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Ecological site R241XY131AK
Arctic Tussock Loamy Frozen Slopes
Last updated: 5/29/2025
Accessed: 10/08/2026
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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.
MLRA notes
Major Land Resource Area (MLRA): 241X–Seward Peninsula Highlands
The Seward Peninsula Highlands (MLRA 241X) occurs in Western Alaska, along the southernmost reaches of Land Resource Region Y, which has an arctic climate and occurs in the zone of continuous permafrost. This MLRA is approximately 13,700 square miles across the central Seward Peninsula. The terrain is defined by broad and extensive rolling hills and plains and solitary groups of rugged mountains expanding from sea level to a high point of 4,714 feet on Mount Osborn. Flood plains systems are common but generally narrow. The MLRA 241X watershed drains into Kotzebue Sound and the Chukchi Sea to the north and the Bering Sea to the West. Major rivers include the Buckland, Kiwalik, Serpentine, Agiapuk-American, Kougarok, and Kuzitrin Rivers. The area is mostly undeveloped wild land that is sparsely populated. Residents use this remote area primarily for subsistence hunting, fishing, and gathering. The largest communities in this predominantly inland MLRA are along the coast and include Teller and Brevig Mission. Reindeer herding is a profitable enterprise and many areas of this MRLA are used for reindeer graze and subsistence activities. Parts of this MLRA were mined for gold during the Nome gold rush. Several mines still operate within this boundary (USDA, 2022). Federally managed lands in this MLRA include parts of the Selawik National Wildlife Refuge and parts of Bering Land Bridge National Preserve.
Geology and Soils
MLRA 241X was mostly unglaciated during the late Pleistocene. Glaciers were present during the middle and early Pleistocene in scattered areas such as the York Mountains in the west, the Kiglauik Mountains to the south, and the Upper Kiwalik River drainage. The present-day landscape is mantled with loess, colluvium, and slope alluvium (USDA, 2022). Modified glacial moraines are evident in areas of past glacial activity. Bedrock material is a mix of rock types, with areas of sedimentary, volcanic and igneous throughout the MLRA. Bedrock is at or near the surface in most upland areas of this MLRA, which is reflected in soil development and vegetative patterns.
This MLRA is in the zone of continuous permafrost. Frozen soils are common across the landscape, though may be absent from high energy systems on floodplains, around lakes and on gravelly, well drained soils. Permafrost is generally shallow to moderately deep (10 to 40 inches) that results in a restrictive layer that perches water and creates poorly to very poorly drained soils. Alongside these permafrost soils (Gelisols), other common soil orders include soils with little to no development in the Entisol and Inceptisol orders. Periglacial features are common and include solifluction lobes, polygonal ground, and thermokarst pits (USDA, 2022). Non-soil areas (rock outcrop, riverwash, and surface water) make up approximated five percent of the MLRA surface.
Climate
Climate is predominantly continental arctic, with brief, cool summers and long, cold winters. Maritime conditions, where summer temperatures are moderated by the proximity to open water, persist through the summer along the Bering Sea coast. Mean annual precipitation is 10 to 15 inches in the north and west, increasing to 20 to 40 inches in the mountainous areas in the south and east (USDA, 2022). Mean annual temperatures ranges from 20 to 26 degrees Fahrenheit (PRISM, 2018; SNAP, 2014).
Vegetation
Vegetation is mainly influenced by climate, site, and soil characteristics such as temperature-degree days, elevation, exposure to wind, soil depth, and soil hydrology. Dwarf scrublands are present across most of the upland, with vegetation further restricted on shallow soils. Lower elevations generally support more developed soils, and host willow-sedge scrublands, mixed ericaceous shrub scrublands, and herbaceous graminoid meadows. Tussock tundra is ubiquitous across much of the poorly drained, low-sloped landforms across the MRLA. Wetland communities dominate in closed depressions and drainages (USDA, 2022).LRU notes
There are currently no Land Resource Areas (LRUs) delineated or described in MLRA 241X. There is potential for two or more LRUs along a climatic break between the lowlands and low-elevation hills of the north and west, and the higher, mountainous regions more prevalent in the south and east. However, vegetation and land management may not differ between these areas, as soils and vegetation are already restricted by cold annual temperatures even at low elevations.
