Natural Resources
Conservation Service
Ecological site R041XB212AZ
Saline Upland 8-12" p.z.
Last updated: 7/28/2020
Accessed: 12/03/2024
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): 041X–Madrean Archipelago
AZ 41.2 – Chihuahuan – Sonoran Desert Shrubs
Elevations range from 2600 to 4000 feet and precipitation ranges from 8 to 12 inches per year. Vegetation includes mesquite, palo verde, catclaw acacia, soaptree yucca, creosotebush, whitethorn, staghorn cholla, desert saltbush, Mormon tea, burroweed, snakeweed, tobosa, black grama, threeawns, bush muhly, dropseed, and burrograss. The soil temperature regime is thermic and the soil moisture regime is typic aridic. This unit occurs within the Basin and Range Physiographic Province and is characterized by numerous mountain ranges that rise abruptly from broad, plain-like valleys and basins. Igneous and metamorphic rock classes dominate the mountain ranges and sediments filling the basins represent combinations of fluvial, lacustrine, colluvial and alluvial deposits.
Associated sites
| F041XB221AZ |
Loamy Bottom 8-12" p.z. woodland |
|---|---|
| F041XB222AZ |
Saline Bottom 8-12" p.z. woodland |
| R041XB206AZ |
Limy Fan 8-12" p.z. |
| R041XB209AZ |
Loamy Swale 8-12" p.z. |
Similar sites
| R040XB212AZ |
Loamy Slopes 7"-10" p.z. |
|---|
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) atriplex polycarpa |
| Herbaceous |
Not specified |
Physiographic features
This site occurs in the lowest elevations of the Madrean Basin and Range province in southeastern Arizona. It occurs as nearly level to gently sloping fan terraces, stream terraces and alluvial fans.
Table 2. Representative physiographic features
| Landforms |
(1)
Alluvial flat
(2) Stream terrace (3) Fan piedmont |
|---|---|
| Flooding frequency | None |
| Ponding frequency | None |
| Elevation | 2,600 – 4,000 ft |
| Slope | 5% |
| Aspect | Aspect is not a significant factor |
Climatic features
Precipitation ranges from 8-12 inches annually. More than half falls during July-Sep in brief, but often heavy, thunderstorms. The rest of the moisture comes as light rain or snow that falls slowly for a day or more, but rarely lasts more than a day. May and June are normally the driest months. Humidity is generally very low.
Temperatures are mild throughout most of the year. Freezing temperatures are common at night Dec-Feb; brief 0 F may be observed some nights. During June, July & August, some days may exceed 100 F.
In years of average or greater winter precipitation, annual grasses and forbs occur abundantly in the interspaces.
Table 3. Representative climatic features
| Frost-free period (average) | 240 days |
|---|---|
| Freeze-free period (average) | |
| Precipitation total (average) |
Figure 2. Monthly precipitation range
Figure 3. Monthly average minimum and maximum temperature
Influencing water features
There are no water features associated with this site.
Soil features
These are deep, well drained, saline and sodic soils. They are sandy to loamy with a surface cap of loamy fine sand to sandy loam. The plant-soil moisture relationships are poor to fair. These soils take water readily, but water available for plant growth is limited by the saline, sodic conditions.
Soil series mapped to date on this site include: SSA-662 Safford area MU TgA Gila & Glendale; SSA-663 Gila-Duncan area MU 16 Gila; SSA-664 San Simon area MU's 7 Gothard, 28 & 29 Hondale.
Table 4. Representative soil features
| Surface texture |
(1) Sandy loam (2) Fine sandy loam (3) Silt loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderately rapid to moderate |
| Soil depth | 60 in |
| Available water capacity (0-40in) |
3.6 – 6.2 in |
| Calcium carbonate equivalent (0-40in) |
1 – 10% |
| Electrical conductivity (0-40in) |
4 – 30 mmhos/cm |
| Sodium adsorption ratio (0-40in) |
6 – 60 |
| Soil reaction (1:1 water) (0-40in) |
7.4 – 8.4 |
Ecological dynamics
The plant communities found on an ecological site are naturally variable. Composition and production will vary with yearly conditions, location, aspect, and the natural variability of the soils. The Historical Climax Plant Community represents the natural potential plant communities found on relict or relatively undisturbed sites. Other plant communities described here represent plant communities that are known to occur when the site is disturbed by factors such as fire, grazing, or drought.
