Natural Resources
Conservation Service
Ecological site R010XC059OR
SR Mahogany Rockland
12+ PZ
Last updated: 5/13/2025
Accessed: 07/05/2026
-
Search
Major Land Resource Area or ecological site by name and/or ID.
PreviousSectionsNextGeneral 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.
Click to explore map
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
R010XC047OR SR Mountain South 12-16 PZ
Mountain South 12-16" PZ
R010XC051OR SR High Mountain South 16-20 PZ
Shallow Mountain South 12-16" PZ
Table 1. Dominant plant species
Tree (1) Juniperus occidentalis
Shrub (1) Cercocarpus ledifolius
(2) Purshia tridentataHerbaceous (1) Pseudoroegneria spicata ssp. spicata
(2) Festuca idahoensisPhysiographic features
This site is on moderate to steep canyon walls and mountain sideslopes. Slopes range from 12 to 60%. Elevations range from 3000 to 6000 feet.
Table 2. Representative physiographic features
Landforms (1) Canyon
(2) Mountain slope
Elevation 3000 – 6000 ft Slope 12 – 60 % Aspect Aspect is not a significant factor Climatic features
The annual precipitation ranges from 12 to over 20 inches, most of which occurs in the form of snow during the months of November through March. The soil temperature regime is frigid to near frigid with a mean annual air temperature ranging from 43 to 48 degrees F. Temperature extremes range from 100 to -30 degrees F. The frost free period ranges from 50 to 90 days. The optimum period for plant growth is from April through June.
Table 3 Representative climatic features
Frost-free period (average) 90 days Freeze-free period (average) Precipitation total (average) 20 in ">Influencing water features
Soil features
The soils of this site are typically shallow to moderately deep and well drained with areas of rock outcrop. Typically the surface layer is a stony, extremely stony loam, very stony clay loam, or very shaley loam from 3 to 7 inches thick. The subsoil is a loam, very gravelly loam; very stony, gravelly, channery clay loam from 6 to 27 inches thick. Depth to bedrock typically ranges from 10 to 30 inches. Permeability is slow to moderate. The available water holding capacity is about 3 to 5 inches for the profile. The potential for erosion is severe.
Table 4. Representative soil features
Surface texture (1) Stony loam
(2) Stony clay loam
Family particle size (1) Loamy
Drainage class Well drained Permeability class Slow to moderate Soil depth 10 – 30 in Available water capacity
(0-40in)3 – 5 in Ecological dynamics
Idaho fescue increases on northerly aspects. Mountain mahogany increases on fractured rock. Antelope bitterbrush follows a similar pattern on both fractured and deeper gravelly areas. Ponderoda pine occurs at upper elevations and precipitation zones.
If the condition of the site deteriorates as a result of overgrazing, bunchgrasses decrease while big sagebrush, squirreltail and Sandberg bluegrass increase. Bluebunch wheatgrass and Idaho fescue are the preferred species during the spring and summer. With further deterioration, annuals and Canadian and Kentucky bluegrasses invade and bare interspaces markedly increase. Excessive erosion in the bare soil interspaces reduces the site productivity and contributes to downstream sedimentation.State and transition model
Custom diagramStandard diagram
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 textEcosystem states
State 1 submodel, plant communities
State 1
Historic Climax Plant CommunityCommunity 1.1
Historic Climax Plant CommunityThe potential native plant community is dominated by curlleaf mountain mahogany, antelope bitterbrush and bluebunch wheatgrass. Western juniper is common in the stand. Vegetative composition of the community is approximately 30% grasses, 5% forbs, and 65% shrubs/trees.
