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MLRA notes
Major Land Resource Area (MLRA): 028B–Central Nevada Basin and Range
MLRA 28B occurs entirely in Nevada and comprises about 23,555 square miles (61,035 square kilometers). More than nine-tenths of this MLRA is federally owned. This area is in the Great Basin Section of the Basin and Range Province of the Intermontane Plateaus. It is an area of nearly level, aggraded desert basins and valleys between a series of mountain ranges trending north to south. The basins are bordered by long, gently sloping to strongly sloping alluvial fans. The mountains are uplifted fault blocks with steep sideslopes. Many of the valleys are closed basins containing sinks or playas. Elevation ranges from 4,900 to 6,550 feet (1,495 to 1,995 meters) in the valleys and basins and from 6,550 to 11,900 feet (1,995 to 3,630 meters) in the mountains.
The mountains in the southern half are dominated by andesite and basalt rocks that were formed in the Miocene and Oligocene. Paleozoic and older carbonate rocks are prominent in the mountains to the north. Scattered outcrops of older Tertiary intrusives and very young tuffaceous sediments are throughout this area. The valleys consist mostly of alluvial fill, but lake deposits are at the lowest elevations in the closed basins. The alluvial valley fill consists of cobbles, gravel, and coarse sand near the mountains in the apex of the alluvial fans. Sands, silts, and clays are on the distal ends of the fans.
The average annual precipitation ranges from 4 to 12 inches (100 to 305 millimeters) in most areas on the valley floors. Average annual precipitation in the mountains ranges from 8 to 36 inches (205 to 915 millimeters) depending on elevation. The driest period is from midsummer to midautumn. The average annual temperature is 34 to 52 degrees F (1 to 11 degrees C). The freeze-free period averages 125 days and ranges from 80 to 170 days, decreasing in length with elevation.
The dominant soil orders in this MLRA are Aridisols, Entisols, and Mollisols. The soils in the area dominantly have a mesic soil temperature regime, an aridic or xeric soil moisture regime, and mixed or carbonatic mineralogy. They generally are well drained, loamy or loamyskeletal, and shallow to very deep.
Nevada’s climate is predominantly arid, with large daily ranges of temperature, infrequent severe storms and heavy snowfall in the higher mountains. Three basic geographical factors largely influence Nevada’s climate: continentality, latitude, and elevation. The strong continental effect is expressed in the form of both dryness and large temperature variations. Nevada lies on the eastern, lee side of the Sierra Nevada Range, a massive mountain barrier that markedly influences the climate of the State. The prevailing winds are from the west, and as the warm moist air from the Pacific Ocean ascend the western slopes of the Sierra Range, the air cools, condensation occurs and most of the moisture falls as precipitation. As the air descends the eastern slope, it is warmed by compression, and very little precipitation occurs. The effects of this mountain barrier are felt not only in the West but throughout the state, as a result the lowlands of Nevada are largely desert or steppes.
The temperature regime is also affected by the blocking of the inland-moving maritime air. Nevada sheltered from maritime winds, has a continental climate with well-developed seasons and the terrain responds quickly to changes in solar heating. Nevada lies within the midlatitude belt of prevailing westerly winds which occur most of the year. These winds bring frequent changes in weather during the late fall, winter and spring months, when most of the precipitation occurs.
To the south of the mid-latitude westerlies, lies a zone of high pressure in subtropical latitudes, with a center over the Pacific Ocean. In the summer, this high-pressure belt shifts northward over the latitudes of Nevada, blocking storms from the ocean. The resulting weather is mostly clear and dry during the summer and early fall, with occasional thundershowers. The eastern portion of the state receives noteworthy summer thunderstorms generated from monsoonal moisture pushed up from the Gulf of California, known as the North American monsoon. The monsoon system peaks in August and by October the monsoon high over the Western U.S. begins to weaken and the precipitation retreats southward towards the tropics (NOAA 2004).
Ecological site concept
This site occurs on drainageways and inset fans. Slope gradients of 0 to 2 percent are most typical and elevations range from 4500 to 7600 feet.
Soils associated with this site are very deep, well drained and derived from mixed alluvium. They typically have a mollic epipedon and a mesic temperature regime. The reference plant community is characterized by a robust stand of basin wildrye, with a component of basin big sagebrush. Production ranges from 2000 to 6000 pounds per acre.
In areas where a plant community dominated by basin wildrye and basin big sagebrush occurs in association with a perennial stream on floodplains or stream terraces it may be the result of channel entrenchment and lowering of the water table and should be considered a degraded state of a Wet Meadow (028BY001NV).Associated sites
R028BY001NV WET MEADOW 10-14 P.Z.
R028BY007NV LOAMY 10-12 P.Z.
R028BY010NV LOAMY 8-10 P.Z.
R028BY041NV DRY FLOODPLAIN
R028BY045NV LOAMY FAN 8-12 P.Z.
R028BY081NV MOIST FLOODPLAIN
Similar sites
R028BY004NV SALINE BOTTOM
LECI4-SPAI codominant grasses; SAVE4 dominant shrub; less productive site.
R028BY024NV LOAMY BOTTOM 14+ P.Z.
ARTRV dominant shrub; less productive site.
R028BY045NV LOAMY FAN 8-12 P.Z.
ACHY and ELLAL important grasses; less productive site.
R028BY082NV LOAMY FAN 12+ P.Z.
LECI4-HECO26 codominant; less productive site.
R028BY041NV DRY FLOODPLAIN
SAVE4 may be present; less productive site.
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Artemisia tridentata subsp. tridentata
Herbaceous (1) Leymus cinereus
Physiographic features
This site occurs on drainage ways and inset fans. Slope gradients of 0 to 8 percent, but slopes of 0 to 2 percent are most typical. Elevations are 4500 to 7600 feet.
Table 2. Representative physiographic features
Landforms (1) Drainageway
(2) Inset fan
Flooding duration Very brief (4 to 48 hours) to brief (2 to 7 days) Flooding frequency Rare to occasional Ponding frequency None Elevation 4500 – 7600 ft Slope 0 – 8 % Ponding depth 0 in Water table depth 12 – 60 in Aspect Aspect is not a significant factor Climatic features
The climate associated with this site is semiarid, characterized by cold, moist winters and warm, dry summers.
