Natural Resources
Conservation Service
Ecological site R040XA113AZ
Loamy Slopes 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
| R040XA103AZ |
Clayey Slopes 10"-13" p.z. |
|---|---|
| R040XA105AZ |
Shallow Hills 10"-13" p.z. |
| R040XA110AZ |
Limy Slopes 10"-13" p.z. |
| R040XA123AZ |
Volcanic Hills 10"-13" P.Z. |
Similar sites
| R041XC314AZ |
Loamy Slopes 12-16" p.z. |
|---|---|
| R040XB212AZ |
Loamy Slopes 7"-10" p.z. |
Table 1. Dominant plant species
| Tree |
(1) Parkinsonia microphylla |
|---|---|
| Shrub |
(1) Ambrosia deltoidea |
| Herbaceous |
(1) Aristida purpurea |
Physiographic features
This site occurs in the upper elevations of the Sonoran Desert in southern Arizona. Slope aspect is site differentiating at elevations near common resource area boundaries.
Table 2. Representative physiographic features
| Landforms |
(1)
Hill
(2) Ridge |
|---|---|
| Flooding frequency | None |
| Ponding frequency | None |
| Elevation | 2,200 – 3,500 ft |
| Slope | 15 – 45% |
| Aspect | N, E, S |
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 and moderately deep soils which have formed in gravelly loamy alluvium of mixed origin. They are not calcareous but calcareous horizons or bedrock may occur at moderate depths. Soil surfaces are well protected by gravel and cobbles. Plant-soil moisture relationships are good.
Soils mapped on this site include:
SSA-627 Southern Mohave County MU's Bucklebar-15 & Pinaleno-41;
SSA-645 Aguila-Carefree area MU Eba-41;
SSA-666 Northwest Cochise County MU Pinaleno-490;
SSA-668 Tucson-Avra Valley area MU's Rough Broken Land-Rw & Rxd;
SSA-669 Eastern Pima County MU Pinaleno-61;
SSA-703 Tohono O'odham area MU Caracara-17.
Table 4. Representative soil features
| Surface texture |
(1) Gravelly sandy loam (2) Very gravelly sandy loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderate to moderately slow |
| Soil depth | 30 – 60 in |
| Surface fragment cover <=3" | 30 – 75% |
| Surface fragment cover >3" | 1 – 30% |
| Available water capacity (0-40in) |
3.6 – 7 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) |
7 – 7.8 |
| Subsurface fragment volume <=3" (Depth not specified) |
35 – 60% |
| Subsurface fragment volume >3" (Depth not specified) |
10% |
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 Slopes 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 a diverse mixture of desert trees, shrubs, cacti, grasses, and forbs. The aspect is shrubland. With continuous, heavy grazing, perennial grasses and forbs are removed from the plant community and shrubs like brittlebush, triangle bursage, prickly pear, and white thorn acacia can increase to dominate the understories. Trees like littleleaf paloverde and mesquite can increase to dominate the overstory. Trees reach moderate size on this site. A 10-15% tree canopy is important on this site to keep diveristy in the understory plant community.
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 | 13 | 70 | 400 |
| Shrub/Vine | 31 | 220 | 300 |
| Tree | 80 | 150 | 200 |
| Forb | 10 | 60 | 195 |
| Total | 134 | 500 | 1095 |
Table 6. Soil surface cover
| Tree basal cover | 0-1% |
|---|---|
| Shrub/vine/liana basal cover | 1-4% |
| Grass/grasslike basal cover | 0-1% |
| Forb basal cover | 0-1% |
| Non-vascular plants | 0% |
| Biological crusts | 0-5% |
| Litter | 10-75% |
| Surface fragments >0.25" and <=3" | 35-75% |
| Surface fragments >3" | 5-35% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 5-50% |
Table 7. Canopy structure (% cover)
| Height Above Ground (ft) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.5 | – | 0-1% | 0-15% | 0-15% |
| >0.5 <= 1 | – | 2-15% | 1-10% | 1-10% |
| >1 <= 2 | – | 5-15% | 0-5% | 0-5% |
| >2 <= 4.5 | 0-1% | 1-5% | – | – |
| >4.5 <= 13 | 2-15% | – | – | – |
| >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
Native tree, cacti and shrubs with fire
Community 2.1
Native tree, cacti and shrubs with fire
This plant community occurs as a result of a single hot season fire. Paloverde and saguaro can be severely impacted and may take long periods of time (30-50 years) to recover to pre-fire levels. Perennial and annual grasses and forbs dominate the community for some time until shrubs like bursage and brittlebush can recover. 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 3
Exotic perennial grasses with natives
Community 3.1
Exotic perennial grasses with natives
This community occurs where bufflegrass, natal grass or fountain grass invade the native plant community. These species occupy the niches of low shrubs like brittlebush or triangle bursage and woody forbs like janusia and twinberry.
