Natural Resources
Conservation Service
Ecological site R035XC306AZ
Clayey Upland 10-14" p.z.
Accessed: 11/24/2024
General information
Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.
Figure 1. Mapped extent
Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated.
MLRA notes
Major Land Resource Area (MLRA): 035X–Colorado Plateau
This ecological site occurs in Common Resource Area 35.3 – the Colorado Plateau Sagebrush – Grasslands
Elevations range from 4800 to 6700 feet, and precipitation averages 10 to 14 inches. Vegetation includes Wyoming big sagebrush, Utah juniper, Colorado pinyon - cliffrose, Mormon tea, fourwing saltbush, blackbrush, Indian ricegrass, needle and thread, western wheatgrass, Galleta, black grama, blue grama, and sand dropseed. The soil temperature regime is mesic, and the soil moisture regime is ustic aridic. This unit occurs within the Colorado Plateau Physiographic Province and is characterized by a sequence of flat to gently dipping sedimentary rocks eroded into plateaus, valleys, and deep canyons. Sedimentary rock classes dominate the plateau with volcanic fields occurring for the most part near its margin.
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) Artemisia tridentata |
| Herbaceous |
(1) Bouteloua gracilis |
Physiographic features
This ecological site occurs in an upland position on mesas, fans, and plateaus. Slopes range from 0 to 15 percent. The soil of this site is deep to very deep to any plant root restricting layer. Soil cracking is noticable on the soil surface when the soil is dry due to the shrink-swell nature of the soil.
Table 2. Representative physiographic features
| Landforms |
(1)
Mesa
(2) Plateau (3) Fan |
|---|---|
| Flooding frequency | None |
| Ponding frequency | None |
| Elevation | 1,463 – 1,768 m |
| Slope | 0 – 15% |
| Aspect | Aspect is not a significant factor |
Climatic features
Winter summer moisture ratios range from 70:30 to 60:40. Late spring is usually the driest period, and early fall moisture can be sporadic. Summer rains fall from June through September; moisture originates in the Gulf of Mexico and creates convective, usually brief, intense thunderstorms. Cool season moisture from October through May tends to be frontal; it originates in the Pacific and the Gulf of California and falls in widespread storms with longer duration and lower intensity. Precipitation generally comes as snow from December through February. Accumulations above 12 inches are not common but can occur. Snow usually lasts for 3-4 days but can persist much longer. Summer daytime temperatures are commonly 95 - 100 F and on occasion exceed 105 F. Winter air temperatures can regularly go below 10 F and have been recorded below - 20 F.
Table 3. Representative climatic features
| Frost-free period (average) | 168 days |
|---|---|
| Freeze-free period (average) | 193 days |
| Precipitation total (average) | 356 mm |
Figure 2. Monthly precipitation range
Figure 3. Monthly average minimum and maximum temperature
Influencing water features
The soil moisture on this ecological site comes from precipitation. The site does not benefit significantly from run-on moisture.
The cracking clay soil allows the site to capture most of the the prcipitation events when the site is dry, and water can be captured by the cracks in the surface of the soil. If the soil is wet, and the cracks have swelled shut, then the the infiltration is very slow, and most of the rainfall will run off.
Soil features
The surface soils on this site are shrink swell clays that create large cracks in the surface when the soil is dry. The soil of this site is moderately deep to very deep to any plant root restricting layer. The surface texture of the soil includes clay, cobbly clay, and silty clay. Subsurface horizon textures are predominantly clay to clay loam but occasionally are loam. The soil reaction ranges from slightly to moderately alkaline (7.4 to 9.0) and is non to slightly effervescent throughout the soil profile. Permeability is slow to very slow.
Soil survey map unit components correlated to this ecological site include:
SSA 625 Mohave County Area NE part 9-Campanile, 43-Campanile/Padilla;
SSA 715 Fort Defiance Area 18-Chafin, 128-Venadito.
Table 4. Representative soil features
| Parent material |
(1)
Alluvium
–
sandstone and shale
|
|---|---|
| Surface texture |
(1) Clay (2) Cobbly |
| Family particle size |
(1) Clayey |
| Drainage class | Well drained |
| Permeability class | Moderately slow to slow |
| Soil depth | 102 – 203 cm |
| Surface fragment cover >3" | 0 – 10% |
| Available water capacity (0-101.6cm) |
21.34 – 24.38 cm |
| Calcium carbonate equivalent (0-101.6cm) |
0 – 5% |
| Electrical conductivity (0-101.6cm) |
0 – 2 mmhos/cm |
| Sodium adsorption ratio (0-101.6cm) |
0 |
| Soil reaction (1:1 water) (0-101.6cm) |
7.4 – 9 |
Ecological dynamics
An ecological site is not a precise assemblage of species for which the proportions are the same from place to place or from year to year. In all plant communities, variability is apparent in productivity and occurrence of individual species. Spatial boundaries of the communities; however, can be recognized by characteristic patterns of species composition, association, and community structure. The historic climax plant community for this ecological site has been described by sampling relict or relatively undisturbed sites and/or reviewing historic records. The historic climax plant community is the plant community that evolved over time with the soil forming process and long term changes in climatic conditions of the area. It is the plant community that was best adapted to the unique combination of environmental factors associated with the site.
