Natural Resources
Conservation Service
-
Search
Major Land Resource Area or ecological site by name and/or ID.
PreviousSectionsNextGeneral information
Draft. A draft ecological site description is either incomplete or has not undergone quality control and quality assurance review.
Classification relationships
Holland, R.F. 1986. Preliminary descriptions of the terrestrial natural communities of California. Unpublished report. State of California, The Resources Agency, Department of Fish and Game, Natural Heritage Division, Sacramento, CA. (Updated September 2003). Element Code: Big Sagebrush-Antelope Bitterbrush 35.110.07
Sawyer, J.O. and T. Keeler-Wolf. 1995. A Manual of California Vegetation. California Native Plant Society, Sacramento, CA. Big Sagebrush Series.
Associated sites
F021XE230CA Pinus ponderosa/Symphoricarpos rotundifolius/Achnatherum
F021XE238CA Populus balsamifera ssp. trichocarpa/Salix lucida ssp. lasiandra/Elymus trachycaulus ssp. trachycaulus
R021XE204CA Eroded Slope 16-30 P.Z.
R021XE210CA Mahogany Savanna
Similar sites
R021XE204CA Eroded Slope 16-30 P.Z.
Shallow soils, less productive site.
R021XE224CA South Slope 30+ P.Z.
More productive site.
R021XE222CA Loamy Slope 30+ P.Z.
More productive site. BRMA4 dominant grass. PUTR2 minor component.
R021XE201CA Ashy Slope 16-30 P.Z.
More productive site. FEID dominant grass.
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Artemisia tridentata ssp. vaseyana
(2) Purshia tridentataHerbaceous (1) Pseudoroegneria spicata ssp. spicata
(2) AchnatherumPhysiographic features
This site occurs on south-facing sideslopes of mountains. Slopes range from 15 to 50 percent. Elevations range from 5000 to 6400 feet.
Table 2. Representative physiographic features
Landforms (1) Mountain slope
Elevation 5000 – 6400 ft Slope 15 – 50 % Aspect S Climatic features
The climate of this site is subhumid, characterized by warm, dry summers and cold, moist winters. The area's precipitation comes mostly from winter Pacific cyclonic storms, with a very slight summer monsoonal season that is erratic but can be locally significant. Most storms have strong winds from the southwest or west, which blow substanial amounts of snow off south and west facing slopes (particularly steep slopes or slopes with short vegetation), and increase snow accumulations on adjacent north and/or east facing slopes, and/or in nearby concave depressions. Average annual precipitation ranges from 16 to 30 inches with most occurring during the winter months. Approximately half the precipitation falls as snow; half as rain. The mean annual air temperature is 41 to 45 degrees F. The average growing season is about 60 to 80 days.
Table 3 Representative climatic features
Frost-free period (average) 80 days Freeze-free period (average) 0 days Precipitation total (average) 30 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
">Influencing water features
There are no influencing water features associated with this site.
Soil features
The soils in the site are shallow, well drained soils that formed in volcanic ash and colluvium over residuum derived from andesite or tuff. These soils are usually moist in winter, spring and early summer, dry later in the summer and fall. These soils have high amounts of vitric volcanic ash and glass throughout the soil profile which enhances the water holding capacity of these soils. A mollic epipedon occurs from the surface to 15 inches. An argillic horizon occurs from 3 to 15 inches. These soils are usually moist in winter, spring, and early summer and dry in late summer and fall. They have a xeric moisture regime and a frigid temperature regime. Soil series associated with this site include Crazybird.
Table 4. Representative soil features
Parent material (1) Volcanic ash – andesite
Surface texture (1) Very gravelly sandy loam
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderate Soil depth 14 – 20 in Surface fragment cover <=3" 30 – 35 % Surface fragment cover >3" 0 – 11 % Available water capacity
(0-40in)2.3 – 2.4 in Calcium carbonate equivalent
(0-40in)Not specified Electrical conductivity
(0-40in)Not specified Sodium adsorption ratio
(0-40in)Not specified Soil reaction (1:1 water)
(0-40in)6.1 – 7.3 Subsurface fragment volume <=3"
(Depth not specified)5 – 40 % Subsurface fragment volume >3"
(Depth not specified)5 – 20 % Ecological dynamics
Fire effects:
Prior to settlement in the mid to late 1800's, the primary disturbance in the sagebrush steppe was fire. Presettlement fire return intervals in mountain big sagebrush communities varied from 15 to 25 years. At this interval, the bunchgrass dominated community will be maintained. Following a fire, mountain big sagebrush will often reestablish within 10 to 15 years. Within 15 to 25 years, the brush community may return to preburn density and cover. When sagebrush canopy cover reaches about 15%, the perennial grasses and forbs start to decline.
