Natural Resources
Conservation Service
Ecological site R040XA102AZ
Clayey Swale 10"-13" p.z.
Accessed: 12/22/2024
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): 040X–Sonoran Basin and Range
AZ 40.1 – Upper Sonoran Desert
Elevations range from 2000 to 3200 feet and precipitation averages 10 to 13 inches per year. Vegetation includes saguaro, palo verde, mesquite, creosotebush, triangle bursage, prickly pear, cholla, limberbush, wolfberry, bush muhly, threeawns, ocotillo, and globe mallow. 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
| R040XA104AZ |
Clayey Upland 10"-13" p.z. |
|---|---|
| R040XA108AZ |
Limy Fan 10"-13" p.z. |
| R040XA112AZ |
Loamy Swale 10"-13" p.z. |
Similar sites
| R040XB203AZ |
Clayey Swale 7"-10" p.z. |
|---|---|
| R041XC302AZ |
Clayey Swale 12-16" p.z. |
| R041XB202AZ |
Clayey Swale 8-12" p.z. |
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) Opuntia chlorotica |
| Herbaceous |
(1) Pleuraphis mutica |
Physiographic features
This site occurs in the upper elevations of the Sonoran Desert in southern Arizona. This site receives extra moisture in the form of runoff from adjacent upland areas. It occurs on floodplains, alluvial fans and swales.
Table 2. Representative physiographic features
| Landforms |
(1)
Alluvial fan
(2) Flood plain (3) Swale |
|---|---|
| Flooding duration | Extremely brief (0.1 to 4 hours) to very brief (4 to 48 hours) |
| Flooding frequency | Rare to occasional |
| Ponding duration | Very brief (4 to 48 hours) to brief (2 to 7 days) |
| Ponding frequency | None to rare |
| Elevation | 1,900 – 3,300 ft |
| Slope | 2% |
| Aspect | Aspect is not a significant factor |
Climatic features
Precipitation in the sub resource area ranges from 10 to 13 inches in the southern part, along the Mexican border with elevations from about 1900 to 3200 feet. Precipitation in the northern part of the resource area ranges from 11 to 14 inches with elevations from about 1700 to 3500 feet. Winter-summer rainfall ratios range from 40%-60% in the southern portions of the land resource unit, to 50%-50% in the central portions, to 60%-40% in the northern part of the land resource unit. As one moves from east to west in this resource area rains become slightly more unpredictable and variable with Coefficients of Variation of annual rainfall equal to 29% at Tucson and 36% at Carefree. Summer rains fall July through Sept., originate in the Gulf of Mexico, and are convective, usually brief, intense thunderstorms. Cool season moisture tends to be frontal, originating in the Pacific and Gulf of California. This winter precipitation falls in widespread storms with long duration and low intensity. Snow is rare and seldom lasts more than an hour or two. May and June are the driest months of the year. Humidity is generally very low.
Winter temperatures are mild, with very few days recording freezing temperatures in the morning. Summer temperatures are warm to hot, with several days in June and July exceeding 105 degrees F.
Both the spring and the summer growing seasons are equally important for perennial grass, forb and shrub growth. Cool and warm season annual forbs and grasses can be common in their respective seasons with above average rainfall. Perennial forage species can remain green throughout the year with available moisture.
Table 3. Representative climatic features
| Frost-free period (average) | 265 days |
|---|---|
| Freeze-free period (average) | 0 days |
| Precipitation total (average) | 13 in |
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 soils on clayey, recent alluvium of mixed origins. They are dark colored and have high shrink-swell potentials. Churning and cracking cause very rough surfaces. Plant-soil moisture relationships are good. The soils mapped on this site are: SSA-645 Aguila-Carefree MU's Guest-67 & 88; SSA-669 Eastern Pima County Hantz-34; SSA-703 Tohono O'odham MU's Tubac-6 & Hantz-34.
Table 4. Representative soil features
| Surface texture |
(1) Clay loam (2) Silty clay loam (3) Clay |
|---|---|
| Family particle size |
(1) Clayey |
| Drainage class | Well drained |
| Permeability class | Slow to very slow |
| Soil depth | 60 in |
| Surface fragment cover <=3" | 10% |
| Surface fragment cover >3" | 1% |
| Available water capacity (0-40in) |
9 – 10 in |
| Calcium carbonate equivalent (0-40in) |
10% |
| Electrical conductivity (0-40in) |
4 mmhos/cm |
| Sodium adsorption ratio (0-40in) |
13 |
| Soil reaction (1:1 water) (0-40in) |
7.2 – 8.2 |
| Subsurface fragment volume <=3" (Depth not specified) |
5% |
| Subsurface fragment volume >3" (Depth not specified) |
Not specified |
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 the 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, Clayey swale 10-13" pz.
