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Ecological site VX226X00A102

Aleutian Dwarf Scrub Volcanics

Last updated: 6/14/2025
Accessed: 12/05/2025

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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): 226X–Aleutian Islands-Western Alaska Peninsula

MLRA 226X is the only MLRA in the Aleutian Alaska Region. It makes up about 5,190 square miles (13,450 square kilometers). The chain of islands includes west of Unimak Island to Attu Island, the Pribilof Islands, and the Sanak Islands. Characteristics and weather patterns of the far western end of the Alaska Peninsula is being included in this MLRA. It is bordered on the south by the Pacific Ocean and on the north by the Bering Sea (the Pribilof Islands are bordered on all sides by the Bering Sea). The coastline is complex, with many prominent headlands, sea cliffs, and narrow, steep-walled bays. Elevation ranges from sea level to more than 4,000 feet (1,220 meters) on many of the islands. Islands drain into the North Pacific and the Bering Sea by numerous short, steep-gradient rivers and streams. Lakes make up less than 2 percent of the area.

Geology
This MLRA includes more than 50 volcanoes, with an estimated 27 with activity since the 1950s. Volcanic rocks and unconsolidated deposits from the Quaternary and Tertiary period overlie a submarine ridge of Tertiary sedimentary rocks. Glacial ice once covered the eastern part of the area to approximately Umnak Island. West of Umnak, only the upper elevations were glaciated. Glaciers account for only 1.5 percent, occurring on the highest volcanoes. Volcanic activity has mantled most of the area with thick deposits of silty volcanic ash, sandy and gravelly cinders, and volcanic rubble. Lower elevations have areas of glacial influenced landforms. Recent coastal and fluvial deposits occur in scattered areas along the coast and on flood plains.

Water
Precipitation is adequate for crops generally. Permanent mountain streams feed most of the MLRA. The surface water generally is suitable for all uses. The ground water used in this MLRA is primarily from unconsolidated river valley sediments and bedrock aquifers. Iron is commonly high in the ground water, causing staining and precipitate in pipes. Wells are shallow with constant recharge by freshwater (rainfall and runoff); and are highly susceptible to contamination from runoff. The intrusion of seawater can be a problem along the coast.

Soils
The dominant soil orders in this MLRA are Andisols and Histosols. Miscellaneous areas (cinder land, rock outcrop, water, riverwash, and beaches) make up about 45 percent of this MLRA. The main soils are: Cryofibrists are poorly drained or very poorly drained and formed in thick deposits of organic material, along the margins of streams and lakeshores.
Tsammana series, Andic Dystrocryepts, Aquandic Dystrocryepts and Vitrandic Dystrocryepts are coarse marine sediments underlain by volcanic deposits. Zolotoi series and other Haplocryands are shallow to deep, well drained to excessively drained, and formed in moderately thick or thick deposits of silty to sandy volcanic ash and coarse sandy to gravelly cinders over basalt bedrock. Polovina series and other Vitricryands are shallow to deep, well drained to excessively drained, and formed in moderately thick or thick deposits of silty to sandy volcanic ash and coarse sandy to gravelly cinders over basalt bedrock.

Biological Resources
Higher elevation vegetation consists of a mosaic of dwarf shrub scrub and lower elevations are wet and dry grasslands. Peatland vegetation consists of low ericaceous shrub scrub. No naturally occurring forests occur on the islands. Aleutian shield fern, Steller sea lion, and the Aleutian Canada goose are currently listed as threatened or endangered. The area is an important winter habitat and nesting habitat for waterfowl and a variety of other birds. Some of the eastern islands support small herds of caribou.

Land Use
Commercial fishing is the primary enterprise, with fur seal harvesting for pelts and meat, Reindeer herding, and small cattle herds. Subsistence hunting, fishing, and gathering are critical for local residents. The major resource concerns are water erosion and mass wasting of soils. Overgrazing by reindeer has impacted vegetation and introduction of rats, dogs, cats, and foxes has severely impacted the nesting bird populations.

LRU notes

MLRA 226X, although very size-limited, contains a very complex and dynamic of weather patterns driven by the Pacific air currents on the southern exposure of the islands, and the Bering Sea to the north. The mixing or colliding of these two systems, creates very dramatic and intense storm systems that batter the islands. Weather variables from the Pacific to the Bering Sea, extent from west to east, as well as the extreme elevational gradient moving from sea level to Alpine life zone lends to a community diversity that is difficult to describe across an MLRA extent. Land Resource Units (LRUs) will need to be developed for this MLRA, as more extensive soils survey mapping is completed.

