USDA United States 

7- a Department 

of Agrrculture 

Forest Service 

A Management-Oriented 

Rocky Mountain 

Research Station 

Classification of PinyonGeneral Technical 

Report RMRS-GTR-12 

Juniper Woodlands of the 

June 1998 Great Basin 

Neil E. West 

Robin J. Tausch 

Paul T. Tueller 
The Authors 

Neil E. West is Professor, Department of Rangeland 

Resources, Utah State University, Logan, UT, where he 

has been located since 1964. He attended Oregon State 

University where he received a bachelor's degree in 

general science and a Ph.D, degree in plant ecology. He 

has served as a National Science Foundation postdoctoral 

fellow at the University of Georgia and visiting professor 

at Yale University, Adelaide University in Australia, and 

Hebrew University in Israel. 

Robin J. Tausch is Supervisory Range Scientist, Rocky 

Mountain Research Station, USDA Forest Service, Fieno, 

NV, where he has been located since 1989. He attended 

Humboldt State University, University of Nevada, Reno 

and Utah State University and holds a bachelor's degree 

in wildlife management, a masters degree in range 

management, and a Ph.D. degree in range ecology. He 

was a member of the faculty in the Department of 

Environmental and Resource Sciences, University of 

Nevada, Reno prior to joining the Forest Service. 

Paul T. Tueller is Professor of Range Ecology, Department of Environmental and Resource Sciences, University of Nevada, Reno. He holds a bachelor's degree from 

Idaho State University in wildlife conservation, an M.S. 

degree from the University of Nevada, Reno in range 

management, and a Ph.D. degree from Oregon State 

University in range ecology. During his 35 year career 

he has taught range and forest ecology and remote 

sensing and traveled extensively, lecturing on rangeland 

remote sensing. 

Research Summary 

Pinyon-juniper woodlands cover about 7.1 million ha 

(17.6 million acres), constituting about 18 percent of the 

land area of the Great Basin, yet no comprehensive 

ecological classification of them has been attempted 

before. To begin a classification, we sampled a random 

set of 66 of the approximately 110 mountain ranges 

within the Great Basin. Macroplots were systematically 

placed at 200 m elevation intervals up and down cardinal 

slopes. ~ata on tree age, vegetational cover, soils, and 

land form were collected from 1972 to 1975 within 463 

stands used to either develop or test the classification 

presented here. 

We used the already delineated National Hierarchical 

Frameworkof Ecological Units (ECOMAP 1993) down to 

the Section level to frame our classification to an intermediate coarseness. This subdivided the Great Basin into 

nine relatively environmentally homogenous Sections. 

Observable vegetational characteristics were used at 

lower layers because ECOMAP delineations are not yet 

available. Nine categories were recognized at the Series 

level based on variation in the relative cover contributions 

by the various junipers and pinyons. Subdividing the nine 

Sections by the nine possible Series gave 45 actual 

geographically distributed Series. The next lower level of 

the vegetation-based classification is the Association, 

identified by the dominant shrub species. Twenty-six 

species of dominant shrubs, combined with the Sections 

and Series, gave 183 Associations. The Sub-association 

level was based primarily on the 23 dominant native 

perennial grasses. When, rarely, a native, perennial 

grass was not present, the native perennial forb showing the greatest relative cover was used instead to 

name the Sub-association. This resulted in 326 Subassociations distributed over the entire Great Basin. The 

manager needs only be concerned with the subset that 

occurs in their Section of interest, however. 

With most Sub-associations found only once, our classification is only a beginning toward the desired end. It 

also reflects the complexity of the communities associated with Great Basin woodlands. Much more sampling 

redundancy will be required before we can begin to find 

out which Sub-associations are most common and how 

they relate to topographic and edaphic patterns. Our 

approach, however, provides a substantial beginning to 

a hierarchical classification of these woodlands and is 

easily modified and expanded. Using and building on our 

approach should allow the manager to better relate the 

results of previous as well as new studies and management experiences to each other. 

Acknowledgments 

We wish to thank Ken Rea, Roger Banner, and Dwight 

Beeson who were graduate research assistants and field 

crew leaders and their many undergraduate helpers too 

numerous to mention. Pat Johnson and Susan Durham 

provided valuable assistance in data coordination and 

analysis. Al Winward of the Forest Service's Intermountain Region is to be credited with keeping after us to 

finish this task. 

Rocky Mountain Research Station 

324 25th Street 

Ogden, UT 84401 
Contents 

Page 

Introduction ............................ .......................... 1 

How the Data Were Obtained ................................... 1 

Results of Previous Analyses of the Data .................. 5 

Previous Attempts at Woodland Classification ........... 8 

Our Approach ....................................... .................. .10 

Hierarchical Levels ........................... ................ 10 

The Classification ................................................. 10 

Using This Classification ...................................... .... 21 

Section 322A (Northern Mohave Desert) .............. 22 

Section 341 A (Bonneville Basin) .......................... 23 

Page 

Section 341 D (Mono-Walker-Owens Basins) ....... 26 

Section 341 E (Lahontan Basin) ............................ 27 

Section 341 F (Southeastern Great Basin) ............ 28 

Section 341 G (Humbolt Basin) .......................... 31 

Section 342B (Northern Great Basin) ................... 32 

Section M341 A (Central Great Basin) .................. 33 

Section M341 C (South Central Utah Highlands) .. 36 

Comparisons of Groupings Between Sections .. ....... 37 

Validation .............................................................. .38 

References .......................................................... ..... 40 

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Rocky Mountain Research Station Rocky Mountain Research Station 

324 25th Street 3825 E. Mulberry Street 

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A Mansgement-Oriented 

Classification of Pinyon-Juniper 

Woodlands of the Great Basin 

Neil E. West 

Robin J. Tausch 

Paul T. Tueller 

Introduction 

Pinyon-juniper woodlands occupy about 18 percent 

(7.1 million ha, 17.6 million acres) of the land area of 

the Great Basin (Tueller and others 1979). The associated tree species are found over a wide range of 

environmental conditions extending from communities representative of the upper fringes of the Mohave 

