Natural Resources
Conservation Service
Ecological site R040XD015CA
Limy 4-6" p.z.
Accessed: 11/23/2024
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
NDDB/Holland, R.F. 1986. Preliminary Descriptions of the Terrestrial Natural Communities of California - Mojave Creosote Bush. Sawyer, J.O. and T. Keeler-Wolf. 1995. Manual of California Vegetation - Creosote Bush-White Bursage Series.
Associated sites
| R040XD010CA |
Valley Wash This site can occur in large adjacent drainages. |
|---|
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) Larrea tridentata |
| Herbaceous |
(1) Plantago ovata |
Physiographic features
This site occurs on alluvial fan, inset fans and washes.
Table 2. Representative physiographic features
| Landforms |
(1)
Alluvial fan
(2) Inset fan (3) Wash |
|---|---|
| Flooding duration | Extremely brief (0.1 to 4 hours) to very brief (4 to 48 hours) |
| Flooding frequency | Rare to occasional |
| Elevation | 152 – 853 m |
| Slope | 2 – 5% |
| Aspect | Aspect is not a significant factor |
Climatic features
The Colorado Desert of California represents the northwesternmost portion of the Sonoran Desert. The subtropical Colorado Desert results from the descent of cold air which is heated by compression and arrives hot and dry at the earth's surface. Precipitation is frontal in nature during the winter and convectional in the summer. Reduced summer rainfall and high potential evapotranspiration make the Colorado Desert one of the most arid regions in North America. Summer temperatures frequently exceed 105 degrees F. The average annual precipitation ranges from 2 to 6 inches with most falling as rain. Snowfall is rare. Approximately 35% of the annual precipitation occurs from July to September as a result of intense convection storms. Spring months are the windiest.
Table 3. Representative climatic features
| Frost-free period (average) | 360 days |
|---|---|
| Freeze-free period (average) | 360 days |
| Precipitation total (average) | 152 mm |
Figure 1. Monthly average minimum and maximum temperature
Influencing water features
Soil features
This site occurs on alluvial fans. Soils consist of very deep, excessively drained soils formed in stratified alluvium from mixed sources and of very deep, excessively drained soils that formed in stratified fan alluvium. Soils series include Carrizo and Riverbend.
Table 4. Representative soil features
| Surface texture |
(1) Extremely gravelly sandy loam |
|---|---|
| Family particle size |
(1) Sandy |
| Drainage class | Moderately well drained to excessively drained |
| Permeability class | Moderate to moderately rapid |
| Soil depth | 102 – 203 cm |
| Surface fragment cover <=3" | 70 – 91% |
| Surface fragment cover >3" | 3 – 10% |
| Available water capacity (0-101.6cm) |
4.5 – 7.49 cm |
| Calcium carbonate equivalent (0-101.6cm) |
7 – 25% |
| Electrical conductivity (0-101.6cm) |
0 – 2 mmhos/cm |
| Sodium adsorption ratio (0-101.6cm) |
0 – 4 |
| Soil reaction (1:1 water) (0-101.6cm) |
7.4 – 8.4 |
| Subsurface fragment volume <=3" (Depth not specified) |
37 – 51% |
| Subsurface fragment volume >3" (Depth not specified) |
2 – 3% |
Ecological dynamics
This creosotebush site is widespread throughout the Sonoran Desert and consists of both long-lived and short-lived perennial species. In stable, old communities, creosotebushes (Larrea tridentata) or clones may attain ages of several thousand years. Defoliation and death of branches of creosotebush may occur as a result of long periods of intense moisture stress. Surface disturbance may reduce plant cover, density, and diversity of this site. These changes can be very subtle or extremely obvious depending on the intensity of disturbance, and an assortment of environmental factors (topography, rainfall, soil type). After surface disturbance, white bursage (Ambrosia dumosa) may initially increase and an invasion of non-native annual grasses and forbs such as Mediterranean grass (Schismus arabicus) and redstem stork’s bill (Erodium cicutarium) may occur.
White burrobush (Hymenoclea salsola) is the primary perennial pioneer plant. Fire effects: Creosotebush is very flammable and is poorly adapted to fire, due to its limited re-sprouting ability. Factors such as season of burning, fuel quantity, fire intensity and age of existing shrubs will affect the ability of creosotebush to re-sprout. White bursage can also be killed by fire, however, it can rapidly reestablish from off-site seed.
