Natural Resources
Conservation Service

Ecological site BX010X00C022

Silty 9-12 PZ Snake River Warm Plains

Last updated: 3/31/2025
Accessed: 04/05/2025

Home / Esd catalog / MLRA 010X / Ecological site BX010X00C022

USC

Metric

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.

MLRA notes

Major Land Resource Area (MLRA): 010X–Central Rocky and Blue Mountain Foothills

This MLRA is characterized by gently rolling to steep hills, plateaus, and low mountains at the foothills of the Blue Mountains in Oregon and the Central Rocky Mountains in Idaho. The geology of this area is highly varied and ranges from Holocene volcanics to Cretaceous sedimentary rocks. Mollisols are the dominant soil order and the soil climate is typified by mesic or frigid soil temperature regimes, and xeric or aridic soil moisture regimes. Elevation ranges from 1,300 to 6,600 feet (395 to 2,010 meters), increasing from west to east. The climate is characterized by dry summers and snow dominated winters with precipitation averaging 8 to 16 inches (205 to 405 millimeters) and increasing from west to east. These factors support plant communities with shrub-grass associations with considerable acreage of sagebrush grassland. Big sagebrush, bluebunch wheatgrass, and Idaho fescue are the dominant species. Stiff sagebrush, low sagebrush, and Sandberg bluegrass are often dominant on sites with shallow restrictive layers. Western juniper is one of the few common tree species and since European settlement has greatly expanded its extent in Oregon. Nearly half of the MLRA is federally owned and managed by the Bureau of Land Management. Most of the area is used for livestock grazing with areas accessible by irrigation often used for irrigated agriculture.

LRU notes

Snake River Warm Plains:

Located between Oregon's Blue and Wallowa Mountains and the northwestern Snake River Plain. Characterized by rangeland soils on hills and mountains associated with basalt and exposed tuffaceous sediments. Plants are subject to wide temperature ranges, high evapotranspiration, and high early-season moisture stress. Temperature regime is mesic and the moisture regime is aridic. Mean annual precipitation is 9 to 12 inches.

Ecological site concept

This site typically occurs on mid-elevation terraces in areas with gentle slopes typically less than twelve percent. Soils are moderately deep to deep consisting of predominately silt loams. In the reference condition, this site supports vegetation communities dominated by Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) and bluebunch wheatgrass (Pseudoroegneria spicata) in lower precipitation areas and transitions to basin big sagebrush (Artemisia tridentata ssp. tridentata) in higher precipitation areas. The site receives nine to twelve inches annual precipitation and soil temperature regime is mesic. Resistance and resilience to disturbance is low.

Associated sites

R010XC020OR	SR Loamy 9-12 PZ SR Loamy 9-12 PZ
R010XC025OR	SR Sandy 9-12 PZ SR Sandy 9-12 PZ
R010XC043OR	SR South 9-12 PZ SR South 9-12
R010XC063OR	SR Droughty North 9-12 PZ SR North 9-12 PZ
R010XC064OR	SR North 9-12 PZ SR Droughty North 9-12

Similar sites

R010XC020OR	SR Loamy 9-12 PZ SR Loamy 9-12 PZ (different composition - bearded bluebunch dominant, less fine sand in surface)

R010XC020OR

SR Loamy 9-12 PZ

SR Loamy 9-12 PZ (different composition - bearded bluebunch dominant, less fine sand in surface)

Table 1. Dominant plant species

Tree	Not specified
Shrub	(1) Artemisia tridentata ssp. wyomingensis (2) Artemisia tridentata ssp. tridentata
Herbaceous	(1) Pseudoroegneria spicata (2) Achnatherum thurberianum

Legacy ID

R010XC022OR

Download full description

Physiographic features

This site occurs on mid elevation terraces in the Malheur, Owyhee, and adjacent Snake River drainage. Slopes typically range from two to twelve percent but sites are most frequently under ten percent. Elevations typically range between 2,500 to 3,500 feet but some sites have been found up to 4,000 feet.

Table 2. Representative physiographic features

Landforms	(1) Terrace (2) Hill
Elevation	2,200 – 3,500 ft
Slope	2 – 12%
Aspect	Aspect is not a significant factor

Climatic features

The annual precipitation ranges from nine to twelve 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 -10 to 10o degrees F. The frost-free period ranges from 100 to 140 days. The optimum period for plant growth is from April through June.

Table 3. Representative climatic features

Frost-free period (characteristic range)	106-112 days
Freeze-free period (characteristic range)	130-134 days
Precipitation total (characteristic range)	10 in
Frost-free period (actual range)	105-114 days
Freeze-free period (actual range)	128-136 days
Precipitation total (actual range)	10 in
Frost-free period (average)	109 days
Freeze-free period (average)	132 days
Precipitation total (average)	10 in

Characteristic range

Actual range

Bar

Line

Figure 1. Monthly precipitation range

Characteristic range

Actual range

Bar

Line

Figure 2. Monthly minimum temperature range

Characteristic range

Actual range

Bar

Line

Figure 3. Monthly maximum temperature range

Bar

Line

Figure 4. Monthly average minimum and maximum temperature

Figure 5. Annual precipitation pattern

Figure 6. Annual average temperature pattern

Climate stations used

(1) WESTFALL [USC00359176], Harper, OR
(2) VALE [USC00358797], Vale, OR

Soil features

The soils of this site are typically moderately deep to deep and well drained. Typically, the surface layer is a silt loam to very fine sandy loam eight to sixteen inches thick. The subsoil is a silt loam to clay loam fifteen to twenty-five inches thick. Depth to lacustrine or tuffaceous sediments range from twenty to greater than sixty inches. A duripan may be present but is infrequently found and moderately deep. Permeability is moderate and saturated hydraulic conductivity expressed as Ksat is moderately high. The available water holding capacity (AWC) is approximately four to six inches for the first forty inches of the profile. The potential for erosion is moderate. Soils are formed by eolian deposits over alluvial material or reworked ash deposits. Soil temperature regime is mesic and soil moisture regime is aridic. Soil series Tubmountain, Farmell, and Morfitt most commonly typify the soils of this site.

Figure 7.

Figure 8.

Table 4. Representative soil features

Parent material	(1) Loess (2) Alluvium
Surface texture	(1) Silt loam (2) Very fine sandy loam
Family particle size	(1) Fine-loamy (2) Fine
Drainage class	Moderately well drained to well drained
Permeability class	Moderate
Soil depth	20 – 60 in
Surface fragment cover <=3"	2%
Surface fragment cover >3"	Not specified
Available water capacity (0-39.4in)	5.43 – 6.43 in
Clay content (0-20in)	17 – 23%

Table 5. Representative soil features (actual values)

Drainage class	Moderately well drained to well drained
Permeability class	Moderate
Soil depth	20 – 60 in
Surface fragment cover <=3"	5%
Surface fragment cover >3"	2%
Available water capacity (0-39.4in)	3.94 – 7.09 in
Clay content (0-20in)	14 – 32%

Ecological dynamics

Indicators and Range of Characteristics:

The potential native plant community is dominated by Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) and bluebunch wheatgrass (Pseudoroegneria spicata). Thurber’s needlegrass (Achnatherum thurberianum) is prominent. Sandberg bluegrass (Poa secunda) is the dominant shallow-rooted perennial grass. A variety of forbs and shrubs are present. Vegetative composition of the reference community is approximately 80 percent grasses, 10 percent forbs and 10 percent shrubs. The approximate ground cover is 70 to 80 percent (basal and crown).