This area supports two life zones defined by the physiological limits of plant communities along an elevational gradient: arctic and alpine. In this MLRA, the arctic life zone occurs below 500 feet elevation on average (Swanson et al. 1986) and is the elevational band where lowland vegetation dominates. For this MLRA, certain vascular plant species are common in the lowlands and much less common in the alpine (i.e. Salix pulchra, Salix fuscescens, Betula nana, Ledum palustre ssp. decumbens, and Calamagrostis canadensis). Above the arctic band of elevation, alpine vegetation dominates. For this MLRA, certain vascular plant and lichen species are common in the alpine and much less common in the lowlands (i.e. Dryas octopetala ssp. octopetala, Diapensia lapponica var. obovata, Anthoxanthum monticola ssp. alpinum, Oxytropis nigrescens, Alectoria ochroleuca, and Flavocetraria nivalis). The lowlands also have much higher potential for lichen biomass yields compared to the alpine (Swanson et al. 1986). The transition between arctic and alpine vegetation can occur within a range of elevations, and is highly dependent on latitude, slope, aspect, and shading from adjacent mountains.

Classification relationships

Alaska-Aleutian province of the Pacific Mountain System.

USFS Description of Ecoregions of the United States
100 Polar Domain
120 Tundra Division
126 Bering Tundra (Southern) Province
M120 Tundra Division - Mountain Province
M127 Aleutian Oceanic Meadow--Heath Province
(USFS, 1994)

United States National Vegetation Classification
C04. Polar & High Montane Scrub, Grassland & Barrens Class
S12. Temperate to Polar Alpine & Tundra Vegetation Subclass
F031. Polar Tundra & Barrens Formation
D044. Arctic Tundra & Barrens Division
(USNVC, 2019)

LandFire BpS Model/Description Version: Nov. 2024
- 17200 Aleutian Ericaceous Dwarf-shrubland, Heath, and Fell-field
(Landfire, 2009)

Ecological site concept

- Soils that are the remnants of or recent deposits of volcanic activity.
- Soils include volcanic cones and lava flow fields.
- Soils typically contact bedrock at moderate to deep depth
- No water table is associated with this site
- Ponding is rare to never, and moisture is related to slow snow melt
- Rock fragments in the profile and stone/boulder fields may be prevalent.
- Vegetation is somewhat sparse but is grazable tundra.
- Site is classified as an Empetrum mat with abundant lichen. Reindeer grazing is prominent on these sites, which impacts the scrub cover and lichen composition.

Associated sites

VX226X00A113	Aleutian Shrub Meadow Ashy Slopes The volcanic ashy slopes are common below or intermixed with the volcanic landforms of the cones and lava flows. Vegetation provides greater cover, and has higher rate of grasses, forbs and dwarf and short shrubs, and less of the mat forming community.

VX226X00A113

Aleutian Shrub Meadow Ashy Slopes

The volcanic ashy slopes are common below or intermixed with the volcanic landforms of the cones and lava flows. Vegetation provides greater cover, and has higher rate of grasses, forbs and dwarf and short shrubs, and less of the mat forming community.

Similar sites

VX226X00A109	Aleutian Shallow Cliffs and Slopes The shallow to bedrock ecological site will commonly have similar tundra characteristics and sparse vegetation seen with the volcanic landforms. Sedges and grasses with dwarf willows and forbs are common on the Shallow to Bedrock Aleutians Site.

VX226X00A109

Aleutian Shallow Cliffs and Slopes

The shallow to bedrock ecological site will commonly have similar tundra characteristics and sparse vegetation seen with the volcanic landforms. Sedges and grasses with dwarf willows and forbs are common on the Shallow to Bedrock Aleutians Site.

Table 1. Dominant plant species

Tree	Not specified
Shrub	(1) Empetrum nigrum (2) Cassiope lycopodioides
Herbaceous	(1) Lichen (2) Carex

Legacy ID

R226XY102AK

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Physiographic features

. Volcanic activity mantled most of the area with thick deposits of silty volcanic ash, sandy and gravelly cinders, and volcanic rubble.
- Elevation ranges from 200 to more than 3,800 feet (1,220 meters).
-A large portion of the higher elevations (greater than approximately 2,500 feet) are steep, raw volcanic cinder, lava flow, and rock faces.
- Heavy fog and storm intensity with the volcanic soils influences vegetation more than the elevational gradient generally does.
- lava flow fields and volcanic cones slopes range from 2 to 55 percent. Slopes above 30 percent, generally, are sparsely populated and are captured as miscellaneous areas.
- Depressions as well as snow bed areas are common.

