Print Report

CEGL000870 Pinus ponderosa / Quercus gambelii Woodland

Type Concept Sentence: No Data Available

Common (Translated Scientific) Name: Ponderosa Pine / Gambel Oak Woodland

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This major ponderosa pine woodland is widespread and has been reported from foothills, mountains and plateaus from Colorado to Texas, west to Arizona and Nevada. Elevation ranges from 1830-2800 m (6000-9200 feet). Stands often occur along drainages, on lower and middle slopes and benches on all aspects. Soils are typically shallow and rocky, ranging from sandy loams to clay loams. At El Malpais National Monument in western New Mexico, it generally occurs on rolling lava plateaus, steep sideslopes of volcano craters, on gentle toeslopes of low cinder hills, or on sandstone outcrops. Substrates are derived from basalt or sandstone, with rock, gravel, and occasional patches of sandy soil. Litter is often abundant in patches. Pinus ponderosa dominates or sometimes codominates the sparse to moderately dense tree canopy with Pinus edulis and Juniperus spp. Pseudotsuga menziesii is accidental and Abies concolor is not present. Quercus gambelii dominates both the subcanopy (tree form, if present) and the typically moderately dense tall-shrub layer consisting of dense clumps of oak. Quercus gambelii must have at least 5% cover, but there is frequently over 25%. At higher elevations, the Quercus gambelii are more treelike, and Symphoricarpos oreophilus will be present with significant cover in the short-shrub layer. At lower elevations, scattered Artemisia tridentata ssp. vaseyana, Pinus edulis, and Juniperus osteosperma are often present. At El Malpais, Forestiera pubescens is the most commonly occurring shrub, along with occasional Ribes cereum. Other common shrub species may include Amelanchier spp., Mahonia repens, and Rosa woodsii. The herbaceous layer is generally sparse and composed of mostly graminoids and scattered forbs.

Diagnostic Characteristics: Must have at least 5% cover of Quercus gambelii. Overstory regeneration is Pinus ponderosa. Pseudotsuga menzensii is absent or accidental.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This ponderosa pine woodland is a broadly defined plant association. Stuever and Hayden (1997a) report seven phases for this plant association: the Quercus gambelii, Festuca arizonica, Muhlenbergia longiligula, Pinus edulis, Muhlenbergia montana, Bouteloua gracilis, and Robinia neomexicana phases. More classification review is needed to further define the relationships between these phases and other similar plant associations.

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

Floristics: This broadly defined coniferous woodland is widespread and is characterized by a sparse to moderately closed evergreen needle-leaved tree canopy dominated by Pinus ponderosa, or sometimes codominated by Pinus edulis and scattered Juniperus scopulorum, Juniperus monosperma, or Juniperus osteosperma. In southern stands Juniperus deppeana and Pinus strobiformis may be present to codominant. Pseudotsuga menziesii is accidental and Abies concolor is not present. Quercus gambelii dominates both the subcanopy (tree form, if present) and the typically moderately dense tall-shrub layer, which consists of dense clumps of oak. This community must have at least 5% cover of Quercus gambelii, but there is frequently over 25%. At higher elevations, the Quercus gambelii are more treelike, and Symphoricarpos oreophilus will be present with significant cover in a short-shrub layer. At lower elevations, scattered Artemisia tridentata ssp. vaseyana, Pinus edulis, and Juniperus osteosperma are often present. At El Malpais, Forestiera pubescens is the most commonly occurring shrub, along with occasional Ribes cereum. Other common shrub species may include Arctostaphylos patula, Amelanchier spp., Cercocarpus montanus, Juniperus communis, Mahonia repens, Robinia neomexicana, Rosa woodsii, and Shepherdia rotundifolia. The herbaceous layer is generally sparse (<10% cover) but may equal the shrub cover. It is composed of mostly graminoids, such as Bouteloua gracilis, Elymus elymoides, Festuca arizonica, Koeleria macrantha, Muhlenbergia longiligula, Muhlenbergia montana, Poa fendleriana, Schizachyrium scoparium, and Carex spp., especially Carex geyeri and Carex rossii. Scattered forbs include Artemisia ludoviciana, Balsamorhiza sagittata, Eriogonum spp., Erigeron spp., Hymenoxys spp., Lithospermum multiflorum, Packera multilobata, and Wyethia amplexicaulis.