Production data provided in this site description is standardized to air dry weight at the end of the summer growing season. The plant communities described in this site description are based on near normal rainfall years.
NRCS uses a Similarity Index to compare existing plant communities to the plant communities described here. Similarity index is determined by comparing the production and composition of a plant community to the production and composition of a plant community described in this site description. To determine Similarity index, compare the production (air dry weight) of each species to that shown in the plant community description. For each species, count no more than the maximum amount shown for the species, and for each group, count no more than the maximum amount shown for each group. Divide the resulting total by the total normal year production shown in the plant community description. If the rainfall has been significantly above or below normal, use the total production shown for above or below normal years. If field data is not collected at the end of the summer growing season, then the field data must be corrected to the end of the year production before comparing it to the site description. The growth curve can be used as a guide for estimating production at the end of the summer growing season.
State and transition model
Figure 4. State and Transition, Saline Upland 8-12" p.z.
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Click on state and transition labels to scroll to the respective text
State 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 1
Historic Climax Plant Community
Community 1.1
Historic Climax Plant Community
The native plant community on this site is dominated by salt tolerant shrubs. Winter and summer annual forbs and grasses are well represented on this site. Perennial grasses and forbs are present in trace amounts in the potential vegetative community. With severe disturbance (such as repeated fire or heavy, continuous grazing) the saltbush species are replaced by annual grasses and forbs. Loss of shrub cover can result in accelerated water and wind erosion. Atriplex species are very sensitive to summer fires on this site.
Figure 5. 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 | 150 | 200 | 315 |
| Grass/Grasslike | 0 | 20 | 155 |
| Forb | 0 | 15 | 100 |
| Total | 150 | 235 | 570 |
Table 6. Soil surface cover
| Tree basal cover | 0% |
|---|---|
| Shrub/vine/liana basal cover | 1% |
| Grass/grasslike basal cover | 0-2% |
| Forb basal cover | 0-2% |
| Non-vascular plants | 0% |
| Biological crusts | 1-20% |
| Litter | 5-50% |
| Surface fragments >0.25" and <=3" | 0-15% |
| Surface fragments >3" | 0-3% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 15-95% |
Table 7. Canopy structure (% cover)
| Height Above Ground (ft) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.5 | – | 0-1% | 0-20% | 0-20% |
| >0.5 <= 1 | – | 0-1% | 0-15% | 0-10% |
| >1 <= 2 | – | 5-10% | – | 0-5% |
| >2 <= 4.5 | – | 5-10% | – | – |
| >4.5 <= 13 | – | – | – | – |
| >13 <= 40 | – | – | – | – |
| >40 <= 80 | – | – | – | – |
| >80 <= 120 | – | – | – | – |
| >120 | – | – | – | – |
State 2
Annuals
Community 2.1
Annuals
This state usually occurs where the site has been cleared for cultivation and irrigation with subsequent abandonment. Native and non-native annual forbs and grasses dominate the plant community. Exotic annual species include tumbleweed, filaree, mediterranean grass, London rocket, malva weed, foxtail barley, red brome and Sahara mustard.
State 3
Shrubs, exotic annuals
Community 3.1
Shrubs, exotic annuals
This state occurs where the native saltbush cover is still intact but the herbaceous layer is dominated by non-native annual forbs and grasses. Exotic annuals include mediterranean grass, tumbleweed, filaree, red brome and London rocket. Exotic annuals can reduce the diversity of native species and may influence their ability to maintain themselves in the soil seed bank.
Transition T1A
State 1 to 2
Usually results from clearing for irrigated agriculture and subsequent abandonment. Seed source for native shrubs is no longer present.
Transition T1B
State 1 to 3
Introduction of a seed source of non-natives. Possible competition of exotics with native species of forbs or grasses.
