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Scientific Name: Northern Rocky Mountain Subalpine Woodland and Parkland
Unique Identifier: CES306.807
Classification Confidence: 2 - Moderate

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Summary: This ecological system of the Northern Rockies, Cascade Range, and northeastern Olympic Mountains is typically a high-elevation mosaic of stunted tree clumps, open woodlands, and herb- or dwarf-shrub-dominated openings, occurring above closed forest ecosystems and below alpine communities. It includes open areas with clumps of Pinus albicaulis, as well as woodlands dominated by Pinus albicaulis or Larix lyallii. In the Cascade Range and northeastern Olympic Mountains, the tree clump pattern is one manifestation, but these are also woodlands with an open canopy, without a tree clump/opening patchiness to them; in fact, that is quite common with Pinus albicaulis. The climate is typically very cold in winter and dry in summer. In the Cascades and Olympic Mountains, the climate is more maritime in nature and wind is not as extreme. The upper and lower elevational limits, due to climatic variability and differing topography, vary considerably; in interior British Columbia, this system occurs between 1000 and 2100 m elevation, and in northwestern Montana, it occurs up to 2380 m. Landforms include ridgetops, mountain slopes, glacial trough walls and moraines, talus slopes, landslides and rockslides, and cirque headwalls and basins. Some sites have little snow accumulation because of high winds and sublimation. Larix lyallii stands generally occur at or near upper treeline on north-facing cirques or slopes where snowfields persist until June or July. In this harsh, often windswept environment, trees are often stunted and flagged from damage associated with wind and blowing snow and ice crystals, especially at the upper elevations of the type. The stands or patches often originate when Picea engelmannii, Larix lyallii, or Pinus albicaulis colonize a sheltered site such as the lee side of a rock. Abies lasiocarpa can then colonize in the shelter of the Picea engelmannii and may form a dense canopy by branch-layering. Major disturbances are windthrow and snow avalanches. Fire is known to occur infrequently in this system, at least where woodlands are present; lightning damage to individual trees is common, but sparse canopies and rocky terrain limit the spread of fire.

These high-elevation coniferous woodlands are dominated by Pinus albicaulis, Abies lasiocarpa, and/or Larix lyallii, with occasional Picea engelmannii. In the Cascades and Olympics, Abies lasiocarpa sometimes dominates the tree layer without Pinus albicaulis, though in this dry parkland Tsuga mertensiana and Abies amabilis are largely absent. The undergrowth is usually somewhat depauperate, but some stands support a near sward of heath plants, such as Phyllodoce glanduliflora, Phyllodoce empetriformis, Empetrum nigrum, Cassiope mertensiana, and Kalmia polifolia, and can include a slightly taller layer of Ribes montigenum, Salix brachycarpa, Salix glauca, Salix planifolia, Vaccinium membranaceum, Vaccinium myrtillus, or Vaccinium scoparium that may be present to codominant. The herbaceous layer is sparse under dense shrub canopies or may be dense where the shrub canopy is open or absent. Vahlodea atropurpurea, Luzula glabrata var. hitchcockii, and Juncus parryi are the most commonly associated graminoids.

In the mountains of northwestern and west-central Wyoming, where this upper-treeline system reaches the edge of its geographic range, the vegetation usually has the form of an open woodland, and only rarely as scattered groves of trees. At the highest elevations, Pinus albicaulis usually has a wind-stunted shrub form. On lower, more favorable sites, upright but wind-shaped Pinus albicaulis forms woodlands, sometimes with Pinus contorta as a codominant or even the dominant species. With decreased altitude, where this system merges into the subalpine forests, Picea engelmannii and Abies lasiocarpa become common tree species as well.

Classification Approach: International Terrestrial Ecological Systems Classification (ITESC)

Classification Comments: There is a proposal to either split the dry, subalpine Pinus albicaulis woodlands of the Blue Mountains (Oregon) and northern Nevada into a different system; or else to include them in Rocky Mountain Subalpine-Montane Limber-Bristlecone Pine Woodland (CES306.819). For Landfire, these Pinus albicaulis woodlands were included in this subalpine parkland system, but ecologically and floristically they are more similar to Rocky Mountain dry subalpine woodlands. In addition, there is a proposal and discussion that tree ribbon spruce-fir woodlands in scattered ranges of southern Wyoming are more ecologically "parklands"; possibly those areas could be included in this system.

