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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) Pinus jeffreyi
Shrub (1) Arctostaphylos
(2) Purshia tridentataHerbaceous Not specified
Physiographic features
This forest site occurs on middle-to upper-sideslopes and ridgetops of mountains. This site occurs on all aspects but is most common on southerly facing slopes. Slopes range from 15 to 75 percent, but slopes are generally 30 to 50 percent. Elevations are from about 6000 feet to over 8000 feet.
Table 2. Representative physiographic features
Landforms (1) Mountain slope
Elevation 6000 – 8000 ft Slope 15 – 75 % Aspect SE, S, SW Climatic features
The climate associated with this site is subhumid with cool, dry summers and cold, wet winters. Average annual precipitation is 16 to 24 inches. Mean annual air temperature is 39 to 45 degrees F. The average growing season is 40 to 70 days.
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
">Influencing water features
There is no influencing water features associated with this site.
Soil features
The soils associated with this site are very shallow and well drained. They are formed in colluvium and residuum derived from hydrothermally altered volcanic rock. The soils typically have an ochric epipedon. Runoff is very high and permeability is moderately rapid. The soil moisture control section is usually moist from late fall, winter, and spring, and dry from July through October. Soils correlated to this site include Newcone.
Table 4. Representative soil features
Surface texture (1) Very gravelly sandy loam
(2) Very gravelly loam
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderately rapid Soil depth 3 – 10 in Surface fragment cover <=3" 45 – 0 % Surface fragment cover >3" 6 – 0 % Available water capacity
(0-40in)0.5 – 0 in Electrical conductivity
(0-40in)Not specified Sodium adsorption ratio
(0-40in)Not specified Soil reaction (1:1 water)
(0-40in)3.5 – 5.5 Subsurface fragment volume <=3"
(Depth not specified)18 – 0 % Subsurface fragment volume >3"
(Depth not specified)25 – 0 % Ecological dynamics
Jeffrey pine occupies many sites from the edges of moist high montane meadows to arid slopes bordering deserts. It generally occurs on the drier or higher elevation sites on soils derived from pumic or granite. Jeffery pine is climax on many of these sites but gradually loses its competitve ability as moisture conditions in the soil and atmosphere become favorable for other species.
Fire Ecology:
Jeffrey pine has been classified as being
moderately resistant to fire. It has a thick, corky bark that withstands high temperatures and has a tall, erect bole free of lower
limbs. The buds develop thick scales able to withstand considerable amounts of heat. Jeffrey pine seedlings have also adapted to
reproducing well on bare mineral soil. Lightning is common in the Sierra Nevada and strongly influences Jeffrey pine through wildfires. Jeffrey pine has adapted to withstand low-severity fires in wellspaced stands. Moderate- to high-severity fires will, however, kill trees pole size and smaller. Mature Jeffrey pines can survive most fires, suffering only bole scorch. These fire effects are intensified with tree density and fuel load. Depending on the season, Jeffrey pine may experience extensive heat-kill of foliage, but may receive only light damage to buds and twigs.
Antelope bitterbrush is very susceptible to fire kill. It is considered a weak sprouter and is often killed by summer or fall fire. Antelope bitterbrush in some areas may sprout after light-severity spring fire. High fuel consumptions increase antelope bitterbrush mortality and therefore favors seedling establishment.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 characterized by an overstory canopy of 25 to 35 percent. This site is dominated by Jeffrey pine. Although of only minor importance, white fir and Sierra juniper are trees commonly associated with this site. Manzanita and antelope bitterbrush are the principal understory shrubs.