The average annual precipitation ranges from 9 to 14 inches. Mean annual air temperature is about 45 to 50 degrees F. The average growing season is 100 to 120 days.
Mean annual precipitaion at the ELY WBO,NEVADA climate station (262631) is 9.72 inches. Monthly mean precipitation is:
January 0.77; February 0.78; March 1.01; April 1.03;
May 1.10; June 0.65; July 0.64; August 0.81;
September 0.75; October 0.82;
November 0.68; December 0.68.Table 3 Representative climatic features
Frost-free period (average) 0 days Freeze-free period (average) 110 days Precipitation total (average) 10 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
Figure 3. Annual precipitation pattern
Figure 4 Annual average temperature pattern
">Influencing water features
Influencing water features are not associated with this site.
Soil features
The soils associated with this site are very deep, well drained and derived from mixed alluvium. Soils are characterized by a thick, dark surface, moderate to high available water holding capacity, a aridic bordering on xeric moisture regime and a mesic temperature regime. Soil series associated with this site are Holtle, Hussa, Pern, Mosida, Bigwash, Tierney and Sevenmile.
A typical soil series is Pern, a fine-silty, mixed, superactive, mesic Aridic Calcixerolls. Diagnostic horizons include a mollic epipedon from the surface to 36 cm, and a calcic horizon from 51 to about 152 cm. Clay content in the particle control section averages 18 to 25 percent. Rock fragments range from 0 to 5 percent and are mainly gravel. Reaction is moderately alkaline. Effervescence increases with depth.
Soil receive run-in from higher landscapes and are susceptible to gully erosion, which intercepts normal overflow patterns causing degradation.Table 4. Representative soil features
Parent material (1) Alluvium – welded tuff
Surface texture (1) Loam
(2) Silt loam
(3) Gravelly loam
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderate to moderately rapid Soil depth 55 – 80 in Surface fragment cover <=3" 0 – 5 % Surface fragment cover >3" Not specified Available water capacity
(0-40in)5 – 7.9 in Calcium carbonate equivalent
(0-40in)0 – 20 % Electrical conductivity
(0-40in)Not specified Sodium adsorption ratio
(0-40in)Not specified Soil reaction (1:1 water)
(0-40in)7.9 – 8.2 Subsurface fragment volume <=3"
(Depth not specified)0 – 5 % Subsurface fragment volume >3"
(Depth not specified)Not specified Ecological dynamics
An ecological site is the product of all the environmental factors responsible for its development and it has a set of key characteristics that influence a site’s resilience to disturbance and resistance to invasives. Key characteristics include 1) climate (precipitation, temperature), 2) topography (aspect, slope, elevation, and landform), 3) hydrology (infiltration, runoff), 4) soils (depth, texture, structure, organic matter), 5) plant communities (functional groups, productivity), and 6) natural disturbance regime (fire, herbivory, etc.) (Caudle 2013). Biotic factors that influence resilience include site productivity, species composition and structure, and population regulation and regeneration (Chambers et al 2013).
The ecological site is dominated by deep-rooted cool season, perennial bunchgrasses and long-lived shrubs (50+ years) with high root to shoot ratios. The dominant shrubs usually root to the full depth of the winter-spring soil moisture recharge, which ranges from 1.0 to over 3.0 m. (Comstock and Ehleringer 1992). Root length of mature sagebrush plants was measured to a depth of 2 meters in alluvial soils in Utah (Richards and Caldwell 1987). These shrubs have a flexible generalized root system with development of both deep taproots and laterals near the surface (Comstock and Ehleringer 1992).
The perennial bunchgrasses generally have somewhat shallower root systems than the shrubs, but root densities are often as high as or higher than those of shrubs in the upper 0.5 m but taper off more rapidly than shrubs. However, basin wildrye is weakly rhizomatous and has been found to root to depths of 1m or more and to exhibit greater lateral root spread than many other grass species (Abbott et al. 1991). General differences in root depth distributions between grasses and shrubs results in resource partitioning in these shrub/grass systems.
The Great Basin sagebrush communities have high spatial and temporal variability in precipitation both among years and within growing seasons. Nutrient availability is typically low but increases with elevation and closely follows moisture availability. The moisture resource supporting the greatest amount of plant growth is usually the water stored in the soil profile during the winter. The invasibility of plant communities is often linked to resource availability. Disturbance can decrease resource uptake due to damage or mortality of the native species and depressed competition or can increase resource pools by the decomposition of dead plant material following disturbance. The invasion of sagebrush communities by cheatgrass has been linked to disturbances (fire, abusive grazing) that have resulted in fluctuations in resources (Chambers et al 2007). A primary disturbance on these ecological sites is channel incision leading to a lowered seasonal water table which facilitates an increase in shrubs and a decrease in perennial bunchgrasses (Chambers and Miller 2004). With continued site degradation, rubber rabbitbrush becomes the dominant plant. There is some evidence that many Loamy Bottom ecological sites are degraded Wet Meadow ecological sites created through channel incision processes. Additionally, the encroachment of Singleleaf pinyon and Utah juniper into associated upland sites has the potential to modify the hydrology of this site through changes to the watersheds overall water budget. Research indicates pinyon and juniper canopies intercept, on average, 44% of incoming rainfall (Lossing 2012) and a 10 to 12 inch dbh tree consumes approximately 10 to 68 liters per day (Snyder et al. 2013). Further investigation and updating of ecological site concepts for this site is warranted.
The introduction of annual weedy species, like cheatgrass, may cause an increase in fire frequency and eventually lead to an annual state or a state dominated by rabbitbrush. Other troublesome non-native weeds such as broadleaved pepperweed, scotch thistle or bull thistle are potential invaders on this site.
This ecological site has moderate resilience to disturbance and resistance to invasion. A primary disturbance on these ecological sites is channel incision or other disturbance leading to a lowered seasonal water table. This facilitates an increase in shrubs and a decrease in basin wildrye. Four possible alternative stable states have been identified for this site.