Bluebunch wheatgrass increases on silty surfaces. Thurber’s needlegrass increases on very fine sandy loam surfaces and drier sites. Needle and thread (Hesperostipa comata) is present on coarser surfaces. Wyoming big sagebrush is dominant at most sites but basin big sagebrush (Artemisia tridentata ssp. tridentata) increases slightly at higher precipitations. Annual production increases at the upper end of the precipitation zone.

Response to Disturbance:

Ecological dynamics of this site are primarily driven by disturbance regimes including wildfire, grazing, and drought. Traditionally, wildfire was the primary driver of ecological change. These infrequent fires, often greater than 100 year return, would result in removal of woody species and create perennial grasslands (Pyke et al. 2014, Smith et al. 2023). Differing fuel loads and weather patterns, fires likely burned in mosaic patterns leaving intact sagebrush pockets and intact soil seed banks. Given enough time, sagebrush would expand back into its original territory (Hosna et al. 2023). Forbs at these sites were likely a minor component, and while important for pollinators, did not play a major role in determining ecological outcomes (Pyke et al. 2014).

With the introduction of invasive annual grasses, chiefly cheatgrass (Bromus tectorum) and medusahead (Taeniatherum caput-medusae), the traditional fire cycle changes. These annual grasses fill interspaces and create continuous fine fuels increasing size and often frequency of fire. The invasive annual grasses are able to recover quickly but Wyoming big sagebrush is killed and may not be able to recolonize before the next fire begins (Smith et al. 2023, Beck et al. 2012). This cycle creates a positive-feedback loop in which shrubs and perennial grasses are removed from the system and invasive annual grasses dominate and noxious forbs continue to invade.

In opposition, some areas have seen an increase in fire return. In these cases, Wyoming big sagebrush and Sandberg bluegrass increase while bluebunch wheatgrass and Thurber’s needlegrass rapidly decrease (Davies et al. 2011). A similar pattern appears due to continued overutilization, since perennial deep-rooted bunchgrasses are preferred forage, through continued grazing pressure they are eventually removed from the system (Pyke et al. 2014). In addition, biological soil crusts are often removed leading to higher bare soil opening opportunities for annual grass invasion or increased soil erosion. The excessive erosion is most pronounced in drainage areas where deep incised gulley’s form.

Within the natural range of variability, this site is considered to have low resistance and resilience to disturbance. This is driven by warm annual temperatures and an aridic soil moisture regime (Chambers et al. 2014) making the site very susceptible to annual grass invasion. Susceptibility may increase even further as climate change and increased atmospheric carbon dioxide is expected to favor invasive annual grasses (Miller et al. 2013, Smith et al. 2022).

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

T1A	-	Introduction of non-native species; inappropriate grazing management
T2A	-	Inappropriate grazing management
T2B	-	Fire, soil disruption, inapropriate grazing management
R3A	-	Shrub removal, possible perennial grass reseeding
T3A	-	Catastrophic fire, soil disturbing treatments, inappropriate grazing management
R4B	-	Annual grass treatment, reseeding
R4A	-	Annual grass treatment, reseeding

State 1 submodel, plant communities

1.1. Deep-rooted Bunchgrass and Wyoming Big Sagebrush

1.2. Perennial grasses

1.1A	-	Fire
1.2A	-	Time without disturbance

State 2 submodel, plant communities

2.1. Deep-rooted Perennial Grasses and Shrubs

2.2. Shrubs and Perennial Grasses

2.3. Perennial Grasses and Annual Grass

2.1A	-	Time and lack of disturbance
2.1B	-	Fire
2.2A	-	Fire
2.3A	-	Time without disturbance

State 3 submodel, plant communities

3.1. Shrubs and Shallow-rooted Perennial Grasses

3.2. Shallow-rooted Perennial Grass and Annual Grasses

3.1A	-	Fire
3.2A	-	Time without disturbance

State 4 submodel, plant communities

4.1. Annual Grass and Shrubs

4.2. Annual Grass

4.1A	-	Fire, mechanical shrub removal

State 1
Reference

The reference state is representative of the natural range of variability in pristine condition. This is not considered a "historical" condition as examples of this site may still occur across the landscape. This state has no introduced plant species. Disturbance patterns reflect historic return cycles or increased return has not reduced the sites resistance and resilience to disturbance. The reference state has two community phases; a grass shrub community and a perennial grass community. Community dynamics are controlled primarily by fire and time. All functional groups are present and a diverse forb component exists although it is not the dominant component. At the time of this writing, no sites were found in the reference state so community information is inferred from current potential sites and historical data.

Characteristics and indicators. •No introduced plant species •All functional groups present •High plant vigor and reproductive capacity

Resilience management. Reference sites should be prioritized for protection whenever possible. Management should focus on conservation and protection above other uses. Surrounding landscapes should be managed to reduce non-native species introductions and other impacts.

Dominant plant species

Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), shrub
basin big sagebrush (Artemisia tridentata ssp. tridentata), shrub
bluebunch wheatgrass (Pseudoroegneria spicata), grass
Thurber's needlegrass (Achnatherum thurberianum), grass
Sandberg bluegrass (Poa secunda), grass

Community 1.1
Deep-rooted Bunchgrass and Wyoming Big Sagebrush

The reference plant community is dominated by Wyoming big sagebrush and bluebunch wheatgrass. Thurber’s needlegrass is prominent. Sandberg bluegrass is the dominant shallow rooted perennial grass. A variety of forbs and shrubs are present. Vegetative composition of the community is approximately 80 percent grasses, 10 percent forbs and 10 percent shrubs. The approximate ground cover is 70 to 80 percent (basal and crown).

Dominant plant species

Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), shrub
bluebunch wheatgrass (Pseudoroegneria spicata), grass
Thurber's needlegrass (Achnatherum thurberianum), grass
Sandberg bluegrass (Poa secunda), grass

Figure 9. Annual production by plant type (representative values) or group (midpoint values)

Table 6. Annual production by plant type

Plant type	Low (lb/acre)	Representative value (lb/acre)	High (lb/acre)
Grass/Grasslike	560	800	1120
Forb	70	100	140
Shrub/Vine	70	100	140
Total	700	1000	1400

Figure 10. Plant community growth curve (percent production by month). OR3711, B10 Low Elevation Mesic 9-12 Good Condition. B10 Low Elevation Mesic 9-12 Good Condition RPC.

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	5	15	35	25	10	0	10	0	0	0

Community 1.2
Perennial grasses

This plant community is dominated by bluebunch wheatgrass and Sandberg bluegrass. This community is the result of low-intensity fire so Wyoming big sagebrush will likely be present but only in an isolated island mosaic distribution. Sprouting shrubs may be present but infrequent. This community would be considered "at risk" since fire would have exposed more bare soil and increased opportunities for introduction of non-native species.

Dominant plant species

Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), shrub
bluebunch wheatgrass (Pseudoroegneria spicata), grass
Thurber's needlegrass (Achnatherum thurberianum), grass
Sandberg bluegrass (Poa secunda), grass

Figure 11. Annual production by plant type (representative values) or group (midpoint values)

Table 7. Annual production by plant type

Plant type	Low (lb/acre)	Representative value (lb/acre)	High (lb/acre)
Grass/Grasslike	500	750	1000
Shrub/Vine	100	200	300
Forb	50	75	100
Total	650	1025	1400

Figure 12. Plant community growth curve (percent production by month). OR3711, B10 Low Elevation Mesic 9-12 Good Condition. B10 Low Elevation Mesic 9-12 Good Condition RPC.

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	5	15	35	25	10	0	10	0	0	0

Pathway 1.1A
Community 1.1 to 1.2

Low-severity fire burns in a mosaic pattern leaving islands of sagebrush with perennial grass dominated areas in between.

