Ecological site R030XB128NV

R030XB124NV	SHALLOW HILL 3-5 P.Z.

R030XB030NV	SHALLOW LIMESTONE SLOPE 5-7 P.Z. ACSP12 dominant grass; less productive site
R030XB015NV	SHALLOW GRAVELLY SLOPE 7-9 P.Z. PLRI3 & BOER4 dominant grasses
R030XB135NV	Steep Limestone Hill MOUT & TICA3 important shrubs
R030XB107NV	COARSE GRAVELLY LOAM 5-7 P.Z. PLRI3 dominant grass; more productive site
R030XB057NV	SHALLOW GRANITIC LOAM 5-7 P.Z. AMDU2 minor species; ACSP12 dominant grass
R030XB014NV	SHALLOW GRAVELLY LOAM 7-9 P.Z. BOER4 dominant grass, more productive site
R030XB029NV	SHALLOW GRAVELLY LOAM 5-7 P.Z. PLRI3 dominant grass
R030XB136NV	SHALLOW LIMESTONE 7-9 P.Z. MOUT & TICA3 important shrubs; more productive site
R030XB056NV	SHALLOW GRANITIC SLOPE 5-7 P.Z. AMDU2 minor species; less productive site

Tree	Not specified
Shrub	(1) Coleogyne ramosissima (2) Ambrosia dumosa
Herbaceous	Not specified

Landforms	(1) Mesa
Elevation	3000 – 4000 ft
Slope	4 – 30 %

Frost-free period (average)	240 days
Freeze-free period (average)
Precipitation total (average)	10 in

Drainage class	Well drained
Permeability class	Moderately rapid

Ecological dynamics

Please refer to group concept R030XB094CA to view the provisional STM.

As ecological condition deteriorates blackbrush increases almost to the exclusion of all other species. Following wildfire, non-native annual grasses and forbs, threeawn and broom snakeweed increase or invade this site. Current understanding of blackbrush ecology indicates that one hundred, or more, years may be required for reestablishment of blackbrush after fire.

Fire Ecology:
Fires in the Mojave desert are infrequent and of low severity because production of annual and perennial herbs seldom provides a fuel load capable of sustaining fire. Fire generally kills white bursage. However, most white bursage plants burned because their canopies contained numerous small branches in proximity to herbaceous fuels. Low amounts of fine fuels in interspaces probably limited fire spread to only extreme fire conditions, during which high winds, low relative humidity, and low fuel moisture led to high intensity stand-replacing crown fires. Historical fire return intervals appear to have been on the order of centuries, allowing late seral blackbrush stands to reestablish. Blackbrush stands are subject to fire, and fire will start and spread easily due to the dense, close spacing nature and resinous foliage of blackbrush. Blackbrush is slow to reestablish. Winterfat is either killed or top-killed by fire, depending on fire severity. Severe fire can kill the perennating buds located several inches above the ground surface and thus kills the plant. In addition, severe fire usually destroys seed on the plant. Low-severity fire scorches or only partially consumes the aboveground portions of winterfat and thus does not cause high mortality.

State and transition model

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Ecosystem states

1. Reference Plant Community

State 1 submodel, plant communities

1.1. Reference Plant Community

State 1
Reference Plant Community

Community 1.1
Reference Plant Community

Blackbrush and white bursage dominate the reference plant community.
Potential vegetative composition is about 10% grasses, 10% annual and perennial forbs, and 80% shrubs. Approximate ground cover (basal and crown) is 15 to 25 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	160	240	400
Grass/Grasslike	20	30	50
Forb	20	30	50
Total	200	300	500

Additional community tables

Table 6. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)
Grass/Grasslike
1	Perennial grasses			6–45
	purple threeawn	ARPU9	Aristida purpurea	2–15	–
	low woollygrass	DAPU7	Dasyochloa pulchella	2–15	–
	bush muhly	MUPO2	Muhlenbergia porteri	2–15	–
	big galleta	PLRI3	Pleuraphis rigida	2–15	–
	slim tridens	TRMU	Tridens muticus	2–15	–
2	Annual Grasses			1–15
Forb
3	Perennial forbs			2–24
	desert globemallow	SPAM2	Sphaeralcea ambigua	2–6	–
4	Annual forbs			1–15
Shrub/Vine
5	Primary shrubs			198–285
	blackbrush	CORA	Coleogyne ramosissima	150–180	–
	burrobush	AMDU2	Ambrosia dumosa	30–60	–
	jointfir	EPHED	Ephedra	6–15	–
	winterfat	KRLA2	Krascheninnikovia lanata	6–15	–
	Fremont's dalea	PSFR	Psorothamnus fremontii	6–15	–
6	Secondary shrubs			15–45
	Fremont's chaffbush	AMFR2	Amphipappus fremontii	3–15	–
	desertholly	ATHY	Atriplex hymenelytra	3–15	–
	cottontop cactus	ECPO2	Echinocactus polycephalus	3–15	–
	white ratany	KRGR	Krameria grayi	3–15	–
	creosote bush	LATR2	Larrea tridentata	3–15	–
	water jacket	LYAN	Lycium andersonii	3–15	–
	Mojave woodyaster	XYTO2	Xylorhiza tortifolia	3–15	–

Location 1: Clark County, NV
Township/Range/Section	T19S R65E S27
General legal description	Approximately three miles southwest of Muddy Peak, north of Gale Hills, east of Las Vegas, Clark County, Nevada.

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	08/19/2026
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:

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Natural ResourcesConservation Service

Ecological site R030XB128NV

SHALLOW LIMESTONE HILL 5-7 P.Z.

Last updated: 2/26/2025 Accessed: 08/19/2026

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Ecological site concept

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Table 1. Dominant plant species

Natural Resources
Conservation Service

Last updated: 2/26/2025
Accessed: 08/19/2026