Fire Ecology:
In many basin big sagebrush communities, changes in fire frequency occurred along with fire suppression, livestock grazing and OHV use. Few if any fire history studies have been conducted on basin big sagebrush; however, Sapsis and Kauffman (1991) suggest that fire return intervals in basin big sagebrush are intermediate between mountain big sagebrush (15 to 25 years) and Wyoming big sagebrush (50 to 100 years). Fire severity in big sagebrush communities is described as "variable" depending on weather, fuels, and topography. However, fire in basin big sagebrush communities are typically stand replacing (Sapsis and Kauffman 1991). Basin big sagebrush does not sprout after fire. Because of the time needed to produce seed, it is eliminated by frequent fires (Bunting et al. 1987). Basin big sagebrush reinvades a site primarily by off-site seed or seed from plants that survive in unburned patches. Approximately 90% of big sagebrush seed is dispersed within 30 feet (9 m) of the parent shrub (Goodrich et al. 1985) with maximum seed dispersal at approximately 108 feet (33 m) from the parent shrub (Shumar and Anderson 1986). Therefore regeneration of basin big sagebrush after stand replacing fires is difficult and dependent upon proximity of residual mature plants and favorable moisture conditions (Johnson and Payne 1968, Humphrey 1984).
The effect of fire on bunchgrasses relates to culm density, culm-leaf morphology, and the size of the plant. The initial condition of bunchgrasses within the site along with seasonality and intensity of the fire all factor into the individual species response. For most forbs and grasses the growing points are located at or below the soil surface providing relative protection from disturbances which decrease above ground biomass, such as grazing or fire. Thus, fire mortality is more correlated to duration and intensity of heat which is related to culm density, culm-leaf morphology, size of plant and abundance of old growth (Wright 1971, Young 1983). In addition, season and severity of the fire will influence plant response as will post-fire soil moisture availability.
Basin wildrye is relatively resistant to fire, particularly dormant season fire, as plants sprout from surviving root crowns and rhizomes (Zschaechner 1985). Miller et al. (2013) reported increased total shoot and reproductive shoot densities in the first year following fire, although by year two there was little difference between burned and control treatments.
Rubber rabbitbrush is top-killed by fire, but can resprout after fire and can also establish from seed (Young 1983). Shortened fire intervals within this ecological site favor a creeping wildrye understory with varying amounts of rabbitbrush dominated overstory.
Hydrologic modification of this site may occur through channel incision or gully formation with post-fire rain events. Channel incision or gully formation has the potential to lower the site water table, drying out the site and favoring the dominance of sagebrush and rabbitbrush over the herbaceous component.State and transition model
Custom diagramStandard diagram
Figure 5. State and Transition Model
Figure 6. Legend
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 textState 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 4 submodel, plant communities
State 1
Reference StateThe Reference State 1.0 is a representative of the natural range of variability under pristine conditions. The Reference State has three general community phases; a shrub-grass dominant phase, a perennial grass dominant phase and a shrub dominant phase. State dynamics are maintained by interactions between climatic patterns and disturbance regimes. Negative feedbacks enhance ecosystem resilience and contribute to the stability of the state. These include the presence of all structural and functional groups, low fine fuel loads, and retention of organic matter and nutrients. Plant community phase changes are primarily driven by fire, periodic drought and/or insect or disease attack. Management of this site would be to maintain high plant species diversity and a healty watershed.
Community 1.1
Community Phase
Figure 7. Loamy Bottom 10-14" (R028BY003NV) P. Novak-Echenique June 2012
This community phase is dominated by basin wildrye and Nevada bluegrass. Shrubs, forbs and other perennial grasses and grass-likes makeup smaller components. Potential vegetative composition is about 85% grasses, 5% forbs, and 10% shrubs. Approximate ground cover (basal and crown) is about 30 to 50 percent.
Figure 8. 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 1700 3400 5100 Shrub/Vine 200 400 600 Forb 100 200 300 Total 2000 4000 6000 Community 1.2
Community PhaseThis community phase is characteristic of a post-disturbance, early-seral community. Basin wildrye, Nevada bluegrass and other perennial grasses and grass-likes dominate. Rabbitbrush is present in minor amounts. Depending on fire severity or intensity of Aroga moth infestations, patches of intact sagebrush may remain.
Community 1.3
Community PhaseSagebrush increases in the absence of disturbance. Decadent sagebrush dominates the overstory and the deep-rooted perennial bunchgrasses in the understory are reduced either from competition with shrubs and/or from herbivory.
Pathway a
Community 1.1 to 1.2Fire will decrease or eliminate the sparse stand of sagebrush and bunchgrasses and grass-likes will remain dominant. A severe infestation of Aroga moth could also cause a large decrease in sagebrush giving a competitive advantage to the perennial grasses and forbs. Rabbitbrush will likely resprout.
Pathway b
Community 1.1 to 1.3Time and lack of disturbance such as fire allows for sagebrush to increase and become decadent. Chronic drought, herbivory, or combinations of these will cause a decline in perennial bunchgrasses and fine fuels leading to a reduced fire frequency and allowing big sagebrush to dominate the site.
Pathway a
Community 1.2 to 1.1Time and lack of disturbance will allow sagebrush to increase.
Pathway a
Community 1.3 to 1.2Fire will decrease or eliminate the overstory of sagebrush and allow for the perennial bunchgrasses to dominate the site. Fire will typically remove most of the sagebrush overstory. A severe infestation of Aroga moth could also cause a large decrease in sagebrush within the community, giving a competitive advantage to the perennial grasses and forbs.
State 2
Current Potential StateThis state is similar to the Reference State 1.0 with three similar community phases. Ecological function has not changed, however the resiliency of the state has been reduced by the presence of invasive weeds. Non-natives may increase in abundance but will not become dominant within this State. These non-natives can be highly flammable and can promote fire where historically fire had been infrequent. Negative feedbacks enhance ecosystem resilience and contribute to the stability of the state. These feedbacks include the presence of all structural and functional groups, low fine fuel loads, and retention of organic matter and nutrients. Positive feedbacks decrease ecosystem resilience and stability of the state. These include the non-natives’ high seed output, persistent seed bank, rapid growth rate, ability to cross pollinate, and adaptations for seed dispersal. Management would be to maintain high diversity of desired species to promote organic matter inputs and prevent the dispersal and seed production of the non-native invasive species.