State 4
Exotic perennial grasses and fire
Community 4.1
Exotic perennial grasses and fire
This community occurs where a native plant community that has been invaded by bufflegrass or fountain grass has burned one or more times. Increasing amounts of bufflegrass 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 5
Native plant community with exotic annuals
Community 5.1
Native plant community with exotic annuals
This plant community occurs where the native community has been invaded by red brome and / or schismus. Red brome occupies the niche of the native winter annual forbs and grasses. This exotic annual grass will fluctuate from nearly nothing in a dry winter to dominance of the understory plant community in a El Nino winter.
State 6
Exotic annuals and fire
Community 6.1
Exotic annuals and fire
This plant community occurs where a native plant community which has been invaded by red brome and / or schismus has burned repeatedly. As fires become more frequent the native trees, shrubs and succulents are removed from the plant community and red brome 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.
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 mid-grasses | 10–100 | ||||
| bush muhly | MUPO2 | Muhlenbergia porteri | 5–60 | – | ||
| purple threeawn | ARPU9 | Aristida purpurea | 1–25 | – | ||
| spidergrass | ARTE3 | Aristida ternipes | 1–25 | – | ||
| big galleta | PLRI3 | Pleuraphis rigida | 0–20 | – | ||
| black grama | BOER4 | Bouteloua eriopoda | 0–15 | – | ||
| Arizona cottontop | DICA8 | Digitaria californica | 0–10 | – | ||
| tanglehead | HECO10 | Heteropogon contortus | 1–10 | – | ||
| sideoats grama | BOCU | Bouteloua curtipendula | 0–5 | – | ||
| plains bristlegrass | SEVU2 | Setaria vulpiseta | 0–5 | – | ||
| 2 | Dominant short grasses | 2–80 | ||||
| curly-mesquite | HIBE | Hilaria belangeri | 1–50 | – | ||
| Rothrock's grama | BORO2 | Bouteloua rothrockii | 0–20 | – | ||
| slim tridens | TRMU | Tridens muticus | 1–20 | – | ||
| red grama | BOTR2 | Bouteloua trifida | 0–10 | – | ||
| low woollygrass | DAPU7 | Dasyochloa pulchella | 0–10 | – | ||
| nineawn pappusgrass | ENDE | Enneapogon desvauxii | 0–10 | – | ||
| slender grama | BORE2 | Bouteloua repens | 0–10 | – | ||
| Hall's panicgrass | PAHA | Panicum hallii | 0–10 | – | ||
| 3 | Misc perennial grasses | 0–20 | ||||
| tobosagrass | PLMU3 | Pleuraphis mutica | 0–10 | – | ||
| sand dropseed | SPCR | Sporobolus cryptandrus | 0–5 | – | ||
| desert needlegrass | ACSP12 | Achnatherum speciosum | 0–5 | – | ||
| Parish's threeawn | ARPUP5 | Aristida purpurea var. parishii | 0–5 | – | ||
| spidergrass | ARTEG | Aristida ternipes var. gentilis | 0–5 | – | ||
| cane bluestem | BOBA3 | Bothriochloa barbinodis | 0–5 | – | ||
| fall witchgrass | DICO6 | Digitaria cognata | 0–2 | – | ||
| squirreltail | ELELE | Elymus elymoides ssp. elymoides | 0–2 | – | ||
| 4 | Annual grasses | 1–200 | ||||
| sixweeks threeawn | ARAD | Aristida adscensionis | 0–100 | – | ||
| Mexican panicgrass | PAHI5 | Panicum hirticaule | 0–100 | – | ||
| mucronate sprangeltop | LEPAB | Leptochloa panicea ssp. brachiata | 0–50 | – | ||
| sixweeks fescue | VUOC | Vulpia octoflora | 0–25 | – | ||
| prairie threeawn | AROL | Aristida oligantha | 0–25 | – | ||
| needle grama | BOAR | Bouteloua aristidoides | 0–25 | – | ||
