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Ecological site R030XB028NV

VALLEY WASH

Last updated: 2/18/2025
Accessed: 04/08/2025

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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.

MLRA notes

Major Land Resource Area (MLRA): 030X–Mojave Basin and Range

The Mojave Desert Major Land Resource Area (MLRA 30) is found in southern California, southern Nevada, the extreme southwest corner of Utah and northwestern Arizona within the Basin and Range Province of the Intermontane Plateaus. The Mojave Desert is a transitional area between hot deserts and cold deserts where close proximity of these desert types exert enough influence on each other to distinguish these desert types from the hot and cold deserts beyond the Mojave. Kottek et. al 2006 defines hot deserts as areas where mean annual air temperatures are above 64 F (18 C) and cold deserts as areas where mean annual air temperatures are below 64 F (18 C). Steep elevation gradients within the Mojave create islands of low elevation hot desert areas surrounded by islands of high elevation cold desert areas.

The Mojave Desert receives less than 10 inches of mean annual precipitation. Mojave Desert low elevation areas are often hyper-arid while high elevation cold deserts are often semi-arid with the majority of the Mojave being an arid climate. Hyper-arid areas receive less than 4 inches of mean annual precipitation and semi-arid areas receive more than 8 inches of precipitation (Salem 1989). The western Mojave receives very little precipitation during the summer months while the eastern Mojave experiences some summer monsoonal activity.

In summary, the Mojave is a land of extremes. Elevation gradients contribute to extremely hot and dry summers and cold moist winters where temperature highs and lows can fluctuate greatly between day and night, from day to day and from winter to summer. Precipitation falls more consistently at higher elevations while lower elevations can experience long intervals without any precipitation. Lower elevations also experience a low frequency of precipitation events so that the majority of annual precipitation may come in only a couple precipitation events during the whole year. Hot desert areas influence cold desert areas by increasing the extreme highs and shortening the length of below freezing events. Cold desert areas influence hot desert areas by increasing the extreme lows and increasing the length of below freezing events. Average precipitation and temperature values contribute little understanding to the extremes which govern wildland plant communities across the Mojave.

Arid Eastern Mojave Land Resource Unit (XB)

LRU notes

The Mojave Desert is currently divided into 4 Land Resource Units (LRUs). This ecological site is within the Arid Eastern Mojave LRU where precipitation is bi-modal, occurring during the winter months and summer months. The Arid Eastern Mojave LRU is designated by the 'XB' symbol within the ecological site ID. This LRU is found across the eastern half of California, much of the mid-elevations of Nevada, the southernmost portions of western Utah, and the mid-elevations of northwestern Arizona. This LRU is essentially equivalent to the Eastern Mojave Basins and Eastern Mojave Low Ranges and Arid Footslopes of EPA Level IV Ecoregions

Elevations range from 1650 to 4000 feet and precipitation is between 4 to 8 inches per year. This LRU is distinguished from the Arid Western Mojave (XA) by the summer precipitation, falling between July and September, which tends to support more warm season plant species. The 'XB' LRU is generally east of the Mojave River and the 117 W meridian (Hereford et. al 2004). Vegetation includes creosote bush, burrobush, Nevada jointfir, ratany, Mojave yucca, Joshua tree, cacti, big galleta grass and several other warm season grasses. At the upper portions of the LRU, plant production and diversity are greater and blackbrush is a common dominant shrub.

Classification relationships

The vegetation classification of this ecological site includes the intersection of the following alliances and associations; Creosotebush - Burrobush Bajada & Valley Desert Scrub Alliance and the Ambrosia dumosa – Larrea tridentata var. tridentata Dwarf-shrubland Association and Desert-willow and the Smoketree Desert Wash Scrub Alliance and Chilopsis linearis / (Ambrosia eriocentra, Salvia dorrii) Desert Wash Scrub Association (USNVC 2017).

Ecological site concept

This site is found on small washes, ephemeral streams, drainageways, channels or other similar landforms with a stream order between 1 and 2 in the upper fan piedmont at elevations between 1650 feet and 3800 feet elevation. The parent material is alluvium from mixed sources but can also be alluvium solely from sedimentary or volcanic sources.

This site is often the upper tributaries of a larger wash where the wash is confined by eroded fan remnants, hills and mountain. Close proximity to hills and mountains means this portion of the wash receives more precipitation and moisture than downstream portions of the wash due to orographic effect and holding moisture closer to the rooting zone.

