Natural Resources
Conservation Service
Ecological site R026XY042NV
SHALLOW CALCAREOUS LOAM 8-10 P.Z.
Accessed: 11/21/2024
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.
Associated sites
| R026XY016NV |
LOAMY 8-10 P.Z. |
|---|---|
| R026XY024NV |
DROUGHTY LOAM 8-10 P.Z. |
Similar sites
| R026XY047NV |
DROUGHTY CLAYPAN 8-10 P.Z. ARARL3 dominant shrub |
|---|---|
| R026XY050NV |
GRAVELLY CLAY 10-12 P.Z. ARAR8 dominant shrub |
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) Artemisia nova |
| Herbaceous |
(1) Achnatherum |
Physiographic features
This site occurs on fan remnants, alluvial fans and foothills. Slopes range from 2 to 30 percent. Elevations are 4600 to 6000 feet.
Table 2. Representative physiographic features
| Landforms |
(1)
Fan remnant
(2) Terrace |
|---|---|
| Elevation | 1,402 – 1,829 m |
| Slope | 2 – 30% |
| Aspect | Aspect is not a significant factor |
Climatic features
The climate associated with this site is semiarid, characterized by cool, moist winters and warm, dry summers.Average annual precipitation is 8 to 10 inches. Mean annual air temperature is 49 to 51 degrees F. The average growing season is about 90 to 120 days. There is no climate station available for this site.
Nevada’s climate is predominantly arid, with large daily ranges of temperature, infrequent severe storms, heavy snowfall in the higher mountains, and great location variations with elevation. Three basic geographical factors largely influence Nevada’s climate: continentality, latitude, and elevation. Continentality is the most important factor. The strong continental effect is expressed in the form of both dryness and large temperature variations. Nevada lies on the eastern, lee side of the Sierra Nevada Range, a massive mountain barrier that markedly influences the climate of the State. The prevailing winds are from the west, and as the warm moist air from the Pacific Ocean ascend the western slopes of the Sierra Range, the air cools, condensation occurs and most of the moisture falls as precipitation. As the air descends the eastern slope, it is warmed by compression, and very little precipitation occurs. The effects of this mountain barrier are felt not only in the West but throughout the state, with the result that the lowlands of Nevada are largely desert or steppes. The temperature regime is also affected by the blocking of the inland-moving maritime air. Nevada sheltered from maritime winds, has a continental climate with well-developed seasons and the terrain responds quickly to changes in solar heating.
Nevada lies within the mid-latitude belt of prevailing westerly winds which occur most of the year. These winds bring frequent changes in weather during the late fall, winter and spring months, when most of the precipitation occurs. To the south of the mid-latitude westerlies, lies a zone of high pressure in subtropical latitudes, with a center over the Pacific Ocean. In the summer, this high-pressure belt shifts northward over the latitudes of Nevada, blocking storms from the ocean. The resulting weather is mostly clear and dry during the summer and early fall, with scattered thundershowers. The eastern portion of the state receives significant summer thunderstorms generated from monsoonal moisture pushed up from the Gulf of California, known as the North American monsoon. The monsoon system peaks in August and by October the monsoon high over the Western U.S. begins to weaken and the precipitation retreats southward towards the tropics (NOAA 2004).
Average annual precipitation is 16 to over 20 inches. Mean annual air temperature is 41 to 44 degrees F. The average growing season is about 50 to 70 days.
Mean annual precipitaion at the Bear Creek, Nevada SNOTEL station (170501020301) is 37.69 inches.
monthly mean precipitation is:
January 3.84; February 3.75; March 4.38; April 4.9;
May 3.99; June 2.82; July .95; August 1.66;
September 1.22; October 2.12;
November 3.67; December 4.38.
Table 3. Representative climatic features
| Frost-free period (average) | 105 days |
|---|---|
| Freeze-free period (average) | 0 days |
| Precipitation total (average) | 229 mm |
Figure 1. Monthly average minimum and maximum temperature
Figure 2. Annual precipitation pattern
Figure 3. Annual average temperature pattern
Influencing water features
There are no influencing water features associated with this site.
Soil features
The soils associated with this site are very deep and well drained. They are formed in alluvium derived from mixed sources of rocks. Runoff is medium to high. The soil moisture regime is aridic bordering on xeric and the soil temperature regime is mesic. The soil series associated with this site includes Phing variant. An ochric epipedon occurs from the soil surface to 23 cm and an argillic horizon occurs from 23 to 79 cm.
