Common (Translated Scientific) Name: Subalpine Fir - Engelmann Spruce / Rusty Menziesia / Clasping Twisted-stalk Woodland

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: 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 Menziesia ferruginea (accompanied by Rhododendron albiflorum 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 Picea engelmannii and Abies lasiocarpa, 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 Menziesia ferruginea is diagnostic and Vaccinium membranaceum approaches 100% constancy. Other shrubs consistently present include Alnus viridis ssp. sinuata, Rubus parviflorus, Ribes lacustre, and Sorbus spp. (predominantly Sorbus sitchensis). The graminoid component is decidedly sparse with only Bromus vulgaris and Luzula glabrata var. hitchcockii being present in more than a third of the sampled stands. Other graminoids present only occasionally, but indicative of a high moisture status, include Cinna latifolia, Calamagrostis canadensis, Vahlodea atropurpurea, and Carex disperma. 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 Athyrium filix-femina (considerably less robust, however, than when occurring in the Thuja plicata alliance), Angelica arguta, Angelica dawsonii, Streptopus amplexifolius, Senecio triangularis, Erigeron peregrinus, Mertensia ciliata, Mertensia paniculata, Aconitum columbianum, Ligusticum canbyi, Veratrum viride, Heracleum maximum, and Trautvetteria caroliniensis; diagnostic forbs of shorter stature include Gymnocarpium dryopteris, Mitella breweri, Mitella pentandra, and Viola glabella.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This association was previously recognized as the Menziesia ferruginea Phase of the Abies lasiocarpa / Streptopus amplexifolius Habitat Type (Cooper et al. 1987). Structurally, compositionally and environmentally this assemblage of stands is sufficiently distinctive to constitute a unique association. It occurs predominantly on upslope positions that are subirrigated and possessing a robust shrub component rather than on subirrigated alluvial bottoms and toeslopes exclusively forb-dominated (or at least lacking the tall-shrub component whose composition is indicative of higher elevation and ostensibly colder sites).

Similar NVC Types: No Data Available

note: No Data Available