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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 monophylla
Shrub (1) Quercus gambelii
(2) Symphoricarpos longiflorusHerbaceous (1) Poa fendleriana
Physiographic features
This forest community occurs on higher mountain crests, summits, and upper sideslopes of mostly northerly exposure. Slopes range from 4 to 75 percent, but are typically 30 to 50 percent. Elevations are 6500 to about 8500 feet.
Table 2. Representative physiographic features
Landforms (1) Mountain
Elevation 4690 – 6330 ft Slope 30 – 75 % Aspect Aspect is not a significant factor Climatic features
Average annual precipitation is 14 inches or more. Mean annual air temperature is 45 to 52 degrees F. The average frost-free period is 70 to 100 days.
Table 3 Representative climatic features
Frost-free period (average) 100 days Freeze-free period (average) 0 days Precipitation total (average) 0 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
">Influencing water features
There are no influencing water features associated with this site.
Soil features
The soils associated with this site are shallow to bedrock and well drained. These soils have formed in residuum and colluvium from limestone or dolomite parent material and the soils are calcareous. Available water capacity is low, but trees and shrubs can extend their roots into fractures in the bedrock allowing them to utilize deep moisture. There are high amounts of rock fragments at the soil surface; gravels (<30%); cobbles (20 to 40%); stones 15 to 30%) and boulders (± 5%). Total soil surface cover of rock fragments is greater than 75 percent. Soil temperature regime is Mesic and soil moisture regime is Ustic. The soil series associated with this site is Virgin Peak.
Table 4. Representative soil features
Surface texture (1) Very gravelly loam
Drainage class Well drained Permeability class Moderately rapid Soil depth 6 – 20 in Surface fragment cover <=3" 49 – 50 % Surface fragment cover >3" 11 – 12 % Available water capacity
(0-40in)0.5 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)6.6 – 7.3 Subsurface fragment volume <=3"
(Depth not specified)52 – 53 % Subsurface fragment volume >3"
(Depth not specified)4 – 5 % Ecological dynamics
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. 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 up to the point where they are obviously a major component of the vegetal structure.
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 FOREST: The visual aspect and vegetal structure are dominated by pinyon trees greater than 4.5 feet in height. The upper crown of singleleaf pinyon are cone or pyramidal shaped. Seedlings and saplings of pinyon are present in the understory. Dominants are the tallest trees on the site. Understory vegetation is moderately influenced by a tree overstory canopy of about 10 to 20 percent.
MATURE FOREST: The visual aspect and vegetal structure are dominated by singleleaf pinyon that have reached or are near maximal heights for the site. Dominant trees average greater than five inches in diameter at one-foot stump. Upper crowns are typically either irregularly or smoothly flat-topped or rounded. Tree canopy cover averages about 25 percent. Understory vegetation is strongly influenced by tree competition, overstory shading, duff accumulation, etc. Infrequent, yet periodic, wildfire is presumed to be a natural factor influencing the understory of mature pinyon forestlands. This stage of community development is assumed to be representative of this forestland site in the pristine environment.
OVER-MATURE FOREST: In the absence of wildfire or other naturally occurring disturbances, the tree canopy on this site can become very dense. At this stage singleleaf pinyon has reached maximal heights for the site. Dominant and co-dominant trees average greater than five inches in diameter at one-foot stump height. Upper crowns are typically irregularly flat-topped or rounded. Understory vegetation is sparse or absent due to tree competition, overstory shading, duff accumulation, etc. Tree canopy cover is commonly greater than 40 percent.
The pinyon-juniper forestland is generally a climax vegetation type throughout its range, reaching climax about 300 years after disturbance, with an ongoing trend toward increased tree density and canopy cover and a decline in understory species over time. Singleleaf pinyon seedling establishment is episodic. Population age structure is affected by drought, which reduces seedling and sapling recruitment more than other age classes. The ecotones between singleleaf pinyon woodlands and adjacent shrublands and grasslands provide favorable microhabitats for singleleaf pinyon seedling establishment since they are active zones for seed dispersal, nurse plants are available, and singleleaf pinyon seedlings are only affected by competition from grass and other herbaceous vegetation for a couple of years.
Several natural and anthropogenic processes can lead to changes in the spatial distribution of pinyon-juniper forestlands over time. These include 1) tree seedling establishment during favorable climatic periods, 2) tree mortality (especially seedlings and saplings) during periods of drought, 3) expansion of trees into adjacent grassland in response to overgrazing and/or fire suppression, and 4) removal of trees by humans, fire, or other disturbance episodes. Specific successional pathways after disturbance in singleleaf pinyon stands are dependent on a number of variables such as plant species present at the time of disturbance and their individual responses to disturbance, past management, type and size of disturbance, available seed sources in the soil or adjacent areas, and site and climatic conditions throughout the successional process.
