Natural Resources
Conservation Service
Ecological site R028AY260UT
Semidesert Very Steep Shallow Loam (Black Sagebrush)
Accessed: 12/22/2024
General information
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.
Figure 1. Mapped extent
Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated.
Associated sites
| R028AY262UT |
Semidesert Very Steep Shallow Loam (Utah Juniper) |
|---|
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) Artemisia nova |
| Herbaceous |
Not specified |
Physiographic features
This site occurs on hillsides and mountainsides.
Table 2. Representative physiographic features
| Landforms |
(1)
Hill
(2) Mountain slope |
|---|---|
| Elevation | 4,500 – 6,700 ft |
| Slope | 50 – 70% |
Climatic features
The climate is semi-arid and characterized by cold snowy winters and warm dry summers. The average annual precipitation is 8 to 12 inches. Approximately 70 percent comes as rain from March through October. On the average, June through September are the driest months and March through May are the wettest months.
Mean Annual Air Temperature: 45-50
Mean Annual Soil Temperature: 48-52
Table 3. Representative climatic features
| Frost-free period (average) | 0 days |
|---|---|
| Freeze-free period (average) | 150 days |
| Precipitation total (average) | 12 in |
Influencing water features
Soil features
The characteristic soils in this site are 10 to 20 inches deep over bedrock and well drained.
They formed in alluvium, colluvium, and residuum derived mainly from limestone, sandstone, and siltstone parent materials. The surface horizon is shallow loam textures 4 inches thick. About 40 percent of the soil surface is covered by rock fragments. The volume of rock fragments in the soil profile is 35 to 60 percent and well drained.
These soils are medium textured and are calcareous throughout. Permeability is generally moderate. The available water capacity is 0.5 to 3.0 inches.
The water supplying capacity is 0.5 to 4.0 inches. Natural geologic erosion in potential is approximately 1 ton/acre/year.
Table 4. Representative soil features
| Drainage class | Well drained |
|---|---|
| Soil depth | 10 – 20 in |
| Surface fragment cover <=3" | 20% |
| Surface fragment cover >3" | 20% |
| Available water capacity (0-40in) |
0.5 – 3 in |
| Subsurface fragment volume <=3" (Depth not specified) |
18 – 30% |
| Subsurface fragment volume >3" (Depth not specified) |
18 – 30% |
Ecological dynamics
As ecological condition deteriorates due to overgrazing, bluebunch wheatgrass, Indian ricegrass decrease, while low rabbitbrush, snakeweed, and threeawn increase.
When the potential natural plant community is burned, bluebunch wheatgrass, Indian ricegrass, and black sagebrush decrease while low rabbitbrush and Sandberg bluegrass increase.
Cheatgrass and annual forbs are most likely to invade this site.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 1
Reference State
Community 1.1
Reference State
The dominant aspect of this plant community is black sagebrush. The composition by air-dry weight is approximately 55 percent perennial grasses, 5 percent forbs, and 40 percent shrubs.
Figure 2. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
| Plant type | Low (lb/acre) |
Representative value (lb/acre) |
High (lb/acre) |
|---|---|---|---|
| Grass/Grasslike | 193 | 289 | 385 |
| Shrub/Vine | 140 | 210 | 280 |
| Forb | 18 | 26 | 35 |
| Total | 351 | 525 | 700 |
Table 6. Ground cover
| Tree foliar cover | 0% |
|---|---|
| Shrub/vine/liana foliar cover | 15-30% |
| Grass/grasslike foliar cover | 15-30% |
| Forb foliar cover | 2-3% |
| Non-vascular plants | 0% |
| Biological crusts | 0% |
| Litter | 0% |
| Surface fragments >0.25" and <=3" | 0% |
| Surface fragments >3" | 0% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 0% |
Table 7. Canopy structure (% cover)
| Height Above Ground (ft) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.5 | – | – | – | – |
| >0.5 <= 1 | – | – | – | – |
| >1 <= 2 | – | 25-35% | 25-35% | 0-5% |
| >2 <= 4.5 | – | – | – | – |
| >4.5 <= 13 | – | – | – | – |
| >13 <= 40 | – | – | – | – |
| >40 <= 80 | – | – | – | – |
| >80 <= 120 | – | – | – | – |
| >120 | – | – | – | – |
Figure 3. Plant community growth curve (percent production by month). UT2601, PNC. Excellent Condition .