Associated sites

R030XB004NV	SANDY 5-7 P.Z.
R030XB005NV	Arid Active Alluvial Fans
R030XB019NV	Eroded Fan Remnant Pavette 4-6 P.Z.

R030XB004NV

SANDY 5-7 P.Z.

R030XB005NV

Arid Active Alluvial Fans

R030XB019NV

Eroded Fan Remnant Pavette 4-6 P.Z.

Similar sites

R030XB103NV	Warm Dry Wash Smoketree dominant plant
R030XB133NV	GRAVELLY INSET FAN 5-7 P.Z. MESP2 & PSFR codominant shrubs with AMDU2
R030XB134NV	QUARTZITE OUTWASH ERFAP & Ephedra spp. codominant shrubs with AMDU2
R030XB051NV	UPLAND WASH Higher elevations cresotebush minor spp., if present
R030XB098NV	GRAVELLY OUTWASH ENFA major shrub; site occurs on outer margins of active
R030XB132NV	GRAVELLY WASH 3-5 P.Z. ACGR-PSFR codominant shrubs
R030XB050NV	Calcic Dry Wash Less productive site; ATPO major shrub

Table 1. Dominant plant species

Tree	Not specified
Shrub	(1) Larrea tridentata (2) Ambrosia
Herbaceous	(1) Pleuraphis rigida

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Physiographic features

This site occurs on ephemeral stream channels of inset fans and floodplains. Slopes range from 0 to 12 percent, but slope gradients of 2 to 8 percent are most typical. Elevations are 500 to 3800 feet.

Table 2. Representative physiographic features

Landforms	(1) Fan piedmont > Drainageway (2) Wash (3) Ephemeral stream
Flooding duration	Extremely brief (0.1 to 4 hours) to very brief (4 to 48 hours)
Flooding frequency	Rare to frequent
Ponding frequency	None
Elevation	500 – 3,800 ft
Slope	12%
Aspect	Aspect is not a significant factor

Climatic features

The climate of the Mojave Desert has extreme fluctuations of daily temperatures, strong seasonal winds, and clear skies. The climate is arid and is characterized with cool, moist winters and hot, dry summers. Most of the rainfall falls between November and April. Summer convection storms from July to September may contribute up to 25 percent of the annual precipitation. Average annual precipitation is 4 to 8 inches. Mean annual air temperature is 69 to 77 degrees F. The average growing season is about 240 to 365 days.

Table 3. Representative climatic features

Frost-free period (average)	365 days
Freeze-free period (average)
Precipitation total (average)	6 in

Bar

Line

Figure 1. Monthly average minimum and maximum temperature

Soil features

The soils associated with this site are very deep, and are formed in alluvium from mixed sources. Textures are loamy sands to moderately coarse sands and are well to excessively drained. Water intake rates are moderately rapid to very rapid. Available water capacity is very low to low. Runoff is negligible to high. Soil series associated with this site include: Arizo, Carrizo, Jean, Maynard Lake, Threelakes, and Yermo.

Table 4. Representative soil features

Parent material	(1) Alluvium – volcanic rock
Surface texture	(1) Sand
Family particle size	(1) Sandy
Drainage class	Well drained to excessively drained
Permeability class	Moderately rapid to very rapid
Soil depth	72 – 84 in
Surface fragment cover <=3"	20 – 47%
Surface fragment cover >3"	1 – 35%
Available water capacity (0-40in)	1.2 – 2.9 in
Calcium carbonate equivalent (0-40in)	10%
Electrical conductivity (0-40in)	15 mmhos/cm
Sodium adsorption ratio (0-40in)	5
Soil reaction (1:1 water) (0-40in)	6.1 – 9.5
Subsurface fragment volume <=3" (Depth not specified)	12 – 70%
Subsurface fragment volume >3" (Depth not specified)	2 – 28%

Ecological dynamics

Ephemeral streams are unique in that they lack permanent flow although they perform the same critical hydrologic functions as perennial streams; they move water, sediment, nutrients and debris through the stream network and provide connectivity within the watershed. These systems experience extreme and rapid variations in flood magnitudes as a response to heavy rain events. The fundamental difference between ephemeral and perennial streams is that ephemeral stream channels have sizeable transmission losses when they flow. Ephemeral streams are also characterized by wider channels, low sinuosity, and flat bed topography. The sparseness of vegetation along the stream banks contributes to channel widening tendencies. (Levick et al 2008).

