Natural Resources
Conservation Service
Ecological site R040XA127AZ
Gypsum Slopes 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.
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
| R040XA110AZ |
Limy Slopes 10"-13" p.z. |
|---|---|
| R040XA111AZ |
Limy Upland 10"-13" p.z. |
| R040XA126AZ |
Gypsum Upland 10"-13" p.z. |
Similar sites
| R041XB219AZ |
Gypsum Upland 8-12" p.z. |
|---|---|
| F041XB218AZ |
Sandy Bottom 8-12" pz. woodland |
Table 1. Dominant plant species
| Tree |
(1) Parkinsonia microphylla |
|---|---|
| Shrub |
(1) Larrea tridentata |
| Herbaceous |
(1) Muhlenbergia porteri |
Physiographic features
This site occurs in the upper elevations of the Sonoran Desert province in southern Arizona. It occurs on fan terraces, hill-slopes and ridge-tops formed on relict lacustrine (lake bed) sediments. It occurs in the Gila and San Pedro river valleys.
Table 2. Representative physiographic features
| Landforms |
(1)
Hill
(2) Fan remnant (3) Ridge |
|---|---|
| Flooding frequency | None |
| Ponding frequency | None |
| Elevation | 792 – 1,097 m |
| Slope | 15 – 55% |
| 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 1. Monthly precipitation range
Figure 2. Monthly average minimum and maximum temperature
Influencing water features
There are no water features associated with this site.
Soil features
These soils are well drained, variable in texture, stratified and high in soluble gypsum (5-30% by volume). They are moderately deep to deep and underlain in places by gypsum. Coarse fragments in the soil profile are usually large gypsum crystals. These soils have formed in relict lacustrine deposits. Soil series mapped on this site include Contention, Ugyp, Whitecliff and haplogypsids.
NOT CURRENTLY CORRELATED to any Soil in an AZ SSA.
Table 4. Representative soil features
| Surface texture |
(1) Silt loam (2) Fine sandy loam (3) Clay |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Moderately well drained to well drained |
| Permeability class | Moderately rapid to slow |
| Soil depth | 152 cm |
| Surface fragment cover <=3" | 0 – 50% |
| Surface fragment cover >3" | 0 – 10% |
| Available water capacity (0-101.6cm) |
11.94 – 19.3 cm |
| Calcium carbonate equivalent (0-101.6cm) |
0 – 20% |
| 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 – 8.4 |
| Subsurface fragment volume <=3" (Depth not specified) |
0 – 30% |
| Subsurface fragment volume >3" (Depth not specified) |
0 – 5% |
Ecological dynamics
The plant communities found on an ecological site are naturally variable. Composition and production will vary with yearly conditions, location, aspect and the natural variability of the soils. The Historical Climax Plant Community represents the natural potential plant community found on relict or relatively undisturbed areas of this site. Other plant communities described here represent plant communities that are known to occur when the site is disturbed by factors such as fire, grazing and 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 described in the 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 amount shown for that 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 the field data is not collected at the end of the summer growing season, then the field data must be corrected to the end of 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.
The historic native state includes the native plant communities that occur on the site, including the historic climax plant community. This state includes other plant communities that naturally occupy the site following fire, drought, flooding, herbivores and other natural disturbances. The historic climax plant community represents the natural climax community that eventually reoccupies the site with proper management and a return to near normal conditions and/or equilibrium.
State and transition model
Figure 3. Gypsum 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 1
Historic Climax Plant Community
Community 1.1
Historic Climax Plant Community
This plant community is dominated by littleleaf paloverde, creosote bush and whitethorn acacia. Annual grasses and forbs are an important part of the plant community. Perennial grasses usually only occur on north hill slopes. Cryptogams are very common on this site, often completely colonizing outcrops of gypsum. The site is extremely susceptible to sheet, rill and gully erosion due to high concentrations of soluble gypsum in the surface soil; once the surface soil has been disturbed.
Figure 4. 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) |
|---|---|---|---|
| Shrub/Vine | 152 | 280 | 471 |
| Grass/Grasslike | 13 | 90 | 224 |
| Forb | 4 | 45 | 140 |
| Tree | 11 | 34 | 112 |
| Total | 180 | 449 | 947 |
Table 6. Soil surface cover
| Tree basal cover | 0-1% |
|---|---|
| Shrub/vine/liana basal cover | 1% |
| Grass/grasslike basal cover | 0-1% |
| Forb basal cover | 0-1% |
| Non-vascular plants | 0% |
| Biological crusts | 5-60% |
| Litter | 5-35% |
| Surface fragments >0.25" and <=3" | 15-45% |
| Surface fragments >3" | 1-15% |
| Bedrock | 0-5% |
| Water | 0% |
| Bare ground | 15-80% |
Table 7. Canopy structure (% cover)
| Height Above Ground (m) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.15 | – | 0-1% | 0-5% | 1-15% |
| >0.15 <= 0.3 | – | 0-1% | 0-10% | 0-5% |
| >0.3 <= 0.6 | – | 0-2% | 0-5% | 0-1% |
| >0.6 <= 1.4 | – | 2-5% | – | – |
| >1.4 <= 4 | 0-5% | 0-2% | – | – |
| >4 <= 12 | – | – | – | – |
| >12 <= 24 | – | – | – | – |
| >24 <= 37 | – | – | – | – |
| >37 | – | – | – | – |
Figure 5. 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 shrubs, cacti and fire
Community 2.1
Native shrubs, cacti and fire
This state occurs where the native tree, cacti and shrub cover has been impacted by a single hot season fire. This will occur only in El Nino years when annual forbs and grasses make enough fuel for a fire. Areas of this site will not burn completely due to patches of soil dominated by gypsum outcrop and high cryptogam covers which will not have fine fuel. The fire impacts paloverde, saguaro and other cacti species. Shrubs like creosote and whitethorn may sprout and recover from the fire.
State 3
Exotic annuals
Community 3.1
Exotic annuals
This state occurs where non-native annuals have invaded the native plant community. Species like red brome, schismus and native annuals dominate the understory of the plant community. Areas of the site adjacent urban areas and near heavily travelled roads may burn more often due to increased chance of ignition.
State 4
Eroded
Community 4.1
Eroded
This state occurs where the site has been graded, bladed or mined and the soil surface (gravelly sandyloam) has been disturbed. The subsurface is extremely erodible due to high concentrations of souble gypsum in the soil profile. Steep slopes also contribute to rilling and gully formation.
Additional community tables
Table 8. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Dominant perennial grasses | 11–90 | ||||
| purple threeawn | ARPUP6 | Aristida purpurea var. purpurea | 6–56 | – | ||
| bush muhly | MUPO2 | Muhlenbergia porteri | 6–17 | – | ||
| slim tridens | TRMU | Tridens muticus | 1–17 | – | ||
| tobosagrass | PLMU3 | Pleuraphis mutica | 0–11 | – | ||
| spike dropseed | SPCO4 | Sporobolus contractus | 0–11 | – | ||
| Parish's threeawn | ARPUP5 | Aristida purpurea var. parishii | 0–11 | – | ||
| big sacaton | SPWR2 | Sporobolus wrightii | 0–6 | – | ||
| alkali sacaton | SPAI | Sporobolus airoides | 0–6 | – | ||
| 2 | Misc. perennial grasses | 1–22 | ||||
| low woollygrass | DAPU7 | Dasyochloa pulchella | 1–11 | – | ||
| nineawn pappusgrass | ENDE | Enneapogon desvauxii | 0–11 | – | ||
| blue threeawn | ARPUN | Aristida purpurea var. nealleyi | 0–6 | – | ||
| spidergrass | ARTE3 | Aristida ternipes | 0–6 | – | ||
| spidergrass | ARTEG | Aristida ternipes var. gentilis | 0–6 | – | ||
| whiplash pappusgrass | PAVA2 | Pappophorum vaginatum | 0–2 | – | ||
| sand dropseed | SPCR | Sporobolus cryptandrus | 0–2 | – | ||
| mesa dropseed | SPFL2 | Sporobolus flexuosus | 0–2 | – | ||
| false Rhodes grass | TRCR9 | Trichloris crinita | 0–2 | – | ||
| burrograss | SCBR2 | Scleropogon brevifolius | 0–1 | – | ||
| plains bristlegrass | SEVU2 | Setaria vulpiseta | 0–1 | – | ||
| Arizona cottontop | DICA8 | Digitaria californica | 0–1 | – | ||
| 3 | Annual grasses | 1–112 | ||||
| sixweeks threeawn | ARAD | Aristida adscensionis | 1–56 | – | ||
| sixweeks grama | BOBA2 | Bouteloua barbata | 0–56 | – | ||
| prairie threeawn | AROL | Aristida oligantha | 0–28 | – | ||
| needle grama | BOAR | Bouteloua aristidoides | 0–22 | – | ||
| mucronate sprangeltop | LEPAB | Leptochloa panicea ssp. brachiata | 0–17 | – | ||
| Rothrock's grama | BORO2 | Bouteloua rothrockii | 0–11 | – | ||
| sixweeks fescue | VUOC | Vulpia octoflora | 0–11 | – | ||
| Mexican panicgrass | PAHI5 | Panicum hirticaule | 0–6 | – | ||
| Bigelow's bluegrass | POBI | Poa bigelovii | 0–2 | – | ||
| Arizona signalgrass | URAR | Urochloa arizonica | 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 | 0–1 | – | ||
| Arizona brome | BRAR4 | Bromus arizonicus | 0–1 | – | ||
| delicate muhly | MUFR | Muhlenbergia fragilis | 0–1 | – | ||
| littleseed muhly | MUMI | Muhlenbergia microsperma | 0–1 | – | ||
|
Forb
|
||||||
| 4 | Perennial forbs | 3–28 | ||||
| lacy tansyaster | MAPIP4 | Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida | 1–11 | – | ||
| desert trumpet | ERIN4 | Eriogonum inflatum | 1–11 | – | ||
| brownplume wirelettuce | STPA4 | Stephanomeria pauciflora | 1–11 | – | ||
| desert globemallow | SPAM2 | Sphaeralcea ambigua | 0–6 | – | ||
| Parry's false prairie-clover | MAPA7 | Marina parryi | 0–2 | – | ||
| wishbone-bush | MILAV | Mirabilis laevis var. villosa | 0–2 | – | ||
| weakleaf bur ragweed | AMCO3 | Ambrosia confertiflora | 0–2 | – | ||
| dwarf desertpeony | ACNA2 | Acourtia nana | 0–2 | – | ||
| stinging serpent | CESI | Cevallia sinuata | 0–2 | – | ||
| whitemargin sandmat | CHAL11 | Chamaesyce albomarginata | 0–1 | – | ||
| leatherweed | CRPOP | Croton pottsii var. pottsii | 0–1 | – | ||
| brownfoot | ACWR5 | Acourtia wrightii | 0–1 | – | ||
| trailing windmills | ALIN | Allionia incarnata | 0–1 | – | ||
| tuber anemone | ANTU | Anemone tuberosa | 0–1 | – | ||
| dense ayenia | AYMI | Ayenia microphylla | 0–1 | – | ||
| hairyseed bahia | BAAB | Bahia absinthifolia | 0–1 | – | ||
| desert marigold | BAMU | Baileya multiradiata | 0–1 | – | ||
| desert tobacco | NIOB | Nicotiana obtusifolia | 0–1 | – | ||
| Coues' cassia | SECO10 | Senna covesii | 0–1 | – | ||
| silverleaf nightshade | SOEL | Solanum elaeagnifolium | 0–1 | – | ||
| San Pedro daisy | LAPO4 | Lasianthaea podocephala | 0–1 | – | ||
| rue of the mountains | THTE2 | Thamnosma texana | 0–1 | – | ||
| 5 | Annual forbs | 1–112 | ||||
| phacelia | PHACE | Phacelia | 0–28 | – | ||
| Coulter's lupine | LUSP2 | Lupinus sparsiflorus | 0–22 | – | ||
| California poppy | ESCAM | Eschscholzia californica ssp. mexicana | 0–22 | – | ||
| bristly fiddleneck | AMTE3 | Amsinckia tessellata | 0–17 | – | ||
| western tansymustard | DEPI | Descurainia pinnata | 0–17 | – | ||
| flatcrown buckwheat | ERDE6 | Eriogonum deflexum | 1–11 | – | ||
| miniature woollystar | ERDI2 | Eriastrum diffusum | 0–11 | – | ||
| exserted Indian paintbrush | CAEXE | Castilleja exserta ssp. exserta | 0–11 | – | ||
| combseed | PECTO | Pectocarya | 0–11 | – | ||
| manybristle chinchweed | PEPA2 | Pectis papposa | 0–11 | – | ||
| desert Indianwheat | PLOV | Plantago ovata | 0–11 | – | ||
| lyreleaf jewelflower | STCAA | Streptanthus carinatus ssp. arizonicus | 0–6 | – | ||
| thelypody | THELY | Thelypodium | 0–6 | – | ||
| slender goldenweed | MAGR10 | Machaeranthera gracilis | 0–6 | – | ||
| cryptantha | CRYPT | Cryptantha | 0–6 | – | ||
| Gordon's bladderpod | LEGO | Lesquerella gordonii | 0–6 | – | ||
| shaggyfruit pepperweed | LELA | Lepidium lasiocarpum | 0–6 | – | ||
| intermediate pepperweed | LEVIM | Lepidium virginicum var. medium | 0–6 | – | ||
| coastal bird's-foot trefoil | LOSAB | Lotus salsuginosus var. brevivexillus | 0–6 | – | ||
| Nuttall's povertyweed | MONU | Monolepis nuttalliana | 0–6 | – | ||
| wheelscale saltbush | ATEL | Atriplex elegans | 0–6 | – | ||
| Coulter's spiderling | BOCO2 | Boerhavia coulteri | 0–6 | – | ||
| carelessweed | AMPA | Amaranthus palmeri | 0–6 | – | ||
| brittle spineflower | CHBR | Chorizanthe brevicornu | 0–6 | – | ||
| hyssopleaf sandmat | CHHY3 | Chamaesyce hyssopifolia | 0–2 | – | ||
| Esteve's pincushion | CHST | Chaenactis stevioides | 0–2 | – | ||
| fringed redmaids | CACI2 | Calandrinia ciliata | 0–2 | – | ||
| white tackstem | CAWR | Calycoseris wrightii | 0–2 | – | ||
| green carpetweed | MOVE | Mollugo verticillata | 0–2 | – | ||
| hairy prairie clover | DAMO | Dalea mollis | 0–2 | – | ||
| American wild carrot | DAPU3 | Daucus pusillus | 0–2 | – | ||
| sorrel buckwheat | ERPO4 | Eriogonum polycladon | 0–2 | – | ||
| Texas stork's bill | ERTE13 | Erodium texanum | 0–2 | – | ||
| hairy desertsunflower | GECA2 | Geraea canescens | 0–2 | – | ||
| star gilia | GIST | Gilia stellata | 0–2 | – | ||
| Arizona poppy | KAGR | Kallstroemia grandiflora | 0–2 | – | ||
| tanseyleaf tansyaster | MATA2 | Machaeranthera tanacetifolia | 0–2 | – | ||
| desert evening primrose | OEPR | Oenothera primiveris | 0–2 | – | ||
| Florida pellitory | PAFL3 | Parietaria floridana | 0–2 | – | ||
| woolly tidestromia | TILA2 | Tidestromia lanuginosa | 0–2 | – | ||
| woollyhead neststraw | STMI2 | Stylocline micropoides | 0–2 | – | ||
| doubleclaw | PRPA2 | Proboscidea parviflora | 0–1 | – | ||
| New Mexico plumeseed | RANE | Rafinesquia neomexicana | 0–1 | – | ||
| sleepy silene | SIAN2 | Silene antirrhina | 0–1 | – | ||
| Coulter's globemallow | SPCO2 | Sphaeralcea coulteri | 0–1 | – | ||
| Arizona popcornflower | PLAR | Plagiobothrys arizonicus | 0–1 | – | ||
| Mexican fireplant | EUHE4 | Euphorbia heterophylla | 0–1 | – | ||
| bristly nama | NAHI | Nama hispidum | 0–1 | – | ||
| glandular threadplant | NEGL | Nemacladus glanduliferus | 0–1 | – | ||
| common woolly sunflower | ERLA6 | Eriophyllum lanatum | 0–1 | – | ||
| milkvetch | ASTRA | Astragalus | 0–1 | – | ||
| hoary bowlesia | BOIN3 | Bowlesia incana | 0–1 | – | ||
| yellow tackstem | CAPA7 | Calycoseris parryi | 0–1 | – | ||
|
Shrub/Vine
|
||||||
| 6 | Dominant shrubs | 140–336 | ||||
| creosote bush | LATR2 | Larrea tridentata | 112–224 | – | ||
| whitethorn acacia | ACCO2 | Acacia constricta | 22–112 | – | ||
| catclaw acacia | ACGR | Acacia greggii | 1–28 | – | ||
| ocotillo | FOSP2 | Fouquieria splendens | 0–22 | – | ||
| 7 | Miscellaneous shrubs | 0–34 | ||||
| fourwing saltbush | ATCA2 | Atriplex canescens | 0–22 | – | ||
| Wright's beebrush | ALWR | Aloysia wrightii | 0–11 | – | ||
| cattle saltbush | ATPO | Atriplex polycarpa | 0–6 | – | ||
| longleaf jointfir | EPTR | Ephedra trifurca | 0–6 | – | ||
| Berlandier's wolfberry | LYBE | Lycium berlandieri | 0–6 | – | ||
| western honey mesquite | PRGLT | Prosopis glandulosa var. torreyana | 0–2 | – | ||
| Warnock's snakewood | COWA | Condalia warnockii | 0–2 | – | ||
| American tarwort | FLCE | Flourensia cernua | 0–1 | – | ||
| crown of thorns | KOSP | Koeberlinia spinosa | 0–1 | – | ||
| lotebush | ZIOB | Ziziphus obtusifolia | 0–1 | – | ||
| pale desert-thorn | LYPA | Lycium pallidum | 0–1 | – | ||
| 8 | Half shrubs | 11–90 | ||||
| brittlebush | ENFA | Encelia farinosa | 1–28 | – | ||
| Parish's goldeneye | VIPA14 | Viguiera parishii | 0–22 | – | ||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 1–17 | – | ||
| triangle bur ragweed | AMDE4 | Ambrosia deltoidea | 0–17 | – | ||
| rayless goldenhead | ACSP | Acamptopappus sphaerocephalus | 0–11 | – | ||
| desert zinnia | ZIAC | Zinnia acerosa | 1–11 | – | ||
| mariola | PAIN2 | Parthenium incanum | 0–11 | – | ||
| whitestem paperflower | PSCO2 | Psilostrophe cooperi | 1–11 | – | ||
| pricklyleaf dogweed | THAC | Thymophylla acerosa | 1–6 | – | ||
| littleleaf ratany | KRER | Krameria erecta | 1–6 | – | ||
| rough menodora | MESC | Menodora scabra | 1–6 | – | ||
| white ratany | KRGR | Krameria grayi | 0–1 | – | ||
| burrobush | AMDU2 | Ambrosia dumosa | 0–1 | – | ||
| threadleaf snakeweed | GUMI | Gutierrezia microcephala | 0–1 | – | ||
| 9 | Succulents | 1–11 | ||||
| jumping cholla | CYFU10 | Cylindropuntia fulgida | 0–17 | – | ||
| cactus apple | OPEN3 | Opuntia engelmannii | 0–17 | – | ||
| staghorn cholla | CYVE3 | Cylindropuntia versicolor | 0–11 | – | ||
| saguaro | CAGI10 | Carnegiea gigantea | 0–6 | – | ||
| buck-horn cholla | CYAC8 | Cylindropuntia acanthocarpa | 0–6 | – | ||
| teddybear cholla | CYBI9 | Cylindropuntia bigelovii | 0–6 | – | ||
| tulip pricklypear | OPPH | Opuntia phaeacantha | 0–6 | – | ||
| purple pricklypear | OPMA8 | Opuntia macrocentra | 0–2 | – | ||
| Christmas cactus | CYLE8 | Cylindropuntia leptocaulis | 0–2 | – | ||
| walkingstick cactus | CYSP8 | Cylindropuntia spinosior | 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 | – | ||
| candy barrelcactus | FEWI | Ferocactus wislizeni | 0–1 | – | ||
| devil's cholla | GRKU | Grusonia kunzei | 0–1 | – | ||
| Graham's nipple cactus | MAGR9 | Mammillaria grahamii | 0–1 | – | ||
| nightblooming cereus | PEGR3 | Peniocereus greggii | 0–1 | – | ||
| banana yucca | YUBA | Yucca baccata | 0–1 | – | ||
| soaptree yucca | YUEL | Yucca elata | 0–1 | – | ||
|
Tree
|
||||||
| 10 | Trees | 11–112 | ||||
| yellow paloverde | PAMI5 | Parkinsonia microphylla | 11–112 | – | ||
| velvet mesquite | PRVE | Prosopis velutina | 0–11 | – | ||
Interpretations
Animal community
This site offers little in the way of forage for livestock. Areas of threeawn, muhly and tridens are grazed on slopes less than 45%. Annual grasses and forbs offer limited grazing in wet winters. High concentrations of soluble gypsum in runoff water that is collected by stock ponds can cause laxative effects in livestock.
Wildlife on this site is limited to small mammals and birds and their associated predators. In areas where the site is adjacent to large stream bottoms, like the San Pedro river, it can be a forage area for mammals like mule deer and javalina.
Hydrological functions
Loamy and silty textured soils and steep slopes make this site a good producer of runoff. High concentrations of soluble gypsum in the soils can cause piping, rilling and gullies to form with heavy rainfall.
Recreational uses
Hunting, horseback riding, hiking, photography, bird watching.
Wood products
Some mesquite, catclaw and paloverde for camp and branding fires.
Other products
Gypsum is mined in some areas for use in making sheet rock.
Supporting information
Type locality
| Location 1: Pinal County, AZ | |
|---|---|
| Township/Range/Section | T5S R17E S15 |
| General legal description | Old Mary Cluff Ranch on the Mineral Strip of the San Carlos Apache Nation. |
| Location 2: Pinal County, AZ | |
| Township/Range/Section | T6S R16E S23 |
| General legal description | Old PZ Ranch, Now Becky Stambaugh ranch |
Contributors
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) | |
|---|---|
| Contact for lead author | |
| Date | |
| Approved by | |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
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Number and extent of rills:
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Presence of water flow patterns:
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Number and height of erosional pedestals or terracettes:
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Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
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Number of gullies and erosion associated with gullies:
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Extent of wind scoured, blowouts and/or depositional areas:
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Amount of litter movement (describe size and distance expected to travel):
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Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
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Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
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Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
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Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
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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:
Sub-dominant:
Other:
Additional:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
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Average percent litter cover (%) and depth ( in):
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Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
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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:
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Perennial plant reproductive capability:
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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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