LOCATION ALDERWOOD               WA

Established Series
Rev. AD/CRF/EED
10/2018

ALDERWOOD SERIES

Landscape--glacial drift plains
Landform--glacially modified hills and ridges
Slope--0 to 65 percent
Parent material-- glacial drift and outwash over dense glaciomarine deposits
Mean annual precipitation--about 1000 mm
Mean annual temperature--about 10 degrees C
Depth class--moderately deep to densic contact
Drainage class--moderately well drained
Soil moisture regime--xeric
Soil temperature regime--mesic
Soil moisture subclass--aquic

TAXONOMIC CLASS: Loamy-skeletal, isotic, mesic Aquic Dystroxerepts

TYPICAL PEDON: Alderwood gravelly sandy loam, forested

A--0 to 18 cm; gravelly sandy loam, brown (10YR 5/3) dry, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine roots; few fine irregular pores; 20 percent gravel; moderately acid (pH 5.8); abrupt smooth boundary

Bw1--18 to 53 cm; very gravelly sandy loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many fine roots; many fine tubular and irregular pores; 35 percent gravel; moderately acid (pH 5.8); gradual smooth boundary;

Bw2--53 to 75 cm; very gravelly sandy loam, pale brown (10YR 6/3) dry, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common fine roots; few very fine tubular pores; 40 percent gravel; moderately acid (pH 5.8); clear wavy boundary

Bg--75 to 89 cm; very gravelly sandy loam, light yellowish brown (2.5Y 6/4) dry, olive brown (2.5Y 4/4) moist, and light brownish gray (2.5Y 6/2) dry, dark grayish brown (2.5Y 4/2) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few fine roots; common fine tubular and interstitial pores; reddish yellow (7.5YR 6/6) dry, strong brown (7.5YR 5/6) moist, masses of oxidized iron around rock fragments; 45 percent gravel; moderately acid (pH 6.0); abrupt wavy boundary

2Cd1--89 to 109 cm; very gravelly sandy loam, light brownish gray (2.5Y 6/2) dry, dark grayish brown (2.5Y 4/2) moist; massive; extremely hard; extremely firm, nonsticky and nonplastic; few fine roots; few fine tubular pores; dark yellowish brown (10YR 4/4) moist, olive (5Y 4/4) moist, yellowish red (5YR 4/6) and strong brown (7.5YR 5/6) moist iron-manganese masses and masses of oxidized iron in cracks; 40 percent gravel; moderately acid (pH 6.0); abrupt irregular boundary

2Cd2--109 to 150 cm; dense glacial till that breaks to very gravelly sandy loam, light gray (2.5Y 7/2) dry grayish brown (2.5Y 5/2) moist; massive; extremely hard, extremely firm, nonsticky and nonplastic; 40 percent gravel; moderately acid (pH 6.0)

TYPE LOCATION: Snohomish County, Washington; about 8 km east of Lynnwood on Maltby road; 61 m south and 122 m east of the center of sec. 28, T. 27 N., R. 5 E., Willamette Meridian; Bothell, Washington, U.S. Geological Survey quadrangle; latitude: 47.798000, longitude: 122.176000 degrees west, WGS84 (coordinates estimated from PLSS details)

RANGE IN CHARACTERISTICS:
*Mean annual soil temperature--10 to 12 degrees C
*Soil moisture control section--dry 60 to 75 consecutive days following the summer solstice
*Depth to densic contact--50 to 100 cm
*Depth to redoximorphic features with chroma of 2 or less--45 to 75 cm
*Reaction (pH)--5.1 to 6.5

Particle-size control section (weighted average):
*Clay content: 5 to 15 percent
*Rock fragments: 35 to 65 percent

A horizon
Hue--10YR or 7.5YR
Value--2 or 3 moist, 3 to 5 dry
Chroma--2 to 4, moist or dry
Total fragments--15 to 65 percent
Gravel content--15 to 65 percent
Cobble content--0 to 5 percent
Stone content--0 to 5 percent
Thickness--5 to 20 cm

