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Ecological site R241XY119AK

Alpine Scrub-Tussock Frozen Silty Slopes

Last updated: 5/29/2025
Accessed: 10/09/2026

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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): 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:
Open low scrub (II.C.2 - level III) / Mixed shrub-sedge tussock tundra (II.C.2.a – level IV)
(Viereck et al., 1992)

BioPhysical Settings: 6816941 – Alaska Arctic Tussock Tundra – Frequent Fire
(LANDFIRE, 2009)

Seward Rangesites
42B – Low Shrub - Cottongrass
(SCS, 1984; Swanson et al., 1985)

Ecological site concept

Ecological Site characteristics:
• Occurs in the alpine on mountain slopes at elevations typically above…
• Soils are frozen and wet, Histoturbels. Permafrost perches water at very shallow depths resulting in very poorly drained soils.
• These soils pond frequently for long durations of time.
• The reference plant community is an open low scrubland with abundant sedge tussock cover.
• Fire is a disturbance resulting in one additional plant community in the reference state.

Associated sites

R241XY111AK	Alpine Sedge-Scrub Frozen Loamy Slopes Soils associated with this ecological site do not pond and abundant tussock cover is absent.
R241XY117AK	Alpine Dwarf Scrub Gravelly Summits R241XY117AK describes a dwarf scrubland on exposed upper mountain slopes. Ponding does not occur
R241XY118AK	Arctic Tall Scrub Loamy Slopes R241XY118AK occurs downslope of site 119 and is associated with tall scrublands composed of willow and alder.

R241XY111AK

Alpine Sedge-Scrub Frozen Loamy Slopes

Soils associated with this ecological site do not pond and abundant tussock cover is absent.

R241XY117AK

Alpine Dwarf Scrub Gravelly Summits

R241XY117AK describes a dwarf scrubland on exposed upper mountain slopes. Ponding does not occur

R241XY118AK

Arctic Tall Scrub Loamy Slopes

R241XY118AK occurs downslope of site 119 and is associated with tall scrublands composed of willow and alder.

Similar sites

R241XY111AK	Alpine Sedge-Scrub Frozen Loamy Slopes R241XY111AK occurs on frozen slopes on upper mountain slopes. R241XY111AK does not generally burn and does not support the tussocks found in R241XY119AK.
R241XY131AK	Arctic Tussock Loamy Frozen Slopes R241Xy131AK describes the tussock-scrub community on lower elevation slopes of hills and plains. It can support repeating scrubland mounds that are not found in this ecological site.

R241XY111AK

Alpine Sedge-Scrub Frozen Loamy Slopes

R241XY111AK occurs on frozen slopes on upper mountain slopes. R241XY111AK does not generally burn and does not support the tussocks found in R241XY119AK.

R241XY131AK

Arctic Tussock Loamy Frozen Slopes

R241Xy131AK describes the tussock-scrub community on lower elevation slopes of hills and plains. It can support repeating scrubland mounds that are not found in this ecological site.

Table 1. Dominant plant species

Tree	Not specified
Shrub	(1) Ledum palustre ssp. decumbens
Herbaceous	(1) Eriophorum vaginatum (2) Carex bigelowii

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Physiographic features

This ecological site occurs on mountain slopes in the alpine. Elevation ranges from 1,000 to 2,500 feet above sea level, though it may be found at much lower and higher elevations if conditions are ideal. Slope gradients are nearly level to strongly slopes (0 to 12 percent) and this site occurs on all aspects. Flooding does not occur. Ponding occurs frequently for long duration of time. Ponding depth ranges up to 24 inches depth in areas between tussocks. A water table is present at the surface throughout the year.