Table 2. Representative physiographic features

Landforms	(1) Island > Volcanic cone (2) Lava flow (3) Depression
Runoff class	Low to high
Flooding frequency	None
Ponding frequency	None
Elevation	210 – 3,840 ft
Slope	2 – 55%
Water table depth	60 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 frequency	None to rare
Elevation	20 – 7,040 ft
Slope	70%
Water table depth	Not specified

Climatic features

The climate is similar to that on the arctic coastal plain, except Islands are impacted by the tides, air movement, and storms influenced by the Pacific Ocean and Bering Sea, and really no inland influence. Winters are less severe than those on the coastal plain, with temperature ranges of 18 to 27 degrees F (10 to 15C), as compared to a 54 degrees F (30C) range on the coastal plain. The climate is characterized by fog and rain, with the amount of precipitation varying little from month to month. Annual precipitation varies from 21 in (530 mm) to more than 78 in (2,000 mm) across all islands. The higher elevations average 46 to 58 inches per year, with smaller islands receiving less precipitation than larger islands. Winds are often severe on the islands. Pacific Ocean water moving northward through the straits between the islands produces complex mixing with Bering Sea water, including upwelling. The Pribilof Islands in the Bering Sea are the southern limit of the arctic ice pack in winter (USDA-NRCS 2022). Weather information below is captured by climate stations located at Dutch Harbor and Cold Bay. The location of these stations represents only a small segment of the dynamic climate across this chain of islands.

Table 4. Representative climatic features

Frost-free period (characteristic range)	78-92 days
Freeze-free period (characteristic range)	122-136 days
Precipitation total (characteristic range)	46-58 in
Frost-free period (actual range)	75-95 days
Freeze-free period (actual range)	119-139 days
Precipitation total (actual range)	43-61 in
Frost-free period (average)	85 days
Freeze-free period (average)	129 days
Precipitation total (average)	52 in

Characteristic range

Actual range

Bar

Line

Figure 1. Monthly precipitation range

Characteristic range

Actual range

Bar

Line

Figure 2. Monthly minimum temperature range

Characteristic range

Actual range

Bar

Line

Figure 3. Monthly maximum temperature range

Bar

Line

Figure 4. Monthly average minimum and maximum temperature

Figure 5. Annual precipitation pattern

Figure 6. Annual average temperature pattern

Climate stations used

(1) DUTCH HARBOR [USC00502587], Unalaska, AK
(2) COLD BAY AP [USW00025624], Cold Bay, AK

Influencing water features

No water table is associated with these volcanic landforms. Runoff from this site does feed into the aquifers and streams influencing lower elevation landforms.

Wetland description

Depressions across the lava flow, may pond water for short periods, and may have some wetland characteristics. But these are small in comparison to the overall landscape and are not classified in the current literature as wetlands.

Soil features

The dominant soil order in this ecological site are Andisols. The main soils in this ecological site are Haplocryands and Vitricryands that are typically moderately deep to deep to bedrock, are well drained, and formed in volcanic ash and/or cinders over basalt or sedimentary bedrock. Areas within depressions and at the base of volcanic cones may have soils that are moderately deep formed in coarse-loamy colluvium over residuum.

Table 5. Representative soil features

Parent material	(1) Colluvium – basalt (2) Cinders (3) Volcanic ash (4) Eolian deposits – basalt (5) Scoria (6) Tephra
Surface texture	(1) Very stony, medial silt loam (2) Gravelly, medial loam (3) Extremely gravelly silt loam
Family particle size	(1) Cindery (2) Medial-skeletal
Drainage class	Well drained
Permeability class	Moderately slow to moderately rapid
Depth to restrictive layer	35 – 51 in
Soil depth	35 – 51 in
Surface fragment cover <=3"	5%
Surface fragment cover >3"	5%
Available water capacity (0-40in)	2.4 – 5.9 in
Soil reaction (1:1 water) (0-40in)	4.2 – 6.5
Subsurface fragment volume <=3" (0-60in)	3 – 45%
Subsurface fragment volume >3" (0-60in)	2 – 33%

Table 6. Representative soil features (actual values)

Drainage class	Not specified
Permeability class	Not specified
Depth to restrictive layer	10 – 60 in
Soil depth	10 – 60 in
Surface fragment cover <=3"	Not specified
Surface fragment cover >3"	Not specified
Available water capacity (0-40in)	Not specified
Soil reaction (1:1 water) (0-40in)	Not specified
Subsurface fragment volume <=3" (0-60in)	Not specified
Subsurface fragment volume >3" (0-60in)	Not specified

