Vegetation alliances of the San Dieguito River Park region, San Diego County, California By Julie Evens and Sau San California Native Plant Society 2707 K Street, Suite 1 Sacramento CA, 95816 In cooperation with the California Natural Heritage Program of the California Department of Fish and Game And San Diego Chapter of the California Native Plant Society Final Report August 2005 Version 2 (Revised May 2006) TABLE OF CONTENTS Introduction...................................................................................................................................... 1 Methods ........................................................................................................................................... 2 Study area ................................................................................................................................... 2 Existing Literature Review........................................................................................................... 2 Sampling ..................................................................................................................................... 2 Figure 1. Study area including the San Dieguito River Park boundary within the ecological subsections color map and within the County inset map............................................................ 3 Figure 2. Locations of the field surveys....................................................................................... 5 Cluster analyses for vegetation classification ............................................................................. 6 Classification and Key................................................................................................................. 7 Description Writing ...................................................................................................................... 8 Results........................................................................................................................................... 10 Figure 3. Example of the cluster analysis of showing the arrangement and relationship of surveys in the clustering diagram and their final association names........................................ 11 Classification.................................................................................................................................. 12 Table 1. Final classification of vegetation alliances and associations from the San Dieguito River Park area, California, nested within the formation-level hierarchy per the National Vegetation Classification System (NVCS) ................................................................................ 13 Table 2. Additional plant communities listed in reports by Sproul (2001) and Moran (2004). .. 20 Crosswalks To Other Classifications............................................................................................. 21 Key and Descriptions..................................................................................................................... 21 Table 3. Field key to the defined vegetation alliances and associations of the San Dieguito River Park area, San Diego County, California......................................................................... 22 Tree Overstory Vegetation Descriptions ....................................................................................... 42 Abies concolor-Calocedrus decurrens Alliance (White Fir – Incense Cedar)........................... 42 Alnus rhombifolia Alliance (White Alder)................................................................................... 44 Calocedrus decurrens Alliance (Incense Cedar) ...................................................................... 46 Eucalyptus spp. Alliance (Eucalyptus) ...................................................................................... 48 i Pinus coulteri Alliance (Coulter Pine)........................................................................................ 50 Pinus coulteri-Quercus chrysolepis Alliance (Coulter Pine - Canyon Live Oak)....................... 52 Pinus torreyana Unique Stands (Torrey Pine) .......................................................................... 54 Platanus racemosa Alliance (California Sycamore).................................................................. 56 Platanus racemosa-Populus fremontii Alliance (California Sycamore - Fremont Cottonwood) 58 Populus fremontii Alliance (Fremont Cottonwood).................................................................... 60 Pseudotsuga macrocarpa Alliance (Bigcone Douglas-fir)......................................................... 62 Quercus agrifolia Alliance (Coast Live Oak) ............................................................................. 64 Quercus chrysolepis Alliance (Canyon Live Oak)..................................................................... 67 Quercus engelmannii Alliance (Engelmann Oak) ..................................................................... 69 Quercus kelloggii Alliance (Black Oak) ..................................................................................... 72 Salix gooddingii Alliance (Black Willow).................................................................................... 74 Salix laevigata Alliance (Red Willow)........................................................................................ 76 Shrub Overstory Vegetation Descriptions ..................................................................................... 78 Acacia greggii Alliance (Catclaw Acacia).................................................................................. 78 Adenostoma fasciculatum Alliance (Chamise).......................................................................... 80 Adenostoma fasciculatum-Arctostaphylos glandulosa Alliance (Chamise - Eastwood Manzanita)................................................................................................................................. 82 Adenostoma fasciculatum-Arctostaphylos glauca Alliance (Chamise - Bigberry Manzanita)... 84 Adenostoma fasciculatum-Ceanothus greggii Alliance (Chamise - Cupleaf Ceanothus)......... 86 Adenostoma fasciculatum-Salvia apiana Alliance (Chamise - White Sage)............................. 88 Adenostoma fasciculatum-Xylococcus bicolor Alliance (Chamise - Mission Manzanita) ......... 90 Arctostaphylos glandulosa Alliance (Eastwood Manzanita)...................................................... 93 Arctostaphylos glauca Alliance (Bigberry Manzanita)............................................................... 95 Arctostaphylos pringlei Alliance (Pink-bracted Manzanita)....................................................... 97 Artemisia californica Alliance (California Sagebrush) ............................................................... 99 Artemisia californica-Eriogonum fasciculatum Alliance (California Sagebrush - California Buckwheat).............................................................................................................................. 101 Artemisia californica-Salvia apiana Alliance (California Sagebrush - White Sage) ................ 103 Artemisia californica-Salvia mellifera Alliance (California Sagebrush - Black Sage).............. 105 Baccharis pilularis Alliance (Coyote Brush) ............................................................................ 107 Baccharis salicifolia Alliance (Mulefat).................................................................................... 109 Ceanothus crassifolius Alliance (Hoaryleaf Ceanothus)......................................................... 111 Ceanothus integerrimus Alliance (Deerbrush) ........................................................................ 113 Ceanothus leucodermis Alliance (Chaparral Whitethorn)....................................................... 115 ii Ceanothus oliganthus Alliance (Hairyleaf Ceanothus)............................................................ 117 Ceanothus verrucosus Alliance (White Coast Ceanothus)..................................................... 120 Cercocarpus minutiflorus Unique Stands (San Diego Mountain-mahogany) ......................... 122 Chilopsis linearis Alliance (Desert Willow) .............................................................................. 124 Dendromecon rigida Alliance (Bush Poppy) ........................................................................... 126 Encelia californica Alliance (California Encelia) ...................................................................... 128 Eriogonum fasciculatum Alliance (California Buckwheat)....................................................... 130 Eriogonum fasciculatum-Salvia apiana Alliance (California Buckwheat - White Sage).......... 132 Eriogonum wrightii Alliance (Wright's Buckwheat).................................................................. 134 Gutierrezia sarothrae Alliance (Matchweed Alliance) ............................................................. 136 Isocoma menziesii Alliance (Goldenbush) .............................................................................. 138 Keckiella antirrhinoides Alliance (Bush Penstemon)............................................................... 140 Lotus scoparius Alliance (Deerweed)...................................................................................... 142 Malosma laurina Alliance (Laurel Sumac)............................................................................... 144 Mesembryanthemum spp. - Carpobrotus