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G319 Racomitrium spp. - Stereocaulon spp. - Phlox spp. North Pacific Alpine-Subalpine Bedrock & Scree Group

Type Concept Sentence: This group consists of communities dominated by Artemisia arctica, Astragalus alpinus, Carex microchaeta, Lomatium spp., Luina hypoleuca, Minuartia arctica, Paxistima myrsinites, Phlox spp., Salix rotundifolia, Saxifraga bronchialis, Saxifraga sibirica, Sibbaldia procumbens, and/or Silene acaulis, as well as a variety of nonvascular (lichen) species. It is found on barren and sparsely vegetated alpine rocky environments of the North Pacific.

Common (Translated Scientific) Name: Racomitrium Moss species - Snow Lichen species - Phlox species North Pacific Alpine-Subalpine Bedrock & Scree Group

Colloquial Name: North Pacific Alpine-Subalpine Bedrock & Scree

Hierarchy Level:  Group

Type Concept: This group consists of exposed rock and rubble above the forestline (subalpine parkland and above) in the North Pacific mountain ranges and is restricted to the highest elevations in the Cascade Range, from southwestern British Columbia south into northern California, and also north into southeastern Alaska. It is composed of barren and sparsely vegetated alpine substrates, typically including bedrock outcrops, scree slopes, rock crevices, upper mountain slopes, summits and nunataks. Species composition is variable and may include Artemisia arctica, Astragalus alpinus, Carex microchaeta, Carex spp., Minuartia arctica, Paxistima myrsinites, Saxifraga spp., Lomatium spp., Luina hypoleuca, Phlox spp., Salix rotundifolia, Saxifraga sibirica, Saxifraga bronchialis, Sibbaldia procumbens, and Silene acaulis. Nonvascular (lichen)-dominated communities are common. Common nonvascular genera include Racomitrium and Stereocaulon. Exposure to desiccating winds, rocky and sometimes unstable substrates, and a short growing season limit plant growth. In Alaska, this group usually occurs above alpine dwarf-shrub, herbaceous meadow, and dwarf-shrub-herbaceous systems typically at elevations higher than 915 m (3000 feet) (possibly higher in southeastern Alaska). There can be sparse cover of forbs, grasses, lichens, shrubs and small trees, but the total vascular plant cover is typically less than 25% due to the high cover of exposed rock.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: No Data Available

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Nonvascular-dominated rocks and vascular-dominated scree and rock crevices above treeline in the Pacific Northwest.

Floristics: There can be sparse cover of forbs, grasses, lichens, shrubs and small trees, but the total vascular plant cover is typically less than 25% due to the high cover of exposed rock. Species composition is variable and may include Artemisia arctica, Astragalus alpinus, Carex microchaeta, Carex spp., Lomatium spp., Luina hypoleuca, Minuartia arctica, Paxistima myrsinites, Phlox spp., Salix rotundifolia, Saxifraga bronchialis, Saxifraga sibirica (= Saxifraga bracteata), Sibbaldia procumbens, and Silene acaulis. Common nonvascular genera include Racomitrium and Stereocaulon. Floristic information compiled from Meidinger and Pojar (1991) and Viereck et al. (1992).

Dynamics:  No Data Available
Environmental Description:  Soil/substrate/hydrology: It is composed of barren and sparsely vegetated alpine substrates, typically including bedrock outcrops, scree slopes, rock crevices, upper mountain slopes, summits and nunataks. Nonvascular (lichen)-dominated communities are common. Exposure to desiccating winds, rocky and sometimes unstable substrates, and a short growing season limit plant growth. Environmental information compiled from Meidinger and Pojar (1991) and Viereck et al. (1992).
Geographic Range: This group is restricted to the highest elevations in the North Pacific ranges, from southeastern Alaska south into northern Oregon.

Nations: CA,US

States/Provinces:  AK, BC, CA, OR, WA


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: GNR

Greasons: No Data Available
Type Name Database Code Classification Code
Class 4 Polar & High Montane Scrub, Grassland & Barrens Class C04 4
Subclass 4.B Temperate to Polar Alpine & Tundra Vegetation Subclass S12 4.B
Formation 4.B.1 Temperate & Boreal Alpine Tundra Formation F037 4.B.1
Division 4.B.1.Nb Western North American Alpine Tundra Division D043 4.B.1.Nb
Macrogroup 4.B.1.Nb.3 Vancouverian Alpine Tundra Macrogroup M101 4.B.1.Nb.3
Group 4.B.1.Nb.3.d Racomitrium Moss species - Snow Lichen species - Phlox species North Pacific Alpine-Subalpine Bedrock & Scree Group G319 4.B.1.Nb.3.d
Alliance A3780 Phlox species - Desert-parsley species - Sedge species Alpine Talus & Scree Sparse Alliance A3780 4.B.1.Nb.3.d
Alliance A3781 Oregon Boxleaf - Saxifrage species - Littleleaf Silverback Alpine Rock Crevice Alliance A3781 4.B.1.Nb.3.d
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: = AN Alpine Sparsely Vegetated (Ecosystems Working Group 1998)
Concept Author(s): R. Crawford, M.S. Reid et al., in Faber-Langendoen et al. (2011)

Author of Description: R. Crawford, M.S. Reid, C. Chappell, T. Boucher, G. Kittel

Acknowledgements: No Data Available

Version Date: 05-20-15
  • Ecosystems Working Group. 1998. Standards for broad terrestrial ecosystem classification and mapping for British Columbia. Prepared by the Ecosystems Working Group, Terrestrial Ecosystem Task Force, Resources Inventory Committee, for the Province of British Columbia. 174 pp. plus appendices. [http://srmwww.gov.bc.ca/risc/pubs/teecolo/tem/indextem.htm]
  • Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
  • Meidinger, D., and J. Pojar, editors. 1991. Ecosystems of British Columbia. British Columbia Ministry of Forests Special Report Series No. 6. Victoria, BC. 330 pp.
  • Viereck, L. A., C. T. Dyrness, A. R. Batten, and K. J. Wenzlick. 1992. The Alaska vegetation classification. General Technical Report PNW-GTR286. USDA Forest Service, Pacific Northwest Research Station, Portland, OR. 278 pp.