Ecological dynamics

The climate of the Aleutian Islands is a harsh climate to survive. The islands experience strong winds and persistent fog. Heavy precipitation events with fairly uniform temperatures throughout the year limit the type of vegetation that will grow. The ash and weather basalt soils also provide a coarse and harsh environment for plants. The soils have limited moisture holding capacity and are flushed of nutrients, outside of high iron levels and low pHs (lot to moderate acidic soils)

Trees are absent from the Aleutian Province in response to the cool average temperatures. Some stunted or dwarf willows occur across the islands, and a few coniferous trees remain as remnants of the Russian period. A little higher up, several types of heath cover vast areas. The vegetation at high elevations and exposed sites consists of dwarf scrub dominated by crowberry or willows. Dry sites are dominated by hairgrasses. Low scrub bogs are dominated by a variety of plants in the heath family, as well as sedges, sphagnum moss, and feathermosses.

Only a limited amount of vegetative analysis has been completed across the island chain. Research is predominantly limited to Amchitka, Buldir, and a few other accessible islands.

Amundsen (1972) describes 10 plant community types on Amchitka; a more detailed description of the vegetation was given by Shacklette and others (1969); they listed 15 habitats with 41 plant communities by using the system presented by Fosberg (1967). More recently, Byrd (1984) describes the vegetation on Buldir Island. Virtually the only general descriptions of vegetation for the entire Aleutian Island chain come from the work of Hultén (1960), Tatewaki and Kobayashi (1934), and Bank (1951).

The volcanic cones and associated lava fields and depressions are described best by the Block Fields and Scree Barren Fellfield habitats with isolated areas of Snow bed habitats. Being at slightly higher elevation, and variable slopes, these volcanic soils are exposed to wind, more potential frost, and snow. The area is also common to frost scares and solifluction.

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

2. Continuously Grazed State

3. Active Volcanic Development

T1a	-	Introduction of Grazing
T3A	-	Time

CP3a	-	Time, Weathering

State 1
Reference State

The Reference State (State 1) is a complex of slopes, depressions, and plateaus that are volcanic cones and lava flows. This complex includes the scars from frost and solifluction, that have created barren soil patches with sparse vegetative cover. The prominent cover is a scrub matt with dwarf shrubs, herbaceous forbs and intermixed sedge and grasses. Mosses and lichens are an important component of this community. Overall ground cover of vegetation averages 20 to 40 percent. The ground not under vegetation has a pebbly/cobbly/stoney surface cover. Within this complex, depressions and protected pockets are wet from snow bed melt and precipitation runoff, creating small meadow areas dominated with willows and increased sedges and grasses. This complex of sites is very inter-related and although uniquely different, are difficult to separate into unique ecological sites. With increased data collection and smaller scaled soils maps, this ecological complex will be re-evaluated.

Dominant plant species

arctic willow (Salix arctica), shrub
black crowberry (Empetrum nigrum), shrub
least willow (Salix rotundifolia), shrub
Alaska curved woodrush (Luzula arcuata ssp. unalaschcensis), grass
wideleaf arctic woodrush (Luzula arctica ssp. latifolia), grass
coiled sedge (Carex circinata), grass
Howell's dicranum moss (Dicranum howellii), other herbaceous
witch's hair lichen (Alectoria), other herbaceous
mountain harebell (Campanula lasiocarpa), other herbaceous
reindeer lichen (Cladina), other herbaceous

