Natural Resources
Conservation Service
Ecological site R008XY130OR
Sandy Loam
10-12 PZ
Last updated: 5/02/2025
Accessed: 08/16/2026
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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.
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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
R008XY110OR Loamy 10-12 PZ
R008XY150OR Very Shallow Loam 10-14 PZ
R008XY200OR South 10-14 PZ
R008XY220OR North 10-14 PZ
Similar sites
R008XY110OR Loamy 10-12 PZ
Finer texture
Table 1. Dominant plant species
Tree Not specified
Shrub Not specified
Herbaceous Not specified
Physiographic features
This site occurs on nearly level to gently rolling uplands.
Table 2. Representative physiographic features
Landforms (1) Hill
Elevation 1000 – 2500 ft Slope 2 – 20 % Climatic features
The annual precipitation ranges from 10 to 12 inches, most of which occurs as rain with snow during the months of November through May. Spring and fall rains are common. The temperature regime is mesic with temperature extremes ranging from 110 degrees F. to -10 degrees F. The frost-free period is 140 to 200 days and the optimum period for plant growth is early April through mid-June.
Table 3 Representative climatic features
Frost-free period (average) 200 days Freeze-free period (average) Precipitation total (average) 10 in ">Influencing water features
Soil features
The soils of this site are very deep, well drained fine sandy loams formed in loess over basalt bedrock. The permeability is moderate and the available water holding capacity is 10 to 12 inches for the profile. The erosion hazard is moderate for wind and slight for water.
Table 4. Representative soil features
Soil depth 60 in Available water capacity
(0-40in)10 – 12 in Ecological dynamics
If heavy grazing causes site deterioration, Idaho fescue, bluebunch wheatgrass, and needle and thread will decrease in the stand in that order. Rabbitbrush, lupine, and big sagebrush will increase. Cheatgrass, fiddleneck, and Russian thistle will invade the site. A lack of occasional fire will encourage an increase of shrubs.
The plant composition on this site depends strongly on soil surface texture and toa lesser extent on apsect. Typically, the very fine sandy loam surface texture gives rise to the high proportion of needleandthread while a shift to finer texture promotes an increase in the amount of bluebunch wheatgrass. North-trending slopes tend to show an increase in Idaho fescue.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
ReferenceCommunity 1.1
Reference Plant CommunityThe potential native plant community is dominated by needleandthread with lesser amounts of bluebunch wheatgrass. Vegetative composition is about 90% grasses, 5% forbs, and 5% 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 450 810 1080 Forb 30 60 80 Shrub/Vine 20 30 40 Total 500 900 1200 Figure 3. Plant community growth curve (percent production by month). OR2521 , B8 Sandy Loam. B8 Sandy Loam RPC, Good Condition .
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 15 20 25 15 5 5 0 5 10 0 0 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 630–990 needle and thread HECO26 Hesperostipa comata 450–630 – bluebunch wheatgrass PSSP6 Pseudoroegneria spicata 180–360 – 2 Sub-dominant deep rooted perennial grasses 45–135 Idaho fescue FEID Festuca idahoensis 45–135 – 4 Sub-dominant shallow rooted perennial grasses 18–45 Sandberg bluegrass POSE Poa secunda 18–45 – 5 Other perennial grasses 0–45 squirreltail ELEL5 Elymus elymoides 0–18 – 6 Annual grasses 9–18 sixweeks fescue VUOC Vulpia octoflora 9–18 – Forb7 Dominant perennial forbs 27–54 common yarrow ACMI2 Achillea millefolium 9–18 – fleabane ERIGE2 Erigeron 9–18 – phlox PHLOX Phlox 9–18 – 9 Other perennial forbs 0–60 pussytoes ANTEN Antennaria 0–10 – milkvetch ASTRA Astragalus 0–10 – arrowleaf balsamroot BASA3 Balsamorhiza sagittata 0–10 – sagebrush mariposa lily CAMA5 Calochortus macrocarpus 0–10 – willowherb EPILO Epilobium 0–10 – buckwheat ERIOG Eriogonum 0–10 – lupine LUPIN Lupinus 0–10 – woolly plantain PLPA2 Plantago patagonica 0–10 – Shrub/Vine11 Dominant shrubs 18–36 basin big sagebrush ARTRT Artemisia tridentata ssp. tridentata 9–18 – rubber rabbitbrush ERNA10 Ericameria nauseosa 9–18 – 15 Other shrubs 0–18 yellow rabbitbrush CHVI8 Chrysothamnus viscidiflorus 0–9 – broom snakeweed GUSA2 Gutierrezia sarothrae 0–9 – Interpretations
Animal community
Where associated with croplands, this site is used by upland game birds including Hungarian partridge, chukars and ring-necked pheasants.
Hydrological functions
The soils of this site have modeate infiltration rates and low runoff potential. The hydrologic soil group is B.
Wood products
None
Other products
This site is suitable for grazing by livestock during all seasons of the year but most ideally, it is suited to fall, winter, and early spring use under a planned grazing system.
Supporting information
Contributors
Barrett, Bahn
E Ersch (OSU)
K.KennedyApproval
Kirt Walstad, 5/02/2025
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 07/26/2012 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
None, slight 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):
10-15% -
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):
Slightly to moderately resistant to erosion; aggregate stability = 3-4 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Very deep, well drained very fine sandy loams; Low OM (2-3%) -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Significant ground cover (40-60%) and level to gently rolling slopes (2-20%) 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:
Needle and thread > Bluebunch wheatgrass > Idaho fescue > Sandberg bluegrass = other grasses = other forbs > annual grasses + dominant forbs = dominant shrubs = other shrubsSub-dominant:
Other:
Additional:
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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: 500 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 group -
Perennial plant reproductive capability:
All species should be capable of reproducing annually
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