Natural Resources
Conservation Service
Ecological site R040XA118AZ
Sandy Loam Upland 10"-13" p.z.
Accessed: 11/13/2024
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.
Classification relationships
Similar to TES mapping unit 287 on the Tonto National Forest. Tonto basin.
Associated sites
| R040XA114AZ |
Loamy Upland 10"-13" p.z. |
|---|---|
| R040XA115AZ |
Sandy Wash 10"-13" p.z. |
| R040XA117AZ |
Sandy Loam Upland, Deep 10"-13" p.z. |
Similar sites
| R041XB215AZ |
Sandy Loam Upland 8-12" p.z. |
|---|---|
| R041XC319AZ |
Sandy Loam Upland 12-16" p.z. |
Table 1. Dominant plant species
| Tree |
(1) Parkinsonia microphylla |
|---|---|
| Shrub |
(1) Ambrosia deltoidea |
| Herbaceous |
(1) Muhlenbergia porteri |
Physiographic features
This site occurs in the upper elevations of the Sonoran Desert in southern Arizona. It occurs on fan terraces and old stream terraces.
Table 2. Representative physiographic features
| Landforms |
(1)
Fan
(2) Terrace (3) Stream terrace |
|---|---|
| Flooding frequency | None |
| Ponding frequency | None |
| Elevation | 1,900 – 3,300 ft |
| Slope | 1 – 15% |
| 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 which have formed in loamy alluvium of mixed origins. Surface textures range from sandy loam to very gravelly sandy loam and must be as thick or thicker than four inches (eight inches for GRV-SL). These soils have clayey horizons at shallow depths (either argillic or cambic). Plant-soil moisture relationships are very good.
Soils mapped on this site include:
SSA-627 Southern Mohave County MU Amole-5;
SSA-645 Aguila-Carefree area MU's Gila-54 & Vado-122;
SSA-659 Western Pinal County Sonoita-35;
SSA-668 Tucson-Avra Valley area MU's Anway-At, Grabe-GgB, Sonoita-AsB, PaB, SmA, SmB, StB & VnB, Tubac-StB, TtA, TtB & TxB, Valencia-CvB, VaA, VaB, VcB, VgB & VnB;
SSA-669 Eastern Pima County MU's Bucklebar-8 & 29, Sahuarita-8, 36 & 55, Tubac-80 & 82 and
SSA-703 Tohono O'odham area MU's Bucklebar-6 & Tubac-58.
Table 4. Representative soil features
| Surface texture |
(1) Sandy loam (2) Gravelly sandy loam (3) Very gravelly sandy loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderate to moderately slow |
| Soil depth | 60 in |
| Surface fragment cover <=3" | 5 – 40% |
| Surface fragment cover >3" | 5% |
| Available water capacity (0-40in) |
6.5 – 8.2 in |
| Calcium carbonate equivalent (0-40in) |
10% |
| Electrical conductivity (0-40in) |
2 mmhos/cm |
| Sodium adsorption ratio (0-40in) |
2 |
| Soil reaction (1:1 water) (0-40in) |
6.6 – 7.8 |
| Subsurface fragment volume <=3" (Depth not specified) |
5 – 55% |
| Subsurface fragment volume >3" (Depth not specified) |
5% |
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, Sandyloam upland 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 7 submodel, plant communities
State 1
Historical Climax Plant Community
Community 1.1
Historical Climax Plant Community
The potential plant community is an open stand of desert trees with a shrub, cacti and grass understory. The major grass species are well dispersed throughout the plant community. The aspect is savannah. With continuous, heavy grazing, perennial grasses and suffrutescent forb species are removed from the plant community and shrubs like; triangle bursage, burroweed, and snakeweed, can increase to dominate the understory. With thick, coarse textured soil surfaces, trees can reach moderate size on the site. A tree canopy of 5 to 10% is important on the site to keep diversity in the plant community. The potential of the site to produce grass is reduced as tree cover exceeds these amounts. Triangle bursage understories are long lived, persistent, and will not easily be replaced by perennial grass (as will burroweed understories) with good grazing management. In severe drought the cover of perennial grasses and herbs as well as bursage and burroweed can be greatly reduced in the plant community. Recovery can go back to perennial grasses and herbs if good summer rains follow drought. Recovery can go back to the half shrubs if good cool season rains follow the drought. Jumping cholla can increase with heavy grazing or increases can be episodic due to climate. Stand lifespans can range from 40-60 years without reproduction. Prickley pear can also increase under heavy grazing pressure.
