LOCATION GUNN WAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Ultic Haploxeralfs
TYPICAL PEDON: Gunn loam - forested on a 3 percent southeast-facing slope at an elevation of 1,780 feet. (Colors are for dry soil unless otherwise noted.)
A1--0 to 6 inches; brown (7.5YR 5/3) loam, dark brown (7.5YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and few medium roots; many fine interstitial pores; slightly acid (pH 6.2); abrupt smooth boundary.
A2--6 to 10 inches; light brown (7.5YR 6/3) loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and few coarse roots; common fine tubular pores; moderately acid (pH 6.0); clear wavy boundary. (Combined thickness of the A horizon is 7 to 14 inches)
BAt--10 to 18 inches; light brown (7.5YR 6/4) loam, brown (7.5YR 4/4) moist; moderate fine and medium subangular block structure; hard, friable, slightly sticky and slightly plastic; common very fine and few medium roots; common fine and medium tubular pores; few faint clay films on faces of peds; slightly acid (pH 6.2); clear wavy boundary.
Bt1--18 to 34 inches; light brown (7.5YR 6/4) clay loam, brown (7.5YR 4/4) moist; moderate fine and medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; few very fine and fine roots; common fine and medium tubular pores; common distinct clay films on faces of peds; slightly acid (pH 6.2); gradual wavy boundary.
Bt2--34 to 45 inches; light brown (7.5YR 6/4) clay loam, brown (7.5YR 4/4) moist; moderate fine and medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; few very fine roots; many fine and many medium tubular pores; common distinct clay films on faces of peds; slightly acid (pH 6.2); clear wavy boundary. (Combined thickness of the Bt horizon is 15 to 30 inches.)
BCt--45 to 66 inches; light brown (7.5YR 6/4) clay loam, brown (7.5YR 4/4) moist; moderate coarse subangular blocky structure; very hard, friable, slightly sticky and slightly plastic; few very fine roots between peds; many fine and medium tubular pores; many distinct clay films on faces of peds; slightly acid (pH 6.2). (10 to 30 inches thick)
TYPE LOCATION: Klickitat County, Washington; 2,500 feet north and 2,600 feet east of the southwest corner of section 25, T. 5N., R. 14 E. Latitude 45 degrees, 53minutes, 22 seconds N. and Longitude 120 degrees, 59 minutes 51 seconds W. NAD27.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 51 degrees F. The soil moisture control section is usually moist, but is dry in all parts for 90 to 105 consecutive days. The solum is 40 to 60 inches or more. Rock fragments in the control section average from 0 to 10 percent. Some pedons have a stony surface layer. The particle-size control section has 22 to 35 percent clay and 0 to 30. Reaction is slightly acid to moderately acid throughout.
The A horizon has hue of 7.5YR or 5YR, value of 4 to 6 dry, 3 or 4 moist and chroma of 2 to 6 dry or moist.
The Bt horizon has hue of 7.5YR or 5YR, value of 5 or 6 dry, 3 or 4 moist and chroma of 2 to 4 dry and moist. Texture is loam or clay loam.
The BCt horizon has hue of 7.5YR or 5YR, value 5 or 6 dry, 3 or 4 moist, and chroma of 4 to 6 dry. Texture of the fine-earth fraction is loam or clay loam. Rock fragments range from 0 to 30 percent gravel and 0 to 45 percent paragravel.
COMPETING SERIES: These are the
Beal,
Boardburn,
Boomer,
Casabonne,
Cherryhill,
Cle Elum,
Cohasset,
Crozier,
Dalig,
Fives,
Fong (T),
Fordcreek,
Hood,
Latourell,
Lettia,
Norling,
Para (T),
Pishpishee (T),
Rosehaven,
Sanhedrin,
Tigit,
Varelum, Wildwohly and
Wohly series.
Beal soils dry for 45 to 60 consecutive days following the summer solstice; 30 to 40 inches to low chroma redox depletions; 15 to 25 inches to redox concentrations; have hue in the Bt horizon of 10YR to 5Y
Boardburn soils 40 to 60 inches to a paralithic contact (andesitic tuff); dry for 110 to 130 consecutive days following the summer solstice
Boomer soils 40 to 80 inches to a paralithic contact (greenstone); dry for 105 to 130 consecutive days following the summer solstice
Casabonne soils 40 to 60 inches to a lithic contact (sandstone); mean annual soil temperature of 54 to 59 degrees F.