Classification relationships
Alaska Vegetation Classification:
Mesic graminoid herbaceous (III.A.2 - level III) / Tussock tundra (III.A.2.d - level IV)
(Viereck et al., 1992)
BioPhysical Settings: 6816942 – Alaska Arctic Tussock Tundra - Infrequent Fire
(LANDFIRE biophysical settings, 2009)
Seward Rangesites:
60 – Lichen (Tussock Tundra)
(SCS, 1984; Swanson et al., 1985)Ecological site concept
Ecological Site characteristics:
• Associated with a tussock tundra community with high lichen ground cover in the reference plant community
• Occurs on gently sloping arctic hill and plain slopes
• Soils contain permafrost and are very poorly drained
• Ponding occurs and is reflected in the facultative to obligate wetland vegetation
• Fire is the major disturbance in the reference state and is responsible for one distinct post-fire community.
• Repeating hummock mounds are common periglacial features on the described landform. These are represented by an alternate state.Associated sites
R241XY130AK Arctic Scrub Loamy Warm Hillslopes
This ecological site describes a productive birch-mixed ericaceous scrubland on warm slopes.
R241XY134AK Arctic Scrub Loamy Hillslopes
This ecological site is a low ericaceous shrub and sedge scrubland without tussocks on hills and plains.
Similar sites
R241XY134AK Arctic Scrub Loamy Hillslopes
R241XY134AK has drier soils that support an ericaceous-sedge scrubland on slopes. Circle features are common. Cottongrass may be present but does not support a tussock tundra.
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Ledum palustre ssp. decumbens
(2) Vaccinium vitis-idaeaHerbaceous (1) Eriophorum vaginatum
(2) Carex bigelowiiPhysiographic features
This site occurs on arctic hills and plains. Elevation ranges from 100 to 1000 feet above sea level. Slope gradients are negligible to gentle (0 to 6 percent), and this ecological site occurs on all aspects. A water table is present throughout the growing season. Ponding occurs in the reference state.
Repeating earth hummock mounds are common periglacial microfeatures. They can be mounded well above the surrounding vegetation. Mounds have unique site and soil properties that result in a mosaic of vegetation.Table 2. Representative physiographic features
Slope shape across (1) Linear
(2) Concave
Slope shape up-down (1) Linear
(2) Concave
Hillslope profile (1) Footslope
Landforms (1) Hills > Hill
(2) Plains > Plain
(3) Plains > Plain > Turf hummock
(4) Plains > Plain > Mound
Runoff class Negligible to low Flooding frequency None Ponding duration Long (7 to 30 days) Ponding frequency Frequent Elevation 100 – 1000 ft Slope 0 – 6 % Ponding depth 0 – 24 in Water table depth 0 in Aspect W, NW, N, NE, E, SE, S, SW Table 3. Representative physiographic features (actual ranges)
Runoff class Negligible to medium Flooding frequency None Ponding duration Long (7 to 30 days) Ponding frequency None to frequent Elevation 20 – 2610 ft Slope 0 – 14 % Ponding depth 0 – 24 in Water table depth 0 in Climatic features
The Arctic climate of this ecological site includes short, cool growing seasons and long, cold winters. Mean annual temperature at sea level is about 22 degrees Fahrenheit in the coastal village of Wales. Approximately 35 percent of total precipitation occurs during the growing season months of June through August. Across the MLRA, snowfall ranges from 40 to 100 inches (USDA-NRCS, 2022).
Table 4 Representative climatic features
Frost-free period (characteristic range) 60-90 days Freeze-free period (characteristic range) 50-80 days Precipitation total (characteristic range) 10-20 in Frost-free period (actual range) 50-90 days Freeze-free period (actual range) 40-80 days Precipitation total (actual range) 10-20 in Frost-free period (average) 80 days Freeze-free period (average) 70 days Precipitation total (average) 20 in Characteristic rangeActual rangeBarLineFigure 1. Monthly precipitation range
Characteristic rangeActual rangeBarLineFigure 2. Monthly minimum temperature range
Characteristic rangeActual rangeBarLineFigure 3. Monthly maximum temperature range
BarLineFigure 4. Monthly average minimum and maximum temperature
Figure 5. Annual precipitation pattern
Figure 6 Annual average temperature pattern
">Influencing water features
This ecological site is not influenced by wetland or riparian water features. Precipitation and snow melt are the main sources of water for this ecological site.
