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A3347 Quercus lobata Woodland Alliance

Type Concept Sentence: This alliance consists of upland stands dominated by Quercus lobata that form woodland or savanna. Other species present may include Aesculus californica, Cercis canadensis var. texensis, Quercus agrifolia, Quercus douglasii, and Quercus wislizeni. It is found throughout the California Central Valley from Lake Shasta south to Los Angeles County.

Common (Translated Scientific) Name: Valley Oak Woodland Alliance

Colloquial Name: Valley Oak Upland Woodland

Hierarchy Level:  Alliance

Type Concept: Quercus lobata is the characteristic oak species of these savannas, though other species are present, including Aesculus californica, Cercis canadensis var. texensis, Juniperus californica, Quercus agrifolia, Quercus douglasii, and Quercus wislizeni. There is some evidence that much of the understory prior to the invasion by non-native annual grasses and forbs was composed of native annual herbs such as species of Calycadenia, Daucus, Eriogonum, Gilia, Hemizonia, Holocarpha, Lessingia, Lotus, Lupinus, Navarretia, and Trifolium. Nassella pulchra also was common. There is considerable seasonal and annual variation in cover of understory species due to phenology and intra-annual precipitation and temperature variation. Historically, these savannas occurred on alluvial terraces and flat plains, often with deep, fertile soils, throughout the California Central Valley from Lake Shasta south to Los Angeles County. This alliance is found from 10-1200 m (30-3600 feet) elevation, receiving on average 50 cm (range 25-100 cm) of precipitation per year, mainly as winter rain. Variable canopy densities in existing occurrences are likely due to variation in soil moisture regime, natural patch dynamics of fire, and land use (fire suppression, livestock grazing, herbivory, etc.).

Diagnostic Characteristics: Stands of Quercus lobata in an upland environment (clearly non-floodplain, non-riparian settings) either alone or mixed with other oaks.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Concept is based on the ecological system ~California Central Valley Mixed Oak Savanna (CES206.935)$$.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This sclerophyllous, extremely xeromorphic evergreen woodland forms an open to continuous tree canopy less than 30 m in height. Shrubs are occasional and lianas are common. The herbaceous layer is dominated by graminoids.

Floristics: Quercus lobata is the characteristic oak species of these savannas, though other species are present, including Aesculus californica, Cercis canadensis var. texensis (= Cercis occidentalis), Juniperus californica, Quercus agrifolia, Quercus douglasii, and Quercus wislizeni. There is some evidence that much of the understory prior to the invasion by non-native annual grasses and forbs was composed of native annual herbs such as species of Calycadenia, Daucus, Eriogonum, Gilia, Hemizonia, Holocarpha, Lessingia, Lotus, Lupinus, Navarretia, and Trifolium. Nassella pulchra also was common.

Dynamics:  Variable canopy densities in existing occurrences are likely due to variation in soil moisture regime, natural patch dynamics of fire, and land use (fire suppression, livestock grazing, herbivory, etc.
Environmental Description:  Historically, these savannas occurred on alluvial terraces and flat plains, often with deep, fertile soils, throughout the California Central Valley from Lake Shasta south to Los Angeles County. This alliance is found from 10-1200 m (30-3600 feet) elevation; receiving on average 50 cm (range 25-100 cm) of precipitation per year, mainly as winter rain.
Geographic Range: Historically, this alliance was found throughout the California Central Valley from Lake Shasta south to Los Angeles County.

Nations: US

States/Provinces:  CA


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: G3

Greasons: No Data Available
Type Name Database Code Classification Code
Class 1 Forest & Woodland Class C01 1
Subclass 1.B Temperate & Boreal Forest & Woodland Subclass S15 1.B
Formation 1.B.1 Warm Temperate Forest & Woodland Formation F018 1.B.1
Division 1.B.1.Nc Californian Forest & Woodland Division D007 1.B.1.Nc
Macrogroup 1.B.1.Nc.1 California Live Oak - California Laurel - Western Cypress species Forest & Woodland Macrogroup M009 1.B.1.Nc.1
Group 1.B.1.Nc.1.a California Live Oak - Valley Oak - California Laurel Forest & Woodland Group G195 1.B.1.Nc.1.a
Alliance A3347 Valley Oak Woodland Alliance A3347 1.B.1.Nc.1.a
Association CEGL002871 Valley Oak / Annual Grass-Herb Woodland CEGL002871 1.B.1.Nc.1.a
Association CEGL002872 Valley Oak - California Live Oak / Annual Grass-Herb Woodland CEGL002872 1.B.1.Nc.1.a
Association CEGL003096 Valley Oak Woodland CEGL003096 1.B.1.Nc.1.a
Concept Lineage: A.618, in parts

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: = Quercus lobata (Valley oak woodland) Alliance (Sawyer et al. 2009) [71.040.00]
= Quercus lobata Woodland Alliance (CNPS 2017) [71.040.00]
>< Great Valley Valley Oak Riparian Forest (#61430) (Holland 1986b)
>< Mainland Cherry Forest (#81820) (Holland 1986b)
>< Valley Oak Woodland (#71130) (Holland 1986b)
= Valley oak series (Sawyer and Keeler-Wolf 1995)
Concept Author(s): M.S. Reid, in Faber-Langendoen et al. (2013)

Author of Description: M.S. Reid

Acknowledgements: No Data Available

Version Date: 12-18-14
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