Desert to communities found at the lower fringes of 

highmountain forests. Over this spatial and elevational 

range, communities associated with pinyon-juniper 

woodlands are highly variable, with complex distribution and compositional patterns. This variability is 

due to climatic changes occurring over the last 10,000 

years and to variation in current environmental conditions (Nowak and others 1994a; Tausch and others 

1993). While juniper has been present somewhere in 

the area for over 30,000 years (Nowak and others 

1994a,b), pinyon is a relatively recent addition with 

a presence ranging from less than 2,000 to about 

8,000 years depending on location. Over the last century many changes have occurred in these woodlands 

and both the types and the pace of change could 

potentially increase into the future. 

In order to successfully inventory, plan, manage, and 

monitor complex wildlands like the pinyon-juniper 

woodlands, ecological classification is required. Ecological classifications result in several benefits. The 

resulting hierarchy of strata can provide guidelines 

for the collection and retrieval of both factual and 

interpretive information. Results and experiences from 

particular sites can be compared to other unstudied 

sites that are shown to be relatively similar by classification. This can increase the chances of the repetition of successful management actions and reduce the 

chances of failure. Research, particularly that research attempting to refine interpretations of factual 

data, can also be better focused if sites are related to an 

existing classification scheme. Creation of a hierarchy 

of ecological strata of increasing similarity enhances 

interpretation through both extrapolation and interpolation of survey data, researchresults, and management experiences. 

How the Data Were Obtained 

Despite their extensive area, the generally low levels of economic return from pinyon-juniper woodlands 

have resulted in relatively little scientific or management attention to them (Evans 1988). Previous inventory, monitoring, and research efforts have beenlargely 

limited to one or a few selected areas (St. Andre and 

others 1965). Some efforts have focused on the limited 

areas with potential for type conversion (Daniel and 

others 1966) while others collected data only on the 

trees (Smith and Schuler 1987). Resulting data are 

often summarized only by political subdivision, classes 

of tree density, or harvestable products (Born and 

others 1992; Van Hooser and Green 1983). Lack of 

regional and synthetic perspectives have limited our 

understanding of how the results of previous studies 

and management experiences relate to each other. 

A cooperative research program designed to provide 

a synecological stratification of the pinyon-juniper 

woodlands of the Great Basin was initiated in 1972. 

The institutions originally involved were the Department of Rangeland Resources at Utah State University; the Department of Environmental and Resource 

Sciences at the University of Nevada, Reno; and the 

USDA Forest Service Intermountain Research Station (now known as the Rocky Mountain Research 

Station, RMRS). Region 4 of the USDA Forest Service 

and RMRS have more recently encouraged reactivation of this effort. 

The study area (fig. I), mainly the Great Basin and 

margins of other physiographic provinces directly adjacent to the Great Basin, was gridded into 1 minute 

subdivisions for both longitude and latitude. A random list of map intersections was then made, and the 

first 66 of the approximately 110 mountain ranges 

(fig. 2) that contacted the listed intersections were 

chosenfor field study (Tueller and others 1979). These 

mountain ranges were then usually visited only once 

by one of several teams, and data on landforms, geology, soils, and vegetation gathered. A total of 463 

macroplots were examined over the summers of 1972 

through 1975, but only 426 were used to develop the 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12.1998 1 
classification presented here. The remainder were 

reserved for testing the validity of the results. 

Although some may be concerned about the age of 

the data used here, Austin (1987) and Yorks and 

others (1994) have shown that once trees dominate, 

very minor changes in understory vegetation take 

place over decades. Kent and Coker (1992) advise 

that minor variations in obtaining percentage cover 

do not greatly affect the results of subsequent community analysis because the several dominant species 

have substantial cover and the many associated species usually amount to minor cover either singly or 

collectively. 

Budgets were not sufficient to take a large, randomized sample within mountain ranges. Sampling 

designs appropriate for large areas inevitably involve 

trade-offs between representativeness, bias, and 

practicality (Austin 1991). Accordingly, our sampling 

was consciously directed toward capturing the main 

variety of site conditions present on the cardinal slope 

aspects. Intermediate aspects and elevations are 

largely intermediate in ecological characteristics. We 

systematically located plots on broad, even slopes 

facing one of the cardinal directions (north, south, 

east, west) at regular contour intervals up and down 

the slope from a baseline of 2,000 m (6,560 feet). This 

is an elevation common to the pinyon-juniper woodland belts around mountain ranges over most of the 

Great Basin (Tueller and others 1979). Overall, the 

percentage of the macroplots that were sampled at 

2,000 m was 37 percent, while 40 percent of them were 

above 2,000 m elevation and 23 percent were at elevations below 2,000 m. 

The criteria used to determine the lowest and uppermost plots on each mountain side were that a plot had 

to contain at least 25 pinyon andlor juniper trees per 

hectare (about 10 per acre). Of these, at least one tree 

had to be ofthe "mature" size-age-form class (Blackburn 

and Tueller 1970). These criteria kept the samples 

from extending into grasslands, shrub steppes, or 

brushlands that have been invaded by small trees 

over only the past few decades. Our sampling was 

thus restricted to sites where woodland was clearly 

established at the time of sampling. 

In order to reduce part of the variability due to 

secondary successional status, sampling was further 

Figure 1-A political map showing, with the 

dashed line, the outer perimeter of thestudy area. 

