Natural Resources
Conservation Service
Ecological site R021XY212OR
SHALLOW LOAM 14-18 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
| R021XY308OR |
SOUTH SLOPES 14-18 PZ |
|---|---|
| R021XY312OR |
NORTH SLOPES 14-18 PZ |
| R021XY314OR |
DRY MEADOW 14-30 PZ |
Similar sites
| R021XY410OR |
DEEP LOAMY 16-20 PZ Deeper soil, thicker surface. |
|---|
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
Not specified |
Physiographic features
This site occurs in mountainous sideslopes, rolling plateaus and colluvial slopes.
Table 2. Representative physiographic features
| Landforms |
(1)
Mountain slope
(2) Plateau |
|---|---|
| Elevation | 4,000 – 6,000 ft |
| Slope | 30% |
| Aspect | Aspect is not a significant factor |
Climatic features
The annual precipitation ranges from 14 to 18 inches, most of which occurs in the form of snow during the months of October through May. The soil temperature regime is mesic with the mean annual air temperature of 47 degrees F. Temperature extremes range from 90 to -30 degrees F. The frost free period ranges from 70 to 140 days. The optimum period for plant growth is from mid-April through late June.
Table 3. Representative climatic features
| Frost-free period (average) | 140 days |
|---|---|
| Freeze-free period (average) | 0 days |
| Precipitation total (average) | 18 in |
Influencing water features
Soil features
The soils of this site range from shallow to moderately deep over bedrock or a restrictive layer and well drained. The subsoil is loamy to clayey and may contain up to 35 percent coarse fragments. Depth to bedrock or an indurated pan is about 20 inches. Permeability is moderate to moderately slow. The available water holding capacity is about 4 to 6 inches. The potential for erosion is slight to moderately severe.
Table 4. Representative soil features
| Family particle size |
(1) Loamy |
|---|---|
| Drainage class | Well drained |
| Permeability class | Moderately slow to moderate |
| Soil depth | 20 – 40 in |
| Available water capacity (0-40in) |
4 – 6 in |
| Subsurface fragment volume <=3" (Depth not specified) |
35% |
Ecological dynamics
If the condition of the site deteriorates as a result of overgrazing, Idaho fescue and bluebunch wheatgrass decrease in the stand to be replaced by needlegrass and Sandberg bluegrass. If deterioration continues, shrubs such as big sagebrush and rabbitbrush will dominant the stand. In the absence of periodic fire, western juniper will invade the site.
This site is typically dominated by Idaho fescue, at the upper end of the precipitation range and bluebunch wheatgrass increases in proportion on the drier end of the range or where gravels increase in the soil.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 1
HCPC, FEID/PUTR2-ARTRV
Community 1.1
HCPC, FEID/PUTR2-ARTRV
The potential native plant community is dominated by Idaho fescue. Mountain big sagebrush and antelope bitterbrush often dominate the aspect. Vegetative composition of the community is approximately 75% grasses, 10% forbs, and 15% 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 | 441 | 608 | 774 |
| Shrub/Vine | 117 | 171 | 225 |
| Forb | 45 | 81 | 117 |
| Tree | 18 | 32 | 45 |
| Total | 621 | 892 | 1161 |
Figure 3. Plant community growth curve (percent production by month). OR5551, D21 Mid Elev., NA, Good Condtion. RPC Growth Curve.
