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Ecological site AX001X01X306

Cryic Aquic Subalpine Wet Meadow

Last updated: 5/15/2025
Accessed: 09/12/2026

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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): 001X–Northern Pacific Coast Range, Foothills, and Valleys

This area consists of a long and narrow range of mountains with associated foothills and valleys that parallels the Pacific Ocean. This area is entirely within the Pacific Border Province of the Pacific Mountain System in Oregon and Washington. MLRA 1 is bounded on the north by the highest elevations of the Olympic Mountains and the strait of Juan de Fuca, and by the Klamath Mountains on the south. The Washington portion of this MLRA is primarily composed of young Tertiary sedimentary rocks (siltstone and sandstone) mixed with some volcanic rocks of the same age. Glacial till and outwash deposits are also found in the northern half of this area in Washington. Much of this area is accreted terrane formed by tectonic processes. The average annual precipitation ranges from 60 to 200 inches (1,525 to 5,580 millimeters), increasing with elevation. Most of the precipitation in this area occurs during low-intensity, Pacific frontal storms and is evenly distributed throughout fall, winter, and spring.

The dominant soil orders in this MLRA are Andisols, Inceptisols, and Ultisols. Soil depths broadly range from shallow to very deep. Soils are primarily well drained, however poorly drained soils may be found in depressional areas and on alluvial floodplains. Surface textures are typically medial and loamy or clayey. Soils in this area dominantly have a mesic or frigid temperature regime and a udic moisture regime. Soils with aquic moisture regimes and cryic temperature regimes also occur.

Ecological site concept

Cryic Aquic Subalpine Wet Meadow sites occur on seeps and depressions on cirques, ridges, and structural benches above 900 meters. These sites are characterized by a community of forbs, sedges, and mosses. Due to their highly stable slope positions, these sites receive additional run-on water from less stable upslope sites. Soils on this site are poorly drained and are subject to frequent, long-duration ponding during the growing season. Frequently saturated soil conditions favor moisture tolerant species including white marsh marigold (Caltha leptosepala), showy sedge (Carex spectabilis), black alpine sedge (Carex nigricans), horsetails (Equisetum spp.), green false hellebore (Veratrum viride), elephanthead lousewort (Pedicularis groenlandica), scentbottle (Platanthera dilatata), and Sierra shootingstar (Dodecatheon jeffreyi).

