LOCATION KOPUA                   HI

Established Series
rev.PGN
05/2012

KOPUA SERIES

The Kopua series consists of very shallow and shallow, moderately well 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, isothermic Lithic Hydrudands

TYPICAL PEDON: Kopua hydrous silty clay loam, on an east facing, slightly convex, 2 percent slope in upland forest at an elevation of 658 meters (2,160 feet). (Colors are for moist soils unless otherwise noted. All textures are "apparent field textures". pH measured using an Oakton microprocessor based pH meter. When described on August 8, 2004, the soil was moist from 0 to 37 centimeters (0 to 15 inches) and wet from 37 to 42 centimeters (15 to 17 inches).

A--0 to 19 centimeters (0 to 7 inches); dark brown (7.5YR 3/3), hydrous silty clay loam, brown (7.5YR 4/3) dry; strong fine granular structure; soft, very friable, slightly sticky and slightly plastic, moderately smeary; common fine and medium roots; common very fine and fine tubular pores; strongly acid (pH 5.1); abrupt smooth boundary. (10 to 25 centimeters {4 to 10 inches} thick)

Bw--19 to 42 centimeters (7 to 17 inches); dark brown (7.5YR 3/4), hydrous cobbly silty clay loam, very brown (7.5YR 4/4) dry; weak fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic, moderately smeary; few medium and common very fine roots; common very fine tubular pores; 5 percent subrounded paragravels and 10 percent subrounded cobbles; common fine and medium tubular pores; common, course, faint, dark reddish brown (5YR 3/4), moist, irregular mottles; strongly acid (pH 5.2); abrupt smooth boundary. (8 to 31 centimeters {3 to 12 inches} thick)

2R--42 centimeters (17 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 2.3 miles to water tank on north side of road and park. From behind water tank proceed 0.1 miles at a bearing of 320 degrees to type location at Puu Makaala Quadrangle; 19 degrees, 34 minutes, and 14.3 seconds North latitude and 155 degrees 09 minutes 27 seconds West longitude. (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.

Oa horizon
May exist in some pedons

A horizon
Hue: 7.5YR or 10YR.
Value: 1 to 3 moist.
Chroma: 1 to 3 moist.
Texture: Hydrous silt loam, loam, or silty clay loam. May be highly organic.
Structure: Weak to strong granular or subangular blocky.
Soil reaction: Very strongly acid or strongly acid (pH 4.5 to 5.5).

Bw horizon
Hue: 5YR to 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).

COMPETING SERIES: This is the Hilea series. Hilea soils have one or more months of normal years, where evapotranspiration exceeds precipitation.

GEOGRAPHIC SETTING: Kopua soils are on eastern slopes and uplands of Kilauea and Mauna Loa volcanoes at elevations from 366 to 1372 meters (1,200 to 4,500 feet). These soils are in 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 3500 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 Ihope, Hao, Makaala, Waiakea, Keei, and Kiloa series. Hao soils have placic horizons. Ihope soils have redoximorphic features. Makaala soils are moderately deep. Waiakea soils are skeletal. Keei and Kiloa soils are organic soils.

DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is high. Permeability is moderately rapid 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 or 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, 2012. Proposed 2004.

REMARKS: Diagnostic horizons and features (9th edition, Keys to Soil Taxonomy) recognized in this pedon are:
Lithic contact - at 42 centimeters (17 inches).
Andic soil properties - from 0 to 42 centimeters (0 to 17 inches).
Isothermic soil temperature regime.
Perudic soil moisture regime
Umbric epipedon-from the surface to 25 centimeters (0 to 10 inches) (A, Bw horizons)
Cambic horizon-from 25 to 42 centimeters (10 to 17 inches) (Bw horizons)

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National Cooperative Soil Survey
U.S.A.