LOCATION ROYST OREstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Pachic Argixerolls
TYPICAL PEDON: Royst gravelly loam, woodland. (Colors are for moist soil unless otherwise noted.)
A1--0 to 3 inches; very dark grayish brown (10YR 3/2) gravelly loam, grayish brown (10YR 5/2) dry; weak very fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine pores; about 30 percent fine gravel; few scattered stones on surfaces; slightly acid (pH 6.5); clear smooth boundary. (2 to 5 inches thick)
A2--3 to 10 inches; very dark grayish brown (10YR 3/2) very gravelly loam, grayish brown (10YR 5/2) dry; weak fine subangular blocky structure parting to weak very fine granular; slightly hard, friable, moderately sticky and slightly plastic; many very fine roots; common very fine tubular pores; about 40 percent fine gravel; slightly acid (pH 6.5); clear smooth boundary. (4 to 10 inches thick)
BA--10 to 15 inches; dark brown (7.5YR 3/3) very gravelly clay loam, brown (7.5YR 5/3) dry; moderate medium and fine subangular blocky structure; hard, firm, very sticky and moderately plastic; many very fine roots; common very fine tubular pores; about 40 percent gravel; slightly acid (pH 6.5); clear wavy boundary. (0 to 10 inches thick)
Bt1--15 to 24 inches; dark reddish brown (7.5YR 3/3) very gravelly clay loam, brown (7.5YR 5/3) dry; moderate medium and fine subangular blocky structure; hard, firm, very sticky and very plastic; common very fine and fine roots; common very fine tubular pores; few faint clay films on faces of peds and in pores; 45 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (0 to 12 inches thick)
Bt2--24 to 34 inches; dark reddish brown (5YR 3/4) very gravelly clay, reddish brown (5YR 5/4) dry; moderate medium and fine subangular blocky structure; hard, very firm, very sticky and very plastic; common very fine and fine roots; common very fine and fine tubular pores; many faint clay films on peds and in pores; about 50 percent gravel; slightly acid (pH 6.4); abrupt wavy boundary. (5 to 12 inches thick)
Cr--34 to 36 inches; dark gray (10YR 4/1) fractured weathered volcanic tuff, light gray (10YR 7/1) dry. (1 to 4 inches thick)
R--36 inches; unweathered volcanic tuff.
TYPE LOCATION: Klamath County, Oregon; about 9 miles north of the town of Bonanza; 700 feet south and 500 feet west of the northeast corner of sec. 35, T. 37 S., R. 11 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 44 to 47 degrees F. The soil temperature is above 41 degrees F. from about March 15 to November 15. The soils are usually moist but are dry in all parts between depths of 4 and 12 inches about 80 to 100 consecutive days following the summer solstice. Depth to bedrock is 20 to 40 inches. A 1 to 4 inch thick paralithic contact is immediately above the lithic contact. The mollic epipedon is 20 to 30 inches thick and includes all or part of the argillic horizon. The argillic horizon has 35 to 85 percent rock fragments. Some pedons have an 0 horizon.
The A horizon has hue of 10YR, 7.5YR, or 5YR, value of 2 or 3 moist, 4 or 5 dry and chroma of 1 to 3 moist and 1 to 4 dry. It has 25 to 50 percent rock fragments. It is strongly acid to neutral.
The Bt horizon has hue of 5YR, 7.5YR, or 10YR, value of 3 or 4 moist, 4 through 6 dry, and chroma of 2 through 4 moist and dry. It is very gravelly, very cobbly, or extremely stony clay and clay loam with 35 to 45 percent clay. It is moderately acid to neutral.
COMPETING SERIES: These are the Longbranch, Menbo (T) Snell, and Winterim series. Longbranch and Winterim soils are over 40 inches deep to bedrock. Snell soils lack a paralithic contact over a lithic contact at a depth of 20 to 40 inches. Menbo soils are dry for 100 to 120 consecutive days after the summer solstice.
GEOGRAPHIC SETTING: Royst soils are on escarpments and rock benches. Elevations range from 3,000 to 6,000 feet. The soils formed in very gravelly material weathered from tuff, basalt, andesite, and small amounts of pumiceous ash. The climate is characterized by cold wet winters and hot dry summers. The mean annual precipitation is 14 to 25 inches. The mean January temperature is 27 degrees F, the mean July temperature is 62 degrees F. The mean annual temperature is 40 to 45 degrees F. The frost-free period is 10 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bly, Booth, Mound, Nuss, and Woodcock soils. Nuss soils lack an argillic horizon, have 18 to 30 percent clay and are underlain by bedrock at depths of 12 to 20 inches. Woodcock soils are on associated north-facing slopes, have cryic soil temperature regime and have 25 to 35 percent clay. Bly soils are fine-loamy and have bedrock at depth of greater than 60 inches. Booth soils are fine and have an abrupt boundary and clay increase between the A and Bt horizons. Mound soils are over 40 inches deep to bedrock, have low base saturation in the upper 30 inches and are on north-facing slopes.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability.
USE AND VEGETATION: The soils are used for limited timber production, livestock grazing and wildlife habitat. Potential native vegetation is ponderosa pine, western juniper, curlleaf mountainmahogany, antelope bitterbrush and Idaho fescue.
DISTRIBUTION AND EXTENT: Colder, northern portions of the Basin and Range Province in south-central and northeastern Oregon, MLRA 10, 21,43. These soils are extensive.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: Klamath County, Oregon; 1977.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Mollic epipedon (pachic) - from 0 to 24 inches (A1, A2, BA, and Bt1 horizons)
Argillic horizon - from 15 to 34 inches (Bt1 and Bt2 horizons)
The Snell Series is similar to the Royst Series. Royst soils when originally described did not describe the R, the description stopped with the Cr contact. The Snell and Royst series were separated on lithic vs. paralithic contact. When the Royst Series was revised and the R contact described these two series became similar. As mapped the Snell series is mapped in MLRA 9 and 43 and Royst in MLRA 10, 21 and 43. The areas mapped as Royst in MLRA 43 should be re-correlated to the Snell series. MLRA 9 is a grass dominated range area with late spring precipitation. MLRA 10 and 21 is a grass-shrub dominated range area which lacks the spring precipitation.