Print Report

CEGL001908 Kobresia myosuroides - Geum rossii Alpine Turf

Type Concept Sentence: No Data Available

Common (Translated Scientific) Name: Bellardi Bog Sedge - Ross'' Avens Alpine Turf

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This association is a major upland alpine turf community of the southern Rocky Mountains extending north into the Uinta Mountains from northern New Mexico to northeastern Utah. Sites are typically dry-mesic meadows and turf in the middle to lower alpine, which may extend into transition areas with fell-fields. Stands often occur on gentle to moderate, convex slopes (1-30%) and saddles, typically with NE-NW aspects that are exposed to prevailing winds which keep sites snow-free during most of the winter. Soils are relatively deep (0.5-1 m) and well-developed for alpine environments. Distinct soil horizons are typically present indicating long periods without significant disturbance. The A horizon has accumulations of organic material and fine soils particles (from loess) that take many years to occur. Soils are fine to coarse loams derived from igneous or metamorphic rocks such as granite and schist. There is often low to moderate (to 50 %) cover of large and small surface rocks. Bare ground cover is generally low but can be moderately high in transition areas with fell-fields. This alpine turf association is characterized by a moderately dense to dense (50-90% cover) herbaceous layer dominated by Kobresia myosuroides with Geum rossii codominant. If present, Carex rupestris var. drummondiana cover does not exceed that of Geum rossii. Thalictrum alpinum and Trifolium dasyphyllum are not codominant and generally have low cover (<5% cover). Minuartia obtusiloba and/or Selaginella densa are often present and may be codominant in some stands. Other important species with lower cover include graminoids Calamagrostis purpurascens, Danthonia intermedia, Deschampsia cespitosa, Festuca brachyphylla, Poa glauca ssp. rupicola, Trisetum spicatum, and forbs Artemisia scopulorum, Gentiana algida, Mertensia oblongifolia, Oreoxis alpina, Polygonum spp., Potentilla spp., Silene acaulis, Tonestus pygmaeus, and Trifolium nanum. Diagnostic of this association is the dominance of Kobresia myosuroides and Geum rossii in a dense alpine turf.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Kobresia myosuroides-dominated alpine turf communities form matrix communities in the southern Rocky Mountains. More survey and classification work are needed to clarify composition and ecological differences among associations.

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

Floristics: This alpine turf association is characterized by a moderately dense to dense (50-90% cover) herbaceous layer dominated by Kobresia myosuroides with Geum rossii codominant. If present, Carex rupestris var. drummondiana cover does not exceed that of Geum rossii. Thalictrum alpinum and Trifolium dasyphyllum are not codominant and generally have low cover (<5% cover). Minuartia obtusiloba (= Arenaria obtusiloba) and/or Selaginella densa are often present and may be codominant in some stands. Other important species with lower cover include graminoids Calamagrostis purpurascens, Carex elynoides, Carex scirpoidea, Danthonia intermedia, Deschampsia cespitosa, Festuca brachyphylla, Luzula spicata, Poa glauca ssp. rupicola (= Poa rupicola), Poa lettermanii, and Trisetum spicatum, and forbs Artemisia scopulorum, Gentiana algida, Mertensia oblongifolia (= Mertensia viridis), Oreoxis alpina, Polygonum bistortoides, Polygonum viviparum, Potentilla diversifolia, Sedum spp., Silene acaulis, Tetraneuris grandiflora, Tonestus pygmaeus, and Trifolium nanum (Lewis 1970, Wasser and Hess 1982, Baker 1983a). Dwarf-shrub species include Artemisia arctica ssp. arctica, Salix planifolia, and Dryas octopetala ssp. hookeriana.

Dynamics:  Kobresia myosuroides turf is a major climax community in the alpine (Cox 1933, Willard 1963, Hess 1981, Komarkova 1986). Willard (1963) states that the Kobresia myosuroides stands on Trail Ridge, Colorado, are very old. Osburn (1958b) estimates that a minimum of 100 years are necessary for the formation of 1 inch of humus soil under present alpine conditions in the Front Range. This estimate would make some stands on Trail Ridge 800 to 1300 years old. Willard (1960) and others state that Kobresia myosuroides is intolerant of snow cover. She observed that Kobresia myosuroides died after roadbanks created snow drifts where none were previously. Kiener (1939) states that Kobresia myosuroides is efficient in obtaining water due to the dense, turf-forming root system. Kobresia myosuroides initiates growth after snowmelt saturates the ground in late spring. It then grows, flowers and produces fruit with very little or no rain (Osburn 1958b). Zwinger and Willard (1996) report that Kobresia myosuroides is a specialized plant that exists mainly on moisture from snow trapped by its dry tussocks in the winter. When culms are grazed down to the ground, no snow is trapped and the plant dies.
Environmental Description:  This association is a major upland alpine turf community of the southern Rocky Mountains that extends north into the Uinta Mountains. Elevations range from 3450-3900 m (11,300-12,800 feet). Sites are typically dry-mesic meadows and turf in the middle to lower alpine, which may extend into transition areas with fell-fields. Stands often occur on gentle to moderate, convex slopes (1-30%) and saddles, typically with NE-NW aspects that are exposed to prevailing winds which keep sites snow-free during most of the winter. Soils are relatively deep (0.5-1 m) and well-developed for alpine environments. Distinct soil horizons are typically present indicating long periods without significant disturbance. The A horizon has accumulations of organic material and fine soil particles (from loess) that take many years to occur (Marr 1967). Soil families include loamy skeletal mixed Typic Cryoborolls, Cryumbrepts Cryorthents, and coarse loamy mixed Pergelic Cryumbrepts (pH ranges from 4.8-6.6 in A horizon) (Wasser and Hess 1982, Komarkova 1986). Parent materials are often igneous or metamorphic rocks such as granite and schist. There is often low to moderate (to 50 %) cover of large and small surface rocks. Bare ground cover is generally low but can be moderately high in transition areas with fell-fields. These areas are less mesic with less developed coarser-textured soils than typical Kobresia myosuroides-dominated alpine turf.
Geographic Range: This association is a major upland alpine turf community of the southern Rocky Mountains and extends north into the Uinta Mountains from northern New Mexico to northeastern Utah.

