Natural Resources
Conservation Service
Ecological site R030XA094NV
SHALLOW GRAVELLY LOAM 5-7 P.Z.
Last updated: 2/18/2025
Accessed: 03/15/2025
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 summits and sideslopes of lower mountains, hills, and upper fan piedmonts. Slopes range from 0 to over 30 percent, but slope gradients of 2 to 15 percent are typical. Elevations are 3300 to about 6500 feet. The soils of this site are shallow to a restrictive layer and have formed in residuum, colluvium, or alluvium from mixed parent materials.
Please refer to group concept R030XB029NV to view the provisional STM.
Associated sites
| R030XA058NV |
LIMY 5-7 P.Z. |
|---|---|
| R030XA095NV |
SHALLOW GRAVELLY SLOPE 5-7 P.Z. |
Similar sites
| R030XA095NV |
SHALLOW GRAVELLY SLOPE 5-7 P.Z. Less productive site. |
|---|---|
| R030XA006NV |
SHALLOW LIMESTONE SLOPE 5-7 P.Z. ATCO codominant shrub. |
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) Coleogyne ramosissima |
| Herbaceous |
(1) Achnatherum hymenoides |
Physiographic features
This site occurs on summits and sideslopes of lower mountains, hills, and upper fan piedmonts. Slopes range from 0 to over 30 percent, but slope gradients of 2 to 15 percent are typical. Elevations are 3300 to about 6500 feet.
Table 2. Representative physiographic features
| Landforms |
(1)
Fan remnant
(2) Pediment (3) Hill |
|---|---|
| Flooding frequency | None |
| Ponding frequency | None |
| Elevation | 1,006 – 1,981 m |
| Slope | 0 – 30% |
| Water table depth | 0 cm |
| Aspect | Aspect is not a significant factor |
Climatic features
The climate on this site is arid, characterized by cold, moist winters, and hot, dry summers. Average annual precipitation is 5 to 7(8) inches. Mean annual air temperature is 53 to 60 degrees F. The average growing season is about 130 to 180 days.
Table 3. Representative climatic features
| Frost-free period (average) | 180 days |
|---|---|
| Freeze-free period (average) | |
| Precipitation total (average) | 178 mm |
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 of this site are shallow to a restrictive layer and have formed in residuum, colluvium, or alluvium from mixed parent materials. A representative surface cover of rock fragments is about 60 percent gravels and 5 percent cobbles. These soils are well drained with slow to medium runoff. The soils series associated with this site includes; Ferrogold, Dedas, and Longjim.
Table 4. Representative soil features
| Surface texture |
(1) Extremely gravelly loam (2) Very gravelly fine sandy loam (3) Gravelly fine sandy loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderate |
| Soil depth | 38 – 152 cm |
| Surface fragment cover <=3" | 25 – 64% |
| Surface fragment cover >3" | 2 – 7% |
| Available water capacity (0-101.6cm) |
2.54 – 6.6 cm |
| Calcium carbonate equivalent (0-101.6cm) |
25 – 50% |
| Electrical conductivity (0-101.6cm) |
0 – 4 mmhos/cm |
| Sodium adsorption ratio (0-101.6cm) |
0 – 5 |
| Soil reaction (1:1 water) (0-101.6cm) |
7.9 – 8.4 |
| Subsurface fragment volume <=3" (Depth not specified) |
25 – 48% |
| Subsurface fragment volume >3" (Depth not specified) |
2 – 6% |
Ecological dynamics
Please refer to group concept R030XB029NV to view the provisional STM.
As ecological condition deteriorates, blackbrush increases almost to the exclusion of all other species. Following wildfire, fire tolerant/crown-sprouting shrubs increase and often dominate this site. Upwards of 60 or more, years, may be required for reestablishing a blackbrush stand following a fire.
Fire Ecology:
Fire return intervals for blackbrush communities range from 35 to 100 years. Blackbrush stands are substantially decreased or eliminated by fire. Blackbrush stands are subject to fire, and fire will start and spread easily due to the dense, close spacing and resinous foliage of blackbrush. There are usually few forbs or grasses in blackbrush stands that might aid in carrying fire, but despite this, blackbrush community’s burn under conditions of high temperature, high wind velocity, and low relative humidity. 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. Spiny menodora often survives fire because its foliage does not readily burn. Desert needlegrass has persistent dead leaf bases, which make it susceptible to burning. Fire probably top-kills desert needlegrass. Most needlegrasses (Achnatherum spp.), especially young plants, are very susceptible to fire damage. Surviving tufts of desert needlegrass are likely to sprout. Indian ricegrass reestablishes on burned sites through seed dispersed from adjacent unburned areas. Indian ricegrass may also sprout from tillers following fire.