Community 2.1
Community PhaseThis community phase is similar to the Reference State Community Phase 1.1, with the presence of non-native species in trace amounts. Basin wildrye and Sandberg bluegrass dominate the site. Forbs and other shrubs and grasses make up smaller components of this site. Potential vegetative composition is about 85% grasses, 5% forbs, and 10% shrubs. Approximate ground cover (basal and crown) is about 30 to 50 percent.
Community 2.2
Community Phase
Figure 9. Loamy Bottom 10-14” (R028BY003NV) T.K. Stringham June 2012
Mountain big sagebrush decreases, perennial bunchgrasses increase and annual non-native species may be present to increasing. This community phase is characteristic of a post-disturbance, early to mid-seral community phase (following fire). Bluebunch wheatgrass, Thurber’s needlegrass, basin wildrye, and other perennial grasses dominate. Rabbitbrush may dominate the overstory aspect for a number of years following fire.
Community 2.3
Community Phase (at risk)
Figure 10. Loamy Bottom 10-14” (R028BY003NV) T.K. Stringham June 2012
This community phase is at risk of crossing a threshold to another state. Sagebrush dominates the overstory and perennial bunchgrasses in the understory are reduced, either from competition with shrubs, inappropriate grazing, lowered water table or a combination of the three. Rabbitbrush may be a significant component. Beardless (creeping) wildrye, mat muhly or Sandbergs or Nevada bluegrass may increase and dominate with deep rooted bunchgrasses. Utah juniper may be present and without management will likely increase. Non-native species may be stable or increasing due to lack of competition with perennial bunchgrasses. This site is susceptible to further degradation from grazing, drought, and fire.
Pathway a
Community 2.1 to 2.2Fire will decrease or eliminate the sparse stand of sagebrush and perennial bunchgrasses and grass-likes remain dominant on the site. Fire will typically remove most of the sagebrush overstory and rabbitbrush will likely resprout. A severe infestation of Aroga moth could also cause a large decrease in sagebrush giving a competitive advantage to the perennial grasses and forbs. Non-native species are likely to increase after fire.
Pathway b
Community 2.1 to 2.3Time and lack of disturbance such as fire allows for sagebrush and rabbitbrush to increase and become decadent. Chronic drought, herbivory, or combinations of these will cause a decline in perennial bunchgrasses and fine fuels leading to a reduced fire frequency and allowing big sagebrush and rabbitbrush to dominate the site. Inappropriate grazing management reduces the perennial bunchgrass understory; conversely beardless (creeping) wildrye and/or mat muhly may increase in the understory depending on grazing management.
Pathway a
Community 2.2 to 2.1Time and lack of disturbance and/or grazing management that favors the establishment and growth of sagebrush and rabbitbrush allows the shrub component to recover. The establishment of big sagebrush can take many years.
Pathway a
Community 2.3 to 2.2
Community Phase (at risk)
Community PhaseFire will decrease or eliminate the overstory of sagebrush and allow for the perennial bunchgrasses to dominate the site. Fire will typically remove most of the sagebrush overstory. A severe infestation of Aroga moth could also cause a large decrease in sagebrush within the community, giving a competitive advantage to the perennial grasses and forbs. Non-native species respond well to fire and may increase post-burn.
State 3
Shrub StateThis state has two community phases a decadent shrub phase and a sprouting shrub phase. This state is a product of many years of heavy grazing during time periods harmful to perennial bunchgrasses and/or hydrologic modification resulting in a lowered water table. Creeping wildrye, mat muhly and/or Sandberg’s bluegrass may become the dominant grass. Sagebrush dominates the overstory and rabbitbrush may be a significant component. Sagebrush cover exceeds site concept and may be decadent, reflecting stand maturity. The shrub overstory and creeping wildrye or mat muhly understory dominate site resources such that soil water, nutrient capture, nutrient cycling and soil organic matter are temporally and spatially redistributed.
Community 3.1
Community Phase
Figure 11. Loamy Bottom 10-14” (R028XY003NV) T.K. Stringham April 2013
Figure 12. Loamy Bottom 10-14” (R028BY003NV) T.K. Stringham June 2012
Figure 13. Loamy Bottom 10-14” (R028BY003NV) T.K. Stringham June 2012
Decadent sagebrush dominates the overstory. Rabbitbrush may be a significant component. Deep-rooted perennial bunchgrasses may be present in trace amounts or absent from the community. Creeping wildrye, mat muhly and Sandberg bluegrass and annual non-native species increase. Bare ground is significant. Western juniper may be present as a result of encroachment from neighboring sites and lack of disturbance. Pinyon may be invading.
Community 3.2
Community Phase
Figure 14. Loamy Bottom 10-14” (R028BY003NV) T.K. Stringham April 2013
Figure 15. Loamy Bottom 10-14” (R028BY003NV) T.K. Stringham June 2012
Creeping wildrye, mat muhly and or Sandberg bluegrass and/or rabbitbrush dominates the site; annual non-native species may be present but are not dominant. Trace amounts of sagebrush may be present.
Pathway a
Community 3.1 to 3.2
Community Phase
Community PhaseFire, heavy fall grazing causing mechanical damage to shrubs, and/or brush treatments with minimal soil disturbance, will greatly reduce the overstory shrubs to trace amounts and allow for creeping wildrye, mat muhly or Sandberg bluegrass to dominate the site.
Pathway a
Community 3.2 to 3.1
Community Phase
Community PhaseTime and lack of disturbance may allow sagebrush to recover.
State 4
Seeded StateThis state has two community phases one that is characterized by the dominance of seeded introduced species and the other with shrubs dominating the overstory. Basin big sagebrush and native and non-native forbs may be present.
Community 4.1
Community PhaseIntroduced bunchgrass species and other non-native species dominate the community. Native and non-native seeded forbs may be present. Trace amounts of basin big sagebrush may be present, especially if seeded. Annual non-native species present.
Community 4.2
Community PhaseBasin big sagebrush and seeded wheatgrass species co-dominate. Basin wildrye, baltic rush and other native species may be present.
Pathway a
Community 4.1 to 4.2Inappropriate grazing management particularly during the growing season reduces perennial bunchgrass vigor and density and facilitates shrub establishment.
Pathway a
Community 4.2 to 4.1Low severity fire, brush management, and/or Aroga moth infestation will reduce the sagebrush overstory and allow seeded wheatgrass species to become dominant.
