Natural Resources
Conservation Service
Ecological site R021XY412OR
LOAMY 18+ PZ
Accessed: 11/23/2024
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.
Similar sites
| R021XY210OR |
LOAMY 14-18 PZ Lower precipitation. |
|---|
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
Not specified |
Physiographic features
This site occurs as openings within forested mountainous areas and on ridgetops.
Table 2. Representative physiographic features
| Landforms |
(1)
Mountain
(2) Ridge |
|---|---|
| Elevation | 5,500 – 7,200 ft |
| Slope | 10 – 40% |
| Aspect | Aspect is not a significant factor |
Climatic features
The annual precipitation ranges from 24 to 40 inches, most of which occurs in the form of snow during the months of October through May. The soil temperature regime is frigid with a mean annual air temperature of about 43 degrees F. Temperature extremes range from 85 to -30 degrees F. The frost free period ranges from 30 to 70 dyas. The optimum period for plant growth is from June through July.
Table 3. Representative climatic features
| Frost-free period (average) | 70 days |
|---|---|
| Freeze-free period (average) | 0 days |
| Precipitation total (average) | 40 in |
Influencing water features
Soil features
The soils of this site are very deep and well drained. The soils are loamy throughout and contain over 35 percent rock fragments in the subsoil. Organic matter content is high and ranges form 2 to 5 percent throughout the upper 20 to 40 inches of the soil profile. Permeability is moderate to moderately slow. The available water holding capacity is about 4 to 8 inches. Runoff is medium. Erosion hazard by water is moderate.
Table 4. Representative soil features
| Surface texture |
(1) Loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderate to moderately slow |
| Soil depth | 60 in |
| Available water capacity (0-40in) |
4 – 8 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 Ross sedge decrease while bottlebrush squirreltail increase. With further deterioration, mountain big sagebrush and snowberry increase.
The consistent soil depth and dependable precipitation lend stability to site production and species composition.
State and transition model
More interactive model formats are also available.
View Interactive Models
More interactive model formats are also available.
View Interactive Models
Click on state and transition labels to scroll to the respective text
Ecosystem states
State 1 submodel, plant communities
State 1
HCPC, CARO5-FEID/ARTRV-SYAL
Community 1.1
HCPC, CARO5-FEID/ARTRV-SYAL
The potential native plant community is dominated by mountain big sagebrush and snowberry. Ross sedge, Idaho fescue, mountain brome, aspen, snowberry, and a variety of forbs are common in the stand. The vegetative composition of the community is approximately 50% grasses, 20% forbs, and 30% 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 | 220 | 450 | 680 |
| Shrub/Vine | 190 | 335 | 480 |
| Forb | 130 | 210 | 290 |
| Tree | 40 | 65 | 90 |
| Total | 580 | 1060 | 1540 |
Figure 3. Plant community growth curve (percent production by month). OR5557, D21 High Elev, NA / South, Good Condition. HPCP 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 | 0 | 5 | 30 | 50 | 15 | 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 | 200–580 | ||||
| Idaho fescue | FEID | Festuca idahoensis | 50–150 | – | ||
| mountain brome | BRMA4 | Bromus marginatus | 50–150 | – | ||
| Ross' sedge | CARO5 | Carex rossii | 50–150 | – | ||
| squirreltail | ELEL5 | Elymus elymoides | 20–50 | – | ||
| western needlegrass | ACOC3 | Achnatherum occidentale | 20–50 | – | ||
| basin wildrye | LECI4 | Leymus cinereus | 10–30 | – | ||
| 5 | Other perennial grasses | 20–100 | ||||
| slender wheatgrass | ELTR7 | Elymus trachycaulus | 0–5 | – | ||
| prairie Junegrass | KOMA | Koeleria macrantha | 0–5 | – | ||
| melicgrass | MELIC | Melica | 0–5 | – | ||
| timothy | PHLEU | Phleum | 0–5 | – | ||
|
Forb
|
||||||
| 7 | Dominant perennial forbs | 100–200 | ||||
| lupine | LUPIN | Lupinus | 50–100 | – | ||
| mule-ears | WYAM | Wyethia amplexicaulis | 50–100 | – | ||
| 8 | Sub-dominant perennial forbs | 20–40 | ||||
| columbine | AQUIL | Aquilegia | 10–20 | – | ||
| phlox | PHLOX | Phlox | 10–20 | – | ||
| 9 | Other perennial forbs | 10–50 | ||||
| common yarrow | ACMI2 | Achillea millefolium | 0–5 | – | ||
| heartleaf arnica | ARCO9 | Arnica cordifolia | 0–5 | – | ||
| strawberry | FRAGA | Fragaria | 0–5 | – | ||
| geranium | GERAN | Geranium | 0–5 | – | ||
| cinquefoil | POTEN | Potentilla | 0–5 | – | ||
| ragwort | SENEC | Senecio | 0–5 | – | ||
| meadow-rue | THALI2 | Thalictrum | 0–5 | – | ||
|
Shrub/Vine
|
||||||
| 11 | Dominant evergreen shrubs | 100–200 | ||||
| mountain big sagebrush | ARTRV | Artemisia tridentata ssp. vaseyana | 100–200 | – | ||
| 13 | Dominant deciduous (or 1/2 shrubs) shrubs | 70–200 | ||||
| common snowberry | SYAL | Symphoricarpos albus | 50–150 | – | ||
| Saskatoon serviceberry | AMAL2 | Amelanchier alnifolia | 20–50 | – | ||
| 15 | Other shrubs | 20–80 | ||||
| rabbitbrush | CHRYS9 | Chrysothamnus | 0–5 | – | ||
| bitter cherry | PREM | Prunus emarginata | 0–5 | – | ||
| Klamath plum | PRSU2 | Prunus subcordata | 0–5 | – | ||
| chokecherry | PRVI | Prunus virginiana | 0–5 | – | ||
| currant | RIBES | Ribes | 0–5 | – | ||
| rose | ROSA5 | Rosa | 0–5 | – | ||
|
Tree
|
||||||
| 16 | Dominant evergreen trees | 10–20 | ||||
| ponderosa pine | PIPO | Pinus ponderosa | 10–20 | – | ||
| 18 | Dominant deciduous trees | 30–70 | ||||
| quaking aspen | POTR5 | Populus tremuloides | 20–50 | – | ||
| willow | SALIX | Salix | 10–20 | – | ||
Interpretations
Animal community
This site offers food and cover for mule deer and blue grouse.
Hydrological functions
The soils are in hydrologic group B.
Other products
This site is suited to use by cattle, sheep and horses in summer under a planned grazing system.
Supporting information
Contributors
Barrett, Carlson
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 | 09/05/2012 |
| 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):
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 = 3-5 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Very deep, well drained loams (>35% rock fragments in the subsoil): Moderate to High OM (2-5%) -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Significant vegetative cover (60-90%), litter cover, and moderate slopes (10-40%) effectively limit rainfall impact and overland flow; 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:
Mountain big sagebrush > dominant forbs > Snowberry = Ross sedge = Idaho fescue = Mountain brome > trees > other grasses > 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: 1000, Unfavorable: 800 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
Print Options
Sections
Font
Other
The Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.
Click on box and path labels to scroll to the respective text.