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Draft. A draft ecological site description is either incomplete or has not undergone quality control and quality assurance review.
Table 1. Dominant plant species
Tree (1) Abies concolor
Shrub (1) Ceanothus velutinus
Herbaceous (1) Pseudoroegneria spicata subsp. spicata
(2) CarexPhysiographic features
The forestland site occurs on cool, moist, north-facing mountain sideslopes and plateaus. Slopes range from 15 to 75 percent, but are typically 15 to 30 percent. Elevations are 6,000 to over 10,000 feet.
Table 2. Representative physiographic features
Landforms (1) Mountain
(2) Plateau
Elevation 6000 – 10000 ft Slope 15 – 75 % Aspect N Climatic features
The climate associated with this site is semiarid and characterized by cold, moist winters and cool, dry summers. Average annual precipitation is 16 to over 20 inches. Mean annual air temperature is 41 to 45 degrees F. The average growing season is 60 to 80 days.
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) 70 days Freeze-free period (average) 0 days Precipitation total (average) 20 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
There are no influencing water features associated with this site.
Soil features
Soils associated with this site are generally moderately deep to deep and well drained. Surface soil textures are very gravelly loams and extremely cobbly loams.The soils are formed in residuum and colluvium derived from volcanic rocks. Rock fragments within the soil profile range from 35 to 80 percent by volume and are dominantly gravels and cobbles. Soils have medium runoff and moderately rapid permeability. The soil series associated with this site include: Easte.
Table 4. Representative soil features
Surface texture (1) Very gravelly sandy loam
(2) Very cobbly loam
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderately rapid Soil depth 40 – 60 in Surface fragment cover <=3" 40 – 46 % Surface fragment cover >3" 0 – 14 % Available water capacity
(0-40in)5.1 – 6.5 in Calcium carbonate equivalent
(0-40in)Not specified Electrical conductivity
(0-40in)Not specified Sodium adsorption ratio
(0-40in)Not specified Soil reaction (1:1 water)
(0-40in)2.6 – 3 Subsurface fragment volume <=3"
(Depth not specified)30 – 57 % Subsurface fragment volume >3"
(Depth not specified)6 – 25 % Ecological dynamics
Fire Ecology:
White fir communities fire return interval averages between 5 an 30 years in the Sierra Nevada. Young white fir is highly susceptible to fire, and mature trees are only moderately fir tolerant. White fir is an aggressive, shade-tolerant species that will seed into the understory of low-elevation ponderosa or Jeffrey pine stands or into mixtures of ponderosa pine, Douglas-fir, quaking aspen, and southwestern white pine. Snowbrush ceanothus burns hot. The foliage contains volatile oils that may contribute to fire hazard and is top-killed by fire. Snowbrush ceanothus has dormant, ground-stored seed that requires heat treatment to germinate. Snowbrush ceanothus also sprouts vigorously from the root crown after fire. Resprouting may be an adaptation to recurring fires, allowing for rapid growth and recovery. Fire creates conditions more favorable for snowbrush ceanothus growth by removing the overstory. Creeping barberry is moderately tolerant of fire. It is a vigorous sprouter following fire and may be favored by intense fire. Mountain big sagebrush is highly susceptible to injury from fire. It is often top-killed by fire and will not resprout.
Major Successional Stages of Forestland Development:
HERBACEOUS: Vegetation is dominated by grasses and forbs under full sunlight. This stage is experienced after a major disturbance such as crown fire or tree harvest. Skeleton forest (dead trees) remaining after fire or residual trees left following harvest have little or no affect on the composition and production of the herbaceous vegetation.
SHRUB-HERBACEOUS: Herbaceous vegetation and woody shrubs dominate the site. Various amounts of tree seedlings (less than 20 inches in height) may be present. Snowbrush ceanothus readily root-sprouts following wildlife and may dominate the community at this stage. Successional development of the community may be arrested by the complete dominance of snowbrush.
SAPLING: In the absence of disturbance the tree seedlings develop into saplings (20 inches to 4.5 feet in height) with a range in canopy cover of about 5 to 10 percent. Vegetation consists of grasses, forbs and shrubs in association with tree saplings.