Figure 2-Map showing the major mountain ranges 

in the study area. The lower mountain boundaries 

are the same as those in Cronquist and others 

(1972). The 66 mountain ranges chosen for study 

are unshaded and numbered. See table 5 for the 

names of the studied mountain ranges associated 

with these numbers. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
restricted to those sites showing no evidence of recent 

stand-replacing fires, tree cutting, chaining, or cabling. Nevertheless, nearly one-half of the macroplots 

sampled had an overstory cover dominated by trees 

established after the beginning of European settlement (Tausch and others 1981). The period of greatest 

tree establishment was apparently 1870 to 1920 

(Tausch and others 1981). In the systematic sampling 

independently done by Born and others (1992), with a 

less restrictive definition of woodlands, about threequarters of their locations involved establishment of 

all trees in the most recent 130 years (D. Born, personal communication). 

Sampled northerly slopes were limited to the northern ends ofmountain ranges or hill systems; southerly 

exposures were limited to the southern ends of mountain ranges. Eastern and western exposures were 

sampled near the center of the generally north-south 

oriented mountainranges. The upper andlower boundaries of the pinyon-juniper woodland for the entire 

mountain slope were marked on topographic maps 

(of at least 1:25,000 scale) in order to check on the 

accuracy of the woodland distribution map made 

from LANDSAT-1 imagery over the entire study area 

(fig. 3). 

Two levels of sampling on the 66 randomly selected 

mountain ranges were employed: 'kapid" and "detailed." In the "rapid" approach, macroplots of approximately 20 by 50 m (66 by 165 feet) were paced off, 

with the long axes positioned perpendicularly to the 

slope contour. The macroplots were located at 200 m 

(660 ft) intervals up the broadest, most even slope 

available within 5 km (2 miles) of a road negotiable by 

4-wheel-drive truck. 

Physiographic features recorded at each macroplot 

location were: elevation, slope aspect, percent slope, 

length of slope, position on slope, landform, and macroand micro-relief. Landforms and percent slope were 

aggregated into the classes listed in table 1. The 

percentage of bare soil, surface stone, gravel and litter 

covering the soil surface were estimated for the entire 

macroplot. 

A soil profile in an interspace between trees was 

briefly examined with an auger. Features noted were 

depths to A, B, and C horizons, their color (both dry 

and wet), texture, structure, and boundary characteristics. The parent material or exposed rock was noted 

when possible. The objective was to classify these soils 

to at least Great Group (Soil Survey Staff 1994). 

Parent material was placed in a three-level hierarchical classification (table 2), where possible, after consulting the latest geologic maps of the area. 

Within each "rapid" plot, all plant species were listed 

in one of five growth forms: trees, shrubs, grasses and 

grass-likes, forbs, or microphytes (mosses, lichens). 

With grasses and forbs combined, the resulting four 

. - '.-5 -----. - - ---- --, 

Figure 3-Map of the pinyon-juniper woodlands of 

the Great Basin derived from LANDSAT-1 colorinfrared imagery and field checking (from Tueller 

and others 1979). 

Table 1-Landform and slope class categories used in this 

study. 

Name Definition 

Landform 

Foothill Lower hills around the base of a main 

mountain mass. 

Terrace Relatively level remnant surface bordered 

by a steep escarpment on one to three 

sides, composed of alluvium or solid rock. 

Bajada Compound alluvial fan that merges with a 

valley floor. 

Plateau Elevated fairly flat surface bordered on all 

sides by steep escarpments. 

Mountain Large, central, upper elevational areas of 

a mount range above 

the foothills and bajadas. 

Slope Class 

0 -5% 

5-15% 

15 -25% 

25 - 35% 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12.1998 
Table 2-Three-level hierarchical classification used to describe surficially exposed rock or parent 

material at each macroplot. 

Abbreviation used in 

Class Supergroup Clan tables 12 and 14-19 

A. Igneous 

1. intrusive 

2. extrusive 

3. unspecifiec 

B. Sedimentary 

1. terrestrial 

2. marine 

Limest./Dolo. 

a. granitoid 

b. granitic 

c. rhyolitid 

d. porphyritic 

a. basaltic 

b. andesitic/rhyolitic 

c. tuff-welded tuff 

a. alluvium 

b. conglomerate 

c. siltstone/sandstone 

d. siltstone/sandstone-alluvium 

b, limestone/dolomite-siltstone/sandstone 

c. shale 

d. quartzite 

e. quartzite-limestone/dolomite 

f. phyllite/quartzite 

3. unspecified 

Rh. 

Porph. 

AndesiticJRh. 

Tuff-Weld. 

Conglom. 

Silt./Sand. 

Qu. 

Qu./Lime. 

Phyllite/Qu. 

Sources: Hintze, L. F. 1963; Ross, C. P. and J. D. Forrester, 1947; Stewart, J. H, and J. E. Carlson, 1974; 

Stokes, W. L., 1963; and Strand, R. G., 1967. 

categories represented the four layers or synusia visible in the physiognomy of the stands of vegetation. 

A cover class rating was assigned to eachplant species 

in the macroplot (Daubenmire 1959). Each of the 

original five growth form categories was then considered separately and the relative cover of each species within each of the four vertical layers of the 

vegetation was assessed. A size-age-form "maturity" 

class rating (Blackburn and Tueller 1970) was assigned to each individual tree within the macroplot 

and densities of each tree species estimated. A total of 

257 plots on 48 mountain ranges were sampled at the 

"rapid" level. 

At the "detailed" level of sampling, the same macroplot size was used, but data were obtained from direct 

measurements, using an expansion and intensification of the methods described for the "rapid" 

approach. That is, the macroplot boundaries were 

measured and permanently marked by a red steel post 

at the lower center point on the 20 m line there (fig. 4). 

Temporary markers were placed at the corners of 

the macroplots and at the ends of the five 20 m lines 

perpendicularly bisecting the center line at randomly 

located meter marks on the center tape. 

