Natural Resources
Conservation Service
Ecological site R030XB125NV
CHANNERY HILL 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 sideslopes of low hills on all exposures. Slopes range from 8 to over 50 percent. Elevations are 2000 to 3000 feet.
The soil associated with this site are shallow and very shallow to bedrock and well drained. The soils are formed in residuum and colluvium from calcareous sandstone and limestone.
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Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) Atriplex confertifolia |
| Herbaceous |
Not specified |
Physiographic features
This site occurs on sideslopes of low hills on all exposures. Slopes range from 8 to over 50 percent. Elevations are 2000 to 3000 feet.
Table 2. Representative physiographic features
| Landforms |
(1)
Hill
|
|---|---|
| Elevation | 2,000 – 3,000 ft |
| Slope | 8 – 50% |
Climatic features
The climate is hot and arid, with mild winters and very hot summers. Precipitation is greatest in the winter with a lesser secondary peak in summer, typical of the Mojave Desert. The average annual precipitation ranges from 3 to 5 inches with most of the moisture falling as rain during the period November through March. At least 30% of the annual precipitation occurs from July to September as a result of summer convection storms. Mean annual air temperature is 64 to 69 degrees F. The average frost-free period is 240 to 300 days.
Table 3. Representative climatic features
| Frost-free period (average) | 300 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 soil associated with this site are shallow and very shallow to bedrock and well drained. The soils are formed in residuum and colluvium from calcareous sandstone and limestone. These soils have very high runoff, moderate to moderately rapid permeability, and very low available water capacity. Soil series correlated to this site include Galehills, a loamy-skeletal, mixed, superactive, calcareous, thermic Lithic Torriorthent and Bitterridge, a loamy-skeletal, carbonatic, thermic shallow Typic Haplocalcid.
Table 4. Representative soil features
| Parent material |
(1)
Alluvium
–
limestone
(2) Alluvium – volcanic sandstone (3) Colluvium – conglomerate |
|---|---|
| Surface texture |
(1) Extremely gravelly fine sandy loam (2) Extremely flaggy loam |
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderate to moderately rapid |
| Soil depth | 7 – 16 in |
| Surface fragment cover <=3" | 25 – 55% |
| Surface fragment cover >3" | 10% |
| Available water capacity (0-40in) |
1 – 2 in |
| Calcium carbonate equivalent (0-40in) |
10 – 45% |
| Electrical conductivity (0-40in) |
2 mmhos/cm |
| Sodium adsorption ratio (0-40in) |
5 |
| Soil reaction (1:1 water) (0-40in) |
8 – 8.4 |
| Subsurface fragment volume <=3" (Depth not specified) |
35 – 65% |
| Subsurface fragment volume >3" (Depth not specified) |
5% |
Ecological dynamics
Plant communities of this ecological site are dynamic is response to changes in disturbance regimes and weather patterns. Natural disturbance mechanisms affecting this site are long-term drought, disease, insect attack and infrequent wildfire. Shadscale is tolerant of arid conditions, but does show high rates of mortality during periods of prolonged drought. Shadscale is able to increase its drought tolerance by shedding some of its leaves (Simonin 2001). This helps to reduce water loss through leaf stomata during periods of high moisture stress. Successive years of above-average precipitation may result in considerable die-off of many species of native shrubs, especially shadscale. Shadscale prefers well drained soils (Simonin 2001).
Abusive land use practices can lead to invasion by non-native annuals. Non-native annual grasses and forbs such as red brome, Mediterranean grass and redstem filaree will readily invade this site. Opportunistic perennials such as white bursage and white burrobush may increase on this site long-lived perennials are removed by disturbance.
Fire Ecology:
Shadscale communities were usually unaffected by fire because of low fuel loads, although a year of exceptionally heavy winter rains can generate fuels by producing a heavy stand of annual forbs and grasses. The historic mean fire return interval for shadscale communities ranges from 35 to 100 years. Increased presence of non-native annual grasses, such as red brome and cheatgrass, can alter fire regimes by increasing fire frequency under wet to near-normal summer moisture conditions.
Fire generally kills white bursage and shadscale and many creosotebush. Shadscale is generally killed by fire and does not readily recover from fire, except for establishment through seed. Creosotebush is poorly adapted to fire because of its limited sprouting ability, although creosotebush survives some fires that burn patchily or are of low severity.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 1
Reference State
The reference state is representative of the natural range of variability under pristine conditions. Community phase changes are primarily driven by natural disturbances such as long-term drought and insect attack. Wildfire is infrequent due to low fuel loading and widely spaced shrubs, fire return intervals are typically. Interactions between disturbance events and weather patterns determines long term plant community dynamics.