IMMATURE FORESTLAND: The visual aspect and vegetal structure are dominated by white fir greater than 4.5 feet in height. The upper crown of dominant and co-dominant are cone or pyramidal shaped. Dominants are the tallest trees on the site; co-dominants are 65 to 85 percent of the height of dominant trees. Understory vegetation is moderately influenced by a tree overstory canopy of about 10 to 20 percent.
MATURE FORESTLAND: The visual aspect and vegetal structure are dominated by white fir that have reached or are near maximal heights for the site. Dominant trees average greater than five inches in diameter at one-foot stump height. Tree canopy cover ranges from 30 to 40 percent. Understory vegetation is strongly influenced by tree competition, overstory shading, duff accumulation, etc. Few tree seedlings and/or saplings occur in the understory.
OVER-MATURE FORESTLAND: In the absence of wildfire or other naturally occurring disturbances, the tree canopy on this site can become very dense. This stage is dominated by white fir trees that have reached maximal heights for the site. Upper crowns are typically irregularly flat-topped or rounded. Understory vegetation is sparse to absent due to tree competition. Tree canopy cover is at the maximum for the site and is commonly greater than 35 percent.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 Plant CommunityCommunity 1.1
Reference Plant CommunityThe reference plant community is dominated by white fir. Snowbrush ceanothus, muttongrass, and sedges are the principal understory shrub. Bluebunch wheatgrass, and muttongrass are the most prevalent understory grasses. An overstory canopy of 30 to 35 percent is assumed to be representative of tree dominance on this site in the pristine environment.
Forest overstory.MATURE FORESTLAND: The visual aspect and vegetal structure are dominated by white fir that have reached or are near maximal heights for the site. Dominant trees average greater than five inches in diameter at one-foot stump height. Tree canopy cover ranges from 30 to 40 percent. Understory vegetation is strongly influenced by tree competition, overstory shading, duff accumulation, etc. Few tree seedlings and/or saplings occur in the understory.
Forest understory. Understory vegetative composition is about 40 percent grasses, 10 percent forbs and 50 percent shrubs and young trees when the average overstory canopy is medium (30 to 40 percent). Average understory production ranges from 300 to 700 pounds per acre with a medium canopy cover. Understory production includes the total annual production of all species within 4½ feet of the ground surface.
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)Shrub/Vine 150 250 350 Grass/Grasslike 99 165 231 Forb 30 50 70 Tree 21 35 49 Total 300 500 700 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 50–90 muttongrass POFE Poa fendleriana 25–45 – bluebunch wheatgrass PSSPS Pseudoroegneria spicata ssp. spicata 25–45 – 2 Secondary Perennial Grasses/Grasslikes 15–75 Letterman's needlegrass ACLE9 Achnatherum lettermanii 5–25 – sedge CAREX Carex 5–25 – Sandberg bluegrass POSE Poa secunda 5–25 – Shrub/Vine3 Primary Shrubs 125–285 snowbrush ceanothus CEVE Ceanothus velutinus 50–120 – creeping barberry MARE11 Mahonia repens 50–120 – mountain big sagebrush ARTRV Artemisia tridentata ssp. vaseyana 25–45 – 4 Secondary Shrubs 11–35 Utah serviceberry AMUT Amelanchier utahensis 5–25 – antelope bitterbrush PUTR2 Purshia tridentata 3–5 – snowberry SYMPH Symphoricarpos 3–5 – Tree5 Evergreen 25–45 white fir ABCO Abies concolor 25–45 – Interpretations
Animal community
Livestock Interpretations:
This site is suited to cattle and sheep grazing during the spring and fall. Livestock will often concentrate on this site taking advantage of the shade and shelter offered by the tree overstory. Many areas are not used because of steep slopes and the lack of adequate water. Attentive grazing management is required due to steep slopes and erosion hazards. Harvesting trees under a sound management program can open up the tree canopy to allow increased production of understory species desirable for grazing.
Stocking rates vary with such factors as kind and class of grazing animal, season of use and fluctuations in climate. Actual use records for individual sites, a determination of the degree to which the sites have been grazed, and an evaluation of trend in site condition offer the most reliable basis for developing initial stocking rates.
Selection of initial stocking rates for given grazing units is a planning decision. This decision should be made ONLY after careful consideration of the total resources available, evaluation of alternatives for use and treatment, and establishment of objectives by the decisionmaker.