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 | 50 | 400 | 770 |
| Forb | 5 | 100 | 220 |
| Tree | 100 | 150 | 200 |
| Shrub/Vine | 20 | 100 | 150 |
| Total | 175 | 750 | 1340 |
Table 6. Soil surface cover
| Tree basal cover | 0-1% |
|---|---|
| Shrub/vine/liana basal cover | 0-4% |
| Grass/grasslike basal cover | 1-8% |
| Forb basal cover | 0-1% |
| Non-vascular plants | 0% |
| Biological crusts | 5-15% |
| Litter | 15-90% |
| Surface fragments >0.25" and <=3" | 0-55% |
| Surface fragments >3" | 0-5% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 5-80% |
Table 7. Canopy structure (% cover)
| Height Above Ground (ft) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.5 | – | 0-1% | 0-30% | 0-15% |
| >0.5 <= 1 | – | 0-5% | 1-25% | 0-10% |
| >1 <= 2 | – | 1-15% | 1-10% | 0-1% |
| >2 <= 4.5 | 0-1% | 0-2% | 0-5% | 0-1% |
| >4.5 <= 13 | 5-10% | – | – | – |
| >13 <= 40 | 0-1% | – | – | – |
| >40 <= 80 | – | – | – | – |
| >80 <= 120 | – | – | – | – |
| >120 | – | – | – | – |
Figure 6. Plant community growth curve (percent production by month). AZ4013, 40.1 10-13" p.z. other sites. Growth begins in the late winter, goes semi-dormant in the drought period of late May through early July, growth continues in the summer through early fall..
| 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 | 5 | 10 | 20 | 15 | 0 | 5 | 20 | 15 | 5 | 5 | 0 |
State 2
Exotic perennial grasses or Euryops with natives
Community 2.1
Exotic perennial grasses or Euryops with natives
This community occurs where bufflegrass, Lehmann lovegrass, Boer lovegrass, natal grass, fountain grass or the African shrubs Euryops multifidus and Pentzia incana invade the native plant community. These species occupy the niches of perennial grasses like bush muhly, spidergrass threeawn, Arizona cottontop and low shrubs like burroweed and triangle bursage.
State 3
Exotic perennial grasses and fire
Community 3.1
Exotic perennial grasses and fire
This community occurs where a native plant community that has been invaded by bufflegrass, Lovegrasses or fountain grass has burned one or more times. Increasing amounts of exotic perennial grasses leads to more uniform fine fuels. In areas adjacent to roads and urban areas the risk of repeated fires will increase. As fire frequency increases the dominance of the exotic grasses increase.
State 4
Exotic annuals
Community 4.1
Exotic annuals
This plant community occurs where the native plant community has been invaded by annuals like schismus, red brome and filaree. These species occupy the niche of the native winter annual forbs and grasses. The exotic annual grasses will fluctuate from nearly nothing in a dry winter to dominance of the understory plant community in a El Nino winter.
State 5
Annuals, half shrubs and fire
Community 5.1
Annuals, half shrubs and fire
This plant community occurs as a result of a single hot season fire. Paloverde, ironwood, cacti and saguaro can be severely impacted and may take long periods of time (30-50 years) to recover to pre-fire levels. Mesquite (except the very old trees and the very young) will sprout after fire. Perennial and annual grasses and forbs dominate the community for some time until shrubs like bursage can recover. Perennial grasses can recover rapidly if grazing pressure is low and summer rains are sufficient. This plant community can produce enough herbaceous fuel from native species of grasses and / or forbs to carry fire in El Nino years or after unusually wet summers. The natural incidence of fire in this MLRA is very low and fires are much more common from man-made ignitions. Areas of the site close to urban zones or along heavily travelled roads and highways will experience a higher rate of fires.
State 6
Annuals and fire
Community 6.1
Annuals and fire
This plant community occurs where a native plant community has burned repeatedly. As fires become more frequent the native trees, shrubs and succulents are removed from the plant community and annuals becomes dominant. In areas of the site near urban areas and along heavily travelled roads this will be a more common occurence due to an increased source of ignitions. This can occur both in areas with only native annuals species present as well as those which have been invaded by schismus and red brome.
