Name:
Pseudotsuga menziesii Scree Woodland
Reference:
Western Ecology Working Group of...
Description:
This association occurs throughout the interior western U.S. but is restricted to steep slopes covered by loose rock and colluvium on mountain or canyon slopes. It has the appearance of a stand of scattered trees with a sparse understory; the vegetation is limited by the lack of soil development. Slopes generally exceed 60% and are generally unstable, with constantly shifting rocks on the slopes as well as additional rockfall from outcrops upslope. Elevations at the northern end of the range (Montana) are from 915 to 2180 m (3100-7150 feet), and sites are usually limited to warm, south- to west-facing slopes in canyons. In northern Arizona, stands occur on various aspects around 2930 m (9600 feet) elevation, and in southern Colorado stands have been documented at around 2560 m (8400 feet). Most of the unvegetated ground surface is covered by rocks and boulders, with small amounts of litter and dead wood. Soils are poorly developed and often too rocky to sample. The rocky slope is the dominant visual element of the community. The sparse to open canopy of this association is generally mixed and rarely exceeds 35% cover. <i>Pseudotsuga menziesii</i> is always present and dominant or codominant; other tree species may include <i>Juniperus osteosperma, Juniperus scopulorum, Picea engelmannii, Pinus edulis, Pinus flexilis, Pinus strobiformis, Pinus ponderosa, Populus tremuloides, Abies concolor</i>, and <i>Abies lasiocarpa</i>. Shrubs are variable depending on the site, but cover is too sparse and the mix either lacks a diagnostic species in the understory or the shrub layer is too poorly developed to be diagnostic. Shrub species present may include <i>Arctostaphylos uva-ursi, Acer glabrum, Amelanchier utahensis, Juniperus communis, Dasiphora fruticosa ssp. floribunda, Holodiscus dumosus, Prunus virginiana, Ribes inerme, Ribes montigenum, Salix scouleriana, Shepherdia canadensis, Shepherdia rotundifolia</i>, and <i>Symphoricarpos oreophilus</i>. Herbaceous species are sparse and inconsistent among sites.
Accession Code:
VB.CC.33276.CEGL000911
Plot-observations of this Community Concept:
0
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