Ecological site group DX035X01GESG24
Chinle Valley Sandstone Moderately Deep to Very Deep, MAST < 54 degrees F
Last updated: 10/12/2022
Accessed: 05/02/2024
Ecological site group description
Key Characteristics
- Chinle Valley
- Sandstone or sandy loam
- Moderately deep to very deep
- MAST < 54 degrees F
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 ecological group occurs in an upland position on gently sloping plains or alluvial fans on treads of high stream terraces, fan remnants of undulating plateaus, structural benches, and cuestas. It neither benefits significantly from run-in nor experiences excessive runoff of moisture. Slopes range from 1 to 8 percent. Elevations range from 4,700 to 6,100 feet.
Climate
Mean annual precipitation varies from 6 to 14 inches. About 60% of this moisture comes as rain from April through October. May and June are the driest months. Most of the moisture from November through March comes as snow. Much of the summer precipitation occurs as convection thunderstorms.
Mean temperatures for the hottest month (July) is 72 degrees F; for the coldest month (January) is 32 degrees F. Extreme temperatures of 105 degrees F and -26 degrees F have been recorded. Long periods with little or no effective moisture are relatively common. Extreme temperatures of 104 degrees F and –17 degrees F have been recorded. The frost-free period ranges from 140 to 160 days.
Winds of high velocity during late winter and early spring are common.
Cool season plants begin growth in early spring and mature in the early summer. Warm season plants take advantage of summer rains and grow from July through September.
Soil features
These soils are moderately deep to very deep and well drained. Surface horizons have textures of sandy loam to fine sandy loam about 4 to 10 inches thick. Subsurface horizons have textures ranging from clay to sandy loam. There may be thin strata of finer and/or coarser textures. They are formed in alluvium or eolian deposits derived from sandstone. Surface textures include loamy fine sand and fine sandy loam. The subsoil has textures of very fine sandy loam, fine sandy loam, loamy coarse sand, and loamy sand. Permeability is moderately rapid. Available water holding capacity is low to moderate. Runoff is very low to low, and the hazard of water erosion is very slight to slight. The hazard of soil blowing is slight to severe. The soils are slightly to strongly alkaline (pH 7.4-9.0), nonsaline to slightly saline below 24 inches (EC 0-8), and nonsodic to slightly sodic (SAR 0-13). Biological crust cover is characterized by a weak crust, with light cyanobacteria and/or isolated moss clumps, with no continuity or isolated pinnacles of lichen and moss with little continuity.
Vegetation dynamics
This group has a plant community made up primarily of short- and mid-grasses, some shrubs, and a small percentage of forbs. In the original plant community there is a mixture of both cool- and warm-season grasses. Plant species most likely to invade or increase on this site when it deteriorates are cheatgrass and other annual weeds, sixweeks fescue, galleta, and broom snakeweed. Continuous livestock grazing during winter and spring will decrease the cool-season grasses, which are replaced by lower forage value grasses and shrubs.
In disturbed areas, rodent activity, water flow patterns, and coppice mounding of shrubs are more common than on sites in the reference state.
As ecological condition deteriorates due to overgrazing, Indian ricegrass, and needleandthread decrease while galleta, spiny hopsage, and Cutler mormontea increase. When the potential natural plant community is burned, spiny hopsage,blackbrush and fourwing saltbush decreases while Cutler mormontea, broom snakeweed, Indian ricegrass and galleta increase. Cheatgrass, Russian thistle, and Utah juniper are most likely to invade this site. As the calcic layer in the soil goes deeper, the spiny hopsage decreases and grasses increase.
Suitability for rangeland seeding is poor to fair. The major limiting factor is precipitation that can be variable with low years. Disturbed areas can be seeded to control erosion. Plants suitable for seeding include Indian ricegrass, crested wheatgrass, and other adapted native plants.
Brush Management and seeding can be used to improve the vegetation in deteriorated areas of the range that are producing more woody shrubs than would be present in the potential natural plant community. Suitable brush management practices include prescribed burning, chemical spraying, and mechanical treatment.
Major Land Resource Area
MLRA 035X
Colorado Plateau
Subclasses
Correlated Map Unit Components
22397389, 22397509, 22397316, 22397317, 22397468, 22397363, 22397396, 22397483, 22397484, 22397488, 22397431, 22397608, 22397606, 22397223, 22397272, 22397614, 22397591, 22397320, 22397321, 22397619, 22397569, 22397568, 22397592, 22397290, 22397572, 22397581, 22999604, 22999623, 22999667, 22999666, 22999813, 22601108, 22601543
Stage
Provisional
Contributors
Curtis Talbot
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