State 7
HCPC 2 - Saguaro state
Community 7.1
HCPC 2 - Saguaro state
There is a 300 year cycle on this site that swings between dominance of native trees and large shrubs (that serve as nurse plants) and mature saguaro forest. Saguaros establish wholesale in very favorable years (El Nino years like 1983) only in the presence of plentiful nurse plants like paloverde, ironwood, mesquite, wolfberry, creosote and jojoba. As saguaro plants top their nurse plants (40-60 years) the trees and shrubs begin to die. Saguaro stands reach maturity at 150 to 200 years and begin to diminish over the next 100 years as the large shrubs and trees come back into the plant community.
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 | Short lived perennial grasses | 10–160 | ||||
| Rothrock's grama | BORO2 | Bouteloua rothrockii | 10–150 | – | ||
| Parry's grama | BOPA2 | Bouteloua parryi | 0–100 | – | ||
| slender grama | BORE2 | Bouteloua repens | 0–40 | – | ||
| 2 | Dominant mid grasses | 20–200 | ||||
| Arizona cottontop | DICA8 | Digitaria californica | 5–100 | – | ||
| whiplash pappusgrass | PAVA2 | Pappophorum vaginatum | 0–100 | – | ||
| purple threeawn | ARPU9 | Aristida purpurea | 0–50 | – | ||
| spidergrass | ARTE3 | Aristida ternipes | 5–45 | – | ||
| spidergrass | ARTEG | Aristida ternipes var. gentilis | 0–25 | – | ||
| Parish's threeawn | ARPUP5 | Aristida purpurea var. parishii | 0–20 | – | ||
| tanglehead | HECO10 | Heteropogon contortus | 0–20 | – | ||
| plains bristlegrass | SEVU2 | Setaria vulpiseta | 0–20 | – | ||
| big galleta | PLRI3 | Pleuraphis rigida | 0–10 | – | ||
| large-spike bristlegrass | SEMA5 | Setaria macrostachya | 0–3 | – | ||
| 3 | Dominant suffrutescent grasses | 10–150 | ||||
| bush muhly | MUPO2 | Muhlenbergia porteri | 5–100 | – | ||
| Santa Rita threeawn | ARCAG | Aristida californica var. glabrata | 1–50 | – | ||
| black grama | BOER4 | Bouteloua eriopoda | 0–40 | – | ||
| 4 | Miscellaneous perennial grasses | 0–10 | ||||
| cane bluestem | BOBA3 | Bothriochloa barbinodis | 0–5 | – | ||
| sand dropseed | SPCR | Sporobolus cryptandrus | 0–5 | – | ||
| mesa dropseed | SPFL2 | Sporobolus flexuosus | 0–2 | – | ||
| slim tridens | TRMU | Tridens muticus | 0–2 | – | ||
| low woollygrass | DAPU7 | Dasyochloa pulchella | 0–2 | – | ||
| Indian ricegrass | ACHY | Achnatherum hymenoides | 0–2 | – | ||
| nineawn pappusgrass | ENDE | Enneapogon desvauxii | 0–2 | – | ||
| spike dropseed | SPCO4 | Sporobolus contractus | 0–1 | – | ||
| desert needlegrass | ACSP12 | Achnatherum speciosum | 0–1 | – | ||
| squirreltail | ELELE | Elymus elymoides ssp. elymoides | 0–1 | – | ||
| sideoats grama | BOCU | Bouteloua curtipendula | 0–1 | – | ||
| 5 | Annual grasses | 10–250 | ||||
| needle grama | BOAR | Bouteloua aristidoides | 5–150 | – | ||
| sixweeks grama | BOBA2 | Bouteloua barbata | 0–50 | – | ||
| Mexican panicgrass | PAHI5 | Panicum hirticaule | 0–50 | – | ||
| sixweeks threeawn | ARAD | Aristida adscensionis | 0–50 | – | ||
| prairie threeawn | AROL | Aristida oligantha | 1–50 | – | ||
| mucronate sprangeltop | LEPAB | Leptochloa panicea ssp. brachiata | 0–25 | – | ||
