Natural Resources
Conservation Service
Ecological site R003XN603WA
High Mountain Unforested Wetlands
Last updated: 5/10/2024
Accessed: 12/22/2024
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.
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
This ecological site is related to the following National Park Service Plant Alliance: Kalmia microphylla Dwarf-shrubland.
Associated sites
| F003XN925WA |
High Cryic/Udic Coniferous Can be found adjacent to this ecological site. |
|---|
Similar sites
| R003XN613WA |
Low Mountain Unforested Wetlands Similar concept, different elevational range. |
|---|
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
Not specified |
Physiographic features
This native plant community is generally found in depressions and flat or gently sloping landscape positions at higher elevations of the North Cascades. This site occupies the high cryic/udic soil temperature/moisture regime and are typically wet sites with very low-velocity surface and subsurface flows. This site may also occur on sub-irrigated sites with slopes up to 15%.
This ecological site has only been mapped within the boundary of the North Cascades National Park Complex.
Table 2. Representative physiographic features
| Landforms |
(1)
Depression
(2) Flood plain (3) Terrace |
|---|---|
| Flooding duration | Very brief (4 to 48 hours) to brief (2 to 7 days) |
| Flooding frequency | None to occasional |
| Ponding duration | Brief (2 to 7 days) to long (7 to 30 days) |
| Ponding frequency | None to frequent |
| Elevation | 610 – 1,402 m |
| Slope | 0 – 15% |
| Ponding depth | 0 – 10 cm |
| Water table depth | 0 – 76 cm |
| Aspect | Aspect is not a significant factor |
Climatic features
This ecological site receives most of its annual precipitation from October to April in the form of snow that will commonly persist into early summer. The mean annual precipitation ranges from 60 to 115 inches (1524 to 2921 mm) and the mean annual temperature ranges from 31 to 47 degrees Fahrenheit (-0.6 to 8.3 degrees C). Generally this site occupies areas with cool dry summers and cold 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) | 97 days |
|---|---|
| Freeze-free period (average) | 157 days |
| Precipitation total (average) | 2,921 mm |
Figure 2. Monthly precipitation range
Figure 3. Monthly average minimum and maximum temperature
Influencing water features
These general kinds of bog and fen wetlands are distinguished by pH, nutrient availability and hydrologic dynamics. Fens have groundwater within the rooting zone of vascular plants, while bogs have built up peat above the influence of groundwater. The vegetation in true bogs is limited by the water available from precipitation and are only found in areas of high precipitation. This site supports vegetation that tolerates occasional flooding of the site and periodic saturation within the soil profile. As such, seasonally high water tables are common and soils typically display some evidence of anaerobic conditions (redoximorphic features) and periodic flooding by nearby streams.
Soil features
Applicable Soils: Bacon, Beaverpass, and Purple
The soils that support this native plant community occur in the cryic soil temperature regime and aquic soil moisture regime. These soils are very poorly drained and soil depth is very deep. Generally these soils have a mantle of decomposing organic material overlying alluvium. Under seasonally high water tables, decomposition rates for the organic material are slowed considerably, allowing for an accumulation of these materials over time. Soils show typical hydric soil characteristics, including high organic content and/or low chroma and redoximorphic features. The Beaverpass classififes as a Histosol, a soil order typified by thick accumulations of decomposing organic materials. The Bacon and Purple soil series are Inceptisols with varying thicknesses of decomposing organic material at the surface.
Table 4. Representative soil features
| Surface texture |
(1) Fine sandy loam (2) Mucky loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Very poorly drained |
| Permeability class | Moderate to very rapid |
| Soil depth | 152 cm |
| Surface fragment cover <=3" | 0 – 5% |
| Surface fragment cover >3" | 0 – 5% |
| Available water capacity (0-101.6cm) |
4.32 – 40.61 cm |
| Soil reaction (1:1 water) (0-101.6cm) |
4 – 6 |
| Subsurface fragment volume <=3" (Depth not specified) |
0 – 45% |
| Subsurface fragment volume >3" (Depth not specified) |
0 – 40% |
Ecological dynamics
The High Mountain Unforested Wetland plant communities (usually including areas with bog and/or fen characteristics) are patch communities throughout the subalpine parklands. The plant communities are a complex mosaic that varies with soil characteristics and water regime. Disturbances that affect the water regime drive changes in the dominant plant community.
