Natural Resources
Conservation Service
Ecological site R010XC066OR
SR Mountain North 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
| R010XC032OR |
SR Mountain 12-16 PZ SR Mountain 12-16 PZ |
|---|---|
| R010XC033OR |
SR Cool 12-16 PZ SR Cool 12-16 PZ |
| R010XC037OR |
SR Mountain Shallow 12-16 PZ SR Mountain Shallow 12-16 PZ |
| R010XC039OR |
SR Very Shallow 12-16 PZ SR Very Shallow 12-16 PZ |
| R010XC047OR |
SR Mountain South 12-16 PZ SR Mountain South 12-16 PZ |
| R010XC068OR |
SR Cool Mountain North 12-16 PZ SR Cool Mountain North 12-16 PZ |
| R010XC075OR |
SR Mountain Shallow North 12-16 PZ SR Mountain Shallow North 12-16 PZ |
Similar sites
| R010XC068OR |
SR Cool Mountain North 12-16 PZ SR Cool Mountain North 12-16 PZ (lower elevation, different composition -basin and xeric big sagebrush present along with mountain big sagebrush) |
|---|---|
| R010XC075OR |
SR Mountain Shallow North 12-16 PZ SR Mountain Shallow North 12-16 PZ (shallower soil, lower production) |
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) Artemisia tridentata var. vaseyana |
| Herbaceous |
(1) Festuca idahoensis |
Physiographic features
This site occurs on north aspects of terraces, tablelands and mountain plateaus. Slopes typically range from 12 to 60%. Elevations typically range from 4,500 to 6,000 feet.
Table 2. Representative physiographic features
| Landforms |
(1)
Terrace
(2) Plateau |
|---|---|
| Flooding frequency | None |
| Ponding frequency | None |
| Elevation | 4,500 – 6,000 ft |
| Slope | 12 – 60% |
| Aspect | N |
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 convection storms occasionally occur during the summer. The soil temperature regime is frigid with a mean air temperature of 44 degrees F. Temperature extremes range from 90 to -30 degrees F. The frost free period ranges from less than 30 to 60 days. The optimum growth period for plant growth is May through July.
Table 3. Representative climatic features
| Frost-free period (average) | 60 days |
|---|---|
| Freeze-free period (average) | 80 days |
| Precipitation total (average) | 16 in |
Figure 2. Monthly precipitation range
Figure 3. Monthly average minimum and maximum temperature
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 silt loam to clay loam about 12 inches thick. The subsoil is a clay loam to clay about 22 inches. Depth to an indurated pan or bedrock ranges from 20 to 60 inches. Permeability is moderate. The available water holding capacity (AWC) is about 6 to 10 inches for the profile. The erosion potential is moderate to severe.
Table 4. Representative soil features
| Surface texture |
(1) Silt loam (2) Stony clay loam |
|---|---|
| Family particle size |
(1) Clayey |
| Drainage class | Well drained |
| Permeability class | Moderate to moderately slow |
| Soil depth | 20 – 60 in |
| Surface fragment cover <=3" | 20% |
| Surface fragment cover >3" | 10% |
| Available water capacity (0-40in) |
6 – 10 in |
| Electrical conductivity (0-40in) |
Not specified |
| Sodium adsorption ratio (0-40in) |
Not specified |
| Subsurface fragment volume <=3" (Depth not specified) |
20% |
| Subsurface fragment volume >3" (Depth not specified) |
20% |
Ecological dynamics
The potential native plant community is strongly dominated by Idaho fescue. Mountain big sagebrush is common. Bluebunch wheatgrass, wax currant, other shrubs and a variety of forbs are present. Vegetative composition of the community is approximately 80 percent grasses, 10 percent forbs and 10 percent shrubs. Approximate ground cover is 80 to 90 percent (basal and crown).
Range in Characteristics:
Idaho fescue is strongly dominant. Bluebunch wheatgrass increases as the aspect changes to the east or northwest. Deciduous shrubs increase over gravelly and fractured substratums. Production increases with soil depth and precipitation.
Disturbance Response -States:
If the condition of the site deteriorates as a result of overgrazing, Idaho fescue decreases while bluebunch wheatgrass and Sandberg bluegrass increases. Mountain big sagebrush rapidly increases and juniper invades from rock outcrops. With continued overgrazing big sagebrush and juniper dominate the overstory and Sandberg bluegrass dominates the understory. Annual invasion is limited unless ground disturbance occurs. With further deterioration and lack of fire juniper invasion continues, shrubs decrease and bare ground increases. With fire and heavy use or ground disturbance, annuals and Sandberg or bulbous bluegrass increase. Bare ground increases and excessive erosion contributes to downstream sedimentation.
