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A3622 Juniperus grandis - Pinus albicaulis Woodland Alliance

Type Concept Sentence: This alliance consists of stands dominated by Juniperus grandis, Pinus albicaulis, and Pinus contorta var. murrayana; other conifers include Pinus flexilis and Pinus monticola. Stands occur on ridges and rocky slopes in the southern Sierra Nevada and Transverse and Peninsular ranges, and in the southern Cascades. Due to landscape position, rocky substrates, and very thin soils, these are harsh sites exposed to desiccating winds with ice and snow blasts.

Common (Translated Scientific) Name: Western Juniper - Whitebark Pine Woodland Alliance

Colloquial Name: Sierra Western Juniper - Whitebark Pine Woodland

Hierarchy Level:  Alliance

Type Concept: This alliance consists of stands dominated by Juniperus grandis (mostly in the central and southern Sierra Nevada), Pinus albicaulis and Pinus contorta var. murrayana; other important conifers may include Pinus flexilis (but only in small patches on the eastern flank of the Sierra Nevada escarpment when it does occur) and Pinus monticola (not in Transverse or Peninsular ranges). Important shrubs include Arctostaphylos nevadensis, Artemisia tridentata, Chrysolepis sempervirens, and Holodiscus discolor. Grasses and forbs include Carex rossii, Carex filifolia, Poa wheeleri, Eriogonum incanum, Penstemon newberryi, and Penstemon davidsonii. This alliance occurs on ridges and rocky slopes around timberline at 2900 m (9500 feet) elevation in the southern Sierra Nevada and Transverse and Peninsular ranges, up to 3500 m (11,800 feet) in the Sierra Nevada, and 2450 m (8000 feet) in the southern Cascades. Due to landscape position, rocky substrates, and very thin soils, these are harsh sites exposed to desiccating winds with ice and snow blasts. Tree species sometimes occur as krummholz growth forms with a wind-pruned, prostrate, and/or shrublike appearance, but in more protected sites they form true woodland physiognomy. In addition, a short growing season limits plant growth.

Diagnostic Characteristics: Dominance of Pinus albicaulis or Juniperus grandis (generally not together in the same stand). Pinus contorta var. murrayana is often common in mixed stands with Pinus albicaulis; Pinus monticola is also occasionally codominant.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This alliance is based upon the concept of the ecological system ~Mediterranean California Subalpine Woodland (CES206.910)$$. This alliance occurs in more severe settings than ~Pinus contorta var. murrayana Subalpine Forest & Woodland Alliance (A3621)$$. Although Pinus monticola can be codominant in some associations in this alliance, most Pinus monticola associations (where it is a codominant with Abies magnifica or Tsuga mertensiana) are generally placed in ~Sierra-Cascade Red Fir - Mountain Hemlock Forest Group (G749)$$, the more mesic of the subalpine conifer forest groups of the Sierra Nevada and southern Cascades.

Sawyer et al. (2009) treat Juniperus occidentalis var. australis as Juniperus grandis. Quote from Sawyer et al. (2009): "Traditionally, Juniperus occidentalis has involved two forms, var. occidentalis (western juniper) and var. australis (mountain juniper) (Hickman 1993). Using sequence and RAPD data, Adams et al. (2006) have shown the varieties to be distant, now called Juniperus grandis and Juniperus occidentalis. In addition, they differ in their essential oils (Adams 2004), and in dioecy. Juniperus occidentalis is monoecious while Juniperus grandis dioecious. Both species hybridize with Juniperus osteosperma in the Warner and White mountains (Dealy 1990, Tirmenstein 1999a). We follow Adams and use the name Juniperus grandis."

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available

Floristics: This alliance consists of stands dominated by Juniperus grandis (= Juniperus occidentalis var. australis) (mostly in the central and southern Sierra Nevada), Pinus albicaulis and Pinus contorta var. murrayana; other important conifers may include Pinus flexilis (but only in small patches on the eastern flank of the Sierra Nevada escarpment when it does occur) and Pinus monticola (not in Transverse or Peninsular ranges). Important shrubs include Arctostaphylos nevadensis, Artemisia tridentata, Chrysolepis sempervirens, and Holodiscus discolor (= Holodiscus microphyllus). Grasses and forbs include Carex rossii, Carex filifolia, Poa wheeleri, Eriogonum incanum, Penstemon newberryi, and Penstemon davidsonii.

