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Montana Animal Field Guide

Montana Field Guides

Rocky Mountain Montane Douglas-fir Forest and Woodland

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Provisional State Rank: S4

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General Description

In Montana, this ecological system occurs on the east side of the Continental Divide, north to about the McDonald Pass area, and along the Rocky Mountain Front. This system is associated with a dry to submesic continental climate regime with annual precipitation ranging from 51 to 102 centimeters (20-40 inches), with a maximum in winter or late spring. Winter snowpacks typically melt off in early spring at lower elevations. Elevations range from valley bottoms to 1,980 meters (6500 feet) in northern Montana and up to 2,286 meters (7500 feet) on warm aspects in southern Montana. It occurs on north-facing aspects in most areas, and south-facing aspects at higher elevations. This is a Douglas-fir (Pseudotsuga menziesii) dominated system without any maritime floristic composition. Fire disturbance intervals are as infrequent as 500 years, and as a result, individual trees and forests can attain great age on some sites (500 to 1,500 years). In Montana, this system occurs from lower montane to lower subalpine environments and is prevalent on calcareous substrates. Common understory shrubs include common ninebark (Physocarpus malvaceus), common juniper (Juniperus communis), Rocky Mountain juniper (Juniperus scopulorum), birch-leaf spiraea (Spiraea betulifolia), snowberry (Symphoricarpos species), creeping Oregon grape (Mahonia repens) and Canadian buffaloberry (Shepherdia canadensis). The Douglas-fir/pinegrass (Calamogrostis rubescens) type is the most ubiquitous association found within this system in Montana.


Diagnostic Characteristics
Forest and Woodland, aridic soils, foothill to montane elevations, moderate persistence (100-500 yr) interval

Similar Systems

Range
This system extends north into Montana on the east side of the Continental Divide to McDonald Pass and along the Rocky Mountain Front. It occurs throughout the Beaverhead Mountains.

Ecological System Distribution
Approximately 9,795 square kilometers are classified as Rocky Mountain Montane Douglas-fir Forest and Woodland in the 2013 Montana Land Cover layers.  Grid on map is based on USGS 7.5 minute quadrangle map boundaries.



Montana Counties of Occurrence
BEAVERHEAD, BIG HORN, BROADWATER, CARBON, CASCADE, DEER LODGE, FLATHEAD, GALLATIN, GLACIER, GRANITE, JEFFERSON, JUDITH BASIN, LEWIS AND CLARK, MADISON, MEAGHER, MISSOULA, PARK, PONDERA, POWELL, RAVALLI, SILVER BOW, STILLWATER, SWEET GRASS, TETON, WHEATLAND

Spatial Pattern
Matrix

Environment
East of the Continental Divide, this ecosystem forms a forest belt on cold, dry to mesic sites in the montane zone. It is found on moderately dry mountain slopes and benches. It generally occurs on gravelly soils with good aeration and drainage and a neutral to slightly acidic pH. This system is subjected to a dry to sub-mesic continental climate. Individual trees and forests can attain great age on some sites (500-1500 years), due to mixed severity fire regimes. It often occurs at the lower treeline immediately above valley grasslands, or sagebrush steppe and shrublands.

Vegetation

This system is dominated by Douglas-fir (Pseudotsuga menziesii) forests. Limber pine (Pinus flexilis) can co-occuron calcareous substrates, and lodepole pine (Pinus contorta) is often frequent in these stands at higher elevations. Engelmann spruce (Picea engelmannii) is found in some stands within the upper montane zone, occurring just below or intergrading with whitebark pine (Pinus albicaulis) forests. Common understory shrubs include common ninebark (Physocarpus malvaceus), common juniper (Juniperus communis), Rocky Mountain juniper (Juniperus scopulorum) birch-leaf spiraea (Spiraea betulifolia), snowberry (Symphoricarpos species), creeping Oregon grape (Mahonia repens) and Canadian buffaloberry (Shepherdia canadensis). Dwarf huckleberry (Vaccinium caespitosum) or mountain huckleberry (Vaccinium membranaceum) are foundon colder, mesic sites. Common graminoids include pinegrass (Calamagrostis rubescens), Ross’ sedge (Carex rossii), and Geyer’s sedge (Carex geyeri). Bluebunch wheatgrass (Pseudoroegneria spicata) and Idaho fescue (Festuca idahoensis) are often common on sites adjacent to upper elevation montane grasslands. The Douglas-fir/pinegrass (Camogrostis rubescens) type is the most ubiquitous association found within this system in Montana. Common forbs within these forests include yarrow (Achillea millefolium), lanceleaf arnica (Arnica latifolia), pussytoes (Antennaria racemosa), wild strawberry (Fragaria virginiana), twinflower (Linnaea borealis), and beargrass (Xerophyllum tenax).