| sixweeks fescue | VUOC | Vulpia octoflora | 0–25 | – | ||
| feather fingergrass | CHVI4 | Chloris virgata | 0–25 | – | ||
| desert lovegrass | ERPEM | Eragrostis pectinacea var. miserrima | 0–10 | – | ||
| tufted lovegrass | ERPEP2 | Eragrostis pectinacea var. pectinacea | 0–10 | – | ||
| Bigelow's bluegrass | POBI | Poa bigelovii | 0–10 | – | ||
| bearded cupgrass | ERAR5 | Eriochloa aristata | 0–5 | – | ||
| witchgrass | PACA6 | Panicum capillare | 0–5 | – | ||
| canyon cupgrass | ERLE7 | Eriochloa lemmonii | 0–2 | – | ||
| Mexican sprangletop | LEFUU | Leptochloa fusca ssp. uninervia | 0–2 | – | ||
| Madagascar dropseed | SPPY2 | Sporobolus pyramidatus | 0–2 | – | ||
| Arizona signalgrass | URAR | Urochloa arizonica | 0–2 | – | ||
| delicate muhly | MUFR | Muhlenbergia fragilis | 0–2 | – | ||
| littleseed muhly | MUMI | Muhlenbergia microsperma | 0–2 | – | ||
| Arizona brome | BRAR4 | Bromus arizonicus | 0–1 | – | ||
|
Forb
|
||||||
| 6 | Perennial forbs | 2–20 | ||||
| desert globemallow | SPAM2 | Sphaeralcea ambigua | 1–10 | – | ||
| weakleaf bur ragweed | AMCO3 | Ambrosia confertiflora | 1–5 | – | ||
| Coues' cassia | SECO10 | Senna covesii | 0–5 | – | ||
| lacy tansyaster | MAPIP4 | Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida | 1–5 | – | ||
| wishbone-bush | MILAV | Mirabilis laevis var. villosa | 0–2 | – | ||
| evening primrose | OENOT | Oenothera | 0–2 | – | ||
| slender poreleaf | POGR5 | Porophyllum gracile | 0–2 | – | ||
| whitemargin sandmat | CHAL11 | Chamaesyce albomarginata | 0–2 | – | ||
| spreading fleabane | ERDI4 | Erigeron divergens | 0–2 | – | ||
| wild dwarf morning-glory | EVAR | Evolvulus arizonicus | 0–2 | – | ||
| desert lily | HEUN2 | Hesperocallis undulata | 0–2 | – | ||
| slender janusia | JAGR | Janusia gracilis | 0–2 | – | ||
| smooth threadleaf ragwort | SEFLM | Senecio flaccidus var. monoensis | 0–2 | – | ||
| spreading fanpetals | SIAB | Sida abutifolia | 0–2 | – | ||
| New Mexico silverbush | ARNE2 | Argythamnia neomexicana | 0–2 | – | ||
| brownplume wirelettuce | STPA4 | Stephanomeria pauciflora | 0–2 | – | ||
| Coulter's wrinklefruit | TECO | Tetraclea coulteri | 0–1 | – | ||
| catnip noseburn | TRNE | Tragia nepetifolia | 0–1 | – | ||
| Watson's dutchman's pipe | ARWA | Aristolochia watsonii | 0–1 | – | ||
| dense ayenia | AYMI | Ayenia microphylla | 0–1 | – | ||
| desert marigold | BAMU | Baileya multiradiata | 0–1 | – | ||
| climbing wartclub | BOSC | Boerhavia scandens | 0–1 | – | ||
| shrubby purslane | POSU3 | Portulaca suffrutescens | 0–1 | – | ||
| canaigre dock | RUHY | Rumex hymenosepalus | 0–1 | – | ||
| twinleaf senna | SEBA3 | Senna bauhinioides | 0–1 | – | ||
| silverleaf nightshade | SOEL | Solanum elaeagnifolium | 0–1 | – | ||
| field anoda | ANPE4 | Anoda pentaschista | 0–1 | – | ||
| dwarf desertpeony | ACNA2 | Acourtia nana | 0–1 | – | ||
| brownfoot | ACWR5 | Acourtia wrightii | 0–1 | – | ||
| San Felipe dogweed | ADPO | Adenophyllum porophylloides | 0–1 | – | ||
| ragged nettlespurge | JAMA | Jatropha macrorhiza | 0–1 | – | ||
| whitemouth dayflower | COER | Commelina erecta | 0–1 | – | ||
| leatherweed | CRPOP | Croton pottsii var. pottsii | 0–1 | – | ||
