Natural Resources
Conservation Service
Ecological site R040XA112AZ
Loamy Swale 10"-13" p.z.
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): 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
| R040XA102AZ |
Clayey Swale 10"-13" p.z. |
|---|---|
| R040XA108AZ |
Limy Fan 10"-13" p.z. |
| R040XA110AZ |
Limy Slopes 10"-13" p.z. |
| R040XA114AZ |
Loamy Upland 10"-13" p.z. |
Similar sites
| R041XC311AZ |
Loamy Swale 12-16" p.z. |
|---|---|
| R040XB211AZ |
Loamy Swale 7"-10" p.z. |
| R041XB209AZ |
Loamy Swale 8-12" p.z. |
Table 1. Dominant plant species
| Tree |
(1) Prosopis velutina |
|---|---|
| Shrub |
(1) Acacia constricta |
| Herbaceous |
(1) Pappophorum vaginatum |
Physiographic features
This site occurs in the upper elevations of the Sonoran Desert in southern Arizona. It benefits on a regular basis from extra moisture received as overbank flooding and/or runoff from adjacent upland sites. It occurs on flood plains and alluvial fans.
Table 2. Representative physiographic features
| Landforms |
(1)
Flood plain
(2) Alluvial fan (3) Stream terrace |
|---|---|
| Flooding duration | Very brief (4 to 48 hours) to brief (2 to 7 days) |
| 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 | 564 – 1,006 m |
| Slope | 0 – 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) | 330 mm |
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, young soils on loamy alluvium from mixed sources. They may or may not be calcareous, and have low shrink-swell potential. Plant-soil moisture relationships are excellent.
Soils on mapped on this site include:
SSA-668 Tucson-Avra Valley area MU's Aqua-Ag, Anthony-Ao, Estrella-Ts3, Gila-Ga, GbA, Ge, Glendale-Gd, Ge, Ge3, Grabe-Gh, GkA, Gm, GoB, Gullied Land-Gu, Pima-Pm, Trix-Tr & Ts3;
SSA-669 Eastern Pima County MU's Glendale-29 & 30;
SSA-703 Tohono O'odham area MU's Glendale-28 & Grabe-31.
Table 4. Representative soil features
| Surface texture |
(1) Fine sandy loam (2) Loam (3) Silt loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderate to moderately slow |
| Soil depth | 152 cm |
| Surface fragment cover <=3" | 0 – 10% |
| Surface fragment cover >3" | 0 – 1% |
| Available water capacity (0-101.6cm) |
14.73 – 27.43 cm |
| Calcium carbonate equivalent (0-101.6cm) |
0 – 10% |
| Electrical conductivity (0-101.6cm) |
0 – 4 mmhos/cm |
| Sodium adsorption ratio (0-101.6cm) |
0 – 13 |
| Soil reaction (1:1 water) (0-101.6cm) |
7 – 8.2 |
| Subsurface fragment volume <=3" (Depth not specified) |
0 – 5% |
| Subsurface fragment volume >3" (Depth not specified) |
0 – 1% |
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 model, Loamy 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 was a mixture of desert trees and shrubs with a midgrass understory. The aspect is savannah. With continuous heavy grazing, perennial midrasses are removed from the plant community. When the grass cover is depleted the site is extemely susceptible to gully erosion. Mesquite, whitethorn acacia and creosotebush can increase quickly to dominate the plant community with heavy use and erosion. Base level changes in large watersheds can lead to eventual gullying of the site. With severe erosion the effectiveness of flooding is greatly reduced as is the site's ability to produce vegetation.
