Abies lasiocarpa/Linnaea borealis plant association 



(ABILAS/LINBOR; subalpine fir/twinflower; MTNHP rank G5/S5; 1 plot) 



Environment: ABILAS/LINBOR was sampled once on a northeast facing moderate slope at 

 7,080 feet elevation near the headwaters of Garden Creek. It is a minor type in the Ruby Range 

 and was found on granitic substrate, which is relatively uncommon in the range. It is upslope 

 from a naiTOW stringer of spruce community {Picea/Eqidsetum arvense or Picea/Carex 

 disperma) in a heavily cattle impacted stream bottom. Slopes with similar aspects on limestone 

 substrates in the vicinity support Pseudotsuga menziesii/Arnica cordifolia communities. 



Soils: The plot is within the MacFarlane stony sandy loam soil mapping unit (USDA Soil 

 Conservation Service 1989). Soils of the MacFarlane series are deep and well drained and are 

 typically covered by 2" of forest litter. They are classified as Cryoboralfs. The soils of the 

 sampled stand are derived from granitic parent material. 



Vegetation: The sampled stand, which was clearcut in the late 1800's, is dominated by serai 70 

 feet tall Piims contort a which contribute over 60% canopy cover. Abies lasiocarpa, the indicated 

 climax species, and Pseudotsuga menziesii are poorly represented and Picea is well represented 

 but not abundant. There is a dense shrub understory which is dominated by Vaccinhim scoparium 

 (ca. 80% cover) and Liimaea borealis (ca. 30% cover), indicating the Vaccinium scoparium 

 phase of ABILAS/LINBOR (Pfister et al. 1977). The grass Calamagrostis rubescens contributes 

 about 40%) cover, while forbs have only about 10%) total cover, with Pyrola chlorantha and 

 Arnica cordifolia being the most common species. There is significant (ca. 40%o) ground cover 

 by mosses. 



Comments: This stand was clearcut in the late 1800's, a time when harvest of timber for fuel and 

 timbers for the mining boom was intense. Timber productivity for ABILAS/LINBOR ranges 

 from low to high and is lowest for the Vaccinium scoparium phase (Pfister et al. 1977) which 

 represents higher elevation sites, generally having acidic parent materials. It is also notable that 

 within the Ruby Range (and elsewhere) Abies lasiocarpa types occur at considerably lower 

 elevations on acidic substrates as opposed to calcareous substrates. 



Picea/Senecio streptantUifolius plant association 



■ (PICEA/SENSTR; spruce/Rocky Mountain butterweed; MTNHP rank G4/S4;3 plots) 



Environment: PICEA/SENSTR, the driest of the Picea series associations identified in Montana 

 (Cooper et al. 1995), is a major forest type at higher elevations on limestone in the northern Ruby 

 Range. It was sampled by four plots on the eastern flank on moderately steep (ca. 50%o) upper 

 slopes with north and east exposures at 7,700 to 8,700 feet elevation. PICEA/SENSTR occupies 

 positions barely moist enough to support Picea; it interdigitates, generally on north- and east- 

 facing spur slopes, with communities of the Pseudotsuga series, which occur on drier exposui-es 

 and positions. 



Soils: The virtually exclusive association of PICEA/SENSTR with calcareous substrates 

 throughout its range is further confimied by its distribution within the Ruby Range. The Ruby 

 Range plots are all witliin the Whitore-rock outcrop complex mapping unit (USDA Soil 



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