| Arizona signalgrass | URAR | Urochloa arizonica | 0–20 | – | ||
| Pacific fescue | VUMIP | Vulpia microstachys var. pauciflora | 0–10 | – | ||
| sixweeks grama | BOBA2 | Bouteloua barbata | 0–10 | – | ||
| Bigelow's bluegrass | POBI | Poa bigelovii | 0–5 | – | ||
| Madagascar dropseed | SPPY2 | Sporobolus pyramidatus | 0–2 | – | ||
| delicate muhly | MUFR | Muhlenbergia fragilis | 0–2 | – | ||
| littleseed muhly | MUMI | Muhlenbergia microsperma | 0–2 | – | ||
| witchgrass | PACA6 | Panicum capillare | 0–2 | – | ||
| Arizona brome | BRAR4 | Bromus arizonicus | 0–2 | – | ||
| feather fingergrass | CHVI4 | Chloris virgata | 0–2 | – | ||
| bearded cupgrass | ERAR5 | Eriochloa aristata | 0–2 | – | ||
| canyon cupgrass | ERLE7 | Eriochloa lemmonii | 0–2 | – | ||
| desert lovegrass | ERPEM | Eragrostis pectinacea var. miserrima | 0–2 | – | ||
| tufted lovegrass | ERPEP2 | Eragrostis pectinacea var. pectinacea | 0–2 | – | ||
| Mexican sprangletop | LEFUU | Leptochloa fusca ssp. uninervia | 0–2 | – | ||
|
Forb
|
||||||
| 5 | Perennial forbs | 10–45 | ||||
| slender janusia | JAGR | Janusia gracilis | 1–15 | – | ||
| Coues' cassia | SECO10 | Senna covesii | 1–15 | – | ||
| desert globemallow | SPAM2 | Sphaeralcea ambigua | 1–10 | – | ||
| slender poreleaf | POGR5 | Porophyllum gracile | 1–10 | – | ||
| lacy tansyaster | MAPIP4 | Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida | 1–10 | – | ||
| wishbone-bush | MILAV | Mirabilis laevis var. villosa | 1–10 | – | ||
| weakleaf bur ragweed | AMCO3 | Ambrosia confertiflora | 0–5 | – | ||
| tuber anemone | ANTU | Anemone tuberosa | 0–5 | – | ||
| desert marigold | BAMU | Baileya multiradiata | 0–5 | – | ||
| Arizona wrightwort | CAAR7 | Carlowrightia arizonica | 0–5 | – | ||
| red-gland spurge | CHME5 | Chamaesyce melanadenia | 0–5 | – | ||
| brownplume wirelettuce | STPA4 | Stephanomeria pauciflora | 1–5 | – | ||
| hairy five eyes | CHSO | Chamaesaracha sordida | 0–2 | – | ||
| dense ayenia | AYMI | Ayenia microphylla | 0–2 | – | ||
| narrowleaf silverbush | ARLA12 | Argythamnia lanceolata | 0–2 | – | ||
| brownfoot | ACWR5 | Acourtia wrightii | 0–2 | – | ||
| San Felipe dogweed | ADPO | Adenophyllum porophylloides | 0–2 | – | ||
| bluedicks | DICA14 | Dichelostemma capitatum | 0–2 | – | ||
| spreading fleabane | ERDI4 | Erigeron divergens | 0–2 | – | ||
| desert trumpet | ERIN4 | Eriogonum inflatum | 0–2 | – | ||
| Parry's beardtongue | PEPA24 | Penstemon parryi | 0–2 | – | ||
| mesquite mistletoe | PHCA8 | Phoradendron californicum | 0–1 | – | ||
| glandleaf milkwort | POMA7 | Polygala macradenia | 0–1 | – | ||
| caliche globemallow | SPLA | Sphaeralcea laxa | 0–1 | – | ||
| spreading fanpetals | SIAB | Sida abutifolia | 0–1 | – | ||
| silverleaf nightshade | SOEL | Solanum elaeagnifolium | 0–1 | – | ||
| wild dwarf morning-glory | EVAR | Evolvulus arizonicus | 0–1 | – | ||
| desert rosemallow | HICO | Hibiscus coulteri | 0–1 | – | ||
| paleface | HIDE | Hibiscus denudatus | 0–1 | – | ||
| desert tobacco | NIOBO | Nicotiana obtusifolia var. obtusifolia | 0–1 | – | ||
| ragged nettlespurge | JAMA | Jatropha macrorhiza | 0–1 | – | ||
| spearleaf | MAPA9 | Matelea parvifolia | 0–1 | – | ||
| trailing windmills | ALIN | Allionia incarnata | 0–1 | – | ||
| largeflower onion | ALMA4 | Allium macropetalum | 0–1 | – | ||