All trees of each species were placed in appropriate 

size-age-form "maturity" classes (Blackburn and 

Tueller 1970). Four trees of each maturity class (if 

available), situated closest to two predetermined random points along the macroplot centerline, were measured for height and basal circumference. Crown spread 

of these trees in the widest and narrowest dimensions 

perpendicular to each other were also recorded. Tree 

cover for the plot was estimated by taking an average 

of tree crown dimensions, computing elliptical area on 

the measured trees, and multiplying by the number of 

trees of each size-age-form "maturity" class in the 

entire macroplot. Individuals of each "maturity" class 

category of each species nearest to the center line were 

cut down at about 10 cm above the ground and a crosssection of the stump taken for growth ring analysis in 

the laboratory. A total of 1,026 juniper (Juniperus) 

2nd 1,290 pine (Pinus) tree basal trunk cross-sections 

4 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
i Point 5 . - - - - . - , _ _ - _) - - - .I - - - . - - -, - - -, - -- - - -, - - - ,..I.. 

.I,.'...# 

.,..... I, 

i Point 4 ..--C---(---..--,-.-,---r---T--l---p--~-- 

##an..,,, ,<,.,<.., 

____-----_-------._,.---------------.- .,a..,*., I 

: point 3 I 

t 

Upslope 

1- 20 meters -----I /- - 2 meters --l 

MACROPLOT MICROPLOT 

Figure 4-Plot layout for detailed sampling of 

vegetation, surface cover, and fecal density. 

were sanded and their growth rings counted to estimate age. 

Tree seedling and animal fecal pellet group density 

data were taken from ten contiguous 2 by 2 m microplots located on each 20 m line parallel to the slope. 

Shrub crown cover was estimated to the nearest 

2 percent (Daubenmire 1959), in ten contiguous 1 by 

2 m microplots also on each transect line. Forb and 

grass basal cover were similarly estimated in two 30 

by 60 cm plots located within each 1 by 2 m microplot 

(fig. 4). 

Slope, exposure, geologic parent material, and topographic class at the "detailed" sites were determined 

using the "rapid" sampling method. At the "detailed" 

sites, however, a soil pedon was exposed with a spade 

to pan or bedrock in an opening between trees (at least 

1 m from any crown edges) near the center of each 

macroplot. A complete pedon description (Soil Survey 

Staff 1951, 1960) was written and half-liter samples 

of soil from each horizon and pieces of rock were 

usually collected for physical and chemical analyses in 

the laboratory necessary to describe the soil to at least 

the Sub-Group level (Soil Survey Staff 1975, 1994). 

The 18 mountain ranges sampled with the "detailed" methods were randomly selected from the set 

of 66 mountain ranges randomly chosen from the 110 

possibilities. A total of 207 stands were sampled in 

detail. However, only 169 were at even 200 m 

elevational increments and thus used for the classification developed here. Two mountain ranges 

(Needle in southwestern Utah, and Shoshone in west 

central Nevada) were sampled more intensively, at 

each 100 m contour interval, with additional procedures to be described later in other related publications. The samples at other than the 200 m intervals 

from these two mountain ranges were used to test the 

classification (see the "Validation" section). One mountain range (Mineral in southwestern Utah) was 

sampled by both "rapid" and "detailed" methods by 

two different teams to compare results. 

Results of Previous Analyses of the 

Data 

Previous analyses of some aspects of this data set 

(involving both "rapid" and "detailed" approaches) 

have already been published. For instance, Tueller 

and others (1979) using our fairly conservative definition ofwoodlands and appropriate LANDSAT-1 imagery, along with field checking of upper and lower 

boundaries of woodlands for about one-third of the 

mountain ranges, found that pinyon-juniper woodlands within our study area cover about 7.1 by lo6 ha 

(17.6 million acres), or about 18 percent of the land 

surface of the study area (fig. 3). They also noticed that 

this vegetation type typically forms broad elevational 

belts encircling mountains in middle latitudes, but 

diminishes to progressively narrower southerly and 

westerly predominance towards the northern latitudinal extremes, and to northerly and easterly exposures in the south. 

West and others (1978a) examined floristic patterns 

from the total data set involving 367 vascular plant 

species. The number of different vascular plant species in a macroplot was positively correlated with size 

and height of the mountain range on which it occurred, 

but negatively correlated with distance from adjacent 

mountains. The most outstanding features of the floristic patterns are: the relatively few species that were 

encountered over such a huge area, the lack of any 

vascular plant species restricted to pinyon-juniper 

woodlands (besides the trees and their parasites), and 

the lack of encounters with plant species on threatened, endangered, or sensitive lists. The latter is 

largely a consequence of avoiding concave topography 

and riparian areas, and not searching out unique 

kinds of parent material at appropriate times of the 

year so as to better record presence of ephemerals. 

Floristic richness within a macroplot declined markedly with successional status (Everett and Koniak 

1981; Tausch and others 1981). That is, as trees come 

to dominate, they outcompete herbaceous understory 

on a much stronger than 1:l basis (Tausch and West 

1995; West and others 1979). 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12.1998 5 
Floristic richness for the entire woodland belt of a 

given mountain range was greatest on the higher 

mountain ranges on the southern end of the Central 

Plateau in south central Nevada (West and others 

1978a). This is also where the elevational breadth of 

the woodland was greatest. This is the region where 

Great Basin and Mohave Desert floras merge and 

where the relative contribution of frontal storm systems moving inland from the Pacific and convectional 

storms associated with moist air from the Gulf of 

Mexico are most equivalent (Houghton 1979; Houghton 

and others 1975). 

Woodland belts are narrow or nonexistent on northern exposures in the northern Great Basin where 

thermal belts can be disrupted easily in the spring 

(West and others 1978a). The woodlandbelt frequently 

retreats to northern exposures in the southeastern 

Great Basin, but also reaches its lowest elevations 

there. Where water from mountains eventually drains 

into the Colorado River, belts of air consistently warmer 

than the valleys below do not persist in winter (Beatley 

1979180). East- and west-facing woodland belts at 

similar latitude are not always at the same elevation 

or of the same width due largely to how mountain 

mass, directional orientation, and elevation of valley 

bottoms alter climate (West and others 1978a). 

