LOCATION LOSTFOREST              OR

Established Series
Rev. JRG-JVC-JBF
04/2011

LOSTFOREST SERIES

The Lostforest series consists of moderately deep, well drained soils that formed in volcanic ash and slope alluvium derived from tuff and tuff-breccia. Lostforest soils are on structural benches. Slopes are 0 to 5 percent. The mean annual precipitation is about 250 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Ashy, glassy, frigid Vitrixerandic Haplocambids

TYPICAL PEDON: Lostforest ashy very fine sandy loam--on a 2 percent slope at an elevation of 1,344 meters--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 5 cm; light brownish gray (10YR 6/2) ashy very fine sandy loam, dark grayish brown (10YR 4/2) moist; weak fine granular structure; soft, very friable, slightly sticky and nonplastic; few very fine and few fine roots; many fine tubular pores; 5 percent gravel; medium through very coarse sand grains are mainly pumiceous ash; slightly alkaline (pH 7.6); clear smooth boundary. (5 to 3 cm thick)

A2--5 to 13 cm; light brownish gray (10YR 6/2) ashy fine sandy loam, dark grayish brown (10YR 4/2) moist; weak fine and medium granular structure; soft, very friable, slightly sticky and nonplastic; common very fine and many fine roots; many fine tubular pores; 10 percent gravel; medium through very coarse sand grains are mainly pumiceous ash; slightly alkaline (pH 7.8); clear smooth boundary. (0 to 15 cm thick)

Bw--13 to 28 cm; light brownish gray (10YR 6/2) ashy loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common fine, few medium, and few coarse roots; many fine tubular pores; 5 percent gravel; medium through very coarse sand grains are mainly pumiceous ash; slightly alkaline (pH 7.8); clear smooth boundary. (8 to 15 cm thick)

2Bk--28 to 46 cm; light brownish gray (10YR 6/2) cobbly ashy loam, dark grayish brown (10YR 4/2) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine, few medium, and few coarse roots; common fine tubular pores; 25 percent cobbles and 5 percent gravel; medium through very coarse sand grains are mainly pumiceous ash; secondary carbonates segregated as common fine coats on bottoms of rock fragments; slightly effervescent; moderately alkaline (pH 8.0); clear smooth boundary. (8 to 20 cm thick)

2Bqk--46 to 56 cm; pale brown (10YR 6/3) cobbly ashy loam, brown (10YR 4/3) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine, few medium, and few coarse roots; common fine tubular pores; 15 percent weakly cemented durinodes; 15 percent cobbles and 5 percent gravel; medium through very coarse sand grains are mainly pumiceous ash; secondary carbonates segregated as few fine threads on durinodes and as few fine coats on bottoms of rock fragments; slightly effervescent; moderately alkaline (pH 8.0); abrupt irregular boundary. (8 to 20 cm thick)

3R--56 cm; basaltic tuff-breccia; calcium carbonate coats on the surface of the bedrock contact.

TYPE LOCATION: Lake County, Oregon; in the Lost Forest Research Natural Area northeast of Christmas Lake Valley; approximately 2,700 feet west and 2,100 feet north of the southeast corner of section 32, T. 25 S., R. 20 E.; USGS Sand Rock 7.5 minute topographic quadrangle; latitude 43 degrees 16 minutes 39 seconds N and longitude 120 degrees 15 minutes 46 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring, dry from mid-June to mid-October; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Depth to base of cambic horizon: 30 to 66 cm.
Depth to bedrock: 50 to 66 cm to a lithic contact.

Particle-size control section - Clay content: 10 to 20 percent.
Rock fragments: 15 to 35 percent, mainly gravel and cobbles. Lithology of fragments are basaltic tuff and tuff-breccia.
Volcanic glass content: 70 to 90 percent glass in the coarse silt through fine sand fractions. Glass is mainly present in pumiceous ash grains, glass aggregates, and glass-coated mineral grains.

A1 horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Structure: Weak fine granular, weak thin platy parting to weak fine and medium granular structure

A2 horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Structure: Weak fine granular, weak thin platy parting to weak fine and medium granular structure
Rock fragments: 0 to 10 percent gravel and cobbles.

