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Ecological site R030XB039NV

LIMY FAN 5-7 P.Z.

Last updated: 3/11/2025
Accessed: 03/15/2025

Home / Esd catalog / MLRA 030X / Ecological site R030XB039NV

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General information

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 fan remnants, fan aprons, and inset fans. Slopes range from 0 to 8 percent, but slope gradients of 2 to 4 percent are most typical. Elevations are 2000 to 4500 feet. These soils typically have 15 to 35 percent gravels on the surface and less than 35 percent rock fragments (by volume) throughout the soil profile.

Please refer to group concept R030XB137CA to view the provisional STM.

Associated sites

R030XB034NV	SANDY PLAIN 5-7 P.Z.
R030XB043NV	CLAYPAN 5-7 P.Z.
R030XB051NV	UPLAND WASH
R030XB107NV	COARSE GRAVELLY LOAM 5-7 P.Z.

Similar sites

R030XB043NV	CLAYPAN 5-7 P.Z. less productive site; KRLA2 & GRSP major shrubs
R030XB004NV	SANDY 5-7 P.Z. ACHY codominant grass; MESP2 and KRLA2 important species
R030XB054NV	SANDY 3-5 P.Z. less productive site; not on inset fans
R030XB121NV	SANDY PLAIN 3-5 P.Z. MUPO2 absent; on broad alluvial plains
R030XB034NV	SANDY PLAIN 5-7 P.Z. more productive site; on broad alluvial plains
R030XB075NV	GRAVELLY FAN 5-7 P.Z. less productive site; MESP2 major shrub

Table 1. Dominant plant species

Tree	Not specified
Shrub	(1) Hilaria rigida
Herbaceous	Not specified

Download full description

Physiographic features

This site occurs on fan remnants, fan aprons, and inset fans. Slopes range from 0 to 8 percent, but slope gradients of 2 to 4 percent are most typical. Elevations are 2000 to 4500 feet.

Table 2. Representative physiographic features

Landforms	(1) Fan remnant (2) Inset fan (3) Fan apron
Flooding duration	Extremely brief (0.1 to 4 hours) to very brief (4 to 48 hours)
Flooding frequency	Very rare to occasional
Ponding frequency	None
Elevation	610 – 1,372 m
Slope	0 – 8%
Aspect	Aspect is not a significant factor

Climatic features

The climate of the Mojave Desert has extreme fluctuations of daily temperatures, strong seasonal winds, and clear skies. The climate is arid and is characterized with cool, moist winters and hot, dry summers. Most of the rainfall falls between November and April. Summer convection storms from July to September may contribute up to 25 percent of the annual precipitation. Average annual precipitation is 5 to 7 inches. Mean annual air temperature is 56 to 65 degrees F. The average growing season is about 190 to 210 days.

Table 3. Representative climatic features

Frost-free period (average)	210 days
Freeze-free period (average)
Precipitation total (average)	178 mm

Bar

Line

Figure 1. Monthly average minimum and maximum temperature

Soil features

These soils typically have 15 to 35 percent gravels on the surface and less than 35 percent rock fragments (by volume) throughout the soil profile. Water intake rates are moderately slow to moderately rapid and runoff is negligible to medium. Although available water capacity is very low to moderate, these soils receive run-in from higher landscapes. The soil series associated with this site include: Bitterspring, Bluepoint, Canutio, Filaree, Kidwell, and Lanip.

Table 4. Representative soil features

Surface texture	(1) Extremely gravelly coarse sandy loam (2) Very gravelly sandy loam (3) Gravelly sandy clay loam
Family particle size	(1) Loamy
Drainage class	Well drained to somewhat excessively drained
Permeability class	Moderately slow to moderately rapid
Soil depth	183 – 213 cm
Surface fragment cover <=3"	6 – 45%
Surface fragment cover >3"	2 – 10%
Available water capacity (0-101.6cm)	5.08 – 14.99 cm
Calcium carbonate equivalent (0-101.6cm)	0 – 25%
Electrical conductivity (0-101.6cm)	0 – 40 mmhos/cm
Sodium adsorption ratio (0-101.6cm)	0 – 12
Soil reaction (1:1 water) (0-101.6cm)	7.4 – 9
Subsurface fragment volume <=3" (Depth not specified)	6 – 59%
Subsurface fragment volume >3" (Depth not specified)	2 – 10%

Ecological dynamics

Please refer to group concept R030XB137CA to view the provisional STM.