Figure 5. 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 | 251 | 1121 | 1737 |
| Forb | 12 | 224 | 527 |
| Tree | 112 | 224 | 336 |
| Shrub/Vine | 12 | 123 | 247 |
| Total | 387 | 1692 | 2847 |
Table 6. Soil surface cover
| Tree basal cover | 0-1% |
|---|---|
| Shrub/vine/liana basal cover | 0-1% |
| Grass/grasslike basal cover | 8-30% |
| Forb basal cover | 1-2% |
| Non-vascular plants | 0% |
| Biological crusts | 5-25% |
| Litter | 30-70% |
| Surface fragments >0.25" and <=3" | 0-5% |
| Surface fragments >3" | 0-1% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 10-50% |
Table 7. Canopy structure (% cover)
| Height Above Ground (m) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.15 | – | – | 1-5% | 0-5% |
| >0.15 <= 0.3 | – | – | 5-25% | 1-5% |
| >0.3 <= 0.6 | – | 0-1% | 15-25% | 0-15% |
| >0.6 <= 1.4 | – | 1-5% | 1-20% | 0-15% |
| >1.4 <= 4 | 1-5% | 0-10% | 0-5% | – |
| >4 <= 12 | 1-15% | – | – | – |
| >12 <= 24 | – | – | – | – |
| >24 <= 37 | – | – | – | – |
| >37 | – | – | – | – |
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 saltbush 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, furrows or borders. 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 perennial grasses with mesquite
Community 4.1
Exotic perennial grasses with mesquite
This state occurs where non-native perennial grasses like bermuda, blue panic, Johnson grass, lovegrass and bufflegrass have been introduced or actually seeded on the site. These species dominate the under-story with mesquite in the over-story. In some areas these species were seeded on abandoned farmland to control weeds and erosion and persist with scattered mesquite.
State 5
Dense mesquite
Community 5.1
Dense mesquite
This state occurs where mesquite has increased in the presence of continuous grazing. Mesquite forms an impenetrable thicket and is shrubby in stature. This can also occur on abandoned farmland where large floods have broken through the old dikes and deposited mesquite seed, organic debris and soil across large areas. The resulting stands of mesquite can be extremely dense.
State 6
Eroded
Community 6.1
Eroded
This state occurs where the site has been gullied. Runoff water from adjacent uplands no longer contributes to flooding of the site and is quickly drained off by deep gullies. Base level changes in large stream systems can contribute to gully formation in areas of this site which are tributary. Loss of herbaceous cover and soil compaction and trailing caused by livestock and roads can lead to gully formation on the site.
Additional community tables
Table 8. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Dominant Perennial Mid Grasses | 112–448 | ||||
| whiplash pappusgrass | PAVA2 | Pappophorum vaginatum | 28–336 | – | ||
| Arizona cottontop | DICA8 | Digitaria californica | 0–112 | – | ||
| bush muhly | MUPO2 | Muhlenbergia porteri | 28–112 | – | ||
| plains bristlegrass | SEVU2 | Setaria vulpiseta | 0–56 | – | ||
| spike dropseed | SPCO4 | Sporobolus contractus | 0–56 | – | ||
| 2 | Dominant sod grass | 112–448 | ||||
| vine mesquite | PAOB | Panicum obtusum | 112–448 | – | ||
| 3 | Misc perennial grasses | 1–112 | ||||
| purple threeawn | ARPU9 | Aristida purpurea | 0–28 | – | ||
| Parish's threeawn | ARPUP5 | Aristida purpurea var. parishii | 0–28 | – | ||
| spidergrass | ARTE3 | Aristida ternipes | 1–28 | – | ||
| spidergrass | ARTEG | Aristida ternipes var. gentilis | 0–22 | – | ||
| cane bluestem | BOBA3 | Bothriochloa barbinodis | 0–22 | – | ||
| sideoats grama | BOCU | Bouteloua curtipendula | 0–22 | – | ||
