Natural Resources
Conservation Service
Ecological site R030XB122NV
LIMY SAND 3-5 P.Z.
Last updated: 3/10/2025
Accessed: 04/25/2025
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 piedmonts having a thin sand sheet. Slopes range from 2 to 15 percent, but slope gradients of 8 to 15 percent are most typical. Elevations are from less than 1400 to about 2800 feet.
The soils associated with this site are very deep and well drained. The soils are fine or very fine sands typically less than 7 inches in depth to a soil textural change (i.e. sand to sandy loam) and/or a change in soil structure (i.e. single-grained to platy).
This site is included in group concept R030XB148CA.
Associated sites
| R030XB004NV |
SANDY 5-7 P.Z. |
|---|---|
| R030XB054NV |
SANDY 3-5 P.Z. |
Similar sites
| R030XB121NV |
SANDY PLAIN 3-5 P.Z. More productive site; on broad alluvial plains |
|---|---|
| R030XB123NV |
LIMESTONE SLOPE 5-7 P.Z. Occurs on hill and lower mountain sideslopes |
| R030XB004NV |
SANDY 5-7 P.Z. More productive site |
| R030XB063NV |
SANDHILL 5-7 P.Z. More productive site; occurs on sand dunes |
| R030XB039NV |
LIMY FAN 5-7 P.Z. More productive site; MUPO2 important species |
| R030XB037NV |
LIMY SAND 5-7 P.Z. ACHY-PLRI3 codominant |
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) Ambrosia dumosa |
| Herbaceous |
(1) Pleuraphis rigida |
Physiographic features
This site occurs on fan piedmonts having a thin sand sheet. Slopes range from 2 to 15 percent, but slope gradients of 8 to 15 percent are most typical. Elevations are from less than 1400 to about 2800 feet.
Table 2. Representative physiographic features
| Landforms |
(1)
Fan piedmont
(2) Sand sheet |
|---|---|
| Flooding duration | Very brief (4 to 48 hours) |
| Flooding frequency | None to rare |
| Elevation | 1,400 – 2,800 ft |
| Slope | 2 – 15% |
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 3 to 5 inches. Mean annual air temperature is 65 to 70 degrees F. The average growing season is about 270 to 340 days.
Table 3. Representative climatic features
| Frost-free period (average) | 340 days |
|---|---|
| Freeze-free period (average) | |
| Precipitation total (average) | 5 in |
Figure 1. 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 very deep and well drained. The soils are fine or very fine sands typically less than 7 inches in depth to a soil textural change (i.e. sand to sandy loam) and/or a change in soil structure (i.e. single-grained to platy). The soil surface has a cover of 15 percent or more gravels (>1.2” diameter) and about 5 percent cobbles. Water intake rates are rapid and available water capacity is very low. Soil series associated with this site include Azsand and Grapevine.
Table 4. Representative soil features
| Parent material |
(1)
Eolian sands
–
sandstone
|
|---|---|
| Surface texture |
(1) Fine sand (2) Gravelly loamy sand (3) Gravelly fine sand |
| Family particle size |
(1) Sandy |
| Drainage class | Well drained to somewhat excessively drained |
| Permeability class | Moderate to rapid |
| Soil depth | 72 in |
| Surface fragment cover <=3" | 5 – 20% |
| Surface fragment cover >3" | 5% |
| Available water capacity (0-40in) |
2.3 – 5 in |
| Calcium carbonate equivalent (0-40in) |
1 – 40% |
| Electrical conductivity (0-40in) |
4 mmhos/cm |
| Sodium adsorption ratio (0-40in) |
5 |
| Soil reaction (1:1 water) (0-40in) |
7.9 – 9 |
| Subsurface fragment volume <=3" (Depth not specified) |
2 – 50% |
| Subsurface fragment volume >3" (Depth not specified) |
Not specified |
Ecological dynamics
The potential natural vegetation is dominanted by shrubs and warm-season perennial bunchgrasses. As ecological condition deteriorates, Indian ricegrass and big galleta decrease as creosotebush and white bursage become more dominant. Introduced annual forbs and grass readily invade this site.
This site is found on sandy soils which contribute to higher productivity and cover of perennial grasses. The primary organizing principle, for these ecological sites, is the inverse-texture hypothesis, which predicts that plant communities on coarse textured soils should have higher above-ground net primary productivity than communities on fine textured soils. Sandy or coarse textured soils have greater rates of infiltration and precipitation is percolated deeper into the soil profile. On sandy sites, the surface horizon dries out quickly and forms a barrier to the conductance and evaporation of water held in the deeper soil horizons (Lane et al. 1998). This process protects moisture from being lost to evaporation, increasing the available water in the soil profile and positively contributing to the primary productivity of these sites.