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| J | F | M | A | M | J | J | A | S | O | N | D |
| 0 | 0 | 5 | 15 | 40 | 30 | 5 | 5 | 0 | 0 | 0 | 0 |
Additional community tables
Table 8. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Shrub/Vine
|
||||||
| 1 | Primary Shrubs | 165–193 | ||||
| black sagebrush | ARNO4 | Artemisia nova | 165–193 | – | ||
| 3 | Secondary Shrubs | 28–55 | ||||
| shadscale saltbush | ATCO | Atriplex confertifolia | 6–17 | – | ||
| yellow rabbitbrush | CHVI8 | Chrysothamnus viscidiflorus | 6–17 | – | ||
| Nevada jointfir | EPNE | Ephedra nevadensis | 6–17 | – | ||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 6–17 | – | ||
| winterfat | KRLA2 | Krascheninnikovia lanata | 6–17 | – | ||
| plains pricklypear | OPPO | Opuntia polyacantha | 6–17 | – | ||
| bud sagebrush | PIDE4 | Picrothamnus desertorum | 6–17 | – | ||
| Mexican cliffrose | PUME | Purshia mexicana | 6–17 | – | ||
|
Grass/Grasslike
|
||||||
| 2 | Primary Grasses | 193–275 | ||||
| pseudoparmelia | PSSP5 | Pseudoparmelia sphaerospora | 110–138 | – | ||
| Indian ricegrass | ACHY | Achnatherum hymenoides | 55–83 | – | ||
| needle and thread | HECO26 | Hesperostipa comata | 28–55 | – | ||
| 1 | Secondary Grasses | 17–28 | ||||
| purple threeawn | ARPU9 | Aristida purpurea | 6–17 | – | ||
| squirreltail | ELEL5 | Elymus elymoides | 6–17 | – | ||
| James' galleta | PLJA | Pleuraphis jamesii | 6–17 | – | ||
| Sandberg bluegrass | POSE | Poa secunda | 6–17 | – | ||
|
Forb
|
||||||
| 2 | Forbs | 17–28 | ||||
| Utah milkvetch | ASUT | Astragalus utahensis | 6–17 | – | ||
| Hooker's balsamroot | BAHO | Balsamorhiza hookeri | 6–17 | – | ||
| cushion buckwheat | EROV | Eriogonum ovalifolium | 6–17 | – | ||
| spiny phlox | PHHO | Phlox hoodii | 6–17 | – | ||
| gooseberryleaf globemallow | SPGR2 | Sphaeralcea grossulariifolia | 6–17 | – | ||
Interpretations
Animal community
This site is unsuited for livestock grazing because of steepness and slopes.
Wildlife using this site include rabbit, coyote, fox, badger, pronghorn antelope, mule deer, and dove.
This is a short list of the more common species found. Many other species are present as well and migratory birds are present at times.
Hydrological functions
This section will be added as information is available.
Recreational uses
Resources that have special aesthetic and landscape values are wildflowers. Some recreation uses of this site are hiking and hunting.
Wood products
None
Other information
Threatened and endangered species include plants and animals.
Supporting information
Contributors
David J. Somorville
DJS
Rangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
| Author(s)/participant(s) |
Jack Alexander, Range Specialist, Synergy Resource Solutions, Inc. Julia Kluck, Soil Scientist, Synergy Resource Solutions, Inc. Shane Green, State Range Specialist, Utah NRCS |
|---|---|
| Contact for lead author | Shane Green, Shane.Green@ut.usda.gov |
| Date | 02/09/2010 |
| Approved by | Shane A. Green |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
Many rills present. This site is subject to rilling even in reference condition due to slope, erodible soils, and percent bare ground. Rill development may increase following large storm events, but should begin to heal during the following growing season. Frost heaving will accelerate recovery. Rill development may increase when run inflow enters site from other sites that produce large amounts of runoff (i.e. steeper sites, slickrock, rock outcrop). -
Presence of water flow patterns:
Water flow patterns are common. Some are long (15-20’). They are generally very widely spaced (about 20-30’ apart). Flow patterns occur in low places associated with microtopography commonly occurring on this site. -
Number and height of erosional pedestals or terracettes:
Plants may have small pedestals (1-3”) where they are adjacent to water flow patterns, but without exposed roots. Terracettes should be few and stable. Terracettes should be small (1-3”) and show little sign of active erosion. Some plants may appear to have a pedestal but rather than be formed by erosion, the only place litter accumulates and soil collects is at plant bases forming the appearance of a pedestal.