Fire Ecology:
On high-productivity sites where sufficient fine fuels existed, pinyon-juniper communities burn every 15 to 20 years, and on less productive sites with patchy fuels, fire return intervals may be in the range of 50 to 100 years or longer. Thin bark and lack of self pruning make singleleaf pinyon very susceptible to intense fire. Mature singleleaf pinyon can survive low-severity surface fires but is killed by more severe fires. Most tree seedlings are killed by fire, but cached seeds may survive. Utah juniper is usually killed by fire, especially when trees are small. Utah juniper habitat types rarely have sufficient fine fuels to produce severe or continuous fires. Common snowberry has high resistance to fire. It is a rhizomatous species with rhizomes buried 2 to 5 inches (5-12.5 cm) deep in mineral soil. After fire has killed the top of the plant, new growth sprouts from these rhizomes. This rhizomatous growth response is highly variable and depends on conditions at specific sites. Regeneration from buried seed is favored by fires of low severity and short duration that remove little of the soil organic level. Aboveground parts of Utah serviceberry may be killed or consumed under fire conditions with sufficient flame lengths. Utah serviceberry may be slightly harmed by fire, depending on moisture conditions, but is generally considered to be fire tolerant. Utah serviceberry sprouts from the root crown following fire. Soil moisture is important to aid sprouting. Mountain big sagebrush is highly susceptible to injury from fire. It is often top-killed by fire and will not resprout. Muttongrass is unharmed to slightly harmed by light-severity fall fires. Muttongrass appears to be harmed by and slow to recover from severe fire. Indian ricegrass can be killed by fire, depending on severity and season of burn. Indian ricegrass reestablishes on burned sites through seed dispersed from adjacent unburned areas.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 singleleaf pinyon. Gambel's oak, snowberry, Utah serviceberry, manzanita, curlleaf mountainmahogany, and mountain big sagebrush are the principal understory shrubs. Muttongrass is the most prevalent understory grass. Cushion daisy (Erigeron compactus) and fineleaf hymenopappus are the most common forbs. Overstory tree canopy composition is about 95 to 100 percent singleleaf pinyon with up to 5 percent curlleaf mountainmahogany or Utah juniper mixing in the overstory canopy. An overstory canopy cover of about 25 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 singleleaf pinyon that have reached or are near maximal heights for the site. Dominant trees average greater than five inches in diameter at one-foot stump. Upper crowns are typically either irregularly or smoothly flat-topped or rounded. Tree canopy cover averages about 25 percent. Understory vegetation is strongly influenced by tree competition, overstory shading, duff accumulation, etc. Infrequent, yet periodic, wildfire is presumed to be a natural factor influencing the understory of mature pinyon forestlands. This stage of community development is assumed to be representative of this forestland site in the pristine environment.
Forest understory. Understory vegetative composition is about 30 percent grasses, 5 percent forbs and 65 percent shrubs and young trees when the average overstory canopy is medium (about 25 percent). Average understory production ranges from 600 to 1000 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 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 270 360 450 Grass/Grasslike 180 240 300 Tree 120 160 200 Forb 30 40 50 Total 600 800 1000 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 80–144 Indian ricegrass ACHY Achnatherum hymenoides 40–72 – muttongrass POFE Poa fendleriana 40–72 – 2 Secondary Perennial Grasses/Grasslikes 32–160 little Parish's needlegrass ACPAD Achnatherum parishii var. depauperatum 8–40 – desert needlegrass ACSP12 Achnatherum speciosum 8–40 – sedge CAREX Carex 8–40 – Sandberg bluegrass POSE Poa secunda 8–40 – Forb3 Perennial 20–64 lupine LUPIN Lupinus 8–40 – goldenweed PYRRO Pyrrocoma 4–8 – cushion daisy ERCO3 Erigeron compactus 4–8 – fineleaf hymenopappus HYFIE Hymenopappus filifolius var. eriopodus 4–8 – Shrub/Vine4 Primary Shrubs 200–360 Utah serviceberry AMUT Amelanchier utahensis 40–72 – manzanita ARCTO3 Arctostaphylos 40–72 – mountain big sagebrush ARTRV Artemisia tridentata ssp. vaseyana 40–72 – Mojave ceanothus CEGRV Ceanothus greggii var. vestitus 40–72 – snowberry SYMPH Symphoricarpos 40–72 – 5 Secondary Shrubs 24–72 Utah agave AGUT Agave utahensis 8–40 – desert sweet CHMI2 Chamaebatiaria millefolium 8–40 – mormon tea EPVI Ephedra viridis 8–40 – ashy silktassel GAFL2 Garrya flavescens 8–40 – Stansbury cliffrose PUST Purshia stansburiana 8–40 – Tree6 Deciduous 88–184 curl-leaf mountain mahogany CELE3 Cercocarpus ledifolius 40–72 – Gambel oak QUGA Quercus gambelii 40–72 – Sonoran scrub oak QUTU2 Quercus turbinella 8–40 – 7 Evergreen 12–48 singleleaf pinyon PIMO Pinus monophylla 8–40 – Utah juniper JUOS Juniperus osteosperma 4–8 – Interpretations
Animal community
Livestock Interpretations:
This site is not well suited to cattle or sheep grazing due to steep slopes, lack opf adequate water, and surface stoniness. Grazing use is generally limited to livestock tailing through the area moving to more favorable terrain. Grazing management should be keyed to muttongrass production. Muttongrass provides palatable, nutritious feed during the late spring and summer. New plants of muttongrass are established entirely from seed and grazing practices should allow for ample seed production and seedling establishment.
