Key to Forests and Woodlands in California
- 1.
Riparian or wetland stands in cismontane California (west of the Cascade—Sierra and Transverse—Peninsular crests), or intermittently flooded to wetland stands mostly in transmontane California (east of the Cascades—Sierra Nevada crest and in southeastern California)
- 2.
Stands with high summer temperatures; they may receive minimal or predictable summer precipitation
- 3.
Stands primarily in transmontane California
- Betula occidentalis alliance*
- Chilopsis linearis alliance
- Parkinsonia florida—Olneya tesota alliance
- Prosopis glandulosa alliance
- Prosopis pubescens alliance
- Psorothamnus spinosus alliance
- Washingtonia filifera alliance
- 3′.
Stands primarily in cismontane California, but sometimes in transmontane California
- Acer negundo alliance
- Cephalanthus occidentalis alliance*
- Callitropsis sargentii alliance
- Chamaecyparis lawsoniana alliance
- Eucalyptus (camaldulensis, globulus) semi-natural stands
- Juglans californica alliance
- Juglans hindsii special and semi-natural stands
- Fraxinus latifolia alliance
- Pinus ponderosa alliance
- Platanus racemosa alliance
- Populus fremontii alliance
- Populus trichocarpa alliance
- Quercus lobata alliance
- Salix gooddingii alliance
- Salix laevigata alliance
- Salix lasiolepis alliance*
- Umbellularia californica alliance
- 2′.
Stands with cool to warm summer temperatures; they may receive fog, some summer precipitation, or direct summer moisture from springs or seeps
- Acer macrophyllum alliance
- Alnus rubra alliance
- Alnus rhombifolia alliance
- Calocedrus decurrens alliance
- Populus tremuloides alliance
- Populus trichocarpa alliance
- Salix lucida alliance
- 1′.
Stands in upland forests and woodlands
-
4. Stands in transmontane California
- 5.
Stands with hardwood trees in lower elevation environments of the Sonoran/Colorado deserts
- Bursera microphylla special stands
- Parkinsonia microphylla provisional alliance
- 5′.
Stands with a juniper, pine, or Joshua tree in middle to upper elevation environments of the Mojave and Great Basin deserts
- 6.
Junipers or Joshua tree dominate or co-dominate
- Juniperus californica alliance
- Juniperus grandis alliance
- Juniperus occidentalis alliance
- Juniperus osteosperma alliance
- Quercus cornelius-mulleri alliance*
- Quercus turbinella alliance*
- Yucca brevifolia alliance
- 6′.
Pines dominate or do-dominate
- Pinus edulis special stands
- Pinus jeffreyi alliance
- Pinus monophylla alliance
- Pinus ponderosa alliance
- Pinus ponderosa var. washoensis alliance
- 4′.
Upland stands mostly in cismontane California
- 7.
Upland stands in cismontane California at lower elevations (typically < 2000 m in elevation); stands receive precipitation mainly in the form of rain, and sometimes snow; many types localized
- 8.
Stands completely dominated by evergreen or winter-deciduous hardwood trees, or conifers may be associated with them and co-dominant
- 9.
Stands primarily dominated or co-dominated by evergreen broadleaf trees
- 10.
Stands in cooler coastal environments in central and northern California, or in inland mid-elevation mountains of southern to northern California; conifers may be co-dominant with hardwoods
- Arbutus menziesii alliance
- Chrysolepis chrysophylla alliance*
- Lithocarpus densiflorus alliance
- Pinus coulteri alliance
- Pseudotsuga macrocarpa alliance
- Pseudotsuga menziesii alliance
- Pseudotsuga menziesii—Lithocarpus densiflorus alliance
- Quercus chrysolepis (tree) alliance
- Sequoia sempervirens alliance
- Umbellularia californica alliance
- 10′.
Stands in warmer coastal environments in southern and central California and islands, or in inland low-elevation and foothills of northern California
- Eucalyptus (camaldulensis, globulus) semi-natural stands
- Lyonothamnus floribundus special stands
- Quercus agrifolia alliance
- Quercus palmeri alliance*
- Quercus parvula var. shrevei provisional alliance
- Quercus tomentella special stands
- Quercus wislizeni (tree) alliance
- Schinus (molle)—Myoporum laetum semi-natural stands
- 9′.