Transition A
State 1 to 2Trigger: This transition is caused by the introduction of non-native annual and perennial plants, such as cheatgrass, mustards, and whitetop (Cardaria draba). Slow variables: Over time the non-native species will increase within the community. Threshold: Any amount of introduced non-native species causes an immediate decrease in the resilience of the site. Non-native species cannot be easily removed from the system and have the potential to significantly alter disturbance regimes from their historic range of variation.
Transition A
State 2 to 3Trigger: To Community Phase 3.1: Repeated, heavy, growing season grazing will decrease or eliminate deep rooted perennial bunchgrasses, increase Sandberg bluegrass and favor shrub growth and establishment. Alteration in the hydrology of the site may also cause an increase in sagebrush; with gullying of associated channel the water table is dropped and may cause a decrease in perennial bunchgrasses. To Community Phase 3.2: Severe fire will remove sagebrush overstory, decrease perennial bunchgrasses and enhance Sandberg bluegrass. Slow variables: Long term decrease in deep-rooted perennial grass density. Threshold: Loss of deep-rooted perennial bunchgrasses changes nutrient cycling, nutrient redistribution, and reduces soil organic matter.
Restoration pathway A
State 3 to 2Brush management such as mowing, coupled with seeding of basin wildrye. May be coupled with restoration of the water table where channel incision has occurred. Engineered structures are recommended. See USDA, NRCS National Engineering Handbook (2008).
Conservation practices
Brush Management Range Planting Restoration pathway B
State 3 to 4Brush management such as mowing, coupled with seeding of deep rooted non-native bunchgrasses.
Transition A
State 3 to 4Trigger: To Community Phase 5.1: Repeated, heavy, growing season grazing will decrease or eliminate deep rooted perennial bunchgrasses, increase cheatgrass and non-native forbs and favor shrub growth and establishment. Alteration in the hydrology of the site may also cause an increase in sagebrush; with gullying of associated channel the water table is dropped and may cause a decrease in perennial bunchgrasses. To Community Phase 5.2: Severe fire will remove sagebrush overstory and cheatgrass will be the dominate plant species. Rabbitbrush may be present. Failed brush management and seeding will also result in Community Phase 5.2. Slow variables: Long term decrease in deep-rooted perennial grass density and increase in shrub overstory. Channel incisement may be occurring. Threshold: Loss of deep-rooted perennial bunchgrasses changes nutrient cycling, nutrient redistribution, and reduces soil organic matter.
Additional community tables
Table 6. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Primary Perennial Grasses 2250–2700 basin wildrye LECI4 Leymus cinereus 2100–2400 – 2 Secondary Perennial Grasses/Grasslikes 60–240 sedge CAREX Carex 20–80 – thickspike wheatgrass ELLA3 Elymus lanceolatus 20–80 – beardless wildrye LETR5 Leymus triticoides 20–80 – mat muhly MURI Muhlenbergia richardsonis 20–80 – Forb3 Perennial 60–240 povertyweed IVAX Iva axillaris 20–80 – lupine LUPIN Lupinus 20–80 – ragwort SENEC Senecio 20–80 – Shrub/Vine4 Primary Shrubs 150–300 basin big sagebrush ARTRT Artemisia tridentata ssp. tridentata 150–300 – mat muhly MURI Muhlenbergia richardsonis 20–80 – 5 Secondary Shrubs 60–150 sedge CAREX Carex 20–80 – rubber rabbitbrush ERNA10 Ericameria nauseosa 20–80 – currant RIBES Ribes 20–80 – Table 7. Community 1.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 8. Community 1.3 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 9. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 10. Community 2.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 11. Community 2.3 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 12. Community 3.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 13. Community 3.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 14. Community 4.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 15. Community 4.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
Livestock Interpretations:
This site is suitable for livestock grazing. Grazing management considerations include timing, duration and intensity. Grazing management should be keyed to basin wildrye and other perennial grass production.
During settlement, many of the cattle in the Great Basin were wintered on extensive basin wildrye stands, however due to sensitivity to spring use many stands were decimated by early in the 20th century (Young et al. 1976). Less palatable species such as black greasewood, rabbitbrush and inland salt grass (Distichlis spicata) increased in dominance along with invasive non-native species such as Russian thistle (Salsola tragus), mustards, and cheatgrass (Roundy 1985). Spring defoliation of basin wildrye and/or consistent, heavy grazing during the growing season has been found to significantly reduce basin wildrye production and density (Krall et al. 1971). Thus, inadequate rest and recovery from defoliation can cause a decrease in basin wildrye and an increase in rabbitbrush, black greasewood, beardless wildrye, inland saltgrass, and non-native weeds (Young et al. 1976, Roundy 1985). Additionally, native basin wildrye seed viability has been found to be low and seedlings lack vigor (Young and Evans 1981). Roundy (1985) found that although basin wildrye is adapted to seasonally dry saline soils, high and frequent spring precipitation is necessary to establish it from seed. This suggests that establishment of native basin wildrye seedlings occurs only during years of unusually high precipitation. Therefore, reestablishment of a stand that has been decimated by grazing may be episodic.
If the site is dependent upon a water table supported by an associated stream channel, excessive livestock or wildlife trampling of the streamside vegetation could lead to channel morphology changes and eventual headcutting, incision or other channel instability processes. Any lowering of the water table associated with channel degradation has potential negative impacts on the associated loamy bottom plant community.
Basin wildrye is valuable forage for livestock (Ganskopp et al. 2007) and wildlife, but is intolerant of heavy, repeated, or spring grazing (Krall et al. 1971). Basin wildrye is used often as a winter feed for livestock and wildlife; not only providing roughage above the snow but also cover in the early spring months (Majerus 1992). Overgrazing leads to an increase in big sagebrush and a decline in understory plants like basin wildrye and Nevada bluegrass. The early growth and abundant production of basin wildrye make it a valuable source of forage for livestock. It is important forage for cattle and is readily grazed by cattle and horses in early spring and fall. Though coarse-textured during the winter, basin wildrye may be utilized more frequently by livestock and wildlife when snow has covered low shrubs and other grasses.
Reduced bunchgrass vigor or density provides an opportunity for creeping wildrye or mat muhly expansion and/or cheatgrass and other invasive species to occupy interspaces. Creeping wildrye, so named due to its rhizomatous rooting characteristic, is tolerant of grazing and increases under grazing pressure (USDA 1937).