Context dependence. As fire severity increases, distance between sagebrush islands increases meaning more time for sagebrush to recover in burned areas.

Pathway 1.2A
Community 1.2 to 1.1

Time without fire allows sagebrush recruitment to increase and become more common across the landscape.

Context dependence. Sagebrush expansion can occur over very long time scales so recover may take many years.

State 2
Current Potential

This state is similar to the refence state but some amount of non-native species occur and species composition has been somewhat altered. Ecological functions often remain intact but due to the presence of these non-native species, resistance and resilience to disturbance has been reduced. This state has three community phases; a grass-shrub phase, a shrub-grass phase, and a grass phase. The latter two representing two different "at-risk" phases, at risk of converting to shrubland and at risk of converting to an annual state.

Characteristics and indicators. •Low cover of introduced plant species (commonly less than fifteen percent total) •Deep-rooted perennial grass cover at or above twenty percent •All functional groups present with no significant decrease in reproductive capability

Resilience management. Sites in the current potential state should be prioritized for protection wherever possible, especially when in good quality condition. Management activities should focus on limited seed sources of invasive annual grasses and promote perennial plant vigor and reproduction.

Dominant plant species

Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), shrub
bluebunch wheatgrass (Pseudoroegneria spicata), grass
Sandberg bluegrass (Poa secunda), grass

Community 2.1
Deep-rooted Perennial Grasses and Shrubs

Deep-rooted perennial grasses, particularly bluebunch wheatgrass and crested wheatgrass, are dominant and Wyoming big sagebrush is sub-dominant. Invasive annual grasses may be present but are not dominant. Forbs are generally a diverse mix of annual and perennial.

Dominant plant species

Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), shrub
basin big sagebrush (Artemisia tridentata ssp. tridentata), shrub
bluebunch wheatgrass (Pseudoroegneria spicata), grass
crested wheatgrass (Agropyron cristatum), grass

Figure 13. Annual production by plant type (representative values) or group (midpoint values)

Table 8. Annual production by plant type

Plant type	Low (lb/acre)	Representative value (lb/acre)	High (lb/acre)
Grass/Grasslike	400	550	700
Shrub/Vine	200	350	500
Forb	20	40	50
Total	620	940	1250

Table 9. Ground cover

Tree foliar cover	0%
Shrub/vine/liana foliar cover	10-20%
Grass/grasslike foliar cover	40-60%
Forb foliar cover	0-5%
Non-vascular plants	0-1%
Biological crusts	0%
Litter	8-12%
Surface fragments >0.25" and <=3"	0-5%
Surface fragments >3"	0-5%
Bedrock	0%
Water	0%
Bare ground	20-30%

Table 10. Soil surface cover

Tree basal cover	0%
Shrub/vine/liana basal cover	0-5%
Grass/grasslike basal cover	5-10%
Forb basal cover	0%
Non-vascular plants	0-5%
Biological crusts	0%
Litter	30-40%
Surface fragments >0.25" and <=3"	0-5%
Surface fragments >3"	0-5%
Bedrock	0%
Water	0%
Bare ground	70-85%

Figure 14. Plant community growth curve (percent production by month). OR3711, B10 Low Elevation Mesic 9-12 Good Condition. B10 Low Elevation Mesic 9-12 Good Condition RPC.

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	5	15	35	25	10	0	10	0	0	0

Community 2.2
Shrubs and Perennial Grasses

Wyoming big sagebrush is the dominant species and perennial grasses are sub-dominant. Sandberg bluegrass increases over deep-rooted perennial species as sagebrush increases to the point of using available deeper resources. Forbs are diverse and widespread. Annual invasive grasses are present but not dominant. This is an "at risk" community of transitioning to the shrubland state.

Dominant plant species

Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), shrub
bluebunch wheatgrass (Pseudoroegneria spicata), grass
Sandberg bluegrass (Poa secunda), grass

Figure 15. Annual production by plant type (representative values) or group (midpoint values)

Table 11. Annual production by plant type

Plant type	Low (lb/acre)	Representative value (lb/acre)	High (lb/acre)
Shrub/Vine	200	350	500
Grass/Grasslike	200	300	450
Forb	10	30	50
Total	410	680	1000

Table 12. Ground cover

Tree foliar cover	0%
Shrub/vine/liana foliar cover	5-15%
Grass/grasslike foliar cover	45-65%
Forb foliar cover	5-10%
Non-vascular plants	0-3%
Biological crusts	0%
Litter	10-15%
Surface fragments >0.25" and <=3"	0-3%
Surface fragments >3"	0-3%
Bedrock	0%
Water	0%
Bare ground	10-30%

Table 13. Soil surface cover

Tree basal cover	0%
Shrub/vine/liana basal cover	0-2%
Grass/grasslike basal cover	5-15%
Forb basal cover	0-2%
Non-vascular plants	0-2%
Biological crusts	0%
Litter	20-40%
Surface fragments >0.25" and <=3"	0-5%
Surface fragments >3"	0-5%
Bedrock	0%
Water	0%
Bare ground	80-90%

Figure 16. Plant community growth curve (percent production by month). OR3711, B10 Low Elevation Mesic 9-12 Good Condition. B10 Low Elevation Mesic 9-12 Good Condition RPC.

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	5	15	35	25	10	0	10	0	0	0

Community 2.3
Perennial Grasses and Annual Grass

Shallow-rooted bunchgrasses, particularly Sandbergs bluegrass, are dominant. Bluebunch wheatgrass is still present but may be reduced compared to other current potential sites. Depending on fire severity, Wyoming big sagebrush may not be present in high severity fires or only found in isolated pockets in lower severity patchy fires. Forbs have reduced diversity. Invasive annual grasses are likely increasing. This community phase is "at risk" of transitioning to an annual state.

Dominant plant species

bluebunch wheatgrass (Pseudoroegneria spicata), grass
Sandberg bluegrass (Poa secunda), grass

Figure 17. Annual production by plant type (representative values) or group (midpoint values)

Table 14. Annual production by plant type

Plant type	Low (lb/acre)	Representative value (lb/acre)	High (lb/acre)
Grass/Grasslike	400	550	700
Shrub/Vine	50	75	100
Forb	40	50	60
Total	490	675	860

Table 15. Ground cover

Tree foliar cover	0%
Shrub/vine/liana foliar cover	0%
Grass/grasslike foliar cover	65-75%
Forb foliar cover	2-5%
Non-vascular plants	0-2%
Biological crusts	0%
Litter	10-15%
Surface fragments >0.25" and <=3"	0-2%
Surface fragments >3"	0-2%
Bedrock	0%
Water	0%
Bare ground	2-10%

Table 16. Soil surface cover

Tree basal cover	0%
Shrub/vine/liana basal cover	0%
Grass/grasslike basal cover	20-30%
Forb basal cover	0-2%
Non-vascular plants	0-2%
Biological crusts	0%
Litter	15-25%
Surface fragments >0.25" and <=3"	0-2%
Surface fragments >3"	0-2%
Bedrock	0%
Water	0%
Bare ground	70-80%

Figure 18. Plant community growth curve (percent production by month). OR3712, B10 Low Elevation Mesic 9-12 Fair Condition. B10 Low Elevation Mesic 9-12 Fair Condition RPC.

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	25	35	20	5	0	5	0	0	0

Pathway 2.1A
Community 2.1 to 2.2

Deep-rooted Perennial Grasses and Shrubs

Shrubs and Perennial Grasses

Time without disturbance allow shrubs to become dominant.

Context dependence. Grazing may speed this transition by reducing deep-rooted perennial grass cover.