Total vascular plant cover in our samples varied 

from 9 to 80 percent, with an average of 35 percent. 

Greater average vascular plant cover is concentrated 

on the high plateau of central Nevada and the higher, 

larger mountain ranges elsewhere. Woodlands on 

mountain ranges with lower average elevation or 

lower latitudinal position, or both, have less average 

total vascular plant cover. The northernmost, largely 

juniper-dominated woodlands in southern Idaho, have 

greater average vascular plant cover than would be 

expected from the relatively low elevation of the 

woodlands there. In other words, latitude strongly 

compensates for elevation. Furthermore, because 

pinyon is largely absent in southern Idaho, it points 

to the strong possibility that pinyon is more competitive with understory than juniper. Total vascular 

plant cover generally increases with elevation in 

pinyon-juniper woodlands, correlating with increased 

precipitation as well as lower temperature, and thus 

greater effectiveness ofprecipitation (Houghton 1979). 

Understory cover and species richness is generally 

least in the middle elevational part of the belt (fig. 5), 

because tree cover most often dominates there (West 

and others 1978a). 

The structurally dominant trees differ over latitude, 

longitude, and elevation. Utah juniper (Juniperus 

osteosperma) usually occurs as a sole dominant along 

the northern boundary of the study area and in a few 

places in the Bonneville Basin of western Utah. Single 

aW AS 26- 

ME +N 

a 

50 1b0 1 8b $0 1 do 

26- 

CI 

E 24- 0 

0 

F 

- X 

5 22- 

'F 

P 

0 = 

20- 

18b 

Number of Species % of Total Cover % of Maximum 

represented by Trees Equitability 

Figure 5-Species density (floristic richness), relative percent of total cover contributed by trees, and 

percent of maximum equitability calculated by the Mclntosh (1967) index plotted by elevation and 

aspect, Needle Range, Beaver-Iron Cos., Utah (from West and others 1978a). 

6 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 

26- 

24- 

t 

i a::: j 22- 

/' 

i 

20- 

\ 

\ 

k ll 

1 1 8-, 110 20 
Elevation Classes (x 1 00m) 

Figure 6-Average relative cover (percent) of 

pinyon (convex-solid line) and juniper (concavedotted line) in relation to elevational interval. 

Vertical bars are equal to one standard error. Lack 

of bars indicates only one plot available (Tausch 

and others 1981). 

needle pinyon (Pinus monophylla) occurs alone only on 

a few mountain ranges along the California-Nevada 

border. Colorado pinyon (Pinus edulis) replaces single 

needle pinyon in central to southwestern Utah where 

summer precipitation exceeds about 10 cm (3 inches). 

Hybridization of the two pinyons is most notable in 

southwestern Utah (Lanner 1974; Tausch and West 

1987). The bulk of the sampled stands have various 

degrees of shared dominance by a pinyon and a 

juniper species. 

There is also strong sorting of the mix of juniper 

and pinyon by elevation, with juniper often the lone 

dominant at sites around 1,600 m or lower elevations. 

As elevation increases, the relative percent cover of 

pinyon typically increases while that of juniper declines. The convexity of the pinyon curve and concavity 

of the juniper curve with elevation (fig. 6) also imply 

that pinyon is competitively superior (Tausch and 

others 1981; Tausch and West 1995). 

Sorting the stands on the basis of slope exposure 

shows that on southerly and westerly exposures, the 

relative percent cover contributed by juniper is slightly 

higher than that on northerly and eastern exposures, 

particularly at higher elevations. This slight difference is probably due to relatively warmer temperatures and effectively drier soils on the southerly and 

westerly exposures receiving more solar radiation 

and thus heating of soil, air, and plants, than on 

northerly or easterly exposures (Tueller and others 

1979). 

We did not find strong latitudinal and longitudinal 

patterns in soil orders found under pinyon-juniper 

woodlands (West and others 197813). Most of the 

consistent patterns in distribution of soil orders are 

related to elevation (fig. 7). We must conclude that 

contemporary climate is much more dominant than 

soils or topography in delimiting the basinwide and 

elevational extent of these woodlands. Present vegetation has also had an apparently minor effect on 

the development of soils in these woodlands. However, had we also sampled soils directly under the 

trees, we could have noted how acidic tree litter could 

be affecting those sites where the carbonate accumulations during previous grassland or shrub steppe 

occupation still persisted. 

Vegetation of the Great Basin has been much 

more dynamic (Tausch and others 1993) than soil 

development. The current plant community is often 

not the one that was most important in the development of a given soil. This, along with more recent 

disturbance, secondary succession, and introduction 

of exotic species, makes use of soils in basin-wide 

synecological subdivision of limited value (Everett 

1985). However, we agree with Brackley (1987), 

Hironaka (1987), Leonard and others (1987), and 

Summerfield and others (1986) in reconsidering 

soils in determination of finer-grained classifications 

of land. 

I 1 

25 50 75 100 

Percentage of Total Number of Pedons 

at Each Elevation 

~i~ure7-percenta~e of the total number of pedons 

in each order at each elevational interval (West and 

others 1987b). 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12.1998 
Previous Attempts at Woodland 

Classification 

While the aforegoing is valuable in helping to understand basin-wide and some mountain range scale 

patterns, the manager's needs usually occur on a 

project, treatment, site, grazing allotment, pasture, or 

small watershed scale. The manager usually needs to 

know whether a planned management adjustment 

or unplanned alteration (for example, wildfire) is 

likely to lead to the expected changes or not. These 

interpretations involve either interpolation between 

or extrapolation of limited factual observations beyond the few other research or intensively managed 

and monitored sites. This begs the question of how 

similar or dissimilar is the new site to those where 

similar management has successfully or unsuccessfully taken place in the past? Managers are usually 

required to make these interpretations intuitively 

with limited reliance on factual information. Confidence in such decisionmaking comes from practice 

and long experience in a region. The newcomer is short 

on both. Might there be a way of making the process 

easier? We contend that a more formalized means of 

comparing appropriate factual similarities of sites 

would be a step in that direction. 

