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Ecological site R003XN543WA

Southern Washington Cascades Alpine Tundra

Last updated: 1/29/2025
Accessed: 09/07/2026

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General information

Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.

MLRA notes

Major Land Resource Area (MLRA): 003X–Olympic and Cascade Mountains

Steep mountains and narrow to broad, gently sloping valleys characterize this region. A triple junction of two oceanic plates and one continental plate is directly offshore from Puget Sound. Subduction of the oceanic plates under the westerly and northwesterly moving continental plate contributes to volcanic activity in the Cascades. Movement between these plates has resulted in major earthquakes in this area in the past and the formation of large stratovolcanoes. The Cascade Mountains consist primarily of volcanic crystalline rocks with some associated metasedimentary rocks. The average annual precipitation ranges from 60 to 100 inches in much of the region and 30 to 60 inches on the east side of the Cascade Mountains.

The dominant soil orders in this MLRA are Andisols, Spodosols, and Inceptisols, with minor amounts of Entisols, and Histosols. The soils in the area dominantly have a frigid or cryic soil temperature regime and an udic soil moisture regime. They generally are shallow to very deep, well drained, ashy to medial, and loamy or sandy and occur on mountain slopes and ridges.

Ecological site concept

This ecological site is typically found at the higher elevations of the Southern Washington Cascades and Mt. Rainier that comprise the upper limits of plant growth, at elevations ranging from 4,600 to 11,000 ft. While this ecological site has a broad range in elevation, it is most commonly found from 7,000 to 11,000 feet. The primary abiotic factors that drive this ecological site are lack of precipitation from a rain shadow and high elevations that result in cool temperatures even in the summer, extremely cold winters, high winds, intense solar radiation, short growing season, and heavy snow pack. As a result, plants are more sparsely located on the landscape and adapted to very challenging growing conditions.
Soils that support this ecological site occur in the cryic soil temperature regime and the udic soil moisture regime and are formed in volcanic ash and colluvium. They are coarse textured, and are low in organic matter. The site is often buried under a heavy snow load which provide more insulation for plants during the dormant season, and often result in a significantly shorter growing season that other sites on Mt. Rainier.
Common plants include Davis’ knotweed (Polygonum davisiae), tundra aster (Oreostemma alpigenum var. alpigenum), alpine leafybract aster (Symphyotrichum foliaceum var. foliaceum), Penstemon (Penstemon sp.), common yarrow (Achillea millefolium), common juniper (Juniperus communis var. montana), spreading phlox (Phlox diffusa), Tiling’s monkeyflower (Mimulus tilingii), arctic lupine (Lupinus arcticus), and asachinea lichen (Asahinea).

Associated sites

R003XN542WA	Southern Washington Cascades Subalpine Parkland Ecological Site R003XN543WA, Southern Washington Cascades Alpine Tundra, and Ecological Site R003XN542WA, Southern Washington Cascades Subalpine Parkland have some associated climatic and physiological features. However, Ecological Site R003XN543WA has a much higher elevation range which limits the growing season and impacts vegetation growth and production considerably. As a result, Ecological Site R003XN542WA is able to grow a wider variety of vegetation species with increased growth production when compared to Ecological Site R003XN543WA.

R003XN542WA

Southern Washington Cascades Subalpine Parkland

Ecological Site R003XN543WA, Southern Washington Cascades Alpine Tundra, and Ecological Site R003XN542WA, Southern Washington Cascades Subalpine Parkland have some associated climatic and physiological features. However, Ecological Site R003XN543WA has a much higher elevation range which limits the growing season and impacts vegetation growth and production considerably. As a result, Ecological Site R003XN542WA is able to grow a wider variety of vegetation species with increased growth production when compared to Ecological Site R003XN543WA.

Similar sites

R003XN544WA	Southern Washington Cascades Wet Alpine Tundra Ecological sites R003XN544WA, Southern Washington Cascades Wet Alpine Tundra, and R003XN543WA, Southern Washington Cascades Alpine Tundra, have some similar climatic and physiological features. Ecological site R003XN544WA is at lower elevations that are slightly warmer and receive more precipitation as compared to site R003XN543WA. As a result of increased moisture availability, site R003XN544WA supports a wider variety of vegetation species that have higher production as compared to site R003XN543WA.

R003XN544WA

Southern Washington Cascades Wet Alpine Tundra

Ecological sites R003XN544WA, Southern Washington Cascades Wet Alpine Tundra, and R003XN543WA, Southern Washington Cascades Alpine Tundra, have some similar climatic and physiological features. Ecological site R003XN544WA is at lower elevations that are slightly warmer and receive more precipitation as compared to site R003XN543WA. As a result of increased moisture availability, site R003XN544WA supports a wider variety of vegetation species that have higher production as compared to site R003XN543WA.

