Name:
Abies lasiocarpa - Populus tremuloides / Acer glabrum Central Rocky Mountain Avalanche Chute Shrubland Alliance
Reference:
NatureServe Biotics 2019
Description:
Stands of this shrubland alliance are composed of a moderately dense to dense, diverse mix of deciduous shrubs and broken and stunted trees. This canopy may be codominated by <i>Abies lasiocarpa, Acer glabrum, Alnus viridis ssp. sinuata, Alnus incana, Amelanchier alnifolia, Populus tremuloides, Ribes lacustre, Rubus parviflorus, Sorbus scopulina</i>, and on drier sites <i>Pseudotsuga menziesii</i>. Where avalanches occur annually or more often, conifers are rare and brushy deciduous trees and shrubs are common. Where avalanches are less frequent, stands dominated by conifers less than 4 m tall develop. The ground layer is composed of graminoids and forbs. The forb component is often very diverse, and mesic forbs prevail. <i>Chamerion angustifolium</i> was present in all sampled plots, a good indicator of periodic disturbance that characterizes this alliance. Other common to abundant species include <i>Angelica arguta, Artemisia ludoviciana, Calamagrostis canadensis, Calamagrostis rubescens, Carex geyeri, Elymus glaucus, Erythronium grandiflorum, Galium triflorum, Heracleum maximum, Osmorhiza occidentalis, Pteridium aquilinum, Solidago canadensis, Thalictrum occidentale, Valeriana sitchensis</i>, and <i>Veratrum viride</i>. This shrubland alliance is found within avalanche chutes at a broad range of elevations within the zone of continuous forest in the upper montane and subalpine zones of the central Rocky Mountains, from Wyoming north and west into British Columbia and Alberta. Stands are located in avalanche tracks and runout zones and can occur on any aspect, but are more common on southeast- to southwest-facing slopes where unstable snowpack conditions frequently occur. Sites are often mesic because avalanche paths are often in stream gullies. Substrate is variable depending on parent materials, but is typically shallow and rocky. Adjacent vegetation may include subalpine forests dominated by <i>Abies lasiocarpa, Picea engelmannii</i>, or <i>Pseudotsuga menziesii</i>, and subalpine meadows.
Accession Code:
urn:lsid:vegbank.org:commConcept:39178-{969C38F6-4197-4D1C-A408-6E97CD5BA71F}
Plot-observations of this Community Concept:
0
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