Wetland description
This ecological site may be classified as a slope wetland under the Hydrogeomorphic (HGM) classification system (Smith et al. 1995; USDA-NRCS 2008). A shallow water table is present in the reference state throughout the year.
Soil features
Soils in the reference state are Gelisols formed primarily on eolian deposits atop alluvium or till (Soil Survey Staff, 2013). Soils are wet and very poorly drained. Rock fragments are absent from the surface. The organic cap is between 9 and 11 inches. Soils are very deep. Permafrost is moderately deep, and strongly contrasting textural stratification is moderately deep when present. Subsurface rock fragment volume is generally low or absent. Soil pH is extremely to moderately acidic.
Soils in the alternate state are highly organic Hemistels (Soil Survey Staff, 2013). Repeating mound features have unique soil properties distinct from the reference state. Microtopography creates a mosaic of well drained highs and very poorly drained lows.Table 5. Representative soil features
Parent material (1) Eolian deposits
(2) Till
(3) Organic material
Surface texture (1) Peat
(2) Mucky peat
Drainage class Very poorly drained Permeability class Moderate Depth to restrictive layer 17 – 29 in Soil depth 60 – 0 in Surface fragment cover <=3" 0 – 1 % Surface fragment cover >3" 0 – 5 % Available water capacity
(0-40in)8.7 – 11.9 in Soil reaction (1:1 water)
(0-10in)3.9 – 5.4 Subsurface fragment volume <=3"
(0-60in)Not specified Subsurface fragment volume >3"
(0-60in)Not specified Table 6. Representative soil features (actual values)
Drainage class Not specified Permeability class Not specified Depth to restrictive layer 12 – 40 in Soil depth 0 in Surface fragment cover <=3" 0 % Surface fragment cover >3" 0 % Available water capacity
(0-40in)0 in Soil reaction (1:1 water)
(0-10in)0 Subsurface fragment volume <=3"
(0-60in)0 % Subsurface fragment volume >3"
(0-60in)0 % Ecological dynamics
The Seward Peninsula Highlands MLRA (MLRA 241X) is in the arctic where the harsh climate limits the composition and structure of plant communities. This area has cool, short summers and long, cold winters. Trees are mostly restricted to the most eastern areas of the MLRA. The expansive tundra is comprised of a mosaic of shrubs, sedges, moss, and lichen.
This ecological site describes a tussock community with various shrubs on plains and hills. Vegetation is restricted by cold temperature, permafrost, and ponding. Vegetation is typically comprised of facultative to facultative wet species. Hydrologically driven processes result in microfeatures such as polygonal ground and frost heaving (Landfire, 2009).
Fire is the major natural disturbance on this ecological site. The fire cycle may range from 50 to 600 years (Landfire, 2009). Fire dynamics in the Arctic region are poorly understood and are likely to vary within and between Arctic regions (Landfire, 2009). This disturbance is responsible for one unique post-disturbance community. Post-fire community composition depends on fire factors such as frequency and severity. Slight to moderate fires may only burn surface vegetation, leaving the wet organic horizon intact. A severe fire burns the insulating organic layer, causing permafrost to drop in the soil profile. Soil drainage improves and less hydric species colonize. Alder may colonize from nearby flood plains. As the organic horizon thickens, permafrost rises, the soil becomes wetter, and the community shifts back to community 1.1.
Frozen mounds are described by an alternate state in this ecological site. Factors such as soil texture, surface heat transfer, and freezing depth are responsible for mound formation (Peterson and Krantz, 2003). Mounds create a repeating microtopography with drier soils at mound tops and wetter soils in inter-mound lows. The variability of soil wetness, exposure, and microclimates creates various niches that results in increased species diversity.
