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
R022AY022NV LOAMY SLOPE 14-16 P.Z.
R022AY023NV LOAMY SLOPE 16-20 P.Z.
R022AY024NV MAHOGANY SAVANNA
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Cercocarpus ledifolius
(2) Artemisia tridentata ssp. vaseyanaHerbaceous (1) Achnatherum
Physiographic features
This site typically occurs in landscape positions favorable for accumulation of snow on upper mountain sideslopes. Slopes range from 4 to over 75 percent, but slope gradients of 8 to 30 percent are common. Elevations are 6500 to over 11,000 feet.
Table 2. Representative physiographic features
Landforms (1) Mountain slope
(2) Mountain
Elevation 6500 – 11000 ft Slope 4 – 75 % Ponding depth 0 in Water table depth 0 in Aspect Aspect is not a significant factor Climatic features
Average annual precipitation is 14 to over 18 inches. Mean annual air temperature is 34 to 45 degrees F. The average growing season is about 30 to 70 days.
Table 3 Representative climatic features
Frost-free period (average) 70 days Freeze-free period (average) 0 days Precipitation total (average) 20 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 this site are shallow to deep and well drained. These soils are modified by high volumes of rock fragments throughout the profile. The available water capacity is very low to low and will vary with soil texture and depth. The soil series associated with this site are Bakscratch, Buggin, Celeridge, Granhogany, Monibasin and Thiefridge. The soil families associated with this site are Bakscratch inclusion, Buggin inclusion, Celeridge inclusion, Granhogany inclusion, Monibasin inclusion, Pachic Argicryolls inclusion and Thiefridge inclusion.
Table 4. Representative soil features
Surface texture (1) Very gravelly coarse sandy loam
(2) Extremely bouldery loamy coarse sand
(3) Very cobbly fine sandy loam
Family particle size (1) Loamy
Drainage class Well drained to somewhat excessively drained Permeability class Moderately rapid to rapid Soil depth 15 – 60 in Surface fragment cover <=3" 15 – 74 % Surface fragment cover >3" 2 – 40 % Available water capacity
(0-40in)0.6 – 4.6 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)16 – 41 % Subsurface fragment volume >3"
(Depth not specified)2 – 30 % Ecological dynamics
As ecological condition declines, curlleaf mountainmahogany plants become decadent with little regeneration in the overstory. Mountain big sagebrush, snowberry, and rabbitbrush increase in the understory.
Fire Ecology:
The presettlement fire regime of curlleaf mountainmahogany communities probably varied with community type and structue. The fire return interval is highly variable, ranging from 13 to 1000 years. Curlleaf mountainmahogany may depend on fire to reduce conifer competition and produce favorable soil conditions for seedling establishment. Some curlleaf mountainmahogany stands occupy sites with very low fuel levels that rarely burn. Individual curlleaf mountainmahogany are severely damaged by fire. Because many dead branches persist in the crown and leaves are slightly resinous, curlleaf mountainmahogany is probably very flammable. Curlleaf mountainmahogany is a weak sprouter after a fire.
Mountain big sagebrush is highly susceptible to injury from fire. It is often top-killed by fire and will not resprout.
Little specific information is available on adaptations of Letterman's needlegrass to fire. It is morphologically similar to Columbia needlegrass, which is only slightly to moderately damaged by fire. Season of burn affects the plant's ability to survive a fire. Post fire regeneration is through seeding and tillering. Muttongrass is unharmed to slightly harmed by light-severity fall fires. Muttongrass appears to be harmed by and slow to recover from severe fire. Sandberg bluegrass is generally unharmed by fire. It produces little litter, and its small bunch size and sparse litter reduces the amount of heat transferred to perennating buds in the soil. Its rapid maturation in the spring also reduces fire damage, since it is dormant when most fires occur. Canby’s bluegrass is generally unharmed by fire. It produces little litter, and its small bunch size and sparse litter reduces the amount of heat transferred to perennating buds in 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 overstory of woody shrubs and trees and an understory of perennial grasses and forbs. The representative plant community is dominated by curlleaf mountainmahogany. Mountain snowberry is the principal understory shrub. Letterman and western needlegrasses are the most prevalent understory grasses. Potential vegetative composition is about 95% shrubs and tree-like shrubs and 5% herbaceous plants.