As ecological condition deteriorates, creosotebush and white bursage increase as Indian ricegrass and bush muhly decline. Big galleta may initially increase but will decline with further site degradation. White burrobrush, introduced annual forbs and grasses readily invade this site.

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. Fire kills many creosotebush. Creosotebush is poorly adapted to fire because of its limited sprouting ability. Creosotebush survives some fires that burn patchily or are of low severity. Range ratany is top-killed by fire. Range ratany resprouts from the root crown after fire. Nevada ephedra is top-killed by fire. Underground regenerative structures commonly survive when aboveground vegetation is consumed by fire. Nevada ephedra generally sprouts after fire damages aboveground vegetation and may increase in plant cover. 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. Spiny hopsage is considered to be somewhat fire tolerant and often survives fires that kill sagebrush. Mature spiny hopsage generally sprout after being burned. Spiny hopsage is reported to be least susceptible to fire during summer dormancy. Fire most likely top-kills big galleta. Big galleta sprouts from rhizomes following fire. Damage to big galleta from fire varies, depending on whether big galleta is dormant when burned. 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. Bush muhly regenerates following fire from soil-stored seed. Fire probably top-kills bush muhly. Burning causes at least short-term decline of bush muhly. Recovery time is thought to vary considerably and is probably dependent on postfire weather and competition. Indian ricegrass can be killed by fire, depending on severity and season of burn. Indian ricegrass reestablishes on burned sites through seed dispersed from adjacent unburned areas.

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 text

Ecosystem states

1. Reference State

2. Invaded

State 1 submodel, plant communities

1.1. Reference Plant Community

State 1
Reference State

Community 1.1
Reference Plant Community

The plant community is dominated by big galleta. Bush muhly, Indian ricegrass, winterfat, spiny hopsage, Krameria spp., and Nevada ephedra are other important species on this site. Potential vegetative composition is about 75% perennial grasses, 5% perennial and annual forbs and 20% shrubs. Approximate ground cover (basal and crown) is 25 to 40 percent.

Figure 2. Annual production by plant type (representative values) or group (midpoint values)

Table 5. Annual production by plant type

Plant type	Low (kg/hectare)	Representative value (kg/hectare)	High (kg/hectare)
Grass/Grasslike	588	841	1177
Shrub/Vine	157	224	314
Forb	39	56	78
Total	784	1121	1569

State 2
Invaded

Introduced annuals such as red brome, schismus and redstem stork's bill have invaded the reference plant community and have become a dominant component of the herbaceous cover. This invasion of non-natives is attributed to a combination of factors including: 1) surface disturbances, 2) changes in the kinds of animals and their grazing patterns, 3) drought, and 4) changes in fire history. These non-natives annuals are highly flammable and promote wildfires where fires historically have been infrequent. LATR would persist after this invasion by non-native annuals, but the other shrubs and desirable grasses would either be unsuccessful in competing with the non-natives or removed from the system. The threshold that is crossed, is the introduction of non-native annuals that cannot be removed from the system and will alter disturbance regimes significantly from their natural or historic range of disturbances.

