Ecological site group DX035X01BESG02
Circle Cliffs - Bottoms and Flats - run in - sodic
Last updated: 10/05/2022
Accessed: 05/02/2024
Ecological site group description
Key Characteristics
- Circle Cliffs
- Bottoms and Flats
- Extra water is from run-in or local water table
- Soils are sodic
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 group occurs on alluvial valleys, alluvial fans, flood plains, valleys, stream terraces, near stream channels, and valley flats. These are run-in sites that receive extra moisture from surrounding uplands and may have a seasonal high water table within 72 inches of the soil surface in the lowest positions. Slopes range from 0-8% and elevations are generally 4200-6600 ft.
Climate
The climate is characterized by hot summers and cool to warm winters. Large fluctuations in daily temperatures are common. Approximately 70-75% occurs as rain from March through October. On the average, April, May, and June are the driest months and August through October are the wettest months. Precipitation is extremely variable from month to month and from year to year but averages between 7-12 inches. Much of the summer precipitation occurs as convection thunderstorms. This is a run-in site that receives additional moisture from adjacent sites. Rare to occasional flooding occurs from April to September.
Soil features
The soils of this site are very deep alluvial deposits, primarily derived form sedimentary materials. Typically soil surface fragments range from 0-10%. Surface and subsurface textures are generally silty loams, clays, fine sandy loams, loamy fine sands, and very fine sandy loams. Permeability ranges from very slow to moderately rapid. Water holding capacity in the upper 40 inches of soil also has a broad range; from 3.7 inches in coarse soils to 7.4 in fine textured soils. These soils typically receive extra water from run in and may have a seasonally high water table. The soils have high salt and sodium content and usually support halophytic plants. The soil temperature regime is mesic and the soil moisture regime can be aridic (torric) or ustic aridic.
Vegetation dynamics
These sites were historically dominated by greasewood and a diverse perennial understory, including seepweed, pale evening primrose, Indian ricegrass, Sporobolus spp, and James' galleta. The historic fire return interval is presumed to be about 35-100 years (Anderson 2004). Greasewood and native grasses would have resprouted within one year following fire and maintained dominance of the site. There is no evidence that prolonged drought would dramatically alter the species composition of the site in reference condition, although production is expected to be lower.
Today this site often burns less frequently due to fire suppression efforts and reduced fine fuel loads resulting from livestock grazing. In addition, excessive livestock grazing during the spring and summer can cause native grasses and forbs to lose vigor or disappear from the community completely.
Cheatgrass and Russian thistle commonly establish on this site, and Tamarisk can become dominant when the site occurs near stream and drainage corridors.
Major Land Resource Area
MLRA 035X
Colorado Plateau
Correlated Map Unit Components
22597330, 22967049, 22967051, 22966911
Stage
Provisional
Contributors
Vic Parslow
Keith Crossland
Curtis Talbot
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