States: ARTRV/POSE-Bare Ground; JUOC/ARTRV/POSE-Bare Ground; POSE-POBU -Annuals-Bare Ground
Juniper Response:
Fine fuel reduction from improper grazing and fire suppression has led to an increase in the historical fire return interval on many western rangelands. A reduction in fire frequency on these sites leads to an increase in juniper cover, a decrease in sagebrush cover followed by a decrease in herbaceous cover and understory diversity. As juniper encroaches on north facing aspects sagebrush declines with a subsequent decrease in forbs, bluebunch wheatgrass and needlegrass. Idaho fescue becomes the primary herbaceous species occurring under the canopy of the juniper trees. Sandberg’s bluegrass increases in the plant community on lower elevation north slopes and warmer non-aspect sites while bare ground increases in the interspaces between trees. Bitterbrush is more resistant to juniper encroachment than sagebrush and maintains its presence in the community, however vigor and fitness (seed production) may be thwarted. The potential for soil erosion increases as the juniper woodland matures and the understory plant community cover declines. The combined effect of overgrazing and juniper invasion increases the rate of decline in ecological function and the probability of crossing a threshold is high.
Treatment Response:
This site responds positively to juniper removal if soil erosion is not significant. Seeding may be necessary if there are less than 1-2 bunchgrass plants per meter square in the understory. Forbs may also need to be needed if adult plants are no longer present in the understory.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 1
Reference Plant Community
Community 1.1
Reference Plant Community
The potential native plant community is strongly dominated by Idaho fescue. Mountain big sagebrush is common. Bluebunch wheatgrass, wax currant, other shrubs and a variety of forbs are present. Vegetative composition of the community is approximately 80 percent grasses, 10 percent forbs and 10 percent shrubs. Approximate ground cover is 80 to 90 percent (basal and crown).
Figure 4. 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 | 960 | 1280 | 1760 |
| Shrub/Vine | 120 | 160 | 220 |
| Forb | 120 | 160 | 220 |
| Total | 1200 | 1600 | 2200 |
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, perennial deep-rooted bunchgrass | 1120–1280 | ||||
| Idaho fescue | FEID | Festuca idahoensis | 1120–1280 | – | ||
| 2 | Sub-dominant, perennial deep-rooted grass | 32–128 | ||||
| bluebunch wheatgrass | PSSPS | Pseudoroegneria spicata ssp. spicata | 32–128 | – | ||
| 5 | Other perennial grasses | 42–208 | ||||
| western needlegrass | ACOC3 | Achnatherum occidentale | 0–32 | – | ||
| Thurber's needlegrass | ACTH7 | Achnatherum thurberianum | 0–32 | – | ||
| prairie Junegrass | KOMA | Koeleria macrantha | 16–32 | – | ||
| basin wildrye | LECI4 | Leymus cinereus | 16–32 | – | ||
| Cusick's bluegrass | POCU3 | Poa cusickii | 0–32 | – | ||
| Sandberg bluegrass | POSE | Poa secunda | 5–16 | – | ||
| threadleaf sedge | CAFI | Carex filifolia | 0–16 | – | ||
| squirreltail | ELEL5 | Elymus elymoides | 5–16 | – | ||
|
Forb
|
||||||
| 7 | Dominant, perennial forbs | 80–192 | ||||
| arrowleaf balsamroot | BASA3 | Balsamorhiza sagittata | 16–48 | – | ||
| parsnipflower buckwheat | ERHE2 | Eriogonum heracleoides | 16–48 | – | ||
| desertparsley | LOMAT | Lomatium | 16–32 | – | ||
| lupine | LUPIN | Lupinus | 16–32 | – | ||
| milkvetch | ASTRA | Astragalus | 16–32 | – | ||
| 9 | Other forbs | 50–160 | ||||
| ragwort | SENEC | Senecio | 0–16 | – | ||
| hawksbeard | CREPI | Crepis | 5–16 | – | ||
| fleabane | ERIGE2 | Erigeron | 5–16 | – | ||
| old man's whiskers | GETR | Geum triflorum | 5–16 | – | ||
| Scouler's woollyweed | HISC2 | Hieracium scouleri | 5–16 | – | ||
| waterleaf | HYDRO4 | Hydrophyllum | 0–16 | – | ||
| woodland-star | LITHO2 | Lithophragma | 5–10 | – | ||
| stoneseed | LITHO3 | Lithospermum | 0–10 | – | ||
| bluebells | MERTE | Mertensia | 0–10 | – | ||
| owl's-clover | ORTHO | Orthocarpus | 0–10 | – | ||
| phlox | PHLOX | Phlox | 5–10 | – | ||
| sagebrush buttercup | RAGL | Ranunculus glaberrimus | 5–10 | – | ||
| stonecrop | SEDUM | Sedum | 0–10 | – | ||
| common yarrow | ACMI2 | Achillea millefolium | 5–10 | – | ||
| agoseris | AGOSE | Agoseris | 5–10 | – | ||
| onion | ALLIU | Allium | 5–10 | – | ||
| brodiaea | BRODI | Brodiaea | 5–10 | – | ||
| mariposa lily | CALOC | Calochortus | 0–10 | – | ||
| Indian paintbrush | CASTI2 | Castilleja | 0–10 | – | ||