Historically, these sites would have experienced infrequent, stand replacing fires, carried by a relatively high cover of perennial grasses and shrubs (Brooks and Minnich 2006). Degree of fire damage is largely dependent on the seasonality of the burn. Plants in dormancy or during drought years may be adversely affected. Fire generally top-kills big galleta and resprouting occurs from the rhizomes (Matthews 2000). Fire damage to Indian ricegrass is variable, however, it readily reestablishes on burned sites through seed dispersed from adjacent unburned areas (Tirmenstein 1999). Severe fires generally kill mature white bursage and winterfat plants. White bursage will not sprout from the root crown, but has been observed to readily establish from seed several years post fire (Marshall 1994). Winterfat is able to re-sprout from the root crown following low intensity fires. More intense fires generally result in high mortality (Carey 1995).
Big galleta has coarse, rigid stems that make it relatively resistant to heavy grazing and trampling and is considered fair forage for cattle, horses and domestic sheep (Matthews 2000). Heavy grazing pressure can result in decreased abundance of big galleta. If heavy to moderate utilization occurs during time of increased water stress, growth and survival of this species may be significantly affected (Robberecht 1988).
Indian ricegrass is highly palatable to all classes of livestock and benefits from grazing use if it is moderately grazed in winter and early spring. Heavy early spring grazing may reduce the vigor of Indian ricegrass and decrease abundance (Tirmenstein 1999). White bursage is a moderately important forage species, but can experience increased grazing pressure during years of low precipitation when production of winter annuals is low (Marshall 1994). Extended periods of heavy grazing can be detrimental to white bursage plants (Pavlik 2008). Winterfat is an extremely important winter forage species. It is considered to be palatable throughout the year, but browsers prefer it during periods of active growth (Carey 1995). Although winterfat is fairly resistant to grazing disturbance, seasonality of the grazing pressure is very important.
Recreation impacts, such as trampling and OHV use can decrease the abundance and vigor of these native species, increase the nutrient availability, and provide pathways for propagule introduction (Webb et al. 2009). Loss of vegetative cover from natural or anthropogenic disturbances will result in establishment of non-native annual species (Sahara mustard, red brome, Mediterranean grass, red-stem filaree). The transition from natives to non-natives will result in increased erosion, increased susceptibility to fire and decreased habitat quality.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 2 submodel, plant communities
State 1
Reference State
This state represents the natural range of variability under pristine condition and is dominated by perennial bunchgrasses. Primary natural disturbance mechanisms affecting this ecological site are wildfire, long-term drought and insect attack. Timing of disturbance in combination with weather events determines plant community dynamics. This site may experience light to moderate grazing by wildlife. Additional run-in moisture aids in maintaining the community phases of this state, by favoring a greater dominance by grasses with a lesser component of shrubs. The sites of this group are distinguished by higher ecological resistance and resilience due to the increased annual production, additional moisture, and higher amounts of organic matter when compared to the surrounding sites.
Community 1.1
Reference Plant Community
The reference plant community is dominated by white bursage and big galleta. Potential vegetative composition is about 35% grasses, 10% forbs and 55% shrubs. Approximate ground cover (basal and crown) is 10 to 15 percent.
Figure 2. 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 | 110 | 220 | 358 |
| Grass/Grasslike | 70 | 140 | 227 |
| Forb | 20 | 40 | 65 |
| Total | 200 | 400 | 650 |
State 2
Invaded
The invaded state is characterized by the presence of non-native species in the understory. 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. A biotic threshold has been crossed by the introduction of non-native annuals that cannot be removed from the system. Ecological function has not changed, however the resiliency of the state has been reduced by the presence of non-native annual species that have the potential to alter disturbance regimes significantly from their natural or historic range. The 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.
Community 2.1
Plant Community Phase 2.1
The plant community composition is similar to the Reference Plant Community. Ecological function has not changed but the resilience has decreased due to the presence of non-native annuals. AMDU will persist afterinvasion by non-native annuals, but other shrubs and desirable grasses may be unsuccessful in competing with the non-natives.
Community 2.2
Plant Community Phase 2.2
This plant community is characterized by a reduction in perennial grass cover and an increase of non-native annuals and bare ground. Heavy disturbance has decreased the perennial vegetative cover that is beneficial for soil stabilization and nutrient cycling.
