Natural Resources
Conservation Service
Ecological site R023XY213OR
SANDY LOAM 10-12 PZ
Accessed: 11/13/2024
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
R023XY212OR |
LOAMY 10-12 PZ Loamy 10-12" PZ |
---|---|
R023XY300OR |
SOUTH SLOPES 10-12 PZ South Slopes 8-12" PZ |
Similar sites
R023XY212OR |
LOAMY 10-12 PZ Loamy 10-12" PZ (finer surface texture) |
---|
Table 1. Dominant plant species
Tree |
Not specified |
---|---|
Shrub |
(1) Artemisia tridentata ssp. tridentata |
Herbaceous |
(1) Hesperostipa comata |
Physiographic features
This site occurs on plateaus and tablelands. Slopes range from 0 to 15 percent. Elevation varies from 4200 to 5500 feet.
Table 2. Representative physiographic features
Landforms |
(1)
Plateau
|
---|---|
Elevation | 4,200 – 5,500 ft |
Slope | 15% |
Water table depth | 60 in |
Aspect | Aspect is not a significant factor |
Climatic features
The annual precipitation ranges from 10 to 12 inches, most of which occurs in the form of snow during the months of December through March. Localized convection storms occasionally occur during the summer. The soil temperature regime is frigid to near frigid with a mean annual air temperature of 47 degrees F. Temperature extremes range from 100 to -30 degrees F. The frost-free period ranges from 50 to 90 days. The optimum growth period for native plants is from mid-April through June.
Table 3. Representative climatic features
Frost-free period (average) | 90 days |
---|---|
Freeze-free period (average) | 0 days |
Precipitation total (average) | 12 in |
Influencing water features
Soil features
The soils of this site are typically moderately deep to deep over a duripan and/or bedrock. The soils have a loamy sand to sandy loam surface texture 10 to 20 inches thick. The surface is often overblown. The subsoil and/or substratum is typically medium to fine-textured. Permeability is moderate to rapid. The available water holding capactiy (AWC) is about 3 to 6 inches for the profile. The potential for wind erosion is moderate to severe.
Table 4. Representative soil features
Surface texture |
(1) Loamy sand (2) Sandy loam |
---|---|
Family particle size |
(1) Loamy |
Drainage class | Well drained |
Permeability class | Moderate to rapid |
Available water capacity (0-40in) |
3 – 6 in |
Ecological dynamics
Range in Characteristics:
Variability in plant composition and production results from variation in soil surface texture and depth. Needle-and-thread will increase on a loamy sand surface. Production will increase with soil depth. Thurber needlegrass will increase on shallower soils where the surface texture is finer and the amount of fine gravels in the surface increases. As a fire susceptible site, the amount of basin big sagebrush is dependent on fire frequency.
Response to Disturbance:
If the condition of the site deteriorates as a result of overgrazing, needle-and-thread, Thurber needlegrass, and Indian ricegrass will decrease while big sagebrush and bottlebrush squirreltail will increase. Annuals will invade. Needlegrasses and Indian ricegrass are the preferred species during all seasons. With further deterioration, bareground will increase and excessive wind erosion in the bare soil interspaces reduces the site productivity.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 1
Reference State
Community 1.1
Reference Plant Community
The potential native plant community is dominated by basin big sagebrush and needle-and-thread. Thurber needlegrass and Indian ricegrass are common. The vegetative composition of the community is approximately 80 percent grasses, 5 percent forbs, and 15 percents shrubs. Approximate ground cover is 50-70 percent (basal and crown).
