Natural Resources
Conservation Service
Ecological site R010XB045OR
JD Clayey South 12-16 PZ
Accessed: 12/21/2024
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
| R010XB027OR |
JD Clayey 12-16 PZ JD Clayey 12-16" PZ |
|---|
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
Not specified |
Physiographic features
This site occurs on southerly exposures of terraces, tablelands, and upper canyons. Slopes range from 12 to 70%. Elevation varies from 2100 to 4000 feet.
Table 2. Representative physiographic features
| Landforms |
(1)
Terrace
(2) Plateau (3) Canyon |
|---|---|
| Flooding frequency | None |
| Elevation | 2,100 – 4,000 ft |
| Slope | 12 – 60% |
| Aspect | S, W |
Climatic features
The annual precipitation ranges from 12 to 16 inches, most of which occurs in the form of snow during the months of November through March. Localized, occasionally severe, convectional storms occur during the summer. The soil temperature regime is mesic with a mean annual air temperature of 50 degrees F. Temperature extremes range from 100 to -10 degrees F. The frost-free period ranges from 90 to 150 days. The optimum period for plant growth is from April through June.
Table 3. Representative climatic features
| Frost-free period (average) | 150 days |
|---|---|
| Freeze-free period (average) | 0 days |
| Precipitation total (average) | 16 in |
Influencing water features
Soil features
The soils of this site are typically moderately deep to deep and well-drained. Typically the surface layer is a cobbly clay loam about 8 inches thick. The subsoil is a cobbly clay loam about 25 inches thick. Depth to bedrock or sediments is 30 to 60 inches. Permeability is slow. The available water holding capacity is about 4 to 6 inches. The potential for erosion is moderate to severe.
Table 4. Representative soil features
| Surface texture |
(1) Cobbly clay loam |
|---|---|
| Family particle size |
(1) Clayey |
| Drainage class | Well drained |
| Permeability class | Slow |
| Soil depth | 30 – 60 in |
| Available water capacity (0-40in) |
4 – 6 in |
Ecological dynamics
Range in Characteristics:
Variability in site productivity results from changes in soil depth. An increase in soil depth particularly on foot slopes will favor an increase in production. Western juniper may increase in the absence of fire.
Response to Disturbance:
If the condition of the site deteriorates as a result of overgrazing, bluebunch wheatgrass decreases while Sandberg bluegrass, broom snakeweed, and western juniper increase. Bluebunch wheatgrass is the preferred species during the late spring, summer, and fall. With further deterioration, annuals invade and bare interspaces increase. Under deteriorated conditions excessive erosion reduces the site productivity and contributes to downstream sedimentation.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 1
Historic Climax Plant Community
Community 1.1
Historic Climax Plant Community
The potential native plant community is dominated by bluebunch wheatgrass. Sandberg bluegrass and antelope bitterbrush are common in the stand. Vegetative composition of the community is approximately 90 percent grasses, 5 percent forbs, and 5 percent shrubs. Approximate ground cover is 50-60 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 | 888 | 1044 | 1200 |
| Forb | 60 | 96 | 132 |
| Shrub/Vine | 36 | 66 | 96 |
| Tree | 12 | 18 | 24 |
| Total | 996 | 1224 | 1452 |
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, dominant | 840–1080 | ||||
| bluebunch wheatgrass | PSSP6 | Pseudoroegneria spicata | 840–1080 | – | ||
| 4 | Perennial, shallow-rooted, sub-dominant | 24–60 | ||||
| Sandberg bluegrass | POSE | Poa secunda | 24–60 | – | ||
| 5 | Other perennial grasses, all | 24–60 | ||||
| Thurber's needlegrass | ACTH7 | Achnatherum thurberianum | 0–20 | – | ||
| squirreltail | ELEL5 | Elymus elymoides | 0–20 | – | ||
| Idaho fescue | FEID | Festuca idahoensis | 0–20 | – | ||
|
Forb
|
||||||
| 7 | Perennial, all, dominant | 48–96 | ||||
| milkvetch | ASTRA | Astragalus | 12–24 | – | ||
| arrowleaf balsamroot | BASA3 | Balsamorhiza sagittata | 12–24 | – | ||
| desertparsley | LOMAT | Lomatium | 12–24 | – | ||
| lupine | LUPIN | Lupinus | 12–24 | – | ||
| 9 | Other perennial forbs, all | 12–36 | ||||
| common yarrow | ACMI2 | Achillea millefolium | 0–6 | – | ||
| agoseris | AGOSE | Agoseris | 0–6 | – | ||
| hawksbeard | CREPI | Crepis | 0–6 | – | ||
| fleabane | ERIGE2 | Erigeron | 0–6 | – | ||
| buckwheat | ERIOG | Eriogonum | 0–6 | – | ||
| phlox | PHLOX | Phlox | 0–6 | – | ||
|
Shrub/Vine
|
||||||
| 11 | Perennial, evergreen, dominant | 12–36 | ||||
| antelope bitterbrush | PUTR2 | Purshia tridentata | 12–36 | – | ||
| 15 | Other perennial shrubs, all | 24–60 | ||||
| basin big sagebrush | ARTRT | Artemisia tridentata ssp. tridentata | 0–20 | – | ||
| rubber rabbitbrush | ERNA10 | Ericameria nauseosa | 0–20 | – | ||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 0–20 | – | ||
|
Tree
|
||||||
| 16 | Perennial, evergreen, dominant | 12–24 | ||||
| western juniper | JUOC | Juniperus occidentalis | 12–24 | – | ||
Interpretations
Animal community
Livestock Grazing:
This site is suited to use by cattle, sheep, and horses in the spring, summer, and fall 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:
Mule deer
Rodents
Hawks
Songbirds
Elk
The southerly aspect of this site offers warm temperatures and early spring growth that attracts several grazing and browsing forms of wildlife and gallinaceous birds in winter and spring. It provides valuable spring forage for elk and deer.
Hydrological functions
The soils are in hydrologic groups C and D. The soils of this site have moderately high to high runoff potential.
Wood products
This site is suspectible to increase in western juniper. Where this has occurred, the site will yield fence posts, firewood, and specialty products.
Other information
Increase in western juniper and the subsequent competition for moisture will lead to a reduction of available forage. Overgrazing can easily reduce ground cover and accelerate soil loss. Improving infiltration and permeability, and reducing runoff should be the immediate goal of juniper or brush control.
Supporting information
Contributors
A. Bahn, J. Thompson, B. O'Donnell, H. Barrett
A. Bahn, J. Thompson, B. O'Donnell, H. Barrett
M. Parks
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 and Bruce Frannsen |
|---|---|
| Contact for lead author | State Rangeland Management Specialist for NRCS - Oregon |
| Date | 08/06/2012 |
| 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 (severe on steeper slopes) -
Presence of water flow patterns:
None (few on steeper slopes) -
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):
10-30% -
Number of gullies and erosion associated with gullies:
None -
Extent of wind scoured, blowouts and/or depositional areas:
None, moderate 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):
Moderate resistance to erosion: aggregate stability = 3-5 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Moderately deep to deep, well drained clay loams, silty clay loams, or very stony clay loams: moderate OM (2-4%) -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Moderate ground cover (50-60%) and gentle to very steep slopes (12-70%) moderately 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:
Bluebunch wheatgrass > other grasses > forbs > 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: 1400, Normal: 1200, Unfavorable: 800 lbs/acre/year st 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:
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 annually
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