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Ecological site R008XY120OR

Loamy 12-14 PZ

Last updated: 7/01/2020
Accessed: 11/21/2024

Home / Esd catalog / MLRA 008X / Ecological site R008XY120OR

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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

R008XY200OR	South 10-14 PZ
R008XY210OR	Shallow South 10-14 PZ
R008XY220OR	North 10-14 PZ

R008XY200OR

South 10-14 PZ

R008XY210OR

Shallow South 10-14 PZ

R008XY220OR

North 10-14 PZ

Similar sites

R008XY110OR	Loamy 10-12 PZ Lower precipitation

R008XY110OR

Loamy 10-12 PZ

Lower precipitation

Table 1. Dominant plant species

Tree	Not specified
Shrub	Not specified
Herbaceous	Not specified

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Physiographic features

This site occurs on the tops of ridges and plateaus underlain by basalt bedrock.

Table 2. Representative physiographic features

Landforms	(1) Ridge (2) Plateau
Elevation	1,000 – 3,000 ft
Slope	2 – 12%
Water table depth	4 – 15 in
Aspect	N, S

Climatic features

The annual precipitation ranges from 12 to 14 inches which occurs mostly as snow during the months of October through May. Spring and fall rains are common. The temperature regime is mesic with extreme temperatures ranging from 100 degrees F. to -20 degrees F. The frost-free period is 100 to 180 days, and the optimum period for plant growth is from mid-April through June.

Table 3. Representative climatic features

Frost-free period (average)	180 days
Freeze-free period (average)
Precipitation total (average)	14 in

Soil features

The soils of this site are moderately deep to very deep, well drained silt loams formed in loess over basalt bedrock. The permeability is moderate and the available water holding capacity is 4 to 15 inches for the profile. The erosion hazard is moderate for water and slight for wind.

Table 4. Representative soil features

Surface texture	(1) Silt loam
Family particle size	(1) Loamy
Drainage class	Well drained
Permeability class	Moderate
Soil depth	60 in
Available water capacity (0-40in)	4 – 15 in

Ecological dynamics

If heavy grazing causes site deterioration, Idaho fescue will decline in vigor and be lost from the stand. Continued abuse will weaken and eventually remove the bluebunch wheatgrass. Gray rabbitbrush will increase, cheagrass, China lettuce, salsify, and other weeds will invade the site.

As slopes dip to the south, the amount of bluebunch wheatgreass will increase. North-trending slopes will favor and increase in Idaho fescue.

State and transition model

Custom diagram

Standard diagram

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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. HCPC, FEID-PSSP6-POSE

State 1 submodel, plant communities

1.1. HCPC, FEID-PSSP6-POSE

State 1
HCPC, FEID-PSSP6-POSE

Dominant plant species

Idaho fescue (Festuca idahoensis), grass
bluebunch wheatgrass (Pseudoroegneria spicata), grass
Sandberg bluegrass (Poa secunda), grass

Community 1.1
HCPC, FEID-PSSP6-POSE

The potential native community is dominated by Idaho fescue and bluebunch wheatgrass with lesser amounts of Sandberg bluegrass. Vegetative composition is about 95% grasses, 3% forbs, and 2% shrubs.

Dominant plant species

Idaho fescue (Festuca idahoensis), grass
bluebunch wheatgrass (Pseudoroegneria spicata), grass
Sandberg bluegrass (Poa secunda), grass

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	704	965	1221
Forb	66	100	132
Shrub/Vine	22	33	44
Total	792	1098	1397

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	Dominant deep rooted perennial grasses			660–1100
	Idaho fescue	FEID	Festuca idahoensis	440–660	–
	bluebunch wheatgrass	PSSP6	Pseudoroegneria spicata	220–440	–
4	Sub-dominant shallow rooted perennial grasses			33–99
	Sandberg bluegrass	POSE	Poa secunda	22–55	–
	prairie Junegrass	KOMA	Koeleria macrantha	11–44	–
5	Other perennial grasses			11–22
	squirreltail	ELEL5	Elymus elymoides	0–5	–
	needle and thread	HECO26	Hesperostipa comata	0–5	–
Forb
7	Dominant perennial forbs			55–110
	common yarrow	ACMI2	Achillea millefolium	11–22	–
	milkvetch	ASTRA	Astragalus	11–22	–
	arrowleaf balsamroot	BASA3	Balsamorhiza sagittata	11–22	–
	flax	LINUM	Linum	11–22	–
	desertparsley	LOMAT	Lomatium	11–22	–
9	Other perennial forbs			11–22
	agoseris	AGOSE	Agoseris	0–11	–
	brodiaea	BRODI	Brodiaea	0–11	–
	fleabane	ERIGE2	Erigeron	0–11	–
	beardtongue	PENST	Penstemon	0–11	–
	deathcamas	ZIGAD	Zigadenus	0–11	–
Shrub/Vine
11	Dominant evergreen shrubs			22–44
	rubber rabbitbrush	ERNA10	Ericameria nauseosa	11–22	–
	yellow rabbitbrush	CHVI8	Chrysothamnus viscidiflorus	11–22	–

Interpretations

Animal community

Mule deer, Pronghorn antelope, Elk

This site offers forage for deer.

Hydrological functions

The soils of this site have moderate infiltration rates and low runoff potential. The hydrologic soil groups are B and C.

Wood products

None

Other products

This site is suited for livestock use during spring, summer, and fall. Snow may prevent witner use in some years. A planned grazing system is needed.

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	State Rangeland Management Specialist
Date	07/26/2012
Approved by	Kendra Moseley
Approval date
Composition (Indicators 10 and 12) based on	Annual Production

Indicators

Number and extent of rills:
None, moderate 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, 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):
Significant resistant to erosion; aggregate stability = 4-5
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Moderately deep to very deep well drained silt 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 (50-70%) limits 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:
Idaho fescue > Bluebunch wheatgrass > Sandberg bluegrass and Prairie junegrass > other grasses = forbs = shrubs

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; 1400, Normal: 1100, Unfavorable: 700 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

Download reference sheet