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Ecological site R011XY013OR

Clayey 8-11 PZ

Accessed: 12/22/2024

Home / Esd catalog / MLRA 011X / Ecological site R011XY013OR

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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.

Associated sites

R011XY012OR	Silty 8-11 PZ Silty 8-11 PZ
R011XY018OR	Shallow Loam 8-11 PZ Shallow Loam 8-11 PZ
R011XY020OR	South Slopes 8-11 PZ South Slopes 8-11 PZ
R011XY032OR	Silty North Slopes 8-11 PZ Silty North Slopes 8-11 PZ

Similar sites

R011XY018OR	Shallow Loam 8-11 PZ Shallow Loam 8-11 PZ (shallower soil, lower production)
R011XY012OR	Silty 8-11 PZ Silty 8-11 PZ (silty to fine sandy loam surface, different composition - beardless wheatgrass co-dominant with Thurber's needlegrass)

R011XY018OR

Shallow Loam 8-11 PZ

Shallow Loam 8-11 PZ (shallower soil, lower production)

R011XY012OR

Silty 8-11 PZ

Silty 8-11 PZ (silty to fine sandy loam surface, different composition - beardless wheatgrass co-dominant with Thurber's needlegrass)

Table 1. Dominant plant species

Tree	Not specified
Shrub	(1) Artemisia tridentata ssp. wyomingensis (2) Grayia spinosa
Herbaceous	(1) Pseudoroegneria spicata ssp. inermis (2) Poa secunda

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Physiographic features

This site occurs on low elevation terraces in the Malheur, Owyhee and Snake River drainage. Slopes typically range from 0 to 12%. Elevations vary from 2,100 to 2,600 feet.

Table 2. Representative physiographic features

Landforms	(1) Terrace
Elevation	640 – 792 m
Slope	0 – 12%
Aspect	Aspect is not a significant factor

Climatic features

The annual precipitation ranges from 8 to 11 inches, most of which occurs in the form of rain during the months of December through April. The soil temperature regime is mesic with a mean air temperature of 53 degrees F. Temperature extremes range from 110 to -10 degrees F. The frost free period ranges from 150 to 190 days. The optimum growth period for plant growth is late March through June.

Table 3. Representative climatic features

Frost-free period (average)	190 days
Freeze-free period (average)	0 days
Precipitation total (average)	279 mm

Bar

Line

Figure 1. Monthly average minimum and maximum temperature

Soil features

The soils of this site are typically deep to very deep and somewhat poortly drained. Typically the surface layer is a clay 8 to 16 inches thick. The subsoil is a clay 24 to over 40 inches thick. Depth to lacustrine or alluvial sediments ranges from 40 to 60 inches. Permeability is moderately slow to slow. The available water holding capacity (AWC) is about 4 to 6 inches for the profile. The erosion potential is moderate to severe.

Table 4. Representative soil features

Surface texture	(1) Clay (2) Clay loam
Family particle size	(1) Clayey
Drainage class	Somewhat poorly drained to poorly drained
Permeability class	Moderately slow to slow
Soil depth	102 – 152 cm
Available water capacity (0-101.6cm)	10.16 – 15.24 cm

Ecological dynamics

The potential native plant community is dominated by Wyoming big sagebrush and beardless wheatgrass. Spiny hopsage, bearded bluebunch wheatgrass and Sandberg bluegrass are prominent. A variety of forbs are present. Vegetative composition of the community is approximately 75 percent grasses, 10 percent forbs and 15 percent shrubs. The approximate ground cover is 60 to 70 percent (basal and crown).

Range in Characteristics:
Wyoming big sagebrush increases at the upper end of the precipitation zone. Spiny hopsage increases on droughtier sites at the lower end of the precipitation zone. Beardless wheatgrass and bearded bluebunch wheatgrass are strongly dominant on clayey surfaces. Thurber’s needlegrass increases on slightly silty surfaces at the lower end of the precipitation zone. Production increases at the upper end of the precipitation zone.

Response to Disturbance:
When the condition of the site deteriorates as a result of over grazing beardless wheatgrass and bearded bluebunch wheatgrass rapidly decrease. Wyoming big sagebrush and basin big sagebrush increase. Cheatgrass, other annuals, biennial weeds and bulbous bluegrass invade. With fire and continued disturbance big sagebrush is severely impacted. Annuals and noxious biennial forbs strongly invade. Bare ground increases and excessive erosion contributes to downstream sedimentation. The excessive erosion is most pronounced in drainage areas where incised gulley’s form.