Restoration pathway R2A
State 2 to 1
Unknown
Restoration pathway R
State 3 to 1
Unknown
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 | Perennial grasses | 0–5 | ||||
| false Rhodes grass | TRCR9 | Trichloris crinita | 0–5 | – | ||
| alkali sacaton | SPAI | Sporobolus airoides | 0–2 | – | ||
| spike dropseed | SPCO4 | Sporobolus contractus | 0–1 | – | ||
| Parish's threeawn | ARPUP5 | Aristida purpurea var. parishii | 0–1 | – | ||
| spidergrass | ARTE3 | Aristida ternipes | 0–1 | – | ||
| bush muhly | MUPO2 | Muhlenbergia porteri | 0–1 | – | ||
| big galleta | PLRI3 | Pleuraphis rigida | 0–1 | – | ||
| 2 | Annual grasses | 0–50 | ||||
| needle grama | BOAR | Bouteloua aristidoides | 0–20 | – | ||
| sixweeks grama | BOBA2 | Bouteloua barbata | 0–20 | – | ||
| Rothrock's grama | BORO2 | Bouteloua rothrockii | 0–20 | – | ||
| feather fingergrass | CHVI4 | Chloris virgata | 0–20 | – | ||
| mucronate sprangeltop | LEPAB | Leptochloa panicea ssp. brachiata | 0–10 | – | ||
| Bigelow's bluegrass | POBI | Poa bigelovii | 0–5 | – | ||
| sixweeks threeawn | ARAD | Aristida adscensionis | 0–5 | – | ||
| prairie threeawn | AROL | Aristida oligantha | 0–5 | – | ||
| sixweeks fescue | VUOC | Vulpia octoflora | 0–5 | – | ||
| Arizona brome | BRAR4 | Bromus arizonicus | 0–2 | – | ||
| Arizona signalgrass | URAR | Urochloa arizonica | 0–2 | – | ||
| witchgrass | PACA6 | Panicum capillare | 0–2 | – | ||
| tapertip cupgrass | ERACA | Eriochloa acuminata var. acuminata | 0–2 | – | ||
| tufted lovegrass | ERPEP2 | Eragrostis pectinacea var. pectinacea | 0–2 | – | ||
| Mexican sprangletop | LEFUU | Leptochloa fusca ssp. uninervia | 0–2 | – | ||
|
Forb
|
||||||
| 3 | Annual forbs | 0–100 | ||||
| desert Indianwheat | PLOV | Plantago ovata | 0–25 | – | ||
| Coulter's spiderling | BOCO2 | Boerhavia coulteri | 0–25 | – | ||
| wheelscale saltbush | ATEL | Atriplex elegans | 0–20 | – | ||
| wheelscale saltbush | ATELF | Atriplex elegans var. fasciculata | 0–20 | – | ||
| Coulter's globemallow | SPCO2 | Sphaeralcea coulteri | 0–20 | – | ||
| woolly tidestromia | TILA2 | Tidestromia lanuginosa | 0–10 | – | ||
| combseed | PECTO | Pectocarya | 0–10 | – | ||
| Nuttall's povertyweed | MONU | Monolepis nuttalliana | 0–10 | – | ||
| Gordon's bladderpod | LEGO | Lesquerella gordonii | 0–10 | – | ||
| shaggyfruit pepperweed | LELA | Lepidium lasiocarpum | 0–5 | – | ||
| intermediate pepperweed | LEVIM | Lepidium virginicum var. medium | 0–5 | – | ||
| manybristle chinchweed | PEPA2 | Pectis papposa | 0–5 | – | ||
| phacelia | PHACE | Phacelia | 0–5 | – | ||
| common fiddleneck | AMMEI2 | Amsinckia menziesii var. intermedia | 0–5 | – | ||
| slender goldenweed | MAGR10 | Machaeranthera gracilis | 0–2 | – | ||
| tanseyleaf tansyaster | MATA2 | Machaeranthera tanacetifolia | 0–2 | – | ||
| New Mexico plumeseed | RANE | Rafinesquia neomexicana | 0–2 | – | ||
| canaigre dock | RUHY | Rumex hymenosepalus | 0–2 | – | ||
| sleepy silene | SIAN2 | Silene antirrhina | 0–2 | – | ||
| aridland goosefoot | CHDE | Chenopodium desiccatum | 0–2 | – | ||
| miniature woollystar | ERDI2 | Eriastrum diffusum | 0–2 | – | ||
| Texas stork's bill | ERTE13 | Erodium texanum | 0–2 | – | ||