Well-developed biological crusts may appear pedestalled, but are actually a characteristic of the crust formation. Some plants may appear to have a pedestal but rather than be formed by erosion, the only place litter accumulates and soil collects is at plant bases forming the appearance of a pedestal. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
20-35% bare ground (soil with no protection from raindrop impact). Herbaceous communities are most likely to have lower values. As species composition by shrubs increases, bare ground is likely to increase. Poorly developed biological soil crust that is susceptible to raindrop splash erosion should be recorded as bare ground. Very few if any bare spaces of greater than 1 square foot. -
Number of gullies and erosion associated with gullies:
No gullies present. -
Extent of wind scoured, blowouts and/or depositional areas:
Very minor evidence of active wind-generated soil movement. Wind scoured (blowouts) and depositional areas are rarely present. If present they have muted features and are mostly stabilized with vegetation and/or biological crust. Gravel or desert pavement protects the site from wind scour. -
Amount of litter movement (describe size and distance expected to travel):
Most litter resides in place with some redistribution caused by water and wind movement. Very minor litter removal may occur in flow patterns and rills with deposition occurring at points of obstruction. The majority of litter accumulates at the base of plants. Some leaves, stems, and small twigs may accumulate in soil depressions adjacent to plants. Woody stems are not likely to move. On steep slopes (>30%), litter will move downhill to next obstruction. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
This site should have an erosion rating of 5 or 6 under plant canopies and a rating of 4 to 5 in the interspaces with an average rating of 5 using the soil stability kit test. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Soil correlation is not yet complete for this site. Due to the natural variability of soil attributes, it is critical to supplement this description with the soil-specific information from the published soil survey. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Bunchgrasses and shrubs equally important for increasing infiltration and reducing runoff. Litter plays a role in increasing infiltration and decreasing runoff. Plants provide microhabitat for seedlings, catch litter and soil, and slow raindrops and runoff. Vascular plants and/or well-developed biological soil crusts (where present) will break raindrop impact and splash erosion. Spatial distribution of vascular plants and interspaces between well-developed biological soil crusts (where present) provide detention storage and surface roughness that slows runoff allowing time for infiltration. Interspaces between plants and any well-developed biological soil crusts (where present) may serve as water flow patterns during episodic runoff events, with natural erosion expected in severe storms. When perennial grasses decrease, reducing ground cover and increasing bare ground, runoff is expected to increase and any associated infiltration reduced. Shrubs catch snow, slow wind evaporation, and provide microhabitat for seedling establishment. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None. Naturally occurring soil horizons may be harder than the surface because of an accumulation calcium carbonate and should not be considered as compaction layers. -
Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):
Dominant:
black sagebrushSub-dominant:
pseudoparmelia > Indian ricegrass > needle and threadOther:
other shrubs > other grasses > forbsAdditional:
In the northern portion of the MLRA cool-season perennial grasses (Indian ricegrass, needle and thread) dominate. In the southernmost portion of the MLRA warm-season perennial grasses (galleta, sand dropseed) dominate. The two groups share dominance in the middle portion of the MLRA.
Functional/structural groups may appropriately contain non-native species if their ecological function is the same as the native species in the reference state (e.g. crested wheatgrass and Russian wildrye may substitute for mid stature cool season perennial native bunchgrasses.). Biological soil crust is variable in its expression on this site and is measured as a component of ground cover. Forbs can be expected to vary widely in their expression in the plant community based upon departures from average growing conditions. -
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
During years with average to above average precipitation, there should be very little recent mortality or decadence apparent in either the shrubs or grasses. Some bunchgrass and shrub mortality may occur during severe droughts, particularly on the shallower and coarser soils associated with this site. -
Average percent litter cover (%) and depth ( in):
Litter cover includes litter under plants. Most litter will be fine litter. Depth should be 1-2 leaf thickness in the interspaces and up to 1/2” under canopies. Litter cover may increase to 15-25% following years with favorable growing conditions. Excess litter may accumulate in absence of disturbance. Vegetative production may be reduced if litter cover exceeds 40%. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
525#/acre.
Even the most stable communities exhibit a range of production values. Production will vary between communities and across the MRLA. Refer to the community descriptions in the ESD. Production will differ across the MLRA due to the naturally occurring variability in weather, soils, and aspect. The biological processes on this site are complex; therefore, representative values are presented in a land management context. -
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
Cheatgrass and annual forbs -
Perennial plant reproductive capability:
Reproduction restricted by effective precipitation, rock cover, soil depth, and generally harsh growing conditions; all to be expected for site. Site provides harsh environment for seedling establishment.
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