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 range site occurs in an upland position on plateaus, benches, mesas or buttes. It is on gently sloping to rolling plains and slopes that are generally 1 - 15% and occasionally up to 30%. It does not benefit from run-in moisture from adjacent areas nor does it suffer from excessive loss of moisture from runoff.

Climate

About 50% of annual precipitation is received as rain from July to September with the least amounts falling during May and June. Most of the moisture that comes from November to February comes as snow. High winds are common during the winter and spring.

Soil features

Soils on this site are very shallow and shallow (5 - 20 inches deep) to bedrock. The surface textures range from loamy sand to loam about 1 - 4 inches thick. The surface may be covered with up to 20-30% gravels or channers. The subsurface horizon has textures of sandy loam or loam and contains less than 35% gravel by volume. Shallow depth to bedrock restricts the root growth and moisture. The soil has very low available water capacity.

Vegetation dynamics

This site has a plant community made up primarily of short and mid grasses with a moderate amount of shrubs. The plant community has a mixture of both cool and warm season plants.
The reference state and the reference (climax) plant community has been determined by study of relict areas or areas protected from excessive disturbances. Trends in plant communities going from heavily grazed areas to lightly grazed areas, seasonal use pastures and historical accounts have also been used.
This reference state is characterized as a native mid and short grassland dominated by black grama and galleta with shrubs like Bigelow sagebrush and shadscale saltbush. Sites dominated by sandstone will show a slight dominance of Bigelow sagebrush and sites dominated by shale will show a slight dominance of shadscale.
Plant species most likely to invade or increase on this site when it deteriorates are broom snakeweed, Russian thistle and cacti.

Repetitive defoliation and high utilization during the winter and spring periods will decrease the cool season grasses, which are replaced by lower forage value grasses and shrubs.

Major Land Resource Area

MLRA 035X
Colorado Plateau

Subclasses

• R035XA111AZ–Limy Upland 10-14" p.z.
• R035XB210AZ–Loamy Upland 6-10" p.z.
• R035XB215AZ–Sandstone/Shale Upland 6-10" p.z.
• R035XB232AZ–Limestone/Sandstone Upland 6-10" p.z.
• R035XB255AZ–Sandstone Rockland 6-10" p.z.
• R035XC313AZ–Loamy Upland 10-14" p.z.
• R035XC319AZ–Limestone/Sandstone Upland 10-14" p.z.
• R035XC337AZ–Sandstone/Shale Upland 10-14" p.z.

Correlated Map Unit Components

22341075, 22341101, 22341102, 22341104, 22341136, 22341178, 22341180, 22341192, 22341193, 22341639, 22341650, 22341648, 22341627, 22341653, 22341651, 22341611, 22341642, 22341655, 22341656, 22341634, 22341658, 22353887, 22353889, 22353974, 22396789, 22396746, 22396645, 22396748, 22396749, 22396668, 22396667, 22396675, 22396711, 22396663, 22396620, 22396735, 22396808, 22396807, 22396706, 22396820, 22396821, 22396852, 22396853, 22396845, 22396630, 22396631, 22396842, 22396843, 22396824, 22396825, 22396613, 22396626, 22484793

Stage

Provisional

Contributors

Curtis Talbot