| fingerleaf gourd | CUDI | Cucurbita digitata | 0–1 | – | ||
| coyote gourd | CUPA | Cucurbita palmata | 0–1 | – | ||
| Arizona wrightwort | CAAR7 | Carlowrightia arizonica | 0–1 | – | ||
| orange fameflower | PHAU13 | Phemeranthus aurantiacus | 0–1 | – | ||
| 7 | Annual forbs | 1–200 | ||||
| bristly fiddleneck | AMTE3 | Amsinckia tessellata | 0–50 | – | ||
| Coulter's spiderling | BOCO2 | Boerhavia coulteri | 0–50 | – | ||
| California poppy | ESCAM | Eschscholzia californica ssp. mexicana | 0–50 | – | ||
| Coulter's lupine | LUSP2 | Lupinus sparsiflorus | 0–50 | – | ||
| combseed | PECTO | Pectocarya | 1–50 | – | ||
| Arizona phacelia | PHAR13 | Phacelia arizonica | 0–25 | – | ||
| shaggyfruit pepperweed | LELA | Lepidium lasiocarpum | 0–25 | – | ||
| Arizona poppy | KAGR | Kallstroemia grandiflora | 0–25 | – | ||
| thelypody | THELY | Thelypodium | 0–25 | – | ||
| woolly tidestromia | TILA2 | Tidestromia lanuginosa | 0–25 | – | ||
| desert Indianwheat | PLOV | Plantago ovata | 0–20 | – | ||
| miniature woollystar | ERDI2 | Eriastrum diffusum | 0–20 | – | ||
| wheelscale saltbush | ATEL | Atriplex elegans | 0–20 | – | ||
| pitseed goosefoot | CHBE4 | Chenopodium berlandieri | 0–20 | – | ||
| milkvetch | ASTRA | Astragalus | 0–15 | – | ||
| western tansymustard | DEPI | Descurainia pinnata | 0–15 | – | ||
| mesa tansyaster | MATA | Machaeranthera tagetina | 0–15 | – | ||
| tanseyleaf tansyaster | MATA2 | Machaeranthera tanacetifolia | 0–10 | – | ||
| Gordon's bladderpod | LEGO | Lesquerella gordonii | 0–10 | – | ||
| Texas stork's bill | ERTE13 | Erodium texanum | 0–10 | – | ||
| cryptantha | CRYPT | Cryptantha | 0–10 | – | ||
| buckwheat | ERIOG | Eriogonum | 0–10 | – | ||
| carelessweed | AMPA | Amaranthus palmeri | 0–10 | – | ||
| Tucson Mountain spiderling | BOME | Boerhavia megaptera | 0–10 | – | ||
| Esteve's pincushion | CHST | Chaenactis stevioides | 0–5 | – | ||
| American wild carrot | DAPU3 | Daucus pusillus | 0–5 | – | ||
| manybristle chinchweed | PEPA2 | Pectis papposa | 0–5 | – | ||
| Arizona lupine | LUAR4 | Lupinus arizonicus | 0–5 | – | ||
| Arizona popcornflower | PLAR | Plagiobothrys arizonicus | 0–5 | – | ||
| purslane | PORTU | Portulaca | 0–5 | – | ||
| sleepy silene | SIAN2 | Silene antirrhina | 0–5 | – | ||
| Coulter's globemallow | SPCO2 | Sphaeralcea coulteri | 0–5 | – | ||
| New Mexico thistle | CINE | Cirsium neomexicanum | 0–3 | – | ||
| hoary bowlesia | BOIN3 | Bowlesia incana | 0–3 | – | ||
| hyssopleaf sandmat | CHHY3 | Chamaesyce hyssopifolia | 0–2 | – | ||
| sensitive partridge pea | CHNI2 | Chamaecrista nictitans | 0–2 | – | ||
| pricklyburr | DAIN2 | Datura inoxia | 0–2 | – | ||
| common woolly sunflower | ERLA6 | Eriophyllum lanatum | 0–2 | – | ||
| Mexican fireplant | EUHE4 | Euphorbia heterophylla | 0–2 | – | ||
| hairy desertsunflower | GECA2 | Geraea canescens | 0–2 | – | ||
| star gilia | GIST | Gilia stellata | 0–2 | – | ||
| slimjim bean | PHFI3 | Phaseolus filiformis | 0–2 | – | ||
| green carpetweed | MOVE | Mollugo verticillata | 0–2 | – | ||
| Arizona cottonrose | LOAR12 | Logfia arizonica | 0–2 | – | ||
