Name:
Pinus contorta / Vaccinium caespitosum / Clintonia uniflora Forest
Reference:
Western Ecology Working Group of...
Description:
This lodgepole pine forest association is a minor small- to large-patch type reported from northwestern Montana and southwestern Canadian Rockies, (it is not reported for northern Idaho), and is a minor type on the Colville and Okanogan national forests of northeastern and north-central Washington. In Montana its elevation range is documented to be 945 to 1650 m (3100-5400 feet); in northeastern Washington it occurs from 610 to 1525 m (2000-5000 feet). In Montana it is described from basins and river terraces and benchlands often having restricted drainages. In Washington it occurs predominantly on xero-riparian sites located in valley bottoms. The commonality of these environments is their potential to be frost pockets or at least areas where cold air ponds; daytime temperatures are contrastingly warm. Parent materials include volcanic ash deposited over glacial drift, coarse alluvium or fine alluvium over, or with, an appreciable gravel content, glacial till. Upper soil profiles are well- to excessively drained, but the compacted subsoils promote seasonally high water tables. The upper canopy generally has an open structure, dominated by Pinus contorta with well-scattered Pseudotsuga menziesii and Larix occidentalis. The subcanopy usually has low cover and is a mix of Abies lasiocarpa, Picea engelmannii, and occasionally Abies grandis. A tall-shrub component is conspicuously absent. The short-shrub component has a minor representation with Vaccinium membranaceum, Spiraea betulifolia, Lonicera utahensis, Paxistima myrsinites, Amelanchier alnifolia, Shepherdia canadensis, and Juniperus communis consistently present and the first-named often having cover in excess of 10%. The dwarf-shrub layer is the dominant component and, within it the appreciable cover (at least 3%) of Vaccinium caespitosum, is strongly indicative of a frosty microclimate and perhaps well-drained substrates. Other high-constancy (and variable cover) dwarf-shrubs include Linnaea borealis, Arctostaphylos uva-ursi, Mahonia repens (= Berberis repens), and Chimaphila umbellata. Calamagrostis rubescens and Carex concinnoides have very high constancy, and Calamagrostis cover is generally in excess of 10%, even capable of forming a sward that partially obscures the dwarf-shrub layer. The diverse forb component, in addition to the indicator Clintonia uniflora, regularly contains Hieracium albiflorum, Osmorhiza berteroi (= Osmorhiza chilensis), Cornus canadensis, Viola orbiculata, Maianthemum stellatum (= Smilacina stellata), Maianthemum racemosum (= Smilacina racemosa), Arnica latifolia, and Goodyera oblongifolia.
Accession Code:
VB.CC.28026.PINUSCONTORTAVA
Plot-observations of this Community Concept:
0
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