Pathway 2.1B
Community 2.1 to 2.3

Deep-rooted Perennial Grasses and Shrubs

Perennial Grasses and Annual Grass

Fire reduces non-sprouting shrubs allowing grasses to become dominant.

Context dependence. Fire severity or likelihood may increase following high precipitation years that increase vegetative production.

Pathway 2.2A
Community 2.2 to 2.3

Shrubs and Perennial Grasses

Perennial Grasses and Annual Grass

Fire removes shrubs and opens space for deep-rooted perennial grasses to become dominant.

Context dependence. Fire severity or likelihood may increase following high precipitation years that increase vegetative production.

Pathway 2.3A
Community 2.3 to 2.1

Perennial Grasses and Annual Grass

Deep-rooted Perennial Grasses and Shrubs

Time without fire allows shrubs to reestablish.

Context dependence. Higher severity fire will increase distance between unburned pockets and increase time for non-sprouting shrubs to reestablish.

State 3
Shrubland

This state is dominated by shrubs and shallow-rooted perennial grasses and is a result of over grazing especially during key growth periods of cool-season bunchgrasses. Deep-rooted perennial grass have been reduced or completely excluded rarely exceeding five percent foliar cover. This state consists of two communities, a Wyoming big sagebrush and shallow-rooted grass community, and a shallow-rooted grass community. Although highly variable, invasive annual grass cover is often higher than in the current potential state. Without deep-rooted grasses, this state is more prone to erosion than the current potential state.

Characteristics and indicators. •Typically less than 5% cover deep-rooted perennial grasses. •High cover of shallow-rooted perennial grass •Increased invasive annual grass but not enough to become a dominant component.

Resilience management. Management actions should focus on reintroduction of deep-rooted perennial grasses. Invasive annual grass control may also be a priority to avoid transitioning to an annual state.

Dominant plant species

Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), shrub
bulbous bluegrass (Poa bulbosa), grass
Sandberg bluegrass (Poa secunda), grass

Community 3.1
Shrubs and Shallow-rooted Perennial Grasses

Wyoming big sagebrush is dominant with Sandberg bluegrass. Deep-rooted perennial grass is much reduced or missing entirely. Invasive annual grasses may be increasing.

Dominant plant species

Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), shrub
Sandberg bluegrass (Poa secunda), grass

Figure 19. Annual production by plant type (representative values) or group (midpoint values)

Table 17. Annual production by plant type

Plant type	Low (lb/acre)	Representative value (lb/acre)	High (lb/acre)
Shrub/Vine	300	350	450
Grass/Grasslike	150	225	350
Forb	5	30	50
Total	455	605	850

Table 18. Ground cover

Tree foliar cover	0%
Shrub/vine/liana foliar cover	15-25%
Grass/grasslike foliar cover	25-35%
Forb foliar cover	0-5%
Non-vascular plants	0%
Biological crusts	0%
Litter	25-35%
Surface fragments >0.25" and <=3"	0-2%
Surface fragments >3"	0-2%
Bedrock	0%
Water	0%
Bare ground	15-25%

Table 19. Soil surface cover

Tree basal cover	0%
Shrub/vine/liana basal cover	0-2%
Grass/grasslike basal cover	2-10%
Forb basal cover	0-2%
Non-vascular plants	0-2%
Biological crusts	0%
Litter	25-50%
Surface fragments >0.25" and <=3"	2-10%
Surface fragments >3"	2-10%
Bedrock	0%
Water	0%
Bare ground	70-90%

Figure 20. Plant community growth curve (percent production by month). OR3712, B10 Low Elevation Mesic 9-12 Fair Condition. B10 Low Elevation Mesic 9-12 Fair Condition RPC.

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	25	35	20	5	0	5	0	0	0

Community 3.2
Shallow-rooted Perennial Grass and Annual Grasses

In this community, Wyoming big sagebrush has become very reduced or missing. Sandberg bluegrass and bulbous bluegrass are dominant. Non-native forbs and invasive annual grasses may increase. Deep-rooted perennial grasses are also a minor component or missing.

Dominant plant species

bulbous bluegrass (Poa bulbosa), grass
Sandberg bluegrass (Poa secunda), grass

Figure 21. Annual production by plant type (representative values) or group (midpoint values)

Table 20. Annual production by plant type

Plant type	Low (lb/acre)	Representative value (lb/acre)	High (lb/acre)
Grass/Grasslike	120	200	270
Forb	50	70	100
Total	170	270	370

Table 21. Ground cover

Tree foliar cover	0%
Shrub/vine/liana foliar cover	0%
Grass/grasslike foliar cover	30-60%
Forb foliar cover	5-10%
Non-vascular plants	0%
Biological crusts	0%
Litter	10-30%
Surface fragments >0.25" and <=3"	0-1%
Surface fragments >3"	0-1%
Bedrock	0%
Water	0%
Bare ground	12-18%

Table 22. Soil surface cover

Tree basal cover	0%
Shrub/vine/liana basal cover	0%
Grass/grasslike basal cover	5-15%
Forb basal cover	0%
Non-vascular plants	0%
Biological crusts	0%
Litter	45-65%
Surface fragments >0.25" and <=3"	0-2%
Surface fragments >3"	0-2%
Bedrock	0%
Water	0%
Bare ground	80-90%

Figure 22. Plant community growth curve (percent production by month). OR3713, B10 Low Elevation 9-12 Annual Dominated. B10 Low Elevation 9-12 Annual Dominated RPC.

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	20	30	40	5	0	0	5	0	0	0

Pathway 3.1A
Community 3.1 to 3.2

Shrubs and Shallow-rooted Perennial Grasses

Shallow-rooted Perennial Grass and Annual Grasses

Increased fire frequency pushes out non-sprouting shrubs allowing shallow-rooted and annual grasses to become dominant.

Context dependence. Higher precipitation may lead to higher litter production and increased fire probability.

Pathway 3.2A
Community 3.2 to 3.1

Shallow-rooted Perennial Grass and Annual Grasses

Shrubs and Shallow-rooted Perennial Grasses

Time without disturbance can allow for shrub recolonization.

Context dependence. Rate of shrub recolonization will depend on distance to a seed source.

State 4
Annual

This state is dominated by invasive annual grasses. These grasses increase litter amounts which inhibits deep-rooted perennial grass recruitment and increases fire frequency. These two effects create a positive feedback loop that increases invasive annual grass populations.

Characteristics and indicators. •Annual grass foliar cover greater than 25% •Sagebrush cover is variable but even when common, interspaces dominated by invasive annual grasses. •Herbaceous litter cover can be higher than other states

Resilience management. Any management actions should focus on reducing annual grass cover and limiting its spread to other areas.

Dominant plant species

cheatgrass (Bromus tectorum), grass
medusahead (Taeniatherum caput-medusae), grass

Community 4.1
Annual Grass and Shrubs

Introduced annual grasses are the dominant component of this community. Wyoming big sagebrush is still present but annual grasses and shallow-rooting perennial grasses fill all interspaces. If fire occurs, sagebrush may be replaced by sprouting rabbitbrush species.

Resilience management. Any action should focus on reducing invasive annual grass population to allow recovery of native species.

