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Draft. A draft ecological site description is either incomplete or has not undergone quality control and quality assurance review.
MLRA notes
Major Land Resource Area (MLRA): 028A–Ancient Lake Bonneville
MLRA 28A occurs in Utah (82%), Nevada (16%), and Idaho (2%). It makes up about 36,775 square miles. A large area west and southwest of Great Salt Lake is a salty playa. This area is the farthest eastern extent of the Great Basin Section of the Basin and Range Province of the Intermontane Plateaus. It is an area of nearly level basins between widely separated mountain ranges trending north to south. The basins are bordered by long, gently sloping alluvial fans. The mountains are uplifted fault blocks with steep side slopes. They are not well dissected because of low rainfall in the MLRA. Most of the valleys are closed basins containing sinks or playa lakes. Elevation ranges from 3,950 to 6,560 ft. in the basins and from 6,560 to 11,150 ft. in the mountains. Most of this area has alluvial valley fill and playa lakebed deposits at the surface. Great Salt Lake is all that remains of glacial Lake Bonneville. A level line on some mountain slopes indicates the former extent of this glacial lake. Most of the mountains in the interior of this area consist of tilted blocks of marine sediments from Cambrian to Mississippian age. Scattered outcrops of Tertiary continental sediments and volcanic rocks are throughout the area. The average annual precipitation is 5 to 12 ins. in the valleys and is as much as 49 ins. in the mountains. Most of the rainfall occurs as high-intensity, convective thunderstorms during the growing season. The driest period is from midsummer to early autumn. Precipitation in winter typically occurs as snow. The average annual temperature is 39 to 53 °F. The freeze-free period averages 165 days and ranges from 110 to 215 days, decreasing in length with elevation. The dominant soil orders in this MLRA are Aridisols, Entisols, and Mollisols. The soils in the area dominantly have a mesic or frigid soil temperature regime, an aridic or xeric soil moisture regime, and mixed mineralogy. They generally are well drained, loamy or loamy-skeletal, and very deep.
Ecological site concept
This site occurs along flood plains and stream terraces and around localized seeps and springs. Slope gradients of 0 to 8 percent are typical. Elevations are 5400 to 9020 feet.
Average annual precipitation is about 12 to over 16 inches. Ground water is the primary source of moisture for this plant community. Mean annual air temperature is 43 to 52 degrees F. Average growing season is about 70 to 110 days.
Soils associated with this site are fertile, very deep and have a moderate available water capacity. The soils are formed an alluvium derived from quartzite, limestone, granite, or welded tuff. They are very poorly to poorly drained and have a water table at or near the surface early in the spring that usually stabilizes within 20 inches through the growing season.
The reference plant community is dominated by tufted hairgrass. Nevada bluegrass, alpine timothy, clover and meadow sedges are important plants associated with this site. Potential vegetative composition is about 75% grasses, 20% forbs, and 5% shrubs. Approximate ground cover (basal and crown) is 75 to 85 percent.Associated sites
F028AY056NV POTR5-ABCOC/ROWO/POA-CAREX
R028AY055NV LOAMY BOTTOM 14+ P.Z.
Table 1. Dominant plant species
Tree Not specified
Shrub Not specified
Herbaceous (1) Deschampsia caespitosa
Physiographic features
This site occurs along flood plains and stream terraces and around localized seeps and springs. Slope gradients of 0 to 8 percent are typical. Elevations are 5400 to 9020 feet.
Table 2. Representative physiographic features
Landforms (1) Flood plain
(2) Stream terrace
Flooding duration Brief (2 to 7 days) to very long (more than 30 days) Flooding frequency Occasional to frequent Ponding frequency None Elevation 5400 – 9020 ft Slope 0 – 8 % Water table depth 9 – 84 in Aspect Aspect is not a significant factor Climatic features
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 about 8 to over 20 inches. Ground water is the primary source of moisture for this plant community. Mean annual air temperature is 39 to 50 degrees F. Average growing season is about 40 to 110 days.
The Mean annual precipitation at the Great Basin Natinal Park Climate Station (263340) is 13.33 inches.
Monthly mean precipitation is:
January 1.05; February 1.18; March 1.37; April 1.21; May 1.24; June .87; July .97; August 1.18; September 1.08; October .96; December .96
Table 3 Representative climatic features
Frost-free period (average) 0 days Freeze-free period (average) 80 days Precipitation total (average) 10 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
Figure 3. Annual precipitation pattern
Figure 4 Annual average temperature pattern
">Influencing water features
The soils are occasionally flooded for brief periods in the spring by stream overflow or unconfined runoff from surrounding areas. Some soils are kept moist through the growing season by springs and seeps.