These sites occur in the forested and non-forested areas of the mid- and high elevation vegetated zones of the Cascade Mountains. These wetlands are found in depressional areas, on slopes, surrounding lakes or ponds, or associated with flat floodplains or ponded landslide surfaces. Often, these areas are shaded for at least a portion of the day because of their landscape position, and snow remains on the site longer into the late spring and early summer than on nearby more exposed sites, shortening the growing season on the site. Also, due to the landscape position, water tables are often at or near the surface for much of the growing season, and the water that collects is typically cold because most of it results from snowmelt. Decomposition of organic materials on top of the soil surface is slow because the natural agents of organic matter breakdown operate slowly under site conditions including high watertable, low soil temperature and low pH. Well-developed hummocks are common, and species common to better-drained soils thrive there. Occasionally this site is found in complex with mounded areas of Subalpine Parkland. Common plants found in these wetlands include bluejoint (Calamagrostis canadensis), water sedge (Carex aquatilis), white marsh marigold (Caltha leptosepala), black alpine sedge (Carex nigricans), tufted hairgrass (Deschampsia caespitosa), Drummond’s rush (Juncus drummondii), mountain sedge (Carex scopulorum) and Northwest Territory sedge (Carex utriculata). The hummock-forming peat-mosses Sphagnum fuscum and S. capillifolium are dominant in the moss layer but a diversity of other mosses also occur. Typical species of better-drained hummocks, mounds or raised edges include subalpine lupine (Lupinus arcticus ssp. subalpinus), false hellebore (Veratrum viride), Sitka valerian (Valeriana sitchensis), showy sedge (Carex spectabilis), American bistort (Polygonum bistortoides), partridgefoot (Luetkea pectinata), white avalanche lily (Erythronium montanum), woolly pussytoes (Antennaria lanata), Sitka mountain-ash (Sorbus sitchensis), black huckleberry(Vaccinium membranaceum), pink mountainheather (Phyllodoce empetriformis), white mountain-heather (Cassiope mertensiana), Cascade huckleberry (Vaccinium deliciosum), subalpine spirea(Spiraea splendens var. splendens) and willow (Salix spp.). Species will be present in varying amounts depending on the Community Phase and degree of recent disturbance.
State and transition model
Figure 4. State and Transition Model
More interactive model formats are also available.
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Ecosystem states
State 1 submodel, plant communities
State 1
Reference State
Community 1.1
Grasses, mosses and grass-like species
Figure 5. Reference Community
Figure 6. Subalpine plant community mosaic.
This community phase is characterized by a water table present during the growing season near or above the soil surface, although hummocks are common. Vegetation is characterized by a predominance of grass-like plants, grasses, forbs and moss. Species present and their percent cover in any particular part of the wetland complex are primarily controlled by the proximity of the water table to the soil surface during the growing season. The watertable is typically maintained by natural blockages to drainage such as landslide or other debris, beaver dams, or fires which reduce the amount of undecomposed organic matter on the soil surface. The edges of the wetland are typically slightly higher in elevation, and these areas, in combination with the hummocks and mounds, typically support species that need better drainage, especially shrubs. Typical species found in the Reference Community include water sedge (Carex aqualtilis), black alpine sedge (C. nigricans) and Northwest Territory sedge (C. utriculata), tufted hairgrass (Deschampsia cespitosa), bluejoint (Calamagrostis Canadensis), Drummond’s rush (Juncus drummondii), white marsh marigold (Caltha leptosepala) and sphagnum mosses, among others.
Figure 7. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Ground cover
| Tree foliar cover | 0% |
|---|---|
| Shrub/vine/liana foliar cover | 1-5% |
| Grass/grasslike foliar cover | 50-100% |
| Forb foliar cover | 5-20% |
| Non-vascular plants | 5-70% |
| Biological crusts | 0% |
| Litter | 5-30% |
| Surface fragments >0.25" and <=3" | 0-5% |
| Surface fragments >3" | 0-5% |
| Bedrock | 0% |
| Water | 0-20% |
| Bare ground | 0% |
Community 1.2
Grasses, mosses, grass-like species and shrubs.
Figure 8. Shrub community.