Bw horizon
Hue--10YR or 7.5YR
Value--2 to 6, dry or moist
Chroma--2 to 6, dry or moist
Fine earth texture--sandy loam, coarse sandy loam, or loam
Total fragments--15 to 65 percent
Gravel content--15 to 65 percent
Cobble content--0 to 15 percent
Stone content--0 to 5 percent
Thickness--20 to 75 cm

Bg horizon
Hue--10YR or 2.5Y
Value--5 to 7 dry
Chroma--2 to 4, moist or dry
Fine earth texture--sandy loam, coarse sandy loam, or loam
Redox concentrations--beginning within 75 cm of the surface
Total fragments--35 to 85 percent
Gravel content--35 to 85 percent
Cobble content--0 to 25 percent
Stone content--0 to 5 percent
Thickness--5 to 50 cm

2Cd horizon
Hues-- 10YR or 2.5Y
Value--4 to 8 dry
Chroma--1 to 3, moist or dry
Fine earth texture--sandy loam, fine sandy loam, coarse sandy loam, or loamy sand
Total fragments--15 to 45 percent
Gravel content--15 to 45 percent
Cobble content--0 to 10 percent
Stone content--0 to 5 percent

An E horizon less than 5 cm thick is sometimes present

COMPETING SERIES:
Whidbey--dry 75 to 90 consecutive days following the summer solstice; less than 15 percent coarse fragments in the surface horizon

GEOGRAPHIC SETTING:
Elevation--0 to 250 m
Mean annual precipitation--410 to 1500 mm
Mean annual air temperature--9 to 11 C
Frost free period--180 to 240

GEOGRAPHICALLY ASSOCIATED SOILS:
Everett, Indianola--lack a densic layer, no aquic conditions within 30 cm of the soil surface, on adjacent glacial outwash or glacial drift plains
McChord--depth to densic contact is between 100 and 150 cm from the soil surface, on similar landforms
Mckenna--on adjacent hillslopes and glacial drift plains

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
*Drainage class--moderately well drained
*Depth to perched seasonal water table--30 to 90 cm at times in December through April
*Flooding--none
*Ponding--none
*Saturated hydraulic conductivity (Ksat)--high saturated hydraulic conductivity above the densic contact and low saturated hydraulic conductivity in the densic material

USE AND VEGETATION:
*Use--timber production, crop production, wildlife habitat, watershed
*Potential natural vegetation-- Douglas-fir, western hemlock, western redcedar, red alder with an understory of salal, Oregon-grape, western brackenfern, western swordfern, Pacific rhododendron, red huckleberry, evergreen huckleberry, and orange honeysuckle

DISTRIBUTION AND EXTENT: Western Washington; MLRA 2. The series is extensive

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Snohomish County, Washington 1936

REMARKS: Diagnostic horizons and features recognized in this soil:
*Particle-size control section--25 to 89 cm
*Ochric epipedon
*Cambic horizon--from 0 to 89 cm
*Episaturation--zone from 75 to 89 cm
*Aquic conditions--zone from 75 to 89 cm
*Depth to densic contact--89 cm
*Depth to lithologic discontinuity--89 cm
*Redoximorphic depletions with chroma of 2 or less--zone from 75 cm to 89 cm

06/2018--Changed from previous 2011 classification of loamy-skeletal, isotic, mesic, Vitrandic Dystroxerepts. Existing laboratory data for this series and other geographically associated soils does not reflect the presence of adequate quantities of volcanic glass to support the Vitrandic subgroup. This OSD was edited according to SSR01 Technical Note--Content and Format of Official Series Descriptions (revised 11/2017).

ADDITIONAL DATA: Partial data available for this series. Sample # S71WA033002, 71WA033003, S04WA061002, and S09WA053098

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National Cooperative Soil Survey
U.S.A.