Ecological site group DX035X01FESG13
Canyonlands - Sandy Grasslands and Shrublands - mid elevation
Last updated: 10/12/2022
Accessed: 05/02/2024
Ecological site group description
Key Characteristics
- Canyonlands
- Sandy Grasslands and Shrublands
- Mid-elevation 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
The ecological sites in this group occur on dunes, sandsheets, and alluvial fans on structural benches, mesas, plateaus, cuestas, terraces, and toeslopes. Elevations range from 3,700 to 6,700 feet. Slopes are 1 to 30 percent. Runoff is very low to low due to the rapid permeability of the soil and may be influenced by local micro-topography.
Climate
The climate is characterized by hot summers and cool to cold winters, which can be slightly modified by local topographic conditions, such as aspect. Large fluctuations in daily temperature are common. Mean annual air temperatures range from 48 to 54 degrees Fahrenheit. On the average, February, May, and June are the driest months and August, September, and October are the wettest months, most of the summer precipitation occurs as convection thunderstorms. Precipitation is variable from month to month and from year to year, but averages range between 6-12 inches annually but may be as much as 18 inches at higher elevations. Snow packs in the lower elevations are generally light and not persistent.
Soil features
The soils are moderately deep to very deep sands and sandy loams formed in eolian deposits and alluvium derived, dominantly from sandstone. Material derived from shale, siltstone and igneous sources may influence the soils locally. Soil drainage ranges from well drained to excessively well drained. Permeability is moderately rapid to rapid. The soils have high potential for erosion by wind and water after disturbance. Rock fragments are generally rare , but may occur in soils influenced by alluvial processes. Soils are typically nonsaline and nonsodic. Biological soil crust cover varies by surface texture and plant community; sandy loams in grass dominated communities being more likely to support biological soil crusts. The more active dunes are generally dominated by shrub communities, supporting sand sagebrush, Cutler's jointfir, Harvard oak, or green Mormon tea depending on precipitation. More stable sites support a higher proportion of grasses. Soil moisture regime ranges from typic aridic to aridic ustic and soil temperature regime is mesic.
Vegetation dynamics
The ecological sites in this group are typically perennial grasslands consisting of a mixture of cool and warm season grasses. A shrub layer consisting of fourwing saltbush, winterfat, sand sagebrush, Cutler’s jointfir, or green Mormon tea is usually present and is the dominant visual aspect of the sites. In areas of recent deposition or soil movement the shrub layer may be more evident.
The natural disturbance regime consisted of fluctuations in precipitation and infrequent fires ignited by both natural causes and by Native Americans. Herbivory by insects and small mammals were localized influences as was use by native large herbivores.
It is estimated that the historic fire regime was 35-100+ years, depending on fine fuel accumulations (Howard 2003).
These ecological sites have been grazed by domestic livestock since they were first introduced into the area. Before grazing began, fires would often only carry when several good moisture years created sufficient fuels for them to burn. With the introduction of domestic livestock, however, these fuel loads have typically been reduced, lengthening the fire return interval and allowing shrubs to increase at the expense of grasses. Conversely, the introduction of cheatgrass, which accompanied livestock grazing but is not restricted to grazed areas, has led to a shorter fire return interval in some cases, which promotes a cheatgrass dominated state.
Major Land Resource Area
MLRA 035X
Colorado Plateau
Subclasses
- R035XY115UT–Desert Sand (Sand Sagebrush)
- R035XY118UT–Desert Sandy Loam (Fourwing Saltbush)
- R035XY211UT–Semidesert Sand (Dune)
- R035XY212UT–Semidesert Sand (Fourwing Saltbush)
- R035XY215UT–Semidesert Sandy Loam (4-Wing Saltbush)
- R035XY217UT–Semidesert Sandy Loam (Spiny Hopsage)
- R035XY309UT–Upland Sand (Mormon Tea)
Correlated Map Unit Components
22340909, 22934177, 22481133, 22481134, 22480932, 22480933, 22480937, 22481078, 22481181, 22481182, 22480897, 22481213, 22480922, 22594027, 22593433, 22593739, 22593741, 22594305, 22593744, 22593474, 22594072, 22594073, 22594347, 22593500, 22593820, 22594081, 22594084, 22593527, 22593837, 22594381, 22594396, 22594397, 22598325, 22597887, 22598201, 22598204, 22598354, 22598068, 22598075, 22598080, 22728241, 22965345, 22965572, 22964723, 22964758, 22964700, 22964698, 22964718, 22964716, 22963829, 22963830, 22963772, 22963770, 22963817, 22963811, 22963812, 22963775, 22963834, 22963745, 22963743, 22963839, 22963724, 22963718, 22963634, 22963739, 22963693, 22963735
Stage
Provisional
Contributors
Vic Parslow
Keith Crossland
Curtis Talbot
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