The information in this Ecological Dynamics section, including the state-and-transition model (STM), was developed based on professional experience and a review of available scientific literature. As a result, all possible scenarios or plant species may not be included. Key indicator plant species, disturbances, and ecological processes are described to inform land management decisions.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 textEcosystem states
T1A - Frost heave mound formation R2A - Mound collapse State 1 submodel, plant communities
1.1A - Fire 1.2A - Fire recovery State 2 submodel, plant communities
State 1
Reference StateThis reference state is developed and characterized using available vegetation models, most notably United States Department of Agriculture - Soil Conservation Service range surveys (SCS, 1984; Swanson et al., 1985).
The reference state describes two distinct vegetative communities under a fire cycle regime. Along with a fire regime, soil wetness, caused by water perched by permafrost, is the major factor influencing vegetation.
There is no indication of an alternate grazing state on this site. Targeted data collection may be able to address whether grazing or browsing in the reference state result in an alternate state.Dominant plant species
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marsh Labrador tea (Ledum palustre ssp. decumbens), shrub
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lingonberry (Vaccinium vitis-idaea), shrub
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cloudberry (Rubus chamaemorus), shrub
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bog blueberry (Vaccinium uliginosum), shrub
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tussock cottongrass (Eriophorum vaginatum), grass
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Bigelow's sedge (Carex bigelowii), grass
Community 1.1
Ledum palustre ssp. decumbens - Vaccinium vitis-idaea / Eriophorum vaginatum - Carex bigelowiiThis community is a tussock tundra (Viereck et al., 1992). Major plant groups are tall and medium graminoids, and low and dwarf shrubs (Swanson et al., 1985). Shrubs grow on and in-between tussocks. Moss is prevalent throughout the spaces between tussocks. Lichens growth both on the moss and tussocks.
Tabular data for this community is from the 1984 Seward range site publication (SCS, 1984), with supplemental information from Swanson et al. (1985).
Forest understory. Live lichen and moss annual production cannot be measured accurately due to a lack of information on growth rates and/or slow annual growth rates. Lichen and moss biomass data below refers to total biomass, while vascular plants biomass refers to annual production.
Dominant plant species
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marsh Labrador tea (Ledum palustre ssp. decumbens), shrub
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lingonberry (Vaccinium vitis-idaea), shrub
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bog blueberry (Vaccinium uliginosum), shrub
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dwarf birch (Betula nana), shrub
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cloudberry (Rubus chamaemorus), shrub
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tussock cottongrass (Eriophorum vaginatum), grass
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Bigelow's sedge (Carex bigelowii), grass
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field horsetail (Equisetum arvense), other herbaceous
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greygreen reindeer lichen (Cladina rangiferina), other herbaceous
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(Flavocetraria cucullata), other herbaceous
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island cetraria lichen (Cetraria islandica), other herbaceous
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reindeer lichen (Cladina mitis), other herbaceous
Figure 7. Annual production by plant type (representative values) or group (midpoint values)
Table 7. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Moss 890 2485 5340 Lichen 850 995 1140 Shrub/Vine 280 310 340 Grass/Grasslike 180 200 220 Forb 50 55 60 Total 2250 4045 7100 Table 8. Ground cover
Tree foliar cover 0% Shrub/vine/liana foliar cover 10-30% Grass/grasslike foliar cover 10-10% Forb foliar cover 10-10% Non-vascular plants 30-80% Biological crusts 0% Litter 10-10% Surface fragments >0.25" and <=3" 0% Surface fragments >3" 0% Bedrock 0% Water 0% Bare ground 0-10% Community 1.2
Eriophorum vaginatum - Carex bigelowii / Chamerion angustifoliumThis community has generally been burned within the last 15 years (Landfire, 2009). It is comprised of extant species present pre-burn, as well as fast-growing colonizing herbaceous species. Major plant groups are tall and medium graminoids, and medium and low forbs (Landfire, 2009). Ground cover varies based on burn severity and time since burn, but usually supports mosses, lichens, herbaceous litter, and water.