Bw horizon
Chroma: 2 or 3, dry or moist.
Texture: Ashy loam, ashy sandy loam, gravelly ashy loam, gravelly ashy sandy loam, cobbly ashy loam, or cobbly ashy sandy loam.
Clay content: 8 to 20 percent.
Rock fragments: 5 to 35 percent gravel and cobbles.
Consistence: Soft to slightly hard dry, very friable to friable moist.

Bk horizon
Chroma: 2 or 3, dry or moist.
Texture: Gravelly ashy loam, gravelly ashy sandy loam, cobbly ashy loam, or cobbly ashy sandy loam.
Clay content: 8 to 20 percent.
Rock fragments: 5 to 35 percent gravel and cobbles.
Consistence: Soft to slightly hard dry, very friable to friable moist.
Reaction: Slightly alkaline or moderately alkaline.
Calcium carbonate equivalent: 1 to 3 percent.

Bqk horizon
Chroma: 2 or 3, dry or moist.
Texture: Ashy loam, ashy sandy loam, gravelly ashy loam, gravelly ashy sandy loam, cobbly ashy loam, or cobbly ashy sandy loam.
Clay content: 12 to 20 percent.
Rock fragments: 10 to 30 percent gravel and cobbles.
Consistence: Slightly hard to hard dry, friable moist.
Durinodes: 10 to 15 percent, weakly cemented or moderately cemented.
Reaction: Slightly alkaline or moderately alkaline.
Calcium carbonate equivalent: 1 to 3 percent.

COMPETING SERIES: There are currently no other series in this family.

GEOGRAPHIC SETTING: Lostforest soils are on structural benches. They formed in volcanic ash and slope alluvium derived from basaltic tuff and tuff-breccia. Slopes are 0 to 5 percent. Elevations range from 1,310 to 1,435 meters. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 200 to 250 mm, with an annual snowfall of about 530 mm. The mean annual temperature is 6 to 7 degrees C. The frost-free period is 50 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Morehouse, Puzzlebark, and Sandrock soils. Morehouse soils are ashy, very deep, do not have diagnostic subsurface horizons, and occur on stable dunes and sand sheets. Puzzlebark soils are ashy, have cambic horizons, and are shallow to thin duripans over lithic contacts. Sandrock soils are ashy, have argillic horizons, and are shallow to lithic contacts.

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

USE AND VEGETATION: Lostforest soils are used for livestock grazing, wildlife habitat, and recreation. The present vegetation is mainly mountain big sagebrush, Thurber's needlegrass, bottlebrush squirreltail, and Sandberg's bluegrass with scattered western juniper and ponderosa pine.

DISTRIBUTION AND EXTENT: South-central Oregon. These soils are not extensive with about 2,500 acres of the series mapped to date. MLRA 23.

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

SERIES ESTABLISHED: Lake County (Northern Part), Oregon, 2006. The name is from the Lost Forest Research Natural Area.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A1 and A2 horizons and part of the Bw horizon).
Cambic horizon - The zone from 13 to 56 cm (Bw, 2Bk, and 2Bqk horizons).
Vitrandic intergrade feature - The zone from the soil surface to 56 cm (A1, A2, Bw, 2Bk, and 2Bqk horizons).
Identifiable secondary carbonates - The zone from 28 to 56 cm (2Bk and 2Bqk horizons).
Durinodes - The zone from 46 to 56 cm (2Bqk horizon).
Lithic contact - The boundary at 56 cm to underlying hard bedrock (3R layer).
Particle-size control section and ashy substitute class with glassy mineralogy - The zone from 25 to 56 cm (2Bk and 2Bqk horizons and part of the Bw horizon).

ADDITIONAL DATA: Volcanic glass percentages in the sand fraction determined locally by optical grain count using a polarizing petrographic microscope. Temperature and precipitation means based on climate data observed at the Silver Lake Ranger Station located 40 miles southwest of the Lost Forest Research Natural Area (43 degrees, 7 minutes N, 121 degrees, 4 minutes W; 1,335 meters elevation) between 1953 and 1999.

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National Cooperative Soil Survey
U.S.A.