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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): 022A–Sierra Nevada and Tehachapi Mountains
This ESD was developed using older policy requirements which have been improved with the intent of improving ESD products overall. Users should approach these materials with some caution as the content herein, while likely useful for some purposes, was developed within parameters now recognized as needing varying levels of improvement. As always, a site-specific investigation is highly recommended when site-specific management alternatives are to be developed and/or management decisions are to be made.
Each ESD is an interpretation of the ecological relationships between biotic and abiotic aspects of the landscape. Users of this document should be aware of the limitations of this tool to the extent that specific local conditions may not be entirely captured within the ESD. In particular, management decisions should be supported by site-specific inventories, assessments and planning processes based on the best available information including and extending beyond the ESD.
An ESD is not a permanent determination of ecological dynamics. Rather, each ESD is an evolving body of work intrinsically tied to the soil surveys and data associated with soil map unit components of correlated soil-ecological site relationships. As new information becomes available, updates may be made or may be underway at any given time. Minor updates may be made without announcement when such changes do not modify the ecological site concept, the soils correlated or the state-and-transition model.
Associated sites
R022AY011NV MOUNTAIN RIDGE 30+ P.Z.
R022AY021NV SOUTH SLOPE 30+ P.Z.
R022AY024NV MAHOGANY SAVANNA
R022AY025NV MAHOGANY THICKET
R022AY027NV MOUNTAIN BASIN
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Artemisia tridentata ssp. vaseyana
(2) Symphoricarpos oreophilusHerbaceous (1) Achnatherum occidentale
Physiographic features
This site occurs on mountain sideslopes on northerly aspects. Slopes range from 4 to 50 percent. Elevations are 7000 to 11,000 feet.
Table 2. Representative physiographic features
Landforms (1) Mountain slope
Elevation 7000 – 11000 ft Slope 4 – 50 % Aspect N, NE, NW Climatic features
The climate is subhumid-continental with cold, moist winters and cool, dry summers. Average annual precipitation is 16 inches to over 40 inches. Mean annual air temperature is 36 to 42 degrees F. The average growing season is about 30 to 70 days. Climate data used to support this section were derived from PRISM and is not specifically tied to any dominant climate station.
Table 3 Representative climatic features
Frost-free period (average) 70 days Freeze-free period (average) 0 days Precipitation total (average) 40 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 associated with this site are deep to very deep and well drained. They are formed in colluvium and residuum from granodiorite or andesite and tuff. Runoff is medium to high and permeability is moderately rapid to very slow. Available water holding capacity is very low to moderate. The soils have a mollic epipedon and an argillic horizon. The soils are moist during late fall, winter, and spring, and dry from July through early October.
The soil series associated with this site include: Delhew, Jackflat, and Sweetmount.
CA729 Toiyabe National Forest Area, California
234;Hawkinspeak-Thiefridge association;Sweetmount
531;Elaero association;Delhew
660;Delhew-Grandridge-Bakscratch association;Delhew
710;Bakscratch-Grandridge-McTom association;Delhew
740;Jackflat-Grandridge association;Jackflat
770;Sweetmount-Hawkinspeak-Hawkridge association;Sweetmount
780;Granhogany-Rock outcrop complex, 15 to 50 percent slopes;Delhew
790;Dab association;Sweetmount
800;Grandridge-Delhew association;Delhew;Jackflat
CA732 Inyo National Forest, Western Part, California
234ty;Hawkinspeak-Thiefridge association;Sweetmount
NV773 Douglas County Area, Nevada
660;Delhew-Grandridge-Bakscratch association;Delhew
800;Grandridge-Delhew association;Delhew;Jackflat
Table 4. Representative soil features
Surface texture (1) Very gravelly coarse sandy loam
(2) Very gravelly loamy coarse sand
(3) Very gravelly sandy loam
Family particle size (1) Loamy
Drainage class Somewhat poorly drained to well drained Permeability class Slow to rapid Soil depth 10 – 60 in Surface fragment cover <=3" 35 – 65 % Surface fragment cover >3" 4 – 14 % Available water capacity
(0-40in)2.5 – 6.2 in 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)32 – 41 % Subsurface fragment volume >3"
(Depth not specified)2 – 25 % Ecological dynamics
As ecological condition declines, big sagebrush, snowberry and other woody plants increase in prevalence as western needlegrass, and other perennial grasses and forbs decline in the understory.
