LOCATION IHOPE HI

Established Series
IRD-PGN
05/2012

IHOPE SERIES

The Ihope series consists of very shallow and shallow, very poorly drained soils formed in basic volcanic ash over pahoehoe lava. Slopes range from 3 to 10 percent. The mean annual rainfall is about 3900 millimeters (157 inches) and the mean annual air temperature is about 17 degrees C. (63 degrees F.)

TAXONOMIC CLASS: Hydrous, ferrihydritic, acid, isothermic Lithic Endoaquands

TYPICAL PEDON: Ihope hydrous silt loam, on an east facing, slightly concave, 1 percent slope in upland forest at an elevation of 777 meters (2,250 feet). (Colors are for moist soils unless otherwise noted. All textures are "apparent field textures". pH measured using organic dyes. When described on August 28, 2003, the soil was moist from 0 to 37 cm (0 to 15 inches).

A--0 to 15 centimeters (0 to 6 inches); dark brown (7.5YR 3/2), hydrous silt loam, brown (7.5YR 4/4) dry; moderate fine subangular blocky structure; very friable, soft, slightly sticky and slightly plastic, moderately smeary; common coarse roots; common fine and few coarse tubular pores; common fine prominent dark reddish brown (5YR 3/4) iron concretions, moist, irregular, In the matrix, weakly cemented; strongly acid (pH 5.4); abrupt smooth boundary. (8 to 10 centimeters {3 to 4 inches} thick)

Bw--15 to 30 centimeters (6 to 12 inches); dark brown (7.5YR 3/4), hydrous silt loam, brown (7.5YR 4/4) dry; moderate fine subangular blocky structure; very friable, soft, slightly sticky and slightly plastic, moderately smeary; few very fine roots; common very fine tubular pores; common coarse distinct dark red (2.5YR 3/6) masses, moist, irregular, In the matrix, clear, and common coarse distinct very dark grayish brown (10YR 3/2) spherical iron depletions, In the matrix; 10 percent subrounded gravel; strongly acid (pH 5.5); abrupt smooth boundary. (8 to 10 centimeters {3 to 4 inches} thick)

Bg--30 to 37 centimeters (12 to 15 inches); dark grayish brown (10YR 4/2), cobbly hydrous silt loam, grayish brown (10YR 5/2) dry; weak fine subangular blocky structure; very friable, slightly sticky and slightly plastic, moderately smeary; few very fine roots; common medium tubular pores; few fine prominent dark brown (7.5YR 3/4) irregular iron masses, on ped faces; 10 percent subangular cobbles and 5 percent subrounded paragravel; strongly acid (pH 5.5); abrupt smooth boundary. (10 to 18 centimeters {4 to 7 inches} thick)

2R--37 centimeters (15 inches); hard, massive pahoehoe lava.

TYPE LOCATION: Island of Hawaii; from the village of Mountain View follow north Kulani road to Ihope road, proceed on Ihope road 2.75 miles and park; follow cleared trail to the south east 56 meters (185 feet) to pedon. Puu Makaala Quadrangle; lat. 19 degrees 33 minutes 53.8 seconds N. and long. 155 degrees 09 minutes 38.0 seconds W. (Old Hawaiian Datum, 12 ft; measured by Garmin GPS)

RANGE IN CHARACTERISTICS:
Depth to bedrock: 12 to 50 centimeters (5 to 20 inches).
Mean annual soil temperature: 16 to 18 degrees C. (61 to 65 degrees F.)
Rock fragments: 0 to 30 percent by volume of the pedon and range in size from gravel to cobble size lava rocks.
Depth to redoximorphic features: 5 to 15 centimeters (2 to 6 inches) and continue to bedrock.

A horizon
Hue: 7.5YR or 10YR
Value: 1 to 3 moist.
Chroma: 1 to 3 moist.
Texture: Hydrous silt loam or silty clay loam. May be mucky.
Structure: Weak to strong granular or subangular blocky.
Soil reaction: Very strongly acid or strongly acid (pH 4.5 to 5.5).
Redoximorphic Features: May or may not appear in horizon.

Bw horizon
Hue: 7.5YR or 10YR.
Value: 2 to 3 moist.
Chroma: 2 to 4 moist
Texture: Hydrous silt loam or silty clay loam, cobbly hydrous silt loam or silty clay loam
Structure: Weak or moderate subangular blocky or angular blocky.
Soil reaction: Very strongly acid or strongly acid (pH 4.5 to 5.5).
Redoximorphic Features: Few to many

Bg horizon
May not appear in all pedons

COMPETING SERIES: This is the Hua series. Hua soils are less than 25 cm deep to bedrock and are located on the leeward side of the island of Hawaii and receive most of the rainfall from April to October.

GEOGRAPHIC SETTING: Ihope soils are on eastern slopes and uplands of Kilauea and Mauna Loa volcanoes at elevations from 305 to 1372 meters (1,000 to 4,500 feet). These soils are in depressions of constructional landscapes consisting of nearly level pahoehoe flows that are 5,000 to 10,000 years old. Slope gradients range from 3 to 10 percent. The soils formed in basic volcanic ash over pahoehoe lava. The mean annual rainfall ranges from 3800 to 5100 millimeters (150 to 200 inches), with most of the rainfall occurring from October through April. The mean annual pan evaporation ranges from 762 to 1016 millimeters (30 to 40 inches). The mean annual air temperature ranges from 16 to 22 degrees C. (61 to 71 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: These are Hao, Kopua, Makaala, Waiakea, Keei, and Kiloa series. Hao soils have placic horizons. Kopua soils do not have redoximorphic features. Makaala soils are moderately deep. Waiakea soils are skeletal. Keei and Kiloa soils are organic soils.

DRAINAGE AND PERMEABILITY: Somewhat poorly or poorly drained. Runoff is moderate to high. Permeability is moderately slow in the soil and very slow in the underlying bedrock.

USE AND VEGETATION: Used for wildlife habitat and pasture. Vegetation is ohia lehua (Metrosideros polymorpha), hapuu or treefern (Cibotium chammisoi), uluhe fern, false staghorn fern (Gleichenia linearis), or strawberry guava (Psidium catleianum).

DISTRIBUTION AND EXTENT: Puna district, Island of Hawaii; MLRA 159A. The soils are of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Island of Hawaii, Hawaii, 2012. Proposed 2004.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Aquic conditions - 0 to 37 centimeters (0 to 15 inches)
Umbric epipedon - from 0 to 30 centimeters (0 to 12 inches) (A and Bw horizons).
Lithic contact - at 37 centimeters (15 inches).
Andic soil properties - from 0 to 37 centimeters (0 to 15 inches).
Isothermic soil temperature regime.

National Cooperative Soil Survey
U.S.A.