Soil features
Soils associated with this site are fertile, very deep and have a moderate available water capacity. The soils are formed an alluvium derived from quartzite, limestone, granite, or welded tuff. They are very poorly to poorly drained and have a water table at or near the surface early in the spring that usually stabilizes within 20 inches through the growing season. The soils are occasionally flooded for very brief to long periods in the spring by stream overflow or unconfined runoff from surrounding areas. Some soils are kept moist through the growing season by springs and seeps. Runoff is low to very high and ponding occurs in some areas. These soils are susceptible to gullying which intercepts normal overflow patterns and results in site degradation. The soils have a mollic epipedon. The soil series associated with this site include: Lehmandon and Springmeadow.
Table 4. Representative soil features
Parent material (1) Alluvium – quartzite
Surface texture (1) Silt loam
(2) Silty clay loam
(3) Extremely gravelly loam
Family particle size (1) Loamy
Drainage class Poorly drained Permeability class Very slow to moderately slow Soil depth 72 – 84 in Surface fragment cover <=3" Not specified Surface fragment cover >3" Not specified Available water capacity
(0-40in)5.3 – 7.2 in Calcium carbonate equivalent
(0-40in)0 – 5 % Electrical conductivity
(0-40in)0 – 2 mmhos/cm Sodium adsorption ratio
(0-40in)0 – 1 Soil reaction (1:1 water)
(0-40in)6.6 – 7.8 Subsurface fragment volume <=3"
(Depth not specified)0 – 28 % Subsurface fragment volume >3"
(Depth not specified)0 – 40 % Ecological dynamics
As ecological condition deteriorates, tufted hairgrass composition is reduced with foxtail barley, rushes, sedges and forbs such as wildiris and yarrow increasing on the site. Shrubby cinquefoil, willows and rose often increase in the overstory. Redtop, Kentucky bluegrass, thistles and quackgrass are species likely to invade this site. Where stream channels become entrenched, the water table is lowered and a more drought tolerant plant community occurs on these soils as characterized by (028AY055NV) Loamy Bottom 14+" PZ site description.
Fire Ecology:
Natural fires are estimated to occur in mountain meadows at intervals of several hundred years. Tufted hairgrass generally survives all but the most severe fires. It usually sprouts from the root crown after aerial portions are burned. Tufts formed by the leaves often protect basal buds from fire damage. Tufted hairgrass seeds occur in the seedbank. After fire, tufted hairgrass may regenerate from soil-stored seed. Nevada bluegrass is generally unharmed by fire. It produces little litter, and its small bunch size and sparse litter reduces the amount of heat transferred to perennating buds in the soil. Moderately severe fires will top-kill timothy, and severe fires may cause damage to or kill the root crown, killing the plant. It reproduces by both seed and shoots from the base. Sedge is top-killed by fire, with rhizomes protected by insulating soil. The rhizomes of sedge species may be killed by high-severity fires that remove most of the soil organic layer. Reestablishment after fire occurs by seed establishment and/or rhizomatous spread.State and transition model
More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective textEcosystem states
State 1 submodel, plant communities
State 1
Reference StateCommunity 1.1
Reference Plant CommunityThe reference plant community is dominated by tufted hairgrass. Nevada bluegrass, alpine timothy, clover and meadow sedges are important plants associated with this site. Potential vegetative composition is about 75% grasses, 20% forbs, and 5% shrubs. Approximate ground cover (basal and crown) is 75 to 85 percent.
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 750 1275 2250 Forb 200 340 600 Shrub/Vine 50 85 150 Total 1000 1700 3000 Additional community tables
Table 6. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Primary Perennial Grasses 765–1105 tufted hairgrass DECE Deschampsia cespitosa 510–595 – alpine timothy PHAL2 Phleum alpinum 85–170 – sedge CAREX Carex 85–170 – 2 Secondary Perennial Grasses 85–255 saltgrass DISP Distichlis spicata 9–34 – needle and thread HECO26 Hesperostipa comata 9–34 – sand dropseed SPCR Sporobolus cryptandrus 9–34 – Forb3 Perennial 204–425 clover TRIFO Trifolium 34–85 – yarrow ACHIL Achillea 9–51 – aster ASTER Aster 9–51 – Rocky Mountain iris IRMI Iris missouriensis 9–51 – ragwort SENEC Senecio 9–51 – blue-eyed grass SISYR Sisyrinchium 9–51 – meadow-rue THALI2 Thalictrum 9–51 – Shrub/Vine4 Primary Shrubs 34–85 shrubby cinquefoil DAFR6 Dasiphora fruticosa 34–85 – 5 Secondary Shrubs 1–85 Woods' rose ROWO Rosa woodsii 17–34 – willow SALIX Salix 17–34 – Interpretations
Animal community
Livestock Interpretations:
This site is suitable for livestock grazing. Grazing management should be keyed to tufted hairgrass. Tufted hairgrass provides good to excellent forage for all classes of livestock. It is often an abundant source of forage throughout its growing season. Nevada bluegrass is a palatable species, but its production is closely tied to weather conditions. It produces little forage in drought years, making it a less dependable food source than other perennial bunchgrasses. Timothy is palatable and nutritious forage for domestic livestock. Timothy maintains itself well with proper management, but it is not resistant to heavy grazing. Sedge provides good to fair forage for domestic grazing. Shrubby cinquefoil is of low palatability for livestock. Leaves have a coarse texture and astringent taste. Young seedlings are more palatable than mature plants. Shrubby cinquefoil is grazed in some areas by domestic goats, sheep, and cattle.
