Common (Translated Scientific) Name: Lodgepole Pine / Grouse Whortleberry / Common Beargrass Forest

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This large-patch to matrix lodgepole pine forest occurs in upper subalpine habitats from central Idaho to northern Idaho and west as far as the eastern slope of the Cascade Range in Washington and east to just beyond the Continental Divide in central Montana and southwestern Alberta. In the northern Rockies of Idaho and Montana, this association ranges from 1585 to 2530 m (5200-8300 feet); just east of the Cascades its elevation range is considerably depressed, from 1310 to 1730 m (4300-5680 feet). Sites are generally cool to cold and have deep snow accumulations. It is found on gentle to moderate slopes of all aspects, mostly associated with shedding terrain, such as backslopes and slope shoulders; it also occurs on well-drained benches associated with ridgetops. Parent materials include volcanics, metamorphic rock, and sedimentary. Soils are uniformly well- to excessively drained with textures predominantly sandy loams and loams. Gravel content is usually at least 10% for the upper profile and increases markedly with depth, averaging about twice that of the surface soil. Soils are also very to moderately acidic. The tree canopy is highly variable with regard to structure, ranging from closed at 60-80% canopy cover in many of the northern Idaho stands to extremely to moderately open (25-50% canopy cover) along the Continental Divide in Montana. Compositionally the canopy is strongly dominated by Pinus contorta; usually Abies lasiocarpa, Tsuga mertensiana, or Picea engelmannii are present. A greater diversity of tree species occur on Washington''s examples of this association. The undergrowth may be quite dense with a layer of Vaccinium scoparium (or Vaccinium myrtillus) surrounding tussocks of Xerophyllum tenax over which a sparse cover of Vaccinium membranaceum is superimposed. Tall shrubs, if present, could be characterized as accidentals. Spiraea betulifolia and Lonicera utahensis are consistently scattered in the short-shrub layer. Carex geyeri and Calamagrostis rubescens are the only graminoids regularly present and their cover seldom exceeds 10%. Other than the abundance of the diagnostic Xerophyllum tenax, the forb layer has low cover and is comparatively depauperate with only Arnica latifolia, Anemone piperi, Goodyera oblongifolia, Orthilia secunda, and Viola orbiculata having a consistent presence.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: With the comparatively recent emphasis on developing descriptions of (and keys to) existing vegetation (Grossman et al. 1998), it has yet to be determined at what cover values forest vegetation types will be distinguished one from another when the canopy tree species are mostly seral in nature and have a broad environmental range (broad niche). This contrasts with the approach of Pfister et al. (1977) who recognize Pinus contorta community types only when virtually no representation of other, more shade-tolerant tree species could be found on site. With Pinus contorta, which is exclusively seral except with respect to some subspecies on unusual substrates or atypical environments, researchers in Glacier National Park have taken the position that this very shade-intolerant, stand-replacing fire-adapted species should have several times the cover of the next most abundant canopy species for a Pinus contorta type to be recognized. What is really being indicated by this approach are areas having experienced stand-replacing fires (or similar catastrophic disturbance, e.g., clearcutting). Another approach would be to simply recognize the tree species with the plurality of canopy cover in assigning stands to particular associations treating existing vegetation. The stands representing this type are climax in two different tree series, Abies lasiocarpa and Tsuga mertensiana. That this association in fact occurs in the states and USFS Sections listed derives from this writer''s interpretation of constancy/cover tables of various authors/publications; where Pinus contorta is listed as a major seral species, the inference has been made that stands quite likely occur on the landscape where this species strongly dominates the upper canopy (often observed throughout northern Idaho and western Montana) (S. Cooper pers. comm.).

Similar NVC Types: No Data Available

note: No Data Available