Like Community Phase 1.1, this community phase also supports predominantly grass-like plants, grasses, forbs and moss, However, the watertable during the growing season is typically near to below the soil surface, allowing species which require better drainage conditions to establish in the site. This slightly lowered water table can result from a buildup of organic matter on the surface into which plants can root, or erosion of materials which hold water on the site, such as beaver dams or landslide or other debris. Control of fire will also promote development of this community. In addition to those species found in the Reference Community, common plants present on the site include many shrubs and less water-tolerant herbaceous species.
Pathway 1.1A
Community 1.1 to 1.2
This pathway may be caused one of two ways: 1) a lack of the natural fire regime which allows surface layers of undecomposed organic matter and moss to build up allowing for the establishment of a shrub community; or 2) an increase in the depth to water table due to a physical event such as the erosion of a natural impoundment structure.
Pathway 1.2A
Community 1.2 to 1.1
This pathway may be caused one of two ways: 1) a resumption of the natural fire regime which will reduce shrub cover and may burn surface layers of organic matter; or 2) a decrease in the depth to water table due to a physical event such as a landslide or a biotic event such as beaver activity.
Additional community tables
Table 6. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | – | |||||
| water sedge | CAAQ | Carex aquatilis | – | 0 | ||
| bluejoint | CACA4 | Calamagrostis canadensis | – | 0 | ||
| black alpine sedge | CANI2 | Carex nigricans | – | 0 | ||
| mountain sedge | CASC12 | Carex scopulorum | – | 0 | ||
| Northwest Territory sedge | CAUT | Carex utriculata | – | 0 | ||
| tufted hairgrass | DECE | Deschampsia cespitosa | – | 0 | ||
| Drummond's rush | JUDR | Juncus drummondii | – | 0 | ||
|
Moss
|
||||||
| 2 | – | |||||
| sphagnum | SPCA70 | Sphagnum capillifolium | – | 0 | ||
| sphagnum | SPFU70 | Sphagnum fuscum | – | 0 | ||
|
Forb
|
||||||
| 3 | – | |||||
| white marsh marigold | CALE4 | Caltha leptosepala | – | 0 | ||
Interpretations
Supporting information
Inventory data references
Type Locality Plot ID: 05-TMR-043
Type locality
| Location 1: Skagit County, WA | |
|---|---|
| Township/Range/Section | T35N R14E S9 |
| UTM zone | N |
| UTM northing | 5376912.87 |
| UTM easting | 648418.153 |
| Latitude | 48° 31′ 40″ |
| Longitude | 120° 59′ 22″ |
Other references
Billings, W.D. 1973. Arctic and Alpine Vegetations: Similarities, Differences, and Susceptibility to Disturbance. BioScience, Vol. 23, No. 12 (Dec., 1973), pp. 697-704.
Billings, W.D. 1987. Constraints to Plant Growth, Reproduction, and Establishment in Arctic Environments. Arctic and Alpine Research, Vol. 19, No. 4, Restoration and Vegetation Succession in Circumpolar Lands: Seventh Conference of the Comité Arctique International (Nov., 1987), pp.357-365
Billings, W.D. and Bliss L.C. 1959. An Alpine Snowbank Environment and Its Effects on Vegetation, Plant Development, and Productivity. Ecology, Vol. 40, No. 3 (Jul., 1959), pp. 388-397.
Canaday, B.B. and Fonda, R.W. 1974. The Influence of Subalpine Snowbanks on Vegetation Pattern, Production, and Phenology. Bulletin of the Torrey Botanical Club, Vol. 101, No. 6 (Nov. - Dec., 1974), 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. 58 pages.
Douglas, G.W. and Bliss L.C. 1977. Alpine and High Subalpine Plant Communities of the North Cascades Range, Washington and British Columbia. Ecological Monographs, Vol. 47, No. 2 (Spring, 1977), pp. 113-150.
Kuramoto, R.T. and Bliss L.C. 1970. Ecology of Subalpine Meadows in the Olympic Mountains, Washington. Ecological Monographs, Vol. 40, No. 3 (Summer, 1970), pp. 317-347.
Contributors
Martha Chaney
Marty Chaney
Approval
Kirt Walstad, 5/10/2024
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 | 12/22/2024 |
| Approved by | Kirt Walstad |
| 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:
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