Natural Resources
Conservation Service
Ecological site R010XA007OR
Juniper Pumice South
9-12 PZ
Last updated: 4/10/2025
Accessed: 07/12/2026
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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
R010XA002OR Juniper Shrubby Pumice Hills 8-10 PZ
R010XA009OR Juniper Shrubby Pumice Flat 10-12 PZ
R010XA023OR Juniper Shrubby Lava Blisters 10-12 PZ
Table 1. Dominant plant species
Tree (1) Juniperus occidentalis
Shrub (1) Artemisia tridentata ssp. tridentata
(2) Artemisia tridentata ssp. vaseyanaHerbaceous (1) Pseudoroegneria spicata ssp. spicata
Physiographic features
This site occurs on moderately steep south facing slopes of canyons, buttes, and ridges. Slopes range from 15 to 65 percent, but are typically from 30 to 60 percent. Elevations range from 2500 feet to 4500 feet.
Table 2. Representative physiographic features
Landforms (1) Canyon
(2) Butte
(3) Ridge
Flooding frequency None Ponding frequency None Elevation 2500 – 4500 ft Slope 15 – 65 % Aspect S Climatic features
The annual precipitation ranges from 9 to 12 inches which occus mainly between the months of October and June, mostly in the form of snow and spring-fall rains. The soil temperature is 49 degreees F. with extreme temperatures ranging from -20 to 104 degrees F. The frost free period is 80 to 110 days. The optimum period for plant growth is from mid-March through June.
Table 3 Representative climatic features
Frost-free period (average) 110 days Freeze-free period (average) 150 days Precipitation total (average) 10 in BarLineFigure 2. Monthly precipitation range
BarLineFigure 3. Monthly average minimum and maximum temperature
">Influencing water features
Soil features
The soils of this site have sandy loam surface layers and loam subsoils. They are usually sotny to very stony on the surface and throughout the profile. Colluvial rock material limits the effective depth to less than 30 inches. Depth to bedrock rangesf rom 10 to 40 inches. Permeability is moderate to rapid and the available water holding capacity is 2 to 6 inches for the profile. The potential for water erosion is high.
Table 4. Representative soil features
Parent material (1) Colluvium – volcanic breccia
(2) Colluvium – shale
(3) Residuum – volcanic breccia
Surface texture (1) Very gravelly loam
(2) Very stony loam
(3) Very stony sandy loam
Family particle size (1) Loamy
Drainage class Well drained to somewhat excessively drained Permeability class Moderately slow to moderately rapid Soil depth 10 – 40 in Surface fragment cover <=3" 0 – 35 % Surface fragment cover >3" 0 – 40 % Available water capacity
(0-40in)1.3 – 5.2 in 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)6.6 – 7.8 Subsurface fragment volume <=3"
(Depth not specified)10 – 60 % Subsurface fragment volume >3"
(Depth not specified)0 – 35 % Ecological dynamics
Fire causes a decline in juniper and sagebrush, but increases in rabbitbrush. Cheatgrass patches occur around the base of burned out juniper.
Bluebunch wheatgrass is the dominant grass but Thurber needlegrass increases with more sandy surface textures. Basin big sagebrush and Mountain big sagbrush are represented in the plant community but both species may occur alone. Antelope bitterbrush and western juniper may increase as precipition approaches 12 inches. The juniper component is greater in areas with larger amounts of coarse fragments.
Stocking rate for the reference plant community calculates to 6 acres per cow per year. As the site deteriorates, this ecosite will require 9 to 14 acres per cow per year in moderate similarity to the reference plant community and a minimum of 50 acres per cow per year in low similarity.State and transition model
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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 western juniper and bluebunch wheatgrass. Basin big sagebrush and/or Mountain big sagebrush (NTE 10% combined), antelope bitterbrush and Sandberg bluegrass are common in the stand.
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 375 525 675 Shrub/Vine 75 105 135 Tree 25 35 45 Forb 25 35 45 Total 500 700 900 Figure 5. Plant community growth curve (percent production by month). OR4021 , B10A Mesic, 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 2 30 60 6 2 0 0 0 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 420–490 bluebunch wheatgrass PSSP6 Pseudoroegneria spicata 420–490 – 2 Sub-dominant deep rooted perennial grasses 28–49 Thurber's needlegrass ACTH7 Achnatherum thurberianum 7–21 – squirreltail ELEL5 Elymus elymoides 7–14 – Idaho fescue FEID Festuca idahoensis 14 – 3 Dominant shallow rooted perennial grasses 35–70 Sandberg bluegrass POSE Poa secunda 35–70 – 4 Sub-dominant shallow rooted perennial grasses 7 prairie Junegrass KOMA Koeleria macrantha 7 – Forb9 Other perennial forbs 7–35 common yarrow ACMI2 Achillea millefolium 0–5 – woollypod milkvetch ASPU9 Astragalus purshii 0–5 – tapertip hawksbeard CRAC2 Crepis acuminata 0–5 – fleabane ERIGE2 Erigeron 0–5 – buckwheat ERIOG Eriogonum 0–5 – desertparsley LOMAT Lomatium 0–5 – phacelia PHACE Phacelia 0–5 – phlox PHLOX Phlox 0–5 – Shrub/Vine11 Dominant evergreen shrubs 35–70 basin big sagebrush ARTRT Artemisia tridentata ssp. tridentata 35–70 – mountain big sagebrush ARTRV Artemisia tridentata ssp. vaseyana 35–70 – 12 Sub-dominant evergreen shrubs 7–35 antelope bitterbrush PUTR2 Purshia tridentata 7–35 – 15 Other shrubs 7–28 Mathias' eryngo ERMA10 Eryngium mathiasiae 0–5 – slender buckwheat ERMI4 Eriogonum microthecum 0–5 – green rabbitbrush ERTE18 Ericameria teretifolia 0–5 – desert gooseberry RIVE Ribes velutinum 0–5 – Tree16 Dominant evergreen trees 35–70 western juniper JUOC Juniperus occidentalis 35–70 – Interpretations
Animal community
Because of this site's south aspect, it is very important to big game during the winter and early spring.
Hydrological functions
The soils are in hydrologic group B. The soils of this site have slow to very rapid runoff potential.
Wood products
This site will yield firewood and other specialty products.
Other products
This site is best suited to use by livestock in spring and fall.
Other information
Adapted species for seedings include crested wheatgrass and Siberian wheatgrass. Due to the shallow and stony soils, this site ahs low potential for range seeding.
Supporting information
Other references
B10B site Droughty South 9-12 PZ #010XB042OR is similar to this site.
Contributors
Barrett, Carlson
Bob Gillaspy
Cici Brooks
K.KennedyApproval
Kirt Walstad, 4/10/2025
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 and Bruce Fransen Contact for lead author Oregon State Rangeland Management Specialist Date 03/15/2005 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):
10-20% -
Number of gullies and erosion associated with gullies:
None -
Extent of wind scoured, blowouts and/or depositional areas:
None to some, Severe wind ersoion 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 = 2-4 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Weak very fine granular structure to moderate medium subangular blocky structure. A-horizon dry color value from 4 to 6 with a thickness of 9 - 13 inches. Low surface organic matter (1-2 %). -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Moderate ground cover (45-60%) and moderately steep to steep slopes (30-60%) 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:
Moderate to deep-rooted perennial bunch grasses >> shallow rooted perennial bunch grasses.Sub-dominant:
Evergreen shrubs and trees.Other:
Forbs and deciduous shrubs.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: 900, Normal: 700, Unfavorable: 500 lbs/acre/year RPC. -
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:
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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