Natural Resources
Conservation Service
Ecological site R040XB216AZ
Sandy Wash 7"-10" 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 40.2 – Middle Sonoran Desert
Elevations range from 1200 to 2000 feet and precipitation averages 7 to 10 inches per year. Vegetation includes saguaro, palo verde, creosotebush, triangle bursage, brittlebush, prickly pear, cholla, desert saltbush, wolfberry bush muhly, threeawns, and big galleta. The soil temperature regime is hyperthermic 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.
Table 1. Dominant plant species
| Tree |
(1) Parkinsonia florida |
|---|---|
| Shrub |
(1) Baccharis sarothroides |
| Herbaceous |
(1) Digitaria californica |
Physiographic features
This site occurs on floodplains and alluvial fans. It benefits on a rgualr basis fro extra moisture received as overbank flooding and/or runoff from adjacent upland sites. Slopes are from 0% to 3%. Elevations range from 900 to 2000 feet.
Table 2. Representative physiographic features
| Landforms |
(1)
Alluvial fan
(2) Flood plain |
|---|---|
| Elevation | 900 – 2,000 ft |
| Slope | 3% |
Climatic features
Precipitation in the sub-resource area ranges from 7 to 10 inches. Elevations range from 900 to 2050 feet. Winter-summer rainfall ratios range from 40% to 60% in the southern part along the international boundary, to 60% to 40% in the central and northern parts of the sub-resource area. As one moves from east to west in this resource area rains become more unpredictable and variable with Coefficients of Variation of annual rainfall equal to 38% at Florence and 46% at Aguila. Summer rains fall July- September, originate in the Gulf of Mexico, and are convective, usually brief, intense thunderstorms. Summer precipitation is extremely erratic and undependable in this area. Cool season moisture tends to be frontal, originates in the Pacific and Gulf of California, and falls in widespread storms with long duration and low intensity. This is the dependable moisture supply for vegetation in the area. Snow is very rare and usually melts on contact. May-June is the driest time of the year. Humidity is very low.
Winter temperatures are very mild with very few days recording freezing for short periods of time. Summertime temperatures are hot to very hot with many days in June-July exceeding 105 degrees F. Frost-free days range from 280 at stations in major river valleys with cold air drainage to 320 to 350 days at upland stations.
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) | 350 days |
|---|---|
| Freeze-free period (average) | 0 days |
| Precipitation total (average) | 10 in |
Figure 2. Monthly precipitation range
Figure 3. Monthly average minimum and maximum temperature
Influencing water features
Soil features
These are very young soils on gravelly and sandy alluvium of mixed origin. Textures range from sandyloam to very cobbly sands. Subsurface texture group includes coarse loamy also. They are deep and excessively well drained. Although coarse textures make for low water holding capacities, plant-soil moisture relationships are very good due to the extra moisture the soils receive. They may or may not be calcareous. This site is mapped on 7 Soil Survey areas in Southwestern Arizona CRA D40-2.
Soils mapped on this site include: SSA-627 Southern Mohave county MU Brazito family-14; SSA-645 Aguila-Carefree area MU's Carrizo-3 & 10, & Brios-10; SSA-651 Central Maricopa county MU's Brios-Ae, Br, Bs, Bt & CF, Carrizo-AfA, AfB, AGB, Cb, CeD, CF & Vr, Maripo-Ma, Torrifluvents-TB & TD, Torrisamments-TD, & Vint-Va, Vh, Vlc, Vn & Vr; SSA-653 Gila Bend-Ajo area MU's Carrizo-5, 6, 37 & 53, Carrizo XGrSL-49, & Why-21 & 22; SSA-658 Gila River Indian Reservation MU's Brios-1, 2 & 36, Carrizo-5 & 9, Why-36; SSA-659 Western Pinal county MU's Antho-2, Carrizo-34, Valencia-48 & Why-49; SSA-661 Eastern Pinal-Southern Gila counties MU's Brios-290, Carrizo-207, 216 & 290, & Vint-280.
Table 4. Representative soil features
| Surface texture |
(1) Gravelly loam (2) Very gravelly loamy sand (3) Sandy loam |
|---|---|
| Family particle size |
(1) Sandy |
| Drainage class | Well drained to excessively drained |
| Permeability class | Moderately rapid to very rapid |
| Soil depth | 60 in |
| Surface fragment cover <=3" | 5 – 45% |
| Surface fragment cover >3" | Not specified |
| Available water capacity (0-40in) |
2.4 – 7.2 in |
| Calcium carbonate equivalent (0-40in) |
1 – 10% |
| Electrical conductivity (0-40in) |
Not specified |
| Sodium adsorption ratio (0-40in) |
Not specified |
| Soil reaction (1:1 water) (0-40in) |
7.4 – 8.4 |
| Subsurface fragment volume <=3" (Depth not specified) |
5 – 45% |
| Subsurface fragment volume >3" (Depth not specified) |
Not specified |
Ecological dynamics
The plant communities found on an ecological site are naturally variable. Composition and production will vary with yearly conditions, location, aspect, and the natural variability of the soils. The Historical Climax Plant Community represents the natural potential plant communities found on relict or relatively undisturbed sites. Other plant communities described here represent plant communities that are known to occur when the site is disturbed by factors such as fire, grazing, or drought.
Production data provided in this site description is standardized to air dry weight at the end of the summer growing season. The plant communities described in this site description are based on near normal rainfall years.
NRCS uses a Similarity Index to compare existing plant communities to the plant communities described here. Similarity Index is determined by comparing the production and composition of a plant community to the production and composition of a plant community described in this site description. To determine Similarity Index, compare the production (air dry weight) of each species to that shown in the plant community description. For each species, count no more than the maximum amount shown for the species, and for each group, count no more than the maximum amount shown for the group. Divide the resulting total by the total normal year production shown in the plant community description. If the rainfall has been significantly above or below normal, use the total production shown for above or below normal years. If field data is not collected at the end of the summer growing season, then the field data must be corrected to the end of the year production before comparing it to the site description. The growth curve can be used as a guide for estimating production at the end of the summer growing season.
State and transition model
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
Ecosystem states
State 1 submodel, plant communities
State 1
Historical Climax Plant Community
Community 1.1
Historical Climax Plant Community
The potential plant community is a diverse mixture of desert trees, shrubs, vines and perennial and annual grasses and forbs. Major species are well dispersed throughout the community with the exception of big bursage and burrobush which are confined to the channel areas. The aspect is shrubland to woodland. With poorly managed grazing, perennial grasses, palatable forbs and shrubs like; slender janusia, yerbe-de-venado, trixis, bricklebush and globemallow disappear from the plant community. When the herbaceous and low shub cover has been depleted, erosion can begin and sandy channels entrench and rapidly remove waters from the site reducing the effectiveness of flooding. With heavy grazing, tree species can increase on the site. Trees reach full sizes due to good water relations and deep sandy soils. Tree canopies range from 10 to 15 percent on the site. Total canopy including tall shrubs like creosotebush, whitethorn, desert hackberry and wolfberry ranges from 25% to 40%. Tree canopies on the largest washes approach woodland densities but when cover is averaged over the entire area of the site it is less than 15%. Plant populations of major species range from 40 to 150 trees per acre for the group of mesquite, littleleaf paloverde, ironwood and blue paloverde, 5 to 30 saguaros per acre, 100 to 300 creosotebush per acre, 20 to 60 whitethorn plants per acre, 10 to 30 desert hackberry per acre, and 20 to 50 wolfberry per acre. There is a relationship between the production, plant density, cover and the watershed size of this bottom site.
Figure 4. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
| Plant type | Low (lb/acre) |
Representative value (lb/acre) |
High (lb/acre) |
|---|---|---|---|
| Shrub/Vine | 525 | – | 900 |
| Tree | 525 | – | 900 |
| Grass/Grasslike | 375 | – | 600 |
| Forb | 225 | – | 375 |
| Total | 1650 | – | 2775 |
Additional community tables
Table 6. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | 49–73 | |||||
| bush muhly | MUPO2 | Muhlenbergia porteri | 49–73 | – | ||
| big galleta | PLRI3 | Pleuraphis rigida | 49–73 | – | ||
| 2 | 49–73 | |||||
| purple threeawn | ARPU9 | Aristida purpurea | 49–73 | – | ||
| blue threeawn | ARPUN | Aristida purpurea var. nealleyi | 49–73 | – | ||
| Parish's threeawn | ARPUP5 | Aristida purpurea var. parishii | 49–73 | – | ||
| spidergrass | ARTE3 | Aristida ternipes | 49–73 | – | ||
| spidergrass | ARTEG | Aristida ternipes var. gentilis | 49–73 | – | ||
| 3 | 24–49 | |||||
| sixweeks threeawn | ARAD | Aristida adscensionis | 24–49 | – | ||
| prairie threeawn | AROL | Aristida oligantha | 24–49 | – | ||
| needle grama | BOAR | Bouteloua aristidoides | 24–49 | – | ||
| sixweeks grama | BOBA2 | Bouteloua barbata | 24–49 | – | ||
| Rothrock's grama | BORO2 | Bouteloua rothrockii | 24–49 | – | ||
| Arizona brome | BRAR4 | Bromus arizonicus | 24–49 | – | ||
| feather fingergrass | CHVI4 | Chloris virgata | 24–49 | – | ||
| bearded cupgrass | ERAR5 | Eriochloa aristata | 24–49 | – | ||
| canyon cupgrass | ERLE7 | Eriochloa lemmonii | 24–49 | – | ||
| desert lovegrass | ERPEM | Eragrostis pectinacea var. miserrima | 24–49 | – | ||
| tufted lovegrass | ERPEP2 | Eragrostis pectinacea var. pectinacea | 24–49 | – | ||
| Mexican sprangletop | LEFUU | Leptochloa fusca ssp. uninervia | 24–49 | – | ||
| mucronate sprangletop | LEPA6 | Leptochloa panicea | 24–49 | – | ||
| delicate muhly | MUFR | Muhlenbergia fragilis | 24–49 | – | ||
| littleseed muhly | MUMI | Muhlenbergia microsperma | 24–49 | – | ||
| Bigelow's bluegrass | POBI | Poa bigelovii | 24–49 | – | ||
| Arizona signalgrass | URAR | Urochloa arizonica | 24–49 | – | ||
| sixweeks fescue | VUOC | Vulpia octoflora | 24–49 | – | ||
| 4 | 5–24 | |||||
| low woollygrass | DAPU7 | Dasyochloa pulchella | 5–24 | – | ||
| Arizona cottontop | DICA8 | Digitaria californica | 5–24 | – | ||
| tanglehead | HECO10 | Heteropogon contortus | 5–24 | – | ||
| plains bristlegrass | SEVU2 | Setaria vulpiseta | 5–24 | – | ||
| spike dropseed | SPCO4 | Sporobolus contractus | 5–24 | – | ||
| sand dropseed | SPCR | Sporobolus cryptandrus | 5–24 | – | ||
| mesa dropseed | SPFL2 | Sporobolus flexuosus | 5–24 | – | ||
| slim tridens | TRMU | Tridens muticus | 5–24 | – | ||
| 5 | 5–24 | |||||
| bigseed alfalfa dodder | CUIN | Cuscuta indecora | 5–24 | – | ||
| mesquite mistletoe | PHCA8 | Phoradendron californicum | 5–24 | – | ||
| 6 | 5–24 | |||||
| Alga | 2ALGA | Alga | 5–24 | – | ||
| Fungus | 2FUNGI | Fungus | 5–24 | – | ||
| Lichen | 2LICHN | Lichen | 5–24 | – | ||
| Moss | 2MOSS | Moss | 5–24 | – | ||
|
Forb
|
||||||
| 7 | 0–30 | |||||
| brownfoot | ACWR5 | Acourtia wrightii | 0–30 | – | ||
| trailing windmills | ALIN | Allionia incarnata | 0–30 | – | ||
| narrowleaf silverbush | ARLA12 | Argythamnia lanceolata | 0–30 | – | ||
| desert marigold | BAMU | Baileya multiradiata | 0–30 | – | ||
| climbing wartclub | BOSC | Boerhavia scandens | 0–30 | – | ||
| whitemargin sandmat | CHAL11 | Chamaesyce albomarginata | 0–30 | – | ||
| desert trumpet | ERIN4 | Eriogonum inflatum | 0–30 | – | ||
| Coulter's lyrepod | LYCO4 | Lyrocarpa coulteri | 0–30 | – | ||
| Parry's false prairie-clover | MAPA7 | Marina parryi | 0–30 | – | ||
| lacy tansyaster | MAPIP4 | Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida | 0–30 | – | ||
| desert tobacco | NIOB | Nicotiana obtusifolia | 0–30 | – | ||
| desert evening primrose | OEPR | Oenothera primiveris | 0–30 | – | ||
| Parry's beardtongue | PEPA24 | Penstemon parryi | 0–30 | – | ||
| slender poreleaf | POGR5 | Porophyllum gracile | 0–30 | – | ||
| desert globemallow | SPAM2 | Sphaeralcea ambigua | 0–30 | – | ||
| brownplume wirelettuce | STPA4 | Stephanomeria pauciflora | 0–30 | – | ||
| 8 | 75–225 | |||||
| weakleaf bur ragweed | AMCO3 | Ambrosia confertiflora | 0–1 | – | ||
| fringed amaranth | AMFI | Amaranthus fimbriatus | 0–1 | – | ||
| common fiddleneck | AMMEI2 | Amsinckia menziesii var. intermedia | 0–1 | – | ||
| carelessweed | AMPA | Amaranthus palmeri | 0–1 | – | ||
| bristly fiddleneck | AMTE3 | Amsinckia tessellata | 0–1 | – | ||
| smallflowered milkvetch | ASNU4 | Astragalus nuttallianus | 0–1 | – | ||
| scarlet spiderling | BOCO | Boerhavia coccinea | 0–1 | – | ||
| Coulter's spiderling | BOCO2 | Boerhavia coulteri | 0–1 | – | ||
| hoary bowlesia | BOIN3 | Bowlesia incana | 0–1 | – | ||
| exserted Indian paintbrush | CAEXE | Castilleja exserta ssp. exserta | 0–1 | – | ||
| yellow tackstem | CAPA7 | Calycoseris parryi | 0–1 | – | ||
| white tackstem | CAWR | Calycoseris wrightii | 0–1 | – | ||
| brittle spineflower | CHBR | Chorizanthe brevicornu | 0–1 | – | ||
| aridland goosefoot | CHDE | Chenopodium desiccatum | 0–1 | – | ||
| devil's spineflower | CHRI | Chorizanthe rigida | 0–1 | – | ||
| New Mexico thistle | CINE | Cirsium neomexicanum | 0–1 | – | ||
| sand pygmyweed | CRCOC | Crassula connata var. connata | 0–1 | – | ||
| cryptantha | CRYPT | Cryptantha | 0–1 | – | ||
| fingerleaf gourd | CUDI | Cucurbita digitata | 0–1 | – | ||
| desert thorn-apple | DADI2 | Datura discolor | 0–1 | – | ||
| pricklyburr | DAIN2 | Datura inoxia | 0–1 | – | ||
| hairy prairie clover | DAMO | Dalea mollis | 0–1 | – | ||
| American wild carrot | DAPU3 | Daucus pusillus | 0–1 | – | ||
| western tansymustard | DEPI | Descurainia pinnata | 0–1 | – | ||
| touristplant | DIWI2 | Dimorphocarpa wislizeni | 0–1 | – | ||
| whisperingbells | EMPE | Emmenanthe penduliflora | 0–1 | – | ||
| flatcrown buckwheat | ERDE6 | Eriogonum deflexum | 0–1 | – | ||
| miniature woollystar | ERDI2 | Eriastrum diffusum | 0–1 | – | ||
| erigenia | ERIGE | Erigenia | 0–1 | – | ||
| woolly sunflower | ERIOP2 | Eriophyllum | 0–1 | – | ||
| Texas stork's bill | ERTE13 | Erodium texanum | 0–1 | – | ||
| California poppy | ESCAM | Eschscholzia californica ssp. mexicana | 0–1 | – | ||
| pygmy poppy | ESMI | Eschscholzia minutiflora | 0–1 | – | ||
| hideseed | EUCRY | Eucrypta | 0–1 | – | ||
| spurge | EUPHO | Euphorbia | 0–1 | – | ||
| fringed twinevine | FUCY | Funastrum cynanchoides | 0–1 | – | ||
| hairy desertsunflower | GECA2 | Geraea canescens | 0–1 | – | ||
| gilia | GILIA | Gilia | 0–1 | – | ||
| Arizona poppy | KAGR | Kallstroemia grandiflora | 0–1 | – | ||
| Gordon's bladderpod | LEGO | Lesquerella gordonii | 0–1 | – | ||
| shaggyfruit pepperweed | LELA | Lepidium lasiocarpum | 0–1 | – | ||
| flax | LINUM | Linum | 0–1 | – | ||
| coastal bird's-foot trefoil | LOSAB | Lotus salsuginosus var. brevivexillus | 0–1 | – | ||
| Arizona lupine | LUAR4 | Lupinus arizonicus | 0–1 | – | ||
| Coulter's lupine | LUSP2 | Lupinus sparsiflorus | 0–1 | – | ||
| Gila manroot | MAGI | Marah gilensis | 0–1 | – | ||
| blazingstar | MENTZ | Mentzelia | 0–1 | – | ||
| bristly nama | NAHI | Nama hispidum | 0–1 | – | ||
| glandular threadplant | NEGL | Nemacladus glanduliferus | 0–1 | – | ||
| lineleaf whitepuff | OLLI | Oligomeris linifolia | 0–1 | – | ||
| Florida pellitory | PAFL3 | Parietaria floridana | 0–1 | – | ||
| combseed | PECTO | Pectocarya | 0–1 | – | ||
| manybristle chinchweed | PEPA2 | Pectis papposa | 0–1 | – | ||
| phacelia | PHACE | Phacelia | 0–1 | – | ||
| desert Indianwheat | PLOV | Plantago ovata | 0–1 | – | ||
| doubleclaw | PRPA2 | Proboscidea parviflora | 0–1 | – | ||
| New Mexico plumeseed | RANE | Rafinesquia neomexicana | 0–1 | – | ||
| chia | SACO6 | Salvia columbariae | 0–1 | – | ||
| sleepy silene | SIAN2 | Silene antirrhina | 0–1 | – | ||
| Coulter's globemallow | SPCO2 | Sphaeralcea coulteri | 0–1 | – | ||
| woollyhead neststraw | STMI2 | Stylocline micropoides | 0–1 | – | ||
| woolly tidestromia | TILA2 | Tidestromia lanuginosa | 0–1 | – | ||
| catnip noseburn | TRNE | Tragia nepetifolia | 0–1 | – | ||
|
Tree
|
||||||
| 9 | 71–143 | |||||
| desert ironwood | OLTE | Olneya tesota | 71–143 | – | ||
| blue paloverde | PAFL6 | Parkinsonia florida | 71–143 | – | ||
| yellow paloverde | PAMI5 | Parkinsonia microphylla | 71–143 | – | ||
| 10 | 36–71 | |||||
| catclaw acacia | ACGR | Acacia greggii | 36–71 | – | ||
| velvet mesquite | PRVE | Prosopis velutina | 36–71 | – | ||
| Fremont cottonwood | POFR2 | Populus fremontii | 0–5 | – | ||
|
Shrub/Vine
|
||||||
| 11 | 71–107 | |||||
| whitethorn acacia | ACCO2 | Acacia constricta | 71–107 | – | ||
| Palmer's cock's comb | CEPA5 | Celosia palmeri | 71–107 | – | ||
| Drummond's clematis | CLDR | Clematis drummondii | 71–107 | – | ||
| ropevine clematis | CLPA2 | Clematis pauciflora | 71–107 | – | ||
| longleaf jointfir | EPTR | Ephedra trifurca | 71–107 | – | ||
| fringed twinevine | FUCY | Funastrum cynanchoides | 71–107 | – | ||
| creosote bush | LATR2 | Larrea tridentata | 71–107 | – | ||
| water jacket | LYAN | Lycium andersonii | 71–107 | – | ||
| Arizona desert-thorn | LYEX | Lycium exsertum | 71–107 | – | ||
| desert wolfberry | LYMA | Lycium macrodon | 71–107 | – | ||
| soaptree yucca | YUEL | Yucca elata | 71–107 | – | ||
| 12 | 7–14 | |||||
| triangle bur ragweed | AMDE4 | Ambrosia deltoidea | 7–14 | – | ||
| holywood | GUSA | Guaiacum sanctum | 7–14 | – | ||
| alkali goldenbush | ISACA2 | Isocoma acradenia var. acradenia | 7–14 | – | ||
| burroweed | ISTE2 | Isocoma tenuisecta | 7–14 | – | ||
| 13 | 36–71 | |||||
| candy barrelcactus | FEWI | Ferocactus wislizeni | 36–71 | – | ||
| senita cactus | PASC14 | Pachycereus schottii | 36–71 | – | ||
| nightblooming cereus | PEGR3 | Peniocereus greggii | 36–71 | – | ||
| organpipe cactus | STTH3 | Stenocereus thurberi | 36–71 | – | ||
| 14 | 7–36 | |||||
| rayless goldenhead | ACSP | Acamptopappus sphaerocephalus | 7–36 | – | ||
| poreleaf dogweed | ADPO2 | Adenophyllum porophyllum | 7–36 | – | ||
| ambrosia leaf bur ragweed | AMAM2 | Ambrosia ambrosioides | 7–36 | – | ||
| Tucson bur ragweed | AMCO4 | Ambrosia cordifolia | 7–36 | – | ||
| burrobush | AMDU2 | Ambrosia dumosa | 7–36 | – | ||
| woolly fruit bur ragweed | AMER | Ambrosia eriocentra | 7–36 | – | ||
| horsetail milkweed | ASSU2 | Asclepias subverticillata | 7–36 | – | ||
| fourwing saltbush | ATCA2 | Atriplex canescens | 7–36 | – | ||
| cattle saltbush | ATPO | Atriplex polycarpa | 7–36 | – | ||
| shortleaf baccharis | BABR | Baccharis brachyphylla | 7–36 | – | ||
| desertbroom | BASA2 | Baccharis sarothroides | 7–36 | – | ||
| sweetbush | BEJU | Bebbia juncea | 7–36 | – | ||
| Coulter's brickellbush | BRCO | Brickellia coulteri | 7–36 | – | ||
| crucifixion thorn | CAEM4 | Castela emoryi | 7–36 | – | ||
| fairyduster | CAER | Calliandra eriophylla | 7–36 | – | ||
| desert willow | CHLI2 | Chilopsis linearis | 7–36 | – | ||
| Nevada jointfir | EPNE | Ephedra nevadensis | 7–36 | – | ||
| Eastern Mojave buckwheat | ERFA2 | Eriogonum fasciculatum | 7–36 | – | ||
| ocotillo | FOSP2 | Fouquieria splendens | 7–36 | – | ||
| desert lavender | HYEM | Hyptis emoryi | 7–36 | – | ||
| singlewhorl burrobrush | HYMO | Hymenoclea monogyra | 7–36 | – | ||
| burrobrush | HYSA | Hymenoclea salsola | 7–36 | – | ||
| sangre de cristo | JACA2 | Jatropha cardiophylla | 7–36 | – | ||
| Arizona nettlespurge | JACI | Jatropha cinerea | 7–36 | – | ||
| slender janusia | JAGR | Janusia gracilis | 7–36 | – | ||
| beloperone | JUCA8 | Justicia californica | 7–36 | – | ||
| littleleaf ratany | KRER | Krameria erecta | 7–36 | – | ||
| white ratany | KRGR | Krameria grayi | 7–36 | – | ||
| Berlandier's wolfberry | LYBE | Lycium berlandieri | 7–36 | – | ||
| Fremont's desert-thorn | LYFR | Lycium fremontii | 7–36 | – | ||
| rough menodora | MESC | Menodora scabra | 7–36 | – | ||
| Thurber's sandpaper plant | PETH4 | Petalonyx thurberi | 7–36 | – | ||
| whitestem paperflower | PSCO2 | Psilostrophe cooperi | 7–36 | – | ||
| Mexican bladdersage | SAME | Salazaria mexicana | 7–36 | – | ||
| arrow poision plant | SEBI9 | Sebastiania bilocularis | 7–36 | – | ||
| jojoba | SICH | Simmondsia chinensis | 7–36 | – | ||
| Hall's shrubby-spurge | TEHA | Tetracoccus hallii | 7–36 | – | ||
| American threefold | TRCA8 | Trixis californica | 7–36 | – | ||
| Parish's goldeneye | VIPA14 | Viguiera parishii | 7–36 | – | ||
| lotebush | ZIOB | Ziziphus obtusifolia | 7–36 | – | ||
Interpretations
Animal community
The plant community on this site is well suited for grazing by all classes of livestock. It usually occurs as small inclusions in large areas of upland sites. Because of this and water availability in the rainy months, long green seasons, shade and easy accessibility, this area is often overused. Within vast areas of unproductive upland areas this site becomes the key grazing area, especially in the hot summers, and grazing management should hinge around proper use and recovery of the forage species in the plant community. The plant community, in good condition, provides adequate nutrition for livestock throughout the year.
Free water can be available on this site in the rainy seasons in small natural charcos in the streambed. Water developments providing free water throughout the year are very imortant to large mammals like mule deer. Forage diversity, shade, cover and structure are very good and make this site home to a great variety of wildlife species including the larger desert mammals. This site occurs in many areas as minor inclusions bisecting vast areas of unproductive upland sites. In these situations it is the only habitat for wildlife and fulfills the needs for a wide variety of bird, reptile, amphibian and insect species as well as most of the desert mammals.
Other information
T&E: Antilocapra Americana sonoriensis
(Sonoran pronghorn)
Leptonycteris curasoae yerbebuena
(Lesser long-nosed bat)
Supporting information
Type locality
| Location 1: Pima County, AZ | |
|---|---|
| Township/Range/Section | T14S R1E S29 |
| General legal description | Sells FO - Pisinemo District SW 1/4 Sec. 29 |
| Location 2: Maricopa County, AZ | |
| Township/Range/Section | T3N R3W S5 |
| General legal description | Phoenix FO - White Tank Mtn. Park |
| Location 3: Pima County, AZ | |
| Township/Range/Section | T15S R7W S30 |
| General legal description | Tucson FO - Organ Pipe National Monument |
| Location 4: Pima County, AZ | |
| Township/Range/Section | T9S R3E S5 |
| General legal description | Sells FO - Sif Oidak Dist. - along EPNG pipeline |
Contributors
Dan Robinett
Dan Robinett, J. Norris
Larry D. Ellicott
Stephen Cassady
Steve Barker
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 Womck, Byron Lambeth, Dan Robinet, Emilio Carrillo |
|---|---|
| Contact for lead author | NRCS Tucson Area Office |
| Date | 03/02/2005 |
| Approved by | S. Cassady |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
Rills are commo on the site as braided channels, but are usually well vegetated and not eroding. -
Presence of water flow patterns:
Water flow paths ar constantly changing due to frequent flooding regimes. -
Number and height of erosional pedestals or terracettes:
No accumulated or erosional pedestals on most perennial plants. Debris dams are common on large shrubs and trees from frequent flooding. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
15-40% -
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):
Highly variable, function of upland overland flow input. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Expect ratings of 1-3 across the site. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Weak platy; Color is 7.5-10YR6/4 dry, 7.5-10YR5/4 moist; thickness to 3 inches. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Canopy 60-70%: 10-30% perennial grass, 40% shrubs, 10% subshrubs, 10% perennial forbs, and 5-10% trees. 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:
shrubs > subshrubs > trees > succulets > forbs = perennial grasses (Note: annual forbs and grasses may be greater in El Nino years.)Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
20-30% canopy mortality of trees & shrubs; 90-100% mortality of 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):
700 lbs/ac unfavorable precipitaton, 1500 lbs/ac normal preciptation, 2200 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:
Mediterranean grass, filare, Sahara mustard, red brome, creosote, triangle leaf bursage, mesquite, desert broom. -
Perennial plant reproductive capability:
Not impaired for shrubs, drought impaired for perennial grasses & 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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