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CEGL001965 Geum rossii - Minuartia obtusiloba Alpine Fell-field
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Ross'' Avens - Twin-flower Sandwort Alpine Fell-field
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This alpine plant association has been documented from southwestern Montana in the East Pioneer and Tobacco Root ranges and the Front Range of north-central Colorado. Stands are common on exposed, windswept upper slopes, slope shoulders, saddles and ridgetops. Typically extreme winds create a deflation surface with bare ground and gravel and rock comprising between 35 and 90% cover. Soils are slightly acidic, have 35-70% coarse fragments, and are predominantly well-drained sandy loams, loams or sand. Stands are found on thin soils weathered from crystalline parent materials including granite. The vegetation is characterized by an open to moderately dense (30-50% cover) low herbaceous layer dominated by Geum rossii and cushion plants with virtually no dwarf-shrub component and a reduced graminoid component. Mean forb cover is 30% with Geum rossii and Minuartia obtusiloba being 100% constant and together constituting about one-quarter to one-half of the total forb cover. Other common forbs are Castilleja occidentalis, Eritrichium nanum, Phlox pulvinata, Douglasia montana, Polygonum viviparum, Silene acaulis, Tonestus pygmaeus, and Trifolium dasyphyllum. Selaginella densa and Selaginella watsonii are locally abundant. Graminoids have low coverage, although some have high constancy and include Carex elynoides, Carex rupestris var. drummondiana, Festuca ovina, Luzula spicata, Poa arctica, and Poa glauca. This cushion plant/fell-field community is identified by the dominance of the diagnostic species Geum rossii and Minuartia obtusiloba, which sets it apart from other cushion plant communities.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This is a weakly documented type confirmed to exist in a relatively circumscribed area. There has been no attempt to crosswalk this type with those of similar composition and environmental parameters from adjacent states and regions. A Geum rossii community type described from the White Cloud Peaks of east-central Idaho appears to have similar vegetation and abiotic parameters, but the species list is too incomplete to make a reasoned call. Geum rossii-dominated types with Polygonum bistortoides and Sibbaldia procumbens as diagnostic species are probably much more indicative of turf or meadow sites and not cushion plant/fell-field conditions. There are many similar Geum rossii-codominated associations that need further review and crosswalking to clarify classification. This is a cushion plant association that is very similar to ~Geum rossii - Selaginella densa Alpine Fell-field (CEGL001968)$$.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: This association is characterized by an open to moderately dense (30-50% cover) low herbaceous layer dominated by Geum rossii and cushion plants with virtually no dwarf-shrub component and a reduced graminoid component. Mean forb cover is 30% with Geum rossii and Minuartia obtusiloba being 100% constant and together constituting about one-quarter to one-half of the total forb cover. Other common forbs are Castilleja occidentalis, Eritrichium nanum, Phlox pulvinata, Douglasia montana, Polygonum viviparum, Silene acaulis, Tonestus pygmaeus, and Trifolium dasyphyllum. Selaginella densa and Selaginella watsonii are locally abundant. Graminoids have low coverage, although some have high constancy and include Carex elynoides, Carex rupestris var. drummondiana, Festuca ovina, Luzula spicata, Poa arctica, and Poa glauca. This is the most characteristic cushion plant/fell-field community of southwestern Montana and is identified by the dominance of the diagnostic species Geum rossii and Minuartia obtusiloba, which sets it apart from other cushion plant communities, such as ~Phlox pulvinata - Trifolium dasyphyllum Alpine Fell-field (CEGL001980)$$ and ~Antennaria microphylla - Artemisia scopulorum Alpine Meadow (CEGL001847)$$. However, there are other Rocky Mountain cushion plant communities, for instance those of the White Cloud Peaks, Idaho, and Beartooth mountains, Montana, dominated by and named for Geum rossii, which may be similar, if not synonymous, with the community described here.
Dynamics: Geum rossii has one of the widest ecological amplitudes among alpine taxa occurring in almost any alpine habitat (Komarkova 1986). However, there are few habitats where it can dominate, including disturbed areas (gopher gardens), and certain snowbed and fellfield communities (Willard 1963, Komarkova 1986).
Environmental Description: This plant association has been documented from southwestern Montana in the East Pioneer and Tobacco Root ranges and the Front Range of north-central Colorado. Stands are common on exposed, windswept upper slopes, slope shoulders, saddles and ridgetops at elevations of 2990 to 3230 m (9800-10,600 feet) in Montana and 3660 to 3760 m (12,000-12,325 feet) in Colorado. Sites are somewhat steep to steep (26-100%) fell-fields and talus slopes to gently sloped (1-9%) ridges and saddles. Aspect is variable but often is northerly and westerly where prevailing winds blow. Typically, extreme winds create a deflation surface with bare ground and gravel and rock comprising between 35 and 90% cover. Soils are slightly acidic, have 35-70% coarse fragments, and are predominantly well-drained sandy loams, loams or sand. Stands are found on thin soils weathered from crystalline parent materials including granite.
Geographic Range: This alpine plant association has been documented from southwestern Montana in the East Pioneer and Tobacco Root ranges and the Front Range in north-central Colorado.
