LOCATION PAHIPA HI
Established Series
REV. MRK
06/2012
PAHIPA SERIES
The Pahipa series consists of moderately deep, well drained soils that formed in basic volcanic ash in `a`a lava. Slopes range from 2 to 20 percent. The mean annual rainfall is about 2032 millimeters (80 inches) and the mean annual temperature about 13 degrees C (55 degrees F).
TAXONOMIC CLASS: Hydrous-skeletal, ferrihydritic, isomesic Thaptic Hydrudands
TYPICAL PEDON: Pahipa hydrous silty clay loam, on a south facing, slightly convex, 4 percent slope, under forest, at an elevation of 1,429 meters (4,687 feet). (Colors are for moist soils unless otherwise noted. All textures are apparent field textures. pH measured with organic dyes. When described on December 15, 1999, the soil moist throughout.)
Oe -- 0 to 5 centimeters (0 to 2 inches); moderately decomposed plant material; abrupt smooth boundary. (3 to 8 centimeters {1 to 3 inches} thick)
A -- 5 to 20 centimeters (2 to 8 inches); dark brown (7.5YR 3/2) hydrous silty clay loam; strong very fine and fine granular structure; very friable, slightly sticky, slightly plastic; moderately smeary; many very fine and fine, and common medium roots; many very fine interstitial and irregular pores; 5 percent angular `a`a gravel and 5 percent angular `a`a cobbles; slightly acid (pH 6.1); clear wavy boundary. (15 to 23 centimeters {6 to 9 inches} thick)
2A -- 20 to 41 centimeters (8 to 16 inches); black (10YR 2/1) gravelly highly organic hydrous silt loam; moderate very fine and fine subangular blocky structure; very friable, moderately sticky, moderately plastic; moderately smeary; common very fine and fine roots; few very fine irregular pores; 15 percent angular `a`a gravel and 5 percent angular `a`a cobbles; moderately acid (pH 5.8); clear smooth boundary.
2Bw1/3C1 -- 41 to 76 centimeters (16 to 30 inches); dark brown (10YR 3/3) very cobbly hydrous silty clay loam; moderate fine subangular blocky structure; friable, moderately sticky, moderately plastic; moderately smeary; common very fine and fine roots; common very fine irregular and vesicular pores; 20 percent angular `a`a gravel and 30 percent angular `a`a cobbles; the 3C part of this horizon consists of unconsolidated `a`a lava fragments of variable size; slightly acid (pH 6.2); gradual wavy boundary.
3C2/2Bw2 -- 76 to 99 centimeters (30 to 39 inches); dark brown (10YR 3/3) extremely cobbly hydrous silty clay loam; weak very fine and fine subangular blocky structure; friable, moderately sticky, moderately plastic; moderately smeary; few very fine and fine roots; common very fine irregular and vesicular pores; 30 percent angular `a`a gravel and 35 percent angular `a`a cobbles; slightly acid (pH 6.2); the 3C part of this horizon consists of unconsolidated `a`a lava fragments of variable size; abrupt wavy boundary. (Combined thickness of the Bw is 50 to 80 centimeters {20 to 31 inches})
3R -- 99 centimeters (39 inches); hard, massive `a`a blue rock.
TYPE LOCATION: Island of Hawaii, Hawaii County, Hawaii; from Kahuku Ranch headquarters drive 0.9 miles east on Highway 11, turn north onto ranch road and drive upslope 6.8 miles, turn east and drive 1.3 miles to eastern edge of 1926 lava flow. Pedon is located 168 meters (550 feet) east in Kau Forest Reserve at an elevation of 1,429 meters (4,687 feet). Puu o Keokeo Quadrangle; lat. 19 degrees 9 minutes 35.2 seconds N. and long. 155 degrees 40 minutes 54.0 seconds W. (GPS/PLGR +/- 45 feet. Old Hawaiian Datum)
RANGE IN CHARACTERISTICS:
Depth to bedrock: 50 to 102 centimeters (20 to 40 inches).
Mean annual soil temperature: 12 to 15 degrees C (54 to 59 degrees F).
Rock fragments: 35 to 65 percent by volume of the pedon and range from gravel to cobble size lava rocks.
A horizon
Chroma: 1or 2 moist.
Texture: Highly organic hydrous silt loam, cobbly hydrous silt loam or hydrous silty clay loam.
Structure: Weak to strong granular.
Smeariness: Weakly or moderately smeary.
Rupture resistance: Very friable or friable.
Stickiness: Slightly sticky or moderately sticky.
Plasticity: Non-plastic or slightly plastic.
2A horizon
Hue: 5YR to 10YR.
Value: 2 or 3 moist.
Chroma: 1 to 3 moist.
Rupture resistance: Very friable or friable.
Plasticity: Slightly plastic or moderately plastic.
2Bw1/3C1 and 3C2/2Bw2 horizons
Hue: 5YR to 10YR.
Value: 2 or 3 moist.
Chroma: 2 or 3 moist.
Texture: Very cobbly or extremely cobbly hydrous silty clay loam.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Pahipa soils are on southeast upper elevation, windward slopes of Mauna Loa Volcano at elevations from 1,220 to 1,524 meters (4000 to 5000 feet). The soils are on all hillslope positions of constructional landscapes consisting of undulating to hilly `a`a flows that are 1,500 to 5,000 years old. Slope gradients range from 2 to 20 percent. The soils formed in basic volcanic ash in `a`a lava. The mean annual rainfall ranges from 1,524 to 2,540 millimeters (60 to 100 inches), with most of the rainfall occurring from October through April. The mean annual pan evaporation ranges from 640 to 1,270 meters (25 to 50 inches). The mean annual temperature ranges from 11 to 15 degrees C (52 to 59 degrees F). The mean summer soil temperature and the mean winter soil temperature differ by less than 6 degrees C (11 degrees F).
GEOGRAPHICALLY ASSOCIATED SOILS: This is the
Puali series. Puali soils have a lithic contact at 5 to 50 centimeters (2 to 20 inches) and are over pahoehoe lava.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is low. Permeability is moderate in the soil and very slow in the underlying bedrock.
USE AND VEGETATION: Used for forest reserve and wildlife habitat. The natural vegetation is ohia lehua (Metrosideros polymorpha), hapuu (Cibotium spp.), and kopiko (Psychotria hawaiiensis).
DISTRIBUTION AND EXTENT: Kau District, Island of Hawaii; MLRA 159B. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Island of Hawaii, Hawaii County, Hawaii, 2012. Proposed 2000.
REMARKS: Soil moisture - moist and not dry in any part for as long as 90 cumulative days in most years (Udic moisture regime).
Diagnostic horizons and features recognized in this pedon are:
Andic soil properties - 5 to 99 centimeters (2 to 39 inches) (A, 2A, 2Bw1/3C1 and 3C2/2Bw2 horizons).
Lithic contact - 99 centimeters (39 inches) (3R horizon).
Hemic materials - 0 to 5 centimeters (0 to 2 inches) (Oe horizon).
Umbric epipedon - 5 to 76 centimeters (2 to 30 inches) (A, 2A and 2Bw/3C1 horizons).
ADDITIONAL DATA: NASIS User Pedon ID 99HI602005.
Edit log: 4/09 MRK. Andic textural modifiers added plus minor edits.
National Cooperative Soil Survey
U.S.A.