Natural Resources
Conservation Service
Ecological site R030XB060NV
GRANITIC NORTH SLOPE 5-7 P.Z.
Last updated: 3/11/2025
Accessed: 08/30/2026
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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.
Ecological site concept
This site occurs on hills and mountain sideslopes having a northerly aspect. Slopes range from 8 to 75 percent, but slope gradients of 15 to 50 percent are typical. Elevations are 3000 to about 4500 feet. The soils associated with this site are 30 to 40 inches and have formed in residuum or colluvium from granitic (gneiss or schist) or quartzite parent material.
Please refer to group concept R030XB076NV to view the provisional STM.Associated sites
R030XA061NV LOAMY 5-7 P.Z.
Similar sites
R030XB087NV GRANITIC SLOPE 5-7 P.Z.
CAAR10 and MESP2 codominant shrubs with AMDU2
R030XB062NV GRANITIC SLOPE 3-5 P.Z.
AMDU2-KRPA codominant shrubs; less productive site
R030XB008NV SHALLOW GRANITIC HILL 5-7 P.Z.
Less productive site
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Eriogonum fasciculatum var. polifolium
(2) EphedraHerbaceous (1) Pleuraphis rigida
Physiographic features
This site occurs on hills and mountain sideslopes having a northerly aspect. Slopes range from 8 to 75 percent, but slope gradients of 15 to 50 percent are typical. Elevations are 3000 to about 4500 feet.
Table 2. Representative physiographic features
Landforms (1) Mountain slope
(2) Hill
Elevation 3000 – 4500 ft Slope 15 – 50 % Aspect N Climatic features
The climate is hot and arid with warm, moist winters and hot, dry summers. Average annual precipitation is about 5 to 7 inches. Mean annual air temperature is 60 to 68 degrees F. The average growing season is about 180 to 290 days.
Table 3 Representative climatic features
Frost-free period (average) 290 days Freeze-free period (average) Precipitation total (average) 10 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 30 to 40 inches and have formed in residuum or colluvium from granitic (gneiss or schist) or quartzite parent material. Surface soils are typically medium to moderately coarse textured. Water intake rate is moderately slow and available water capacity is low. Runoff is very high and the soils are well drained. The soil series associated with this site include Highland.
Table 4. Representative soil features
Parent material (1) Residuum – gneiss
(2) Colluvium – schist
Surface texture (1) Extremely gravelly sandy loam
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderately slow Soil depth 30 – 40 in Surface fragment cover <=3" Not specified Surface fragment cover >3" Not specified Available water capacity
(0-40in)3.2 – 3.3 in Calcium carbonate equivalent
(0-40in)0 – 10 % Electrical conductivity
(0-40in)0 – 2 mmhos/cm Sodium adsorption ratio
(0-40in)0 – 5 Soil reaction (1:1 water)
(0-40in)7.9 – 8.4 Subsurface fragment volume <=3"
(Depth not specified)39 – 63 % Subsurface fragment volume >3"
(Depth not specified)0 – 20 % Ecological dynamics
Please refer to group concept R030XB076NV to view the provisional STM.
As ecological condition deteriorates, creosotebush and Mojave buckwheat increase as perennial grasses decrease. Species likely to invade this site are annual forbs and grasses such filaree and red brome. Concave to gently sloping straight slopes, have a greater proportion of big galleta than is typical for the site.
Fire Ecology:
The fire return interval for Mojave buckwheat communities occurs at approximate 28-year intervals. Damage to big galleta from fire varies. If big galleta is dry, damage may be severe. However, when plants are green, fire will tend to be less severe and damage may be minimal, with big galleta recovering quickly. Ephedra generally sprouts vigorously from the roots or woody root crown after fire and rapidly produces aboveground biomass from surviving meristematic tissue.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 dominated by Mojave buckwheat, ephedra, and big galleta. Bush muhly, desert needlegrass and range ratany are other important species associated with this site.
Potential vegetative composition is about 55% grasses, 5% forbs and 40% shrubs. Approximate ground cover (basal and crown) is 10 to 20 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 220 330 495 Shrub/Vine 160 240 360 Forb 20 30 45 Total 400 600 900 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 282–450 big galleta PLRI3 Pleuraphis rigida 240–300 – bush muhly MUPO2 Muhlenbergia porteri 30–90 – desert needlegrass ACSP12 Achnatherum speciosum 12–60 – 2 Secondary Perennial Grasses 1–30 Indian ricegrass ACHY Achnatherum hymenoides 3–12 – threeawn ARIST Aristida 3–12 – low woollygrass DAPU7 Dasyochloa pulchella 3–12 – Forb3 Perennial 12–48 desert needlegrass ACSP12 Achnatherum speciosum 12–60 – desert marigold BAMU Baileya multiradiata 3–18 – desert globemallow SPAM2 Sphaeralcea ambigua 3–18 – Indian ricegrass ACHY Achnatherum hymenoides 3–12 – 4 Annual 1–13 Shrub/Vine5 Primary shrubs 73–228 Eastern Mojave buckwheat ERFAP Eriogonum fasciculatum var. polifolium 30–90 – burrobush AMDU2 Ambrosia dumosa 1–48 – California jointfir EPCA2 Ephedra californica 10–20 – Nevada jointfir EPNE Ephedra nevadensis 10–20 – Torrey's jointfir EPTO Ephedra torreyana 10–20 – 6 Secondary shrubs 30–90 Virgin River brittlebush ENVI Encelia virginensis 6–18 – California barrel cactus FECY Ferocactus cylindraceus 6–18 – spiny hopsage GRSP Grayia spinosa 6–18 – winterfat KRLA2 Krascheninnikovia lanata 6–18 – creosote bush LATR2 Larrea tridentata 6–18 – whitestem paperflower PSCO2 Psilostrophe cooperi 6–18 – Mojave woodyaster XYTO2 Xylorhiza tortifolia 6–18 – Joshua tree YUBR Yucca brevifolia 6–18 – Mojave yucca YUSC2 Yucca schidigera 6–18 – Interpretations
Animal community
Livestock Interpretations:
This site is suited to livestock grazing. Grazing management should be keyed to Big galleta grass production. Big galleta is considered a valuable forage plant for cattle and domestic sheep. Its coarse, rigid culms make it relatively resistant to heavy grazing and trampling. Ephedra is heavily browsed by livestock on winter range but only moderately or lightly browsed during other seasons. Mojave buckwheat is also an important forage species for several livestock species.
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:
Ephedra is an important browse species for big game animals. Green ephedra is heavily used by wildlife on winter ranges. Mojave buckwheat and Big Galleta are important forage species for several wildlife species.Hydrological functions
Unoff is very high.
Other information
Big galleta's clumped growth form stabilizes blowing sand. Green ephedra is listed as a successful shrub for restoring western rangeland communities and can be used to rehabilitate disturbed lands. It also has value for reducing soil erosion on both clay and sandy soils. Green ephedra establishes readily through direct seeding, transplants, and stem cuttings.
Supporting information
Type locality
Location 1: Clark County, NV Township/Range/Section T25S R62E S19 General legal description Section 19, T25S. R62E. MDBM. McCullough Pass area. North-facing sideslopes on the west side of McCullough Range, Clark County, Nevada. Other references
Fire Effects Information System (Online; http://www.fs.fed.us/database/feis/plants/).
USDA-NRCS Plants Database (Online; http://www.plants.usda.gov).
Contributors
GKB
Approval
Kendra Moseley, 3/11/2025
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 08/30/2026 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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