National Park Service U.S. Department of the Interior Natural Resource Program Center Gradsect and Field Sampling Plan for Amistad National Recreation Area Natural Resource Report NPS/CHDN/NRR—2011/298 ON THE COVER Photograph within Amistad National Recreation Area Image provided by Cogan Technology, Inc. Gradsect and Field Sampling Plan for Amistad National Recreation Area Natural Resource Report NPS/CHDN/NRR—2011/298 Dan Cogan Cogan Technology, Inc. 21 Valley Road Galena, Illinois 61036 James Von Loh Cogan Technology, Inc. 8140 East Lightening View Drive Parker, Colorado 80134 February 2011 U.S. Department of the Interior National Park Service Natural Resource Program Center Fort Collins, Colorado The National Park Service, Natural Resource Program Center publishes a range of reports that address natural resource topics 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. 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 NPS Chihuahuan Desert Network website (http://science.nature.nps.gov/im/units/chdn/) and the Natural Resource Publications Management website (http://www.nature.nps.gov/publications/NRPM). Please cite this publication as: Cogan, D. and J. VonLoh. 2011. Gradsect and field sampling plan for Amistad National Recreation Area. Natural Resource Report NPS/CHDN/NRR—2011/298. National Park Service, Fort Collins, Colorado.. NPS 621/106601, February 2011 ii Contents Page Figures............................................................................................................................................ iv Tables ............................................................................................................................................. iv Appendices ...................................................................................................................................... v Executive Summary ...................................................................................................................... vii Introduction ..................................................................................................................................... 1 Amistad National Recreation Area .......................................................................................... 2 Gradsect and Biophysical Units ............................................................................................... 2 Methods and Results ....................................................................................................................... 3 Reservoir Contours .................................................................................................................. 3 Soils ......................................................................................................................................... 3 Vegetation Cover ..................................................................................................................... 6 2010 NAIP Imagery ................................................................................................................. 6 Potential Sampling Target Sites ............................................................................................... 8 Discussion ..................................................................................................................................... 11 Literature Cited ............................................................................................................................. 15 iii Figures Page Figure 1. Park and Project Boundaries for Amistad National Recreation Area. ........................... 4 Figure 2. Example of the General Soils Map for AMIS. ............................................................... 5 Figure 3. Example of the General Vegetation and Topology Map for AMIS ............................... 7 Figure 4. Example of the Final BPU map and potential sampling target sites for AMIS............................................................................................................................................... 9 Figure 5. Field Map Example for AMIS with 2010 NAIP Image Background. .......................... 12 Figure 6. Field Map Example for AMIS with Topographic Map Background. .......................... 13 Tables Page Table 1. AMIS BPU Attirbute Items and Categories in the Gradsect GIS Layer. ......................... 8 iv Appendices Page Appendix 1: Potential Sampling Target Points ............................................................................. 17 Appendix 2: 2010 Field Sampling Instructions ............................................................................ 51 Appendix 3: List of Preliminary Plant Associations and Alliances at AMIS ............................... 93 Appendix 4: Plant Species List for AMIS .................................................................................. 103 v Executive Summary Amistad National Recreation Area (AMIS, NRA) occupies approximately 57,292 acres in and around the Amistad Reservoir and along the Rio Grande in south Texas. In 2009 the NRA began a vegetation mapping project under the National Park Service (NPS) Vegetation Inventory Program (NVIP) by preparing a detailed Study Plan. One of the first tasks in the study plan is the development of a field-based sampling approach using a gradient oriented transect (gradsect) consisting of biophysical units (BPUs). The purpose of this task is to create spatial databases and supporting materials that can assist field crews in economically accessing and sampling representative stands of vegetation in AMIS. In 2010 Cogan Technology, Inc. (CTI) was contracted to create the gradsect and sampling approach using existing data layers. Following careful examination and review, CTI created a BPU layer based on four parameters, the parameters include: 1) Two Reservoir Contours (i.e. Water Levels) 1080 feet above sea level = Base or Low Pool 1118 feet about sea level = Conservation Pool and Current Level (2010) 2) Val Verde County General Soils Database and Spatial Data (SSURGO) – 18 Types: 1) Acuna silty clay, 10) Olmos very gravelly loam, 2) Amistad flaggy clay loam, 11) Pits, 3) Dev soils, 12) Rio Grande soils, frequently flooded, 4) Felipe and Zorra soils, 13) Riverwash, 5) Jimenez-Quemado complex, 14) Valverde silty clay loam, 6) Langtry cobbly silt loam, very rocky, 15) Zapata-Vinegarroon complex, 7) Langtry-Rock outcrop association, very 16) Zorra-Rock outcrop association, steep, 17) Zorra-Rock outcrop association-steep, 8) Lozier-Shumla association, undulating, 18) Unknown = Water and Unlabeled 9) Mariscal-Lozier association, 3) Five Texas Vegetation Cover Types (derived from the The Vegetation Types of Texas): 1) Ceniza-Blackbrush-Creosotebush Brush, 2) Mesquite-Blackbrush Brush 3) Mesquite-Juniper-Live Oak Brush 4) Mixed Vegetation 5) Submerged 4) General Topology and Vegetation Types (manually delineated from 2010 imagery): Topology Vegetation Draw-down Annual Herbaceous Vegetation Riparian Upland Herbaceous Vegetation Upland Upland Shrubs Upland Trees and Tall Shrubs Riparian Herbaceous Vegetation Riparian Shrubs Riparian Trees and Tall Shrubs Mixed Shrubs vii In addition to the BPU layer, potential sampling target sites were created for each BPU polygon. Potential sampling points contain the X-Y coordinates (Universal Transverse Mercator (UTM) coordinates) and unique BPU codes relating to the soil type, topology, and likely vegetation at each site. Since most of AMIS can be assessed by boat, canoe, or on foot no cost estimate for travel to each unique site was estimated. Together, the BPU polygons and sample target points were summarized and these findings were incorporated into field maps and manuals. This report summarizes the gradsect concept, describes the variables used to model the vegetation distribution at AMIS, summarizes the methods, and presents the results. viii Introduction The National Vegetation Inventory Program (NVIP) consists of multi-stage projects for all NPS natural resource sites that use vegetation plot data to create plant association and vegetation alliance lists based on parameters specified by the National Vegetation Classification System (NVCS). The vegetation alliance list and supporting descriptions ultimately are used in the preparation of a vegetation geo-database (i.e. map) using geographic information system (GIS) software. Accessing