Name:
Pinus contorta / Arctostaphylos uva-ursi Forest
Reference:
Western Ecology Working Group of...
Description:
This association occurs in the upper montane and subalpine zone of the Rocky Mountains from central Colorado to the Big Horn Mountains in north-central Wyoming, but also in the Uinta Mountains of northern Utah, and Cascade Mountains of central Oregon and Washington. Elevations range from 2640 to 2860 m (8680-10,600 feet) in Colorado down to 2500 to 2895 m (8200-9500 feet) in the Uinta Mountains, 2390 to 2512 m (7835-8235 feet) in the Bighorn Mountains, and 1280 to 1676 m (4200-5500 feet) in central Oregon. Stands typically occur on warm, dry sites. Sites are gentle to steep slopes on any aspect. Soils are typically well-drained, shallow to moderately deep, gravelly loamy sand or sandy loam derived from granite, quartzite or other noncalcareous parent materials, typically with low fertility. Ground surface may have high cover of gravel and small and/or large rock. Some stands in the Cascades occur on flat, seasonally ponded soils with water table levels at 2 feet during summer. Substrates in central Oregon are volcanics (pumice, lava, tuff) resulting in xeric, loamy sand- to sandy loam-textured soils. The vegetation is characterized by an open to moderately dense tree canopy strongly dominated by <i>Pinus contorta</i>, with a patchy to continuous dwarf-shrub layer dominated by <i>Arctostaphylos uva-ursi</i> (15-65% cover). <i>Pinus flexilis</i> (to 10% cover) and scattered <i>Populus tremuloides</i> may be present, especially in the subcanopy, with occasional <i>Pseudotsuga menziesii</i> and <i>Abies lasiocarpa</i> trees restricted to mesic microsites. Associated shrubs and dwarf-shrubs include low cover of <i>Juniperus communis, Mahonia repens, Purshia tridentata, Spiraea betulifolia, Rosa</i> spp., <i>Ribes</i> spp., or <i>Vaccinium caespitosum</i>. The herbaceous cover is sparse. Common associates include <i>Antennaria parvifolia, Arnica cordifolia, Carex geyeri, Carex rossii, Festuca brachyphylla, Poa nervosa, Lupinus argenteus, Sedum lanceolatum, Packera streptanthifolia (= Senecio streptanthifolius), Solidago simplex (= Solidago spathulata), Thermopsis divaricarpa</i>, and <i>Trisetum spicatum</i>. If <i>Juniperus communis</i> is present, it generally has less than half the cover of <i>Arctostaphylos uva-ursi</i>.
Accession Code:
VB.CC.33071.CEGL000134
Plot-observations of this Community Concept:
0
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