Along the desert washes, vegetation composition and structure overlap considerably with those of the surrounding desert uplands. An example of this is creosotebush and white bursage commonly occur in the washes and adjoining uplands. As water availability increases, the vegetation becomes increasingly distinct from the upland vegetation with respect of physiognomy and species composition. Canopy cover increases and mesoriparian and hydroriparian species increase in abundance (Levick et al 2008).

As a result of decreased flow rates in the downstream direction, more silts and fines are deposited in the channel, which can be advantageous to biotic communities. Many of the species (white burrobush, desert rabbitbrush, baccharis, sweetbush) occurring on these sites are generally considered to be increasers or pioneers in the presence of disturbance (Abella 2010). These species produce prolific numbers of wind-dispersed seeds and are more abundant in ephemeral streams with intense flood scour (Levick et al 2008). Rainfall and flood flow events can trigger a pulse of germination of annual and perennial forbs from a diverse soil seed bank. Some species, such as catclaw acacia, desert willow, purple sage (Salvia dorrii), and bladdersage (Salazaria mexicana) have resprouting capabilities; an adaptation to withstand flooding flows. Catclaw acacia also has nitrogen fixing bacteria associated with its roots, which can be an important influence on local nitrogen availability. The increased availability of nutrients on these sites compared to the surrounding area increases the likelihood of encountering invasive species, like saltcedar (Tamarix spp.). Saltcedar is successful in arid environments due to its ability to tolerate unpredictable periods of moisture. Perturbation of these systems by natural or anthropogenic causes can result in the development of continuous incised channels.

Flooding is a natural disturbance within these ecological sites due to their location on the landscape. Floods help to redistribute nutrients across the landscape, as well as, encouraging resprouting and seedling establishment. Seedling establishment and canopy expansion is greater for plants growing in the drainageways than the surrounding area. However, these plants are less tolerant of extended dry periods because they are adapted to increased soil moisture (Hamerlynk and McAuliffe 2008). Very large rainfall events rarely occur but have the potential to remove existing vegetation and deposit new sediment, initiating secondary succession.

Fire Ecology:
Wildfire is infrequent and patchy in this system. However, years with increased annual precipitation result in increased production from annuals and increase the chances of wildfire. Post fire creosotebush, baccharis and other fire intolerant shrubs decrease. Fire tolerant species such as bursage, burrobrush, ephedra, desert willow and catclaw acacia are able to sprout from the root crown and may increase following wildfire. Fire also favors an increase of perennial native grasses. Creosotebush survives some fires that burn patchily or are of low severity. Fire generally kills white bursage. Damage to big galleta from fire varies. If big galleta is dry, damage may be severe. However, when plants are green, fire will tend to be less severe and damage may be minimal, with big galleta recovering quickly.

State and transition model

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Click on state and transition labels to scroll to the respective text

State 1
Reference State

The reference state is representative of the natural range of variability under pristine conditions. It is maintained by periodic flooding in response to heavy rainfall events and has increased available moisture and nutrients. Fire is rare in this system. This ecological site experiences seasonal flooding and is important for redistributing moisture and nutrients throughout the landscape. Timing of disturbances combined with weather events determines plant community dynamics.

Community 1.1
Reference Plant Community

The plant community is dominated by creosotebush, bursage and big galleta. Baccharis is an important shrub species associated with this site. Potential vegetative composition is about 25 percent perennial and annual grasses, 10 percent annual and perennial forbs and 65 percent shrubs. Approximate ground cover (basal and crown) is 10 to 30 percent.

Figure 2. 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	130	228	325
Grass/Grasslike	50	88	125
Forb	20	34	50
Total	200	350	500

Community 1.2
Plant Community 1.2

This plant community is characteristic of a post-disturbance plant community phase. Initially, it is heavily dominated by herbaceous vegetation and short-lived perennials. Sprouting shrubs quickly recover and provide a favorable environment for establishment of shrub seedlings. Additional run-in moisture from the surrounding landscape increases the ecological resilience and helps this site recover quickly following disturbance. This plant community is ‘at-risk’ of invasion by non-natives. Non-native species are able to take advantage of increased availability of critical resources following disturbances.

