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Ecological site R010XC018OR

SR Adobeland 9-12 PZ

Accessed: 12/21/2024

Home / Esd catalog / MLRA 010X / Ecological site R010XC018OR

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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.

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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

R010XC021OR	SR Clayey 9-12 PZ SR Clayey 9-12" PZ
R010XC043OR	SR South 9-12 PZ SR Clayey South 9-12" PZ

R010XC021OR

SR Clayey 9-12 PZ

SR Clayey 9-12" PZ

R010XC043OR

SR South 9-12 PZ

SR Clayey South 9-12" PZ

Table 1. Dominant plant species

Tree	Not specified
Shrub	(1) Artemisia tridentata ssp. tridentata
Herbaceous	(1) Leymus cinereus (2) Pseudoroegneria spicata ssp. spicata

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Physiographic features

This site occurs in ancient lacustrine sediments on low terraces and rolling hills. Slopes range from 0 to 12 percent. Elevations range from 2000 to 4000 feet.

Table 2. Representative physiographic features

Landforms	(1) Terrace (2) Hill
Elevation	2,000 – 4,000 ft
Slope	12%
Water table depth	60 in
Aspect	Aspect is not a significant factor

Climatic features

The annual precipitation ranges from 9 to 12 inches, most of which occurs in the form of snow during the months of December through March. Localized, occasionally severe, convectional storms occur during the summer. The soil temperature regime is mesic with a mean annual air temperature of 52 degrees F. Temperature extremes range from 100 to -10 degrees F. The frost-free period ranges from 110 to 140 days. The optimum period for plant growth is from April through June.

Table 3. Representative climatic features

Frost-free period (average)	140 days
Freeze-free period (average)	0 days
Precipitation total (average)	12 in

Soil features

The soils of this site are typically deep clays over lacustrine sediments or bedrock. They are generally well-drained. Typically both the surface and subsoil are clays with high shrink well potentials. Soil churning is prevalent. Depth to bedrock is usually greater than 60 inches. Permeability is very slow. The available water holding capacity is about 6 to 8 inches for the profile. The potential for erosion is moderate to severe.

Table 4. Representative soil features

Surface texture	(1) Clay
Family particle size	(1) Clayey
Drainage class	Well drained
Permeability class	Very slow
Soil depth	60 in
Available water capacity (0-40in)	6 – 8 in

Ecological dynamics

Response to Disturbance:

If the condition of the site deteriorates as a result of overgrazing, basin wildrye and bluebunch wheatgrass decrease. Both of these grasses are preferred species during the spring. Bareground increases and annual grasses and forbs such as China lettuce invade. Under deteriorated conditions, excessive erosion in the bare soil interspaces reduces the site productivity and contributes to downstream sedimentation.

State and transition model

Custom diagram

Standard 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 text

Ecosystem states

1. Historic Climax Plant Community

State 1 submodel, plant communities

1.1. Historic Climax Plant Community

State 1
Historic Climax Plant Community

Community 1.1
Historic Climax Plant Community

The potential native plant community is dominated by basin wildrye. Basin big sagebrush and bluebunch wheatgrass are common in the stand. Vegetative composition of the community is approximately 95 percent grasses, 2 percent forbs, and 3 percent shrubs. Approximate ground cover is 40-60 percent (basal and crown).

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	1080	1395	1710
Shrub/Vine	30	53	75
Forb	30	45	60
Total	1140	1493	1845

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	Perennial, deep-rooted, dominant			900–1200
	basin wildrye	LECI4	Leymus cinereus	900–1200	–
2	Perennial, deep-rooted, sub-dominant			165–480
	bluebunch wheatgrass	PSSP6	Pseudoroegneria spicata	150–450	–
	squirreltail	ELEL5	Elymus elymoides	15–30	–
5	Other perennial grasses, all			15–30
	bluegrass	POA	Poa	0–15	–
	Sandberg bluegrass	POSE	Poa secunda	0–15	–
Forb
9	Other perennial forbs, all			15–30
10	Other annual forbs, all			15–30
Shrub/Vine
11	Perennial, evergreen, dominant			30–75
	basin big sagebrush	ARTRT	Artemisia tridentata ssp. tridentata	30–75	–

Interpretations

Animal community

Livestock Grazing:

This site is suited to use by cattle, sheep, and horses during most seasons under a planned grazing system. Limitations are associated with the churning nature of the soil during the late winter and early spring. Care should be taken to avoid trampling damage and soil compaction when the soils are wet.

Native Wildlife Associated with the Potential Climax Community:

Mule deer
Antelope
Hawks
Rodents

This site offers food and cover for mule deer, antelope, rodents, and a variety of birds.

Hydrological functions

The soils are in hydrologic group D. The soils of this site have high runoff potential.

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	Bob Gillaspy
Approval date
Composition (Indicators 10 and 12) based on	Annual Production

Indicators

Number and extent of rills:
None, moderate to severe sheet & rill erosion hazard
Presence of water flow patterns:
None to some - soil churning is prevalent
Number and height of erosional pedestals or terracettes:
None to some - soil churning is prevalent
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):
Significantly resistant to erosion: aggregate stability = 4-6
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Deep, well drained clays with high shrink-swell potential: moderate OM (2-4%)
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Moderate ground cover (40-60%) and gentle slopes (2-12%) effectively 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:
Basin wildrye > Bluebunch wheatgrass > shrubs > other grasses > forbs

Sub-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: 1800, Normal: 1500, Unfavorable: 1000 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. 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

Download reference sheet