Dominant plant species

Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), shrub
yellow rabbitbrush (Chrysothamnus viscidiflorus), shrub
cheatgrass (Bromus tectorum), grass
medusahead (Taeniatherum caput-medusae), grass
Sandberg bluegrass (Poa secunda), grass

Figure 23. Annual production by plant type (representative values) or group (midpoint values)

Table 23. Annual production by plant type

Plant type	Low (lb/acre)	Representative value (lb/acre)	High (lb/acre)
Grass/Grasslike	200	350	500
Shrub/Vine	150	200	250
Forb	50	75	100
Total	400	625	850

Table 24. Ground cover

Tree foliar cover	0%
Shrub/vine/liana foliar cover	18-25%
Grass/grasslike foliar cover	50-60%
Forb foliar cover	0-2%
Non-vascular plants	0%
Biological crusts	0%
Litter	12-16%
Surface fragments >0.25" and <=3"	0-2%
Surface fragments >3"	0-2%
Bedrock	0%
Water	0%
Bare ground	3-7%

Table 25. Soil surface cover

Tree basal cover	0%
Shrub/vine/liana basal cover	0%
Grass/grasslike basal cover	2-7%
Forb basal cover	0-5%
Non-vascular plants	0-3%
Biological crusts	0%
Litter	55-65%
Surface fragments >0.25" and <=3"	0-5%
Surface fragments >3"	0-5%
Bedrock	0%
Water	0%
Bare ground	85-95%

Figure 24. Plant community growth curve (percent production by month). OR3713, B10 Low Elevation 9-12 Annual Dominated. B10 Low Elevation 9-12 Annual Dominated RPC.

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	20	30	40	5	0	0	5	0	0	0

Community 4.2
Annual Grass

Introduced annual grasses are dominant. Dominant invasive grasses are cheatgrass and medusahead. Introduced forbs such as prickly lettuce, redstem stork's bill, and Scotch cottonthistle may be common throughout. Basin big sagebrush and Wyoming big sagebrush may be present but only in trace amounts and will likely be removed completely with repeated burns.

Resilience management. Any management actions should focus on the removal of invasive annual grasses. Seedbanks in this community may be depleted of native species so management actions may need to incorporate seeding with desirable plant species.

Dominant plant species

cheatgrass (Bromus tectorum), grass
medusahead (Taeniatherum caput-medusae), grass

Figure 25. Annual production by plant type (representative values) or group (midpoint values)

Table 26. Annual production by plant type

Plant type	Low (lb/acre)	Representative value (lb/acre)	High (lb/acre)
Grass/Grasslike	350	500	750
Forb	50	70	120
Shrub/Vine	10	50	100
Total	410	620	970

Table 27. Ground cover

Tree foliar cover	0%
Shrub/vine/liana foliar cover	3-5%
Grass/grasslike foliar cover	80-90%
Forb foliar cover	0-5%
Non-vascular plants	0%
Biological crusts	0%
Litter	3-5%
Surface fragments >0.25" and <=3"	0-1%
Surface fragments >3"	0-1%
Bedrock	0%
Water	0%
Bare ground	1-5%

Table 28. Soil surface cover

Tree basal cover	0%
Shrub/vine/liana basal cover	0%
Grass/grasslike basal cover	10-25%
Forb basal cover	0%
Non-vascular plants	0-3%
Biological crusts	0%
Litter	40-80%
Surface fragments >0.25" and <=3"	2-8%
Surface fragments >3"	2-8%
Bedrock	0%
Water	0%
Bare ground	70-90%

Figure 26. Plant community growth curve (percent production by month). OR3713, B10 Low Elevation 9-12 Annual Dominated. B10 Low Elevation 9-12 Annual Dominated RPC.

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	20	30	40	5	0	0	5	0	0	0

Pathway 4.1A
Community 4.1 to 4.2

Annual Grass and Shrubs

Annual Grass

Fire occurs eliminating shrub component. Mechanical shrub removal could cause a similar shift.

Context dependence. High precipitation may lead to higher annual grass biomass and an increase in fine fuels. Fine fuel increase can cause more frequent fire return.

Transition T1A
State 1 to 2

Reference

Current Potential

Introduction of non-native species. Inappropriate grazing management could also aid in susceptibility of the site to invasion.

Context dependence. Circumstances that increase bare soil such as drought or soil disturbing activities, may increase opportunities for non-native species to invade.

Transition T2A
State 2 to 3

Current Potential

Shrubland

Inappropriate grazing management, repeated over grazing reduces deep-rooted perennial grasses and shifts to shrubs and shallow-rooted grasses increasing bare soil and possible soil erosion.

Context dependence. Soil vulnerability to compaction will be highest in spring when soil is saturated and unfrozen.

Transition T2B
State 2 to 4

Current Potential

Annual

High intensity or frequent fire that removes sagebrush component from the site. Soil disturbing treatments or repeated overutilization may also cause this transition.

Context dependence. Transition rate will depend on a number of factors including existing plant cover, biological soil crust integrity, seed bank integrity, and recent weather patterns.

Restoration pathway R3A
State 3 to 2

Shrubland

Current Potential

Mowing shrubs may allow for perennial grasses to become more dominant.

Context dependence. Actions to remove Wyoming big sagebrush increase the risk of invasive annual grasses becoming prevalent. Recovery may depend on existing plant understory and the ability to control annual grasses while recovery takes place.

Transition T3A
State 3 to 4

Shrubland

Annual

High intensity or frequent fire. Sagebrush removal activities that disturb soil.

Context dependence. Transition rate will depend on existing cover and seedbank integrity.

Restoration pathway R4B
State 4 to 2

Annual

Current Potential

Treatment of annual grasses with herbicide coupled with seeding of desired native species.

Context dependence. Overall success may depend on above average yearly precipitation increasing establishment success.

Restoration pathway R4A
State 4 to 3

Annual

Shrubland

Targeted shrub planting and fire breaks may keep fire out of the site long enough for shrubs to recover.

Context dependence. Herbicide application can help control invasive annual grass populations to support shrub growth.

Additional community tables

Table 29. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Perennial moderately deep-rooted bunchgrasses			460–800
	bluebunch wheatgrass	PSSP6	Pseudoroegneria spicata	550–650	–
	Thurber's needlegrass	ACTH7	Achnatherum thurberianum	100–200	–
4	Perennial shallow-rooted bunchgrasses			30–70
	Sandberg bluegrass	POSE	Poa secunda	30–70	–
5	Other perennial grasses			70–250
	needle and thread	HECO26	Hesperostipa comata	0–80	–
	basin wildrye	LECI4	Leymus cinereus	0–30	–
	squirreltail	ELEL5	Elymus elymoides	0–30	–
	Idaho fescue	FEID	Festuca idahoensis	0–30	–
	foxtail wheatgrass	PSSA2	×Pseudelymus saxicola	0–20	–
Forb
7	Perennial forbs			50–80
	arrowleaf balsamroot	BASA3	Balsamorhiza sagittata	5–30	–
	fleabane	ERIGE2	Erigeron	10–20	–
	buckwheat	ERIOG	Eriogonum	10–20	–
	desertparsley	LOMAT	Lomatium	10–20	–
	lupine	LUPIN	Lupinus	0–20	–
	phlox	PHLOX	Phlox	0–20	–
	common yarrow	ACMI2	Achillea millefolium	0–20	–
9	Other perennial forbs			20–60
	agoseris	AGOSE	Agoseris	0–10	–
	onion	ALLIU	Allium	0–10	–
	pussytoes	ANTEN	Antennaria	0–10	–
	milkvetch	ASTRA	Astragalus	0–10	–
	Indian paintbrush	CASTI2	Castilleja	0–10	–
	bastard toadflax	COMAN	Comandra	0–10	–
	tapertip hawksbeard	CRAC2	Crepis acuminata	0–10	–
	common woolly sunflower	ERLA6	Eriophyllum lanatum	0–10	–
	haplopappus	HAPLO11	Haplopappus	0–10	–
	woodland-star	LITHO2	Lithophragma	0–10	–
	stoneseed	LITHO3	Lithospermum	0–10	–
	hoary tansyaster	MACA2	Machaeranthera canescens	0–10	–
	beardtongue	PENST	Penstemon	0–10	–
	deathcamas	ZIGAD	Zigadenus	0–10	–
Shrub/Vine
11	Shrubs			40–80
	Wyoming big sagebrush	ARTRW8	Artemisia tridentata ssp. wyomingensis	20–50	–
	basin big sagebrush	ARTRT	Artemisia tridentata ssp. tridentata	10–30	–
15	Other shrubs			30–60
	threetip sagebrush	ARTR4	Artemisia tripartita	0–10	–
	yellow rabbitbrush	CHVI8	Chrysothamnus viscidiflorus	0–10	–
	rubber rabbitbrush	ERNA10	Ericameria nauseosa	0–10	–
	spiny hopsage	GRSP	Grayia spinosa	0–10	–
	broom snakeweed	GUSA2	Gutierrezia sarothrae	0–10	–
	littleleaf horsebrush	TEGL	Tetradymia glabrata	0–10	–

