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CEGL001890 Dryas integrifolia - Carex spp. Alpine Dwarf-shrub Meadow
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Entireleaf Mountain-avens - Sedge species Alpine Dwarf-shrub Meadow
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This association is documented only from the alpine zone of the Big Snowy Mountains of north-central Montana, though reconnaissance information places it as well in the Tobacco Root Range of southwestern Montana. Stands occur from 2360-2700 m (7750-8850 feet) elevation on gently sloping topography developed on Madison Limestone. This substrate is resistant to chemical weathering, but has been acted upon by frost to produce stepped terraces, rock polygons, sorted/non-sorted frost boils, and ''spotted tundra'' (oval, spaced mats of Dryas integrifolia surrounded by rock rubble) and solifluction lobes on lee slopes. Soils are shallow, alkaline, cobbly and covered by a layer of gravels and rock fragments. The mat-forming dwarf-shrub Dryas integrifolia and turf-forming and perennial sedge Carex rupestris are diagnostic for the type and dominate small vegetated patches that are regularly interspersed in a matrix of unvegetated to sparsely vegetated rocky ground. Carex scirpoidea ssp. pseudoscirpoidea, Saxifraga oppositifolia, Polygonum viviparum, Oxytropis sericea, Androsace chamaejasme and Lloydia serotina have high constancy but their individual cover seldom exceeds 5%. This association, in both floristic and environmental param (with some local variation in the forb component), is highly similar to ~Dryas octopetala - Carex rupestris Alpine Dwarf-shrub Meadow (CEGL001892)$$ which is found from the Canadian Rockies south to Colorado.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: Although this is an extremely restricted type, it is based on detailed plot work and considerable regional reconnaissance. The correspondence of this type to Dryas integrifolia-dominated sites in Canada and Alaska has not been explored. There is a question regarding the taxonomy of Dryas spp. from the sample sites; that the dominant of this type is in fact Dryas integrifolia and not Dryas octopetala. To the best of our knowledge, a Dryas expert has not examined the vouchers filed at University of Colorado, Boulder and University of California, Davis. If the Dryas spp. in question is in fact Dryas integrifolia it is strongly recommended the type be renamed to Dryas integrifolia - Carex rupestris because this Carex is both dominant and 100% constant; this name would call attention to the fact that this type is a virtual biological analogue of ~Dryas octopetala - Carex rupestris Alpine Dwarf-shrub Meadow (CEGL001892)$$.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: This is an alpine tundra association dominated by the low, mat-forming evergreen shrub Dryas integrifolia and the perennial sedge Carex rupestris. The mats of Dryas and Carex occur within a matrix of active frost-patterned bare soil, cobbles and rocks. Most other species occurring in this association are found within these Dryas mats. Carex scirpoidea ssp. pseudoscirpoidea (= Carex pseudoscirpoidea), Polygonum viviparum, Oxytropis sericea, Androsace chamaejasme and Lloydia serotina have high constancy but their individual cover seldom exceeds 5%. In addition to the abundant or constant species, the perennials Aquilegia jonesii, Physaria didymocarpa, Rhodiola rosea (= Sedum rosea), and Saxifraga oppositifolia grow scattered in the rock rubble covering the soil. Richness is relatively low compared to other Rocky Mountain alpine tundras.
Dynamics: No Data Available
Environmental Description: This association occurs from 2300 to 2700 m (7550-8850 feet) elevation in the alpine of an isolated mountain range (separated from the main crest of the Rockies by 240 km). The climate is unusual, in that there is a distinct summer peak of precipitation and a winter minimum. Summers are cool and winters cold. The geologic substrate is Madison limestone, and has formed a gentle topography of low relief. The limestone is very resistant to chemical erosion, but is mechanically fractured and has been shaped into numerous frost-patterning phenomena. Soils are very shallow, alkaline and cobbly, with carbonate accumulations in the lower horizons and high clay content. The surface is covered with a layer of small gravel and rock fragments 5-18 cm deep, overlying small ridges of soil. The top soil horizon is characterized by organic enrichment (26% organic matter). The soils are unstable and in a constant state of change due to the action of frost.
Geographic Range: This association is documented only from the alpine zone of the Big Snowy Mountains of north-central Montana, though reconnaissance information places it as well in the Tobacco Root Range of southwestern Montana.
Nations: US
States/Provinces: MT
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.683989
Confidence Level: Low
Confidence Level Comments: No Data Available
Grank: G3Q
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.a Eight-petal Mountain-avens - Mountain-heath species - Arctic Willow Alpine Dwarf-shrubland & Krummholz Group | G316 | 4.B.1.Nb.2.a |
| Alliance | A3178 Entireleaf Mountain-avens - Eight-petal Mountain-avens - Kinnikinnick Rocky Mountain Fell-field Dwarf-shrubland Alliance | A3178 | 4.B.1.Nb.2.a |
| Association | CEGL001890 Entireleaf Mountain-avens - Sedge species Alpine Dwarf-shrub Meadow | CEGL001890 | 4.B.1.Nb.2.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: > Dryas Vegetation (Bamberg and Major 1968)
? Eleocharis pauciflora type (Tuhy and Jensen 1982)
? Eleocharis pauciflora type (Tuhy and Jensen 1982)
- Bamberg, S. A. 1961. Plant ecology of alpine tundra area in Montana and adjacent Wyoming. Unpublished dissertation, University of Colorado, Boulder. 163 pp.
- Bamberg, S. A., and J. Major. 1968. Ecology of the vegetation and soils associated with calcareous parent materials in three alpine regions of Montana. Ecological Monographs 38(2):127-167.
- 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.
- MTNHP [Montana Natural Heritage Program]. 2002b. List of ecological communities for Montana. Montana Natural Heritage Program, Montana State Library, Helena, MT.
- Tuhy, J. S., and S. Jensen. 1982. Riparian classification for the Upper Salmon and Middle Fork Salmon River drainages, Idaho. Unpublished report prepared for the USDA Forest Service, Intermountain Region by White Horse Associates, Smithfield, UT. 183 pp.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.