Associated sites

AX001X01X410	Low Cryic Udic Forest Low Cryic Udic Forest sites are often found in association with Cryic Aquic Subalpine Wet Meadows. Low Cryic Udic Forests occur on topographic highs and run-off positions associated with Cryic Aquic Subalpine Wet Meadows. Cryic Aquic Subalpine Wet Meadow sites may be found on seeps adjacent to or surrounded by Low Cryic Udic Forests. Cryic Aquic Subalpine Wet Meadows are easily distinguished by the hydrophilic vegetation and lack of tree cover.
AX001X01X413	High Cryic Udic Forest High Cryic Udic Forest sites are found in association with Cryic Aquic Subalpine Wet Meadows. High Cryic Udic Forests exist on topographic highs and run-off positions associated with Cryic Aquic Subalpine Wet Meadows. Cryic Aquic Subalpine Wet Meadow sites may be found on seeps adjacent to or surrounded by High Cryic Udic Forests. Cryic Aquic Subalpine Wet Meadows are easily distinguished by the hydrophilic vegetation and lack of tree cover.
AX001X01X414	High Cryic Udic Moist Forest High Cryic Udic Moist Forest sites are often found in association with Cryic Aquic Subalpine Wet Meadows. High Cryic Udic Moist Forests occur on topographic highs and run-off positions associated with Cryic Aquic Subalpine Wet Meadows. Cryic Aquic Subalpine Wet Meadow sites may be found on seeps adjacent to or surrounded by High Cryic Udic Moist Forests. Cryic Aquic Subalpine Wet Meadows are easily distinguished by the hydrophilic vegetation and lack of tree cover.
AX001X01X415	High Cryic Udic Dry Forest High Cryic Udic Dry Forest sites are found in association with Cryic Aquic Subalpine Wet Meadows. High Cryic Udic Dry Forests exist on topographic highs and run-off positions associated with Cryic Aquic Subalpine Wet Meadows. Cryic Aquic Subalpine Wet Meadow sites may be found on seeps adjacent to or surrounded by High Cryic Udic Dry Forests. Cryic Aquic Subalpine Wet Meadows are easily distinguished by the hydrophilic vegetation and lack of tree cover.
AX001X01X303	Cryic Udic Subalpine Meadow Cryic Udic Subalpine Meadows are drier sites found on topographic highs and run-off positions associated with Cryic Aquic Subalpine Wet Meadows. Cryic Aquic Subalpine Wet Meadows may occur on seeps adjacent to or surrounded by Cryic Udic Subalpine Meadows.
AX001X01X304	Cryic Udic Moist Subalpine Meadow Cryic Udic Moist Subalpine Meadows are drier sites found on topographic highs and run-off positions associated with Cryic Aquic Subalpine Wet Meadows. Cryic Aquic Subalpine Wet Meadows may be found on seeps adjacent to or surrounded by Cryic Udic Moist Subalpine Meadows.
AX001X01X301	Cryic Udic Shallow Subalpine Meadow Cryic Udic Shallow Subalpine Meadows are much drier sites found on topographic highs and run-off positions associated with Cryic Aquic Subalpine Wet Meadows. Cryic Udic Shallow Subalpine Meadows occur on depth-limited soils which further limit plant-available water.
AX001X01X412	Low Cryic Udic Dry Forest Low Cryic Udic Dry Forest sites are found in association with Cryic Aquic Subalpine Wet Meadows. Low Cryic Udic Dry Forests exist on topographic highs and run-off positions associated with Cryic Aquic Subalpine Wet Meadows. Cryic Aquic Subalpine Wet Meadow sites may be found on seeps adjacent to or surrounded by Low Cryic Udic Dry Forests. Cryic Aquic Subalpine Wet Meadows are easily distinguished by the hydrophilic vegetation and lack of tree cover.
AX001X01X411	Low Cryic Udic Moist Forest Low Cryic Udic Moist Forest sites are often found in association with Cryic Aquic Subalpine Wet Meadows. Low Cryic Udic Moist Forests occur on topographic highs and run-off positions associated with Cryic Aquic Subalpine Wet Meadows. Cryic Aquic Subalpine Wet Meadow sites may be found on seeps adjacent to or surrounded by Low Cryic Udic Moist Forests. Cryic Aquic Subalpine Wet Meadows are easily distinguished by the hydrophilic vegetation and lack of tree cover.

Similar sites

AX001X01X305	Cryic Udic Wet Subalpine Meadow Cryic Udic Wet Subalpine Meadow sites are somewhat poorly drained and do not pond. Cryic Udic Wet Subalpine Meadow sites support shrub – forb associations, with tree islands sometimes scattered on site.
AX001X01X203	Cryic Aquic Shrubland Cryic Aquic Shrublands are less frequently ponded and support shrubs and scattered trees.

AX001X01X305

Cryic Udic Wet Subalpine Meadow

Cryic Udic Wet Subalpine Meadow sites are somewhat poorly drained and do not pond. Cryic Udic Wet Subalpine Meadow sites support shrub – forb associations, with tree islands sometimes scattered on site.

AX001X01X203

Cryic Aquic Shrubland

Cryic Aquic Shrublands are less frequently ponded and support shrubs and scattered trees.

Table 1. Dominant plant species

Tree	Not specified
Shrub	Not specified
Herbaceous	(1) Caltha leptosepala (2) Carex nigricans

Legacy ID

R001XA306WA

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Physiographic features

This site primarily occurs on glacial valley walls and colluvial aprons on mountains. Cryic Aquic Subalpine Wet Meadow sites occur on topographic depressions and seeps. These sites collect a significant amount of run-on moisture from less stable upslope sites.