Table 4. Representative soil features
| Surface texture |
(1) Extremely cobbly sandy loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderately slow |
| Soil depth | 183 – 213 cm |
| Surface fragment cover <=3" | 15 – 45% |
| Surface fragment cover >3" | 2 – 20% |
| Available water capacity (0-101.6cm) |
7.62 – 9.91 cm |
| Calcium carbonate equivalent (0-101.6cm) |
0 – 2% |
| Electrical conductivity (0-101.6cm) |
0 mmhos/cm |
| Sodium adsorption ratio (0-101.6cm) |
0 |
| Soil reaction (1:1 water) (0-101.6cm) |
7.2 – 8 |
| Subsurface fragment volume <=3" (Depth not specified) |
5 – 30% |
| Subsurface fragment volume >3" (Depth not specified) |
0 – 2% |
Ecological dynamics
Where management results in abusive livestock use, black sagebrush and rabbitbrush increase. Species likely to invade this site are cheatgrass, Russian thistle and annual mustards.
Fire Ecology:
Black sagebrush communities generally lack enough fine fuels to carry a fire. In addition to low fine fuel loading, wide shrub spacing makes fire infrequent or difficult to prescribe in black sagebrush types.
Black sagebrush is highly susceptible to fire-caused mortality; plants are readily killed by all fire intensities. Following burning, reestablishment occurs through off-site sources. Desert needlegrass has persistent dead leaf bases, which make it susceptible to burning. Fire removes the accumulation; a rapid, cool fire will not burn deep into the root crown. Thurber’s needlegrass is classified as moderately resistant, but depending on season of burn, phenology, and fire severity, this perennial bunchgrass is moderately to severely damaged by fire. Burning has been found to decrease the vegetation and reproductive vigor. Early season burning is more damaging to this needlegrass than late season burning.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 1
Reference State
Community 1.1
Reference Plant Community
The reference plant community is dominated by black sagebrush and Thurber’s needlegrass. Potential vegetative composition is about 50% grasses, 5% forbs and 45% shrubs.
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 | 112 | 168 | 224 |
| Shrub/Vine | 101 | 151 | 202 |
| Forb | 11 | 17 | 22 |
| Total | 224 | 336 | 448 |
Additional community tables
Table 6. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Primary Perennial Grasses | 108–161 | ||||
| desert needlegrass | ACSP12 | Achnatherum speciosum | 50–67 | – | ||
| Thurber's needlegrass | ACTH7 | Achnatherum thurberianum | 50–67 | – | ||
| Sandberg bluegrass | POSE | Poa secunda | 7–27 | – | ||
| 2 | Secondary Perennial Grasses | 17–34 | ||||
| Indian ricegrass | ACHY | Achnatherum hymenoides | 2–10 | – | ||
| squirreltail | ELEL5 | Elymus elymoides | 2–10 | – | ||
| needle and thread | HECO26 | Hesperostipa comata | 2–10 | – | ||
|
Forb
|
||||||
| 3 | Perennial | 7–34 | ||||
| 4 | Annual | 1–17 | ||||
|
Shrub/Vine
|
||||||
| 5 | Primary Shrubs | 91–135 | ||||
| black sagebrush | ARNO4 | Artemisia nova | 84–118 | – | ||
| bud sagebrush | PIDE4 | Picrothamnus desertorum | 7–17 | – | ||
| 6 | Secondary Shrubs | 17–34 | ||||
| yellow rabbitbrush | CHVI8 | Chrysothamnus viscidiflorus | 3–10 | – | ||
| spiny hopsage | GRSP | Grayia spinosa | 3–10 | – | ||
Interpretations
Animal community
Livestock Interpretaions:
This site is suited to livestock grazing. Grazing management should be keyed to perennial grass and palatable forb production. Thurber’s needlegrass species begin growth early in the year and remain green throughout a relatively long growing season. This pattern of development enables animals to use Thurber’s needlegrass when many other grasses are unavailable. Cattle prefer Thurber’s needlegrass in early spring before fruits have developed as it becomes less palatable when mature. Thurber’s needlegrasses are grazed in the fall only if the fruits are softened by rain. Desert needlegrass produces considerable basal foliage and is good forage while young. Young desert needlegrass is palatable to all classes of livestock. Mature herbage is moderately grazed by horses and cattle but rarely grazed by sheep. In winter, at lower elevations, black sagebrush is heavily utilized by domestic sheep.