Fire plays a major role in recycling organic matter in these communities. Without fire, nutrients are tied up in dead woody vegetation. Fire return intervals of 25 to 50 years will maintain a shrub-dominated site. Western juniper and ponderosa pine commonly increase on this site when fire return intervals exceed 50 years.
Perennial grasses generally produce small to moderate amounts of seed per plant during wet years, and little or no seed during dry years. Most of the seed does not survive for more than one year, thus seedbanks are small or absent. The initial response from grasses is largely from existing plants that survived the fire. Existing plants provide seed, which if the amount and timing of precipitation is adequate, can result in many new grass plants. Perennial grasses increase less rapidly than forbs, but quicker than sagebrush and most other shrubs than reestablish from seed.
Mountain big sagebrush communities are considered low risk for cheatgrass displacement due to lower winter temperatures and more moisture availability for perennial grasses to reestablish after fire. Although, fire on this site in fair to poor condition can result in cheatgrass-Douglas' rabbitbrush dominant communities.
Fire Effects:
First order effects are the immediate actions of fire and include plant mortality, consumption of organic material, creation of smoke and changes to the physical-chemical environment. Second order effects include the following:
1. Change in microclimate
2. Increase in range of soil temperatures
3. Change in soil nutrients and microbial activity
4. Regeneration of vegetation
5. Succession and new vegetation patterns
6. Change in plant growth rates and competitive interactions
7. Altered wildlife habitat and activity of invertebrates and vertebrates
8. Changed water storage capacity and pattern of runoff.
Fire Effects:
Mountain big sagebrush is highly susceptible to injury from fire. Plants are readily killed in all seasons, even light severity fires. Mountain big sagebrush plants top-killed by fire will not resprout.
Season of burning and environmental conditions impact antelope bitterbrush ability to survive fire and sprout. It is considered a weak sprouter and is often killed by summer or fall fire. Antelope bitterbrush in some areas may sprout after light-severity spring fire. High fuel consumptions increase antelope bitterbrush mortality and therefore favors seedling establishment.
Thurber needlegrass is classified as moderately resistant, but depending on season of burn, phenology, and fire severity, this perennial bunchgrass is moderately to severely damaged by fire. Burning has been found to decrease the vegetation and reproductive vigor. Early season burning is more damaging to this needlegrass than late season burning.
Burning bluebunch wheatgrass may remove most of the aboveground biomass but does not usually result in plant mortality. Bluebunch wheatgrass is generally favored by burning. Burning stimulates flowering and seed production. However, season of burning affects mortality.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 textEcosystem states
State 1 submodel, plant communities
State 1
Reference StateCommunity 1.1
Reference Plant Community
Figure 3. South Slope
The reference plant community is characterized as a dense stand of shrubs, perennial grasses and forbs. The plant community is dominated by bluebunch wheatgrass, needlegrasses, mountain big sagebrush and antelope bitterbrush. Potential vegetative composition is about 50% grasses, 20% forbs and 30% shrubs. Approximate canopy cover is 35 to 40 percent. Basal cover is approximately 5 to 10 percent. Litter cover is approximately 25 to 30 percent.
Figure 4. 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 300 400 600 Shrub/Vine 180 240 360 Forb 120 160 240 Total 600 800 1200 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 246–504 bluebunch wheatgrass PSSPS Pseudoroegneria spicata ssp. spicata 160–240 – bluegrass POA Poa 40–80 – mountain brome BRMA4 Bromus marginatus 16–64 – Lemmon's needlegrass ACLE8 Achnatherum lemmonii 10–40 – Columbia needlegrass ACNE9 Achnatherum nelsonii 10–40 – Thurber's needlegrass ACTH7 Achnatherum thurberianum 10–40 – 2 Secondary Perennial Grasses/Grasslikes 16–32 sedge CAREX Carex 4–8 – squirreltail ELEL5 Elymus elymoides 4–8 – slender wheatgrass ELTRT Elymus trachycaulus ssp. trachycaulus 4–8 – basin wildrye LECI4 Leymus cinereus 4–8 – Forb3 Perennial Forbs 52–104 slender wheatgrass ELTRT Elymus trachycaulus ssp. trachycaulus 10–25 – common yarrow ACMI2 Achillea millefolium 4–8 – pale agoseris AGGL Agoseris glauca 4–8 – woollypod milkvetch ASPU9 Astragalus purshii 4–8 – sagebrush mariposa lily CAMAM9 Calochortus macrocarpus var. macrocarpus 4–8 – Indian paintbrush CASTI2 Castilleja 4–8 – tapertip hawksbeard CRAC2 Crepis acuminata 4–8 – Lewis flax LILE3 Linum lewisii 4–8 – desertparsley LOMAT Lomatium 4–8 – lupine LUPIN Lupinus 4–8 – beardtongue PENST Penstemon 4–8 – cold-desert phlox PHST11 Phlox stansburyi 4–8 – woolly mule-ears WYMO Wyethia mollis 4–8 – foothill deathcamas ZIPA2 Zigadenus paniculatus 4–8 – 4 Annual Forbs 8–16 grand collomia COGR4 Collomia grandiflora 4–8 – phacelia PHACE Phacelia 4–8 – sedge CAREX Carex 4–8 – Shrub/Vine5 Primary Shrubs 120–200 mountain big sagebrush ARTRV Artemisia tridentata ssp. vaseyana 120–200 – antelope bitterbrush PUTR2 Purshia tridentata 40–120 – 6 Secondary Shrubs 32–96 Utah serviceberry AMUT Amelanchier utahensis 8–24 – American black elderberry SANIC4 Sambucus nigra ssp. canadensis 8–24 – roundleaf snowberry SYRO Symphoricarpos rotundifolius 8–24 – Interpretations
