Natural Resources
Conservation Service
Ecological site R010XB043OR
JD Droughty Clayey South 9-12 PZ
Accessed: 11/21/2024
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.
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
Not specified |
Physiographic features
This site occurs on southerly exposures of low elevation terraces composed of early cenezoic tuffaceous sedimetns. Slopes range from 5 to 70% with slopes of 12 to 60% being most typical . Elevation varies from 1300 to 2400 feet.
Table 2. Representative physiographic features
| Landforms |
(1)
Hillside
(2) Ridge |
|---|---|
| Flooding frequency | None |
| Ponding frequency | None |
| Elevation | 396 – 732 m |
| Slope | 5 – 70% |
| Water table depth | 183 cm |
| Aspect | S, SW, W |
Climatic features
Elevation and aspect affect precipitation and the relative effectiveness of the precipitation and temperatures. Temperature changes can occur rapidly. In addition, the topography also results in localized cold air drainages, along with occasional cold air entrapment and inversions in the valleys.
Table 3. Representative climatic features
| Frost-free period (average) | 150 days |
|---|---|
| Freeze-free period (average) | 180 days |
| Precipitation total (average) | 305 mm |
Figure 1. Monthly precipitation range
Figure 2. Monthly average minimum and maximum temperature
Influencing water features
Soil features
Soils on this site typically have a stony clay surface over clay and are shallow to deep. Soils are well drained. They have formed in colluvium and loess.
Table 4. Representative soil features
| Surface texture |
(1) Very cobbly clay loam |
|---|---|
| Family particle size |
(1) Clayey |
| Drainage class | Well drained |
| Permeability class | Very slow |
| Soil depth | 23 – 152 cm |
| Surface fragment cover <=3" | 5% |
| Surface fragment cover >3" | 10% |
| Available water capacity (0-101.6cm) |
2.9 – 27.28 cm |
| Calcium carbonate equivalent (0-101.6cm) |
1 – 10% |
| Electrical conductivity (0-101.6cm) |
0 – 2 mmhos/cm |
| Sodium adsorption ratio (0-101.6cm) |
0 |
| Soil reaction (1:1 water) (0-101.6cm) |
6.6 – 9 |
| Subsurface fragment volume <=3" (Depth not specified) |
0% |
| Subsurface fragment volume >3" (Depth not specified) |
0% |
Ecological dynamics
This site occurs on hillslopes and ridgetops. Grasses dominate this plant community with a fair amount of shrubs with few forbs. Fluctuations in species composition and relative production may change from year to year dependent upon abnormal precipitation or other climatic factors. Shadscale is stronly correlated with a clay surface and decreases as the surface becomes coarser The interpretive plant community for this site is the Historic Climax Plant Community (HCPC). State and transition pathways: 1) Overgrazing (constant grazing); 2) Rest and time.
State and transition model
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Click on state and transition labels to scroll to the respective text
State 1 submodel, plant communities
State 2 submodel, plant communities
State 1
HCPC: Shadscale/Bluebunch wheatgrass
Community 1.1
HCPC: Shadscale/Bluebunch wheatgrass
This site is dominated by Bluebunch wheatgrass with a subdominance of Shadscale. Forbs make up a minor component of this site.
Figure 3. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
| Plant type | Low (kg/hectare) |
Representative value (kg/hectare) |
High (kg/hectare) |
|---|---|---|---|
| Grass/Grasslike | 327 | 491 | 655 |
| Shrub/Vine | 112 | 168 | 224 |
| Forb | 9 | 13 | 18 |
| Total | 448 | 672 | 897 |
Figure 4. Plant community growth curve (percent production by month). OR4191, B10 JD Droughty, Clayey, Souths RPC. JD Droughty, Clayey, Souths RPC(Shadscale/Bluebunch wheatgrass).
| 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 | 10 | 15 | 20 | 30 | 15 | 0 | 5 | 5 | 0 | 0 |
State 2
State B: Disturbance (Broom snakeweed/cheatgrass)
Community 2.1
State B: Disturbance (Broom snakeweed/cheatgrass)
This site is dominated by Broom snakeweed. Forbs and grasses make up a small percent of the community. Broom snakeweed increases. Medusahead rye invades locally.
Figure 5. Annual production by plant type (representative values) or group (midpoint values)
Table 6. Annual production by plant type
| Plant type | Low (kg/hectare) |
Representative value (kg/hectare) |
High (kg/hectare) |
|---|---|---|---|
| Shrub/Vine | 168 | 336 | 504 |
| Grass/Grasslike | 45 | 90 | 135 |
| Forb | 11 | 22 | 34 |
| Total | 224 | 448 | 673 |
Figure 6. Plant community growth curve (percent production by month). OR4192, B10 JD Droughty Clayey South B. Disturbance (GUSA2/BRTE).