Community 1.1
Crowberry-Heath/Lichen

The reference community (1.1 Crowberry-Heath/Lichen) is a scrub heath tundra community with no overstory. The community is highly variable from island to island due to age of volcanic activity, natural disturbances, exposure, and more. The general species compositions provided are relative to Amchitka, Buldir, Adak, and Umnak Islands. The lower and mid-elevation slopes, windswept ridges and plateaus are characterized by a very short stature community (less than 2 to 3 inches). Willows (Salix spp.), clubmoss mountain heather (Cassiope lycopodioides) and other middle story species are recorded. The ground story is crowberry (Empetrum nigrum) and then mostly bare or covered by gravel. Mosses are the most dominant species, and lichens occur in every plot. Lower elevations in protected areas, lower sloping, older volcanic deposits (more degraded) support a more consistent mat of vegetation with only small areas of frost action. These areas are dominated by crowberry (Empetrum nigrum) in the lower story, and red fescue (Festuca rubra) can be prominent in the middle story. Spreading woodfern (Dryopteris expansa), seacoast angelica (Angelica lucida), boreal yarrow (Achillea borealis), and Hornemann's willowherb (Epilobium behringianum) are found frequently, but in low cover. The ground story has a mix of Mosses and other pincushion species. Species sch as starworts (Stellaria spp.), umbel bittercress (Cardamine umbellata), liverworts, and bract saxifrage (Saxifraga bracteata) are all important. As move into higher and steeper slopes, soil movement (solifluction) and frost action increases creating large strips of bare soil alternating with tundra mat. The dominant species are black crowberry (Empetrum nigrum), stoloniferous pussytoes (Antennaria dioica), Bering's tufted hairgrass (Deschampsia beringensis), and lichens. Other shrubs include least willow (Salix rotundifolia) and clubmoss mountain heather (Cassiope lycopodioides). Herbaceous species include mountain harebell (Campanula lasiocarpa), alpine bistort (Polygonum viviparum), umbell bittercress (Cardamine umbellata), wedgeleaf primrose (Primula cuneifolia), weaselsnout (Lagotis glauca), curved woodrush (Luzula arcuata), and Wahlenberg's oncophorus moss (Oncophorus wahlenbergii). The highest most areas are covered with boulder fields in which only a few heath mats occur. These mats are comprised of crowberry (Empetrum), willow (Salix), rhododendron, blueberry (Vaccinium), and azalea (Loiseleuria).

Dominant plant species

black crowberry (Empetrum nigrum), shrub
clubmoss mountain heather (Cassiope lycopodioides), shrub
willow (Salix), shrub
red fescue (Festuca rubra), grass
Bering's tufted hairgrass (Deschampsia beringensis), grass
spreading woodfern (Dryopteris expansa), other herbaceous
seacoast angelica (Angelica lucida), other herbaceous
boreal yarrow (Achillea millefolium var. borealis), other herbaceous

Figure 7. Annual production by plant type (representative values) or group (midpoint values)

Community 1.2
Moss/Willow/Sedge Snow-beds

Across the narrow bands of alpine tundra in the volcanic fields and slopes of the volcanic cones, occur areas of wind break and protection. The reduced wind creates areas of snow catch. These snow beds will occur in small pockets, swales along the ridges and in small depressions across the landscape. At the higher elevations and on north slope faces snow can persist into mid-June. Wet meadow depressions form where snow melt water saturates the ground. Characteristic species include sedges, alpine silverwort (Anthelia julacea), floppy earwort (Scapania paludosa), yellow marsh saxifrage (Saxifraga hirculus), and fireleaf leptarrhena (Leptarrhena pyrolifolia). On lower lava flow areas, on the edge of the uplands overlooking the valleys, a small patchy Moss-willow-Empetrum Community occurs. There is no overstory, and only a thinly vegetated middle story. The common species are willows (Salix spp.); calthaleaf avens (Geum calthifolium), and coiled sedge (Carex circinata). A thick mat of black crowberry (Empetrum nigrum), mosses, white mountain heather (Cassiope lycopodioides), and other dwarf plants, interspersed with bare areas.

Dominant plant species

arctic willow (Salix arctica), shrub
least willow (Salix rotundifolia), shrub
black crowberry (Empetrum nigrum), shrub
clubmoss mountain heather (Cassiope lycopodioides), shrub
coiled sedge (Carex circinata), grass
(Anthelia julacea), other herbaceous
(Scapania paludosa), other herbaceous
yellow marsh saxifrage (Saxifraga hirculus), other herbaceous
fireleaf leptarrhena (Leptarrhena pyrolifolia), other herbaceous
calthaleaf avens (Geum calthifolium), other herbaceous

State 2
Continuously Grazed State

Caribou and managed herds of reindeer are common to certain Aleutian Islands. Small herds of cattle are also found on some islands. The grazing of these higher land tundra is common during the winter especially but are utilized year-round. The pressure on these tundra communities causes degradation over time, losing desirable lichen cover and other sedge and grass communities, reducing overall cover and vigor of the community. The change in vegetation leads to soil movement by wind and by water movement over the surface.

Dominant plant species

black crowberry (Empetrum nigrum), shrub
rush (Juncus), grass
woodrush (Luzula), grass
draba (Draba), other herbaceous
navel lichen (Umbilicaria), other herbaceous
crabseye lichen (Ochrolechia), other herbaceous
shield lichen (Parmelia), other herbaceous

Community 2.1
Scrub/Lichen Community

With increased pressure with grazing, lichen species shift to a less desirable cover. Reindeer/caribou selectivity in species impact the lichen and scrub species. The community overall decreases in cover and shifts to grasses and sedges. Lichens decrease with a change to undesirable lichen. Grazing specific data for the Aleutian Islands was not located. Once more information is gathered, this State and Community will be updated.