Nations: US

States/Provinces:  CO, NM, UT


Confidence Level: Low

Confidence Level Comments: No Data Available
Grank: G5

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 A3155 Blackroot Sedge - Curly Sedge - Bellardi Bog Sedge Rocky Mountain Alpine Turf Alliance A3155 4.B.1.Nb.2.b
Association CEGL001908 Bellardi Bog Sedge - Ross'' Avens Alpine Turf CEGL001908 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: < Elynetum bellardii Meadow Association (Kiener 1967)
= Kobresia bellardii / Geum rossii Habitat Type (Wasser and Hess 1982) [Concept includes up to 6% Carex rupestris and 14% Geum rossii.]
= Kobresia bellardii / Geum rossii Habitat Type (Hess and Wasser 1982)
= Kobresia bellardii / Geum rossii Habitat Type (Hess 1981)
= Kobresia bellardii Meadow Stand (Osburn 1958b) [Dominated by Kobresia myosuroides (>50% cover), with high cover of Trifolium dasyphyllum, Geum rossii, Minuartia obtusiloba (= Arenaria obtusiloba), and Selaginella densa.]
< Kobresia myosuroides - Acomastylis rossii ssp. turbinata Habitat Type/Association (Komarkova 1986) [Plots 67 and 71. Both have Carex rupestris (2 and 6% cover, respectively); only #71 has Geum rossii (2% cover), but stands were classified to this habitat type anyway.]
= Kobresia myosuroides - Geum rossii Alpine Turf Plant Association (Baker 1984a)
< Kobresia myosuroides - Selaginella densa; Dry Meadow Nodum I (May 1973) [Moderately dry sedge meadow with 150- to 200-day annual snow-free period. Dominated by Kobresia myosuroides, Selaginella densa, Carex rupestris, and Geum rossii.]
< Kobresia myosuroides / Acomastylis rossii - Carex rupestris Plant Association (Johnston 1987)
= Kobresia myosuroides Meadow Site (Fareed and Caldwell 1975) [Geum rossii, Polygonum bistortoides, and Trifolium parryi mentioned as associated species. No mention of Carex rupestris var. drummondiana.]
= Kobresia-Carex Alpine Meadow (Braun 1969) [Unit R-4. Kobresia myosuroides (25-50%), Carex spp. and Geum rossii (5-25% each). Slopes are gentle, few rocks exposed.]
= Kobresia-Geum Turf Community Type (Baker 1983a) [Wheeler Peak in New Mexico.]
= Kobresia - Turf Community (Eddleman 1967) [Carex rupestris var. drummondiana, Geum rossii, Trifolium dasyphyllum, and Festuca brachyphylla all have high importance values (>10), only Geum rossii has both high frequency and relatively high cover, whereas Carex rupestris var. drummondiana has high frequency and low cover (<2%) only.]
< Kobresia Meadow Stand-Type (Marr 1967)
< Selaginello - Kobresietum myosuroidis (Komarkova 1976) (Komarkova 1979) [Geum rossii and Carex rupestris var. drummondiana are listed as constant species.]
< Dry Kobresia myosuroides Meadow Nodum I (May and Webber 1982)
< Habitat Type 10: Kobresia bellardii, Oreoxis alpina - Fellfields and Fellfield Turf (Shepherd 1975) [Buffalo Peaks Winter Range.]
>< Habitat Type 15: Kobresia bellardii, Dodecatheon pulchellum, Potentilla fruticosa - Steep Fellfield Turf (Shepherd 1975)
= Habitat Type 7: Kobresia bellardii, Antennaria parvifolia, Geum turbinatum - Steep Boulder Slopes (Shepherd 1975) [Buffalo Peaks Summer Range.]
< Sedge-Grass Community (Lewis 1970) [Either Kobresia myosuroides or Carex elynoides dominates. Geum rossii, Carex scirpoidea ssp. pseudoscirpoidea (= Carex pseudoscirpoidea), Festuca brachyphylla, Poa lettermanii, and Poa glauca ssp. rupicola (= Poa rupicola) are important species.]
Concept Author(s): Western Ecology Group

Author of Description: K.A. Schulz

Acknowledgements: No Data Available

Version Date: 08-02-05
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