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A3336 Eriogonum spp. - Luzula spp. Alpine Snowbed Alliance
Type Concept Sentence: This alliance is characterized by low-growing (3-8 cm), mat-forming perennial forbs and graminoids. It is found in the subalpine and alpine of the Cascade Range of Washington and British Columbia.
Common (Translated Scientific) Name: Buckwheat species - Woodrush species Alpine Snowbed Alliance
Colloquial Name: Buckwheat - Woodrush Alpine Snowbed
Hierarchy Level: Alliance
Type Concept: The vegetation is characterized by low-growing (3-8 cm), mat-forming perennial forbs and graminoids, which can be sparse, with less than 25% total cover. Eriogonum pyrolifolium, Saxifraga tolmiei, and Luzula piperi can be dominant to codominant. Other commonly associated herbaceous species include Carex nigricans, Carex pyrenaica, Carex spectabilis, Juncus drummondii, Luetkea pectinata, Lupinus arcticus ssp. subalpinus, Lupinus latifolius, or Oreostemma alpigenum var. alpigenum. Bryophytes such as Polytrichum sexangulare and Marsupella brevissima may also be present. This alliance is found in the subalpine and alpine of the Cascade Range of Washington and British Columbia. It appears to be restricted to the western side of the North Cascades where a maritime climate predominates. Stands occur between 1750 and 2100 m elevation on gentle to moderately steep north- or south-facing slopes. It is a snowbed habitat where snow remains on the ground until late July or early August, occurring above treeline on north-facing, gentle to moderate slopes with very late snowmelt and well-drained soils. It can also occur in subalpine parklands, where it tends to occur on north-facing slopes. Soils can be unstable, poorly to moderately well-drained, and somewhat acidic with a pH between 4.7 and 5.9.
Diagnostic Characteristics: Snowbank communities of the Cascade Range of Washington and British Columbia dominated by low-growing, mat-forming species Eriogonum pyrolifolium, Saxifraga tolmiei, and Luzula piperi typically at <25% cover.
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: Vegetation in this alliance is characterized by a moderately sparse cover of low-growing perennial forbs and grasses. Mosses are common, but have less cover than the herbaceous species.
Floristics: Stands are characterized by a moderate cover (20-50%) of herbaceous vegetation and a few number of species. The forbs Eriogonum pyrolifolium and Saxifraga tolmiei and the rush Luzula piperi can be dominant to codominant. Other commonly associated herbaceous species include Carex nigricans, Carex pyrenaica, Carex spectabilis, Juncus drummondii, Luetkea pectinata, Lupinus arcticus ssp. subalpinus, Lupinus latifolius, and Oreostemma alpigenum var. alpigenum. Bryophytes such as Polytrichum sexangulare and Marsupella brevissima may also be present.
Dynamics: The vegetation is restricted to the western side of the northern Cascade Range, which receives considerably more snowfall and has a steeper gradient than the eastern side of the range. This results in patches of varying snow depths and snowmelt times and a distinct mosaic of communities. The following information is based on Douglas and Bliss (1977). The time of snowmelt seems to be the most important environmental factor determining the pattern of the North Cascades tundra communities. The snowmelt date influences the summer soil moisture regime, at least during the early part of the growing season. The communities described within this alliance have the latest snowmelt dates (late July-early August) of any of the alpine communities.
Environmental Description: Stands occur between 1750 and 2100 m elevation on gentle to moderately steep south-facing slopes. This vegetation appears to be restricted to the western side of the North Cascades where a maritime climate predominates. The mean annual precipitation is 280 cm, with a large majority of the precipitation falling as snow; only an average of 28 cm falls in the summer. This alliance is associated with a snowbed habitat where snow remains on the ground until late July or early August. Soils are unstable and poorly to moderately well-drained. Soils are classified as Entisols and are young and poorly developed. If present, A through C horizons are thin. Soils are somewhat acidic with a pH between 4.7 and 5.9 and have low organic matter content, cation-exchange capacity, and nutrient levels.
Geographic Range: This alliance is found in the subalpine and alpine of the northern Cascade Range and Olympic Mountains of Washington and the Coast Mountains of British Columbia, Canada.
Nations: CA,US
States/Provinces: BC, WA
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899460
Confidence Level: Low
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.b Longawn Sedge - Showy Sedge - Spreading Phlox Alpine-Subalpine Tundra Group | G320 | 4.B.1.Nb.3.b |
| Alliance | A3336 Buckwheat species - Woodrush species Alpine Snowbed Alliance | A3336 | 4.B.1.Nb.3.b |
| Association | CEGL001963 Shasta Buckwheat - Piper''s Woodrush Alpine Snowbed | CEGL001963 | 4.B.1.Nb.3.b |
| Association | CEGL001986 Tolmie''s Saxifrage - Piper''s Woodrush Alpine Snowbed | CEGL001986 | 4.B.1.Nb.3.b |
Concept Lineage: A.1644, A.1650, A.1653.
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: ? Saxifraga tolmiei - Luzula piperi community (Douglas and Bliss 1977)
- Douglas, G. W., and L. C. Bliss. 1977. Alpine and high subalpine plant communities of the North Cascades Range, Washington and British Columbia. Ecological Monographs 47:113-150.
- 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.