| tobosagrass | PLMU3 | Pleuraphis mutica | 0–22 | – | ||
| false Rhodes grass | TRCR9 | Trichloris crinita | 0–22 | – | ||
| slim tridens | TRMU | Tridens muticus | 0–6 | – | ||
| big galleta | PLRI3 | Pleuraphis rigida | 0–6 | – | ||
| large-spike bristlegrass | SEMA5 | Setaria macrostachya | 0–6 | – | ||
| sand dropseed | SPCR | Sporobolus cryptandrus | 0–6 | – | ||
| black grama | BOER4 | Bouteloua eriopoda | 0–6 | – | ||
| tanglehead | HECO10 | Heteropogon contortus | 0–6 | – | ||
| Santa Rita threeawn | ARCAG | Aristida californica var. glabrata | 0–6 | – | ||
| Indian ricegrass | ACHY | Achnatherum hymenoides | 0–3 | – | ||
| giant dropseed | SPGI | Sporobolus giganteus | 0–3 | – | ||
| low woollygrass | DAPU7 | Dasyochloa pulchella | 0–2 | – | ||
| squirreltail | ELELE | Elymus elymoides ssp. elymoides | 0–1 | – | ||
| mesa dropseed | SPFL2 | Sporobolus flexuosus | 0–1 | – | ||
| 4 | Tall grass | 1–280 | ||||
| big sacaton | SPWR2 | Sporobolus wrightii | 1–280 | – | ||
| 5 | Annual grasses | 25–448 | ||||
| Rothrock's grama | BORO2 | Bouteloua rothrockii | 22–224 | – | ||
| feather fingergrass | CHVI4 | Chloris virgata | 1–112 | – | ||
| mucronate sprangeltop | LEPAB | Leptochloa panicea ssp. brachiata | 0–112 | – | ||
| Mexican panicgrass | PAHI5 | Panicum hirticaule | 0–112 | – | ||
| sixweeks fescue | VUOC | Vulpia octoflora | 0–56 | – | ||
| Mexican sprangletop | LEFUU | Leptochloa fusca ssp. uninervia | 0–56 | – | ||
| sticky sprangletop | LEVI5 | Leptochloa viscida | 0–56 | – | ||
| canyon cupgrass | ERLE7 | Eriochloa lemmonii | 0–56 | – | ||
| Arizona brome | BRAR4 | Bromus arizonicus | 0–56 | – | ||
| prairie threeawn | AROL | Aristida oligantha | 1–56 | – | ||
| Bigelow's bluegrass | POBI | Poa bigelovii | 0–34 | – | ||
| needle grama | BOAR | Bouteloua aristidoides | 0–28 | – | ||
| sixweeks grama | BOBA2 | Bouteloua barbata | 0–28 | – | ||
| Parry's grama | BOPA2 | Bouteloua parryi | 0–28 | – | ||
| desert lovegrass | ERPEM | Eragrostis pectinacea var. miserrima | 0–28 | – | ||
| tufted lovegrass | ERPEP2 | Eragrostis pectinacea var. pectinacea | 0–28 | – | ||
| bearded cupgrass | ERAR5 | Eriochloa aristata | 0–28 | – | ||
| sixweeks threeawn | ARAD | Aristida adscensionis | 0–28 | – | ||
| Arizona signalgrass | URAR | Urochloa arizonica | 0–22 | – | ||
| delicate muhly | MUFR | Muhlenbergia fragilis | 0–6 | – | ||
| littleseed muhly | MUMI | Muhlenbergia microsperma | 0–6 | – | ||
| witchgrass | PACA6 | Panicum capillare | 0–6 | – | ||
| Eastwood fescue | VUMIC | Vulpia microstachys var. ciliata | 0–2 | – | ||
| bristlegrass | SETAR | Setaria | 0–2 | – | ||
|
Forb
|
||||||
| 6 | Parasites | 1–22 | ||||
| mesquite mistletoe | PHCA8 | Phoradendron californicum | 1–22 | – | ||
| bigseed alfalfa dodder | CUIN | Cuscuta indecora | 0–6 | – | ||
| 7 | Perennial forbs | 6–56 | ||||
| violet wild petunia | RUNU | Ruellia nudiflora | 1–22 | – | ||
| desert globemallow | SPAM2 | Sphaeralcea ambigua | 0–22 | – | ||
| spear globemallow | SPHA | Sphaeralcea hastulata | 0–11 | – | ||
| spreading fleabane | ERDI4 | Erigeron divergens | 0–11 | – | ||
| Indian rushpea | HOGL2 | Hoffmannseggia glauca | 1–11 | – | ||
| fingerleaf gourd | CUDI | Cucurbita digitata | 0–6 | – | ||
| coyote gourd | CUPA | Cucurbita palmata | 0–6 | – | ||
| scarlet spiderling | BOCO | Boerhavia coccinea | 0–6 | – | ||
| climbing wartclub | BOSC | Boerhavia scandens | 0–6 | – | ||
| dwarf desertpeony | ACNA2 | Acourtia nana | 0–6 | – | ||
| weakleaf bur ragweed | AMCO3 | Ambrosia confertiflora | 0–6 | – | ||
| red-gland spurge | CHME5 | Chamaesyce melanadenia | 0–2 | – | ||