Community 2.3
Plant Community Phase 2.3
This plant community is characterized by few surviving mature perennials. Disturbance tolerant shrubs and rhizomatous bunchgrasses are scattered through the plant community. Loss of mature vegetation will encourage seedling growth of burrobush and Indian ricegrass. Seed is provided by surrounding unburned areas. Non-native annuals are common throughout the site.
Community 2.4
Plant Community Phase 2.4
This plant community is characterized by the dominance of non-native annuals; perennial vegetative cover is severely reduced.
Pathway 2.1a
Community 2.1 to 2.2
Frequent and repeated disturbance, heavy grazing, small fire, or prolonged drought will decrease abundance of perennial bunchgrasses.
Pathway 2.1b
Community 2.1 to 2.3
Large fire will initially remove shrubs and perennial grasses.
Pathway 2.2a
Community 2.2 to 2.3
A decreased level of disturbance or a year with increased precipitation will encourage a flush of vegetative growth.
Pathway 2.3a
Community 2.3 to 2.1
Controlling disturbance on this site allows perennials to mature, successfully reproduce and return to dominance.
Pathway 2.3b
Community 2.3 to 2.4
Increased fire, resulting from a continuous bed of fine fuels reduces perennial vegetative cover.
Pathway 2.4a
Community 2.4 to 2.3
Reducing the level of disturbance initiates native species regeneration.
Transition 1
State 1 to 2
Introduction of non-native species due to anthropogenic disturbance including OHV use, dry land farming, grazing, linear corridors, mining, military training operations, and settlements.
Additional community tables
Table 6. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Primary Perennial Grasses | 128–272 | ||||
| big galleta | PLRI3 | Pleuraphis rigida | 100–180 | – | ||
| Indian ricegrass | ACHY | Achnatherum hymenoides | 20–60 | – | ||
| sand dropseed | SPCR | Sporobolus cryptandrus | 4–16 | – | ||
| mesa dropseed | SPFL2 | Sporobolus flexuosus | 4–16 | – | ||
| 2 | Perennial Grasses | 1–20 | ||||
| 3 | Annual Grasses | 1–12 | ||||
|
Forb
|
||||||
| 4 | Perennial Forbs | 8–32 | ||||
| desert globemallow | SPAM2 | Sphaeralcea ambigua | 2–12 | – | ||
| 5 | Annual Forbs | 1–40 | ||||
| desert trumpet | ERIN4 | Eriogonum inflatum | 2–12 | – | ||
| evening primrose | OENOT | Oenothera | 2–12 | – | ||
|
Shrub/Vine
|
||||||
| 6 | Primary Shrubs | 148–240 | ||||
| burrobush | AMDU2 | Ambrosia dumosa | 120–160 | – | ||
| creosote bush | LATR2 | Larrea tridentata | 20–60 | – | ||
| white ratany | KRGR | Krameria grayi | 4–10 | – | ||
| 7 | Secondary Shrubs | 20–60 | ||||
| Shockley's goldenhead | ACSH | Acamptopappus shockleyi | 4–12 | – | ||
| Fremont's chaffbush | AMFR2 | Amphipappus fremontii | 4–12 | – | ||
| Nevada jointfir | EPNE | Ephedra nevadensis | 4–12 | – | ||
| winterfat | KRLA2 | Krascheninnikovia lanata | 4–12 | – | ||
| Joshua tree | YUBR | Yucca brevifolia | 4–12 | – | ||
| Mojave yucca | YUSC2 | Yucca schidigera | 4–12 | – | ||
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. Big galleta's clumped growth form stabilizes blowing sand. Indian ricegrass benefits from grazing use if it is moderately grazed in winter and early spring. Heavy early spring grazing may sharply reduce the vigor of Indian ricegrass and decrease the stand. Cattle eat mesa dropseed all year long. Use is heaviest during the summer when the plant is actively growing. Mesa dropseed becomes unpalatable and low in nutrition at maturity. 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. Creosotebush is unpalatable to livestock and most browsing wildlife. Consumption of creosotebush may be fatal to sheep. Range ratany is an important forage species for all classes of livestock and for deer. Range ratany decreases in response to heavy grazing. White ratany is important forage for all classes of livestock. It is one of the most important browse species for mule deer and desert bighorn sheep. Black-tailed jack rabbits rely almost exclusively on white ratany during the winter. White ratany decreases in response to grazing. Under heavy grazing pressure white ratany produces phenolic acids to reduce herbivory by reducing the palatability.
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. Sand dropseed’s responses to grazing are variable, with increases, decreases and no changes reported.
