Department of Fish and Game Biogeographic Data Branch Vegetation Classification and Mapping Program List of California Vegetation Alliances October 22, 2007 Introduction: This document provides the Vegetation Classification and Mapping Program’s currently accepted list of vegetation alliances. It is based on the classification put forth in the upcoming second edition of “A Manual of California Vegetation,” (MCV) which is the California expression of the National Vegetation Classification (Grossman et al. 1998). This classification is hierarchical in nature: alliances are the generic vegetation unit and associations the specific unit. We hope to publish a list of accepted associations in the near future. This list is structured differently than previous lists. It emphasizes the relationship of the California alliances with the current National Vegetation Classification System (NVC). NVC codes and names, if they have been identified, are shown in brackets. Those lacking NVC codes and titles indicate new alliances that have not been discovered in currently funded collaborative projects with NatureServe. Those listed in brackets have full descriptions viewable using the following link: http://www.natureserve.org/explorer/servlet/NatureServe?init=Ecol California community codes follow the same format as in previous editions and are based on the Holland coding system (Holland 1986) with additional modifiers to accommodate for new types and the richer detail now currently understood in the California vegetation classification. Semi-natural Stands and Unique Stands: In addition to alliances, this list includes Semi-natural stands and unique stands. Semi-natural stands are strongly dominated by non-native plants that have become naturalized in the state; no alliances are defined by non-natives. Unique stands (which will be called “Special Stands” in the second edition of the MCV) are specific patches of vegetation in the landscape that are unique from other patches, which may appear structurally distinctive as well as rare. These are defined by the presence of specific rare or threatened CNPS list plants that typically define a type, and that usually establish in less redundancy (e.g., less than 10 stands) across the landscape than other vegetation types. Certain rare plants establish with a unique set of species within certain climatic and edaphic conditions, and they typically co-dominate with a rare assemblage of species. Rarity Ranking: One of the primary purposes of the classification is to assist in the location and determinations of significance and rarity of vegetation types for tracking purposes in the California Natural Diversity Database (CNDDB). Thus, ranking of types by their rarity and threat is an important facet of the classification. In previous documents, asterisks (*) denoted special vegetation types that were either known or believed to have been of high priority for inventory in the CNDDB. Currently, this list refines the asterisks to actual “Global” or “State” rankings analogous to those provided with species reported in the CNDDB. These are ranked either G1, G2, G3, G4, or G5 using NatureServe’s standard heritage program methodology (http://www.natureserve.org/explorer/ranking.htm#interpret). If an alliance is marked with a G1 through a G3 code, this means that all of the associations within it will also be considered of high inventory priority. If marked as G4 or G5, these alliances are generally considered common enough to not be of concern. However, it does not mean that certain associations contained within them are not rare (G3 or lower). The forthcoming full association and alliance level ranking list will clarify these relationships. Lead and trustee agencies may request that impacts to these communities be addressed in environmental documents. For example, impacts to wetland community types should be addressed under the state’s no-net-loss of wetlands policy, or local agencies may have policies requiring avoidance of rare community types. Vegetation classification is an active field in California and new types will continue to be defined and their relationships refined for some time. Currently, we define approximately 500 alliances. We relish information on all vegetation types, whether it is a new record or re-assessment of existing information. Please contact us at VegCAMP at (916) 324-6857, and we can help you determine the most useful way to collect information on vegetation types. References: Grossman, D. H., K. Goodin, M. Anderson, P. Bourgeron, M. T. Bryer, R. Crawford, L. Engelking, D. Faber-Langendoen, M. Gallyoun, S. Landaal, K. Metzler, K. D. Patterson, M. Pyne, M. Reid, L. Sneddon, and A. S. Weakley. 