Natural Resources
Conservation Service
Ecological site DX035X03E001
Loamy
Accessed: 12/22/2024
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.
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
Not specified |
Legacy ID
R035XB001NM
Physiographic features
This site is relatively level to gently sloping with an occasional swale. It usually occurs on mesas, plateaus, and upland valleys. Slopes range from 1 to 8 percent. Elevations range from 5,000 to 7,000 feet above sea level.
Table 2. Representative physiographic features
| Landforms |
(1)
Mesa
(2) Plateau (3) Valley |
|---|---|
| Elevation | 1,524 – 2,134 m |
| Slope | 1 – 8% |
| Aspect | Aspect is not a significant factor |
Climatic features
This site has an arid, mild, dry climate with distinct seasonal temperature variations and large annual and diurnal temperature changes.
Mean annual precipitation varies from 7 to 10 inches. Deviations of 4 inches or more are quite common. Distribution is 65% during the native-plant growth period, which is from April through September. May and June are the dry months. During July, August, and September, 3.5 inches of precipitation influences the presence and production of warm-season plants. Late-fall and winter moisture is conducive to the production of cool-season plants, which usually begin growth in March and end with plant maturity and seed dissemination. This usually takes place in the early part of June when the moisture deficiency and warmer temperatures occur. The Gulf of Mexico is the principal source of moisture for summer precipitation, which is characterized by brief afternoon thundershowers. Winter moisture occurs as light rain or snow.
Temperatures vary from a monthly mean of 75 degrees F in July to 27 degrees F in January, and from an annual maximum of 106 degrees F to an annual minimum of -35 degrees F. The average last killing frost in the spring is May 8, and the average first killing frost in the fall is October 10. The frost-free season is approximately 160 days. Temperatures are conducive for native grass and forb growth from April through September. Maximum shrub growth occurs in the spring months.
The wind blows most frequently from an easterly direction; however, a majority of the stronger winds (10 – 25 miles per hour) are from a westerly quadrant. Spring is the windiest season. Average hourly wind velocities are near 6 miles per hour. Spring and summer winds increase transpiration rate of native plants and rapidly dry the surface soil. Small soil particles are often displaced by the wind near the soil surface and often results in structural damage to native plants, especially young seedlings.
Climate data were obtained from http://www.wrcc.sage.dri.edu/summary/climsmnm.html web site using 50% probability for freeze-free and frost-free seasons using 28.5 degrees F and 32.5 degrees F, respectively.
Table 3. Representative climatic features
| Frost-free period (average) | 151 days |
|---|---|
| Freeze-free period (average) | 177 days |
| Precipitation total (average) | 254 mm |
Figure 2. Monthly precipitation range
Figure 3. Monthly average minimum and maximum temperature
Influencing water features
This site is not influenced by water from a wetland or stream.
Soil features
The soils on this ecological site are moderately deep to deep and well-drained. The surface layer is a brown fine sandy loam or loam about 6 inches thick. The subsoil, substratum, or underlying layer is medium or moderately fine textured, ranging from 20 to 54 inches thick.
These soils formed in alluvial and eolian material derived from sandstone and shale. Water intake rate is medium to moderately rapid. Available water rate is medium to moderately rapid. Available water-holding capacity ranges from 3.12 to 11.2 inches for a 5-foot profile.
Table 4. Representative soil features
| Surface texture |
(1) Very fine sandy loam (2) Loam (3) Fine sandy loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Somewhat poorly drained to well drained |
| Permeability class | Slow to moderately rapid |
| Soil depth | 152 – 203 cm |
| Available water capacity (0-101.6cm) |
7.62 – 30.48 cm |
| Electrical conductivity (0-101.6cm) |
0 – 8 mmhos/cm |
| Sodium adsorption ratio (0-101.6cm) |
0 – 13 |
| Soil reaction (1:1 water) (0-101.6cm) |
6.1 – 9 |
| Subsurface fragment volume <=3" (Depth not specified) |
15 – 35% |
| Subsurface fragment volume >3" (Depth not specified) |
15 – 35% |
Ecological dynamics
The aspect of vegetation on this site is dominantly grassland characterized by short- and mid-grasses. Shrubs and perennial forbs are a minor component of the plant community. Big sagebrush will occur in higher concentrations on the upper slopes of the site, often as an understory to invading juniper trees. Annual forbs occur in relative abundance during the spring months in years of above average growth conditions.
