Ecological site group DX035X01IESG14
Little Colorado River Basin-Shale or clayey shallow soils. Dominantly shale (non run in moisture)
Last updated: 10/25/2022
Accessed: 05/02/2024
Ecological site group description
Key Characteristics
- Little Colorado River Basin
- Shale or Clayey
- Does not receive extra water from run-in moisture
- Generally shallow soils on hills, benches and slopes
- landforms are dominantly shale
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 gently sloping plains, plateaus or fan remnants. Also occurs on summits and footslopes of mesas and buttes, hills, benches and escarpments, and pediments. Slopes generally range from 0 to 15 percent, but can reach up to 25 percent for short distances.
This site occurs in an upland position. It neither benefits from run-in moisture nor sustains excessive runoff unless denuded of its vegetation.
Climate
Area has a very dry and windy climate that is hot in the summer and cold in the winter. Average annual precipitation is from 6 to 10 inches. Soil moisture regime is typic aridic and the soil temperature regime is mesic. A slight majority of the precipitation arrives during the late fall, winter, and early spring. this winter season moisture originates in the Pacific Ocean and arrives as rain, or sometimes snow, during widespread frontal storms of generally low intensity. The majority of the snow falls from December through February, but rarely lasts more than a few days. The driest period is from late May to early July. Summer rains occur from July through September during brief intense local thunderstorms. The rain is sporadic in intensity and location. Windy conditions are common year round with the strongest most frequently in the spring.
Soil features
Soils in this site are shallow and well drained to the parent material. Highly weathered clayey shale is the parent material. The surface layer is clay, silty clay, or clay loam. The substratum is clay or silty clay. The soils are typically saline/sodic to sodic. Permeability is very slow. Available water capacity is 1 to 3 inches. Salinity is low to high. The water erosion hazard is moderate to severe and the wind erosion hazard is slight. Effective rooting depth is typically shallow into the fractured parent material.
Vegetation dynamics
Reference State
The general aspect of the site is made up of primarily mid and short grasses with a significant percentage of cold desert shrubs and a few 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 saltbushes, broom snakeweed and annuals. Repetitive herbivory with high utilization during the winter and spring periods will decrease the cool season grasses, which are replaced by warm season, lower forage value grasses and shrubs.
Reference Plant Community
The mixed shrubs/grass plant community is made up of primarily mid and short grasses with a significant percentage of cold desert shrubs and a few forbs. The plant composition for the site is typically 65-70% grasses, 5-10% forbs and 20-25% shrubs. Plant species most likely to invade or increase on this site when it deteriorates are broom snakeweed and annuals. Continuous grazing during the winter and spring periods will decrease the cool season grasses, which are replaced by warm season, lower forage value grasses and shrubs.
Major Land Resource Area
MLRA 035X
Colorado Plateau
Correlated Map Unit Components
22341106, 22353854, 22353877, 22353989, 22354041, 22354031, 22396714, 22396723, 22484755, 22484787
Stage
Provisional
Contributors
Curtis Talbot
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