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
State 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 4 submodel, plant communities
State 5 submodel, plant communities
State 6 submodel, plant communities
State 1
Historical Climax Plant Community
Community 1.1
Historical Climax Plant Community
The potential plant community on this site is dominated by tobosa grass. A few shrubby species like soaptree yucca and prickley pear dot this open grassland site. With continuous, heavy grazing, the tobosa cover is depleted in patches. This site is extremely susceptable to gully erosion when grass cover has been removed. Shrubby species like snakeweed, prickley pear, and mesquite can invade or increase to become dominant where gully formation drains water off rapidly and dries the 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) |
|---|---|---|---|
| Grass/Grasslike | 815 | 1300 | 1850 |
| Forb | 10 | 100 | 460 |
| Shrub/Vine | 1 | 5 | 30 |
| Tree | 0 | 0 | 10 |
| Total | 826 | 1405 | 2350 |
Table 6. Soil surface cover
| Tree basal cover | 0% |
|---|---|
| Shrub/vine/liana basal cover | 0% |
| Grass/grasslike basal cover | 10-35% |
| Forb basal cover | 0-1% |
| Non-vascular plants | 0% |
| Biological crusts | 5-15% |
| Litter | 30-80% |
| Surface fragments >0.25" and <=3" | 0-5% |
| Surface fragments >3" | 0-1% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 5-40% |
Table 7. Canopy structure (% cover)
| Height Above Ground (ft) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.5 | – | – | 0-5% | 0-5% |
| >0.5 <= 1 | – | – | 5-15% | 1-5% |
| >1 <= 2 | – | 0-1% | 10-35% | 0-15% |
| >2 <= 4.5 | – | 0-1% | 0-5% | 0-1% |
| >4.5 <= 13 | 0-1% | – | – | – |
| >13 <= 40 | – | – | – | – |
| >40 <= 80 | – | – | – | – |
| >80 <= 120 | – | – | – | – |
| >120 | – | – | – | – |
Figure 6. Plant community growth curve (percent production by month). AZ4012, 40.1 10-13" p.z. bottom sites. Growth begins in the late winter, most growth occurs in 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 | 2 | 8 | 10 | 10 | 10 | 15 | 20 | 15 | 5 | 5 | 0 |
State 2
Annuals and desert broom
Community 2.1
Annuals and desert broom
This state occurs after clearing for irrigation and subsequent abandonment. Early stages of plant succession lead to dominance by annual forbs and grasses (both native and non-native). Tumbleweed (Russian thistle) will persist with continued disturbance like disking. Desert broom can invade and may dominate the upper layer of the plant community. This state will persist for several years before other shrubs and desert trees come in and assume dominance. It will persist for long periods of time with continued disturbance. Natural flooding is reduced or eliminated by dikes, ditches and levees that were built to protect irrigated fields.
State 3
Mesquite, grass and shrubs
Community 3.1
Mesquite, grass and shrubs
This state will result from long term rest of areas that were cleared and then abandoned. Without disturbance for 30 or 40 years mesquite will come in with other shrubs like pencil cholla and whitethorn acacia and form an open overstory. Perennial grasses, both native and non-native will dominate the understory especially in areas where water accumulates; the bottom ends of fields and along borders and old ditches. Some areas (with heavy soil crusting due to silty clayloam textures) may be entirely barren until a wet winter is effective in producing a crop of annuals. Annual forbs and grasses (both native and exotic) will fluctuate with climate. This appears to be a stable community without fire or other disturbance like continuous grazing. Usually water control features (dikes, ditches) are left intact and natural flooding of these areas does not occur.
State 4
Exotic grasses and forbs
Community 4.1
Exotic grasses and forbs
Non-native perennial grasses like bermuda, Johnson grass, bufflegrass and exotic annuals like filaree, red brome, schismus, London rocket, Carolina canarygrass and purslane invade the native plant community. These species displace native perennial and annual grasses and forbs.
State 5
Gullied
Community 5.1
Gullied
This state occurs where the site has severe sheet, rill and gully erosion. Lack of plant cover, soil compaction and concentration of surface water flow will lead to rilling and gully formation. Usually these areas lack any perennial cover except along drainage ways. Base level changes in large stream systems can lead to gullying of this site where it is tributary to the main stream.