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)Shrub/Vine 378 558 738 Grass/Grasslike 279 392 504 Forb 63 90 117 Tree 18 54 90 Total 738 1094 1449 Additional community tables
Table 6. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Dominant, deep-rooted, perennial grasses 207–360 bluebunch wheatgrass PSSP6 Pseudoroegneria spicata 180–270 – Idaho fescue FEID Festuca idahoensis 27–90 – 2 Sub-dominant, deep-rooted, perennial grasses 36–81 Thurber's needlegrass ACTH7 Achnatherum thurberianum 18–45 – squirreltail ELEL5 Elymus elymoides 9–18 – western needlegrass ACOC3 Achnatherum occidentale 9–18 – 4 Sub-dominant, shallow-rooted, perennial grasses 18–36 prairie Junegrass KOMA Koeleria macrantha 9–18 – Sandberg bluegrass POSE Poa secunda 9–18 – 5 All other perennial grasses 18–27 needlegrass ACHNA Achnatherum 4–5 – mountain brome BRMA4 Bromus marginatus 4–5 – elk sedge CAGA3 Carex garberi 4–5 – pinegrass CARU Calamagrostis rubescens 4–5 – Cusick's bluegrass POCU3 Poa cusickii 4–5 – Forb7 All dominant, perennial forbs 18–36 arrowleaf balsamroot BASA3 Balsamorhiza sagittata 18–36 – arrowleaf balsamroot BASA3 Balsamorhiza sagittata 18–36 – 8 All sub-dominant, perennial forbs 27–54 buckwheat ERIOG Eriogonum 9–18 – phlox PHLOX Phlox 9–18 – ragwort SENEC Senecio 9–18 – buckwheat ERIOG Eriogonum 9–18 – phlox PHLOX Phlox 9–18 – ragwort SENEC Senecio 9–18 – 9 All other perennial forbs 18–27 common yarrow ACMI2 Achillea millefolium 1–4 – heartleaf arnica ARCO9 Arnica cordifolia 1–4 – waterleaf HYDRO4 Hydrophyllum 1–4 – woodland-star LITHO2 Lithophragma 1–4 – phacelia PHACE Phacelia 1–4 – cinquefoil POTEN Potentilla 1–4 – buttercup RANUN Ranunculus 1–4 – Shrub/Vine11 Dominant, evergreen, perennial shrubs 45–135 antelope bitterbrush PUTR2 Purshia tridentata 45–135 – 12 Sub-dominant, evergreen, perennial shrubs 27–72 mountain big sagebrush ARTRV Artemisia tridentata ssp. vaseyana 18–45 – basin big sagebrush ARTRT Artemisia tridentata ssp. tridentata 9–27 – 13 Dominant, deciduous, perennial shrubs 270–450 curl-leaf mountain mahogany CELE3 Cercocarpus ledifolius 270–450 – 14 Sub-dominant, deciduous, perennial shrubs 18–36 wax currant RICE Ribes cereum 9–18 – common snowberry SYAL Symphoricarpos albus 9–18 – 15 All other perennial shrubs 18–45 rubber rabbitbrush ERNA10 Ericameria nauseosa 6–15 – peraphyllum PERAP Peraphyllum 6–15 – rose ROSA5 Rosa 6–15 – Tree16 Dominant, evergreen, perennial trees 18–72 western juniper JUOC Juniperus occidentalis 18–72 – 17 Sub-dominant, evergreen, perennial trees 0–18 ponderosa pine PIPO Pinus ponderosa 0–9 – Douglas-fir PSME Pseudotsuga menziesii 0–9 – Interpretations
Animal community
This site provides critical cover and forage for deer and elk during the winter and early spring.
Hawks
Rodents
SongbirdsHydrological functions
The soils are in hydrologic group D. The soils of this site have high runoff potential.
Other products
This site is suited to limited use by cattle in the late spring and summer. It is very fragile site. Care should be taken to avoid trampling damage when soils are wet.
Other information
This site is not conducive to mechanical improvement measures due to steepness of slope and unstable soils.
Supporting information
Contributors
A Bahn, G Kuehl, H Barrett
E ErschApproval
Kirt Walstad, 5/13/2025
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 08/07/2012 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
-
Number and extent of rills:
None to some, severe sheet & rill erosion hazard -
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):
10-25% -
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):
Moderately to significantly resistant to erosion: aggregate stability = 3-6 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Shallow to moderately deep well drained extremely stony loam, very stony clay loam, or very shaly loam (3-7 inches thick): Moderate OM (2-4%) -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Low to moderate ground cover (40-60%) and gentle to steep slopes (12-60%) slightly to 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:
Curlleaf Mountain Mahogany > Bluebunch wheatgrass > other shrubs > other grasses > 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: 1300, 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
Print Options
Sections
Font
AAAAOther
PrintThe 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.
Accessibility statement
