Name:
Populus balsamifera ssp. trichocarpa / Symphoricarpos albus Forest
Reference:
Western Ecology Working Group of...
Description:
This association is known from the Blue Mountains of eastern Oregon, through the Columbia Basin to the Cascades of eastern Washington, into central and northern Idaho, western Wyoming, and north to the mountains of southern British Columbia. This late-seral association typically occurs at low elevations from 579 to 2040 m (1900-6693 feet) in broad mountain valleys and canyons of low- to moderate-gradient streams and rivers. The association occupies alluvial terraces with deep silty loam soils (over cobble and gravel) on infrequently flooded sites well above the average high-water line and summer water table. Tall and mature Populus balsamifera ssp. trichocarpa form the open to closed overstory canopy, with occasional understory asexual reproduction and conifers present. Conifer species, especially Pinus ponderosa and Pseudotsuga menziesii, may indicate the potential successional pathway on these relatively dry terrace sites. The shrub layer is clearly dominated by Symphoricarpos albus (usually with at least 20% cover), although a variety of other tall and medium shrubs (all with cover less than Symphoricarpos albus) are usually present. The most consistently prominent shrubs are Acer glabrum, Amelanchier alnifolia, Crataegus douglasii, Philadelphus lewisii, Prunus virginiana, Rosa spp., and Rubus parviflorus, the presence of which may reflect successional relationships with other alluvial terrace associations. The herbaceous layer is diverse, but has only moderate cover, and often includes exotic species indicative of past disturbance. Perennial grasses, especially Elymus glaucus, Phalaris arundinacea, and Poa pratensis, often codominate with various tall forbs and Equisetum spp. The most important forbs include Clematis ligusticifolia, Heracleum maximum, Maianthemum spp., Thalictrum occidentale, and Urtica dioica.
Accession Code:
VB.CC.22564.POPULUSBALSAMIF
Plot-observations of this Community Concept:
0
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