Table 2. Representative physiographic features

Slope shape across	(1) Linear
Slope shape up-down	(1) Linear
Landforms	(1) Mountains > Mountain (2) Mountains > Mountain > Hummock (3) Hills > Hill
Runoff class	Negligible to medium
Flooding frequency	None
Ponding duration	Long (7 to 30 days)
Ponding frequency	Frequent
Elevation	1000 – 2500 ft
Slope	0 – 12 %
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	Not specified
Flooding frequency	Not specified
Ponding duration	Not specified
Ponding frequency	Not specified
Elevation	500 – 4000 ft
Slope	0 %
Ponding depth	0 in
Water table depth	0 in

Climatic features

The alpine climate of this ecological site includes short, cool growing seasons and long, cold winters. Mean annual temperature ranges from 17 to 29 degrees Fahrenheit, with temperatures typically below freezing from October through April. 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)	50-80 days
Freeze-free period (characteristic range)	40-70 days
Precipitation total (characteristic range)	10-20 in
Frost-free period (actual range)	40-80 days
Freeze-free period (actual range)	30-70 days
Precipitation total (actual range)	10-30 in
Frost-free period (average)	60 days
Freeze-free period (average)	50 days
Precipitation total (average)	20 in

Characteristic range

Actual range

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Figure 1. Monthly precipitation range

Characteristic range

Actual range

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Figure 2. Monthly minimum temperature range

Characteristic range

Actual range

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Figure 3. Monthly maximum temperature range

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Figure 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 associated with or influenced by discrete water features. Precipitation and throughflow are the main water sources. Evidence of ground discharge may be present. Surface runoff and throughflow contribute water to downslope ecological sites.

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 water table is present throughout the year.

Soil features

Soils are wet, highly organic, frozen, cryoturbated Histoturbels (Soil Survey Staff, 2013). Soils formed in silty parent material like loess that is cryoturbated. Rock fragments are absent from the soil surface and subsurface. The saturated organic cap is 12 inches or more thick. While soils are very deep, permafrost is a root restrictive layer that perches water and occurs at moderate depth. These very deep and silty soils have high available water capacity. Soils are considered very poorly drained and are wet throughout the growing season. Soil pH is very strongly to moderately acidic.

Table 5. Representative soil features

Parent material	(1) Organic material (2) Cryoturbate (3) Eolian deposits
Surface texture	(1) Peat
Drainage class	Very poorly drained
Permeability class	Moderate
Depth to restrictive layer	20 – 32 in
Soil depth	60 – 0 in
Surface fragment cover <=3"	Not specified
Surface fragment cover >3"	Not specified
Available water capacity (0-40in)	9.2 – 13.1 in
Soil reaction (1:1 water) (0-10in)	Not specified
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 – 32 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 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. Limited warmth during the short growing season inhibits trees from occurring. Both lowland and upland landscapes are a mix of shrubs, graminoids, forbs, mosses, and lichens. Cold temperatures limit the vertical structure of shrubs and other functional groups (Raynolds et al., 2006). Cold temperatures along with adequate organic insulation can lead to near-surface permafrost, which can affect hydrology and vegetation.

This ecological site describes alpine tussock-scrub communities. Cold temperatures and a thick, insulating organic horizon at the soil surface result in moderately deep permafrost. Permafrost perches water and supports a community of hydrophytic vegetation. The reference plant community is an open low scrubland. Scrubs are primarily evergreen species. Facultative to obligate wetland graminoids including tussock-forming cottongrasses and sedges are present throughout.

Fire is the major disturbance on this ecological site. It is responsible for a unique post-disturbance community. Post-fire community composition depends on fire factors such as frequency and severity (Innes, 2013). 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. As the organic horizon reforms, permafrost rises, the soil becomes wetter, and the community shifts back to community 1.1.

Cryoturbated or frost-heaved earth hummocks may be present on this site. The causes that form earth hummocks are poorly understood, but site factors may include available water, soil temperatures, and slope.

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 text

Ecosystem states

1. Reference State

State 1 submodel, plant communities

1.1. Ledum palustre ssp. decumbens / Eriophorum vaginatum - Carex bigelowii

1.2. Eriophorum vaginatum - Carex bigelowii / Chamerion angustifolium

1.1A	-	Fire
1.2A	-	Fire recovery, 10-15 years post-fire

State 1
Reference State

This 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 supported by 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

marsh Labrador tea (Ledum palustre ssp. decumbens), shrub
lingonberry (Vaccinium vitis-idaea), shrub
dwarf birch (Betula nana), shrub
tussock cottongrass (Eriophorum vaginatum), grass
Bigelow's sedge (Carex bigelowii), grass

Community 1.1
Ledum palustre ssp. decumbens / Eriophorum vaginatum - Carex bigelowii

This 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.