Fire Ecology:
The fire return interval for mountain big sagebrush communities ranges from 15 to 40 years. Mountain big sagebrush is highly susceptible to injury from fire. Plants are readily killed in all seasons, even by light severity fires. Mountain big sagebrush plants are top-killed by fire and will not resprout. Regeneration of mountain big sagebrush is from on-site or off-site seed. Depending on circumstances of the environment and seed source, mountain big sagebrush seeds may sprout profusely the spring after burning, or very sparsely.
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 Plant CommunityCommunity 1.1
Reference Plant CommunityThe reference plant community is characterized by an open canopy of soft-woody shrubs and a dense understory of perennial grasses. The plant community is dominated by western needlegrass, and mountain big sagebrush. Potential vegetative composition is about 35% grasses, 5% forbs, and 60% shrubs. Approximate ground cover(basal and crown) is 40 to 60 percent.
Figure 3. 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)Shrub/Vine 420 540 660 Grass/Grasslike 245 315 385 Forb 35 45 55 Total 700 900 1100 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 225–315 western needlegrass ACOCO Achnatherum occidentale ssp. occidentale 225–315 – 2 Secondary Perennnial Grasses/Grasslikes 45–135 Letterman's needlegrass ACLE9 Achnatherum lettermanii 5–27 – Thurber's needlegrass ACTH7 Achnatherum thurberianum 5–27 – mountain brome BRMA4 Bromus marginatus 5–27 – sedge CAREX Carex 5–27 – big squirreltail ELMU3 Elymus multisetus 5–27 – needle and thread HECO26 Hesperostipa comata 5–27 – prairie Junegrass KOMA Koeleria macrantha 5–27 – basin wildrye LECI4 Leymus cinereus 5–27 – spike fescue LEKI2 Leucopoa kingii 5–27 – purple oniongrass MESP Melica spectabilis 5–27 – Sandberg bluegrass POSE Poa secunda 10–20 – Forb3 Perennial Forbs 18–72 tapertip hawksbeard CRAC2 Crepis acuminata 5–18 – buckwheat ERIOG Eriogonum 5–18 – lupine LUPIN Lupinus 5–18 – phlox PHLOX Phlox 5–18 – ragwort SENEC Senecio 5–18 – vetch VICIA Vicia 5–18 – Shrub/Vine4 Primary Shrubs 160–320 roundleaf snowberry SYRO Symphoricarpos rotundifolius 90–180 – mountain big sagebrush ARTRV Artemisia tridentata ssp. vaseyana 70–140 – 5 Secondary Shrubs 45–135 yellow rabbitbrush CHVI8 Chrysothamnus viscidiflorus 5–18 – antelope bitterbrush PUTR2 Purshia tridentata 5–18 – currant RIBES Ribes 5–18 – mountain snowberry SYOR2 Symphoricarpos oreophilus 5–18 – Interpretations
Animal community
Livestock Interpretations:
Mountain big sagebrush is eaten by domestic livestock but has long been considered to be of low palatability, and a competitor to more desirable species.
Wildlife Interpretations:
Mountain big sagebrush is highly preferred and nutritious winter forage for mule deer and elk.
Sage-grouse: Sagebrush-grassland communities provide critical sage-grouse breeding and nesting habitats. Meadows surrounded by sagebrush may be used as feeding and strutting grounds. Sagebrush is a crucial component of their diet year-round, and sage-grouse select sagebrush almost exclusively for cover. Sage-grouse prefer mountain big sagebrush and Wyoming big sagebrush communities to basin big sagebrush communities.
Other products
Native Americans 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
Mountain big sagebrush is easily propagated from seed under greenhouse, nursery, and common garden conditions and has been successfully seeded directly into field sites. Mountain big sagebrush has also been successfully planted in field sites using nursery-grown bareroot and containerized stock.
Supporting information
Type locality
Location 1: Mono County, CA Latitude 38° 16′ 20″ Longitude 119° 36′ 40″ General legal description Toiyabe National Forest Other references
Fire Effect Information System (Online; http://www.fs.fed.us/database/feis/plants/).
USDA-NRCS Plants Database (Online; http://plants.usda.gov/).
Contributors
A LM
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
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Number and extent of rills:
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Presence of water flow patterns:
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Number and height of erosional pedestals or terracettes:
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Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
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Number of gullies and erosion associated with gullies:
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Extent of wind scoured, blowouts and/or depositional areas:
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Amount of litter movement (describe size and distance expected to travel):
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Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
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Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
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Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
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Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
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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:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
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Average percent litter cover (%) and depth ( in):
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Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
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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:
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Perennial plant reproductive capability:
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