LOCATION GRANDPON WAEstablished Series
TAXONOMIC CLASS: Ashy over loamy-skeletal, amorphic over isotic, frigid Humic Vitrixerands
TYPICAL PEDON: Grandpon ashy loam - forested on a 15 percent east-facing backslope at an elevation of 4,400 feet. (Colors are for dry soil unless otherwise noted. All textures are apparent field textures.)
0i--0 to 1 inch; slightly decomposed needles and twigs.
A1--1 to 4 inches; brown (7.5YR 4/2) ashy loam, dark reddish brown (5YR 2/2) moist; weak very fine granular structure; soft, friable, slightly sticky and nonplastic; weakly smeary; many very fine and few fine roots; many fine irregular pores; slightly acid (pH 6.1); clear smooth boundary. (3 to 5 inches thick)
A2--4 to 10 inches; brown (7.5YR 4/2) ashy loam, dark reddish brown (5YR 2/2) moist; weak very fine granular structure; soft, very friable, slightly sticky and nonplastic; weakly smeary; common fine and very fine roots; many very fine irregular pores; 10 percent pebbles; slightly acid (pH 6.1); clear smooth boundary. (0 to 6 inches thick)
AB--10 to 21 inches; brown (7.5YR 4/2) ashy loam, dark reddish brown (5YR 3/2) moist; weak very fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; weakly smeary; many very fine and common medium roots; many very fine irregular pores; 10 percent pebbles; moderately acid (pH 6.0); NaF 10.7; gradual smooth boundary. (10 to 15 inches thick)
BA--21 to 31 inches; reddish brown (5YR 5/3) ashy loam, dark reddish brown (5YR 3/2) moist; weak very fine subangular blocky structure; slightly hard, friable, slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; many very fine and few medium roots; many very fine irregular pores; 10 percent pebbles; moderately acid (pH 5.8); NaF pH 10.7; gradual smooth boundary. (10 to 15 inches thick)
2Bw--31 to 61 inches; brown (7.5YR 5/4) very gravelly loam, dark reddish brown (5YR 3/4) moist; weak very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; many very fine irregular pores; 35 percent gravel and 5 percent cobbles; moderately acid (pH 5.8).
TYPE LOCATION: Klickitat County, Washington; about 10 miles north of Goldendale, 1,000 feet south and 2,500 feet east of the northwest corner of section 34, T.6N., R.16E. (Latitude 45 degrees, 58 minutes, 03 seconds N. and Longitude 120 degrees, 47 minutes, 30 seconds W)
RANGE IN CHARACTERISTICS: The mean soil temperature is 40 to 44 degrees F. The soil moisture control section is usually moist, but is dry in all parts for 45 to 60 consecutive days. The thickness of volcanic ash influence ranges from 25 to 35 inches. The upper part of the 0 to 40 inch particle-size control section has an estimated moist bulk density of 0.80 to 0.90 g/cc, volcanic glass content of 30 to 60 percent, acid oxalate extractable aluminum plus one-half iron of 1.0 to 2.0 percent, phosphate retention of 50 to 75 percent, and 15 bar water retention of 8 to 12 percent. The lower part has a moist bulk density of 1.25 to 1.55 g/cc, clay of 15 to 20 percent and 35 to 60 percent rock fragments. Depth to bedrock is 60 inches or more. Reaction is moderately acid or slightly acid.
The A and AB horizons have hue of 5YR or 7.5YR, value of 4 or 5 dry, 2 or 3 moist and chroma of 2 or 3 dry and moist.
The BA horizon has hue of 5YR or 7.5YR, value of 4 or 5 dry, 2 or 3 moist and chroma of 2 to 4 dry and moist. Texture is ashy loam or ashy very fine sandy loam. It has 0 to 15 percent gravel.
The 2Bw horizon has hue of 5YR or 7.5YRTexture is very gravelly loam, very gravelly fine sandy loam or very gravelly very fine sandy loam. . It is l5 to 20 percent clay and 35 to 50 percent gravel and l0 to 10 percent cobbles.
COMPETING SERIES: There are no competing series. A similar classification except for mixed mineralogy is the Pinecreek series. Pinecreek soils have volcanic ash 14 to 22 inches thick and have a mean annual soil temperature of 44 to 46 degrees F.
GEOGRAPHIC SETTING: Grandpon soils are on mountains at elevations of 4,000 to 4,600 feet. Slopes are 0 to 60 percent. The soils formed in volcanic ash overlying colluvium from basalt. The climate is characterized by cool, dry summers and cool, moist winters with snow cover from November through May. The mean annual precipitation is 30 to 35 inches. The average January temperature is 20 degrees F. and the average July temperature is 57 degrees F. The mean annual temperature is 38 to 42 degrees F. The frost-free season is 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Pird and Satus soils. Pird soils are on mountains, have cryic soil temperature regimes and are ashy-skeletal. Satus soils are on mountains and are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used mainly for timber production, livestock grazing and wildlife habitat. Vegetation is grand fir, ponderosa pine and Douglas-fir, with an understory of pinegrass, elk sedge, prince's pine and rose.
DISTRIBUTION AND EXTENT: Klickitat and Yakima Counties, Washington; MLRA 6. The series is inextensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Klickitat County, Washington, 2003.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon - the zone from 1 to 31 inches
Cambic horizon - the zone from 31 to 61 inches
Particle-size control section - the zone from 11 to 41 inches
Depth to diagnostic horizons and features are measured from the top of the first mineral layer.
ADDITIONAL DATA: Partial laboratory data from NSSL, pedon No. 7P149440.