| Braun's rockcress | ARPE3 | Arabis perstellata | 0–1 | – | ||
| Palmer's Indian mallow | ABPA | Abutilon palmeri | 0–1 | – | ||
| climbing wartclub | BOSC | Boerhavia scandens | 0–1 | – | ||
| leatherweed | CRPOP | Croton pottsii var. pottsii | 0–1 | – | ||
| Parish's larkspur | DEPAP3 | Delphinium parishii ssp. parishii | 0–1 | – | ||
| tall mountain larkspur | DESC | Delphinium scaposum | 0–1 | – | ||
| Coulter's wrinklefruit | TECO | Tetraclea coulteri | 0–1 | – | ||
| 6 | Annual forbs | 0–150 | ||||
| California poppy | ESCAM | Eschscholzia californica ssp. mexicana | 0–80 | – | ||
| Coulter's lupine | LUSP2 | Lupinus sparsiflorus | 0–50 | – | ||
| bristly fiddleneck | AMTE3 | Amsinckia tessellata | 0–25 | – | ||
| western tansymustard | DEPI | Descurainia pinnata | 0–25 | – | ||
| exserted Indian paintbrush | CAEXE | Castilleja exserta ssp. exserta | 0–20 | – | ||
| woolly plantain | PLPA2 | Plantago patagonica | 0–20 | – | ||
| coastal bird's-foot trefoil | LOSA | Lotus salsuginosus | 0–20 | – | ||
| Arizona poppy | KAGR | Kallstroemia grandiflora | 0–15 | – | ||
| distant phacelia | PHDI | Phacelia distans | 0–15 | – | ||
| woolly tidestromia | TILA2 | Tidestromia lanuginosa | 0–15 | – | ||
| smallflowered milkvetch | ASNU4 | Astragalus nuttallianus | 0–15 | – | ||
| Coulter's spiderling | BOCO2 | Boerhavia coulteri | 0–15 | – | ||
| wedgeleaf draba | DRCU | Draba cuneifolia | 0–10 | – | ||
| cryptantha | CRYPT | Cryptantha | 0–10 | – | ||
| lyreleaf jewelflower | STCAA | Streptanthus carinatus ssp. arizonicus | 0–10 | – | ||
| Arizona popcornflower | PLAR | Plagiobothrys arizonicus | 0–10 | – | ||
| slender goldenweed | MAGR10 | Machaeranthera gracilis | 0–10 | – | ||
| mesa tansyaster | MATA | Machaeranthera tagetina | 0–10 | – | ||
| foothill deervetch | LOHU2 | Lotus humistratus | 0–10 | – | ||
| shaggyfruit pepperweed | LELA | Lepidium lasiocarpum | 0–10 | – | ||
| American wild carrot | DAPU3 | Daucus pusillus | 0–5 | – | ||
| Arizona phacelia | PHAR13 | Phacelia arizonica | 0–5 | – | ||
| Louisiana vetch | VILU | Vicia ludoviciana | 0–5 | – | ||
| sleepy silene | SIAN2 | Silene antirrhina | 0–5 | – | ||
| Sonoran sandmat | CHMI7 | Chamaesyce micromera | 0–5 | – | ||
| miniature woollystar | ERDI2 | Eriastrum diffusum | 0–5 | – | ||
| fringed amaranth | AMFI | Amaranthus fimbriatus | 0–5 | – | ||
| carelessweed | AMPA | Amaranthus palmeri | 0–5 | – | ||
| yellow tackstem | CAPA7 | Calycoseris parryi | 0–5 | – | ||
| white tackstem | CAWR | Calycoseris wrightii | 0–5 | – | ||
| fringed redmaids | CACI2 | Calandrinia ciliata | 0–5 | – | ||
| New Mexico thistle | CINE | Cirsium neomexicanum | 0–3 | – | ||
| Esteve's pincushion | CHST | Chaenactis stevioides | 0–2 | – | ||
| pincushion flower | CHFR | Chaenactis fremontii | 0–2 | – | ||
| hyssopleaf sandmat | CHHY3 | Chamaesyce hyssopifolia | 0–2 | – | ||
| California suncup | CACA32 | Camissonia californica | 0–2 | – | ||
| chia | SACO6 | Salvia columbariae | 0–2 | – | ||
| cleftleaf wildheliotrope | PHCR | Phacelia crenulata | 0–2 | – | ||
| whitestem blazingstar | MEAL6 | Mentzelia albicaulis | 0–2 | – | ||
| California goldfields | LACAC2 | Lasthenia californica ssp. californica | 0–2 | – | ||
| limestone bedstraw | GAPR | Galium proliferum | 0–2 | – | ||
| hairy desertsunflower | GECA2 | Geraea canescens | 0–1 | – | ||
| star gilia | GIST | Gilia stellata | 0–1 | – | ||
| California mustard | GULA4 | Guillenia lasiophylla | 0–1 | – | ||
| Palmer's grapplinghook | HAPA7 | Harpagonella palmeri | 0–1 | – | ||
| flatspine stickseed | LAOCO | Lappula occidentalis var. occidentalis | 0–1 | – | ||
| Gordon's bladderpod | LEGO | Lesquerella gordonii | 0–1 | – | ||
| Arizona lupine | LUAR4 | Lupinus arizonicus | 0–1 | – | ||
| Arizona cottonrose | LOAR12 | Logfia arizonica | 0–1 | – | ||
| Mexican fireplant | EUHE4 | Euphorbia heterophylla | 0–1 | – | ||
| Lindley's silverpuffs | MILI5 | Microseris lindleyi | 0–1 | – | ||
| Nuttall's povertyweed | MONU | Monolepis nuttalliana | 0–1 | – | ||
| green carpetweed | MOVE | Mollugo verticillata | 0–1 | – | ||
| desert evening primrose | OEPR | Oenothera primiveris | 0–1 | – | ||
| Florida pellitory | PAFL3 | Parietaria floridana | 0–1 | – | ||
| manybristle chinchweed | PEPA2 | Pectis papposa | 0–1 | – | ||
| California desertdandelion | MACA6 | Malacothrix californica | 0–1 | – | ||
| doubleclaw | PRPA2 | Proboscidea parviflora | 0–1 | – | ||
| New Mexico plumeseed | RANE | Rafinesquia neomexicana | 0–1 | – | ||
| Lemmon's ragwort | SELE8 | Senecio lemmonii | 0–1 | – | ||
| Coulter's globemallow | SPCO2 | Sphaeralcea coulteri | 0–1 | – | ||
| woollyhead neststraw | STMI2 | Stylocline micropoides | 0–1 | – | ||
| sand fringepod | THCU | Thysanocarpus curvipes | 0–1 | – | ||
| white easterbonnets | ANLA7 | Antheropeas lanosum | 0–1 | – | ||
| Chiricahua Mountain sandmat | CHFL3 | Chamaesyce florida | 0–1 | – | ||
| hoary bowlesia | BOIN3 | Bowlesia incana | 0–1 | – | ||
| Tucson Mountain spiderling | BOME | Boerhavia megaptera | 0–1 | – | ||
| sand pygmyweed | CRCOC | Crassula connata var. connata | 0–1 | – | ||
| pricklyburr | DAIN2 | Datura inoxia | 0–1 | – | ||
| buckwheat | ERIOG | Eriogonum | 0–1 | – | ||
| sorrel buckwheat | ERPO4 | Eriogonum polycladon | 0–1 | – | ||
| Texas stork's bill | ERTE13 | Erodium texanum | 0–1 | – | ||
| Thurber's buckwheat | ERTH3 | Eriogonum thurberi | 0–1 | – | ||
| Abert's buckwheat | ERAB2 | Eriogonum abertianum | 0–1 | – | ||
| Palmer's spectaclepod | DICA31 | Dimorphocarpa candicans | 0–1 | – | ||
|
Shrub/Vine
|
||||||
| 7 | Dominant half shrubs | 10–100 | ||||
| triangle bur ragweed | AMDE4 | Ambrosia deltoidea | 5–25 | – | ||
| brittlebush | ENFA | Encelia farinosa | 1–20 | – | ||
| Eastern Mojave buckwheat | ERFA2 | Eriogonum fasciculatum | 0–10 | – | ||
| bastardsage | ERWR | Eriogonum wrightii | 0–10 | – | ||
| littleleaf ratany | KRER | Krameria erecta | 2–10 | – | ||
| fairyduster | CAER | Calliandra eriophylla | 1–10 | – | ||
| rough menodora | MESC | Menodora scabra | 0–5 | – | ||
| American threefold | TRCA8 | Trixis californica | 0–5 | – | ||
| desert zinnia | ZIAC | Zinnia acerosa | 0–5 | – | ||
| Coulter's brickellbush | BRCO | Brickellia coulteri | 0–5 | – | ||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 0–2 | – | ||
| 8 | Dominant large shrubs | 10–100 | ||||
| jojoba | SICH | Simmondsia chinensis | 1–30 | – | ||
| whitethorn acacia | ACCO2 | Acacia constricta | 0–20 | – | ||
| ocotillo | FOSP2 | Fouquieria splendens | 1–15 | – | ||
| sangre de cristo | JACA2 | Jatropha cardiophylla | 0–10 | – | ||
| Berlandier's wolfberry | LYBE | Lycium berlandieri | 1–10 | – | ||
