Print Report
CEGL001647 Muhlenbergia montana - Hesperostipa comata Grassland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Mountain Muhly - Needle-and-Thread Grassland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This association has been described from north-central and central Colorado, in the northeastern portion of the Roosevelt National Forest. The association also occurs in Rocky Mountain National Park in the Mummy Range, Florissant Fossil Beds National Monument, and extends east out onto the Palmer Divide. Sites where the association is found are typically xeric forest openings in the ponderosa pine zone, on south-facing slopes and ridgetops. Elevations range from 2286 to 2650 m (7500-8710 feet), and the slopes are moderately steep. Occasionally the association occupies rolling parklands. Strong westerly winds probably result in removal of snow cover from the open sites and increased desiccation of plants. Soils are moderately deep Mollisols, with high coarse-fragment content, sandy loam textures, and a distinct clay horizon. Bare soil, exposed gravels, and small rocks account for as much as 30% of the ground surface area. This typically moderately dense grassland is strongly dominated by the perennial bunchgrasses Muhlenbergia montana and Hesperostipa comata. Several other graminoids are commonly present, including Carex duriuscula, Pascopyrum smithii, Koeleria macrantha, Danthonia parryi, Muhlenbergia filiculmis, and Poa secunda. Total graminoid cover averages 45%. Forb species are much less abundant. The most important include Allium geyeri, Antennaria spp., Harbouria trachypleura, Mertensia lanceolata, and Penstemon secundiflorus. Shrubs are absent or scarce, except for the suffrutescent Artemisia frigida, with 5% average cover. This association can be distinguished from ~Muhlenbergia montana Grassland (CEGL001646)$$ by the abundance to codominance of Hesperostipa comata.
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: No Data Available
Floristics: This grassland association is strongly dominated by the perennial bunchgrasses Muhlenbergia montana and Hesperostipa comata (= Stipa comata), averaging 11% and 22% cover, respectively. Several other graminoids are commonly present, including Carex duriuscula (= Carex eleocharis), Pascopyrum smithii, Koeleria macrantha, Danthonia parryi, Muhlenbergia filiculmis, and Poa secunda. Total graminoid cover averages 45%. Forbs species are much less abundant, totaling <10% cover. The most important include Allium geyeri, Antennaria rosea, Arenaria fendleri, Harbouria trachypleura, Mertensia lanceolata, and Penstemon secundiflorus. Shrubs are absent or scarce, scattered in clumps, and include Ribes cereum and Purshia tridentata, the suffrutescent Artemisia frigida, and occasional Acer glabrum. Stands on harsher sites and those which have been intensively grazed have increased abundances of Antennaria rosea and Muhlenbergia filiculmis.
Dynamics: Muhlenbergia montana often grows in association with montane conifer forests, especially ones dominated by Pinus ponderosa, and has developed a tolerance for relatively frequent fire regimes. Although Muhlenbergia montana resprouts after burning, it may take a few years to recover to pre-burn density (Fischer and Bradley 1987). These grasslands may be considered seral or an edaphic climax depending on whether there are environmental factors, such as aridity, that are preventing establishment of trees. Historically, much of the area where this association occurs was heavily grazed by livestock, primarily sheep and cattle (Shepherd 1975). Season of use is important in stands with both Hesperostipa comata and Muhlenbergia montana; fall grazing will favor Hesperostipa comata over the later-blooming Muhlenbergia montana (Clary 1978). The reverse is true if grazing is always limited to summer. Overgrazing will reduce or eliminate Hesperostipa comata, Muhlenbergia montana, and the other palatable species, leaving the more grazing-tolerant Bouteloua gracilis and less palatable plants, such as Hymenoxys, Artemisia and Chrysothamnus species, to dominate the site (Clary 1978).
Environmental Description: This type occurs in a mountainous region subject to a continental climate regime, with warm summers and cold winters. Precipitation patterns differ between the eastern and western sides of the Continental Divide, but the overall difference is warmer and drier winters on the east slope of the Front Range. Sites where found are typically xeric forest openings in the ponderosa pine zone, on south-facing slopes and ridgetops. Elevations range from 2205 to 2650 m (7230-8710 feet), and the slopes are moderately steep. Occasionally the association occupies rolling parklands. Strong westerly winds probably result in removal of snow cover from the open sites and increased desiccation of plants. Parent materials are primarily colluvium of granitic and gneiss origins. Soils are moderately deep Mollisols, with high coarse-fragment content, sandy loam textures, and a distinct clay horizon. Bare soil, exposed gravels, and small rocks account for as much as 30% of the ground surface area.
Geographic Range: This grassland association is described from north-central Colorado, primarily within the northern portion of the Front Range in Larimer County and farther south along the Front Range to Teller County and east into El Paso County in the Palmer Divide area.
