Natural Resources
Conservation Service
Ecological site R041XB210AZ
Loamy Upland
8-12" p.z.
Last updated: 4/12/2021
Accessed: 09/03/2026
-
Search
Major Land Resource Area or ecological site by name and/or ID.
PreviousSectionsNextGeneral 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.
Click to explore map
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
(2) ephedra fasciculataHerbaceous (1) Pleuraphis mutica
(2) aristidaPhysiographic 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 2600 – 4000 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) 160-190 days Freeze-free period (characteristic range) 190-230 days Precipitation total (characteristic range) 10-10 in Frost-free period (actual range) 150-190 days Freeze-free period (actual range) 170-230 days Precipitation total (actual range) 10-10 in Frost-free period (average) 170 days Freeze-free period (average) 200 days Precipitation total (average) 10 in Characteristic rangeActual rangeBarLineFigure 2. Monthly precipitation range
Characteristic rangeActual rangeBarLineFigure 3. Monthly minimum temperature range
Characteristic rangeActual rangeBarLineFigure 4. Monthly maximum temperature range
BarLineFigure 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" 0 – 10 % Available water capacity
(0-40in)5 – 10.1 in Calcium carbonate equivalent
(0-40in)0 – 25 % Electrical conductivity
(0-40in)0 – 2 mmhos/cm Sodium adsorption ratio
(0-40in)0 – 2 Soil reaction (1:1 water)
(0-40in)7.4 – 8.4 Subsurface fragment volume <=3"
(Depth not specified)0 – 65 % Subsurface fragment volume >3"
(Depth not specified)0 – 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
Custom diagramStandard diagram
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 textEcosystem states
State 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 4 submodel, plant communities
State 1
Native Grass-ShrublandState 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 0-0% Grass/grasslike basal cover 0-0% Forb basal cover 0-0% Non-vascular plants 0% Biological crusts 10-20% Litter 10-60% Surface fragments >0.25" and <=3" 20-50% Surface fragments >3" 0-20% Bedrock 0% Water 0% Bare ground 10-70% Table 7. Canopy structure (% cover)
Height Above Ground (ft) Tree Shrub/Vine Grass/
GrasslikeForb <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-SuffutescentDuring 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 GrassState 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 GrassCommunity 2.2
Shrubs-AnnualsThis 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 GrassState 3
Large Shrub-AnnualsState 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, ErodedState 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, ErosionThis 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 3Heavy, continuous livestock grazing
Transition T2A
State 2 to 4heavy, continuous grazing
Restoration pathway R3B
State 3 to 1None known
Restoration pathway R3A
State 3 to 2Prescribed grazing, introduction of non-native lovegrass, brush management, mechanical land treatment
Transition T3A
State 3 to 4heavy, continuous grazing
Restoration pathway R4A
State 4 to 2brush 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 () Foliar cover (%) Grass/Grasslike1 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 – Forb5 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/Vine7 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 – Table 9. Community 1.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 10. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 11. Community 2.2 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 12. Community 2.3 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 13. Community 3.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 14. Community 4.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) 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. EllicottApproval
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 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.
Print Options
Sections
Font
AAAAOther
PrintThe 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.
Accessibility statement