Community 1.1
Reference Plant Community
The reference plant community is characterized by a healthy mid-seral condition. Total ground cover is <10%, dominated by shadscale and white bursage. Potential vegetative composition is about 5% annual and perennial grasses, 10% forbs and 85% shrubs. Native annuals may be abundant in years of increased spring time precipitation. Shadscale is relatively short lived, but extremely drought tolerant. Mature shadscale plants can experience die-back during extended periods of extreme drought and during consecutive years of higher than normal precipitation.
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 | 85 | 212 | 297 |
| Forb | 10 | 25 | 35 |
| Grass/Grasslike | 5 | 13 | 18 |
| Total | 100 | 250 | 350 |
Community 1.2
Plant Community 1.2
This plant community is characteristic of an early-seral plant community phase. Initially, this plant community shows an increase of herbaceous vegetation. Shadscale seedlings commonly establish under the skeletons of dead shadscale plants. This plant community is considered to be ‘at-risk’ of invasion by non-natives. Non-native species take advantage of increased availability of critical resources following a disturbance.
Pathway 1.1a
Community 1.1 to 1.2
Prolonged drought, consecutive years of higher than average precipitation, infrequent wildfire, disease and/or insect attack.
Pathway 1.2a
Community 1.2 to 1.1
Absence from disturbance, return to normal weather patterns and natural regeneration over time.
State 2
Invaded State
The invaded state is characterized by the presence of non-native species in the understory. A biotic threshold has been crossed with the introduction of non-native species, which cannot be easily removed from the system and have the potential to alter disturbance regimes significantly from their historic range of variation. Non-native annuals are highly flammable and promote fires where fire have historically been infrequent.
Community 2.1
Plant Community 2.1
This plant community is compositionally similar to the reference plant community with non-natives in the understory. Ecological processes have not been compromised at this time, however, the ecological resilience is reduced by the presence of non-natives. This plant community may respond differently following a disturbance, when compared to the reference plant community. Dominant shrubs persist through invasion by non-natives, but other shrubs and desirable grasses may be unsuccessful in competing with the non-natives following a disturbance.
Community 2.2
Plant Community 2.2
This plant community is characteristic of a early-seral plant community. Initially, there is an increase in herbaceous biomass, which may or may not be dominated by non-native annuals, such as red brome, Mediterranean grass and redstem filaree. Sprouting shrubs will recover and provide favorable sites for germination and establishment of other shrubs. This plant community is identified as “at-risk”. The decreased native perennial vegetation and dominance by non-native annuals reduces the soil stability and leaves the site vulnerable to erosion from wind and water. Management should focus on reducing surface disturbances and protecting remaining native vegetation.
Pathway 2.1a
Community 2.1 to 2.2
Prolonged drought, consecutive years of higher than average precipitation, infrequent wildfire, disease and/or insect attack.
Pathway 2.2a
Community 2.2 to 2.1
Absence of disturbance and natural regeneration over time.
State 3
Eroded State
The eroded state is characterized by increased erosion and the presence of rills and gullies and a frequent disturbance return interval. Low shrub recruitment rates and loss of deep-rooted perennial grasses have resulted in decreased nutrient cycling, water storage and energy capture. Loss of native perennial vegetation has pushed this site across an abiotic threshold leading to obvious soil erosion, water flow patterns, rills and gullies.
Community 3.1
Plant Community 3.1
This plant community is characterized by the loss of perennial vegetation, soil and soil nutrients are being relocated down slope. Feedbacks contributing to the stability of this plant community within state 3 include reduced infiltration and nutrient cycling. Non-natives persist in the eroded plant community due to their annual growth form, persistent seed bank and competitive ability. Management should focus on reducing disturbance and protecting native vegetation in order to increase soil-site stability.
Community 3.2
Plant Community 3.2
This plant community is characterized by the loss of native vegetation. Non-natives persist in the plant community. Soil is increasingly redistributed down slope. This plant community relies on a nearby seed source for the recovery of native vegetation.
Pathway 3.1a
Community 3.1 to 3.2
Frequently occurring surface disturbance or intense rainfall event
Pathway 3.2a
Community 3.2 to 3.1
Absence from disturbance and natural regeneration over time.
Transition T1
State 1 to 2
Introduction of non-native species due 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.
Transition T2
State 2 to 3
Large scale disturbances remove native perennial vegetation, increasing the amount of bare ground leading to higher levels water erosion, decreased soil infiltration rates, and loosening of the soil surface causing channeling.
Restoration pathway R3
State 3 to 2
Possible restoration techniques, to stabilize the site and reestablish native perennials, include flattening and terracing hill slopes, closing roads, vertical, horizontal and rock mulching, as well as, planting container stock.
