Natural Resources
Conservation Service
Ecological site R040XA107AZ
Limestone 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
| R040XA110AZ |
Limy Slopes 10"-13" p.z. |
|---|---|
| R040XA111AZ |
Limy Upland 10"-13" p.z. |
| R040XA106AZ |
Limy Upland, Deep 10"-13" p.z. |
Similar sites
| R038XA105AZ |
Limestone Hills 12-16" p.z. |
|---|---|
| R041XC307AZ |
Limestone Hills 12-16" p.z. |
| R041XB220AZ |
Limestone Hills 8-12" p.z. |
Table 1. Dominant plant species
| Tree |
(1) Parkinsonia microphylla |
|---|---|
| Shrub |
(1) Zinnia acerosa |
| Herbaceous |
(1) Bouteloua trifida |
Physiographic features
This site occurs in the upper elevations of the Sonoran Desert in southern Arizona. Limestone rock outcrops are associated with this site and may make up as much as 50% of the area. Slope aspect is site differentiating at elevations near land 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 | 2,000 – 4,000 ft |
| 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) | 13 in |
Figure 2. Monthly precipitation range
Figure 3. Monthly average minimum and maximum temperature
Influencing water features
There are no water features associated with this site.
Soil features
These are shallow and very shallow soils over hard limestone bedrock. They are calcareous throughout and are very gravelly to cobbly. Plant-soil moisture relationships are poor but large areas of rock outcrop tend to magnify the amount of moisture received by soil areas. Soils mapped on this site include: SSA-669 Eastern Pima County MU Saguaro-71 & SSA-703 Tohono O'odham area MU Kohatk-39.
Table 4. Representative soil features
| Surface texture |
(1) Very gravelly sandy loam (2) Gravelly sandy loam (3) Gravelly loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Excessively drained to well drained |
| Permeability class | Rapid to moderately rapid |
| Soil depth | 5 – 20 in |
| Surface fragment cover <=3" | 30 – 60% |
| Surface fragment cover >3" | 5 – 20% |
| Available water capacity (0-40in) |
0.5 – 2 in |
| Calcium carbonate equivalent (0-40in) |
15 – 60% |
| Electrical conductivity (0-40in) |
2 mmhos/cm |
| Sodium adsorption ratio (0-40in) |
2 |
| Soil reaction (1:1 water) (0-40in) |
8 – 8.4 |
| Subsurface fragment volume <=3" (Depth not specified) |
35 – 65% |
| Subsurface fragment volume >3" (Depth not specified) |
10% |
Ecological dynamics
The plant communities found on an ecological site are naturally variable. Composition and production will vary with yearly conditions, location, aspect, and the natural variability of the soils. The Historical Climax Plant Community represents the natural potential plant communities found on relict or relatively undisturbed sites. Other plant communities described here represent plant communities that are known to occur when the site is disturbed by factors such as fire, grazing, or drought.
Production data provided in this site description is standardized to air dry weight at the end of the summer growing season. The plant communities described in this site description are based on near normal rainfall years.
NRCS uses a Similarity Index to compare existing plant communities to the plant communities described here. Similarity Index is determined by comparing the production and composition of a plant community to the production and composition of a plant community described in this site description. To determine Similarity Index, compare the production (air dry weight) of each species to that shown in the plant community description. For each species, count no more than the maximum amount shown for the species, and for each group, count no more than the maximum amount shown for the group. Divide the resulting total by the total normal year production shown in the plant community description. If the rainfall has been significantly above or below normal, use the total production shown for above or below normal years. If field data is not collected at the end of the summer growing season, then the field data must be corrected to the end of the year production before comparing it to the site description. The growth curve can be used as a guide for estimating production at the end of the summer growing season.
State and transition model
Figure 4. State and Transition, Limestone 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 trees, shrubs, cacti, and perennial grasses and forbs. Most perennial species are well dispersed throughout the plant community. The aspect is shrubland. With continuous heavy grazing, herbaceous and suffrutescent forage species are replaced by increases in shrubs, cacti and trees. Well developed gravel and cobble covers protect the soil from erosion and help protect forage species from heavy utilization. The large amount of rock outcrop on this site tends to magnify water received by adjacent soil areas. 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 (lb/acre) |
Representative value (lb/acre) |
High (lb/acre) |
|---|---|---|---|
| Shrub/Vine | 100 | 250 | 345 |
| Forb | 18 | 75 | 175 |
| Grass/Grasslike | 5 | 75 | 170 |
| Tree | 50 | 100 | 150 |
| Total | 173 | 500 | 840 |
Table 6. Soil surface cover
| Tree basal cover | 0-1% |
|---|---|
| Shrub/vine/liana basal cover | 1-3% |
| Grass/grasslike basal cover | 0-1% |
| Forb basal cover | 0-1% |
| Non-vascular plants | 0% |
| Biological crusts | 0-5% |
| Litter | 5-40% |
| Surface fragments >0.25" and <=3" | 30-60% |
| Surface fragments >3" | 5-25% |
| Bedrock | 5-20% |
| Water | 0% |
| Bare ground | 5-25% |
Table 7. Canopy structure (% cover)
| Height Above Ground (ft) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.5 | – | 0-2% | 0-10% | 1-10% |
| >0.5 <= 1 | – | 0-2% | 1-5% | 1-10% |
| >1 <= 2 | – | 1-5% | 0-1% | 0-2% |
| >2 <= 4.5 | 0-1% | 1-5% | 0-1% | 0-1% |
| >4.5 <= 13 | 5-10% | – | – | – |
| >13 <= 40 | 0-1% | – | – | – |
| >40 <= 80 | – | – | – | – |
| >80 <= 120 | – | – | – | – |
| >120 | – | – | – | – |
Figure 6. Plant community growth curve (percent production by month). 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, ironwood 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 ocotillo, wolfberry 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 desert zinnia, brittlebush and grasses like red grama and slim tridens.
State 4
Exotic perennial grasses and fire
Community 4.1
Exotic perennial grasses and fire
This community occurs where a native plant community that has been invaded by bufflegrass or fountain grass has burned one or more times. Increasing amounts of bufflegrass leads to more uniform fine fuels. In areas adjacent to roads and urban areas the risk of repeated fires will increase. As fire frequency increases the dominance of the exotic grasses increase.
State 5
Native plant community with exotic annuals
Community 5.1
Native plant community with exotic annuals
This plant community occurs where the native community has been invaded by red brome and / or schismus. Red brome occupies the niche of the native winter annual forbs and grasses. This exotic annual grass will fluctuate from nearly nothing in a dry winter to dominance of the understory plant community in a El Nino winter.
State 6
Exotic annuals and fire
Community 6.1
Exotic annuals and fire
This plant community occurs where a native plant community which has been invaded by red brome and / or schismus, and has burned repeatedly. As fires become more frequent the native trees, shrubs and succulents are removed from the plant community and red brome becomes dominant. In areas of the site near urban areas and along heavily travelled roads this will be a more common occurence due to an increased source of ignitions.
Additional community tables
Table 8. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Dominant perennial grasses | 5–100 | ||||
| slim tridens | TRMU | Tridens muticus | 1–35 | – | ||
| blue threeawn | ARPUN | Aristida purpurea var. nealleyi | 1–30 | – | ||
| bush muhly | MUPO2 | Muhlenbergia porteri | 1–30 | – | ||
| red grama | BOTR2 | Bouteloua trifida | 0–25 | – | ||
| low woollygrass | DAPU7 | Dasyochloa pulchella | 1–25 | – | ||
| black grama | BOER4 | Bouteloua eriopoda | 0–20 | – | ||
| nineawn pappusgrass | ENDE | Enneapogon desvauxii | 1–15 | – | ||
| purple threeawn | ARPU9 | Aristida purpurea | 0–10 | – | ||
| slender grama | BORE2 | Bouteloua repens | 0–5 | – | ||
| Hall's panicgrass | PAHA | Panicum hallii | 0–5 | – | ||
| 2 | Miscellaneous perennial grasses | 0–25 | ||||
| sideoats grama | BOCU | Bouteloua curtipendula | 0–10 | – | ||
| tanglehead | HECO10 | Heteropogon contortus | 0–10 | – | ||
| plains bristlegrass | SEVU2 | Setaria vulpiseta | 0–5 | – | ||
| Parish's threeawn | ARPUP5 | Aristida purpurea var. parishii | 0–5 | – | ||
| Wright's threeawn | ARPUW | Aristida purpurea var. wrightii | 0–5 | – | ||
| spidergrass | ARTE3 | Aristida ternipes | 0–5 | – | ||
| cane bluestem | BOBA3 | Bothriochloa barbinodis | 0–2 | – | ||
| Arizona cottontop | DICA8 | Digitaria californica | 0–2 | – | ||
| squirreltail | ELELE | Elymus elymoides ssp. elymoides | 0–2 | – | ||
| desert needlegrass | ACSP12 | Achnatherum speciosum | 0–2 | – | ||
| Havard's threeawn | ARHA3 | Aristida havardii | 0–2 | – | ||
| spike dropseed | SPCO4 | Sporobolus contractus | 0–2 | – | ||
| sand dropseed | SPCR | Sporobolus cryptandrus | 0–2 | – | ||
| 3 | Annual grasses | 0–45 | ||||
| sixweeks threeawn | ARAD | Aristida adscensionis | 0–10 | – | ||
| mucronate sprangeltop | LEPAB | Leptochloa panicea ssp. brachiata | 0–10 | – | ||
| Rothrock's grama | BORO2 | Bouteloua rothrockii | 0–10 | – | ||
| sixweeks fescue | VUOC | Vulpia octoflora | 0–10 | – | ||
| prairie threeawn | AROL | Aristida oligantha | 0–5 | – | ||
| delicate muhly | MUFR | Muhlenbergia fragilis | 0–3 | – | ||
| littleseed muhly | MUMI | Muhlenbergia microsperma | 0–3 | – | ||
| Bigelow's bluegrass | POBI | Poa bigelovii | 0–2 | – | ||
| Arizona signalgrass | URAR | Urochloa arizonica | 0–2 | – | ||
| desert lovegrass | ERPEM | Eragrostis pectinacea var. miserrima | 0–2 | – | ||
| Arizona brome | BRAR4 | Bromus arizonicus | 0–1 | – | ||
| needle grama | BOAR | Bouteloua aristidoides | 0–1 | – | ||
| sixweeks grama | BOBA2 | Bouteloua barbata | 0–1 | – | ||
|
Forb
|
||||||
| 4 | Dominant perennial forbs | 10–50 | ||||
| paleface | HIDE | Hibiscus denudatus | 1–15 | – | ||
| slender janusia | JAGR | Janusia gracilis | 2–15 | – | ||
| Parry's false prairie-clover | MAPA7 | Marina parryi | 1–10 | – | ||
| rough menodora | MESC | Menodora scabra | 0–10 | – | ||
| glandleaf milkwort | POMA7 | Polygala macradenia | 1–10 | – | ||
| trailing windmills | ALIN | Allionia incarnata | 1–10 | – | ||
| desert globemallow | SPAM2 | Sphaeralcea ambigua | 1–10 | – | ||
| desert marigold | BAMU | Baileya multiradiata | 1–5 | – | ||
| leatherweed | CRPOP | Croton pottsii var. pottsii | 1–5 | – | ||
| lacy tansyaster | MAPIP4 | Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida | 1–5 | – | ||
| Coues' cassia | SECO10 | Senna covesii | 0–3 | – | ||
| desert trumpet | ERIN4 | Eriogonum inflatum | 1–3 | – | ||
| white sagebrush | ARLU | Artemisia ludoviciana | 0–3 | – | ||
| dense ayenia | AYMI | Ayenia microphylla | 0–3 | – | ||
| New Mexico silverbush | ARNE2 | Argythamnia neomexicana | 0–2 | – | ||
| weakleaf bur ragweed | AMCO3 | Ambrosia confertiflora | 0–2 | – | ||
| narrowleaf silverbush | ARLA12 | Argythamnia lanceolata | 0–2 | – | ||
| California fagonbush | FALA | Fagonia laevis | 0–2 | – | ||
| Parry's beardtongue | PEPA24 | Penstemon parryi | 0–2 | – | ||
| slender poreleaf | POGR5 | Porophyllum gracile | 0–2 | – | ||
| brownplume wirelettuce | STPA4 | Stephanomeria pauciflora | 0–2 | – | ||
| plains blackfoot | MELE2 | Melampodium leucanthum | 0–1 | – | ||
| scarlet spiderling | BOCO | Boerhavia coccinea | 0–1 | – | ||
| 5 | Ferns and fern allies | 7–55 | ||||
| Arizona spikemoss | SEAR2 | Selaginella arizonica | 5–30 | – | ||
| lipfern | CHEIL | Cheilanthes | 1–10 | – | ||
| cliffbrake | PELLA | Pellaea | 1–10 | – | ||
| cloak fern | NOTHO | Notholaena | 0–5 | – | ||
| 6 | Annual forbs and minor perennials | 1–65 | ||||
| phacelia | PHACE | Phacelia | 0–15 | – | ||
| desert Indianwheat | PLOV | Plantago ovata | 0–10 | – | ||
| lyreleaf jewelflower | STCA5 | Streptanthus carinatus | 0–10 | – | ||
| western tansymustard | DEPI | Descurainia pinnata | 0–10 | – | ||
| cryptantha | CRYPT | Cryptantha | 0–10 | – | ||
| California poppy | ESCAM | Eschscholzia californica ssp. mexicana | 0–10 | – | ||
| Gordon's bladderpod | LEGO | Lesquerella gordonii | 0–10 | – | ||
| Coulter's lupine | LUSP2 | Lupinus sparsiflorus | 0–10 | – | ||
| exserted Indian paintbrush | CAEXE | Castilleja exserta ssp. exserta | 0–10 | – | ||
| shaggyfruit pepperweed | LELA | Lepidium lasiocarpum | 0–5 | – | ||
| hairy prairie clover | DAMO | Dalea mollis | 0–5 | – | ||
| thelypody | THELY | Thelypodium | 0–5 | – | ||
| Texas stork's bill | ERTE13 | Erodium texanum | 0–5 | – | ||
| chia | SACO6 | Salvia columbariae | 0–2 | – | ||
| American wild carrot | DAPU3 | Daucus pusillus | 0–2 | – | ||
| wishbone-bush | MILAV | Mirabilis laevis var. villosa | 0–2 | – | ||
| Florida pellitory | PAFL3 | Parietaria floridana | 0–1 | – | ||
| whitestem blazingstar | MEAL6 | Mentzelia albicaulis | 0–1 | – | ||
| foothill deervetch | LOHU2 | Lotus humistratus | 0–1 | – | ||
| Mexican fireplant | EUHE4 | Euphorbia heterophylla | 0–1 | – | ||
| Parish's larkspur | DEPAP3 | Delphinium parishii ssp. parishii | 0–1 | – | ||
| bluedicks | DICAC5 | Dichelostemma capitatum ssp. capitatum | 0–1 | – | ||
| flatcrown buckwheat | ERDE6 | Eriogonum deflexum | 0–1 | – | ||
| sleepy silene | SIAN2 | Silene antirrhina | 0–1 | – | ||
| slimjim bean | PHFI3 | Phaseolus filiformis | 0–1 | – | ||
| Arizona popcornflower | PLAR | Plagiobothrys arizonicus | 0–1 | – | ||
| woolly tidestromia | TILA2 | Tidestromia lanuginosa | 0–1 | – | ||
| pricklyleaf dogweed | THAC | Thymophylla acerosa | 0–1 | – | ||
| sand fringepod | THCU | Thysanocarpus curvipes | 0–1 | – | ||
| desert mariposa lily | CAKE | Calochortus kennedyi | 0–1 | – | ||
| whitemargin sandmat | CHAL11 | Chamaesyce albomarginata | 0–1 | – | ||
| brittle spineflower | CHBR | Chorizanthe brevicornu | 0–1 | – | ||
| hyssopleaf sandmat | CHHY3 | Chamaesyce hyssopifolia | 0–1 | – | ||
| Palmer's Indian mallow | ABPA | Abutilon palmeri | 0–1 | – | ||
| brownfoot | ACWR5 | Acourtia wrightii | 0–1 | – | ||
| San Felipe dogweed | ADPO | Adenophyllum porophylloides | 0–1 | – | ||
| tuber anemone | ANTU | Anemone tuberosa | 0–1 | – | ||
| rockcress | ARABI2 | Arabis | 0–1 | – | ||
| aster | ASTER | Aster | 0–1 | – | ||
| hairyseed bahia | BAAB | Bahia absinthifolia | 0–1 | – | ||
| Coulter's spiderling | BOCO2 | Boerhavia coulteri | 0–1 | – | ||
| hoary bowlesia | BOIN3 | Bowlesia incana | 0–1 | – | ||
| Arizona wrightwort | CAAR7 | Carlowrightia arizonica | 0–1 | – | ||
|
Shrub/Vine
|
||||||
| 7 | Dominant low shrubs | 40–145 | ||||
| desert zinnia | ZIAC | Zinnia acerosa | 20–40 | – | ||
| mariola | PAIN2 | Parthenium incanum | 15–30 | – | ||
| woody crinklemat | TICAC | Tiquilia canescens var. canescens | 5–25 | – | ||
| white ratany | KRGR | Krameria grayi | 5–25 | – | ||
| fairyduster | CAER | Calliandra eriophylla | 1–20 | – | ||
| featherplume | DAFO | Dalea formosa | 1–10 | – | ||
| brittlebush | ENFA | Encelia farinosa | 0–10 | – | ||
| whitestem paperflower | PSCO2 | Psilostrophe cooperi | 1–10 | – | ||
| littleleaf ratany | KRER | Krameria erecta | 1–10 | – | ||
| pelotazo | ABIN | Abutilon incanum | 0–10 | – | ||
| triangle bur ragweed | AMDE4 | Ambrosia deltoidea | 0–10 | – | ||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 0–2 | – | ||
| American threefold | TRCA8 | Trixis californica | 0–2 | – | ||
| 8 | Dominant large shrubs | 40–100 | ||||
| ocotillo | FOSP2 | Fouquieria splendens | 15–50 | – | ||
| whitethorn acacia | ACCO2 | Acacia constricta | 10–30 | – | ||
| creosote bush | LATRT | Larrea tridentata var. tridentata | 10–25 | – | ||
| jojoba | SICH | Simmondsia chinensis | 0–20 | – | ||
| 9 | Miscellaneous shrubs | 5–25 | ||||
| Wright's beebrush | ALWR | Aloysia wrightii | 1–10 | – | ||
| Nevada jointfir | EPNE | Ephedra nevadensis | 0–2 | – | ||
| fourwing saltbush | ATCA2 | Atriplex canescens | 0–2 | – | ||
| Warnock's snakewood | COWA | Condalia warnockii | 1–2 | – | ||
| Rio Grande saddlebush | MOSC | Mortonia scabrella | 0–2 | – | ||
| Parish's goldeneye | VIPA14 | Viguiera parishii | 0–2 | – | ||
| lotebush | ZIOB | Ziziphus obtusifolia | 0–1 | – | ||
| littleleaf sumac | RHMI3 | Rhus microphylla | 0–1 | – | ||
| spiny hackberry | CEEH | Celtis ehrenbergiana | 0–1 | – | ||
| javelina bush | COER5 | Condalia ericoides | 0–1 | – | ||
| knifeleaf condalia | COSP3 | Condalia spathulata | 0–1 | – | ||
| desert lavender | HYEM | Hyptis emoryi | 0–1 | – | ||
| sangre de cristo | JACA2 | Jatropha cardiophylla | 0–1 | – | ||
| water jacket | LYAN | Lycium andersonii | 0–1 | – | ||
| Arizona desert-thorn | LYEX | Lycium exsertum | 0–1 | – | ||
| algerita | MATR3 | Mahonia trifoliolata | 0–1 | – | ||
| catclaw acacia | ACGR | Acacia greggii | 0–1 | – | ||
| 10 | Succulents | 15–75 | ||||
| saguaro | CAGI10 | Carnegiea gigantea | 1–20 | – | ||
| buck-horn cholla | CYAC8 | Cylindropuntia acanthocarpa | 1–15 | – | ||
| teddybear cholla | CYBI9 | Cylindropuntia bigelovii | 0–10 | – | ||
| cactus apple | OPEN3 | Opuntia engelmannii | 1–10 | – | ||
| purple pricklypear | OPMA8 | Opuntia macrocentra | 0–10 | – | ||
| tulip pricklypear | OPPH | Opuntia phaeacantha | 1–10 | – | ||
| banana yucca | YUBA | Yucca baccata | 1–5 | – | ||
| Nichol's echinocactus | ECHON | Echinocactus horizonthalonius var. nicholii | 0–5 | – | ||
| Bigelow's nolina | NOBI | Nolina bigelovii | 0–5 | – | ||
| jumping cholla | CYFU10 | Cylindropuntia fulgida | 0–5 | – | ||
| Christmas cactus | CYLE8 | Cylindropuntia leptocaulis | 1–5 | – | ||
| staghorn cholla | CYVE3 | Cylindropuntia versicolor | 0–5 | – | ||
| common sotol | DAWH2 | Dasylirion wheeleri | 1–5 | – | ||
| desert agave | AGDE | Agave deserti | 0–5 | – | ||
| Schott's century plant | AGSC3 | Agave schottii | 0–5 | – | ||
| California barrel cactus | FECY | Ferocactus cylindraceus | 0–2 | – | ||
| Emory's barrel cactus | FEEM | Ferocactus emoryi | 0–2 | – | ||
| candy barrelcactus | FEWI | Ferocactus wislizeni | 0–2 | – | ||
| Graham's nipple cactus | MAGR9 | Mammillaria grahamii | 0–1 | – | ||
| Thornber's nipple cactus | MATH | Mammillaria thornberi | 0–1 | – | ||
| rainbow cactus | ECPE | Echinocereus pectinatus | 0–1 | – | ||
| desert woollystar | ERER2 | Eriastrum eremicum | 0–1 | – | ||
| spinystar | ESVIV | Escobaria vivipara var. vivipara | 0–1 | – | ||
| Scheer's beehive cactus | COROS | Coryphantha robustispina ssp. scheeri | 0–1 | – | ||
| Engelmann's hedgehog cactus | ECEN | Echinocereus engelmannii | 0–1 | – | ||
| redspine fishhook cactus | ECER2 | Echinomastus erectocentrus | 0–1 | – | ||
|
Tree
|
||||||
| 11 | Trees | 50–150 | ||||
| yellow paloverde | PAMI5 | Parkinsonia microphylla | 50–150 | – | ||
| velvet mesquite | PRVE | Prosopis velutina | 0–10 | – | ||
| Arizona rosewood | VACA5 | Vauquelinia californica | 0–10 | – | ||
| oneseed juniper | JUMO | Juniperus monosperma | 0–10 | – | ||
| desert ironwood | OLTE | Olneya tesota | 0–10 | – | ||
Interpretations
Animal community
Herbaceous forage produced on this site is less palatable than that of other hill sites because high pH (due to lime) ties up essential plant nutrients and the very droughty soils make for a short green season. The plant community has a good variety of perennial grasses and low browse species for year-round use but steep, rocky slopes hinder utilization in the heat of summer. The site is best suited to cool season use with dry cows or stocker types. Slope aspect affects both the intensity of utilization as well as seasonal use patterns. South facing slopes are used more in winter due to warm temperatures and early greenup. North aspects, being shaded and cooler, are used more in the fall due to the longer green periods for forage species. This site tends to be dry even in the winter when other hill sites have canyon water.
Water developments are very important to wildlife on this site. Cover, forage plant diversity, and topography are good enough to make this site home to a wide variety of wildlife including the large desert mammals.
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, fossil collecting
Wood products
Some paloverde, ironwood and mesquite for camp-fires and branding fires.
Other products
Stones and cobbles; limestone for cement and flux. Saguaro ribs, cholla skeletons and rosewood. Tradtional foods like saguaro fruits, prickly pear tunas, cactus flower buds and jojoba nuts. Traditional herbs like coyote tobacco, mint bush, club moss, croton, creosotebush and limberbush.
Supporting information
Inventory data references
Range 417s include 2 in good condition
Type locality
| Location 1: Pima County, AZ | |
|---|---|
| Township/Range/Section | T12S R9E S36 |
| General legal description | Tucson Field Office: Waterman Mountains NW 1/4 sec. 36 |
| Location 2: Pima County, AZ | |
| Township/Range/Section | T9S R12E S22 |
| General legal description | Sells Field Office: Vekol Mountains NE 1/4 sec. 22 |
| Location 3: Pima County, AZ | |
| Township/Range/Section | T10S R17E S244 |
| General legal description | Tucson Field Office: Magma Copper Co Lime Quarry SE 1/4 sec. 244 |
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 | 03/07/2005 |
| 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 but seem to follow bedding planes, joints and fractures in the bedrock parent materials. -
Presence of water flow patterns:
Uncommon; probably cover no more than 10% of the area; discontinuous, usually less than 10-15 feet in length -
Number and height of erosional pedestals or terracettes:
Pedestals are uncommon on perennial grass and shrubs; terracettes uncommon. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
10-15% -
Number of gullies and erosion associated with gullies:
none -
Extent of wind scoured, blowouts and/or depositional areas:
none -
Amount of litter movement (describe size and distance expected to travel):
most litter size classes stay in place -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Expect values of 1-3 in canopy interspaces, and 4-6 under plant canopies. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Weak thin platy to weak granular; color is 7.5-10YR6/4 dry; 7.5-10YR4/4 moist; thickness to 1 inch. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
canopy 15-25%, 70-80% of canopy cover is shrubs, 5% trees, and 10-15% succulents, 1-2% perennial grass. Cover is well dispersed throughout the 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:
subshrubs > shrubs & trees > annual grasses & forbs > succulents = 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):
50% basal cover of perennial grassess has likely been lost in recent prolonged drought. -
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
173 lbs/ac unfavorable precipitation; 500 lbs/ac normal precipitaton; 840 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:
bufflegrass, whitethorn, mesquite, prickly pear, cane cholla & ocotillo may increase -
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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