| 9 | Misc shrubs | 1–20 | ||||
| pelotazo | ABIN | Abutilon incanum | 0–5 | – | ||
| fourwing saltbush | ATCA2 | Atriplex canescens | 0–5 | – | ||
| Warnock's snakewood | COWA | Condalia warnockii | 0–5 | – | ||
| button brittlebush | ENFR | Encelia frutescens | 0–5 | – | ||
| Wright's beebrush | ALWR | Aloysia wrightii | 0–4 | – | ||
| water jacket | LYAN | Lycium andersonii | 0–3 | – | ||
| Arizona desert-thorn | LYEX | Lycium exsertum | 0–3 | – | ||
| Arizona mimosa | MIDIL | Mimosa distachya var. laxiflora | 0–3 | – | ||
| Parish's goldeneye | VIPA14 | Viguiera parishii | 0–2 | – | ||
| banana yucca | YUBA | Yucca baccata | 0–2 | – | ||
| lotebush | ZIOB | Ziziphus obtusifolia | 0–2 | – | ||
| prairie acacia | ACANH | Acacia angustissima var. hirta | 0–2 | – | ||
| rayless goldenhead | ACSP | Acamptopappus sphaerocephalus | 0–2 | – | ||
| Nevada jointfir | EPNE | Ephedra nevadensis | 0–1 | – | ||
| longleaf jointfir | EPTR | Ephedra trifurca | 0–1 | – | ||
| turpentine bush | ERLA12 | Ericameria laricifolia | 0–1 | – | ||
| burroweed | ISTE2 | Isocoma tenuisecta | 0–1 | – | ||
| whitestem paperflower | PSCO2 | Psilostrophe cooperi | 0–1 | – | ||
| 10 | Succulents | 10–75 | ||||
| saguaro | CAGI10 | Carnegiea gigantea | 5–25 | – | ||
| cactus apple | OPEN3 | Opuntia engelmannii | 2–20 | – | ||
| tulip pricklypear | OPPH | Opuntia phaeacantha | 1–10 | – | ||
| purple pricklypear | OPMA8 | Opuntia macrocentra | 0–5 | – | ||
| jumping cholla | CYFU10 | Cylindropuntia fulgida | 0–5 | – | ||
| buck-horn cholla | CYAC8 | Cylindropuntia acanthocarpa | 1–5 | – | ||
| walkingstick cactus | CYSP8 | Cylindropuntia spinosior | 0–5 | – | ||
| staghorn cholla | CYVE3 | Cylindropuntia versicolor | 1–5 | – | ||
| teddybear cholla | CYBI9 | Cylindropuntia bigelovii | 0–2 | – | ||
| candy barrelcactus | FEWI | Ferocactus wislizeni | 0–2 | – | ||
| Graham's nipple cactus | MAGR9 | Mammillaria grahamii | 0–2 | – | ||
| Thornber's nipple cactus | MATH | Mammillaria thornberi | 0–1 | – | ||
| Christmas cactus | CYLE8 | Cylindropuntia leptocaulis | 0–1 | – | ||
| organpipe cactus | STTH3 | Stenocereus thurberi | 0–1 | – | ||
| Engelmann's hedgehog cactus | ECEN | Echinocereus engelmannii | 0–1 | – | ||
| redspine fishhook cactus | ECER2 | Echinomastus erectocentrus | 0–1 | – | ||
| pinkflower hedgehog cactus | ECFA | Echinocereus fasciculatus | 0–1 | – | ||
| rainbow cactus | ECPE | Echinocereus pectinatus | 0–1 | – | ||
| spinystar | ESVIV | Escobaria vivipara var. vivipara | 0–1 | – | ||
| desert agave | AGDE | Agave deserti | 0–1 | – | ||
|
Tree
|
||||||
| 11 | Trees | 80–200 | ||||
| yellow paloverde | PAMI5 | Parkinsonia microphylla | 80–160 | – | ||
| desert ironwood | OLTE | Olneya tesota | 0–60 | – | ||
| velvet mesquite | PRVE | Prosopis velutina | 0–20 | – | ||
| catclaw acacia | ACGR | Acacia greggii | 0–10 | – | ||
Interpretations
Animal community
Steep slopes and gravelly surfaces limit grazing distribution especially in the hotter months of the year. Stocker cattle will use areas of this site fairly well at any season. Forage species grow year round with available moisture. The potential plant community provides adequate nutrition for livestock throughout the year at low stocking rates.