Forest overstory.Overstory tree canopy composition is about 95 to 100 percent Jeffrey pine with up to 5 percent collectively of white fir and/or Sirra juniper.<br /> <br /> Major Successional Stages of Woodland Development<br /> <br /> HERBACEOUS: Vegetation is dominated by grasses and forbs under full sunlight. This stage is experienced for a short period after 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.<br /> <br /> SHRUB-HERBACEOUS: Herbaceous vegetation and woody shrubs dominate the site. This stage is experienced within two to three years after fire or harvest. Various amounts of tree seedlings (less than 20 inches in height) may be present up to the point where they are obviously a major component of the vegetal structure.<br /> <br /> 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. Understory shrubs dominate the plant community.<br /> <br /> IMMATURE WOODLAND: The visual aspect and vegetal structure are dominated by Jeffrey pine greater than 4.5 feet in height. At this stage of woodland development, the tree canopy has successfully broken through the suppression of early successional shrub communities. The young pines are still very susceptible to fire at this stage. The upper crown of dominant and co-dominant Jeffrey pine are cone or pyramidal shaped. Seedlings and saplings of pines are common in the understory. Dominants are the tallest trees on the site; co-dominants are 65 to 85 percent of the highest of dominant trees. Understory vegetation is moderately influenced by a tree overstory canopy of about 10 to 20 percent.<br /> <br /> MATURE WOODLAND: The visual aspect and vegetal structure are dominated by Jeffrey pine that have reached or are near maximal heights for the site. Tree canopy cover ranges from 25 to 35 percent. Although infrequent wildfire is presumed to be a natural factor influencing the understory of these mature woodlands, Jeffrey pine, at this stage of growth, is relatively resistant to cool, slow-burning, wildfires because of its thick, insulating bark. This stage of community development is assumed to be representative of this woodland site in the pristine environment.<br /> <br /> OVER-MATURE WOODLAND: 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 Jeffrey pine that have reached maximal heights for the site. Understory vegetation is sparse due to tree competition, overstory shading, duff accumulation, etc. Few seedlings or saplings of Jeffrey pine are found in the understory. Tree canopy cover is commonly greater than 50 percent.<br /> <br />
Forest understory. Understory vegetative composition is about 30 percent grasses, 15 percent forbs and 55 percent shrubs and young trees when the average overstory canopy is medium (25 to 35 percent). Average understory production ranges from 150 to 350 pounds per acre with a medium canopy cover. Understory production includes the total annual production of all species within 4 1/2 feet of the ground surface.
Figure 3. 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 60 100 140 Grass/Grasslike 45 75 105 Tree 23 38 53 Forb 22 37 52 Total 150 250 350 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 26–44 Letterman's needlegrass ACLE9 Achnatherum lettermanii 13–22 – western needlegrass ACOCO Achnatherum occidentale ssp. occidentale 13–22 – 2 Secondary Perennial Grasses 3–13 squirreltail ELEL5 Elymus elymoides 3–13 – Forb3 Perennial 25–74 lousewort PEDIC Pedicularis 13–22 – rockcress ARABI2 Arabis 3–13 – cascade wallflower ERAR15 Erysimum arenicola 3–13 – buckwheat ERIOG Eriogonum 3–13 – mountain monardella MOOD Monardella odoratissima 3–13 – Shrub/Vine4 Primary Shrubs 51–104 greenleaf manzanita ARPA6 Arctostaphylos patula 25–60 – currant RIBES Ribes 13–22 – snowberry SYMPH Symphoricarpos 13–22 – 5 Secondary Shrubs 1–3 bush chinquapin CHSE11 Chrysolepis sempervirens 1–3 – Tree6 Evergreen 19–48 white fir ABCO Abies concolor 13–22 – Jeffrey pine PIJE Pinus jeffreyi 3–13 – Interpretations
Animal community
Livestock Interpretations:
This site is suited to cattle and sheep grazing where terrain permits. Grazing management should be keyed to Letterman's and western needlegrass production. Letterman's and western needlegrass provide palatable, nutrious feed during the late spring and early summer. New plants of these grasses are established entirely from seed and grazing practices should allow for ample seed production and seedling establishment. Many areas are not used because of steep slopes or lack of adequate water.
Initial Stocking Rates
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 decision maker.
Example: Sample Calculations using Favorable Year production amounts:
500 lbs of available forage/ac x. 25 (Harvest Efficiency) = 125 lbs forage consumed
125 lbs/790 lbs = .16 AUMs/ac or 6.32 ac/AUM
NOTE: 790 lbs/month for one Animal Unit is used as the baseline for maintenance requirements. This equates to 30 lbs/day of air-dry forage (1000 lb cow at 2.6% of body weight). See NRCS National Range and Pasture Handbook.