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 3400 4250 5100 Grass/Grasslike 400 500 600 Forb 200 250 300 Total 4000 5000 6000 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 280–850 Letterman's needlegrass ACLE9 Achnatherum lettermanii 70–250 – western needlegrass ACOCO Achnatherum occidentale ssp. occidentale 70–250 – muttongrass POFE Poa fendleriana 46–116 – Sandberg bluegrass POSE Poa secunda 46–116 – 2 Secondary Perennial Grasses/Grasslikes 140–350 Columbia needlegrass ACNEN2 Achnatherum nelsonii ssp. nelsonii 35–140 – pine needlegrass ACPI2 Achnatherum pinetorum 35–140 – Thurber's needlegrass ACTH7 Achnatherum thurberianum 35–140 – mountain brome BRMA4 Bromus marginatus 35–140 – basin wildrye LECI4 Leymus cinereus 35–140 – spike fescue LEKI2 Leucopoa kingii 35–140 – 4 Primary Shrubs 4900–6300 curl-leaf mountain mahogany CELE3 Cercocarpus ledifolius 4900–5950 – curl-leaf mountain mahogany CELE3 Cercocarpus ledifolius 4900–5950 – roundleaf snowberry SYRO Symphoricarpos rotundifolius 0–350 – mountain snowberry SYOR2 Symphoricarpos oreophilus 0–18 – currant RIBES Ribes 2–6 – 5 Secondary Shrubs 140–350 mountain big sagebrush ARTRV Artemisia tridentata ssp. vaseyana 35–210 – currant RIBES Ribes 35–210 – mountain big sagebrush ARTRV Artemisia tridentata ssp. vaseyana 2–7 – Forb3 Perennial Forbs 140–560 tapertip hawksbeard CRAC2 Crepis acuminata 35–140 – lupine LUPIN Lupinus 35–140 – Tree6 Trees 100–600 white fir ABCO Abies concolor 35–210 – lodgepole pine PICO Pinus contorta 35–210 – Interpretations
Animal community
Livestock Interpretations:
This site is marginally suited to livestock grazing, due to the low herbaceous forage production. Grazing management should be keyed to needlegrass production. Mountain 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. Letterman’s needlegrass begins growth early in the year and remains green throughout the relatively long growing season, thus, making it valuable forage for livestock. Muttongrass is excellent forage for domestic livestock especially in the early spring. Muttongrass begins growth in late winter and early spring, which makes it available before many other forage plants. Sandberg 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. Canby’s 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.
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:
Curlleaf mountainmahogany is good forage for all classes of browsing animals in both summer and winter; it is one of the few browse species that meets or exceeds the protein requirements for wintering big game animals. In mature stands, much of curlleaf mountainmahogany foliage is out of reach of browsing animals but provides excellent winter cover. Curlleaf mountainmahogany stands provide hiding and thermal cover for a variety of wildlife species. Mountain big sagebrush is highly preferred and nutritious winter forage for mule deer. Letterman's needlegrass provides valuable forage for many species of wildlife. It is consumed by mule deer. This species begins growth early in the year and like most needlegrasses it remains green throughout a relatively long growing season. This pattern of development enables animals to use Letterman's needlegrass when many other grasses are unavailable. It is grazed in early spring before fruits have developed as it becomes less palatable when mature. It is usually grazed in the fall only if the fruits are softened by rain. Letterman's needlegrass provides some cover for small birds and mammals. Deer and elk make heavy use of muttongrass, especially in early spring when other green forage is scarce. Depending upon availability of other nutritious forage, deer may use muttongrass in all seasons. Muttongrass cures well and is an important fall and winter deer food in some areas. Sandberg bluegrass is desirable for pronghorn antelope and mule deer in the spring and preferable in the spring, summer, and fall for elk and desirable as part of their winter range. Canby’s bluegrass is desirable for pronghorn antelope and mule deer in the spring and preferable in the spring, summer, and fall for elk and desirable as part of their winter range.
Hydrological functions
Runoff is very high and permeability is moderately rapid to rapid.
Other products
Curlleaf mountainmahogany wood burns slowly, it was the preferred charcoal wood used for smelting ores in the nineteenth century. It is also highly prized as a barbecue fuel. Because of its tolerance to heat and drought, curlleaf mountainmahogany can be used for water-efficient landscaping in arid environments.
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
Curlleaf mountainmahogany may be planted to help stabilize soil in disturbed areas such as roadcuts and mine spoils. Curlleaf mountainmahogany may be seeded to improve range, although shrub seedlings may exhibit low seedling vigor and slow initial growth rates. It is particularly recommended for southwestern exposures.
Mountain big sagebrush is easily propagated from seed under greenhouse, nursery, and common garden conditions and has been successfully seeded directly into field sites.
Letterman's needlegrass has been used successfully in revegetating mine spoils. This species also has good potential for erosion control.Supporting information
Type locality
Location 1: Alpine County, CA Latitude 38° 25′ 14″ Longitude 119° 30′ 28″ General legal description Toyaibe National Forest. Other references
Fire Effects Information System (Online; http://www.fs.fed.us/database/feis/plants/).
USDA-NRCS Plant 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
