Natural Resources
Conservation Service
Ecological site R021XY308OR
SOUTH SLOPES 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
| R021XY210OR |
LOAMY 14-18 PZ |
|---|---|
| R021XY214OR |
CLAYPAN 14-18 PZ |
| R021XY216OR |
STONY CLAYPAN 14-20 PZ |
| R021XY306OR |
STONY CLAYPAN SOUTH 14-18 PZ |
Similar sites
| R021XY200OR |
LOAMY 10-14 PZ Lower precipitation. |
|---|
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
Not specified |
Physiographic features
This site occurs on south exposures of mountain sideslopes. Slopes range from 15 to 70%, but slopes of 30 to 70% are most typical. Elevations range from 4400 to 6500 feet, but are typically above 4700 feet.
Table 2. Representative physiographic features
| Landforms |
(1)
Mountainside
|
|---|---|
| Elevation | 4,400 – 6,500 ft |
| Slope | 15 – 70% |
| Aspect | S |
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 April. Spring rains are common. The soil temperature regime is mesic to frigid. Temperature extremes range from 100 to -30 degrees F. The frost-free period ranges from 50 to 120 days. The optimum period for plant growth is from early April to early July.
Table 3. Representative climatic features
| Frost-free period (average) | 120 days |
|---|---|
| Freeze-free period (average) | 150 days |
| Precipitation total (average) | 18 in |
Figure 2. Monthly average minimum and maximum temperature
Influencing water features
Soil features
The soils of this site are well drained, have a loamy surface texture, and contain 1 to 3 percent organic matter and over 35 percent rock fragments (primarily stones) in the surface. The soils lack root restrictive layers within the upper 10 inches or more of this soil surface. The subsoil textures and rock fragment content are variable. The soils range in depth from 10 to over 60 inches deep to bedrock. Runoff is medium to rapid. Erosion hazard by water is moderate to high.
Table 4. Representative soil features
| Surface texture |
(1) Loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderate |
| Soil depth | 10 – 60 in |
| Surface fragment cover >3" | 35% |
| Available water capacity (0-40in) |
Not specified |
| 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) |
7 |
Ecological dynamics
Bluebunch wheatgrass is the dominant grass, however Thurber needlegrass is more prevalent at lower elevation and precipitation ranges of this site. Idaho fescue, mountain brome, oniongrass and big bluegrass increase in the plant community with an increase in elevation and higher annual precipitation.
If the condition of the site deteriorates as a result of overgrazing, mountain big sagebrush increases and will become dominant with rabbitbrush and arrowleaf balsamroot. Cheatgrass and western juniper are likely to invade this site. In the absence of fire, western juniper may establish and increase on the site.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 1
HCPC, PSSP6/ARTRV-PUTR2
Community 1.1
HCPC, PSSP6/ARTRV-PUTR2
The potential native plant community is dominated by bluebunch wheatgrass and Idaho fescue although mountain big sagebrush and antelope bitterbrush may be prevalent enough to dominate the aspect. Vegetative composition of the community is approximately 70% grasses, 10% forbs, and 20% shrubs.
Figure 3. 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 | 450 | 662 | 873 |
| Shrub/Vine | 81 | 176 | 270 |
| Forb | 45 | 95 | 144 |
| Tree | 18 | 54 | 90 |
| Total | 594 | 987 | 1377 |
Figure 4. Plant community growth curve (percent production by month). OR5554, D21 Mid Elev., South, Good Condition. HCPC 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 | 45 | 40 | 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 | 360–540 | ||||
| bluebunch wheatgrass | PSSP6 | Pseudoroegneria spicata | 360–540 | – | ||
| 2 | Sub-dominant deep rooted perennial grasses | 27–108 | ||||
| Idaho fescue | FEID | Festuca idahoensis | 18–90 | – | ||
| Thurber's needlegrass | ACTH7 | Achnatherum thurberianum | 9–18 | – | ||
| 4 | Sub-dominant shallow rooted perennial grasses | 45–90 | ||||
| Sandberg bluegrass | POSE | Poa secunda | 45–90 | – | ||
| 5 | Other perennial grasses | 18–135 | ||||
| Lemmon's needlegrass | ACLE8 | Achnatherum lemmonii | 0–5 | – | ||
