Name:
Pinus albicaulis - Abies lasiocarpa Woodland [Provisional]
Reference:
Western Ecology Working Group of...
Description:
This patchy or open woodland association occurs in the upper subalpine zone at, or just below, treeline across the central and northern Rocky Mountains. Elevations range from 2180-2870 m (5428-9400 feet). Sites are cold with a short growing season. They range from dry to relatively mesic depending on elevation, slope and aspect as they relate to wind exposure and snow accumulation. Stands occur predominantly on moderately to very steep slopes but also are found on exposed, wind-scoured flats. Substrates are typically rocky, with shallow to moderately deep soils, which are well- to excessively well-drained, gravelly or coarse-sandy loam or clay loam. Parent materials are variable, both calcareous and noncalcareous but are more often igneous or metamorphic, acidic rocks rather than calcareous sedimentary rocks, which seem to favor Pseudotsuga menziesii regeneration. This association is characterized by an open canopy (15-40% cover). Pinus albicaulis with scattered Picea engelmannii and Abies lasiocarpa form the overstory with the subcanopy dominated by Abies lasiocarpa. Trees may be scattered or clustered in groves and are often wind-deformed and stunted, growing only 6-18 m (20-60 feet) tall or less. Occasionally Pinus flexilis or Pseudotsuga menziesii may be present, but sites are generally too cold. The undergrowth is variable, depending on relative moisture, and typically depauperate. Juniperus communis often dominates the dwarf-shrub layer (<0.5 m tall, though a short shrub in more optimal habitats) with 5-15% cover; Arctostaphylos uva-ursi is often present with low cover. Other shrubs may be present; Ribes montigenum, Ribes lacustre, and Vaccinium scoparium occur scattered. The herbaceous layer is typically sparse (<15% cover). Herbaceous species of moderate to high constancy include Antennaria spp., Arnica cordifolia, Carex geyeri, Carex rossii, Chamerion angustifolium, Lupinus argenteus, Penstemon virens, Sedum lanceolatum, Selaginella densa, Packera neomexicana (= Senecio neomexicanus), Thalictrum fendleri, and Thermopsis divaricarpa. Disturbed sites often have higher cover of Polygonum phytolaccifolium.
Accession Code:
VB.CC.26118.PINUSALBICAULIS
Plot-observations of this Community Concept:
0
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