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CEGL001656 Poa nervosa - Achnatherum lettermanii Grassland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Hooker''s Bluegrass - Letterman''s Needlegrass Grassland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This plant association occurs at elevations between 3230 and 3450 m (10,600-11,300 feet) and on slopes that are generally less than 15%. The landscape relief is most often concave which lends itself to favorable soil moisture conditions despite the southerly aspects preferred by this community. The soils are deep, well-drained loam with gravel and sand present in the subsurface as well. Parent material for this association is sandstone. In this community, Poa nervosa has approximately 15% cover and Achnatherum lettermanii 11% cover. Associated species include Festuca brachyphylla, Phleum alpinum, Poa fendleriana, Trisetum spicatum, Achillea millefolium var. occidentalis, Agoseris glauca, Erigeron peregrinus, Erigeron simplex, Hymenoxys hoopesii, Polygonum bistortoides, Packera crocata and Viola nuttallii. This classification is based on three stands found in the southeastern and south-central portions of the White River Plateau in Colorado. This community has only been documented in Colorado.
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 is a subalpine grassland association, dominated by the perennial graminoids Poa nervosa and Achnatherum lettermanii (= Stipa lettermanii), with 15% and 11% cover, respectively. Other common grasses include Festuca ovina, Phleum alpinum and Poa fendleriana. Perennial forbs are common in this association as well; the most important are Achillea millefolium var. occidentalis (= Achillea lanulosa), Erigeron peregrinus, Erigeron simplex, Agoseris glauca, Hymenoxys hoopesii (= Helenium hoopesii), Polygonum bistortoides (= Bistorta bistortoides), Packera crocata (= Senecio crocatus), and Viola nuttallii. Total graminoid cover averages 50%, as does forb cover. Species richness is relatively high, with 53 species reported for this association.
Dynamics: No Data Available
Environmental Description: This type occurs in a mountainous region subject to a continental climate regime, with warm summers and cold winters. The region is characterized by level to rolling terrain with occasional rocky outcrops and deep canyons formed by streams. This association is found from 3250 to 3420 m (10,660-11,230 feet) elevation, on gentle toeslopes and on slopes bordering upland benches. Typically the sites have southerly aspect and concave topographic relief, resulting in snow accumulation and runoff retention. Soils are derived from sandstones; and are deep, well-drained gravelly loams.
Geographic Range: Stands are found in the southeastern and south-central portions of the White River Plateau in Colorado.
Nations: US
States/Provinces: CO
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.683772
Confidence Level: Low - Poorly Documented
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 | A3954 Thurber''s Fescue - Timber Oatgrass - Letterman''s Bluegrass Southern Rocky Mountain Subalpine Grassland Alliance | A3954 | 2.B.2.Nf.3.a |
| Association | CEGL001656 Hooker''s Bluegrass - Letterman''s Needlegrass Grassland | CEGL001656 | 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: = Poa nervosa - Stipa lettermanii Habitat Type (Wasser and Hess 1982)
= Poa nervosa - Stipa lettermanii Habitat Type (Hess and Wasser 1982)
= Poa nervosa - Stipa lettermanii Plant Association (Johnston 1987)
= Poa nervosa - Stipa lettermanii Habitat Type (Hess and Wasser 1982)
= Poa nervosa - Stipa lettermanii Plant Association (Johnston 1987)
- 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.
- CNHP Ecology Team [Colorado Natural Heritage Program Ecology Team]. 2001. A classification of the native vegetation of Colorado. Colorado Natural Heritage Program, Colorado State University, Fort Collins.
- 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/]
- Hess, K., and C. H. Wasser. 1982. Grassland, shrubland, and forest habitat types of the White River-Arapaho National Forest. Unpublished final report 53-82 FT-1-19. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 335 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.
- 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.