| western needlegrass | ACOC3 | Achnatherum occidentale | 0–5 | – | ||
| mountain brome | BRMA4 | Bromus marginatus | 0–5 | – | ||
| squirreltail | ELEL5 | Elymus elymoides | 0–5 | – | ||
| prairie Junegrass | KOMA | Koeleria macrantha | 0–5 | – | ||
| oniongrass | MEBU | Melica bulbosa | 0–5 | – | ||
| Cusick's bluegrass | POCU3 | Poa cusickii | 0–5 | – | ||
|
Forb
|
||||||
| 7 | Dominant perennial forbs | 15–45 | ||||
| arrowleaf balsamroot | BASA3 | Balsamorhiza sagittata | 18–45 | – | ||
| 8 | Sub-dominant perennial forbs | 18–54 | ||||
| tapertip hawksbeard | CRAC2 | Crepis acuminata | 9–27 | – | ||
| lupine | LUPIN | Lupinus | 9–27 | – | ||
| 9 | Other perennial forbs | 9–45 | ||||
| common yarrow | ACMI2 | Achillea millefolium | 0–5 | – | ||
| pussytoes | ANTEN | Antennaria | 0–5 | – | ||
| milkvetch | ASTRA | Astragalus | 0–5 | – | ||
| naked mariposa lily | CANU2 | Calochortus nudus | 0–5 | – | ||
| Indian paintbrush | CASTI2 | Castilleja | 0–5 | – | ||
| buckwheat | ERIOG | Eriogonum | 0–5 | – | ||
| oneflower helianthella | HEUN | Helianthella uniflora | 0–5 | – | ||
| desertparsley | LOMAT | Lomatium | 0–5 | – | ||
| phacelia | PHACE | Phacelia | 0–5 | – | ||
| phlox | PHLOX | Phlox | 0–5 | – | ||
| goatsbeard | TRAGO | Tragopogon | 0–5 | – | ||
| woolly mule-ears | WYMO | Wyethia mollis | 0–5 | – | ||
|
Shrub/Vine
|
||||||
| 11 | Dominant evergreen shrubs | 45–90 | ||||
| mountain big sagebrush | ARTRV | Artemisia tridentata ssp. vaseyana | 45–90 | – | ||
| 13 | Dominant deciduous (or 1/2 shrubs) shrubs | 18–90 | ||||
| antelope bitterbrush | PUTR2 | Purshia tridentata | 18–90 | – | ||
| 15 | Other shrubs | 18–90 | ||||
| Saskatoon serviceberry | AMAL2 | Amelanchier alnifolia | 0–5 | – | ||
| little sagebrush | ARAR8 | Artemisia arbuscula | 0–5 | – | ||
| rubber rabbitbrush | ERNA10 | Ericameria nauseosa | 0–5 | – | ||
| green rabbitbrush | ERTE18 | Ericameria teretifolia | 0–5 | – | ||
| wild crab apple | PERA4 | Peraphyllum ramosissimum | 0–5 | – | ||
| Klamath plum | PRSU2 | Prunus subcordata | 0–5 | – | ||
| currant | RIBES | Ribes | 0–5 | – | ||
| wax currant | RICE | Ribes cereum | 0–5 | – | ||
| spineless horsebrush | TECA2 | Tetradymia canescens | 0–5 | – | ||
|
Tree
|
||||||
| 16 | Dominant evergreen trees | 18–90 | ||||
| western juniper | JUOC | Juniperus occidentalis | 18–90 | – | ||
Interpretations
Animal community
Wildlife- Heavily utilized winter and spring range of bighorn sheep. Preferred habitat of chukar.
Hydrological functions
The soils are in hydrologic groups B, C and D.
Recreational uses
The diversity of vegetation and native wildlife associated with this site provide many opportunities of enjoyment for recreationists, photographers and hunters.
Wood products
Where western juniper occurs, this site yeields fence posts, firewood and specialty products.
Other products
Livestock grazing- This site is suitable for livestock grazing use in spring, summer and fall. At slopes greater than 50%, cattle use will be reduced.
Other information
Increase in western juniper and the subsequent competition for mositure will lead to a reduction of soil cover and accelerated soil loss. Improving infiltration and permeability, and reducing runoff should be the immediate goal of juniper control.
Supporting information
Contributors
Barrett, Carlson, BLM ESI Team
E Ersch
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 to some, moderate to severe sheet & rill erosion hazard -
Presence of water flow patterns:
Some in interspaces on steeper slopes (15-70%) -
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):
5-15% -
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 = 4-6 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Shallow to deep, well drained stony loams (35+% surface rock fragments): Morderate OM (1-3%) -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Moderate vegetative cover (40-60%) reduces potential excess run off on all but steepest slopes (15-70%); infiltration is 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:
Bluebunch wheatgrass > other grasses > Mountain big sagebrush > Idaho fescue = Antelope bitterbrush > dominant forbs > other shrubs > other forbsSub-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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