State 6
Dense mesquite
Community 6.1
Dense mesquite
This state occurs where large floods have breached the dikes and levees and filled the drainage ditches that used to protect the irrigated lands. Floods bring large amounts of mesquite seed, organic debris and water in and can cause a mesquite thicket to form. Usually the shrub density in these thickets is so high that they are impenetrable. This state can also form on areas that have not been converted to cropland by continuous heavy grazing, depletion of grass cover, soil compaction and subsequent invasion and increase by mesquite.
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 | Dominant perennial grass | 800–1200 | ||||
| tobosagrass | PLMU3 | Pleuraphis mutica | 800–1200 | – | ||
| 2 | Misc perennial grasses | 10–150 | ||||
| vine mesquite | PAOB | Panicum obtusum | 5–100 | – | ||
| whiplash pappusgrass | PAVA2 | Pappophorum vaginatum | 0–20 | – | ||
| bush muhly | MUPO2 | Muhlenbergia porteri | 0–20 | – | ||
| burrograss | SCBR2 | Scleropogon brevifolius | 0–10 | – | ||
| sideoats grama | BOCU | Bouteloua curtipendula | 0–10 | – | ||
| plains bristlegrass | SEVU2 | Setaria vulpiseta | 0–10 | – | ||
| Parish's threeawn | ARPUP5 | Aristida purpurea var. parishii | 0–10 | – | ||
| spidergrass | ARTE3 | Aristida ternipes | 0–10 | – | ||
| spidergrass | ARTEG | Aristida ternipes var. gentilis | 0–10 | – | ||
| spike dropseed | SPCO4 | Sporobolus contractus | 0–5 | – | ||
| Arizona cottontop | DICA8 | Digitaria californica | 0–5 | – | ||
| large-spike bristlegrass | SEMA5 | Setaria macrostachya | 0–5 | – | ||
| western wheatgrass | PASM | Pascopyrum smithii | 0–5 | – | ||
| curly-mesquite | HIBE | Hilaria belangeri | 0–4 | – | ||
| cane bluestem | BOBA3 | Bothriochloa barbinodis | 0–3 | – | ||
| green sprangletop | LEDU | Leptochloa dubia | 0–2 | – | ||
| 3 | Annual grasses | 5–500 | ||||
| mucronate sprangeltop | LEPAB | Leptochloa panicea ssp. brachiata | 1–200 | – | ||
| little barley | HOPU | Hordeum pusillum | 1–200 | – | ||
| sixweeks fescue | VUOC | Vulpia octoflora | 0–150 | – | ||
| sticky sprangletop | LEVI5 | Leptochloa viscida | 0–100 | – | ||
| Rothrock's grama | BORO2 | Bouteloua rothrockii | 0–100 | – | ||
| sixweeks threeawn | ARAD | Aristida adscensionis | 0–50 | – | ||
| feather fingergrass | CHVI4 | Chloris virgata | 0–50 | – | ||
| Mexican panicgrass | PAHI5 | Panicum hirticaule | 0–50 | – | ||
| canyon cupgrass | ERLE7 | Eriochloa lemmonii | 0–25 | – | ||
| needle grama | BOAR | Bouteloua aristidoides | 0–25 | – | ||
| sixweeks grama | BOBA2 | Bouteloua barbata | 0–25 | – | ||
| Arizona signalgrass | URAR | Urochloa arizonica | 0–25 | – | ||
| bearded cupgrass | ERAR5 | Eriochloa aristata | 0–15 | – | ||
| Mexican sprangletop | LEFUU | Leptochloa fusca ssp. uninervia | 0–10 | – | ||
| Bigelow's bluegrass | POBI | Poa bigelovii | 0–5 | – | ||
| delicate muhly | MUFR | Muhlenbergia fragilis | 0–5 | – | ||
| littleseed muhly | MUMI | Muhlenbergia microsperma | 0–5 | – | ||
| Arizona brome | BRAR4 | Bromus arizonicus | 0–5 | – | ||
| prairie threeawn | AROL | Aristida oligantha | 0–5 | – | ||
| Eastwood fescue | VUMIC | Vulpia microstachys var. ciliata | 0–3 | – | ||
| tufted lovegrass | ERPEP2 | Eragrostis pectinacea var. pectinacea | 0–2 | – | ||
|
Forb
|
||||||
| 4 | Perennial forbs | 5–60 | ||||
| bluedicks | DICAC5 | Dichelostemma capitatum ssp. capitatum | 1–20 | – | ||
| spear globemallow | SPHA | Sphaeralcea hastulata | 1–20 | – | ||
| desert globemallow | SPAM2 | Sphaeralcea ambigua | 0–10 | – | ||
| spreading fleabane | ERDI4 | Erigeron divergens | 0–10 | – | ||
| Indian rushpea | HOGL2 | Hoffmannseggia glauca | 1–10 | – | ||
| dwarf desertpeony | ACNA2 | Acourtia nana | 0–5 | – | ||