Table 1. Dominant plant species

Tree	Not specified
Shrub	Not specified
Herbaceous	(1) Polygonum davisiae (2) Lupinus arcticus

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Physiographic features

This ecological site occurs across many landscape positions on volcanic cones, ridges, and cirques in the Cascade Mountains (4,600-11,000 ft) in Mt. Rainier National Park. The site is found on most slopes, however it most commonly occurs between 10 to 65 percent slopes.

Table 2. Representative physiographic features

Landforms	(1) Volcanic cone (2) Ridge (3) Cirque
Flooding frequency	None
Ponding frequency	None
Elevation	4600 – 11000 ft
Slope	5 – 100 %
Water table depth	10 – 0 in
Aspect	W, NW, N, NE, E, SE, S, SW

Climatic features

This ecological site receives most of its annual precipitation from October to March. The mean annual precipitation ranges from 85 to 186 inches and the annual temperature ranges from 26 to 41 degrees Fahrenheit. Microclimate may vary depending on soil temperature and site specific features. Generally, this site occupies areas with cool, dry summers and cold, wet winters.

Table 3 Representative climatic features

Frost-free period (characteristic range)	30-60 days
Freeze-free period (characteristic range)
Precipitation total (characteristic range)	90-190 in

Bar

Line

Figure 1. Monthly precipitation range

Bar

Line

Figure 2. Monthly minimum temperature range

Influencing water features

This site is located in the middle to high elevations on volcanic cones, ridges and cirques in Mount Rainier National Park. This site does not experience ponding or flooding. The water table will typically rise during the spring and summer months and recede in the fall.

Soil features

Applicable Soils: Burroughs, Chenuis, Mountwow, Sarvant, Tatoosh, Wahpenayo

Applicable Soil Map Units within Mt. Rainier National Park: 9260, 9261, 9262, 9996

Soils that support this ecological site occur in the cryic soil temperature regime and the udic soil moisture regime. Soils representative of this ecological site vary in drainage and depth, however the over-riding factor for this ecological site is the position on the landscape and the amount of time and duration of snowpack during the growing season. Burroughs, Chenuis, Sarvant, and Tatoosh soils are well drained. Mountwow and Wahpenayo soils are somewhat poorly drained. Chenuis, and Mountwow soils are very deep. Burroughs, Sarvant and Wahpenayo soils are moderately deep, while Tatoosh soils are shallow. These soils are found on volcanic cones, ridges and cirques and are formed from volcanic ash and andesite colluvium, with or without andesite bedrock. Mountwow and Wahpenayo soils have a seasonally high water table between 10 and 20 inches of the surface at some point during the growing season. None of these soils have flooding or ponding potential. Chenuis and Sarvant soils have greater than 35 percent rock fragments in the control section, while all others do not. Soil textures are coarse, primarily medial sandy loams and medial loamy sands. These soils exhibit andic soil properties in all mineral horizons. Melanization is the dominant pedogenic process and podsolization is not evident in these profiles given the lack of coniferous forest cover. An umbric epipedon and cambic horizons are present in most soils. Thin organic horizons soils, serving to protect the soil from wind and water erosion.

Table 4. Representative soil features

Parent material	(1) Volcanic ash (2) Colluvium – andesite (3) Residuum – andesite
Surface texture	(1) Sandy loam (2) Loamy sand
Drainage class	Well drained to somewhat poorly drained
Soil depth	18 – 60 in
Surface fragment cover <=3"	0 – 70 %
Surface fragment cover >3"	0 – 40 %
Available water capacity (Depth not specified)	2.5 – 9 in
Soil reaction (1:1 water) (Depth not specified)	4.5 – 5.5
Subsurface fragment volume <=3" (Depth not specified)	0 – 70 %
Subsurface fragment volume >3" (Depth not specified)	0 – 50 %

Ecological dynamics

This ecological site is found at middle and high elevations that range from 4,600 to 11,000 feet in the Southern Washington Cascades. The site is typically found at the higher elevation range, between 7,000 to 11,000 feet, which comprise the upper limits of plant growth on Mount Rainier. Plants are specifically adapted to surviving under harsh winters, high winds, intense solar radiation, and a short growing season. Plant production is directly correlated to the snow release date which can be highly variable from year to year. A shorter growing season may impact the ability for plants to flower and disperse seed before snow returns in late summer (Canaday, 1974). These plants are relatively dwarfed in stature and slow growing. These conditions increase plant vulnerability to additional disturbances and take a long period of time to recover. Sites occurring at the lower elevation band are typically affected by unique weather and are located in an area that is cooler than other places at the same elevation due to factors such as proximity to permanent ice.