Forest understory. Live lichen and moss annual production cannot be measured accurately due to a lack of information on growth rates and/or slow annual growth rates. Lichen and moss biomass data below refers to total biomass, while vascular plants biomass refers to annual production.
Dominant plant species
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tussock cottongrass (Eriophorum vaginatum), grass
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Bigelow's sedge (Carex bigelowii), grass
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bluejoint (Calamagrostis canadensis), grass
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polargrass (Arctagrostis), grass
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fireweed (Chamerion angustifolium), other herbaceous
Pathway 1.1A
Community 1.1 to 1.2Fire is the major disturbance on this site. Mean fire return intervals vary and may range from 50 years to greater than 600 years (Landfire, 2009). Fire typically burns the insulating layer of herbaceous litter, mosses and lichens. Soils thaw and create conditions where quickly growing forbs and graminoids colonize and intermix with surviving plants.
Key drivers
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Fire
Pathway 1.2A
Community 1.2 to 1.1Fire recovery occurs regularly quickly. Fire typically burns the insulating layer of herbaceous litter, mosses and lichens. Soils thaw, but typically stabilize or return to prefire conditions within ten years (Racine et al., 1987). Cottongrass spreads and shrubs recolonize and spread from surviving rootstock or via seed.
State 2
Mound StateThis state is characterized using available vegetation models, most notably United States Department of Agriculture - Soil Conservation Service range surveys (SCS, 1984; Swanson et al., 1985).
This alternate state describes a scrub community across frost heaved mounds. The conditions required for this microfeature to develop are not fully understood. Available water, an insulating organic horizon and an absence of fire are suspected to be factors needed for the necessary ice cores to form and for mounds to develop.Dominant plant species
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black crowberry (Empetrum nigrum), shrub
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marsh Labrador tea (Ledum palustre ssp. decumbens), shrub
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lingonberry (Vaccinium vitis-idaea), shrub
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bog blueberry (Vaccinium uliginosum), shrub
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cloudberry (Rubus chamaemorus), shrub
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Bigelow's sedge (Carex bigelowii), grass
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tussock cottongrass (Eriophorum vaginatum), grass
Community 2.1
Empetrum nigrum - Ledum palustre ssp. decumbens / Carex bigelowiiThis community is characterized as a crowberry tundra (Viereck et al., 1992). Major plan groups are low and dwarf shrubs, and medium and dwarf graminoids. This community is recognized by the repeating pattern of mounds across the landform.
Dominant plant species
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black crowberry (Empetrum nigrum), shrub
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marsh Labrador tea (Ledum palustre ssp. decumbens), shrub
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bog blueberry (Vaccinium uliginosum), shrub
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lingonberry (Vaccinium vitis-idaea), shrub
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cloudberry (Rubus chamaemorus), shrub
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Bigelow's sedge (Carex bigelowii), grass
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tussock cottongrass (Eriophorum vaginatum), grass
Transition T1A
State 1 to 2Mounds develop when ice cores form under an insulating layer of organics. Ice cores pull in surrounding water via capillary action and push the overlying vegetation upwards. This process can only be initiated in ideal conditions. The normal fire regime typically favors cottongrasses. The absence of a fire disturbance can allow low shrubs to dominate (Landfire, 2009; Racine et al., 1987), which adds to the insulating effect.
Restoration pathway R2A
State 2 to 1Collapse of the ice core within the frost heave mound results in a return to a tussock tundra community. Frost heave mounds collapse when the insulating organic layer is no longer sufficient. This can be due to natural dieback of the moss layer due to overgrowth of the ice core. Fire can also remove the organic layer and melt the ice core. The post-mound collapse community composition will be dependent on the method of mound collapse, with fire leading to community 1.2, and natural die-back leading to either community 1.1 or 1.2.