Component Associations
Association Unique ID Association Name
CEGL000128 Pinus albicaulis - Abies lasiocarpa Woodland
CEGL000129 Pinus albicaulis / Carex rossii Forest
CEGL000131 Pinus albicaulis / Vaccinium scoparium Forest
CEGL000329 Abies lasiocarpa - Picea engelmannii Tree Island Forest
CEGL000751 Abies lasiocarpa - Pinus albicaulis / Arctostaphylos uva-ursi Woodland
CEGL000752 Abies lasiocarpa - Pinus albicaulis / Vaccinium scoparium Woodland
CEGL000753 Pinus albicaulis / Calamagrostis rubescens Woodland
CEGL000754 Pinus albicaulis - (Abies lasiocarpa) / Carex geyeri Woodland
CEGL000755 Pinus albicaulis / Festuca idahoensis Woodland
CEGL000756 Pinus albicaulis / Juniperus communis Woodland
CEGL000758 Pinus albicaulis / Luzula glabrata var. hitchcockii Woodland
CEGL000951 Larix lyallii / Vaccinium scoparium / Luzula glabrata var. hitchcockii Woodland
CEGL000952 Larix lyallii / Vaccinium deliciosum Woodland
CEGL000985 Abies lasiocarpa - Picea engelmannii Krummholz
CEGL005836 Pinus albicaulis - Abies lasiocarpa / Menziesia ferruginea / Xerophyllum tenax Woodland
CEGL005837 Pinus albicaulis - Abies lasiocarpa / Vaccinium membranaceum / Xerophyllum tenax Woodland
CEGL005838 Pinus albicaulis - Abies lasiocarpa / Vaccinium scoparium / Xerophyllum tenax Woodland
CEGL005839 Pinus albicaulis - Abies lasiocarpa / Vaccinium scoparium / Luzula glabrata var. hitchcockii Woodland
CEGL005840 Pinus albicaulis - (Picea engelmannii) / Dryas octopetala Woodland


Land Cover Class: Forest and Woodland
Spatial Pattern: Large patch
Natural/Seminatural: No
Vegetated ( > 10% vascular cover):
Upland: Yes
Wetland: No
Isolated Wetland: No

Diagnostic Classifiers
Primary Classifier Secondary Classifier
Montane Upper Montane
Forest and Woodland (Treed)  
Ridge/Summit/Upper Slope  
Oligotrophic Soil  
Very Short Disturbance Interval  
W-Patch/High Intensity  
W-Patch/Medium Intensity  
W-Landscape/Medium Intensity  
Larix lyallii  
Upper Treeline  
Long (>500 yrs) Persistence  

Non-diagnostic Classifiers
Primary Classifier Secondary Classifier
Cirque headwall  
Glaciated uplands  
Temperate Temperate Continental
Mesotrophic Soil  
Shallow Soil  

At-Risk Species Reported for this Ecological System
Scientific Name
  (Common Name)
NatureServe Global Status U.S. Endangered Species Act Status
Astragalus cottonii
  (Cotton's Milkvetch)
Botrychium ascendens
  (Upward-lobed Moonwort)
Botrychium paradoxum
  (Peculiar Moonwort)
Castilleja cryptantha
  (Obscure Indian-paintbrush)
Chaenactis thompsonii
  (Thompson's Pincushion)
Elaphomyces subviscidus
  (a fungus)
Micranthes tischii
  (Olympic Saxifrage)
Nisquallia olympica
  (Olympic Grasshopper)
Pedicularis rainierensis
  (Mount Rainier Lousewort)
Pinus albicaulis
  (Whitebark Pine)
G3? C: Candidate
Silene seelyi
  (Seely's Silene)
Synthyris pinnatifida var. lanuginosa
  (Cutleaf Synthyris)