| desert marigold | BAMU | Baileya multiradiata | 0–2 | – | ||
| Missouri gourd | CUFO | Cucurbita foetidissima | 0–2 | – | ||
| slender janusia | JAGR | Janusia gracilis | 0–2 | – | ||
| wishbone-bush | MILAV | Mirabilis laevis var. villosa | 0–2 | – | ||
| desert tobacco | NIOBO | Nicotiana obtusifolia var. obtusifolia | 0–2 | – | ||
| spreading fanpetals | SIAB | Sida abutifolia | 0–2 | – | ||
| New Mexico fanpetals | SINE | Sida neomexicana | 0–2 | – | ||
| silverleaf nightshade | SOEL | Solanum elaeagnifolium | 0–2 | – | ||
| Coulter's wrinklefruit | TECO | Tetraclea coulteri | 0–2 | – | ||
| Louisiana vetch | VILUL2 | Vicia ludoviciana ssp. ludoviciana | 0–2 | – | ||
| canaigre dock | RUHY | Rumex hymenosepalus | 0–2 | – | ||
| Tumamoc globeberry | TUMA | Tumamoca macdougalii | 0–1 | – | ||
| orange fameflower | PHAU13 | Phemeranthus aurantiacus | 0–1 | – | ||
| brownplume wirelettuce | STPA4 | Stephanomeria pauciflora | 0–1 | – | ||
| spearleaf | MAPA9 | Matelea parvifolia | 0–1 | – | ||
| lacy tansyaster | MAPIP4 | Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida | 0–1 | – | ||
| bluedicks | DICA14 | Dichelostemma capitatum | 0–1 | – | ||
| Watson's dutchman's pipe | ARWA | Aristolochia watsonii | 0–1 | – | ||
| brownfoot | ACWR5 | Acourtia wrightii | 0–1 | – | ||
| 8 | Annual forbs | 6–448 | ||||
| carelessweed | AMPA | Amaranthus palmeri | 1–280 | – | ||
| wheelscale saltbush | ATEL | Atriplex elegans | 0–112 | – | ||
| Nuttall's povertyweed | MONU | Monolepis nuttalliana | 0–112 | – | ||
| Arizona popcornflower | PLAR | Plagiobothrys arizonicus | 0–56 | – | ||
| bristly fiddleneck | AMTE3 | Amsinckia tessellata | 0–56 | – | ||
| pitseed goosefoot | CHBE4 | Chenopodium berlandieri | 0–56 | – | ||
| western tansymustard | DEPI | Descurainia pinnata | 1–56 | – | ||
| Gordon's bladderpod | LEGO | Lesquerella gordonii | 0–28 | – | ||
| shaggyfruit pepperweed | LELA | Lepidium lasiocarpum | 0–22 | – | ||
| smallflowered milkvetch | ASNU4 | Astragalus nuttallianus | 0–22 | – | ||
| Coulter's globemallow | SPCO2 | Sphaeralcea coulteri | 0–22 | – | ||
| thelypody | THELY | Thelypodium | 0–17 | – | ||
| ivyleaf morning-glory | IPHE | Ipomoea hederacea | 0–17 | – | ||
| tripleleaf morning-glory | IPTE5 | Ipomoea ternifolia | 0–17 | – | ||
| Arizona poppy | KAGR | Kallstroemia grandiflora | 0–11 | – | ||
| biannual lettuce | LALU | Lactuca ludoviciana | 0–11 | – | ||
| mesa tansyaster | MATA | Machaeranthera tagetina | 0–11 | – | ||
| tanseyleaf tansyaster | MATA2 | Machaeranthera tanacetifolia | 0–11 | – | ||
| hyssopleaf sandmat | CHHY3 | Chamaesyce hyssopifolia | 0–11 | – | ||
| yellow tackstem | CAPA7 | Calycoseris parryi | 0–11 | – | ||
| white tackstem | CAWR | Calycoseris wrightii | 0–11 | – | ||
| Coulter's spiderling | BOCO2 | Boerhavia coulteri | 0–11 | – | ||
| fringed amaranth | AMFI | Amaranthus fimbriatus | 0–11 | – | ||
| woolly tidestromia | TILA2 | Tidestromia lanuginosa | 0–11 | – | ||
| New Mexico plumeseed | RANE | Rafinesquia neomexicana | 0–11 | – | ||
| Lemmon's ragwort | SELE8 | Senecio lemmonii | 0–11 | – | ||
| desert Indianwheat | PLOV | Plantago ovata | 0–11 | – | ||
| woolly plantain | PLPA2 | Plantago patagonica | 0–11 | – | ||
| purslane | PORTU | Portulaca | 0–11 | – | ||
| manybristle chinchweed | PEPA2 | Pectis papposa | 0–11 | – | ||
| Arizona phacelia | PHAR13 | Phacelia arizonica | 0–11 | – | ||
| cleftleaf wildheliotrope | PHCR | Phacelia crenulata | 0–11 | – | ||
| coastal bird's-foot trefoil | LOSAB | Lotus salsuginosus var. brevivexillus | 0–11 | – | ||
| bean | PHASE | Phaseolus | 2–10 | – | ||
