LOCATION POLKAPENN AK
Established Series
IRD. ATD/NDP/SCD
02/2022
POLKAPENN SERIES
Landscape--glaciated hills and mountains
Landform--hillslopes, mountain slopes
Slope--20 to 95 percent
Parent material--till over residuum
Mean annual precipitation--about 1400 mm
Mean annual air temperature--about 5 degrees C
Depth class--shallow
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, nonacid Lithic Cryorthents
TYPICAL PEDON: Polkapenn coarse sandy loam, forested, on a hillslope of 20 percent at an elevation of 44 m (When described on August 31, 2013, the soil was moist from the surface to a depth of 42 cm.)
Oi--0 to 10 cm; slightly decomposed plant material; moderately acid (pH 5.6); clear smooth boundary
A--10 to 22 cm; extremely cobbly coarse sandy loam, grayish brown (2.5Y 5/2) dry, very dark grayish brown (2.5Y 3/2) moist; weak fine granular structure; slightly hard, friable, nonsticky and nonplastic; many very fine and common fine and medium roots throughout; common very fine and fine irregular pores; 20 percent gravel and 45 percent cobbles; noneffervescent (HCL, 1N); slightly acid (pH 6.3); gradual smooth boundary
C--22 to 42 cm; very cobbly coarse sandy loam, light grayish green (5GY 6/2) dry, grayish green (5GY 5/2) moist; massive; slightly hard, friable, nonsticky and nonplastic; common very fine, fine, and medium roots throughout; common very fine and few fine irregular pores; 5 percent medium dark yellowish brown (10YR 4/6) mottles; 15 percent gravel and 30 percent cobbles; noneffervescent (HCL, 1N); neutral (pH 6.9); abrupt smooth boundary
2R--42 cm; bedrock
TYPE LOCATION: Glacier Bay National Park and Preserve-Gustavus Area, Alaska; Hoonah-Angoon Census Area; latitude 58.7408444, longitude -136.5051581, datum WGS84 (coordinates determined by a GPS unit)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--1 to 7 degrees C
Soil moisture control section--dry less than 45 consecutive days in June through October (udic)
Depth to lithic contact--25 to 50 cm (shallow)
Other features--lithologic discontinuity
Particle-size control section
*Clay content--4 to 6 percent
*Total rock fragment content--35 to 65 percent
Oi horizon
Thickness--0 to 12 cm
A horizon
Hue--10YR or 2.5Y moist or dry
Value--2 or 3 moist, 4 or 5 dry
Chroma--2 to 4 moist or dry
Fine-earth texture--coarse sandy loam, sandy loam
Clay content--4 to 6 percent
Total rock fragment content--35 to 65 percent
Gravel content--5 to 25 percent
Cobble content--3 to 45 percent
Reaction (pH)--5.8 to 6.3
Thickness--5 to 17 cm
C horizon
Hue--10YR to 5GY moist or dry
Value--3 to 5 moist, 5 or 7 dry
Chroma--2 to 6 moist or dry
Fine-earth texture--coarse sandy loam, sandy loam
Clay content--4 to 6 percent
Total rock fragment content--35 to 65 percent
Gravel content--5 to 25 percent
Cobble content--5 to 40 percent
Reaction (pH)--6.0 to 6.9
Thickness--10 to 25 cm
COMPETING SERIES:
Escures--50 to 100 cm (moderately deep) to a lithic contact
Larkspur--15 to 25 cm (very shallow) to a lithic contact (rhyolitic tuff); elevation of more than 1500 m
GEOGRAPHIC SETTING:
Elevation--20 to 280 m
Climate--cool, moist summers; mild, wet winters
Mean annual precipitation--850 to 1850 mm
Mean annual air temperature--0 to 9 degrees C
Frost-free period--90 to 154 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Bearisland--no lithic contact within a depth of more than 150 cm (very deep); on similar landforms
Dagelet--50 to 100 cm (moderately deep) to a lithic contact; on similar landforms
Enigma--50 to 100 cm (moderately deep) to a lithic contact; in avalanche chutes of adjacent landforms
Kadachan--no lithic contact within a depth of more than 150 cm (very deep); in drainageways of similar landforms
Nunatak--cambic horizon; on similar landforms
Skarn--100 to 150 cm (deep) to a lithic contact; on similar landforms
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Depth to saturation in normal years--more than 42 cm year round
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--very high in A and C horizons
USE AND VEGETATION:
Use--wildlife habitat, recreation, subsistence
Potential native vegetation--Sitka alder, bride's feathers, common ladyfern, spreading woodfern, heartleaf twayblade, devilsclub, Sitka spruce, balsam poplar, salmonberry, western hemlock
DISTRIBUTION AND EXTENT: Alexander Archipelago-Gulf of Alaska Coast, Alaska; MLRA 220; moderate extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Glacier Bay National Park and Preserve-Gustavus Area, Alaska; 2020.
REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Ochric epipedon
*Depth to lithologic discontinuity--42 cm
*Depth to lithic contact--42 cm
*Particle-size control section--zone from 10 to 42 cm
National Cooperative Soil Survey
U.S.A.