Natural Resources
Conservation Service
Ecological site R030XA115AZ
Sandy Wash
3-6" p.z.
Last updated: 10/21/2024
Accessed: 08/30/2026
-
Search
Major Land Resource Area or ecological site by name and/or ID.
PreviousSectionsNextGeneral 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.
Click to explore map
Figure 1. Mapped extent
Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated.
MLRA notes
Major Land Resource Area (MLRA): 030X–Mojave Basin and Range
This unit occurs within the Basin and Range Province and is characterized by broad basins, valleys, and old lakebeds. Widely spaced mountains trending north to south occur throughout the area. Isolated, short mountain ranges are separated by an aggraded desert plain. The mountains are fault blocks that have been tilted up. Long alluvial fans coalesce with dry lakebeds between some of the ranges.
LRU notes
AZ LRU 30-1 – Lower Mohave Desert
Elevations range from 400 to 2500 feet and precipitation averages 3 to 6 inches per year. Vegetation includes creosotebush, white bursage, Mormon tea, and brittlebush. The soil temperature regime is hyperthermic and the soil moisture regime is typic aridic.Ecological site concept
This ecological site is located in bottom position. A readily identified water flow channel of unconsolidated sand and gravel is braided throughout this ecological site. Soil textures are a wide range of gravelly sand.
Table 1. Dominant plant species
Tree Not specified
Shrub (1) Hymenoclea salsola
(2) Acacia greggiiHerbaceous (1) Pleuraphis rigida
(2) Muhlenbergia porteriPhysiographic features
This ecological site occurs as ephemeral washes. It occasionally receives additional run-in moisture from the surrounding ecological sites. These flows are generally of a short duration, rarely more that 1 or 2 days in duration.
Table 2. Representative physiographic features
Landforms (1) Wash
Flooding duration Very brief (4 to 48 hours) Flooding frequency Occasional Ponding frequency None Elevation 400 – 2000 ft Slope 0 – 3 % Aspect Aspect is not a significant factor Climatic features
The 30-1AZ Lower Mohave Desert Shrub land resource unit is characterized by a hot, dry climate. The average annual rainfall is 3 to 6 inches, but it can be extremely variable (e.g. from 0 to 11 inches). There can be long periods when little or no precipitation is received. Most of the precipitation for the year could arrive in just a couple of storms. The soil moisture regime is typic aridic and the soil temperature regime is hyperthermic. Winter precipitation from November through April occurs as gentle rains from storms coming out of the Pacific Ocean. Snow is very rare and only falls in the highest mountains. A seasonal drought occurs in May and June. Summer/fall precipitation from July through October comes from spotty, unreliable, and sometimes violent thunderstorms. The moisture originates in the Gulf of Mexico (and the Pacific Ocean in the fall) and flows into the state on the north end of the Mexican monsoon. Strong winds are common, especially during the spring.
Table 3 Representative climatic features
Frost-free period (average) 330 days Freeze-free period (average) 370 days Precipitation total (average) 10 in BarLineFigure 2. Monthly precipitation range
BarLineFigure 3. Monthly average minimum and maximum temperature
">Influencing water features
Soil features
The soil of this ecological site is deep to very deep to any plant root restricting layer. The surface texture is loamy sand to coarse sand and is gravelly to very cobbly. Subsurface textures are loamy sand to coarse sand and is gravelly to extremely gravelly.
A typical soil profile is:
0 to 3 inches; very gravelly loamy sand
3 to 60 inches; very gravelly coarse sand and very gravelly loamy sand
This ecological site has been correlated to map unit 623015, Carrizo Series, Shivwits Area, AZ, Part of Mohave County SSA, and map units 701108 and 701109, Carrizo Series, Grand Canyon Area, AZ, Parts of Coconino and Mohave Counties SSATable 4. Representative soil features
Surface texture (1) Gravelly loamy sand
(2) Very gravelly sand
(3) Very cobbly sandy clay
Family particle size (1) Sandy
Drainage class Excessively drained Permeability class Very rapid Soil depth 60 – 0 in Surface fragment cover <=3" 50 – 60 % Surface fragment cover >3" 5 – 45 % Available water capacity
(0-40in)1 – 3 in Calcium carbonate equivalent
(0-40in)5 – 10 % Electrical conductivity
(0-40in)0 – 2 mmhos/cm Sodium adsorption ratio
(0-40in)Not specified Soil reaction (1:1 water)
(0-40in)7.9 – 8.4 Subsurface fragment volume <=3"
(Depth not specified)40 – 60 % Subsurface fragment volume >3"
(Depth not specified)5 – 20 % Ecological dynamics
Sandy Wash, 6"-9" p.z., is a highly productive ecological site that is at the lowest point of the watershed. Water flow is intense and flashy during and after heavy rains. The plant community is mixed shrubs with a diverse understory of perennial grass and forbs. Non-native forbs and grasses are well-established on this ecological site.