The usual approach by the Forest Service in the 

Intermountain West during the past several decades 

has been to develop a hierarchical classification of 

land based on potential vegetation (Ferguson and 

others 1989; Hill and others 1992; Johnston 1987; 

Kennedy 1983; Moir and Carleton 1987; Wellner 1989; 

West 1982). Several problems intervene in easily doing this for pinyon-juniper woodlands in the Great 

Basin (Cooper 1978; Everett 1985; Everett and Bruner 

1990; Hironaka 1987). 

First, the dominant species of all Great Basin vegetation have very wide distributions, implying broad 

ecological amplitudes and thus broad indicatorvalues. 

Pinyon and juniper trees range from the upper fringes 

of the Mohave Desert where they co-occur with joshua 

tree (Yucca brevifolia), cholla cactus (Opuntia sp.), 

and blackbrush (Coleogyne ramossima), to the lower 

fringes of high mountain forests in the Northern Great 

Basin where they co-occur with limber pine (Pinus 

flexilis), bristlecone pine (P. longaeva), and western 

juniper (Juniperus occidentalis ssp. australis). There 

is no easy source of unambiguous evidence of what 

environmental or biotic controls determine where one 

species enters and another drops out. Trees have 

become so dominant in recent decades that some have 

assumed that this has always been the case and, 

furthermore, that there is little ecological variation 

in the pinyon-juniper woodlands of the Great Basin. 

This is an illusion. 

If one will search a site well, one can usually find 

openings where lower staturedplants still exist. None, 

however, are species exclusively identified with treedominated situations as is more commonly the case 

for most forest types of more mesic environments. 

Instead, most of present understory remnants were 

part of the sagebrush steppe and sagebrush semidesert vegetation types that occupied these sites up 

until about a century ago. 

Unfortunately, these "understory" plants also have 

wide distributions and broad indicator values that 

can increase the difficulty of classification based on 

vegetation alone. Different combinations of controlling factors can, in different locations, result in the 

same apparent plant community type that may or 

may not respond similarly to management. Probably, 

only the most genetically variable species have survived the 20 or so glacial cooling and interglacial 

warming interludes in this region during the Pleistocene (Betancourt 1987; Brown 1995; Nowak and 

others 1994a,b; Tausch and others 1993). This genetic 

variation is, however, impossible to see with the 

naked eye, limiting the timely indicator value of particular species and species combinations in the field. 

An additional complication to classifying vegetation 

in the Great Basin is the long and complex history of 

human uses in the region during the Holocene. These 

impacts started at least 11,000 years ago when the 

first wave of hunters helped drive to extinction about 

32 genera of mammals (Grayson 1993; Owen-Smith 

1989; Stuart 1991). Many of these were very large 

browsers who regularly consumed conifer foliage. 

As these easy sources of human sustenance disappeared, the early peoples had to switch their diet to 

smaller animals and plants. Amerindians regularly 

used fire to manipulate the landscape to their benefit 

(Creque 1996). Seeds of perennial grasses were a 

mainstay of their diet. These grasses produced seed 

more abundantly and dependably with frequent intentional burning than with less frequent wildfires. 

Some annual and biennial forbs were even sown into 

the ash to provide foods and ceremonial needs (for 

example, tobaccos). Pinyon and juniper trees of all age 

classes remained on the steeper, rockier sites that 

wouldn't burn easily. The gentler slopes with deeper 

soils were actively managed by these aboriginal people 

to remain as a grassland mosaic with scattered trees. 

The region was thus far from an uninfluenced wilderness prior to Columbus (Denevan 1992). 

The first itinerant Europeans (explorers, missionaries, trappers) who visited the region, beginning in 

1776, remarked about the openness of the vegetation 

and abundance of fires (Gruel1 1985). However, aboriginal influence already may have been waning 

because European diseases had preceded the appearance of the explorers by a century or so and reduced 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Amerindian population densities to a small fraction of 

what they had been previously (Kay 1996). The cooler, 

wetter climate of the Little Ice Age may have also 

favored tree expansion from about 1400 to 1850 AD 

(Gottfried and others 1995). 

The most widespread influence associated with permanent European settlement, beginning in the midnineteenth century in this region, was from livestock. 

Unrestrained levels of use of the palatable herbaceous 

fraction of the vegetation by livestock led to reduction 

in fine, continuous fuels for surface fires. Since fences 

and buildings were also built of wood then, there was 

also conscious fire control. While there was intensive 

harvesting of trees for charcoal, mine timbers, railroad ties, and domestic fuels around mining districts 

(Lanner 1981; Young and Budy 1987) for a few decades 

before the turn of the twentieth century, new trees 

established abundantly from about 1870 to 1920 

(Tausch and others 1981). 

Cattle and horses were the first domestic species 

introduced on these rangelands. They focused on the 

grasses. This probably first led to an expansion of 

shrubs. Sheep grazing dominated in the first half of 

this century. Sheep utilized steeper, rockier areas and 

more browse species further from water than cattle 

and horses. Deer populations exploded in the 1940- 

607s, probably in response to reduced sheep populations and more abundant and taller shrubs (Peek and 

Krausman 1996; Workman and Low 1976). Tree expansion became most noticeable in the 1950's and 60's. 