Dynamics:  Pinus ponderosa is a drought-resistant, shade-intolerant conifer that when mature has thick bark that allows it to withstand surface fires (Bradley et al. 1992). Natural fire frequency is estimated to be 3-20 years for this community (Youngblood and Mauk 1985). Quercus gambelii is a fire-adapted species with a well-developed root system that draws moisture from a large volume of soil and allows for rapid resprouting after fire (Clary 1992). Both species are well-adapted to relatively frequent surface fires that prevent Pseudotsuga menziesii or Abies concolor from regenerating. These woodlands grade into ~Abies concolor / Quercus gambelii Forest (CEGL000261)$$ or ~Pseudotsuga menziesii / Quercus gambelii Forest (CEGL000452)$$ as sites become cooler and wetter (DeVelice et al. 1986). Mosaics of Pinus ponderosa stands with grass- or oak-dominated understories occur in response to different substrates with Quercus gambelii dominating the rocky sites and grass understory woodland types (Festuca spp., Muhlenbergia montana) in areas with deeper soils (Peet 1981, DeVelice et al. 1986). Although Gambel oak is moderately shade-tolerant, if pine canopies close (>60% cover), especially with the addition of Douglas-fir to the canopy, oak tends to drop out of the understory (Nixon 1967b).
Environmental Description:  This woodland association is widespread and has been reported from foothills, mountains and plateaus from Colorado to Trans-Pecos Texas, west to Arizona and Nevada. Elevation ranges from 1830-2800 m (6000-9200 feet). Stands often occur along drainages, on lower and middle slopes and benches on all aspects. Slopes are typically gentle or moderate, but may also be steep (>45%). Soils are typically shallow and rocky ranging from sandy loams to clay loams. Parent materials are commonly sandstones, but fractured limestone, basalt, andesite, and alluvium are also reported. At El Malpais National Monument in western New Mexico, it gently occurs on rolling lava plateaus, steep sideslopes of volcano craters, on gentle toeslopes of low cinder hills, or on sandstone outcrops. Substrates are derived from basalt or sandstone, with rock, gravel, and occasional patches of sandy soil. High litter cover (70-90%) about 5 cm deep is common in many stands. Rock outcrops (about 10%) and some bare soil are not uncommon. This conifer woodland transitions to Quercus gambelii shrubland in drier sites and at lower elevations. This community is the highest elevation Pinus ponderosa / oak woodland present in Trans-Pecos Texas. It typically grades downslope to ~Pinus ponderosa / Quercus hypoleucoides Woodland (CEGL000872)$$.
Geographic Range: This ponderosa pine woodland association is widespread in the southern Rocky Mountains and southwestern U.S. and occurs in foothills, mountains and plateaus from Colorado to Trans-Pecos Texas, west to Arizona and Nevada.

Nations: US

States/Provinces:  AZ, CO, NM, NV, TX, UT


Confidence Level: High

Confidence Level Comments: No Data Available
Grank: G5

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.1 White Fir - Douglas-fir - Blue Spruce Forest Macrogroup M022 1.B.2.Nb.1
Group 1.B.2.Nb.1.b Ponderosa Pine Southern Rocky Mountain Forest & Woodland Group G228 1.B.2.Nb.1.b
Alliance A3398 Ponderosa Pine Southern Rocky Mountain Forest & Woodland Alliance A3398 1.B.2.Nb.1.b
Association CEGL000870 Ponderosa Pine / Gambel Oak Woodland CEGL000870 1.B.2.Nb.1.b
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: = Pinus ponderosa / Poa fendleriana Community Type (Hanks et al. 1983) [According to Fitzhugh et al. (1987).]
= Pinus ponderosa / Quercus gambelii / Carex geyeri Habitat Type (Wasser and Hess 1982)
= Pinus ponderosa / Quercus gambelii / Carex geyeri Habitat Type (Hess and Wasser 1982)
= Pinus ponderosa / Quercus gambelii (Stuever and Hayden 1997a)
= Pinus ponderosa / Quercus gambelii Community (Blackburn et al. 1969e)
= Pinus ponderosa / Quercus gambelii Habitat Type (Muldavin et al. 1996)
= Pinus ponderosa / Quercus gambelii Habitat Type (Fitzhugh et al. 1987)
= Pinus ponderosa / Quercus gambelii Habitat Type (Youngblood and Mauk 1985)
= Pinus ponderosa / Quercus gambelii Habitat Type (DeVelice et al. 1986)
= Pinus ponderosa / Quercus gambelii Habitat Type (Alexander et al. 1984a)
= Pinus ponderosa / Quercus gambelii Habitat Type (Alexander et al. 1987)
= Pinus ponderosa / Quercus gambelii Plant Association (Johnston 1987)
= Pinus ponderosa / Quercus gambelii Plant Association (Larson and Moir 1987)
= Pinus ponderosa / Quercus gambelii Plant Community (Roberts et al. 1992)
Concept Author(s): M.C. Stuever and J.S. Hayden (1997a)

Author of Description: K.A. Schulz, J. Coles and M.E. Hall

Acknowledgements: No Data Available

Version Date: 10-18-18
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