Pathway 1.1a
Community 1.1 to 1.2

Pathway 1.2a
Community 1.2 to 1.1

Absence from disturbance and natural regeneration over time.

State 2
Invaded

The invaded state is characterized by the presence of non-native species in the understory. A biotic threshold is crossed with the introduction of non-natives that are difficult to remove from the system and have they potential to significantly alter disturbance regimes from their historic range of variation. Non-native annuals will persist once introduced into the plant community, due to their annual growth form, abundant seed production and long term seed viability. Non-native annuals such as red brome and cheatgrass are potential invaders on this ecological site. These non-native annuals are highly flammable and promote wildfires where fires historically have been infrequent.

Community 2.1
Plant Community Phase 2.1

Species composition is similar to the reference plant community. Ecological processes have not been compromised at this time, however, ecological resilience is reduced by the presence of non-natives. This plant community phase will respond differently following disturbance, when compared to the reference plant community. Management focused on decreasing the amount of anthropogenic disturbance is important for maintaining the health of perennial native species that protect the site against erosion.

Community 2.2
Plant Community Phase 2.2

This plant community is characteristic of a post-disturbance plant community. It is dominated by herbaceous vegetation, which may or may not be non-native, woody perennials are increasing. Nevada ephedra, desert almond and desert willow commonly sprout from rhizomes following disturbance. Sprouting species provide favorable sites for germination of species such as brittlebush, ratany, and bursage which reproduce sexually and are prolific seed producers. This plant community is ‘at-risk’ of increased erosion due to reduction of deep rooted perennials and increased non-native annuals.

Pathway 2.1a
Community 2.1 to 2.2

Seasonal flooding, wildfire, disease or insect attack.

Pathway 2.2a
Community 2.2 to 2.1

Absence of disturbance and natural regeneration over time.

State 3
Eroded State

This state is characterized by reduced cover of woody perennials. Bare ground is increasing, leading to increased erosion, decreased infiltration and loosening of the soil surface causing channeling. An abiotic threshold has been crossed preventing the natural repair of this plant community. Feedbacks keeping this state stable include reduced perennial vegetative cover causing increased runoff and decreased infiltration preventing the establishment of desirable perennial vegetation.

Community 3.1
Plant Community Phase 3.1

This plant community is characteristic of a short disturbance return interval. Long-lived woody perennials are decreasing. The ability of this site to dissipate energy during large flow events is severely reduced contributing to ecological damage downstream.

Community 3.2
Plant Community Phase 3.2

This plant community is characterized by the loss of long-lived woody perennials. Ecological processes have been altered including connectivity within the watershed, ground water recharge and habitat quality. Soil and soil nutrients are being redistributed down stream, leading to down cutting and channel widening.

Pathway 3.1a
Community 3.1 to 3.2

Seasonal flooding, wildfire, disease or insect attack.

Pathway 3.2a
Community 3.2 to 3.1

Absence from disturbance and natural regeneration over time, allow some perennials to return to the system increasing stability.

Transition T1
State 1 to 2

Introduction of non-native species due to a combination of factors including: 1) surface disturbance, 2) changes in the kinds of animals and their grazing patterns, 3) drought and/or 4) changes in fire history.

Transition T2
State 2 to 3

Large scale reoccurring disturbance, natural or anthropogenic.

Restoration pathway R3
State 3 to 2

Ecological processes can be restored to the site, but non-natives remain. Possible restoration techniques include stabilizing the site by reestablishing native perennials and the use of artificial rip-rap to dissipate energy and reestablish the flood plain.

Additional community tables

Table 6. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (lb/acre)	Foliar cover (%)
Grass/Grasslike
1	Primary perennial grasses			15–53
	big galleta	PLRI3	Pleuraphis rigida	15–35	–
	bush muhly	MUPO2	Muhlenbergia porteri	1–18	–
2	Secondary perennial grasses			7–35
	bush muhly	MUPO2	Muhlenbergia porteri	1–18	–
	Indian ricegrass	ACHY	Achnatherum hymenoides	2–7	–
3	Annual grasses			0–18
Forb
4	Perennial			7–35
5	Annual			0–35
Shrub/Vine
6	Primary shrubs			64–259
	creosote bush	LATR2	Larrea tridentata	15–70	–
	burrobush	AMDU2	Ambrosia dumosa	7–35	–
	woolly fruit bur ragweed	AMER	Ambrosia eriocentra	7–35	–
	desertbroom	BASA2	Baccharis sarothroides	8–27	–
	Emory's baccharis	BAEM	Baccharis emoryi	7–26	–
	Mojave yucca	YUSC2	Yucca schidigera	2–18	–
	Nevada jointfir	EPNE	Ephedra nevadensis	3–18	–
	Eastern Mojave buckwheat	ERFAP	Eriogonum fasciculatum var. polifolium	3–18	–
	burrobrush	HYSA	Hymenoclea salsola	7–18	–
	desert willow	CHLI2	Chilopsis linearis	3–10	–
	catclaw acacia	ACGR	Acacia greggii	3–10	–
7	Secondary shrubs			15–53
	cattle saltbush	ATPO	Atriplex polycarpa	2–18	–
	sweetbush	BEJU	Bebbia juncea	2–18	–
	brittlebush	ENFA	Encelia farinosa	2–18	–
	Mojave rabbitbrush	ERPA29	Ericameria paniculata	2–18	–
	ratany	KRAME	Krameria	2–18	–
	desert-thorn	LYCIU	Lycium	2–18	–
	desert almond	PRFA	Prunus fasciculata	2–18	–
	purple sage	SADOI	Salvia dorrii ssp. dorrii var. incana	2–18	–
	Mexican bladdersage	SAME	Salazaria mexicana	2–18	–
	Schott's yucca	YUSC	Yucca ×schottii	2–7	–

Interpretations

Animal community

Livestock Interpretations:
This site has limited value for livestock grazing due to low forage production. Grazing management should be keyed to perennial grass and palatable shrub production. Many animals bed in or under creosotebush. Domestic sheep dig shallow beds under creosotebush because it provides the only shade in the desert scrub community. Creosotebush is unpalatable to livestock. Consumption of creosotebush may be fatal to sheep. White bursage is an important browse species. Browsing pressure on white bursage is particularly heavy during years of low precipitation, when production of winter annuals is low. White bursage is of intermediate forage value. It is fair to good forage for horses and fair to poor for cattle and sheep. However, because there is often little other forage where white bursage grows, it is often highly valuable to browsing animals. Big galleta is considered a valuable forage plant for cattle and domestic sheep in the Mojave Desert. Its coarse, rigid culms make it relatively resistant to heavy grazing and trampling.

Stocking rates vary over time depending upon season of use, climate variations, site, and previous and current management goals. A safe starting stocking rate is an estimated stocking rate that is fine tuned by the client by adaptive management through the year and from year to year.

Wildlife Interpretations:
Desert washes provide valuable habitat for many species of birds, reptiles, amphibians and mammals. Many small mammals browse creosotebush or consume its seeds. Desert reptiles and amphibians use creosotebush as a food source and perch site and hibernate or estivate in burrows under creosotebush, avoiding predators and excessive daytime temperatures. White bursage is an important browse species for wildlife. Various species of birds eat desert willow seeds. Hummingbirds are attracted to the showy flowers and feed on the nectar. Catclaw acacia provides food, shelter, nesting sites, and nesting material to a host of wildlife and livestock species. Catclaw acacia browsers include deer, livestock, and rabbits. Both game and nongame bird species feed on catclaw acacia.

Hydrological functions

Runoff is negligible to high. Permeability is moderately rapid to very rapid.

Recreational uses

Aesthetic value is derived from the diverse floral and faunal composition and the colorful flowering of wildflowers and shrubs during the spring and early summer. Several species of birds also utilize this site. This site offers rewarding opportunities for photographers and those interested in nature study.

Other products

Creosotebush has been highly valued for its medicinal properties by Native Americans. Twigs and leaves may be boiled as tea, steamed, pounded into a powder, pressed into a poultice, or heated into an infusion. White bursage is a host for sandfood (Pholisma sonorae), a parasitic plant with a sweet, succulent, subterranean flowerstalk. Sandfood was a valuable food supply for Native Americans. Native Americans used the wood of desert willow to make bows and baskets.

Other information

Creosotebush and white bursage may be used to rehabilitate disturbed environments in southwestern deserts. Once established, these species may improve sites for annuals and other perennials that grow under their canopies by trapping fine soil, organic matter, and symbiont propagules. Water infiltration and storage may also increase. Desert willow is cultivated as an ornamental because of its attractive flowers. It has been used for roadside beautification, border rows, screenings, and mass plantings.

Supporting information

Type locality

Location 1: Lincoln County, NV
General legal description	This site also occurs in southern Lincoln Co. Nevada.
Location 2: Clark County, NV
Township/Range/Section	T20 R64 S28
General legal description	About 12 air miles southeast of Beatty, Crater Flat area, Nye County, Nevada.

Other references

Abella, S.R. 2010. Disturbance and plant succession in the Mojave and Sonoran Desert of the American Southwest. Int. J. Environ. Res. Public Health. 7: 1248-1284.

Fire Effects Information System (Online; http://www.fs.fed.us/database/feis/plants/).

Hereford, R., R.H. Webb and C. I. Longpre. 2004. Precipitation history of the Mojave Desert region, 1893-2001 (No. 117-03).

Kottek, M., Grieser, J., Beck, C., Rudolf, B., & Rubel, F. (2006). World map of the Köppen-Geiger climate classification updated. Meteorologische Zeitschrift, 15(3), 259-263.

Levick, L.R., D.C Goodrich, M. Hernandez, J. Fonseca, D.J. Semmens, J. Stromberg, M. Tluczek, R.A. Leidy, M. Scianni, D.P. Guertin, and W.G. Kepner. 2008. The Ecological and Hydrological Significance of Ephemeral and Intermittent Streams in the Arid and Semi-arid American Southwest. U.S. Environmental Protection Agency. Office of Research and Development.Washington D.C.

Salem, B.B. 1989. Arid zone forestry: a guide for field technicians (No. 20). Food and Agriculture Organization (FAO).

USDA-NRCS Plants Database (Online; http://www.plants.usda.gov).

USNVC [United States National Vegetation Classification]. 2017. United States National Vegetation Classification Database, V2.01. Federal Geographic Data Committee, Vegetation Subcommittee, Washington DC. [usnvc.org] (accessed 01 Oct., 2018).

Contributors

RWD
Dustin Detweiler

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)	P NOVAK-ECHENIQUE
Contact for lead author	State Rangeland Management Specialist
Date	04/01/2010
Approved by	Kendra Moseley
Approval date
Composition (Indicators 10 and 12) based on	Annual Production

Indicators

Number and extent of rills:
Rills are none to few.
Presence of water flow patterns:
Water flow patterns are common and may be long (>3 m) and connected.
Number and height of erosional pedestals or terracettes:
Pedestals are rare with occurrence typically limited to areas within water flow patterns.
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare Ground to 20%; surface rock fragments to 75%; shrub canopy to 10%; basal area for perennial herbaceous plants (Trace).
Number of gullies and erosion associated with gullies:
None
Extent of wind scoured, blowouts and/or depositional areas:
None
Amount of litter movement (describe size and distance expected to travel):
Fine litter (foliage from grasses and annual & perennial forbs) expected to move distance of slope length during intense summer convection storms or rapid snowmelt events. Persistent litter (large woody material) will remain in place except during rainfall or runoff events.
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil stability values should be 1 to 4 on most soil textures found on this site. (To be field tested.)
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Surface structure is typically weak coarse to weak medium platy. Soil surface colors are pale browns and soils are typified by an ochric epipedon. Organic matter of the surface 2 to 3 inches is less than 0.5 percent.
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Sparse shrub canopy and associated litter break raindrop impact .Perennial bunchgrasses and forbs aid in infiltration.
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None.
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:
Mojave Desert shrubs

Sub-dominant:
deep-rooted, warm-season, bunchgrasses > perennial forbs > deep-rooted, cool-season, bunchgrasses > annual forbs > shallow-rooted grasses

Other:

Additional:
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Dead branches within individual shrubs common and standing dead shrub canopy material may be as much as 25% of total woody canopy; mature bunchgrasses commonly (±25%) have dead centers.
Average percent litter cover (%) and depth ( in):
Between plant interspaces 10-20% and depth (<¼-inch).
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
For normal or average growing season ±350 lbs/ac. Favorable years ± 500 lbs/ac and unfavorable years ±200 lbs/ac
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:
Potential invaders on this site include red brome, annual mustards, salt cedar, Mediterranean grass, and redstem filaree.
Perennial plant reproductive capability:
All functional groups should reproduce in above average and average growing season years. Less reproduction will occur in below average precipitation years.

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