Additional community tables
Table 9. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Undefined1 Vascular Plants 510–620 Shrub/Vine2 Shrub 280–340 marsh Labrador tea LEPAD Ledum palustre ssp. decumbens 110–130 – bog blueberry VAUL Vaccinium uliginosum 35–45 – lingonberry VAVI Vaccinium vitis-idaea 30–40 – dwarf birch BENA Betula nana 25–30 – black crowberry EMNI Empetrum nigrum 15–20 – Alaska bog willow SAFU Salix fuscescens 10–12 – resin birch BEGL Betula glandulosa 6–7 – white arctic mountain heather CATE11 Cassiope tetragona 2 – tealeaf willow SAPU15 Salix pulchra 2 – red fruit bearberry ARRU Arctostaphylos rubra 2 – bog rosemary ANPO Andromeda polifolia 0–1 – netleaf willow SARE2 Salix reticulata 1 – small cranberry VAOX Vaccinium oxycoccos 0–1 – alpine azalea LOPR Loiseleuria procumbens 1 – Grass/Grasslike3 Grass/Grasslike 180–220 tussock cottongrass ERVA4 Eriophorum vaginatum 130–160 – Bigelow's sedge CABI5 Carex bigelowii 45–50 – water sedge CAAQ Carex aquatilis 15–20 – Forb4 Forb 50–60 cloudberry RUCH Rubus chamaemorus 55–65 – field horsetail EQAR Equisetum arvense 2 – arctic sweet coltsfoot PEFR5 Petasites frigidus 1 – starwort STELL Stellaria 1 – Lichen5 Live lichen biomass 850–1140 greygreen reindeer lichen CLRA60 Cladina rangiferina 270–365 – FLCU Flavocetraria cucullata 160–215 – cup lichen CLADO3 Cladonia 120–160 – reindeer lichen CLMI60 Cladina mitis 100–130 – island cetraria lichen CEIS60 Cetraria islandica 95–125 – reindeer lichen CLAR60 Cladina arbuscula 75–100 – cup lichen CLGR13 Cladonia gracilis 20–25 – cup lichen CLUN60 Cladonia uncialis 5–7 – whiteworm lichen THSU60 Thamnolia subuliformis 4–6 – star reindeer lichen CLST60 Cladina stellaris 3 – Lichen 2LICHN Lichen 1 – FLNI Flavocetraria nivalis 1 – Moss6 Moss 890–5340 Table 10. Community 1.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 11. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
This site supports a relatively large number of small mammals, such as lemmings, voles, shrews and the tundra hare. The needs of a large variety of these small herbivores and insectivores can be met by the diversity of microhabitats found on this site. Well developed tussocks provide islands of relative warmth and dryness for small mammals preferring such conditions, while species adapted to use moist or wet food or terrain for food and cover can find suitable conditions between the tussocks and among the depressions created by frost heaving. Cottongrass, sedges, and forbs provide small bird and mammal herbivores with a variety of seeds, shoots, stems, and other nutritious plant parts, and with sources of insects, for feeding young, building fat reserves, or strong food for winter. Where small birds and mammals are abundant, so are their predators; red fox, least weasel, pomarine jaeger, snowy owl, rough-legged hawk and other predators feed on small mammals, birds, and/or the eggs and nestlings. Large herbivores, especially caribou, may feed on the variety of plant foods on this site, especially in winter and early spring when the lush growth of lichens represent the most abundant and nutritious forage seasonally available.
Recreational uses
This site is used for snowmobiling, dogsledding, hunting for caribou and ptarmigan and trapping of red fox. It has potential for sightseeing and photography since the general area includes canyons, rock formations, lakes, lava beds, and hot springs, besides the wildlife and plant communities. Some low bush cranberry and blueberry picking is also found on this site.
Wood products
No wood products available from this site.
Other products
Grazing
This site is a good winter range and due to the fragile characteristics of lichen this site should not be used for any other season. Grasses, sedges, and the new growth of shrubs provide good forage during the early part of the season. Water and salt are fairly accessible on this site.Supporting information
Inventory data references
Vegetative communities and transitions are described using existing models and expert knowledge. There are no vegetation inventory data points in NASIS associated with this ecological site. External data sources: The Alaska Vegetation Classification (Viereck et al., 1992) LANDFIRE Biophysical Settings Models (LANDFIRE Biophysical Settings, 2009) Ecological site descriptions of the Seward Peninsula (SCS, 1984). Range survey of the Seward Peninsula reindeer ranges (Swanson et al., 1985)
References
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Viereck, L.A., C. T. Dyrness, A. R. Batten, and K. J. Wenzlick. 1992. The Alaska vegetation classification. U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station General Technical Report PNW-GTR-286..
