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A3676 Pinus jeffreyi - Pinus ponderosa var. washoensis Mixed Conifer Woodland Alliance

Type Concept Sentence: The alliance is dominated by Pinus jeffreyi or Pinus ponderosa var. washoensis with a dense to open canopy ranging from forests to woodlands to wooded herbaceous stands. Other trees that can be codominant include Pinus ponderosa, Calocedrus decurrens, Chrysolepis chrysophylla, Pseudotsuga menziesii, Pinus monticola, Pinus monophylla, Abies magnifica, and Abies lowiana. This alliance occurs on well-drained, productive or infertile soils regardless of parent material throughout much of California, including the east side of the Sierra Nevada and Modoc Plateau area, the Klamath Mountains and northern Coast Ranges.

Common (Translated Scientific) Name: Jeffrey Pine - Washoe Pine Mixed Conifer Woodland Alliance

Colloquial Name: Jeffrey Pine - Washoe Pine Mixed Conifer Woodland

Hierarchy Level:  Alliance

Type Concept: The alliance is dominated by Pinus jeffreyi or Pinus ponderosa var. washoensis with a dense to open canopy ranging from forests to woodlands to wooded herbaceous stands. Other codominant trees include Pinus ponderosa, Calocedrus decurrens, Chrysolepis chrysophylla, Pseudotsuga menziesii, Pinus monticola, Pinus monophylla, Abies magnifica, and Abies lowiana. Additional trees that may be present include Arbutus menziesii, Quercus kelloggii, Quercus chrysolepis, Quercus wislizeni, Pinus ponderosa, and Chamaecyparis lawsoniana. Shrubs present may include Artemisia tridentata ssp. vaseyana, Arctostaphylos nevadensis, Arctostaphylos patula, Arctostaphylos canescens, Ceanothus pumilus, Ceanothus cuneatus, Ceanothus cordulatus, Ceanothus velutinus, Cercocarpus ledifolius, Chrysolepis sempervirens, Ericameria ophitidis, Purshia tridentata, Quercus vacciniifolia, Rhus trilobata, and/or Symphoricarpos longiflorus. This alliance is found throughout much of California, including the east side of the Sierra Nevada and Modoc Plateau area, the Klamath Mountains and northern Coast Ranges. Stands occur on well-drained, productive or infertile soils regardless of parent material. Some self-replicating stands are found on strongly serpentinized peridotite. Most commonly, stands are found on ultramafic-derived soils.

Diagnostic Characteristics: Pinus jeffreyi or Pinus ponderosa var. washoensis with >50% relative cover or similar cover to that of other conifer tree species present.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This includes stands where Pinus jeffreyi or Pinus ponderosa var. washoensis is the sole tree present, as well as mixed stands. The hybridization between Pinus ponderosa var. ponderosa, Pinus jeffreyi, and Pinus ponderosa var. washoensis may cause some confusion.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This rounded-crown, needle-leaved evergreen woodland forms an open or intermittent canopy less than 25 m in height. The shrub layer is sparse and the herbaceous layer is grassy.