Additional community tables

Table 6. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (kg/hectare)	Foliar cover (%)
Grass/Grasslike
1	Primary Perennial Grasses			527–986
	big galleta	PLRI3	Pleuraphis rigida	448–729	–
	bush muhly	MUPO2	Muhlenbergia porteri	56–168	–
	Indian ricegrass	ACHY	Achnatherum hymenoides	22–90	–
2	Secondary Perennial Grasses			1–90
	desert needlegrass	ACSP12	Achnatherum speciosum	6–22	–
	threeawn	ARIST	Aristida	6–22	–
	low woollygrass	DAPU7	Dasyochloa pulchella	6–22	–
	dropseed	SPORO	Sporobolus	6–22	–
3	Annual Grasses			1–34
	sixweeks grama	BOBA2	Bouteloua barbata	6–22	–
Forb
4	Perennial forbs			22–56
	desert globemallow	SPAM2	Sphaeralcea ambigua	6–22	–
5	Annual forbs			1–112
Shrub/Vine
6	Primary shrubs			28–336
	burrobush	AMDU2	Ambrosia dumosa	1–56	–
	Nevada jointfir	EPNE	Ephedra nevadensis	1–56	–
	spiny hopsage	GRSP	Grayia spinosa	1–56	–
	winterfat	KRLA2	Krascheninnikovia lanata	1–56	–
	creosote bush	LATR2	Larrea tridentata	22–56	–
7	Secondary shrubs			56–168
	catclaw acacia	ACGR	Acacia greggii	11–34	–
	rayless goldenhead	ACSP	Acamptopappus sphaerocephalus	11–34	–
	blackbrush	CORA	Coleogyne ramosissima	11–34	–
	Eastern Mojave buckwheat	ERFAP	Eriogonum fasciculatum var. polifolium	11–34	–
	burrobrush	HYSA	Hymenoclea salsola	11–34	–
	white ratany	KRGR	Krameria grayi	11–34	–
	desert pepperweed	LEFR2	Lepidium fremontii	11–34	–
	water jacket	LYAN	Lycium andersonii	11–34	–

Interpretations

Animal community

Livestock Interpretations:
This site is suitable for livestock grazing. 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. Bush muhly is readily eaten by livestock throughout the year when available; however, it is usually not abundant enough to provide much forage. It is grazed heavily in winter when other species become scarce. Because of its branching habit, it is extremely susceptible to heavy grazing. Bush muhly is damaged when continuously grazed to a stubble height of less than 4 inches (10 cm). Indian ricegrass is highly palatable to all classes of livestock in both green and cured condition. It supplies a source of green feed before most other native grasses have produced much new growth. Creosotebush is unpalatable to livestock. Consumption of creosotebush may be fatal to sheep. White bursage is of intermediate forage value. It is fair to good forage for horses and fair to poor for cattle and sheep. However, because there is often little other forage where white bursage grows, it is often highly valuable to browsing animals and is sensitive to browsing. Range ratany is an important forage species for all classes of livestock. Palatability of range ratany is rated fair to good for cattle and sheep. Nevada ephedra is important winter range browse for domestic cattle, sheep and goats. Winterfat is an important forage plant for livestock. Winterfat palatability is rated as good for sheep, good to fair for horses, and fair for cattle. Abusive grazing practices have reduced or eliminated winterfat on some areas even though it is fairly resistant to browsing. Grazing season has more influence on winterfat than grazing intensity. Early winter grazing may actually be beneficial. Spiny hopsage as being browsed by livestock in the fall, winter, and spring. Spiny hopsage is used as forage to at least some extent by domestic sheep and goats. The large quantities of seeds produced are valuable for fattening domestic sheep. Spiny hopsage readily establishes and increases on overgrazed and denuded ranges.

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:
Creosotebush is unpalatable to most browsing wildlife. White bursage is an important browse species for wildlife. Range ratany is an important forage species for deer. Mule deer browse range ratany year-long with seasonal peaks. Mule deer peak use is from February to April and from August to October. Mule deer, bighorn sheep, and pronghorn browse Nevada ephedra, especially in spring and late summer when new growth is available. Mountain quail eat ephedra seeds. Winterfat is an important forage plant for wildlife. Animals that browse winterfat include mule deer, desert bighorn sheep, and pronghorn antelope. Spiny hopsage provides a palatable and nutritious food source for big game, particularly during late winter through spring. The palatability of bush muhly for wildlife species is rated fair to poor. Indian ricegrass is eaten by pronghorn in moderate amounts whenever available. In Nevada it is consumed by desert bighorns. A number of heteromyid rodents inhabiting desert rangelands show preference for seed of Indian ricegrass. Indian ricegrass is an important component of jackrabbit diets in spring and summer. In Nevada, Indian ricegrass may even dominate jackrabbit diets during the spring through early summer months. Indian ricegrass seed provides food for many species of birds. Doves, for example, eat large amounts of shattered Indian ricegrass seed lying on the ground.