Alliances and Associations
Alliances
  • (A.157) Douglas-fir Forest Alliance
  • (A.552) Douglas-fir Woodland Alliance

Dynamic Processes

This system experiences 100- to 500-year fire disturbance intervals, but can be more frqeuent in some stands. Douglas-fir regenerates well following fire and is tolerant of repeated, low-intensity surface fires. In the absence of disturbance, Douglas-fir is the only species that continues to regenerate under shaded conditions, and becomes dominant in undisturbed stands. Pre-settlement fire regimes may have been characterized by frequent, low-intensity ground fires that maintained relatively open stands. Under present conditions, the fire regime is mixed severity and more variable, with stand-replacing fires more common, and the forests are more homogeneous. With vigorous fire suppression, longer fire-return intervals are now common, and multi-layered stands provide fuel "ladders," making these forests more susceptible to high-intensity, stand-replacing fires. In some areas, these forests have been priorities for timber harvesting and grazing. In recent years, these forests have been subjected to prolonged periods of drought, creating conditions where stands are susceptible to outbreaks of Douglas-fir tussock moth (Orgyia pseudotsugata) and Douglas-fir bark beetle (Dendroctonus pseudotsugae).


Management
In the absence of natural fire, periodic prescribed burns can be used to maintain this system.

Restoration Considerations
Post-fire Douglas-fir forest restoration strategies will depend largely on the severity of the fire. Because these forest recover well following light to moderate intensity burns, restoration practices are not necessary. Severely burned sites on steep slopes will require sediment retention and erosion control actions before and during restoration.

Species Associated with this Ecological System
  • Details on Creation and Suggested Uses and Limitations
    How Associations Were Made
    We associated the use and habitat quality (high, medium, or low) of each of the 82 ecological systems mapped in Montana for vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
    1. Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2001, Adams 2003, and Werner et al. 2004);
    2. Evaluating structural characteristics and distribution of each ecological system relative to the species’ range and habitat requirements;
    3. Examining the observation records for each species in the state-wide point database associated with each ecological system;
    4. Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of “observations versus availability of habitat”.
    Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.  In general, species were associated as using an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.  However, species were not associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if point observations were associated with that system.  High, medium, and low habitat quality was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species in the literature.  The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignments of habitat quality.  If you have any questions or comments on species associations with ecological systems, please contact Bryce Maxell at bmaxell@mt.gov or (406) 444-3655.

    Suggested Uses and Limitations
    Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.  These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: http://mtnhp.org/requests/default.asp) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.  Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.  Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.  Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).  Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species’ known geographic range.

    Literature Cited
    • Adams, R.A.  2003.  Bats of the Rocky Mountain West; natural history, ecology, and conservation.  Boulder, CO: University Press of Colorado.  289 p.
    • Dobkin, D. S.  1992.  Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34.  Missoula, MT.
    • Foresman, K.R.  2001.  The wild mammals of Montana.  Special Publication No. 12.  Lawrence, KS: The American Society of Mammalogists.  278 p.
    • Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998.  Montana atlas of terrestrial vertebrates.  Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT.  1302 p.
    • Hutto, R.L. and J.S. Young.  1999.  Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32.  72 p.
    • Maxell, B.A.  2000.  Management of Montana’s amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species.  Report to U.S. Forest Service Region 1.  Missoula, MT: Wildlife Biology Program, University of Montana.  161 p.
    • Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath.  2004.  Amphibians and reptiles of Montana.  Missoula, MT: Mountain Press Publishing Company. 262 p.

Original Concept Authors
M.S. Reid

Montana Version Authors
L.K. Vance, T. Luna

Version Date
1/21/2010

References
  • Classification and Map Identifiers

    Cowardian Wetland Classification: Not applicable

    National Vegetation Classification Standard:
    Class Mesomorphic Tree Vegetation (Forest and Woodland)
    Subclass Temperate Forest
    Formation Cool Temperate Forest
    Division Western North America Cool Temperate Forest
    Macrogroup Northern Rocky Mountain Lower Montane and Foothill Forest

    NatureServe Identifiers:
    Element Global ID
    System Code CES306.959, Middle Rocky Mountain Montane Douglas-Fir Forest and Woodland

    National Land Cover Dataset:
    42: Evergreen Forest

    ReGAP:
    4266: Middle Rocky Mountain Montane Douglas-Fir Forest and Woodland


  • Additional ReferencesLegend:   View WorldCat Record   View Online Publication
    Do you know of a citation we're missing?
    • Arno, S. F. 1980. Forest fire history in the northern Rockies. Journal of Forestry 78(8):460-465.
    • Pfister, R. D., B. L. Kovalchik, S. F. Arno, and R. C. Presby. 1977. Forest habitat types of Montana. USDA Forest Service. General Technical Report INT-34. Intermountain Forest and Range Experiment Station, Ogden, UT. 174 pp.

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Citation for data on this website:
Rocky Mountain Montane Douglas-fir Forest and Woodland — Middle Rocky Mountain Montane Douglas-Fir Forest and Woodland.  Montana Field Guide.  Retrieved on November 22, 2014, from http://FieldGuide.mt.gov/displayES_Detail.aspx?ES=4266
 
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