| redseed plantain | PLRH | Plantago rhodosperma | 0–5 | – | ||
| buffpetal | RHPH2 | Rhynchosida physocalyx | 0–5 | – | ||
| spreading fanpetals | SIAB | Sida abutifolia | 0–5 | – | ||
| silverleaf nightshade | SOEL | Solanum elaeagnifolium | 0–2 | – | ||
| weakleaf bur ragweed | AMCO3 | Ambrosia confertiflora | 0–2 | – | ||
| red-gland spurge | CHME5 | Chamaesyce melanadenia | 0–2 | – | ||
| fingerleaf gourd | CUDI | Cucurbita digitata | 0–2 | – | ||
| Missouri gourd | CUFO | Cucurbita foetidissima | 0–2 | – | ||
| coyote gourd | CUPA | Cucurbita palmata | 0–2 | – | ||
| pricklyburr | DAIN2 | Datura inoxia | 0–1 | – | ||
| desert tobacco | NIOBO | Nicotiana obtusifolia var. obtusifolia | 0–1 | – | ||
| orange fameflower | PHAU13 | Phemeranthus aurantiacus | 0–1 | – | ||
| canaigre dock | RUHY | Rumex hymenosepalus | 0–1 | – | ||
| brownplume wirelettuce | STPA4 | Stephanomeria pauciflora | 0–1 | – | ||
| 5 | Annual forbs | 5–400 | ||||
| coastal bird's-foot trefoil | LOSA | Lotus salsuginosus | 0–100 | – | ||
| Arizona popcornflower | PLAR | Plagiobothrys arizonicus | 0–100 | – | ||
| foothill deervetch | LOHU2 | Lotus humistratus | 0–50 | – | ||
| pitseed goosefoot | CHBE4 | Chenopodium berlandieri | 0–50 | – | ||
| California poppy | ESCAM | Eschscholzia californica ssp. mexicana | 0–50 | – | ||
| wheelscale saltbush | ATEL | Atriplex elegans | 0–50 | – | ||
| smallflowered milkvetch | ASNU4 | Astragalus nuttallianus | 0–25 | – | ||
| bristly fiddleneck | AMTE3 | Amsinckia tessellata | 0–25 | – | ||
| fringed redmaids | CACI2 | Calandrinia ciliata | 0–25 | – | ||
| Arizona poppy | KAGR | Kallstroemia grandiflora | 0–25 | – | ||
| desert Indianwheat | PLOV | Plantago ovata | 1–25 | – | ||
| woolly plantain | PLPA2 | Plantago patagonica | 0–20 | – | ||
| Louisiana vetch | VILU | Vicia ludoviciana | 0–20 | – | ||
| California desertdandelion | MACA6 | Malacothrix californica | 0–20 | – | ||
| western tansymustard | DEPI | Descurainia pinnata | 0–20 | – | ||
| carelessweed | AMPA | Amaranthus palmeri | 0–20 | – | ||
| white easterbonnets | ANLA7 | Antheropeas lanosum | 0–10 | – | ||
| fringed amaranth | AMFI | Amaranthus fimbriatus | 0–10 | – | ||
| white tackstem | CAWR | Calycoseris wrightii | 0–10 | – | ||
| miniature woollystar | ERDI2 | Eriastrum diffusum | 0–10 | – | ||
| hyssopleaf sandmat | CHHY3 | Chamaesyce hyssopifolia | 0–10 | – | ||
| Esteve's pincushion | CHST | Chaenactis stevioides | 0–10 | – | ||
| cryptantha | CRYPT | Cryptantha | 0–10 | – | ||
| hollowleaf annual lupine | LUSU3 | Lupinus succulentus | 0–10 | – | ||
| mesa tansyaster | MATA | Machaeranthera tagetina | 0–10 | – | ||
| Lindley's silverpuffs | MILI5 | Microseris lindleyi | 0–10 | – | ||
| Texas stork's bill | ERTE13 | Erodium texanum | 0–10 | – | ||
| distant phacelia | PHDI | Phacelia distans | 0–10 | – | ||
| purslane | PORTU | Portulaca | 0–10 | – | ||
| Nuttall's povertyweed | MONU | Monolepis nuttalliana | 0–10 | – | ||
| Arizona phacelia | PHAR13 | Phacelia arizonica | 0–10 | – | ||
| cleftleaf wildheliotrope | PHCR | Phacelia crenulata | 0–5 | – | ||
| New Mexico plumeseed | RANE | Rafinesquia neomexicana | 0–5 | – | ||
| Lemmon's ragwort | SELE8 | Senecio lemmonii | 0–5 | – | ||
| Coulter's globemallow | SPCO2 | Sphaeralcea coulteri | 0–5 | – | ||
| California mustard | GULA4 | Guillenia lasiophylla | 0–5 | – | ||
| California goldfields | LACAC2 | Lasthenia californica ssp. californica | 0–5 | – | ||
| flatspine stickseed | LAOCO | Lappula occidentalis var. occidentalis | 0–5 | – | ||
| Gordon's bladderpod | LEGO | Lesquerella gordonii | 0–5 | – | ||
| American wild carrot | DAPU3 | Daucus pusillus | 0–5 | – | ||
| red-gland spurge | CHME5 | Chamaesyce melanadenia | 0–5 | – | ||