| distant phacelia | PHDI | Phacelia distans | 0–6 | – | ||
| slimjim bean | PHFI3 | Phaseolus filiformis | 0–6 | – | ||
| doubleclaw | PRPA2 | Proboscidea parviflora | 0–6 | – | ||
| California desertdandelion | MACA6 | Malacothrix californica | 0–6 | – | ||
| sleepy silene | SIAN2 | Silene antirrhina | 0–6 | – | ||
| Louisiana vetch | VILUL2 | Vicia ludoviciana ssp. ludoviciana | 0–6 | – | ||
| hoary bowlesia | BOIN3 | Bowlesia incana | 0–6 | – | ||
| cryptantha | CRYPT | Cryptantha | 0–6 | – | ||
| Sonoran sandmat | CHMI7 | Chamaesyce micromera | 0–6 | – | ||
| fringed redmaids | CACI2 | Calandrinia ciliata | 0–6 | – | ||
| whitestem blazingstar | MEAL6 | Mentzelia albicaulis | 0–6 | – | ||
| American wild carrot | DAPU3 | Daucus pusillus | 0–6 | – | ||
| star gilia | GIST | Gilia stellata | 0–6 | – | ||
| crestrib morning-glory | IPCO2 | Ipomoea costellata | 0–6 | – | ||
| redstar | IPCO3 | Ipomoea coccinea | 0–6 | – | ||
| California poppy | ESCAM | Eschscholzia californica ssp. mexicana | 0–2 | – | ||
| California goldfields | LACAC2 | Lasthenia californica ssp. californica | 0–2 | – | ||
| New Mexico thistle | CINE | Cirsium neomexicanum | 0–2 | – | ||
| desert thorn-apple | DADI2 | Datura discolor | 0–2 | – | ||
| pricklyburr | DAIN2 | Datura inoxia | 0–2 | – | ||
| miniature woollystar | ERDI2 | Eriastrum diffusum | 0–2 | – | ||
| buckwheat | ERIOG | Eriogonum | 0–2 | – | ||
| California suncup | CACA32 | Camissonia californica | 0–2 | – | ||
| woollyhead neststraw | STMI2 | Stylocline micropoides | 0–2 | – | ||
| sand fringepod | THCU | Thysanocarpus curvipes | 0–2 | – | ||
| hedgemustard | SISYM | Sisymbrium | 0–2 | – | ||
| green carpetweed | MOVE | Mollugo verticillata | 0–2 | – | ||
| desert evening primrose | OEPR | Oenothera primiveris | 0–2 | – | ||
| Florida pellitory | PAFL3 | Parietaria floridana | 0–2 | – | ||
| pellitory | PARIE | Parietaria | 0–2 | – | ||
| combseed | PECTO | Pectocarya | 0–2 | – | ||
| Mexican passionflower | PAME2 | Passiflora mexicana | 0–1 | – | ||
| bristly nama | NAHI | Nama hispidum | 0–1 | – | ||
| slender goldenweed | MAGR10 | Machaeranthera gracilis | 0–1 | – | ||
| London rocket | SIIR | Sisymbrium irio | 0–1 | – | ||
| Texas stork's bill | ERTE13 | Erodium texanum | 0–1 | – | ||
| Palmer's spectaclepod | DICA31 | Dimorphocarpa candicans | 0–1 | – | ||
| wedgeleaf draba | DRCU | Draba cuneifolia | 0–1 | – | ||
| Mexican fireplant | EUHE4 | Euphorbia heterophylla | 0–1 | – | ||
| Arizona cottonrose | LOAR12 | Logfia arizonica | 0–1 | – | ||
| Lindley's silverpuffs | MILI5 | Microseris lindleyi | 0–1 | – | ||
|
Shrub/Vine
|
||||||
| 9 | Large shrubs | 11–168 | ||||
| whitethorn acacia | ACCO2 | Acacia constricta | 2–112 | – | ||
| creosote bush | LATRT | Larrea tridentata var. tridentata | 1–56 | – | ||
| fourwing saltbush | ATCA2 | Atriplex canescens | 1–28 | – | ||
| Arizona desert-thorn | LYEX | Lycium exsertum | 0–17 | – | ||
| cattle saltbush | ATPO | Atriplex polycarpa | 0–11 | – | ||
| spiny hackberry | CEEH | Celtis ehrenbergiana | 0–11 | – | ||
| crucifixion thorn | CAEM4 | Castela emoryi | 0–6 | – | ||
| soaptree yucca | YUEL | Yucca elata | 0–6 | – | ||
| lotebush | ZIOB | Ziziphus obtusifolia | 0–6 | – | ||
| Berlandier's wolfberry | LYBE | Lycium berlandieri | 0–6 | – | ||
| desertbroom | BASA2 | Baccharis sarothroides | 0–2 | – | ||
| desert willow | CHLI2 | Chilopsis linearis | 0–2 | – | ||
| Nevada jointfir | EPNE | Ephedra nevadensis | 0–2 | – | ||
| ambrosia leaf bur ragweed | AMAM2 | Ambrosia ambrosioides | 0–2 | – | ||
