This system occurs in north-central Montana in the Big Snowy Mountain range, at elevations of 2,012-2,195 meters (6,600-7,200 feet). Occurrences are typically on gentle to steep slopes on any aspect. Soils in this mountain range are derived from alluvium, colluvium, and residuum from calcareous parent materials. Most current occurrences represent a late-seral stage of aspen (Populus tremuloides) forest changing to a pure conifer forest. Nearly a hundred years of fire suppression and livestock grazing have converted much of the pure aspen occurrences to the present-day aspen-conifer forest and woodland ecological system, with conifers increasing in dominance. Conifers in this system include Douglas-fir (Pseudotsuga menziesii), subalpine fir (Abies lasiocarpa), Engelmann spruce (Picea engelmannii) and lodgepole pine (Pinus contorta). Common shrubs include serviceberry (Amelanchier alnifolia), creeping Oregon grape (Mahonia repens), chokecherry (Prunus virginiana), Woods’ rose (Rosa woodsii), birch-leaf spiraea (Spiraea betulifolia), and snowberry (Symphoricarpos species).
The tree canopy is composed of a mix of deciduous and coniferous species, co-dominated by aspen (Populus tremuloides) and conifers, including Douglas-fir (Pseudotsuga menziesii), subalpine fir (Abies lasiocarpa), Engelmann spruce (Picea engelmannii), lodgepole pine (Pinus contorta) and ponderosa pine (Pinus ponderosa). Common understory shrubs include serviceberry (Amelanchier alnifolia), creeping Oregon grape (Mahonia repens), chokecherry (Prunus virginiana), Woods’ rose (Rosa woodsii), birch-leaf spiraea (Spiraea betulifolia), and snowberry (Symphoricarpos species). Graminoid composition varies depending on available site moisture, but often includes mountain brome (Bromus carinatus), pinegrass (Calamagrostis rubescens), Geyer’s sedge (Carex geyeri), blue wild rye (Elymus glaucus), and needlegrasses (Achnatherum and Nassella species). Common forbs include yarrow (Achillea millefolium), heart-leafarnica (Arnica cordifolia), aspen daisy (Erigeron speciosus), northern bedstraw (Galium boreale), silver lupine (Lupinus argenteus), starry Solomon’s seal (Maianthemum stellatum), and meadow rue (Thalictrum species). Exotic species such as Kentucky bluegrass (Poa pratensis), timothy (Phleum pratense) and common dandelion (Taraxacum officinale) are frequentin areas impacted by grazing.
Restoration strategies for Inter-Mountain Basins Aspen-Mixed Conifer Forest and Woodland will depend largely on the severity of the fire or other land use impacts. Early successional stages may be dominated by fireweed (Chamerion angustifolium) and other forbs, small amounts of forest graminoids, and by resprouting of dominant shrubs. Quaking aspen will resprout vigorously following fires of low to moderate severity. Some sprouting will occur after higher intensity fires from root suckers that are deeper in the soil profile. However, the ability of aspen to resprout following removal can vary widely among clones (Schier et al, 1985).
Hardy, Colin C., and Stephen F. Arno. 1996. The use of fire in forest restoration a general session at the annual meeting of the Society for Ecological Restoration : Seattle, WA, September 14-16, 1995. Ogden, Utah (324 25th Street, Ogden 84401): U.S. Dept. of Agriculture, Forest Service, Intermountain Research Station.
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