Ecological site group DX035X01DESG03
Henry Mtns-Saline Uplands & Flats
Last updated: 09/01/2021
Accessed: 05/02/2024
Ecological site group description
Key Characteristics
- Henry Mountains
- Saline Uplands & Flats
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 mesas, benches, hillslopes, pediments, valleys, cuestas, and ridges. Run off is medium to high and is often influenced by micro-topography. Typically slopes range from 2-15% however sites have been mapped on slopes up to 50%.
Climate
The climate is characterized by hot summers and cool to warm winters, which can be slightly modified by local topographic conditions, such as aspect. Large fluctuations in daily temperatures are common. Mean annual high temperatures range from 67-75 degrees Fahrenheit and mean annual low temperatures range from 35-50 degrees Fahrenheit. Approximately 65-70% of moisture occurs as rain from July-November, mostly as convection thunderstorms and snow. Precipitation is variable from month to month and from year to year but averages between 5-9 inches. Snow packs when present are generally light and not persistent.
Soil features
This site occurs on shallow to moderately deep soils. The dry surface layer color is typically reddish or grayish and the surface soil textures range from sandy loams to very fine sandy loams which can include a stony or channery modifier. These soils are poorly developed, well drained, and have moderate water holding capacities. Soil temperature regime is mesic and moisture regime ranges typic aridic to ustic aridic. Erosion potential of soils on reference state sites typically depends on surface rock fragments. Sites with greater than 30% rock fragments have lower wind and water erosion potentials than sites with less than 30% surface rock fragments. Biological crust cover is characterized as crustless with the possible occurrence of light cyanobacteria and/or isolated lichen and moss pinnacles.
Vegetation dynamics
This site developed under the Colorado Plateau climatic conditions and included the natural influences of herbivory and climate. The site is dominated by shadscale, Torrey's jointfir is also commonly present. Cool season grasses, such as Indian ricegrass, are more prevalent in sites found on soils with more structural development. For example sites mapped on Lime Ridge, near Bluff, UT, found on Limeridge soils, which have more development, are dominated by Indian ricegrass, James galleta, and shadscale. Conversely, sites mapped on the White Rim of Canyonlands National Park, near Moab, UT, found on Moenkopie and Tsaya soils, which are very weakly developed, are dominated by James galleta and shadscale. Indian ricegrass may or may not be present.
Vegetation on salt desert shrub lands is generally very sparse and thus fire did not carry well and therefore is not part of the historic natural disturbance regime (Simonin, 2001). Due to scarcity of local water sources this site was minimally influenced by large grazing ungulates before European settlement. Drought and other climatic conditions was the major natural disturbances influencing this site.
This site has been grazed by domestic livestock since they were introduced into the area. This introduction of livestock with it's use of fencing, and the development of reliable water sources have impacted the disturbance regime of this site. Improper livestock grazing (i.e., continuous season long grazing, heavy stocking rates, etc.) can cause this site to depart from it's reference plant communities and allow annual grasses, such as cheatgrass, to invade, and broom snakeweed to increase dramatically. These annual grasses can increase the sites fine fuel loads and make fire more prevalent, increasing the possibility that it will convert to an annual grassland community(Simonin, 2001).
Major Land Resource Area
MLRA 035X
Colorado Plateau
Subclasses
Stage
Provisional
Contributors
Victor Parslow, Keith Crossland
Click on box and path labels to scroll to the respective text.
Ecosystem states
T1A | - | D = Drought ILG = Improper livestock grazing SD = Surface disturbances WS = Establishment of non-native invasive species |
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T2A | - | D = Drought F = Fire ILG = Improper livestock grazing |
T2B | - | ILG = Improper livestock grazing SD = Surface disturbances |
R4A | - | BC = Biological Control PLG = Proper livestock grazing T = Time without disturbances W = Wet weather periods |
State 1 submodel, plant communities
1.1a | - | PLG = Proper livestock grazing T = Time without disturbances W = Wet weather periods |
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1.2a | - | D = Drought ILG = Improper livestock grazing SD = Surface disturbances |
State 2 submodel, plant communities
2.1a | - | PLG = Proper livestock grazing T = Time without disturbances W = Wet weather periods |
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2.2a | - | D = Drought ILG = Improper livestock grazing SD = Surface disturbances |
State 3 submodel, plant communities
3.1a | - | D = Drought F = Fire ILG = Improper livestock grazing |
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