Attentive grazing management is required due to steep slopes and erosion hazards.
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.
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 site has high value for mule deer during the summer, fall and winter. Pinyon trees provide shelter from winter storms. Sites where water is available offer good quail habitat and are visited seasonally by mourning dove. It is also used by various song birds, rodents, reptiles and associated predators natural to the area.Hydrological functions
The hydrologic cover condition of this site is fair in a representative stand. The average runoff curve is about 85 for group C soils and about 90 for group D Soils.
Recreational uses
The trees on this site provide a welcome break in an otherwise open landscape. It has potential for hiking, cross-country skiing, camping, and deer and upland game hunting.
Wood products
Pinyon wood is rather soft, brittle, heavy with pitch, and yellowish brown in color. Singleleaf pinyon has played an important role as a source of fuelwood and mine props. It has been a source of wood for charcoal used in ore smelting. It still has a promising potential for charcoal production. Other important uses for this tree are for Christmas trees and as a source of nuts for wildlife and human food.
PRODUCTIVE CAPACITY
This forestland community is of very low site quality for tree production. Site index ranges from 20 to 35 (Howell, 1940).
Productivity Class: 0
CMAI*: 1.3 to 2.7 ft3/ac/yr;
0.10 to 0.20 m3/ha/yr.
Culmination is estimated to be at 100 years.
*CMAI: is the culmination of mean annual increment or highest average growth rate of the stand in the units specified.
Fuelwood Production: 2 to 5 cords per acre for stands averaging 5 inches in diameter at 1 foot height with a medium canopy cover. There are about 289,000 gross British Thermal Units (BTUs) heat content per cubic foot of pinyon pine wood and about 274,000 gross BTUs heat content per cubic foot of Utah juniper. 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 21 million BTUs of heat value in a cord of mixed pinyon pine and Utah juniper.
Posts (7 foot): About 10 to 20 posts per acre in stands of medium canopy.
Christmas trees: About 5 trees per acre per year in stands of medium canopy.
Pinyon nuts: Production varies year to year, but mature woodland stage can yield about 100 pounds per acre in favorable years.
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 moderate to severe equipment limitations on sites having extreme surface stoniness.
c. Proper spacing is the key to a well managed, multiple use and multi-product pinyon forestland.
2. ESSENTIAL REQUIREMENTS
a. Adequately protect from wildfire.
b. Protect soils from accelerated erosion.
c. Apply proper grazing management.
3. SILVICULTURAL PRACTICES
Silvicultural treatments are not reasonably applied on this site due to very poor site quality and severe limitations to to equipment and tree harvest.Other products
The pitch of singleleaf pinyon was used by Native Americans as an adhesive, caulking material, and a paint binder. It may also be used medicinally and chewed like gum. Pinyon seeds are a valuable food source for humans, and a valuable commercial crop. Common snowberry fruit fruits were eaten fresh and also dried for winter use by Native Americans. Common snowberry was also used on hair as soap, and the fruits and leaves mashed and applied to cuts or skin sores as a poultice and to soothe sore, runny eyes. Tea from the bark was used as a remedy for tuberculosis and sexually transmitted diseases. A brew made from the entire plant was used as a physic tonic. Arrowshafts and pipestems were made from the stems. Utah serviceberry fruits were used by Native Americans and early European explorers in North America for food and medicine. 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. Indian ricegrass was traditionally eaten by some Native Americans. The Paiutes used the seed as a reserve food source.
Other information
Utah serviceberry has been used to revegetate big game winter range and for surface stabilization. It grows slowly from seed and therefore transplanting may be more successful than seeding for revegetation projects.
Supporting information
Other references
Howell, J., 1940. Pinyon and juniper: a preliminary study of volume, growth, and yield. Regional Bulletin 71. Albuquerque, NM: USDA, SCS; 90p.
Jordan, M., 1974. An Inventory of Two Selected Woodland Sites in the Pine Nut Hills of Western Nevada. MS Thesis, UNReno.
USDA-NRCS. 1980. National Forestry Manual - Part 537. Washington, D.C.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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