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CEGL000208 Pinus ponderosa - Pseudotsuga menziesii / Arctostaphylos nevadensis Woodland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Ponderosa Pine / Douglas-fir / Pinemat Manzanita Woodland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: Steep, rocky slopes near ridgetops that receive intense solar radiation are typical sites for this association which occurs in Oregon and possibly northern California. Aspects generally range from southeastern to western, and slope averages 50%. This association usually occupies small areas that are surrounded by more dense forest stands and unforested ridgetops. The rocky, shallow soils have so little moisture-holding capacity that these sites are effectively very dry for plant growth despite the substantial input of precipitation, which ranges from 147-229 cm (58-90 inches). These sites are exposed to high winds. Wind detracts from soil moisture status by blowing off snow, directly desiccating plants, and eroding soil. Elevation ranges from 1280 to 1400 m (4200-4600 feet) to the north and 1280 to 1555 m (4200-5100 feet) to the south. This association includes sparse, mixed age stands of Pinus ponderosa and Pseudotsuga menziesii. In the northern portion of its range trace amounts of Abies grandis occur. These sites are too exposed and hot for Abies grandis to thrive. At the southern end of its range scattered Pinus lambertiana, Abies lowiana, and Calocedrus decurrens can be found in the stands, and Abies grandis will not be found. Shrub growth is patchy, dominated by Arctostaphylos nevadensis. In the northern portion of the range common associated shrubs include Arctostaphylos patula, Chrysolepis chrysophylla, and Spiraea betulifolia. Common herbaceous species include Calamagrostis rubescens, Achnatherum occidentale, Carex geyeri, Festuca occidentalis, Achillea millefolium, Pteridium aquilinum, and Penstemon species. In the southern portion of the range common associated shrubs include Quercus vacciniifolia, Symphoricarpos mollis, Mahonia aquifolium, Whipplea modesta, and Ceanothus integerrimus. Common herbaceous species include Lupinus albicaulis, Apocynum androsaemifolium, Moehringia macrophylla, Eriophyllum lanatum, Pyrola picta, and Eriogonum species.
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 association is characterized by relatively open mixed-age stands of the evergreen needle-leaved trees Pinus ponderosa and Pseudotsuga menziesii. Apparently, Pseudotsuga is slowly invading these sites due to recent fire suppression, as most Pinus ponderosa are older. Total tree cover is about 40%. Regeneration of both species is occurring in most stands, but is not abundant. Stands in the Siskiyous may also include scattered individuals of the conifer Pinus lambertiana. The shrub layer is patchy, but averages 50% or higher cover, and is dominated by the low, broad-leaved evergreen Arctostaphylos nevadensis. Other shrubs may include Arctostaphylos patula and Chrysolepis chrysophylla (= Castanopsis chrysophylla). Many other shrubs can occur, but none are abundant or constant. At the southern end of its range scattered Pinus lambertiana, Abies lowiana (= Abies concolor var. lowiana), and Calocedrus decurrens can be found in the stands, and Abies grandis will not be found. Shrub growth is patchy, dominated by Arctostaphylos nevadensis. In the northern portion of the range common associated shrubs include Arctostaphylos patula, Chrysolepis chrysophylla (= Castanopsis chrysophylla), and Spiraea betulifolia. Common herbaceous species include Calamagrostis rubescens, Achnatherum occidentale (= Stipa occidentalis), Carex geyeri, Festuca occidentalis, Achillea millefolium, Pteridium aquilinum, and Penstemon species. In the southern portion of the range common associated shrubs include Quercus vacciniifolia, Symphoricarpos mollis, Mahonia aquifolium (= Berberis piperiana), Whipplea modesta, and Ceanothus integerrimus. Common herbaceous species include Lupinus albicaulis, Apocynum androsaemifolium, Moehringia macrophylla (= Arenaria macrophylla), Eriophyllum lanatum, Pyrola picta (= Pyrola dentata), and Eriogonum species. Moss cover is low (<3%), while litter cover is typically over 50%.
Dynamics: No Data Available
Environmental Description: This association is found on the eastern side of the Cascade Range crest and the eastern slope of the Siskiyous, regions with steep precipitation gradients created by topographic rainshadow effects of the higher mountains to the west. Annual precipitation ranges from 150-225 cm, with a distinct summer drought. Summers are warm to hot, while winters can be cold. This association occurs at moderate elevations, from 1280-1405 m, on steep to very steep, rocky slopes near ridgetops which receive intense solar radiation. These sites are exposed to high winds which remove snow and desiccate plants. Parent materials are from basalt or breccia substrates in the eastern Cascades, and from metavolcanics, schist and granodiorite in the Siskiyous. The soils are shallow and very rocky. Due to the soils and winds, effective soil moisture is very low despite the relatively high precipitation. The surface is characterized by open, rocky ground.
Geographic Range: This association is restricted to hot, dry, high-elevation sites, with low moisture-holding capacity soils, in the Oregon Cascades. These abiotic requirements cause this association to once have been a widespread but uncommon forest type.
Nations: US
States/Provinces: CA?, OR
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.683982
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: G2
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.Nd Vancouverian Forest & Woodland Division | D192 | 1.B.2.Nd |
| Macrogroup | 1.B.2.Nd.2 Incense-cedar - Jeffrey Pine - Sierra White Fir Forest Macrogroup | M023 | 1.B.2.Nd.2 |
| Group | 1.B.2.Nd.2.a Incense-cedar - Sugar Pine - Sierra White Fir Forest & Woodland Group | G344 | 1.B.2.Nd.2.a |
| Alliance | A3673 Ponderosa Pine - Incense-cedar - Douglas-fir Forest Alliance | A3673 | 1.B.2.Nd.2.a |
| Association | CEGL000208 Ponderosa Pine / Douglas-fir / Pinemat Manzanita Woodland | CEGL000208 | 1.B.2.Nd.2.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: ? Pinus ponderosa - Pseudotsuga menziesii association (Atzet and Wheeler 1984)
? Pseudotsuga menziesii / Arctostaphylos nevadensis (Topik et al. 1988) [(p.63)]
? Pseudotsuga menziesii / Arctostaphylos nevadensis (Topik et al. 1988) [(p.63)]
- Atzet, T., and D. L. Wheeler. 1984. Preliminary plant associations of the Siskiyou Mountains Province, Siskiyou National Forest. USDA Forest Service, Pacific Northwest Region, Portland, OR.
- 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.
- Kagan, J. S., J. A. Christy, M. P. Murray, and J. A. Titus. 2004. Classification of native vegetation of Oregon. January 2004. Oregon Natural Heritage Information Center, Portland. 52 pp.
- Mitchell, R., and W. Moir. 1976. Vegetation of the Abbott Creek Research Natural Area. Northwest Science 50:42-58.
- Topik, C., N. M. Halverson, and T. High. 1988. Plant associations and management guide of the ponderosa pine, Douglas-fir, and grand fir zone, Mt. Hood National Forest. R6-ECOL-TP-004-88. USDA Forest Service, Pacific Northwest Region, Portland, OR. 136 pp.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.