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. Lichen and moss biomass data below refers to total biomass, while vascular plants biomass refers to annual production.

Dominant plant species

marsh Labrador tea (Ledum palustre ssp. decumbens), shrub
lingonberry (Vaccinium vitis-idaea), shrub
dwarf birch (Betula nana), shrub
bog blueberry (Vaccinium uliginosum), shrub
cloudberry (Rubus chamaemorus), shrub
tussock cottongrass (Eriophorum vaginatum), grass
Bigelow's sedge (Carex bigelowii), grass

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	1000	1420	3000
Shrub/Vine	320	350	375
Grass/Grasslike	255	280	300
Lichen	80	110	140
Forb	65	70	75
Total	1720	2230	3890

Table 8. Ground cover

Tree foliar cover	0%
Shrub/vine/liana foliar cover	30-50%
Grass/grasslike foliar cover	30-50%
Forb foliar cover	0-10%
Non-vascular plants	20-50%
Biological crusts	0%
Litter	30-50%
Surface fragments >0.25" and <=3"	0%
Surface fragments >3"	0%
Bedrock	0-10%
Water	0-10%
Bare ground	0-10%

Community 1.2
Eriophorum vaginatum - Carex bigelowii / Chamerion angustifolium

This 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. Lichen and moss biomass data below refers to total biomass, while vascular plants biomass refers to annual production.

Dominant plant species

tussock cottongrass (Eriophorum vaginatum), grass
Bigelow's sedge (Carex bigelowii), grass
bluejoint (Calamagrostis canadensis), grass
polargrass (Arctagrostis), grass
fireweed (Chamerion angustifolium), other herbaceous

Pathway 1.1A
Community 1.1 to 1.2

Fire is the major disturbance on this ecological 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 quick growing forbs and graminoids colonize and intermix with surviving plants.

Key drivers

Fire

Pathway 1.2A
Community 1.2 to 1.1

Fire 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.

Additional community tables

Table 9. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)
Undefined
1	Vascular Plants			640–750
Shrub/Vine
2	Shrub			320–375
	marsh Labrador tea	LEPAD	Ledum palustre ssp. decumbens	150–175	–
	lingonberry	VAVI	Vaccinium vitis-idaea	80–95	–
	dwarf birch	BENA	Betula nana	50–60	–
	bog blueberry	VAUL	Vaccinium uliginosum	40–45	–
	black crowberry	EMNI	Empetrum nigrum	15	–
	red fruit bearberry	ARRU	Arctostaphylos rubra	10–11	–
	Alaska bog willow	SAFU	Salix fuscescens	3	–
	alpine bearberry	ARAL2	Arctostaphylos alpina	0–1	–
Grass/Grasslike
3	Grass/Grasslike			255–300
	tussock cottongrass	ERVA4	Eriophorum vaginatum	160–190	–
	Bigelow's sedge	CABI5	Carex bigelowii	65–75	–
	cottongrass	ERIOP	Eriophorum	9–11	–
	water sedge	CAAQ	Carex aquatilis	4–5	–
	white cottongrass	ERSC2	Eriophorum scheuchzeri	3	–
	woodrush	LUZUL	Luzula	0–1	–
	tall cottongrass	ERAN6	Eriophorum angustifolium	1	–
	bluejoint	CACA4	Calamagrostis canadensis	0–1	–
	sedge	CAREX	Carex	0–1	–
Forb
4	Forb			65–75
	cloudberry	RUCH	Rubus chamaemorus	55–65	–
Lichen
5	Live lichen biomass			80–140
		FLCU	Flavocetraria cucullata	20–35	–
	greygreen reindeer lichen	CLRA60	Cladina rangiferina	20–30	–
	cup lichen	CLADO3	Cladonia	15–25	–
	reindeer lichen	CLAR60	Cladina arbuscula	15–25	–
	island cetraria lichen	CEIS60	Cetraria islandica	9–16	–
	cup lichen	CLGR13	Cladonia gracilis	2–4	–
	whiteworm lichen	THSU60	Thamnolia subuliformis	2–3	–
	cup lichen	CLUN60	Cladonia uncialis	1–2	–
	reindeer lichen	CLMI60	Cladina mitis	0–1	–
Moss
6	Moss/Clubmoss biomass			1000–3000