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:
Shrubby cinquefoil is of low palatability to big game animals. Leaves have a coarse texture and astringent taste. Young seedlings are more palatable than mature plants, and the seeds are palatable to small mammals. Though it is not preferred forage for deer, shrubby cinquefoil is lightly browsed by mule deer, elk, mountain goats, and bighorn sheep throughout its range. Winter use of shrubby cinquefoil by deer and elk is also typically light. It is a low preference shrub for bighorn sheep, though it receives moderate to heavy use when new growth begins. Small birds and mammals consume shrubby cinquefoil seeds. Tufted hairgrass has a high to moderate resource value for elk and a medium value for mule deer. Use of tufted hairgrass by wildlife species is variable. Tufted hairgrass forage value for wildlife has been rated fair to good. Nevada bluegrass is an important forage species for several wildlife species. Timothy provides important cover for a variety of game birds, small mammals, and waterfowl. Sedges have a high to moderate resource value for elk and a medium value for mule deer. Elk consume beaked sedge later in the growing season.Hydrological functions
Runoff is low to very high. Permeability is very slow to moderately slow. Hydrologic soil group is D.
Recreational uses
Aesthetic value is derived from the diverse floral and faunal composition and the colorful flowering of wild flowers and shrubs during the spring and early summer. This site offers rewarding opportunities to photographers and for nature study. This site is used for hiking and has potential for upland and big game hunting.
Other products
The dried leaves of shrubby cinquefoil were commonly used by Native Americans to make tea. Dried leaves were also made into a mixture considered an arrow poison that was thought to go directly to the heart. Dried, finely powdered leaves were believed to protect the body from severe, temporary heat.
Other information
Shrubby cinquefoil is useful for erosion control and soil stabilization, and may be useful in wildlife habitat mitigation. Due to its virtually continuous summer blooming, shrubby cinquefoil is a valuable landscape ornamental, and is recommended for landscaping in deer winter range areas because it is seldom browsed. Tufted hairgrass has a broad ecological range and is useful for revegetation, particularly on disturbances at high elevation or high latitude. Tufted hairgrass has been successfully established by seeding on alpine disturbances. It is a valuable soil stabilizer, especially in wet, acid locations. Timothy is used for reseeding rangelands where the soil is moist and the growing season long enough for seed production.
Supporting information
Type locality
Location 1: White Pine County, NV Township/Range/Section T13N R69E S21 Latitude 38° 59′ 5″ Longitude 114° 14′ 0″ General legal description Along Baker Creek, east of Baker Creek Campground, Great Basin National Park, Snake Range, White Pine County, Nevada. Also occurs in Elko County, Nevada. Other references
Fire Effects Information System (Online; http://www.fs.fed.us/database/feis/plants/).
Houghton, J.G., C.M. Sakamoto, and R.O. Gifford. 1975. Nevada’s Weather and Climate, Special Publication 2. Nevada Bureau of Mines and Geology, Mackay School of Mines, University of Nevada, Reno, NV.
National Oceanic and Atmospheric Administration. 2004. The North American Monsoon. Reports to the Nation. National Weather Service, Climate Prediction Center. Available online: http://www.weather.gov/
USDA-NRCS Plants Database (Online; http://www.plants.usda.gov).
Contributors
DBP/GKB
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
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Number and extent of rills:
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Presence of water flow patterns:
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Number and height of erosional pedestals or terracettes:
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Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
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Number of gullies and erosion associated with gullies:
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Extent of wind scoured, blowouts and/or depositional areas:
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Amount of litter movement (describe size and distance expected to travel):
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Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
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Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
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Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
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Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
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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:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
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Average percent litter cover (%) and depth ( in):
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Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
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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:
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Perennial plant reproductive capability:
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