The forage value rating is not an ecological evaluation of the understory as is the range condition rating for rangeland. The forage value rating is a utilitarian rating of the existing understory plants for use by specific kinds of grazing animals.
Wildlife Interpretations:
This area has high value for mule deer and elk during the summer and fall. It is used by upland game species and various song birds, rodents and associated predators natural to the area. It is also used by various song birds, rodents, reptiles and associated predators natural to the area.Hydrological functions
Runoff is medium. Permeability is moderately rapid. Hydrologic soil group is B.
Recreational uses
The trees on this site provide a welcome break in an otherwise open landscape. Steep slopes inhibit many forms of recreation. It has potential for hiking, camping, cross-country skiing, and deer and upland game hunting. Off-road vehicles can destroy the fragile soil-vegetation complex causing severe erosion problems.
Wood products
Principle uses of white fir are poles, fuelwood, and some lumber. The wood produced is generally of poor quality; however, this tree has a good potential for the production of pulp, possibly boxwood, and other manufactured wood items.
PRODUCTIVE CAPACITY
This site has a low to medium site quality for tree production. Site index ranges from about 41 to 45 (Schumacher, F.X. 1926).
Productivity class: 5
CMAI*: 67 to 77 ft3/ac/yr;
4.7 to 5.4 m3/ha/yr.
*CMAI: is the culmination of mean annual increment or highest average growth rate of the stand in the units specified.
Fuelwood production: About 45 to 55 cords per acre for stands averaging 30 to 40 feet in height and 70 years of age. There are about 205,000 British Thermal Units (BTUs) heat energy per cubic foot of white fir wood. Firewood is commonly measured in cords, or a stacked unit equivalent to 128 cubic feet. Solid wood volume in a cord varies, but usually ranges from 65 to 90 cubic feet of solid wood per cord. Assuming an average of 75 cubic feet of solid wood per cord, there are about 15 million BTUs of heat value in a cord of white fir.
Tree volume per acre: 3600 to 4500 cu ft/ac for stands averaging 30 to 40 feet in height and 70 years old.
MANAGEMENT GUIDES AND INTERPRETATIONS
1. LIMITATIONS AND CONSIDERATIONS
a. Potential for sheet and rill erosion is moderate to severe depending on slope.
b. Moderate to severe equipment limitations on steeper slopes and on sites having extreme surface stoniness.
c. Proper spacing is the key to a well managed, multiple use, and multi-product forestland.
2. ESSENTIAL REQUIREMENTS
a. Adequately protect from wildfire.
b. Protect soils from accelerated erosion.
c. Apply proper grazing management.
3. SILVICULTURAL PRACTICES
Due to the low production of this site, silvicultural practices are not addressed.Other products
Native Americans used big sagebrush leaves and branches for medicinal teas, and the leaves as a fumigant. Bark was woven into mats, bags and clothing.
Table 7. Representative site productivity
Common name Symbol Site index low Site index high CMAI low CMAI high Age of CMAI Site index curve code Site index curve basis Citation white fir ABCO 41 45 67 77 – – – Supporting information
Type locality
Location 1: Washoe County, NV Township/Range/Section T47N R19E S28 UTM zone N UTM northing 263017 UTM easting 4649988 Latitude 41° 57′ 58″ Longitude 119° 51′ 35″ General legal description SE 1/4 SE 1/4, About 3 miles west of the Coleman Ranch, Bally Mountain area, Washoe County, Nevada. This site also occurs in Humboldt County, Nevada. Other references
Cochran, P. H. 1979. Gross Yield for Even-Aged Stands of Douglas-fir and White Fir East of the Cascades in Oregon and Washington. USDA-FS Research Paper PNW-263, Pacific Northwest Forest and Range Experiment Station, Portland, OR.
Eyre, F. H. (editor) 1980. Forest Cover Types of the United States and Canada. Society of American Foresters, Washington, D.C.
Fire Effects Information System (Online; http://www.fs.fed.us/database/feis/plants/).
Schumacher, F.X. 1926. Normal Yield Tables for White Fir. Calif. Ag. Ext. Sta. Bulletin No. 407
USDA-NRCS Plants Database (Online; http://www.plants.usda.gov).Contributors
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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