Stands with a noticeable proportion (usually > 50% relative cover) of winter-deciduous trees
- Aesculus californica alliance
- Juglans californica alliance
- Quercus douglasii alliance
- Quercus engelmannii alliance
- Quercus garryana (tree) alliance
- Quercus kelloggii alliance
- Quercus lobata alliance
- Quercus (agrifolia, douglasii, garryana, kelloggii, lobata, wislizeni) alliance
- 8′.
Forest and woodland stands dominated by conifers
- 11.
Stands occur in the Pacific Northwest, sometimes widespread, and reach their southern distributions coastally in northern or central California
- Abies grandis alliance
- Chamaecyparis lawsoniana alliance
- Picea sitchensis alliance
- Pinus contorta ssp. contorta alliance
- Pseudotsuga menziesii alliance
- Sequoia sempervirens alliance
- Tsuga heterophylla alliance
- 11′.
Stands endemic to cismontane California and sometimes in Baja California, but not present and widespread in the Pacific Northwest
- 12.
A cypress dominant or diagnostically present
- Hesperocyparis abramsiana special stands
- Hesperocyparis bakeri stands
- Hesperocyparis forbesii stands
- Hesperocyparis goveniana special stands
- Hesperocyparis macnabiana alliance
- Hesperocyparis macrocarpa special stands
- Hesperocyparis nevadensis stands
- Hesperocyparis pigmaea alliance
- Hesperocyparis sargentii alliance
- Hesperocyparis stephensonii special stands
- 12′.
A juniper or pine dominant or diagnostically present
- Juniperus californica alliance
- Pinus attenuata alliance
- Pinus coulteri alliance
- Pinus muricata alliance
- Pinus ponderosa alliance
- Pinus quadrifolia alliance
- Pinus radiata alliance
- Pinus sabiniana alliance
- Pinus torreyana special stands
- 7′.
Upland stands of colder cismontane California in the mountains (typically > 2000 m in elevation); stands receive precipitation mainly in the form of snow; diagnostic taxa widespread in California mountains and the western cordilleran
- 13.
Stands at upper montane to subalpine elevations; some types may be part of timberline or form extensive subalpine woodlands, others may be localized
- 14.
Stands at higher montane and subalpine elevations in the Klamath Mountains south into the central Sierra Nevada
- Abies amabilis alliance
- Abies lasiocarpa alliance
- Abies magnifica alliance
- Abies magnifica—Abies concolor alliance
- Callitropsis nootkatensis special stands
- Picea breweriana alliance
- Picea engelmannii alliance
- Pinus albicaulis alliance
- Pinus balfouriana alliance
- Pinus contorta ssp. murrayana alliance
- Pinus monticola alliance
- Populus tremuloides alliance
- Tsuga mertensiana alliance
- 14′.
Stands at subalpine elevations in the mountains in central and southern California
- Pinus albicaulis alliance
- Pinus balfouriana alliance
- Pinus contorta ssp. murrayana alliance
- Pinus monticola alliance
- Pinus flexilis alliance
- Pinus longaeva alliance
- Pinus monticola alliance
- 13′.
Stands of mid-elevations in the California’s mountains of cismontane California, or interior plateaus; winters are cold, but climate less extreme than at upper montane to subalpine elevations
- 15.
A fir is dominant or co-dominant with other conifers
- Abies bracteata alliance
- Abies concolor alliance
- Abies concolor—Pinus lambertiana alliance
- Abies concolor—Pseudotsuga menziesii alliance
- Abies magnifica—Abies concolor alliance
- 15′.
Another tree is dominant or co-dominant with other conifers
- 16.
A pine or incense cedar is dominant or co-dominant with other conifers
- Calocedrus decurrens alliance
- Pinus jeffreyi alliance
- Pinus lambertiana alliance
- Pinus ponderosa alliance
- Pinus ponderosa—Calocedrus decurrens alliance
- Pseudotsuga menziesii—Calocedrus decurrens alliance
- Pseudotsuga menziesii—Pinus ponderosa alliance
- 16′.
A hardwood is dominant to co-dominant with conifers
- Acer macrophyllum alliance
- Calocedrus decurrens alliance
- Pinus ponderosa alliance
- Pseudotsuga macrocarpa alliance
- Pseudotsuga menziesii alliance
- Pseudotsuga menziesii—Lithocarpus densiflorus alliance
- Pseudotsuga macrocarpa alliance
- Quercus garryana (tree) alliance
- Quercus kelloggii alliance
- Sequoiadendron giganteum alliance
*Treated in the shrub alliance descriptions