| coastal bird's-foot trefoil | LOSA | Lotus salsuginosus | 0–2 | – | ||
| slender goldenweed | MAGR10 | Machaeranthera gracilis | 0–2 | – | ||
| doubleclaw | PRPA2 | Proboscidea parviflora | 0–2 | – | ||
| sand fringepod | THCU | Thysanocarpus curvipes | 0–2 | – | ||
| New Mexico plumeseed | RANE | Rafinesquia neomexicana | 0–1 | – | ||
| lyreleaf jewelflower | STCAA | Streptanthus carinatus ssp. arizonicus | 0–1 | – | ||
| woolly plantain | PLPA2 | Plantago patagonica | 0–1 | – | ||
| Florida pellitory | PAFL3 | Parietaria floridana | 0–1 | – | ||
| desert trumpet | ERIN4 | Eriogonum inflatum | 0–1 | – | ||
| hairy prairie clover | DAMO | Dalea mollis | 0–1 | – | ||
| Palmer's spectaclepod | DICA31 | Dimorphocarpa candicans | 0–1 | – | ||
| desert thorn-apple | DADI2 | Datura discolor | 0–1 | – | ||
| prostrate sandmat | CHPR6 | Chamaesyce prostrata | 0–1 | – | ||
| milkweed | ASCLE | Asclepias | 0–1 | – | ||
| desert sand verbena | ABVI | Abronia villosa | 0–1 | – | ||
| trailing windmills | ALIN | Allionia incarnata | 0–1 | – | ||
| common fiddleneck | AMMEI2 | Amsinckia menziesii var. intermedia | 0–1 | – | ||
|
Shrub/Vine
|
||||||
| 8 | Dominant half shrubs | 5–95 | ||||
| triangle bur ragweed | AMDE4 | Ambrosia deltoidea | 0–50 | – | ||
| burroweed | ISTE2 | Isocoma tenuisecta | 1–50 | – | ||
| desert zinnia | ZIAC | Zinnia acerosa | 1–30 | – | ||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 0–10 | – | ||
| rough menodora | MESC | Menodora scabra | 0–1 | – | ||
| buckwheat | ERIOG | Eriogonum | 0–1 | – | ||
| 9 | Miscellaneous shrubs | 0–10 | ||||
| Thurber's penstemon | PETH3 | Penstemon thurberi | 0–5 | – | ||
| shortleaf baccharis | BABR | Baccharis brachyphylla | 0–3 | – | ||
| Eastern Mojave buckwheat | ERFA2 | Eriogonum fasciculatum | 0–2 | – | ||
| narrowleaf goldenbush | ERLI6 | Ericameria linearifolia | 0–2 | – | ||
| San Felipe dogweed | ADPO | Adenophyllum porophylloides | 0–2 | – | ||
| burrobush | AMDU2 | Ambrosia dumosa | 0–2 | – | ||
| snakewood | CONDA | Condalia | 0–2 | – | ||
| littleleaf ratany | KRER | Krameria erecta | 0–2 | – | ||
| winterfat | KRLA2 | Krascheninnikovia lanata | 0–2 | – | ||
| Goodding's tansyaster | MAPIG | Machaeranthera pinnatifida ssp. gooddingii | 0–2 | – | ||
| Mexican bladdersage | SAME | Salazaria mexicana | 0–2 | – | ||
| jojoba | SICH | Simmondsia chinensis | 0–2 | – | ||
| turpentinebroom | THMO | Thamnosma montana | 0–2 | – | ||
| American threefold | TRCA8 | Trixis californica | 0–1 | – | ||
| banana yucca | YUBA | Yucca baccata | 0–1 | – | ||
| lacy tansyaster | MAPIP4 | Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida | 0–1 | – | ||
| white ratany | KRGR | Krameria grayi | 0–1 | – | ||
| whitestem paperflower | PSCO2 | Psilostrophe cooperi | 0–1 | – | ||
| rayless goldenhead | ACSP | Acamptopappus sphaerocephalus | 0–1 | – | ||
| bastardsage | ERWR | Eriogonum wrightii | 0–1 | – | ||
| Nevada jointfir | EPNE | Ephedra nevadensis | 0–1 | – | ||
| longleaf jointfir | EPTR | Ephedra trifurca | 0–1 | – | ||
| yerba de pasmo | BAPT | Baccharis pteronioides | 0–1 | – | ||
| Coulter's brickellbush | BRCO | Brickellia coulteri | 0–1 | – | ||
