Name:
Pseudotsuga menziesii / Menziesia ferruginea / Clintonia uniflora Forest
Reference:
Western Ecology Working Group of...
Description:
This seral, large-patch to matrix type occupies relatively cold and moist environments across a number of climax tree series and associated geographic regions of the northern Rockies. Thus this cold, mesic type is found throughout the northern Rocky Mountains and may extend as far west as the Cascade Crest on environments characterized as montane to lower and even mid subalpine. The association's possible elevation range is from 915 to 1800 m (4000-5700 feet), and regardless of the climax series in which it is found, it consistently occurs on cool northwest- through east-facing slopes with moderate to extreme degrees of slope. It has been recorded as low as 910 m (3000 feet) on benches and swales where cold air ponds. The range of parent materials is, with the exception of highly unusual substrates like serpentine, literally as great as possible types occurring in the northern Rocky Mountains and northernmost middle Rocky Mountains and may include some ultramafics east of the Cascade Crest. It is difficult to simply characterize the soils as well, but they are uniformly moderately well-drained to well-drained and have a highly variable coarse-fragment content, but are mostly moderately gravelly throughout. Soil reactions vary from acidic to very acidic. Ground surfaces have virtually no exposed rock or bare soil and duff accumulations vary from moderate to deep. The overstory is dominated by Pseudotsuga menziesii, but its cover is often less than 30%, and canopy cover of the upper stratum often does not much exceed 60%. A whole host of tree species are capable of playing a subordinate role; on warmer sites these include Thuja plicata, Tsuga heterophylla, Abies grandis, and on colder or higher elevation sites are found Abies lasiocarpa, Tsuga mertensiana, and Picea engelmannii. However, the most frequent canopy codominants or associates are the seral species Larix occidentalis, Pinus contorta, and in a restricted portion of the type's range, Pinus monticola. Menziesia ferruginea conspicuously dominates the tall-shrub layer. Alnus viridis ssp. sinuata and Taxus brevifolia (predominantly in Idaho and western Montana) are the only other tall shrubs consistently present. The short-shrub layer exhibits greater diversity than the other shrub components with Vaccinium membranaceum, Paxistima myrsinites, Rosa gymnocarpa, Rubus parviflorus, and Spiraea betulifolia being consistently present, along with Linnaea borealis, Chimaphila umbellata, and Vaccinium scoparium in the dwarf-shrub layer. Bromus vulgaris (or Bromus ciliatus) are the only graminoids of note. The diagnostic forbs Clintonia uniflora and Tiarella trifoliata have high constancy (both approaching 100%) and/or cover, however, a number of other forbs also exhibit high constancy across this type's range, including Arnica latifolia, (Arnica cordifolia at lower elevations), Coptis occidentalis (peculiar to central and northern Idaho), Cornus canadensis, Galium triflorum, Goodyera oblongifolia, Maianthemum stellatum, Osmorhiza berteroi (= Osmorhiza chilensis), Orthilia secunda (= Pyrola secunda), Thalictrum occidentale, Trillium ovatum, Viola orbiculata, and Xerophyllum tenax.
Accession Code:
VB.CC.28320.PSEUDOTSUGAMENZ
Plot-observations of this Community Concept:
0
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