Print Report
G195 Quercus agrifolia - Quercus lobata - Umbellularia californica Forest & Woodland Group
Type Concept Sentence: This group consists of oak and other broadleaf woodlands largely endemic to the California Floristic Province that forms one of the most extensive and conspicuous vegetation types in California. Anchored by six endemic, widespread and overlapping characteristic oak species which are (in alphabetical order): Quercus agrifolia, Quercus chrysolepis, Quercus douglasii, Quercus kelloggii, Quercus lobata, and Quercus wislizeni.
Common (Translated Scientific) Name: California Live Oak - Valley Oak - California Laurel Forest & Woodland Group
Colloquial Name: Californian Broadleaf Forest & Woodland
Hierarchy Level: Group
Type Concept: This group consists of oak and other broadleaf woodlands largely endemic to the California Floristic Province. It forms one of the most extensive and conspicuous vegetation types in California. Anchored by six endemic, widespread and overlapping characteristic oak species which are (in alphabetical order): Quercus agrifolia, Quercus chrysolepis, Quercus douglasii, Quercus kelloggii, Quercus lobata, and Quercus wislizeni. These occur throughout California on coastal plains, in the coastal mountains from north to south, in the foothills surrounding the Central Valley, in the Sierra Nevada foothills up to 2000 m (rarely as high as 2500 m [8200 feet]) elevation, in the Klamath Mountains of the northwest, in the Peninsula Ranges in the south, as well as on the Channel Islands. Quercus wislizeni intermixes extensively with Quercus douglasii throughout almost all of its range. The same is true with Quercus lobata and Quercus douglasii or Quercus wislizeni. Quercus lobata and Quercus wislizeni may both be found in riparian or semi-riparian settings, and Quercus lobata is often found in mountains and foothills at higher elevations than Quercus douglasii in the foothills and Coast Ranges. On the Channel Islands, there are several island endemic broadleaf tree species; however, these are associated and intermix with non-island endemics, for example Lyonothamnus spp. and Quercus tomentella are often associated with Quercus agrifolia and are clearly ecologically related to them. Although Umbellularia californica is typically more mesic than many oaks, it is regularly associated with Quercus agrifolia in the Coast Ranges and with Quercus chrysolepis in the Klamath Mountains, in the Sierra Nevada and the southern California mountains. The "mixed" oak alliance (Quercus agrifolia, Quercus douglasii, Quercus kelloggii, Quercus lobata, and Quercus wislizeni) is another example of why a split between evergreen and deciduous species or montane versus lower-elevation types cannot represent the ecology of these woodland communities. There are many stands in the Coast Ranges and other parts of the state where two or more species of evergreen and deciduous oaks codominate.
The species with the widest range is Quercus chrysolepis, ranging up into central Oregon and east into Arizona. Looking at association-level diversity, these stands are primarily in the California Floristic Province. Quercus chrysolepis-dominated stands are clearly associated with warm California Mediterranean climate and are regularly associated with Quercus kelloggii, Aesculus californica, and Quercus wislizeni throughout much of the state. Thus, although Quercus chrysolepis and Quercus kelloggii are often considered more "montane" than other California oaks, they overlap extensively with other oaks in the Sierra Nevada foothills and in the Coast Ranges. Similarly, Quercus douglasii and Quercus wislizeni, a deciduous and an evergreen oak, respectively, are the most commonly overlapping species in the warmer inland foothills surrounding the Great Valley.
In addition, in southern California, in the Peninsular Ranges, Quercus engelmannii occurs and mixes with several of the above-mentioned species. Also included in this group are distinctive woodlands of other California endemic broadleaf tree species that occur as pure stands adjacent to oak woodlands, but also commonly are components of oak woodland canopy. These are Aesculus californica, Juglans californica, and Umbellularia californica.
These woodlands vary in density from open savannas, moderately closed woodlands to closed canopy forests. In some cases, oak woodlands are of a single oak dominance by Quercus douglasii, Quercus lobata, Quercus agrifolia, Quercus kelloggii, Quercus chrysolepis, or Quercus wislizeni trees that are scattered across the landscape, and in other cases, trees of mixed composition form a closed tree canopy. They share strong adaptation to dry summers and relatively warm rainy winters, characteristic of the Californian Mediterranean climate.