| fairyduster | CAER | Calliandra eriophylla | 0–1 | – | ||
| 10 | Large shrubs | 1–20 | ||||
| fourwing saltbush | ATCA2 | Atriplex canescens | 0–5 | – | ||
| creosote bush | LATRT | Larrea tridentata var. tridentata | 0–5 | – | ||
| ocotillo | FOSP2 | Fouquieria splendens | 0–2 | – | ||
| Berlandier's wolfberry | LYBE | Lycium berlandieri | 0–2 | – | ||
| Arizona desert-thorn | LYEX | Lycium exsertum | 0–2 | – | ||
| cattle saltbush | ATPO | Atriplex polycarpa | 0–2 | – | ||
| spiny hackberry | CEEH | Celtis ehrenbergiana | 0–2 | – | ||
| catclaw acacia | ACGR | Acacia greggii | 0–2 | – | ||
| Warnock's snakewood | COWA | Condalia warnockii | 0–1 | – | ||
| whitethorn acacia | ACCO2 | Acacia constricta | 0–1 | – | ||
| lotebush | ZIOB | Ziziphus obtusifolia | 0–1 | – | ||
| sangre de cristo | JACA2 | Jatropha cardiophylla | 0–1 | – | ||
| water jacket | LYAN | Lycium andersonii | 0–1 | – | ||
| 11 | Succulents | 5–25 | ||||
| saguaro | CAGI10 | Carnegiea gigantea | 1–15 | – | ||
| cactus apple | OPEN3 | Opuntia engelmannii | 1–10 | – | ||
| tulip pricklypear | OPPH | Opuntia phaeacantha | 0–5 | – | ||
| staghorn cholla | CYVE3 | Cylindropuntia versicolor | 0–5 | – | ||
| candy barrelcactus | FEWI | Ferocactus wislizeni | 1–5 | – | ||
| Arizona pencil cholla | CYAR14 | Cylindropuntia arbuscula | 0–2 | – | ||
| jumping cholla | CYFU10 | Cylindropuntia fulgida | 0–2 | – | ||
| purple pricklypear | OPMA8 | Opuntia macrocentra | 0–2 | – | ||
| soaptree yucca | YUEL | Yucca elata | 0–2 | – | ||
| walkingstick cactus | CYSP8 | Cylindropuntia spinosior | 0–2 | – | ||
| Santa Rita pricklypear | OPSA | Opuntia santa-rita | 0–1 | – | ||
| nightblooming cereus | PEGR3 | Peniocereus greggii | 0–1 | – | ||
| Christmas cactus | CYLE8 | Cylindropuntia leptocaulis | 0–1 | – | ||
| Graham's nipple cactus | MAGR9 | Mammillaria grahamii | 0–1 | – | ||
| Engelmann's hedgehog cactus | ECEN | Echinocereus engelmannii | 0–1 | – | ||
| pinkflower hedgehog cactus | ECFA | Echinocereus fasciculatus | 0–1 | – | ||
| spinystar | ESVIV | Escobaria vivipara var. vivipara | 0–1 | – | ||
| long-tubercle beehive cactus | COROR | Coryphantha robustispina ssp. robustispina | 0–1 | – | ||
| buck-horn cholla | CYAC8 | Cylindropuntia acanthocarpa | 0–1 | – | ||
|
Tree
|
||||||
| 14 | Trees | 100–200 | ||||
| yellow paloverde | PAMI5 | Parkinsonia microphylla | 50–150 | – | ||
| velvet mesquite | PRVE | Prosopis velutina | 50–100 | – | ||
| desert ironwood | OLTE | Olneya tesota | 0–50 | – | ||
| blue paloverde | PAFL6 | Parkinsonia florida | 0–15 | – | ||
| Joshua tree | YUBR | Yucca brevifolia | 0–2 | – | ||
Interpretations
Animal community
The plant community on this site is suitable for grazing by all classes of livestock at any season. Forage species grow year-round with available moisture. Due to thick, coarse-textured surfaces, which can absorb intense rainfall, and clayey horizons below, which can slowly release this moisture to plants, this site has a longer green season than other, coarse textured sites. The plant community on this site provides adequate nutrition for livestock throughout the year.