Dominant plant species

black crowberry (Empetrum nigrum), shrub
clubmoss mountain heather (Cassiope lycopodioides), shrub
arctic willow (Salix arctica), shrub
least willow (Salix rotundifolia), shrub
navel lichen (Umbilicaria), other herbaceous
shield lichen (Parmelia), other herbaceous
crabseye lichen (Ochrolechia), other herbaceous

State 3
Active Volcanic Development

The volcanic activity across the Aleutian Islands is still a common occurrence. The successional phases of recovery of the recent deposits of lava and exposed or deposited cinder blocks are a slow but extremely important system within the Aleutian Chain. Although there is very little to no data available on this process from the Aleutians, the State is being captured with preliminary information.

Dominant plant species

black crowberry (Empetrum nigrum), shrub
clubmoss mountain heather (Cassiope lycopodioides), shrub
coiled sedge (Carex circinata), grass
sedge (Carex), grass
woodrush (Luzula), grass
Bering's tufted hairgrass (Deschampsia beringensis), grass
northern bentgrass (Agrostis mertensii), grass
starwort (Stellaria), other herbaceous
Moss (Moss), other herbaceous
Lichen (Lichen), other herbaceous
draba (Draba), other herbaceous
diapensia (Diapensia), other herbaceous

Community 3.1
Early Successional Community

The initial response to volcanic activity recovery is dependent on the soil type there prior to the disturbance, the conditions following the eruption, the type of deposits that are received, and the vegetation that is there prior to. This makes it difficult to classify any one specific community. There is research captured on the Kasatochi Island of the Aleutians, that erupted in 2008. The discovery that many of the pre-eruption plant species were able to maintain or gain dominance if they survive the disturbance. In areas with minimal survival, the primary establishment was found to be fungus, mosses and lichens. (Talbot et al. 2010)

Dominant plant species

andreaea moss (Andreaea), other herbaceous
racomitrium moss (Racomitrium), other herbaceous
schistidium moss (Schistidium), other herbaceous
navel lichen (Umbilicaria), other herbaceous
crabseye lichen (Ochrolechia), other herbaceous
shield lichen (Parmelia), other herbaceous

Community 3.2
Late Successional Community

Late successional recovery is highly variable on the type and extent of the eruption, frequency of disturbance, and the parent material that is available following the eruption. It has been seen to take 120 to 150 years in prime condition to begin to see colonization by late successional plants. But in some areas, it has taken over 2000 years. (Talbot et. al. 2010).

Dominant plant species

black crowberry (Empetrum nigrum), shrub
clubmoss mountain heather (Cassiope lycopodioides), shrub
woodrush (Luzula), grass
rush (Juncus), grass
draba (Draba), other herbaceous
sibbaldia (Sibbaldia), other herbaceous
pincushion plant (Diapensia lapponica), other herbaceous
conostomum moss (Conostomum), other herbaceous
racomitrium moss (Racomitrium), other herbaceous

Pathway CP3a
Community 3.1 to 3.2

Over time, natural weathering and deposition of soils will occur on the volcanic rock surfaces, ash, and cinder. As this abrasive parent material begins to break down and as other soil sources are deposited, primary succession will advance. New primary growth and ongoing weathering, allows for a more developed and prominent community to establish.

Transition T1a
State 1 to 2

Introduced herds of reindeer, cattle and other animals has removed higher levels of desirable species as well as created soil disturbance (compaction and churning by hoof action). Increased human activity also shifts the natural patterns of use placing higher pressure on select locations.

Transition T3A
State 3 to 1

Given time, under the harsh climate conditions, the volcanic deposited lava and materials will weather and begin to form soil. As fractures and sediment deposits accumulate with the weathered rock, plants will begin to colonize. Time required will be highly variable.