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
State 1 submodel, plant communities
State 1
Reference Plant Community
Community 1.1
Reference Plant Community
The reference plant community is characterized by an open canopy of shrubs and perennial grasses. The plant community is dominated by blackbrush. Potential vegetative composition is about 10% grasses, 10% annual and perennial forbs, and 80% shrubs. Approximate ground cover (basal and crown) is 15 to 20 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) |
|---|---|---|---|
| Shrub/Vine | 157 | 269 | 404 |
| Grass/Grasslike | 19 | 34 | 50 |
| Forb | 20 | 34 | 50 |
| Total | 196 | 337 | 504 |
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 | 13–34 | ||||
| Indian ricegrass | ACHY | Achnatherum hymenoides | 7–17 | – | ||
| desert needlegrass | ACSP12 | Achnatherum speciosum | 7–17 | – | ||
| 2 | Secondary Perennial Grasses | 7–27 | ||||
| threeawn | ARIST | Aristida | 2–10 | – | ||
| King's eyelashgrass | BLKI | Blepharidachne kingii | 2–10 | – | ||
| squirreltail | ELEL5 | Elymus elymoides | 2–10 | – | ||
| James' galleta | PLJA | Pleuraphis jamesii | 2–10 | – | ||
| bluegrass | POA | Poa | 2–10 | – | ||
| 3 | Annual Grasses | 1–10 | ||||
|
Forb
|
||||||
| 4 | Perennial Forbs | 1–17 | ||||
| desert globemallow | SPAM2 | Sphaeralcea ambigua | 2–7 | – | ||
| threeawn | ARIST | Aristida | 0–4 | – | ||
| 5 | Annual Forbs | 1–17 | ||||
|
Shrub/Vine
|
||||||
| 6 | Primary shrubs | 176–289 | ||||
| blackbrush | CORA | Coleogyne ramosissima | 168–235 | – | ||
| Nevada jointfir | EPNE | Ephedra nevadensis | 7–27 | – | ||
| spiny menodora | MESP2 | Menodora spinescens | 1–27 | – | ||
| 7 | Secondary shrubs | 17–50 | ||||
| burrobush | AMDU2 | Ambrosia dumosa | 3–17 | – | ||
| winterfat | KRLA2 | Krascheninnikovia lanata | 3–17 | – | ||
| creosote bush | LATR2 | Larrea tridentata | 3–17 | – | ||
| desert pepperweed | LEFR2 | Lepidium fremontii | 3–17 | – | ||
| water jacket | LYAN | Lycium andersonii | 3–17 | – | ||
| yucca | YUCCA | Yucca | 3–17 | – | ||
Interpretations
Animal community
Livestock Interpretations:
This site is suitable for spring sheep grazing and marginally suitable for cattle grazing due to low forage producation and limited water availability. Blackbrush is not preferred as forage by domestic livestock, deer, or pronghorn, but it does provide poor forage during the spring, summer, and fall for domestic cattle, horses, and domestic sheep. Blackbrush provides poor to good forage for domestic goats.
Big galleta is considered a valuable forage plant for cattle and domestic sheep in the Mohave Desert. Its coarse, rigid culms make it relatively resistant to heavy grazing and trampling.
Desert needlegrass produces considerable basal foliage and is good forage while young. Young desert needlegrass is palatable to all classes of livestock. Mature herbage is moderately grazed by horses and cattle but rarely grazed by sheep.
Indian ricegrass is described as highly palatable to all classes of livestock in both green and cured condition.
Wildlife Interpretations:
Mule deer and bighorn sheep generally use the blackbrush vegetation type in winter. The principal forage value of blackbrush appears to be as a browse species for bighorn sheep. In southern Nevada, blackbrush communities with an understory including big galleta are preferred cover for desert bighorn sheep. Blackbrush provides cover for nongame birds and small mammals.
Indian ricegrass is eaten by pronghorn in moderate amounts whenever available. Indian ricegrass receives moderate pronghorn use from March through May. Indian ricegrass is consumed by desert bighorn sheep. Indian ricegrass is eaten by mule deer in the spring.
Hydrological functions
Permeability is moderately rapid and available water capacity is low.
Other products
Indian ricegrass seeds make a gluten-free, nutritious flour with a potentially good market. Indian ricegrass was traditionally eaten by some Native American people. The Paiutes used the seed as a reserve food source. The large-seeded panicle is often used in dry floral arrangements.
Other information
Blackbrush contributes to desert fertility by protecting the soil against wind erosion through retarding the movement of soil and increasing the accumulation of fine soil particles around its base. Blackbrush protects under story vegetation from the effects of high temperatures, thereby helping to retain surface nitrogen and adding organic matter to the soil. Blackbrush also serves as a nitrogen reservoir through the storage of nitrogen in roots, leaves, and stems.
Desert needlegrass seeds are easily germinated and have potential for commercial use. Desert needlegrass may be used for groundcover in areas of light disturbance, but it is susceptible to excessive trampling.
Indian ricegrass is well-suited for surface erosion control and desert revegetation although it is not highly effective in controlling sand movement. Certain native ecotypes exhibit desirable characteristics such as drought and salinity tolerance, low seed dormancy, and good nutritional qualities.
Supporting information
Inventory data references
NV-ECS-1: 2 records
Type locality
| Location 1: Nye County, NV | |
|---|---|
| Township/Range/Section | T8 S R48 E S21 |
| General legal description | Thirsty Canyon area, Pahute Mesa just east of Sarcobatus Flat, Nye County, Nevada. |
Other references
USDA-NRCS Plant Databse (Online, http://plants.usda.gov/).
Fire Effect Information System (Online, http://www.fs.fed.us/database/feis/).
Contributors
HA
Approval
Kendra Moseley, 2/18/2025
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 | 03/15/2025 |
| Approved by | Kendra Moseley |
| 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:
Print Options
Sections
Font
Other
The Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.
Click on box and path labels to scroll to the respective text.