Water developments are very important to wildlife species on this site. Vegetative cover and forage diversity are good enough for a great variety of wildlife including the large mammals.
Hydrological functions
This site has coarse textured soil surfaces and low gradient slopes and is a poor producer of runoff.
Recreational uses
Hunting, horseback riding, hiking, photography, birdwatching, camping
Wood products
Mesquite furnishes limited firewood. In freeze free areas dead ironwood trees furnish wood for hobby uses and firewood.
Other products
Saguaro ribs, cholla skeletons, prickly pear tunas and pads, cholla buds and mesquite beans.
Supporting information
Inventory data references
Range 417s include 2 in good condition.
Type locality
| Location 1: Pima County, AZ | |
|---|---|
| Township/Range/Section | T16S R7E S3 |
| General legal description | Sells Field Office - Tribal Herd Ranch |
| Location 2: Pima County, AZ | |
| Township/Range/Section | T17S R9E S30 |
| General legal description | Palo Alto ranch, NW corner of West pasture |
| Location 3: Pima County, AZ | |
| Township/Range/Section | T15S R9E S1 |
| General legal description | La Tortuga Ranch, Tortuga pasture, Transect location T-6. Ungrazed 18 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, Tom Reis, Emilio Carrillo |
|---|---|
| Contact for lead author | NRCS Tucson Area Office |
| Date | 02/08/2005 |
| Approved by | S. Cassady |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
Infrequent, 40-60 feet apart, not well defined. -
Presence of water flow patterns:
Fairly common, cover approximately 10% of the area; approximately 30-50 feet in length before hitting an obstruction. -
Number and height of erosional pedestals or terracettes:
Most perennial grass and shrub plants have accumulated pedestals 1-2 inches in height, respectively. Terrecettes are 15-20 feet apart along water flow paths with a 2-inch elevation difference from above to below the terracete. Terracettes are not as stable as those observed in 12-16" pz, in that they are breached more often on this site. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
40-45%; some areas have higher cover on gentler slopes and lower cover on steeper slopes. -
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):
Herbaceous litter transported in water flow paths 30-50 feet in length and herbaceous litter moving from bare soil areas. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
No slake test done. Expect ratings of 2-3 in bare areas, and 4-5 under shrub and perennial grass canopies. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Weak angular to subangular blocky; color is 10YR7/3 dry, 10YR5/3 moist; thickness to 13 inches. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
30% canopy cover of large shrubs, succulents, half shrubs and grasses; 50-55% litter cover; approximately 2.5% basal cover; 25% of cover is perennial grasses; 30% of cover is trees and shrubs; cover is well dispersed throughout the site. Note: reference area has a higher cover of mesquite than expected for the site. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
No compaction layer on this site; bare soil areas have thin laminar crust from raindrop impact; penetrometer tests with weight drop distance from top of weight to top of impact ring = 2.24 feet were: average = 3.92 inches, s.d. = 1.19 inches. Tests outside IBP exclosure on SRER were average = 2.17, s.d. = 0.4. -
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:
large shrubs (mesquite #1, desert hackberry #2, blue paloverde #3, and mormon tea) > perennial grasses > succulents > half shrubs = annual forbs & grasses.Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Approximately 50% basal cover of perennial grass species and 50% basal cover of sub shrub species has been lost due to prolonged drought. -
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
175 lbs/ac unfavorable precipitation; 750 lbs/ac normal precipitation; 1340 lbs/ac favorable precipitaton. -
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, Opuntia, burroweed, & snakeweed are increasing not invading. Bufflegrass and Lehmann lovegrass. -
Perennial plant reproductive capability:
Not affected even following several years of drought period for the region. Good age class distribution of plants.
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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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