Table 10. Community 1.2 plant community composition

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

Interpretations

Animal community

This site has seasonally abundant food resources in the form of sedges, forbs, and dwarf shrubs, but offers cover only to small mammals and ground-nesting birds. As in other open types, wildlife use of this site changes dramatically with the seasons. In spring and early summer, grizzly bear, caribou, and several nesting birds, including lapland longspurs, pintail ducks, willow ptarmigan, yellow wagtails, and dunlin, arrive to take advantage of emerging sedges and forbs. These seasonal visitors join year-round residents, such as lemmings and voles, emerging from the subnivean and underground burrows and trails in which they have overwintered. As dwarf shrubs begin to leaf out, moose join the caribou in taking advantage of emerging deciduous browse. Increasing numbers of insects provide abundant food for nesting birds and for shrews, but they may drive caribou to insect-free sites on windy uplands or coastal beaches. Populations of small rodents, increased by litters of young, provide food for wide-ranging predators such as red fox, wolverine, wolf, raptors, and jaegers, most of which are rearing their own young in more sheltered sites. In the fall, seeds and berries are food for fledgling birds and breeding adults preparing for southward migrations, as well as rodents preparing for winter. Grizzlies return from salmon streams to join in harvesting berries. As winter returns, most birds and large mammals depart, leaving only those mammals small enough to utilize the protection found under snow or in the ground, or hardy and wide-ranging enough to hunt in these snowy barrens.

Recreational uses

This site is used for snowmobiling, dogsledding, hunting (Canada goose, wolf), and trapping red fox. It has potential for sightseeing, panning for gold, photography, fishing and bird watching since the general area includes canyons, rock formations, lakes, lava beds and hot mineral springs. Blueberry cloudberry and low bush cranberry can be found by the berry picker on this site.

Wood products

No wood products available from this site.

Other products

Grazing

This site is a fair spring and summer range and a poor fall range. Sedges and grasses provide high levels of digestible protein during the growing season. Browse species such as northern labrador tea (Ledum palustre ssp. decumbens), can provide a fair amount of forage value during late summer and fall.

Other information

These interpretive narratives were developed for USDA reports of range sites on the Seward Peninsula and appear here as written when originally published (SCS, 1984; Swanson et al., 1985).

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, 2009) Ecological site descriptions of the Seward Peninsula (SCS, 1984). Range survey of the Seward Peninsula reindeer ranges (Swanson et al., 1985)

References

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

Brinson, M.M. 1993. A hydrogeomorphic classification for wetlands. Wetlands Research Program, US Army Corp of Engineers. Technical Report WRP-DE-4.

Innes, R.J. 2013. Fire regimes of Alaskan tundra communities. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: www.fs.fed.us/database/feis/fire_regimes/AK_tundra/all.html [2025, February 14].

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 6816941 – Alaska Arctic Tussock Tundra – Frequent 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 24, 2024

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.

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.

United States Department of Agriculture, Natural Resources Conservation Service. 2008. Hydrogeomorphic Wetland Classification System: an overview and modification to better meet the needs of the Natural Resources Conservation Service. Technical Note No 190-8-76.

Western Regional Climate Center. 2021. Climate of Alaska. Retrieved from https://wrcc.dri.edu/Climate/narrative_ak.php. Accessed November 15, 2024.

Contributors

Phil Barber
Blaine Spellman
Marji Patz
Steph Schmit
Karin Sonnen
Abigail Clapp

Approval

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	10/09/2026
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:

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Ecological site R241XY119AK

Alpine Scrub-Tussock Frozen Silty Slopes

Last updated: 5/29/2025 Accessed: 10/09/2026

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Table 1. Dominant plant species

Natural Resources
Conservation Service

Last updated: 5/29/2025
Accessed: 10/09/2026