park vegetation classification and mapping project report. Natural Resource Report NPS/NCCN/NRR—2012/603. National Park Service, Fort Collins, Colorado. NPS 438/118224, December 2012 ii Contents Page Figures........................................................................................................................................... vii Tables ............................................................................................................................................. ix Appendices ..................................................................................................................................... xi Executive Summary ..................................................................................................................... xiii Acknowledgments........................................................................................................................ xiv Acronyms .................................................................................................................................... xvii 1.0 Introduction ............................................................................................................................... 1 1.1 Project Overview ............................................................................................................... 1 1.1.1 Background ................................................................................................................ 1 1.1.2 Project Scope and Products ........................................................................................ 1 1.2 National Park Service Vegetation Inventory Program ...................................................... 2 1.3 The National Vegetation Classification Standard .............................................................. 3 1.4 Nomenclature and Naming Conventions ........................................................................... 5 2.0 Study Area ................................................................................................................................ 7 2.1 Location ............................................................................................................................. 7 2.2 Climate ............................................................................................................................... 8 2.3 Geology and Topography .................................................................................................. 8 2.3.1 Geology ...................................................................................................................... 8 2.3.2 Topography ................................................................................................................ 9 2.4 Soils ................................................................................................................................. 11 2.5 Hydrology and Water Resources ..................................................................................... 11 2.6 Land Use and Settlement History .................................................................................... 12 2.7 Vegetation ........................................................................................................................ 14 iii Contents (continued) Page 2.7.1 American Camp Vegetation ..................................................................................... 14 2.7.2 English Camp and Mitchell Hill Vegetation ............................................................ 16 2.8 Previous Vegetation Studies ............................................................................................ 18 3.0 Classification of Vegetation Types ......................................................................................... 21 3.1 Methods ........................................................................................................................... 21 3.1.1 Use of Previously collected Data ............................................................................. 21 3.1.2 Field Sampling ......................................................................................................... 21 3.1.3 Data Analysis and Product Development ................................................................ 22 3.1.4 Standardizing Vegetation Nomenclature ................................................................. 23 3.1.5 Conservation Rank ................................................................................................... 23 3.1.6 Taxonomic Treatments ............................................................................................ 25 3.2 Results.............................................................................................................................. 25 3.2.1. Plot Data Used for Classification ............................................................................ 25 3.2.2 Ruderal Types .......................................................................................................... 25 3.2.3 Vegetation Classification Summary ........................................................................ 27 3.2.4 Imperiled Plant Associations ................................................................................... 30 3.3 Conclusions...................................................................................................................... 34 4.0 Mapping Vegetation Types ..................................................................................................... 35 4.1 Methods ........................................................................................................................... 35 4.1.1 Preliminary Mapping ............................................................................................... 35 4.1.2 Field Sampling ......................................................................................................... 35 4.1.3 Finalization of Vegetation Map ............................................................................... 36 4.2 Vegetation Map Summary ............................................................................................... 36 iv Contents (continued) Page 4.3 Vegetation Patterns .......................................................................................................... 42 4.3.1 Vegetation Patterns at American Camp ................................................................... 42 4.3.2 Vegetation Patterns at English Camp and Mitchell Hill .......................................... 49 4.3.3 Conclusions