Natural Resources
Conservation Service
Ecological site F003XN928WA
Frigid/Xeric Active Natural Disturbance
Last updated: 1/30/2025
Accessed: 08/30/2026
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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.
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Figure 1. Mapped extent
Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated.
Classification relationships
Related National Park Service Plant Alliances: Pseudotsuga menziesii-(Pinus contorta var. latifolia) Forest Alliance, Pseudotsuga menziesii-(Pinus ponderosa) Forest Alliance, Pinus ponderosa-(Pseudotsuga menziesii) Woodland and Savanna Alliance.
Associated sites
F003XN923WA Cryic/Xeric Coniferous
F003XN927WA Frigid/Xeric Coniferous
Table 1. Dominant plant species
Tree (1) Acer macrophyllum
(2) Prunus emarginataShrub (1) Corylus cornuta
(2) Acer circinatumHerbaceous (1) Maianthemum stellatum
(2) Streptopus amplexifoliusPhysiographic features
This native plant community is of limited extent on mountain slope positions at lower elevations along the east slope of the North Cascades. This site is confined to areas with a higher frequency of disturbance than the surrounding coniferous forest. These areas include rock fall and debris torrent deposits or, less often, avalanche paths and their runout areas.
This ecological site has only been mapped within the boundary of the North Cascades National Park Complex. This site, where mapped, ranged from 1000 to 5000 feet in elevation. The table below refers to the representative elevations of this site.Table 2. Representative physiographic features
Landforms (1) Mountain slope
(2) Valley side
Flooding frequency None Ponding frequency None Elevation 1000 – 3500 ft Slope 5 – 100 % Water table depth 60 – 0 in Aspect Aspect is not a significant factor Climatic features
This ecological site receives most of its annual precipitation from October to April. The mean annual precipitation ranges from 20 to 65 inches and the mean annual temperature ranges from 35 to 49 degrees Fahrenheit. Generally this site occupies areas with warm dry summers and cool wet winters.
Precipitation and temperature data in the tables below was extracted from: PRISM Climate Group, Oregon State University, http://prism.oregonstate.edu, created February 2004. Information from the Ross Dam weather station, was used by the PRISM Climate Group to generate climate data for the North Cascades region.Table 3 Representative climatic features
Frost-free period (average) 100 days Freeze-free period (average) 120 days Precipitation total (average) 70 in BarLineFigure 2. Monthly precipitation range
BarLineFigure 3. Monthly average minimum and maximum temperature
">Influencing water features
This ecological site is not influenced by wetland or riparian water features but may be found adjacent to incised streams.
Soil features
Applicable soils: Inspiration, Mesahchie.
The soils that support this native plant community occur in the frigid soil temperature regime (average annual temperature less than 8 degrees C, with a greater than 5 degrees C summer-winter fluctuation) and xeric soil moisture regime (the rooting zone is usually moist throughout the winter with prominent summer drought). In the xeric soil moisture regime, the soil profile typically dries out during the summer months for longer stretches of time than the udic counterparts of the North Cascades west slope. These soils are well drained and very deep and typically have significant course fragments within the soil profile, owing to the active nature of the landforms they occupy. The Inspiration soil series is an Andisol and has a mantle of material with significant volcanic ash influence overlying colluvium. The Mesahchie soil series is an Inceptisol has a thinner ash mantle than the Inspiration series. The upper mantle of both series is characterized by a low bulk density and relatively high water holding capacity although an abundance of coarse fragments within the profile may limit the amount of moisture available. Soil moisture can be a limiting factor to forest growth on these soils owing to the lower precipitation totals in this zone and the resulting moisture deficit during the summer months. Soil profiles under this plant community tend to have thicker A horizons (umbric epipedons) than their coniferous forest counterparts, owing to the abundance of deciduous forest litter and herbaceous root matter incorporated into the soil profile.
A blank entry under soil depth column indicates no depth restriction within the soil profile.