Natural disturbances, such as drought, fire, grazing of native fauna, and insects, are inherent in the development and maintenance of these plant communities. The effects of these disturbances are part of the range of characteristics of the ecological site. Fluctuations in plant community structure and function caused by the effects of natural disturbances help establish the boundaries and characteristics of an ecological site. They are accounted for as part of the range of characteristics of the ecological site. Recognizable plant community phases are identified in the reference state of the ecological site. Some sites may have a small range of variation, while others have a large range. Some plant community phases may exist for long periods of time, while others may only occur for a couple of years after a disturbance.
Deterioration of the plant community, hydrology, or soil site stability on an ecological site can result in crossing a threshold or potentially irreversible boundary to another state, or equilibrium. This can occur as a result of the loss of soil surface through erosion, the loss of the stability of the site due to disturbances that cause active erosion on the site, increases in the amounts and/or patterns or runoff from rainstorms, changes in availability of surface and subsurface water, significant changes in plant structural and functional types, or the introduction of non-native species. When these thresholds are crossed, the potential of the ecological site to return to the historic climax plant community can be lost, or restoration will require significant inputs . There may be multiple states possible for an ecological site, determined by the type and or severity of disturbance.
The known states and transition pathways for this ecological site are described in the state and transition model. Within each state, there may be one or more known plant community phases. These community phases describe the different plant community that can be recognized and mapped across this ecological site. The state and transition model is intended to help land users recognize the current plant community on the ecological site, and the management options for improving the plant community to the desired plant community.
Plant production information in this site description is standardized to the annual production on an air-dry weight basis in near normal rainfall years.
State and transition model
Figure 4. 352 ClayeyUpland S&T
More interactive model formats are also available.
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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
Ecosystem states
State 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 1
Reference State
This state, which includes the Historic Climax Plant Community is a grassland site with scattered shrubs and trees. Plant species most likely to invade or increase on the site are big sagebrush, broom snakeweed, juniper and annuals.
Community 1.1
Native Grassland (HCPC)
Figure 5. 35.3 Clayey Upland
This plant community is dominated by a mixture of both cool and warm season grasses with scattered shrubs, scattered pinyon and juniper and some forbs. Dominant grasses include; blue grama, black grama, sideoats grama, squirreltail and Indian ricegrass. Shrubs include big sagebrush, fourwing saltbush and Mormon tea.
Figure 6. 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) |
|---|---|---|---|
| Grass/Grasslike | 448 | 673 | 897 |
| Shrub/Vine | 112 | 179 | 280 |
| Tree | – | 45 | 84 |
| Forb | 11 | 28 | 39 |
| Total | 571 | 925 | 1300 |
Figure 7. Plant community growth curve (percent production by month). AZ3531, 35.3 10-14" p.z. all sites. Growth begins in the spring and continues through the summer..
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| J | F | M | A | M | J | J | A | S | O | N | D |
| 0 | 1 | 3 | 17 | 18 | 10 | 19 | 20 | 10 | 1 | 1 | 0 |
State 2
Natives/Introduced State
This site is a grassland with increased shrubs, scattered trees and non-native annual species.
Community 2.1
Shrub/ Grasses
This plant community is similar to the Historic Climax Plant Community (1.1) as a grass dominated site with an increase in shrubs and a few trees. Non-native annuals such as cheatgrass and Russian thistle occur throughout the site.
State 3
Invaded State
This site has a juniper overstory with shrubs dominating the understory and non-native annual species.
Community 3.1
Juniper-Shrub Community
This site has become invaded with Utah juniper, pinyon, big sagebrush and non-native annual species. Perennial grasses have decreased on the site, but are still present. There is an increase in bareground and erosion on the site.
Transition T1A
State 1 to 2
Fire exclusion/Lack of natural fire, favorable precipitation for trees/shrubs, Unmanaged grazing.
Transition T2A
State 2 to 3
Heavy ground disturbance, unmanaged grazing, exclusion of fire.
Restoration pathway R3A
State 3 to 2
Favorable precipitation, managed grazing, fire, range seeding.
