Natural Resources
Conservation Service
Ecological site R042BB036NM
Salt Flats, Desert Shrub
Accessed: 11/13/2024
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.
Associated sites
| R042BB006NM |
Gyp Upland, Desert Shrub |
|---|---|
| R042BB014NM |
Loamy, Desert Shrub |
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
Not specified |
Physiographic features
This site usually occurs on level to gently sloping, broad alluvial flats. Slopes usually do not exceed 3 percent. Elevations range from 3,800 feet to 5,000 feet.
Table 2. Representative physiographic features
| Landforms |
(1)
Alluvial flat
(2) Basin floor (3) Fan piedmont |
|---|---|
| Flooding duration | Extremely brief (0.1 to 4 hours) to brief (2 to 7 days) |
| Flooding frequency | Very rare to rare |
| Ponding duration | Very brief (4 to 48 hours) to brief (2 to 7 days) |
| Ponding frequency | Rare to occasional |
| Elevation | 3,800 – 5,000 ft |
| Slope | 3% |
| Ponding depth | 1 – 4 in |
| Water table depth |
Not specified |
| Aspect | Aspect is not a significant factor |
Climatic features
Annual average precipitation ranges from 7.35 to 11.90 inches. Wide fluctuations from year to year are common, ranging from a low of about 2 inches to a high of over 20 inches. At least one-half of the annual precipitation comes in the form of rainfall during July, August, and September. Precipitation in the form of snow or sleet averages less than 4 inches annually. The average annual air temperature is about 60 degree F. Summer maximums can exceed 100 degrees F. and winter minimums can go below zero. The average frost-free season exceeds 200 days and extends from April 1 to November 1. Both the temperature regime and rainfall distribution favor warm-season perennial plants on this site. Spring moisture conditions are only occasionally adequate to cause significant growth during this period of year. High winds from the west and southwest are common from March to June, which further tends to create poor soil moisture conditions in the springtime.
Climate data was obtained from
http://www.wrcc.dri.edu/summary/climsmnm.html
Table 3. Representative climatic features
| Frost-free period (average) | 205 days |
|---|---|
| Freeze-free period (average) | 227 days |
| Precipitation total (average) | 12 in |
Figure 2. Monthly precipitation range
Figure 3. Monthly average minimum and maximum temperature
Influencing water features
This site is not influenced by water from wetlands or streams.
Soil features
The soils of this site are deep to shallow, medium to moderately fine-textured in the surface and have moderately to slowly permeable subsoils. Soils contain varying amounts of salt and alkali accumulations which are inhibitory to certain plant species.
Table 4. Representative soil features
| Surface texture |
(1) Silty clay loam (2) Loam (3) Clay loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Moderately well drained to well drained |
| Permeability class | Slow to moderate |
| Soil depth | 20 – 72 in |
| Surface fragment cover <=3" | Not specified |
| Surface fragment cover >3" | Not specified |
| Available water capacity (0-40in) |
3 – 7 in |
| Electrical conductivity (0-40in) |
2 – 16 mmhos/cm |
| Sodium adsorption ratio (0-40in) |
1 – 13 |
| Soil reaction (1:1 water) (0-40in) |
7.9 – 9.6 |
| Subsurface fragment volume <=3" (Depth not specified) |
Not specified |
| Subsurface fragment volume >3" (Depth not specified) |
Not specified |
Ecological dynamics
Overview
The soils and vegetation of this site intergrades with that of the Gyp Upland (the “gyp flats” type) and Loamy sites, depending on the levels of gypsum and sodicity/salinity, respectively. Salt flats can be associated with playas that are barren because they are inundated for long periods. Differences in sodicity within the Salt Flats site have important effects on soil properties. Differences in salinity control plant composition directly. The historic plant community type of the salt flats site is dominated by alkali sacaton (Sporobolus airoides) and scattered small shrubs, especially four-wing saltbush (Atriplex canescens), other Atriplex species, and iodinebush (Allenrolfea occidentalis). Alkali sacaton is patchily distributed in this site, and large patches of bare ground may be common. Fluctuations in sacaton cover may occur in response to drought or grazing pressure. Drought and/or overgrazing may lead to plant mortality. Subsequent reductions of water infiltration through the soil surface may inhibit reestablishment. The concentration of sodium and/or salts at the soil surface may also play a role in retarding sacaton establishment in patches and larger areas. Bare areas may persist for decades or longer. Alteration of surface hydrology, such that run-in water is diverted away from grass patches, may also lead to grass loss.
