Natural Resources
Conservation Service
Ecological site R030XY158CA
Sodic Bottom 3-5" p.z.
Last updated: 2/24/2025
Accessed: 05/11/2025
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.
Classification relationships
California Natural Diversity Database, May 2002. List of California terrestrial natural communities recognized by the California Natural Diversity Database – Desert Saltbrush Scrub.
Sawyer, J.O. and T. Keeler-Wolf. 1995. Manual of California Vegetation – No series described.
Ecological site concept
This site occurs on hummocky lake plains. The soils associated with this site are well drained and very deep. These soils are saline and sodic.
Please refer to group concept R030XB025CA to view the provisional STM.
Associated sites
| R030XY047NV |
ALLUVIAL PLAIN Alluvial Plain Occurs on adjacent hummocks. |
|---|---|
| R030XY156CA |
Sodic Loam 3-5" p.z. Sodic Loam 3-5” P.Z. Occurs on lake plains. |
Similar sites
| R030XY047NV |
ALLUVIAL PLAIN Alluvial Plain ATPO is the dominant shrub. |
|---|
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) Atriplex torreyi |
| Herbaceous |
(1) Malacothrix glabrata |
Physiographic features
This site occurs on hummocky lake plains.
Table 2. Representative physiographic features
| Landforms |
(1)
Lake plain
|
|---|---|
| Ponding duration | Very brief (4 to 48 hours) |
| Ponding frequency | Rare |
| Elevation | 2,580 – 2,800 ft |
| Slope | 4% |
| Ponding depth | 1 – 4 in |
| Water table depth | 60 in |
| Aspect | Aspect is not a significant factor |
Climatic features
The primary air masses affecting California are cold maritime polar air from the Gulf of Alaska and warmer, moist maritime subtropical air from lower latitudes. Occasionally there are invasions of cold continental polar air from northern Canada or the Rocky Mountains. Precipitation in the area results primarily from the passage of cyclones with associated fronts during fall, winter and spring; from closed cyclones in late winter and spring; and from the flow of moist tropical air from the southeast to the southwest quadrant in the summer.
Barstow Fire Station, occurs at a lower elevation and has a long-term record from 1980 to 2002. Twentynine Palms Station, occurs at a lower elevation and has a long-term record from 1948 to 2002. This climate summary is based on data from both locations. Warm, moist winters (35 to 70 degrees F) and hot, dry summers (60 to 105 degrees F) characterize the climate on this site. Mean annual air temperature is 65 to 70 degrees F. The average annual precipitation is 3 to 5 inches, with most falling as rain from December through March. Approximately 20 to 45% of the annual precipitation occurs from July to September as a result of intense, convection storms.
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 well drained and very deep. These soils are saline and sodic. Available water capacity is very low (due to salinity) and permeability is slow. Effective rooting depth is 60 inches or more. Water tables are greater than 60 inches.
Soils:
Mojave Desert Area, West Central Part Soil Survey Area (CA698): Typic Haplosalids, MU 4702 (minor component).
Table 4. Representative soil features
| Surface texture |
(1) Silty clay |
|---|---|
| Family particle size |
(1) Clayey |
| Drainage class | Well drained |
| Permeability class | Slow |
| Soil depth | 60 in |
| Surface fragment cover <=3" | 1 – 5% |
| Available water capacity (0-40in) |
0.3 – 0.6 in |
| Calcium carbonate equivalent (0-40in) |
5 – 8% |
| Electrical conductivity (0-40in) |
10 – 60 mmhos/cm |
| Sodium adsorption ratio (0-40in) |
6 – 20 |
| Soil reaction (1:1 water) (0-40in) |
8 – 9.2 |
| Subsurface fragment volume <=3" (Depth not specified) |
1 – 5% |
Ecological dynamics
Please refer to group concept R030XY129CA to view the provisional STM.
The interpretive plant community for this site is the historic climax plant community. The historic site potential is characterized a continuous canopy of shrubs, 0.5 to 1.5 meters tall. This community is dominated by Torrey saltbush (Atriplex torreyi). The understory is sparse. Perennial grasses that may occur include saltgrass (Distichlis spicata) and alkali sacaton (Sporobolus airoides). The majority of annuals are winter annuals that are especially abundant after winters of above average precipitation. Potential vegetative composition is approximately 5% grasses, 5% forbs and 90% shrubs. This site is stable in this condition.
Torrey saltbush is a phreatophyte and halophyte found along valley bottoms and margins of dry lakebeds. Mature plants produce an abundance of seeds that readily germinate without pretreatment or light, allowing this species to quickly colonize disturbed sites. Torrey saltbush is an invader of alkaline meadows where groundwater tables have been altered.
Fire effects: Most North American species of Atriplex are highly tolerant of fire. If top-killed they sprout prolifically.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 1
Desert Saltbush Scrub
Community 1.1
Desert Saltbush Scrub
Figure 2. Sodic Bottom
The interpretive plant community for this site is the historic climax plant community. The historic site potential is characterized a continuous canopy of shrubs, 0.5 to 1.5 meters tall. This community is dominated by Torrey saltbush (Atriplex torreyi). The understory is sparse. Perennial grasses that may occur include saltgrass (Distichlis spicata) and alkali sacaton (Sporobolus airoides). The majority of annuals are winter annuals that are especially abundant after winters of above average precipitation. Potential vegetative composition is approximately 5% grasses, 5% forbs and 90% shrubs. This site is stable in this condition. This list of plants and their relative proportions are based on near normal years. Fluctuations in species composition and relative production may change from year to year dependent upon abnormal precipitation or other climatic factors. The historic climax plant community has been determined by study of rangeland relict areas or other protected areas and historical accounts.