| 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 | 15 | 25 | 30 | 20 | 0 | 0 | 5 | 5 | 0 | 0 |
Additional community tables
Table 7. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | 34–112 | |||||
| Sandberg bluegrass | POSE | Poa secunda | 22–67 | – | ||
| sand dropseed | SPCR | Sporobolus cryptandrus | 22–67 | – | ||
| 2 | 392–504 | |||||
| bluebunch wheatgrass | PSSPS | Pseudoroegneria spicata ssp. spicata | 404–538 | – | ||
| squirreltail | ELEL5 | Elymus elymoides | 11–45 | – | ||
|
Forb
|
||||||
| 3 | 22–67 | |||||
| milkvetch | ASTRA | Astragalus | 11–22 | – | ||
| common yarrow | ACMI2 | Achillea millefolium | 11–22 | – | ||
| desertparsley | LOMAT | Lomatium | 11–22 | – | ||
| phlox | PHLOX | Phlox | 6–11 | – | ||
| agoseris | AGOSE | Agoseris | 6–11 | – | ||
| tapertip hawksbeard | CRAC2 | Crepis acuminata | 6–11 | – | ||
| fleabane | ERIGE2 | Erigeron | 6–11 | – | ||
| buckwheat | ERIOG | Eriogonum | 6–11 | – | ||
|
Shrub/Vine
|
||||||
| 4 | 84–252 | |||||
| shadscale saltbush | ATCO | Atriplex confertifolia | 67–202 | – | ||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 13–54 | – | ||
| basin big sagebrush | ARTRT | Artemisia tridentata ssp. tridentata | 13–34 | – | ||
| purple sage | SADOI | Salvia dorrii ssp. dorrii var. incana | 7–13 | – | ||
Table 8. Community 2.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | 56–135 | |||||
| cheatgrass | BRTE | Bromus tectorum | 28–67 | – | ||
| Sandberg bluegrass | POSE | Poa secunda | 11–34 | – | ||
| soft brome | BRHO2 | Bromus hordeaceus | 11–34 | – | ||
| 2 | 11–34 | |||||
| bluebunch wheatgrass | PSSPS | Pseudoroegneria spicata ssp. spicata | 11–34 | – | ||
|
Forb
|
||||||
| 3 | 11–45 | |||||
| mustard | BRASS2 | Brassica | 6–22 | – | ||
| prickly lettuce | LASE | Lactuca serriola | 6–22 | – | ||
|
Shrub/Vine
|
||||||
| 4 | 168–235 | |||||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 90–135 | – | ||
| basin big sagebrush | ARTRT | Artemisia tridentata ssp. tridentata | 17–45 | – | ||
| purple sage | SADOI | Salvia dorrii ssp. dorrii var. incana | 17–45 | – | ||
| shadscale saltbush | ATCO | Atriplex confertifolia | 11–34 | – | ||
| yellow rabbitbrush | CHVIS5 | Chrysothamnus viscidiflorus ssp. viscidiflorus var. stenophyllus | 11–34 | – | ||
| western juniper | JUOC | Juniperus occidentalis | 11–34 | – | ||
Interpretations
Animal community
Grazing- Livestock grazing is suitable for this site as long as management objectives include the improvement or maintenance of this site. It is easy to overuse this site and cause a shift in vegetation that is difficult to change. This site has the potential to produce a large amount of high quality forage. Management should be aimed at harvesting the forage as quickly as possible, letting the site recover from the grazing event prior to fall dormancy. Initial stocking rates will be determined with the landowner or decisionmaker. They will be based on past use histories and type and condition of the vegetation. Calculations used to determine an initial starting stocking rate will be based on forage preference ratings.
Wildlife- The main wildlife species of concern on this site are large herbivores. These are mule deer and elk. These wildlife species can possibly overuse this site before the time cattle or sheep are planned to be grazed. Being an open grassland, this site is home to a variety of small herbivores, birds, and their associated predators. This site is mainly a foraging area for the larger wildlife. No theratened or endangered wildlife species rely on this site for any of their habitat requirements.
Hydrological functions
The site has a high potential in low seral condition to produce significant run-off to receiving waters. The hydrology of this site is characterized by high intensity thunderstorms during the summer months and by low intensity frontal storms during the winter.
Other information
Increase in Western juniper and the subsequent competition for moisture will lead to a reduction of available forage. Overgrazing can easily reduce ground cover and accelerate soil loss. Improving infiltration and permeability, and reducing runoff should be the immediate goal of juniper control.
Supporting information
Type locality
| Location 1: Wheeler County, OR | |
|---|---|
| Township/Range/Section | T10S R20E S36 |
| General legal description | SE 1/4 SE 1/4 Sec. 36 T10S R20E Carroll Rim Trail- Painted Hills (80% S.I.) |
| Location 2: Grant County, OR | |
| Township/Range/Section | T10S R26E S31 |
| General legal description | NW 1/4 SE 1/4 Sec. 31 T10S R26E North side of Foree Unit (80% S.I.) |
Other references
Soil Conservation Service, Relative Forage Preference of Plants for Grazing Use by Season, Range Technical Note No. 16, 1982.
Western Regional Climate Center, NOAA, National Weather Service, Portland, OR, web site- http://nimbo.wrh.noaa.gov/Portland/climate.html
Natural Vegetation of Oregon and Washington, Jerry F. Franklin and C.T. Dyrness.
The Ecological Provinces of Oregon, E. William Anderson, Michael M. Borman, and William C. Krueger.
Contributors
Ed Petersen, Alan 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 | State Rangeland Management Specialist for NRCS - Oregon |
| Date | 08/06/2012 |
| Approved by | Bob Gillaspy |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
None to few on steeper slopes, moderate sheet & rill erosion hazard -
Presence of water flow patterns:
None to few on steeper slopes -
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):
10-30% -
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):
Significantly resistant to erosion: aggregate stability = 4-6 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Shallow to deep, well drained clay loams or very cobbly clay loams: moderate OM (1-3%) -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Moderate ground cover (50-60%) and gentle to very steep slopes (5-70%) 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:
Bluebunch wheatgrass > Shadscale > forbs > other shrubs > other grassesSub-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: 800, Normal: 600, Unfavorable: 400 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:
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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