Additional community tables
Table 6. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Warm Season Perennial Grasses | 224–560 | ||||
| blue grama | BOGR2 | Bouteloua gracilis | 112–252 | – | ||
| sideoats grama | BOCU | Bouteloua curtipendula | 84–168 | – | ||
| black grama | BOER4 | Bouteloua eriopoda | 56–168 | – | ||
| James' galleta | PLJA | Pleuraphis jamesii | 28–84 | – | ||
| 2 | Cool Season Perennial Grasses | 168–504 | ||||
| squirreltail | ELELE | Elymus elymoides ssp. elymoides | 84–168 | – | ||
| needle and thread | HECOC8 | Hesperostipa comata ssp. comata | 56–140 | – | ||
| western wheatgrass | PASM | Pascopyrum smithii | 56–140 | – | ||
| Indian ricegrass | ACHY | Achnatherum hymenoides | 56–140 | – | ||
| 3 | Other Grasses | 45–112 | ||||
| threeawn | ARIST | Aristida | 11–39 | – | ||
| ring muhly | MUTO2 | Muhlenbergia torreyi | 11–39 | – | ||
| spike muhly | MUWR | Muhlenbergia wrightii | 11–39 | – | ||
| sand dropseed | SPCR | Sporobolus cryptandrus | 11–39 | – | ||
| Grass, perennial | 2GP | Grass, perennial | 0–17 | – | ||
| Grass, annual | 2GA | Grass, annual | 0–11 | – | ||
|
Forb
|
||||||
| 4 | Forbs | 11–39 | ||||
| sideoats grama | BOCU | Bouteloua curtipendula | 84–168 | – | ||
| Forb, annual | 2FA | Forb, annual | 0–22 | – | ||
| Forb, perennial | 2FP | Forb, perennial | 0–22 | – | ||
| globemallow | SPHAE | Sphaeralcea | 0–22 | – | ||
|
Shrub/Vine
|
||||||
| 5 | Shrubs | 112–280 | ||||
| black grama | BOER4 | Bouteloua eriopoda | 84–168 | – | ||
| Wyoming big sagebrush | ARTRW8 | Artemisia tridentata ssp. wyomingensis | 45–140 | – | ||
| fourwing saltbush | ATCA2 | Atriplex canescens | 45–140 | – | ||
| jointfir | EPHED | Ephedra | 45–140 | – | ||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 6–11 | – | ||
|
Tree
|
||||||
| 6 | Trees | 0–84 | ||||
| blue grama | BOGR2 | Bouteloua gracilis | 126–252 | – | ||
| Utah juniper | JUOS | Juniperus osteosperma | 0–84 | – | ||
| twoneedle pinyon | PIED | Pinus edulis | 0–84 | – | ||
Interpretations
Animal community
This site is suitable for grazing throughout most of the year with shrubs providing forage during the period when snow covers palatable grasses.
Habitat diversity on this site is fair when moderate amounts of shrubs and trees are present. Permanent waters are lacking as are diverse tree species and growth forms. Typical animals on the site include rabbits, mule deer, antelope, various song birds, and raptors.
Recreational uses
The land form of this site is old basalt flows or eroded clay bottoms or swales. This site is a grassland interspersed with shrubs and a few trees. Winters are cold and spring tends to be windy. Late spring, summer, and fall provide attractive recreation weather. Sport hunting is the main activity of this site. Other recreation activities, such as cross country riding, photography, and wildlife observation are incidental.
Wood products
No wood products are produced from this site.
Supporting information
Other references
Updates and revisions for this ESD were conducted as part of a 2007-2012 Interagency Technical Assistance Agreement between the Bureau of Indian Affairs–Navajo Region and the NRCS-Arizona.
Contributors
Byron Lambeth
Ken Gishi
Larry D. Ellicott
Stephen Cassady
Unknown
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) | Steve Cassady, Kyle Spencer, Tobiah Salvail |
|---|---|
| Contact for lead author | State Rangeland Management Specialist, NRCS-Arizona State Office, Phoenix,AZ |
| Date | 04/29/2008 |
| Approved by | S. Cassady |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
None -
Presence of water flow patterns:
None -
Number and height of erosional pedestals or terracettes:
No pedestals, but turf building is common under long-lived perennial grasses and shrubs. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare ground is <50%. -
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):
Litter does not move appreciably except during the largest storm events. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil surface of this site normally seals, developing a very strong cap very resistant to erosion. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
The surface of soils associated with this site are moderate thin platy structure parting to strong very fine angular blocky; extremely hared, very firm, very sticky, and very plastic. Color is reddish brown (2.5YR 4/4) dry and dark reddish brown (2.5YR 3/4) moist. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Randomly scattered plants consisting of about 75 percent grasses, 20 percent shrubs and 5 percent forbs promote infiltration and reduce runoff. The average distance to the nearest perennial plant (fetch) ranges from 4 to 8 inches with the majority ranging from 1 to 10 inches but occasionally as far as 20 inches. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
No compaction layer, although a harder clay layer is encountered about 15 inches below the soil surface. -
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:
Grasses (65-80%) >> shrubs (15-30%) > forbs (1-5%)Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
In “normal” precipitation years mortality should be no more than 10 percent. During periods of prolonged drought mortality may be much higher, especially on half-shrubs and 80 to 90 percent death on Wyoming big sagebrush has been observed. -
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
Average annual production on this site is expected to be 700-800 lbs/ac in a year of average precipitation. -
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:
Russian thistle (Salsola kali), cheatgrass (Bromus tectorum), and lambsquarter (Chenopodium album) are commonly found in small amounts on the site (< 2 percent). During years of above average winter and spring moisture the composition of these may increase slightly. Severe disturbance may cause an increase in one or all of these plants creating a potential for a shortened fire frequency on the site which could result in crossing a threshold to a state with increased introduced annual plants and fewer native shrubs. -
Perennial plant reproductive capability:
All plants native to this site are adapted to the climate and are capable of producing seeds, stolons, and/or rhizomes except during the most severe droughts.
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