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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.
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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
R041XC308AZ Limy Slopes 12-16" p.z.
R041XC313AZ Loamy Upland 12"-16" p.z.
R041XC319AZ Sandy Loam Upland 12-16" p.z.
Similar sites
R041XC302AZ Clayey Swale 12-16" p.z.
R041XC312AZ Loamy Bottom 12-16" p.z.
R040XA112AZ Loamy Swale 10"-13" p.z.
Table 1. Dominant plant species
Tree Not specified
Shrub Not specified
Herbaceous (1) bouteloua gracilis
(2) bouteloua curtipendulaPhysiographic features
This site occurs in the middle elevations of the Madrean Basin and Range province in southeastern Arizona. It occurs in headwater areas; on floodplains of minor tributaries and in swales. It benefits on a regular basis from extra moisture received as runoff from adjacent upland sites. It does not benefit from any kind of water table.
Table 2. Representative physiographic features
Landforms (1) Flood plain
(2) Alluvial fan
(3) Swale
Flooding duration Extremely brief (0.1 to 4 hours) to very brief (4 to 48 hours) Flooding frequency Occasional to frequent Ponding duration Very brief (4 to 48 hours) Ponding frequency None to rare Elevation 3200 – 5000 ft Slope 0 – 2 % 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) 0 days 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 young soils on loamy to clayey alluvium of mixed origin. They are deep and dark colored. They do not have vertic properties. Soil churning and cracking are not features of this site. Plant-soil moisture relationships are excellent.
Soils mapped on this site include: SSA-665 Willcox area Gr & Gs Grabe, Pm Pima; SSA-666 Cochise county Northwest part MU 81 Tenneco; SSA-667 Santa Cruz area MU's Pn Pima CL SCL subsoil, Th haplustolls & torrifluvents, GbD Grabe; SSA-671 Cochise county Douglas-Tombstone part MU's 65 Forrest CL, 67 Forrest SL, 68 Forrest SL, 70 Forrest, 125 Ubik, 129 Sasabe SiL frequently flooded, 139 Tenneco FSL, 144 Ubic FSL, 147 Ubic SL, 148 Ubic SL saline-sodic.Table 4. Representative soil features
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderate to moderately slow Soil depth 60 in Surface fragment cover <=3" 0 – 5 % Surface fragment cover >3" 0 – 1 % Available water capacity
(0-40in)10.2 – 12.6 in Calcium carbonate equivalent
(0-40in)0 – 20 % 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 – 5 % Subsurface fragment volume >3"
(Depth not specified)0 – 1 % Ecological dynamics
The plant communities found on an ecological site are naturally variable. Composition and production will vary with yearly conditions, location, aspect, and the natural variability of the soils. The Historical Climax Plant Community represents the natural potential plant communities found on relict or relatively undisturbed sites. Other plant communities described here represent plant communities that are known to occur when the site is disturbed by factors such as fire, grazing, or drought.
Production data provided in this site description is standardized to air dry weight at the end of the summer growing season. The plant communities described in this site description are based on near normal rainfall years.
NRCS uses a Similarity Index to compare existing plant communities to the plant communities described here. Similarity index is determined by comparing the production and composition of a plant community to the production and composition of a plant community described in this site description. To determine Similarity index, compare the production (air dry weight) of each species to that shown in the plant community description. For each species, count no more than the maximum amount shown for the species, and for each group, count no more than the maximum amount shown for each group. Divide the resulting total by the total normal year production shown in the plant community description. If the rainfall has been significantly above or below normal, use the total production shown for above or below normal years. If field data is not collected at the end of the summer growing season, then the field data must be corrected to the end of the year production before comparing it to the site description. The growth curve can be used as a guide for estimating production at the end of the summer growing season.
The site is dominated by warm season perennial grasses. Occasional clumps of trees and shrubs occur in the plant community. Fire was very important in the development of this plant community. The site is very susceptible to gully erosion. Base level changes in large watersheds can lead to erosion of these minor tributaries over time. Woody species like mesquite can invade and increase to dominate the site in the absence of fire for long periods. Johnson grass and bermuda grass are exotic species that occur on many areas of the site and may become dominant.State and transition model
Custom diagramStandard diagram
Figure 4. State and Transition, Loamy Swale 12-16" p.z.
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 5 submodel, plant communities
State 1
Historical Climax Plant CommunityCommunity 1.1
Historical Climax Plant Community
Figure 5. Loamy Swale 12-16" pz. HCPC
The historical native state includes the native plant communities that occur on the site, including the historic climax plant community. This state includes other plant communities that naturally occupy the site following fire, drought, flooding, herbivores, and other natural disturbances. The historic climax plant community represents the natural climax community that eventually reoccupies the site with proper management.
The potential plant community is dominated by warm season perennial grasses. Occasional trees and shrubs occur in the plant community. The major perennial grasses like blue grama, sideoats grama, tobosa, creeping muhly and vine mesquite, occur in large patches throughout the plant community. Giant sacaton can occur at about 10% cover in the plant community. Annual forbs and grasses can produce heavy stands in wet seasons following drought and/or fire. With continuous grazing, tall and mid grasses are replaced by short grasses like blue grama and creeping muhly. With grazing management the mid to tall species can resume dominance in the plant community. The aspect is grassland.Figure 6. 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 730 1600 2600 Forb 15 50 250 Shrub/Vine 10 25 100 Tree 0 10 100 Total 755 1685 3050 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 20-70% Surface fragments >0.25" and <=3" 0-10% 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 – – 1-10% 0-5% >0.5 <= 1 – 0-1% 10-20% 0-5% >1 <= 2 – 0-1% 30-60% 0-10% >2 <= 4.5 – 0-1% 0-10% 0-10% >4.5 <= 13 0-2% 0-1% 0-5% – >13 <= 40 – – – – >40 <= 80 – – – – >80 <= 120 – – – – >120 – – – – Figure 7. 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
Exotic grassesCommunity 2.1
Exotic grassesThis state occurs where the native plant community has been replaced by non-native warm season perennial grasses like Lehmann, Boers, Wilman and Cochise lovegrass; and / or Johnson and bermuda grass. These species either were directly seeded or invaded areas of this site. Many small areas of this state were cultivated in the past and have come back to exotics. In other areas the natural flooding regime has been altered by diversions, ROWs, and drainage ditches, leaving the native plant community open to invasion by exotics.
State 3
Annual Grasses and ForbsCommunity 3.1
Annual Grasses and ForbsIn some areas the interaction of continuous heavy grazing with drought, flood and fire has removed native perennial grass species from the plant community. Some areas of this state have been created by cultivation for irrigated farming and subsequent abandonment. Other areas have been created by diversion of normal patterns of runoff that provides extra water to the site. Native and non-native annual forbs and grasses dominate the site. Perennial grasses are limited to threeawns and short lived natives like Rothrock grama.
State 4
Mesquite, native grassesCommunity 4.1
Mesquite, native grassesMesquite has invaded the site in the absence of fire for long periods of time. Mesquite canopy ranges from 2 to 15%. Native perennial grasses dominate the under-story. Annuals fluctuate with climate (drought / El Nino). Sediment accumulation around the base of trees protects them from the heat of fires. Non-native perennial grasses like bermuda and Johnson grass can exist in minor amounts.
State 5
Eroded with or w/o mesquiteCommunity 5.1
Eroded with or w/o mesquiteThe interaction of continuous heavy grazing with drought, flood and fire; with or without mesquite invasion, can lead to gully formation. Other areas of this state are caused by head-ward gully erosion coming from the down-cutting of major stream systems. The site no longer holds the flood water it receives from adjacent upland areas. The under-story deteriorates to annual forbs and grasses. Other shrubs and cacti can grow in the understory. Mesquite canopy ranges from 1 to 35%.
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 500–1000 blue grama BOGR2 Bouteloua gracilis 400–800 – creeping muhly MURE Muhlenbergia repens 10–300 – tobosagrass PLMU3 Pleuraphis mutica 0–300 – vine mesquite PAOB Panicum obtusum 50–200 – 2 Dominant tall grasses 200–1000 sideoats grama BOCU Bouteloua curtipendula 100–600 – big sacaton SPWR2 Sporobolus wrightii 0–400 – cane bluestem BOBA3 Bothriochloa barbinodis 50–300 – Arizona cottontop DICA8 Digitaria californica 10–200 – 3 Miscellaneous perennial grasses 20–200 Rothrock's grama BORO2 Bouteloua rothrockii 10–200 – Arizona cottontop DICA8 Digitaria californica 10–100 – green sprangletop LEDU Leptochloa dubia 0–50 – squirreltail ELEL5 Elymus elymoides 0–50 – hairy grama BOHI2 Bouteloua hirsuta 0–50 – spidergrass ARTE3 Aristida ternipes 10–50 – spidergrass ARTEG Aristida ternipes var. gentilis 0–50 – bush muhly MUPO2 Muhlenbergia porteri 0–50 – whiplash pappusgrass PAVA2 Pappophorum vaginatum 0–50 – plains bristlegrass SEVU2 Setaria vulpiseta 0–50 – burrograss SCBR2 Scleropogon brevifolius 0–25 – plains lovegrass ERIN Eragrostis intermedia 0–25 – tanglehead HECO10 Heteropogon contortus 0–25 – prairie threeawn AROL Aristida oligantha 0–25 – curly-mesquite HIBE Hilaria belangeri 0–20 – common wolfstail LYPH Lycurus phleoides 0–20 – fall witchgrass DICO6 Digitaria cognata 0–20 – sprucetop grama BOCH Bouteloua chondrosioides 0–20 – spike dropseed SPCO4 Sporobolus contractus 0–20 – sand dropseed SPCR Sporobolus cryptandrus 0–20 – alkali sacaton SPAI Sporobolus airoides 0–15 – Parish's threeawn ARPUP5 Aristida purpurea var. parishii 0–10 – slender grama BORE2 Bouteloua repens 0–10 – sedge CAREX Carex 0–10 – purple threeawn ARPU9 Aristida purpurea 0–10 – poverty threeawn ARDI5 Aristida divaricata 0–10 – Havard's threeawn ARHA3 Aristida havardii 0–5 – Fendler threeawn ARPUL Aristida purpurea var. longiseta 0–5 – Wooton's threeawn ARPA9 Aristida pansa 0–5 – 4 Annual grasses 10–400 prairie threeawn AROL Aristida oligantha 1–100 – feather fingergrass CHVI4 Chloris virgata 1–100 – tapertip cupgrass ERACA Eriochloa acuminata var. acuminata 0–100 – bearded sprangletop LEFUF Leptochloa fusca ssp. fascicularis 1–100 – Mexican sprangletop LEFUU Leptochloa fusca ssp. uninervia 0–100 – mucronate sprangeltop LEPAB Leptochloa panicea ssp. brachiata 0–100 – sixweeks fescue VUOC Vulpia octoflora 0–100 – Arizona signalgrass URAR Urochloa arizonica 0–50 – Mexican panicgrass PAHI5 Panicum hirticaule 0–50 – sticky sprangletop LEVI5 Leptochloa viscida 0–50 – needle grama BOAR Bouteloua aristidoides 0–50 – sixweeks grama BOBA2 Bouteloua barbata 0–25 – Parry's grama BOPA2 Bouteloua parryi 0–25 – Bigelow's bluegrass POBI Poa bigelovii 0–25 – sixweeks threeawn ARAD Aristida adscensionis 0–25 – witchgrass PACA6 Panicum capillare 0–25 – Arizona brome BRAR4 Bromus arizonicus 0–20 – Mexican lovegrass ERME Eragrostis mexicana 0–20 – desert lovegrass ERPEM Eragrostis pectinacea var. miserrima 0–20 – tufted lovegrass ERPEP2 Eragrostis pectinacea var. pectinacea 0–20 – Arizona barley HOAR Hordeum arizonicum 0–10 – delicate muhly MUFR Muhlenbergia fragilis 0–10 – littleseed muhly MUMI Muhlenbergia microsperma 0–10 – Forb5 Perennial Forbs 10–50 weakleaf bur ragweed AMCO3 Ambrosia confertiflora 1–50 – fingerleaf gourd CUDI Cucurbita digitata 0–25 – Missouri gourd CUFO Cucurbita foetidissima 0–25 – coyote gourd CUPA Cucurbita palmata 0–25 – Cooley's bundleflower DECO2 Desmanthus cooleyi 0–25 – beeblossom GAURA Gaura 0–25 – desert globemallow SPAM2 Sphaeralcea ambigua 0–25 – gooseberryleaf globemallow SPGR2 Sphaeralcea grossulariifolia 0–25 – spear globemallow SPHA Sphaeralcea hastulata 0–15 – brownplume wirelettuce STPA4 Stephanomeria pauciflora 0–15 – Lemmon's ragwort SELE8 Senecio lemmonii 0–15 – Louisiana vetch VILUL2 Vicia ludoviciana ssp. ludoviciana 0–15 – variableleaf bushbean MAGI2 Macroptilium gibbosifolium 0–15 – lacy tansyaster MAPI Machaeranthera pinnatifida 0–15 – bean PHASE Phaseolus 0–15 – Lewis flax LILE3 Linum lewisii 0–15 – Texas bindweed COEQ Convolvulus equitans 1–15 – spreading fleabane ERDI4 Erigeron divergens 0–15 – small matweed GUDED Guilleminea densa var. densa 0–15 – Indian rushpea HOGL2 Hoffmannseggia glauca 0–15 – scarlet spiderling BOCO Boerhavia coccinea 0–15 – rose heath CHER2 Chaetopappa ericoides 0–10 – velvet leaf senna SELI4 Senna lindheimeriana 0–10 – Wright's cudweed PSCAC2 Pseudognaphalium canescens ssp. canescens 0–10 – canaigre dock RUHY Rumex hymenosepalus 0–10 – silverleaf nightshade SOEL Solanum elaeagnifolium 1–10 – New Mexico fanpetals SINE Sida neomexicana 0–5 – white prairie aster SYFAC Symphyotrichum falcatum var. commutatum 0–5 – Sonoita noseburn TRLA Tragia laciniata 0–5 – American vetch VIAM Vicia americana 0–5 – Greene's bird's-foot trefoil LOGR4 Lotus greenei 0–5 – Wright's deervetch LOWR Lotus wrightii 0–5 – ivyleaf groundcherry PHHE4 Physalis hederifolia 0–5 – shrubby purslane POSU3 Portulaca suffrutescens 0–5 – tufted evening primrose OECA10 Oenothera caespitosa 0–5 – woodsorrel OXALI Oxalis 0–5 – desert marigold BAMU Baileya multiradiata 0–5 – lyreleaf greeneyes BELY Berlandiera lyrata 0–5 – bluedicks DICA14 Dichelostemma capitatum 0–5 – spreading snakeherb DYSCD Dyschoriste schiedeana var. decumbens 0–5 – southwestern pricklypoppy ARPL3 Argemone pleiacantha 0–5 – dwarf desertpeony ACNA2 Acourtia nana 0–5 – Trans-Pecos thimblehead HYWI Hymenothrix wislizeni 0–5 – wild dwarf morning-glory EVAR Evolvulus arizonicus 0–5 – whitemouth dayflower COER Commelina erecta 0–5 – Arizona snakecotton FRAR2 Froelichia arizonica 0–2 – ragged nettlespurge JAMA Jatropha macrorhiza 0–2 – southwestern mock vervain GLGO Glandularia gooddingii 0–2 – brownfoot ACWR5 Acourtia wrightii 0–2 – trailing windmills ALIN Allionia incarnata 0–2 – largeflower onion ALMA4 Allium macropetalum 0–2 – Watson's dutchman's pipe ARWA Aristolochia watsonii 0–2 – tuber anemone ANTU Anemone tuberosa 0–2 – desert mariposa lily CAKE Calochortus kennedyi 0–2 – sego lily CANU3 Calochortus nuttallii 0–2 – velvetseed milkwort POOB Polygala obscura 0–2 – orange fameflower PHAU13 Phemeranthus aurantiacus 0–2 – jewels of Opar TAPA2 Talinum paniculatum 0–2 – Coulter's wrinklefruit TECO Tetraclea coulteri 0–2 – 6 Annual forbs 5–200 carelessweed AMPA Amaranthus palmeri 1–100 – western tansymustard DEPI Descurainia pinnata 1–50 – sensitive partridge pea CHNI2 Chamaecrista nictitans 1–50 – common sunflower HEAN3 Helianthus annuus 1–50 – longleaf false goldeneye HELOA2 Heliomeris longifolia var. annua 1–50 – camphorweed HESU3 Heterotheca subaxillaris 1–50 – intermediate pepperweed LEVIM Lepidium virginicum var. medium 1–50 – shaggyfruit pepperweed LELA Lepidium lasiocarpum 0–25 – morning-glory IPOMO Ipomoea 0–25 – longleaf false goldeneye HELOL Heliomeris longifolia var. longifolia 0–25 – New Mexico thistle CINE Cirsium neomexicanum 1–25 – fewflower beggarticks BILE Bidens leptocephala 0–25 – goosefoot CHENO Chenopodium 0–25 – sorrel buckwheat ERPO4 Eriogonum polycladon 1–25 – tanseyleaf tansyaster MATA2 Machaeranthera tanacetifolia 0–25 – Nuttall's povertyweed MONU Monolepis nuttalliana 0–25 – desert Indianwheat PLOV Plantago ovata 0–25 – bristly fiddleneck AMTE3 Amsinckia tessellata 0–25 – milkvetch ASTRA Astragalus 0–25 – New Mexico copperleaf ACNE Acalypha neomexicana 0–25 – San Pedro matchweed XAGY Xanthocephalum gymnospermoides 0–25 – woolly tidestromia TILA2 Tidestromia lanuginosa 0–15 – spreading fanpetals SIAB Sida abutifolia 0–15 – wheelscale saltbush ATEL Atriplex elegans 0–15 – woolly plantain PLPA2 Plantago patagonica 0–15 – combseed PECTO Pectocarya 0–15 – Arizona popcornflower PLAR Plagiobothrys arizonicus 0–15 – California poppy ESCAM Eschscholzia californica ssp. mexicana 0–15 – Coulter's spiderling BOCO2 Boerhavia coulteri 0–15 – scrambled eggs COAU2 Corydalis aurea 0–15 – horseweed CONYZ Conyza 0–15 – Arizona gumweed GRAR2 Grindelia arizonica 0–15 – crestrib morning-glory IPCO2 Ipomoea costellata 0–15 – coastal bird's-foot trefoil LOSAB Lotus salsuginosus var. brevivexillus 0–15 – Gordon's bladderpod LEGO Lesquerella gordonii 0–10 – Arizona poppy KAGR Kallstroemia grandiflora 0–10 – sacred thorn-apple DAWR2 Datura wrightii 0–10 – hoary bowlesia BOIN3 Bowlesia incana 0–10 – purslane PORTU Portulaca 0–10 – foothill deervetch LOHU2 Lotus humistratus 0–10 – doubleclaw PRPA2 Proboscidea parviflora 0–10 – New Mexico plumeseed RANE Rafinesquia neomexicana 0–5 – sawtooth sage SASU7 Salvia subincisa 0–5 – desert unicorn-plant PRAL4 Proboscidea althaeifolia 0–5 – slender goldenweed MAGR10 Machaeranthera gracilis 0–5 – whitestem blazingstar MEAL6 Mentzelia albicaulis 0–5 – minerslettuce MONTI Montia 0–5 – green carpetweed MOVE Mollugo verticillata 0–5 – desert evening primrose OEPR Oenothera primiveris 0–5 – Florida pellitory PAFL3 Parietaria floridana 0–5 – Mexican passionflower PAME2 Passiflora mexicana 0–5 – phlox PHLOX Phlox 0–5 – fringed redmaids CACI2 Calandrinia ciliata 0–5 – cryptantha CRYPT Cryptantha 0–5 – spurge EUPHO Euphorbia 0–5 – blanketflower GAILL Gaillardia 0–5 – star gilia GIST Gilia stellata 0–5 – pearly globe amaranth GONI Gomphrena nitida 0–5 – wedgeleaf draba DRCU Draba cuneifolia 0–5 – miniature woollystar ERDI2 Eriastrum diffusum 0–5 – warty caltrop KAPA Kallstroemia parviflora 0–5 – Arizona lupine LUAR4 Lupinus arizonicus 0–5 – Coulter's lupine LUSP2 Lupinus sparsiflorus 0–5 – hollowleaf annual lupine LUSU3 Lupinus succulentus 0–5 – plains flax LIPU4 Linum puberulum 0–2 – American wild carrot DAPU3 Daucus pusillus 0–2 – phacelia PHACE Phacelia 0–2 – sleepy silene SIAN2 Silene antirrhina 0–2 – golden crownbeard VEEN Verbesina encelioides 0–2 – rough cocklebur XAST Xanthium strumarium 0–2 – Fendler's desertdandelion MAFE Malacothrix fendleri 0–1 – Shrub/Vine7 Miscellaneous shrubs 10–100 skunkbush sumac RHTR Rhus trilobata 20–100 – gum bully SILAL3 Sideroxylon lanuginosum ssp. lanuginosum 0–25 – Apache plume FAPA Fallugia paradoxa 0–25 – bastardsage ERWR Eriogonum wrightii 0–20 – fourwing saltbush ATCA2 Atriplex canescens 0–15 – catclaw mimosa MIACB Mimosa aculeaticarpa var. biuncifera 0–15 – winterfat KRLA2 Krascheninnikovia lanata 0–15 – woolly groundsel PACA15 Packera cana 0–10 – littleleaf sumac RHMI3 Rhus microphylla 0–10 – soaptree yucca YUEL Yucca elata 0–10 – yerba de pasmo BAPT Baccharis pteronioides 0–10 – whitethorn acacia ACCO2 Acacia constricta 0–10 – Thurber's desert honeysuckle ANTH2 Anisacanthus thurberi 0–10 – spiny hackberry CEEH Celtis ehrenbergiana 0–5 – Drummond's clematis CLDR Clematis drummondii 0–5 – knifeleaf condalia COSP3 Condalia spathulata 0–5 – Warnock's snakewood COWA Condalia warnockii 0–5 – walkingstick cactus CYSP8 Cylindropuntia spinosior 0–5 – longleaf jointfir EPTR Ephedra trifurca 0–5 – fringed twinevine FUCYC Funastrum cynanchoides ssp. cynanchoides 0–5 – lotebush ZIOB Ziziphus obtusifolia 0–5 – pale desert-thorn LYPA Lycium pallidum 0–5 – velvetpod mimosa MIDY Mimosa dysocarpa 0–5 – sacahuista NOMI Nolina microcarpa 0–5 – cactus apple OPEN3 Opuntia engelmannii 0–5 – burroweed ISTE2 Isocoma tenuisecta 0–2 – trailing krameria KRLA Krameria lanceolata 0–2 – broom snakeweed GUSA2 Gutierrezia sarothrae 0–2 – candy barrelcactus FEWI Ferocactus wislizeni 0–2 – American tarwort FLCE Flourensia cernua 0–2 – shortleaf baccharis BABR Baccharis brachyphylla 0–2 – Christmas cactus CYLE8 Cylindropuntia leptocaulis 0–2 – Tree8 Trees 0–100 mesquite PROSO Prosopis 0–100 – catclaw acacia ACGR Acacia greggii 0–25 – netleaf hackberry CELAR Celtis laevigata var. reticulata 0–25 – desert willow CHLI2 Chilopsis linearis 0–25 – velvet ash FRVE2 Fraxinus velutina 0–10 – Arizona walnut JUMA Juglans major 0–10 – Jerusalem thorn PAAC3 Parkinsonia aculeata 0–10 – western soapberry SASAD Sapindus saponaria var. drummondii 0–10 – 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
This site is suitable for grazing by domestic livestock at any time of the year. This site has a long green season, during and after the summer rainy season, has occasional free water in potholes and will often be overused before proper use is made of adjacent upland areas. Shade is lacking unless mesquite has increased on the site. The plant community is excellent habitat for a wide variety of native wildlife species of desert grasslands. Nesting cover for ground nesting birds is usually very good.
Hydrological functions
These small floodplains receive and hold flood water from adjacent upland areas for short periods of time (1-2 days). They are important in the hydrology of major streams by trapping sediment eroding from uplands and retaining flood waters for slower release to the larger stream system. Gullied swales pass large flood events in less than one day.
Recreational uses
Hunting, hiking, horseback riding, bird-watching, photography.
Wood products
Swales that are invaded by mesquite furnish good quantities of fuel-wood and limited quantities of posts.
Supporting information
Inventory data references
Range 417s include 2 in excellent condition, 6 in good condition and 3 in fair condition.
Type locality
Location 1: Pima County, AZ Township/Range/Section T19S R17E S30 General legal description Empire Ranch Location 2: Santa Cruz County, AZ Township/Range/Section T21S R18E S23 General legal description Research Ranch Location 3: Pima County, AZ Township/Range/Section T19S R17E S33 General legal description Empire ranch at KA 10 in the Johnson Pasture. Contributors
Dan Robinett
Larry D. Ellicott
Steve Barker
UnknownRangeland 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, Emilio Carrillo, Dan Robinett Contact for lead author NRCS Tucson Area Office Date 02/16/2005 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
None -
Presence of water flow patterns:
Uncommon; probably cover no more than 3-5% of area; short, 2-4 feet in length. Discontinuous. -
Number and height of erosional pedestals or terracettes:
Pedestals are uncommon, only observed where basal area killed by recent fire 0.5-0.75 inches of soil loss at these spots. Terracettes are fairly common, 3-8 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):
5-10%; areas dominated by blue grama have higher bare ground than areas dominated by sideoats grama, mat muhly and vie mesquite. -
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):
Very little litter movement occuring only in flow paths. -
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 5-6 across site. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Weak granular to subangular blocky; color is 10YR3/2 dry, 10YR2/2 moist; thickness to 10+ inches. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Cover estimated at: canopy 60%; Basal 15%; litter 30%: 60% of canopy cover is perennial mid grasses, 10% is short grasses, 25% is annual forbs, and 5% is perennial forbs and annual grasses. Cover is well dispersed throughout the site. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None -
Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):
Dominant:
mid-grasses >> short grasses > annual forbs > annual grasses = perennial forbsSub-dominant:
Other:
Additional:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Very low basal area loss is masked by litter decomposition. Only a few plants lost by recent fire. -
Average percent litter cover (%) and depth ( in):
Some areas dominated by vine mesquite have litter 5-6 inches deep. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
1000 lbs/ac unfavorable precipitation; 2000 lbs/ac normal precipitation; 2500 lbs/ac favorable precipitation -
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
wait-a-bit, Lehmann lovegrass, emsquite, bermuda grass, johnson grass, burroweed -
Perennial plant reproductive capability:
Not affected even following several years of prolonged drought period for region.
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