The species with the widest range is Quercus chrysolepis, ranging up into central Oregon and east into Arizona. Looking at association-level diversity, these stands are primarily in the California Floristic Province. Quercus chrysolepis-dominated stands are clearly associated with warm California Mediterranean climate and are regularly associated with Quercus kelloggii, Aesculus californica, and Quercus wislizeni throughout much of the state. Thus, although Quercus chrysolepis and Quercus kelloggii are often considered more "montane" than other California oaks, they overlap extensively with other oaks in the Sierra Nevada foothills and in the Coast Ranges. Similarly, Quercus douglasii and Quercus wislizeni, a deciduous and an evergreen oak, respectively, are the most commonly overlapping species in the warmer inland foothills surrounding the Great Valley.
In addition, in southern California, in the Peninsular Ranges, Quercus engelmannii occurs and mixes with several of the above-mentioned species. Also included in this group are distinctive woodlands of other California endemic broadleaf tree species that occur as pure stands adjacent to oak woodlands, but also commonly are components of oak woodland canopy. These are Aesculus californica, Juglans californica, and Umbellularia californica.
These woodlands vary in density from open savannas, moderately closed woodlands to closed canopy forests. In some cases, oak woodlands are of a single oak dominance by Quercus douglasii, Quercus lobata, Quercus agrifolia, Quercus kelloggii, Quercus chrysolepis, or Quercus wislizeni trees that are scattered across the landscape, and in other cases, trees of mixed composition form a closed tree canopy. They share strong adaptation to dry summers and relatively warm rainy winters, characteristic of the Californian Mediterranean climate.
Diagnostic Characteristics: These woodlands are characterized by warm Mediterranean climate-adapted evergreen and deciduous sclerophyllous broad-leaved trees. Characteristic taxa include Quercus agrifolia, Quercus douglasii, Quercus wislizeni, Quercus chrysolepis, Quercus wislizeni, Quercus engelmannii, Quercus lobata, Aesculus californica, Juglans californica, and Umbellularia californica.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: While it is possible to characterize large categories within this group, such as Quercus douglasii woodlands, Quercus douglasii - Pinus sabiniana woodlands, coast oak woodlands, and montane hardwood forests, as noted in Barbour et al. (2007) and Allen-Diaz et al. (2007), quantitative plot data and vegetation mapping projects (for example, Evens et al. 2004, Keeler-Wolf et al. 2003, and Klein et al. 2007) show that all of these woodlands co-occur, intermix, hybridize, and share similar understory shrub and herbaceous species.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Medium tall 10-15 m trees, that are evergreen and deciduous sclerophyllous broad-leaved. They occur with and without shrub understory or an herbaceous understory. Upper canopy structure ranges from open savanna to dense woodlands. They can form gallery forests along riparian corridors, and are known to form a mosaic with chaparral and conifer woodlands.
Floristics: This large group consists of various mixtures of oak and/or other broadleaf species in the overstory canopy with many combinations possible among the six wide-ranging oaks. For example, Quercus douglasii can share dominance with Quercus lobata, Quercus agrifolia, Quercus kelloggii, Quercus chrysolepis, Quercus wislizeni, or Quercus engelmannii. However, Quercus chrysolepis and Quercus kelloggii often co-occur at slightly higher montane settings. They also often mix with Quercus douglasii, Aesculus californica, and Quercus wislizeni or with Quercus lobata and Quercus agrifolia (only in the coastal ranges) in canyon bottoms and riparian settings. Along the coast, Quercus agrifolia is frequently dominant but may be found with all of the other oaks and Umbellularia, Juglans, and Aesculus. In the Coast Ranges, Sierra Nevada foothills and elsewhere, Quercus lobata stands occur in riparian zones or alluvial valley floors at higher elevations than its upslope neighbor Quercus douglasii. These two species intermix in narrow tributary drainages. In southern California, Quercus engelmannii is limited to the Peninsular Ranges but may co-occur with Quercus agrifolia, Quercus chrysolepis, Quercus wislizeni, and Quercus kelloggii. On the Channel Islands, the island oak endemics form pure stands and stands mixed with Quercus agrifolia, and rarely with Quercus chrysolepis, Quercus douglasii, and Quercus lobata.