Nations: US
States/Provinces: AZ, CO
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.687390
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: G1G2
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 2 Shrub & Herb Vegetation Class | C02 | 2 |
| Subclass | 2.B Temperate & Boreal Grassland & Shrubland Subclass | S18 | 2.B |
| Formation | 2.B.2 Temperate Grassland & Shrubland Formation | F012 | 2.B.2 |
| Division | 2.B.2.Nf Western North American Grassland & Shrubland Division | D022 | 2.B.2.Nf |
| Macrogroup | 2.B.2.Nf.3 Tufted Hairgrass - Licorice-root species - Mountain Muhly Subalpine-High Montane Mesic Meadow Macrogroup | M168 | 2.B.2.Nf.3 |
| Group | 2.B.2.Nf.3.a Arizona Fescue - Thurber''s Fescue - Mountain Muhly Grassland Group | G268 | 2.B.2.Nf.3.a |
| Alliance | A3953 Arizona Fescue - Mountain Muhly - Muttongrass Southern Rocky Mountain Montane Grassland Alliance | A3953 | 2.B.2.Nf.3.a |
| Association | CEGL001647 Mountain Muhly - Needle-and-Thread Grassland | CEGL001647 | 2.B.2.Nf.3.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Stipa comata / Muhlenbergia montana Habitat Type (Wasser and Hess 1982)
= Stipa comata / Muhlenbergia montana Habitat Type (Hess 1981)
= Stipa comata / Muhlenbergia montana Plant Association (Johnston 1987)
= Grass Turf-Shrub Type (Baumann 1978a) [Ribes cereum and Purshia tridentata are often present.]
< Habitat Type 7: Muhlenbergia montana, Festuca arizonica, Hymenoxys richardsonii, Artemisia frigida (Shepherd 1975)
< Natural Dry Meadows (Mutel 1976) [general reference.]
< Open Aspen Area (Buttery 1955) [apparently a meadow within sparse aspen.]
= Study site K-79 (Fish 1966) [sampled near the Black Forest in Palmer Divide area. Eastonville at 7233 feet.]
= Stipa comata / Muhlenbergia montana Habitat Type (Hess 1981)
= Stipa comata / Muhlenbergia montana Plant Association (Johnston 1987)
= Grass Turf-Shrub Type (Baumann 1978a) [Ribes cereum and Purshia tridentata are often present.]
< Habitat Type 7: Muhlenbergia montana, Festuca arizonica, Hymenoxys richardsonii, Artemisia frigida (Shepherd 1975)
< Natural Dry Meadows (Mutel 1976) [general reference.]
< Open Aspen Area (Buttery 1955) [apparently a meadow within sparse aspen.]
= Study site K-79 (Fish 1966) [sampled near the Black Forest in Palmer Divide area. Eastonville at 7233 feet.]
- Baumann, T. G. 1978a. Winter ecology of bighorn sheep in the Mummy Range, Colorado. Unpublished thesis, Colorado State University, Fort Collins.
- 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.
- Buttery, R. F. 1955. Range conditions and trends resulting from winter concentrations of elk in Rocky Mountain National Park, Colorado. Unpublished thesis. Colorado Agricultural and Mechanical College, Fort Collins. 117 pp.
- CNHP [Colorado Natural Heritage Program]. 2006-2017. Tracked natural plant communities. Colorado Natural Heritage Program, Colorado State University, Fort Collins. [https://cnhp.colostate.edu/ourdata/trackinglist/plant_communities/]
- Clary, W. P. 1978. Arizona fescue mountain rangelands. Pages 205-207 in: D. N. Hyder, editor. Proceedings of the First International Rangeland Congress, Denver, CO, 14-18 August 1978. Society for Range Management, Denver.
- Fischer, W. C., and A. F. Bradley. 1987. Fire ecology of western Montana forest habitat types. General Technical Report INT-223. USDA Forest Service, Intermountain Research Station, Ogden, UT. 95 pp.
- Fish, E. B. 1966. Secondary succession on upper Kiowa Creek watershed. Unpublished thesis, Colorado State University, Fort Collins. 102 pp.
- Hess, K. 1981. Phyto-edaphic study of habitat types of the Arapaho-Roosevelt National Forest, Colorado. Unpublished dissertation, Colorado State University, Fort Collins. 558 pp.
- Johnston, B. C. 1987. Plant associations of Region Two: Potential plant communities of Wyoming, South Dakota, Nebraska, Colorado, and Kansas. R2-ECOL-87-2. USDA Forest Service, Rocky Mountain Region. Lakewood, CO. 429 pp.
- Kearsley, M. J. C., K. Green, M. Tukman, M. Reid, M. Hall, T. J. Ayers, and K. Christie. 2015. Grand Canyon National Park-Grand Canyon / Parashant National Monument vegetation classification and mapping project. Natural Resource Report NPS/GRCA/NRR--2015/913. National Park Service, Fort Collins, CO. 75 pp. plus appendices.
- Mutel, C. F. 1976. From grassland to glacier: An ecology of Boulder County, Colorado. Johnson Publishing Company, Boulder. 169 pp.
- Owns, T., project coordinator, et al. 2004. U.S. Geological Survey and National Park Service Vegetation Mapping Program: Florissant Fossil Beds National Monument. U.S. Geological Survey and National Park Service. 390 pp.
- Reid, M. S., and M. E. Hall. 2010. Vegetation classification of Grand Canyon National Park. Draft report submitted to National Park Service, Fort Collins, CO.
- 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.).
- Shepherd, H. R. 1975. Vegetation of two dissimilar bighorn sheep ranges in Colorado. Colorado Division of Wildlife Report 4. 223 pp.
- Wasser, C. H., and K. Hess. 1982. The habitat types of Region II. USDA Forest Service: A synthesis. Final report prepared for USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 140 pp.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.