| yellow tackstem | CAPA7 | Calycoseris parryi | 0–5 | – | ||
| spreading fleabane | ERDI4 | Erigeron divergens | 0–5 | – | ||
| wedgeleaf draba | DRCU | Draba cuneifolia | 0–5 | – | ||
| California suncup | CACA32 | Camissonia californica | 0–5 | – | ||
| New Mexico thistle | CINE | Cirsium neomexicanum | 0–2 | – | ||
| star gilia | GIST | Gilia stellata | 0–2 | – | ||
| sand fringepod | THCU | Thysanocarpus curvipes | 0–2 | – | ||
| Fendler's horsenettle | SOFE | Solanum fendleri | 0–1 | – | ||
| doubleclaw | PRPA2 | Proboscidea parviflora | 0–1 | – | ||
| redseed plantain | PLRH | Plantago rhodosperma | 0–1 | – | ||
| shaggyfruit pepperweed | LELA | Lepidium lasiocarpum | 0–1 | – | ||
| Mojave desertstar | MOBE2 | Monoptilon bellioides | 0–1 | – | ||
| tanseyleaf tansyaster | MATA2 | Machaeranthera tanacetifolia | 0–1 | – | ||
| disc mayweed | MADI6 | Matricaria discoidea | 0–1 | – | ||
| slender goldenweed | MAGR10 | Machaeranthera gracilis | 0–1 | – | ||
| Palmer's spectaclepod | DICA31 | Dimorphocarpa candicans | 0–1 | – | ||
| touristplant | DIWI2 | Dimorphocarpa wislizeni | 0–1 | – | ||
| Mexican fireplant | EUHE4 | Euphorbia heterophylla | 0–1 | – | ||
| hoary bowlesia | BOIN3 | Bowlesia incana | 0–1 | – | ||
| common fiddleneck | AMMEI2 | Amsinckia menziesii var. intermedia | 0–1 | – | ||
| desert tobacco | NIOBO | Nicotiana obtusifolia var. obtusifolia | 0–1 | – | ||
| desert evening primrose | OEPR | Oenothera primiveris | 0–1 | – | ||
| Florida pellitory | PAFL3 | Parietaria floridana | 0–1 | – | ||
| manybristle chinchweed | PEPA2 | Pectis papposa | 0–1 | – | ||
|
Shrub/Vine
|
||||||
| 6 | Misc shrubs | 0–10 | ||||
| fairyduster | CAER | Calliandra eriophylla | 0–2 | – | ||
| spiny hackberry | CEEH | Celtis ehrenbergiana | 0–2 | – | ||
| snakewood | CONDA | Condalia | 0–2 | – | ||
| soaptree yucca | YUEL | Yucca elata | 0–2 | – | ||
| lotebush | ZIOB | Ziziphus obtusifolia | 0–1 | – | ||
| Nevada jointfir | EPNE | Ephedra nevadensis | 0–1 | – | ||
| water jacket | LYAN | Lycium andersonii | 0–1 | – | ||
| Berlandier's wolfberry | LYBE | Lycium berlandieri | 0–1 | – | ||
| Arizona desert-thorn | LYEX | Lycium exsertum | 0–1 | – | ||
| pale desert-thorn | LYPA | Lycium pallidum | 0–1 | – | ||
| rough menodora | MESC | Menodora scabra | 0–1 | – | ||
| whitethorn acacia | ACCO2 | Acacia constricta | 0–1 | – | ||
| catclaw acacia | ACGR | Acacia greggii | 0–1 | – | ||
| fourwing saltbush | ATCA2 | Atriplex canescens | 0–1 | – | ||
| crucifixion thorn | CAEM4 | Castela emoryi | 0–1 | – | ||
| 7 | Succulents | 1–20 | ||||
| walkingstick cactus | CYSP8 | Cylindropuntia spinosior | 0–5 | – | ||
| dollarjoint pricklypear | OPCH | Opuntia chlorotica | 0–5 | – | ||
| cactus apple | OPEN3 | Opuntia engelmannii | 0–5 | – | ||
| staghorn cholla | CYVE3 | Cylindropuntia versicolor | 0–1 | – | ||
| Engelmann's hedgehog cactus | ECEN | Echinocereus engelmannii | 0–1 | – | ||
| candy barrelcactus | FEWI | Ferocactus wislizeni | 0–1 | – | ||
| devil's cholla | GRKU | Grusonia kunzei | 0–1 | – | ||
| buck-horn cholla | CYAC8 | Cylindropuntia acanthocarpa | 0–1 | – | ||
| Arizona pencil cholla | CYAR14 | Cylindropuntia arbuscula | 0–1 | – | ||
| jumping cholla | CYFU10 | Cylindropuntia fulgida | 0–1 | – | ||
| Christmas cactus | CYLE8 | Cylindropuntia leptocaulis | 0–1 | – | ||
|
Tree
|
||||||
| 8 | Trees | 0–10 | ||||
| velvet mesquite | PRVE | Prosopis velutina | 0–10 | – | ||
| blue paloverde | PAFL6 | Parkinsonia florida | 0–2 | – | ||
| yellow paloverde | PAMI5 | Parkinsonia microphylla | 0–2 | – | ||
Interpretations
Animal community
