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CEGL000759 Pinus aristata / Festuca arizonica Woodland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Bristlecone Pine / Arizona Fescue Woodland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This is an association confined to exposed, windswept ridges and steep slopes in the upper montane and subalpine zones of the southern Rocky Mountains. These open to moderately closed woodlands occur on all aspects, but are most common on drier south- and west-facing slopes. Slopes are typically moderate to steep, but may also be gentle. Soils are typically well-drained, shallow, and skeletal. Stands have an open to moderately closed canopy typically 5-15 m tall that is solely dominated or codominated by Pinus aristata. Individual trees may reach 20 m. In some stands trees are clumped with grassy patches interspersed. Other tree species that may be present to codominant vary geographically within its range. Picea engelmannii and Pseudotsuga menziesii are the most common. Pinus flexilis has also been reported as an associate in some stands. Abies lasiocarpa and Populus tremuloides may be scattered in some stands, but are generally restricted to more mesic sites and are typically absent in the drier southern extent of this association. The understory vegetation ranges from moderately dense to sparse (typically) because sites are dry and often have large amounts of rock cover. The sparse to moderately dense herbaceous layer often dominates the understory. The most common species are typically graminoids, especially species of Festuca. This association differs from ~Pinus aristata / Trifolium dasyphyllum Woodland (CEGL000762)$$ by having a higher and more consistent cover of perennial grasses.
Diagnostic Characteristics: Pinus aristata is dominant or is codominant with Pseudotsuga menziesii in the overstory. Grasses dominate the understory with Festuca arizonica as the indicator species. Populus tremuloides occurs as an accidental species.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This association differs from ~Pinus aristata / Trifolium dasyphyllum Woodland (CEGL000762)$$ by having a higher and more consistent cover of perennial grasses.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: Stands have an open to moderately closed canopy typically 5-15 m tall that is solely dominated or codominated by the long-lived evergreen, needle-leaved tree Pinus aristata. Individual trees may reach 20 m. In some stands trees are clumped with grassy patches interspersed. Other tree species that may be present to codominant vary geographically within its range. Picea engelmannii and Pseudotsuga menziesii are the most common. Picea pungens is common in the southern extent where stands occur at high elevations, and Pinus flexilis has also been reported as an associate in some stands. Abies lasiocarpa and Populus tremuloides may be scattered in some stands, but are generally restricted to more mesic sites and are typically absent in the drier southern extent of this association.
The understory vegetation ranges from moderately dense to typically sparse because sites are dry and often have large amounts of rock cover. The sparse to moderately dense herbaceous layer often dominates the understory. The most common species are typically graminoids, especially species of Festuca. Common species may include Calamagrostis purpurascens, Carex spp., Danthonia parryi, Festuca arizonica, Festuca brachyphylla, Festuca idahoensis, Festuca thurberi, Koeleria macrantha, Muhlenbergia filiculmis, Muhlenbergia montana, Poa fendleriana, and Trisetum spicatum. Forbs are generally sparse, but Trifolium dasyphyllum may reach 10% cover. Other scattered forbs may include species of Achillea, Antennaria, Artemisia, Arenaria, Arnica, Astragalus, Campanula, Erigeron, Hymenoxys, Penstemon, Polemonium, Sedum, Senecio, and Thalictrum. This association differs from ~Pinus aristata / Trifolium dasyphyllum Woodland (CEGL000762)$$ by having a higher and more consistent cover of perennial grasses.
The understory vegetation ranges from moderately dense to typically sparse because sites are dry and often have large amounts of rock cover. The sparse to moderately dense herbaceous layer often dominates the understory. The most common species are typically graminoids, especially species of Festuca. Common species may include Calamagrostis purpurascens, Carex spp., Danthonia parryi, Festuca arizonica, Festuca brachyphylla, Festuca idahoensis, Festuca thurberi, Koeleria macrantha, Muhlenbergia filiculmis, Muhlenbergia montana, Poa fendleriana, and Trisetum spicatum. Forbs are generally sparse, but Trifolium dasyphyllum may reach 10% cover. Other scattered forbs may include species of Achillea, Antennaria, Artemisia, Arenaria, Arnica, Astragalus, Campanula, Erigeron, Hymenoxys, Penstemon, Polemonium, Sedum, Senecio, and Thalictrum. This association differs from ~Pinus aristata / Trifolium dasyphyllum Woodland (CEGL000762)$$ by having a higher and more consistent cover of perennial grasses.