Cheryhill soils 40 to 60 inches to paralithic contact (tuffaceous sandstone); dry for 60 to 80 consecutive days following the summer solstice
Cle Elum soils 20 to 40 inches to a paralithic contact (sandstone); dry for 75 to 90 consecutive days following the summer solstice
Cohasset soils 40 to 80 inches to a lithic or paralithic contact (andesitic breccia); dry for 120 to 150 consecutive days following the summer solstice
Crozier soils 20 to 40 inches to lithic or paralithic contact (andesitic breccia); dry for 120 to 150 consecutive days following the summer solstice
Dalig soils dry for 60 to 75 consecutive days following the summer solstice
Fives soils dry for 45 to 60 consecutive days following the summer solstice
Fong soils 40 to 60 inches to a lithic contact (schist)
Fordcreek soils 40 to 60 inches to a paralithic contact (granite);
Hood soils dry for 60 to 75 consecutive days following the summer solstice
Latourell soils dry for 45 to 80 consecutive days following the summer solstice; mean annual soil temperature of 54 to 59 degrees F.
Lettia soils 40 to 60 inches to a paralithic contact (granodiorite); dry for 45 to 60 consecutive days following the summer solstice
Norling soils 20 to 40 inches to a paralithic contact (metavolcanic); dry for 45 to 60 consecutive days following the summer solstice
Para soils dry for 45 to 60 consecutive days following the summer solstice
Pishpishee soils particle-size control section with 10 to 30 percent rock fragments of metasedimentary origin
Rosehaven soils dry for 45 to 60 consecutive days following the summer solstice; mean annual soil temperature of 52 to 57 degrees F.
Sanhedrin soils 40 to 60 inches to a lithic contact (interbedded sandstone and siltstone)
Tigit soils 20 to 40 inches to a paralithic contact (basalt); dry for 60 to 75 consecutive days following the summer solstice
Varelum soils 40 to more than 60 inches to a paralithic contact (sandstone); dry for 60 to 75 consecutive days following the summer solstice
Wildwohly soils unable to compete; series not in OSD database
Wohly soils 20 to 40 inches to a paralithic contact (sandstone)
GEOGRAPHIC SETTING: Gunn soils are on plateaus, benches, hillslopes and ridgetops at elevations of 600 to 3,800 feet. Slopes are 0 to 65 percent. The soils formed in loess mixed with colluvium and residuum derived from basalt. Summers are warm and dry and winters are cool and moist. The mean annual precipitation is 15 to 25 inches. The average January temperature is 28 degrees F. and average July temperature is 66 degrees F. The mean annual temperature is 46 to 50 degrees F. The frost-free season is 100 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Goldendale, Itat, Kiakus, Leidl, Munset, Quiden, and Wahoo soils and the competing Dalig soils. Itat soils on plateaus, Leidl soils on canyon side slopes and Wahoo soils on canyon breaks are loamy-skeletal and lack an argillic horizon. Kiakus soils on plateaus and Munset soils in depressions have bedrock at a depth of 20 to 40 inches. Quiden soils on plateaus lack an argillic horizon. Goldendale soils on plateaus have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used mainly for timber production, livestock grazing, wildlife habitat and cropland. Principal farm crops are wheat, alfalfa, and pasture. Native vegetation is predominantly ponderosa pine and Oregon white oak with scattered Douglas-fir and an understory of redstem ceanothus, snowbrush ceanothus, pinemat manzanita, squawcarpet, elk sedge, Oregon-grape, Idaho fescue, bluebunch wheatgrass, antelope bitterbrush, poison-oak, yarrow and lupine.
DISTRIBUTION AND EXTENT: Central Klickitat County, Washington; MLRA 6. The series is moderately extensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Klickitat County, Washington, 2003.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 10 inches
Argillic horizon - 18 to 45 inches.
Particle-size control section - 18 to 38 inches.