Forage Value Rating
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:
Birds and mammals use Jeffrey pine as a food source. Seeds are eaten by the Clark's nutcracker and other birds. Many small mammals
such as mice, chipmunks, squirrels, and voles eat the stems and roots of young Jeffrey pine. During harsh winters or drought, large mammals such as deer will browse on the needles and bark. Young Jeffrey pine seedlings provide ground shelter for small birds and mammals. Older stands serve as windbreaks for larger mammals. Insect-killed trees provide snags and fallen logs which become habitat
for nesting birds and cavity dwellers.Recreational uses
Hiking and cross country skiing is the main revreation in this area. Some areas are also suitable for camping.
Wood products
Low-grade trees are processed into dimensional lumber and other products for the construction market. High-grade lumber is an important raw material for molding, mill work, cabinets, doors, and windows. Jeffrey pine is also widely used for firewood.
PRODUCTIVE CAPACITY
Low quality site for tree production.
Site index for Jeffrey pine ranges from about <40 to 48. (Table 21, SCS, 190-V-NFM Amend.3; from Meyer, 1938. USDA Tech Bull 630.)
Productivity Class (Jeffrey pine): 2
CMAI*:<30 to 36 cu ft/ac/yr; <2.1 to 2.5 cu m/ha/yr.
*CMAI: is the culmination of mean annual increment highest average growth rate of the stand in the units specified.
Basal Area: 80 sq. ft./acre.(AB129)
??Fuelwood Production: 35 to 50 cords per acre for Jeffrey pine stands averaging 11.6 inches and more in diameter and 110 years of age. There are about 213,750 gross British Thermal Units (BTUs) heat content per cubic foot of Jeffrey pine wood. Solid wood volume in a cord varies but usually ranges from 65 to 90 cubic feet. Assuming an average of 75 cubic feet of solid wood per cord, there are about 16 million BTUs of heat value in a cord of Jeffrey pine wood.
??Board-foot Volume per Acre (Scribner Rule): For Jeffrey pine stands averaging 11.6 inches and more in diameter and 110 years of age:
Site Index 66 = 16,500 bd ft
Site Index 77 = 20,000 bd ft
MANAGEMENT GUIDES AND INTERPRETATIONS
1. LIMITATIONS AND CONSIDERATIONS
a. Significant restrictions or limitations for forest land use or management due to steep slopes.
2. ESSENTIAL REQUIREMENTS
a. Protect soils from accelerated erosion.
b. Apply proper grazing management
3. SILVICULTURAL PRACTICES
a. Harvest cut selectively or in small patches (size dependent upon site conditions) to enhance forage production.
1) Thinning and improvement cutting- Removal of poorly formed, diseased and low vigor trees for firewood.
2) Harvest cutting- Selectively harvest surplus trees to achieve desired spacing. Do not select only "high grade" trees for harvest.
3) Slash disposal- broadcasting slash improves reestablishment of native understory species and establishment of seeded grasses and forbs after tree harvest.
b. Prescription burning program to maintain desired canopy cover and manage site reproduction.
c. Mechanical tree removal on suitable sites to enhance forage production and manage site reproduction.
d. Pest control-porcupines can cause extensive damage and populations should be controlled.
e. Fire hazard- Fire usually not a problem in well-managed, mature stands.
Other information
Antelope bitterbrush has been used extensively in land reclamation. Antelope bitterbrush enhances succession by retaining soil and depositing organic material and in some habitats and with some ecotypes, by fixing nitrogen.
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 Jeffrey pine PIJE 40 64 30 50 – – – Supporting information
Type locality
Location 1: Mono County, CA Latitude 38° 40′ 2″ Longitude 119° 41′ 54″ General legal description Toiyabe National Forest.a Other references
Fire Effects Information System[Online], http://www.fs.fed.us/database/feis
Plants Database [Online], http://www.plants.usda.gov
Lanner, Ronald M.. 1984. Trees of the Great Basin, A Natural History. Reno University of Nevada Press.
Meyer, W.H. 1938. Even-aged Stands of Ponderosa Pine. USDA Tech. Bull. 630
USDA-NRCS. 1980. National Forestry Manual - Part 537. Washington, D.C.
Potter, D. A. 1998. Forested Communities of the Upper Montane in the Central and Southern Sierra Nevada. USDA FA PSW GTR 169.
Contributors
Angela Mushrush
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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