Soils that support this ecological site occur in the cryic soil temperature regime and the udic soil moisture regime. These soils formed in volcanic ash and colluvium, are coarse textured, and are low in organic matter. The climate is characterized by cool, dry summers and cold, wet winters. The site is often buried under heavy snow load which provide more insulation for plants during the dormant season. As a consequence of the climate, this is one of the latest sites in the subalpine zone to start plant growth in the summer. Also, both air and soil temperatures are significantly cooler, resulting in a significantly shorter growing season than other sites on Mount Rainier. These sites are extremely sensitive to disturbances such as soil compaction and damage to vegetation and recovery may take long periods of time.

The reference community may be most common, but it is likely that all community phases occur as a matrix across the landscape. Common plants include Davis’ knotweed (Polygonum davisiae), arctic lupine (Lupinus arcticus), common yarrow (Achillea millefolium), partridgefoot (Luetkea pectinata), tundra aster (Oreostemma alpigenum var. alpigenum), alpine leafybract aster (Symphyotrichum foliaceum var. foliaceum), Penstemon (Penstemon sp.), common juniper (Juniperus communis var. montana), spreading phlox (Phlox diffusa), Tiling’s monkeyflower (Mimulus tilingii), and asachinea lichen (Asahinea).

State and transition model

Custom diagram

Standard diagram

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Ecosystem states

1. Reference

State 1 submodel, plant communities

1.1. Davis’ Knotweed and Arctic Lupine

1.2. Pink Mountain Heather, Davis’ Knotweed, Arctic Lupine, Spreading Phlox, Black Sedge, and Idaho Fescue

1.3. Black Sedge and Alpine Timothy

State 1
Reference

Community 1.1
Davis’ Knotweed and Arctic Lupine

Structure: subalpine parkland of shrubs, forbs, and grasses

The reference community is sparsely vegetated with a mixture of shrubs, forbs, and grass species that have been relatively undisturbed by natural and human influences. These subalpine ecosystems are located on aspects where snowmelt occurs in mid-summer, which restricts the growing season. Plant percent cover is variable but the reference community plants are common throughout the entire ecological site. Low-growing subshrubs such as Davis’ knotweed is most prolific. Pink mountain-heather and common juniper are sometimes present. Forbs including arctic lupine, tundra aster, common yarrow, and spreading phlox cover the landscape with black sedge interspersed.
Small natural disturbances such as frost heaving, wind blasting, and variation in snowpack can have significant impacts on alpine vegetation. Soil compaction and damage to vegetation may have significant impacts on the ecological site integrity. Herbivores such as marmots, pikas, elk, migratory birds, and mountain goats will forage on the vegetation which may create patches of open ground (Martin, 2001).

Dominant plant species

Davis' knotweed (Polygonum davisiae), shrub
pink mountainheath (Phyllodoce empetriformis), shrub
western juniper (Juniperus occidentalis), shrub
arctic lupine (Lupinus arcticus), other herbaceous
tundra aster (Oreostemma alpigenum var. alpigenum), other herbaceous
spreading phlox (Phlox diffusa), other herbaceous
American bistort (Polygonum bistortoides), other herbaceous
black alpine sedge (Carex nigricans), other herbaceous

Community 1.2
Pink Mountain Heather, Davis’ Knotweed, Arctic Lupine, Spreading Phlox, Black Sedge, and Idaho Fescue

Structure: subalpine parkland dominated by shrubs and forbs

Community phase 1.2 represents a community stage of shrubs and forbs that are developed over long periods without disturbance. The establishment of shrubs such as pink mountain heather, common juniper, and Davis’ knotweed create pockets of low growing vegetation. Common understory species also include arctic lupine and spreading phlox.

Dominant plant species

pink mountainheath (Phyllodoce empetriformis), shrub
western juniper (Juniperus occidentalis), shrub
Davis' knotweed (Polygonum davisiae), shrub
arctic lupine (Lupinus arcticus), other herbaceous
spreading phlox (Phlox diffusa), other herbaceous
black alpine sedge (Carex nigricans), other herbaceous
Idaho fescue (Festuca idahoensis), other herbaceous

Community 1.3
Black Sedge and Alpine Timothy

Structure: Grass meadow

As the plant community recovers without disturbance, an increase of grasses and forbs are established. Common plants such as arctic lupine, American bistort, Idaho fescue, and black sedge begin to dominate.