Additional plants which usually grow on this site in varying amounts dependent on current growing season conditions are: foxtail barley, sixweeks fescue, sixweeks grama, annual brome, silverleaf nightshade, ring muhly, fiddleneck, tansymustard, and yerba-de-pasmo.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 1
Historic Climax Plant Community
Community 1.1
Historic Climax Plant Community
The aspect of vegetation on this site is dominantly grassland characterized by short- and mid-grasses. Shrubs and perennial forbs are a minor component of the plant community. Big sagebrush will occur in higher concentrations on the upper slopes of the site, often as an understory to invading juniper trees. Annual forbs occur in relative abundance during the spring months in years of above average growth conditions. Additional plants which usually grow on this site in varying amounts dependent on current growing season conditions are: foxtail barley, sixweeks fescue, sixweeks grama, annual brome, silverleaf nightshade, ring muhly, fiddleneck, tansymustard, and yerba-de-pasmo.
Figure 4. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
| Plant type | Low (kg/hectare) |
Representative value (kg/hectare) |
High (kg/hectare) |
|---|---|---|---|
| Grass/Grasslike | 235 | 392 | 628 |
| Forb | 50 | 93 | 135 |
| Total | 285 | 485 | 763 |
Table 6. Ground cover
| Tree foliar cover | 0% |
|---|---|
| Shrub/vine/liana foliar cover | 0% |
| Grass/grasslike foliar cover | 0% |
| Forb foliar cover | 0% |
| Non-vascular plants | 0% |
| Biological crusts | 0% |
| Litter | 10% |
| Surface fragments >0.25" and <=3" | 0% |
| Surface fragments >3" | 0% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 65% |
Figure 5. Plant community growth curve (percent production by month). NM0901, R035XB001NM-Loamy-HCPC. Mixed short/mid-grasses with shrubs and forbs as a minor component. .
| 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 | 7 | 10 | 10 | 25 | 30 | 10 | 3 | 0 | 0 |
Additional community tables
Table 7. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | 62–93 | |||||
| James' galleta | PLJA | Pleuraphis jamesii | 62–93 | – | ||
| 2 | 62–123 | |||||
| Indian ricegrass | ACHY | Achnatherum hymenoides | 62–123 | – | ||
| 3 | 31–62 | |||||
| needle and thread | HECO26 | Hesperostipa comata | 31–62 | – | ||
| New Mexico feathergrass | HENE5 | Hesperostipa neomexicana | 31–62 | – | ||
| 4 | 19–31 | |||||
| western wheatgrass | PASM | Pascopyrum smithii | 19–31 | – | ||
| 5 | 31–62 | |||||
| squirreltail | ELEL5 | Elymus elymoides | 31–62 | – | ||
| 6 | 62–123 | |||||
| blue grama | BOGR2 | Bouteloua gracilis | 62–123 | – | ||
| 7 | 31–62 | |||||
| sand dropseed | SPCR | Sporobolus cryptandrus | 31–62 | – | ||
| 8 | 12–43 | |||||
| sideoats grama | BOCU | Bouteloua curtipendula | 12–43 | – | ||
| 9 | 19–31 | |||||
| threeawn | ARIST | Aristida | 19–31 | – | ||
| 10 | 19–49 | |||||
| alkali sacaton | SPAI | Sporobolus airoides | 19–49 | – | ||
|
Forb
|
||||||
| 11 | 19–31 | |||||
| threadleaf ragwort | SEFLF | Senecio flaccidus var. flaccidus | 19–31 | – | ||
| scarlet globemallow | SPCO | Sphaeralcea coccinea | 19–31 | – | ||
| 12 | 19–31 | |||||
| fleabane | ERIGE2 | Erigeron | 19–31 | – | ||
| woolly plantain | PLPA2 | Plantago patagonica | 19–31 | – | ||
| 13 | 19–31 | |||||
| Cuman ragweed | AMPS | Ambrosia psilostachya | 19–31 | – | ||
| milkweed | ASCLE | Asclepias | 19–31 | – | ||
| aster | ASTER | Aster | 19–31 | – | ||