Dynamics:  No Data Available
Environmental Description:  Stands occur on ridges and rocky slopes around timberline at 2900 m (9500 feet) elevation in the southern Sierra Nevada and Transverse and Peninsular ranges, up to 3500 m (11,800 feet) in the Sierra Nevada, and 2450 m (8000 feet) in the southern Cascades. Due to landscape position, rocky substrates, and very thin soils, these are harsh sites exposed to desiccating winds with ice and snow blasts.
Geographic Range: This alliance occurs on ridges and rocky slopes around timberline in the southern Sierra Nevada and Transverse and Peninsular ranges, and in the southern Cascades.

Nations: US

States/Provinces:  CA, 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.4 California Red Fir - Mountain Hemlock - Sierra Lodgepole Pine Forest Macrogroup M025 1.B.2.Nd.4
Group 1.B.2.Nd.4.b Sierra Lodgepole Pine Woodland Group G243 1.B.2.Nd.4.b
Alliance A3622 Western Juniper - Whitebark Pine Woodland Alliance A3622 1.B.2.Nd.4.b
Association CEGL000130 Whitebark Pine - Lodgepole Pine / Mountain Blue Penstemon Forest CEGL000130 1.B.2.Nd.4.b
Association CEGL003133 Whitebark Pine / Threadleaf Sedge Woodland CEGL003133 1.B.2.Nd.4.b
Association CEGL003134 Whitebark Pine / Davidson''s Penstemon Woodland CEGL003134 1.B.2.Nd.4.b
Association CEGL003135 Whitebark Pine / Ross'' Sedge Woodland CEGL003135 1.B.2.Nd.4.b
Association CEGL003136 Western Juniper / Sparse Understory Woodland CEGL003136 1.B.2.Nd.4.b
Association CEGL003137 Western Juniper / Oceanspray Woodland CEGL003137 1.B.2.Nd.4.b
Association CEGL003150 Western Juniper - Curl-leaf Mountain-mahogany / Big Sagebrush Woodland CEGL003150 1.B.2.Nd.4.b
Association CEGL003151 Western Juniper / Big Sagebrush Woodland CEGL003151 1.B.2.Nd.4.b
Association CEGL003157 Western White Pine - Sierra Lodgepole Pine / Sparse Understory Woodland CEGL003157 1.B.2.Nd.4.b
Association CEGL008670 Sierra Lodgepole Pine - Whitebark Pine - Ross'' Sedge Forest CEGL008670 1.B.2.Nd.4.b
Association CEGL008671 Sierra Lodgepole Pine - Whitebark Pine / Threadleaf Sedge Forest CEGL008671 1.B.2.Nd.4.b
Concept Lineage: Includes parts of A.531 and A.535

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: > Juniperus grandis (Mountain juniper woodland) Alliance (Sawyer et al. 2009) [89.200.00]
> Juniperus grandis Woodland Alliance (Evens et al. 2014)
> Pinus albicaulis (Whitebark pine forest) Alliance (Sawyer et al. 2009) [87.180.00]
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
  • Adams, R. P. 2004. Identification of essential oil components by gas chromatography mass spectrometry. Allured, Carol Stream, IL.
  • Adams, R. P., M. S. González Elizondo, M. González Elizondo, and E. Slinkman. 2006. DNA fingerprinting and terpenoid analysis of Juniperus blancoi var. huehuentensis (Cupressaceae), a new subalpine variety from Durango, Mexico. Biochemical Systematics and Ecology 34:205-211.
  • Dealy, J. E. 1990. Juniperus occidentalis Hook. western juniper. Pages 109-115 in: R. M. Burns and B. H. Honkala, technical coordinators. Silvics of North America. Volume 1. Conifers. Agricultural Handbook 654. USDA Forest Service, Washington, DC.
  • Evens, J. M., K. Sikes, D. Hastings, and J. Ratchford. 2014. Vegetation alliance descriptions for Lake Mead National Recreation Area, Death Valley National Park and Mojave National Preserve. Unpublished report submitted to USDI National Park Service, Mojave Desert Network Inventory and Monitoring Program. California Native Plant Society, Sacramento, CA.
  • 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.
  • Hickman, J. C. 1993. The Jepson manual: Higher plants of California. University of California Press, Ltd., Berkeley, CA. 1400 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.
  • Potter, D. A. 1998. Forested communities of the upper montane in the central and southern Sierra Nevada. USDA Forest Service, Pacific Southwest Research Station, Albany, CA. 319 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.
  • Tirmenstein, D. 1999a. Juniperus communis. In: Fire Effects Information System [Online]. USDA Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). [http://www.fs.fed.us/database/feis/] (accessed 9 March 2005).