For more information on soils and their terminology, please refer to Soil taxonomy: A Basic System of Soil Classification for Making and Interpreting Soil Surveys (Soil Survey Staff, 1999; http://soils.usda.gov/technical/classification/taxonomy/).Table 4. Representative soil features
Surface texture (1) Ashy fine sandy loam
(2) Ashy sandy loam
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderately rapid to very rapid Soil depth 60 – 0 in Surface fragment cover <=3" 0 – 10 % Surface fragment cover >3" 0 – 10 % Available water capacity
(0-40in)4.2 – 15.99 in Soil reaction (1:1 water)
(0-40in)4 – 7 Subsurface fragment volume <=3"
(Depth not specified)5 – 65 % Subsurface fragment volume >3"
(Depth not specified)5 – 50 % Ecological dynamics
This site is found on cool, dry, low elevations east of the Cascade Crest where there is active natural disturbance – most commonly debris torrents and less often avalanches. The repeated disturbance of these sites prevents the establishment of a coniferous overstory. Both bigleaf maple (Acer macrophyllum) and bitter cherry (Prunus emarginata) may be broken by falling debris or snow but both sprout prolifically from their roots (unlike conifers), leading to their continued presence on these sites. Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa) will occasionally be found on these sites. Common understory shrubs include beaked hazelnut (Corylus cornuta), vine maple (Acer circinatum), Sitka willow (Salix sitchensis), myrtle pachistima (Paxistima myrsinites), serviceberry (Amelanchier alnifolia), thimbleberry (Rubus parviflorus) and snowberry (Symphoriacarpos albus). Common forbs include starry false Solomon’s seal (Maianthemum stellatum), claspleaf twistedstalk (Streptopus amplexifolius), and broadleaf starflower (Trientalis borealis).
*This proposed ecological site requires further investigation as only four inventory plots were found to sample.State and transition model
Custom diagramStandard diagram
Figure 4. State and Transition Model
More interactive model formats are also available. View Interactive Models
More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective textState 1
ReferenceCommunity 1.1
Multistory, Bigleaf Maple, Bitter Cherry, Beaked Hazelnut, Vine Maple, and Starry False Solomon’s Seal
Figure 5. Reference Community
Structure: multi-story deciduous forest with small gap dynamics
This community phase appears to be fairly stable with only minor disturbances such as the death of a single tree. Bigleaf maple is a host species of several decay causing organisms but this is seldom an issue until the trees are mature to overmature. The dense canopy of bigleaf maple and bitter cherry, coupled with a secondary canopy of beaked hazelnut and vine maple leads to an understory of more shade tolerant species than the surrounding coniferous forests, such as claspleaf twistedstalk, starry false lily of the valley and broadleaf starflower. Bigleaf maple is also shade tolerant so it can perpetuate itself without major disturbance. Scattered conifers (Douglas-fir and ponderosa pine) may seed in when there are openings in the canopy.Community 1.2
Single Story, Bigleaf Maple, Bitter Cherry, Beaked Hazelnut, Vine Maple, and Starry False Solomon’s SealStructure: dense single story/shrub with diminished understory
C.P. 1.2 is forestland in regeneration after a major disturbance; there may be few, scattered mature trees that survived the disturbance. Bigleaf maple, bitter cherry, beaked hazelnut, vine maple, serviceberry, Sitka willow and thimbleberry all stump sprout prolifically and it seems that this ability out competes any conifer seedlings that may become established on these sites. The dense nature of this regeneration would limit the abundance of the forb layer for some time. Moisture can also be a limiting factor in these forests and, since the deciduous species will still have an intact root system after these disturbances, this may also give them a competitive advantage over new coniferous seedlings.Pathway 1.1A
Community 1.1 to 1.2This pathway represents a major stand-replacing disturbance, most commonly a debris torrent and less commonly an avalanche release.
Pathway 1.2A
Community 1.2 to 1.1This pathway represents growth over time with no further major disturbance.