Wildlife Interpretations:
White bursage is an important browse species for wildlife. Many small mammals browse creosotebush or consume its seeds. Desert reptiles and amphibians use creosotebush as a food source and perch site and hibernate or estivate in burrows under creosotebush, avoiding predators and excessive daytime temperatures. 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. Sand dropseed provides poor forage for wildlife and is not preferred by pronghorn, elk, and deer. Small mammals and birds utilize sand dropseed to a greater extent than large mammals. Pronghorn consume mesa dropseed. Mesa dropseed becomes unpalatable and low in nutrition at maturity.
Hydrological functions
Water intake rates are rapid and available water capacity is very low to low.
Recreational uses
Aesthetic value is derived from the diverse floral and faunal composition and the colorful flowering of wild flowers and shrubs during the spring and early summer. This site offers rewarding opportunities to photographers and for nature study. This site is used for hiking and has potential for upland and big game hunting.
Other products
Indian ricegrass was traditionally eaten by some Native Americans. The Paiutes used seed as a reserve food source. Sand dropseed is an edible grass used by Native Americans. Native Americans used mesa dropseed seeds as food. Creosotebush has been highly valued for its medicinal properties by desert peoples. It has been used to treat at least 14 illnesses. 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 with a sweet, succulent, subterranean flowerstalk. Sandfood was a valuable food supply for desert peoples.
Other information
Big galleta's clumped growth form stabilizes blowing sand. Sand dropseed is recommended as a component of grass seed mixtures for sandy and heavy to semi-sandy soils. Mesa dropseed is important in depleted stands of black grama. It stabilizes the loose, sandy soils giving the slower-growing black grama time to revegetate. Creosotebush may be used to rehabilitate disturbed environments in southwestern deserts. 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 and is a nurse plant for creosotebush.
Supporting information
Type locality
| Location 1: Clark County, NV | |
|---|---|
| Township/Range/Section | T14S R68E S5 |
| General legal description | Just south of US Interstate 15, about 1.5 miles east of Carp-Elgin Interchange. Lower Morman Mesa area, Clark County, Nevada. |
Other references
Brooks, M.L. and J.R. Matchett. 2006. Spatial and temporal patterns of wildfire in the Mojave Desert, 1980-2004. J. of Arid Environments. 67: 148-164.
Fire Effects Information System (Online; http://www.fs.fed.us/database/feis/plants/).
Lane, D.R., D.P. Coffin and W. K. Lauenroth. 1998. Effects of soil texture and precipitation on above-ground net primary productivity and vegetation structure across the Central Grassland region of the United States. J. of Vegetation Science. 9: 239-250.
USDA-NRCS Plants Database (Online; http://www.plants.usda.gov).
Contributors
GKB
Approval
Kendra Moseley, 3/10/2025
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 Rangeland Management Specialist |
| Date | 06/17/2010 |
| Approved by | Kendra Moseley |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
Rills are none to rare. -
Presence of water flow patterns:
Water flow patterns none to rare. -
Number and height of erosional pedestals or terracettes:
Pedestals are rare with occurrence typically limited to areas affected by wind scouring. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare Ground to 60-70%. -
Number of gullies and erosion associated with gullies:
None -
Extent of wind scoured, blowouts and/or depositional areas:
None to slight. If observed, wind scour spots are isolated and of small extent. -
Amount of litter movement (describe size and distance expected to travel):
Fine litter (foliage from grasses and annual & perennial forbs) expected to move distance of slope length during intense summer storms. Persistent litter (large woody material) will remain in place except during catastrophic 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 1 to 3 on the sandy soil textures found on this site. (To be field tested.) -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Surface structure is typically single grain. Soil surface colors are light and soils are typified by an ochric epipedon. Organic matter of the surface 2 to 3 inches is typically less then1 percent dropping off quickly below. Organic matter content can be more or less depending on micro-topography. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Perennial herbaceous plants slow runoff and increase infiltration. Shrub canopy and associated litter break raindrop impact. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None -
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:
Mojave Desert shrubsSub-dominant:
deep-rooted, warm season, perennial bunchgrasses >> deep-rooted, cool season, perennial bunchgrasses > annual forbs > perennial forbs > annual grassesOther:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Dead branches within individual shrubs common and standing dead shrub canopy material may be as much as 25% of total woody canopy; some of the mature bunchgrasses (<20%) have dead centers. -
Average percent litter cover (%) and depth ( in):
Between plant interspaces (15-25%) and depth of litter is ±¼ inch. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
For normal or average growing season ±400 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:
Invaders on this site include Mediterranean grass, red brome, and filaree. -
Perennial plant reproductive capability:
All functional groups should reproduce in average (or normal) and above average growing season years.
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