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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.
MLRA notes
Major Land Resource Area (MLRA): 041X–Madrean Archipelago
AZ 41.2 – Chihuahuan – Sonoran Desert Shrubs
Elevations range from 2600 to 4000 feet and precipitation ranges from 8 to 12 inches per year. Vegetation includes mesquite, palo verde, catclaw acacia, soaptree yucca, creosotebush, whitethorn, staghorn cholla, desert saltbush, Mormon tea, burroweed, snakeweed, tobosa, black grama, threeawns, bush muhly, dropseed, and burrograss. The soil temperature regime is thermic and the soil moisture regime is typic aridic. 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
R041XB207AZ Limy Slopes 8-12" p.z.
R041XB208AZ Limy Upland 8-12" p.z.
R041XB220AZ Limestone Hills 8-12" p.z.
Similar sites
R041XB201AZ Breaks 8-12" p.z.
Table 1. Dominant plant species
Tree (1) canotia holacantha
Shrub (1) acamptopappus sphaerocephalus
Herbaceous (1) tridens muticus
(2) aristidaPhysiographic features
This site occurs in the lowest elevations of the Madrean Basin and Range province in southeastern Arizona. It occurs on steep escarpments, hill-slopes and ridge-tops. This site is characterized by highly eroded scarps with lenses of sandstone rock out-crop, intermingled with vegetated areas on more moderate slopes.
Table 2. Representative physiographic features
Landforms (1) Hill
(2) Ridge
(3) Escarpment
Flooding frequency None Ponding frequency None Elevation 2600 – 4000 ft Slope 10 – 75 % Aspect N, E, S Climatic features
Precipitation ranges from 8-12 inches annually. More than half falls during July-Sep in brief, but often heavy, thunderstorms. The rest of the moisture comes as light rain or snow that falls slowly for a day or more, but rarely lasts more than a day. May and June are normally the driest months. Humidity is generally very low.
Temperatures are mild throughout most of the year. Freezing temperatures are common at night Dec-Feb; brief 0 F may be observed some nights. During June, July & August, some days may exceed 100 F.
In years of average or greater winter precipitation, annual grasses and forbs occur abundantly in the interspaces.Table 3 Representative climatic features
Frost-free period (average) 240 days Freeze-free period (average) 0 days Precipitation total (average) 0 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
">Influencing water features
There are no water features associated with this site.
Soil features
These are deep soils that are variable in texture, ranging from sandy loam to clayloam. They have formed in, mostly, unconsolidated mudstones and sandstones, formed on lacustrine deposits along the Gila river near San Carlos. The soils are calcareous and have soluble gypsum (1 to 10%) in the profile. Areas of sandstone rock outcrop occurs as thin (1-2 feet thick) ledges on steep slopes.
Soils mapped on this site include torriorthents and haplogypsids. THIS SITE is NOT CURRENTLY CORRELATED on a SOIL in any SSA in AZ.Table 4. Representative soil features
Surface texture (1) Sandy loam
(2) Silt loam
(3) Clay loam
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderately rapid to slow Soil depth 60 in Surface fragment cover <=3" 5 – 35 % Surface fragment cover >3" 1 – 15 % Available water capacity
(0-40in)3.7 – 5.6 in Calcium carbonate equivalent
(0-40in)1 – 15 % Electrical conductivity
(0-40in)0 – 3 mmhos/cm Sodium adsorption ratio
(0-40in)0 – 3 Soil reaction (1:1 water)
(0-40in)7.4 – 8.4 Subsurface fragment volume <=3"
(Depth not specified)5 – 35 % Subsurface fragment volume >3"
(Depth not specified)1 – 5 % 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 community found on relict or relatively undisturbed areas of this site. Other plant communities described here represent plant communities that are known to occur when the site is disturbed by factors such as fire, grazing and 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 described in the 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 amount shown for that 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 the field data is not collected at the end of the summer growing season, then the field data must be corrected to the end of 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 historic 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 and a return to near normal conditions and/or equilibrium.
State and transition model
Custom diagramStandard diagram
Figure 3. State & Transition, Sandstone/Mudstone Hills 8-12
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 textState 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 1
Historic Climax Plant CommunityCommunity 1.1
Historic Climax Plant Community
Figure 4. Sandstone / Mudstone Hills 8-12" pz., HCPC
The native potential plant community found on this site is dominated by desert trees, especially canotia, and shrubs. Perennial grasses and herbs are found in minor amounts and fluctuate widely from wet to dry years.
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)Tree 5 35 200 Grass/Grasslike 17 55 170 Shrub/Vine 51 100 145 Forb 1 10 65 Total 74 200 580 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 10-40% Surface fragments >0.25" and <=3" 10-20% Surface fragments >3" 0-10% Bedrock 0-10% Water 0% Bare ground 30-90% Table 7. Canopy structure (% cover)
Height Above Ground (ft) Tree Shrub/Vine Grass/
GrasslikeForb <0.5 – 0-2% 1-5% 0-5% >0.5 <= 1 – 1-5% 1-5% 0-5% >1 <= 2 – 1-5% 1-5% 0-2% >2 <= 4.5 – 5-10% – – >4.5 <= 13 0-10% 1-5% – – >13 <= 40 0-5% – – – >40 <= 80 – – – – >80 <= 120 – – – – >120 – – – – State 2
Shrubs, exotic annualsCommunity 2.1
Shrubs, exotic annualsThis state occurs where non-native annual forbs and grasses have increased to dominate the herbaceous component of the plant community. Species include red brome, cheatgrass, filaree, purslane and Sahara mustard. Native annuals and perennial grasses and forbs exist in the plant community but are diminished in cover and diversity. The native tree and shrub cover is intact.
State 3
AnnualsCommunity 3.1
Annuals
Figure 6. Sandstone / Mudstone Hills 8-12" pz., annuals
This state occurs where repeated fires have eliminated desert shrubs and trees from the plant community. It occurs near residential areas where the chances of fires are much greater. Native and non-native annual forbs and grasses dominate 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 Dominant perennial grasses 15–100 blue threeawn ARPUN Aristida purpurea var. nealleyi 5–50 – tobosagrass PLMU3 Pleuraphis mutica 5–50 – slim tridens TRMU Tridens muticus 1–20 – bush muhly MUPO2 Muhlenbergia porteri 5–15 – Parish's threeawn ARPUP5 Aristida purpurea var. parishii 0–10 – 2 Misc. perennial grasses 1–20 Indian ricegrass ACHY Achnatherum hymenoides 0–10 – desert needlegrass ACSP12 Achnatherum speciosum 0–10 – low woollygrass DAPU7 Dasyochloa pulchella 1–10 – alkali sacaton SPAI Sporobolus airoides 0–5 – spike dropseed SPCO4 Sporobolus contractus 0–5 – purple threeawn ARPU9 Aristida purpurea 0–5 – spidergrass ARTE3 Aristida ternipes 0–5 – spidergrass ARTEG Aristida ternipes var. gentilis 0–5 – sideoats grama BOCU Bouteloua curtipendula 0–5 – black grama BOER4 Bouteloua eriopoda 0–5 – burrograss SCBR2 Scleropogon brevifolius 0–5 – big sacaton SPWR2 Sporobolus wrightii 0–5 – false Rhodes grass TRCR9 Trichloris crinita 0–2 – poverty threeawn ARDI5 Aristida divaricata 0–2 – sand dropseed SPCR Sporobolus cryptandrus 0–2 – mesa dropseed SPFL2 Sporobolus flexuosus 0–2 – New Mexico feathergrass HENE5 Hesperostipa neomexicana 0–2 – whiplash pappusgrass PAVA2 Pappophorum vaginatum 0–2 – Arizona cottontop DICA8 Digitaria californica 0–1 – nineawn pappusgrass ENDE Enneapogon desvauxii 0–1 – plains bristlegrass SEVU2 Setaria vulpiseta 0–1 – 3 Annual grasses 1–50 needle grama BOAR Bouteloua aristidoides 0–20 – sixweeks grama BOBA2 Bouteloua barbata 0–20 – Rothrock's grama BORO2 Bouteloua rothrockii 0–10 – Eastwood fescue VUMIC Vulpia microstachys var. ciliata 0–10 – desert fescue VUMIM Vulpia microstachys var. microstachys 0–10 – sixweeks fescue VUOC Vulpia octoflora 1–10 – sixweeks threeawn ARAD Aristida adscensionis 0–5 – prairie threeawn AROL Aristida oligantha 0–5 – mucronate sprangeltop LEPAB Leptochloa panicea ssp. brachiata 0–5 – delicate muhly MUFR Muhlenbergia fragilis 0–2 – littleseed muhly MUMI Muhlenbergia microsperma 0–2 – witchgrass PACA6 Panicum capillare 0–2 – Mexican panicgrass PAHI5 Panicum hirticaule 0–2 – Bigelow's bluegrass POBI Poa bigelovii 0–2 – Arizona signalgrass URAR Urochloa arizonica 0–2 – Arizona brome BRAR4 Bromus arizonicus 0–2 – feather fingergrass CHVI4 Chloris virgata 0–2 – canyon cupgrass ERLE7 Eriochloa lemmonii 0–2 – Mexican lovegrass ERME Eragrostis mexicana 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 0–1 – Forb4 Perennial forbs 1–15 dwarf desertpeony ACNA2 Acourtia nana 1–5 – lacy tansyaster MAPIP4 Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida 0–5 – pricklyleaf dogweed THAC Thymophylla acerosa 0–5 – glandleaf milkwort POMA7 Polygala macradenia 0–2 – desert globemallow SPAM2 Sphaeralcea ambigua 0–2 – weakleaf bur ragweed AMCO3 Ambrosia confertiflora 0–2 – stinging serpent CESI Cevallia sinuata 0–2 – whitemargin sandmat CHAL11 Chamaesyce albomarginata 0–1 – leatherweed CRPO5 Croton pottsii 0–1 – bluedicks DICA14 Dichelostemma capitatum 0–1 – spreading fleabane ERDI4 Erigeron divergens 0–1 – desert trumpet ERIN4 Eriogonum inflatum 0–1 – southwestern mock vervain GLGO Glandularia gooddingii 0–1 – paleface HIDE Hibiscus denudatus 0–1 – San Pedro daisy LAPO4 Lasianthaea podocephala 0–1 – Fendler's bladderpod LEFE Lesquerella fendleri 0–1 – tuber anemone ANTU Anemone tuberosa 0–1 – perennial rockcress ARPE2 Arabis perennans 0–1 – dense ayenia AYMI Ayenia microphylla 0–1 – hairyseed bahia BAAB Bahia absinthifolia 0–1 – desert marigold BAMU Baileya multiradiata 0–1 – desert mariposa lily CAKE Calochortus kennedyi 0–1 – sego lily CANU3 Calochortus nuttallii 0–1 – brownplume wirelettuce STPA4 Stephanomeria pauciflora 0–1 – Coues' cassia SECO10 Senna covesii 0–1 – silverleaf nightshade SOEL Solanum elaeagnifolium 0–1 – wishbone-bush MILAV Mirabilis laevis var. villosa 0–1 – desert tobacco NIOB Nicotiana obtusifolia 0–1 – brownfoot ACWR5 Acourtia wrightii 0–1 – trailing windmills ALIN Allionia incarnata 0–1 – rue of the mountains THTE2 Thamnosma texana 0–1 – branched noseburn TRRA5 Tragia ramosa 0–1 – 5 Annual forbs 0–50 western tansymustard DEPI Descurainia pinnata 0–10 – flatcrown buckwheat ERDE6 Eriogonum deflexum 0–10 – desert Indianwheat PLOV Plantago ovata 0–10 – miniature woollystar ERDI2 Eriastrum diffusum 0–5 – cryptantha CRYPT Cryptantha 0–5 – Gordon's bladderpod LEGO Lesquerella gordonii 0–5 – shaggyfruit pepperweed LELA Lepidium lasiocarpum 0–5 – intermediate pepperweed LEVIM Lepidium virginicum var. medium 0–5 – coastal bird's-foot trefoil LOSAB Lotus salsuginosus var. brevivexillus 0–5 – Nuttall's povertyweed MONU Monolepis nuttalliana 0–5 – slender goldenweed MAGR10 Machaeranthera gracilis 0–5 – carelessweed AMPA Amaranthus palmeri 0–5 – bristly fiddleneck AMTE3 Amsinckia tessellata 0–5 – wheelscale saltbush ATEL Atriplex elegans 0–5 – Coulter's spiderling BOCO2 Boerhavia coulteri 0–5 – fringed redmaids CACI2 Calandrinia ciliata 0–2 – tanseyleaf tansyaster MATA2 Machaeranthera tanacetifolia 0–2 – phacelia PHACE Phacelia 0–2 – desert evening primrose OEPR Oenothera primiveris 0–2 – Florida pellitory PAFL3 Parietaria floridana 0–2 – combseed PECTO Pectocarya 0–2 – green carpetweed MOVE Mollugo verticillata 0–2 – Coulter's lupine LUSP2 Lupinus sparsiflorus 0–2 – hairy prairie clover DAMO Dalea mollis 0–2 – American wild carrot DAPU3 Daucus pusillus 0–2 – hairy desertsunflower GECA2 Geraea canescens 0–2 – star gilia GIST Gilia stellata 0–2 – Arizona poppy KAGR Kallstroemia grandiflora 0–2 – sorrel buckwheat ERPO4 Eriogonum polycladon 0–2 – Texas stork's bill ERTE13 Erodium texanum 0–2 – California poppy ESCAM Eschscholzia californica ssp. mexicana 0–2 – white tackstem CAWR Calycoseris wrightii 0–2 – brittle spineflower CHBR Chorizanthe brevicornu 0–2 – hyssopleaf sandmat CHHY3 Chamaesyce hyssopifolia 0–2 – Esteve's pincushion CHST Chaenactis stevioides 0–2 – woollyhead neststraw STMI2 Stylocline micropoides 0–2 – woolly tidestromia TILA2 Tidestromia lanuginosa 0–2 – doubleclaw PRPA2 Proboscidea parviflora 0–1 – New Mexico plumeseed RANE Rafinesquia neomexicana 0–1 – sleepy silene SIAN2 Silene antirrhina 0–1 – Coulter's globemallow SPCO2 Sphaeralcea coulteri 0–1 – common woolly sunflower ERLA6 Eriophyllum lanatum 0–1 – Mexican fireplant EUHE4 Euphorbia heterophylla 0–1 – bristly nama NAHI Nama hispidum 0–1 – glandular threadplant NEGL Nemacladus glanduliferus 0–1 – manybristle chinchweed PEPA2 Pectis papposa 0–1 – Arizona popcornflower PLAR Plagiobothrys arizonicus 0–1 – whitestem blazingstar MEAL6 Mentzelia albicaulis 0–1 – exserted Indian paintbrush CAEXE Castilleja exserta ssp. exserta 0–1 – yellow tackstem CAPA7 Calycoseris parryi 0–1 – hoary bowlesia BOIN3 Bowlesia incana 0–1 – milkvetch ASTRA Astragalus 0–1 – Shrub/Vine6 Dominant shrubs 50–100 whitethorn acacia ACCO2 Acacia constricta 10–50 – creosote bush LATR2 Larrea tridentata 10–50 – catclaw acacia ACGR Acacia greggii 1–20 – viscid acacia ACNE4 Acacia neovernicosa 0–20 – longleaf jointfir EPTR Ephedra trifurca 0–10 – ocotillo FOSP2 Fouquieria splendens 0–10 – jojoba SICH Simmondsia chinensis 0–10 – 7 Miscellaneous shrubs 0–15 Wright's beebrush ALWR Aloysia wrightii 0–5 – mariola PAIN2 Parthenium incanum 0–5 – western honey mesquite PRGLT Prosopis glandulosa var. torreyana 0–2 – Parish's goldeneye VIPA14 Viguiera parishii 0–1 – lotebush ZIOB Ziziphus obtusifolia 0–1 – fourwing saltbush ATCA2 Atriplex canescens 0–1 – cattle saltbush ATPO Atriplex polycarpa 0–1 – brittlebush ENFA Encelia farinosa 0–1 – button brittlebush ENFR Encelia frutescens 0–1 – American tarwort FLCE Flourensia cernua 0–1 – crown of thorns KOSP Koeberlinia spinosa 0–1 – water jacket LYAN Lycium andersonii 0–1 – pale desert-thorn LYPA Lycium pallidum 0–1 – 8 Half shrubs 1–20 Eastern Mojave buckwheat ERFA2 Eriogonum fasciculatum 0–15 – rayless goldenhead ACSP Acamptopappus sphaerocephalus 0–10 – fairyduster CAER Calliandra eriophylla 0–5 – broom snakeweed GUSA2 Gutierrezia sarothrae 0–5 – littleleaf ratany KRER Krameria erecta 0–5 – desert zinnia ZIAC Zinnia acerosa 0–5 – rough menodora MESC Menodora scabra 0–5 – whitestem paperflower PSCO2 Psilostrophe cooperi 0–2 – winterfat KRLA2 Krascheninnikovia lanata 0–1 – threadleaf snakeweed GUMI Gutierrezia microcephala 0–1 – burrobush AMDU2 Ambrosia dumosa 0–1 – resinleaf brickellbush BRBA2 Brickellia baccharidea 0–1 – 9 Succulents 0–10 banana yucca YUBA Yucca baccata 1–10 – common sotol DAWH2 Dasylirion wheeleri 0–5 – soaptree yucca YUEL Yucca elata 0–2 – Engelmann's hedgehog cactus ECEN Echinocereus engelmannii 0–1 – candy barrelcactus FEWI Ferocactus wislizeni 0–1 – devil's cholla GRKU Grusonia kunzei 0–1 – cactus apple OPEN3 Opuntia engelmannii 0–1 – purple pricklypear OPMA8 Opuntia macrocentra 0–1 – tulip pricklypear OPPH Opuntia phaeacantha 0–1 – nightblooming cereus PEGR3 Peniocereus greggii 0–1 – buck-horn cholla CYAC8 Cylindropuntia acanthocarpa 0–1 – Christmas cactus CYLE8 Cylindropuntia leptocaulis 0–1 – walkingstick cactus CYSP8 Cylindropuntia spinosior 0–1 – Tree10 Dominant tree 5–200 crucifixion thorn CAHO3 Canotia holacantha 10–180 – oneseed juniper JUMO Juniperus monosperma 0–25 – 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 (%) Interpretations
Animal community
This site is a poor producer of livestock forage. Steep slopes and lack of perennial forage plants limit utilization of the site.
Wildlife on the site are limited mainly to small mammals and birds and their associated predators. At the higher elevations in this CRA, mule deer use this site for cover and forage. Water developments are very important for both livestock and wildlife on the site.Hydrological functions
These are medium to heavy textured soils with steep slopes making them good producers of runoff and sediment.
Recreational uses
Hunting, horseback riding, hiking, photography, bird watching
Wood products
Limited wood from shrubby mesquite and canotia.
Other products
Sandstone slabs for building blocks and flag-stone.
Supporting information
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) Contact for lead author Date Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
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Presence of water flow patterns:
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Number and height of erosional pedestals or terracettes:
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Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
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Number of gullies and erosion associated with gullies:
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Extent of wind scoured, blowouts and/or depositional areas:
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Amount of litter movement (describe size and distance expected to travel):
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Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
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Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
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Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
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Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
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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:
Sub-dominant:
Other:
Additional:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
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Average percent litter cover (%) and depth ( in):
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Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
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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:
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Perennial plant reproductive capability:
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