Nations: US
States/Provinces: CO, MT
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.685934
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: G3?
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.2 Eight-petal Mountain-avens - Blackroot Sedge - Moss Campion Alpine Tundra Macrogroup | M099 | 4.B.1.Nb.2 |
| Group | 4.B.1.Nb.2.b Blackroot Sedge - Bellardi Bog Sedge - Cushion Phlox Alpine Turf & Fell-field Group | G314 | 4.B.1.Nb.2.b |
| Alliance | A3154 Twin-flower Sandwort - Rocky Mountain Nailwort - Moss Campion Alpine Fell-field Alliance | A3154 | 4.B.1.Nb.2.b |
| Association | CEGL001965 Ross'' Avens - Twin-flower Sandwort Alpine Fell-field | CEGL001965 | 4.B.1.Nb.2.b |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Geum rossii - Minuartia obtusiloba Herbaceous Vegetation (Cooper et al. 1999)
>< Geum rossii - Selaginella densa Community Type (Potkin and Munn 1989) [Stands are codominated by Geum rossii and Selaginella densa and cushion plants including Minuartia obtusiloba. ~Geum rossii - Selaginella densa Alpine Fell-field (CEGL001968)$$ may better describe stands in this community type.]
= Geum rossii/Arenaria obtusiloba c.t. (Cooper et al. 1997)
< Geum rossii Series (Potkin and Munn 1989)
< Geum Turf (Johnson and Billings 1962) [research from Beartooth Plateau in Montana and Wyoming. Many stands are codominated by Geum rossii and Carex rupestris var. drummondiana, which may be better classified as ~Carex rupestris - Geum rossii Alpine Turf (CEGL001861)$$.]
>< Geum rossii - Selaginella densa Community Type (Potkin and Munn 1989) [Stands are codominated by Geum rossii and Selaginella densa and cushion plants including Minuartia obtusiloba. ~Geum rossii - Selaginella densa Alpine Fell-field (CEGL001968)$$ may better describe stands in this community type.]
= Geum rossii/Arenaria obtusiloba c.t. (Cooper et al. 1997)
< Geum rossii Series (Potkin and Munn 1989)
< Geum Turf (Johnson and Billings 1962) [research from Beartooth Plateau in Montana and Wyoming. Many stands are codominated by Geum rossii and Carex rupestris var. drummondiana, which may be better classified as ~Carex rupestris - Geum rossii Alpine Turf (CEGL001861)$$.]
- Bourgeron, P. S., and L. D. Engelking, editors. 1994. A preliminary vegetation classification of the western United States. Unpublished report. The Nature Conservancy, Western Heritage Task Force, Boulder, CO. 175 pp. plus appendix.
- Cooper, S. V., C. Jean, and B. L. Heidel. 1999. Plant associations and related botanical inventory of the Beaverhead Mountains Section, Montana. Unpublished report to the Bureau of Land Management. Montana Natural Heritage Program, Helena. 235 pp.
- Cooper, S. V., P. Lesica, and D. Page-Dumroese. 1997. Plant community classification for alpine vegetation on Beaverhead National Forest, Montana. Report INT-GTR-362. USDA Forest Service, Intermountain Research Station, Ogden, UT. 61 pp.
- Cooper, S. V., and P. Lesica. 1992. Plant community classification for alpine vegetation on Beaverhead National Forest, Montana. Conservation Biology Research, Helena, MT. 80 pp.
- Johnson, P. L., and W. D. Billings. 1962. The alpine vegetation of the Beartooth Plateau in relation to cryopedogenic processes and patterns. Ecological Monographs 32(2):105-133.
- Komarkova, V. 1986. Habitat types on selected parts of the Gunnison and Uncompahgre national forests. Unpublished final report prepared for USDA Forest Service, Rocky Mountain Forest and Range Experiment Station. Fort Collins, CO. 270 pp. plus appendices.
- MTNHP [Montana Natural Heritage Program]. 2002b. List of ecological communities for Montana. Montana Natural Heritage Program, Montana State Library, Helena, MT.
- Potkin, M., and L. Munn. 1989. Subalpine and alpine plant communities in the Bridger Wilderness, Wind River Range, Wyoming. USDA Forest Service Contract No. 53-8555-3-00015. Department of Plant, Soil, and Insect Sciences, University of Wyoming, Laramie. 117 pp. plus appendix.
- Richardson, C. A., and D. M. Henderson. 1999. Classification and ordination of the alpine plant communities of Railroad Ridge, White Cloud Peaks, Idaho. Great Basin Naturalist 59(1):63-78.
- Salas, D., J. Stevens, and K. Schulz. 2005. USGS-NPS Vegetation Mapping Program: Rocky Mountain National Park, Colorado. Technical Memorandum No. 8260-05-02. USDI Bureau of Reclamation, Denver, CO. 161 pp. plus Appendices A-L (733 pp.).
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.
- Willard, B. E. 1963. Phytosociology of the alpine tundra of Trail Ridge, Rocky Mountain National Park, Colorado. Unpublished dissertation, University of Colorado, Boulder.