LOCATION AIRSTRIP CA

Established Series
Rev: JHP/JPS/ET/RLM/SAA
07/2016

AIRSTRIP SERIES

The Airstrip series consists of moderately deep, well drained soils formed in colluvium and residuum derived from sandstone and siltstone. Airstrip soils are on mountains and have slopes of 9 to 50 percent. The mean annual precipitation is about 2290 millimeters (90 inches) and the mean annual temperature is about 11 degrees C (52 degrees F).

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Pachic Humixerepts

TYPICAL PEDON: Airstrip gravelly loam - on a southwest-facing, convex slope of 5 percent under annual and perennial grasses at 910 meters (2985 feet) elevation. (Colors are for dry soil unless otherwise stated. When described October 31, 2002, the soil was moist throughout.)

A1--0 to 7 centimeters (0 to 3 inches); dark grayish brown (10YR 4/2) gravelly loam, very dark brown (10YR 2/2) moist; weak fine and medium and granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; common very fine and fine interstitial and very fine and fine tubular pores; 15 percent gravel; very strongly acid (pH 5.0); clear wavy boundary.

A2--7 to 20 centimeters (3 to 8 inches); dark grayish brown (10YR 4/2) gravelly loam, very dark brown (10YR 2/2) moist; moderate fine and medium granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine interstitial and very fine and fine tubular pores; 15 percent gravel; very strongly acid (pH 5.0); gradual wavy boundary.

A3--20 to 42 centimeters (8 to 16 inches); dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; weak medium and coarse subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine, and few medium roots; common very fine and fine and few medium tubular pores; 10 percent gravel; strongly acid (pH 5.2); clear wavy boundary. (Combined thickness of A horizons is 15 to 50 centimeters)

AC--42 to 67 centimeters (16 to 26 inches); brown (10YR 5/3) extremely gravelly loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine and few medium and coarse roots; common very fine and fine interstitial pores; 45 percent gravel and 15 percent cobbles; strongly acid (pH 5.4); gradual wavy boundary. (0 to 30 centimeters thick)

R--67 centimeters (26 inches); fractured greywacke sandstone, fractures greater than 10 centimeters apart.

TYPE LOCATION: Trail Ridge, Humboldt County, California; located in Trail Ridge Prairie, southeast quarter of the northeast quarter, Section 5, T. 8 N., R. 3 E.; WGS84 Decimal degrees 41.1683056 latitude and -123.7490000 longitude; HBLM; USGS Hupa Mountain Quadrangle. UTM Zone 10 428469mE 4551271mN; NAD83.

RANGE IN CHARACTERISTICS:

Soil moisture: The soil is dry in all parts in the moisture control section from about July 10 to September 20, and is moist in all parts from about October 1 to June 1. The soils have xeric moisture regime.

Soil temperature: The mean annual soil temperature is 10 to 15 degrees C (50 to 59 degrees F). The difference between mean summer and mean winter temperature is 6 to 10 degrees C. The soils have a mesic soil temperature regime.

Depth to a lithic contact: 50 to 100 centimeters.

The umbric epipedon is 50 to 75 centimeters thick.

Base saturation, by ammonium acetate, is less than 35 percent throughout.

Surface fragments: 15 to 35 percent gravel, 0 to 5 percent cobbles

Particle-Size Control Section (weighted average):

Rock fragments: 35 to 60 percent gravel and 0 to 25 percent cobbles.
Clay content: 12 to 26 percent clay.

Some pedons have an Oi horizon (0 to 4 centimeters thick) and some pedons have a Cambic horizon.
A horizon

Hue: 10YR or 2.5Y.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 1 through 3 dry, 1 through 3 moist.

Texture of fine earth: loam.
Rock fragments: 10 to 35 percent gravel and 0 to 10 percent cobbles.
Clay content: 12 to 24 percent clay.
Reaction: strongly or very strongly acid.

Some pedons have a Bw horizon

Hue: 10YR or 2.5Y.
Value: 5 through 7 dry, 3 through 5 moist.
Chroma: 3 or 4 dry, 3 moist.

Texture of fine earth: loam.
Rock fragments: 35 to 60 percent gravel and 0 to 25 percent cobbles.
Clay content: 20 to 26 percent clay.
Reaction: strongly or very strongly acid.

Some pedons have a C horizon

Hue: 2.5Y.
Value: 5 through 7 dry, 3 through 5 moist.
Chroma: 2 through 4 dry, 2 through 4 moist.

Texture of fine earth: loam.
Rock fragments: 35 to 60 percent gravel and 0 to 25 percent cobbles.
Clay content: 20 to 26 percent clay.
Reaction: strongly or very strongly acid.

COMPETING SERIES: These are the Wyeth soils. Wyeth soils are very deep, and do not have a lithic contact.

GEOGRAPHIC SETTING: Airstrip soils are on strongly convex ridge tops, spur ridges and mountain slopes. Slopes are 9 to 50 percent. Elevations are 67 to 1032 meters (500 to 3385 feet). The soils formed in colluvium and residuum derived from sandstone and siltstone. The climate is humid with cool, foggy summers and cool, rainy winters. Mean annual precipitation is 1780to 2550 millimeters (70 to 100 inches). Mean January temperature is about 7 degrees C; mean July temperature is about 15 degrees C; and the mean annual temperature is 10 to 15 degrees C (50 to 59 degrees F). Frost-free season is about 200 to 280 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Countshill and Dolason soils. Countshill and Dolason soils are fine-loamy and have umbric epipedons that are 50 to 102 centimeters (20 to 40 inches) thick. The Countshill soils are on smooth ridgetops and the Dolason soils are on smooth sideslopes and ridgetop saddles.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: This soil has been used for livestock grazing, wildlife habitat, and watershed. Natural vegetation consists of California oatgrass, dogtail grass, foxtail fescue, tall oatgrass, plantain, sheep sorrel, hairy cat's ear, and annual legumes. Invasion by Douglas-fir and other forest species occurs primarily in disturbed areas and along forest borders.

DISTRIBUTION AND EXTENT: California Coastal Redwood Belt; MLRA 4B. The series is not extensive.

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

SERIES ESTABLISHED: Redwood National Park portion, Humboldt and Del Norte Area Soil Survey, California, 2007. The source of the name is from Airstrip Prairie, located in Redwood National Park south of the town of Orick.

REMARKS: The series type location was moved in 2004 to better reflect the series concept.

Diagnostic horizons and features recognized in this pedon are:

1. Umbric epipedon - the zone from 0 to 67 centimeters (A horizon)
2. Lithic contact - the bedrock interface at 67 centimeters depth

3. Particle-size control section - the zone from 25 to 67 centimeters, averages 14 percent clay, by field estimate, and 36 percent rock fragments, by volume. CEC/clay ratio averages 0.60

ADDITIONAL DATA: Soil samples 83-RNP-9 and 86-RNP-8 were collected from a similar pedon and analyzed chemically at the Oregon State University Soil Testing. Laboratory (lab numbers 71712-71714, 82918 and 82919). Bulk density and moisture retention were determined at Humboldt State
University.

NASIS User Pedon ID 02CA605REDW060

Soil classified using the 12th Edition of the Keys to Soil Taxonomy.

National Cooperative Soil Survey
U.S.A.