Ecological site group DX035X01EESG04
Green River Desert - Saline Hills and Badlands
Last updated: 09/01/2021
Accessed: 05/02/2024
Ecological site group description
Key Characteristics
- Green River Desert
- Saline Hills and Badlands
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 of this group occur on hills, structural benches, mesas, dissected pediments and on alluvial fans and valley floors associated with these landforms. Slopes range from 2 to 50 percent. Runoff is typically high. Elevations generally range from 3500 to 6800 feet.
Climate
The climate is characterized by hot, dry summers, cold winters and moist springs. March, April amd July through October are the wettest months of the year with May, June and November through February being the driest. Approximately 65 to 70% of the precipitation occurs as rain from May through October. Precipitation is extremely variable from month to month and from year to year but averages between 5-13 inches. Mean annual air temperature ranges from 46 to 52 degrees Fahrenheit. Large fluctuations in daily temperatures are typical. Much of the summer precipitation occurs as convection thunderstorms. Some years are so dry that little plant growth occurs, and some plants remain dormant.
Soil features
The soils associated with this ecological site group range from very shallow to very deep and formed in residuum, colluvium, slope alluvium and alluvium derived from marine shales and gypsiferous shale. The areas dominated by gypsiferous parent material are typically medium textured and usually support a sparse overstory of Torrey's jointfir and sparse grass and forb cover usually associated with thin, patchy eolian deposits on the lee side of the shrubs or of pinnacles in the biotic crust which commonly covers the interspaces in the gypsiferous sites. The marine shale sites usually support a sparse overstory of saltbush and a very sparse understory of native grasses. They are usually moderately fine to fine textured and strongly saline. Biotic crusts are uncommon on these sites due to high salinity. Thin physical crusts often form in the plant interspaces.
Soil moisture regime is aridic and soil temperature regime is mesic.
Vegetation dynamics
The general aspect of the sites in this group in the reference state is represented by a shrub layer dominated by saltbush or Torrey's jointfir with a highly variable herbaceous layer of perennial grasses, principally James galleta and Indian ricegrass.
Large gaps between plants in relic areas indicate that these sites did not historically burn often enough for fire to strongly influence the ecological processes of this site. Other disturbances such as brush treatments, invasive species, and OHV use, could reduce the resilience of the reference community, creating risk.
These sites provides only marginal livestock grazing due to the small amount forage available and the shortage of drinking water. Torrey's jointfir, found on the gypsiferous sites has low palatability. However, other plants present are easily accessible and relatively nutritious. Improper grazing practices can cause any grasses, and perennial forbs present to be grazed out. Improper grazing coupled with drought can also remove the saltbush and other shrubs. Once the native community is lost on these soils it is very difficult to get desirable vegetation back.
Halogeton and Russian thistle are most likely to invade these sites. At this time, cheatgrass is not readily invading these sites likely due the chemical properties of the soil. Drought, erosion or improper grazing, in combination, can permanently alter the reference plant community.
Other natural disturbance mechanisms include fluctuations in climate, which influence the soil/water/vegetation relationships. These fluctuations can facilitate changes in production from one year to the next.
Major Land Resource Area
MLRA 035X
Colorado Plateau
Subclasses
Stage
Provisional
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Ecosystem states
T1A | - | D = Drought E = Establishment of non-native invasive species HWB = Heavy wildlife browsing ILG = Improper livestock grazing |
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T2A | - | D = Drought F = Fire HWB = Heavy wildlife browsing ILG = Improper livestock grazing SD = Surface disturbances |