Vegetation Classification, Descriptions, and Mapping of the Clear Creek Management Area, Joaquin Ridge, Monocline Ridge, and Environs in San Benito and Western Fresno Counties, California Prepared By California Native Plant Society And California Department of Fish and Game Final Report Project funded by Funding Source: Resource Assessment Program California Department of Fish and Game And Funding Source: Resources Legacy Fund Foundation Grant Project Name: Central Coast Mapping Grant #: 2004-0173 2006 Vegetation Classification, Descriptions, and Mapping of the Clear Creek Management Area, Joaquin Ridge, Monocline Ridge, and Environs in San Benito and Western Fresno Counties, California 2006 Principal Investigators: California Native Plant Society staff: California Department of Fish and Game staff: Julie Evens, Senior Vegetation Ecologist Todd Keeler-Wolf, Ph.D., Senior Vegetation Anne Klein, Vegetation Ecologist Ecologist Jeanne Taylor, Vegetation Assistant Diana Hickson, Senior Biologist (Botany) Addresses: California Native Plant Society California Department of Fish and Game 2707 K Street, Suite 1 Biogeographic Data Branch Sacramento, CA 95816 1807 13th Street, Suite 202 Sacramento, CA 95814 Reviewers: Bureau of Land Management: Julie Anne Delgado, Botanist California State University: John Sawyer, Ph.D., Professor Emeritus TABLE OF CONTENTS ABSTRACT ................................................................................................................................................. 1 BACKGROUND............................................................................................................................................ 1 INTRODUCTION .......................................................................................................................................... 2 METHODS.................................................................................................................................................. 3 Study Area........................................................................................................................................... 3 Figure 1. Map of study area for vegetation classification and fine-scale mapping in the inner Central Coast Ranges. .................................................................................................................................... 5 Site Selection and Sampling ............................................................................................................... 6 Figure 2. Juxtaposition of serpentine barrens, dense chaparral, and open coniferous woodland within the heart of the Clear Creek Management Area....................................................................... 7 Figure 3. Map of the study area with locations of the vegetation rapid assessment surveys............. 8 Fine-scale Classification Analysis..................................................................................................... 10 Medium-scale Mapping Methodology ............................................................................................... 13 Fine-scale Mapping Methodology ..................................................................................................... 14 Polygon Attributes and Issues of Compatibility................................................................................. 15 Assessing Accuracy of the Mapping Methods .................................................................................. 17 Figure 4. Project area showing study boundary, four Test Areas, BLM’s Management Areas lines, and sample points from the vegetation surveys................................................................................ 18 Fuzzy Logic Rules for Accuracy Assessment of Vegetation Mapping.............................................. 19 Testing Spatial Accuracy of Mapping................................................................................................ 20 Diagnostic Key to the Alliances and Associations ............................................................................ 21 Description Writing ............................................................................................................................ 21 RESULTS ................................................................................................................................................. 23 Table 1. Rare plant species and number of occurrences found in vegetation surveys within the Clear Creek Management Area and adjacent lands, including the CNPS List ranking (per CNPS 2005). ................................................................................................................................................ 24 Figure 5. Example of the cluster analysis output showing the arrangement and relationship of surveys in the clustering diagram and their final association names................................................ 26 CLASSIFICATION ...................................................................................................................................... 27 Table 2. Vegetation classification and geology in the study area of Clear Creek Management Area, i Joaquin Ridge, and Monocline Ridge in San Benito and W Fresno Counties, California. ............... 28 Table 3. List of high priority vegetation types in the study area based on their global and state rankings............................................................................................................................................. 32 Table 4. Vegetation types impacted by off-road vehicle (ORV) and non-native species impacts in the study area including Clear Creek Management Area, Joaquin Ridge, and Monocline Ridge.... 33 Figure 6. Off-road vehicle impacts in study area, particularly in the sparsely vegetated areas of the Foothill Pine - Coulter Pine Barrens.................................................................................................. 36 CROSSWALKS TO OTHER CLASSIFICATIONS .............................................................................................. 37 ASSESSMENT OF THE ASSOCIATED MAPPING EFFORTS.............................................................................. 37 Table 5. The type and number of vegetation attributes (habitats, alliances, and/or associations) used in the two mapping efforts within the test areas of Congdon Peaks and Joaquin Rocks. ....... 38 Table 6. Accuracy assessment comparisons for Habitat type scores between the medium-scale (USFS-CalVeg) and fine-scale (AIS-Heads-up) methods................................................................. 41 Table 7. Comparison of the vegetation types attributed in the two mapping efforts, organized by the Alliance names identified in the accuracy assessment (AA) surveys............................................... 41 Figure 7. Example of medium-scale map with 4 polygons mapped as Blue Oak within which the fine-scale map had 28 polygons with 11 mapped as Blue Oak ........................................................ 43 Table 8. Accuracy assessment comparisons for under-delineation (or heterogeneity) scores between the medium-scale (USFS-CalVeg) and fine-scale (AIS-Heads-up) methods. ................... 45 Table 9. Accuracy assessment comparisons for Over-delineation scores between the medium-scale (USFS-CalVeg) and fine-scale (AIS-Heads-up) methods................................................................. 45 Figure 8. Example of medium-scale map with one large polygon mapped as Lower Elevation Mixed Chaparral habitat within which the fine-scale map had 323 polygons with 21 different alliances and habitats mapped................................................................................................................................ 46 Figure 9. Medium-scale map depicting 62 polygons with attributes of 5 vegetation types including Coastal Scrub, Blue Oak, and Chamise compared to the fine-scale map of 7 polygons including Herbaceous and Coastal Scrub. ....................................................................................................... 47 Conclusions of Accuracy Assessment .............................................................................................. 48 Assessment of Feasibility and Recommendations for the Interagency MOU Mapping Standards .. 48 Figure 10. Finer image segmentation by USFS as compared to the medium-scale polygon by USFS and as compared to the fine-scale delineation by AIS...................................................................... 50 DIAGNOSTIC VEGETATION KEY AND DESCRIPTIONS ................................................................................... 52 Table 10. Field key to the defined vegetation associations of the Clear Creek Management Area, ii Joaquin Ridge, and Monocline Ridge in the interior Central Coast, California................................. 53 TREE-OVERSTORY VEGETATION............................................................................................................... 65 Pinus coulteri-Calocedrus decurrens/Quercus durata Association....................................................... 65 Pinus coulteri-Calocedrus decurrens/Rhamnus tomentella/Aquilegia eximia Association ................... 67 Pinus coulteri-Calocedrus decurrens-Pinus jeffreyi/Quercus durata Association................................. 69 Pinus coulteri-Pinus sabiniana/Quercus durata-Arctostaphylos pungens Association......................... 71 Pinus coulteri/Arctostaphylos glauca Association