Natural Resources
Conservation Service
Ecological site R040XA123AZ
Volcanic Hills 10"-13" P.Z.
Accessed: 11/21/2024
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
| R040XA101AZ |
Basalt Hills 10"-13" p.z. |
|---|---|
| R040XA103AZ |
Clayey Slopes 10"-13" p.z. |
| R040XA105AZ |
Shallow Hills 10"-13" p.z. |
Similar sites
| R040XB222AZ |
Volcanic Hills 7"-10" p.z. |
|---|---|
| R041XC323AZ |
Volcanic Hills 12-16" p.z. Loamy |
| R038XA133AZ |
Volcanic/Metamorphic Hills 12-16" p.z. |
Table 1. Dominant plant species
| Tree |
(1) Parkinsonia microphylla |
|---|---|
| Shrub |
(1) Simmondsia chinensis |
| Herbaceous |
(1) Sphaeralcea ambigua |
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. It occurs on steep hill-slopes and ridge-tops.
Table 2. Representative physiographic features
| Landforms |
(1)
Hill
(2) Ridge (3) Mountain slope |
|---|---|
| Flooding frequency | None |
| Ponding frequency | None |
| Elevation | 671 – 1,219 m |
| Slope | 15 – 75% |
| 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) | 330 mm |
Figure 2. Monthly precipitation range
Figure 3. Monthly average minimum and maximum temperature
Influencing water features
There are no water features associated with this site.
Soil features
These are shallow soils formed on intermediate igneous parent material (Andesite, Dacite, Diorite) related agglomerates, tuffs and breccia. Bedrock is usually hard and unweathered. They are non to slightly calcareous, loamy textured and have well developed covers of gravels, cobbles and stones. Numerous areas of rock outcrop occur intermingled with soil areas. Outcrops can be as high as 35% of the area. Plant-soil moisture relationships are fair to good.
Soils mapped on this site include: in
SSA-645 Aguilla-Carefree MU's Lehmans-72, 73, 104 & 105;
SSA-661 Eastern Pinal Southern Gila counties MU Lehmans-835;
SSA-669 Eastern Pima county MU Lehmans-41;
SSA-703 Tohono O'odham MU's Bosa-40 & Lahitas-40.
Table 4. Representative soil features
| Parent material |
(1)
Residuum
–
andesite
|
|---|---|
| Surface texture |
(1) Very gravelly sandy loam (2) Very cobbly sandy loam (3) Very gravelly loam |
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderately rapid to moderate |
| Soil depth | 13 – 51 cm |
| Surface fragment cover <=3" | 40 – 60% |
| Surface fragment cover >3" | 10 – 30% |
| Available water capacity (0-101.6cm) |
2.79 – 6.35 cm |
| Calcium carbonate equivalent (0-101.6cm) |
0 – 5% |
| Electrical conductivity (0-101.6cm) |
0 – 2 mmhos/cm |
| Sodium adsorption ratio (0-101.6cm) |
0 – 2 |
| Soil reaction (1:1 water) (0-101.6cm) |
7.4 – 8.2 |
| Subsurface fragment volume <=3" (Depth not specified) |
35 – 65% |
| Subsurface fragment volume >3" (Depth not specified) |
0 – 20% |
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, Volcanic Hills 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 shrubs, trees, cacti and perennial grasses and forbs. The aspect is shrubland. With continuous, heavy grazing, herbaceous and suffrutescent forage species are removed from the plant community and shrubs like triangle bursage, white brittle bush, whitethorn acacia, hopseed bush, prickly pear and cholla can increase to occupy the vacancy. Well developed gravel and cobble covers protect the soil from erosion and protect forage species from heavy utilization. The dark color of surface rocks warms the soil allowing plants to grow later into the fall with available moisture and to green up earlier in the spring. Areas of rock outcrop tend to magnify water received by adjacent soil areas. Percent bare ground on the site ranges from 5 to 20. Plant populations for major shrub species range form 10 to 300 per acre for jojoba, 10 to 200 per acre for creosotebush or whitethorn, 20 to 250 per acre for littleleaf paloverde, 50 to 200 ocotillo per acre, 50 to 200 wolfberry per acre, 50 to 300 mormon tea per acre, 10 to 200 mint bush per acre and 0 to 20 saguaro per acre. North exposures have a higher percentage cover of perennial grasses and forbs than warm exposures. Grass cover ranges from 0-10% on north slopes and 0-2% on south slopes. Forb cover ranges from 1-25% on north slopes and 0-6% on south slopes. Warm exposures have a higher percentage of trees and succulents than north slopes. The half shrub community on north slopes is dominated by species like calliandra, goldeneye, mintbush and mormon tea while on south slopes brittlebush, ratany, limberbush and bursage are dominant. Jojoba will have its higher cover on north aspects while southern aspects will have more ocotillo, whitethorn and wolfberry. The percent of annual forbs and grasses in the plant community can range from 5% in dry years to nearly 70% in very wet winters or summers. The yearly production of annuals ranges from 20 lbs per acre to over 1500 lbs. per acre (from dry year to wet year). Severe drought can reduce the cover of perennial grasses and suffrutescent forbs to less than 1%. Drought can also reduce the cover of sub-shrubs like brittlebush and bursage. The dynamics of Saguaro on this site is unlike the 200-300 year cycle found on deep upland sites in the Upper Sonoran desert. Saguaro recruitment can occur in any favorable year due to numerous rocky habitats favorable for establishment. Saguaro populations tend to be multi-aged and persistent on this site although very favorable years for establishment may result in very heavy stands on some slopes many years later.
Figure 5. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
| Plant type | Low (kg/hectare) |
Representative value (kg/hectare) |
High (kg/hectare) |
|---|---|---|---|
| Forb | 56 | 84 | 712 |
| Shrub/Vine | 114 | 448 | 577 |
| Grass/Grasslike | 28 | 112 | 504 |
| Tree | 73 | 224 | 280 |
| Total | 271 | 868 | 2073 |
Table 6. Soil surface cover
| Tree basal cover | 0-1% |
|---|---|
| Shrub/vine/liana basal cover | 1-6% |
| Grass/grasslike basal cover | 0-1% |
| Forb basal cover | 0-1% |
| Non-vascular plants | 0% |
| Biological crusts | 0-5% |
| Litter | 5-65% |
| Surface fragments >0.25" and <=3" | 30-60% |
| Surface fragments >3" | 5-35% |
| Bedrock | 1-20% |
| Water | 0% |
| Bare ground | 5-25% |
Table 7. Canopy structure (% cover)
| Height Above Ground (m) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.15 | – | 0-1% | 0-15% | 0-15% |
| >0.15 <= 0.3 | – | 0-10% | 1-15% | 1-20% |
| >0.3 <= 0.6 | – | 2-12% | 0-5% | 1-5% |
| >0.6 <= 1.4 | 0-1% | 1-5% | 0-1% | 0-1% |
| >1.4 <= 4 | 0-15% | 0-1% | – | – |
| >4 <= 12 | 0-1% | – | – | – |
| >12 <= 24 | – | – | – | – |
| >24 <= 37 | – | – | – | – |
| >37 | – | – | – | – |
Figure 6. Plant community growth curve (percent production by month). AZ4011, 40.1 10-13" p.z. hill 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 | 15 | 20 | 5 | 5 | 10 | 15 | 15 | 5 | 5 | 0 |
State 2
Native trees, cacti, shrubs and fire
Community 2.1
Native trees, cacti, shrubs and 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 wolfberry, ocotillo and jojoba 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 and / or fountain grass invade the native plant community. These species occupy the niches of low shrubs like false mesquite, janusia, twinberry or triangle goldeneye and can displace species like wolfberry and jojoba.
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 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 (kg/hectare) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Dominant short grasses | 6–67 | ||||
| slender grama | BORE2 | Bouteloua repens | 1–56 | – | ||
| curly-mesquite | HIBE | Hilaria belangeri | 0–56 | – | ||
| slim tridens | TRMU | Tridens muticus | 1–22 | – | ||
| 2 | Dominant mid grasses | 17–123 | ||||
| sideoats grama | BOCU | Bouteloua curtipendula | 6–56 | – | ||
| tobosagrass | PLMU3 | Pleuraphis mutica | 6–56 | – | ||
| tanglehead | HECO10 | Heteropogon contortus | 6–45 | – | ||
| bush muhly | MUPO2 | Muhlenbergia porteri | 1–34 | – | ||
| desert needlegrass | ACSP12 | Achnatherum speciosum | 0–28 | – | ||
| cane bluestem | BOBA3 | Bothriochloa barbinodis | 0–11 | – | ||
| Arizona cottontop | DICA8 | Digitaria californica | 0–11 | – | ||
| 3 | Miscellaneous perennial grasses | 2–34 | ||||
| spidergrass | ARTE3 | Aristida ternipes | 1–28 | – | ||
| Parish's threeawn | ARPUP5 | Aristida purpurea var. parishii | 1–17 | – | ||
| purple threeawn | ARPU9 | Aristida purpurea | 0–11 | – | ||
| red grama | BOTR2 | Bouteloua trifida | 0–11 | – | ||
| Hall's panicgrass | PAHA | Panicum hallii | 0–11 | – | ||
| big galleta | PLRI3 | Pleuraphis rigida | 0–11 | – | ||
| large-spike bristlegrass | SEMA5 | Setaria macrostachya | 0–6 | – | ||
| black grama | BOER4 | Bouteloua eriopoda | 0–6 | – | ||
| blue grama | BOGR2 | Bouteloua gracilis | 0–6 | – | ||
| hairy grama | BOHI2 | Bouteloua hirsuta | 0–2 | – | ||
| fall witchgrass | DICO6 | Digitaria cognata | 0–2 | – | ||
| southwestern bristlegrass | SESC2 | Setaria scheelei | 0–2 | – | ||
| plains bristlegrass | SEVU2 | Setaria vulpiseta | 0–2 | – | ||
| muttongrass | POFE | Poa fendleriana | 0–2 | – | ||
| prairie Junegrass | KOMA | Koeleria macrantha | 0–2 | – | ||
| common wolfstail | LYPH | Lycurus phleoides | 0–2 | – | ||
| Wright's threeawn | ARPUW | Aristida purpurea var. wrightii | 0–2 | – | ||
| Havard's threeawn | ARHA3 | Aristida havardii | 0–2 | – | ||
| sand dropseed | SPCR | Sporobolus cryptandrus | 0–1 | – | ||
| squirreltail | ELELE | Elymus elymoides ssp. elymoides | 0–1 | – | ||
| nineawn pappusgrass | ENDE | Enneapogon desvauxii | 0–1 | – | ||
| low woollygrass | DAPU7 | Dasyochloa pulchella | 0–1 | – | ||
| 4 | Annual grasses | 2–448 | ||||
| mucronate sprangeltop | LEPAB | Leptochloa panicea ssp. brachiata | 0–224 | – | ||
| Mexican panicgrass | PAHI5 | Panicum hirticaule | 0–140 | – | ||
| sixweeks threeawn | ARAD | Aristida adscensionis | 1–112 | – | ||
| needle grama | BOAR | Bouteloua aristidoides | 0–56 | – | ||
| sixweeks grama | BOBA2 | Bouteloua barbata | 0–56 | – | ||
| Rothrock's grama | BORO2 | Bouteloua rothrockii | 0–56 | – | ||
| prairie threeawn | AROL | Aristida oligantha | 0–28 | – | ||
| Eastwood fescue | VUMIC | Vulpia microstachys var. ciliata | 0–28 | – | ||
| Pacific fescue | VUMIP | Vulpia microstachys var. pauciflora | 0–28 | – | ||
| sixweeks fescue | VUOC | Vulpia octoflora | 1–28 | – | ||
| Mexican sprangletop | LEFUU | Leptochloa fusca ssp. uninervia | 0–28 | – | ||
| Bigelow's bluegrass | POBI | Poa bigelovii | 0–11 | – | ||
| delicate muhly | MUFR | Muhlenbergia fragilis | 0–11 | – | ||
| littleseed muhly | MUMI | Muhlenbergia microsperma | 0–11 | – | ||
| witchgrass | PACA6 | Panicum capillare | 0–6 | – | ||
| Grisebach's bristlegrass | SEGR6 | Setaria grisebachii | 0–6 | – | ||
| Madagascar dropseed | SPPY2 | Sporobolus pyramidatus | 0–2 | – | ||
| Arizona signalgrass | URAR | Urochloa arizonica | 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 | – | ||
| little barley | HOPU | Hordeum pusillum | 0–2 | – | ||
| goldentop grass | LAAU | Lamarckia aurea | 0–2 | – | ||
| fragilegrass | AETE | Aegopogon tenellus | 0–1 | – | ||
|
Forb
|
||||||
| 5 | Parasites | 1–17 | ||||
| mesquite mistletoe | PHCA8 | Phoradendron californicum | 1–11 | – | ||
| bigseed alfalfa dodder | CUIN | Cuscuta indecora | 0–6 | – | ||
| 6 | Dominant perennial forbs | 45–78 | ||||
| slender janusia | JAGR | Janusia gracilis | 11–28 | – | ||
| rough menodora | MESC | Menodora scabra | 6–28 | – | ||
| desert globemallow | SPAM2 | Sphaeralcea ambigua | 2–28 | – | ||
| brownplume wirelettuce | STPA4 | Stephanomeria pauciflora | 1–11 | – | ||
| longflower tube tongue | JULO3 | Justicia longii | 0–11 | – | ||
| narrowleaf silverbush | ARLA12 | Argythamnia lanceolata | 1–11 | – | ||
| weakleaf bur ragweed | AMCO3 | Ambrosia confertiflora | 1–6 | – | ||
| dwarf Indian mallow | ABPA3 | Abutilon parvulum | 0–6 | – | ||
| Parry's false prairie-clover | MAPA7 | Marina parryi | 0–6 | – | ||
| lacy tansyaster | MAPIP4 | Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida | 1–6 | – | ||
| wishbone-bush | MILAV | Mirabilis laevis var. villosa | 0–6 | – | ||
| cockroachplant | HACR3 | Haplophyton crooksii | 0–6 | – | ||
| slender poreleaf | POGR5 | Porophyllum gracile | 1–6 | – | ||
| Coues' cassia | SECO10 | Senna covesii | 1–6 | – | ||
| desert rosemallow | HICO | Hibiscus coulteri | 2–4 | – | ||
| brownfoot | ACWR5 | Acourtia wrightii | 0–4 | – | ||
| dense ayenia | AYMI | Ayenia microphylla | 0–4 | – | ||
| Arizona wrightwort | CAAR7 | Carlowrightia arizonica | 0–4 | – | ||
| bluedicks | DICA14 | Dichelostemma capitatum | 0–3 | – | ||
| white sagebrush | ARLU | Artemisia ludoviciana | 0–2 | – | ||
| San Felipe dogweed | ADPO | Adenophyllum porophylloides | 0–2 | – | ||
| trailing windmills | ALIN | Allionia incarnata | 0–2 | – | ||
| Parry's beardtongue | PEPA24 | Penstemon parryi | 1–2 | – | ||
| Louisiana vetch | VILUL2 | Vicia ludoviciana ssp. ludoviciana | 0–1 | – | ||
| pelotazo | ABIN | Abutilon incanum | 0–1 | – | ||
| perennial rockcress | ARPE2 | Arabis perennans | 0–1 | – | ||
| spurge | EUPHO | Euphorbia | 0–1 | – | ||
| California suncup | CACA32 | Camissonia californica | 0–1 | – | ||
| desert larkspur | DEPA | Delphinium parishii | 0–1 | – | ||
| tall mountain larkspur | DESC | Delphinium scaposum | 0–1 | – | ||
| 7 | Annual forbs | 6–527 | ||||
| bristly fiddleneck | AMTE3 | Amsinckia tessellata | 0–112 | – | ||
| California poppy | ESCAM | Eschscholzia californica ssp. mexicana | 0–112 | – | ||
| Coulter's lupine | LUSP2 | Lupinus sparsiflorus | 0–112 | – | ||
| thelypody | THELY | Thelypodium | 0–56 | – | ||
| Arizona poppy | KAGR | Kallstroemia grandiflora | 0–56 | – | ||
| western tansymustard | DEPI | Descurainia pinnata | 1–56 | – | ||
| exserted Indian paintbrush | CAEXE | Castilleja exserta ssp. exserta | 0–28 | – | ||
| phacelia | PHACE | Phacelia | 0–28 | – | ||
| woolly tidestromia | TILA2 | Tidestromia lanuginosa | 0–11 | – | ||
| sleepy silene | SIAN2 | Silene antirrhina | 0–11 | – | ||
| coastal bird's-foot trefoil | LOSAB | Lotus salsuginosus var. brevivexillus | 0–11 | – | ||
| milkvetch | ASTRA | Astragalus | 0–11 | – | ||
| American wild carrot | DAPU3 | Daucus pusillus | 0–11 | – | ||
| goosefoot | CHENO | Chenopodium | 0–11 | – | ||
| shaggyfruit pepperweed | LELA | Lepidium lasiocarpum | 0–11 | – | ||
| miniature woollystar | ERDI2 | Eriastrum diffusum | 0–6 | – | ||
| New Mexico thistle | CINE | Cirsium neomexicanum | 0–6 | – | ||
| carelessweed | AMPA | Amaranthus palmeri | 0–6 | – | ||
| desert Indianwheat | PLOV | Plantago ovata | 1–6 | – | ||
| buckwheat | ERIOG | Eriogonum | 1–6 | – | ||
| combseed | PECTO | Pectocarya | 0–6 | – | ||
| shrubby deervetch | LORI3 | Lotus rigidus | 1–3 | – | ||
| plains blackfoot | MELE2 | Melampodium leucanthum | 0–2 | – | ||
| cryptantha | CRYPT | Cryptantha | 0–2 | – | ||
| spreading fleabane | ERDI4 | Erigeron divergens | 0–2 | – | ||
| crestrib morning-glory | IPCO2 | Ipomoea costellata | 0–2 | – | ||
| redstar | IPCO3 | Ipomoea coccinea | 0–2 | – | ||
| desert trumpet | ERIN4 | Eriogonum inflatum | 0–1 | – | ||
| Arizona cottonrose | LOAR12 | Logfia arizonica | 0–1 | – | ||
| Gordon's bladderpod | LEGO | Lesquerella gordonii | 0–1 | – | ||
| spurge | EUPHO | Euphorbia | 0–1 | – | ||
| California fagonbush | FALA | Fagonia laevis | 0–1 | – | ||
| fringed twinevine | FUCYC | Funastrum cynanchoides ssp. cynanchoides | 0–1 | – | ||
| Davis Mountain mock vervain | GLBIC | Glandularia bipinnatifida var. ciliata | 0–1 | – | ||
| paleface | HIDE | Hibiscus denudatus | 0–1 | – | ||
| Newberry's velvetmallow | HONE | Horsfordia newberryi | 0–1 | – | ||
| hyssopleaf sandmat | CHHY3 | Chamaesyce hyssopifolia | 0–1 | – | ||
| flatcrown buckwheat | ERDE6 | Eriogonum deflexum | 0–1 | – | ||
| desert marigold | BAMU | Baileya multiradiata | 0–1 | – | ||
| scarlet spiderling | BOCO | Boerhavia coccinea | 0–1 | – | ||
| spiderling | BOERH2 | Boerhavia | 0–1 | – | ||
| hoary bowlesia | BOIN3 | Bowlesia incana | 0–1 | – | ||
| fringed redmaids | CACI2 | Calandrinia ciliata | 0–1 | – | ||
| naked mariposa lily | CANU2 | Calochortus nudus | 0–1 | – | ||
| whitemargin sandmat | CHAL11 | Chamaesyce albomarginata | 0–1 | – | ||
| brittle spineflower | CHBR | Chorizanthe brevicornu | 0–1 | – | ||
| tuber anemone | ANTU | Anemone tuberosa | 0–1 | – | ||
| New Mexico silverbush | ARNE2 | Argythamnia neomexicana | 0–1 | – | ||
| largeflower onion | ALMA4 | Allium macropetalum | 0–1 | – | ||
| common fiddleneck | AMMEI2 | Amsinckia menziesii var. intermedia | 0–1 | – | ||
| blazingstar | MENTZ | Mentzelia | 0–1 | – | ||
| Lindley's silverpuffs | MILI5 | Microseris lindleyi | 0–1 | – | ||
| green carpetweed | MOVE | Mollugo verticillata | 0–1 | – | ||
| glandular threadplant | NEGL | Nemacladus glanduliferus | 0–1 | – | ||
| desert tobacco | NIOBO | Nicotiana obtusifolia var. obtusifolia | 0–1 | – | ||
| evening primrose | OENOT | Oenothera | 0–1 | – | ||
| Florida pellitory | PAFL3 | Parietaria floridana | 0–1 | – | ||
| Emory's rockdaisy | PEEM | Perityle emoryi | 0–1 | – | ||
| Coulter's lyrepod | LYCO4 | Lyrocarpa coulteri | 0–1 | – | ||
| tansyaster | MACHA | Machaeranthera | 0–1 | – | ||
| whitestem blazingstar | MEAL6 | Mentzelia albicaulis | 0–1 | – | ||
| glandleaf milkwort | POMA7 | Polygala macradenia | 0–1 | – | ||
| New Mexico plumeseed | RANE | Rafinesquia neomexicana | 0–1 | – | ||
| chia | SACO6 | Salvia columbariae | 0–1 | – | ||
| Leiberg stonecrop | SELE | Sedum leibergii | 0–1 | – | ||
| ragwort | SENEC | Senecio | 0–1 | – | ||
| bean | PHASE | Phaseolus | 0–1 | – | ||
| orange fameflower | PHAU13 | Phemeranthus aurantiacus | 0–1 | – | ||
| Arizona popcornflower | PLAR | Plagiobothrys arizonicus | 0–1 | – | ||
| silverleaf nightshade | SOEL | Solanum elaeagnifolium | 0–1 | – | ||
| lyreleaf jewelflower | STCA5 | Streptanthus carinatus | 0–1 | – | ||
| woollyhead neststraw | STMI2 | Stylocline micropoides | 0–1 | – | ||
| sand fringepod | THCU | Thysanocarpus curvipes | 0–1 | – | ||
| vervain | VERBE | Verbena | 0–1 | – | ||
| 8 | Ferns and fern allies | 6–90 | ||||
| Arizona spikemoss | SEAR2 | Selaginella arizonica | 2–84 | – | ||
| cliffbrake | PELLA | Pellaea | 1–6 | – | ||
| lipfern | CHEIL | Cheilanthes | 1–6 | – | ||
| cloak fern | NOTHO | Notholaena | 0–2 | – | ||
|
Shrub/Vine
|
||||||
| 9 | Dominant low shrubs | 34–224 | ||||
| triangle bur ragweed | AMDE4 | Ambrosia deltoidea | 0–45 | – | ||
| brittlebush | ENFA | Encelia farinosa | 0–34 | – | ||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 1–28 | – | ||
| bastardsage | ERWR | Eriogonum wrightii | 0–17 | – | ||
| Parish's goldeneye | VIPA14 | Viguiera parishii | 2–17 | – | ||
| Eastern Mojave buckwheat | ERFA2 | Eriogonum fasciculatum | 1–17 | – | ||
| fairyduster | CAER | Calliandra eriophylla | 6–17 | – | ||
| pelotazo | ABIN | Abutilon incanum | 1–17 | – | ||
| California copperleaf | ACCA3 | Acalypha californica | 0–6 | – | ||
| rayless goldenhead | ACSP | Acamptopappus sphaerocephalus | 0–6 | – | ||
| sweetbush | BEJU | Bebbia juncea | 0–6 | – | ||
| Coulter's brickellbush | BRCO | Brickellia coulteri | 1–6 | – | ||
| ragged rockflower | CRBI2 | Crossosoma bigelovii | 1–6 | – | ||
| turpentine bush | ERLA12 | Ericameria laricifolia | 0–6 | – | ||
| rock sage | SAPI2 | Salvia pinguifolia | 0–6 | – | ||
| American threefold | TRCA8 | Trixis californica | 1–6 | – | ||
| littleleaf ratany | KRER | Krameria erecta | 0–6 | – | ||
| white ratany | KRGR | Krameria grayi | 0–6 | – | ||
| slender poreleaf | POGR5 | Porophyllum gracile | 0–2 | – | ||
| whitestem paperflower | PSCO2 | Psilostrophe cooperi | 0–2 | – | ||
| Mexican bladdersage | SAME | Salazaria mexicana | 0–2 | – | ||
| Mojave sage | SAMO3 | Salvia mohavensis | 0–2 | – | ||
| starry bedstraw | GAST | Galium stellatum | 0–2 | – | ||
| desert rosemallow | HICO | Hibiscus coulteri | 0–2 | – | ||
| toothleaf goldeneye | VIDE3 | Viguiera dentata | 0–2 | – | ||
| woody crinklemat | TICAC | Tiquilia canescens var. canescens | 0–2 | – | ||
| Mojave woodyaster | XYTOT | Xylorhiza tortifolia var. tortifolia | 0–2 | – | ||
| desert zinnia | ZIAC | Zinnia acerosa | 0–2 | – | ||
| Chihuahuan brickellbush | BRFL | Brickellia floribunda | 0–2 | – | ||
| rough brickellbush | BRMIS | Brickellia microphylla var. scabra | 0–2 | – | ||
| desert yellow fleabane | ERLI | Erigeron linearis | 0–1 | – | ||
| Sonoran croton | CRSO | Croton sonorae | 0–1 | – | ||
| 12 | Succulents | 45–146 | ||||
| saguaro | CAGI10 | Carnegiea gigantea | 6–84 | – | ||
| cactus apple | OPEN3 | Opuntia engelmannii | 17–50 | – | ||
| staghorn cholla | CYVE3 | Cylindropuntia versicolor | 1–22 | – | ||
| banana yucca | YUBA | Yucca baccata | 0–17 | – | ||
| purple pricklypear | OPMA8 | Opuntia macrocentra | 0–11 | – | ||
| tulip pricklypear | OPPH | Opuntia phaeacantha | 1–11 | – | ||
| buck-horn cholla | CYAC8 | Cylindropuntia acanthocarpa | 0–11 | – | ||
| Schott's century plant | AGSC3 | Agave schottii | 0–11 | – | ||
| teddybear cholla | CYBI9 | Cylindropuntia bigelovii | 0–6 | – | ||
| jumping cholla | CYFUF | Cylindropuntia fulgida var. fulgida | 0–6 | – | ||
| candy barrelcactus | FEWI | Ferocactus wislizeni | 1–6 | – | ||
| senita cactus | PASC14 | Pachycereus schottii | 0–6 | – | ||
| organpipe cactus | STTH3 | Stenocereus thurberi | 0–6 | – | ||
| Leding's hedgehog cactus | ECLE2 | Echinocereus ledingii | 0–3 | – | ||
| Christmas cactus | CYLE8 | Cylindropuntia leptocaulis | 0–2 | – | ||
| Graham's nipple cactus | MAGR9 | Mammillaria grahamii | 0–2 | – | ||
| Thornber's nipple cactus | MATH | Mammillaria thornberi | 0–2 | – | ||
| beavertail pricklypear | OPBA2 | Opuntia basilaris | 0–2 | – | ||
| dollarjoint pricklypear | OPCH | Opuntia chlorotica | 0–2 | – | ||
| common sotol | DAWH2 | Dasylirion wheeleri | 0–2 | – | ||
| desert agave | AGDE | Agave deserti | 0–2 | – | ||
| Leconte's barrel cactus | FECYL | Ferocactus cylindraceus var. lecontei | 0–2 | – | ||
| Santa Rita pricklypear | OPSA | Opuntia santa-rita | 0–2 | – | ||
| Emory's barrel cactus | FEEM | Ferocactus emoryi | 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 | – | ||
| Arizona pencil cholla | CYAR14 | Cylindropuntia arbuscula | 0–1 | – | ||
| rainbow cactus | ECPE | Echinocereus pectinatus | 0–1 | – | ||
| spinystar | ESVIV | Escobaria vivipara var. vivipara | 0–1 | – | ||
| 13 | Dominant large shrubs | 34–168 | ||||
| jojoba | SICH | Simmondsia chinensis | 11–112 | – | ||
| ocotillo | FOSP2 | Fouquieria splendens | 6–67 | – | ||
| whitethorn acacia | ACCO2 | Acacia constricta | 1–56 | – | ||
| catclaw acacia | ACGR | Acacia greggii | 6–34 | – | ||
| Berlandier's wolfberry | LYBE | Lycium berlandieri | 6–28 | – | ||
| Wright's beebrush | ALWR | Aloysia wrightii | 1–11 | – | ||
| spiny hackberry | CEEH | Celtis ehrenbergiana | 1–11 | – | ||
| creosote bush | LATRT | Larrea tridentata var. tridentata | 1–11 | – | ||
| water jacket | LYAN | Lycium andersonii | 0–6 | – | ||
| snapdragon penstemon | KEANM | Keckiella antirrhinoides ssp. microphylla | 0–6 | – | ||
| Arizona desert-thorn | LYEX | Lycium exsertum | 1–6 | – | ||
| Warnock's snakewood | COWA | Condalia warnockii | 0–6 | – | ||
| stretchberry | FOPUP | Forestiera pubescens var. pubescens | 0–3 | – | ||
| desert ceanothus | CEGR | Ceanothus greggii | 0–3 | – | ||
| alderleaf mountain mahogany | CEMO2 | Cercocarpus montanus | 0–3 | – | ||
| red barberry | MAHA4 | Mahonia haematocarpa | 0–3 | – | ||
| catclaw mimosa | MIACB | Mimosa aculeaticarpa var. biuncifera | 0–3 | – | ||
| Mexican cliffrose | PUME | Purshia mexicana | 0–3 | – | ||
| sugar sumac | RHOV | Rhus ovata | 0–3 | – | ||
| skunkbush sumac | RHTR | Rhus trilobata | 0–3 | – | ||
| Sonoran scrub oak | QUTU2 | Quercus turbinella | 0–2 | – | ||
| Schott's pygmycedar | PESC4 | Peucephyllum schottii | 0–2 | – | ||
| Nevada jointfir | EPNE | Ephedra nevadensis | 0–2 | – | ||
| cliff fendlerbush | FERU | Fendlera rupicola | 0–2 | – | ||
| 14 | Miscellaneous shrubs | 2–39 | ||||
| Las Animas nakedwood | COCA18 | Colubrina californica | 0–6 | – | ||
| sangre de cristo | JACA2 | Jatropha cardiophylla | 0–6 | – | ||
| Arizona mimosa | MIDIL | Mimosa distachya var. laxiflora | 0–6 | – | ||
| Ajo Mountain scrub oak | QUAJ | Quercus ajoensis | 0–6 | – | ||
| arrow poision plant | SEBI9 | Sebastiania bilocularis | 0–2 | – | ||
| Lemmon's ragwort | SELE8 | Senecio lemmonii | 0–2 | – | ||
| Schott's yellowhood | NISC | Nissolia schottii | 0–2 | – | ||
| Florida hopbush | DOVI | Dodonaea viscosa | 0–2 | – | ||
| Tahitian kidneywood | EYOR | Eysenhardtia orthocarpa | 0–2 | – | ||
| desert lavender | HYEM | Hyptis emoryi | 0–2 | – | ||
| beloperone | JUCA8 | Justicia californica | 0–2 | – | ||
| Goodding's tansyaster | MAPIG2 | Machaeranthera pinnatifida ssp. gooddingii var. gooddingii | 0–2 | – | ||
| lacy tansyaster | MAPIP4 | Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida | 0–2 | – | ||
| mouse's eye | BEMY | Bernardia myricifolia | 0–2 | – | ||
| fragrant bursera | BUFA | Bursera fagaroides | 1–2 | – | ||
| Arizona wrightwort | CAAR7 | Carlowrightia arizonica | 0–2 | – | ||
| fourwing saltbush | ATCA2 | Atriplex canescens | 0–2 | – | ||
| shortleaf baccharis | BABR | Baccharis brachyphylla | 0–2 | – | ||
| yerba de pasmo | BAPT | Baccharis pteronioides | 0–2 | – | ||
| desertbroom | BASA2 | Baccharis sarothroides | 0–1 | – | ||
| cattle saltbush | ATPO | Atriplex polycarpa | 0–1 | – | ||
| knifeleaf condalia | COSP3 | Condalia spathulata | 0–1 | – | ||
| Arizona rosewood | VACA5 | Vauquelinia californica | 0–1 | – | ||
| lotebush | ZIOB | Ziziphus obtusifolia | 0–1 | – | ||
| prairie acacia | ACANH | Acacia angustissima var. hirta | 0–1 | – | ||
| whitestem milkweed | ASAL | Asclepias albicans | 0–1 | – | ||
| horsetail milkweed | ASSU2 | Asclepias subverticillata | 0–1 | – | ||
|
Tree
|
||||||
| 15 | Trees | 73–280 | ||||
| yellow paloverde | PAMI5 | Parkinsonia microphylla | 11–224 | – | ||
| desert ironwood | OLTE | Olneya tesota | 0–112 | – | ||
| velvet mesquite | PRVE | Prosopis velutina | 0–56 | – | ||
| crucifixion thorn | CAHO3 | Canotia holacantha | 0–17 | – | ||
Interpretations
Animal community
Steep slopes, very cobbly surfaces and numerous areas of rock outcrop hinder livestock distribution. The site is not well suited to grazing by cows in the hot season except in areas where ridges trend north-south and western exposures are shady in the morning and eastern exposures in the afternoon. In such cases, distribution will be fairly good even in the summer. South facing slopes are used more in the winter due to warm temperatures and early spring greenup. North aspects, being shady and cooler, are used more in the fall due to a longer green season. The plant community has an excellent variety of browse, perennial grasses and forbs providing adequate nutrition throughout the year. Herbaceous forage is high quality due to soils with high exchangeable bases. Seep and canyon water are usually available in the winter-spring rainy season and also for short periods in the summer rainy season. Areas of slick-rock outcrop and hard rock in canyon bottoms offer good opportunity for tricktank water developments. Bluff and rimrock outcrops can form natural barriers with the addition of minimal actual fence construction.
Seasonally available water, forage diversity, cover and topography make this site home to a great variety of wildlife including the larger desert mammals. Large areas of bluff and rimrock outcrop make this site a favorite of desert bighorn sheep. Water developemts are especially important to larger mammals to make the seasonal supplies more permanent. The desert tortoise dens on cobble covered southern exposures in the winter.
Hydrological functions
This site is a fair producer of runoff due to steep slopes and shallow soils. Very gravelly and cobbly soil surfaces tend to hold water on the site. In areas with lots of rock outcrop there is a potential to develop water sources using rock catchments.
Recreational uses
Hunting, hiking, bird watching, 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, club moss, globe mallow and limberbush.
Supporting information
Inventory data references
Range 417s include 3 in excellent condition and 3 in good condition.
Type locality
| Location 1: Pima County, AZ | |
|---|---|
| Township/Range/Section | T14S R12E S10 |
| General legal description | Tucson FO - Tucson Mtn. Park - Gates Pass |
| Location 2: Pima County, AZ | |
| General legal description | Sells Field Office - South Mountain 32 degrees 00' X 112 degrees 9' |
| Location 3: Pima County, AZ | |
| General legal description | Sells Field Office - Artesia Mtn. 31 degrees 52' 30" X 111 degrees 51' 30" |
| Location 4: Gila County, AZ | |
| Township/Range/Section | T4S R17E S23 |
| General legal description | San Carlos FO - Mineral Strip - Deer Creek |
| Location 5: Maricopa County, AZ | |
| Township/Range/Section | T1N R10E S35 |
| General legal description | Chandler FO - Quarter Circle U Ranch, Frazier Pas. |
| Location 6: Pinal County, AZ | |
| Township/Range/Section | T9S R9E S15 |
| General legal description | Casa Grande FO - Picacho Peak State Park |
| Location 7: Pima County, AZ | |
| UTM zone | N |
| UTM northing | 3615043.46 |
| UTM easting | 373662.66 |
| General legal description | Barry Goldwater Gunnery Range, Sand Tank Mountains, Sonoran Desert National Monument |
| Location 8: Pima County, AZ | |
| Township/Range/Section | T14S R13E S15 |
| General legal description | Tumamoc Hills, UA Desert Botanical Laboratory, ungrazed since 1906 |
Other references
Vegetation change and plant demography in permanent plots in the Sonoran Desert. Deb Goldberg, Ray Turner. Ecology 67(3), 1986, pp. 695-712.
Effects of drought on shrub survival and longevity in the northern Sonoran Desert. Janice Bowers. Journal of the Torrey Botanical Society 132(3), 2005, pp. 421-431.
The Changing Mile Re-visited. Ray Turner, Robert Webb. University of Arizona press, 2003.
Exotic plants at the desert Laboratory, Tucson, Arizona. Tony Burgess, Janice Bowers and Ray Turner. Madrono, 38(2). 1991, pp. 96-114.
Contributors
C..Michaels
Dan Robinett
Larry D. Ellicott
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 | 12/13/2005 |
| Approved by | S. Cassady |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
Rills are present on this site with high gravel cover but follow fractures, bedding planes and joints in the bedrock parent materials. Soils with high rock cover have no natural rills. -
Presence of water flow patterns:
Uncommon; broken primarily by high rock and gravel cover. -
Number and height of erosional pedestals or terracettes:
Pedestals are uncommon on perennial grass and shrubs (1-2 per 50 plants and no more than 1 inch of root exposed); limited soil material not conducive to forming continuous stands of plants that promote terracettes; high rock cover forms limited natural terracettes. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Estimated at 1-2%. Gravel cover 90-95%, rock 2-3%. Some soils may have 90-95% rock cover. -
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):
Woody litter stays in place, herbaceous litter transported in limited flow paths. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Expect values of 1-2 in canopy interspaces, and 4-5 under plant canopies. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Weak thin platy to weak granular; thickness to 5 inches. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Canopy cover = 26%; 35-40% of canopy cover is shrubs, 20-25% half shrubs, 15-20% paloverde, 7-8% succulents, 3-4% perennial grass, 3-4% perennial forbs. Cover is well dispersed throughout the site. North facing slopes may have tree and shrub cover values reversed versus above values and higher values for succulents. -
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 > half shrubs > trees > succulents > perennial grasses and forbs (Note: In El Nino years, annual forbs and grasses are #1 in above ground weight). North slopes may have trees > succulents > half shrubs > shrubs > perennial forbs > perennial grasses.Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
3 and 15% canopy mortality of triangle bursage and jojoba, respectively at Gates Pass west slope. 5-10% mortality of bursage at Tumamoc Hill north slope. -
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
242 lbs/ac unfavorable precipitation; 775 lbs/ac normal precipitation; 1850 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:
Filaree, Red brome, bufflegrass -
Perennial plant reproductive capability:
Not impaired for shrubs, drought impaired 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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