Dynamics: Pinus aristata is a slow-growing, extremely long-lived tree (Brunstein and Yamaguchi 1992). Several individuals over 2000 years old have been found in Colorado. DeVelice et al. (1986) observed that it occurs in open park-like stands and on steep rocky slopes where Picea engelmannii - Abies lasiocarpa stands are excluded by drought. Fire is important in the grass-dominated stands but is rarely intense enough to result in tree-killing crown fires (DeVelice et al. 1986). In some stands, suppression of grass fires has allowed encroachment of the trees into meadows (Larson and Moir 1987). Forage production is good in some stands, but rarely utilized by livestock because stands are steep and generally remote which makes access difficult.
Peet (1978b, 1981) noted that Pinus aristata is dominant at higher elevations in much of the southern Rocky Mountains, where Pinus flexilis is restricted to lower elevations. This is attributed to apparent competitive exclusion, because Pinus flexilis is dominant at high elevations in northern Colorado, Wyoming and Montana.
Peet (1978b, 1981) noted that Pinus aristata is dominant at higher elevations in much of the southern Rocky Mountains, where Pinus flexilis is restricted to lower elevations. This is attributed to apparent competitive exclusion, because Pinus flexilis is dominant at high elevations in northern Colorado, Wyoming and Montana.
Environmental Description: This woodland association occurs on semi-xeric sites in the subalpine zone in the southern Rocky Mountains. Elevations range from 2600-3670 m (8500-12,050 feet). Climate is semi-arid, cold temperate with cool summers. Annual precipitation patterns and amounts vary with latitude, but locally the sites are typically xeric on exposed, wind-swept rocky slopes and ridges. These open to moderately closed woodlands occur on all aspects, but are most common on drier south- and west-facing slopes. Slopes are typically moderate to steep, but may also be gentle. Soils are typically well-drained, shallow, skeletal and coarse-textured such as gravelly, sandy loams or loams. Stands occur most frequently on igneous, metamorphic and volcanic substrates such as andesite, granite, gneiss, breccia, tuff, conglomerate, but also occur on sedimentary rocks like sandstone. Exposed bedrock is common. Soil pH is 4.5-6.9, acidic to slightly acidic.
Geographic Range: This association is known from the southern Rocky Mountains and from the Colorado Plateau regions of Colorado and New Mexico.