| weakleaf bur ragweed | AMCO3 | Ambrosia confertiflora | 0–2 | – | ||
| fringed amaranth | AMFI | Amaranthus fimbriatus | 0–2 | – | ||
| fringed redmaids | CACI2 | Calandrinia ciliata | 0–2 | – | ||
| yellow tackstem | CAPA7 | Calycoseris parryi | 0–2 | – | ||
| white tackstem | CAWR | Calycoseris wrightii | 0–2 | – | ||
| whitemargin sandmat | CHAL11 | Chamaesyce albomarginata | 0–1 | – | ||
| cryptantha | CRYPT | Cryptantha | 0–1 | – | ||
| American wild carrot | DAPU3 | Daucus pusillus | 0–1 | – | ||
| coastal bird's-foot trefoil | LOSA | Lotus salsuginosus | 0–1 | – | ||
| Coulter's lupine | LUSP2 | Lupinus sparsiflorus | 0–1 | – | ||
| bristly nama | NAHI | Nama hispidum | 0–1 | – | ||
| desert evening primrose | OEPR | Oenothera primiveris | 0–1 | – | ||
|
Shrub/Vine
|
||||||
| 4 | Dominant shrub | 150–250 | ||||
| cattle saltbush | ATPO | Atriplex polycarpa | 150–250 | – | ||
| 5 | Miscellaneous shrubs | 0–40 | ||||
| fourwing saltbush | ATCA2 | Atriplex canescens | 0–10 | – | ||
| mound saltbush | ATOB | Atriplex obovata | 0–10 | – | ||
| creosote bush | LATR2 | Larrea tridentata | 0–10 | – | ||
| water jacket | LYAN | Lycium andersonii | 0–10 | – | ||
| western honey mesquite | PRGLT | Prosopis glandulosa var. torreyana | 0–10 | – | ||
| lotebush | ZIOB | Ziziphus obtusifolia | 0–1 | – | ||
| pale desert-thorn | LYPA | Lycium pallidum | 0–1 | – | ||
| 6 | Half shrubs | 0–15 | ||||
| Griffiths' saltbush | ATGR2 | Atriplex griffithsii | 0–10 | – | ||
| seepweed | SUAED | Suaeda | 0–5 | – | ||
| burrobush | AMDU2 | Ambrosia dumosa | 0–5 | – | ||
| shadscale saltbush | ATCO | Atriplex confertifolia | 0–5 | – | ||
| 7 | Succulents | 0–10 | ||||
| Christmas cactus | CYLE8 | Cylindropuntia leptocaulis | 0–5 | – | ||
| devil's cholla | GRKU | Grusonia kunzei | 0–5 | – | ||
| Engelmann's hedgehog cactus | ECEN | Echinocereus engelmannii | 0–1 | – | ||
| candy barrelcactus | FEWI | Ferocactus wislizeni | 0–1 | – | ||
Interpretations
Animal community
This site produces forage for year-round use by livestock. Salt desert shrub species will provide adequate protein throughout the year, however, energy will usually be lacking from Jun-Jan (except when summer rains are sufficient to produce a crop of summer annual grasses and forbs). Spring is the main season for plant growth and production of annual species. Proper use of the shrub species should be no more than 50% of the spring production of twigs and leaves. Water developments are very important to both livestock and wildlife on the site.
Lack of natural water and poor cover limits the value of this site as wildlife habitat. The site is mainly home to small desert animals and a forage area for birds.
Hydrological functions
These soils are medium textured and poor producers of runoff.
Recreational uses
Hunting, horseback riding, hiking, four wheeling.
Supporting information
Contributors
Dan Robinett
Larry D. Ellicott
Approval
Scott Woodall, 7/28/2020
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 | 09/09/2022 |
| Approved by | Scott Woodall |
| 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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