Water developments are very important to wildlife species on this site. Vegetative cover, topography, and forage diversity are good enough for a great variety of wildlife including the larger desert mammals.
Hydrological functions
This site is a fair to good producer of runoff due to steep slopes and soils with argillic horizons near the surface. Very gravelly and cobbly soil surfaces tend to hold water on the site.
Recreational uses
Hunting, hiking, birdwatching, photography, horseback riding, rock hounding.
Wood products
Some paloverde, ironwood and mesquite for camp-fires and branding fires.
Other products
Stones and cobbles, saguaro ribs, cholla skeletons. Tradtional foods like saguaro fruits, prickly pear tunas, cactus flower buds and jojoba nuts. Traditional herbs like coyote tobacco, mint bush, globe mallow and limberbush.
Supporting information
Type locality
| Location 1: Pima County, AZ | |
|---|---|
| Township/Range/Section | T9S R18E S26 |
| General legal description | Tucson FO - YLE Ranch |
| Location 2: Pima County, AZ | |
| Township/Range/Section | T20S R6E S29 |
| General legal description | Sells FO - Chutum Vaya Assoc. unsurveyed - along San Juan Trail in Mtn. Pass |
| Location 3: Pima County, AZ | |
| General legal description | Catalina, Az. Waste Transfer Station, fenced in 1974. |
| Location 4: Pima County, AZ | |
| General legal description | Catalina State Park, Ridges along Sutherland and Canyon del Oro washes. |
Contributors
Dan Robinett
Larry D. Ellicott
Wilma Renken
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:
None -
Presence of water flow patterns:
Uncommon, probably cover no more than 10% of area; discontinuous; 10-15 feet in length. -
Number and height of erosional pedestals or terracettes:
Pedestals are uncomon on perennial grass and shrubs; terracettes are uncommon. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
15-20% -
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):
Most litter size classes stay in place. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Expect values of 1-3 in canopy interspaces, 4-6 under plant canopies. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Weak thin platy to weak granuar; color is 7.5-10YR4/4 dry, 7.5-10YR3/2 moist; thickness to 1 inch. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Canopy cover 15-25%; 20-30% perennial grasses, 5% perennial forbs,40-50% trees and 10-20% shrubs and subshrubs. Cover is well dispersed throughout site. -
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:
trees > shrubs > annual grasses and forbs > succulents = perennial forbs = perennial grasses (Note: this is following several years of prolonged regional drought.)Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
90-100% perennial grass plants have likely been lost in recent prolonged drought; 20-50% canopy mortality of shrubs and trees. -
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
134 lbs/ac unfavorable precipitation; 500 lbs/ac normal precipitation; 1095 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:
triangle bursage, prickly pear, white thorn acacia, bufflegrass -
Perennial plant reproductive capability:
Not impaired for shrubs; drought impaire for perennial grasses and forbs.
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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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