Name:
Abies lasiocarpa - Picea engelmannii / Menziesia ferruginea / Streptopus amplexifolius Woodland
Reference:
Western Ecology Working Group of...
Description:
This association has been described primarily as a linear to small-patch type within the northern Rocky Mountains of the U.S. and Canada. It is found from the Clearwater National Forest northward into British Columbia and Alberta, though perhaps it is best developed within northern Idaho and northwestern Montana. Virtually the only site parameter characteristic of all sampled stands is a seasonally high water table, yielding a hygric to subhydric moisture regime. This association is found from mid to upper subalpine sites with elevations ranging from 1340 to 2075 m. It is found on all degrees of slope, in all slope positions and occupying all aspects, with no particular condition considered modal. It should be inferred from the dense canopy of <i>Menziesia ferruginea</i> (accompanied by <i>Rhododendron albiflorum</i> in northern Idaho-eastern Washington) that these sites are also relatively cold. Parent materials run the gamut from sedimentary to intrusive igneous to glacial till and drift with compaction layers. Throughout much of this association's range a high ash content is present when the type occurs on north- and east-facing slopes. The tree canopy is relatively open, seldom exceeding 60% combined cover and dominated by a combination of <i>Picea engelmannii</i> and <i>Abies lasiocarpa</i>, that can vary between the extremes of nearly monospecific dominance of either species. The undergrowth is dominated by a dense shrub layer, often exceeding 60% canopy cover, in which <i>Menziesia ferruginea</i> is diagnostic and <i>Vaccinium membranaceum</i> approaches 100% constancy. Other shrubs consistently present include <i>Alnus viridis ssp. sinuata, Rubus parviflorus, Ribes lacustre</i>, and <i>Sorbus</i> spp. (predominantly <i>Sorbus sitchensis</i>). The graminoid component is decidedly sparse with only <i>Bromus vulgaris</i> and <i>Luzula glabrata var. hitchcockii</i> being present in more than a third of the sampled stands. Other graminoids present only occasionally, but indicative of a high moisture status, include <i>Cinna latifolia, Calamagrostis canadensis, Vahlodea atropurpurea (= Deschampsia atropurpurea)</i>, and <i>Carex disperma</i>. The forb layer is generally quite species-rich with dominance shifting between any number of species indicative of mesic to relatively wet conditions. The relatively tall forb species considered diagnostic for the type include <i>Athyrium filix-femina</i> (considerably less robust, however, than when occurring in the <i>Thuja plicata</i> alliance), <i>Angelica arguta, Angelica dawsonii, Streptopus amplexifolius, Senecio triangularis, Erigeron peregrinus, Mertensia ciliata, Mertensia paniculata, Aconitum columbianum, Ligusticum canbyi, Veratrum viride, Heracleum maximum</i>, and <i>Trautvetteria caroliniensis</i>; diagnostic forbs of shorter stature include <i>Gymnocarpium dryopteris, Mitella breweri, Mitella pentandra</i>, and <i>Viola glabella</i>.
Accession Code:
VB.CC.32241.CEGL005897
Plot-observations of this Community Concept:
0
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