Additional community tables

Table 7. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Shrub/Vine
1				–
	black crowberry	EMNI	Empetrum nigrum	–	–
	arctic willow	SAAR27	Salix arctica	–	–
	northern willow	SAAR6	Salix arctophila	–	–
	northern mountain cranberry	VAVIM	Vaccinium vitis-idaea ssp. minus	–	–
	clubmoss mountain heather	CALY4	Cassiope lycopodioides	–	–
	alpine bearberry	ARAL2	Arctostaphylos alpina	–	–
	bog blueberry	VAUL	Vaccinium uliginosum	–	–
	netleaf willow	SARE2	Salix reticulata	–	–
	twinflower	LIBO3	Linnaea borealis	–	–
Grass/Grasslike
1				–
	coiled sedge	CACI5	Carex circinata	–	–
	Lyngbye's sedge	CALY3	Carex lyngbyei	–	–
	manyflower sedge	CAPL6	Carex pluriflora	–	–
	longawn sedge	CAMA11	Carex macrochaeta	–	–
	alpine sweetgrass	ANMO7	Anthoxanthum monticola	–	–
	purple reedgrass	CAPU	Calamagrostis purpurascens	–	–
	sedge	CAREX	Carex	–	–
	wideleaf polargrass	ARLA2	Arctagrostis latifolia	–	–
	common woodrush	LUMU2	Luzula multiflora	–	–
	red fescue	FERU2	Festuca rubra	–	–
	spike trisetum	TRSP2	Trisetum spicatum	–	–
	smallflowered woodrush	LUPA4	Luzula parviflora	–	–
	Bering's tufted hairgrass	DEBE2	Deschampsia beringensis	–	–
Forb
1				–
	seacoast angelica	ANLU	Angelica lucida	–	–
	spreading woodfern	DREX2	Dryopteris expansa	–	–
	woolly lousewort	PELA14	Pedicularis lanata	–	–
	Lapland cornel	COSU4	Cornus suecica	–	–
	boreal draba	DRBO	Draba borealis	–	–
	pygmy pussytoes	ANMO9	Antennaria monocephala	–	–
	narcissus anemone	ANNA	Anemone narcissiflora	–	–
	arctic stitchwort	MIAR3	Minuartia arctica	–	–
	Hornemann's willowherb	EPHOB	Epilobium hornemannii ssp. behringianum	–	–
	calthaleaf avens	GECA6	Geum calthifolium	–	–
	villous cinquefoil	POVI4	Potentilla villosa	–	–
	moss campion	SIAC	Silene acaulis	–	–
	northern starwort	STCA	Stellaria calycantha	–	–
	alpine bistort	POVI3	Polygonum viviparum	–	–
	Nootka lupine	LUNO	Lupinus nootkatensis	–	–
	alpine speedwell	VEAL80	Veronica alpina	–	–
	saxifrage	SAXIF	Saxifraga	–	–
Lichen
1				–
	racomitrium moss	RALA70	Racomitrium lanuginosum	–	–
	running clubmoss	LYCL	Lycopodium clavatum	–	–
	alpine clubmoss	LYAL3	Lycopodium alpinum	–	–
	fir clubmoss	HUSE	Huperzia selago	–	–
	Pacific reindeer lichen	CLPOP	Cladina portentosa ssp. pacifica	–	–
	Liverwort	2LW	Liverwort	–	–
	whiteworm lichen	THAMN3	Thamnolia	–	–

Interpretations

Animal community

The area is an important winter habitat for emperor geese and other waterfowl. It provides nesting habitat for a variety of birds, including green-winged teal, rock sandpiper, whiskered auklet, rock ptarmigan, song sparrow, rosy finch, and winter wren. The introduction of dogs, cats, and foxes has severely reduced the population of ground-nesting birds. Rats, coming from ships, also are a danger to these birds. Some of the eastern islands support small herds of caribou. Overgrazing by reindeer is a local concern. Control of animal numbers and proper herd management help to prevent overgrazing and allow natural restoration of depleted range.

Recreational uses

Tourism and wildland recreation are becoming increasingly important. Subsistence hunting and gathering provide food and a variety of other resources to local residents and are a major component of the local economy.

Wood products

None

Other products

Reindeer herding and small herds of cattle are a commodity and source of subsistence on the islands.

Other information

The major soil resource concerns are water erosion and mass wasting of soils that formed in volcanic ash and cinders, particularly on steep slopes. Minimizing the degree and extent
of surface disturbance during construction helps to control erosion.

Supporting information

Inventory data references

Very limited data is available and resides more on the coastal zone than the higher volcanics. Information used to build this ecological site was obtained from existing land cover and vegetation maps, literature review, and vegetative summaries from partnering agencies.

References

Hansford T. Shacklette, L. W. Durrell, James A. Erdman, John R. Keith, William M. Klein, Hildur Krog, Herman Persson, H. Skuja, and William A. Weber. 1969. Vegetation of Amchitka Island, Aleutian Islands, Alaska. Geological Survey Professional Paper 648. United States Geological Survey, United States Government Printing Office, Washington : 1969.
Swanson, J.D., D. Lehner, J. Zimmerman, and D. Pauling. 1986. Range survey of Nunivak Island, Alaska.