Table 30. Community 1.2 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Perennial, deep-rooted, dominant			400–800
	bluebunch wheatgrass	PSSP6	Pseudoroegneria spicata	300–500	–
	Thurber's needlegrass	ACTH7	Achnatherum thurberianum	100–300	–
2	Perennial, deep-rooted			70–150
	needle and thread	HECO26	Hesperostipa comata	0–80	–
	squirreltail	ELEL5	Elymus elymoides	0–30	–
	Idaho fescue	FEID	Festuca idahoensis	0–30	–
3	Perennial, shallow-rooted			30–50
	Sandberg bluegrass	POSE	Poa secunda	30–50	–
Forb
5	Perennial forb			30–70
	arrowleaf balsamroot	BASA3	Balsamorhiza sagittata	0–30	–
	low pussytoes	ANDI2	Antennaria dimorpha	5–15	–
	tapertip hawksbeard	CRAC2	Crepis acuminata	0–10	–
	longleaf phlox	PHLO2	Phlox longifolia	0–10	–
	woollypod milkvetch	ASPU9	Astragalus purshii	0–10	–
	cushion buckwheat	EROV	Eriogonum ovalifolium	0–10	–
	common yarrow	ACMI2	Achillea millefolium	0–10	–
6	Annual forb			20–30
	maiden blue eyed Mary	COPA3	Collinsia parviflora	0–5	–
	rough eyelashweed	BLSC	Blepharipappus scaber	0–5	–
	slender phlox	MIGR	Microsteris gracilis	0–5	–
	tall annual willowherb	EPBR3	Epilobium brachycarpum	0–5	–
Shrub/Vine
11	Other shrubs			100–300
	Wyoming big sagebrush	ARTRW8	Artemisia tridentata ssp. wyomingensis	20–150	–
	rubber rabbitbrush	ERNA10	Ericameria nauseosa	0–30	–
	yellow rabbitbrush	CHVI8	Chrysothamnus viscidiflorus	0–30	–

Table 31. Community 2.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Perennial, deep-rooted, dominant			350–600
	bluebunch wheatgrass	PSSP6	Pseudoroegneria spicata	400–500	15–30
	crested wheatgrass	AGCR	Agropyron cristatum	150–250	0–15
2	Perennial, deep-rooted			20–50
	Thurber's needlegrass	ACTH7	Achnatherum thurberianum	0–30	0–2
	squirreltail	ELEL5	Elymus elymoides	0–30	0–2
3	Perennial, shallow-rooted			30–40
	Sandberg bluegrass	POSE	Poa secunda	30–50	10–20
9	Annual grass, introduced			0–10
	cheatgrass	BRTE	Bromus tectorum	0–10	5–10
Forb
5	Perennial forb			10–20
	low pussytoes	ANDI2	Antennaria dimorpha	0–10	0–3
	tapertip hawksbeard	CRAC2	Crepis acuminata	0–10	0–3
	longleaf phlox	PHLO2	Phlox longifolia	0–10	0–3
	woollypod milkvetch	ASPU9	Astragalus purshii	0–10	0–1
	tapertip onion	ALAC4	Allium acuminatum	0–10	0–1
6	Annual forb, native			10–20
	slender phlox	MIGR	Microsteris gracilis	0–10	0–2
	rough eyelashweed	BLSC	Blepharipappus scaber	0–10	0–1
	maiden blue eyed Mary	COPA3	Collinsia parviflora	0–10	0–1
	tall annual willowherb	EPBR3	Epilobium brachycarpum	0–10	0–1
7	Annual forb, introduced			0–10
	desert madwort	ALDE	Alyssum desertorum	0–10	0–2
Shrub/Vine
10	Shrubs, dominant			200–500
	Wyoming big sagebrush	ARTRW8	Artemisia tridentata ssp. wyomingensis	200–500	15–20

Table 32. Community 2.2 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Perennial, deep-rooted, dominant			120–300
	bluebunch wheatgrass	PSSP6	Pseudoroegneria spicata	150–300	15–20
2	Perennial, deep-rooted			30–50
	Thurber's needlegrass	ACTH7	Achnatherum thurberianum	30–50	0–5
	squirreltail	ELEL5	Elymus elymoides	0–30	0–2
3	Perennial, shallow-rooted			50–90
	Sandberg bluegrass	POSE	Poa secunda	50–100	25–35
	bulbous bluegrass	POBU	Poa bulbosa	0–20	0–5
9	Annual grass, introduced			0–10
	cheatgrass	BRTE	Bromus tectorum	0–10	5–10
Forb
5	Perennial forb			5–20
	woollypod milkvetch	ASPU9	Astragalus purshii	0–10	0–2
	cushion buckwheat	EROV	Eriogonum ovalifolium	0–10	0–2
6	Annual forb, native			0–15
	maiden blue eyed Mary	COPA3	Collinsia parviflora	0–10	0–1
7	Annual forb, introduced			5–15
	curveseed butterwort	CETE5	Ceratocephala testiculata	0–10	0–2
	spring draba	DRVE2	Draba verna	0–10	0–2
Shrub/Vine
10	Shrub, dominant			200–500
	Wyoming big sagebrush	ARTRW8	Artemisia tridentata ssp. wyomingensis	200–500	5–15

Table 33. Community 2.3 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Perennial, deep-rooted, dominant			200–400
	bluebunch wheatgrass	PSSP6	Pseudoroegneria spicata	200–400	20–30
2	Perennial, deep-rooted			40–50
	Idaho fescue	FEID	Festuca idahoensis	0–50	0–5
3	Perennial, shallow-rooted			150–220
	Sandberg bluegrass	POSE	Poa secunda	200–300	30–40
9	Annual grass, introduced			10–30
	cheatgrass	BRTE	Bromus tectorum	10–30	0–10
Forb
5	Perennial forb			40–60
	arrowleaf balsamroot	BASA3	Balsamorhiza sagittata	10–20	0–3
	longleaf phlox	PHLO2	Phlox longifolia	0–10	0–3
Shrub/Vine
11	Other Shrubs			50–100
	Wyoming big sagebrush	ARTRW8	Artemisia tridentata ssp. wyomingensis	0–20	–
	yellow rabbitbrush	CHVI8	Chrysothamnus viscidiflorus	0–20	–
	rubber rabbitbrush	ERNA10	Ericameria nauseosa	0–20	–