All of these species can occur as pure or nearly pure single-species canopies. Mosaics of Aesculus woodlands with Quercus douglasii woodlands and a few Quercus agrifolia woodlands are characteristic of portions of the interior coastal ranges. In the Sierra Nevada foothills, mosaics of Quercus douglasii, Quercus chrysolepis, and Quercus kelloggii woodlands occur and can have Quercus lobata along broader valley bottoms. In addition to these mosaics of single-oak-dominated woodlands, there are many associations of mixed canopies, depending on soil, exposure and past disturbance history. As such, these woodlands intermix and interchange throughout their range, making floristic separation into natural distinct subcategories impossible. Despite the overlap of several species, individual integrity of the component alliances is strong. Modal stands of Quercus chrysolepis occur in the lower montane zone on well-drained rocky sites, while Quercus kelloggii modal stands occur on deeper soils with more mesic conditions. In the foothills and valleys of central and northern California, modal stands of Quercus douglasii tend to occur on fine-textured soils, while Quercus wislizeni stands are more common on well-drained soils. Conversely, in the foothills, Aesculus californica occurs on very rocky but sheltered well-drained sites, and Quercus lobata on loamy soils or soils with higher moisture potential. Closer to the coast, Quercus agrifolia stands are found on loamy soils on better-drained sites compared to Umbellularia californica stands, which occur on sheltered slopes or on slopes exposed to moist sea breezes, while Quercus parvula var. shrevei stands occur in sheltered locations intermediate between Quercus agrifolia and Pseudotsuga menziesii or Sequoia sempervirens stands.
In coastal California south of the crest of the Transverse Ranges, Quercus lobata stands are rare and localized and may be replaced by Quercus engelmannii, which can occur on finer-textured soils of warm slopes and valleys. Quercus douglasii and Aesculus californica are also largely absent. As it does in northern and central California, Quercus wislizeni occurs on coarse-textured slopes often adjacent to chaparral, or on lower slopes with well-drained soil. The winter deciduous tree Juglans californica forms stands on sheltered slopes and on lower slopes on moist terraces sometimes in similar ecological settings to Quercus lobata, sometimes with Quercus agrifolia.
All of these species can occur as pure or nearly pure single-species canopies. Mosaics of Aesculus woodlands with Quercus douglasii woodlands and a few Quercus agrifolia woodlands are characteristic of portions of the interior coastal ranges. In the Sierra Nevada foothills, mosaics of Quercus douglasii, Quercus chrysolepis, and Quercus kelloggii woodlands occur and can have Quercus lobata along broader valley bottoms. In addition to these mosaics of single-oak-dominated woodlands, there are many associations of mixed canopies, depending on soil, exposure and past disturbance history. As such, these woodlands intermix and interchange throughout their range, making floristic separation into natural distinct subcategories impossible. Despite the overlap of several species, individual integrity of the component alliances is strong. Modal stands of Quercus chrysolepis occur in the lower montane zone on well-drained rocky sites, while Quercus kelloggii modal stands occur on deeper soils with more mesic conditions. In the foothills and valleys of central and northern California, modal stands of Quercus douglasii tend to occur on fine-textured soils, while Quercus wislizeni stands are more common on well-drained soils. Conversely, in the foothills, Aesculus californica occurs on very rocky but sheltered well-drained sites, and Quercus lobata on loamy soils or soils with higher moisture potential. Closer to the coast, Quercus agrifolia stands are found on loamy soils on better-drained sites compared to Umbellularia californica stands, which occur on sheltered slopes or on slopes exposed to moist sea breezes, while Quercus parvula var. shrevei stands occur in sheltered locations intermediate between Quercus agrifolia and Pseudotsuga menziesii or Sequoia sempervirens stands.
In coastal California south of the crest of the Transverse Ranges, Quercus lobata stands are rare and localized and may be replaced by Quercus engelmannii, which can occur on finer-textured soils of warm slopes and valleys. Quercus douglasii and Aesculus californica are also largely absent. As it does in northern and central California, Quercus wislizeni occurs on coarse-textured slopes often adjacent to chaparral, or on lower slopes with well-drained soil. The winter deciduous tree Juglans californica forms stands on sheltered slopes and on lower slopes on moist terraces sometimes in similar ecological settings to Quercus lobata, sometimes with Quercus agrifolia.
Dynamics: No Data Available
Environmental Description: Woodlands of this group occur on a wide variety of habitats. All occur in valley bottoms, stream benches and terraces in canyon bottoms near streams, on gentle lower upland slopes, steep upper slopes, foothills, and on rocky outcrops, on all aspects. Slopes range from gentle to steep. Quercus lobata and Quercus agrifolia woodlands prefer deeper alluvial, residual or organic soils, while Quercus douglasii, Quercus kelloggii, Quercus chrysolepis, and Quercus wislizeni woodlands tolerate, and are more commonly found on, moderately to excessively well-drained, thin, rocky nutrient-poor soils which can have extensive rock fragments. Channel Island endemics occur on marine sedimentary (including calcareous), granitic, or volcanic substrates. Aesculus californica, Juglans californica, and Umbellularia californica tend to occur on slightly more mesic sites or concavities, and are more often in association with Quercus agrifolia, but are also known from a wide variety of habitats. The dominate tree species have considerable overlap in elevational range, from sea level to 2500 m. In general terms, Quercus lobata, Quercus tomentella, and Lyonothamnus floribundus range from sea level to about 700 m; Quercus agrifolia and Umbellularia californica range from sea level to 1200 m; Quercus douglasii, Quercus engelmannii, and Quercus kelloggii range from about 50 to 2500 m; Aesculus californica and Juglans californica range from about from 100 to 1500 m; and Quercus chrysolepis and Quercus wislizeni range from about 500 to 2000 m.
