Natural Resources
Conservation Service
Ecological site F041XA125AZ
Sandy Bottom
20-23" p.z.
Subirrigated (PLWR2, JUMA, QUERC)
Last updated: 4/09/2021
Accessed: 09/11/2026
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Draft. A draft ecological site description is either incomplete or has not undergone quality control and quality assurance review.
MLRA notes
Major Land Resource Area (MLRA): 041X–Madrean Archipelago
AZ 41.1 – Mexican Oak-Pine Forest and Oak Savannah
Elevations range from 4500 to 10,700 feet and precipitation ranges from 16 to 30 inches. Vegetation includes Emory oak, Mexican blue oak, Arizona white oak, one-seed juniper, alligator juniper, sacahuista, California bricklebush, skunkbush sumac, Arizona rosewood, wait-a-bit mimosa, sideoats grama, blue grama, purple grama, wooly bunchgrass, plains lovegrass, squirreltail, and pinyon ricegrass. The soil temperature regime ranges from thermic to mesic and the soil moisture regime ranges from aridic ustic to typic ustic. 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) Platanus wrightii
(2) Juglans majorShrub Not specified
Herbaceous (1) Muhlenbergia rigens
Physiographic features
This site occurs on floodplains, low stream terraces and along the banks of stream channels in major drainageways. It benefits on a regular basis from extra moisture received as overbank blooding. It also benefits from seasonally high water tables at depths of 3-10 feet.
Table 2. Representative physiographic features
Landforms (1) Flood plain
(2) Stream terrace
(3) Channel
Flooding duration Very brief (4 to 48 hours) to brief (2 to 7 days) Flooding frequency Rare to occasional Ponding frequency None Elevation 5700 – 7200 ft Slope 0 – 4 % Water table depth 24 – 84 in Climatic features
Precipitation in this zone of the common resource area ranges from 16-20 inches per year with elevations from 4700-5500 feet. Approximately 40% of this moisture comes as gentle rain or snow during the winter-spring (Oct-Apr) season; originates in the north Pacific and Gulf of California and comes as frontal storms with long duration and low intensity. The remaining 60% falls in the summer season (May-Sep); originates in the Gulf of Mexico and are convective, usually brief, intense thunderstorms. Snow is common Dec-Mar, averaging 5-15 inches per year, but rarely lasts more than a week. May and June are the driest months. Humidity is low.
Temperatures are mild. Freezing temperatures are common at night from Oct-May, but daytime temperatures are almost always over 40 F. Below 0 F temperatures can occur Dec-Feb. Daytime summer highs rarely exceed 95 F.
Species like plains lovegrass, bottlebrush squirreltail, Arizona white oak and Emory oak begin growth in late March to April. Warm season grasses begin growth in July or August with receipt of the first summer rains.Table 3 Representative climatic features
Frost-free period (average) 200 days Freeze-free period (average) Precipitation total (average) 20 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
">Influencing water features
Soil features
These soils are very young soils on sandy and gravelly alluvium of mixed origins. They are deep and dark colored. They are well to somewhat poorly drained. Surface textures range from very cobbly sand to gravelly sandy loam. Soils are sandy to coarse loamy. There are inclusions of hydric soils. These are sandy and do not exhibit any of the visible characteristics of wetland soils like greying or mottling, but are wet at or near the surface for extended periods during the growing season. Plant-soil moisture relationships are very good.
Soils mapped in this unit include: SSA-671 Cochise county Douglas-Tombstone part MU 86 fluvaquents & haplustolls.Table 4. Representative soil features
Surface texture (1) Very cobbly loamy sand
(2) Extremely cobbly coarse sand
Family particle size (1) Sandy
Drainage class Somewhat poorly drained to poorly drained Permeability class Moderately rapid to very rapid Soil depth 40 – 60 in Available water capacity
(0-40in)2.5 – 5 in Ecological dynamics
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.
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
Historical Climax Plant CommunityCommunity 1.1
Historical Climax Plant CommunityThis site has a mixed plant community with an overstory of large trees like Arizona sycamore, maple, walnut and ash with an understory of liveoak, young trees, shrubs and perennial and annual grasses and forbe. Boradleaf tree species leaf out in March and shed their leaves with the first hard freeze of winter, usually in October. The aspect is deciduous raparian woodland.
Channel and streambank erosion and sedimentation are natural features of this site. Numerous old channels lined with trees can be seen across these narrow floodplains. Tree species present are vigorous root and stem sprouters after cutting or injury from floods. Streamblow is intermittent, but surface flow occurs reliably during the winter-spring months. Perennial streamflow occurs in reaches where inperfious rock lalyers intercept and perch water moving through more permeable bedrock. This springflow usually persists in some areas even through the driest (May-June) season. These warm temperature riparian forests require abundant water in March and April when most of the tree species leaf, set seed and germinate. Summer rainfall usually does not result in sustained streamflow on this site, limiting the dominant riparian communities to vernally adapted species. Sycamore and Maple reproduce mainly by sprouting into clones. Walnut, cottonwood, willow and ash reproduce by seed that germinates in the spring. Tree canopy ranges from 70-90%. Understory composition and production varies greatly with percent canopy cover. Trees reach maximum size on this site. Numbers of trees per acre range from 50-150. Excessive ground water pumping, damming, or diverting can reduce streamflow and eventually lead to thinning of the tree canopy on the site. Management of understory should be aimed at leaving enough cover to protect soils from erosion and to trap sediment in teh summer flooding season. Heavy winter runoff can cause much erosion due to prolonged flow and increased viscosity of the water.Additional community tables
Table 5. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
The understory plant community is sparse at high canopy covers and offers little useable forage for livestock grazing. Grazing areas of this site, in larger mountain pastures, should be limited to the fall-winter season. The degree of livestock grazing use and traffic should be designed to allow for enough understory vegetation to protect soils from erosion and to trap sediment from spring and summer floods.
An extremly productive and widely used wildlife habitat. The multi-layered tree canopy, good diversity of food and cover and water availabilitiy year-round make this site home to a tremendous variety of native wildlife. This site is sued by a number of threatened and/or endangered species, as well as unique migratory species like the elegant trogon.Wood products
Equipment limitations: no slopes, no unsurfaced roads. Severe to extremely stony, cobbly soils. Water table is high. Flooding is common. There is perennial streamflow in some reaches.
Sheet, fill and gully erosion potential is severe in cleared areas, on bare ground and roads/trails during flooding.
Compaction potential of soils is poor due to coarse textured soils. Workability for roads is poor due to cobbly, stony sandy soils. Rutting potential is low due to coarse textured gravelly soils. Revegetation potential is very good-excellent throughout the growing season.
Harvest cutting should be limited to oak-juniper and/or downed and dead trees.
Thinning and improvement is not recommended.
When prescribed burning watersheds, leave buffer strips along areas of this site to help catch coarse sediments eroding from hillslopes.
Mechanical tree removal is severely limited due to wet soils and flooding.
Control pests to limit tree damage and loss (mistletoe, tent caterpillars, etc.)
Replanting is suitable for broadleaf riparian species.
Natural regeneration is good, as long as natural flooding regime is not altered.
Some seedling species need protection from fire or grazing for 2-3 years to establish.
Plant competition is moderately to severely limited due to high cnaopy covers and tree stocking.
Windthrow hazard is slight to none.
Pollution hazard is severe; perennial streamflow in reaches are easily polluted by sediments, vehicle contaminents, ash, and organic matter.Other information
Threatened or endangered plants and animals include:
Lesser longnosed bat (Leptonycteris curasoae yerbabuena); Sonoran chub (Gila ditaenia); Yaqui chub (Gila purpurea); Ocelot (Felis pardalis); Mexican grey wolf (Canis lupus baileyi); New Mexican ridge nose rattlesnake (Crotalus willardi obscurus); Mexican spotted owl (Strix occidentalis lucida); and American peregrine falcon (Falco peregrinus anatum)Supporting information
Contributors
Karlynn Huling
Larry D. EllicottApproval
Curtis Talbot, 4/09/2021
Rangeland 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 09/11/2026 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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