States:
ARTRW/POSE-BRTE (degraded without fire); POSE-POBU/biennial forbs and BRTE/biennial forbs (following fire on degraded range)

State and transition model

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

Figure 2. 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	504	757	1009
Shrub/Vine	101	151	202
Forb	67	101	135
Total	672	1009	1346

Additional community tables

Table 6. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (kg/hectare)	Foliar cover (%)
Grass/Grasslike
1	Dominanat, perennial, deep-rooted bunchgrass			504–706
	beardless wheatgrass	PSSPI	Pseudoroegneria spicata ssp. inermis	504–706	–
2	Sub-dominant, perennial deep-rooted bunchgrass			50–151
	bluebunch wheatgrass	PSSPS	Pseudoroegneria spicata ssp. spicata	50–151	–
4	Sub-dominant, perennial, shallow-rooted grass			20–50
	Sandberg bluegrass	POSE	Poa secunda	20–50	–
5	Other perennial grasses			31–63
	Thurber's needlegrass	ACTH7	Achnatherum thurberianum	10–20	–
	basin wildrye	LECI4	Leymus cinereus	10–20	–
	foxtail wheatgrass	PSSA2	×Pseudelymus saxicola	6–11	–
	squirreltail	ELEL5	Elymus elymoides	6–11	–
Forb
8	Dominant, perennial forbs			49–111
	arrowleaf balsamroot	BASA3	Balsamorhiza sagittata	20–30	–
	fleabane	ERIGE2	Erigeron	10–20	–
	buckwheat	ERIOG	Eriogonum	10–20	–
	phlox	PHLOX	Phlox	10–20	–
	common yarrow	ACMI2	Achillea millefolium	10–20	–
9	Other perennial forbs			13–85
	milkvetch	ASTRA	Astragalus	4–10	–
	tapertip hawksbeard	CRAC2	Crepis acuminata	0–10	–
	desertparsley	LOMAT	Lomatium	4–10	–
	lupine	LUPIN	Lupinus	4–10	–
	hoary tansyaster	MACA2	Machaeranthera canescens	0–4	–
	plains pricklypear	OPPO	Opuntia polyacantha	0–4	–
	beardtongue	PENST	Penstemon	0–4	–
	scarlet globemallow	SPCO	Sphaeralcea coccinea	0–4	–
	common woolly sunflower	ERLA6	Eriophyllum lanatum	0–4	–
	haplopappus	HAPLO11	Haplopappus	0–4	–
	western stoneseed	LIRU4	Lithospermum ruderale	0–4	–
	woodland-star	LITHO2	Lithophragma	0–4	–
	bastard toadflax	COMAN	Comandra	0–4	–
	onion	ALLIU	Allium	0–4	–
Shrub/Vine
11	Dominant, evergreen shrub			50–101
12	Sub-dominate shrub			20–50
	spiny hopsage	GRSP	Grayia spinosa	20–50	–
15	Other shrubs			9–25
	basin big sagebrush	ARTRT	Artemisia tridentata ssp. tridentata	4–10	–
	rubber rabbitbrush	ERNA10	Ericameria nauseosa	4–10	–
	broom snakeweed	GUSA2	Gutierrezia sarothrae	0–4	–

Interpretations

Animal community

Livestock Grazing:
This site is suitable for livestock grazing use in the late fall, winter and early spring under a planned grazing system. Use should be postponed until the soils are firm enough to prevent trampling damage and soil compaction. Grazing management should be keyed for beardless wheatgrass and beardcd bluebunch wheatgrass. Deferred grazing or rest is recommended at least once every three years.

Native Wildlife Associated with the Potential Climax Community:
This site is commonly used by pronghorn antelope, mule deer, rabbits, rodents, upland birds and various predators. It is a preferred site for sage grouse wintering. Antelope and mule deer make excellent use of the site for winter and early spring forage.

Hydrological functions

The soils of this site are typically in an upland topographic position. They have moderate high runoff potential and medium infiltration rates when the hydrologic cover is high. Hydrologic cover is high when the beardless wheatgrass deep rooted bunchgrass component is greater than 70 percent of 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)
Contact for lead author
Date
Approved by
Approval date
Composition (Indicators 10 and 12) based on	Annual Production

Indicators

Number and extent of rills:
Presence of water flow patterns:
Number and height of erosional pedestals or terracettes:
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Number of gullies and erosion associated with gullies:
Extent of wind scoured, blowouts and/or depositional areas:
Amount of litter movement (describe size and distance expected to travel):
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
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:

Sub-dominant:

Other:

Additional:
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Average percent litter cover (%) and depth ( in):
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
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 plant reproductive capability:

Download reference sheet