Grazing by feral horses, rabbits, and elk in recent 

decades may be focusing on the modicum of perennial 

herbsremaining(Y0rks and others 1994). Even though 

livestock and deer grazing has generally been reduced 

on these mostly public lands in recent decades, the 

trees continue to grow and outcompete the understory 

over their very long lives (pinyons live for 500 to 800 

years, junipers up to 2,000 years). Analysis of pollen 

deposited in sediments at selected sites in the northwestern Great Basin shows a greater abundance of 

juniper pollen during the Twentieth Century than at 

any other time in the past 5,000 years (Mehringer and 

Wigand 1990; Miller and Wigand 1994). When the 

paleo-information is combined with modern studies 

indicating major expansion in woodland extent and 

density, the implication is that we are currently 

dealing with a vastly greater amount of juniper and 

pinyon-dominated lands than any humans have encountered over the last 5,000 years. 

The competitive powers of the herbaceous plants 

were and continue to be reduced by grazing, but more 

importantly, the fire return intervals have been 

greatly lengthened because of reduced fine, continuous fuelnear the soil surface (Wright and others 1979). 

Climatic warming, the fertilizing effect of increasing 

atmospheric COz, increases in some bird, rodent, 

lagomorph, and wild ungulate (for example, elk) 

species, along with conscious fire control, led to an 

increase of both individual tree growth and stand 

densities (West 1984, 1988). Nevertheless, the relatively small differences in detectable growth rate of 

trees between sites has largely prevented the usual 

height-over-age approach to site classification from 

succeeding (Chojnacky 1987; Daniel and others 1966; 

Meeuwig and Cooper 1981; Smith and Schuler 1987, 

1988), although one application has been useful 

(Tausch and Tueller 1990). 

The tree-dominated woodlands of the present time 

with sparse understory are both structurally and 

functionally dissimilar to what probably prevailed 

before European occupation. Tree canopy dominance 

and a root system that extends three to five times 

beyond the crown diameter (Everett and Bruner 1990) 

has frequently led to mounds under the protection of 

trees and lower topography in the uncovered 

interspaces (Price 1993). Exposure of datable roots at 

many sites indicates accelerated soil erosion over 

about the past 120 years (Carrara and Carroll 1979). 

Soil degradation at many sites may have proceeded to 

the point where only partial recovery of site potential 

is now possible (Baxter 1977; McDaniel and Graham 

1992). 

With expected significant future changes from climate warming (Gates 1993; Kerr 1995) and increases 

in pollutants, including the fertilization effect of increased C02 (Graham and others 1990; Tinus 1995), it 

seems that these woodlands will continue to develop 

larger, more continuous tree canopies that facilitate 

summer firestorms. Indeed, such firestorms are becoming an increasingly common event. These hot fires 

result in loss of nearly all biotic reserves and in the 

invasion of vagile introduced species such as cheatgrass (Bromus tectorum L.) and red brome (Bromus 

rubens L.). Sites dominated by these winter annual 

grasses then re-burn about every 3 to 5 years. The 

result is a rapid, downward spiral of site degradation 

that only restabilizes when rock or other resistant soil 

layers dominate the surface. The total area affected by 

these summer crown fires is steadily increasing, particularly on the gentler topography that has easy 

access to livestock and vehicles. Few recognizable 

"climax" stands are left (West 1991). 

Without reliable reference areas, reconstructing 

successional pathways through chronosequences 

(space-for-time substitutions) is highly speculative 

(Everett and Bruner 1990; Hironaka 1987; West and 

Van Pelt 1987). Remnant plants, soil seed reserves, 

seed rain, stage of succession, kind and timing of 

disturbance, subsequent climate and management, as 

well as landscape position and physical site variables, 

all determine trajectories of vegetation recovery. 

Thus, Everett (1985) suggests that the most probable 

plant community types at maximum understory expression be focused on in any classification effort. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Our Approach 

The above problems have forced us to focus our 

classification on how we find pinyon-juniper woodlands now, rather than what they may have been or 

could be. Scientists and land managers in California 

have faced similar problems and yet developed a 

hierarchical approach (Paysen and others 1982). 

Everett and Bruner (1990) made a beginning toward 

adopting this approach, using data gathered from 

350 stands in the extreme western Great Basin. We 

have modeled our approach on theirs, and on the 

example for California's hardwood rangelands (Allen 

and others 1991), but modified it to fit within the 

National Hierarchical Framework of Ecological Units 

(ECOMAP 1993). 

The basic reason for adopting a hierarchical approach is that land managers can choose whatever 

level is appropriate for their particular focus. The 

higher-level, broader units are used when greater 

generality is needed. This classification also divides 

geographic subdivisions of the Great Basin into more 

localized areas that can be successfully used for management and research purposes. However, potentials 

for and responses to specific management alternatives differ greatly between project locales. Therefore, 

finer-grained levels will be needed when more detail 

and specificity are desired. Completion of the finer 

levels of classification are not possible with the data 

set used here because of the extensive nature of our 

sampling of woodlands and location-to-location variability. Much more redundancy of sampling of the 

stands representing Associations and Sub-associations 

will be needed in each local area to more firmly 

establish their identity, area occupied by those entities, their successional variation, and their relationships to the environment and to each other. 

The first thing we did before we started the present 

synthesis was to truncate the data sets from the most 

intensively studied Shoshone and Needle Ranges such 

that the density of data was the same as for the other 

mountain ranges. Thus, only woodland stands at contours spaced at 200 m intervals from the 2,000 m 

elevation baseline were included in the construction 

of classified entities used here. The stands at 1,900, 

2,100, 2,300, and 2,500 m on the Shoshone and 

Needle Ranges were reserved to test the extrapolatability and interpolatability ofthe classification scheme. 

In a few macroplots, no understory whatsoever was 

encountered. This complicates the classification approach used here. In retrospect, we should have 

sampled beyond the 20 by 50 m macroplot boundaries 

when no understory was recorded within our plots. 

