Name:
Pseudotsuga menziesii / Mahonia repens Forest
Reference:
Western Ecology Working Group of...
Description:
This forest association occurs on dry, often nutrient-poor sites in the southern and central Rocky Mountains and high plateaus of the Colorado Plateau from northern Arizona and New Mexico north through Colorado and Utah into central Idaho, Wyoming and Montana, and extends to the eastern Cascades in Oregon. Stands occur on lower mountain slopes and upper canyon slopes. Elevations range from 1740 to 2930 m (5700-9600 feet) in northern New Mexico, Arizona and Colorado, and 1375 to 2595 m (4500-8500 feet) in Utah, Wyoming and southern Idaho. Soils are variable in texture and parent material but are usually deep and often rocky. The vegetation is representative of closed-canopy stands of <i>Pseudotsuga menziesii</i> where most species other than <i>Mahonia repens</i> have been shaded out. In some stands, a few individual <i>Pinus ponderosa, Pinus contorta, Pinus flexilis, Pinus strobiformis, Populus tremuloides</i>, or <i>Juniperus scopulorum</i> may persist in the canopy or subcanopy. The understory may be sparse, with 10% or less total cover, but sometimes will have up to 30% total herbaceous and shrub cover. <i>Mahonia repens</i> is the dominant species with at least 1% cover, but other species are usually present with at least trace cover, including <i>Juniperus communis, Symphoricarpos oreophilus, Paxistima myrsinites</i>, and <i>Prunus virginiana</i>. The herbaceous layer is generally sparse but may include small amounts of graminoids such as <i>Poa fendleriana, Festuca arizonica, Carex geyeri, Carex rossii</i>, and scattered forbs such as <i>Arnica cordifolia, Galium boreale</i>, and <i>Thalictrum fendleri</i>. The mature, older canopy trees in some stands are fire-scarred, indicating that ground-fire activity may be important in stands of this type. Some stands appear to be ponderosa pine woodlands that have filled in within the last 150 years with a closed canopy of Douglas-fir.
Accession Code:
VB.CC.33325.CEGL000442
Plot-observations of this Community Concept:
0
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