The plant community on this site is suitable for grazing by all classes of cattle. Tobosa grass is very unpalatable when cured and dormant and best use is made of this species in either spring or summer growing seasons. Prescribed burning or mowing can be used to freshen old growth tobosa grass. Burning should only be done in February or March and only in years with good enough winter rainfall for soils to have 3 inches of available moisture in the profile. Spring regrowth should then be rested until the first summer flood. The plant community will be deficient in digestible protein in the fall or winter.
This site is mainly a foraging area for large wildlife species. Free water is usually available in the summer rainy season in natural charcos and discontinuous gullies. Being open grassland, this site is home to a variety of small wildlife species and their predators.
Hydrological functions
When dry, these soils produce little runoff due to cracks and depressions that hold water. When wet they produce good amounts of runoff due to heavy soil textures and swelling to seal cracks and holes.
Recreational uses
Hunting, hiking, horseback riding, photography, camping
Wood products
Little to nothing except in areas where mesquite has increased. In areas heavily invaded by mesquite good supplies of fuelwood are available.
Other products
Grass nuts, hog potatoes, prickly pear tunas and clay.
Supporting information
Inventory data references
Range 417s include 2 in fair condition.
Type locality
| Location 1: Pima County, AZ | |
|---|---|
| Township/Range/Section | T9S R2E S7 |
| General legal description | SELLS FIELD OFFICE - HICKIWAN DIST. HEADWATERS OF THE VEKOL VALLEY |
| Location 2: Pima County, AZ | |
| Township/Range/Section | T16S R15E S14 |
| General legal description | TUCSON FIELD OFFICE - PIMA COUNTY FAIRGROUNDS |
Contributors
C.Michaels
Dan Robinett
Larry D. Ellicott
M.G.Lameroux
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 | |
| Approved by | |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
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Number and extent of rills:
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Presence of water flow patterns:
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Number and height of erosional pedestals or terracettes:
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Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
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Number of gullies and erosion associated with gullies:
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Extent of wind scoured, blowouts and/or depositional areas:
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Amount of litter movement (describe size and distance expected to travel):
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Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
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Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
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Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
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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:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
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Average percent litter cover (%) and depth ( in):
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Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
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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:
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Perennial plant reproductive capability:
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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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