Animal community
Livestock Interpretations:
This site is suited to cattle and sheep use during the spring, early summer and fall. Due to its southerly exposure, this site loses its snow cover earlier in the spring and plant growth is initiated before that of most adjacent sites. Thus, livestock may concentrate on this site during early spring grazing periods. Grazing should be keyed to perennial grass and palatable shrub production. Big sagebrush is eaten by domestic sheep and cattle, but has long been considered to be of low palatability to domestic livestock, a competitor with more desirable species, and a physical impediment to grazing. Antelope bitterbrush is important browse for livestock. Where management results in abusive grazing use by livestock, bluebunch wheatgrass and Thurbers needlegrass decrease as sagebrush density increases.
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:
Big sagebrush is highly preferred and nutritious winter forage for mule deer. Sage grouse are also highly dependent on big sagebrush for both food and cover. Mule deer and elk utilize antelope bitterbrush extensively. Antelope bitterbrush is palatable to all types of wildlife. It is critical browse for mule deer in the winter.Hydrological functions
Runoff is medium to high. Perennial herbaceous plants (especially deep-rooted bunchgrasses) slow runoff and increase infiltration. Rills and gullies are none to rare. Water flow patterns are none to rare but may be expected on steeper slopes in areas recently subjected to summer convection storms or rapid snowmelt.
Recreational uses
This site is suitable for hiking, birdwatching and hunting.
Other products
Native peoples used big sagebrush leaves and branches for medicinal teas, and the leaves as a fumigant. Bark was woven into mats, bags and clothing.
Other information
Antelope bitterbrush is extensively used in land reclamation. Antelope bitterbrush enhances succession by retaining soil and depositing organic material, and, in some habitats and with some ecotypes, by fixing nitrogen. Mountain big sagebrush has potential for range restoration and soil stabilization.
Supporting information
Type locality
Location 1: Modoc County, CA Township/Range/Section T46N R15E S25 Latitude 41° 49′ 29″ Longitude 120° 11′ 51″ General legal description On the Modoc National Forest in the Warner Mountains, Modoc County, CA. Other references
Brown, J. K. 2000. Ecological principles, shifting fire regimes and management considerations. In: Wildland fire in ecosystems: effects of fire on flora. Gen. Tech. Rep. RMRS-GTR-42-vol. 2. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 257 p.
Fire Effects Information System [Online]. http://www.fs.fed.us/feis
Miles, S.R. and C.B. Goudey. 1997. Ecological Subregions of California Section and Subsection Descriptions. United States Department of Agriculture Forest Service, Pacific Southwest Region R5-EM-TP-005. Subsection M261Gf-Warner Mountains.
Modoc Elk Working Group. 2000. The Greater Modoc Area - A Strategic Plan for Elk Management. Modoc County, CA
Wisdom, M.J., M.M. Rowland, and L.H. Suring (eds). 2005. Habitat threats in the sagebrush ecosystem: methods of regional assessment and applications in the Great Basin. Alliance Communications Group, Lawrence, KS.
Contributors
P.NOVAK-ECHENIQUE
Rangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
Author(s)/participant(s) Contact for lead author Date Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
-
Number and extent of rills:
-
Presence of water flow patterns:
-
Number and height of erosional pedestals or terracettes:
-
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
-
Number of gullies and erosion associated with gullies:
-
Extent of wind scoured, blowouts and/or depositional areas:
-
Amount of litter movement (describe size and distance expected to travel):
-
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
-
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
-
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
-
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
-
Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):
Dominant:
Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
-
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
-
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
-
Perennial plant reproductive capability:
Print Options
Sections
Font
AAAAOther
PrintThe Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.
Accessibility statement
