Natural Resources
Conservation Service
Ecological site R030XA027CA
Sandy
5-7" P.Z.
Last updated: 10/21/2024
Accessed: 08/29/2026
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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 sand sheets on basin floors and toe slopes of fan piedmonts. Elevations are 2300 to 3000 feet. Slopes range from 0 to 5 percent.
The soils that characterize this site are very deep and somewhat excessively drained. They are formed in granitic alluvium. Surface textures are loamy sands. Subsoils are sands, and loamy sands which are slightly to moderately alkaline.
Please refer to group concept R030XA016CA to view the provisional STM.Associated sites
R030XA031CA Sodic Dunes 5-7" P.Z.
Sodic Dune 5-7
Similar sites
R030XA031CA Sodic Dunes 5-7" P.Z.
Sodic Dune 5-7
R030XA019CA Dune 5-7" p.z.
Dune 5-7
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Atriplex canescens
(2) Krascheninnikovia lanataHerbaceous (1) Achnatherum hymenoides
Physiographic features
This site occurs on sand sheets on basin floors and toe slopes of fan piedmonts. Elevations are 2300 to 3000 feet. Slopes range from 0 to 5 percent.
Table 2. Representative physiographic features
Landforms (1) Sand sheet
Flooding frequency Rare Elevation 2300 – 3000 ft Slope 0 – 5 % Aspect Aspect is not a significant factor Climatic features
The climate on this site is characterized by cool, relatively dry winters (30 to 60 degrees F) and hot, dry summers (70 to 100 degrees F). The average annual precipitation ranges from 3 to 7 inches with most falling as rain from November to March. Mean annual air temperature is 60 to 64 degrees F.
The average frost free period is 200 to 250 days.Table 3 Representative climatic features
Frost-free period (average) 350 days Freeze-free period (average) Precipitation total (average) 10 in ">Influencing water features
Soil features
The soils that characterize this site are very deep and somewhat excessively drained. They are formed in granitic alluvium. Surface textures are loamy sands. Subsoils are sands, and loamy sands which are slightly to moderately alkaline. Available water capacity is low and the hazard of water erosion is slight. Wind erosion hazard is severe. Effective rooting depth is 60 inches or more. Water tables are greater than 60 inches.
Soil Map Units
102 Cajon loamy sand, 0-2% slopes
108 Cajon-Norob complex, 0-5% slopes
117 Helendale-Cajon complex, 2-5% slopes
Ecological dynamics
Please refer to group concept R030XA016CA to view the provisional STM.
As ecological condition deteriorates, Indian ricegrass, desert needlegrass, fourwing saltbush and winterfat decrease, while horsebrush and ephedra increase. Burrobush, snakeweed and goldenhead will dominate disturbed areas resulting from land clearing. Other species likely to invade this site include non-native annual forbs and grasses such as Russian thistle, filaree, brome and schismus.
Fire is infrequent and is not recommended as a management tool due to the sparse cover, severe hazard of wind erosion and slow recovery rates.
Water is the main limitation on this site. Water developments would greatly increase the diversity of species. Management for this site would be to protect it from excessive disturbance and maintain existing plant cover.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 textEcosystem states
State 1 submodel, plant communities
State 2 submodel, plant communities
State 1
Reference State - Plant Community 1.1Community 1.1
Reference State - Plant Community 1.1The representative natural plant community is Stabilized and Partially Stabilized Desert Sand Fields or Fourwing saltbush series. This community is dominated by fourwing saltbush, winterfat and Indian ricegrass. Potential vegetative composition is about 30% grasses, 10% forbs, and 60% shrubs.
The historic site potential varies from an open to nearly continuous canopy of shrubs less than 2 meters tall. Perennial grasses and forbs are common. Annuals are seasonally present and are especially abundant in favorable years. This site occurs on desert sand accumulations that are not obviously worked into dune landforms. This site increases in stability as vegetative cover increases.
The following table lists the major plant species and percentages by weight, air dry, of the total plant community that each contributes in an average production year. Fluctuations in species composition and relative production may change from year to year dependent upon abnormal precipitation or other climatic factors.