| 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 | 0 | 10 | 40 | 45 | 5 | 0 | 0 | 0 | 0 | 0 |
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 | Dominant deep rooted perennial grasses | 360–585 | ||||
| Idaho fescue | FEID | Festuca idahoensis | 270–450 | – | ||
| bluebunch wheatgrass | PSSP6 | Pseudoroegneria spicata | 90–135 | – | ||
| 2 | Sub-dominant deep rooted perennial grasses | 36–90 | ||||
| Thurber's needlegrass | ACTH7 | Achnatherum thurberianum | 18–45 | – | ||
| basin wildrye | LECI4 | Leymus cinereus | 18–45 | – | ||
| 4 | Sub-dominant shallow rooted perennial grasses | 27–54 | ||||
| Sandberg bluegrass | POSE | Poa secunda | 27–54 | – | ||
| 5 | Other perennial grasses | 18–45 | ||||
| western needlegrass | ACOC3 | Achnatherum occidentale | 0–5 | – | ||
| prairie Junegrass | KOMA | Koeleria macrantha | 0–5 | – | ||
|
Forb
|
||||||
| 7 | Dominant perennial forbs | 36–72 | ||||
| milkvetch | ASTRA | Astragalus | 9–18 | – | ||
| desertparsley | LOMAT | Lomatium | 9–18 | – | ||
| lupine | LUPIN | Lupinus | 9–18 | – | ||
| phlox | PHLOX | Phlox | 9–18 | – | ||
| 9 | Other perennial forbs | 9–45 | ||||
| tapertip hawksbeard | CRAC2 | Crepis acuminata | 0–5 | – | ||
| fleabane | ERIGE2 | Erigeron | 0–5 | – | ||
| buckwheat | ERIOG | Eriogonum | 0–5 | – | ||
| flax | LINUM | Linum | 0–5 | – | ||
| woolly plantain | PLPA2 | Plantago patagonica | 0–5 | – | ||
|
Shrub/Vine
|
||||||
| 12 | Sub-dominant evergreen shrubs | 18–45 | ||||
| mountain big sagebrush | ARTRV | Artemisia tridentata ssp. vaseyana | 18–45 | – | ||
| 13 | Dominant deciduous (or 1/2 shrubs) shrubs | 90–135 | ||||
| antelope bitterbrush | PUTR2 | Purshia tridentata | 90–135 | – | ||
| 15 | Other shrubs | 9–45 | ||||
| Saskatoon serviceberry | AMAL2 | Amelanchier alnifolia | 0–5 | – | ||
| Klamath plum | PRSU2 | Prunus subcordata | 0–5 | – | ||
| chokecherry | PRVI | Prunus virginiana | 0–5 | – | ||
| wax currant | RICE | Ribes cereum | 0–5 | – | ||
| rose | ROSA5 | Rosa | 0–5 | – | ||
| mountain snowberry | SYOR2 | Symphoricarpos oreophilus | 0–5 | – | ||
| horsebrush | TETRA3 | Tetradymia | 0–5 | – | ||
|
Tree
|
||||||
| 16 | Dominant evergreen trees | 18–45 | ||||
| western juniper | JUOC | Juniperus occidentalis | 18–45 | – | ||
Interpretations
Animal community
This site provides forage for deer, sage grouse and pronghorn antelope and cover for various bird species.
Hydrological functions
The soils are in hydrologic groups C and D.
Recreational uses
This site provides opportunity for observing and hunting mule deer, pronghorn antelope and various game birds.
Other products
This site is suited to livestock grazing in late spring, summer and fall under a planned grazing system.
Supporting information
Contributors
Barrett, Carlson
K.Kennedy
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 | 08/22/2012 |
| Approved by | Bob Gillaspy |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
None, slight to moderately severe sheet & rill erosion hazard -
Presence of water flow patterns:
None -
Number and height of erosional pedestals or terracettes:
None to few (shallow rooted grasses) -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
5-10% -
Number of gullies and erosion associated with gullies:
None -
Extent of wind scoured, blowouts and/or depositional areas:
None, slight 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):
Moderately resistant to erosion: aggregate stability = 4-5 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Shallow to moderately deep, well drained loams (sometimes gravelly or stony on the surface): Low OM (1-2%) -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
High amount of plant cover (70-90%), rock gragments, and moderate slopes (0-30%) effectively limit rainfall impact and overland flow; infiltration is moderate to moderately slow -
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:
Idaho fescue > Bluebunch wheatgrass = Antelope bitterbrush > dominant grasses > dominant forbs > Mountain big sagebrush = other grasses > other 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: 1200, Normal: 900, 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 annually
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