Name:
Pseudotsuga menziesii / Clintonia uniflora Forest
Reference:
Western Ecology Working Group of...
Description:
Broadly distributed throughout the northern Rocky Mountains and adjacent terrain, this large-patch to matrix seral community occupies relatively moist (mesic) and warm to cool sites having free air drainage and lacking frost-pocket conditions. It occurs on slopes of all degrees of steepness and aspect orientation, though it is more likely to occur from toeslope through midslope positions (predominantly collecting positions). At the dry extreme of its distribution it is more strongly associated with protected positions such as concave slopes, moist depressions in gently sloping plateau areas, stringers along perennial stream bottoms, toeslopes and northeastern aspects. In the north it ranges from 760 to 1585 m, whereas to the south it ranges from 1060 to 1710 m (3500-5600 feet). A wide variety of parent materials are represented, including those as disparate as granite and limestone, including all manner of glacial-fluvial material. In northern Idaho and northwestern Montana it is routinely found on ash caps, ranging from 3 to 60 cm in depth. The soil textures are predominantly loams and silt loams; soils typically have less than 15% coarse-fragment content and are well-drained. This mesic seral association is characterized by Pseudotsuga menziesii dominating the upper canopy, though other tree species occur with lesser cover, including Larix occidentalis, Pinus contorta, and Pinus monticola and including those from warmer environments, Pinus ponderosa, Thuja plicata, and Tsuga heterophylla, and those of colder environments, Abies lasiocarpa, Abies grandis, and Picea engelmannii. The shrub layer may be highly diverse with tall shrubs (e.g., Acer glabrum, Taxus brevifolia, Amelanchier alnifolia), short shrubs (e.g., Symphoricarpos albus, Paxistima myrsinites, Rubus parviflorus, Spiraea betulifolia), and dwarf-shrubs (e.g., Chimaphila umbellata, Linnaea borealis, Mahonia repens) abundantly represented. The graminoid component is inconspicuous with no one species exhibiting high constancy, though Bromus vulgaris, Bromus ciliatus, and Calamagrostis rubescens are more consistently present and with greater cover than other graminoids. The cover of the diagnostic forbs Clintonia uniflora and Tiarella trifoliata is greatest when this type occurs in the zones potentially dominated by Thuja plicata and Tsuga heterophylla, up to 30% canopy cover (can even be a dominant forb), whereas in the colder environments characterized by Abies lasiocarpa, Abies grandis, and Picea engelmannii, potential dominance cover of these diagnostics and all forbs is generally less. Other forbs of high constancy, at least in some portion of this association's considerable range, are Aralia nudicaulis, Adenocaulon bicolor, Coptis occidentalis, Cornus canadensis, Galium triflorum, Goodyera oblongifolia, Maianthemum stellatum, Osmorhiza berteroi (= Osmorhiza chilensis), Orthilia secunda (= Pyrola secunda), Thalictrum occidentale, Trillium ovatum, Viola glabella (or Viola canadensis), and Viola orbiculata.
Accession Code:
VB.CC.28316.PSEUDOTSUGAMENZ
Plot-observations of this Community Concept:
0
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