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Ecological site R030XB009CA

Loamy Cool Aridic Fans 6-8

Last updated: 2/18/2025
Accessed: 03/16/2025

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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

MLRA Description:
Major Land Resource Area (MLRA) 30, Mojave Desert, 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 climate of the area is hot and dry with mostly hyperthermic and thermic soil temperature regimes and typic-aridic soil moisture regimes. Mean annual air temperatures are between 59-68 degrees F (15-20 C) with average summer maximum temperatures between 100-115 degrees F (38-46 C) and average winter minimum temperatures between 32-59 degrees F (0-15 C). This MLRA is within the arid climate zone however steep elevational gradients contribute to microclimates where semi-arid [mean annual precipitation is greater than 8 inches (200mm)] and hyper-arid [mean annual precipitation is less than 4 inches (100mm)] islands exist. Elevations range from below sea level to over 12,000 feet (3650 meters) in the higher mountain areas. Generally above 5,000 feet, soil temperature regimes can be mesic, cryic and frigid with soil moisture regimes being xeric or ustic. Orographic effects and low elevations can create hyper-arid conditions where the soil moisture regime is aridic-aridic. Due to the extreme elevational range found within this MLRA, land resource units (LRUs) were designated to group areas within the MLRA into similar land units.

LRU Description:
The arid climate zone (XB in ESD ID) 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. Elevations range from 1800-5000 feet and precipitation ranges from 4-8 inches/year. Precipitation is bi-modal for most of the Mojave with precipitation occurring in winter and summer. Areas west of the 117 degree W meridian near Barstow, CA receive precipitation mainly during the winter months (Hereford et al. 2004). The soil temperature regimes are hyperthermic and thermic with a typic-aridic soil moisture regime. Vegetation includes creosote bush (Larrea tridentata), burrobush (Ambrosia dumosa), Mojave yucca (Yucca schidigera) Joshua tree (Yucca brevifolia), chollas, cactus, big galleta grass (Pleuraphis rigida) and several other warm season grasses. At the upper portions of the LRU, where the mean annual precipitation is between 6 to 8 inches (150-200 mm), plant production and diversity are greater and blackbrush (Coleogyne ramosissima) is a common dominant shrub.

Classification relationships

Class - 3 Xeromorphic Woodland, Scrub & Herb Vegetation Class

Subclass - 3.B Cool Semi-Desert Scrub & Grassland Subclass

Formation - 3.B.1 Cool Semi-Desert Scrub & Grassland Formation

Division - 3.B.1.Ne Western North American Cool Semi-Desert Scrub & Grassland Division

Macrogroup - 3.B.1.Ne.1 Chrysothamnus viscidiflorus - Coleogyne ramosissima / Achnatherum hymenoides Great Basin & Intermountain Dry Shrubland & Grassland Macrogroup

Group - 3.B.1.Ne.1.a Yucca brevifolia - Eriogonum fasciculatum - Ephedra fasciculata Mixed Desert Scrub Group

Alliance - 3.B.1.Ne.1.a Coleogyne ramosissima Mojave Desert Shrubland Alliance

(Schulz 2014)

Ecological site concept

This ecological site is linked to group concept R030XB188CA.

This ecological site occurs on fan remnants within the lower fan piedmont. Soils have a typic-aridic soil moisture regime, and a cool thermic soil temperature regime. Soils are moderately deep to very deep, with a fine-loamy particle size control section. The upper boundary of an argillic or calcic horizon is present within the top 25cm of the soil profile. In rare instances a root restrictive horizon such as a duripan or petrocalcic horizon may be present. The representative plant community is dominated by blackbrush (Coleogyne ramosissima). Creosote bush (Larrea tridentate) and Mojave yucca (Yucca schidigera)are subdominants. Joshua Tree (Yucca brevifolia var. jaegeriana) is often an emergent canopy species at 0 to 3 percent cover.

Associated sites

R030XC047CA	Bi-Modal Semi-Arid Order 3 Ephemeral Wash Occurs in stream order 3 size washes which drain the semi-arid zones (greater than 8 inches of mean annual precipitation).
R030XB039NV	LIMY FAN 5-7 P.Z. Occurs on nearby alluvial fans with moderately deep or deeper soils [soil profile depth is greater than 40 inches (100 cm)] with no shallow diagnostic horizons.
R030XB172CA	Warm Gravelly Shallow Hills Occurs on nearby warm hills with a thermic and/or hyperthermic soil temperature regime. Mean annual air temperature is generally greater than 17 degrees C.

R030XC047CA

Bi-Modal Semi-Arid Order 3 Ephemeral Wash

Occurs in stream order 3 size washes which drain the semi-arid zones (greater than 8 inches of mean annual precipitation).

R030XB039NV

LIMY FAN 5-7 P.Z.

Occurs on nearby alluvial fans with moderately deep or deeper soils [soil profile depth is greater than 40 inches (100 cm)] with no shallow diagnostic horizons.

R030XB172CA

Warm Gravelly Shallow Hills

Occurs on nearby warm hills with a thermic and/or hyperthermic soil temperature regime. Mean annual air temperature is generally greater than 17 degrees C.

Similar sites

R030XB173CA	Coarse Loamy Very Deep Fan Remnants The same ecological site concept. Plant Community Phase 2.4.
R030XB043NV	CLAYPAN 5-7 P.Z. The same ecological site concept. Plant Community Phase 3.2.
R030XB137CA	Granitic Loam This ecological site occurs at lower elevations, has lower production, and is co-dominated by white bursage.
R030XB107NV	COARSE GRAVELLY LOAM 5-7 P.Z. The same ecological site concept. Plant Community Phase 2.4.
R030XB039NV	LIMY FAN 5-7 P.Z. This ecological site has higher production and a greater diversity of native perennial grasses.
R030XB143CA	Shallow Granitic Loam 5-7" P.Z. The same ecological site concept. Plant Community Phase 2.2.
R030XB183CA	Loamy Very Deep Fan Remnants The same ecological site concept. Plant Community Phase 2.3.

Table 1. Dominant plant species

Tree	Not specified
Shrub	(1) Coleogyne ramosissima
Herbaceous	Not specified

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Physiographic features

This ecological site occurs on fan remnants with 1 to 4% slopes at elevations of 3600 to 4200 feet.

Table 2. Representative physiographic features

Landforms	(1) Fan remnant
Flooding frequency	Very rare to rare
Elevation	1,097 – 1,280 m
Slope	1 – 4%
Aspect	Aspect is not a significant factor

Climatic features

The mean annual precipitation is between 6 to 8 inches (150 to 200 mm) and the mean annual air temperature ranges from 59 to 62.5 degrees F (15-17 degrees C) across the elevation range of the site. For outlying areas just outside of this temperature and precipitation range, temperature and precipitation are directly proportional. For example, areas where climate models suggest the air temperature is higher than 17 degrees C should also show the area receives more than 8 inches of precipitation, otherwise the site should be in the 4-6 precipitation zone.

Precipitation amounts can vary greatly. Some years the mean annual precipitation can exceed 18 inches, other years the mean annual precipitation can be less 4 inches.
The Society of Range Management (1989) define drought as "... prolonged dry weather when precipitation is less than 75% of the average amount". By this definition, it is not uncommon for this site to experience drought every 2 to 5 years. Some decades can pass with no drought and other decades may have several consecutive years of drought.

Precipitation is bi-modal with precipitation mainly occurring during the winter and summer. June, like much of the Mojave and areas west of the Mojave, is typically the driest month of the year with mean temperatures near 80 degrees F. It is not uncommon for June to experience temperatures over 90 degrees F. July and August are the hottest months of the year and can have average maximum temperatures above 95 degrees F.

Table 3. Representative climatic features

Frost-free period (average)	278 days
Freeze-free period (average)	310 days
Precipitation total (average)	203 mm

Bar

Line

Figure 1. Monthly precipitation range

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Line

Figure 2. Monthly average minimum and maximum temperature

Figure 3. Annual precipitation pattern

Figure 4. Annual average temperature pattern

Climate stations used

(1) SEARCHLIGHT [USC00267369], Searchlight, NV

Soil features

The soils associated with this ecological site are moderately to very deep soils formed in alluvium from mixed sources. The particle size control section ranges from being a fine-loam to a coarse-loam or loamy-skeletal. The upper boundary of an argillic and/or a calcic horizon is often within the top 10 inches (25cm) of the soil profile. Depth to a root restrictive layer such as a petrocalcic horizon or duripan, when present, is typically 20 inches (50cm) or deeper. Soils have a thermic temperature regime and a typic aridic moisture regime.

Surface textures are sandy loams, loams and loamy sands, often with a gravelly modifier. Surface rock fragments range from 10 to 90% surface cover. Fine gravels often make up more than 30% of the surface cover whereas large surface fragments are scarce and often make up less than 30% of the surface cover. Soil subgroups include Argic Petrocalcids, Typic Haplargids, Typic Calciargids and Typic Haplocalcids with Typic Haplargids being most common.

Table 4. Representative soil features

Parent material	(1) Alluvium – granite
Surface texture	(1) Sandy loam (2) Very gravelly loam (3) Loamy sand
Family particle size	(1) Loamy
Drainage class	Well drained to excessively drained
Permeability class	Very slow to rapid
Soil depth	10 – 152 cm
Surface fragment cover <=3"	10 – 90%
Surface fragment cover >3"	0 – 30%
Available water capacity (0-101.6cm)	2.79 – 16.76 cm
Calcium carbonate equivalent (0-101.6cm)	0 – 15%
Electrical conductivity (0-101.6cm)	0 – 4 mmhos/cm
Sodium adsorption ratio (0-101.6cm)	0 – 5
Soil reaction (1:1 water) (0-101.6cm)	6.1 – 9
Subsurface fragment volume <=3" (Depth not specified)	0 – 50%
Subsurface fragment volume >3" (Depth not specified)	0 – 30%

Ecological dynamics

This ecological site is within the broad creosote and blackbrush eco-tone. At the highest elevations of this ecological site, monospecific stands of blackbrush (Coleogyne ramosissima) exist with a wide range of other species. Sub dominant species include Mojave Yucca (Yucca schidigera) and creosote bush (Larrea tridentata). Joshua Tree (Yucca brevifolia var. jaegeriana) is often an emergent canopy species at 0 to 3 percent cover.

At the lower elevations of this ecological site blackbrush tends to be a co-dominant with creosote bush. Disturbance at this site can create a variety of responses with an overall trend in reduction of blackbrush and an increase in pioneering species. In some cases creosote bush and white bursage may replace blackbrush as the long-lived perennial species following disturbance.

Typical disturbance for this ecological site include prolonged severe drought, flash flooding and fire. Prior to European colonization of the Mojave Desert, widespread fire was an unlikely event due to the lack of a continuous fuel layer. Small burned areas were probably common due to lightning strikes.

Fire frequency and extent probably increased following the arrival of homesteaders in the Mojave. The proximity of this site to more mesic mountainous areas and it's relatively flat topography made this site a target for land clearing and plowing as required by the Homestead Law (U.S. BLM 1971). Land clearing allowed annual and pioneering species to create a continuous fuel layer for fire to spread.

State and transition model

Custom diagram

Standard diagram

Figure 5. State and Transition Model for R030XB009CA

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More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective text

State 1
Historic

State 1 represents the historic-natural condition for this ecological site. It is similar to State 2,but non-native species are not present. Data is not available for this State. If we were to include dynamics for this state it would be similar to that displayed in State 2.

State 2
Blackbrush Shrubland

Non-native annuals, including red brome (Bromus rubens) and red-stem storks bill (Erodium cicutarium) are naturalized in this state. Their abundance varies with precipitation but they are, at a minimum, sparsely present. Non-native annuals may be present in current year's growth or in the soil seedbank. Given that this ecological site generally lies at the base of high elevation mountains and can support perennial bunch grasses, unlike the more harsh Mojave Desert environments, this ecological site attracted ranchers who started livestock operations in the Mojave Desert. The long history of livestock grazing, land clearing and an increase in fire frequency from chimney fires, etc. is likely to have obscured our understanding of state and community pathways as well as vegetation composition.

Community 2.1
Representative Plant Community

Figure 6. Community Phase 2.1 black brush

The Representative Plant Community is a community phase very similar to the Reference Plant Community Phase but annual exotics are present. This mixed stand of blackbrush and creosote bush often exists with many other plant species. Because this site is a broad eco-tone where blackbrush scrub and creosote bush scrub co-exist, at higher elevations creosote bush decreases and blackbrush increases while the inverse is true at lower elevations. At higher elevations creosote bush often exists in small patches and does not form a continuous canopy cover across the site. At lower elevations blackbrush is often replaced by white bursage where the effects of drought are a natural disturbance regime which prevents blackbrush seedling recruitment and supports white bursage recruitment (Meyer and Pendleton 2005, Hunter 1989). Domestic sheep and goat grazing operations, rather than cattle, are likely to reduce blackbrush cover (Sampson and Jespersen 1963). Although blackbrush is not preferred forage for livestock and wildlife, it can make up a substantial part of their diet in blackbrush dominated sites (Bowns and West 1976). At it's lowest elevational extent, blackbrush is unlikely able to recover from any disturbance.

Figure 7. 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	319	392	448
Forb	11	34	67
Grass/Grasslike	6	22	50
Total	336	448	565

Community 2.2
Mixed Shrub and Herbaceous Plants

Grazing this community phase will tend to maintain a mixed shrub cover; however aggressive sediment deposition or overburden from surrounding denuded areas may increase big galleta cover (Bestelmeyer 2005). Perennial grass dominance may also indicate a middle aged burn (greater than one year and less than 15 years) while older burned areas are likely to be dominated by shrubs (Callison et. al 1985). Large scale intense fires are unlikely to have occurred within this community phase because a continual fuel layer to carry the fire does not exist between shrubs (Minnich 2003, Webb et al. 1987). Small scale low intensity fires are more likely at this ecological site due to lightning strikes on Joshua trees. Response to fire is unpredictable and can vary greatly depending on the climatic conditions at the time of fire, dynamic soil properties as well as varying land uses pre and post-fire (Bowns and West 1976a). The overall response is decreased blackbrush cover and an increase in mixed shrub and herbaceous cover. These low intensity burns may have also increased the number of individual Joshua trees which have been reported to sprout vigorously post fire (Gorder et al. 2005). Creosote bush may also gain a competitive advantage in low intensity burns where it's seedling germination and survival rate may be greater than blackbrush germination and survival rates. Abella et al. (2009) observed creosote bush seedlings at a post-burn where no creosote bush seedlings were observed in the unburned site. No blackbrush seedling were observed at either a post-burn or unburned site. Prolonged and severe drought may have a similar effect as fire and livestock grazing by forcing blackbrush into drought dormancy. Schutlz and Oster (1996) found severe drought killed more than 50% of low elevation blackbrush crowns. While in drought dormancy or standing dead, seedlings from other, more drought tolerant species may take advantage of the more favorable micro-habitat provided by the damaged blackbrush cover (personal observation). This is also an at risk community phase. The loss of blackbrush cover allows interspaces to become occupied by a more continuous herbaceous and shrub cover which can help spread fire (D'Antonio and Vitousek 1992, Brooks and Matchett 2003, Brooks et al. 2004, Brooks and Matchett 2006). If the fire return interval is less than 100 years, this community is very likely to transition to State 3.

Community 2.3
Mixed Shrubs

Although shrubs dominate this site, perennial grasses may be relatively abundant. Heavy grazing and drought will reduce perennial grass cover and maintain a mixed shrub plant community (Lei 1999 and Gibbons et al. 2005). For these reasons, southwardly facing and lower elevational areas will tend to have more shrubs while northwardly facing and moister areas tend to have more grasses.

Pathway 2.1a
Community 2.1 to 2.2

Occurs with low intensity, patchy fire especially when flash flooding events cause aggressive sediment deposition.

Pathway 2.2a
Community 2.2 to 2.3

With 25-20 years following fire, shrubs are likely to dominate the sites (Bates 1983). Shrubs may dominate sooner than 25-30 years if the site is not experiencing active overburden or if the site is being used for livestock grazing.

Pathway 2.3a
Community 2.3 to 2.1

This pathway occurs with time, on the order of 100 years, without fire.

Pathway 2.3b
Community 2.3 to 2.2

Occurs with low intensity, patchy fire especially when flash flooding events cause aggressive sediment deposition.

State 3
Burned, blackbrush lost

This state is a result of land clearing and burning which has removed blackbrush and severely limited it's ability to recolonize the site. Although large scale, high intensity fires are not common for this site, upslope vegetation removal by either fire or land clearing has the potential to increase sediment deposition leading to an increase in perennial grass cover (Bestelmeyer 2005). Any increase in perennial grass cover or other pioneer species has the potential to create a continuous fuel cover. There is no certain plant response to intense and widespread disturbance in a land of extreme and variable weather patterns. Response to fire and mechanical land clearing can vary greatly from plant cover being less than the undisturbed sites or with disturbed sites having more total plant cover than undisturbed sites (Vasek et al. 1975, Carpenter et al. 1986). This ecological state may have existed prior to European influences at this ecological site due to Indigenous land management practices. It is highly likely that the Chemehuevi who resided in and around this area used fire as a land management tool. Several bands of Chemehuevi (Hokwaits, Kauyaichits, and the Timpashauwagotsits) spent time in and around the Providence and New York Mountains and used fire as a hunting technique to capture rabbits and deer (Miller and Miller 1967). Laird (1984) also describes Chemehuevi tales where fire was used to improve the growth and quality of basketry materials as well as to char seeds to be eaten. Native American fires were observed near this ecological site in 1866 and recorded by Army Inspector Rusling at Fort Soda (Hart 1965). Whether intentional or not, the greatest differences recorded between pre- and post-fire vegetation demographics, aside from the blackbrush removal, is an increase in Yucca schidigera and Yucca baccata individuals. Abella et al. (2009) found Mojave yucca (Yucca schidigera) to exhibit the highest post-fire sprouting rate than any other plant species in a study of post-fire recovery in the Mojave and Sonoran Deserts. Abella et al (2009) also described vigorous Yucca baccata and schidigera resprouting following a Mojave Desert burn. In yet another study of post-fire effects, a similar yucca (Yucca glauca) increased the number of rosettes, from pre-burn conditions, by 17% two years following the experimental fire (Parmenter 2008). Many tribes such as the Chemehuevi used Yucca species for food, soap, baskets, bowstrings, sandals and many other items (Bean and Saubel 1972). Soil erosion and deposition resulting from Indigenous land management could have created conditions which promoted perennial grass cover and attracted ranchers to the area in the late 1800s. The areas in and around this often have experienced varying degrees of mechanical land clearing, fire, livestock grazing and drought over the last century or longer with equally varying degrees of responses, making characterization of these responses very difficult. Engel and Abella (2011) also found that post-disturbance succession of similar vegetation types varies greatly.

Community 3.1
Annual Herbaceous Plant Community

This community phase occurs within the first couple years following a large scale, high intensity fire or mechanical brush removal. Red brome, redstem stork's bill, six weeks grama, and other annual plant species are common early seral stage colonizers.

Community 3.2
Mixed Shrubs and grasses

Figure 8. Area cleared by homesteaders, probably around 1920

Figure 9. Area not cleared by homesteaders but grazed

Although perennial grasses can dominate this community phase, pioneer shrubs are also abundant. This community phase, especially following favorable climatic conditions, is susceptible to repeated burning because a continuous fuel layer exists. Short-lived pioneer species will dominate sites with a history of heavy and repeated substrate disturbance due to land clearing. Long-lived species at these kinds of sites,such as creosote bush, are unlikely able to recover to their pre-disturbance levels (Prose et. al 1987). Long-lived species such as creosote bush may be more prevalent on sites which burned but did not experience heavy and repeated substrate disturbance.

Community 3.3
Mixed Shrubs

Although shrubs dominate this site, perennial grasses may be relatively abundant. Heavy grazing and drought will reduce perennial grass cover and maintain a mixed shrub plant community. For these reasons, southwardly facing and lower elevational areas will tend to have more shrubs while northwardly facing and moister areas tend to have more grasses.

Pathway 1a
Community 3.1 to 3.2

With 10-15 years following fire, perennial grasses and shrubs will become established (Bates 1983). Perennial grasses will dominate sites with active overburden or sediment deposition.

Pathway 1b
Community 3.1 to 3.3

With 25-30 years following fire, shrubs are likely to dominate the sites (Bates 1983). Shrubs may dominate sooner than 25-30 years if the site is not experiencing active overburden or if the site is being used for livestock grazing.

Pathway 2a
Community 3.2 to 3.1

A high intensity fire will return this community phase to an annual herbaceous plant community.

Pathway 2b
Community 3.2 to 3.3

With time, shrubs stabilize the soil surface and allow shrub islands to develop, eventually dominating the site (Bates 1983). Heavy livestock grazing will reduce big galleta and other perennial grasses (Nelson 1934, Canfield 1939, Miller and Donart 1979, Hughes 1982). Shrub dominance can occur merely by grass removal but also by reduced competition from the grasses. Another mechanism which triggers this pathway is severe drought (Lei 1999).

Pathway 3.3b
Community 3.3 to 3.1

A high intensity fire will return this community phase to an annual herbaceous plant community.

Pathway 3.3a
Community 3.3 to 3.2

Rest from livestock grazing can increase perennial grass cover in less than 15 years (Hughes 1990, Parmenter 2008.). Drought will limit the ability of this community phase pathway to occur. Shrub control is likely necessary to convert and maintain at least a semi-grassland community (Gibbens et al. 2005).

Transition T1
State 1 to 2

This transition occurs when non-native annuals have been introduced to the site.

Transition T2
State 2 to 3

This transition occurs when large scale, high intensity fire has removed blackbrush from the site and surrounding areas.

Additional community tables

Table 6. Community 2.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production (kg/hectare)	Foliar cover (%)
Shrub/Vine
1	Native shrubs			319–448
	blackbrush	CORA	Coleogyne ramosissima	84–280	9–16
	creosote bush	LATR2	Larrea tridentata	56–168	7–17
	Nevada jointfir	EPNE	Ephedra nevadensis	0–67	0–4
	Mojave yucca	YUSC2	Yucca schidigera	39–67	2–3
	spiny menodora	MESP2	Menodora spinescens	0–11	0–3
	buck-horn cholla	CYAC8	Cylindropuntia acanthocarpa	0–11	0–1
	burrobush	AMDU2	Ambrosia dumosa	0–7	0–1
	branched pencil cholla	CYRA9	Cylindropuntia ramosissima	0–6	0–2
	rayless goldenhead	ACSP	Acamptopappus sphaerocephalus	0–6	0–1
	beavertail pricklypear	OPBA2	Opuntia basilaris	0–6	0–1
	banana yucca	YUBA	Yucca baccata	0–6	0–1
	Cooper's goldenbush	ERCO23	Ericameria cooperi	0–6	0–1
	turpentinebroom	THMO	Thamnosma montana	0–4	0–1
	Engelmann's hedgehog cactus	ECEN	Echinocereus engelmannii	0–2	0–1
	littleleaf ratany	KRER	Krameria erecta	0–2	0–1
	Jaeger's Joshua tree	YUBRJ	Yucca brevifolia var. jaegeriana	0–1	1–3
	whitestem paperflower	PSCO2	Psilostrophe cooperi	0–1	0–1
	winterfat	KRLA2	Krascheninnikovia lanata	0–1	0–1
	water jacket	LYAN	Lycium andersonii	0–1	0–1
	Eastern Mojave buckwheat	ERFA2	Eriogonum fasciculatum	0–1	0–1
	burrobrush	HYSA	Hymenoclea salsola	0–1	0–1
Grass/Grasslike
2	Native perennial grasses			0–17
	big galleta	PLRI3	Pleuraphis rigida	0–17	0–3
	bush muhly	MUPO2	Muhlenbergia porteri	0–1	0–1
3	Non-native annual grasses			0–34
	red brome	BRRU2	Bromus rubens	0–34	0–2
	sixweeks grama	BOBA2	Bouteloua barbata	0–3	0–5
	cheatgrass	BRTE	Bromus tectorum	0–1	0–1
Forb
4	Native forbs			0–22
	little deserttrumpet	ERTR8	Eriogonum trichopes	0–20	0–6
	desert marigold	BAMU	Baileya multiradiata	0–11	0–1
	chia	SACO6	Salvia columbariae	0–6	0–1
	combseed	PECTO	Pectocarya	0–1	0–1
	bristly fiddleneck	AMTE3	Amsinckia tessellata	0–1	0–1
5	Non-native annual forbs			0–45
	redstem stork's bill	ERCI6	Erodium cicutarium	0–2	0–1

Supporting information

Inventory data references

High intensity sampling (Caudle et al. 2013) was used to describe this ecological site. Site characteristics such as aspect, slope, elevation and UTMS were recorded for each plot, along with complete species inventory by ocular percent cover. The line-point intercept method was used to measure foliar cover, groundcover, and vegetation structure. At either 300 or 100 points along a 600- or 400-foot step transect, ground cover and intercepted plant species were recorded by height. The first hit method (Herrick et al. 2009) was used to generate the foliar cover values entered in the community phase composition tables. Annual production was estimated using the double-weight sampling method outlined in the 2003 National Range and Pasture Handbook. For herbaceous vegetation, ten 9.6 square foot circular sub-plots were evenly distributed along a 200 foot transect. For woody and larger herbaceous species production was estimated in four 21’X21’ square plots along the same transect. Weight units were collected for each species encountered in the production plots. The number of weight units for each species is then estimated for all plots.

Other references

Abella, S.R., Engel, E.C., Lund, C.L., & Spencer, J.E. 2009. Early post-fire plant establishment on a Mojave Desert burn. Madroño, 56(3), 137-148.

Bates, P.A. 1983. Prescribed burning blackbrush for deer habitat improvement. Cal-Neva Wildlife Transactions. [Volume unknown]: 174-182.

Bean, L. and K.S. Saubel. 1972. Temalpakh (from the earth); Cahuilla Indian knowledge and usage of plants.

Bestelmeyer, B. 2005. "Patterns In Chihuahuan Desert State-And-Transition Models". Presentation: MLRA42 Ecological Site Description Workshop. Alpine, TX.

Bowns, J.E. and N.E. West. 1976a. Blackbrush (Coleogyne ramosissima Torr.) on southwestern Utah rangelands. Res. Rep. Utah Agric. Exp. Stat, 27.

Bowns, J.E. and N.E. West. 1976b. "Blackbrush and the Poorly Understood Rangelands It Occupies." Rangeman's Journal 3.6 (1976): 179-180.

Brooks, M.L., C.M. D'Antonio, D.M. Richardson, J.B. Grace, J.E. Keeley, J.M. DiTomaso, R.J. Hobbs, M. Pellant, and D. Pyke. 2004. Effects of invasive alien plants on fire regimes. Bioscience 54:677-689. Brooks, M. L., T. C.

Caudle, D., H. Sanchez, J. DiBenedetto, C. Talbot, and M. Karl. 2013. Interagency ecological site handbook for rangelands. USDA-NRCS, USDA-FS, DOI-BLM.

Esque, and T. Duck. 2007. Creosotebush, blackbrush, and interior chaparral shrublands. RMRS-GTR-202.

Brooks, M.L. and J.R. Matchett. 2003. Plant community patterns in unburned and burned blackbrush (Coleogyne ramosissima Torr.) shrublands in the Mojave Desert. Western North American Naturalist, 283-298.

Brooks, M.L. and J.R. Matchett. 2006. Spatial and temporal patterns of wildfires in the Mojave Desert, 1980-2004. Journal of Arid Environments 67:148-164.

Buffington, L.C.; Herbel, Carlton H. 1965. Vegetational changes on a semidesert grassland range from 1858 to 1963. Ecological Monographs. 35: 139-164.

Canfield, R.H. 1939. The effect of intensity and frequency of clipping on density and yield of black grama and tobosa grass (Vol. 676). US Dept. of Agriculture.

Callison, J., J.D. Brotherson, and J.E. Bowns. 1985. The effects of fire on the blackbrush [Coleogyne ramosissima] community of southwestern Utah. Journal of Range Management, 535-538.

Carpenter, D.E., M.G. Barbour, and C.J. Bahre. 1986. Old field succession in Mojave Desert scrub. Madrono, 111-122.

Dalton, P.D., Jr. 1962. Ecology of the creosotebush Larrea tridentata (DC.) Cov.. Tucson, AZ: University of Arizona. 170 p. In: Dissertation Abstracts International: 2556. [Abstract].

D'Antonio, C.M. and P.M. Vitousek. 1992. Biological invasions by exotic grasses, the grass/fire cycle, and global change. Annual Review of Ecology and Systematics 23:63-87.

Engel, E., and S.R. Abella. 2011. Vegetation recovery in a desert landscape after wildfires: influences of community type, time since fire and contingency effects. Journal of Applied Ecology, 48(6), 1401-1410.

Gibbens, R.P., R.P. McNeely, K.M. Havstad, R.F. Beck and B. Nolen. 2005. Vegetation changes in the Jornada Basin from 1858 to 1998. Journal of Arid Environments, 61(4), 651-668.

Gorder, J.,; R. Shaw, R. Whitney. 2005. Joshua Tree National Park: Fire management plan. Environmental Assessment. Twentynine Palms, CA: U.S. Department of the Interior, National Park Service, Joshua Tree National Park.

Hart, H.M. 1965. Old Forts of the Far West (Vol. 3). Superior Publishing Company.

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

Herrick, J.E., J.W.V. Zee, K.M. Havstad, L.M. Burkett, and W.G. Whitford. 2009. Monitoring manual for grassland, shrubland, and savanna ecosystems. Volume I: Quick Start. USDA-ARS Jornada Experimental Range, Tucson, AZ.

Hughes, L.E. 1982. A grazing system in the Mohave Desert. Rangelands 4:256-257.

Hughes, L.E. 1990. Twenty Years of Rest-Rotation Grazing on the Arizona Strip: An Observation. Rangelands, 173-176.

Hunter R. 1989. Competition between adult and seedling shrubs of Ambrosia dumosa in the Mojave Desert, Nevada. Great Basin Nat. 49: 79–84.

Jeffries, D.L. and J.M. Klopatek. 1987. Effects of grazing on the vegetation of the blackbrush association. J. Range Manage. 40: 390–392.

Laird, C. 1984. Mirror and Pattern: George Laird's World of Chemehuevi Mythology. Malki Museum Press.

Lei S.A. 1999. Effects of Severe Drought on Biodiversity and Productivity in a Creosote Bush-Blackbrush Ecotone of Southern Nevada. Proceedings: shrubland ecotones. RMRS-P-11. Ogden, Utah: Rocky Mountain Research Station.

Meyer, S.E. and B.K. Pendleton. 2005. Factors affecting seed germination and seedling establishment of a long-lived desert shrub (Coleogyne ramosissima: Rosaceae). Plant Ecology, 178(2), 171-187.

Miller, R.D. and P.J. Miller. 1967. The Chemehuevi Indians of Southern California. Malki Museum Brochure No. 3.

Miller, R.F. and G.B. Donart. 1979. Response of Bouteloua eriopoda (Torr.) Torr. and Sporobolus flexuosus (Thurb.) Rybd. to season of defoliation. Journal of Range Management, 63-67.

Minnich, R. A. 2003. Fire and dynamics of temperature desert woodlands in Joshua Tree National Park. Contract, Joshua Tree National Park.

Nelson, E.W. 1934. The influence of precipitation and grazing on black grama range. US Dept. Agr. Tech. Bull, 409.

Parmenter, R.R. 2008. Long-term effects of a summer fire on desert grassland plant demographics in New Mexico. Rangeland Ecology & Management, 61(2), 156-168.

Plummer, A.P., D.R. Christensen and S.B. Monsen. 1968. Restoring big game range in Utah. Publ. 68-3. Salt Lake City, UT: Utah Division of Fish and Game. 183 p.

Prose, D.V., S.K. Metzger and H.G. Wilshire. 1987. Effects of substrate disturbance on secondary plant succession; Mojave Desert, California. Journal of Applied Ecology, 305-313.

Provenza, F.D. and P.J. Urness. 1981. Diameter-length, weight relations for blackbrush branches. J. Range Manage. 30:68-70.

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

Sampson, A.W. and B.S. Jespersen. 1963. California range brushlands and browse plants (No. 4010). UCANR Publications.

Schultz, B.W. and W.K. Ostler. 1996. Effects of prolonged drought on vegetation associations in the northern Mojave Desert. In Wild Land Shrub and Arid Land Restoration Symposium: Proceedings (p. 228). DIANE Publishing.

Schulz K.A. 2014. Coleogyne ramosissima Mojave Desert Shrubland Alliance. United States National Vegetation Classification. Federal Geographic Data Committee, Washington, D.C.

Society for Range Management. 1989. A glossary of terms used in range management (Third ed.). Society for Range Management, Denver, Colo.

U.S. Bureau of Land Management. 1971. Regulations pertaining to: disposition, occupancy and use - Desert Land Entries. Cir. No. 2291. U.S. Dept. Interior.

Vasek, F.C., H.B. Johnson, and D.H. Eslinger. 1975. Effects of pipeline construction on creosote bush scrub vegetation of the Mojave Desert. Madrono, 23(1), 1-13.

Webb, R.H., J.W. Steiger and R.M. Turner. 1987. Dynamics of Mojave desert shrub assemblages in the Panamint Mountains, California. Ecology, 68(3), 478-490.

West, N.E. 1969. Soil-vegetation relationships in arid southeastern Utah. In: International conference on arid lands in a changing world. Univ. of Arizona.

Contributors

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)
Contact for lead author
Date	03/16/2025
Approved by	Kendra Moseley
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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