Hydrological functions

Runoff is negligible to medium. Permeability is moderately slow to moderately rapid.

Other products

Indian ricegrass was traditionally eaten by some Native Americans. The Paiutes used seed as a reserve food source. Creosotebush has been highly valued for its medicinal properties by Native Americans. Twigs and leaves may be boiled as tea, steamed, pounded into a powder, pressed into a poultice, or heated into an infusion. White bursage is a host for sandfood, a parasitic plant. Sandfood was a valuable food supply for Native Americans. Some Native American tribes steeped the twigs of Nevada ephedra and drank the tea as a general beverage. Some Native American peoples traditionally ground parched seeds of spiny hopsage to make pinole flour.

Other information

Big galleta's clumped growth form stabilizes blowing sand. Once established, creosotebush may improve sites for annuals that grow under its canopy by trapping fine soil, organic matter, and symbiont propagules. It may also increase water infiltration and storage. White bursage may be used to revegetate disturbed sites in southwestern deserts. Spiny hopsage has moderate potential for erosion control and low to high potential for long-term revegetation projects. It can improve forage, control wind erosion, and increase soil stability on gentle to moderate slopes. Spiny hopsage is suitable for highway plantings on dry sites in Nevada.

Supporting information

Type locality

Location 1: Clark County, NV
Township/Range/Section	T28S R63E S11
General legal description	About 4 miles north of Searchlight along east side of US Highway 95, Clark County, Nevada.
Location 2: Lincoln County, NV
Township/Range/Section	T10S R10 S68E
Latitude	37° 7′ 12″
Longitude	114° 21′ 48″
General legal description	Latitude 37 degrees 7’ 12” Longitude 114 degrees 21’ 48” About ¾ mile northwest of Tule Desert Well, Tule Desert, Lincoln County, Nevada. This site also occurs in 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

BO'D/GKB
BO'D/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)	P Novak-Echenique
Contact for lead author	State Rangland Management Specialist
Date	04/27/2011
Approved by	Kendra Moseley
Approval date
Composition (Indicators 10 and 12) based on	Annual Production

Indicators

Number and extent of rills:
Rills are none.
Presence of water flow patterns:
Water flow patterns are none.
Number and height of erosional pedestals or terracettes:
Pedestals and terracettes are none.
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare ground up to 20% depending on amount of surface rock fragments
Number of gullies and erosion associated with gullies:
None
Extent of wind scoured, blowouts and/or depositional areas:
None
Amount of litter movement (describe size and distance expected to travel):
Litter typically remains in place. Fine litter (foliage from grasses and annual and perennial forbs) may move the distance of slope length (<5 ft) during intense summer convection storms or rapid snowmelt events. Persistent litter (large woody material) will remain in place expect during large rainfall events.
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil stability values should be 3 to 6 (To be field tested.)
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Soil surface structure is typically moderate thin to moderate thick platy or weak fine granular. Soil surface colors are light and soils have an ochric epipedon. Organic matter of the surface 2 to 3 inches is less than 1 percent.
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Sparse shrub canopy (10-15%) and associated litter break raindrop impact. Deep-rooted perennial grasses slow runoff and increase infiltration.
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None, argillic or calcic horizons are not to be interpreted as compacted layers.
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:
warm-season, perennial bunchgrasses

Sub-dominant:
Mojave Desert shrubs > cool-season, perennial bunchgrasses = annual forbs > perennial forbs > annual grasses

Other:

Additional:
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Dead branches within individual shrubs are common and standing dead shrub canopy material may be as much as 25% of total woody canopy.
Average percent litter cover (%) and depth ( in):
Interspaces up to 35% and < ¼ in depth
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
For normal or average growing season ± 1000 lbs/ac. Favorable years ± 1400 lbs/ac and unfavorable years ± 700 lbs/ac
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:
Potential invaders include red brome, red-stem filaree, mustards, cheatgrass, and Mediterranean grass
Perennial plant reproductive capability:
All functional groups should reproduce in normal and above-normal rainfall years. Little growth or reproduction occurs during extreme or extended drought periods.

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