Common (Translated Scientific) Name: Subalpine Fir - Engelmann Spruce / Rusty Menziesia / Smooth Woodrush Woodland

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This association is a major upper subalpine woodland type in northwestern Montana (primarily west of the Continental Divide), Idaho, from the Idaho Batholith country northward, and southwestern Alberta, occurring primarily as a large-patch community but, also as a small-patch to matrix community type. It occurs as an open woodland. It generally forms a zone extending about 215 m (700 feet) vertically from various base elevations, which decrease with increasing latitude; in west-central Montana it ranges from 2075 to 2320 m, in northwestern Montana it ranges from 1830 to 2075 m. It usually occurs on moderate to steep slopes, just below the ridgeline or slope shoulder, with aspects ranging from just west of north-facing to east-facing. At its upper distributional limits it may occur on warmer aspects and flatter ground, often associated with the heads of cirque basins or shallow to deep swales. These are cold, relatively harsh sites where snowpack may persist long into the growing season. Soils are derived from a broad range of parent materials including Idaho Batholith granitics, calcareous and noncalcareous sedimentary, and metamorphic mica schists. Ground surfaces are usually litter-covered, but the soil generally contains a high fraction of coarse material, averaging about 30% and content increasing with depth. Vegetation structure is distinctly that of a woodland with widely spaced individual trees or a clumped distribution thereof to produce a total canopy cover of less than 50% dominated by Abies lasiocarpa with lesser representation by Picea engelmannii. Pinus contorta has a very limited presence; however, Larix lyallii may have 30% or greater cover, but its presence is rather unpredictable. The shrub component is dominated by Menziesia ferruginea, which ranges in height from 0.7 to 1.5 m (far less than its potential of 3+ m). Though the cover of Luzula glabrata (average about 8%) is much less than in ~Abies lasiocarpa - Picea engelmannii / Luzula glabrata var. hitchcockii Woodland (CEGL000317)$$, it is still sufficient to be indicative of this cold and snowpacked environment. The forb component has several consistently present species, including Xerophyllum tenax, Arnica latifolia, Orthilia secunda, and Viola orbiculata; only the first two named contribute more than trace amounts of cover in what is a depauperate layer.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This association has resulted from elevating a couple of phase levels of habitat types that appeared to define unique environments. The association defined here is not so broad as the Abies lasiocarpa / Luzula glabrata Habitat Type, Menziesia ferruginea Phase of Pfister et al. (1977) because it does not include stands with other seral tree species having appreciable cover, nor does this concept accept Pinus albicaulis as an alternative indicator to Luzula glabrata, where this latter species is lacking (Pfister et al. 1977). Stands with an appreciable cover (5%) of Pinus albicaulis have been placed into a separate association due to their unique ecology in light of blister rust (Cronartium ribicola) induced mortality. There is apparently much environmental overlap between Rhododendron albiflorum and Menziesia ferruginea but some distinct distributional differences; where the two geographically overlap intensive analysis and crosswalking need to be conducted to produce a seamless classification across geopolitical boundaries.

Similar NVC Types: No Data Available

note: No Data Available