Table 34. Community 3.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
2	Perennial, deep-rooted			20–50
	crested wheatgrass	AGCR	Agropyron cristatum	0–10	0–2
	squirreltail	ELEL5	Elymus elymoides	0–10	0–2
3	Perennial, shallow-rooted			100–250
	Sandberg bluegrass	POSE	Poa secunda	100–200	20–30
	bulbous bluegrass	POBU	Poa bulbosa	0–30	0–5
9	Annual grass, introduced			30–50
	cheatgrass	BRTE	Bromus tectorum	20–50	5–10
Forb
5	Perennial forb			5–25
	longleaf phlox	PHLO2	Phlox longifolia	0–10	0–2
	fleabane	ERIGE2	Erigeron	0–10	0–1
6	Annual forb, native			0–10
	maiden blue eyed Mary	COPA3	Collinsia parviflora	0–10	0–2
7	Annual forb, invasive			0–15
	curveseed butterwort	CETE5	Ceratocephala testiculata	0–10	1–3
Shrub/Vine
10	Shrub, dominant			250–350
	Wyoming big sagebrush	ARTRW8	Artemisia tridentata ssp. wyomingensis	300–500	15–20
11	Other shrubs			50–100
	basin big sagebrush	ARTRT	Artemisia tridentata ssp. tridentata	10–40	0–2
	yellow rabbitbrush	CHVI8	Chrysothamnus viscidiflorus	0–20	0–2

Table 35. Community 3.2 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
2	Perennial, deep-rooted			0–10
	bluebunch wheatgrass	PSSP6	Pseudoroegneria spicata	0–10	0–2
3	Perennial, shallow-rooted			120–250
	bulbous bluegrass	POBU	Poa bulbosa	100–230	30–60
	Sandberg bluegrass	POSE	Poa secunda	0–20	0–5
9	Annual grass, introduced			0–10
	cheatgrass	BRTE	Bromus tectorum	0–10	5–10
Forb
5	Perennial forb			10–20
	tapertip onion	ALAC4	Allium acuminatum	0–10	0–3
	bulbous woodland-star	LIGL2	Lithophragma glabrum	0–10	0–3
6	Annual forb, native			20–40
	Menzies' fiddleneck	AMME	Amsinckia menziesii	10–20	0–5
	common sunflower	HEAN3	Helianthus annuus	10–20	0–2
	maiden blue eyed Mary	COPA3	Collinsia parviflora	0–10	0–2
7	Annual forb, introduced			20–40
	tall tumblemustard	SIAL2	Sisymbrium altissimum	10–20	0–3
	curveseed butterwort	CETE5	Ceratocephala testiculata	0–10	0–2
	clasping pepperweed	LEPE2	Lepidium perfoliatum	0–10	0–2
	prostrate pigweed	AMAL	Amaranthus albus	0–10	0–1

Table 36. Community 4.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
2	Perennial, deep-rooted			40–150
	crested wheatgrass	AGCR	Agropyron cristatum	50–100	0–10
	squirreltail	ELEL5	Elymus elymoides	0–20	0–2
	bluebunch wheatgrass	PSSP6	Pseudoroegneria spicata	0–20	0–2
	basin wildrye	LECI4	Leymus cinereus	0–20	0–1
	Thurber's needlegrass	ACTH7	Achnatherum thurberianum	5–15	2–10
3	Perennial, shallow-rooted			20–100
	Sandberg bluegrass	POSE	Poa secunda	15–30	10–30
	bulbous bluegrass	POBU	Poa bulbosa	0–20	0–5
9	Annual grass, introduced			140–250
	cheatgrass	BRTE	Bromus tectorum	80–120	30–50
	medusahead	TACA8	Taeniatherum caput-medusae	80–120	10–30
	field brome	BRAR5	Bromus arvensis	0–10	0–2
Forb
5	Perennial forb			20–30
	longleaf phlox	PHLO2	Phlox longifolia	0–10	0–2
	pussytoes	ANTEN	Antennaria	0–10	0–1
	Douglas' dustymaiden	CHDO	Chaenactis douglasii	0–10	0–1
	hoary tansyaster	MACA2	Machaeranthera canescens	0–10	0–1
6	Annual forb, native			10–20
	maiden blue eyed Mary	COPA3	Collinsia parviflora	0–10	0–1
	slender phlox	MIGR	Microsteris gracilis	0–10	0–1
7	Annual forb, introduced			20–30
	desert madwort	ALDE	Alyssum desertorum	10–20	2–5
	spring draba	DRVE2	Draba verna	0–10	0–1
	jagged chickweed	HOUM	Holosteum umbellatum	0–10	0–1
	tall tumblemustard	SIAL2	Sisymbrium altissimum	0–10	0–1
Shrub/Vine
10	Shrubs			120–200
	Wyoming big sagebrush	ARTRW8	Artemisia tridentata ssp. wyomingensis	100–200	10–20
11	Other shrubs			30–50
	basin big sagebrush	ARTRT	Artemisia tridentata ssp. tridentata	20–50	0–10
	yellow rabbitbrush	CHVI8	Chrysothamnus viscidiflorus	0–10	0–5
	slender buckwheat	ERMI4	Eriogonum microthecum	0–10	0–1

Table 37. Community 4.2 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
2	Perennial, deep-rooted			20–100
	bluebunch wheatgrass	PSSP6	Pseudoroegneria spicata	10–50	0–5
	Thurber's needlegrass	ACTH7	Achnatherum thurberianum	0–30	0–2
	crested wheatgrass	AGCR	Agropyron cristatum	0–30	0–2
	squirreltail	ELEL5	Elymus elymoides	0–30	0–2
3	Perennial, shallow-rooted			50–150
	Sandberg bluegrass	POSE	Poa secunda	20–80	5–15
	bulbous bluegrass	POBU	Poa bulbosa	20–80	5–15
8	Annual grass, introduced			280–500
	cheatgrass	BRTE	Bromus tectorum	200–400	50–70
	medusahead	TACA8	Taeniatherum caput-medusae	100–400	30–45
Forb
5	Perennial forb			0–10
	tapertip hawksbeard	CRAC2	Crepis acuminata	0–10	0–1
6	Annual forb, native			0–10
	willowherb	EPILO	Epilobium	0–10	0–2
7	Annual forb, introduced			50–100
	prickly lettuce	LASE	Lactuca serriola	20–50	0–5
	herb sophia	DESO2	Descurainia sophia	20–30	0–5
	clasping pepperweed	LEPE2	Lepidium perfoliatum	10–30	0–3
	jagged chickweed	HOUM	Holosteum umbellatum	0–10	0–5
	redstem stork's bill	ERCI6	Erodium cicutarium	0–10	0–3
	desert madwort	ALDE	Alyssum desertorum	0–10	0–2
	Scotch cottonthistle	ONAC	Onopordum acanthium	0–10	0–2
	tall tumblemustard	SIAL2	Sisymbrium altissimum	0–10	0–1
	crossflower	CHTE2	Chorispora tenella	0–10	0–1
Shrub/Vine
11	Other shrubs			10–100
	Wyoming big sagebrush	ARTRW8	Artemisia tridentata ssp. wyomingensis	10–40	0–2
	basin big sagebrush	ARTRT	Artemisia tridentata ssp. tridentata	0–30	0–2
	rubber rabbitbrush	ERNA10	Ericameria nauseosa	0–20	0–1

Interpretations

Animal community

Livestock Grazing:
This site is suitable for livestock grazing use in the late winter, spring, and fall 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 Thurber’s
needlegrass. 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 nesting, rearing and wintering. Antelope and mule deer make excellent use of the site for winter and spring forage.

Hydrological functions

The soils of this site are typically in an upland topographic position. They have moderate runoff potential and medium infiltration rates when the hydrologic cover is high. Hydrologic cover is high when beardless wheatgrass, Thurber’s needlegrass and other deep rooted bunchgrass component is greater than 70 percent of potential.