1998. International classification of ecological communities: Terrestrial vegetation of the United States. The Nature Conservancy. Arlington, Virginia. Holland, R. 1986. Preliminary list of terrestrial natural communities of California. Department of Fish and Game, Sacramento, CA. Sawyer, J. O. and T. Keeler-Wolf. 1995. A Manual of California Vegetation. California Native Plant Society. Sacramento, CA. Global California Alliance Rarity California Scientific Name Classification Level Code Key Rank Abies amabilis Alliance 88.800.00 A.102 G5S2 Abies bracteata Alliance 88.300.00 A.147 G2S2 Abies concolor Alliance 88.500.00 A.103 G5S4 Abies concolor - Pinus lambertiana Alliance 88.510.00 A.2560 G4S4 Abies concolor - Pseudotsuga menziesii Alliance 88.530.00 G4S4 Abies grandis Alliance 88.100.00 A.153 G4S2 Abies lasiocarpa Alliance 88.400.00 A.177 G5S2 Abies magnifica Alliance 88.200.00 A.161 G4S4 Abies magnifica - Abies concolor Alliance 88.520.00 G4S4 Abronia latifolia - Ambrosia chamissonis Alliance 21.100.00 G3S3 Acacia greggii Alliance 33.040.00 A.1036 G4S3 Acer glabrum Proposed Alliance 61.430.00 A.915 G4S3? Acer macrophyllum Proposed Alliance 61.450.00 G4S3 Acer negundo Alliance 61.440.00 A.278 G5S3? Achnatherum hymenoides Alliance 41.120.00 A.1262 G4S2 Achnatherum speciosum Alliance 41.090.00 A.1290 G4S3 Adenostoma fasciculatum Alliance 37.101.00 A.755 G5S5 Adenostoma fasciculatum - Salvia apiana Alliance 37.103.00 G4S4 Adenostoma fasciculatum - Salvia mellifera Alliance 37.102.00 G4S4 Adenostoma fasciculatum - Xylococcus bicolor Alliance 37.109.00 G4S3 Adenostoma sparsifolium Alliance 37.501.00 A.756 G4S4 Aegilops triuncialis Semi-natural Non-native 42.003.00 U Aesculus californica Alliance 75.100.00 A.602 G3S3 Agave deserti Alliance 33.075.00 G4S3? Agropyron cristatum Semi-natural Non-native 42.030.00 A.3563 U Agrostis gigantea Proposed Alliance 45.105.00 G4?S3? Agrostis scabra Proposed Alliance 41.320.00 A.1351 G4S4? Agrostis stolonifera Semi-natural Non-native 41.330.00 A.1405 U Allenrolfea occidentalis Alliance 36.120.00 A.866 G4S3 Alnus incana Alliance 63.210.00 A.986 G5S4 Alnus rhombifolia Alliance 61.420.00 A.306 G4S4 Alnus rubra Alliance 61.410.00 A.342 G5S4 Alnus viridis Alliance 63.220.00 A.966 G5S3 Global California Alliance Rarity California Scientific Name Classification Level Code Key Rank Alopecurus geniculatus Proposed Alliance 42.006.00 G3S3? Ambrosia chamissonis Association 21.110.00 A.1614 G4S3 Ambrosia dumosa Alliance 33.060.00 A.1102 G5S4 Ambrosia psilostachya Proposed Alliance 33.065.00 G4S4 Ambrosia salsola Alliance 33.200.00 A.2512 G5S5 Ammophila arenaria Semi-natural Non-native 42.010.00 A.1206 U Anemopsis californica Proposed Alliance 52.214.00 G3S3? Arbutus menziesii Alliance 73.200.00 G4S4? Arctostaphylos bakeri Alliance 37.317.00 G2S2 Arctostaphylos canescens Proposed Alliance 37.311.00 G2S2 Arctostaphylos glandulosa Alliance 37.302.00 A.757 G4S4 Arctostaphylos glauca Alliance 37.301.00 A.759 G4S4 Arctostaphylos hookeri subsp. montana Alliance 37.307.00 A.2604 G2S2 Arctostaphylos hooveri Alliance 37.312.00 G3S3 Arctostaphylos manzanita Proposed Alliance 37.313.00 G4S4? Arctostaphylos montereyensis Proposed Alliance 37.314.00 G5S5 Arctostaphylos morroensis Alliance 37.315.00 G1S1 Arctostaphylos myrtifolia Alliance 37.304.00 A.760 G2S2 Arctostaphylos nummularia Alliance 37.306.00 A.2605 G3S3 Arctostaphylos pajaroensis Alliance 37.316.00 G1S1 Arctostaphylos patula Alliance 37.303.00 A.788 G5S4 Arctostaphylos pringlei subsp. drupacea Alliance 37.310.00 G4S3? Arctostaphylos pumila Proposed Alliance 37.318.00 G1S1 Arctostaphylos silvicola Proposed Alliance 37.320.00 G2S2 Arctostaphylos stanfordiana Proposed Alliance 37.319.00 G3S3 Arctostaphylos tomentosa subsp. tomentosa Alliance 37.308.00 A.761 G3S3 Arctostaphylos viscida Alliance 37.305.00 A.790 G4S4 Argentina anserina (egedii) Alliance 38.140.00 A.2621 G5S3? Aristida purpurea Proposed Alliance 45.425.00 A.2570 G4S3 Arnica amplexicaulis Proposed Alliance 45.424.00 G4S3? Artemisia arbuscula Alliance 35.120.00 A.1071 G4S4 Artemisia arbuscula subsp. longicaulis Proposed Alliance 35.121.00 G4S3? Artemisia californica Alliance 32.010.00 A.815 G5S4 Global California Alliance Rarity California Scientific Name Classification Level Code Key Rank Artemisia californica - Eriogonum fasciculatum Alliance 32.110.00 A.813 G4S4 Artemisia californica - Salvia mellifera Alliance 32.120.00 A.814 G4S4 Artemisia cana Alliance 35.150.00 A.2557 G4S3 Artemisia nova Alliance 35.130.00 A.1105 G5S3 Artemisia rothrockii Alliance 35.140.00 A.1098 G3S3 Artemisia tridentata Alliance 35.110.00 A.829 G5S4 Artemisia tridentata subsp. vaseyana Alliance 35.111.00 G5S4 Arthrocnemum subterminalis Alliance 52.212.00 G3S2? Arundo donax Semi-natural Non-native 42.080.00 A.1339 U Atriplex canescens Alliance 36.310.00 A.871 G5S4 Atriplex confertifolia