Vegetation Composition (incomplete)
Species Name Rounded Global Status Growth Form Stratum Char-
Domi-nant Con-stant
Cover Class %
Abies lasiocarpa G5 Needle-leaved tree Tree canopy    
Larix lyallii G5 Needle-leaved tree Tree canopy    
Pinus albicaulis G3 Needle-leaved tree Tree canopy    
Vaccinium scoparium G5 Broad-leaved deciduous shrub Shrub/sapling (tall & short)    
Paxistima myrsinites G4 Broad-leaved evergreen shrub Shrub/sapling (tall & short)    
Phyllodoce empetriformis G5 Broad-leaved evergreen shrub Short shrub/sapling    
Arnica cordifolia G5 Flowering forb Herb (field)    
Astragalus cottonii G2 Flowering forb Herb (field)      
Castilleja cryptantha G2 Flowering forb Herb (field)      
Chaenactis thompsonii G3 Flowering forb Herb (field)      
Micranthes tischii G2 Flowering forb Herb (field)      
Pedicularis rainierensis G2 Flowering forb Herb (field)      
Silene seelyi G3 Flowering forb Herb (field)      
Synthyris pinnatifida var. lanuginosa T3 Flowering forb Herb (field)      
Xerophyllum tenax G5 Flowering forb Herb (field)    
Botrychium ascendens G3 Fern (Spore-bearing forb) Herb (field)      
Botrychium paradoxum G3 Fern (Spore-bearing forb) Herb (field)      
Elaphomyces subviscidus G2 Non-plant Nonvascular      

Animal Species Reported for this Ecological System
Scientific Name
  (Common Name)
Global Status U.S. Endangered Species Act Status Charact-
Lepus americanus
  (Snowshoe Hare)
Marmota flaviventris
  (Yellow-bellied Marmot)
Neotamias amoenus
  (Yellow-pine Chipmunk)
Nisquallia olympica
  (Olympic Grasshopper)

Color legend for Distribution Map
Nation: United States
United States Distribution: ID, MT, WA, WY
Nation: Canada
Canadian Province Distribution: AB, BC
Global Range: This system occurs in the northern Rocky Mountains, west into the Cascade Range and northeastern Olympic Mountains, and east into the mountain "islands" of central Montana.

Biogeographic Divisions
Division Code and Name Primary Occurrence Status
204-North American Pacific Maritime C: Confident or certain
306-Rocky Mountain C: Confident or certain

The Nature Conservancy's Conservation Ecoregions
Code Name Occurrence Status
26 Northern Great Plains Steppe Confident or certain
3 North Cascades Confident or certain
68 Okanagan Confident or certain
7 Canadian Rocky Mountains Confident or certain
8 Middle Rockies - Blue Mountains Confident or certain
9 Utah-Wyoming Rocky Mountains Predicted or probable

MRLC 2000 Mapzones
Code Name Occurrence Status
1 Northern Cascades Confident or certain
7 Cascade Mountain Range Possible
9 Blue Mountain Region Predicted or probable
10 Northwestern Rocky Mountains Confident or certain
12 Western Great Basin Confident or certain
16 Utah High Plateaus Possible
18 Snake River Plain Confident or certain
19 Northern Rocky Mountains Confident or certain
20 Missouri River Plateau Confident or certain
21 Middle Rocky Mountains Confident or certain
22 Wyoming Basin Possible
29 Wyoming Highlands Possible

National Mapping
ESLF Code (Ecological System Lifeform): 4233
ESP Code (Environmental Site Potential): 1046
EVT Code (Existing Vegetation Type): 2046

West Landfire Legend: Yes
East Landfire Legend: No

Element Description Edition Date: 03Feb2017
Element Description Author(s): C. Chappell, R. Crawford, G. Kittel, M.S. Reid, K.A. Schulz and G.P. Jones

Ecological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).

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  • Burns, R. M., and B. H. Honkala, technical coordinators. 1990a. Silvics of North America: Volume 1. Conifers. Agriculture Handbook 654. USDA Forest Service, Washington, DC. 675 pp.

  • Callaway, R. M. 1998. Competition and facilitation on elevation gradients in subalpine forests of the northern Rocky Mountains, USA. Oikos 82:561-573.

  • Comer, P., D. Faber-Langendoen, R. Evans, S. Gawler, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, K. Snow, J. Teague, and R. White. 2003-present. Ecological systems of the United States: A working classification of U.S. terrestrial systems. NatureServe, Arlington, VA.

  • Cooper, S. V., C. Jean, and B. L. Heidel. 1999. Plant associations and related botanical inventory of the Beaverhead Mountains Section, Montana. Unpublished report to the Bureau of Land Management. Montana Natural Heritage Program, Helena. 235 pp.

  • Ecosystems Working Group. 1998. Standards for broad terrestrial ecosystem classification and mapping for British Columbia. Prepared by the Ecosystems Working Group, Terrestrial Ecosystem Task Force, Resources Inventory Committee, for the Province of British Columbia. 174 pp. plus appendices. []

  • Eyre, F. H., editor. 1980. Forest cover types of the United States and Canada. Society of American Foresters, Washington, DC. 148 pp.