Table 2. Representative physiographic features

Landforms	(1) Mountains (2) Glacial-valley wall (3) Colluvial apron
Flooding frequency	None
Ponding duration	Long (7 to 30 days)
Ponding frequency	Frequent
Elevation	2953 – 6234 ft
Slope	0 – 5 %
Water table depth	0 – 10 in
Aspect	W, NW, N, NE, E, SE, S, SW

Climatic features

This site occurs in a cryic temperature and aquic moisture regime. Precipitation arrives mostly via low-intensity, Pacific frontal storms. Precipitation is unevenly distributed, with the lowest amounts on the leeward side of the Coast Range mountains. Precipitation falls largely as snow in higher elevations. Precipitation is evenly distributed throughout the fall, winter, and spring, while summers are dry. Air temperatures vary significantly along the elevation gradient.

Table 3 Representative climatic features

Frost-free period (characteristic range)	30-90 days
Freeze-free period (characteristic range)
Precipitation total (characteristic range)	60-160 in

Influencing water features

This site is frequently ponded for a long duration during the growing season. The high water table and frequently ponded conditions favor plants with tolerance for anaerobic conditions. Changes in plant community composition are closely tied to variations in snowfall amounts. Periods of above-average snowfall favor alpine black sedge (<a class="species-link" href="https://plants.usda.gov/core/profile?symbol=CANI2" target="_blank" title="Open in plants.usda.gov"><i>Carex nigricans</i></a>) and sphagnum (Sphagnum spp.), while periods of below-average snowfall favor forbs and shrubs.

Soil features

The soils that support this ecological site occur in the cryic soil temperature regime and the aquic soil moisture regime. Ringlake soils are very deep, poorly drained, formed from residuum, and occur on depressions of ridges, structural benches, glacial valley walls, and colluvial aprons. Saturated hydraulic conductivity is high or very high throughout. These soils have a seasonally high water table that is within zero to 10 inches of the surface during the growing season, and a frequent ponding occurrence November through June. These soils contain a thick organic layer that protects the soil from wind and water erosion. Ponding frequency and soil saturation are the limiting factors for plant growth on these soils. Although representative of this site, these soils may exist across multiple ecological sites because of naturally variable slope, texture, rock fragments, and pH. An on-site soil pit and the most current ecological site key are necessary to classify a site.

Table 4. Representative soil features

Parent material	(1) Residuum
Surface texture	(1) Very gravelly silt loam (2) Very gravelly loam (3) Very gravelly sandy loam
Drainage class	Poorly drained
Soil depth	60 – 0 in
Surface fragment cover <=3"	Not specified
Surface fragment cover >3"	Not specified
Available water capacity (0-40in)	5.4 – 9.8 in
Soil reaction (1:1 water) (0-10in)	3.5 – 5.5
Subsurface fragment volume <=3" (0-20in)	25 – 50 %
Subsurface fragment volume >3" (0-20in)	0 – 20 %

Ecological dynamics

The Cryic Aquic Subalpine Wet Meadow site is found at mid-to-high elevations in the park where snowpack persists long into the spring and summer. Long-duration snowpack cover significantly reduces growing degree days on site. These sites receive additional run-on moisture from upslope sites. Soils on this site are poorly drained and are subject to frequent, long-duration ponding. High effective precipitation favors moisture-tolerant species including white marsh marigold (Caltha leptosepala), showy sedge (Carex spectabilis), black alpine sedge (Carex nigricans), horsetails (Equisetum spp.), green false hellebore (Veratrum viride), elephanthead lousewort (Pedicularis groenlandica), scentbottle (Platanthera dilatata), and Sierra shootingstar (Dodecatheon jeffreyi).

Cryic Aquic Subalpine Wet Meadows are generally protected from mass movement or avalanches due to their stable slope positions. Fires are incredibly rare on these sites due to saturated or ponded moisture conditions. It is conceivable that a dry phase of this site may be capable of burning, although this burned condition has not been observed. Even in a dry phase, burns on this site would likely be highly discontinuous and low extent.