Floristics: The alliance is dominated by Pinus jeffreyi or Pinus ponderosa var. washoensis (= Pinus washoensis) with a dense to open canopy ranging from forests to woodlands to wooded herbaceous stands. Other codominant trees include Pinus ponderosa, Calocedrus decurrens, Chrysolepis chrysophylla, Pseudotsuga menziesii, Pinus monticola, Pinus monophylla, Abies magnifica, and Abies lowiana (= Abies concolor var. lowiana). Additional trees that may be present include Arbutus menziesii, Quercus kelloggii, Quercus chrysolepis, Quercus wislizeni, Pinus attenuata, Pinus contorta var. murrayana, Pinus ponderosa, and Chamaecyparis lawsoniana. Shrubs present may include Ceanothus pumilus (= Ceanothus prostratus ssp. pumilus), Ceanothus cuneatus, Ceanothus velutinus , Arctostaphylos patula, Arctostaphylos canescens, Purshia tridentata, Rhus trilobata, Cercocarpus ledifolius, Symphoricarpos longiflorus, Quercus vacciniifolia, Artemisia tridentata ssp. vaseyana, Ceanothus cordulatus, Arctostaphylos nevadensis, Ericameria ophitidis, Pseudostellaria jamesiana and Chrysolepis sempervirens. Graminoid undergrowth species include Achnatherum occidentale (= Stipa occidentalis), Calamagrostis koelerioides, Elymus glaucus, Elymus elymoides, Festuca californica, Festuca idahoensis, Koeleria macrantha, Poa secunda, and Poa wheeleri. Forb species include Achillea millefolium, Allium falcifolium, Castilleja applegatei, Eriogonum umbellatum, Eriophyllum lanatum, Iris innominata, Lupinus caudatus, Phlox divaricata, Wyethia mollis, and Xerophyllum tenax. Pinus contorta var. murrayana, Pinus jeffreyi, Pinus ponderosa, Abies magnifica, Pinus monticola, and Abies lowiana may also be present.

Dynamics:  No Data Available
Environmental Description:  Stands occur from 60 to 2900 m in elevation. The climate throughout most of this alliance''s range is Mediterranean, with warm, dry summers and moist winters. Precipitation ranges from 60-150 cm per year, mostly as rain. The bulk of the rain falls between November and May. Stands occur on rolling topography with moderately steep to steep slopes (12-60%). It occurs on all aspects, but north. Soils are well-drained, gravelly clays and clay loams with 0-25% cobbles. Average bare ground and rock cover is less than 20% each. Most commonly stands are found on serpentine, mixed-ultramafic with metavolcanics and peridotite-derived soils. Some self-replicating stands are found on strongly serpentinized peridotite. Most commonly, stands are found on ultramafic-derived soils.
Geographic Range: This alliance is found throughout much of California, including the east side of the Sierra Nevada and Modoc Plateau area, the Klamath Mountains and northern Coast Ranges. Pinus ponderosa var. washoensis is limited to the northern portion of this range (northern Sierra Nevada, southern Cascades, and Modoc Plateau).