| bastard toadflax | COMAN | Comandra | 0–10 | – | ||
| bushy bird's beak | CORA5 | Cordylanthus ramosus | 0–10 | – | ||
| buckwheat | ERIOG | Eriogonum | 5–10 | – | ||
| larkspur | DELPH | Delphinium | 0–10 | – | ||
| deathcamas | ZIGAD | Zigadenus | 0–10 | – | ||
|
Shrub/Vine
|
||||||
| 11 | Dominant, evergreen shrub | 80–160 | ||||
| mountain big sagebrush | ARTRV | Artemisia tridentata ssp. vaseyana | 80–160 | – | ||
| 15 | Other shrubs | 32–336 | ||||
| Saskatoon serviceberry | AMAL2 | Amelanchier alnifolia | 0–32 | – | ||
| basin big sagebrush | ARTRT | Artemisia tridentata ssp. tridentata | 0–32 | – | ||
| big sagebrush | ARTRX | Artemisia tridentata ssp. xericensis | 0–32 | – | ||
| yellow rabbitbrush | CHVI8 | Chrysothamnus viscidiflorus | 16–32 | – | ||
| wild crab apple | PERA4 | Peraphyllum ramosissimum | 0–32 | – | ||
| chokecherry | PRVI | Prunus virginiana | 0–32 | – | ||
| antelope bitterbrush | PUTR2 | Purshia tridentata | 0–32 | – | ||
| wax currant | RICE | Ribes cereum | 16–32 | – | ||
| Woods' rose | ROWO | Rosa woodsii | 0–32 | – | ||
| common snowberry | SYAL | Symphoricarpos albus | 0–32 | – | ||
| littleleaf horsebrush | TEGL | Tetradymia glabrata | 0–16 | – | ||
|
Tree
|
||||||
| 16 | Trees | 0–64 | ||||
| ponderosa pine | PIPO | Pinus ponderosa | 0–32 | – | ||
| Douglas-fir | PSME | Pseudotsuga menziesii | 0–32 | – | ||
Interpretations
Animal community
Livestock Grazing:
This site is suitable for livestock grazing use in the summer and fall under a planned grazing system. Use should be postponed until the soils are firm enough to prevent trampling damage and soil compaction. Grazing management should be keyed for Idaho fescue. Deferred grazing or rest is recommended at least once every three years.
Native Wildlife Associated with the Potential Climax Community:
This site is commonly used by mule deer, elk, antelope, rabbits, rodents, upland birds and various predators. It is a preferred site for upland bird nesting and rearing areas. Mule deer and elk make excellent use of the site for summer and fall forage.
Hydrological functions
The soils of this site are typically in an upland topographic position. They have moderate high runoff potential and medium infiltration rates when the hydrologic cover is good. Under frozen ground conditions runoff potential is significantly increased. This occurs for extended periods when deep rooted perennial bunchgrass cover is negligible. Hydrologic cover is good when the Idaho fescue deep rooted bunchgrass component is >70 percent of potential.
Other information
Juniper invasion is a major risk on this site. Control measures include prescribed burning and/or cutting followed by rest to improve vigor, density and seed production of existing deep rooted perennial bunchgrasses. Consider seeding following control measures if an inadequate stand of bunchgrass is present.
Green rabbitbrush, when present, should be targeted in a herbicide brush control program. It can increase markedly.
Supporting information
Contributors
A Bahn, G Kuehl, H Barrett
E Ersch
T.Bloomer, B.Gillaspy, E.Petersen, A.Bahn
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 | NRCS Oregon State Rangeland Management Specialist |
| Date | 04/24/2003 |
| Approved by | Bob Gillaspy |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
None to some -
Presence of water flow patterns:
None to some -
Number and height of erosional pedestals or terracettes:
None to very few (some frost heaving) -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
0-5% -
Number of gullies and erosion associated with gullies:
None -
Extent of wind scoured, blowouts and/or depositional areas:
None -
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):
Significantly resistant to erosion: aggregate stability = 5-6 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Weak fine granular to platy, to very fine subangular blocky structure, dry color value 4-5, 4-20 inches thick; Moderate OM (2-4%) -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Significant ground cover (80-90%) moderately to significnatly limit rainfall impact and overland flow on these gentle to steep slopes (12-80%) -
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:
Deep-rooted, perennial, cool-season bunch-grassesSub-dominant:
Evergreen shrubs > deciduous shrubsOther:
Forbs >= other perennial grassesAdditional:
-
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: 2200, Normal: 1600, Unfavorable: 1000 lbs/acre/year at high RSI -
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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