Natural Resources
Conservation Service
Ecological site R041XB202AZ
Clayey Swale 8-12" p.z.
Last updated: 4/09/2021
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 41.2 – 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
| R041XB203AZ |
Clayey Upland 8-12" p.z. |
|---|---|
| R041XB204AZ |
Clay Loam Upland 8-12" p.z. |
| R041XB223AZ |
Basalt Hills 8-12" p.z. |
Similar sites
| R041XC302AZ |
Clayey Swale 12-16" p.z. |
|---|---|
| R040XA102AZ |
Clayey Swale 10"-13" p.z. |
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
(1) Pleuraphis mutica |
Physiographic features
This site occurs in the lowest elevations of the Madrean Basin and Range province in southeastern Arizona. It occurs on small floodplains, alluvial fans and swales; usually associated with basalt and andesite mountains. The site benefits on an irregular basis from extra water received as runoff from adjacent uplands.
Table 2. Representative physiographic features
| Landforms |
(1)
Flood plain
(2) Alluvial fan (3) Swale |
|---|---|
| Flooding duration | Very brief (4 to 48 hours) to brief (2 to 7 days) |
| Flooding frequency | Rare to occasional |
| Ponding duration | Very brief (4 to 48 hours) to brief (2 to 7 days) |
| Ponding frequency | Rare to occasional |
| Elevation | 2,600 – 4,000 ft |
| Slope | 6% |
| Aspect | Aspect is not a significant factor |
Climatic features
Precipitation ranges from 8-12 inches annually. More than half falls during Jul-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) | |
| Precipitation total (average) |
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 soils are deep and clayey textured. They have thin (1-2 inch) surface horizons that range from clayloam to silty clay in texture. They exhibit strong vertic soil properties. Surface soils (10 inches) are usually non-calcareous, but some soils have calcic horizons below the argillic horizon.
Soil series mapped on areas of this site include: SSA-662 Safford area MU Gy Guest; SSA-664 San Simon area MU's 26 Guest & 27 Guest and Hantz; SSA-666 Cochise county Northwestern part MU's 29, 30, 31, 32 Contention; SSA-671 Cochise county Douglas-Tombstone part MU 35 Contention.
Table 4. Representative soil features
| Surface texture |
(1) Clay (2) Clay loam (3) Silty clay loam |
|---|---|
| Family particle size |
(1) Clayey |
| Drainage class | Well drained |
| Permeability class | Slow to very slow |
| Soil depth | 60 in |
| Surface fragment cover <=3" | 10% |
| Surface fragment cover >3" | 1% |
| Available water capacity (0-40in) |
9 – 10 in |
| Calcium carbonate equivalent (0-40in) |
10% |
| Electrical conductivity (0-40in) |
2 mmhos/cm |
| Sodium adsorption ratio (0-40in) |
2 |
| Soil reaction (1:1 water) (0-40in) |
7 – 8.2 |
| 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 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
Figure 4. State and Transition, Clayey Swale 8-12" pz.
More interactive model formats are also available.
View Interactive Models
More interactive model formats are also available.
View Interactive Models
Click on state and transition labels to scroll to the respective 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 1
Historic Climax Plant Community
Community 1.1
Historic Climax Plant Community
The native potential plant community on this site is grassland with a scattering of desert shrubs and cacti. Annual forbs and grasses, of both winter and summer seasons, are very important in the plant community in their respective (wet) seasons. Tobosa is the dominant perennial grass with lesser amounts of vine mesquite.
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) |
|---|---|---|---|
| Grass/Grasslike | 226 | 650 | 935 |
| Forb | 5 | 50 | 175 |
| Shrub/Vine | 0 | 5 | 30 |
| Total | 231 | 705 | 1140 |
Table 6. Soil surface cover
| Tree basal cover | 0-1% |
|---|---|
| Shrub/vine/liana basal cover | 0-1% |
| Grass/grasslike basal cover | 5-10% |
| Forb basal cover | 0-1% |
| Non-vascular plants | 0% |
| Biological crusts | 1-10% |
| Litter | 35-65% |
| Surface fragments >0.25" and <=3" | 1-15% |
| Surface fragments >3" | 0-5% |
| 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 | – | 0-2% | 1-15% | 1-15% |
| >0.5 <= 1 | – | 0-2% | 10-35% | 1-10% |
| >1 <= 2 | – | 0-2% | 10-20% | 0-5% |
| >2 <= 4.5 | – | 0-2% | – | 0-1% |
| >4.5 <= 13 | – | 0-2% | – | – |
| >13 <= 40 | – | – | – | – |
| >40 <= 80 | – | – | – | – |
| >80 <= 120 | – | – | – | – |
| >120 | – | – | – | – |
Figure 6. Plant community growth curve (percent production by month). AZ4121, 41.2 7-12" p.z. all sites. Growth begins in the late winter to early spring, semi-dormancy occurs during the May through June drought, 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 | 5 | 5 | 10 | 0 | 0 | 25 | 30 | 15 | 5 | 5 | 0 |
State 2
Tobosa - unflooded
Community 2.1
Tobosa - unflooded
This plant community occurs where the site is no longer flooded. The reasons can include the interruption of flood flows by roads, diversions and or floodways. The site acts as Clayey Upland #R041BX203AZ.
State 3
Mesquite, tobosa
Community 3.1
Mesquite, tobosa
This community occurs where mesquite has invaded and increased to dominate the plant community. Tree canopy ranges from 2 to 20%. Mesquite is well established and sprouts readily after fire to quickly assume dominance. Tobosa cover remains intact and production remains high.
State 4
Annual forbs and grasses
Community 4.1
Annual forbs and grasses
This community occurs where the tobosa grass cover has been depleted to less than 5% canopy, and is not uniformly dispersed. Causes include the interactions of drought, fire and continuous grazing. In some cases areas of this state occur where the site was cultivated for irrigation and then abandoned. Native and non-native annual forbs and grasses persist to dominate the community.
State 5
Eroded
Community 5.1
Eroded
This state occurs where the perennial grass cover has been depleted and accelerated erosion has left an imprint of rills and gullies on the site. Flooding is no longer effective as gullies rapidly drain extra water from the site. The plant community is a low production mixture of annuals and shrubs like mesquite and snakeweed. Causes can include the lowering of base levels of larger stream systems causing valley side swales to down-cut. Also in some areas adjacent to the Gila and San Pedro river bottom; these soils have a high percentage of gypsum in the soil profile and erode easily with compaction, trailing and continuous grazing.
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 Perennial Grasses | 220–700 | ||||
| tobosagrass | PLMU3 | Pleuraphis mutica | 200–600 | – | ||
| vine mesquite | PAOB | Panicum obtusum | 20–100 | – | ||
| 2 | Miscellaneous Perennial Grasses | 1–35 | ||||
| sideoats grama | BOCU | Bouteloua curtipendula | 0–10 | – | ||
| blue grama | BOGR2 | Bouteloua gracilis | 0–10 | – | ||
| big sacaton | SPWR2 | Sporobolus wrightii | 0–10 | – | ||
| burrograss | SCBR2 | Scleropogon brevifolius | 0–5 | – | ||
| plains bristlegrass | SEVU2 | Setaria vulpiseta | 0–5 | – | ||
| alkali sacaton | SPAI | Sporobolus airoides | 0–5 | – | ||
| black grama | BOER4 | Bouteloua eriopoda | 0–5 | – | ||
| curly-mesquite | HIBE | Hilaria belangeri | 0–5 | – | ||
| green sprangletop | LEDU | Leptochloa dubia | 0–5 | – | ||
| creeping muhly | MURE | Muhlenbergia repens | 0–5 | – | ||
| cane bluestem | BOBA3 | Bothriochloa barbinodis | 0–5 | – | ||
| spidergrass | ARTE3 | Aristida ternipes | 0–2 | – | ||
| poverty threeawn | ARDI5 | Aristida divaricata | 0–2 | – | ||
| Fendler threeawn | ARPUL | Aristida purpurea var. longiseta | 0–2 | – | ||
| whiplash pappusgrass | PAVA2 | Pappophorum vaginatum | 0–2 | – | ||
| squirreltail | ELEL5 | Elymus elymoides | 0–2 | – | ||
| Parish's threeawn | ARPUP5 | Aristida purpurea var. parishii | 0–1 | – | ||
| purple threeawn | ARPU9 | Aristida purpurea | 0–1 | – | ||
| spidergrass | ARTEG | Aristida ternipes var. gentilis | 0–1 | – | ||
| 3 | Annual grasses | 5–200 | ||||
| mucronate sprangeltop | LEPAB | Leptochloa panicea ssp. brachiata | 1–100 | – | ||
| little barley | HOPU | Hordeum pusillum | 1–100 | – | ||
| Arizona signalgrass | URAR | Urochloa arizonica | 1–50 | – | ||
| Mexican panicgrass | PAHI5 | Panicum hirticaule | 0–30 | – | ||
| sixweeks fescue | VUOC | Vulpia octoflora | 1–25 | – | ||
| sticky sprangletop | LEVI5 | Leptochloa viscida | 0–25 | – | ||
| sixweeks threeawn | ARAD | Aristida adscensionis | 1–25 | – | ||
| needle grama | BOAR | Bouteloua aristidoides | 0–20 | – | ||
| sixweeks grama | BOBA2 | Bouteloua barbata | 0–20 | – | ||
| Rothrock's grama | BORO2 | Bouteloua rothrockii | 0–15 | – | ||
| prairie threeawn | AROL | Aristida oligantha | 1–10 | – | ||
| witchgrass | PACA6 | Panicum capillare | 0–10 | – | ||
| Bigelow's bluegrass | POBI | Poa bigelovii | 0–5 | – | ||
| Mexican sprangletop | LEFUU | Leptochloa fusca ssp. uninervia | 0–5 | – | ||
| Arizona brome | BRAR4 | Bromus arizonicus | 0–5 | – | ||
| feather fingergrass | CHVI4 | Chloris virgata | 0–5 | – | ||
| tapertip cupgrass | ERACA | Eriochloa acuminata var. acuminata | 0–5 | – | ||
| desert lovegrass | ERPEM | Eragrostis pectinacea var. miserrima | 0–5 | – | ||
| tufted lovegrass | ERPEP2 | Eragrostis pectinacea var. pectinacea | 0–5 | – | ||
| delicate muhly | MUFR | Muhlenbergia fragilis | 0–2 | – | ||
| littleseed muhly | MUMI | Muhlenbergia microsperma | 0–2 | – | ||
|
Forb
|
||||||
| 4 | Perennial Forbs | 5–25 | ||||
| dwarf desertpeony | ACNA2 | Acourtia nana | 1–10 | – | ||
| bluedicks | DICA14 | Dichelostemma capitatum | 0–5 | – | ||
| Indian rushpea | HOGL2 | Hoffmannseggia glauca | 1–5 | – | ||
| weakleaf bur ragweed | AMCO3 | Ambrosia confertiflora | 1–5 | – | ||
| desert globemallow | SPAM2 | Sphaeralcea ambigua | 1–5 | – | ||
| brownplume wirelettuce | STPA4 | Stephanomeria pauciflora | 0–5 | – | ||
| slender poreleaf | POGR5 | Porophyllum gracile | 1–5 | – | ||
| Coues' cassia | SECO10 | Senna covesii | 0–1 | – | ||
| silverleaf nightshade | SOEL | Solanum elaeagnifolium | 0–1 | – | ||
| pricklyleaf dogweed | THAC | Thymophylla acerosa | 0–1 | – | ||
| Rocky Mountain zinnia | ZIGR | Zinnia grandiflora | 0–1 | – | ||
| tuber anemone | ANTU | Anemone tuberosa | 0–1 | – | ||
| narrowleaf silverbush | ARLA12 | Argythamnia lanceolata | 0–1 | – | ||
| New Mexico silverbush | ARNE2 | Argythamnia neomexicana | 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 | – | ||
| scarlet spiderling | BOCO | Boerhavia coccinea | 0–1 | – | ||
| desert mariposa lily | CAKE | Calochortus kennedyi | 0–1 | – | ||
| sego lily | CANU3 | Calochortus nuttallii | 0–1 | – | ||
| whitemargin sandmat | CHAL11 | Chamaesyce albomarginata | 0–1 | – | ||
| whitemouth dayflower | COER | Commelina erecta | 0–1 | – | ||
| leatherweed | CRPO5 | Croton pottsii | 0–1 | – | ||
| fingerleaf gourd | CUDI | Cucurbita digitata | 0–1 | – | ||
| Missouri gourd | CUFO | Cucurbita foetidissima | 0–1 | – | ||
| coyote gourd | CUPA | Cucurbita palmata | 0–1 | – | ||
| ragged nettlespurge | JAMA | Jatropha macrorhiza | 0–1 | – | ||
| San Pedro daisy | LAPO4 | Lasianthaea podocephala | 0–1 | – | ||
| Parry's false prairie-clover | MAPA7 | Marina parryi | 0–1 | – | ||
| lacy tansyaster | MAPIP4 | Machaeranthera pinnatifida ssp. pinnatifida var. pinnatifida | 0–1 | – | ||
| plains blackfoot | MELE2 | Melampodium leucanthum | 0–1 | – | ||
| wishbone-bush | MILAV | Mirabilis laevis var. villosa | 0–1 | – | ||
| desert tobacco | NIOB | Nicotiana obtusifolia | 0–1 | – | ||
| spreading fleabane | ERDI4 | Erigeron divergens | 0–1 | – | ||
| desert trumpet | ERIN4 | Eriogonum inflatum | 0–1 | – | ||
| southwestern mock vervain | GLGO | Glandularia gooddingii | 0–1 | – | ||
| brownfoot | ACWR5 | Acourtia wrightii | 0–1 | – | ||
| poreleaf dogweed | ADPO2 | Adenophyllum porophyllum | 0–1 | – | ||
| trailing windmills | ALIN | Allionia incarnata | 0–1 | – | ||
| largeflower onion | ALMA4 | Allium macropetalum | 0–1 | – | ||
| 5 | Annual forbs | 0–150 | ||||
| California poppy | ESCAM | Eschscholzia californica ssp. mexicana | 0–25 | – | ||
| western tansymustard | DEPI | Descurainia pinnata | 0–20 | – | ||
| combseed | PECTO | Pectocarya | 0–20 | – | ||
| Arizona popcornflower | PLAR | Plagiobothrys arizonicus | 0–20 | – | ||
| desert Indianwheat | PLOV | Plantago ovata | 0–20 | – | ||
| shaggyfruit pepperweed | LELA | Lepidium lasiocarpum | 0–15 | – | ||
| intermediate pepperweed | LEVIM | Lepidium virginicum var. medium | 0–15 | – | ||
| coastal bird's-foot trefoil | LOSAB | Lotus salsuginosus var. brevivexillus | 0–15 | – | ||
| tanseyleaf tansyaster | MATA2 | Machaeranthera tanacetifolia | 0–15 | – | ||
| bristly fiddleneck | AMTE3 | Amsinckia tessellata | 0–15 | – | ||
| miniature woollystar | ERDI2 | Eriastrum diffusum | 0–10 | – | ||
| Coulter's lupine | LUSP2 | Lupinus sparsiflorus | 0–10 | – | ||
| Arizona poppy | KAGR | Kallstroemia grandiflora | 0–10 | – | ||
| manybristle chinchweed | PEPA2 | Pectis papposa | 0–10 | – | ||
| New Mexico plumeseed | RANE | Rafinesquia neomexicana | 0–5 | – | ||
| slender goldenweed | MAGR10 | Machaeranthera gracilis | 0–5 | – | ||
| Gordon's bladderpod | LEGO | Lesquerella gordonii | 0–5 | – | ||
| longleaf false goldeneye | HELOA2 | Heliomeris longifolia var. annua | 0–5 | – | ||
| camphorweed | HESU3 | Heterotheca subaxillaris | 0–5 | – | ||
| foothill deervetch | LOHU2 | Lotus humistratus | 0–5 | – | ||
| Nuttall's povertyweed | MONU | Monolepis nuttalliana | 0–5 | – | ||
| sorrel buckwheat | ERPO4 | Eriogonum polycladon | 0–5 | – | ||
| Texas stork's bill | ERTE13 | Erodium texanum | 0–5 | – | ||
| wedgeleaf draba | DRCU | Draba cuneifolia | 0–5 | – | ||
| flatcrown buckwheat | ERDE6 | Eriogonum deflexum | 0–5 | – | ||
| cryptantha | CRYPT | Cryptantha | 0–5 | – | ||
| pitseed goosefoot | CHBE4 | Chenopodium berlandieri | 0–5 | – | ||
| milkvetch | ASTRA | Astragalus | 0–5 | – | ||
| wheelscale saltbush | ATEL | Atriplex elegans | 0–5 | – | ||
| Coulter's spiderling | BOCO2 | Boerhavia coulteri | 0–5 | – | ||
| carelessweed | AMPA | Amaranthus palmeri | 0–5 | – | ||
| white tackstem | CAWR | Calycoseris wrightii | 0–2 | – | ||
| fringed redmaids | CACI2 | Calandrinia ciliata | 0–2 | – | ||
| brittle spineflower | CHBR | Chorizanthe brevicornu | 0–2 | – | ||
| hyssopleaf sandmat | CHHY3 | Chamaesyce hyssopifolia | 0–2 | – | ||
| Esteve's pincushion | CHST | Chaenactis stevioides | 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 | – | ||
| green carpetweed | MOVE | Mollugo verticillata | 0–2 | – | ||
| Arizona lupine | LUAR4 | Lupinus arizonicus | 0–2 | – | ||
| woolly tidestromia | TILA2 | Tidestromia lanuginosa | 0–2 | – | ||
| woollyhead neststraw | STMI2 | Stylocline micropoides | 0–2 | – | ||
| sleepy silene | SIAN2 | Silene antirrhina | 0–2 | – | ||
| phacelia | PHACE | Phacelia | 0–2 | – | ||
| desert evening primrose | OEPR | Oenothera primiveris | 0–2 | – | ||
| Florida pellitory | PAFL3 | Parietaria floridana | 0–2 | – | ||
| chia | SACO6 | Salvia columbariae | 0–1 | – | ||
| sawtooth sage | SASU7 | Salvia subincisa | 0–1 | – | ||
| spreading fanpetals | SIAB | Sida abutifolia | 0–1 | – | ||
| Coulter's globemallow | SPCO2 | Sphaeralcea coulteri | 0–1 | – | ||
| doubleclaw | PRPA2 | Proboscidea parviflora | 0–1 | – | ||
| sand fringepod | THCU | Thysanocarpus curvipes | 0–1 | – | ||
| tumblemustard | THELY3 | Thelypodiopsis | 0–1 | – | ||
| crestrib morning-glory | IPCO2 | Ipomoea costellata | 0–1 | – | ||
| bristly nama | NAHI | Nama hispidum | 0–1 | – | ||
| glandular threadplant | NEGL | Nemacladus glanduliferus | 0–1 | – | ||
| Fendler's desertdandelion | MAFE | Malacothrix fendleri | 0–1 | – | ||
| whitestem blazingstar | MEAL6 | Mentzelia albicaulis | 0–1 | – | ||
| Mexican fireplant | EUHE4 | Euphorbia heterophylla | 0–1 | – | ||
| common woolly sunflower | ERLA6 | Eriophyllum lanatum | 0–1 | – | ||
| scrambled eggs | COAU2 | Corydalis aurea | 0–1 | – | ||
| Canadian horseweed | COCA5 | Conyza canadensis | 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 | – | ||
| southwestern pricklypoppy | ARPL3 | Argemone pleiacantha | 0–1 | – | ||
| annual agoseris | AGHE2 | Agoseris heterophylla | 0–1 | – | ||
|
Shrub/Vine
|
||||||
| 6 | Miscellaneous Shrubs | 0–10 | ||||
| fourwing saltbush | ATCA2 | Atriplex canescens | 0–5 | – | ||
| western honey mesquite | PRGLT | Prosopis glandulosa var. torreyana | 0–5 | – | ||
| lotebush | ZIOB | Ziziphus obtusifolia | 0–1 | – | ||
| spiny hackberry | CEEH | Celtis ehrenbergiana | 0–1 | – | ||
| longleaf jointfir | EPTR | Ephedra trifurca | 0–1 | – | ||
| American tarwort | FLCE | Flourensia cernua | 0–1 | – | ||
| creosote bush | LATR2 | Larrea tridentata | 0–1 | – | ||
| water jacket | LYAN | Lycium andersonii | 0–1 | – | ||
| pale desert-thorn | LYPA | Lycium pallidum | 0–1 | – | ||
| catclaw mimosa | MIACB | Mimosa aculeaticarpa var. biuncifera | 0–1 | – | ||
| whitethorn acacia | ACCO2 | Acacia constricta | 0–1 | – | ||
| catclaw acacia | ACGR | Acacia greggii | 0–1 | – | ||
| 7 | Half shrubs | 0–10 | ||||
| bastardsage | ERWR | Eriogonum wrightii | 0–5 | – | ||
| fairyduster | CAER | Calliandra eriophylla | 0–2 | – | ||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 0–2 | – | ||
| burroweed | ISTE2 | Isocoma tenuisecta | 0–1 | – | ||
| littleleaf ratany | KRER | Krameria erecta | 0–1 | – | ||
| winterfat | KRLA2 | Krascheninnikovia lanata | 0–1 | – | ||
| rough menodora | MESC | Menodora scabra | 0–1 | – | ||
| turpentine bush | ERLA12 | Ericameria laricifolia | 0–1 | – | ||
| threadleaf snakeweed | GUMI | Gutierrezia microcephala | 0–1 | – | ||
| 9 | Succulents | 0–10 | ||||
| tulip pricklypear | OPPH | Opuntia phaeacantha | 0–5 | – | ||
| banana yucca | YUBA | Yucca baccata | 0–2 | – | ||
| soaptree yucca | YUEL | Yucca elata | 0–2 | – | ||
| dollarjoint pricklypear | OPCH | Opuntia chlorotica | 0–2 | – | ||
| cactus apple | OPEN3 | Opuntia engelmannii | 0–2 | – | ||
| Christmas cactus | CYLE8 | Cylindropuntia leptocaulis | 0–2 | – | ||
| walkingstick cactus | CYSP8 | Cylindropuntia spinosior | 0–2 | – | ||
| candy barrelcactus | FEWI | Ferocactus wislizeni | 0–1 | – | ||
| devil's cholla | GRKU | Grusonia kunzei | 0–1 | – | ||
| buck-horn cholla | CYAC8 | Cylindropuntia acanthocarpa | 0–1 | – | ||
Interpretations
Animal community
This site produces considerable perennial forage for livestock. Tobosa is very poor quality forage when cured and only fair forage when green. In wet (El Nino) winters the site produces a tremendous amount of annual forbs and grasses, all of which are excellent forage. The site is home to a variety of small mammals and grassland bird species and their associated predators. It is mainly a foraging area for larger mammals like mule deer and javalina.
Hydrological functions
These soils are heavy textured and good producers of runoff.
Recreational uses
Hunting, horseback riding, hiking, wildlife observation, photography, rock hounding and bird watching.
Wood products
None unless the site has been invaded by mesquite.
Other products
Red clay for pot making. Herbs like grass nuts, wild onions and hog potatos.
Supporting information
Type locality
| Location 1: Cochise County, AZ | |
|---|---|
| Township/Range/Section | T17S R21E S19 |
| General legal description | Kartchner Ranch, Lonesome Valley, St. David area. |
Contributors
Dan Robinett
Larry D. Ellicott
Approval
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) | Wilma Renken, Dan Robinett, Larry Humphrey, Gwen Dominguez, Clay Stewart |
|---|---|
| Contact for lead author | Tucson MLRA Soil Survey Office |
| Date | 08/07/2013 |
| Approved by | Curtis Talbot |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
None -
Presence of water flow patterns:
Water flow paths occupy less than 5% of the surface area. Sheet flow dominates as a process on this site. Sheet flow lengths are 20-40 feet. -
Number and height of erosional pedestals or terracettes:
Pedestals are common on tobosa and about 1 inch high. Terracettes (1-2’ diam x 0.5” ht) are not common on the site making up less than 5% of the area. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare ground is approximately 35-40%. Bare areas, 2’-8’ in diameter, occasionally connected, are common. Bare areas are often masked by annuals and perennial herbaceous overstory. -
Number of gullies and erosion associated with gullies:
None -
Extent of wind scoured, blowouts and/or depositional areas:
None -
Amount of litter movement (describe size and distance expected to travel):
Fine litter size classes are moving a 2-3 feet in sheet flow areas. Coarse litter staying in place. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Values of 2-3 in bare areas and 4-6 within vegetated patches. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
A horizon is a silty clayloam, 0-3 inches thick with weak platy to weak, fine and medium subangular blocky structure. Colors are 10 YR 6/4 dry and 10 YR 4/3 moist. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Aspect is grassland. Perennial grasses (tobosa, burrograss and vine mesquite) dominate the site. Hydrology functions as sheet flow run-off supplementing soil moisture to perennial grass patches. Bare areas contribute to sheet flow and make up approximately 38% of area; vegetated areas are dense and occupy the remaining 62% of the area. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None present, average depth of penetration from an ARS field penetrometer with a 2.2 kg. sliding hammer, set at 20 inches fall height, is 5 cm. The dense (massive structure) silty clay C2 horizon at 3 inches can feel like a compacted layer. -
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 grasses >Sub-dominant:
annual grasses >> annual forbs > perennial forbs > large shrubs > sub-shrubs > succulentsOther:
large shrubs, sub-shrubs and succulents absent or in minor amountsAdditional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Mortality estimated at about 10% on perennial grasses, as expected for this site. -
Average percent litter cover (%) and depth ( in):
From the ESD, litter cover can be from 35-60% on this site. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
231 lbs/ac. in a below average year; 705 lbs/ac. in an average year; 1140 lbs/ac. in an above average year. Production of summer annual grasses can exceed expected on years with above average seasonal 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, wolfberry, creosotebush, tumbleweed are present and can increase on the site but occur in trace amounts at present -
Perennial plant reproductive capability:
Not impaired.
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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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