Bluegrass is a widespread forage grass. It is one of the earliest grasses in the spring and is sought by domestic livestock and several wildlife species. Nevada bluegrass is a palatable species, but its production is closely tied to weather conditions. It produces little forage in drought years, making it a less dependable food source than other perennial bunchgrasses.
The sagebrush/rabbitbrush component will expand with a lowering of the seasonal water table. The root length of mature sagebrush was measured to a depth of 2 meters in alluvial soils in Utah (Richards and Caldwell 1987). Basin big sagebrush may serve as emergency food during severe winter weather, but it is not usually sought out by livestock.
Stocking rates vary over time depending upon season of use, climate variations, site, and previous and current management goals. A safe starting stocking rate is an estimated stocking rate that is fine-tuned by the client by adaptive management through the year and from year to year.
Wildlife Interpretations:
This site provides valuable habitat for several species of wildlife. Wild ungulates use aasin big sagebrush for cover and feed. Mule deer, pronghorn and elk will browse basin big sagebrush from autumn through early spring (Wambolt et al. 1994). Early and midseral basin big sagebrush provide forage and protection from predators for mule deer (Nevada Wildlife Action Plan 2012). Mule deer preference for the shrub varies seasonally. Basin big sagebrush was used more by mule deer populations in Oregon and Utah in winter than by the same populations in fall. (Sheehy and Winward 1981, Welch et al. 1981) This could be because basin big sagebrush is consumed as a last resort plant and browsed when plants considered more palatable were no longer available (Welch et al. 1981). Elk and pronghorn antelope will browse basin big sagebrush in areas where mountain and Wyoming sagebrush are unavailable (Beale and Smith 1970, Wambolt 1996). A study by Brown (1977) determined that desert bighorn sheep preferred big sagebrush over other shrub types; however, the variety was not noted.
Basin big sagebrush communities also serve as cover and food for smaller desert wildlife such as lagomorphs and rodents. Pygmy rabbits rely on tall basin big sagebrush in deep soil for shelter and food throughout the year (Green and Flinders 1980, White et al. 1991, Nevada Wildlife Action Plan 2012). A study by Larrison and Johnson (1973) captured deer mice in big sagebrush communities more than any other plant community, suggesting the mice prefer these plant communities for cover over other plant communities. No specific variety of big sagebrush was mentioned in the study.
Basin big sagebrush serves as valuable habitat for native birds. Studies have suggested that sage grouse use basin big sagebrush for cover and food where mountain and Wyoming big sagebrush are absent (Welch et al. 1991). Birds such as Brewer’s sparrows are considered dependent on sagebrush communities for cover and will nest in basin big sagebrush. Thus when basin big sagebrush communities are converted to agriculture fields, Brewer’s sparrow populations can decline due to loss of habitat (Knick et al. 2003). In fact, mature basin big sagebrush act as nesting structures, protection from predators and thermal cover for sage grouse, the loggerhead shrike, the sage and Brewer’s sparrow and sage thrasher (Nevada Wildlife Action Plan 2012).
Several reptiles and amphibians are distributed throughout the sagebrush steppe in the west in Nevada, where basin big sagebrush is known to grow (Bernard and Brown 1977). Studies have not determined if reptiles and amphibians prefer certain species of sage; however, researchers agree that maintaining habitat where basin big sagebrush and reptiles and amphibians occur is important. In fact, wildlife biologists have noticed declines in reptiles where sagebrush steppe habitat has been seeded with introduced grasses (West 1999 and ref. therein).
Furthermore, wildlife use a variety of associated understory plants and soils that occur in basin big sagebrush habitat. For example: sage grouse, Columbian sharp-tailed grouse, sagebrush vole, Merriam’s shrew and Preble’s shrew use the grasses that occur with basin big sagebrush for nesting, cover and forage. Basin big sagebrush sandy soil sites provide burrowing opportunities and protection from predators for burrowing owls, dark and pale kangaroo mice. Basin big sagebrush that occur on woodland and rock ecotnes provides nesting and foraging habitat for the ferruginous hawk (Nevada Wildlife Action Plan 2012).
Other animals such as the ferruginous hawk, bald eagle, prairie flacon, desert horned lizard, greater and pygmy short-horned lizard feed on animals that inhabit basin big sagebrush habitat types (Nevada Wildlife Action Plan 2012).
Hydrological functions
Runoff is very low to medium with poor to well drained soils. There are no rills, waterflow patterns erosional pedestals or terracettes. Gullies are rare to common depending on severity of associated stream channel entrenchment. Gullies and head cuts are healing or stable. Where this site is not associated with perennial or ephemeral channels gullies are none. Deep-rooted, perennial, bunchgrasses slow runoff and increase infiltration. Tall stature and relatively coarse foliage of basin wildrye and associated litter break raindrop impact and provide opportunity for snow catch and snow accumulation on site.
The typical seasonally high water table occurs at depths of 30 to 60 inches which allows for significant production of basin wildrye. In many areas, this site occurs where a channel has become entrenched lowering the water table required to support a meadow plant community. However, with further channel incisement and associated water table lowering site degradation occurs. Most Great Basin streams have been prone to incision for the past two thousand years, thus separating changes attributable to ongoing stream incision from those caused by human impact can be difficult (Chambers et al. 2004). The most direct evidence that anthropogenic disturbance has attributed to stream incision in the central Great Basin is derived from research on the effects of roads on riparian areas (Forman and Deblinger 2000; Trombulak and Frissel 2000). Assigning cause and effect to more diffuse disturbances such as livestock grazing is more difficult. In general, overuse of the riparian area by livestock can negatively affect stream bank and channel stability, and localized changes in stream morphology have been associated with heavy livestock use in the western United States (see reviews in Trimble and Mendle 1995; Belsky et al. 1999). However, data that clearly demonstrate the relationship between regional stream incision and overuse by livestock have not been collected for the Great Basin (Chambers et al. 2004). The impact of feral horse use on riparian systems is also in need of documentation. In regards to restoration and management it is important to recognize that particular streams have a greater sensitivity to both natural and management disturbances. For further guidance see Chambers et al. (2004), Rosgen (2006), or USDA, NRCS Stream Visual Assessment Protocol (1998).
