Common (Translated Scientific) Name: Quaking Aspen - Subalpine Fir - Engelmann Spruce / Clasping Twisted-stalk Forest

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This mesic to subhygric, montane to lower subalpine association is located on cool, moist toeslopes to midslopes on both sides of the Continental Divide of Glacier National Park, Montana. It occurs on mostly moderate to gentle toeslopes and midslopes between 1450 and 1830 m (4760-6000 feet) elevation on the east side of the Continental Divide and near 1120 m (3680 feet) west of the Continental Divide. This type generally occurs on north- and west-facing slopes; it can also occur on south-facing slopes. Soils are well- to somewhat poorly drained silty clay loams that are medium to dark in color and have little rock content. These are also classified as Orthic Grey Luvisols and Orthic Regosols within Waterton Lakes National Park and occur on glacio-fluvial and morainal landforms. Litter comprises 40-75% of the ground cover. This is a moist, mixed evergreen-deciduous wet forest. Tree canopy ranges from 10-70%. Picea engelmannii, Populus tremuloides, Populus balsamifera ssp. trichocarpa, and Abies lasiocarpa are the most frequent tree species. Pinus contorta and Betula papyrifera also occur infrequently in the overstory. Tree height averages 10-20 m, although trees can reach 35 m in height, and stand age ranges from 120 to 160 years. Shrub cover is variable, ranging between 0 and 70%, and includes Rubus parviflorus, Cornus sericea, Amelanchier alnifolia, Ribes lacustre, Lonicera utahensis, Acer glabrum, Salix geyeriana, and Alnus viridis ssp. sinuata. Other shrubs less frequently encountered include Symphoricarpos albus, Symphoricarpos occidentalis, Shepherdia canadensis, Spiraea betulifolia, and Rosa acicularis. Herbaceous cover is high, ranging from 40-90%. The diagnostic forb for this association is Streptopus amplexifolius, which is always accompanied by other species such as Senecio triangularis, Mitella pentandra, Mitella breweri, Gymnocarpium dryopteris, Angelica arguta, Athyrium filix-femina, Trautvetteria caroliniensis, and Trollius laxus. Dominant species include Thalictrum occidentale and Heracleum maximum, although Actaea rubra, Chamerion angustifolium, Eucephalus engelmannii, Geranium richardsonii, Maianthemum racemosum ssp. amplexicaule, Fragaria virginiana, and Lathyrus ochroleucus are commonly present. Maianthemum stellatum, Arnica cordifolia, Eurybia conspicua, Osmorhiza occidentalis, Bromus vulgaris, Veratrum viride, and Viola canadensis are also relatively common. Nonvascular cover ranges from 5-20%.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This is a successional forest type, occupying sites classified as the Abies lasiocarpa - Picea engelmannii / Streptopus amplexifolius Habitat Type, Streptopus amplexifolius Phase (Hansen et al. 1995). It is defined by having at least 25% of the canopy cover comprised of either Populus tremuloides or Populus balsamifera ssp. trichocarpa.

Similar NVC Types: No Data Available

note: No Data Available