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
Creosotebush - white bursage series
Community 1.1
Creosotebush - white bursage series
Figure 2. Limy 4-6
The interpretative plant community is the historic climax community prior to European colonization. This site is co-dominated by creosotebush and white bursage, with white ratany as a minor shrub component. Perennial grasses are a minor component at most and often absent. Native annual forbs include desert Indianwheat (Plantago ovata) and cryptantha (Cryptantha spp.). Non-native forbs have invaded the site and include peppergrass (Lepidium spp.) and Mediterranean grass. The site occurs primarily on fan piedmonts but can also be found in some minor drainageways. Receiving slightly higher run-off and/or rainfall than other creosotebush-white bursage communities, it is a higher producing site. The potential plant community is 85% shrubs, 10% forbs, and 5% grasses. The total vegetation cover is 35%.
Figure 3. 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 | 112 | 156 | 207 |
| Forb | – | 10 | 13 |
| Grass/Grasslike | – | 2 | 3 |
| Total | 112 | 168 | 223 |
Table 6. Ground cover
| Tree foliar cover | 0% |
|---|---|
| Shrub/vine/liana foliar cover | 25-30% |
| Grass/grasslike foliar cover | 0-3% |
| Forb foliar cover | 0-5% |
| 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 | 10-15% |
| Grass/grasslike basal cover | 0% |
| Forb basal cover | 0% |
| Non-vascular plants | 0% |
| Biological crusts | 0% |
| Litter | 5-10% |
| Surface fragments >0.25" and <=3" | 65-70% |
| Surface fragments >3" | 0% |
| Bedrock | 1-2% |
| Water | 0% |
| Bare ground | 10-15% |
Table 8. Canopy structure (% cover)
| Height Above Ground (m) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.15 | – | – | 0-3% | 0-5% |
| >0.15 <= 0.3 | – | – | – | – |
| >0.3 <= 0.6 | – | 10-15% | – | – |
| >0.6 <= 1.4 | – | 10-15% | – | – |
| >1.4 <= 4 | – | 1-3% | – | – |
| >4 <= 12 | – | – | – | – |
| >12 <= 24 | – | – | – | – |
| >24 <= 37 | – | – | – | – |
| >37 | – | – | – | – |
Additional community tables
Table 9. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Shrub/Vine
|
||||||
| 1 | Native shrubs | 112–207 | ||||
| burrobush | AMDU2 | Ambrosia dumosa | 49–95 | – | ||
| creosote bush | LATR2 | Larrea tridentata | 50–92 | – | ||
| white ratany | KRGR | Krameria grayi | 12–20 | – | ||
|
Grass/Grasslike
|
||||||
| 2 | Native grass | 0–3 | ||||
| sixweeks threeawn | ARAD | Aristida adscensionis | 0–3 | – | ||
|
Forb
|
||||||
| 3 | Native Forbs | 0–11 | ||||
| cryptantha | CRYPT | Cryptantha | 0–7 | – | ||
| desert Indianwheat | PLOV | Plantago ovata | 0–4 | – | ||
| 4 | Opportunistic forbs | 0–2 | ||||
| yellow pepperweed | LEFL2 | Lepidium flavum | 0–2 | – | ||
Interpretations
Animal community
This site is dominated by two shrubs highly valued by burrowing animals, creosotebush and white bursage. Desert tortoise, lizards, ground squirrels and other rodents all make burrows in the root-mounds of creosotebushes. The medium stature of creosotebushes also allow for some perching by both birds and rodents. The partially shaded apron around the creosotebush also gives rise to abundant annual plants when rainfall allows. This then provides a food source for the above-mentioned wildlife. White bursage, although not as well suited as creosote, also provides good burrowing among its roots and provides good cover from predators.
Recreational uses
This site is highly valued for open space and those interested in desert ecology. Desert tortoise, annual wildflowers and shrubs may also attract visitors during the spring months.
Other information
Non-native plants on this site include Mediterranean grass. This grass is rarely eaten by the native animals and increases fire potential, providing a fuel load in between shrubs.
Supporting information
Type locality
| Location 1: San Bernardino County, CA | |
|---|---|
| UTM zone | N |
| UTM northing | 3808638 |
| UTM easting | 718563 |
| Latitude | 34° 23′ 45″ |
| Longitude | 114° 37′ 20″ |
| General legal description | The type locality is within the southern Chemehuevi Wash OHV area. The site occurs about 1/2 mile east of CA HWY 95. |
Contributors
Heath McAllister
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 | |
| Approved by | |
| 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.