No systematic studies of communities, states or transitions have been performed in the salt flats site.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 2 submodel, plant communities
State 1
Historic Climax Plant Community
Community 1.1
Historic Climax Plant Community
Figure 4. stateMLRA 42; SD-2 and 3; Salt flats
Alkali sacaton State Alkali sacaton grassland: Alkali sacaton is dominant and four-wing saltbush and/or iodinebush are scattered throughout. Iodinebush may be considered as an index species for this site. Other Atriplex species may also be present (some are rare, such as Atriplex griffithsii). In some cases, a moderate diversity of grasses may be present, including vine mesquite (Panicum obtusum) and tobosa (Pleuraphis mutica). In other cases (e.g. soils with higher salinity), alkali sacaton is the sole perennial grass. In some cases, mesquite (Prosopis glandulosa) may be present but this shrub should be limited on saline soils. Mesquite increases may be associated with soils more closely allied to loamy ecological sites. Bare patches or even large, continuous areas may naturally occur, perhaps reflecting the consequences of past drought events, areas with very high salinity (e.g. greater than ca. 3% dry soil weight in the top 10 cm; Ungar 1966), or areas in which water ponds for long periods. Heavy grazing may result in the loss of alkali sacaton plants and, in some cases, increases in the relative abundance of other grasses such as burrograss (Scleropogon brevifolius). Distinguishing human-caused bare areas from naturally bare areas may be difficult in this site. Diagnosis: Alkali sacaton cover is high in favorable topographic positions. Some bare patches are present. Additional States: Transition to bare state (1a): Factors leading to the loss of sacaton, such as drought, grazing, or other disturbances can set this transition in motion. Once grasses are lost, the loss of soil organic matter, root channels and structures that intercept water may lead to soil sealing and reduced infiltration. Furthermore, the sodic (alkali) subsoil layers that are exposed following loss of topsoil are highly susceptible to soil sealing. Once soil sealing occurs, salts can accumulate at the soil surface and increase to toxic levels. Soil compaction and degradation by trampling may also contribute to soil sealing. In addition, interruption of overland water flow (e.g. by a road) may reduce soil water availability to the point where sacaton plants die and cannot reestablish. These factors inhibit grass reestablishment and may lead to long-term soil degradation. Key indicators of approach to transition: Decadence and mortality in alkali sacaton, reduced litter, increased bare ground, increases in topsoil salinity and sodicity.
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 | 260 | 488 | 715 |
| Shrub/Vine | 96 | 180 | 264 |
| Forb | 44 | 82 | 121 |
| Total | 400 | 750 | 1100 |
Table 6. Soil surface cover
| Tree basal cover | 0% |
|---|---|
| Shrub/vine/liana basal cover | 0% |
| Grass/grasslike basal cover | 20% |
| Forb basal cover | 0% |
| Non-vascular plants | 0% |
| Biological crusts | 0% |
| Litter | 15% |
| Surface fragments >0.25" and <=3" | 0% |
| Surface fragments >3" | 0% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 60% |
Figure 6. Plant community growth curve (percent production by month). NM2518, R042XB036NM-Salt Flats-Warm Season Plant-HCPC. SD-3 Warm Season Plant Community.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| J | F | M | A | M | J | J | A | S | O | N | D |
| 5 | 10 | 10 | 25 | 30 | 15 | 5 |
State 2
Bare
Community 2.1
Bare
Bare: These communities are largely barren with a variable cover of alkali sacaton or perhaps other grasses. Sacaton plants often appear decadent. Diagnosis: Bare ground predominates. Transition to alkali sacaton grassland (1b): Run-in water must be restored if it was interrupted. If erosion, high surface salinity, and reduced infiltration restrict grass abundance, restoration is probably impossible. Flushing and leaching of salts is limited by natric horizons. Accumulation of non-saline sediments that have eroded from areas upslope may facilitate grass recolonization over time. Seed germination seems to be favored by cracks in the soil (De Alba-Avila and Cox 1988), so such sites could be favorable for seeding attempts where salinity is not limiting. Information sources and theoretical background: Communities, states, and transitions are based upon information in the ecological site description and observations by Brandon Bestelmeyer, Jornada Experimental Range and Arlene Tugel, NRCS. Information on the causes of patchiness in alkali sacaton is sorely needed.