Significant variance in community composition on this site results from interannual variations in soil moisture conditions. This site is typically co-dominated by an assortment of forb, sedge, and moss species. Periods of higher moisture conditions on site can promote a shift towards dominance of sedges and sphagnum mosses. Alternatively, drier than typical periods may lead to encroachment of oxylophytic shrubs and less moisture tolerant forb species. Microtopographical variation on site may lead to differences in community expression, with microtopographical depressions expressing moist communities and microtopographical highs expressing dry communities.
Sphagnum mosses are often considered to be autogenic and allogenic ecosystem engineers due to their ability to strongly influence site conditions, ameliorating conditions for itself while creating less favorable conditions for competing vascular plant species.

Sphagnum mosses alter surface and subsurface hydrology on sites, often increasing the duration of saturation and contributing to anoxic surface and subsurface conditions. Dead sphagnum contributes a significant amount of plant phenols, particularly Sphagnum acid. Phenols further slow decomposition of sphagnum, preventing nutrient recycling. Sphagnum material also lowers soil and peat pH, excluding calcicole plants (Breeman, 1995). The sphagnum-dominated phase on this site has high inertia and resists pathways back to a forb and sedge-dominated community.

State and transition model

More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective text

Ecosystem states

1. Reference

State 1 submodel, plant communities

1.1. White Marsh Marigold, Fireleaf Leptarrhena, Black Alpine Sedge, and Showy Sedge

1.2. Black Alpine Sedge and Sphagnum

1.3. Western Moss Heather, Rose Meadowsweet, High Mountain Cinquefoil, American Bistort, and Showy Sedge

1.1B	-	Period of saturation
1.1A	-	Period of dry conditions
1.2A	-	Period of dry conditions
1.3A	-	Period of wet conditions

State 1
Reference

The reference state of the Cryic Aquic Subalpine Wet Meadow site is comprised one of three communities depending on moisture conditions. The site is dominated by forbs, sedges, and mosses. Some shrubs may be present on site in drier areas on site.

Dominant plant species

western moss heather (Cassiope mertensiana), shrub
rose meadowsweet (Spiraea splendens), shrub
white marsh marigold (Caltha leptosepala), other herbaceous
fireleaf leptarrhena (Leptarrhena pyrolifolia), other herbaceous
black alpine sedge (Carex nigricans), other herbaceous
showy sedge (Carex spectabilis), other herbaceous
horsetail (Equisetum), other herbaceous
elephanthead lousewort (Pedicularis groenlandica), other herbaceous
sphagnum (Sphagnum), other herbaceous
high mountain cinquefoil (Potentilla flabellifolia), other herbaceous
American bistort (Polygonum bistortoides), other herbaceous

Community 1.1
White Marsh Marigold, Fireleaf Leptarrhena, Black Alpine Sedge, and Showy Sedge

Structure: wet depression dominated by forbs, sedges, and mosses
This community is characterized by a diverse composition of forbs, sedges, and mosses. Common reference community plants include white marsh marigold (Caltha leptosepala), fireleaf leptarrhena (Leptarrhena pyrolifolia), black alpine sedge (Carex nigricans), showy sedge (Carex spectabilis), horsetails (Equisetum spp.), and elephanthead lousewort (Pedicularis groenlandica).

Community 1.2
Black Alpine Sedge and Sphagnum

Structure: saturated depression dominated by sedges and sphagnum mosses
This community phase is dominated by sphagnum mosses and alpine black sedge (Carex nigricans). Due to sphagnum’s proclivity for autogenic and allogenic ecosystem engineering, this community phase tends to self-perpetuate and resist the pathway back to phase 1.1.

Community 1.3
Western Moss Heather, Rose Meadowsweet, High Mountain Cinquefoil, American Bistort, and Showy Sedge

Structure: dry phase depression or slightly elevated organic deposits, with shrub and forb encroachment
This site may be found during and after a period of drier than typical conditions that allow less water tolerant species to encroach on site. This phase may also be found on hummocks formed by organic deposits such as from fallen logs from adjacent forested sites. Microtopographical highs may also express this community phase due to less saturated surface conditions.

