Print Report

CEGL005648 Pinus ponderosa / Purshia tridentata Central Rocky Mountain Woodland

Type Concept Sentence: No Data Available


Common (Translated Scientific) Name: Ponderosa Pine / Antelope Bitterbrush Central Rocky Mountain Woodland

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This Pinus ponderosa woodland occurs in montane zones in the central Rocky Mountains and interior Pacific Northwest from Montana, Idaho, Washington, Oregon, and California. Stands tend to occupy south-facing, moderate to somewhat steep slopes (10-49%). Elevations range from 1450-2300 m (4760-7550 feet). Soils are relatively deep, mesic, well-drained sandy loams or loamy sands derived from sandstone, granite, colluvium or alluvium. Ground cover of litter and duff is often significant (30-60%). This Pinus ponderosa woodland is strongly dominated by Pinus ponderosa, often in open stands (10-40% cover) 10 to 35 m tall. Pseudotsuga menziesii, Juniperus scopulorum, and Populus tremuloides are common associates. The shrub layer is characterized and dominated by Purshia tridentata, although cover may be as low as 1% in sparsely vegetated stands. Additional species include Amelanchier alnifolia, Arctostaphylos uva-ursi, Artemisia tridentata, Mahonia repens, Juniperus communis, Prunus virginiana, Ribes cereum, and Symphoricarpos albus. The herbaceous layer is inversely proportional to shrub cover and is dominated by graminoids, especially Pseudoroegneria spicata. Additional graminoids include Bouteloua gracilis, Carex geyeri, Carex rossii, Danthonia parryi, Poa fendleriana, Hesperostipa comata, Leucopoa kingii, and Festuca idahoensis. Forbs are present and often diverse but have low cover. Forb composition largely depends on geographic region but often includes Achillea millefolium var. occidentalis, Antennaria spp., Artemisia ludoviciana, Eriogonum racemosum, Penstemon virens, and Sedum lanceolatum, among many others. Bare ground and needle duff can be prevalent in some stands.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Taxonomists (Kartesz 1999) recognize two varieties of Pinus ponderosa, a Pacific form, Pinus ponderosa var. ponderosa, and an interior form, Pinus ponderosa var. scopulorum. This association may be dominated by either variety in Montana, but Pinus ponderosa var. ponderosa further west.

Similar NVC Types: No Data Available
note: No Data Available

Physiognomy and Structure: No Data Available

Floristics: This Pinus ponderosa woodland is strongly dominated by Pinus ponderosa (predominantly Pinus ponderosa var. ponderosa), often in open stands (10-40% cover) 10 to 35 m tall. Pseudotsuga menziesii, Juniperus scopulorum, and Populus tremuloides are common associates. The shrub layer is characterized and dominated by Purshia tridentata, although cover may be as low as 1% in sparsely vegetated stands. Additional species include Amelanchier alnifolia, Arctostaphylos uva-ursi, Artemisia tridentata, Juniperus communis, Mahonia repens, Ribes cereum, and Prunus virginiana, Symphoricarpos albus. The herbaceous layer is inversely proportional to shrub cover and is dominated by graminoids, especially Festuca idahoensis and Pseudoroegneria spicata. Additional graminoids include Bouteloua gracilis, Carex geyeri, Carex rossii, Danthonia parryi, Hesperostipa comata, Leucopoa kingii, and Poa fendleriana. Forbs are present and often diverse but have low cover. Forb composition largely depends on geographic region but often includes Achillea millefolium var. occidentalis (= Achillea lanulosa), Antennaria spp., Artemisia ludoviciana, Eriogonum racemosum, Penstemon virens, and Sedum lanceolatum, among many others. Bare ground and needle duff can be prevalent in some stands.

Dynamics:  Purshia tridentata is important browse for wildlife and livestock. It is shade-intolerant and an early colonizer (Zlatnik 1999). It is killed by fire, although reinvades quickly (Daubenmire and Daubenmire 1968). Stands in the Colorado Plateau would not carry fire well because they are typically sparsely vegetated. Fire in denser stands would likely result in removal of ponderosa pine canopies and result in the possible formation of a mixed shrub or shrub-herbaceous community.

Environmental Description:  This Pinus ponderosa woodland occurs in montane zones in the central Rocky Mountains and interior Pacific Northwest. Stands tend to occupy south-facing, moderate to somewhat steep slopes (10-49%). Elevations range from 1450-2300 m (4760-7550 feet). Soils are relatively deep, mesic, well-drained sandy loams or loamy sands derived from sandstone, granite, colluvium or alluvium. Ground cover of litter and duff is often significant (30-60%).

Geographic Range: This Pinus ponderosa woodland occurs in montane zones in the western United States from Montana, Idaho, Washington, Oregon and California.

Nations: US

States/Provinces:  CA, ID, MT, WA




Confidence Level: Low - Poorly Documented

Confidence Level Comments: No Data Available

Grank: GNR

Greasons: No Data Available


Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: = Pinus ponderosa / Purshia tridentata Habitat Type (Steele et al. 1981)
= Pinus ponderosa / Purshia tridentata Habitat Type (Pfister et al. 1977)
>< Ponderosa pine / bitterbrush / fescue (CP-S2-12) (Hopkins 1979b)

Concept Author(s): M.S. Reid

Author of Description: S.L. Neid, J. Coles and M.S. Reid

Acknowledgements: No Data Available

Version Date: 01-13-16

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