Name:
Pinus contorta var. murrayana Woodland Group
Reference:
NatureServe Biotics 2019
Description:
This forested group occurs on ridges and rocky slopes around timberline at (1800-2450 m [6000-8000 feet] in the north and 2450-3600 m [8000-11,800 feet] in the south) up to 3600 m (11,800 feet) in the Sierra Nevada, and 2450 m (8000 feet) in the southern Cascades. It also occurs on extensive broad ridges and pumice plateaus of the southern Cascades in Oregon. Tree species often occur as krummholz growth forms with a wind-pruned, prostrate, and/or shrub-like appearance, but in more protected sites they form full-height woodland physiognomy. Soils are often shallow and coarse-textured. Avalanches, tree mortality from insect outbreak and disease, drought, and associated wildfire are drivers of vegetation structure and composition. Stands are dominated by <i>Juniperus grandis, Pinus albicaulis</i>, and/or <i>Pinus contorta var. murrayana</i>; other important conifers and locally dominant species include <i>Pinus balfouriana</i> (only in the Klamath Mountains and southern Sierra Nevada where it may replace <i>Pinus albicaulis</i>), <i>Pinus flexilis</i> (but only in small patches on the eastern flank of the Sierra Nevada escarpment when it does occur), and <i>Pinus monticola</i> (not in Transverse or Peninsular ranges). <i>Juniperus grandis</i> occurs mostly in the central and southern Sierra Nevada but not in the Klamath Mountains. Important shrubs include <i>Arctostaphylos nevadensis, Ceanothus cordulatus, Cercocarpus ledifolius, Chrysolepis sempervirens, Artemisia tridentata, Phyllodoce breweri, Ribes montigenum</i>, and <i>Holodiscus discolor</i>. Grasses and forbs include <i>Carex exserta, Carex rossii, Carex filifolia, Poa wheeleri, Eriogonum incanum, Penstemon newberryi</i>, and <i>Penstemon davidsonii</i>. Due to landscape position and very thin soils, these are harsh sites exposed to desiccating winds with ice and snow blasts and rocky substrates. In addition, a short growing season limits plant growth. Understories are open, with scattered shrubs and herbaceous species, which do not provide a continuous fuel bed. Trees can be old and can attain diameters of 1.2 m (4 feet). The highest tree diversity occurs in the Klamath Mountains, with sometimes five or more conifers sharing codominance in one stand.
Accession Code:
urn:lsid:vegbank.org:commConcept:40028-{02DC8DDF-1EB9-4CB0-9531-EFBD2398EFE7}
Plot-observations of this Community Concept:
0
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