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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): 040X–Sonoran Basin and Range
AZ 40.1 – Upper Sonoran Desert
Elevations range from 2000 to 3200 feet and precipitation averages 10 to 13 inches per year. Vegetation includes saguaro, palo verde, mesquite, creosotebush, triangle bursage, prickly pear, cholla, limberbush, wolfberry, bush muhly, threeawns, ocotillo, and globe mallow. The soil temperature regime is thermic and the soil moisture regime is typic aridic. This unit occurs within the Basin and Range Physiographic Province and is characterized by numerous mountain ranges that rise abruptly from broad, plain-like valleys and basins. Igneous and metamorphic rock classes dominate the mountain ranges and sediments filling the basins represent combinations of fluvial, lacustrine, colluvial and alluvial deposits.Associated sites
R040XA103AZ Clayey Slopes 10"-13" p.z.
R040XA105AZ Shallow Hills 10"-13" p.z.
R040XA110AZ Limy Slopes 10"-13" p.z.
R040XA123AZ Volcanic Hills 10"-13" P.Z.
Similar sites
R041XC314AZ Loamy Slopes 12-16" p.z.
R040XB212AZ Loamy Slopes 7"-10" p.z.
Table 1. Dominant plant species
Tree (1) Parkinsonia microphylla
Shrub (1) Ambrosia deltoidea
(2) Encelia farinosaHerbaceous (1) Aristida purpurea
Physiographic features
This site occurs in the upper elevations of the Sonoran Desert in southern Arizona. Slope aspect is site differentiating at elevations near common resource area boundaries.
Table 2. Representative physiographic features
Landforms (1) Hill
(2) Ridge
Flooding frequency None Ponding frequency None Elevation 2200 – 3500 ft Slope 15 – 45 % Aspect N, E, S Climatic features
Precipitation in the sub resource area ranges from 10 to 13 inches in the southern part, along the Mexican border with elevations from about 1900 to 3200 feet. Precipitation in the northern part of the resource area ranges from 11 to 14 inches with elevations from about 1700 to 3500 feet. Winter-summer rainfall ratios range from 40%-60% in the southern portions of the land resource unit, to 50%-50% in the central portions, to 60%-40% in the northern part of the land resource unit. As one moves from east to west in this resource area rains become slightly more unpredictable and variable with Coefficients of Variation of annual rainfall equal to 29% at Tucson and 36% at Carefree. Summer rains fall July through Sept., originate in the Gulf of Mexico, and are convective, usually brief, intense thunderstorms. Cool season moisture tends to be frontal, originating in the Pacific and Gulf of California. This winter precipitation falls in widespread storms with long duration and low intensity. Snow is rare and seldom lasts more than an hour or two. May and June are the driest months of the year. Humidity is generally very low.
Winter temperatures are mild, with very few days recording freezing temperatures in the morning. Summer temperatures are warm to hot, with several days in June and July exceeding 105 degrees F.
Both the spring and the summer growing seasons are equally important for perennial grass, forb and shrub growth. Cool and warm season annual forbs and grasses can be common in their respective seasons with above average rainfall. Perennial forage species can remain green throughout the year with available moisture.Table 3 Representative climatic features
Frost-free period (average) 270 days Freeze-free period (average) 0 days Precipitation total (average) 10 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 and moderately deep soils which have formed in gravelly loamy alluvium of mixed origin. They are not calcareous but calcareous horizons or bedrock may occur at moderate depths. Soil surfaces are well protected by gravel and cobbles. Plant-soil moisture relationships are good.
Soils mapped on this site include:
SSA-627 Southern Mohave County MU's Bucklebar-15 & Pinaleno-41;
SSA-645 Aguila-Carefree area MU Eba-41;
SSA-666 Northwest Cochise County MU Pinaleno-490;
SSA-668 Tucson-Avra Valley area MU's Rough Broken Land-Rw & Rxd;
SSA-669 Eastern Pima County MU Pinaleno-61;
SSA-703 Tohono O'odham area MU Caracara-17.Table 4. Representative soil features
Surface texture (1) Gravelly sandy loam
(2) Very gravelly sandy loam
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderate to moderately slow Soil depth 30 – 60 in Surface fragment cover <=3" 30 – 75 % Surface fragment cover >3" 1 – 30 % Available water capacity
(0-40in)3.6 – 7 in Calcium carbonate equivalent
(0-40in)0 – 10 % Electrical conductivity
(0-40in)0 – 2 mmhos/cm Sodium adsorption ratio
(0-40in)0 – 2 Soil reaction (1:1 water)
(0-40in)7 – 7.8 Subsurface fragment volume <=3"
(Depth not specified)35 – 60 % Subsurface fragment volume >3"
(Depth not specified)0 – 10 % Ecological dynamics
The plant communities found on an ecological site are naturally variable. Composition and production will vary with yearly conditions, location, aspect, and the natural variability of the soils. The Historical Climax Plant Community represents the natural potential plant communities found on relict or relatively undisturbed sites. Other plant communities described here represent plant communities that are known to occur when the site is disturbed by factors such as fire, grazing, or drought.
Production data provided in this site description is standardized to air dry weight at the end of the summer growing season. The plant communities described in this site description are based on near normal rainfall years.
NRCS uses a Similarity Index to compare existing plant communities to the plant communities described here. Similarity Index is determined by comparing the production and composition of a plant community to the production and composition of a plant community described in this site description. To determine Similarity Index, compare the production (air dry weight) of each species to that shown in the plant community description. For each species, count no more than the maximum amount shown for the species, and for each group, count no more than the maximum amount shown for the group. Divide the resulting total by the total normal year production shown in the plant community description. If the rainfall has been significantly above or below normal, use the total production shown for above or below normal years. If field data is not collected at the end of the summer growing season, then the field data must be corrected to the end of the year production before comparing it to the site description. The growth curve can be used as a guide for estimating production at the end of the summer growing season.
State and transition model
Custom diagramStandard diagram
Figure 4. State and Transition model, Loamy Slopes 10-13" pz
More interactive model formats are also available. View Interactive Models
More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective 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 6 submodel, plant communities
State 1
Historical Climax Plant CommunityCommunity 1.1
Historical Climax Plant CommunityThe potential plant community on this site is a diverse mixture of desert trees, shrubs, cacti, grasses, and forbs. The aspect is shrubland.
With continuous, heavy grazing, perennial grasses and forbs are removed from the plant community and shrubs like brittlebush, triangle bursage, prickly pear, and white thorn acacia can increase to dominate the understories. Trees like littleleaf paloverde and mesquite can increase to dominate the overstory. Trees reach moderate size on this site. A 10-15% tree canopy is important on this site to keep diveristy in the understory plant community.
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 13 70 400 Shrub/Vine 31 220 300 Tree 80 150 200 Forb 10 60 195 Total 134 500 1095 Table 6. Soil surface cover
Tree basal cover 0-0% Shrub/vine/liana basal cover 0-0% Grass/grasslike basal cover 0-0% Forb basal cover 0-0% Non-vascular plants 0% Biological crusts 0-10% Litter 10-80% Surface fragments >0.25" and <=3" 40-80% Surface fragments >3" 10-40% Bedrock 0% Water 0% Bare ground 10-50% Table 7. Canopy structure (% cover)
Height Above Ground (ft) Tree Shrub/Vine Grass/
GrasslikeForb <0.5 – 0-1% 0-15% 0-15% >0.5 <= 1 – 2-15% 1-10% 1-10% >1 <= 2 – 5-15% 0-5% 0-5% >2 <= 4.5 0-1% 1-5% – – >4.5 <= 13 2-15% – – – >13 <= 40 0-1% – – – >40 <= 80 – – – – >80 <= 120 – – – – >120 – – – – Figure 6. Plant community growth curve (percent production by month). AZ4013 , 40.1 10-13" p.z. other sites. Growth begins in the late winter, goes semi-dormant in the drought period of late May through early July, growth continues in the summer through early fall..
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 0 5 10 20 15 0 5 20 15 5 5 0 State 2
Native tree, cacti and shrubs with fireCommunity 2.1
Native tree, cacti and shrubs with fireThis plant community occurs as a result of a single hot season fire. Paloverde and saguaro can be severely impacted and may take long periods of time (30-50 years) to recover to pre-fire levels. Perennial and annual grasses and forbs dominate the community for some time until shrubs like bursage and brittlebush can recover.
This plant community can produce enough herbaceous fuel from native species of grasses and / or forbs to carry fire in El Nino years or after unusually wet summers. The natural incidence of fire in this MLRA is very low and fires are much more common from man-made ignitions. Areas of the site close to urban zones or along heavily travelled roads and highways will experience a higher rate of fires.State 3
Exotic perennial grasses with nativesCommunity 3.1
Exotic perennial grasses with nativesThis community occurs where bufflegrass, natal grass or fountain grass invade the native plant community. These species occupy the niches of low shrubs like brittlebush or triangle bursage and woody forbs like janusia and twinberry.
State 4
Exotic perennial grasses and fireCommunity 4.1
Exotic perennial grasses and fireThis community occurs where a native plant community that has been invaded by bufflegrass or fountain grass has burned one or more times. Increasing amounts of bufflegrass leads to more uniform fine fuels. In areas adjacent to roads and urban areas the risk of repeated fires will increase. As fire frequency increases the dominance of the exotic grasses increase.
State 5
Native plant community with exotic annualsCommunity 5.1
Native plant community with exotic annualsThis plant community occurs where the native community has been invaded by red brome and / or schismus. Red brome occupies the niche of the native winter annual forbs and grasses. This exotic annual grass will fluctuate from nearly nothing in a dry winter to dominance of the understory plant community in a El Nino winter.
State 6
Exotic annuals and fireCommunity 6.1
Exotic annuals and fireThis plant community occurs where a native plant community which has been invaded by red brome and / or schismus has burned repeatedly. As fires become more frequent the native trees, shrubs and succulents are removed from the plant community and red brome becomes dominant. In areas of the site near urban areas and along heavily travelled roads this will be a more common occurence due to an increased source of ignitions.
Additional community tables
Table 8. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Dominant mid-grasses 10–100 bush muhly MUPO2 Muhlenbergia porteri 5–60 – purple threeawn ARPU9 Aristida purpurea 1–25 – spidergrass ARTE3 Aristida ternipes 1–25 – big galleta PLRI3 Pleuraphis rigida 0–20 – black grama BOER4 Bouteloua eriopoda 0–15 – Arizona cottontop DICA8 Digitaria californica 0–10 – tanglehead HECO10 Heteropogon contortus 1–10 – sideoats grama BOCU Bouteloua curtipendula 0–5 – plains bristlegrass SEVU2 Setaria vulpiseta 0–5 – 2 Dominant short grasses 2–80 curly-mesquite HIBE Hilaria belangeri 1–50 – Rothrock's grama BORO2 Bouteloua rothrockii 0–20 – slim tridens TRMU Tridens muticus 1–20 – red grama BOTR2 Bouteloua trifida 0–10 – low woollygrass DAPU7 Dasyochloa pulchella 0–10 – nineawn pappusgrass ENDE Enneapogon desvauxii 0–10 – slender grama BORE2 Bouteloua repens 0–10 – Hall's panicgrass PAHA Panicum hallii 0–10 – 3 Misc perennial grasses 0–20 tobosagrass PLMU3 Pleuraphis mutica 0–10 – sand dropseed SPCR Sporobolus cryptandrus 0–5 – desert needlegrass ACSP12 Achnatherum speciosum 0–5 – Parish's threeawn ARPUP5 Aristida purpurea var. parishii 0–5 – spidergrass ARTEG Aristida ternipes var. gentilis 0–5 – cane bluestem BOBA3 Bothriochloa barbinodis 0–5 – fall witchgrass DICO6 Digitaria cognata 0–2 – squirreltail ELELE Elymus elymoides ssp. elymoides 0–2 – 4 Annual grasses 1–200 sixweeks threeawn ARAD Aristida adscensionis 0–100 – Mexican panicgrass PAHI5 Panicum hirticaule 0–100 – mucronate sprangeltop LEPAB Leptochloa panicea ssp. brachiata 0–50 – sixweeks fescue VUOC Vulpia octoflora 0–25 – prairie threeawn AROL Aristida oligantha 0–25 – needle grama BOAR Bouteloua aristidoides 0–25 – Arizona signalgrass URAR Urochloa arizonica 0–20 – Pacific fescue VUMIP Vulpia microstachys var. pauciflora 0–10 – sixweeks grama BOBA2 Bouteloua barbata 0–10 – Bigelow's bluegrass POBI Poa bigelovii 0–5 – Madagascar dropseed SPPY2 Sporobolus pyramidatus 0–2 – delicate muhly MUFR Muhlenbergia fragilis 0–2 – littleseed muhly MUMI Muhlenbergia microsperma 0–2 – witchgrass PACA6 Panicum capillare 0–2 – Arizona brome BRAR4 Bromus arizonicus 0–2 – feather fingergrass CHVI4 Chloris virgata 0–2 – bearded cupgrass ERAR5 Eriochloa aristata 0–2 – canyon cupgrass ERLE7 Eriochloa lemmonii 0–2 – desert lovegrass ERPEM Eragrostis pectinacea var. miserrima 0–2 – tufted lovegrass ERPEP2 Eragrostis pectinacea var. pectinacea 0–2 – Mexican sprangletop LEFUU Leptochloa fusca ssp. uninervia 0–2 – Forb5 Perennial forbs 10–45 slender janusia JAGR Janusia gracilis 1–15 – Coues' cassia SECO10 Senna covesii 1–15 – desert globemallow SPAM2 Sphaeralcea ambigua 1–10 – slender poreleaf POGR5 Porophyllum gracile 1–10 – lacy tansyaster MAPIP4 Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida 1–10 – wishbone-bush MILAV Mirabilis laevis var. villosa 1–10 – weakleaf bur ragweed AMCO3 Ambrosia confertiflora 0–5 – tuber anemone ANTU Anemone tuberosa 0–5 – desert marigold BAMU Baileya multiradiata 0–5 – Arizona wrightwort CAAR7 Carlowrightia arizonica 0–5 – red-gland spurge CHME5 Chamaesyce melanadenia 0–5 – brownplume wirelettuce STPA4 Stephanomeria pauciflora 1–5 – hairy five eyes CHSO Chamaesaracha sordida 0–2 – dense ayenia AYMI Ayenia microphylla 0–2 – narrowleaf silverbush ARLA12 Argythamnia lanceolata 0–2 – brownfoot ACWR5 Acourtia wrightii 0–2 – San Felipe dogweed ADPO Adenophyllum porophylloides 0–2 – bluedicks DICA14 Dichelostemma capitatum 0–2 – spreading fleabane ERDI4 Erigeron divergens 0–2 – desert trumpet ERIN4 Eriogonum inflatum 0–2 – Parry's beardtongue PEPA24 Penstemon parryi 0–2 – mesquite mistletoe PHCA8 Phoradendron californicum 0–1 – glandleaf milkwort POMA7 Polygala macradenia 0–1 – caliche globemallow SPLA Sphaeralcea laxa 0–1 – spreading fanpetals SIAB Sida abutifolia 0–1 – silverleaf nightshade SOEL Solanum elaeagnifolium 0–1 – wild dwarf morning-glory EVAR Evolvulus arizonicus 0–1 – desert rosemallow HICO Hibiscus coulteri 0–1 – paleface HIDE Hibiscus denudatus 0–1 – desert tobacco NIOBO Nicotiana obtusifolia var. obtusifolia 0–1 – ragged nettlespurge JAMA Jatropha macrorhiza 0–1 – spearleaf MAPA9 Matelea parvifolia 0–1 – trailing windmills ALIN Allionia incarnata 0–1 – largeflower onion ALMA4 Allium macropetalum 0–1 – Braun's rockcress ARPE3 Arabis perstellata 0–1 – Palmer's Indian mallow ABPA Abutilon palmeri 0–1 – climbing wartclub BOSC Boerhavia scandens 0–1 – leatherweed CRPOP Croton pottsii var. pottsii 0–1 – Parish's larkspur DEPAP3 Delphinium parishii ssp. parishii 0–1 – tall mountain larkspur DESC Delphinium scaposum 0–1 – Coulter's wrinklefruit TECO Tetraclea coulteri 0–1 – 6 Annual forbs 0–150 California poppy ESCAM Eschscholzia californica ssp. mexicana 0–80 – Coulter's lupine LUSP2 Lupinus sparsiflorus 0–50 – bristly fiddleneck AMTE3 Amsinckia tessellata 0–25 – western tansymustard DEPI Descurainia pinnata 0–25 – exserted Indian paintbrush CAEXE Castilleja exserta ssp. exserta 0–20 – woolly plantain PLPA2 Plantago patagonica 0–20 – coastal bird's-foot trefoil LOSA Lotus salsuginosus 0–20 – Arizona poppy KAGR Kallstroemia grandiflora 0–15 – distant phacelia PHDI Phacelia distans 0–15 – woolly tidestromia TILA2 Tidestromia lanuginosa 0–15 – smallflowered milkvetch ASNU4 Astragalus nuttallianus 0–15 – Coulter's spiderling BOCO2 Boerhavia coulteri 0–15 – wedgeleaf draba DRCU Draba cuneifolia 0–10 – cryptantha CRYPT Cryptantha 0–10 – lyreleaf jewelflower STCAA Streptanthus carinatus ssp. arizonicus 0–10 – Arizona popcornflower PLAR Plagiobothrys arizonicus 0–10 – slender goldenweed MAGR10 Machaeranthera gracilis 0–10 – mesa tansyaster MATA Machaeranthera tagetina 0–10 – foothill deervetch LOHU2 Lotus humistratus 0–10 – shaggyfruit pepperweed LELA Lepidium lasiocarpum 0–10 – American wild carrot DAPU3 Daucus pusillus 0–5 – Arizona phacelia PHAR13 Phacelia arizonica 0–5 – Louisiana vetch VILU Vicia ludoviciana 0–5 – sleepy silene SIAN2 Silene antirrhina 0–5 – Sonoran sandmat CHMI7 Chamaesyce micromera 0–5 – miniature woollystar ERDI2 Eriastrum diffusum 0–5 – fringed amaranth AMFI Amaranthus fimbriatus 0–5 – carelessweed AMPA Amaranthus palmeri 0–5 – yellow tackstem CAPA7 Calycoseris parryi 0–5 – white tackstem CAWR Calycoseris wrightii 0–5 – fringed redmaids CACI2 Calandrinia ciliata 0–5 – New Mexico thistle CINE Cirsium neomexicanum 0–3 – Esteve's pincushion CHST Chaenactis stevioides 0–2 – pincushion flower CHFR Chaenactis fremontii 0–2 – hyssopleaf sandmat CHHY3 Chamaesyce hyssopifolia 0–2 – California suncup CACA32 Camissonia californica 0–2 – chia SACO6 Salvia columbariae 0–2 – cleftleaf wildheliotrope PHCR Phacelia crenulata 0–2 – whitestem blazingstar MEAL6 Mentzelia albicaulis 0–2 – California goldfields LACAC2 Lasthenia californica ssp. californica 0–2 – limestone bedstraw GAPR Galium proliferum 0–2 – hairy desertsunflower GECA2 Geraea canescens 0–1 – star gilia GIST Gilia stellata 0–1 – California mustard GULA4 Guillenia lasiophylla 0–1 – Palmer's grapplinghook HAPA7 Harpagonella palmeri 0–1 – flatspine stickseed LAOCO Lappula occidentalis var. occidentalis 0–1 – Gordon's bladderpod LEGO Lesquerella gordonii 0–1 – Arizona lupine LUAR4 Lupinus arizonicus 0–1 – Arizona cottonrose LOAR12 Logfia arizonica 0–1 – Mexican fireplant EUHE4 Euphorbia heterophylla 0–1 – Lindley's silverpuffs MILI5 Microseris lindleyi 0–1 – Nuttall's povertyweed MONU Monolepis nuttalliana 0–1 – green carpetweed MOVE Mollugo verticillata 0–1 – desert evening primrose OEPR Oenothera primiveris 0–1 – Florida pellitory PAFL3 Parietaria floridana 0–1 – manybristle chinchweed PEPA2 Pectis papposa 0–1 – California desertdandelion MACA6 Malacothrix californica 0–1 – doubleclaw PRPA2 Proboscidea parviflora 0–1 – New Mexico plumeseed RANE Rafinesquia neomexicana 0–1 – Lemmon's ragwort SELE8 Senecio lemmonii 0–1 – Coulter's globemallow SPCO2 Sphaeralcea coulteri 0–1 – woollyhead neststraw STMI2 Stylocline micropoides 0–1 – sand fringepod THCU Thysanocarpus curvipes 0–1 – white easterbonnets ANLA7 Antheropeas lanosum 0–1 – Chiricahua Mountain sandmat CHFL3 Chamaesyce florida 0–1 – hoary bowlesia BOIN3 Bowlesia incana 0–1 – Tucson Mountain spiderling BOME Boerhavia megaptera 0–1 – sand pygmyweed CRCOC Crassula connata var. connata 0–1 – pricklyburr DAIN2 Datura inoxia 0–1 – buckwheat ERIOG Eriogonum 0–1 – sorrel buckwheat ERPO4 Eriogonum polycladon 0–1 – Texas stork's bill ERTE13 Erodium texanum 0–1 – Thurber's buckwheat ERTH3 Eriogonum thurberi 0–1 – Abert's buckwheat ERAB2 Eriogonum abertianum 0–1 – Palmer's spectaclepod DICA31 Dimorphocarpa candicans 0–1 – Shrub/Vine7 Dominant half shrubs 10–100 triangle bur ragweed AMDE4 Ambrosia deltoidea 5–25 – brittlebush ENFA Encelia farinosa 1–20 – Eastern Mojave buckwheat ERFA2 Eriogonum fasciculatum 0–10 – bastardsage ERWR Eriogonum wrightii 0–10 – littleleaf ratany KRER Krameria erecta 2–10 – fairyduster CAER Calliandra eriophylla 1–10 – rough menodora MESC Menodora scabra 0–5 – American threefold TRCA8 Trixis californica 0–5 – desert zinnia ZIAC Zinnia acerosa 0–5 – Coulter's brickellbush BRCO Brickellia coulteri 0–5 – broom snakeweed GUSA2 Gutierrezia sarothrae 0–2 – 8 Dominant large shrubs 10–100 jojoba SICH Simmondsia chinensis 1–30 – whitethorn acacia ACCO2 Acacia constricta 0–20 – ocotillo FOSP2 Fouquieria splendens 1–15 – sangre de cristo JACA2 Jatropha cardiophylla 0–10 – Berlandier's wolfberry LYBE Lycium berlandieri 1–10 – 9 Misc shrubs 1–20 pelotazo ABIN Abutilon incanum 0–5 – fourwing saltbush ATCA2 Atriplex canescens 0–5 – Warnock's snakewood COWA Condalia warnockii 0–5 – button brittlebush ENFR Encelia frutescens 0–5 – Wright's beebrush ALWR Aloysia wrightii 0–4 – water jacket LYAN Lycium andersonii 0–3 – Arizona desert-thorn LYEX Lycium exsertum 0–3 – Arizona mimosa MIDIL Mimosa distachya var. laxiflora 0–3 – Parish's goldeneye VIPA14 Viguiera parishii 0–2 – banana yucca YUBA Yucca baccata 0–2 – lotebush ZIOB Ziziphus obtusifolia 0–2 – prairie acacia ACANH Acacia angustissima var. hirta 0–2 – rayless goldenhead ACSP Acamptopappus sphaerocephalus 0–2 – Nevada jointfir EPNE Ephedra nevadensis 0–1 – longleaf jointfir EPTR Ephedra trifurca 0–1 – turpentine bush ERLA12 Ericameria laricifolia 0–1 – burroweed ISTE2 Isocoma tenuisecta 0–1 – whitestem paperflower PSCO2 Psilostrophe cooperi 0–1 – 10 Succulents 10–75 saguaro CAGI10 Carnegiea gigantea 5–25 – cactus apple OPEN3 Opuntia engelmannii 2–20 – tulip pricklypear OPPH Opuntia phaeacantha 1–10 – purple pricklypear OPMA8 Opuntia macrocentra 0–5 – jumping cholla CYFU10 Cylindropuntia fulgida 0–5 – buck-horn cholla CYAC8 Cylindropuntia acanthocarpa 1–5 – walkingstick cactus CYSP8 Cylindropuntia spinosior 0–5 – staghorn cholla CYVE3 Cylindropuntia versicolor 1–5 – teddybear cholla CYBI9 Cylindropuntia bigelovii 0–2 – candy barrelcactus FEWI Ferocactus wislizeni 0–2 – Graham's nipple cactus MAGR9 Mammillaria grahamii 0–2 – Thornber's nipple cactus MATH Mammillaria thornberi 0–1 – Christmas cactus CYLE8 Cylindropuntia leptocaulis 0–1 – organpipe cactus STTH3 Stenocereus thurberi 0–1 – Engelmann's hedgehog cactus ECEN Echinocereus engelmannii 0–1 – redspine fishhook cactus ECER2 Echinomastus erectocentrus 0–1 – pinkflower hedgehog cactus ECFA Echinocereus fasciculatus 0–1 – rainbow cactus ECPE Echinocereus pectinatus 0–1 – spinystar ESVIV Escobaria vivipara var. vivipara 0–1 – desert agave AGDE Agave deserti 0–1 – Tree11 Trees 80–200 yellow paloverde PAMI5 Parkinsonia microphylla 80–160 – desert ironwood OLTE Olneya tesota 0–60 – velvet mesquite PRVE Prosopis velutina 0–20 – catclaw acacia ACGR Acacia greggii 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 (%) Table 13. Community 6.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
Steep slopes and gravelly surfaces limit grazing distribution especially in the hotter months of the year. Stocker cattle will use areas of this site fairly well at any season. Forage species grow year round with available moisture. The potential plant community provides adequate nutrition for livestock throughout the year at low stocking rates.
Water developments are very important to wildlife species on this site. Vegetative cover, topography, and forage diversity are good enough for a great variety of wildlife including the larger desert mammals.
Hydrological functions
This site is a fair to good producer of runoff due to steep slopes and soils with argillic horizons near the surface. Very gravelly and cobbly soil surfaces tend to hold water on the site.
Recreational uses
Hunting, hiking, birdwatching, photography, horseback riding, rock hounding.
Wood products
Some paloverde, ironwood and mesquite for camp-fires and branding fires.
Other products
Stones and cobbles, saguaro ribs, cholla skeletons. Tradtional foods like saguaro fruits, prickly pear tunas, cactus flower buds and jojoba nuts. Traditional herbs like coyote tobacco, mint bush, globe mallow and limberbush.
Supporting information
Type locality
Location 1: Pima County, AZ Township/Range/Section T9S R18E S26 General legal description Tucson FO - YLE Ranch Location 2: Pima County, AZ Township/Range/Section T20S R6E S29 General legal description Sells FO - Chutum Vaya Assoc. unsurveyed - along San Juan Trail in Mtn. Pass Location 3: Pima County, AZ General legal description Catalina, Az. Waste Transfer Station, fenced in 1974. Location 4: Pima County, AZ General legal description Catalina State Park, Ridges along Sutherland and Canyon del Oro washes. Contributors
Dan Robinett
Larry D. Ellicott
Wilma RenkenRangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
Author(s)/participant(s) Dave Womack, Dan Robinett, Emilio Carrillo Contact for lead author NRCS Tucson Area Office Date 03/08/2005 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 10% of area; discontinuous; 10-15 feet in length. -
Number and height of erosional pedestals or terracettes:
Pedestals are uncomon on perennial grass and shrubs; terracettes are uncommon. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
15-20% -
Number of gullies and erosion associated with gullies:
None -
Extent of wind scoured, blowouts and/or depositional areas:
None -
Amount of litter movement (describe size and distance expected to travel):
Most litter size classes stay in place. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Expect values of 1-3 in canopy interspaces, 4-6 under plant canopies. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Weak thin platy to weak granuar; color is 7.5-10YR4/4 dry, 7.5-10YR3/2 moist; thickness to 1 inch. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Canopy cover 15-25%; 20-30% perennial grasses, 5% perennial forbs,40-50% trees and 10-20% shrubs and subshrubs. Cover is well dispersed throughout 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:
trees > shrubs > annual grasses and forbs > succulents = perennial forbs = perennial grasses (Note: this is following several years of prolonged regional drought.)Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
90-100% perennial grass plants have likely been lost in recent prolonged drought; 20-50% canopy mortality of shrubs and trees. -
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
134 lbs/ac unfavorable precipitation; 500 lbs/ac normal precipitation; 1095 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:
triangle bursage, prickly pear, white thorn acacia, bufflegrass -
Perennial plant reproductive capability:
Not impaired for shrubs; drought impaire for perennial grasses and forbs.
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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.
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