Name:
Abies lasiocarpa - Picea engelmannii / Menziesia ferruginea / Clintonia uniflora Forest
Reference:
Western Ecology Working Group of...
Description:
This is a broadly distributed association strongly associated with Pacific maritime climatic regime which penetrates with ever diminishing influence just east of the Continental Divide in the northern Rocky Mountains. It is well-documented from north-central Idaho and western Montana northwards into neighboring provinces of Alberta and British Columbia. This is a type of lower to mid-elevation subalpine environments with a relatively narrow elevation range in any given locality and an overall range of 1280 to 1770 m. It is characteristic of cool, moist exposures, typically occupying moderate to steep slopes with north- and east-facing slope aspects. Soils are derived from a variety of noncalcareous and calcareous sedimentary rock, as well as metamorphic types (including quartzites, mica schists), volcanics (both intrusive and extrusive, including granitics and basalts), and glacial till and drift. Surface horizon soil textures are predominantly silt loams and loams. In northern Idaho and western Montana an ash cap of variable depth (1-24 inches) increases the moisture-holding capacity and nutrient content of these soils. The overstory is dominated by a variable combination of Abies lasiocarpa and Picea engelmannii; total tree canopy cover is generally in the range of 50 to 80%. This association represents predominantly mature to old-growth conditions, but seral species can be present, in declining order of importance, Pinus contorta, Pseudotsuga menziesii, Larix occidentalis, Pinus monticola, and Pinus albicaulis. The undergrowth generally has a lush aspect with a tall to mid-sized shrub layer dominated by Menziesia ferruginea, Vaccinium membranaceum, Alnus viridis ssp. sinuata, Sorbus spp., Lonicera utahensis, and Ribes lacustre. Vaccinium scoparium (or Vaccinium myrtillus) and Linnaea borealis are the predominant dwarf-shrubs. Graminoids are scarce with only Bromus vulgaris and Bromus ciliatus being present with any constancy at all. The forb component is virtually always dominated by one, or a combination of, the following three species: Xerophyllum tenax, Arnica latifolia (or Arnica cordifolia), or Thalictrum occidentale. However, the type is recognized by the presence of either Clintonia uniflora or Tiarella trifoliata, which have much more restricted environmental ranges (mesic to hygric moisture regimes) than the above-named forb dominants; their cover seldom exceeds 10%. Other forbs consistently present with low coverages include Veratrum viride, Heracleum maximum, Galium triflorum, and Senecio triangularis.
Accession Code:
VB.CC.28262.ABIESLASIOCARPA
Plot-observations of this Community Concept:
0
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