Supporting information

Inventory data references

This site was verified using vegetation and soils data summarized across 28 plots collected on this ecological site across MLRA 10 in Oregon from 2011 to 2024. Data was sourced from NRCS ecological site plots, BLM assessment, inventory, and monitoring plots, and NRCS natural resource inventory plots. A list of plots with names, locations, data collection intensity, and associated plant communities is available to users with EDIT developer privileges. For these plots, locations listed are in WGS84 and decimal degree format. Site IDs included but not in NASIS are preceded by "Oregon_ESR" or "OregonNRI."

References

Chambers, J.C., D.A. Pyke, J.D. Maestas, M. Pellant, C.S. Boyd, S.B. Campbell, S. Esipinosa, D.W. Havlina, K.E. Mayer, and A. Wuenschel. 2014. Using resistance and resilience concepts to reduce impacts of invasive annual grasses and altered fire regimes on the sagebrush ecosystem and greater sage-grouse: A strategic multi-scale approach.. Gen. Tech. Rep. RMRS-GTR-326.. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station., Fort Collins, CO. 73.
Miller, R.F., J.C. Chambers, D.A. Pyke, F.B. Pierson, and C.J. Williams. 2013. A Review of Fire Effects on Vegetation and Soils in the Great Basin Region: Response and Ecological Site Characteristics. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station.
Stringham, T.K., D. Snyder, P. Novak-Echenique, A. Wartgow, A. Badertscher, and K. O'Neill. 2019. Great Basin Ecological Site Development Project: State and Transition Models for Major Land Resource Area 23, Nevada and portions of California. Nevada Agricultural Experiment Station Research Report 2019-01. University of Nevada Reno, Reno, Nevada.
Stringham, T.k., D. Snyder, and A. Wartgow. 2016. State-and-Transition Models for USFS Crooked River National Grassland Major Land Resource Area B10 Oregon. DRAFT Report.. University of Nevada Reno, Reno, NV.
United States Department of Agriculture, . 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin... USDA Handbook 296 1–682.

Other references

Beck, J. L., Connelly, J. W., & Wambolt, C. L. (2012). Consequences of treating wyoming big sagebrush to enhance wildlife habitats. Rangeland Ecology & Management, 65(5), 444–455. https://doi.org/10.2111/REM-D-10-00123.1

Davies, K. W., Bates, J. D., & Nafus, A. M. (2011). Are there benefits to mowing wyoming big sagebrush plant communities? An evaluation in southeastern oregon. Environmental Management, 48(3), 539–546. https://doi.org/10.1007/s00267-011-9715-3

Hanna, S. K., & Fulgham, K. O. (2015). Post-fire vegetation dynamics of a sagebrush steppe community change significantly over time. California Agriculture, 69(1), 36–42. https://doi.org/10.3733/ca.v069n01p36

Hosna, R. K., Reed, S. C., & Faist, A. M. (2023). Long‐term relationships between seed bank communities and wildfire across four North American desert sites. Ecosphere, 14(3), e4398. https://doi.org/10.1002/ecs2.4398

Maestas, J. D., Porter, M., Cahill, M., & Twidwell, D. (2022). Defend the core: Maintaining intact rangelands by reducing vulnerability to invasive annual grasses. Rangelands, 44(3), 181–186. https://doi.org/10.1016/j.rala.2021.12.008

Pyke, D. A., Shaff, S. E., Lindgren, A. I., Schupp, E. W., Doescher, P. S., Chambers, J. C., Burnham, J. S., & Huso, M. M. (2014). Region-wide ecological responses of arid wyoming big sagebrush communities to fuel treatments. Rangeland Ecology & Management, 67(5), 455–467. https://doi.org/10.2111/REM-D-13-00090.1

Reisner, M. D., Grace, J. B., Pyke, D. A., & Doescher, P. S. (2013). Conditions favouring Bromus tectorum dominance of endangered sagebrush steppe ecosystems. Journal of Applied Ecology, 50(4), 1039–1049. https://doi.org/10.1111/1365-2664.12097

Smith, J. T., Allred, B. W., Boyd, C. S., Davies, K. W., Jones, M. O., Kleinhesselink, A. R., Maestas, J. D., Morford, S. L., & Naugle, D. E. (2022). The elevational ascent and spread of exotic annual grass dominance in the Great Basin, USA. Diversity and Distributions, 28(1), 83–96. http://https://doi.org/10.1111/ddi.13440

Smith, J. T., Allred, B. W., Boyd, C. S., Davies, K. W., Kleinhesselink, A. R., Morford, S. L., & Naugle, D. E. (2023). Fire needs annual grasses more than annual grasses need fire. Biological Conservation, 286, 110299. https://doi.org/10.1016/j.biocon.2023.110299

Contributors

Bob Gillaspy
T.Bloomer, E.Petersen, A. Bahn
Erik Peterson - Verification Project 2025

Approval

Kirt Walstad, 3/31/2025

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)	Bob Gillaspy
Contact for lead author	State Rangeland Management Specialist for NRCS Oregon
Date	11/09/2016
Approved by	Kirt Walstad
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, except following extremely high intensity storms when short (less than 1 meter) flow patterns may appear on steeper slopes. Minimal evidence of past or current soil deposition or erosion.
Number and height of erosional pedestals or terracettes:
None, except few pedestals or terracettes on steeper slopes.
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
5-15% bare ground, typically bare patches are associated with shrubs. Larger bare patches maybe
associated with ant mounds, rodent, and/or other natural disturbances.
Number of gullies and erosion associated with gullies:
None.
Extent of wind scoured, blowouts and/or depositional areas:
None. Wind erosion hazard is moderate.
Amount of litter movement (describe size and distance expected to travel):
Litter size is Small/Fine. Litter movement is limited, minimal, and short, associated with water flow patterns following extremely high intensity storms. Litter also may be moved during intense wind storms.
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Site is slightly to moderately resistant to erosion. Stability class (Herrick et al. 2001) anticipated to be 3-6 at surface under perennial vegetation. Stability class at surface in the interspaces is anticipated to be less than or equal to that under perennial vegetation.
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Surface layer structure is weak fine granular to weak fine subangular blocky. The A horizon has a dry color of 5 - 6 and is 3 - 16 inches thick. The Soil Organic Matter (SOM) content is low (0.75 to 2.5%).
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Plant foliar cover and basal cover with small gaps between plants should reduce raindrop impact and slow overland flow, providing increased time for infiltration to occur. High herbaceous vegetation on this site will retain more water from precipitation. Vegetative ground cover (70-80%) and gentle slopes (2-15%) 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:
Cool Season Deep Rooted Perennial Bunchgrass [Beardless Wheatgrass > Thurber's Needlegrass] > Evergreen Shrubs [sagebrush]

Sub-dominant:
Forbs > other grasses > other shrubs

Other:

Additional:
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Grasses will nearly always show some mortality and decadence. Normal decadence and mortality expected on other plants.
Average percent litter cover (%) and depth ( in):
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
Annual production: Low 700 lbs/acre, Representative Value 1000 lbs/acre, High 1400 lbs/acre
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, Medusahead, and bulbous bluegrass 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

Click on box and path labels to scroll to the respective text.

Ecosystem states

T1A	-	Introduction of non-native species; inappropriate grazing management
T2A	-	Inappropriate grazing management
T2B	-	Fire, soil disruption, inapropriate grazing management
R3A	-	Shrub removal, possible perennial grass reseeding
T3A	-	Catastrophic fire, soil disturbing treatments, inappropriate grazing management
R4B	-	Annual grass treatment, reseeding
R4A	-	Annual grass treatment, reseeding