Other references
Kautz, D.R., P. Taber, and S. Nield, editors. 2012. Land Resource Regions and Major Land Resource Areas of Alaska. United States Department of Agriculture, Natural Resources Conservation Service (USDA–NRCS).
LANDFIRE Biophysical Settings. 2009. Biophysical Setting 6816942 – Alaska Arctic Tussock Tundra - Infrequent Fire. In: LANDFIRE Biophysical Setting Model: Map zone 68, [Online]. In: Vegetation Dynamics Models. In: LANDFIRE. Washington, DC: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory; U.S. Geological Survey; Arlington, VA: The Nature Conservancy (Producers). Available: https://www.landfire.gov/national_veg_models_op2.php. Accessed Sept 30, 2024.
Peterson R.A. and W.B. Krantz. 2003. A mechanism for differential frost heave and its implications for patterned-ground formation. Journal of Glaciology. 49(164):69-80. doi:10.3189/172756503781830854
PRISM Climate Group. 2018. “Alaska – average monthly and annual precipitation and minimum, maximum, and mean temperature for the period 1981-2010.” Oregon State University, Corvallis, Oregon. https://prism.oregonstate.edu/projects/alaska.php. Accessed Sept 17, 2024.
Racine C.H., L.A. Jonson and L.A Viereck. 1987. Patterns of vegetation recovery after tundra fires in northwestern Alaska, USA. Arctic and Alpine Research. 19(4), 461-469.
Raynolds, M.K., D.A. Walker and H.A Maier. 2006. Alaska Arctic Tundra Vegetation Map. Scale 1:4,000,000. Conservation of Arctic Flora and Fauna (CAFF) Map No. 2, U.S. Fish and Wildlife Service, Anchorage, Alaska.
Scenarios network for Alaska and arctic planning (SNAP). 2014. “Historical Monthly Temperature – 1km, 1901-2009”. http://ckan.snap.uaf.edu/dataset/. Accessed Sept 17, 2024.
Scenarios network for Alaska and arctic planning (SNAP). 2014. “Historical monthly and derived precipitation products downscaled from CRU TS data via the delta methods – 2km, 1901-2009”. http://ckan.snap.uaf.edu/dataset/. Accessed Sept 17, 2024.
SCS (Soil Conservation Service). 1984. Ecological site descriptions, Seward Peninsula. U.S. Department of Agriculture, Soil Conservation Service, Alaska Field Office, Anchorage.
Soil Survey Staff. 2013. Simplified Guide to Soil Taxonomy. USDA-Natural Resources Conservation Service, National Soil Survey Center, Lincoln, NE.
Swanson, J.D., M. Schuman, and P.C. Scorup. 1985. Range survey of the Seward Peninsula reindeer ranges, Alaska. US Department of Agriculture, Soil Conservation Service.
United States Department of Agriculture, Natural Resources Conservation Service. 2022. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296.
Western Regional Climate Center. 2021. Climate of Alaska. Retrieved from https://wrcc.dri.edu/Climate/narrative_ak.php. Accessed April 9, 2021.Contributors
Phil Barber
Blaine Spellman
Marji Patz
Steph Schmit
Karin SonnenApproval
Blaine Spellman, 5/29/2025
Acknowledgments
The described soil – ecological site correlations described in this document were reviewed during a February 2024 Provisional Ecological Site workshop in Wasilla, AK. Many thanks are given to the NRCS staff who have provided feedback regarding the MLRA 241X ecological site key and ESDs delivered under the PES national initiative. This ecological site description (ESD) fulfills the requirements of the Provisional Ecological Site (PES) national initiative. This ESD is published to fit current site-soil correlations as they are currently mapped and understood. Further data collection may provide the information to update this ESD from the provisional level to the approved level.
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 10/08/2026 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):
-
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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PrintThe Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.
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