Nations: US
States/Provinces: CO, NM
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.684122
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: G4
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 1 Forest & Woodland Class | C01 | 1 |
| Subclass | 1.B Temperate & Boreal Forest & Woodland Subclass | S15 | 1.B |
| Formation | 1.B.2 Cool Temperate Forest & Woodland Formation | F008 | 1.B.2 |
| Division | 1.B.2.Nb Rocky Mountain Forest & Woodland Division | D194 | 1.B.2.Nb |
| Macrogroup | 1.B.2.Nb.5 Subalpine Fir - Engelmann Spruce - Whitebark Pine Rocky Mountain Forest Macrogroup | M020 | 1.B.2.Nb.5 |
| Group | 1.B.2.Nb.5.e Limber Pine - Bristlecone Pine Rocky Mountain Subalpine-Montane Woodland Group | G221 | 1.B.2.Nb.5.e |
| Alliance | A0537 Bristlecone Pine Woodland Alliance | A0537 | 1.B.2.Nb.5.e |
| Association | CEGL000759 Bristlecone Pine / Arizona Fescue Woodland | CEGL000759 | 1.B.2.Nb.5.e |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Pinus aristata / Festuca arizonica (Stuever and Hayden 1997a)
= Pinus aristata / Festuca arizonica Habitat Type (DeVelice et al. 1986)
= Pinus aristata / Festuca arizonica Habitat Type (Komarkova et al. 1988a)
= Pinus aristata / Festuca arizonica Habitat Type (Larson and Moir 1987)
= Pinus aristata / Festuca arizonica Plant Association (Johnston 1987)
= Pinus aristata - Festuca arizonica Habitat Type/Association (Komarkova 1986)
= Pinus aristata, Festuca arizonica, Muhlenbergia montana, Ribes cereum Habitat Type (Shepherd 1975)
= Pinus aristata / Festuca arizonica Habitat Type (DeVelice et al. 1986)
= Pinus aristata / Festuca arizonica Habitat Type (Komarkova et al. 1988a)
= Pinus aristata / Festuca arizonica Habitat Type (Larson and Moir 1987)
= Pinus aristata / Festuca arizonica Plant Association (Johnston 1987)
= Pinus aristata - Festuca arizonica Habitat Type/Association (Komarkova 1986)
= Pinus aristata, Festuca arizonica, Muhlenbergia montana, Ribes cereum Habitat Type (Shepherd 1975)
- 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.
- Brunstein, C. R., and D. K. Yamaguchi. 1992. The oldest known Rocky Mountain bristlecone pines (Pinus aristata Engelm.). Arctic and Alpine Research 24:253-256.
- 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/]
- DeVelice, R. L. 1983. Forest vegetation of northern New Mexico and southern Colorado. Unpublished dissertation, New Mexico State University, Las Cruces. 191 pp.
- DeVelice, R. L., J. A. Ludwig, W. H. Moir, and F. Ronco, Jr. 1986. A classification of forest habitat types of northern New Mexico and southern Colorado. General Technical Report RM-131. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CO. 59 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.
- 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.
- Komarkova, V., A. Peters, G. Kamani, W. Jones, V. Howard, H. Gordon, and K. Southwick. 1988a. Natural recovery of plant communities on disturbance plots and history of land use in the Niwot Ridge/Green Lakes Valley, Front Range, Colorado. University of Colorado Longterm Ecological Research Working Paper 88/1. Boulder, CO. 46 pp.
- Larson, M., and W. H. Moir. 1987. Forest and woodland habitat types of northern New Mexico and northern Arizona. Edition 2. USDA Forest Service, Southwestern Region, Albuquerque, NM.
- 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.
- Peet, R. K. 1978b. Forest vegetation of the Colorado Front Range: Patterns of species diversity. Vegetatio 37:65-78.
- Peet, R. K. 1981. Forest vegetation of the Colorado Front Range. Vegetatio 45:3-75.
- Salas, D. E., J. Stevens, K. Schulz, M. Artmann, B. Friesen, S. Blauer, E. W. Schweiger, and A. Valdez. 2010b. Vegetation classification and mapping project report: Great Sand Dunes National Park and Preserve. Natural Resource Report NPS/ROMN/NRR--2010/179. National Park Service, Fort Collins, CO.
- Shepherd, H. R. 1975. Vegetation of two dissimilar bighorn sheep ranges in Colorado. Colorado Division of Wildlife Report 4. 223 pp.
- Stewart, B. K. 1940. Plant ecology and paleoecology of the Creede Valley, Colorado. Unpublished dissertation, University of Colorado, Boulder. 154 pp.
- Stuever, M. C., and J. S. Hayden. 1997a. Plant associations of Arizona and New Mexico, edition 3. Volume 1: Forests. USDA Forest Service, Southwestern Region. Habitat Typing Guides. 291 pp.
- USFS [U.S. Forest Service]. 1987a. Forest and woodland habitat types (plant associations) of northern New Mexico and northern Arizona. USDA Forest Service, Southwestern Region, Albuquerque, NM. Second edition, 170 pp. plus insert.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.