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A0618 Quercus lobata Riparian Forest Alliance

The U.S. National
Vegetation Classification
Type Concept Sentence: This California riparian woodland alliance is dominated by Quercus lobata that occurs in valley bottoms and gentle slopes that are intermittently flooded with seasonally saturated soils. This alliance is not to be confused with an upland Quercus lobata alliance.
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Common (Translated Scientific) Name: Valley Oak Riparian Forest Alliance
Colloquial Name: Valley Oak Riparian Forest
Hierarchy Level: Alliance
Type Concept: This California riparian woodland alliance is dominated by Quercus lobata. Other trees in the canopy may include Alnus rhombifolia, Fraxinus latifolia, Platanus racemosa, Quercus agrifolia, Quercus douglasii, Quercus kelloggii, and Salix spp. Occasional shrubs may include Frangula californica ssp. californica, Rubus armeniacus, and Toxicodendron diversilobum. Lianas such as Vitis californica are common. Annual grasses dominate the ground layer. Stands occur in valley bottoms and on gentle slopes and require intermittently flooded, seasonally saturated soils. Soils are deep and alluvial or residual, and the water must be fresh. Elevations range from sea level to 1158 m. The climate regime throughout the range of this alliance is strongly Mediterranean, with cool, moist winters and warm, dry summers. Most precipitation falls as rain between November and April. Yearly rainfall totals average approximately 60 cm.
Diagnostic Characteristics: Valley bottom and intermittent stream stands of Quercus lobata.
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: Deep alluvial soils, valley bottom stands.
Similar NVC Types:
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: Stands of this California woodland alliance are dominated by Quercus lobata. Other trees in the canopy may include Alnus rhombifolia, Fraxinus latifolia, Platanus racemosa, Quercus agrifolia, Quercus douglasii, Quercus kelloggii, and Salix spp. Occasional shrubs may include Frangula californica ssp. californica, Rubus armeniacus (= Rubus discolor), and Toxicodendron diversilobum. Lianas such as Vitis californica are common. Annual grasses dominate the ground layer.
Dynamics: Periodic, low-intensity floods help maintain this alliance. Stands are usually found outside the immediate zone of high-energy floodwaters, in the lower-energy margins of the floodplain.
Environmental Description: This woodland alliance of valley bottoms and gentle slopes requires intermittently flooded, seasonally saturated soils. The soils are deep and alluvial or residual, and the water must be fresh. Elevations range from sea level to 1158 m. The climate regime throughout the range of this alliance is strongly Mediterranean, with cool, moist winters and warm, dry summers. Most precipitation falls as rain between November and April. Yearly rainfall totals average approximately 60 cm.
Geographic Range: Stands of this alliance are found in California's Coast Ranges, the Great Central Valley, the foothills of the Sierra Nevada, the Cascade Range and the Klamath Mountains.
Nations: US
States/Provinces: CA
US Forest Service Ecoregions (1994/1995)
Domain Name:
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Omernik Ecoregions:
Confidence Level: Moderate
Confidence Level Comments:
Grank: GNR
Greasons:
Name:Database Code:Classification Code:
Class 1 Forest & Woodland C01 1
Subclass 1.B Temperate & Boreal Forest & Woodland S15 1.B
Formation 1.B.3 Temperate Flooded & Swamp Forest F026 1.B.3
Division 1.B.3.Nd Western North American Interior Flooded Forest D013 1.B.3.Nd
Macrogroup M036 Interior Warm & Cool Desert Riparian Forest M036 1.B.3.Nd.2
Group G797 Western Interior Riparian Forest & Woodland G797 1.B.3.Nd.2.b
Alliance A0618 Valley Oak Riparian Forest A0618
Association CEGL002873 CEGL002873
Concept Lineage:
Predecessors:
Obsolete Names:
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Synonomy: = Quercus lobata Woodland Alliance (Keeler-Wolf et al. 2012)
< Quercus lobata (Valley oak woodland) Alliance (Sawyer et al. 2009) [71.040.00]
= Quercus lobata Alliance (Valley oak woodland) (Buck-Diaz et al. 2012)
? Great Valley Valley Oak Riparian Forest (#61430) (Holland 1986b)
? Valley Oak Woodland (#71130) (Holland 1986b)
Concept Author(s): M. Schindel, J. Evens and A. Klein, in Faber-Langendoen et al. (2013)
Author of Description: G. Kittel
Acknowledgements:
Version Date: 26Sep2014
References:
  • Buck-Diaz, J., S. Batiuk, and J. M. Evens. 2012. Vegetation alliances and associations of the Great Valley ecoregion, California. California Native Society, Sacramento, CA. [http://cnps.org/cnps/vegetation/pdf/great_valley_eco-vegclass2012.pdf]
  • Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
  • Holland, R. F. 1986b. Preliminary descriptions of the terrestrial natural communities of California. Unpublished report prepared for the California Department of Fish and Game, Nongame-Heritage Program and Natural Diversity Database, Sacramento. 156 pp.
  • Keeler-Wolf, T., P. E. Moore, E. T. Reyes, J. M. Menke, D. N. Johnson, and D. L. Karavidas. 2012. Yosemite National Park vegetation classification and mapping project report. Natural Resource Technical Report NPS/YOSE/NRTR--2012/598. National Park Service, Fort Collins, CO.
  • Sawyer, J. O., and T. Keeler-Wolf. 1995. A manual of California vegetation. California Native Plant Society, Sacramento. 471 pp.
  • Sawyer, J. O., T. Keeler-Wolf, and J. Evens. 2009. A manual of California vegetation. Second edition. California Native Plant Society, Sacramento CA. 1300 pp.