Ecological site group description

Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.

Physiography

This site occurs on relatively flat upland areas as including plateaus, valley floors and fans. Slopes range from 0 to 15 percent but are mostly less than 10 percent. The soils are deep, and have a clay loam to clay surface texture.

Climate

Winter summer moisture ratios range from 70:30 to 60:40. Late spring is usually the driest period, and early fall moisture can be sporadic. Summer rains fall from June through September; moisture originates in the Gulf of Mexico and creates convective, usually brief, intense thunderstorms. Cool season moisture from October through May tends to be frontal; it originates in the Pacific and the Gulf of California and falls in widespread storms with longer duration and lower intensity. Precipitation generally comes as snow from December through February. Accumulations above 12 inches are not common but can occur. Snow usually lasts for 3-4 days, but can persist much longer. Summer daytime temperatures are commonly 95 - 100 F and on occasion exceed 105 F. Winter air temperatures can regularly go below 10 F and have been recorded below - 20 F.

Soil features

The soils grouped into this range site are moderately deep or deep to any plant root restriction layer. The surface textures range from sandy clay loam to clay. This ecological site does not include soils with cracking clay surfaces. The subsurface textures are clay loam to clay and can have rock fragments ranging from 10 to 35 percent. Permeability is slow. The soil reaction is slightly to moderately alkaline (pH 7.4 to 8.4). The water erosion hazard is moderate to high.

Vegetation dynamics

Reference State
This site is a grassland community with scattered shrubs and a few forbs. The grasses are a mixture of cool and warm season grasses. The shrubs are four wing saltbush at the lower elevation and precipitation areas and Wyoming big sagebrush at the higher elevation and precipitation areas.

Major Land Resource Area

MLRA 035X
Colorado Plateau

Subclasses

• R035XA106AZ–Clayey Upland 10-14" p.z.
• R035XA107AZ–Clay Loam Upland 10-14" p.z.
• R035XB239AZ–Clayey Fan 6-10" p.z.
• R035XC307AZ–Clay Loam Upland 10-14" p.z.
• R035XG706AZ–Clayey Upland 14-18" p.z.
• R035XG707AZ–Clay Loam Upland 14-18" p.z.

Correlated Map Unit Components

22341065, 22341097, 22341100, 22341115, 22341143, 22341145, 22341147, 22341149, 22341150, 22341151, 22341152, 22341155, 22341154, 22341159, 22341161, 22341165, 22341163, 22353947, 22353999, 22353377, 22353381, 22353379, 22353436, 22353431, 22484735, 22484724, 22484758, 22484730, 22484775

Stage

Provisional

Contributors

Curtis Talbot