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 | Perennial Grasses | 1–20 | ||||
| low woollygrass | DAPU7 | Dasyochloa pulchella | 1–13 | – | ||
| big galleta | PLRI3 | Pleuraphis rigida | 1–13 | – | ||
| 2 | Annual Grasses | 1–20 | ||||
|
Forb
|
||||||
| 3 | Perennial Forbs | 5–20 | ||||
| globemallow | SPHAE | Sphaeralcea | 1–8 | – | ||
| 4 | Annual Forbs | 1–20 | ||||
|
Shrub/Vine
|
||||||
| 5 | Primary Shrubs | 148–228 | ||||
| shadscale saltbush | ATCO | Atriplex confertifolia | 75–100 | – | ||
| burrobush | AMDU2 | Ambrosia dumosa | 63–88 | – | ||
| creosote bush | LATR2 | Larrea tridentata | 5–20 | – | ||
| Fremont's dalea | PSFR | Psorothamnus fremontii | 5–20 | – | ||
| 6 | Secondary Shrubs | 13–88 | ||||
| Fremont's chaffbush | AMFR2 | Amphipappus fremontii | 3–8 | – | ||
| desertholly | ATHY | Atriplex hymenelytra | 3–8 | – | ||
| Nevada jointfir | EPNE | Ephedra nevadensis | 3–8 | – | ||
| white ratany | KRGR | Krameria grayi | 3–8 | – | ||
| water jacket | LYAN | Lycium andersonii | 3–8 | – | ||
Interpretations
Animal community
Livestock Interpretations:
This site has limited value for livestock grazing, due to the low forage production, steep slopes and stony surfaces. Shadscale provides good browse for domestic sheep and goats. Shadscale leaves and seeds are an important component of domestic sheep and cattle winter diets. Shadscale tends to be browse tolerant. Heavy grazing during the winter and/or spring reduces shadscale. Die-off can also occur during extended periods of high precipitation. Shadscale is tolerant of early spring light-intensity browsing. 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. Consumption of creosotebush may be fatal to sheep.
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:
Shadscale is a valuable browse species providing a source of palatable, nutritious forage for a wide variety of wildlife. The fruits and leaves are a food source for deer, desert bighorn sheep and pronghorn antelope. White bursage is an important browse species for wildlife. Creosotebush is unpalatable to most browsing wildlife.
Hydrological functions
Runoff is very high and permeability is moderately rapid. Rills and waterflow patterns are none to rare. Rock fragments protect the soil surface from raindrop impact.
Other products
Seeds of shadscale were used by Native Americans for bread and mush. White bursage is a host for sandfood, a parasitic plant. Sandfood was a valuable food supply for Native Americans. Creosotebush has been highly valued for its medicinal properties by Native Americans. 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.
Other information
White bursage and shadscale are widely used to revegetate disturbed sites 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.
Supporting information
Type locality
| Location 1: Clark County, NV | |
|---|---|
| Township/Range/Section | T19S R64E S28 |
| General legal description | Gale Hills area, east of Las Vegas, 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
PN-E
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 | 11/08/2011 |
| Approved by | Kendra Moseley |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
Rills are none to rare. Rock fragments armor the soil surface. -
Presence of water flow patterns:
Water flow patterns are none to rare. Rock fragments armor the soil surface. -
Number and height of erosional pedestals or terracettes:
Pedestals are none to rare. Occurrence is usually limited to areas of water flow patterns. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare ground <25%, depending on amount of 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):
Fine litter (foliage from grasses and annual & perennial forbs) expected to move distance of slope length during intense summer convection storms. Persistent litter (large woody material) will remain in place except 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 1 to 4 on most 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 medium platy or medium subangular blocky. Soil surface colors are browns and yellowish browns and soils are typified by an ochric epipedon. Organic matter of the surface 2 to 3 inches is typically < 1 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 (perennial bunchgrasses and large perennial forbs) slow runoff and increase infiltration. Sparse shrub canopy and associated litter break provide some protection from raindrop impact. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
Compacted layers are none. Subsoil 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:
Low shrubs (shadscale and white bursage)>>Sub-dominant:
associated shrubs>>perennial forbs>warm-season, perennial bunchgrasses=fibrous, shallow-rooted, annual grasses=fibrous, shallow-rooted, annual forbs.Other:
Annual grassesAdditional:
-
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):
Within plant interspaces and under canopy (±5-10%) and depth of litter is <0.25 inch. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
For normal or average growing season (end of May) ±250 lbs/ac; Spring moisture significantly affects total production. Favorable years 350 lbs/ac and unfavorable years 100 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, redstem filaree, annual mustards, and Mediterranean grass. -
Perennial plant reproductive capability:
All functional groups should reproduce in average (or normal) and above average growing season years. Little to now growth or reproduction occurs during below average years.
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