Geographic Range: Northern California Coast, Northern California Coast Ranges, Northern California Interior Coast Ranges, Klamath Mountains, Southern Cascades, Central California Coast, Central California Coast Ranges, throughout the Great Valley, Sierra Nevada lower montane elevations, Sierra Nevada Foothills, Southern California Coast, Southern Californian Mountain and Valleys, the Channel Islands, and canyons of the Mojave Desert.
Nations: MX,US
States/Provinces: CA, MXBCN, OR
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.833203
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
Concept Lineage: G207, G196 & G197 merged into G195
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: > Quercus agrifolia Alliance (Sawyer et al. 2009) [71.060.00]
> Quercus chyrsolepis Alliance (Sawyer et al. 2009) [71.050.00]
> Quercus douglasii Alliance (Sawyer et al. 2009) [71.020.00]
> Quercus engelmanii Alliance (Sawyer et al. 2009) [71.070.00]
> Quercus kelloggii Alliance (Sawyer et al. 2009) [71.010.00]
> Quercus lobata Alliance (Sawyer et al. 2009) [71.040.00]
> Quercus wislizenii Alliance (Sawyer et al. 2009) [71.080.00]
> Umbellularia californica Alliance (Sawyer et al. 2009) [74.100.00]
= Oak Woodland and Forests (Barbour et al. 2007a) [this is only missing the Channel Island endemics.]
> Quercus chyrsolepis Alliance (Sawyer et al. 2009) [71.050.00]
> Quercus douglasii Alliance (Sawyer et al. 2009) [71.020.00]
> Quercus engelmanii Alliance (Sawyer et al. 2009) [71.070.00]
> Quercus kelloggii Alliance (Sawyer et al. 2009) [71.010.00]
> Quercus lobata Alliance (Sawyer et al. 2009) [71.040.00]
> Quercus wislizenii Alliance (Sawyer et al. 2009) [71.080.00]
> Umbellularia californica Alliance (Sawyer et al. 2009) [74.100.00]
= Oak Woodland and Forests (Barbour et al. 2007a) [this is only missing the Channel Island endemics.]
- Allen-Diaz, B., R. Standiford, and R. D. Jackson. 2007. Oak woodlands and forests. Pages 313-338 in: M. G. Barbour, T. Keeler-Wolf, and A. Schoenherr, editors. Terrestrial vegetation of California. Third edition. University of California Press, Berkeley, CA.
- Barbour, M. G., T. Keeler-Wolf, and A. A. Schoenherr, editors. 2007a. Terrestrial vegetation of California, third edition. University of California Press, Berkeley.
- Barbour, M. G., and J. Major, editors. 1988. Terrestrial vegetation of California: New expanded edition. California Native Plant Society, Special Publication 9, Sacramento. 1030 pp.
- Barbour, M. G., and W. D. Billings, editors. 2000. North American terrestrial vegetation. Second edition. Cambridge University Press, New York. 434 pp.
- Evens, J. M., S. San, and J. Taylor. 2004. Vegetation classification and mapping of Peoria Wildlife Area, south of New Melones Lake, Tuolumne County, California. Prepared by California Native Plant Society, Sacramento, CA, in collaboration with J. Menke of Aerial Information Systems, Redlands, CA. 175 pp.
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- Holland, V. L., and D. J. Keil. 1995. California vegetation. Kendall/Hunt Publishing Company, Dubuque, IA. 516 pp.
- Keeler-Wolf, T., M. Schindel, S. San, P. Moore, and D. Hickson. 2003a. Classification of the vegetation of Yosemite National Park and surrounding environs in Tuolumne, Mariposa, Madera and Mono counties, California. Unpublished report by NatureServe in cooperation with the California Native Plant Society and California Department of Fish and Game, Wildlife and Habitat Data Analysis Branch, Sacramento, CA.
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- Shiflet, T. N., editor. 1994. Rangeland cover types of the United States. Society for Range Management. Denver, CO. 152 pp.
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