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
Historic Climax Plant CommunityCommunity 1.1
Historic Climax Plant CommunityThe dominant aspect of the site is a desert-shrub community. Grasses and forbs are present among the shrubs. Catclaw acacia can be the tallest shrub, especially in the drainage channels. White burrobrush is the dominant shrub. Big galleta and bush muhly are the major perennial grasses.
Figure 4. 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 250 300 325 Grass/Grasslike 100 135 150 Forb 50 65 75 Total 400 500 550 Table 6. Ground cover
Tree foliar cover 0% Shrub/vine/liana foliar cover 0-0% Grass/grasslike foliar cover 0% Forb foliar cover 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% Table 7. Canopy structure (% cover)
Height Above Ground (ft) Tree Shrub/Vine Grass/
GrasslikeForb <0.5 – – – 0-2% >0.5 <= 1 – – 1-3% – >1 <= 2 – – – – >2 <= 4.5 – 6-10% – – >4.5 <= 13 – – – – >13 <= 40 – – – – >40 <= 80 – – – – >80 <= 120 – – – – >120 – – – – Figure 5. Plant community growth curve (percent production by month). AZ3011 , 30.1 3-6" p.z. all sites. Growth begins in late winter, most growth occurs in the spring..
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 7 30 32 13 7 3 5 2 1 0 0 Figure 6. Plant community growth curve (percent production by month). AZ3083 , 30.27 3-6" p.z. white bursage. Growth begins in early spring. Dormancy occurs during the hot summer months. With sufficient summer/fall precipitation, some plants may break dormancy and produce a flush of growth. Flowers and sets seed by July..
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 20 40 20 15 0 0 0 0 0 0 Figure 7. Plant community growth curve (percent production by month). AZ3086 , 30.27 3-6" p.z. big galleta. Growth begins in the late winter and early spring, goes dormant in May through June, most growth occurs during the summer rainy season..
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 20 10 0 0 15 40 5 0 0 0 Figure 8. Plant community growth curve (percent production by month). AZ3090 , 30.27 3-6" p.z. bush muhly. Growth begins in the winter to early spring, goes semi-dormant in May through June, most growth occurs during the summer rainy season, green most of the year..
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 10 10 5 5 15 20 20 5 0 0 Figure 9. Plant community growth curve (percent production by month). AZ3091 , 30.23 6-10" p.z. catclaw acacia. Growth begins in spring and continues through summer. Flowers from May through June. Seeds from July through September..
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 0 5 15 10 15 30 15 10 0 0 Figure 10. Plant community growth curve (percent production by month). AZ3092 , 30.28 10-13" p.z. white burrobrush. Growth begins in the spring and continues through the summer. Flowers and sets seed during the summer rainy season..
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 20 10 10 20 20 10 0 0 0 State 2
Historic Native Plant Community plus Introduced AnnualsCommunity 2.1
Non-native AnnualsThis plant community resembles the historic native plant community, but exotic annuals have been introduced. Non-native species include Asian mustard (Brassica tournefortii), red brome, Mediterranean grass (Schismus spp.), and filaree. The flourish of non-native annuals that occurs following rainfalls may preclude native annuals.
Figure 11. Annual production by plant type (representative values) or group (midpoint values)
Table 8. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Shrub/Vine 250 305 325 Grass/Grasslike 100 125 150 Forb 50 70 75 Total 400 500 550 Table 9. Ground cover
Tree foliar cover 0% Shrub/vine/liana foliar cover 0-0% Grass/grasslike foliar cover 0% Forb foliar cover 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% Table 10. Canopy structure (% cover)
Height Above Ground (ft) Tree Shrub/Vine Grass/
GrasslikeForb <0.5 – – – 0-2% >0.5 <= 1 – – 1-3% – >1 <= 2 – – – – >2 <= 4.5 – 6-10% – – >4.5 <= 13 – – – – >13 <= 40 – – – – >40 <= 80 – – – – >80 <= 120 – – – – >120 – – – – Figure 12. Plant community growth curve (percent production by month). AZ3011 , 30.1 3-6" p.z. all sites. Growth begins in late winter, most growth occurs in the spring..