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 | 684 | 877 | 1067 |
| Forb | 14 | 19 | 24 |
| Grass/Grasslike | 1 | 4 | 10 |
| Total | 699 | 900 | 1101 |
Table 6. Ground cover
| Tree foliar cover | 0% |
|---|---|
| Shrub/vine/liana foliar cover | 15-20% |
| Grass/grasslike foliar cover | 0-1% |
| Forb foliar cover | 0-1% |
| Non-vascular plants | 0% |
| Biological crusts | 0% |
| Litter | 0% |
| Surface fragments >0.25" and <=3" | 0% |
| Surface fragments >3" | 0% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 0% |
Table 7. Soil surface cover
| Tree basal cover | 0% |
|---|---|
| Shrub/vine/liana basal cover | 0% |
| Grass/grasslike basal cover | 0% |
| Forb basal cover | 0% |
| Non-vascular plants | 0% |
| Biological crusts | 0% |
| Litter | 15-25% |
| Surface fragments >0.25" and <=3" | 0-5% |
| Surface fragments >3" | 0% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 50-80% |
Table 8. Canopy structure (% cover)
| Height Above Ground (ft) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.5 | – | – | – | – |
| >0.5 <= 1 | – | – | 1-5% | – |
| >1 <= 2 | – | – | – | 1-5% |
| >2 <= 4.5 | – | 30-35% | – | – |
| >4.5 <= 13 | – | – | – | – |
| >13 <= 40 | – | – | – | – |
| >40 <= 80 | – | – | – | – |
| >80 <= 120 | – | – | – | – |
| >120 | – | – | – | – |
Figure 4. Plant community growth curve (percent production by month). CA3032, Torrey Saltbush. Growth begins in spring: flowering occurs from June to September. Fruits mature from September to October. Maximum growth occurs in early summer..
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| J | F | M | A | M | J | J | A | S | O | N | D |
| 0 | 0 | 10 | 10 | 30 | 30 | 10 | 5 | 5 | 0 | 0 | 0 |
Additional community tables
Table 9. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Perennial Grasses | 0–4 | ||||
| saltgrass | DISP | Distichlis spicata | 0–2 | – | ||
| alkali sacaton | SPAI | Sporobolus airoides | 0–2 | – | ||
| 2 | Annual Grasses | 1–5 | ||||
| Grass, annual | 2GA | Grass, annual | 1–5 | – | ||
|
Forb
|
||||||
| 3 | Perennial Forbs | 0–2 | ||||
| desert princesplume | STPI | Stanleya pinnata | 0–2 | – | ||
| 4 | Annual Forbs | 14–22 | ||||
| smooth desertdandelion | MAGL3 | Malacothrix glabrata | 7–11 | – | ||
| New Mexico plumeseed | RANE | Rafinesquia neomexicana | 7–11 | – | ||
|
Shrub/Vine
|
||||||
| 5 | Dominant Shrubs | 664–1034 | ||||
| Torrey's saltbush | ATTO | Atriplex torreyi | 424–660 | – | ||
| shadscale saltbush | ATCO | Atriplex confertifolia | 240–374 | – | ||
| 6 | Other Shrubs | 21–33 | ||||
| fourwing saltbush | ATCA2 | Atriplex canescens | 7–11 | – | ||
| cattle saltbush | ATPO | Atriplex polycarpa | 7–11 | – | ||
| Mojave seablite | SUMO | Suaeda moquinii | 7–11 | – | ||
Interpretations
Animal community
Atriplex spp. are known for their high productivity and quality forage. Torrey saltbush is high in protein, fats, and carbohydrates. Forage quality is influenced by age and phenological stage at the time of harvest. Shadscale is often eaten during the early spring before spines mature.
The twigs and foliage of the saltbushes provide forage for mule deer and small mammals. The seeds are consumed by small mammals and birds. Torrey saltbush grows in dense stands providing fair to good cover for wildlife.
Torrey saltbush stems and seeds are desirable to Black-tailed jackrabbits, non-game birds and small mammals.
Shadscale is a desirable cover and forage species to Black-tailed jackrabbits, non-game birds and small mammals.
Recreational uses
Heavy off-road vehicle usage due to proximity to dry lake bed. Dry lake beds are heavily used for recreation in the survey area.
Supporting information
Inventory data references
NV-ECS-1: 1. 8/02 in San Bernardino, CA
Type locality
| Location 1: San Bernardino County, CA | |
|---|---|
| UTM zone | N |
| UTM northing | 3812663 |
| UTM easting | 537366 |
| Latitude | 34° 27′ 17″ |
| Longitude | 116° 35′ 32″ |
| General legal description | Melville Lake, Johnson Valley, California. Elevation 2734 feet. |
Other references
Hickman, J.C. (ed).1993. The Jepson Manual: Higher plants of California. University of California Press, Berkeley, CA.
U.S. Department of Agriculture, NRCS. National Range and Pasture Handbook, September 1997.
U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory. 2002. Fire Effects Information System [Online] Available: http://www.fs.fed.us/database/feis/plants)
Western Regional Climate Center, Desert Research Institute, Reno, Nevada (http://www.wrcc.dri.edu/index.html)
Locator map image generated using TopoZone.com © 1999-2004 Maps a la carte, Inc. - All rights reserved.
Contributors
Patti Novak-Echenique, Heath M. McAllister
Approval
Sarah Quistberg, 2/24/2025
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 | 02/26/2025 |
| Approved by | Sarah Quistberg |
| 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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