Forest overstory.Allow no more than 3% of each species of this group, and no more than 15% in aggregate<br /> <br />
Forest understory. Allow no more than 2% of each species of the grasses group, and no more than 5% in aggregate<br /> <br /> Allow no more than 2% of each species of the forbs group, and no more than 5% in aggregate<br />
Figure 1. Annual production by plant type (representative values) or group (midpoint values)
Table 4. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Shrub/Vine 120 240 360 Grass/Grasslike 60 120 180 Forb 20 40 60 Total 200 400 600 Table 5. Ground cover
Tree foliar cover 0% Shrub/vine/liana foliar cover 10-20% Grass/grasslike foliar cover 0-10% Forb foliar cover 0-0% 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% Figure 2. Plant community growth curve (percent production by month). CA3008 , Fourwing saltbush. Growth begins in spring to early summer. Flowering occurs from May through September, and fruit ripens from October to December. Seed dispersal occurs from October through April. Seed may remain on the plants from one to two years..
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 5 25 35 15 10 5 5 0 0 0 Figure 3. Plant community growth curve (percent production by month). CA3009 , Winterfat. Growth starts in late winter. Flowering and seed set occur by June. Seeds remain on the shrubs for several months. Dormancy occurs during the hot summer months..
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 10 25 40 20 5 0 0 0 0 0 0 Figure 4. Plant community growth curve (percent production by month). CA3022 , Indian ricegrass. Growth begins in late winter, flowering and fruiting finished by the hot summer months. Early fall rains can trigger a flush of new growth..
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 5 15 30 35 5 0 0 5 5 0 0 State 2
Plant Community 2Community 2.1
Plant Community 2This plant community occurs across the west end of the MLRA. Introduced annuals such as red brome, schismus, and filaree have invaded the historic climax plant community and have become a dominant component of the herbaceous cover. It is hypothesized that the change from natives to non-natives is due to a combination of factors such as (1) invasion of alien species, (2)changes in the kinds of animals and grazing pressure, (3)drought, and (4)changes in fire patterns. This site increases in stability as vegetative cover increases.
Additional community tables
Table 6. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 7. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
Historically, this site may have provided habitat for antelope and wild burros. At present, this site provides habitat for small mammals such as kangaroo rats and ground squirrels, and fur and game mammals such as coyotes and rabbits. The Joshua trees provide song perches, lookout posts and nest sites for birds. Other wildlife species occurring on this site include: ravens, raptors, reptiles and various songbirds. The soils of this site are poorly suited for desert tortoise as the sandy subsoil horizons have reduced burrow stability.
Other Mgt. Considerations: This site is suitable for limited spring grazing by sheep and also cattle where water is available. In favorable years, annual forbs and grasses provide additional forage.
General guide to initial stocking rate. Before making specific recommendations, an on-site evaluation must be made. Stocking rate based on proper use factors and proportion of grazeable forage.
Pounds/acre
Airdry AUM/AC AC/AUM
Normal Years 400 20-25
Hydrological functions
Runoff is negligible to very low. Hydrologic soil condition A - soils having high infiltration rates even when thoroughly wetted and consisting chiefly of deep, well-drained to excessively drained sands or gravels. These soils have a high rate of water transmission. Hydrologic condition: good - >70% ground cover (includes litter, grass and brush overstory); fair - 30 to 70% ground cover; poor - <30% ground cover.
Soil Series:Cajon
Hydrologic Group: A
Hydrologic Conditions and Runoff Curves:
Good 49; Fair 55; Poor 63
Recreational uses
This site has value for open space and is used by mountain bikers and other off-road enthusiasts. Flowering wildflowers may also attract visitors during the spring. Off-road vehicle use can easily damage the soil structure and vegetative cover, causing increased soil blowing.
Other information
Military Operations - Clearing or any other disturbance that destroys the soil structure and vegetation can result in increased soil blowing and barren areas. Vehicles should be restricted to existing roads and trails. Native species indigenous to this site are recommended for any revegetation efforts.
Supporting information
Inventory data references
Sampling technique _3_ NV-ECS-1 _1_ SCS-Range 417 ___ Other
Type locality
Location 1: Kern County, CA Township/Range/Section TT9N RR8W S6 General legal description SW 1/4 Section 6, T9N, R8W East of Rogers Lake, Kern Co., CA Contributors
P. Novak-Echenique
Approval
Kendra Moseley, 10/21/2024
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 08/29/2026 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
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Presence of water flow patterns:
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Number and height of erosional pedestals or terracettes:
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Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
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Number of gullies and erosion associated with gullies:
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Extent of wind scoured, blowouts and/or depositional areas:
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Amount of litter movement (describe size and distance expected to travel):
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Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
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Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
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Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
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Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
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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:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
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Average percent litter cover (%) and depth ( in):
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Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
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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:
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Perennial plant reproductive capability:
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