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 overstory composition
Common name Symbol Scientific name Nativity Height ft Canopy cover (%) Diameter in Basal area (square ft/acre) Treebigleaf maple ACMA3 Acer macrophyllum Native – – – 0 bitter cherry PREM Prunus emarginata Native – – – 0 Douglas-fir PSME Pseudotsuga menziesii Native – – – 0 ponderosa pine PIPO Pinus ponderosa Native – – – 0 Table 7. Community 1.1 forest understory composition
Common name Symbol Scientific name Nativity Height (ft) Canopy cover (%) Forb/Herbstarry false lily of the valley MAST4 Maianthemum stellatum Native 1–2 1–10 broadleaf starflower TRBOL Trientalis borealis ssp. latifolia Native 0.5–1 1–10 claspleaf twistedstalk STAM2 Streptopus amplexifolius Native 1–3 1–10 Shrub/Subshrubvine maple ACCI Acer circinatum Native 2–15 40–60 beaked hazelnut COCO6 Corylus cornuta Native 2–15 20–40 Sitka willow SASI2 Salix sitchensis Native 6–20 10–30 Saskatoon serviceberry AMAL2 Amelanchier alnifolia Native 2–5 5–20 common snowberry SYAL Symphoricarpos albus Native 2–6 5–20 Oregon boxleaf PAMY Paxistima myrsinites Native 0.5–2 1–10 thimbleberry RUPA Rubus parviflorus Native 1–5 1–10 Table 8. Community 1.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Supporting information
Inventory data references
Type Locality Plot ID: 07-CAB-071
Type locality
Location 1: Chelan County, WA Township/Range/Section T34N R16E S34 UTM zone N UTM northing 5363461 UTM easting 659184 Latitude 48° 24′ 15″ Longitude 120° 50′ 58″ Other references
Agee, J.K. 1993. Fire ecology of Pacific Northwest forests. Covelo, CA: Island Press. 493 pages.
Burns, Russell M., and Barbara H. Honkala, technical coordinators. 1990. Silvics of North America. U.S. Department of Agriculture, Forest Service, Agriculture Handbook 654. http://www.na.fs.fed.us/pubs/silvics_manual/table_of_contents.shtm
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. 58 pages.
Fire Effects Information System, [Online].
U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer).
http://www.fs.fed.us/database/feis/
Kovalchik, Bernard L.; Clausnitzer, Rodrick R. 2004. Classification and management
of aquatic, riparian, and wetland sites on the national forests of eastern Washington:
series descripton. Gen. Tech. Rep. PNW-GTR-593. Portland, OR: U.S. Department of
Agriculture, Forest Service, Pacific Northwest Research Station. 354 p. In cooperation
with: Pacific Northwest Region, Colville, Okanogan, and Wenatchee National Forests.
Miller, Margaret M.; Miller, Joseph W. 1976. Succession after wildfire in the North Cascades National Park complex. In: Proceedings, annual Tall Timbers fire ecology conference: Pacific Northwest; 1974 October 16-17; Portland, OR. No. 15. Tallahassee, FL: Tall Timbers Research Station: 71-83. [6574]
Perry, D.A. Forest Ecosystems. Baltimore, MD: The Johns Hopkins University Press; 1994. 649 pages.
Pojar, J., and A. MacKinnon. 1994. Plants of the Pacific Northwest Coast. Lone Pine,
Vancouver, British Columbia. 528 pages.
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service. U.S. Department of Agriculture Handbook 436. http://soils.usda.gov/technical/classification/taxonomy/Contributors
Kathryn Smith
Approval
Kirt Walstad, 1/30/2025
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 01/30/2025 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
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Presence of water flow patterns:
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Number and height of erosional pedestals or terracettes:
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Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
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Number of gullies and erosion associated with gullies:
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Extent of wind scoured, blowouts and/or depositional areas:
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Amount of litter movement (describe size and distance expected to travel):
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Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
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Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
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Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
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Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
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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:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
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Average percent litter cover (%) and depth ( in):
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Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
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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:
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Perennial plant reproductive capability:
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