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 7 30 32 13 7 3 5 2 1 0 0 Figure 13. Plant community growth curve (percent production by month). AZ3080 , 30.27 3-6" p.z. red brome (exotic). Germinates in October with fall precipitation, most growth occurs in February through April..
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 15 60 20 0 0 0 0 0 5 0 0 Figure 14. Plant community growth curve (percent production by month). AZ3081 , 30.27 3-6" p.z. redstem filaree (exotic). Germinates in October with fall precipitation, most growth occurs in February through April..
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 15 60 20 0 0 0 0 0 5 0 0 Transition T1A
State 1 to 2Introduction of non-native forb and grass seed.
Restoration pathway R2A
State 2 to 1None known.
Additional community tables
Table 11. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 25–50 big galleta PLRI3 Pleuraphis rigida 25–50 – 2 25–50 bush muhly MUPO2 Muhlenbergia porteri 25–50 – 3 0–5 sixweeks grama BOBA2 Bouteloua barbata 0–5 – 4 0–5 sixweeks fescue VUOC Vulpia octoflora 0–5 – 5 0–10 Parish's threeawn ARPUP5 Aristida purpurea var. parishii 0–10 – 6 10–40 Grass, annual 2GA Grass, annual 10–40 – Forb7 25–50 desert Indianwheat PLOV Plantago ovata 25–50 – 8 5–40 Forb, annual 2FA Forb, annual 5–40 – 9 5–10 Forb, perennial 2FP Forb, perennial 5–10 – Shrub/Vine10 25–50 catclaw acacia ACGR Acacia greggii 25–50 – 11 125–175 burrobrush HYSA Hymenoclea salsola 125–175 – 12 5–25 smoketree PSSP3 Psorothamnus spinosus 5–25 – 13 5–25 creosote bush LATR2 Larrea tridentata 5–25 – 14 5–25 burrobush AMDU2 Ambrosia dumosa 5–25 – 15 0–15 yellow paloverde PAMI5 Parkinsonia microphylla 0–15 – 16 5–25 water jacket LYAN Lycium andersonii 5–25 – 17 5–25 brittlebush ENFA Encelia farinosa 5–25 – 18 0–10 sweetbush BEJU Bebbia juncea 0–10 – 19 0–15 Mexican bladdersage SAME Salazaria mexicana 0–15 – 20 5–25 Shrub (>.5m) 2SHRUB Shrub (>.5m) 5–25 – Table 12. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 25–50 big galleta PLRI3 Pleuraphis rigida 25–50 – 2 25–50 bush muhly MUPO2 Muhlenbergia porteri 25–50 – 3 5–25 red brome BRRU2 Bromus rubens 5–25 – 4 0–5 sixweeks grama BOBA2 Bouteloua barbata 0–5 – 5 0–5 sixweeks fescue VUOC Vulpia octoflora 0–5 – 6 0–10 Parish's threeawn ARPUP5 Aristida purpurea var. parishii 0–10 – 7 5–15 Grass, annual 2GA Grass, annual 5–15 – Forb8 5–15 redstem stork's bill ERCI6 Erodium cicutarium 5–15 – 9 25–50 desert Indianwheat PLOV Plantago ovata 25–50 – 10 0–25 Forb, annual 2FA Forb, annual 0–25 – 11 5–10 Forb, perennial 2FP Forb, perennial 5–10 – Shrub/Vine12 25–50 catclaw acacia ACGR Acacia greggii 25–50 – 13 125–175 burrobrush HYSA Hymenoclea salsola 125–175 – 14 5–25 smoketree PSSP3 Psorothamnus spinosus 5–25 – 15 5–25 creosote bush LATR2 Larrea tridentata 5–25 – 16 5–25 burrobush AMDU2 Ambrosia dumosa 5–25 – 17 0–15 yellow paloverde PAMI5 Parkinsonia microphylla 0–15 – 18 5–25 water jacket LYAN Lycium andersonii 5–25 – 19 5–25 brittlebush ENFA Encelia farinosa 5–25 – 20 0–10 sweetbush BEJU Bebbia juncea 0–10 – 21 0–15 Mexican bladdersage SAME Salazaria mexicana 0–15 – 22 5–25 Shrub (>.5m) 2SHRUB Shrub (>.5m) 5–25 – Interpretations
Supporting information
Contributors
Harmon Hodgkinson
Harmon S. Hodgkinson
Larry D. Ellicott
Stephen CassadyApproval
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 08/30/2026 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
AAAAOther
PrintThe 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.
Accessibility statement