Stocking rates vary over time depending upon season of use, climate variations, site, and previous and current management goals. A safe starting stocking rate is an estimated stocking rate that is fine tuned by the client by adaptive management through the year and from year to year.
Wildlife Interpretations:
Black sagebrush is a significant browse species within the Intermountain region. It is especially important on low elevation winter ranges in the southern Great Basin, where extended snow free periods allow animal’s access to plants throughout most of the winter. In these areas it is heavily utilized by pronghorn and mule deer. Thurber needlegrass and desert needlegrass are valuable forage species for several wildlife species.
Hydrological functions
Runoff is medium to high. Permeability is moderately slow.
Recreational uses
Aesthetic value is derived from the diverse floral and faunal composition. This site offers rewarding opportunities to photographers and for nature study. This site is used for camping and hiking and has potential for upland and big game hunting.
Other information
Black sagebrush is an excellent species to establish on sites where management objectives include restoration or improvement of domestic sheep, pronghorn, or mule deer winter range. Desert needlegrass seeds are easily germinated and have potential for commercial use. Desert needlegrass may be used for groundcover in areas of light disturbance, but it is susceptible to excessive trampling.
Supporting information
Type locality
| Location 1: Carson City County, NV | |
|---|---|
| General legal description | This site also occurs in Douglas, Lyon, Mineral, Storey, and Washoe Counties, Nevada. |
Other references
Fire Effects Information System (Online; http://www.fs.fed.us/database/feis/plants/).
USDA-NRCS Plants Database (Online; http://www.plants.usda.gov).
Contributors
DK.FR
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) | P NOVAK-ECHENIQUE |
|---|---|
| Contact for lead author | State Rangeland Management Specialist |
| Date | 07/12/2012 |
| Approved by | |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
Rills are none to rare. A few can be expected on steeper slopes in areas subjected to summer convection storms or rapid spring snowmelt. -
Presence of water flow patterns:
Waterflow patterns are none to rare and can be expected in areas subjected to summer convection storms or rapid snowmelt. -
Number and height of erosional pedestals or terracettes:
Pedestals are none to rare. Occurrence is usually limited to areas of water flow patterns. Frost heaving of shallow rooted plants should not be considered a "normal" condition. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare Ground ± 50% depending on amount of surface rock fragments. -
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 (foliage from grasses and annual & perennial forbs) expected to move distance of slope length during intense summer convection storms or rapid snowmelt events. Persistent litter (large woody material) will remain in place except during large rainfall events. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil stability values should be 3 to 6 on most soil textures found on this site. (To be field tested.) -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Surface structure is typically weak medium platy. Soil surface colors are grayish browns and soils are typified by an ochric epipedon. Organic matter of the surface 2 to 3 inches is typically 1 to 1.5 percent dropping off quickly below. Organic matter content can be more or less depending on micro-topography. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Perennial herbaceous plants (especially deep-rooted bunchgrasses [i.e., needlegrasses] slow runoff and increase infiltration. Shrub canopy and associated litter break raindrop impact. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
Compacted layers are none. Prismatic structure or argillic horizons are not to be interpreted as compacted layers. -
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:
Deep-rooted, cool season, perennial bunchgrasses (needlegrasses) > low shrubs (black sagebrushSub-dominant:
deep-rooted, cool season, perennial forbs > shallow-rooted, cool season, grasses > fibrous, shallow-rooted, cool season, perennial and annual forbs.Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Dead branches within individual shrubs common and standing dead shrub canopy material may be as much as 25% of total woody canopy; some of the mature bunchgrasses (<20%) have dead centers. -
Average percent litter cover (%) and depth ( in):
Reference Plant Community: Under shrubs and between plant interspaces (15-30%) and depth of litter is <½ inch. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
For normal or average growing season (end of May) ± 300 lbs/ac; Favorable years ± 400 lbs/ac and unfavorable years ± 200 lbs/ac -
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:
Potential invaders include Russian thistle, annual mustards, and cheatgrass. -
Perennial plant reproductive capability:
All functional groups should reproduce in average (or normal) and above average growing season years. Little growth or reproduction occurs in drought years.
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