Dominant plant species

Idaho fescue (Festuca idahoensis), grass
alpine timothy (Phleum alpinum), grass
arctic lupine (Lupinus arcticus), other herbaceous
American bistort (Polygonum bistortoides), other herbaceous
black alpine sedge (Carex nigricans), other herbaceous

Pathway 1.1A
Community 1.1 to 1.2

This pathway represents an ongoing lack of disturbance, which favors the establishment of pockets of shrubs.

Pathway 1.1B
Community 1.1 to 1.3

Davis’ Knotweed and Arctic Lupine

Black Sedge and Alpine Timothy

This pathway represents major disturbances, such as continuous snowpack, avalanches, landslides, and slower mass movement, that remove most of the vegetation.

Pathway 1.2A
Community 1.2 to 1.3

This pathway represents extreme disturbances, such as continuous snowpack, avalanches, landslides, and slow mass movement, that remove a majority of the vegetation.

Pathway 1.3A
Community 1.3 to 1.1

Black Sedge and Alpine Timothy

Davis’ Knotweed and Arctic Lupine

This pathway represents an area with no further major disturbance. Continued growth over time has led to increased vertical diversification of forbs.

Additional community tables

Table 5. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)

Table 6. Community 1.1 forest understory composition

Common name	Symbol	Scientific name	Nativity	Height (ft)	Canopy cover (%)
Grass/grass-like (Graminoids)
black alpine sedge	CANI2	Carex nigricans	Native	1–24	0–30
Forb/Herb
arctic lupine	LUAR2	Lupinus arcticus	Native	1–12	0–30
tundra aster	ORALA2	Oreostemma alpigenum var. alpigenum	Native	1–12	0–10
spreading phlox	PHDI3	Phlox diffusa	Native	1–6	0–5
American bistort	POBI6	Polygonum bistortoides	Native	1–12	0–3
Shrub/Subshrub
pink mountainheath	PHEM	Phyllodoce empetriformis	Native	1–18	1–20
Davis' knotweed	PODA	Polygonum davisiae	Native	1–12	1–5

Table 7. Community 1.2 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)

Table 8. Community 1.3 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)

Supporting information

Inventory data references

National vegetation classification group: Northern Rocky Mountain Vancouverian Subalpine-Montane Dry Herbaceous Meadow U.S. Department of the Interior, National Park Service, plant association: POLDAV

Type locality

Location 1: Pierce County, WA
Township/Range/Section	T15N R09E S3
Latitude	46° 49′ 12″
Longitude	121° 40′ 15″