  • Greater Yellowstone Coordinating Committee. 2011. Whitebark pine strategy for the Greater Yellowstone Area. Greater Yellowstone Coordinating Committee Whitebark Pine Subcommittee. National Park Service and USDA Forest Service. 41 pp. []

  • Johnson, C. G. 2004. Alpine and subalpine vegetation of the Wallowa, Seven Devils and Blue mountains. R6-NR-ECOL-TP-0304. USDA Forest Service, Pacific Northwest Region, Portland, OR. 612 pp. plus appendices.

  • Johnson, C. G., Jr., and D. K. Swanson. 2005. Bunchgrass plant communities of the Blue and Ochoco Mountains: A guide for managers. General Technical Report PNW-GTR-641. USDA Forest Service, Pacific Northwest Research Station, Portland, OR. 119 pp.

  • Keane, R. E., and R. A. Parsons. 2010. Restoring whitebark pine forests of the northern Rocky Mountains, USA. Ecological Restoration 28(1):56-70.

  • Kendall, K. C., and R. E. Keane. 2001. Chapter 11. Whitebark pine decline: Infection, mortality and population trends. Pages 221-242 in: D. F. Tomack, S. F. Arno, and R. E. Keane, editors. Whitebark pine communities. Island Press.

  • LANDFIRE [Landfire National Vegetation Dynamics Database]. 2007a. Landfire National Vegetation Dynamics Models. Landfire Project, USDA Forest Service, U.S. Department of Interior. (January - last update) [] (accessed 8 February 2007).

  • Lillybridge, T. R., B. L. Kovalchik, C. K. Williams, and B. G. Smith. 1995. Field guide for forested plant associations of the Wenatchee National Forest. General Technical Report PNW-GTR-359. USDA Forest Service, Pacific Northwest Research Station, Portland, OR. 335 pp.

  • Littell, J. S., M. McGuire Elsner, L. C. Whitely Binder, and A. K. Snover, editors. 2009. The Washington climate change impacts assessment: Evaluating Washington's future in a changing climate. Executive summary. Climate Impacts Group, University of Washington, Seattle. []

  • Macfarlane W. W., J. A. Logan, and W. R Kern. 2009. Using the landscape assessment system (LAS) to assess mountain pine beetle-caused mortality of whitebark pine, Greater Yellowstone Ecosystem, 2009. Project report prepared for the Greater Yellowstone Coordinating Committee, Whitebark Pine Subcommittee, Jackson, WY. 69 pp.

  • Meidinger, D., and J. Pojar, editors. 1991. Ecosystems of British Columbia. British Columbia Ministry of Forests Special Report Series No. 6. Victoria, BC. 330 pp.

  • NCC [The Nature Conservancy of Canada]. 2002. Canadian Rockies ecoregional plan. The Nature Conservancy of Canada, Victoria, BC.

  • Rice, J., A. Tredennick, and L. A. Joyce. 2012a. Climate change on the Shoshone National Forest, Wyoming: A synthesis of past climate, climate projections, and ecosystem implications. General Technical Report RMRS-GTR-264. USDA Forest Service, Rocky Mountain Research Station, Fort Collins, CO. 60 pp. []

  • Steele, R., S. V. Cooper, D. M. Ondov, D. W. Roberts, and R. D. Pfister. 1983. Forest habitat types of eastern Idaho - western Wyoming. General Technical Report INT-144. USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT. 122 pp.

  • WNDD [Wyoming Natural Diversity Database]. 2013. Unpublished analysis using a raster dataset of Pinus albicaulis modeled occurrence provided by the Forest Health Technology Enterprise Team, USDA Forest Service.

  • WNHP [Washington Natural Heritage Program]. 2011. Ecological integrity assessments for the ecological systems of Washington. Version: 2.22.2011. Washington Natural Heritage Program, Department of Natural Resources, Olympia. [] (accessed September 9, 2013).

  • WNHP [Washington Natural Heritage Program]. 2018. Unpublished data files. Washington Natural Heritage Program, Department of Natural Resources, Olympia, WA.

  • Williams, C. K., and B. G. Smith. 1990. Forested plant associations of the Wenatchee National Forest. Unpublished draft prepared by the USDA Forest Service, Pacific Northwest Region, Portland, OR. 217 pp.

  • Williams, C. K., and T. R. Lillybridge. 1983. Forested plant associations of the Okanogan National Forest. R6-Ecol-132b-1983. USDA Forest Service, Pacific Northwest Region, Portland, OR. 140 pp.

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