Natural Resources
Conservation Service
Ecological site R025XY315UT
Upland Shallow Gravelly Loam (Thurber Needlegrass)
Accessed: 11/21/2024
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
R025XY320UT |
Upland Stony Clay (Low Sagebrush) Also R025XY326UT-Upland Shallow Loam (Utah Juniper) |
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Table 1. Dominant plant species
Tree |
Not specified |
---|---|
Shrub |
(1) Artemisia tridentata var. wyomingensis |
Herbaceous |
Not specified |
Physiographic features
This site can be found on hills between slopes of 15 to 40%. It can occur at elevations between 5,200 to 7,200 feet. Flooding and ponding do not occur on this site.
Table 2. Representative physiographic features
Landforms |
(1)
Hill
|
---|---|
Flooding frequency | None |
Ponding frequency | None |
Elevation | 5,200 – 7,200 ft |
Slope | 15 – 40% |
Climatic features
The climate is cold and snowy in the winter and warm and dry in the summer.
Mean Annual Air Temperature: 41-45
Mean Annual Soil Temperature: 43-47
Table 3. Representative climatic features
Frost-free period (average) | 0 days |
---|---|
Freeze-free period (average) | 120 days |
Precipitation total (average) | 17 in |
Influencing water features
Water Erosion Hazard is slight.
Soil features
The soils on this site were formed in residuum and colluvium derived from rhyolite. The soil is well drained with moderately slow permeability in the upper 10 inches of soil. The soil is also shallow with bedrock less than 20 inches beneath the soil surface. A lithic bedrock layer is found between 4 and 12 inches below the soil surface. The soil texture at the surface is very gravelly loam. Surface and subsurface rock fragments between 2 mm and 3 inches are 41% and 40% by cover and volume, respectively. Surface and subsurface rocks over 3 inches in diameter are less than 5% by cover and volume. Available water capacity is between 0.5 and 1 in the upper 40 inches of soil. The soil pH is between 6.6 and 7.3. The soil temperature regime is frigid.
Soils associated with this site:
Box Elder Co UT601: Shalper (68)
Table 4. Representative soil features
Surface texture |
(1) Very gravelly loam |
---|---|
Drainage class | Well drained |
Permeability class | Moderately slow |
Soil depth | 4 – 12 in |
Surface fragment cover <=3" | 41% |
Surface fragment cover >3" | 3% |
Available water capacity (0-40in) |
0.5 – 1 in |
Calcium carbonate equivalent (0-40in) |
Not specified |
Electrical conductivity (0-40in) |
Not specified |
Sodium adsorption ratio (0-40in) |
Not specified |
Soil reaction (1:1 water) (0-40in) |
6.6 – 7.3 |
Subsurface fragment volume <=3" (Depth not specified) |
40% |
Subsurface fragment volume >3" (Depth not specified) |
5% |
Ecological dynamics
As this site deteriorates due to grazing pressure bluebunch wheatgrass, Thurber needlegrass, and bitterbrush decrease while big sagebrush, rabbitbrush, Sandberg bluegrass, phlox, and balsamroot increase. When the potential natural plant community is burned, big sagebrush, bitterbrush, and Thurber needlegrass decrease while rabbitbrush, Sandberg bluegrass, and milkvetch increase.
