Natural Resources
Conservation Service
Ecological site R041XC312AZ
Loamy Bottom 12-16" p.z.
Last updated: 4/12/2021
Accessed: 12/21/2024
General information
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.
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): 041X–Madrean Archipelago
AZ 41.3 – Chihuahuan – Sonoran Semidesert Grasslands
Elevations range from 3200 to 5000 feet and precipitation ranges from 12 to 16 inches per year. Vegetation includes mesquite, catclaw acacia, netleaf hackberry, palo verde, false mesquite, range ratany, fourwing saltbush, tarbush, littleleaf sumac, sideoats grama, black grama, plains lovegrass, cane beardgrass, tobosa, vine mesquite, threeawns, Arizona cottontop and bush muhly. The soil temperature regime is thermic and the soil moisture regime is ustic 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
| R041XC311AZ |
Loamy Swale 12-16" p.z. |
|---|
Similar sites
| R041XA114AZ |
Loamy Bottom 16-20" p.z. |
|---|---|
| R041XC302AZ |
Clayey Swale 12-16" p.z. |
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
(1) sporobolus wrightii |
Physiographic features
This site occurs in the middle elevations of the Madrean Basin and Range province in southeastern Arizona. It occurs on floodplains and low stream terraces of major drainage ways and first and second order tributaries. It benefits on a regular basis from extra moisture received as over-bank flooding. It also benefits from shallow water tables at depths of 5-20 feet; or from subsurface clay lenses that perch available water for growth after flood events.
Table 2. Representative physiographic features
| Landforms |
(1)
Flood plain
(2) Stream terrace |
|---|---|
| Flooding duration | Very brief (4 to 48 hours) to brief (2 to 7 days) |
| Flooding frequency | Occasional to frequent |
| Ponding duration | Very brief (4 to 48 hours) |
| Ponding frequency | None to rare |
| Elevation | 3,200 – 5,000 ft |
| Slope | 2% |
| Aspect | Aspect is not a significant factor |
Climatic features
Precipitation in this common resource area ranges from 12-16 inches yearly in the eastern part with elevations from 3600-5000 feet, and 13-17 inches in the western part where elevations are 3300-4500 feet. Winter-Summer rainfall ratios are 40-60% in the west and 30-70% in the east. Summer rains fall July-September, originate in the Gulf of Mexico and are convective, usually brief, intense thunderstorms. Cool season moisture tends to be frontal, originates in the Pacific and Gulf of California, and falls in widespread storms with long duration and low intensity. Snow rarely lasts more than one day. May and June are the driest months of the year. Humidity is generally very low.
Temperatures are mild. Freezing temperatures are common at night from December-April; however temperatures during the day are frequently above 50 F. Occasionally in December-February, brief 0 F temperatures may be experienced some nights. During June, July and August, some days may exceed 100 F.
Cool season plants start growth in early spring and mature in early summer. Warm season plants take advantage of summer rains and are growing and nutritious July-September. Warm season grasses may remain green throughout the year.
Table 3. Representative climatic features
| Frost-free period (average) | 220 days |
|---|---|
| Freeze-free period (average) | |
| Precipitation total (average) | 16 in |
Figure 2. Monthly precipitation range
Figure 3. Monthly average minimum and maximum temperature
Influencing water features
There are no water features associated with this site.
Soil features
These are young soils on loamy to clayey alluvium of mixed origin. They are deep and dark colored. Plant-soil moisture relationships are excellent.
Soils mapped on this site include: SSA-666 Cochise county Northwest part MU 47 Guest; SSA-667 Santa Cruz area MU's Pm Pima and Ge Grabe; SSA-671 Cochise county Douglas-Tombstone part MU's 84 & 125 Riveroad, 144 Ubik SiL, 145 Ubic L and Ubic L saline-sodic.
Table 4. Representative soil features
| Surface texture |
(1) Fine sandy loam (2) Silt loam (3) Silty clay loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderately slow to moderately rapid |
| Soil depth | 60 in |
| Surface fragment cover <=3" | 5% |
| Surface fragment cover >3" | 1% |
| Available water capacity (0-40in) |
8.4 – 12.6 in |
| Calcium carbonate equivalent (0-40in) |
5% |
| Electrical conductivity (0-40in) |
2 mmhos/cm |
| Sodium adsorption ratio (0-40in) |
2 |
| Soil reaction (1:1 water) (0-40in) |
7.4 – 8.4 |
| Subsurface fragment volume <=3" (Depth not specified) |
5% |
| Subsurface fragment volume >3" (Depth not specified) |
1% |
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 each 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.
The potential plant community on this site is giant sacaton grassland. Occasional clumps and strands of trees occur along shallow drainage ways and discontinuous gullies. Natural fires during the summer months were important in maintaining the plant community.
The site is very susceptible to gully, channel and bank erosion, especially when the tall grass cover is depleted due to repeated burning and overgrazing or when structures such as dikes, roads, etc., are placed on the floodplain. The lowering of the base level of the axial stream of a watershed will eventually cause channeling of the site. Grade stabilization will be required to prevent deterioration under such conditions. Excessive pumping of ground water can, over time, lower water tables causing depletion of grass cover and site deterioration from gully erosion. With severe erosion, the effectiveness of flooding is reduced, water tables are lowered, the grass cover is thinned and woody plants, especially mesquite, will increase to dominate the plant community. Bermuda grass and Johnson grass are introduced species which can be troublesome on this site.
State and transition model
Figure 4. State and Transition, Loamy Bottom 12-16" p.z.
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 text
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
Historic Climax Plant Community
Community 1.1
Historic Climax Plant Community
Figure 5. Loamy Bottom 12-16" pz. burned mesquite
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 plant community represents the natural climax community that eventually re-occupies the site with proper management. The potential plant community is dominated by nearly pure stands of giant sacaton. Frequent flooding and groundwater available within the rooting depth of sacaton (20 feet) account for dense and productive stands of grass. Occasional clumps and strands of trees occur along shallow drainages. Naturally occurring fires, June thru September, were an important factor in maintaining the plant community on this site. The aspect is tall grassland. Mesquite can invade and increase in the native plant community; but high intensity fires can remove even well established mesquite trees as long as sediment accumulation around the stem bases has not occurred. Even repeated fires at these intensities will not remove established mesquite if their bud zones are buried by sediment. The interaction of drought, fire, flooding and grazing can reduce sacaton canopy to 25%. It will recover to normal levels in a short time. Annual composite forbs like ragweed, goldeneye, sunflower and xanthocephalum can make tremendous stands in wet seasons after fire or drought has opened the grass community.
Figure 6. 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 | 3035 | 4000 | 5450 |
| Forb | 20 | 75 | 600 |
| Tree | 10 | 25 | 100 |
| Shrub/Vine | 0 | 10 | 50 |
| Total | 3065 | 4110 | 6200 |
Table 6. Soil surface cover
| Tree basal cover | 0-1% |
|---|---|
| Shrub/vine/liana basal cover | 0-1% |
| Grass/grasslike basal cover | 20-35% |
| Forb basal cover | 0-1% |
| Non-vascular plants | 0% |
| Biological crusts | 0-5% |
| Litter | 20-65% |
| Surface fragments >0.25" and <=3" | 0-5% |
| Surface fragments >3" | 0-1% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 10-60% |
Table 7. Canopy structure (% cover)
| Height Above Ground (ft) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.5 | – | – | 0-5% | 0-5% |
| >0.5 <= 1 | – | – | 0-10% | 0-5% |
| >1 <= 2 | – | – | 0-5% | 0-5% |
| >2 <= 4.5 | – | 0-2% | 30-60% | 0-10% |
| >4.5 <= 13 | 0-2% | 0-2% | 0-20% | 0-5% |
| >13 <= 40 | 0-2% | – | – | – |
| >40 <= 80 | – | – | – | – |
| >80 <= 120 | – | – | – | – |
| >120 | – | – | – | – |
Figure 7. Plant community growth curve (percent production by month). AZ4134, 41.3 12-16" p.z. other sites. Growth begins in the spring, semi-dormancy occurs during the May through June drought, most growth occurs during the summer rains..
| 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 | 5 | 10 | 0 | 0 | 30 | 35 | 15 | 5 | 0 | 0 |
State 2
Sacaton, eroded
Community 2.1
Sacaton, eroded
Figure 8. Loamy Bottom 12-16" pz. gullied
Head-cutting and gully erosion have drained the site. It no longer benefits from extra water received as flooding. The cover of sacaton thins to less than 25%. Groundwater may become out of reach to sacaton roots if incision is deeper than 20 feet. Annual production becomes a function of seasonal rainfall. Annual forbs and grasses may equal sacaton in production.
State 3
Annual Forbs and Grasses
Community 3.1
Annual Forbs and Grasses
Some areas of this state have been created by cultivation for irrigated farming and subsequent abandonment. Former cultivated areas usually have been altered by the diversion of floodwaters with dikes or drainage ditches. In other areas erosion and lowering of water tables have reduced sacaton to less than 5% canopy cover and allowed annual species to dominate. Native and non-native annual forbs and grasses dominate the plant community with minor amounts of sacaton and other native and non-native perennial grasses.
State 4
Non-native perennial grasses
Community 4.1
Non-native perennial grasses
Non-native perennial grasses like Johnson grass, bermuda grass and blue panic dominate the plant community. In some areas this state was made by plowing (and/or burning) of sacaton and seeding of the non-native species. In other areas non-native species invaded from disturbed areas like highway ROWs into areas where the native sacaton stands had been reduced by the interactions of continuous grazing, drought and fire. In other areas this state is a result of the abandonment of cultivated land which is still flooded and had a weed component of the non-native grasses. This state may or may not have a mesquite canopy. Fires can still burn at historic intensities due to the high productivity of grass species with frequent flooding.
State 5
Mesquite, sacaton
Community 5.1
Mesquite, sacaton
Figure 9. Loamy Bottom 12-16" pz. Mesquite
Mesquite has invaded the site in the absence of fire for long periods of time. Mesquite canopy ranges from 20 to 40%. Trees are well established and the crowns are protected from the heat of surface fires due to sediment accumulation around the stem bases. Sacaton is co-dominant as the state still benefits from frequent flooding and groundwater within the reach of grass roots.
State 6
Mesquite, eroded
Community 6.1
Mesquite, eroded
The down-cutting of major stream systems and subsequent "valley side" gullying have left many areas of this state along side of rivers like the San Pedro, Santa Cruz and Cienega and Babocomari creeks. Groundwater has dropped beyond the root zone of sacaton (25 feet); but still within the root zone of mesquite (50 feet). The site no longer benefits from flooding. The plant community is dominated by mature mesquite trees with little or no perennial under-story. This state is recognized as a mesquite woodland site as it occurs and forms naturally in the geomorphic dynamics of southwestern stream systems. For details see Forestland site number F041XC310AZ.
Additional community tables
Table 8. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Dominant tall grass | 3000–5000 | ||||
| big sacaton | SPWR2 | Sporobolus wrightii | 3000–5000 | – | ||
| alkali sacaton | SPAI | Sporobolus airoides | 0–150 | – | ||
| 2 | Subdominant perennial grasses | 25–200 | ||||
| vine mesquite | PAOB | Panicum obtusum | 0–100 | – | ||
| sideoats grama | BOCU | Bouteloua curtipendula | 0–100 | – | ||
| blue grama | BOGR2 | Bouteloua gracilis | 0–100 | – | ||
| creeping muhly | MURE | Muhlenbergia repens | 0–50 | – | ||
| tobosagrass | PLMU3 | Pleuraphis mutica | 0–50 | – | ||
| 3 | Miscellaneous perennial grasses | 0–100 | ||||
| cane bluestem | BOBA3 | Bothriochloa barbinodis | 0–50 | – | ||
| Rothrock's grama | BORO2 | Bouteloua rothrockii | 0–25 | – | ||
| Arizona cottontop | DICA8 | Digitaria californica | 0–25 | – | ||
| squirreltail | ELELE | Elymus elymoides ssp. elymoides | 0–25 | – | ||
| green sprangletop | LEDU | Leptochloa dubia | 0–25 | – | ||
| whiplash pappusgrass | PAVA2 | Pappophorum vaginatum | 0–25 | – | ||
| plains bristlegrass | SEVU2 | Setaria vulpiseta | 0–25 | – | ||
| spidergrass | ARTE3 | Aristida ternipes | 0–20 | – | ||
| spidergrass | ARTEG | Aristida ternipes var. gentilis | 0–15 | – | ||
| Orcutt's threeawn | ARSCO | Aristida schiedeana var. orcuttiana | 0–15 | – | ||
| flatsedge | CYPER | Cyperus | 0–15 | – | ||
| mat muhly | MURI | Muhlenbergia richardsonis | 0–15 | – | ||
| bush muhly | MUPO2 | Muhlenbergia porteri | 0–10 | – | ||
| bulrush | SCIRP | Scirpus | 0–10 | – | ||
| spike dropseed | SPCO4 | Sporobolus contractus | 0–10 | – | ||
| plains lovegrass | ERIN | Eragrostis intermedia | 0–10 | – | ||
| mountain rush | JUARL | Juncus arcticus ssp. littoralis | 0–10 | – | ||
| hairy grama | BOHI2 | Bouteloua hirsuta | 0–10 | – | ||
| sedge | CAREX | Carex | 0–5 | – | ||
| sand dropseed | SPCR | Sporobolus cryptandrus | 0–5 | – | ||
| burrograss | SCBR2 | Scleropogon brevifolius | 0–5 | – | ||
| bulb panicgrass | PABU | Panicum bulbosum | 0–5 | – | ||
| bullgrass | MUEM | Muhlenbergia emersleyi | 0–5 | – | ||
| poverty threeawn | ARDI5 | Aristida divaricata | 0–3 | – | ||
| 4 | Annual grasses | 10–150 | ||||
| feather fingergrass | CHVI4 | Chloris virgata | 0–50 | – | ||
| Mexican sprangletop | LEFUU | Leptochloa fusca ssp. uninervia | 0–50 | – | ||
| sticky sprangletop | LEVI5 | Leptochloa viscida | 0–50 | – | ||
| mucronate sprangeltop | LEPAB | Leptochloa panicea ssp. brachiata | 0–25 | – | ||
| Arizona signalgrass | URAR | Urochloa arizonica | 0–25 | – | ||
| sixweeks fescue | VUOC | Vulpia octoflora | 0–25 | – | ||
| Mexican panicgrass | PAHI5 | Panicum hirticaule | 0–25 | – | ||
| needle grama | BOAR | Bouteloua aristidoides | 0–20 | – | ||
| tapertip cupgrass | ERACA | Eriochloa acuminata var. acuminata | 0–15 | – | ||
| Mexican lovegrass | ERME | Eragrostis mexicana | 0–5 | – | ||
| desert lovegrass | ERPEM | Eragrostis pectinacea var. miserrima | 0–5 | – | ||
| tufted lovegrass | ERPEP2 | Eragrostis pectinacea var. pectinacea | 0–5 | – | ||
| sixweeks threeawn | ARAD | Aristida adscensionis | 0–5 | – | ||
| prairie threeawn | AROL | Aristida oligantha | 0–5 | – | ||
| sixweeks grama | BOBA2 | Bouteloua barbata | 0–5 | – | ||
| Arizona brome | BRAR4 | Bromus arizonicus | 0–5 | – | ||
| delicate muhly | MUFR | Muhlenbergia fragilis | 0–5 | – | ||
| littleseed muhly | MUMI | Muhlenbergia microsperma | 0–5 | – | ||
| witchgrass | PACA6 | Panicum capillare | 0–5 | – | ||
| Bigelow's bluegrass | POBI | Poa bigelovii | 0–5 | – | ||
|
Forb
|
||||||
| 5 | Perennial Forbs | 10–100 | ||||
| sedge | CAREX | Carex | 50–250 | – | ||
| flatsedge | CYPER | Cyperus | 50–250 | – | ||
| slimleaf sneezeweed | HELI | Helenium linifolium | 50–250 | – | ||
| rush | JUNCU | Juncus | 50–250 | – | ||
| Missouri gourd | CUFO | Cucurbita foetidissima | 0–50 | – | ||
| coyote gourd | CUPA | Cucurbita palmata | 0–25 | – | ||
| fingerleaf gourd | CUDI | Cucurbita digitata | 0–25 | – | ||
| weakleaf bur ragweed | AMCO3 | Ambrosia confertiflora | 1–25 | – | ||
| gooseberryleaf globemallow | SPGR2 | Sphaeralcea grossulariifolia | 0–20 | – | ||
| white sagebrush | ARLU | Artemisia ludoviciana | 0–15 | – | ||
| scarlet spiderling | BOCO | Boerhavia coccinea | 0–15 | – | ||
| spreading fleabane | ERDI4 | Erigeron divergens | 0–10 | – | ||
| spear globemallow | SPHA | Sphaeralcea hastulata | 0–10 | – | ||
| canaigre dock | RUHY | Rumex hymenosepalus | 0–10 | – | ||
| Indian rushpea | HOGL2 | Hoffmannseggia glauca | 0–10 | – | ||
| slimleaf bean | PHAN3 | Phaseolus angustissimus | 0–10 | – | ||
| desert globemallow | SPAM2 | Sphaeralcea ambigua | 0–10 | – | ||
| Wright's cudweed | PSCAC2 | Pseudognaphalium canescens ssp. canescens | 0–5 | – | ||
| American vetch | VIAM | Vicia americana | 0–5 | – | ||
| Louisiana vetch | VILUL2 | Vicia ludoviciana ssp. ludoviciana | 0–5 | – | ||
| Trans-Pecos thimblehead | HYWI | Hymenothrix wislizeni | 0–5 | – | ||
| Lewis flax | LILE3 | Linum lewisii | 0–5 | – | ||
| Greene's bird's-foot trefoil | LOGR4 | Lotus greenei | 0–5 | – | ||
| Wright's deervetch | LOWR | Lotus wrightii | 0–5 | – | ||
| woodsorrel | OXALI | Oxalis | 0–5 | – | ||
| Lemmon's ragwort | SELE8 | Senecio lemmonii | 0–5 | – | ||
| New Mexico fanpetals | SINE | Sida neomexicana | 0–5 | – | ||
| silverleaf nightshade | SOEL | Solanum elaeagnifolium | 0–5 | – | ||
| Missouri goldenrod | SOMI2 | Solidago missouriensis | 0–5 | – | ||
| brownplume wirelettuce | STPA4 | Stephanomeria pauciflora | 0–5 | – | ||
| white prairie aster | SYFAC | Symphyotrichum falcatum var. commutatum | 0–5 | – | ||
| beeblossom | GAURA | Gaura | 0–5 | – | ||
| southwestern mock vervain | GLGO | Glandularia gooddingii | 0–5 | – | ||
| small matweed | GUDED | Guilleminea densa var. densa | 0–5 | – | ||
| tarragon | ARDR4 | Artemisia dracunculus | 0–5 | – | ||
| bluedicks | DICA14 | Dichelostemma capitatum | 0–5 | – | ||
| leastdaisy | CHAET2 | Chaetopappa | 0–5 | – | ||
| whitemouth dayflower | COER | Commelina erecta | 0–2 | – | ||
| yerba mansa | ANCA10 | Anemopsis californica | 0–2 | – | ||
| wild dwarf morning-glory | EVAR | Evolvulus arizonicus | 0–2 | – | ||
| jewels of Opar | TAPA2 | Talinum paniculatum | 0–2 | – | ||
| ragged nettlespurge | JAMA | Jatropha macrorhiza | 0–2 | – | ||
| orange fameflower | PHAU13 | Phemeranthus aurantiacus | 0–2 | – | ||
| ivyleaf groundcherry | PHHE4 | Physalis hederifolia | 0–2 | – | ||
| milkweed | ASCLE | Asclepias | 0–1 | – | ||
| 6 | Annual forbs | 10–500 | ||||
| common sunflower | HEAN3 | Helianthus annuus | 1–200 | – | ||
| San Pedro matchweed | XAGY | Xanthocephalum gymnospermoides | 1–200 | – | ||
| longleaf false goldeneye | HELOL | Heliomeris longifolia var. longifolia | 1–150 | – | ||
| camphorweed | HESU3 | Heterotheca subaxillaris | 0–100 | – | ||
| longleaf false goldeneye | HELOA2 | Heliomeris longifolia var. annua | 1–100 | – | ||
| western tansymustard | DEPI | Descurainia pinnata | 0–50 | – | ||
| carelessweed | AMPA | Amaranthus palmeri | 0–50 | – | ||
| wheelscale saltbush | ATEL | Atriplex elegans | 0–25 | – | ||
| Coulter's spiderling | BOCO2 | Boerhavia coulteri | 0–25 | – | ||
| sensitive partridge pea | CHNI2 | Chamaecrista nictitans | 0–25 | – | ||
| New Mexico thistle | CINE | Cirsium neomexicanum | 0–25 | – | ||
| horseweed | CONYZ | Conyza | 0–15 | – | ||
| cryptantha | CRYPT | Cryptantha | 0–15 | – | ||
| Wright's saltbush | ATWR | Atriplex wrightii | 0–15 | – | ||
| New Mexico copperleaf | ACNE | Acalypha neomexicana | 0–15 | – | ||
| crestrib morning-glory | IPCO2 | Ipomoea costellata | 0–15 | – | ||
| morning-glory | IPOMO | Ipomoea | 0–15 | – | ||
| Arizona poppy | KAGR | Kallstroemia grandiflora | 0–15 | – | ||
| Arizona popcornflower | PLAR | Plagiobothrys arizonicus | 0–15 | – | ||
| intermediate pepperweed | LEVIM | Lepidium virginicum var. medium | 0–15 | – | ||
| Nuttall's povertyweed | MONU | Monolepis nuttalliana | 0–15 | – | ||
| woolly plantain | PLPA2 | Plantago patagonica | 0–10 | – | ||
| purslane | PORTU | Portulaca | 0–5 | – | ||
| desert unicorn-plant | PRAL4 | Proboscidea althaeifolia | 0–5 | – | ||
| doubleclaw | PRPA2 | Proboscidea parviflora | 0–5 | – | ||
| chia | SACO6 | Salvia columbariae | 0–5 | – | ||
| sawtooth sage | SASU7 | Salvia subincisa | 0–5 | – | ||
| spreading fanpetals | SIAB | Sida abutifolia | 0–5 | – | ||
| desert Indianwheat | PLOV | Plantago ovata | 0–5 | – | ||
| rough cocklebur | XAST | Xanthium strumarium | 0–5 | – | ||
| Florida pellitory | PAFL3 | Parietaria floridana | 0–5 | – | ||
| combseed | PECTO | Pectocarya | 0–5 | – | ||
| phacelia | PHACE | Phacelia | 0–5 | – | ||
| phlox | PHLOX | Phlox | 0–5 | – | ||
| foothill deervetch | LOHU2 | Lotus humistratus | 0–5 | – | ||
| coastal bird's-foot trefoil | LOSAB | Lotus salsuginosus var. brevivexillus | 0–5 | – | ||
| Arizona lupine | LUAR4 | Lupinus arizonicus | 0–5 | – | ||
| Coulter's lupine | LUSP2 | Lupinus sparsiflorus | 0–5 | – | ||
| hollowleaf annual lupine | LUSU3 | Lupinus succulentus | 0–5 | – | ||
| slender goldenweed | MAGR10 | Machaeranthera gracilis | 0–5 | – | ||
| tanseyleaf tansyaster | MATA2 | Machaeranthera tanacetifolia | 0–5 | – | ||
| whitestem blazingstar | MEAL6 | Mentzelia albicaulis | 0–5 | – | ||
| warty caltrop | KAPA | Kallstroemia parviflora | 0–5 | – | ||
| goosefoot | CHENO | Chenopodium | 0–5 | – | ||
| shaggyfruit pepperweed | LELA | Lepidium lasiocarpum | 0–5 | – | ||
| miniature woollystar | ERDI2 | Eriastrum diffusum | 0–5 | – | ||
| sorrel buckwheat | ERPO4 | Eriogonum polycladon | 0–5 | – | ||
| California poppy | ESCAM | Eschscholzia californica ssp. mexicana | 0–5 | – | ||
| spurge | EUPHO | Euphorbia | 0–5 | – | ||
| Arizona blanketflower | GAAR2 | Gaillardia arizonica | 0–5 | – | ||
| southwestern pricklypoppy | ARPL3 | Argemone pleiacantha | 0–5 | – | ||
| milkvetch | ASTRA | Astragalus | 0–5 | – | ||
| American wild carrot | DAPU3 | Daucus pusillus | 0–5 | – | ||
| jimsonweed | DAST | Datura stramonium | 0–5 | – | ||
| sacred thorn-apple | DAWR2 | Datura wrightii | 0–5 | – | ||
| scrambled eggs | COAU2 | Corydalis aurea | 0–5 | – | ||
| hoary bowlesia | BOIN3 | Bowlesia incana | 0–5 | – | ||
| golden crownbeard | VEEN | Verbesina encelioides | 0–5 | – | ||
| sleepy silene | SIAN2 | Silene antirrhina | 0–3 | – | ||
| New Mexico plumeseed | RANE | Rafinesquia neomexicana | 0–3 | – | ||
| woolly tidestromia | TILA2 | Tidestromia lanuginosa | 0–2 | – | ||
| Mexican passionflower | PAME2 | Passiflora mexicana | 0–2 | – | ||
| green carpetweed | MOVE | Mollugo verticillata | 0–2 | – | ||
| plains flax | LIPU4 | Linum puberulum | 0–2 | – | ||
| fringed redmaids | CACI2 | Calandrinia ciliata | 0–2 | – | ||
| star gilia | GIST | Gilia stellata | 0–2 | – | ||
| Texas stork's bill | ERTE13 | Erodium texanum | 0–2 | – | ||
| Goodding's bladderpod | LEGO2 | Lesquerella gooddingii | 0–2 | – | ||
|
Shrub/Vine
|
||||||
| 7 | Miscellaneous shrubs | 0–50 | ||||
| fourwing saltbush | ATCA2 | Atriplex canescens | 0–10 | – | ||
| mule-fat | BASA4 | Baccharis salicifolia | 0–10 | – | ||
| Apache plume | FAPA | Fallugia paradoxa | 0–10 | – | ||
| singlewhorl burrobrush | HYMO | Hymenoclea monogyra | 0–10 | – | ||
| American black elderberry | SANIC4 | Sambucus nigra ssp. canadensis | 0–10 | – | ||
| canyon grape | VIAR2 | Vitis arizonica | 0–5 | – | ||
| soaptree yucca | YUEL | Yucca elata | 0–5 | – | ||
| fringed twinevine | FUCYC | Funastrum cynanchoides ssp. cynanchoides | 0–5 | – | ||
| pale desert-thorn | LYPA | Lycium pallidum | 0–5 | – | ||
| catclaw mimosa | MIACB | Mimosa aculeaticarpa var. biuncifera | 0–5 | – | ||
| Texas mulberry | MOMI | Morus microphylla | 0–5 | – | ||
| sacahuista | NOMI | Nolina microcarpa | 0–5 | – | ||
| Drummond's clematis | CLDR | Clematis drummondii | 0–5 | – | ||
| Thurber's desert honeysuckle | ANTH2 | Anisacanthus thurberi | 0–5 | – | ||
| rubber rabbitbrush | ERNA10 | Ericameria nauseosa | 0–5 | – | ||
| walkingstick cactus | CYSP8 | Cylindropuntia spinosior | 0–2 | – | ||
| yerba de pasmo | BAPT | Baccharis pteronioides | 0–2 | – | ||
| desertbroom | BASA2 | Baccharis sarothroides | 0–2 | – | ||
| whitethorn acacia | ACCO2 | Acacia constricta | 0–2 | – | ||
| fetid passionflower | PAFO2 | Passiflora foetida | 0–2 | – | ||
| skunkbush sumac | RHTR | Rhus trilobata | 0–2 | – | ||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 0–2 | – | ||
| burroweed | ISTE2 | Isocoma tenuisecta | 0–2 | – | ||
|
Tree
|
||||||
| 8 | Common trees | 10–50 | ||||
| desert willow | CHLI2 | Chilopsis linearis | 0–50 | – | ||
| mesquite | PROSO | Prosopis | 0–50 | – | ||
| 9 | Miscellaneous trees | 0–50 | ||||
| Arizona sycamore | PLWR2 | Platanus wrightii | 0–50 | – | ||
| Fremont cottonwood | POFR2 | Populus fremontii | 0–50 | – | ||
| Goodding's willow | SAGO | Salix gooddingii | 0–25 | – | ||
| western soapberry | SASAD | Sapindus saponaria var. drummondii | 0–10 | – | ||
| netleaf hackberry | CELAR | Celtis laevigata var. reticulata | 0–10 | – | ||
| velvet ash | FRVE2 | Fraxinus velutina | 0–10 | – | ||
| Arizona walnut | JUMA | Juglans major | 0–10 | – | ||
| catclaw acacia | ACGR | Acacia greggii | 0–5 | – | ||
Interpretations
Animal community
Big sacaton begins growth in the spring about mid April. The green season extends through September. Grazing must be concentrated on areas of this site to achieve reasonable utilization of sacaton and keep it in a vegetative state. Heat, humidity and insects are severe enough during summer flooding in July-August , to greatly affect livestock performance. Burning or mowing can be used periodically to freshen old growth sacaton. Burning should be done in February or early March; only in years when November thru February moisture equals or exceeds 4 inches. Burning can be done in July or August, after the first summer rains, to freshen sacaton for winter grazing. Areas of this site should be fenced exclusively for best management of the forage resources. Sacaton is very coarse and unpalatable, but provides adequate nutrition for livestock when green.
Sacaton bottoms are very important habitat for a variety of ground nesting birds and small mammals. They are important cover and foraging areas for javalina, whitetail and mule deer.
Hydrological functions
Sacaton floodplains are extremely important in the hydrologic regime of southeastern Arizona stream systems. Intact sacaton floodplains retain floodwaters for 3 to 4 weeks after major flooding events. Channeled or gullied bottomlands often pass the same flood in 2 or 3 days. Water tables in healthy sacaton bottoms range from 5 to 20 feet alongside major streams and creeks and their larger tributaries. In other sacaton bottoms, clay lenses at moderate depths, perch and hold water in the root zone of sacaton after flood events.
Recreational uses
Hunting, bird-watching, hiking, horseback riding, photography.
Wood products
Sacaton bottoms invaded by mesquite furnish large quantities of fuel-wood and posts.
Other products
Sacaton seed
Supporting information
Inventory data references
Range 417s include 1 in excellent condition, 7 in good condition and 6 in fair condition.
Type locality
| Location 1: Cochise County, AZ | |
|---|---|
| Township/Range/Section | T23S R22E S9 |
| General legal description | San Pedro River |
| Location 2: Santa Cruz County, AZ | |
| Township/Range/Section | T21S R19E S18 |
| General legal description | Lyle Canyon |
| Location 3: Pima County, AZ | |
| Township/Range/Section | T19S R17E S11 |
| General legal description | Empire Ranch, Key Area 19 in the 5 Wire (east) Pasture. |
Contributors
Dan Robinett
Larry D. Ellicott
Steve Barker
Unknown
Approval
Curtis Talbot, 4/12/2021
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) | Wilma Renken, Dave Womack, Emilio Carrillo, Dan Robinett |
|---|---|
| Contact for lead author | USDA-NRCS Tucson MLRA Soil Survey Office |
| Date | 07/22/2013 |
| Approved by | Curtis Talbot |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
None Present on this site. -
Presence of water flow patterns:
Uncommon; probably cover no more than 5% of area; very short and discontinuous, 1-3 feet in length. -
Number and height of erosional pedestals or terracettes:
Slope is 0-1% and not conducive to forming pedestals and terracettes. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
3-10% basd on monitoring data. Bare areas are <3 feet in diameter; perennial grasses are evenly distributed. -
Number of gullies and erosion associated with gullies:
Occasional, discontinuous gullies. These gullies can be 50-200 feet in length, 2-5 feet wide and 2-5 feet deep. -
Extent of wind scoured, blowouts and/or depositional areas:
None present on this site. -
Amount of litter movement (describe size and distance expected to travel):
All litter size classes staying in place, occasionally being transported in flow paths. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
No slake test performed. Expect values of 5’s & 6’s across site. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Weak granular to moderate subangular blocky; Color is 10YR5/2 Dry, 10YR3/2 Moist; thickness to 20+ inches. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Cover estimated as follows: Canopy 47-93%, Basal 17-24%, Litter 65-79%; 95% of canopy cover is perennial tall grasses, 3% is short grasses, and 2 % is grass like and forbs. Short grass species cover occupy scattered patches throughout site. Canopy cover is temporally dynamic. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None present on this site. -
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:
Perennial tall grasses >>Sub-dominant:
short grasses > grasslike species > perennial forbs > annuals grasses & forbs.Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
10-20% basal area lost on short grasses, 5% basal area lost on tall grasses. -
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
3,500 lbs/acre unfavorable precipitation, 5,000 lbs/acre normal precipitation, 6,500 lbs/acre 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:
mesquite, wait-a-bit, burrobrush, rubber rabbitbrush, johnson grass, bermuda grass. -
Perennial plant reproductive capability:
Not affected even following several years of prolonged drought period for region.
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The 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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