Additional community tables
Table 7. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (lb/acre) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Warm Season | 263–338 | ||||
| alkali sacaton | SPAI | Sporobolus airoides | 263–338 | – | ||
| 2 | Warm Season | 23–60 | ||||
| vine mesquite | PAOB | Panicum obtusum | 23–60 | – | ||
| 3 | Warm Season | 8–38 | ||||
| black grama | BOER4 | Bouteloua eriopoda | 8–38 | – | ||
| 4 | Warm Season | 23–60 | ||||
| cane bluestem | BOBA3 | Bothriochloa barbinodis | 23–60 | – | ||
| plains bristlegrass | SEVU2 | Setaria vulpiseta | 23–60 | – | ||
| sand dropseed | SPCR | Sporobolus cryptandrus | 23–60 | – | ||
| big sacaton | SPWR2 | Sporobolus wrightii | 23–60 | – | ||
| 5 | Warm Season | 8–38 | ||||
| saltgrass | DISP | Distichlis spicata | 8–38 | – | ||
| 6 | Warm Season | 23–60 | ||||
| threeawn | ARIST | Aristida | 23–60 | – | ||
| low woollygrass | DAPU7 | Dasyochloa pulchella | 23–60 | – | ||
| tobosagrass | PLMU3 | Pleuraphis mutica | 23–60 | – | ||
| burrograss | SCBR2 | Scleropogon brevifolius | 23–60 | – | ||
| 7 | Warm Season | 8–23 | ||||
| Graminoid (grass or grass-like) | 2GRAM | Graminoid (grass or grass-like) | 8–23 | – | ||
|
Shrub/Vine
|
||||||
| 8 | Shrub | 23–60 | ||||
| fourwing saltbush | ATCA2 | Atriplex canescens | 23–60 | – | ||
| 9 | Shrub | 60–90 | ||||
| iodinebush | ALOC2 | Allenrolfea occidentalis | 60–90 | – | ||
| saltbush | ATRIP | Atriplex | 60–90 | – | ||
| 10 | Shrub | 8–23 | ||||
| crown of thorns | KOSP | Koeberlinia spinosa | 8–23 | – | ||
| 11 | Shrub | 8–23 | ||||
| broom snakeweed | GUSA2 | Gutierrezia sarothrae | 8–23 | – | ||
| 12 | Shrub | 8–23 | ||||
| baccharis | BACCH | Baccharis | 8–23 | – | ||
| mormon tea | EPVI | Ephedra viridis | 8–23 | – | ||
|
Forb
|
||||||
| 13 | Forb | 23–60 | ||||
| dwarf desertpeony | ACNA2 | Acourtia nana | 23–60 | – | ||
| goldenbush | ISOCO | Isocoma | 23–60 | – | ||
| southern goldenbush | ISPL | Isocoma pluriflora | 23–60 | – | ||
| desert seepweed | SUSU | Suaeda suffrutescens | 23–60 | – | ||
| crinklemat | TIQUI | Tiquilia | 23–60 | – | ||
| 14 | Annual Forbs | 8–38 | ||||
| Forb, annual | 2FA | Forb, annual | 8–38 | – | ||
| 15 | Perennial Forbs | 8–38 | ||||
| Forb, perennial | 2FP | Forb, perennial | 8–38 | – | ||
Interpretations
Animal community
This site provides habitat which support a resident animal community that is characterized by coyote, black-tailed jackrabbit, desert cottontail, bannertail kangaroo rat, scaled quail, loggerhead shrike, horned lark, meadowlark, little striped whiptail lizard, and Texas horned lizard.
Hydrological functions
The runoff curve numbers are determined by field investigations using hydraulic cover conditions and hydrologic soil groups.
Hydrologic Interpretations
Soil Series--------Hydrologic Group
Hondale------------D
Mimbres------------C
Recreational uses
Suitability for camping and picnicking is fair to poor, limited mostly by weather extremes. Hunting is fair for pronghorn antelope, quail, dove, small game, and waterfowl where seasonal open water occurs. Photography and bird watching can be fair to good, especially during migration seasons. Most small animals of the site are nocturnal and secretive, seen only at night, early morning or evening. Scenic beauty is greatest during spring and sometimes summer months when flowering of forbs, shrubs, and cacti occurs.
Wood products
This site has no significant value for wood products.
Other products
This site is suitable for grazing in all seasons of the year. Most of the palatable green forage for livestock is produced in the summer months and lends the site to seasonal use. It is suited to grazing by cattle, sheep, goats, and horses, generally without regard to class of livestock. Retrogression caused by inadequately managed grazing usually results in such plants as black grama, and fourwing saltbush being replaced by burrograss, tobosa, other Atriplex species, and seepweed. Mesquite and allthorn may dominate the site eventually, and recovery may be slow under grazing management alone.
Other information
Guide to Suggested Initial Stocking Rate Acres per Animal Unit Month
Similarity Index--------Ac/AUM
100 - 76----------------2.8 – 3.7
75 – 51-----------------3.5 – 5.5
50 – 26-----------------5.0 – 10.5
25 – 0------------------10.5 - +
Supporting information
Other references
Other References:
Data collection for this site was done in conjunction with the progressive soil surveys within the Southern Desertic Basins, Plains and Mountains, Major Land Resource Areas of New Mexico. This site has been mapped and correlated with soils in the following soil surveys. Sierra County Dona Ana County Grant County Hidalgo County Luna County Otero County
Characteristic Soils Are:
Hondale silt loam, strongly alkali
Hondale loam, strongly alkali
Hondale soils, strongly alkali
Hondale sandy clay loam
Mimbres silty clay loam, alkali, not flooded
Other Soils included are:
Marcial silty clay loam
Ubar silt loam
Mead silt oam
Reagan loam, saline
Hurley loam, saline
Reeves loam, saline
Karro loam, saline
Bigetty loam, moderately saline
Contributors
Don Sylvester
Dr. Brandon Bestelmeyer
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 | |
| Approved by | |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
-
Presence of water flow patterns:
-
Number and height of erosional pedestals or terracettes:
-
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
-
Number of gullies and erosion associated with gullies:
-
Extent of wind scoured, blowouts and/or depositional areas:
-
Amount of litter movement (describe size and distance expected to travel):
-
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
-
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
-
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
-
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction 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:
Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
-
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
-
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:
-
Perennial plant reproductive capability:
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