Other references

Landfire National Vegetation Dynamics Models; USGS; http://www.LANDFIRE.gov/index.php, 2009 (Date accessed)

USDA PLANTS Database; http://plants.usda.gov, 2021

USNVC [United States National Vegetation Classification]. 2019. United States National Vegetation Classification Database, V2.03. Federal Geographic Data Committee, Vegetation Subcommittee, Washington DC. USNVC: http://usnvc.org/

AMUNDSEN, C.C. 1972. Amchitka Bioenvironmental Program: Plant ecology of Amchitka Island, Final Report. Batelle, Columbus Laboratories, under AEC Prime, Contract No. AT(26-l)-171. 27 p.

AMUNDSEN, c.c. and E.E.C. CLEBSCH. 1971. Dynamics of the terrestrial ecosystem vegetation of Amchitka Island, Alaska. Bioscience 21:619-623.

AMUNDSEN, C.C. 1977. Terrestrial plant ecology. Pages 203-226 in M.L. Merritt and R.G. Fuller, eds. The environment of Amchitka Island, Alaska. ERDA TID-26712.

Bailey, R.G. [in prep.] Description of the ecoregions of the United States. 2d ed. Misc. Publ. No. 1391 [rev.]. Washington, DC: U.S. Department of Agriculture, Forest Service.
Bailey, Robert G.; Avers, Peter E.; King, Thomas; McNab, W. Henry, eds. 1994. Ecoregions and subregions of the United States (map). Washington, DC: U.S. Geological Survey. Scale 1: 7,500,000; colored. Accompanied by a supplementary table of map unit descriptions compiled and edited by McNab, W. Henry, and Bailey, Robert G. Prepared for the U.S. Department of Agriculture, Forest Service.

BANK, T.B. II. 1951. Botanical and ethnobotanical studies in the Aleutian Islands. I. Aleutian vegetation and Aleut culture. Mich. Acad. Sci., Arts, and Lett. 37:13-30 + 6 plates.

BYRD, G.V. 1984. Vascular vegetation of Buldir Island, Aleutian Islands, Alaska compared to another Aleutian Island. Arctic 37(1):37-48.

Fosberg, Francis Raymond. "Succession and condition of ecosystems." (1967).

Hansford T. Shacklette, L. W. Durrell, James A. Erdman, John R. Keith, William M. Klein, Hildur Krog, Herman Persson, H. Skuja, and William A. Weber Geological Survey Professional Paper 648, United States Geological Survey, United States Government Printing Office, Washington: 1969, 1969

Hultén, Eric (1937) Flora of the Aleutian Islands and westernmost Alaska Peninsula with notes on the flora of Commander islands. Stockholm, Thule. 397 pp. 2nd ed. 1960 (series: Flora et vegetation mundi, vol. 1) Weinheim, Cramer. 376 pp.

SHACKLETTE, H.T., L.W. ERDMAN-J.R. KEITH, W.M. KLEIN, H. KROG, H. PERSSON, H. SKUJA, and W.A. WEBER. 1969. Vegetation of Amchitka Island, Aleutian Islands, Alaska. U.S. Geol. Surv. Prof. Pap. 648. 66p.

TATEWAKI. M. 1963. Phytogeography of. the islands of the north Pacific Ocean. Pages 23-27 in J.L. Gressitt, ed. Pacific Basin Biogeography. lOth Pacific Science Congress. Bishop Museum Press, Honolulu.

TALBOT, S.S., S.L. TALBOT, and L.R. Walker. 2010. Post-eruption legacy effects and their implications for long-term recovery of the vegetation on Kasatochi Island, Alaska. Arctic, Antarctic, and Alpine Research, Vol. 42, No. 3, pp. 285-296

Swanson, D.J., Lehner, D., Zimmerman, J., and Pauling, D. Range survey of Nunivak Island, Alaska, 1986.

WALKER., H. 1945. Plants of the Aleutian Islands. Pages 63-;71 in Collins, H.B., Jr., A.H. Clark, and E.H. Walker, eds. The Aleutian Islands: Their people and natural history. Smithsonian Inst. War Background Studies 21, Publ. 3775.

Contributors

Marji Patz
Tyler Annetts

Approval

Blaine Spellman, 6/14/2025

Acknowledgments

Blaine Spellman, Ecological Site Data Quality Specialist and Phil Barber, Ecological Site Specialist within Alaska, for your review and guidance of the PES development. Matt Mayer for assisting with R Scripts on weather, as well as Nathan Roe for assistance with R scripts on site data summaries.

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	06/15/2025
Approved by	Blaine Spellman
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: