Natural Resources
Conservation Service
Ecological site R030XC034NV
SHALLOW GRAVELLY LOAM 9-11 P.Z.
Last updated: 2/25/2025
Accessed: 03/17/2025
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.
Ecological site concept
This site occurs on fan remnants with slopes from 4 to 30 percent. Elevations range from 4800 to 7500 feet. Depth to the calcic horizon ranges from 18 to 43 centimeters. Depth to the petrocalcic horizon is 43 to 75 centimeters.
This is a group concept and provisional STM that also covers the following ecological sites: R030XC007NV, R030XB142NV, R030XC018NV, R030XC024NV, R030XC037NV, R030XC232CA.
Associated sites
| R030XC033NV |
SANDY LOAM 9-11 P.Z. |
|---|---|
| R030XC038NV |
SHALLOW GRAVELLY SLOPE 9-11 P.Z. |
Similar sites
| R030XC037NV |
SHALLOW LOAM 9-11 P.Z. ATCA2 important shrub; more productive. |
|---|---|
| R030XC040NV |
STEEP NORTH SLOPE 9-11 P.Z. ACHNA dominant grasses; less productive. |
| R030XC007NV |
SHALLOW GRAVELLY LOAM 7-9 P.Z. No BOGR2, PUST important species. |
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) Coleogyne ramosissima |
| Herbaceous |
(1) Hesperostipa comata |
Physiographic features
This site occurs on fan remnants with slopes from 4 to 30 percent. Elevations range from 4800 to 7500 feet.
Table 2. Representative physiographic features
| Landforms |
(1)
Fan remnant
|
|---|---|
| Flooding frequency | None |
| Ponding frequency | None |
| Elevation | 4,800 – 7,500 ft |
| Slope | 4 – 15% |
Climatic features
The climate is semiarid with cool, moist winters and warm, intermittently moist summers. Precipitation is greatest in the winter with lesser secondary peak in summer, typical of the Mojave Desert transition to the Great Basin. Average annual precipitation is 9 to 11 inches. Mean annual air temperature is 51 to 56 degrees F. The average growing season is about 130 to 180 days.
Table 3. Representative climatic features
| Frost-free period (average) | 180 days |
|---|---|
| Freeze-free period (average) | |
| Precipitation total (average) | 11 in |
Figure 1. Monthly precipitation range
Figure 2. Monthly average minimum and maximum temperature
Influencing water features
There are no influencing water features associated with this site.
Soil features
The soils associated with this site are shallow and well drained. They formed in alluvium derived from limestone parent material. Soils are characterized by very high runoff, moderately high saturated hydraulic conductivity above the petrocalcic horizon and very low in the lower part of the petrocalcic. Depth to the calcic horizon ranges from 18 to 43 centimeters. Depth to the petrocalcic horizon is 43 to 75 centimeters. Total surface rock fragments range from 60 to 80 percent. Surface rock fragments help to protect the soil surface from wind and water erosion. Soil series correlated to this ecological site include Wamp, a loamy-skeletal, carbonatic, mesic, shallow, Calcic Petrocalcids.
Table 4. Representative soil features
| Parent material |
(1)
Alluvium
–
limestone
|
|---|---|
| Surface texture |
(1) Very gravelly loam (2) Very gravelly fine sandy loam (3) Gravelly loam |
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderately rapid |
| Soil depth | 17 – 30 in |
| Surface fragment cover <=3" | 60 – 80% |
| Surface fragment cover >3" | 4 – 10% |
| Available water capacity (0-40in) |
0.49 – 1.06 in |
| Calcium carbonate equivalent (0-40in) |
20 – 50% |
| Electrical conductivity (0-40in) |
2 mmhos/cm |
| Sodium adsorption ratio (0-40in) |
5 |
| Soil reaction (1:1 water) (0-40in) |
8.2 – 8.4 |
| Subsurface fragment volume <=3" (Depth not specified) |
35 – 60% |
| Subsurface fragment volume >3" (Depth not specified) |
7% |
Ecological dynamics
Blackbrush communities are most prevalent in the transitional zone between the Mojave Desert and Great Basin. Blackbrush is a paleoendemic species as originally postulated by Stebbins and Major (1965). Blackbrush is a transitional species that occupies a boundary that has shifted in recent geologic time. Analysis of packrat middens suggests a 50–100-m downward movement of the blackbrush zone along elevational gradients in the Mojave Desert (Cole and Webb, 1985; Hunter and McAuliffe, 1994).
Blackbrush is long-lived and generally considered a climax species. It is a non-sprouter; regeneration depends on wind pollinated seed and heavy winter precipitation, and is therefore slow to re-colonize burned areas (Anderson 2001). Blackbrush recruitment is episodic, like many shrubs in arid systems, when conditions are favorable large seed crops are produced and the rest of the time is characterized by minimal seed output (Pendleton and Meyer 2004). Blackbrush seeds are frequently cached away by rodents, until conditions are conducive for germination. Typically, germination occurs during the winter and early spring, given the proper moisture conditions and cool soil temperatures (Pendleton 2008). Seeds require cold stratification before germination and the survival of seedlings following germination is dependent on the availability of spring time moisture (Pendleton 2008).
On undisturbed sites, blackbrush dominates the landscape and species diversity is generally low. Undisturbed blackbrush communities are fairly resistant to invasion by non-natives (Brooks and Matchett 2003). Mature blackbrush plants are well adapted to persist under less than optimal conditions, and individuals’ may live as long as 400 years (Pendleton and Meyer 2004).
Fire Ecology:
Blackbrush stands are considered to be one of the most flammable native plant assemblages in the Mojave Desert. Fire will start and spread easily due to the close spacing nature and resinous foliage of blackbrush. During periods with high winds, low relative humidity and low fuel moisture blackbrush will experience stand replacing fires. The short-lived seed of blackbrush is readily destroyed by fire and it may take upwards of 60 years for blackbrush to achieve pre-fire conditions. There is frequently 100 percent mortality of mature blackbrush following fire (Brooks and Matchett 2003). Mountain big sagebrush is readily killed by wildfire and establishes soley from seed. Sagebrush is characterized by a pulse recruitment pattern durring periods of favorable climate. Ephedra generally sprouts after fire damages aboveground vegetation and may increase in cover and density post-fire. Needleandthread is top killed by fire and sprouts from the surviving root crown. Indian ricegrass can be killed by fire, depending on severity and season of burn. Indian ricegrass reestablishes on burned sites through seed dispersed from adjacent unburned areas. Blue grama is tolerant of fire when dormant, but can be killed if burned during active growing season. It frequently increases in cover and production following fire.
Post-fire plant communities vary, depending on use history and species present prior to the fire. Post fire sprouting shrub species such as yucca, Apache plume and ephedra increase along with perennial grasses. Species that readily reestablish from seed such as snakeweed also increase. Generally, non-natives increase and native species decrease post fire (Brooks and Matchett 2003). The effects of fire on blackbrush appear to be long term, it is killed by fire and is slow to reestablish. Blackbrush communities are also susceptible to replacement by mountain big sagebrush.
State and transition model
More interactive model formats are also available.
View Interactive Models
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 2 submodel, plant communities
State 3 submodel, plant communities
State 1
Reference State
The reference state is representative of the natural range for variability under pristine conditions. This site is dominated by an evergreen shrub community. Community phase changes are primarily driven by long-term drought and infrequent wildfire. Historically, blackbrush associations were long-lived stable communities. Fire was infrequent and patchy due to low fuel loading. Reproduction and recruitment are episodic, based on favorable environmental conditions (Pendleton and Meyer 2004). Very old stands of blackbrush may have established hundreds to thousands of years ago under very different climatic conditions and will take a considerable amount of time to recover following disturbances.
Community 1.1
Reference Plant Community
Figure 3. Shallow Gravelly Loam
The reference plant community is dominated by blackbrush, needleandthread, and Indian ricegrass. Mountain big sagebrush is another important species associated with this site. Potential vegetative composition is about 20 percent grasses, 10 percent forbs and 70 percent shrubs and trees. Approximate ground cover (basal and crown) is about 25 to 40 percent. This plant community phase can persist under undisturbed conditions for an extended period of time.
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 | 244 | 347 | 485 |
| Grass/Grasslike | 70 | 100 | 140 |
| Forb | 35 | 50 | 70 |
| Tree | 1 | 3 | 5 |
| Total | 350 | 500 | 700 |
Community 1.2
Plant Community 1.2
Figure 5. burned
This plant community is characteristic of an early-seral, post-disturbance plant community and is initially heavily dominated by herbaceous vegetation. Sprouting shrubs quickly return and provide favorable environment for the establishment of other shrub seedlings. Fast-moving, low intensity fires result in the incomplete removal of blackbrush allowing for direct reestablishment through on site seed. This plant community is ‘at-risk’ of invasion by non-native annuals, like red brome, cheatgrass and red stem filaree. Invasion of non-natives will cause this plant community to cross a biotic threshold into state 2. Composition of post-fire plant communities may vary depending on season of burn. Summer fires commonly result in reduced cover of needleandthread and blue grama, while mesa dropseed increases in cover.
Community 1.3
Plant Community 1.3
Figure 6. mountain big sagebrush community phase
This plant community is characterized by dominance of mountain big sagebrush. Natural succession post fire may result in dominance by big sagebrush, blackbrush is present in trace amounts. Blackbrush establishes solely from seed and is characterized by pulse recruitment pattern dependant on ideal climatic conditions. This ecological site is near the elevational limit for blackbrush communities, sagebrush readily establishes in this zone and is capable of replacing blackbrush if climatic patterns are conducive.
Community 1.4
Plant Community 1.4
This plant community is characterized by encroachment of pinyon and juniper and loss of other structural and functional groups. This community phase is identified as ‘at-risk’, total tree cover is near 20 percent and without fire or other disturbance tree cover will increase. The at-risk community phase is in danger of crossing an irreversible biotic threshold to state 3. Management options to keep this community phase from crossing a threshold include cutting trees and reducing dominance by woody vegetation and encouraging herbaceous vegetation to return balance of structural and functional groups.
Figure 7. Annual production by plant type (representative values) or group (midpoint values)
Table 6. Annual production by plant type
| Plant type | Low (lb/acre) |
Representative value (lb/acre) |
High (lb/acre) |
|---|---|---|---|
| Shrub/Vine | 240 | 400 | 530 |
| Tree | 130 | 300 | 500 |
| Grass/Grasslike | 24 | 40 | 55 |
| Forb | 6 | 10 | 15 |
| Total | 400 | 750 | 1100 |
Pathway 1.1a
Community 1.1 to 1.2
Wildfire, disease, insect attack and/or prolonged drought.
Pathway 1.1b
Community 1.1 to 1.4
Natural regeneration over time and encroachment of pinyon and juniper trees. This ecological site is at higher risk of pinyon-juniper invasion when it is located near a woodland. Invasion may occur with out previous disturbance.
Pathway 1.2a
Community 1.2 to 1.1
Absence from disturbance and natural regeneration over time. Regeneration of blackbrush is dependent on nearby seed source and favorable climatic conditions. Recovery of blackbrush to pre-fire conditions can take greater than 60 years.
Pathway 1.2b
Community 1.2 to 1.3
Natural regeneration post-wildfire may result in sagebrush dominance.
Pathway 1.3a
Community 1.3 to 1.4
Absence of fire and other natural disturbance. Without fire, shrubs become over mature and decadent. Lack of disturbance allows tree seedlings to encroach.
Pathway 1.4a
Community 1.4 to 1.2
Wildfire, disease/insect attack or prolonged drought removes shrub cover, tree seedlings and saplings and encourages growth of perennial bunchgrasses. Non-natives may increase post fire.
State 2
Invaded State
The invaded state is characterized by the presence of non-native annuals. A biotic threshold is crossed, with the introduction of non-natives that are difficult to remove from the system and have the potential to alter disturbance regimes significantly from their natural range of variability. Introduced annuals such as red brome, cheatgrass and redstem filaree have invaded the reference plant community. These non-natives annuals are highly flammable and promote wildfires where fires historically have been infrequent. Following a disturbance this state relies on the availability of a nearby seed source.
Community 2.1
Plant Community 2.1
This plant community is compositionally similar to the reference plant community with the presence of non-natives in the understory. Ecological processes have not been compromised at this time, however the ecological resilience of the site is reduced by the presence of non-natives. This plant community is respond differently following a disturbance when compared to the reference plant community. Management focused on reducing anthropogenic impacts is important for maintaining the health of perennial native species and protecting the site from further degradation.
Community 2.2
Plant Community 2.2
This plant community is characteristic of a post-disturbance plant community. Initially post-fire plant communities are heavily dominated by herbaceous vegetation. Shrubs capable of sprouting and those that readily establish from seed quickly return. Sprouting species are the first to achieve dominance, including Ephedra, Yucca and Purshia. Species that readily establish from seed such as Atriplex and Gutierrizea are also common. Fast-moving, low-intensity fires result in the incomplete removal of blackbrush allowing for direct reestablishment. Blackbrush and sagebrush reestablish provided favorable climatic conditions and available seed source. Abundance of non-native biomass varies annual depending on weather. Droughty conditions can favor native perennials and decrease abundance of non-natives. Post-fire plant communities vary in response to the season of burn. Summer fires result in decreased cover of needleandthread and blue grama, while mesa dropseed increases in cover and production.
Figure 8. Annual production by plant type (representative values) or group (midpoint values)
Table 7. Annual production by plant type
| Plant type | Low (lb/acre) |
Representative value (lb/acre) |
High (lb/acre) |
|---|---|---|---|
| Grass/Grasslike | 180 | 300 | 420 |
| Shrub/Vine | 75 | 125 | 175 |
| Forb | 45 | 75 | 105 |
| Total | 300 | 500 | 700 |
Community 2.3
Plant Communtiy 2.3
This plant community is characterized by dominance of mountain big sagebrush. Natural succession post fire may result in dominance by big sagebrush, blackbrush is present in trace amounts. Blackbrush establishes solely from seed and is characterized by a pulse recruitment pattern dependent on ideal climatic conditions. This ecological site is near the elevational limit for blackbrush communities, sagebrush readily establishes in this zone and is capable of replacing blackbrush if climatic patterns are conducive. Non-native species remain in plant community.
Community 2.4
Plant Community 2.4
This plant community is characterized by encroachment of pinyon and juniper trees. Total tree cover is near 20% and seedlings and saplings are prevalent in the plant community. This community phase is identified as ‘at-risk’, without fire or other disturbance, tree cover will increase. The at-risk community phase is in danger of crossing an irreversible biotic threshold to state 3. Management options to keep this community phase from crossing a threshold include cutting trees and reducing dominance by woody vegetation and encouraging growth of perennial bunchgrasses.
Pathway 2.1a
Community 2.1 to 2.2
Wildfire, disease, insect attack and/or prolonged drought.
Pathway 2.1b
Community 2.1 to 2.4
Natural regeneration over time and absence from disturbance allows trees to encroach.
Pathway 2.2a
Community 2.2 to 2.1
Absence from disturbance and natural regeneration over time. Regeneration of black brush is dependent on nearby seed source and favorable climatic conditions. Recovery of blackbrush to pre-fire conditions can take greater than 60 years.
Pathway 2.2b
Community 2.2 to 2.3
Changes in climatic patterns allow mountain big sagebrush to replace blackbrush as the dominant species.
Pathway 2.3a
Community 2.3 to 2.4
Absence of fire and other natural disturbance. Without fire, shrubs become over mature and decadent. Lack of disturbance allows tree seedlings to encroach into the plant community.
Pathway 2.4a
Community 2.4 to 2.2
Wildfire, prolonged drought and/or insect/disease attack removes decadent shrub cover, tree seedlings and saplings. Non-natives may increase post fire.
State 3
Tree State
The tree state is characterized by the invasion of pinyon-juniper and tree cover greater than 20 percent. Lack of fire and other disturbance allows seedlings and saplings to infill and eventually dominate, changing the ecological dynamics of the site. Non-native annuals may or may not be present in the understory. This state experiences reduced infiltration and increased runoff during precipitation events, diminishing soil moisture. Feedbacks contributing to the stability of this state include reduced understory vegetation resulting from decreased soil moisture and overstory shading. An abiotic threshold has been crossed changing the ecological dynamics of the site.
Community 3.1
Plant Community 3.1
Figure 9. Burned - tree invasion
This plant community is characterized by an immature forest, trees constitute more than half of the plant community. Understory vegetation is moderately affected by overstory shading. Shrubs and grasses are decreasing. Non-natives may or may not be present in understory. Tree canopy is greater than 20 percent.
Community 3.2
Plant Community 3.2
This plant community is characterized by pinyon and juniper trees that have reached or are near maximal height for the site. Remaining understory vegetation is strongly influenced by overstory shading, competition and duff accumulation. Dead shrubs are common in understory, perennial grasses and forbs are mostly absent. Non-native species may or may not be present. Tree canopy ranges from 30-50 percent.
Community 3.3
Plant Communtiy 3.3
This plant community is characterized by an over mature forest. Upper crowns of dominant trees are normally flat topped or rounded. Without disturbance, the trees on this site become very old. Understory herbaceous production is greatly reduced or even absent due to tree competition and overstory shading, tree canopy is generally greater than 50 percent. Surface erosion is common and bare ground is dominant. Non-natives are able to survive dense canopy cover, if present in plant community.
Community 3.4
Plant Community 3.4
This community phase is characteristic of an early-seral, post-disturbance plant community and is initially dominated by herbaceous vegetation. Standing snags remaining after disturbance have little to no effect on the composition and production of the herbaceous vegetation. Sprouting shrubs and those that readily establish from seed are the first to appear. Long lived perennials and late successional species will colonize the site, given protection from large scale disturbance or abusive management. Increased availability of critical resources following wildfire may result in increased non-native biomass.
Pathway 3.1a
Community 3.1 to 3.2
Absence of disturbance and continued infilling by pinyon and juniper. Bare ground increasing.
Pathway 3.2a
Community 3.2 to 3.3
Continued infilling by pinyon-juniper trees leading to a closed canopy.
Pathway 3.3a
Community 3.3 to 3.4
Wildfire, disease/insect attack or prolonged drought removes tree canopy.
Pathway 3.4a
Community 3.4 to 3.1
Absence from disturbance and natural regeneration over time. Seedling and saplings begin to encroach from neighboring sites.
Transition T1a
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 T1b
State 1 to 3
Continued lack of disturbance. Encroachment and establishment of pinyon and juniper. Tree canopy is 20 percent or greater and bare ground is increasing.
Transition T2
State 2 to 3
Continued lack of disturbance. Encroachment and establishment of pinyon and juniper. Tree canopy is 20 percent or greater and bare ground is increasing.
Additional community tables
Table 8. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Primmary Perennial Grasses | 60–125 | ||||
| needle and thread | HECO26 | Hesperostipa comata | 25–50 | – | ||
| Indian ricegrass | ACHY | Achnatherum hymenoides | 25–50 | – | ||
| blue grama | BOGR2 | Bouteloua gracilis | 10–25 | – | ||
| 2 | Secondary Perennial Grasses | 1–25 | ||||
| Mormon needlegrass | ACAR14 | Achnatherum aridum | 3–15 | – | ||
| desert needlegrass | ACSP12 | Achnatherum speciosum | 3–15 | – | ||
| squirreltail | ELEL5 | Elymus elymoides | 3–15 | – | ||
| mesa dropseed | SPFL2 | Sporobolus flexuosus | 3–15 | – | ||
| 3 | Annual Grasses | 1–10 | ||||
| sixweeks fescue | VUOC | Vulpia octoflora | 1–10 | – | ||
|
Forb
|
||||||
| 4 | Perennial Forbs | 10–50 | ||||
| Mojave sandwort | ARMA3 | Arenaria macradenia | 3–10 | – | ||
| castilla | CASTI | Castilla | 3–10 | – | ||
| Cooper's rubberweed | HYCO2 | Hymenoxys cooperi | 3–10 | – | ||
| hoary tansyaster | MACA2 | Machaeranthera canescens | 3–10 | – | ||
| 5 | Annual Forbs | 1–25 | ||||
| cryptantha | CRYPT | Cryptantha | 1–10 | – | ||
| gilia | GILIA | Gilia | 1–10 | – | ||
| manybristle chinchweed | PEPA2 | Pectis papposa | 1–10 | – | ||
| phacelia | PHACE | Phacelia | 1–10 | – | ||
|
Shrub/Vine
|
||||||
| 6 | Primary Shrubs | 250–350 | ||||
| blackbrush | CORA | Coleogyne ramosissima | 200–250 | – | ||
| mountain big sagebrush | ARTRV | Artemisia tridentata ssp. vaseyana | 25–75 | – | ||
| 7 | Secondary Shrubs | 25–100 | ||||
| black sagebrush | ARNO4 | Artemisia nova | 3–15 | – | ||
| fourwing saltbush | ATCA2 | Atriplex canescens | 3–15 | – | ||
| desert ceanothus | CEGR | Ceanothus greggii | 3–15 | – | ||
| yellow rabbitbrush | CHVI8 | Chrysothamnus viscidiflorus | 3–15 | – | ||
| Nevada jointfir | EPNE | Ephedra nevadensis | 3–15 | – | ||
| mormon tea | EPVI | Ephedra viridis | 3–15 | – | ||
| Apache plume | FAPA | Fallugia paradoxa | 3–15 | – | ||
| spiny greasebush | GLSP | Glossopetalon spinescens | 3–15 | – | ||
| threadleaf snakeweed | GUMI | Gutierrezia microcephala | 3–15 | – | ||
| Fremont's mahonia | MAFR3 | Mahonia fremontii | 3–15 | – | ||
| Stansbury cliffrose | PUST | Purshia stansburiana | 3–15 | – | ||
| banana yucca | YUBA | Yucca baccata | 3–15 | – | ||
| Joshua tree | YUBR | Yucca brevifolia | 3–15 | – | ||
| beavertail pricklypear | OPBA2 | Opuntia basilaris | 1–7 | – | ||
| grizzlybear pricklypear | OPPOE | Opuntia polyacantha var. erinacea | 1–7 | – | ||
| spinystar | ESVI2 | Escobaria vivipara | 1–7 | – | ||
| Whipple cholla | CYWH | Cylindropuntia whipplei | 1–7 | – | ||
|
Tree
|
||||||
| 8 | Trees | 1–5 | ||||
| singleleaf pinyon | PIMO | Pinus monophylla | 1–3 | – | ||
| Utah juniper | JUOS | Juniperus osteosperma | 1–2 | – | ||
Table 9. Community 1.4 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Perennial Grasses | 24–55 | ||||
| squirreltail | ELEL5 | Elymus elymoides | 5–15 | – | ||
| needle and thread | HECO26 | Hesperostipa comata | 3–10 | – | ||
| mesa dropseed | SPFL2 | Sporobolus flexuosus | 3–10 | – | ||
| Indian ricegrass | ACHY | Achnatherum hymenoides | 5–10 | – | ||
| desert needlegrass | ACSP12 | Achnatherum speciosum | 3–10 | – | ||
| blue grama | BOGR2 | Bouteloua gracilis | 5–10 | – | ||
|
Forb
|
||||||
| 2 | Perennial Forbs | 6–15 | ||||
| rockcress | ARABI2 | Arabis | 1–10 | – | ||
| castilla | CASTI | Castilla | 1–10 | – | ||
| desert frasera | FRAL5 | Frasera albomarginata | 1–10 | – | ||
| Cooper's rubberweed | HYCOC | Hymenoxys cooperi var. canescens | 1–10 | – | ||
| hoary tansyaster | MACA2 | Machaeranthera canescens | 1–10 | – | ||
| beardtongue | PENST | Penstemon | 1–10 | – | ||
| 3 | Annual Forbs | 1–15 | ||||
| cryptantha | CRYPT | Cryptantha | 1–10 | – | ||
| gilia | GILIA | Gilia | 1–10 | – | ||
|
Shrub/Vine
|
||||||
| 4 | Primary Shrubs | 100–400 | ||||
| mountain big sagebrush | ARTRV | Artemisia tridentata ssp. vaseyana | 100–200 | – | ||
| blackbrush | CORA | Coleogyne ramosissima | 100–200 | – | ||
| 5 | Secondary Shrubs | 25–100 | ||||
| fourwing saltbush | ATCA2 | Atriplex canescens | 5–25 | – | ||
| yellow rabbitbrush | CHVI8 | Chrysothamnus viscidiflorus | 5–25 | – | ||
| Nevada jointfir | EPNE | Ephedra nevadensis | 5–25 | – | ||
| mormon tea | EPVI | Ephedra viridis | 5–25 | – | ||
| Fremont's mahonia | MAFR3 | Mahonia fremontii | 5–25 | – | ||
| banana yucca | YUBA | Yucca baccata | 5–25 | – | ||
| Joshua tree | YUBR | Yucca brevifolia | 5–25 | – | ||
| beavertail pricklypear | OPBA2 | Opuntia basilaris | 1–5 | – | ||
| grizzlybear pricklypear | OPPOE | Opuntia polyacantha var. erinacea | 1–5 | – | ||
| Whipple cholla | CYWH | Cylindropuntia whipplei | 1–5 | – | ||
|
Tree
|
||||||
| 6 | Evergreen | 100–500 | ||||
| Utah juniper | JUOS | Juniperus osteosperma | 50–200 | – | ||
| singleleaf pinyon | PIMO | Pinus monophylla | 50–200 | – | ||
Table 10. Community 2.2 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Primary Perennial Grasses | 100–350 | ||||
| mesa dropseed | SPFL2 | Sporobolus flexuosus | 50–150 | – | ||
| Indian ricegrass | ACHY | Achnatherum hymenoides | 50–125 | – | ||
| 2 | Secondary Perennial Grasses | 25–50 | ||||
| needle and thread | HECO26 | Hesperostipa comata | 5–25 | – | ||
| desert needlegrass | ACSP12 | Achnatherum speciosum | 1–15 | – | ||
| King's eyelashgrass | BLKI | Blepharidachne kingii | 1–15 | – | ||
| blue grama | BOGR2 | Bouteloua gracilis | 1–15 | – | ||
| 3 | Annual Non-native Grasses | 1–25 | ||||
| red brome | BRRU2 | Bromus rubens | 1–15 | – | ||
|
Forb
|
||||||
| 4 | Perennial Forbs | 10–50 | ||||
| Cooper's rubberweed | HYCOC | Hymenoxys cooperi var. canescens | 1–15 | – | ||
| hoary tansyaster | MACA2 | Machaeranthera canescens | 1–15 | – | ||
| desert globemallow | SPAM2 | Sphaeralcea ambigua | 1–15 | – | ||
| small wirelettuce | STEXE | Stephanomeria exigua ssp. exigua | 1–15 | – | ||
| 5 | Annual Forbs | 1–25 | ||||
| cryptantha | CRYPT | Cryptantha | 1–15 | – | ||
| phacelia | PHACE | Phacelia | 1–15 | – | ||
|
Shrub/Vine
|
||||||
| 6 | Primary Shrubs | 65–150 | ||||
| fourwing saltbush | ATCA2 | Atriplex canescens | 25–50 | – | ||
| banana yucca | YUBA | Yucca baccata | 25–50 | – | ||
| rubber rabbitbrush | ERNA10 | Ericameria nauseosa | 10–25 | – | ||
| 7 | Secondary Shrubs | 25–75 | ||||
| mountain big sagebrush | ARTRV | Artemisia tridentata ssp. vaseyana | 1–15 | – | ||
| blackbrush | CORA | Coleogyne ramosissima | 1–15 | – | ||
| button brittlebush | ENFR | Encelia frutescens | 1–15 | – | ||
| Apache plume | FAPA | Fallugia paradoxa | 1–15 | – | ||
| threadleaf snakeweed | GUMI | Gutierrezia microcephala | 1–15 | – | ||
| Joshua tree | YUBR | Yucca brevifolia | 1–15 | – | ||
| Whipple cholla | CYWH | Cylindropuntia whipplei | 1–5 | – | ||
Interpretations
Animal community
Livestock Interpretations:
This site is suitable for livestock grazing. Grazing management should be keyed to dominant grasses and palatable shrub production. Blackbrush is not preferred as forage by domestic livestock, but does provide some forage during the spring, summer and fall. Mountain big sagebrush is eaten by domestic livestock but has long been considered to be of low palatability, and a competitor to more desirable species. Needleandthread provides highly palatable forage, especially in the spring before fruits have developed. Needlegrasses are grazed in the fall only if the fruits are softened by rain. Indian ricegrass is highly palatable to all classes of livestock in both green and cured condition. It supplies a source of green feed before most other native grasses have produced much new growth. Blue grama is valuable forage for all classes of domestic livestock, providing excellent forage for cattle and sheep. Blue grama tends to be most productive following summer rains, but it cures well and provides forage year round.
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:
Blackbrush is a valuable browse species for bighorn sheep. It may also comprise up to 25% of the mule deer winter diet. Blackbrush provides cover for upland game birds, nongame birds and small mammals. Mountain big sagebrush is highly preferred and nutritious winter forage for mule deer. Needleandthread is moderately important spring forage for mule deer, but use declines considerably as more preferred forages become available. Indian ricegrass is eaten by pronghorn in moderate amounts whenever available. A number of heteromyid rodents inhabiting desert rangelands show preference for seed of Indian ricegrass. Indian ricegrass is an important component of jackrabbit diets in spring and summer. Indian ricegrass seed provides food for many species of birds. Doves, for example, eat large amounts of shattered Indian ricegrass seed lying on the ground. Blue grama also provides important forage for mule deer. Quail and some songbirds eat the seeds of blue grama. Small mammals also eat blue grama seeds and stems. Flower heads and seeds of blue grama are also consumed by grasshoppers, which can all but eliminate an annual seed crop.
Hydrological functions
Soils associated with this site are characterized by very high runoff and moderately rapid permeability.
Recreational uses
Aesthetic value is derived from the diverse floral and faunal composition and the colorful flowering of wild flowers and shrubs during the spring and early summer. This site offers rewarding opportunities to photographers and for nature study. This site is used for camping and hiking and has potential for upland and big game hunting.
Other products
Native Americans used big sagebrush leaves and branches for medicinal teas, and the leaves as a fumigant. Bark was woven into mats, bags and clothing. Indian ricegrass was traditionally eaten by some Native Americans. The Paiutes used the seed as a reserve food source.
Other information
Blackbrush contributes to desert fertility by 1) protecting the soil against wind erosion through retarding the movement of soil and increasing the accumulation of fine soil particles around its base; 2) protecting understory vegetation from the effects of high temperatures, thereby helping to retain surface nitrogen and adding organic matter to the soil; and 3) serving as a nitrogen reservoir through the storage of nitrogen in roots, leaves, and stems. Needleandthread is useful for stabilizing eroded or degraded sites. Because of its wide adaptation, ease of establishment, and economic value, blue grama is used extensively for conservation purposes, rangeland seeding, and landscaping. Blue grama is useful for reclamation and for erosion control in arid and semiarid regions.
Supporting information
Type locality
| Location 1: Clark County, NV | |
|---|---|
| Township/Range/Section | T13S R61E S29 |
| UTM zone | N |
| UTM northing | 4071507 |
| UTM easting | 663676 |
| Latitude | 36° 46′ 30″ |
| Longitude | 115° 9′ 57″ |
| General legal description | Occurs on Mule Deer Ridge, approximately 2 miles from Dead Horse Trail, between the East Desert Range and the Sheep Range, west of U.S. Highway 93. Section 29, T13S. R61E. MDBM. USGS Mule Deer Ridge. NV 7.5 minute series quadrangle. |
Other references
Anderson, M. D. 2001. Coleogyne ramosissima. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/
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. 63.3: 283-298.
Cole, K.L., and Webb, R.H. 1985. Late Holocene vegetation changes in Greenwater Valley, Mojave Desert, California, Quaternary Research. 23. 2: 227-235.
Hunter, K.L. and J.R. McAuliffe. 1994. Elevational Shifts of Coleogyne ramosissima in the Mojave Desert during the Little Ice Age. Quaternary Research. 42. 2: 216-221.
Pendleton, B.K. 2008. Coleogyne ramosissima Torr. Available: http://www.nsl.fs.fed.us/wpsm/index.html [2010, August 11].
Pendleton, B.K. and S.E. Meyer. 2004. Habitat-correlated variation in blackbrush (Coleogyne ramosissima: Rosaceae) seed germination response. J. of Arid Environments. 59: 229-243.
Stebbins, G.L. and J. Major. 1965. Endemism abd Speciation in the California flora. Ecological Monographs 35, 1-35.
Contributors
PN-E
Approval
Sarah Quistberg, 2/25/2025
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) | Patti Novak-Echenique |
|---|---|
| Contact for lead author | State Rangeland Management Specialist |
| Date | 06/28/2011 |
| Approved by | Sarah Quistberg |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
Rills are none to rare. A few rills (<1/10 m or 30 ft) will occur, especially following summer convective storms due to very shallow skeletal soils and steep slopes. -
Presence of water flow patterns:
A few (<1/10 m or 30 ft) water flow patterns may occur in interspaces between shrubs, rarely connected. These should be limited to times following intense summer storms on steeper slopes or to natural drainages within the ecological site. -
Number and height of erosional pedestals or terracettes:
Few to none. Should only occur when associated with rills or water flow patterns on steeper slopes or natural drainages. Height < 0.5 inch. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare Ground <10%. Soil is mostly covered by gravels, vegetation and some lichens/mosses. When patches of bare ground (3 ft. diameter) occur, they should be associated with rodent burrow activity. -
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 (<10 ft) during intense summer convection storms or rapid snowmelt events. Persistent litter (large woody material) will remain in place except during intense summer storms. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil stability values range from 1 to 3 in the interspaces and 4 to 6 under canopy. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
A-horizon thickness is 2 inches. Surface structure is typically moderate, medium subangular blocky. Soil surface colors are brown and soils are typified by an ochric epipedon. Organic matter of the surface horizon is typically less than 1 percent dropping off quickly below. Organic matter content can be more or less depending on micro-topography. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Deep-rooted bunchgrasses and shrub canopy break raindrop impact, slow runoff, increase infiltration and provide some opportunity for snow catch on this site. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
Compacted layers are none. Subsoil calcic horizons are not to be interpreted as compacted. -
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:
non-sprouting evergreen shrubsSub-dominant:
deep-rooted, cool-season, perennial bunchgrasses = deciduous shrubs > shallow-rooted cool-season perennial bunchgrasses > deep-rooted, cool-season perennial forbs <> annual forbs <> succulentsOther:
Other: warm-season, perennial grasses, biological soil crustAdditional:
-
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 30% of total woody canopy; some of the mature bunchgrasses (<20%) have dead centers, especially with multi-year droughts. -
Average percent litter cover (%) and depth ( in):
Litter cover is concentrated under shrubs and grasses and totals 25-35%. Litter depth is <0.25 inches. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
For normal or average growing season (through mid-June) is ± 500 lbs/ac, ranging from 350 in poor growth years to 700 lbs/ac in optimal growth years. -
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:
Red brome and cheatgrass can invade and persist on this site. Utah juniper will increase. -
Perennial plant reproductive capability:
All functional groups should reproduce in average (or normal) and above average growing season years. Less reproduction, although, rarely none, will occur in below-average precipitation years.
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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.
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