Other references

Barnes, George H. 1962. Yield of even-aged stands of western hemlock. USDA, Forest Service. Pacific Northwest Forest and Range Experiment Station Technical Bulletin 1273.
Canaday, B.B., Fonda, R.W. 1974. The Influence of Subalpine Snowbanks on Vegetation Pattern, Production, and Phenology. Bulletin for Torrey Botanic Club, Vol 101 pp 340-350.
Crawford, R. C., C. B. Chappell, C. C. Thompson, and F. J. Rocchio. 2009. Vegetation Classification of Mount Rainier, North Cascades, and Olympic National Parks. Natural Resource Technical Report NPS/NCCN/NRTR-2009/211. National Park Service, Fort Collins, Colorado.
Czuba, J., Magirl, C., Czuba, C., Curran, K. et. al. 2012. Geomorphic Analysis of the River Response to Sedimentation Downstream of Mount Rainier, Washington. Open-file Report 2012-1242. U.S. Geological Survey, Reston, Virginia.
Dwire, K. and Kauffman, J. 2003. Fire and Riparian Ecosystems in Landscapes in the Western United States. Forest Ecology and Management, Vol. 178 pg. 61-74.
Franklin, J.F., and Dyrness C.T. 1973. Natural Vegetation of Oregon and Washington. Oregon State University press, Corvallis, USA.
Douglas, G.W., and Bliss, L.C. 1972. Alpine and high subalpine plant communities of the western north cascades, Washington. Arctic and Alpine Research, Vol 4, No. 2, pp 147-166.
Hanley, D.P and D.M. Baumgartner. 2002. Forest Ecology in Washington. Washington State University Extension Publishing. Technical Report EB 1943.
Hanson, E.J., D.L. Azuma and B.A. Hiserote. 2002. Site Index Equations and Mean Annual Increment Equations for Pacific Northwest Research Station Forest Inventory and Analysis Inventories, 1985-2001. USDA Forest Service Pacific Northwest Research Station, Research Note PNW-RN-533.
Hemstrom, M., Franklin, J. 1982. Fire and Other Disturbances of the Forests in Mount Rainier National Park. Quaternary Research, Vol 18 pp 32-61.
Henderson, J.A., R.D. Lesher, D.H. Peter, and D.C. Shaw. 1992. Field Guide to the Forested Plant Associations of the Mt. Baker-Snoqualmie National Forest. USDA Forest Service Pacific Northwest Region Technical Paper R6-ECOL-TP-028-91.
King, James E. 1966. Site index curves for Douglas-fir in the Pacific Northwest. Weyerhaeuser Company, Forestry Research Center. Forestry Paper 8.
Kittel, G., Meidinger D., and Faber-Langendoen, D. 2013. G240 Pseudotsuga menziesii – Tsuga heterophylla / Gaultheria shallon Forest Group. United States National Vegetation Classification. Federal Geographic Data Committee, Washington, D. C.
Martin, K. 2001. Wildlife in Alpine and Sub-alpine Habitats. Wildlife-Habitat Relationships in Oregon and Washington. Oregon State University Press. pp 285-310
Naiman, R., Bechtold, S., Beechie, T., Latterell, J., Van Pelt, R. 2009. A Process-Based View of Floodplain Forest Patterns in Coastal River Valleys of the Pacific Northwest. Ecosystems, Vol 13 pp 1-31.
Nierenberg, T., Hibbs, D. 2000. A characterization of unmanaged riparian areas in the central Coast Range of western Oregon. Forest Ecology and Management, Vol. 129 pp 195-206.
Pojar J., and MacKinnon. 1994. Plants of the Pacific Northwest Coast. Lone Pine, Vancouver, British Columbia. 528 pages.
PRISM Climate Group, Oregon State University, http://prism.orgeonstate.edu, visited February, 2015.
Rochefort, R.M. and Peterson, D.L. 1996. Temporal and Spatial Distribution of Trees in Subalpine Meadows of Mount Rainier National Park. Arctic and Alpine Research, Vol. 28, No. 1 pp 52-59.
Seastedt, T.R., Adams, G.A. 2001. Effects of Mobile Tree Islands on Alpine Tundra Soils. Ecology, Vol 82 pp 8-17.
Smith, K., G. Kuhn, and L. Townsend. 2008. Culmination of Mean Annual Increment for Indicator Tree Species in the State of Washington. USDA-NRCS Technical Note Forestry-9.
Topik, C., N. M. Halverson, and D. G. Brockway. 1986. Plant Associations and Management Guide for the Western Hemlock Zone, Gifford Pinchot National Forest. USDA Forest Service Pacific Northwest Region Technical Paper R6-ECOL-230A-1986.
United States Department of Agriculture, Forest Service, 2015. Silvics Manual Vol 1. http://na.fs.fed.us/spfo/pubs/silvics_manual/Volume_1/vol1_Table_of_contents.htm, visited December 2015.
United States Department of Agriculture, Natural Resources Conservation Service, and United States Department of the Interior, National Park Service. 2014. Ecological Site Descriptions for North Cascades National Park Complex, Washington.
United States National Vegetation Classification. 2016. United States National Vegetation Classification Database, V2.0. Federal Geographic Data Committee, Vegetation Subcommittee, Washington DC. (accessed 28, November, 2016.
Washington Department of Natural Resources, Natural Heritage Program. 2015. Ecological Systems of Washington State. A Guide to Identification.

Contributors

Erin Kreutz
Erik Dahlke
Philip Roberts
Marty Chaney

Approval

Kirt Walstad, 1/29/2025

Rangeland health reference sheet

Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.

Author(s)/participant(s)
Contact for lead author
Date	05/10/2024
Approved by
Approval date
Composition (Indicators 10 and 12) based on	Annual Production

Indicators

Number and extent of rills:
Presence of water flow patterns:
Number and height of erosional pedestals or terracettes:
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Number of gullies and erosion associated with gullies:
Extent of wind scoured, blowouts and/or depositional areas:
Amount of litter movement (describe size and distance expected to travel):
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):

Dominant:

Sub-dominant:

Other:

Additional:
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Average percent litter cover (%) and depth ( in):
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
Perennial plant reproductive capability:

Download reference sheet

Natural ResourcesConservation Service

Ecological site R003XN543WA

Southern Washington Cascades Alpine Tundra

Last updated: 1/29/2025 Accessed: 09/07/2026

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General information

MLRA notes

Ecological site concept

Associated sites

Similar sites

Table 1. Dominant plant species

Natural Resources
Conservation Service

Last updated: 1/29/2025
Accessed: 09/07/2026