Pathway 1.1B
Community 1.1 to 1.2

A period of very long saturated conditions may promote sphagnum and sedge dominance on site.

Pathway 1.1A
Community 1.1 to 1.3

A period of drier than typical conditions may promote shrub and dry forb encroachment on site.

Pathway 1.2A
Community 1.2 to 1.1

Long period of dry conditions may favor vascular plants over sphagnum moss. Gradual loss of sphagnum cover may restore an environment favorable for forbs and sedges.

Pathway 1.3A
Community 1.3 to 1.1

A period of typical wet conditions favors return to reference plant community composition.

Additional community tables

Table 5. Community 1.1 plant community composition

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

Table 6. Community 1.2 plant community composition

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

Table 7. Community 1.3 plant community composition

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

Supporting information

Other references

Breemen, Nico van. “How Sphagnum Bogs down Other Plants.” Trends in Ecology & Evolution 10, no. 7 (July 1, 1995): 270–75. 90007-1.

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, Jerry F.; Cromack, Kermit, Jr.; Denison, William; [and others]. 1981. Ecological characteristics of old-growth Douglas-fir forests. Gen. Tech. Rep. PNW-118. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 48 p. [7551]

Gavin, D., Brubaker, L. (2015). The Modern Landscape of the Olympic Peninsula. In: Late Pleistocene and Holocene Environmental Change on the Olympic Peninsula, Washington. Ecological Studies, vol 222. Springer, Cham. https://doi.org/10.1007/978-3-319-11014-1_1

Geertsema, Marten & Pojar, James. (2007). Influence of landslides on biophysical diversity — A perspective from British Columbia. Geomorphology. 89. 55-69. 10.1016/j.geomorph.2006.07.019.

Goheen, E.M. and Willhite, E.A. 2006. Field Guide to Common Diseases and Inspect Pests of Oregon and Washington Conifers. Portland, Oregon: USDA Forest Service, Pacific Northwest Region R6-NR-FID-PR-01-06.

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.

James K. Agee and Mark H. Huff. 1987. Fuel succession in a western hemlock/Douglas-fir forest. Canadian Journal of Forest Research. 17(7): 697-704. https://doi.org/10.1139/x87-112

Nielsen, E. M., R. L. Brunner, C. Copass and L. K. Wise, 2021. Olympic National Park map class descriptions. National Park Service, Fort Collins.

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 October 2023.

Reed Wendel, Darlene Zabowskl "Fire History within the Lower Elwha River Watershed, Olympic National Park, Washington," Northwest Science, 84(1), 88-97, (1 January 2010)

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.

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 Department of Agriculture, Natural Resources Conservation Service, and United States Department of the Interior, National Park Service. Ecological Site Descriptions for Mount Rainier National Park, Washington.

Van Pelt, R. 2007. Identifying Mature and Old Forests in Western Washington. Washington State Department of Natural Resources, Olympia, WA. 104 p

Washington Department of Natural Resources, Natural Heritage Program. 2015. Ecological Systems of Washington State. A Guide to Identification.

Wood, David, and Moral, Roger del. “Mechanisms of Early Primary Succession in Subalpine Habitats on Mount St. Helens.” Ecology 68, no. 4 (1987).

Zhao, Yunpeng, Chengzhu Liu, Simin Wang, Yiyun Wang, Xiaoqing Liu, Wanqing Luo, and Xiaojuan Feng. “‘Triple Locks’ on Soil Organic Carbon Exerted by Sphagnum Acid in Wetlands.” Geochimica et Cosmochimica Acta 315 (December 2021): 24–37. https://doi.org/10.1016/j.gca.2021.09.028.

Contributors

Alec Haulotte
Erin Kreutz
Abigail Field
Max Ross
Erik Dahlke

Approval

Grant Petersen, 5/15/2025

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	09/12/2026
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

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