40 27—Lapine paragravelly ashy loamy coarse sand, 35 to 55 percent south slopes

27—Lapine paragravelly ashy loamy coarse sand, 35 to 55 percent south slopes

 Map Unit Setting

General location: Mountainsides in the southeastern corner of the park

Major land resource area (MLRA): 6

Elevation: 4,500 to 6,500 feet

Average annual precipitation: 30 to 50 inches

Average annual air temperature: 38 to 42 degrees F

Frost-free period: 10 to 50 days

 Map Unit Composition

 Lapine and similar soils: 90 percent

Minor components: 10 percent

 Characteristics of the Lapine and Similar Soils


 Landform: Ashflow

Geomorphic position: Pumice and ashfall and ashflow material on mountainsides

Parent material: Ash and pumice

 Properties and qualities

 Slope: 35 to 55 percent; northeast to northwest aspects

Percentage of surface covered with stones and boulders: None

Restrictive features: None within a depth of 60 inches

Drainage class: Excessively drained

Permeability: Very rapid

Flooding: Not present

Water table: Not present

Ponding: Not present

Available water capacity: About 6.2 inches

 Interpretive groups

 Ecological site: Forestland—(006XY700OR) Pinus ponderosa-Abies/Symphoricarpos hesperius

 Typical profile

 Oi—0 to 2 inches; slightly decomposed plant material

A—2 to 8 inches; paragravelly ashy loamy coarse sand

Bw1—8 to 15 inches; paragravelly ashy loamy sand

Bw2—15 to 24 inches; very paragravelly ashy sand

C—24 to 60 inches; extremely paragravelly ashy sand

 Characteristics of the Minor Components

 Similar soils that have buried soil material at a depth of 25 to 40 inches

 Percentage of map unit: 9 percent

Landform: Ashfall

Geomorphic position: Mountainsides

 Rock outcrop

 Percentage of map unit: 1 percent

Landform: Mountain

Geomorphic position: Lava flows on mountainsides

 Major Soil Features and Properties Affecting Management

 Lapine soil

 • Low soil strength

• Steepness of slope

• High pumice content

• Water erosion

• Very rapid permeability

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