| locoweed | OXYTR | Oxytropis | 19–31 | – | ||
| beardtongue | PENST | Penstemon | 19–31 | – | ||
|
Shrub/Vine
|
||||||
| 14 | 31–93 | |||||
| big sagebrush | ARTR2 | Artemisia tridentata | 31–93 | – | ||
| 15 | 31–62 | |||||
| fourwing saltbush | ATCA2 | Atriplex canescens | 31–62 | – | ||
| 16 | 19–31 | |||||
| Cutler's jointfir | EPCU | Ephedra cutleri | 19–31 | – | ||
| winterfat | KRLA2 | Krascheninnikovia lanata | 19–31 | – | ||
| 17 | 19–31 | |||||
| yellow rabbitbrush | CHVI8 | Chrysothamnus viscidiflorus | 19–31 | – | ||
| pale desert-thorn | LYPA | Lycium pallidum | 19–31 | – | ||
| camphor tansy | TACA2 | Tanacetum camphoratum | 19–31 | – | ||
| spineless horsebrush | TECA2 | Tetradymia canescens | 19–31 | – | ||
Interpretations
Animal community
Habitat for Wildlife:
This ecological site provides habitats which support a resident animal community that is characterized by pronghorn antelope, coyote, black-tailed jackrabbit, white-tailed prairie dog, silky pocket mouse, sparrow hawk, raven, horned lark, mourning dove, Great Basin spadefoot toad, side-blotched lizard, and gopher snake.
The burrowing owl, loggerhead shrike, and mockingbird are summer residents of these sites. Woody plants are used for nesting by vesper, sage, and Brewer's sparrows.
Hydrological functions
The runoff curve numbers are determined by field investigations using hydrologic cover conditions and hydrologic soil groups.
Hydrologic Interpretations
Soil Series----------------Hydrologic Group
Blancot-----------------------------B
Doak--------------------------------B
Doakum------------------------------B
El Rancho---------------------------B
Florita-----------------------------B
Fruitland---------------------------B
Las Lucas---------------------------B
Tapicito----------------------------B
Werlog------------------------------C
Recreational uses
No data.
Wood products
No data.
Other products
Grazing:
This site is well suited for grazing use by cattle, sheep, horses, antelope, burros, and small herbivorous animals.
Under the pressure of uncontrolled grazing, the potential plant community deteriorates, and there is a marked increase in amounts of shrubs and forbs; shrubs dominate the site.
Other information
Guide to Suggested Initial Stocking Rate Acres per Animal Unit Month
Similarity Index------------------Ac/AUM
100 - 76------------------------5.0 – 9.0
75 – 51-------------------------7.0 – 14.0
50 – 26-------------------------9.0 – 18.0
25 – 0--------------------------14.0 – 26.0
Supporting information
Type locality
| Location 1: San Juan County, NM | |
|---|---|
| Township/Range/Section | T32 N R13 W S26 |
| General legal description | A typical pedon of Doak loam in San Juan County, New Mexico, near La Plata on a mesa top, 2,475 feet west, 825 feet south of the northeast corner of Section 26, T32N, R13W. |
Other references
Data collection for this site was done in conjunction with the progressive soil surveys within the San Juan River Valley, Mesas and Plateaus, Major Land Resource Area 35 of New Mexico. This site has been mapped and correlated with soils in the following soil surveys: San Juan, McKinley.
Characteristic soils are:
Azfield, Blancot, Doak, Saddle
Other soils included are:
Doakum, El Rancho, Florita, Fruitland, Las Lucas, Tapicito, Werlog
Contributors
Don Sylvester
Elizabeth Wright
John Tunberg
Michael Carpinelli
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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