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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.Table 1. Dominant plant species
Tree (1) Parkinsonia microphylla
Shrub (1) Eriogonum fasciculatum
(2) Ephedra nevadensisHerbaceous (1) Muhlenbergia porteri
(2) Tridens muticusPhysiographic features
This site occurs as rough hills and low mountains. In areas, rock outcrop and granite boulders tend to hide the site. Numerous canyons and natural drainages occur within the site.
Table 2. Representative physiographic features
Landforms (1) Hill
(2) Mountain slope
Flooding frequency None Ponding frequency None Elevation 2000 – 4000 ft Slope 15 – 80 % 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
Soil features
These soils are shallow to moderately deep over highly weathered granitic and diabase bedrock. They take rainfall well but available water capacity is limited by depth. Plant-soil relationships are fair. Soils are gravelly and/or cobbly on the surface. The fractured bedrock offers good opportunity for plant root penetration. Rock outcrop will make up from 5-25% of the area.
Soils mapped on this site include: in
SSA-627 Southern Mohave county MU's Cellar-26, Akela-62 & Quilotosa-90 and in
SSA-645 Aguila-Carefree area MU's Cellar-17, Gran-64 & Wickenburg-64.Table 4. Representative soil features
Surface texture (1) Very gravelly sandy loam
(2) Very gravelly loam
Family particle size (1) Loamy
Drainage class Well drained to somewhat excessively drained Permeability class Moderately rapid to rapid Soil depth 10 – 40 in Surface fragment cover <=3" 35 – 60 % Surface fragment cover >3" 0 – 5 % Available water capacity
(0-40in)0 – 5 in Soil reaction (1:1 water)
(0-40in)6.1 – 8.4 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 grazing, fire, 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 shown for the group. Divide the resulting total by the total normal year production shown in the plant community description. If rainfall has been significantly above or below normal, use the total production shown for above or below normal years. If field data is not collected at the end of the summer growing season, then the field data must be corrected to the end of the year production before comparing it to the site description. The growth curve can be used as a guide for estimating production at the end of the summer growing season.
State and transition model
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Click on state and transition labels to scroll to the respective textEcosystem states
State 1 submodel, plant communities
State 1
Historic Climax Plant CommunityCommunity 1.1
Historic Climax Plant CommunityThe native, potential community on this site is a mixture of perennial grasses, forbs and desert shrub species.
As the site deteriorates from improper use or the lack of natural fires, desert shrub species and cacti increase to dominate it.Figure 4. 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 275 303 330 Shrub/Vine 193 206 220 Forb 55 69 83 Tree 5 8 10 Total 528 586 643 Figure 5. Plant community growth curve (percent production by month). AZ4011 , 40.1 10-13" p.z. hill 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 15 20 5 5 10 15 15 5 5 0 Figure 6. Plant community growth curve (percent production by month). AZ4032 , 40-3AZ 10-12" p.z. all sites. Growth begins in the spring, most growth occurs during the summer rainy season..
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 0 10 15 20 30 20 5 0 0 0 Additional community tables
Table 6. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike0 Dominant Perennial Grasses 140–250 tobosagrass PLMU3 Pleuraphis mutica 83–110 – big galleta PLRI3 Pleuraphis rigida 28–83 – desert needlegrass ACSP12 Achnatherum speciosum 28–55 – 1 Other Perennial Grasses 55–110 bush muhly MUPO2 Muhlenbergia porteri 15–30 – slim tridens TRMU Tridens muticus 15–30 – black grama BOER4 Bouteloua eriopoda 10–25 – Arizona cottontop DICA8 Digitaria californica 15–25 – 2 Misc Perennial Grasses 55–83 cane bluestem BOBA3 Bothriochloa barbinodis 10–15 – nineawn pappusgrass ENDE Enneapogon desvauxii 10–15 – tanglehead HECO10 Heteropogon contortus 10–15 – curly-mesquite HIBE Hilaria belangeri 5–10 – large-spike bristlegrass SEMA5 Setaria macrostachya 5–10 – sideoats grama BOCU Bouteloua curtipendula 5–10 – squirreltail ELELE Elymus elymoides ssp. elymoides 5–10 – threeawn ARIST Aristida 5–10 – 3 Annual Grasses 6–28 Bigelow's bluegrass POBI Poa bigelovii 1–5 – Arizona signalgrass URAR Urochloa arizonica 1–5 – Arizona brome BRAR4 Bromus arizonicus 2–4 – mucronate sprangeltop LEPAB Leptochloa panicea ssp. brachiata 2–4 – Hall's panicgrass PAHA Panicum hallii 1–3 – low woollygrass DAPU7 Dasyochloa pulchella 1–3 – Pacific fescue VUMIP Vulpia microstachys var. pauciflora 0–3 – sixweeks threeawn ARAD Aristida adscensionis 0–3 – sixweeks grama BOBA2 Bouteloua barbata 1–3 – needle grama BOAR Bouteloua aristidoides 0–2 – sixweeks fescue VUOC Vulpia octoflora 0–2 – Forb4 Forbs 28–83 pelotazo ABIN Abutilon incanum 3–8 – dwarf Indian mallow ABPA3 Abutilon parvulum 3–8 – trailing windmills ALIN Allionia incarnata 3–8 – white sagebrush ARLU Artemisia ludoviciana 3–8 – New Mexico silverbush ARNE2 Argythamnia neomexicana 3–8 – desert trumpet ERIN4 Eriogonum inflatum 3–8 – shrubby deervetch LORI3 Lotus rigidus 3–8 – Parry's false prairie-clover MAPA7 Marina parryi 3–8 – wishbone-bush MILAV Mirabilis laevis var. villosa 3–8 – Colorado four o'clock MIMU Mirabilis multiflora 3–8 – Coues' cassia SECO10 Senna covesii 3–8 – globemallow SPHAE Sphaeralcea 3–8 – 5 Annual Forbs 6–28 brownfoot ACWR5 Acourtia wrightii 1–3 – fiddleneck AMSIN Amsinckia 1–3 – American wild carrot DAPU3 Daucus pusillus 1–3 – hoary bowlesia BOIN3 Bowlesia incana 0–3 – California suncup CACA32 Camissonia californica 0–3 – phacelia PHACE Phacelia 0–3 – desert Indianwheat PLOV Plantago ovata 1–3 – woolly plantain PLPA2 Plantago patagonica 0–2 – woolly tidestromia TILA2 Tidestromia lanuginosa 0–2 – pepperweed LEPID Lepidium 1–2 – coastal bird's-foot trefoil LOSAB Lotus salsuginosus var. brevivexillus 0–2 – Coulter's lupine LUSP2 Lupinus sparsiflorus 1–2 – combseed PECTO Pectocarya 0–2 – desert larkspur DEPA Delphinium parishii 0–2 – tall mountain larkspur DESC Delphinium scaposum 0–2 – bluedicks DICAC5 Dichelostemma capitatum ssp. capitatum 0–2 – buckwheat ERIOG Eriogonum 1–2 – California poppy ESCAM Eschscholzia californica ssp. mexicana 0–2 – spurge EUPHO Euphorbia 1–2 – spiderling BOERH2 Boerhavia 1–2 – oakfern GYMNO Gymnocarpium 0–1 – mariposa lily CALOC Calochortus 0–1 – clubmoss LYCOP2 Lycopodium 0–1 – Shrub/Vine6 Dominant Shrubs 83–110 Mexican bladdersage SAME Salazaria mexicana 10–20 – Eastern Mojave buckwheat ERFA2 Eriogonum fasciculatum 10–20 – bastardsage ERWR Eriogonum wrightii 10–20 – Nevada jointfir EPNE Ephedra nevadensis 8–15 – Wright's beebrush ALWR Aloysia wrightii 10–15 – brickellbush BRICK Brickellia 5–10 – fairyduster CAER Calliandra eriophylla 5–10 – slender janusia JAGR Janusia gracilis 2–8 – 7 Other Shrubs 55–83 littleleaf ratany KRER Krameria erecta 8–15 – plains blackfoot MELE2 Melampodium leucanthum 5–10 – Mojave sage SAMO3 Salvia mohavensis 5–10 – rock sage SAPI2 Salvia pinguifolia 5–10 – toothleaf goldeneye VIDE3 Viguiera dentata 5–10 – Arizona wrightwort CAAR7 Carlowrightia arizonica 5–10 – California fagonbush FALA Fagonia laevis 5–10 – Newberry's velvetmallow HONE Horsfordia newberryi 5–10 – narrowleaf silverbush ARLA12 Argythamnia lanceolata 6–9 – desert rosemallow HICO Hibiscus coulteri 3–8 – desert lavender HYEM Hyptis emoryi 3–8 – buckwheat ERIOG Eriogonum 3–8 – San Felipe dogweed ADPO Adenophyllum porophylloides 3–8 – bedstraw GALIU Galium 2–5 – 8 Misc. Shrubs 28–55 alderleaf mountain mahogany CEMO2 Cercocarpus montanus 2–10 – Sonoran scrub oak QUTU2 Quercus turbinella 5–10 – sugar sumac RHOV Rhus ovata 3–8 – whitethorn acacia ACCO2 Acacia constricta 2–8 – catclaw acacia ACGR Acacia greggii 3–5 – rayless goldenhead ACSP Acamptopappus sphaerocephalus 1–5 – yerba de pasmo BAPT Baccharis pteronioides 1–5 – crucifixion thorn CAHO3 Canotia holacantha 1–5 – Indian mallow ABUTI Abutilon 1–5 – snakeweed GUTIE Gutierrezia 1–5 – desert-thorn LYCIU Lycium 3–5 – American threefold TRCA8 Trixis californica 1–5 – Schott's pygmycedar PESC4 Peucephyllum schottii 2–5 – slender poreleaf POGR5 Porophyllum gracile 1–5 – jojoba SICH Simmondsia chinensis 3–5 – turpentinebroom THMO Thamnosma montana 1–5 – whitestem paperflower PSCO2 Psilostrophe cooperi 2–4 – Lemmon's ragwort SELE8 Senecio lemmonii 2–4 – woody crinklemat TICAC Tiquilia canescens var. canescens 1–3 – lacy tansyaster MAPIP4 Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida 1–3 – snapdragon penstemon KEANM Keckiella antirrhinoides ssp. microphylla 1–3 – Florida hopbush DOVI Dodonaea viscosa 1–3 – brittlebush ENFA Encelia farinosa 1–3 – desert yellow fleabane ERLI Erigeron linearis 1–3 – 9 Succulents 6–28 desert agave AGDE Agave deserti 1–2 – saguaro CAGI10 Carnegiea gigantea 1–2 – buckhorn cholla CYACA2 Cylindropuntia acanthocarpa var. acanthocarpa 1–2 – teddybear cholla CYBI9 Cylindropuntia bigelovii 1–2 – Gila County liveforever DUCO Dudleya collomiae 1–2 – Engelmann's hedgehog cactus ECEN Echinocereus engelmannii 1–2 – hedgehog cactus ECHIN3 Echinocereus 1–2 – candy barrelcactus FEWI Ferocactus wislizeni 1–2 – ocotillo FOSP2 Fouquieria splendens 1–2 – globe cactus MAMMI Mammillaria 1–2 – beargrass NOLIN Nolina 1–2 – beavertail pricklypear OPBA2 Opuntia basilaris 1–2 – dollarjoint pricklypear OPCH Opuntia chlorotica 1–2 – cactus apple OPEN3 Opuntia engelmannii 1–2 – banana yucca YUBA Yucca baccata 1–2 – Tree10 Tree 5–10 yellow paloverde PAMI5 Parkinsonia microphylla 5–10 – Interpretations
Animal community
This site is suitable for yearlong grazing by all classes of livestock. Yearlong stocking results in overuse of canyon bottoms, ridgetops and saddles with moany other areas deteriorating from little or no use. Fencing, to control use of the site, along with water developments and stock trails may all be needed to improve grazing distribution and facilitate management.
The site has good cover and a wide diversty of forage plants with variable green seasons. Natural water is lacking and stockwater developments are important to wildlife in these areas.Recreational uses
The landscape quality consists of grassy slopes interrupted by bouldery rock-outcrop areas. In good winter rainfall years, desert wildflowers lend much color to the site.
Very few days in the fall, winter and spring restrict outdoor activities. Afternoon temperatures in June, July and August make such activities less enjoyable.
Activities include hunting, prospecting, hiking, horseback riding and photography.Wood products
None.
Other products
Mining occurs in places on this site.
Supporting information
Type locality
Location 1: Yavapai County, AZ Township/Range/Section T10N R7W S9 General legal description Phoenix F.O. Section 17, T7N, R6W Vulture Mountains, Echeverria Ranch. Prescott F.O. Section 9, T10N, R7W Date Creek Mountains, Knight Ranch. Prescott F.O. Section 3, T9N, R4W Stanton Hills, JJ Coughlin Ranch. Contributors
Larry D. Ellicott
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) 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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