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.
Associated sites
F022AY116NV PIJE/ARTRV/ACOCO
F022AY118NV ABMA-PICO/ARTRV/BRMA4
R022AY017NV SEMI-WET MEADOW
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Artemisia tridentata ssp. vaseyana
Herbaceous (1) Achnatherum occidentale
Physiographic features
This site occurs on intermountain valley fans. Slopes range from 2 to 30 percent, but slope gradients of 2 to 8 percent are most typical. Elevations are 7000 to 10000 feet.
Table 2. Representative physiographic features
Landforms (1) Moraine
(2) Stream terrace
(3) Fan
Flooding frequency None Ponding frequency None Elevation 7000 – 10000 ft Slope 2 – 30 % Ponding depth 0 in Water table depth 0 in Aspect Aspect is not a significant factor Climatic features
The climate on this site is subhumid-continental, characterized by cold, moist winters, and cool dry summers. The average annual precipitation is over 20 inches, mostly occuring as snow. The linear to convex slope shape associated with this site cause much of the precipitation to be removed from the site because of wind action, thus reducing the moisture available for plant growth. The mean annual air temperature ranges from 36 to 45 degrees F. The average frost free growing seasons is 30 to 70 days.
Table 3 Representative climatic features
Frost-free period (average) 70 days Freeze-free period (average) 0 days Precipitation total (average) 50 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 that support this ecological site are typically very shallow to very deep and are well drained. They formed in residuum and colluvium derived from volcanic or granitic rocks and from mixed glacial till. Surface layers are moderately coarse with greater than 35 percent rock fragments. Subsoil layers range from moderately coarse to moderately fine textured and are modified by over 35 percent rock fragments. The soil families that are associated with this site are Typic Haploxerepts inclusion and Ultic Haploxerolls inclusion.
Table 4. Representative soil features
Parent material (1) Residuum – granite
Surface texture (1) Very bouldery loamy coarse sand
(2) Extremely gravelly sandy loam
(3) Very bouldery sandy loam
Family particle size (1) Loamy
Drainage class Somewhat excessively drained to well drained Permeability class Rapid to moderately rapid Soil depth 36 – 60 in Surface fragment cover <=3" 17 – 40 % Surface fragment cover >3" 7 – 25 % Available water capacity
(0-40in)1.8 – 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)5.6 – 7.3 Subsurface fragment volume <=3"
(Depth not specified)35 – 60 % Subsurface fragment volume >3"
(Depth not specified)0 – 12 % Ecological dynamics
As ecological conditions 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:
Presettlement fire return intervals in mountain big sagebrush communities varied from 15 to 25 years. Plants are readily killed in all seasons, even light severity fires. Mountain big sagebrush is highly susceptible to injury from fire. It is often top-killed by fire and will not resprout.
Perennial needlegrasses tend to be among the least fire resistant bunchgrass due to the densely tufted stems. Western needlegrass is only slightly to moderately damaged by fire, because it has relatively few culms per clump which may help to minimize the amount of subsurface heat transfer and subsequent damage. Sedge is top-killed by fire, with rhizomes protected by insulating soil. The rhizomes of sedge species may be killed by high-severity fires that remove most of the soil organic layer. Reestablishment after fire occurs by seed establishment and/or rhizomatous spread. Mat muhly is top killed be fire. Fire does not harm mat muhly to any great extent because the rhizome buds are insulated by the soil.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 CommunityThe reference plant community is characterized by an open canopy of woody shrubs and perennial grasses. The representative plant community is dominanted by mountain big sagebrush and western needlegrass. Potential vegetative composition is about 70% grasses, 10% forbs, and 20% shrubs. Approxiamte ground cover (basal and crown) is 35 to 50 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)Grass/Grasslike 420 560 770 Shrub/Vine 120 160 220 Forb 60 80 110 Total 600 800 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/Grasslikes 448–600 western needlegrass ACOC3 Achnatherum occidentale 400–480 – sedge CAREX Carex 16–40 – mat muhly MURI Muhlenbergia richardsonis 16–40 – bluegrass POA Poa 16–40 – 2 Secondary Perennnial Grasses 16–80 squirreltail ELEL5 Elymus elymoides 4–24 – slender wheatgrass ELTR7 Elymus trachycaulus 4–24 – needle and thread HECO26 Hesperostipa comata 4–24 – spike fescue LEKI2 Leucopoa kingii 4–24 – Forb3 Perennial Forbs 40–120 sedge CAREX Carex 16–40 – buckwheat ERIOG Eriogonum 4–24 – phlox PHLOX Phlox 4–24 – cinquefoil POTEN Potentilla 4–24 – Shrub/Vine4 Primary Shrubs 120–160 mountain big sagebrush ARTRV Artemisia tridentata ssp. vaseyana 120–160 – 5 Secondary Shrubs 8–16 rabbitbrush CHRYS9 Chrysothamnus 8–16 – Tree6 Evergreen 8–32 lodgepole pine PICO Pinus contorta 8–32 – Interpretations
Animal community
Livestock Interpretations:
This site is suited to livestock grazing. Grazing management should be keyed to western needlegrass production. 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. Western needlegrass begins growth early in the year and remains green throughout the relatively long growing season, thus, making it valuable forage for livestock. Sedge provides good to fair forage for domestic grazing. Young mat muhly is readily eaten by livestock. Plants become less palatable as they mature. Mat muhly plants usually grow in scattered patches, so they are seldom sufficiently abundant to be of major importance to livestock. In the northern part of its range, mat muhly is rated as good to very good forage for cattle and horses and fairly good for domestic sheep.
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:
Mountain big sagebrush is highly preferred and nutritious winter forage for mule deer. Western needlegrass and mountain brome are important forage species for several wildlife species. Sedges have a high to moderate resource value for elk and a medium value for mule deer. Elk consume beaked sedge later in the growing season. The palatability of mat muhly for wildlife species has been rated as fair to poor.Hydrological functions
Runoff is low to very low and permeability is rapid to moderately rapid.
Other products
Native people used mountain 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.
Supporting information
Type locality
Location 1: Alpine County, CA Latitude 36° 46′ 48″ Longitude 119° 55′ 39″ General legal description Toiyabe National Forest. Other references
Fire Effects Information System (Online; http://www.fs.fed.us/database/feis/plants).
USDA-NRCS Plants Database (Online; http://plants.usda.gov/).Contributors
ALC/GKB
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