Recreational uses
Aesthetic value is derived from the diverse floral and faunal composition and the colorful flowering of wild flowers during the spring and early summer. This site offers rewarding opportunities to photographers and for nature study.
Other products
Some Native American peoples used the bark of big sagebrush to make rope and baskets. Basin wildrye was used as bedding for various Native American ceremonies, providing a cool place for dancers to stand.
Other information
Basin big sagebrush shows high potential for range restoration and soil stabilization. Basin big sagebrush grows rapidly and spreads readily from seed. Basin wildrye is useful in mine reclamation, fire rehabilitation and stabilizing disturbed areas. Its usefulness in range seeding, however, may be limited by initially weak stand establishment.
Supporting information
Type locality
Location 1: White Pine County, NV Township/Range/Section T16 N R63 E S18 Latitude 39° 15′ 5″ Longitude 114° 55′ 35″ General legal description Approximately 3 miles west of Ely on the south side of US-HWY 50. Along margin of Gleason Creek, Robinson Canyon area near Lane City, White Pine County, Nevada. This site also occurs in Elko, Eureka, Lander, and Churchill counties, Nevada. Other references
Abbott, M. L., L. Fraley Jr., and T. D. Reynolds. 1991. Root profiles of selected cold desert shrubs and grasses in disturbed and undisturbed soils. Environmental and Experimental Botany 31(2): 165- 178.
Belsky, A.J., A. Matzke, and S. Uselman. 1999. Survey of livestock influences on stream and riparian ecosytems in the western United States. J. of Soil an Water Conservation 54:419-431.
Bunting, S. C., B. M. Kilgore, and C. L. Bushey. 1987. Guidelines for prescribed burning sagebrush-grass rangelands in the northern Great Basin. US Department of Agriculture, Forest Service, Intermountain Research Station Ogden, UT, USA.
Caudle, D., J. DiBenedetto, M. Karl, H. Sanchez, and C. Talbot. 2013. Interagency ecological site handbook for rangelands. Available at: http://jornada.nmsu.edu/sites/jornada.nmsu.edu/files/InteragencyEcolSiteHandbook.pdf. Accessed 4 October 2013.
Chambers, J.C., J.R. Miller, D. Germanoski, and D.A. Weixelman. 2004. Process-based approaches for managing and restoring riparian ecosystems. In: Great Basin Riparian Ecoystems, Island Press, Washington, DC. Chp. 9. pp 261-292.
Chambers, J.C., B.A. Roundy, R.R. Blank, S.E. Meyer, and A. Whittaker. 2007. What makes Great Basin sagebrush ecosystems invasible by Bromus tectorum? Ecological Monographs 77: 117-145.
Chambers, J. C., B. A. Bradley, C. S. Brown, C. D’Antonio, M. J. Germino, J. B. Grace, S. P. Hardegree, R. F. Miller, and D. A. Pyke. 2013. Resilience to stress and disturbance, and resistance to Bromus tectorum L. invasion in cold desert shrublands of western North America. Ecosystems:1-16.
Comstock, J.P. and J.R. Ehleringer. 1992. Plant adaptation in the Great Basin and Colorado Plateau. The Great Basin Naturalist 52: 195-215.
Daubenmire, R. 1970. Steppe vegetation of Washington.131 pp.
Daubenmire, R. 1975. Plant succession on abandoned fields, and fire influences in a steppe area in southeastern Washington. Northwest Science 49:36-48.
Dobkin, D. S. and J. D. Sauder. 2004. Shrubsteppe landscapes in jeopardy: distributions, abundances, and the uncertain future of birds and small mammals in the Intermountain West. High Desert Ecological Research Institute.
Fire Effects Information System (Online; http://www.fs.fed.us/database/feis/plants/index.html).
Ganskopp, D., L. Aguilera, and M. Vavra. 2007. Livestock forage conditioning among six northern Great Basin grasses. Rangeland Ecology & Management 60:71-78.
Goodrich, S., E. D. McArthur, and A. H. Winward. 1985. A new combination and a new variety in Artemisia tridentata. The Great Basin Naturalist 45:99-104.
Houghton, J.G., C.M. Sakamoto, and R.O. Gifford. 1975. Nevada’s Weather and Climate, Special Publication 2. Nevada Bureau of Mines and Geology, Mackay School of Mines, University of Nevada, Reno, NV.
Humphrey, L. D. 1984. Patterns and mechanisms of plant succession after fire on Artemisia-grass sites in southeastern Idaho. Vegetatio 57:91-101.
Johanson, J. K. 2011. An evaluation of state-and-transition model development for ecological sites in northern Utah. All graduate theses and dissertations. Paper 920. http://digitalcommons.usu.edu/etd/920
Johnson, J. R. and G. F. Payne. 1968. Sagebrush reinvasion as affected by some environmental influences. Journal of Range Management 21:209-213.
Krall, J. L., J. R. Stroh, C. S. Cooper, and S. R. Chapman. 1971. Effect of Time and Extent of Harvesting Basin Wildrye. Journal of Range Management 24:414-418.
Lossing, S. 2012. Singleleaf pinyon and Utah juniper canopy interception and understory characteristics in central Nevada. Unpublished M.S. Thesis. Univ. of Idaho. pp.65
Majerus, M. E. 1992. High-stature grasses for winter grazing. Journal of soil and water conservation 47:224-225.
McKell, C. M. and W. W. Chilcote. 1957. Response of Rabbitbrush Following Removal of Competing Vegetation. Journal of Range Management Archives 10:228-229.
Miller, R. F. C., Jeanne C.; Pyke, David A.; Pierson, Fred B.; Williams, C. Jason 2013. A review of fire effects on vegetation and soils in the Great Basin Region: response and ecological site characteristics. USDA, United State Forest Service RMRS-GTR-308.
National Oceanic and Atmospheric Administration. 2004. The North American Monsoon. Reports to the Nation. National Weather Service, Climate Prediction Center. Available online: http://www.weather.gov/.
Richards, J.H. and M.M. Caldwell. 1987. Hydraulic lift: substantial nocturnal water transport between layers by Artemisia tridentata roots. Oecologia 73: 486-489.
Robberecht, R. and G. Defossé. 1995. The relative sensitivity of two bunchgrass species to fire. International Journal of Wildland Fire 5:127-134.
