National Park Service U.S. Department of the Interior Natural Resource Stewardship and Science San Antonio Missions National Historical Park Natural Resource Condition Assessment Natural Resource Report NPS/SAAN/NRR—2016/1191 ON THE COVER Mission San José at San Antonio Missions National Historical Park Photograph courtesy of the National Park Service San Antonio Missions National Historical Park Natural Resource Condition Assessment Natural Resource Report NPS/SAAN/NRR—2016/1191 Kathy Allen Sarah Gardner Andy J. Nadeau Anna M. Davis Kevin Benck Lonnie Meinke Shannon Amberg Thomas Walker GeoSpatial Services Saint Mary’s University of Minnesota 890 Prairie Island Road Winona, Minnesota 55987 March 2016 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 comprehensive information and analysis about natural resources and related topics concerning lands managed by the National Park Service. The series supports the advancement of science, informed decision-making, and the achievement of the National Park Service mission. The series also provides a forum for presenting more lengthy results that may not be accepted by publications with page limitations. 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 formal peer review by subject-matter experts who were not directly involved in the collection, analysis, or reporting of the data, and whose background and expertise put them on par technically and scientifically with the authors of the information. 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 in digital format from from the Integrated Resource Management Applications website (http://irma.nps.gov) and the Natural Resource Publications Management website (http://www.nature.nps.gov/publications/nrpm/). To receive this report in a format optimized for screen readers, please email [email protected]. Please cite this publication as: Allen, K., S. Gardner, A. J. Nadeau, A. Davis, K. Benck, L. Meinke, S. Amberg, and T. Walker. 20XX. San Antonio Missions National Historical Park: Natural resources condition assessment. Natural Resource Report NPS/SAAN/NRR—2016/1191. National Park Service, Fort Collins, Colorado. NPS XXXXXX,472/132206, Month March 201X 2016 (The Fort Collins Support Office will fill out this line for you) ii Contents Page Figures................................................................................................................................................... ix Tables ..................................................................................................................................................xiii Photos ................................................................................................................................................. xvii Appendices .......................................................................................................................................... xxi Executive Summary ..........................................................................................................................xxiii Acknowledgments .............................................................................................................................. xxv Acronyms and Abbreviations............................................................................................................ xxvi Chapter 1 NRCA Background Information ........................................................................................... 1 Chapter 2 Introduction and Resource Setting ........................................................................................ 5 2.1 Introduction .............................................................................................................................. 5 2.1.1 Enabling Legislation ......................................................................................................... 5 2.1.2 Geographic Setting ........................................................................................................... 5 2.1.3 Visitation Statistics ........................................................................................................... 8 2.2 Natural Resources ..................................................................................................................... 8 2.2.1 Ecological Units and Watersheds ..................................................................................... 8 2.2.2 Resource Descriptions .................................................................................................... 11 2.2.3 Resource Issues Overview .............................................................................................. 13 2.3 Resource Stewardship ............................................................................................................ 21 2.3.1 Management Directives and Planning Guidance............................................................ 21 2.3.2 Status of Supporting Science .......................................................................................... 21 2.4 Literature Cited ....................................................................................................................... 23 Chapter 3 Study Scoping and Design .................................................................................................. 27 3.1 Preliminary Scoping ............................................................................................................... 27 3.2 Study Design .......................................................................................................................... 28 3.2.1 Indicator Framework, Focal Study Resources and Indicators ........................................ 28 3.2.2 General Approach and Methods ..................................................................................... 32 3.3 Literature Cited ....................................................................................................................... 37 Chapter 4 Natural Resource Conditions............................................................................................... 39 iii Contents (continued) Page 4.1 Forested Riparian Corridors ................................................................................................... 40 4.1.1 Description ..................................................................................................................... 40 4.1.2 Measures ......................................................................................................................... 41 4.1.3 Reference Conditions/Values ......................................................................................... 41 4.1.4 Data and Methods ........................................................................................................... 41 4.1.5 Current Condition and Trend .......................................................................................... 43 4.1.6 Sources of Expertise ....................................................................................................... 53 4.1.7 Literature Cited ............................................................................................................... 53 4.2 Native Grasslands ................................................................................................................... 55 4.2.1 Description ..................................................................................................................... 55 4.2.2 Measures ......................................................................................................................... 56 4.2.3 Reference Conditions/Values ......................................................................................... 56 4.2.4 Data and Methods ........................................................................................................... 56 4.2.5 Current Condition and Trend .......................................................................................... 56 4.2.6 Sources of Expertise ....................................................................................................... 60 4.2.7 Literature Cited ............................................................................................................... 61 4.3 Upland Shrublands/Woodlands .............................................................................................. 63 4.3.1 Description ....................................................................................................................