Name:
Pseudotsuga menziesii / Juniperus communis Forest
Reference:
Western Ecology Working Group of...
Description:
This Rocky Mountain forest association occurs from northwestern Montana south into central and eastern Idaho, western Wyoming and north-central Colorado. These forests occupy gentle to steep slopes (11-100%), on dry, exposed rocky slopes and ridgetops, at lower to mid elevations of the forested zone, from 1430 to 2930 m (4690-9620 feet) in elevation. Sites are relatively dry and occur on all aspects. Substrates are typically coarse-textured soils derived from a variety of parent materials. This association includes stands dominated by the evergreen needle-leaved tree <i>Pseudotsuga menziesii</i> or a mixed montane conifer tree canopy. <i>Pseudotsuga menziesii</i> is the dominant tree species in the overstory and often in the understory as well. <i>Pinus ponderosa, Pinus flexilis, Pinus contorta</i>, or <i>Pinus albicaulis</i> are occasionally present to codominant on drier sites, <i>Populus tremuloides</i> on moister sites. The low-shrub layer is dominated by near-continuous to large patches of <i>Juniperus communis</i>. Other shrubs include <i>Arctostaphylos uva-ursi, Jamesia americana, Juniperus horizontalis, Mahonia repens, Purshia tridentata, Ribes cereum, Symphoricarpos oreophilus</i>, or <i>Shepherdia canadensis</i>. The herbaceous cover is generally depauperate in the southern and central Rockies, with less than 10% cover of grasses or forbs. Forb species typically provide less than 5% cover and include <i>Achillea millefolium, Arnica cordifolia, Astragalus miser</i>, and <i>Packera streptanthifolia (= Senecio streptanthifolius)</i>. Grass species also contribute less than 5% herbaceous canopy cover and include <i>Muhlenbergia montana, Danthonia parryi, Bouteloua gracilis</i>, or <i>Festuca arizonica</i>. However, occurrences in the northern Rockies may have relatively high herbaceous cover (30-60%), and individual stands can be diverse. Common grasses include <i>Pseudoroegneria spicata</i> and <i>Festuca campestris</i>. A number of forbs contribute to the overall diversity, although the cover for any one species is not high. <i>Antennaria rosea, Penstemon confertus</i>, and <i>Allium cernuum</i> have high constancy, and <i>Selaginella densa var. scopulorum</i> may be abundant on some sites, particularly those where rock outcrops are present.
Accession Code:
VB.CC.32818.CEGL000439
Plot-observations of this Community Concept:
0
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