| Thurber's desert honeysuckle | ANTH2 | Anisacanthus thurberi | 0–1 | – | ||
| longleaf jointfir | EPTR | Ephedra trifurca | 0–1 | – | ||
| 10 | Dominant vines | 1–45 | ||||
| Drummond's clematis | CLDR | Clematis drummondii | 0–22 | – | ||
| fringed twinevine | FUCYC | Funastrum cynanchoides ssp. cynanchoides | 0–11 | – | ||
| Gila manroot | MAGI | Marah gilensis | 0–11 | – | ||
| yellowhood | NISSO | Nissolia | 0–6 | – | ||
| fetid passionflower | PAFO2 | Passiflora foetida | 0–6 | – | ||
| climbing arrowheads | SIGR | Sicyosperma gracile | 0–6 | – | ||
| 11 | Succulents | 0–22 | ||||
| cactus apple | OPEN3 | Opuntia engelmannii | 0–11 | – | ||
| tulip pricklypear | OPPH | Opuntia phaeacantha | 0–6 | – | ||
| Arizona pencil cholla | CYAR14 | Cylindropuntia arbuscula | 0–6 | – | ||
| Christmas cactus | CYLE8 | Cylindropuntia leptocaulis | 0–6 | – | ||
| staghorn cholla | CYVE3 | Cylindropuntia versicolor | 0–2 | – | ||
| dollarjoint pricklypear | OPCH | Opuntia chlorotica | 0–2 | – | ||
| nightblooming cereus | PEGRG | Peniocereus greggii var. greggii | 0–1 | – | ||
| candy barrelcactus | FEWI | Ferocactus wislizeni | 0–1 | – | ||
| devil's cholla | GRKU | Grusonia kunzei | 0–1 | – | ||
| walkingstick cactus | CYSP8 | Cylindropuntia spinosior | 0–1 | – | ||
| jumping cholla | CYFU10 | Cylindropuntia fulgida | 0–1 | – | ||
| buck-horn cholla | CYAC8 | Cylindropuntia acanthocarpa | 0–1 | – | ||
| 12 | Half shrubs | 0–11 | ||||
| fairyduster | CAER | Calliandra eriophylla | 0–6 | – | ||
| snakewood | CONDA | Condalia | 0–2 | – | ||
| alkali goldenbush | ISACA2 | Isocoma acradenia var. acradenia | 0–2 | – | ||
| burroweed | ISTE2 | Isocoma tenuisecta | 0–2 | – | ||
| littleleaf ratany | KRER | Krameria erecta | 0–2 | – | ||
| white ratany | KRGR | Krameria grayi | 0–2 | – | ||
| woolly fruit bur ragweed | AMER | Ambrosia eriocentra | 0–2 | – | ||
| rubber rabbitbrush | ERNAG | Ericameria nauseosa ssp. nauseosa var. glabrata | 0–2 | – | ||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 0–1 | – | ||
| shortleaf baccharis | BABR | Baccharis brachyphylla | 0–1 | – | ||
| Coulter's brickellbush | BRCO | Brickellia coulteri | 0–1 | – | ||
| whitestem paperflower | PSCO2 | Psilostrophe cooperi | 0–1 | – | ||
| Mexican bladdersage | SAME | Salazaria mexicana | 0–1 | – | ||
| American threefold | TRCA8 | Trixis californica | 0–1 | – | ||
| toothleaf goldeneye | VIDE3 | Viguiera dentata | 0–1 | – | ||
| brittlebush | ENFA | Encelia farinosa | 0–1 | – | ||
| buckwheat | ERIOG | Eriogonum | 0–1 | – | ||
| rayless goldenhead | ACSP | Acamptopappus sphaerocephalus | 0–1 | – | ||
| triangle bur ragweed | AMDE4 | Ambrosia deltoidea | 0–1 | – | ||
|
Tree
|
||||||
| 13 | Trees | 112–336 | ||||
| velvet mesquite | PRVE | Prosopis velutina | 112–336 | – | ||
| catclaw acacia | ACGR | Acacia greggii | 0–56 | – | ||
| Jerusalem thorn | PAAC3 | Parkinsonia aculeata | 0–22 | – | ||
| blue paloverde | PAFL6 | Parkinsonia florida | 0–22 | – | ||
| yellow paloverde | PAMI5 | Parkinsonia microphylla | 0–22 | – | ||
| desert ironwood | OLTE | Olneya tesota | 0–11 | – | ||
| Joshua tree | YUBR | Yucca brevifolia | 0–2 | – | ||
Interpretations
Animal community
The plant community on this site is suitable for grazing by all classes of cattle. Because of water availability in the rainy seasons,long green seasons, shade and easy accessibility, this site is often overused. Large areas should be fenced and managed separately from adjacent upland sites. Grazing should be avoided during the summer flood season to avoid damage by trampling the muddy soils and because heat, humidity and insects reduce livestock performance. The plant community provides adequate nutrition for livestock throughout the year.
