Name:
Pinus albicaulis - Abies lasiocarpa - Larix lyallii Northern Rocky Mountain Woodland Group
Reference:
NatureServe Biotics 2019
Description:
This group of the Northern Rockies is typically a high-elevation mosaic of stunted tree clumps, open woodlands, with herb- or dwarf-shrub-dominated openings, occurring above upper subalpine closed forest ecosystems and below alpine communities. The climate is typically very cold and snowy in winter and relatively dry and cool in summer. The upper and lower elevational limits, due to climatic variability and differing topography, vary considerably; in interior British Columbia, this group occurs between 1400 and 2200 m elevation, and in northwestern Montana, it occurs up to 2400 m. Landforms include ridgetops, mountain slopes, glacial trough walls and moraines, talus slopes, landslides and rockslides, cirque headwalls and basins. Some sites have little snow accumulation because of high winds and sublimation. In this harsh, often windswept environment, trees are typically stunted and flagged from damage associated with wind, blowing snow and ice crystals, especially at the upper elevations of the type. The stands or patches often originate when <i>Pinus albicaulis</i>, and in some communities <i>Picea engelmannii</i>, colonize a sheltered site such as the lee side of a rock. <i>Abies lasiocarpa</i> can then colonize in the shelter of either species. These high-elevation coniferous woodlands are dominated by <i>Pinus albicaulis</i> and <i>Abies lasiocarpa</i>, or <i>Larix lyallii</i>. The undergrowth is usually somewhat depauperate, but some stands support a near sward of heath plants, such as <i>Phyllodoce empetriformis, Vaccinium myrtillus</i>, and <i>Vaccinium scoparium</i>, that may be present to codominant. The herbaceous layer is sparse under dense shrub canopies or may be dense where the shrub canopy is open or absent. Common species include <i>Ligusticum grayi</i>(?), <i>Arnica latifolia, Xerophyllum tenax, Carex rossii, Carex geyeri</i>, and <i>Luzula glabrata var. hitchcockii</i>. Major disturbances are windthrow and snow avalanches. Fire is known to occur infrequently in this group, at least where woodlands are present; lightning damage to individual trees is common, but sparse canopies and rocky terrain limit the spread of fire.
Accession Code:
urn:lsid:vegbank.org:commConcept:40018-{0899F53B-F727-4D57-A570-90335AFC47A3}
Plot-observations of this Community Concept:
0
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