Natural Resources
Conservation Service
Ecological site R041XB210AZ
Loamy Upland 8-12" p.z.
Last updated: 4/12/2021
Accessed: 12/03/2024
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): 041X–Madrean Archipelago
Major Land Resource Area (MLRA) 41 represents the most northern extent of the Sierra Madre Occidental, or in English, the “mother mountains of the west.” The Sierra Madre Occidental is a massive, rugged mountain system that runs northwest from the Rio Grande de Santiago, in the state of Jalisco, Mexico, through the states of Sonora and Chihuahua, and ending in Arizona and New Mexico. Through Mexico, this mountain system runs parallel to the Pacific coast and, as it crosses into the United States and confronts the tectonic folding and rifting of the Basin and Range Physiographic Province, the land mass geographically breaks into smaller, isolated mountain ranges, called “sky islands.” The centralizing theme for this MLRA can be summed up as a series of inland islands extending from their mainland, the Sierra Madre Occidental, surrounded by a sea of desert grassland. To the west, the Madrean Archipelago bounds the Sonoran Basin and Range where several sky islands in southern Arizona grade into Sonoran Desert basins; to the north it bounds the contiguous mountains and geology of the Mogollon Transition area; and to the east, in New Mexico, it bounds the geology of the Rio Grande Rift. MLRA 41 is primarily a rangeland subdivision with small amounts of irrigated cropland. It encompasses approximately 13M acres.
LRU notes
Land Resource Unit 41-2, Chihuahuan-Sonoran Desert Shrub. Elevations range from 2600 to 4000 feet and precipitation ranges from 8 to 12 inches per year. Vegetation includes mesquite, palo verde, catclaw acacia, soaptree yucca, creosotebush, whitethorn, staghorn cholla, desert saltbush, Mormon tea, burroweed, snakeweed, tobosa, black grama, threeawns, bush muhly, dropseed, and burrograss. The soil temperature regime is thermic and the soil moisture regime is typic aridic.
Classification relationships
USDA-NRCS Land Resource Regions and Major Land Resource Areas of the United States, the Caribbean, and the Pacific Basin: Western Range and Irrigated Region D; Major Land Resource Area 41, Southeastern Arizona Basin and Range; Land Resource Unit 41-2, Chihuahuan-Sonoran Desert Shrub; Ecological Site Loamy Upland, 8"-12" p.z.
U.S. Environmental Protection Agency, Ecological Regions of North America: Level I, Region 12, Southern Semi-Arid Highlands; Level II, 12.1 Western Sierra Madre Piedmont, Level III, Ecoregion 79 Madrean Archipelago, 79a, Apachian Valleys and Low Hills.
USDA-USFS Ecological Subregions: Sections of the Conterminous United States: Section 321 Basin and Range; Section 321A, Basin and Range Section.
Ecological site concept
Loamy Upland, 8"-12" p.z., is found on gently sloping uplands with deep soils. Surface soils are non-calcareous sandy loam to loam with an underlying argillic horizon. When the soil above the argillic is sandy loam textured, it is less than 4" thick.
Associated sites
| R041XB204AZ |
Clay Loam Upland 8-12" p.z. adjacent, lacking sandy loam (loam) surface horizon, clays exhibit vertic (shrink-swell) properties |
|---|---|
| R041XB208AZ |
Limy Upland 8-12" p.z. adjacent, shallow soil, calcareous to surface |
| R041XB203AZ |
Clayey Upland 8-12" p.z. adjacent, lacking sandy loam (loam) surface horizon |
Similar sites
| R040XA114AZ |
Loamy Upland 10"-13" p.z. elevation range 4,500-6,500 ft., precipitation zone 16-20 inches |
|---|---|
| R041XC313AZ |
Loamy Upland 12"-16" p.z. elevation range 3,200-4,500 ft., precipitation zone 12-16 inches |
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) Prosopis glandulosa var. torreyana |
| Herbaceous |
(1) Pleuraphis mutica |
Physiographic features
This site occurs in the lowest elevations of the Madrean Basin and Range province in southeastern Arizona. It occurs on rolling low ridges, fan terraces, mesas and gently sloping uplands; generally below the hills and above the plains.
Table 2. Representative physiographic features
| Landforms |
(1)
Ridge
(2) Fan piedmont (3) Mesa |
|---|---|
| Flooding frequency | None |
| Ponding frequency | None |
| Elevation | 2,600 – 4,000 ft |
| Slope | 1 – 15% |
| Aspect | Aspect is not a significant factor |
Climatic features
Precipitation ranges from 8-12 inches annually. More than half falls during Jul-Sep in brief, but often heavy, thunderstorms. The rest of the moisture comes as light rain or snow that falls slowly for a day or more, but rarely lasts more than a day. May and June are normally the driest months. Humidity is generally very low.
Temperatures are mild throughout most of the year. Freezing temperatures are common at night Dec-Feb; brief 0 F may be observed some nights. During June, July & August, some days may exceed 100 F.
In years of average or greater winter precipitation, annual grasses and forbs occur abundantly in the interspaces.
Table 3. Representative climatic features
| Frost-free period (characteristic range) | 160-185 days |
|---|---|
| Freeze-free period (characteristic range) | 185-227 days |
| Precipitation total (characteristic range) | 11-12 in |
| Frost-free period (actual range) | 149-186 days |
| Freeze-free period (actual range) | 171-228 days |
| Precipitation total (actual range) | 10-12 in |
| Frost-free period (average) | 172 days |
| Freeze-free period (average) | 204 days |
| Precipitation total (average) | 11 in |
Figure 2. Monthly precipitation range
Figure 3. Monthly minimum temperature range
Figure 4. Monthly maximum temperature range
Figure 5. Monthly average minimum and maximum temperature
Figure 6. Annual precipitation pattern
Figure 7. Annual average temperature pattern
Climate stations used
-
(1) SAN SIMON [USC00027560], San Simon, AZ
-
(2) BOWIE [USC00020958], San Simon, AZ
-
(3) DUNCAN [USC00022754], Duncan, AZ
-
(4) SAFFORD AGRICULTRL CTR [USC00027390], Safford, AZ
Influencing water features
There are no water features associated with this site.
Soil features
These soils are moderately deep to deep and loamy textured. They have thin (2-4 inch) surface horizons that range from sandyloam to loam in texture, over an argillic horizon. Surface soils (10 inches) are non-calcareous, while some soils have calcic horizons below the argillic horizon. Some soil series have a lime or silica cemented pan at moderate depths. Although several soil series are correlated in map unit components to this ecological site, Bucklebar soil series is most representative of Loamy Upland, 8-12” p.z..
Table 4. Representative soil features
| Surface texture |
(1) Sandy loam (2) Very gravelly sandy loam (3) Gravelly loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderately slow to slow |
| Soil depth | 60 in |
| Surface fragment cover <=3" | 5 – 50% |
| Surface fragment cover >3" | 10% |
| Available water capacity (0-40in) |
5 – 10.1 in |
| Calcium carbonate equivalent (0-40in) |
25% |
| Electrical conductivity (0-40in) |
2 mmhos/cm |
| Sodium adsorption ratio (0-40in) |
2 |
| Soil reaction (1:1 water) (0-40in) |
7.4 – 8.4 |
| Subsurface fragment volume <=3" (Depth not specified) |
65% |
| Subsurface fragment volume >3" (Depth not specified) |
10% |
Ecological dynamics
Loamy Upland, 8"-12" pz, ecological site is a mixed shrubland with a perennial grass understory. Plant community variation occurs both along the precipitation gradient (from low end of the precipitation zone to the high) and with depth to argillic horizon. Perennial grass composition, basal cover, and distribution are affected. At the lower end of the precipitation gradient (and with thin surface horizon over argillic), bare areas increase in diameter and connectivity, tobosa grass dominates perennial grasses; while at the high end of the precipitation gradient (and with increased depth to argillic), bush muhly and black grama dominate and bare areas are less commonly connected. Several species of perennial grasses, sand dropseed and three-awns for example, come in and out of the plant community as weather patterns fluctuate between wet and dry cycles. Drought is the primary natural disturbance on this ecological site. As human-driven disturbances disrupt this site, 3 alternative states arise: State 2, Non-native Grass; State 3, Large Shrub-Annuals, and State 4, Large Shrub-Eroded.
State and transition model
More interactive model formats are also available.
View Interactive Models
More interactive model formats are also available.
View Interactive Models
Click on state and transition labels to scroll to the respective text
State 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 4 submodel, plant communities
State 1
Native Grass-Shrubland
State 1. Native Grass-Shrub State has two Community Phases that fluctuate with dry/wet weather cycling. The Reference Plant Community (CP1.1) is a an open community of perennial grasses and desert shrubs and cacti. Annual forbs and grasses, of both the winter and summer wet seasons, are very important in the plant community in their respective (wet) seasons. Tobosa, black grama and bush muhly are the dominant perennial grasses, with lesser amounts of perennial mid-grasses such as threeawns and dropseeds. The cover of some shallow rooted grass species, like curly mesquite and Rothrock grama fluctuate widely from wet to dry years. Climate fluctuations, cycling of wet winters, favors shrub growth thus allowing the shrub dominance in CP1.1; extended drought will contract both perennial grass and shrub canopy covers, transitioning the community phase to CP1.2. Natural fire may occasionally occur in this LRU but is not thought to have recurred with a frequency to shape this plant community.
Community 1.1
Shrub-Suffrutescent-MidGrass
Figure 8. Loamy Upland 8-12" pz. soils pit
The native potential plant community on this site is a mixture of perennial grasses and desert shrubs and cacti. Annual forbs and grasses, of both the winter and summer seasons, are very important in the plant community in their respective (wet) seasons. Tobosa, black grama and bush muhly are the dominant perennial grasses, with lesser amounts of threeawns. The cover of some shallow rooted grass species, like curly mesquite and Rothrock grama fluctuate widely from wet to dry years.
Figure 9. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
| Plant type | Low (lb/acre) |
Representative value (lb/acre) |
High (lb/acre) |
|---|---|---|---|
| Grass/Grasslike | 100 | 250 | 525 |
| Forb | 3 | 50 | 170 |
| Shrub/Vine | 45 | 100 | 130 |
| Total | 148 | 400 | 825 |
Table 6. Soil surface cover
| Tree basal cover | 0% |
|---|---|
| Shrub/vine/liana basal cover | 1-2% |
| Grass/grasslike basal cover | 1-2% |
| Forb basal cover | 1-2% |
| Non-vascular plants | 0% |
| Biological crusts | 5-15% |
| Litter | 10-55% |
| Surface fragments >0.25" and <=3" | 15-50% |
| Surface fragments >3" | 0-15% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 5-70% |
Table 7. Canopy structure (% cover)
| Height Above Ground (ft) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.5 | – | 1-5% | 1-15% | 1-20% |
| >0.5 <= 1 | – | 1-5% | 5-10% | 1-15% |
| >1 <= 2 | – | 1-5% | 5-10% | 0-5% |
| >2 <= 4.5 | – | 5-10% | 0-2% | 0-2% |
| >4.5 <= 13 | – | – | – | – |
| >13 <= 40 | – | – | – | – |
| >40 <= 80 | – | – | – | – |
| >80 <= 120 | – | – | – | – |
| >120 | – | – | – | – |
Community 1.2
Shrub-Suffutescent
During periods of drought, short-rooted grasses and mid-grasses diminish in basal cover; half-shrub mortality occurs after consecutive dry winters.
State 2
Non-Native Grass
State 2, Non-Native Grass State, predominantly cycles between two Community Phases: large shrub-annual forbs (CP2.2) / large shrub-Lehmann lovegrass (CP2.3). Community Phase 2.1 persists for about 10 years after brush management before shrub dominance resumes. Restoration from State 3, prescribed grazing without brush management, will result in CP 2.2. The prevalence of Lehamnn lovegrass within the soil seedbank no longer requires range seeding. Once a soil seedbank is established, LL persists in the plant community while its basal cover varies with climate, elevation, and depth of surface soil over argillic. Lehmann lovegrass only dominates the entire plant community in CP 2.1, after brush management and seeding, but it will dominate the herbaceous layer of the plant community once established. Lehmann lovegrass production does not exceed 400# / ac during Non-Native lovegrass cycles.
Community 2.1
Non-native Grass
Community 2.2
Shrubs-Annuals
This state occurs where mesquite has increased from between 2 and 10% canopy cover and some cover of native perennial (suffrutescent) grasses and forbs remains. Other shrubs and succulents exist in minor amounts. Annual forbs and grasses (both native and non-native) are very important in their respective (wet) seasons.
Community 2.3
Shrubs-NonNative Grass
State 3
Large Shrub-Annuals
State 3, Large Shrubs-Annuals, comes about after years of heavy grazing. Suffrutescent grasses are confined to tightly protected areas within shrub and cactus canopies leaving large bare areas as inter-shrub spaces.
Community 3.1
Mesquite, annuals
Figure 10. Loamy Upland 8-12" pz., mesquite, annuals
This state occurs where mesquite and other shrubs (creosotebush) and cacti dominate the plant community. Native perennial grasses and forbs have been removed from the plant community and native and non-native annual species dominate the herbaceous layer.
State 4
Large Shrub, Eroded
State 4, Large Shrubs, Eroded, has active, accelerated erosion. This state occurs where mesquite canopy is heavy (15-25%) and the interaction of drought and continuous grazing has resulted in severe sheet, rill and, in some cases, gully erosion on the site. These areas are usually near historic watering locations and are characterized by soil compaction due to trailing and heavy livestock traffic.
Community 4.1
Mesquite, Erosion
This state occurs where mesquite canopy is heavy (15-25%) and the interaction of drought and continuous grazing has resulted in severe sheet, rill and, in some cases, gully erosion on the site. These areas are usually near historic watering locations and are characterized by soil compaction due to trailing and heavy livestock traffic.
Transition T1A
State 1 to 3
Heavy, continuous livestock grazing
Transition T2A
State 2 to 4
heavy, continuous grazing
Restoration pathway R3B
State 3 to 1
None known
Restoration pathway R3A
State 3 to 2
Prescribed grazing, introduction of non-native lovegrass, brush management, mechanical land treatment
Transition T3A
State 3 to 4
heavy, continuous grazing
Restoration pathway R4A
State 4 to 2
brush management, mechanical land treatment, range planting, prescribed grazing
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 | 80–200 | ||||
| tobosagrass | PLMU3 | Pleuraphis mutica | 30–100 | – | ||
| bush muhly | MUPO2 | Muhlenbergia porteri | 25–75 | – | ||
| black grama | BOER4 | Bouteloua eriopoda | 25–50 | – | ||
| 2 | Miscellaneous Perennial Grasses | 5–75 | ||||
| curly-mesquite | HIBE | Hilaria belangeri | 1–50 | – | ||
| sideoats grama | BOCU | Bouteloua curtipendula | 1–20 | – | ||
| low woollygrass | DAPU7 | Dasyochloa pulchella | 1–20 | – | ||
| Arizona cottontop | DICA8 | Digitaria californica | 0–20 | – | ||
| cane bluestem | BOBA3 | Bothriochloa barbinodis | 0–15 | – | ||
| blue grama | BOGR2 | Bouteloua gracilis | 0–10 | – | ||
| green sprangletop | LEDU | Leptochloa dubia | 0–10 | – | ||
| Hall's panicgrass | PAHA | Panicum hallii | 0–10 | – | ||
| burrograss | SCBR2 | Scleropogon brevifolius | 0–10 | – | ||
| plains bristlegrass | SEVU2 | Setaria vulpiseta | 0–10 | – | ||
| sand dropseed | SPCR | Sporobolus cryptandrus | 0–5 | – | ||
| vine mesquite | PAOB | Panicum obtusum | 0–5 | – | ||
| Arizona muhly | MUAR3 | Muhlenbergia arizonica | 0–2 | – | ||
| squirreltail | ELEL5 | Elymus elymoides | 0–2 | – | ||
| tanglehead | HECO10 | Heteropogon contortus | 0–2 | – | ||
| big sacaton | SPWR2 | Sporobolus wrightii | 0–1 | – | ||
| 3 | Perennial threeawns | 10–100 | ||||
| purple threeawn | ARPU9 | Aristida purpurea | 5–50 | – | ||
| Parish's threeawn | ARPUP5 | Aristida purpurea var. parishii | 0–25 | – | ||
| spidergrass | ARTE3 | Aristida ternipes | 5–25 | – | ||
| spidergrass | ARTEG | Aristida ternipes var. gentilis | 0–15 | – | ||
| Fendler threeawn | ARPUL | Aristida purpurea var. longiseta | 0–15 | – | ||
| blue threeawn | ARPUN | Aristida purpurea var. nealleyi | 0–5 | – | ||
| poverty threeawn | ARDI5 | Aristida divaricata | 0–5 | – | ||
| 4 | Annual grasses | 1–150 | ||||
| needle grama | BOAR | Bouteloua aristidoides | 0–50 | – | ||
| Rothrock's grama | BORO2 | Bouteloua rothrockii | 0–50 | – | ||
| mucronate sprangeltop | LEPAB | Leptochloa panicea ssp. brachiata | 0–25 | – | ||
| sixweeks fescue | VUOC | Vulpia octoflora | 1–25 | – | ||
| sixweeks threeawn | ARAD | Aristida adscensionis | 1–25 | – | ||
| sixweeks grama | BOBA2 | Bouteloua barbata | 0–20 | – | ||
| Arizona signalgrass | URAR | Urochloa arizonica | 0–20 | – | ||
| feather fingergrass | CHVI4 | Chloris virgata | 0–15 | – | ||
| witchgrass | PACA6 | Panicum capillare | 0–10 | – | ||
| Mexican panicgrass | PAHI5 | Panicum hirticaule | 0–10 | – | ||
| prairie threeawn | AROL | Aristida oligantha | 1–10 | – | ||
| Bigelow's bluegrass | POBI | Poa bigelovii | 0–5 | – | ||
| tapertip cupgrass | ERACA | Eriochloa acuminata var. acuminata | 0–5 | – | ||
| desert lovegrass | ERPEM | Eragrostis pectinacea var. miserrima | 0–5 | – | ||
| tufted lovegrass | ERPEP2 | Eragrostis pectinacea var. pectinacea | 0–5 | – | ||
| Mexican sprangletop | LEFUU | Leptochloa fusca ssp. uninervia | 0–5 | – | ||
| Arizona brome | BRAR4 | Bromus arizonicus | 0–5 | – | ||
| delicate muhly | MUFR | Muhlenbergia fragilis | 0–2 | – | ||
| littleseed muhly | MUMI | Muhlenbergia microsperma | 0–2 | – | ||
|
Forb
|
||||||
| 5 | Perennial Forbs | 2–20 | ||||
| dwarf desertpeony | ACNA2 | Acourtia nana | 1–10 | – | ||
| weakleaf bur ragweed | AMCO3 | Ambrosia confertiflora | 1–5 | – | ||
| slender poreleaf | POGR5 | Porophyllum gracile | 0–5 | – | ||
| desert globemallow | SPAM2 | Sphaeralcea ambigua | 1–5 | – | ||
| Indian rushpea | HOGL2 | Hoffmannseggia glauca | 0–2 | – | ||
| slender janusia | JAGR | Janusia gracilis | 0–2 | – | ||
| bluedicks | DICA14 | Dichelostemma capitatum | 0–2 | – | ||
| spreading fleabane | ERDI4 | Erigeron divergens | 0–1 | – | ||
| desert trumpet | ERIN4 | Eriogonum inflatum | 0–1 | – | ||
| southwestern mock vervain | GLGO | Glandularia gooddingii | 0–1 | – | ||
| brownfoot | ACWR5 | Acourtia wrightii | 0–1 | – | ||
| poreleaf dogweed | ADPO2 | Adenophyllum porophyllum | 0–1 | – | ||
| trailing windmills | ALIN | Allionia incarnata | 0–1 | – | ||
| largeflower onion | ALMA4 | Allium macropetalum | 0–1 | – | ||
| tuber anemone | ANTU | Anemone tuberosa | 0–1 | – | ||
| narrowleaf silverbush | ARLA12 | Argythamnia lanceolata | 0–1 | – | ||
| New Mexico silverbush | ARNE2 | Argythamnia neomexicana | 0–1 | – | ||
| perennial rockcress | ARPE2 | Arabis perennans | 0–1 | – | ||
| dense ayenia | AYMI | Ayenia microphylla | 0–1 | – | ||
| hairyseed bahia | BAAB | Bahia absinthifolia | 0–1 | – | ||
| desert marigold | BAMU | Baileya multiradiata | 0–1 | – | ||
| scarlet spiderling | BOCO | Boerhavia coccinea | 0–1 | – | ||
| desert mariposa lily | CAKE | Calochortus kennedyi | 0–1 | – | ||
| sego lily | CANU3 | Calochortus nuttallii | 0–1 | – | ||
| whitemargin sandmat | CHAL11 | Chamaesyce albomarginata | 0–1 | – | ||
| leatherweed | CRPO5 | Croton pottsii | 0–1 | – | ||
| fingerleaf gourd | CUDI | Cucurbita digitata | 0–1 | – | ||
| coyote gourd | CUPA | Cucurbita palmata | 0–1 | – | ||
| ragged nettlespurge | JAMA | Jatropha macrorhiza | 0–1 | – | ||
| Parry's false prairie-clover | MAPA7 | Marina parryi | 0–1 | – | ||
| lacy tansyaster | MAPIP4 | Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida | 0–1 | – | ||
| plains blackfoot | MELE2 | Melampodium leucanthum | 0–1 | – | ||
| wishbone-bush | MILAV | Mirabilis laevis var. villosa | 0–1 | – | ||
| desert tobacco | NIOB | Nicotiana obtusifolia | 0–1 | – | ||
| brownplume wirelettuce | STPA4 | Stephanomeria pauciflora | 0–1 | – | ||
| pricklyleaf dogweed | THAC | Thymophylla acerosa | 0–1 | – | ||
| Rocky Mountain zinnia | ZIGR | Zinnia grandiflora | 0–1 | – | ||
| canaigre dock | RUHY | Rumex hymenosepalus | 0–1 | – | ||
| twinleaf senna | SEBA3 | Senna bauhinioides | 0–1 | – | ||
| Coues' cassia | SECO10 | Senna covesii | 0–1 | – | ||
| silverleaf nightshade | SOEL | Solanum elaeagnifolium | 0–1 | – | ||
| 6 | Annual forbs | 1–150 | ||||
| tanseyleaf tansyaster | MATA2 | Machaeranthera tanacetifolia | 0–50 | – | ||
| California poppy | ESCAM | Eschscholzia californica ssp. mexicana | 0–25 | – | ||
| Coulter's lupine | LUSP2 | Lupinus sparsiflorus | 0–25 | – | ||
| western tansymustard | DEPI | Descurainia pinnata | 0–20 | – | ||
| combseed | PECTO | Pectocarya | 0–20 | – | ||
| Arizona popcornflower | PLAR | Plagiobothrys arizonicus | 0–20 | – | ||
| desert Indianwheat | PLOV | Plantago ovata | 0–20 | – | ||
| bristly fiddleneck | AMTE3 | Amsinckia tessellata | 0–15 | – | ||
| coastal bird's-foot trefoil | LOSAB | Lotus salsuginosus var. brevivexillus | 0–15 | – | ||
| shaggyfruit pepperweed | LELA | Lepidium lasiocarpum | 0–15 | – | ||
| intermediate pepperweed | LEVIM | Lepidium virginicum var. medium | 0–15 | – | ||
| Arizona poppy | KAGR | Kallstroemia grandiflora | 0–10 | – | ||
| miniature woollystar | ERDI2 | Eriastrum diffusum | 0–10 | – | ||
| manybristle chinchweed | PEPA2 | Pectis papposa | 0–10 | – | ||
| New Mexico plumeseed | RANE | Rafinesquia neomexicana | 0–5 | – | ||
| Nuttall's povertyweed | MONU | Monolepis nuttalliana | 0–5 | – | ||
| carelessweed | AMPA | Amaranthus palmeri | 0–5 | – | ||
| sorrel buckwheat | ERPO4 | Eriogonum polycladon | 0–5 | – | ||
| Texas stork's bill | ERTE13 | Erodium texanum | 0–5 | – | ||
| Gordon's bladderpod | LEGO | Lesquerella gordonii | 0–5 | – | ||
| foothill deervetch | LOHU2 | Lotus humistratus | 0–5 | – | ||
| slender goldenweed | MAGR10 | Machaeranthera gracilis | 0–5 | – | ||
| milkvetch | ASTRA | Astragalus | 0–5 | – | ||
| wheelscale saltbush | ATEL | Atriplex elegans | 0–5 | – | ||
| Coulter's spiderling | BOCO2 | Boerhavia coulteri | 0–5 | – | ||
| wedgeleaf draba | DRCU | Draba cuneifolia | 0–5 | – | ||
| flatcrown buckwheat | ERDE6 | Eriogonum deflexum | 0–5 | – | ||
| cryptantha | CRYPT | Cryptantha | 0–5 | – | ||
| hairy prairie clover | DAMO | Dalea mollis | 0–2 | – | ||
| American wild carrot | DAPU3 | Daucus pusillus | 0–2 | – | ||
| white tackstem | CAWR | Calycoseris wrightii | 0–2 | – | ||
| brittle spineflower | CHBR | Chorizanthe brevicornu | 0–2 | – | ||
| hyssopleaf sandmat | CHHY3 | Chamaesyce hyssopifolia | 0–2 | – | ||
| Esteve's pincushion | CHST | Chaenactis stevioides | 0–2 | – | ||
| fringed redmaids | CACI2 | Calandrinia ciliata | 0–2 | – | ||
| Arizona lupine | LUAR4 | Lupinus arizonicus | 0–2 | – | ||
| hairy desertsunflower | GECA2 | Geraea canescens | 0–2 | – | ||
| star gilia | GIST | Gilia stellata | 0–2 | – | ||
| woolly tidestromia | TILA2 | Tidestromia lanuginosa | 0–2 | – | ||
| sleepy silene | SIAN2 | Silene antirrhina | 0–2 | – | ||
| woollyhead neststraw | STMI2 | Stylocline micropoides | 0–2 | – | ||
| green carpetweed | MOVE | Mollugo verticillata | 0–2 | – | ||
| desert evening primrose | OEPR | Oenothera primiveris | 0–2 | – | ||
| Florida pellitory | PAFL3 | Parietaria floridana | 0–2 | – | ||
| phacelia | PHACE | Phacelia | 0–2 | – | ||
| doubleclaw | PRPA2 | Proboscidea parviflora | 0–1 | – | ||
| chia | SACO6 | Salvia columbariae | 0–1 | – | ||
| sawtooth sage | SASU7 | Salvia subincisa | 0–1 | – | ||
| spreading fanpetals | SIAB | Sida abutifolia | 0–1 | – | ||
| whitestem blazingstar | MEAL6 | Mentzelia albicaulis | 0–1 | – | ||
| bristly nama | NAHI | Nama hispidum | 0–1 | – | ||
| glandular threadplant | NEGL | Nemacladus glanduliferus | 0–1 | – | ||
| sand fringepod | THCU | Thysanocarpus curvipes | 0–1 | – | ||
| tumblemustard | THELY3 | Thelypodiopsis | 0–1 | – | ||
| Coulter's globemallow | SPCO2 | Sphaeralcea coulteri | 0–1 | – | ||
| crestrib morning-glory | IPCO2 | Ipomoea costellata | 0–1 | – | ||
| Mexican fireplant | EUHE4 | Euphorbia heterophylla | 0–1 | – | ||
| common woolly sunflower | ERLA6 | Eriophyllum lanatum | 0–1 | – | ||
| exserted Indian paintbrush | CAEXE | Castilleja exserta ssp. exserta | 0–1 | – | ||
| yellow tackstem | CAPA7 | Calycoseris parryi | 0–1 | – | ||
| southwestern pricklypoppy | ARPL3 | Argemone pleiacantha | 0–1 | – | ||
| hoary bowlesia | BOIN3 | Bowlesia incana | 0–1 | – | ||
| scrambled eggs | COAU2 | Corydalis aurea | 0–1 | – | ||
| annual agoseris | AGHE2 | Agoseris heterophylla | 0–1 | – | ||
|
Shrub/Vine
|
||||||
| 7 | Dominant shrubs | 7–70 | ||||
| western honey mesquite | PRGLT | Prosopis glandulosa var. torreyana | 15–30 | – | ||
| jojoba | SICH | Simmondsia chinensis | 0–20 | – | ||
| creosote bush | LATR2 | Larrea tridentata | 0–15 | – | ||
| catclaw acacia | ACGR | Acacia greggii | 5–15 | – | ||
| fourwing saltbush | ATCA2 | Atriplex canescens | 1–10 | – | ||
| whitethorn acacia | ACCO2 | Acacia constricta | 0–10 | – | ||
| longleaf jointfir | EPTR | Ephedra trifurca | 0–5 | – | ||
| 8 | Miscellaneous shrubs | 0–10 | ||||
| Wright's beebrush | ALWR | Aloysia wrightii | 0–1 | – | ||
| crucifixion thorn | CAHO3 | Canotia holacantha | 0–1 | – | ||
| spiny hackberry | CEEH | Celtis ehrenbergiana | 0–1 | – | ||
| American tarwort | FLCE | Flourensia cernua | 0–1 | – | ||
| ocotillo | FOSP2 | Fouquieria splendens | 0–1 | – | ||
| water jacket | LYAN | Lycium andersonii | 0–1 | – | ||
| Berlandier's wolfberry | LYBE | Lycium berlandieri | 0–1 | – | ||
| pale desert-thorn | LYPA | Lycium pallidum | 0–1 | – | ||
| catclaw mimosa | MIACB | Mimosa aculeaticarpa var. biuncifera | 0–1 | – | ||
| blue paloverde | PAFL6 | Parkinsonia florida | 0–1 | – | ||
| yellow paloverde | PAMI5 | Parkinsonia microphylla | 0–1 | – | ||
| lotebush | ZIOB | Ziziphus obtusifolia | 0–1 | – | ||
| 9 | Half shrubs | 5–30 | ||||
| fairyduster | CAER | Calliandra eriophylla | 1–15 | – | ||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 0–10 | – | ||
| bastardsage | ERWR | Eriogonum wrightii | 1–10 | – | ||
| desert zinnia | ZIAC | Zinnia acerosa | 1–10 | – | ||
| shortleaf baccharis | BABR | Baccharis brachyphylla | 1–10 | – | ||
| rough menodora | MESC | Menodora scabra | 0–5 | – | ||
| burroweed | ISTE2 | Isocoma tenuisecta | 0–5 | – | ||
| littleleaf ratany | KRER | Krameria erecta | 1–5 | – | ||
| winterfat | KRLA2 | Krascheninnikovia lanata | 0–1 | – | ||
| turpentine bush | ERLA12 | Ericameria laricifolia | 0–1 | – | ||
| rayless goldenhead | ACSP | Acamptopappus sphaerocephalus | 0–1 | – | ||
| whitestem paperflower | PSCO2 | Psilostrophe cooperi | 0–1 | – | ||
| threadleaf snakeweed | GUMI | Gutierrezia microcephala | 0–1 | – | ||
| 10 | Succulents | 5–20 | ||||
| devil's cholla | GRKU | Grusonia kunzei | 0–5 | – | ||
| cactus apple | OPEN3 | Opuntia engelmannii | 0–5 | – | ||
| tulip pricklypear | OPPH | Opuntia phaeacantha | 1–5 | – | ||
| soaptree yucca | YUEL | Yucca elata | 1–5 | – | ||
| banana yucca | YUBA | Yucca baccata | 0–2 | – | ||
| purple pricklypear | OPMA8 | Opuntia macrocentra | 0–2 | – | ||
| saguaro | CAGI10 | Carnegiea gigantea | 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 | – | ||
| pinkflower hedgehog cactus | ECFA | Echinocereus fasciculatus | 0–1 | – | ||
| candy barrelcactus | FEWI | Ferocactus wislizeni | 0–1 | – | ||
| buck-horn cholla | CYAC8 | Cylindropuntia acanthocarpa | 0–1 | – | ||
| Graham's nipple cactus | MAGR9 | Mammillaria grahamii | 0–1 | – | ||
Interpretations
Animal community
This site produces some perennial forage for livestock. It wet (El Nino) winters it produces a tremendous amount of annual forbs and grasses, all of which are excellent forage. The site is home to a variety of small mammals and birds and their associated predators. It is mainly a foraging area for larger mammals like mule deer and javalina.
Hydrological functions
These soils are medium textured and fair producers of runoff.
Recreational uses
Hunting, horseback riding, hiking, wildlife observation, photography, rock hounding and bird watching.
Wood products
Limited mesquite wood for campfires.
Supporting information
Other references
Griffith, G.E., Omernik, J.M., Johnson, C.B., and Turner, D.S., 2014, Ecoregions of Arizona (poster): U.S. Geological Survey Open-File Report 2014-1141, with map, scale 1:1,325,000, https://dx.doi.org/10.3133/ofr20141141. ISSN 2331-1258 (online)
United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land Resource Regions and Major Land Resource Areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296.
McNab, W.H.; Cleland, D.T.; Freeouf, J.A.; Keys, Jr., J.E.; Nowacki, G.J.; Carpenter, C.A., comps. 2007.
Description of ecological subregions: sections of the conterminous United States [CD-ROM]. Gen. Tech.
Report WO-76B. Washington, DC: U.S. Department of Agriculture, Forest Service. 80 p.
Contributors
Dan Robinett
Larry D. Ellicott
Approval
Curtis Talbot, 4/12/2021
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) | Wilma Renken, Dan Robinett, Larry Humphrey |
|---|---|
| Contact for lead author | USDA-NRCS Tucson MLRA Soil Survey Office |
| Date | 12/12/2012 |
| Approved by | Curtis Talbot |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
None -
Presence of water flow patterns:
Water flow paths occupy less than 5% of the surface area. Sheet flow predominates as a process on this site. Sheet flow lengths are less than 5 feet. -
Number and height of erosional pedestals or terracettes:
Pedestals are infrequent on all longer lived grasses and sub-shrubs. Terracettes are common on the site only in black grama areas. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Twenty-three percent (23%) bare ground. Ground cover was collected as point cover data concurrently with pace frequency method (300 pts). Bare areas are up to 3’ in diameter, somewhat connected, and evenly distributed. -
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):
Fine litter size classes are moving less than a foot. Coarse litter staying in place. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Slake test values range from 4-6 across site. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
A horizon is a gravelly sandyloam 3 inches thick with a weak subangular blocky structure. Colors are 7.5 YR 5/4 dry and 7.5 YR 3/4 moist. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Perennial grasses dominate the site, are well-distributed across the site, and play an important role in the infiltration/hydrologic functioning by interrupting, slowing, overland sheet-flow of water. Black grama canopy is 17% and spidergrass canopy is 29% on this site. Only cane cholla and prickly pear have increased on the site. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None present, average depth of penetration from an ARS field penetrometer with a 2.2 kg. sliding hammer is 4.9 cm. The clayey argillic horizon at 3 inches can feel like a compacted layer. -
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:
Dom.Per.Grasses = Per.Three-Awns >Sub-dominant:
Dom.Shrubs > Misc.Per.Grasses = Half Shrubs = Succulents = Per.Forbs > AnnualsOther:
Additional:
Annual grasses and forbs can fluctuate within the ranking based on seasonal precipitation. -
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Mortality due to drought (2009 and very dry winter spring of 2011) is significant only on cane cholla. All other species show only natural rates of mortality. -
Average percent litter cover (%) and depth ( in):
Litter cover can vary widely due to annual grass and forb production fluctuating with rainfall cycles. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
148 lbs/ac. in a below average year; 400 lbs/ac. in an average year; 825 lbs/ac. in an above average year. Annual grass and forb production can exceed expected values based on recent weather patterns. -
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:
Cholla and prickly pear are to natural to this site and expand to 9% canopy (about 200 plants/ac.) Mesquite and catclaw acacia are natural to this site and appears to exist in normal amounts at 8% canopy cover and with a density of 40 plants/ac. Other invasive species present include both Lehmann lovegrass and Boer lovegrass. -
Perennial plant reproductive capability:
Not impaired by drought on any species.
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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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