Free water is available in the summer rainy season in natural charcos and discontinuous gullies. Forage diversity, shade and cover are very good and make this site home to a great variety of wildlife species including the larger desert mammals. Water developments which prolong the availability of free water are very important to the larger wildlife species on the site.
Hydrological functions
Medium to heavy textured soils and flat slopes make this site a fair producer of runoff. The site recieves extra water in the form of runin from adjacent uplands and watershed areas.
Recreational uses
Hunting, camping, hiking, birdwatching, photography, horseback riding.
Wood products
Good supplies of mesquite for firewood.
Other products
Mesquite beans and cactus fruits
Supporting information
Inventory data references
Range 417s include 4 in good condition.
Type locality
| Location 1: Pima County, AZ | |
|---|---|
| Township/Range/Section | T16S R15E S14 |
| General legal description | Tucson FO - Pima County Fairgrounds |
| Location 2: Pima County, AZ | |
| Township/Range/Section | T20S R5E S23 |
| General legal description | Sells FO - Chutum Vaya Assoc. Community Pastures |
| Location 3: Pima County, AZ | |
| Township/Range/Section | T14S R11E S31 |
| General legal description | La Tortuga Ranch, In Conservation Ditch Pasture at KA 1. Ungrazed 7 years |
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) | Dave Womack, Dan Robinett, Emilio Carrillo |
|---|---|
| Contact for lead author | NRCS Tucson Area Office |
| Date | 03/08/2005 |
| Approved by | S. Cassady |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
Rills are present on this site but are well vegetated and not eroding. -
Presence of water flow patterns:
Uncommon; probably cover no more than 5% of area; very short and discontinuous, 1-2 terracetes. -
Number and height of erosional pedestals or terracettes:
Slope is 0-1% and not onducive to forming pedestals and terracettes. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
5-15% -
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):
All litter size classes staying in place, occasionally transported in flow paths. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Expect values of 5-6 across site. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
WEak thin platy to weak granular to moderate subangular block; color is 7.5-10YR6/4 dry, .5-10YR4/4 moist; thickness to 4 inches. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Canopy 60-70%; asa 15-25%, litter 15%: 80% canopy covery is perennial grasses, 2-5% forbs, 15% shrubs and trees. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None -
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:
perennial mid grasses > trees & shrubs > short grasses > grasslike species > perennial forbs > annual grasses and forbs.Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
50% basal area lost on perennial grasses. -
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
346 lbs/ac unfavorable precipitation, 1510 lbs/ac normal precipitation, 2540 lbs/ac favorable 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:
mesquite, whitethorn, creosote, Bermuda grass, Johnson grass, blue panic, bufflegrass, yellow bluestem, London Rocket, malta starthistle, cheeseweed, cocklebur -
Perennial plant reproductive capability:
Nt affected even following several years of prolonged drought period for region.
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