Nations: US

States/Provinces:  CA, NV, OR


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: GNR

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.2 Cool Temperate Forest & Woodland Formation F008 1.B.2
Division 1.B.2.Nd Vancouverian Forest & Woodland Division D192 1.B.2.Nd
Macrogroup 1.B.2.Nd.2 Incense-cedar - Jeffrey Pine - Sierra White Fir Forest Macrogroup M023 1.B.2.Nd.2
Group 1.B.2.Nd.2.a Incense-cedar - Sugar Pine - Sierra White Fir Forest & Woodland Group G344 1.B.2.Nd.2.a
Alliance A3676 Jeffrey Pine - Washoe Pine Mixed Conifer Woodland Alliance A3676 1.B.2.Nd.2.a
Association CEGL000816 Jeffrey Pine / Siskiyou-mat Wooded Grassland CEGL000816 1.B.2.Nd.2.a
Association CEGL000817 Jeffrey Pine / Roemer''s Fescue Wooded Grassland CEGL000817 1.B.2.Nd.2.a
Association CEGL000818 Pitted Beardgrass Polynesian Ruderal Grassland CEGL000818 1.B.2.Nd.2.a
Association CEGL000819 Jeffrey Pine - Douglas-fir / Sticky Whiteleaf Manzanita Woodland CEGL000819 1.B.2.Nd.2.a
Association CEGL000820 Jeffrey Pine - Incense-cedar / Huckleberry Oak Woodland CEGL000820 1.B.2.Nd.2.a
Association CEGL003078 Washoe Pine Woodland CEGL003078 1.B.2.Nd.2.a
Association CEGL003156 Jeffrey Pine - Canyon Live Oak / Sticky Whiteleaf Manzanita Woodland CEGL003156 1.B.2.Nd.2.a
Association CEGL003447 Jeffrey Pine / Huckleberry Oak - Dwarf Silktassel Woodland CEGL003447 1.B.2.Nd.2.a
Association CEGL003448 Jeffrey Pine / Huckleberry Oak - Pinemat Manzanita Woodland CEGL003448 1.B.2.Nd.2.a
Association CEGL008624 Jeffrey Pine / Antelope Bitterbrush Woodland CEGL008624 1.B.2.Nd.2.a
Association CEGL008625 Jeffrey Pine / Bush Chinquapin Woodland CEGL008625 1.B.2.Nd.2.a
Association CEGL008626 Jeffrey Pine / Curl-leaf Mountain-mahogany Woodland CEGL008626 1.B.2.Nd.2.a
Association CEGL008627 Jeffrey Pine / Greenleaf Manzanita Woodland CEGL008627 1.B.2.Nd.2.a
Association CEGL008628 Jeffrey Pine / Mountain Whitethorn Woodland CEGL008628 1.B.2.Nd.2.a
Association CEGL008629 Jeffrey Pine - Singleleaf Pinyon Woodland CEGL008629 1.B.2.Nd.2.a
Association CEGL008630 Jeffrey Pine - Sierra White Fir Woodland CEGL008630 1.B.2.Nd.2.a
Association CEGL008631 Jeffrey Pine - Sierra White Fir / Roundleaf Snowberry / Squirreltail Woodland CEGL008631 1.B.2.Nd.2.a
Association CEGL008632 Jeffrey Pine - California Red Fir Woodland CEGL008632 1.B.2.Nd.2.a
Association CEGL008714 Jeffrey Pine / Huckleberry Oak Sierra Nevada Woodland CEGL008714 1.B.2.Nd.2.a
Concept Lineage: A.541, A.1501, A.529

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: ? Pinus jeffreyi / Arctostaphylos canescens - Festuca idahoensis Plant Association (Atzet et al. 1996)
? Pinus jeffreyi / Festuca idahoensis Plant Association (Atzet et al. 1996)
> Pinus jeffreyi (Jeffrey pine forest) Alliance (Sawyer et al. 2009) [87.020.00]
< Pinus ponderosa (Ponderosa pine forest) Alliance (Sawyer et al. 2009) [87.010.00]
> Pinus washoensis (Washoe pine woodland) Alliance (Sawyer et al. 2009) [87.120.00]
? Jeffrey Pine Forest (#85100) (Holland 1986b)
>< Jeffrey Pine Series (Sawyer and Keeler-Wolf 1995)
? Jeffrey Pine: 247 (Eyre 1980)
? Northern Ultramafic Jeffrey Pine Forest (#84171) (Holland 1986b)
? Southern Ultramafic Jeffrey Pine Forest (#84172) (Holland 1986b)
>< Washoe Pine-Fir Forest (#85220) (Holland 1986b)
Concept Author(s): G. Kittel, in Faber-Langendoen et al. (2013)

Author of Description: G. Kittel and J. Evens

Acknowledgements: We have incorporated significant descriptive information previously compiled by J. Evens.

Version Date: 12-18-14
  • Atzet, T. A., D. E. White, L. A. McCrimmon, P. A. Martinez, P. R. Fong, and V. D. Randall. 1996. Field guide to the forested plant associations of southwestern Oregon. Technical Paper R6-NR-ECOL-TP-17-96. USDA Forest Service, Pacific Northwest Region, Portland, OR.
  • Atzet, T., and D. L. Wheeler. 1984. Preliminary plant associations of the Siskiyou Mountains Province, Siskiyou National Forest. USDA Forest Service, Pacific Northwest Region, Portland, OR.
  • Eyre, F. H., editor. 1980. Forest cover types of the United States and Canada. Society of American Foresters, Washington, DC. 148 pp.
  • 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.
  • 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.
  • Sawyer, J. O., and T. Keeler-Wolf. 1995. A manual of California vegetation. California Native Plant Society, Sacramento. 471 pp.