State and transition model
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Click on state and transition labels to scroll to the respective text
Ecosystem states
State 1 submodel, plant communities
State 1
Reference State
Community 1.1
Reference State
The general view of this site is Wyoming big sagebrush and grass. The composition by air-dry weight is approximately 55 percent perennial grasses, 25 percent forbs, and 20 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 | 83 | 193 | 275 |
Forb | 38 | 88 | 125 |
Shrub/Vine | 30 | 70 | 100 |
Total | 151 | 351 | 500 |
Table 6. Ground cover
Tree foliar cover | 0% |
---|---|
Shrub/vine/liana foliar cover | 5-10% |
Grass/grasslike foliar cover | 10-30% |
Forb foliar cover | 5-15% |
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 | – | – | – | 10-20% |
>1 <= 2 | – | – | 25-35% | – |
>2 <= 4.5 | – | 5-15% | – | – |
>4.5 <= 13 | – | – | – | – |
>13 <= 40 | – | – | – | – |
>40 <= 80 | – | – | – | – |
>80 <= 120 | – | – | – | – |
>120 | – | – | – | – |
Figure 3. Plant community growth curve (percent production by month). UT3151, 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 | 20 | 10 | 5 | 5 | 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 | 32–60 | ||||
mountain big sagebrush | ARTRV | Artemisia tridentata ssp. vaseyana | 20–40 | – | ||
antelope bitterbrush | PUTR2 | Purshia tridentata | 12–20 | – | ||
3 | Secondary Shrubs | 12–20 | ||||
yellow rabbitbrush | CHVI8 | Chrysothamnus viscidiflorus | 4–12 | – | ||
rubber rabbitbrush | ERNA10 | Ericameria nauseosa | 4–12 | – | ||
littleleaf horsebrush | TEGL | Tetradymia glabrata | 4–12 | – | ||
Grass/Grasslike
|
||||||
2 | Primary Grasses | 160–200 | ||||
Thurber's needlegrass | ACTH7 | Achnatherum thurberianum | 80–100 | – | ||
bluebunch wheatgrass | PSSP6 | Pseudoroegneria spicata | 80–100 | – | ||
1 | Secondary Grasses | 40–60 | ||||
squirreltail | ELEL5 | Elymus elymoides | 12–20 | – | ||
basin wildrye | LECI4 | Leymus cinereus | 12–20 | – | ||
Sandberg bluegrass | POSE | Poa secunda | 12–20 | – | ||
Forb
|
||||||
2 | Forbs | 80–100 | ||||
Torrey's milkvetch | ASCA9 | Astragalus calycosus | 12–20 | – | ||
arrowleaf balsamroot | BASA3 | Balsamorhiza sagittata | 12–20 | – | ||
tapertip hawksbeard | CRAC2 | Crepis acuminata | 12–20 | – | ||
shortstem buckwheat | ERBR5 | Eriogonum brevicaule | 12–20 | – | ||
tailcup lupine | LUCAC3 | Lupinus caudatus ssp. caudatus | 12–20 | – | ||
spiny phlox | PHHO | Phlox hoodii | 12–20 | – |
Interpretations
Animal community
This site provides proper grazing for cattle and sheep during spring, summer, and fall.
Wildlife using this site include blacktail jackrabbit, coyote, sage grouse, and mule deer.
Hydrological functions
The soil series is in Hydrologic group D. The runoff curve number is 80 when the vegetation is in good condition.
Recreational uses
Hunting and Hiking
Wood products
None
Other information
Threatened and endangered speicies include plants and animals.
Supporting information
Type locality
Location 1: Box Elder County, UT | |
---|---|
Township/Range/Section | T10N R19W S3 |
General legal description | 100 ft N 2400 ft E of SW Corner Section 3, Township 10N, Range 19W. Two miles SW of Bill Thomas ranch house at Etna, Utah |
Contributors
GBB
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) | Shane A. Green (NRCS), Brock Benson (NRCS), Robert D. Stager (BLM), Mike Gates (BLM), Tyler Staggs (BLM), Alan Bass (BLM). Revised to include updated terminology and concepts by V. Keith Wadman (NRCS Retired). |
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Contact for lead author | shane.green@ut.usda.gov |
Date | 12/15/2011 |
Approved by | Shane A. Green |
Approval date | |
Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
None to very few rills present. Some very minor rill development may occur on steeper slopes or on areas located below exposed bedrock or other water shedding areas where increased runoff may occur. Any rills present should be <1 inch deep, fairly short (<8 feet long) and somewhat widely spaced (6-8 feet). Minor rill development may be observed following major thunderstorm or spring runoff events but should heal during the next growing season. -
Presence of water flow patterns:
Some very minor evidence of water flow patterns may be found around perennial plant bases. They show little evidence of current erosion. They are expected to be somewhat short (4-8 feet), stable, sinuous and not connected. There may be very minor evidence of deposition. Evidence of water flow may increase somewhat with slope. -
Number and height of erosional pedestals or terracettes:
Perennial vegetation shows little evidence of erosional pedestalling (2 to 3% of individual plants). Plant roots are covered and litter remains in place around plant crowns. Terracettes should be absent or, if present, stable. A slight increase in both pedestal and terracette development may occur with increasing slope. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
10-30% bare ground. Soil surface is typically covered by approximately 35% coarse fragments. Bare ground spaces should not be greater than 2 to 3 feet in diameter. -
Number of gullies and erosion associated with gullies:
None to very few gullies present on site. A few gullies may be present in landscape settings where they transport runoff from areas of greater water flow such as exposed bedrock. These gullies will be limited to slopes exceeding 20% slope and adjacent to sites where this runoff accumulation occurs. Any gullies present should show little sign of accelerated erosion and should be stabilized with perennial vegetation. -
Extent of wind scoured, blowouts and/or depositional areas:
None. No evidence of wind generated soil movement is present. Wind caused blowouts and deposition are not present. -
Amount of litter movement (describe size and distance expected to travel):
Most litter resides in place with some redistribution caused by water movement. Minor litter removal may occur in flow channels with deposition occurring within 1 to 2 feet at points of obstruction. The majority of litter accumulates at the base of plants. Some grass leaves and small twigs (grass stems) may accumulate in soil depressions adjacent to plants. Woody stems are not likely to move. However, some litter movement is expected (up to 6 feet) with increases in slopes >15% and/or increased runoff resulting from heavy thunderstorms. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
This site should have a soil stability rating of 4 or 5 under the plant canopies, and a rating of 3 to 4 in the interspaces. The average rating should be a 4. Soil surface texture is typically a very gravelly loam. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
(Shalper) Soil surface 0-5 inches. Texture is a very gravelly loam; color is brown (10YR5/3); and structure is moderately fine subangular blocky. Mollic epipedon ranges from 4 to 12 inches. Use the specific information for the soil you are assessing found in the published soil survey to supplement this description. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Perennial vegetation produces sufficient cover and spatial arrangement to intercept most raindrops and reduce raindrop splash erosion. Litter on soil surface also protects soil from splash erosion and encourages a higher rate of infiltration. Plant spatial distribution should slow runoff, allowing additional time for infiltration. Bare spaces are expected to be small and irregular in shape and are usually not connected. Vegetative structure is usually adequate to capture snow and ensure that snowmelt occurs in a controlled manner, allowing maximum time for infiltration, and reducing runoff and erosion in all but the most extreme storm events. When perennial grasses and shrubs decrease due to natural events including drought, insect damage, etc., which reduce ground cover and increasing bare ground, runoff is expected to increase and any associated infiltration reduced. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None. The moderately fine subangular blocky structure and fractured rhyolite bedrock which occurs at approximately 12 inches are not 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:
Perennial bunchgrasses (bluebunch wheatgrass, Thurber needlegrass) > Non-sprouting shrubs (mountain big sagebrush).Sub-dominant:
Rhizomatous grasses (western wheatgrass) > Sprouting shrubs (antelope bitterbrush, green rabbitbrush) > Perennial forbs (arrowleaf balsamroot).Other:
A wide variety of other perennial grasses and both perennial and annual forbs can be expected to occur in the plant community.Additional:
Natural disturbance regimes include fire, drought, and insects. Assumed fire cycle of 30 to 40+ years. 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, Smooth brome, intermediate wheatgrass, Siberian Wheatgrass etc.)
Following a disturbance such as fire, drought, rodents or insects that remove woody vegetation, forbs and perennial grasses (herbaceous species) may dominate the community for a period of time. If a disturbance has not occurred for an extended period of time, woody species may continue to increase. These conditions would reflect a functional community phase within the reference state. -
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
All age classes of perennial grasses should be present under average to above average growing conditions with age class expression likely subdued during periods of extended drought. Slight decadence in the principle shrubs could occur near the end of the fire cycle or during periods of extended drought, or insect infestations. In general, a mix of age classes should be expected with some dead and decadent plants present. -
Average percent litter cover (%) and depth ( in):
Litter cover will be heavier under plants. Most litter will be herbaceous and depths of 1/4 to 1/2 inch would be considered normal. Perennial vegetation should be well distributed on the site. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
Annual production in air-dry herbage should be approximately 300 - 400#/acre on an average year, but could range from 150 to 500#/acre during periods of prolonged drought or above average precipitation.
-
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, Russian thistle, Utah juniper, and non-native invasive annual forbs such a alyssum. -
Perennial plant reproductive capability:
All perennial plants should have the ability to reproduce in all years, except in extreme drought years. Green rabbitbrush sprouts vigorously following fire. There are no restrictions on either seed or vegetative reproduction. Some seedling recruitment of major species is present during average and above average growing years.
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