Natural Resources
Conservation Service
Ecological site R041XC318AZ
Sandy Loam
12-16" p.z.
Deep
Last updated: 7/21/2020
Accessed: 09/24/2026
-
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
AZ 41.3 – Chihuahuan – Sonoran Semidesert Grasslands
Elevations range from 3200 to 5000 feet and precipitation ranges from 12 to 16 inches per year. Vegetation includes mesquite, catclaw acacia, netleaf hackberry, palo verde, false mesquite, range ratany, fourwing saltbush, tarbush, littleleaf sumac, sideoats grama, black grama, plains lovegrass, cane beardgrass, tobosa, vine mesquite, threeawns, Arizona cottontop and bush muhly. The soil temperature regime is thermic and the soil moisture regime is ustic 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
R041XC306AZ Shallow Hills 12-16" p.z.
R041XC319AZ Sandy Loam Upland 12-16" p.z.
R041XC322AZ Shallow Upland 12-16" p.z.
Similar sites
R040XA117AZ Sandy Loam Upland, Deep 10"-13" p.z.
R041XA110AZ Sandy Loam Upland 16-20" p.z.
Table 1. Dominant plant species
Tree Not specified
Shrub (1) eriogonum wrightii
Herbaceous (1) bouteloua curtipendula
(2) digitaria californicaPhysiographic features
This site occurs in the middle elevations of the Madrean Basin and Range province in southeastern Arizona. This site occurs on fan terraces and stream terraces. It is always in an upland position. Slopes are mainly 1-3%, but may range as high as 8%.
Table 2. Representative physiographic features
Landforms (1) Terrace
(2) Fan piedmont
(3) Plain
Flooding frequency None Ponding frequency None Elevation 3300 – 5000 ft Slope 1 – 8 % Aspect Aspect is not a significant factor Climatic features
Precipitation in this common resource area ranges from 12-16 inches yearly in the eastern part with elevations from 3600-5000 feet, and 13-17 inches in the western part where elevations are 3300-4500 feet. Winter-Summer rainfall ratios are 40-60% in the west and 30-70% in the east. Summer rains fall July-September, originate in the Gulf of Mexico and are convective, usually brief, intense thunderstorms. Cool season moisture tends to be frontal, originates in the Pacific and Gulf of California, and falls in widespread storms with long duration and low intensity. Snow rarely lasts more than one day. May and June are the driest months of the year. Humidity is generally very low.
Temperatures are mild. Freezing temperatures are common at night from December-April; however temperatures during the day are frequently above 50 F. Occasionally in December-February, brief 0 F temperatures may be experienced some nights. During June, July and August, some days may exceed 100 F.
Cool season plants start growth in early spring and mature in early summer. Warm season plants take advantage of summer rains and are growing and nutritious July-September. Warm season grasses may remain green throughout the year.Table 3 Representative climatic features
Frost-free period (average) 220 days Freeze-free period (average) Precipitation total (average) 20 in BarLineFigure 2. Monthly precipitation range
BarLineFigure 3. Monthly average minimum and maximum temperature
">Influencing water features
There are no water features associated with this site.
Soil features
These are deep soils which have formed in recent sandy alluvium, usually, of granitic origin. They are sandy loam throughout at least to moderate depths (40 inches). Surface textures range from loamy sand to gravelly sandyloam. Soil surfaces are thick and dark colored. Plant-soil moisture relationships are good.
Soil series mapped on this site include: SSA-661 Eastern Pinal & Southern Gila counties MU's 21 Mallet, 23 & 71 Combate; SSA-664 San Simon area MU 12 Comoro; SSA-665 Willcox area MU's CmA, CnA & CnC Comoro, Cs Cowan, SnA, SnB & SoA Sonoita; SSA-666 Cochise county Northwest part MU's 25 & 26 Combate, 38 Durazo, 59 Mallet & Hooks; SSA-667 Santa Cruz area MU's An Anthony and Ao Anthony GrV; SSA-669 Pima county Eastern part MU's 18 Combate and 37 Keesto; SSA-671 Cochise county Douglas-Tombstone part MU's 1 Altar & Mallet, 5 Combate, 32 Combate LS, 105 Mallet, 112 Ruins thick surface, 120 Perilla, 137 Swisshelm SL and 138 Swisshelm SL saline-sodic; SSA-703 Tohono O'odham Nation MU's 5 & 14 Combate.Table 4. Representative soil features
Parent material (1) Alluvium – granite
Surface texture (1) Loamy sand
(2) Sandy loam
(3) Gravelly sandy loam
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderately rapid to rapid Soil depth 40 – 60 in Surface fragment cover <=3" 1 – 20 % Surface fragment cover >3" 0 – 2 % Available water capacity
(0-40in)4.8 – 7.8 in Calcium carbonate equivalent
(0-40in)0 – 5 % Electrical conductivity
(0-40in)0 – 2 mmhos/cm Sodium adsorption ratio
(0-40in)0 – 2 Soil reaction (1:1 water)
(0-40in)6.6 – 8.4 Subsurface fragment volume <=3"
(Depth not specified)2 – 20 % Subsurface fragment volume >3"
(Depth not specified)0 – 2 % 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 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 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
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
States 2 and 5 (additional transitions)
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 1
Historic Climax Plant CommunityCommunity 1.1
Historic Climax Plant Community
Figure 4. Sandy Loam Deep 12-16" pz.
The potential plant community on this site is dominated by warm season perennial grasses. The major perennial grass species on the site tend to be well dispersed throughout the plant community. Several species of half-shrubs are well represented in the plant community. The aspect is grassland with occasional clumps of desert hackberry, catclaw acacia or mesquite.
With continuous heavy grazing, palatable perennial grasses are removed from the potential plant community and species such as Rothrock grama, mesa threeawn, and spidergrass increase. In areas where burroweed dominates the plant community the potential production of perennial mid-grasses is equal to the present production of burroweed once it is removed from the plant community. Even with low plant cover, these soils produce very little runoff and have very low erosion rates. Some soils are sandy textured but have enough coarse fragments that they are not subject to wind erosion. Naturally occurring wildfires (June through August) were important in the development of the potential plant community, and helped maintain a grassland aspect. Hydrologic relationships are good with very little runoff in most years due to coarse textured soils, high plant and litter cover and low soil bulk densities.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)Grass/Grasslike 435 850 1330 Shrub/Vine 56 100 260 Forb 30 50 250 Tree 0 5 15 Total 521 1005 1855 Table 6. Soil surface cover
Tree basal cover 0-0% Shrub/vine/liana basal cover 0-0% Grass/grasslike basal cover 10-20% Forb basal cover 0-0% Non-vascular plants 0-0% Biological crusts 0-10% Litter 30-80% Surface fragments >0.25" and <=3" 10-20% Surface fragments >3" 0-0% Bedrock 0% Water 0% Bare ground 10-30% Table 7. Canopy structure (% cover)
Height Above Ground (ft) Tree Shrub/Vine Grass/
GrasslikeForb <0.5 – 0-5% 0-10% 0-5% >0.5 <= 1 – 2-10% 10-20% 1-5% >1 <= 2 – 0-10% 20-40% 0-5% >2 <= 4.5 – 0-1% 0-10% – >4.5 <= 13 0-1% 0-1% – – >13 <= 40 – – – – >40 <= 80 – – – – >80 <= 120 – – – – >120 – – – – Figure 6. Plant community growth curve (percent production by month). AZ4134 , 41.3 12-16" p.z. other sites. Growth begins in the spring, semi-dormancy occurs during the May through June drought, most growth occurs during the summer rains..
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 0 5 10 0 0 30 35 15 5 0 0 State 2
Mesquite, native grassCommunity 2.1
Mesquite, native grass
Figure 7. Sandy Loam Deep 12-16" pz. Combate soils
Mesquite increases in the absence of fire for long periods of time. Native perennial grasses maintain dominance, with good grazing management, and mesquite canopy levels up to 10%. Burroweed fluctuates in the plant community with climate, but never becomes dominant. Cholla and prickly pear can cycle through the plant community. Some soil compaction has occurred due to livestock traffic, but hydrologic relationships have not been impaired.
State 3
Mesquite, annual grass and forb stateCommunity 3.1
Mesquite, annual grass and forb state
Figure 8. Sandy Loam Deep 12-16" pz. mesquite, annuals
Mesquite is dominant with canopy levels of 10 to 15%. Native and non-native annual forbs and grasses, both cool and warm season, dominate the under-story. Burroweed and snakeweed cycle with climate, but are always important in the under-story. Native perennial grasses are gone due to the interactions of drought, fire and continuous heavy grazing. Usually, soil compaction and the loss of herbaceous cover have resulted in sheet, rill and gully erosion on the site. Hydrologic relationships have changed to increase the amount of runoff.
State 4
Mesquite, Lehmann lovegrassCommunity 4.1
Mesquite, Lehmann lovegrass
Figure 9. Sandy Loam Deep 12-16" pz. Lehmann invasion
Mesquite has increased in the absence of fires for long periods of time to canopy levels of 10%. Lehmann lovegrass has invaded from seeded areas and is dominant in the under-story. Remnant native perennial grasses diminish over time. Native annual forbs and grasses diminish in the soil seed-bank over time. Fire may act to increase dominance of lehmann lovegrass at the expense of native perennial grasses, but may allow native annual species a chance to make seed and persist in the seed-bank. Some soil compaction has occurred due to livestock traffic, but hydrologic relationships have not been impaired.
State 5
Dense mesquite and other shrubs, succulentsCommunity 5.1
Dense mesquite and other shrubs, succulents
Figure 10. Sandy Loam Deep 12-16" pz. dense mesquite, eroded
Mesquite continues to increase in the absence of fire up to canopy levels of 25%. Other shrubs and succulents like prickly pear and cholla, dominate the under-story. Remnant perennial grasses exist only in the protection of cacti and shrubs. Occasional fires may burn after extremely wet seasons, but mesquite is well established and sprouts back to a thorn-scrub stage. Soil compaction and reduced herbaceous cover has resulted in sheet, rill and gully erosion on the site. Hydrologic relationships have been impaired and runoff is increased.
Transition T1A
State 1 to 2Lack of fire but proper grazing or no grazing
Transition T1B
State 1 to 3Continuous Heavy Grazing (managing for annuals), persistent low perennial grass cover.
Transition T1C
State 1 to 4Proximity to seed source, introduction of seeds, possibly management related to perennial grass cover.
Restoration pathway R2A
State 2 to 1Brush management, prescribed grazing
Transition T2A
State 2 to 3Continuous Heavy Grazing with drought, compaction, sheet, rill and gully erosion
Transition T2B
State 2 to 5Continuous Heavy Grazing with drought, compaction, sheet, rill and gully erosion
Restoration pathway R3A
State 3 to 1Prescribed Grazing/No Grazing, seeding or planting of native grasses, possibly herbicide treatment of annuals, brush management, mechanical land treatment. Transition to State 4 most likely result.
Restoration pathway R3B
State 3 to 4Prescribed Grazing/No Grazing, with or without seeding non-native grasses, possibly herbicide treatment of annuals, brush management, mechanical land treatment.
Transition T3A
State 3 to 5Continuous Heavy Grazing (managing for annuals) with drought, low grass cover
Restoration pathway R1A
State 4 to 1None known
Transition T4A
State 4 to 5Continuous Heavy Grazing (managing for annuals) with drought, low grass cover
Restoration pathway R5A
State 5 to 3Brush management, range seeding, rill and gully erosion control, Prescribed Grazing/No Grazing. Transition to State 4 (restoration pathway R5B) is likely outcome due to prevalence of non-native perennial seedbank throughout the LRU.
Restoration pathway R5B
State 5 to 4Brush management, range seeding, rill and gully erosion control, Prescribed Grazing/No 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 mid-grasses 200–450 sideoats grama BOCU Bouteloua curtipendula 100–350 – Arizona cottontop DICA8 Digitaria californica 100–350 – spike dropseed SPCO4 Sporobolus contractus 50–150 – 2 subdom mid-grasses 50–200 cane bluestem BOBA3 Bothriochloa barbinodis 20–100 – tanglehead HECO10 Heteropogon contortus 25–100 – green sprangletop LEDU Leptochloa dubia 0–100 – plains bristlegrass SEVU2 Setaria vulpiseta 5–50 – 3 suffrutescent grasses 110–230 black grama BOER4 Bouteloua eriopoda 50–130 – bush muhly MUPO2 Muhlenbergia porteri 50–130 – Santa Rita threeawn ARCAG Aristida californica var. glabrata 10–100 – 4 short lived grasses 35–150 Rothrock's grama BORO2 Bouteloua rothrockii 10–150 – slender grama BORE2 Bouteloua repens 25–100 – 5 miscellaneous perennial grasses 10–100 sand dropseed SPCR Sporobolus cryptandrus 5–80 – mesa dropseed SPFL2 Sporobolus flexuosus 0–50 – plains lovegrass ERIN Eragrostis intermedia 0–40 – whiplash pappusgrass PAVA2 Pappophorum vaginatum 0–40 – fall witchgrass DICO6 Digitaria cognata 0–25 – squirreltail ELELE Elymus elymoides ssp. elymoides 5–25 – blue grama BOGR2 Bouteloua gracilis 0–25 – hairy grama BOHI2 Bouteloua hirsuta 0–20 – slim tridens TRMU Tridens muticus 0–20 – common wolfstail LYPH Lycurus phleoides 0–15 – Arizona muhly MUAR3 Muhlenbergia arizonica 0–15 – Hall's panicgrass PAHA Panicum hallii 0–15 – nineawn pappusgrass ENDE Enneapogon desvauxii 0–10 – curly-mesquite HIBE Hilaria belangeri 0–5 – low woollygrass DAPU7 Dasyochloa pulchella 0–5 – 6 perennial threeawns 10–80 spidergrass ARTE3 Aristida ternipes 10–50 – spidergrass ARTEG Aristida ternipes var. gentilis 0–25 – Parish's threeawn ARPUP5 Aristida purpurea var. parishii 0–25 – Orcutt's threeawn ARSCO Aristida schiedeana var. orcuttiana 0–10 – purple threeawn ARPU9 Aristida purpurea 0–10 – Fendler threeawn ARPUL Aristida purpurea var. longiseta 0–5 – blue threeawn ARPUN Aristida purpurea var. nealleyi 0–5 – poverty threeawn ARDI5 Aristida divaricata 0–5 – Havard's threeawn ARHA3 Aristida havardii 0–5 – Wooton's threeawn ARPA9 Aristida pansa 0–5 – 7 annual grasses 10–150 Parry's grama BOPA2 Bouteloua parryi 0–75 – prairie threeawn AROL Aristida oligantha 0–50 – needle grama BOAR Bouteloua aristidoides 0–50 – Mexican panicgrass PAHI5 Panicum hirticaule 0–50 – Arizona signalgrass URAR Urochloa arizonica 0–50 – sixweeks fescue VUOC Vulpia octoflora 0–50 – tapertip cupgrass ERACA Eriochloa acuminata var. acuminata 0–50 – canyon cupgrass ERLE7 Eriochloa lemmonii 0–25 – desert lovegrass ERPEM Eragrostis pectinacea var. miserrima 0–25 – tufted lovegrass ERPEP2 Eragrostis pectinacea var. pectinacea 0–25 – sixweeks threeawn ARAD Aristida adscensionis 0–25 – Bigelow's bluegrass POBI Poa bigelovii 0–25 – feather fingergrass CHVI4 Chloris virgata 0–25 – sixweeks grama BOBA2 Bouteloua barbata 0–25 – Mexican sprangletop LEFUU Leptochloa fusca ssp. uninervia 0–20 – mucronate sprangeltop LEPAB Leptochloa panicea ssp. brachiata 0–20 – witchgrass PACA6 Panicum capillare 0–20 – Arizona brome BRAR4 Bromus arizonicus 0–15 – delicate muhly MUFR Muhlenbergia fragilis 0–10 – littleseed muhly MUMI Muhlenbergia microsperma 0–10 – Forb8 perennial forbs 20–100 weakleaf bur ragweed AMCO3 Ambrosia confertiflora 1–25 – desert marigold BAMU Baileya multiradiata 1–25 – fingerleaf gourd CUDI Cucurbita digitata 0–25 – coyote gourd CUPA Cucurbita palmata 0–25 – scarlet spiderling BOCO Boerhavia coccinea 1–25 – Arizona foldwing DIRE4 Dicliptera resupinata 0–25 – spreading fleabane ERDI4 Erigeron divergens 0–25 – wild dwarf morning-glory EVAR Evolvulus arizonicus 1–25 – southwestern mock vervain GLGO Glandularia gooddingii 0–25 – Wright's deervetch LOWR Lotus wrightii 0–25 – lacy tansyaster MAPI Machaeranthera pinnatifida 0–25 – canaigre dock RUHY Rumex hymenosepalus 1–25 – desert globemallow SPAM2 Sphaeralcea ambigua 0–25 – brownplume wirelettuce STPA4 Stephanomeria pauciflora 1–25 – hairy fournwort TENE Tetramerium nervosum 0–25 – New Mexico fanpetals SINE Sida neomexicana 0–20 – Wright's cudweed PSCAC2 Pseudognaphalium canescens ssp. canescens 0–20 – New Mexico silverbush ARNE2 Argythamnia neomexicana 0–20 – Watson's dutchman's pipe ARWA Aristolochia watsonii 0–15 – trailing windmills ALIN Allionia incarnata 0–15 – Arizona wrightwort CAAR7 Carlowrightia arizonica 0–15 – Greene's bird's-foot trefoil LOGR4 Lotus greenei 0–10 – slender poreleaf POGR5 Porophyllum gracile 0–5 – Lemmon's ragwort SELE8 Senecio lemmonii 0–5 – Rocky Mountain zinnia ZIGR Zinnia grandiflora 0–5 – Cooley's bundleflower DECO2 Desmanthus cooleyi 0–5 – brownfoot ACWR5 Acourtia wrightii 0–5 – variableleaf bushbean MAGI2 Macroptilium gibbosifolium 0–5 – tufted evening primrose OECA10 Oenothera caespitosa 0–5 – slimleaf bean PHAN3 Phaseolus angustissimus 0–5 – orange fameflower PHAU13 Phemeranthus aurantiacus 0–5 – whitemouth dayflower COER Commelina erecta 0–5 – bluedicks DICA14 Dichelostemma capitatum 0–2 – climbing wartclub BOSC Boerhavia scandens 0–2 – small matweed GUDE Guilleminea densa 0–2 – Wright's thimblehead HYWR Hymenothrix wrightii 0–2 – ivyleaf groundcherry PHHE4 Physalis hederifolia 0–2 – wishbone-bush MILAV Mirabilis laevis var. villosa 0–2 – desert tobacco NIOB Nicotiana obtusifolia 0–2 – San Felipe dogweed ADPO Adenophyllum porophylloides 0–2 – dwarf desertpeony ACNA2 Acourtia nana 0–2 – Louisiana vetch VILU Vicia ludoviciana 0–2 – silverleaf nightshade SOEL Solanum elaeagnifolium 0–2 – shrubby purslane POSU3 Portulaca suffrutescens 0–2 – Coulter's wrinklefruit TECO Tetraclea coulteri 0–2 – white prairie aster SYFAC Symphyotrichum falcatum var. commutatum 0–1 – jewels of Opar TAPA2 Talinum paniculatum 0–1 – lyreleaf greeneyes BELY Berlandiera lyrata 0–1 – desert larkspur DEPA Delphinium parishii 0–1 – desert mariposa lily CAKE Calochortus kennedyi 0–1 – sego lily CANU3 Calochortus nuttallii 0–1 – rose heath CHER2 Chaetopappa ericoides 0–1 – 9 annual forbs 10–150 Coulter's spiderling BOCO2 Boerhavia coulteri 5–100 – carelessweed AMPA Amaranthus palmeri 0–55 – bristly fiddleneck AMTE3 Amsinckia tessellata 0–55 – New Mexico thistle CINE Cirsium neomexicanum 1–55 – western tansymustard DEPI Descurainia pinnata 1–55 – miniature woollystar ERDI2 Eriastrum diffusum 1–55 – combseed PECTO Pectocarya 1–55 – Arizona popcornflower PLAR Plagiobothrys arizonicus 1–55 – California poppy ESCAM Eschscholzia californica ssp. mexicana 1–50 – Arizona poppy KAGR Kallstroemia grandiflora 1–35 – shaggyfruit pepperweed LELA Lepidium lasiocarpum 0–25 – longleaf false goldeneye HELOA2 Heliomeris longifolia var. annua 0–25 – camphorweed HESU3 Heterotheca subaxillaris 0–25 – woolly plantain PLPA2 Plantago patagonica 1–25 – Coulter's lupine LUSP2 Lupinus sparsiflorus 0–25 – hollowleaf annual lupine LUSU3 Lupinus succulentus 0–25 – intermediate pepperweed LEVIM Lepidium virginicum var. medium 0–25 – coastal bird's-foot trefoil LOSA Lotus salsuginosus 0–25 – slender goldenweed MAGR10 Machaeranthera gracilis 0–25 – tanseyleaf tansyaster MATA2 Machaeranthera tanacetifolia 0–25 – whitestem blazingstar MEAL6 Mentzelia albicaulis 0–25 – New Mexico plumeseed RANE Rafinesquia neomexicana 0–25 – sacred thorn-apple DAWR2 Datura wrightii 0–25 – goosefoot CHENO Chenopodium 0–25 – sensitive partridge pea CHNI2 Chamaecrista nictitans 1–25 – aster ASTER Aster 0–25 – milkvetch ASTRA Astragalus 0–25 – wheelscale saltbush ATEL Atriplex elegans 0–15 – desert unicorn-plant PRAL4 Proboscidea althaeifolia 0–15 – desert evening primrose OEPR Oenothera primiveris 0–15 – spreading fanpetals SIAB Sida abutifolia 0–15 – woolly tidestromia TILA2 Tidestromia lanuginosa 0–15 – Arizona lupine LUAR4 Lupinus arizonicus 0–15 – foothill deervetch LOHU2 Lotus humistratus 0–15 – desert Indianwheat PLOV Plantago ovata 0–15 – crestrib morning-glory IPCO2 Ipomoea costellata 0–15 – sorrel buckwheat ERPO4 Eriogonum polycladon 0–15 – Palmer's spectaclepod DICA31 Dimorphocarpa candicans 1–15 – spurge EUPHO Euphorbia 1–15 – Thurber's morning-glory IPTH Ipomoea thurberi 0–10 – Gordon's bladderpod LEGO Lesquerella gordonii 0–10 – Lemmon's linanthus LELE29 Leptosiphon lemmonii 0–5 – blanketflower GAILL Gaillardia 0–5 – spreading snakeherb DYSCD Dyschoriste schiedeana var. decumbens 0–5 – redstar IPCO3 Ipomoea coccinea 0–5 – purslane PORTU Portulaca 0–5 – phacelia PHACE Phacelia 1–5 – phlox PHLOX Phlox 0–5 – green carpetweed MOVE Mollugo verticillata 0–5 – sleepy silene SIAN2 Silene antirrhina 0–5 – sawtooth sage SASU7 Salvia subincisa 0–5 – doubleclaw PRPA2 Proboscidea parviflora 0–5 – hairyseed bahia BAAB Bahia absinthifolia 0–5 – hoary bowlesia BOIN3 Bowlesia incana 0–5 – fringed redmaids CACI2 Calandrinia ciliata 0–5 – Paiute suncup CASCM Camissonia scapoidea ssp. macrocarpa 0–5 – croton CRHE4 Croton heterocarpus 0–5 – cryptantha CRYPT Cryptantha 0–5 – American wild carrot DAPU3 Daucus pusillus 0–5 – New Mexico copperleaf ACNE Acalypha neomexicana 0–5 – chia SACO6 Salvia columbariae 0–2 – golden crownbeard VEEN Verbesina encelioides 0–2 – Fendler's desertdandelion MAFE Malacothrix fendleri 0–2 – warty caltrop KAPA Kallstroemia parviflora 0–2 – Shrub/Vine10 half shrubs 30–110 bastardsage ERWR Eriogonum wrightii 25–100 – shortleaf baccharis BABR Baccharis brachyphylla 5–40 – fairyduster CAER Calliandra eriophylla 5–40 – Parish's goldeneye VIPA14 Viguiera parishii 0–30 – desert zinnia ZIAC Zinnia acerosa 0–25 – Thurber's penstemon PETH3 Penstemon thurberi 0–10 – 11 large shrubs 25–60 spiny hackberry CEEH Celtis ehrenbergiana 20–50 – longleaf jointfir EPTR Ephedra trifurca 5–30 – soaptree yucca YUEL Yucca elata 0–30 – fourwing saltbush ATCA2 Atriplex canescens 0–20 – catclaw acacia ACGR Acacia greggii 0–15 – 12 miscellaneous shrubs 0–40 littleleaf ratany KRER Krameria erecta 0–15 – whitethorn acacia ACCO2 Acacia constricta 1–10 – Thurber's desert honeysuckle ANTH2 Anisacanthus thurberi 0–5 – yerba de pasmo BAPT Baccharis pteronioides 0–5 – beehive cactus CORYP Coryphantha 0–5 – jumping cholla CYFU10 Cylindropuntia fulgida 0–5 – candle cholla CYKL Cylindropuntia kleiniae 0–5 – walkingstick cactus CYSP8 Cylindropuntia spinosior 0–5 – staghorn cholla CYVE3 Cylindropuntia versicolor 0–5 – common sotol DAWH2 Dasylirion wheeleri 0–5 – hedgehog cactus ECHIN3 Echinocereus 0–5 – candy barrelcactus FEWI Ferocactus wislizeni 0–5 – desert-thorn LYCIU Lycium 0–5 – catclaw mimosa MIACB Mimosa aculeaticarpa var. biuncifera 0–5 – velvetpod mimosa MIDY Mimosa dysocarpa 0–5 – sacahuista NOMI Nolina microcarpa 0–5 – cactus apple OPEN3 Opuntia engelmannii 0–5 – purple pricklypear OPMAM Opuntia macrocentra var. macrocentra 0–5 – Santa Rita pricklypear OPSA Opuntia santa-rita 0–5 – lotebush ZIOB Ziziphus obtusifolia 0–5 – 13 increaser half shrubs 1–50 burroweed ISTE2 Isocoma tenuisecta 1–50 – turpentine bush ERLA12 Ericameria laricifolia 0–25 – broom snakeweed GUSA2 Gutierrezia sarothrae 0–25 – Tree14 trees 0–15 western honey mesquite PRGLT Prosopis glandulosa var. torreyana 0–10 – velvet mesquite PRVE Prosopis velutina 0–10 – Jerusalem thorn PAAC3 Parkinsonia aculeata 0–5 – blue paloverde PAFL6 Parkinsonia florida 0–5 – Table 9. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 10. Community 3.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 11. Community 4.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 12. Community 5.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
The plant community on this site is suitable for grazing by all classes of cattle at any season. The summer green season for forage species is moderate due to coarse textured, somewhat droughty soils. Shallow rooted grasses are severely affected by drought on this site. Management should be designed to maintain deeper rooted mid-grasses on the site. The plant community on the site includes a variety of browse and many perennial forbs, providing good forage in the spring and fall. Herbaceous forage is deficient in protein in the winter.
Water developments are very important to wildlife species on this site. Being grassland, the site is home to a number of small herbivores and their predators. Larger wildlife species use the site mainly as a foraging area.Hydrological functions
Hydrologic relationships are very good. Coarse textured soils, high plant and litter cover and low bulk densities result in very little runoff in most years.
Recreational uses
Hunting, hiking, horseback riding, photography
Wood products
Where mesquite has increased and grown to tree size, it provides both fuel-wood and posts.
Supporting information
Inventory data references
Six 417's are from Enclosure # 22 on the Santa Rita Experimental Range.
Type locality
Location 1: Pima County, AZ Township/Range/Section T18S R8E S9 General legal description Anvil Ranch - Redondo Camp Location 2: Pima County, AZ Township/Range/Section T21S R8E S17 General legal description Buenos Aires NWR - Bailey Wash terrace Location 3: Cochise County, AZ Township/Range/Section T21S R20E S4 General legal description Fort Huachuca - South Range Location 4: Pima County, AZ Township/Range/Section T18S R15E S16 General legal description Enclosure # 22 and Eriopoda enclosures on the Santa Rita Experimental Range. Contributors
Dan Robinett
Larry D. Ellicott
Steve Barker
UnknownApproval
Scott Woodall, 7/21/2020
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, Tom Reis Contact for lead author NRCS Tucson Area Office Date 02/08/2005 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
-
Number and extent of rills:
None present on this site. -
Presence of water flow patterns:
Water flow paths occupy 10-15% of the area; short (3-5 feet) in length and discontinuous. -
Number and height of erosional pedestals or terracettes:
Pedestals are infrequent on long-lived perennial grasses. Approximately 10% of perennial grass plants have pedestals no more than 1 inch above surrounding soil surface. Black grama dominated areas have formed terracettes 2-5 feet apart with a 1-inch elevation difference from above to below the terracette. Bunchgrass dominated areas have formed terracettes 10-15 feet apart with a 1-inch elevation difference from above to below the terracette. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Estimated in 20, 9.6 ft square frames at 22%. Note: this is following several years of regional drought. -
Number of gullies and erosion associated with gullies:
None present on this site. -
Extent of wind scoured, blowouts and/or depositional areas:
None present on this site. -
Amount of litter movement (describe size and distance expected to travel):
All iltter size classes are staying in pace and mask water flow patterns. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
No slake test done. Expect ratings of 4-6 under shrubs and grass canopies and in openings. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Weak granular; color is 10YR3/2 Dry, 10YR2/2 Moist; thickness to 10+ inches. Lab data from Combate soil series from SRER soil inventory was around 2-3% organic carbon. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Cover estimated in 20, 9.6 ft square frames: Canopy 31%, basal 6%, litter 76%, and gravel 5%. 75-80% of canopy cover is perennial grasses and 5-10% is trees and shrubs. 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 present on this site. Penetrometer tests with weight drop distance from top of weight to top of impact ring = 2.24 feet were: average = 3.55 inches, sd = 0.59 inches. Tests outside enclosure on SRER were: average = 1.84, s.d. = 0.22, tests off SRER to east of Exclosure 22 were: average = 1.35m s,d, = 0.24. -
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:
Perennial mid-grasses (tanglehead, sideoats grama, bush muhly, black grama) > annual forbs & grasses > shrubs > succulents > short grasses (slender grama, Rothrock grama).Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Some. Approximately 50% basal cover of midgrass species and 75-80% basal cover of short grass species has been lost due to 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):
600 lbs/ac unfavorable precipitation, 1100 lbs/ac normal precipitation, 1800 lbs/ac faborable 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:
Mesquite, Lehmann lovegrass and prickley pear -
Perennial plant reproductive capability:
No affected even following several years of prolonged drought period for region. Black grama producing stolons, all other species produce seed.
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