Rosgen D. 2006. Watershed Assessment of River Stability and Sediment Supply. Wildland Hydrology. Fort Collins, CO.
Sapsis, D. B. and J. B. Kauffman. 1991. Fuel consumption and fire behavior associated with prescribed fires in sagebrush ecosystems. Northwest Science 65:173-179.
Shumar, M. L. and J. E. Anderson. 1986. Water relations of two subspecies of big sagebrush on sand dunes in southeastern Idaho. Northwest Science 60:179-185.
Snyder, K.A., T.K. Stringham, J. Huntington, R. Carroll, A.C. Dittrich and M.Weltz. 2013. Porter Canyon Experimental Watershed: Quantifying the Effects of Pinyon and Juniper Control on Ecosystem Processes. Poster presented at Great Basin Landscape Coalition Conference, Reno NV.
Stringham, T.K., P. Novak-Echenique, P. Blackburn, C. Coombs, D. Snyder and A. Wartgow. 2015. Final Report for USDA Ecological Site Description State-and-Transition Models, Major Land Resource Area 28A and 28B Nevada. University of Nevada Reno, Nevada Agricultural Experiment Station Research Report 2015-01. p. 1524.
Tisdale, E. W. and M. Hironaka. 1981. The sagebrush-grass region: A review of the ecological literature. University of Idaho, Forest, Wildlife and Range Experiment Station.
Trimble, S.W. and A.C. Mendel. 1995. The cow as a geomorphic agent: A critical review. Geomorphology 13:233-253.
USDA NRCS Plants Database (Online; http://plants.usda.gov/index.html).
USDA-Natural Resources Conservation Service. 2008. National Engineering Handbook. Washington D.C.
USDA-Natural Resources Conservation Service. 1998. Stream Visual Assessment Protocol. Technical Note 99-1. National Water and Climate Center. Portland, OR. 36pp.
USDA, Forest Service. 1937. Range Plant Handbook. Dover Publicatons, Inc., New York, NY. p. 816
Wright, H. A. 1971. Why Squirreltail Is More Tolerant to Burning than Needle-and-Thread. Journal of Range Management 24:277-284.
Young, J.A.; Evans, R.A. 1974. Populations dynamics of green rabbitbrush in disturbed big sagebrush communities. Journal of Range Management 27:127-132.
Young, R. P. 1983. Fire as a vegetation management tool in rangelands of the intermountain region. Pages 18-31 in Managing intermountain rangelands - improvement of range and wildlife habitats. USDA, Forest Service.
Zschaechner, G. A. 1985. Studying rangeland fire effects: a case study in Nevada. Pages 66-84 in Rangeland fire effects, a symposium. Bureau of Land Management, Boise, Idaho.
Fire Effects Information System (Online; http://www.fs.fed.us/database/feis/plants/).
Houghton, J.G., C.M. Sakamoto, and R.O. Gifford. 1975. Nevada’s Weather and Climate, Special Publication 2. Nevada Bureau of Mines and Geology, Mackay School of Mines, University of Nevada, Reno, NV.
National Oceanic and Atmospheric Administration. 2004. The North American Monsoon. Reports to the Nation. National Weather Service, Climate Prediction Center. Available online: http://www.weather.gov/
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Contributors
CP/HA
T. Stringham/P.Novak-EcheniqueRangeland 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) GK BRACKLEY/P.NOVAK-ECHENIQUE Contact for lead author State Rangeland Management Specialist Date 06/20/2006 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
No rills are present. This site is nearly level and rills typically do not form. -
Presence of water flow patterns:
Water flow patterns are few and will typically occur after the site has been flooded during spring runoff or summer convection storms. Flow patterns are meandering and may be long (up to 20 ft) but are less than 6 inches wide and are widely spaced (5-10 ft). -
Number and height of erosional pedestals or terracettes:
Pedestals are few and typically occur in flow paths. Terracettes are none to rare and would be small and stable. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare Ground ± 10-20%. -
Number of gullies and erosion associated with gullies:
Gullies may be present but are rare. They would occur on the lowest part of the site where flows concentrate. There may be active erosion on the side walls, but the bottoms would be stabilized with perennial vegetation. -
Extent of wind scoured, blowouts and/or depositional areas:
None -
Amount of litter movement (describe size and distance expected to travel):
Fine litter (foliage of grasses and annual & perennial forbs) only expected to move during periods of flooding by adjacent streams. Persistent litter (large woody material) will remain in place except during large flooding events. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil stability values will range from 5 to 6 under plant canopies and 4 to 5 in the interspaces. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Soil surface structure is weak thin platy or granular. Soil surface colors are dark browns or grayish browns and the soils have thick mollic epipedons. Surface textures are loams or silt loams. Organic matter can range from 2 to 3 percent for much of the upper 20 inches. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Deep-rooted, perennial, bunchgrasses slow runoff and increase infiltration. Tall stature and relatively coarse foliage of basin wildrye and associated litter break raindrop impact and provide opportunity for snow catch and snow accumulation on site. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None - Massive subsurface structure should not be interpreted as compaction. -
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:
Reference State: Tall-statured, deep-rooted, cool season, perennial bunchgrassesSub-dominant:
deep-rooted, cool season, perennial forbs = tall shrubs > rhizomatous, cool season, perennial grasses and shallow-rooted grass-like plants = fibrous, shallow-rooted, cool season, annual and perennial forbsOther:
Additional:
With an extended fire return interval or water table drawdown, the shrub component will increase at the expense of the herbaceous component. -
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Dead branches within individual shrubs common; standing dead shrub canopy material may be as much as 25% of total woody canopy. -
Average percent litter cover (%) and depth ( in):
Between plant interspaces (25-35%) and litter depth is ± 0.5 to 1 inch. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
For normal or average growing season (through June) ± 4000 lbs/ac; Winter moisture significantly affects total production. Favorable years ± 6000 lbs/ac and unfavorable years ± 2000 lbs/ac. -
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:
Potential invaders include annual mustards, thistles, whitetop, broadleaved pepperweed, cheatgrass, Russian thistle, and salt cedar. -
Perennial plant reproductive capability:
All functional groups should reproduce in most years. Reduced growth and reproduction would occur in drought years.
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