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 | 560 | 720 | 880 |
Shrub/Vine | 105 | 135 | 165 |
Forb | 35 | 45 | 55 |
Total | 700 | 900 | 1100 |
Additional community tables
Table 6. Community 1.1 plant community composition
Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
---|---|---|---|---|---|---|
Grass/Grasslike
|
||||||
1 | Perennial, deep-rooted, bunchgrass | 505–810 | ||||
needle and thread | HECO26 | Hesperostipa comata | 360–540 | – | ||
Thurber's needlegrass | ACTH7 | Achnatherum thurberianum | 135–270 | – | ||
2 | Perennial, deep-rooted, bunchgrass | 63–135 | ||||
Indian ricegrass | ACHY | Achnatherum hymenoides | 45–90 | – | ||
basin wildrye | LECI4 | Leymus cinereus | 18–45 | – | ||
3 | Perennial, deep rooted, rhizomatous | 9–27 | ||||
beardless wildrye | LETR5 | Leymus triticoides | 9–27 | – | ||
5 | Other perennial grasses, all | 18–54 | ||||
squirreltail | ELEL5 | Elymus elymoides | 0–18 | – | ||
prairie Junegrass | KOMA | Koeleria macrantha | 0–18 | – | ||
Sandberg bluegrass | POSE | Poa secunda | 0–18 | – | ||
bluebunch wheatgrass | PSSP6 | Pseudoroegneria spicata | 0–18 | – | ||
Forb
|
||||||
7 | Perennial, nitrogen-fixing | 9–27 | ||||
milkvetch | ASTRA | Astragalus | 9–27 | – | ||
9 | Other perennial forbs | 9–45 | ||||
common yarrow | ACMI2 | Achillea millefolium | 0–9 | – | ||
hawksbeard | CREPI | Crepis | 0–9 | – | ||
buckwheat | ERIOG | Eriogonum | 0–9 | – | ||
lupine | LUPIN | Lupinus | 0–9 | – | ||
phlox | PHLOX | Phlox | 0–9 | – | ||
Shrub/Vine
|
||||||
11 | Evergreen | 90–135 | ||||
basin big sagebrush | ARTRT | Artemisia tridentata ssp. tridentata | 90–135 | – | ||
15 | Other shrubs | 9–45 | ||||
Wyoming big sagebrush | ARTRW8 | Artemisia tridentata ssp. wyomingensis | 9–45 | – | ||
yellow rabbitbrush | CHVI8 | Chrysothamnus viscidiflorus | 0–9 | – | ||
antelope bitterbrush | PUTR2 | Purshia tridentata | 0–9 | – |
Interpretations
Animal community
Livestock Grazing:
This site is suited to use by cattle, sheep, and horses in the spring, summer, fall, and early winter under a planned grazing system. Use should be postponed until the soils are firm enough to avoid trampling damage and soil compaction.
Native Wildlife Associated with the Potential Climax Community:
Deer
Antelope
Hawks
Songbirds
Rodents
This site will offer food and cover for antelope, mule deer, rodents, and a variety of birds. It is an important wintering area for antelope and mule deer.
Hydrological functions
The soils are in hydrologic group B. The soils of this site have moderately low runoff potential.
Supporting information
Contributors
Bob Gillaspy
M. Parks (OSU)
SCS/BLM Team - Hines, OR
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) | Jeff Repp |
---|---|
Contact for lead author | Oregon NRCS State Rangeland Management Specialist |
Date | 08/15/2012 |
Approved by | Bob Gillaspy |
Approval date | |
Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
None, Moderate sheet & rill erosion hazard -
Presence of water flow patterns:
None -
Number and height of erosional pedestals or terracettes:
None -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
10-20% -
Number of gullies and erosion associated with gullies:
None -
Extent of wind scoured, blowouts and/or depositional areas:
None to some, Moderate to severe wind erosion hazard -
Amount of litter movement (describe size and distance expected to travel):
Fine - limited movement -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Slightly resistant to erosion: aggregate stability = 1-2 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Moderately deep to deep loamy sand to sandy loam (10-20 inches thick): Low OM (1-2%) -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Moderate to significant ground cover (50-70%) and gentle slopes (0-15%) effectively limit rainfall impact and overland flow -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None -
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:
Needle and thread grass > Thurber needlegrass > Basin big sagebrush > Indian ricegrass > other grasses > forbs > other shrubsSub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Normal decadence and mortality expected -
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
Favorable: 900, Normal: 750, Unfavorable: 600 lbs/acre/year at high RSI (HCPC) -
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:
Perennial brush species will increase with deterioration of plant community. Western Juniper readily invades the site. Cheatgrass and Medusahead invade sites that have lost deep rooted perennial grass functional groups. -
Perennial plant reproductive capability:
All species should be capable of reproducing anually
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