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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
R040XA110AZ Limy Slopes 10"-13" p.z.
R040XA111AZ Limy Upland 10"-13" p.z.
R040XA114AZ Loamy Upland 10"-13" p.z.
R040XA115AZ Sandy Wash 10"-13" p.z.
Similar sites
R040XB208AZ Limy Upland, Deep 7"-10" p.z.
Table 1. Dominant plant species
Tree (1) Parkinsonia microphylla
Shrub (1) Larrea tridentata
(2) Zinnia acerosaHerbaceous (1) Dasyochloa pulchella
Physiographic features
This site occurs in the upper elevations of the Sonoran Desert in southern Arizona. It occurs on fan terraces, old stream terraces and ridge-tops.
Table 2. Representative physiographic features
Landforms (1) Fan piedmont
(2) Terrace
Flooding frequency None Ponding frequency None Elevation 2200 – 3600 ft Slope 1 – 15 % Aspect Aspect is not a significant factor 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 soils are deep and moderately deep soils formed in limy and gravelly loamy alluvium or colluvium of mixed origin. They are calcareous throughout. Some soil series have lime cemented layers at moderate depths (20-40 inches). Soil surfaces are well covered with rocks and gravels. Plant-soil moisture relationships are fair.
Soils mapped on this site include: SSA-661 Eastern Pinal-Southern Gila Counties MU' Stagecoach-490 & 665; SSA-666 Northwest Cochise County MU's Stagecoach-423 & Rillino-423; SSA669 Eastern Pima County MU's Stagecoach-22, 49, 60 & 78; SSA-703 Tohono O'odham area MU's Stagecoach-16 & 45, Vado-31 & 60.Table 4. Representative soil features
Surface texture (1) Gravelly sandy loam
(2) Very gravelly sandy loam
(3) Cobbly sandy loam
Family particle size (1) Loamy
Drainage class Somewhat excessively drained to well drained Permeability class Rapid to moderately rapid Soil depth 20 – 60 in Surface fragment cover <=3" 20 – 85 % Surface fragment cover >3" 0 – 15 % Available water capacity
(0-40in)2.1 – 5 in Calcium carbonate equivalent
(0-40in)5 – 30 % Electrical conductivity
(0-40in)0 – 2 mmhos/cm Sodium adsorption ratio
(0-40in)0 – 2 Soil reaction (1:1 water)
(0-40in)7.8 – 8.4 Subsurface fragment volume <=3"
(Depth not specified)15 – 65 % Subsurface fragment volume >3"
(Depth not specified)0 – 20 % 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, Limy Upland, deep 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 7 submodel, plant communities
State 1
Historical Climax Plant CommunityCommunity 1.1
Historical Climax Plant CommunityThe potential plant community is a diverse community of desert trees, shrubs, cacti, and perennial forbs and grasses.
With continuous heavy grazing, herbaceous and suffrutescent forage species are replaced by increases in shrubs, cacti and trees. Well developed gravel covers help protect the soil from erosion.
This site has a cycle of dominance by saguaro, alternating with large shrubs and trees that act as nurse plants for the giant cacti. This cycle takes approximately 300 years and starts from exceptionally wet years (El Nino) where saguaro establishes in large numbers.
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)Shrub/Vine 80 250 375 Grass/Grasslike 11 50 220 Forb 3 50 125 Tree 5 50 100 Total 99 400 820 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 10-30% Litter 10-50% Surface fragments >0.25" and <=3" 20-90% Surface fragments >3" 0-20% 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% 0-10% 0-10% >0.5 <= 1 – 0-2% 1-10% 1-10% >1 <= 2 – 1-5% 0-2% 0-5% >2 <= 4.5 0-1% 1-15% 0-1% 0-1% >4.5 <= 13 1-10% 0-2% – – >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
Exotic perennial grasses with nativesCommunity 2.1
Exotic perennial grasses with nativesThis community occurs where bufflegrass and / or fountain grass invade the native plant community. These species occupy the niches of low shrubs like ratany, desert zinnia, brittlebush and grasses like black grama, red grama and slim tridens.
State 3
Exotic perennial grasses and fireCommunity 3.1
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 4
Native trees, cacti, shrubs and fireCommunity 4.1
Native trees, cacti, shrubs and fireThis plant community occurs as a result of a single hot season fire. Creosotebush, whitethorn, 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 ocotillo, whitethorn and jojoba 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 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 species like 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, and 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.
State 7
HCPC 2 - Saguaro stateCommunity 7.1
HCPC 2 - Saguaro stateThere is a 300 year cycle on this site that swings between dominance of native trees and large shrubs (that serve as nurse plants) and mature saguaro forest. Saguaro establishes wholesale in very favorable years (El Nino years like 1979 and 1983) only in the presence of plentiful nurse plants like paloverde, mesquite, whitethorn and creosote. As saguaro plants top their nurse plants (40-60 years) the trees and shrubs begin to die. Saguaro stands reach maturity at 150 to 200 years and begin to diminish over the next 100 years as the large shrubs and trees come back into the plant community.
Additional community tables
Table 8. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Suffrutescent grasses 5–50 bush muhly MUPO2 Muhlenbergia porteri 5–50 – black grama BOER4 Bouteloua eriopoda 0–15 – 2 Subdominant perennial grasses 5–50 low woollygrass DAPU7 Dasyochloa pulchella 1–25 – purple threeawn ARPU9 Aristida purpurea 0–20 – blue threeawn ARPUN Aristida purpurea var. nealleyi 0–20 – big galleta PLRI3 Pleuraphis rigida 0–15 – slim tridens TRMU Tridens muticus 0–10 – red grama BOTR2 Bouteloua trifida 0–10 – nineawn pappusgrass ENDE Enneapogon desvauxii 0–10 – Hall's panicgrass PAHA Panicum hallii 0–5 – 3 Misc. perennial grasses 0–20 spidergrass ARTE3 Aristida ternipes 0–20 – spidergrass ARTEG Aristida ternipes var. gentilis 0–15 – Parish's threeawn ARPUP5 Aristida purpurea var. parishii 0–10 – desert needlegrass ACSP12 Achnatherum speciosum 0–7 – hairy woollygrass ERPI5 Erioneuron pilosum 0–7 – tanglehead HECO10 Heteropogon contortus 0–1 – plains bristlegrass SEVU2 Setaria vulpiseta 0–1 – spike dropseed SPCO4 Sporobolus contractus 0–1 – sand dropseed SPCR Sporobolus cryptandrus 0–1 – mesa dropseed SPFL2 Sporobolus flexuosus 0–1 – sideoats grama BOCU Bouteloua curtipendula 0–1 – Arizona cottontop DICA8 Digitaria californica 0–1 – 4 Annual grasses 1–100 sixweeks grama BOBA2 Bouteloua barbata 1–50 – Mexican panicgrass PAHI5 Panicum hirticaule 0–15 – sixweeks threeawn ARAD Aristida adscensionis 0–15 – prairie threeawn AROL Aristida oligantha 0–15 – needle grama BOAR Bouteloua aristidoides 0–15 – mucronate sprangeltop LEPAB Leptochloa panicea ssp. brachiata 0–10 – Bigelow's bluegrass POBI Poa bigelovii 0–5 – desert lovegrass ERPEM Eragrostis pectinacea var. miserrima 0–5 – Rothrock's grama BORO2 Bouteloua rothrockii 0–5 – sixweeks fescue VUOC Vulpia octoflora 0–5 – tufted lovegrass ERPEP2 Eragrostis pectinacea var. pectinacea 0–2 – feather fingergrass CHVI4 Chloris virgata 0–2 – Arizona signalgrass URAR Urochloa arizonica 0–1 – delicate muhly MUFR Muhlenbergia fragilis 0–1 – littleseed muhly MUMI Muhlenbergia microsperma 0–1 – Arizona brome BRAR4 Bromus arizonicus 0–1 – Forb5 Perennial forbs 2–25 paleface HIDE Hibiscus denudatus 0–10 – slender janusia JAGR Janusia gracilis 0–10 – lacy tansyaster MAPIP4 Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida 1–10 – Coues' cassia SECO10 Senna covesii 0–5 – Parry's false prairie-clover MAPA7 Marina parryi 0–5 – trailing windmills ALIN Allionia incarnata 1–5 – dense ayenia AYMI Ayenia microphylla 0–5 – hairyseed bahia BAAB Bahia absinthifolia 0–5 – desert marigold BAMU Baileya multiradiata 0–5 – leatherweed CRPOP Croton pottsii var. pottsii 0–5 – red-gland spurge CHME5 Chamaesyce melanadenia 0–5 – desert globemallow SPAM2 Sphaeralcea ambigua 0–5 – Mojave woodyaster XYTOT Xylorhiza tortifolia var. tortifolia 0–2 – hairy five eyes CHSO Chamaesaracha sordida 0–2 – desert trumpet ERIN4 Eriogonum inflatum 0–2 – weakleaf bur ragweed AMCO3 Ambrosia confertiflora 0–2 – dwarf desertpeony ACNA2 Acourtia nana 0–2 – California fagonbush FALA Fagonia laevis 0–2 – slender poreleaf POGR5 Porophyllum gracile 0–2 – plains blackfoot MELE2 Melampodium leucanthum 0–2 – wishbone-bush MILAV Mirabilis laevis var. villosa 0–1 – desert tobacco NIOBO Nicotiana obtusifolia var. obtusifolia 0–1 – Parry's beardtongue PEPA24 Penstemon parryi 0–1 – orange fameflower PHAU13 Phemeranthus aurantiacus 0–1 – mesquite mistletoe PHCA8 Phoradendron californicum 0–1 – glandleaf milkwort POMA7 Polygala macradenia 0–1 – spreading fanpetals SIAB Sida abutifolia 0–1 – fringed twinevine FUCYC Funastrum cynanchoides ssp. cynanchoides 0–1 – Davis Mountain mock vervain GLBIC Glandularia bipinnatifida var. ciliata 0–1 – desert rosemallow HICO Hibiscus coulteri 0–1 – spearleaf MAPA9 Matelea parvifolia 0–1 – brownfoot ACWR5 Acourtia wrightii 0–1 – San Felipe dogweed ADPO Adenophyllum porophylloides 0–1 – narrowleaf silverbush ARLA12 Argythamnia lanceolata 0–1 – climbing wartclub BOSC Boerhavia scandens 0–1 – desert mariposa lily CAKE Calochortus kennedyi 0–1 – naked mariposa lily CANU2 Calochortus nudus 0–1 – wild dwarf morning-glory EVAR Evolvulus arizonicus 0–1 – desert larkspur DEPA Delphinium parishii 0–1 – tall mountain larkspur DESC Delphinium scaposum 0–1 – bluedicks DICA14 Dichelostemma capitatum 0–1 – spreading fleabane ERDI4 Erigeron divergens 0–1 – caliche globemallow SPLA Sphaeralcea laxa 0–1 – brownplume wirelettuce STPA4 Stephanomeria pauciflora 0–1 – Coulter's wrinklefruit TECO Tetraclea coulteri 0–1 – rue of the mountains THTE2 Thamnosma texana 0–1 – 6 Annual forbs 1–100 bristly fiddleneck AMTE3 Amsinckia tessellata 0–25 – cleftleaf wildheliotrope PHCR Phacelia crenulata 0–25 – desert Indianwheat PLOV Plantago ovata 1–25 – lyreleaf jewelflower STCAA Streptanthus carinatus ssp. arizonicus 0–25 – California poppy ESCAM Eschscholzia californica ssp. mexicana 0–25 – Arizona phacelia PHAR13 Phacelia arizonica 0–25 – Coulter's lupine LUSP2 Lupinus sparsiflorus 0–20 – thelypody THELY Thelypodium 0–15 – exserted Indian paintbrush CAEXE Castilleja exserta ssp. exserta 0–15 – western tansymustard DEPI Descurainia pinnata 0–15 – flatcrown buckwheat ERDE6 Eriogonum deflexum 0–15 – Sonoran sandmat CHMI7 Chamaesyce micromera 0–10 – smallflowered milkvetch ASNU4 Astragalus nuttallianus 0–10 – Coulter's spiderling BOCO2 Boerhavia coulteri 0–10 – woolly tidestromia TILA2 Tidestromia lanuginosa 0–10 – chia SACO6 Salvia columbariae 0–10 – Gordon's bladderpod LEGO Lesquerella gordonii 0–10 – shaggyfruit pepperweed LELA Lepidium lasiocarpum 0–10 – foothill deervetch LOHU2 Lotus humistratus 0–10 – coastal bird's-foot trefoil LOSAB Lotus salsuginosus var. brevivexillus 0–5 – Arizona lupine LUAR4 Lupinus arizonicus 0–5 – Texas stork's bill ERTE13 Erodium texanum 0–5 – Arizona poppy KAGR Kallstroemia grandiflora 0–5 – California goldfields LACAC2 Lasthenia californica ssp. californica 0–5 – combseed PECTO Pectocarya 0–5 – manybristle chinchweed PEPA2 Pectis papposa 0–5 – slender goldenweed MAGR10 Machaeranthera gracilis 0–5 – mesa tansyaster MATA Machaeranthera tagetina 0–5 – tanseyleaf tansyaster MATA2 Machaeranthera tanacetifolia 0–5 – American wild carrot DAPU3 Daucus pusillus 0–5 – New Mexico plumeseed RANE Rafinesquia neomexicana 0–5 – wheelscale saltbush ATEL Atriplex elegans 0–5 – pincushion flower CHFR Chaenactis fremontii 0–5 – pitseed goosefoot CHBE4 Chenopodium berlandieri 0–5 – brittle spineflower CHBR Chorizanthe brevicornu 0–5 – miniature woollystar ERDI2 Eriastrum diffusum 0–5 – buckwheat ERIOG Eriogonum 0–2 – hyssopleaf sandmat CHHY3 Chamaesyce hyssopifolia 0–2 – Arizona popcornflower PLAR Plagiobothrys arizonicus 0–2 – sleepy silene SIAN2 Silene antirrhina 0–2 – glandular threadplant NEGL Nemacladus glanduliferus 0–2 – desert evening primrose OEPR Oenothera primiveris 0–1 – Florida pellitory PAFL3 Parietaria floridana 0–1 – California desertdandelion MACA6 Malacothrix californica 0–1 – mesquite mistletoe PHCA8 Phoradendron californicum 0–1 – whitestem blazingstar MEAL6 Mentzelia albicaulis 0–1 – Lindley's silverpuffs MILI5 Microseris lindleyi 0–1 – Mojave desertstar MOBE2 Monoptilon bellioides 0–1 – Nuttall's povertyweed MONU Monolepis nuttalliana 0–1 – bristly nama NAHI Nama hispidum 0–1 – flatspine stickseed LAOCO Lappula occidentalis var. occidentalis 0–1 – Thurber's buckwheat ERTH3 Eriogonum thurberi 0–1 – Arizona cottonrose LOAR12 Logfia arizonica 0–1 – Mexican fireplant EUHE4 Euphorbia heterophylla 0–1 – dainty desert hideseed EUMI2 Eucrypta micrantha 0–1 – spring pygmycudweed EVVE Evax verna 0–1 – 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 – bristly scaleseed SPEC2 Spermolepis echinata 0–1 – woollyhead neststraw STMI2 Stylocline micropoides 0–1 – sand fringepod THCU Thysanocarpus curvipes 0–1 – Louisiana vetch VILU Vicia ludoviciana 0–1 – false carrot YAMI Yabea microcarpa 0–1 – distant phacelia PHDI Phacelia distans 0–1 – slimjim bean PHFI3 Phaseolus filiformis 0–1 – Lemmon's ragwort SELE8 Senecio lemmonii 0–1 – woolly plantain PLPA2 Plantago patagonica 0–1 – lipfern CHEIL Cheilanthes 0–1 – Chiricahua Mountain sandmat CHFL3 Chamaesyce florida 0–1 – wedgeleaf draba DRCU Draba cuneifolia 0–1 – Abert's buckwheat ERAB2 Eriogonum abertianum 0–1 – devil's spineflower CHRI Chorizanthe rigida 0–1 – Esteve's pincushion CHST Chaenactis stevioides 0–1 – New Mexico thistle CINE Cirsium neomexicanum 0–1 – sand pygmyweed CRCOC Crassula connata var. connata 0–1 – cryptantha CRYPT Cryptantha 0–1 – hairy prairie clover DAMO Dalea mollis 0–1 – hoary bowlesia BOIN3 Bowlesia incana 0–1 – California suncup CACA32 Camissonia californica 0–1 – browneyes CACL4 Camissonia claviformis 0–1 – yellow tackstem CAPA7 Calycoseris parryi 0–1 – white tackstem CAWR Calycoseris wrightii 0–1 – whitemargin sandmat CHAL11 Chamaesyce albomarginata 0–1 – white easterbonnets ANLA7 Antheropeas lanosum 0–1 – fringed amaranth AMFI Amaranthus fimbriatus 0–1 – carelessweed AMPA Amaranthus palmeri 0–1 – Shrub/Vine7 Dominant large shrubs 50–200 creosote bush LATRT Larrea tridentata var. tridentata 50–180 – whitethorn acacia ACCO2 Acacia constricta 0–100 – ocotillo FOSP2 Fouquieria splendens 0–25 – 8 Dominant half shrubs 25–100 desert zinnia ZIAC Zinnia acerosa 20–50 – triangle bur ragweed AMDE4 Ambrosia deltoidea 0–25 – brittlebush ENFA Encelia farinosa 0–20 – littleleaf ratany KRER Krameria erecta 1–20 – rough menodora MESC Menodora scabra 0–20 – whitestem paperflower PSCO2 Psilostrophe cooperi 1–10 – woody crinklemat TICAC Tiquilia canescens var. canescens 0–10 – white ratany KRGR Krameria grayi 0–10 – button brittlebush ENFR Encelia frutescens 0–10 – burrobush AMDU2 Ambrosia dumosa 0–5 – broom snakeweed GUSA2 Gutierrezia sarothrae 0–5 – pricklyleaf dogweed THAC Thymophylla acerosa 0–5 – threadleaf snakeweed GUMI Gutierrezia microcephala 0–2 – 9 Miscellaneous shrubs 0–30 Warnock's snakewood COWA Condalia warnockii 0–5 – mariola PAIN2 Parthenium incanum 0–5 – jojoba SICH Simmondsia chinensis 0–5 – winterfat KRLA2 Krascheninnikovia lanata 0–3 – Nevada jointfir EPNE Ephedra nevadensis 0–3 – plains blackfoot MELE2 Melampodium leucanthum 0–3 – common sotol DAWH2 Dasylirion wheeleri 0–2 – fourwing saltbush ATCA2 Atriplex canescens 0–2 – banana yucca YUBA Yucca baccata 0–2 – Joshua tree YUBR Yucca brevifolia 0–2 – Eastern Mojave buckwheat ERFA2 Eriogonum fasciculatum 0–2 – sangre de cristo JACA2 Jatropha cardiophylla 0–2 – catclaw acacia ACGR Acacia greggii 0–2 – rayless goldenhead ACSP Acamptopappus sphaerocephalus 0–1 – Wright's beebrush ALWR Aloysia wrightii 0–1 – pelotazo ABIN Abutilon incanum 0–1 – soaptree yucca YUEL Yucca elata 0–1 – lotebush ZIOB Ziziphus obtusifolia 0–1 – Coulter's brickellbush BRCO Brickellia coulteri 0–1 – fairyduster CAER Calliandra eriophylla 0–1 – knifeleaf condalia COSP3 Condalia spathulata 0–1 – longleaf jointfir EPTR Ephedra trifurca 0–1 – water jacket LYAN Lycium andersonii 0–1 – Berlandier's wolfberry LYBE Lycium berlandieri 0–1 – Arizona desert-thorn LYEX Lycium exsertum 0–1 – American threefold TRCA8 Trixis californica 0–1 – Parish's goldeneye VIPA14 Viguiera parishii 0–1 – 10 Succulents 5–45 saguaro CAGI10 Carnegiea gigantea 0–20 – cactus apple OPEN3 Opuntia engelmannii 1–10 – purple pricklypear OPMA8 Opuntia macrocentra 0–5 – tulip pricklypear OPPH Opuntia phaeacantha 1–5 – teddybear cholla CYBI9 Cylindropuntia bigelovii 0–5 – walkingstick cactus CYSP8 Cylindropuntia spinosior 0–5 – staghorn cholla CYVE3 Cylindropuntia versicolor 1–5 – jumping cholla CYFU10 Cylindropuntia fulgida 0–3 – Christmas cactus CYLE8 Cylindropuntia leptocaulis 0–3 – candy barrelcactus FEWI Ferocactus wislizeni 0–2 – buck-horn cholla CYAC8 Cylindropuntia acanthocarpa 0–2 – Arizona pencil cholla CYAR14 Cylindropuntia arbuscula 0–2 – candle cholla CYKL Cylindropuntia kleiniae 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 – Nichol's echinocactus ECHON Echinocactus horizonthalonius var. nicholii 0–1 – spinystar ESVIV Escobaria vivipara var. vivipara 0–1 – Scheer's beehive cactus COROS Coryphantha robustispina ssp. scheeri 0–1 – desert agave AGDE Agave deserti 0–1 – devil's cholla GRKU Grusonia kunzei 0–1 – Graham's nipple cactus MAGR9 Mammillaria grahamii 0–1 – Thornber's nipple cactus MATH Mammillaria thornberi 0–1 – beavertail pricklypear OPBA2 Opuntia basilaris 0–1 – Tree11 Trees 5–100 yellow paloverde PAMI5 Parkinsonia microphylla 5–100 – velvet mesquite PRVE Prosopis velutina 0–20 – desert ironwood OLTE Olneya tesota 0–20 – crucifixion thorn CAHO3 Canotia holacantha 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 (%) Table 14. Community 7.1 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 cattle primarily in the spring and / or summer growing seasons when annual forbs and grasses are avialable. Forage species can grow year-round with available moisture. High pH due to lime may tie up soil nutrients and influence forage species palatability.
Water developments are very important to wildlife species on this site. Vegetative cover and forage diversity are suitable for a variety of small desert mammals and birds and their predators.Hydrological functions
This site has deep coarse textured soils and moderate to gentle slopes making it a poor producer of runoff.
Recreational uses
Hunting, hiking, horseback riding, camping, photography, birdwatching
Wood products
Limited firewood from whitethorn and paloverde for camp fires and branding fires.
Other products
Cactus fruits from saguaro, prickly pear and cholla. Saguaro ribs and ocotillo canes.
Creosote used medicinally.Supporting information
Inventory data references
Range 417s include 4 in good condition.
Type locality
Location 1: Pima County, AZ Township/Range/Section T18S R14E S30 General legal description Santa Rita Experimental Range, Gravelly Ridge enclosure. Northern end of fenced area. Fence built in 1937. Location 2: Pima County, AZ Township/Range/Section T14S R10E S34 General legal description La Tortuga Ranch, Yodi Pasture at transect # 37. Concrete dam nearby in canyon. Was ungrazed for 20 years. Location 3: Pima County, AZ Township/Range/Section T14S R13E S16 General legal description Tumamoc Hill Reserve, Desert Laboratory UA, Northwest corner. Other references
The Changing Mile - Revisited. Ray Turner, Robert Webb, University of Arizona Press, Tucson, Arizona, 2003. Photo Station 81
Contributors
Dan Robinett
Larry D. EllicottRangeland 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:
Rills are common and continuous in absence of high gravel cover. -
Presence of water flow patterns:
Water flow patterns are common, continuous, occupy 15-20% of area. -
Number and height of erosional pedestals or terracettes:
Accumulated pedestals on most perennial plants, not so much so in high gravel cover areas, 2-5 inches high. Erosional pedestals not present on most perennial plants. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
10-60% (low values in high gravel cover areas and/or El Nino years. -
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):
Woody litter mostly stays under plant canopy, herbaceous litter can travel long distances. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil surface resistance to erosion is good under shrub canopies to moderate in interspaces due to crusts formed by raindrop inpact. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Weak thin platy to weak granular; color is 7.5-10YR6-2-4 dry, 7.5-10YR4/4 moist; thickness to 4 inches -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Canopy 20-25%; basal 1-2%; 50-60% canopy cover is shrubs, 15-20% trees, and 15-20% succulents. 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:
shrubs > sub shrubs > trees > succulents > forbs = perennial grasses (In ''''El Nino'''' years, the production of winter annuals can exceed all other plants.Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
10-50% canopy mortality. -
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
99 lbs/ac unfavorable precipitation; 400 lbs/ac normal precipitation; 820 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:
schismus, filaree, malta starthistle -
Perennial plant reproductive capability:
Not impaired for shrubs, drought impaired for perennial grasses and forbs.
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