LOCATION AHTELL AK

Established Series
SDB/MJS
08/2025

AHTELL SERIES

Depth class: very deep
Drainage class: well drained
Parent material: Organic material over till
Landscape: mountains and foothills
Landform: mountain slopes and till plains
Slopes: 2 to 25 percent
Mean annual precipitation: about 360 mm (14 in)
Mean annual air temperature: about -3 degrees C. (27 degrees F)
Frost-free period: 32 to 75 days

TAXONOMIC CLASS: Fine-loamy, mixed, superactive Typic Humicryepts

TYPICAL PEDON: Ahtell peat in a shrub-birch white spruce woodland community on a west facing linear slope on a till plain, slope of 6 percent at an elevation of 1054m (3460 ft)

Oi--0 to 26 cm (0 to 10 in); slightly decomposed plant material, brown (7.5YR 4/3) dry, very dark brown (7.5YR 2.5/3) broken face moist; many very fine, fine, medium, and coarse roots throughout; very strongly acid (pH 4.8); clear wavy boundary. (10 to 28 cm, 4 to 11in)

Oe--26 to 35 cm (10 to 14 in); moderately decomposed plant material, very dark brown (7.5YR 2.5/2) broken face moist; many very fine, fine, and medium roots throughout; strongly acid (pH 5.1); abrupt wavy boundary. (5 to 10 cm, 2 to 4 in)

Bw1--35 to 63 cm (14 to 25 in); sandy loam, dark brown (10YR 3/3) broken face moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; nonsmeary; common very fine and fine roots throughout; very fine and fine dendritic tubular pores; 6 percent subrounded gravel by volume; moderately acid (pH 5.7); gradual wavy boundary. (12 to 32 cm, 5 to 13 in)

Bw2--63 to 86 cm (25 to 34 in); sandy loam, very dark grayish brown (10YR 3/2) broken face moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; nonsmeary; common very fine and fine roots throughout; very fine and fine dendritic tubular pores; 5 percent subrounded gravel by volume; moderately acid (pH 5.8); very abrupt wavy boundary. (8 to 30 cm, 3 to 12 inches)

C--86 to 200 cm (34 to 79 in); loam, dark grayish brown (2.5Y 4/2) broken face moist; massive; very hard, firm, moderately sticky, moderately plastic; nonsmeary; very few very fine roots throughout; very fine interstitial pores; 4 percent subrounded gravel by volume; moderately acid (pH 5.7). (100 to 165 cm, 39 to 65 in)

TYPE LOCATION: North Copper River Soil Survey Area, Alaska; Latitude 62.94636 N, Longitude -145.464585 W, UTM 6980542.82 north, and 577909.89 east, zone 6, Datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: udic
Soil temperature regime: cryic
Mean annual soil temperature: -1 to 5 degrees C. (30 to 41 degrees F)
Thickness of folistic epipedon: 15 to 38 cm (6 to 15 in)
Thickness of umbric epipedon: 20 to 51 cm (8 to 20 in)

Oi or Oe horizon:
Hue: 7.5YR or 10YR
Value: 2 to 3
Chroma: 1 to 3
Texture: slightly decomposed organic matter, to moderately decomposed organic matter.
Organic matter: 60 to 90 percent
Reaction class: extremely acid to moderately acid (pH 3.5 to 6.0)

Bw1 horizons:
Hue: 7.5YR or 10YR
Value: 3
Chroma: 1 to 3
Texture: Loam to Sandy loam
Sand: 35 to 70 percent
Silt: 12 to 50 percent
Clay: 6 to 18 percent
Rock fragments: 0 to 25 percent gravels
Organic matter: 1 to 3 percent
Reaction class: strongly acid to slightly acid (pH 5.1 to 6.5)

Bw2 or BC horizon (if present):
Hue: 10YR or 2.5YR
Value: 3 to 4
Chroma: 2 to 3
Texture: Loam to Sandy loam
Sand: 35 to 70 percent
Silt: 10 to 50 percent
Clay: 8 to 20 percent
Rock fragments: 0 to 25 percent gravels
Reaction class: extremely acid to moderately acid (pH 5.1 to 6.5)

C horizon:
Hue: 10YR or 2.5Y
Value: 3 or 4
Chroma: 1 to 3
Texture: Loam to Sandy loam
Sand: 30 to 65 percent
Silt: 15 to 50 percent
Clay: 18 to 27 percent
Rock fragments: 0 to 25 percent gravels
Organic matter: 0.5 to 1 percent
Reaction class: extremely acid to moderately acid (pH 5.1 to 6.5)

Some pedons have a silt loam A horizon forming some, or all, of the umbric epipedon rather than a B horizon.
On steeper slopes, a buried A horizons may also be present within or beneath the umbric epipedon

COMPETING SERIES: These are the Archabal (ID), Domo (CO), Nickolna (AK), and Packtrail (CO) soils
Archabal, Domo and Packtrail lack a folistic epipedon and presumably have a mean annual air temperature above 0 C (32 F).
Packtrail soils have bedrock between 51 and 102 cm (20 and 40 in)
Nikolna lack a folistic epipedon, and have fine-loamy textures in the umbric horizon.

GEOGRAPHIC SETTING:
Elevation: 600 to 1200 meters (1970 to 3935 ft)
Parent material: Organic material over till
Landform: mountain slopes and till plains
Slopes: 2 to 25 percent
Mean annual precipitation: 330 to 800 mm (13 to 31 in)
Mean annual air temperature: -4 to -2 degrees C. (25 to 28 degrees F)
Frost free period: 32 to 75 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are Chelina, Fields, Haleycreek, Nathlie, and Summitlake soils.
Chelina soils lack an umbric epipedon, have a cambic horizon, and occur on the ancient shorelines of lake plains.
Fields soils lack a folistic epipedon, have a coarse-loamy particle size family class and occur on hillslopes and mountain slopes.
Haleycreek soils have a mollic epipedon, sandy-skeletal particle size family class, and occur in mountain valleys
Nathlie soils have a histic epipedon and aquic conditions in the top 50 cm (20 in), they occur on flood plains.
Summitlake soils lack an umbric epipedon, have redox concentrations and depletions within 12 cm (5 in) of the surface, and occur on drumlins and hillslopes on glacial valley floors.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: well
Saturated hydraulic Conductivity: Very high in the organic horizons, high in the B horizons, moderately high in the C horizon
Permeability: very rapid in the organic horizons and sandy loam B horizons, rapid in the loamy C horizon.
Runoff: low

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: Resin birch, bog blueberry, marsh labrador tea, feather moss, red stem moss,

DISTRIBUTION AND EXTENT: MLRA 228 Interior Alaska mountains.
Extent: extensive

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Wasilla, Alaska

SERIES ESTABLISHED: North Copper River Soil Survey, Alaska, 2024.

REMARKS: Diagnostic features and horizons recognized in this profile include:

Particle-size control section: 40 to 115 cm (16 to 45 in)

Umbric epipedon: 20 to 62 cm (8 to 24 in) (Bw1 and Bw2 horizons)

Folistic epipedon: 15 to 38 cm (6 to 15 in) (Oe and Oa horizons)

ADDITIONAL DATA:

User pedon Id: 2023AK261281

National Cooperative Soil Survey
U.S.A.