LOCATION CISPUS WAEstablished Series
TAXONOMIC CLASS: Pumiceous, glassy, mesic Humic Vitrixerands
TYPICAL PEDON: Cispus cindery sandy loam - forested. (Colors are for moist soil unless otherwise stated. When described pedon was dry to depth of 43 inches and moist below.)
Oe--2 inches to 0; partially decomposed organic litter including twigs, leaves, and needles of coniferous and deciduous trees.
A--0 to l0 inches; very dark grayish brown (l0YR 3/2) cindery sandy loam, grayish brown (l0YR 5/2) dry; moderate very fine and fine granular structure; soft very friable, nonsticky, nonplastic and weakly smeary; many very fine, fine, medium, and coarse roots; many very fine interstitial pores; 30 percent pumice; neutral (pH 6.6); clear smooth boundary. (l0 to l5 inches thick)
Bw--l0 to l5 inches; yellowish brown (l0YR 5/4) very cindery sandy loam, very pale brown (l0YR 8/4) dry; weak very fine granular structure; soft very friable, nonsticky, nonplastic and weakly smeary; many very fine through coarse roots; many very fine, fine, and medium interstitial pores; 40 percent pumice; neutral (pH 6.6); abrupt smooth boundary. (4 to 5 inches thick)
C--l5 to 43 inches; yellow (l0YR 8/8) pumice cinders, very pale brown (l0YR 8/4) dry; single grained; loose; common very fine and fine roots;many very fine, fine and medium interstitial pores; neutral (pH 6.6); abrupt smooth boundary. (25 to 55 inches thick)
2Bwb--43 to 60 inches; dark yellowish brown (l0YR 4/4) silt loam, pale brown (l0YR 6/3) dry; few fine prominent grayish brown (2.5Y 5/2) mottles, not visible when dry; weak medium and coarse subangular blocky structure; soft, very friable, slightly sticky, slightly plastic and weakly smeary; few very fine and fine roots; many very fine and fine tubular pores; slightly acid (pH 6.2).
TYPE LOCATION: Lewis County, Washington; 200 feet south and 200 feet east of the N corner of section 26, T. l2 N., R. 6 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches ranges from 47 degrees to 52 degrees F. Depth to the 2Bwb horizon ranges from 40 to 60 inches or more. The particle-size control section consists of 90 to 95 percent pyroclastic material, mostly volcanic pumice from 2 mm to l inch in diameter. The l5 bar water is less than 20 percent based on the whole soil in the control section. Reaction is moderately acid to neutral throughout.
The A horizon ranges from very dark grayish brown to black. It ranges from 20 to 35 percent pumiceous cinders.
The Bw horizon has value of 4 or 5, 7 or 8 dry and chroma of 2 to 6 moist and dry. It is very cindery sandy loam or very cindery loamy sand.
The C horizon ranges from yellow to very pale brown, and from 60 to 95 percent pumiceous cinders. The 2Bwb horizon, where present, ranges from dark yellowish brown to dark brown. It is silt loam or loam with 0 to l0 percent hard gravel.
COMPETING SERIES: This is the Glenoma series. Glenoma soils are loamy in the fine-earth fraction throughout the particle-size control section.
GEOGRAPHIC SETTING: These soils occur on mountains, benches, and terraces at elevations of 500 to 2,000 feet. The soils formed in pumiceous cinders and ash. Cispus soils occur in a humid climate having a mean annual precipitation of 60 to 90 inches with dry summers and cool wet winters; an average January temperature is 35 degrees F.; a mean July temperature is 63 degrees F.; an average annual temperature of 50 degrees F.; a average frost-free season (32 degrees F.) of l25 to l75 days. The growing season (28 degrees F.) is 150 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cinebar and Glenoma soils and the competing Bromo soils. Cinebar soils are medial and have an apparent silt loam field texture. Glenoma soils have an apparent gravelly loam or gravelly sandy loam field texture in the particle-size control section.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow to medium runoff; rapid permeability in the particle-size control section. Moderate permeability in the 2Bwb horizon.
USE AND VEGETATION: Used for timber production, watershed, and wildlife habitat. Vegetation is Douglas-fir, bigleaf maple, vine maple, cherry, and alder with an understory of western swordfern, elderberry, hazel and dogwood.
DISTRIBUTION AND EXTENT: Western Washington and possibly eastern Oregon. Series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lewis County, Washington, l945.
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy.
Diagnostic horizons and features recognized in this pedon are an umbric epipedon from the mineral surface to 10 inches and a cambic horizon from 10 to 15 inches.