The actual boundaries of the represented stand irregularly extend beyond what occurs within the 

macroplot. If a larger area on the same ecological site 

is searched until less dense canopy is located, some 

understory will be encountered to make the following 

approach possible in nearly all instances. 

Hierarchical Levels 

The hierarchical levels proposed for this classification, the criteria used, their relationship to the size of 

polygons created, and the Ecoregion Classification of 

the United States (Bailey and others 1994; McNab and 

Avers 1994) are outlined in table 3. The Ecoregion 

approach is geographically explicit, whereas the vegetation units are abstract. The user should understand that only part of the information needed to 

construct the land classification hierarchy recommended by Bailey and others (1994) currently exists. 

Vegetation classifications need not require geographic information to make them work. It is, however, easier to use a classification with at least some 

geographic delineations. Accordingly, we merged the 

two systems. We chose the particular vegetation-based 

hierarchical levels and variables that were already 

within the Ecoregion Classification so that land managers would, with the aid of this report, be able to see 

differences in the field, and move forward in applying 

the classification on the ground. 

We agree with Hironaka (1987) that a usable cIassification must employ readily observable variables, be 

consistent, and be simple to work through. There are 

so many potential land type associations and land 

types, that only a few examples ofvegetational proxies 

for these can possibly be covered here. Instead, we 

establish an open-ended system that can be expanded 

as needed. 

We readily admit that the classification scheme that 

follows is more arbitrary and subjective than "natural." A completely "natural" approach is impossible 

(Kent and Coker 1992) and inadequate anyway 

(Nolet and others 1995). Our approach has value only 

if it simplifies and enhances human understanding by 

identifying factual information that can be effectively 

applied in interpretations by land managers. 

The Classification 

The hierarchical approaches suggested by Hunter 

and Paysen (1986) were merged with the National 

Hierarchical Framework of Ecological Units (ECOMAP 

1993). Bailey and others (1994) have already defined 

the higher levels of this geographic subdivising. 

For this classification, pinyon and juniper woodlands are placed in the Dry Domain of the Ecoregion 

Hierarchy (Bailey and others 1994). The Woodland 

Formation is added between the Dry Domain and the 

Desert Division (table 3). Following the Desert Division from Bailey and others (1994), we have inserted 

10 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Table3-Hierarchical levels of classifrcation usedforpinyon-juniperwoodlands of the Great Basin. ECOMAP (1 993) ecological units are capital~zed. 

Vegetational units are in lower case. Numbers used are from Bailey and others (1994). 

Criteria 

Map number in 

Great 

Mohave Basin Mountains 

Polvaon size Name of unit -------- Lowlands---- ---- 

DOMAIN Broad climatic zones millions of nai2 Dry Domain 

Formation Structurally dominant Woodland 

plant life forms 

DIVISION Koppen-Trewartha hundreds of Desert 

regional climatic types thousands of mi2 

Broad vegetational affinities 

Dominant soil order 

Subformation Further division of Conifer 

dominant lifeforms Woodland 

PROVINCE Dominant potential tens of thdusands mi2 American Desert 

natural vegetation and Semi-Desert 

(Kuchler 1970) Intermountain Desert 

and Semi-Desert 

Nevada-Utah Mountains 

Semi-Desert-Coniferous 

Forest-Alpine Meadow 

Subtropical - - -Temperate - - - 320 340 M340 

SECTION Geologic age, stratigraphy, thousands of mi2 Northern Mohave Desert 322A 

lithology, morphology Bonneville Basin 341 A 

Regional climate Mono-Walker-Owens Basins 341 D 

Soil sub-orders and great groups Lahontan Basin 341 E 

Potential natural communities Southeastern Great Basin 341 F 

Mumboldt Basin 341 G 

Northern Great Basin 342 B 

Central Great Basin 

South Central Utah Highlands 

SUBSECTION Geomorphic process, 

surficial geology 

Soil sub-orders and great groups 

Sub-regional climate 

Vegetational series 

Series Relative dominance 

of largest species 

LANDTYPE geomorphic process and 

ASSOCl ATlON surficial geology 

Elevation 

Soil sub-groups, 

families or series 

Potential natural communities 

LANDTYPE 

tens to low Only mountainous 

thousands of mi2 Forest Service areas 

yet covered 

(see Nelson 1994) 

Pinus monophylla 

P, edub 

Juniperus osteosperma 

highhundreds to 

about 1,000 acres 

Elevation, aspect, slope tens to hundreds 

gradtent and position of acres 

Soil familles and series 

Rock type 

Plant associations 

Association Dominant shrub 

(see table 6) 

(see table 10) 

LANDTYPE PHASE Land form and slope position less than 100 acres 

So11 families and series 

(see table 10) 

Phase of plant association 

Subassociation Dominant native perennial 

grasslforbs 

Stand Uniform vegetation due to 

uniform environment and 

drsturbance history 

Macroplot Area of stand sampled 0.1 ha 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
the Conifer Woodland Subformation. At these levels 

and above, the highest proportion of the land area 

considered (fig. 1) is desert. The mountain masses, 

around which most of the Great Basin's pinyon-juniper woodlands are centered (fig. 2), are like islands in 

a "sea" of desert. 

Great Basin vegetation is characterized by very low 

floristic species richness considering the huge area 

involved. Many of the plant species we encountered, 

particularly the cover dominants, have such wide 

ecological tolerances that they have only coarse indicator value. That is, the same species mean different 

things in different places. We suspect that the rapidly 

changing environments of the past fostered much 

natural selection, but at the intraspecific rather than 

specific level (Tausch and others 1993). Except for 

sagebrush sub-species (West and others 1978c), intraspecific difference~ are difficult to discern in the 

field. Thus, we found it useful to employ "Sections" 

from Bailey and others (1994) (table 4). Only coarsetextured maps designating locations to the Section 

level of ECOMAP (McNab and Bailey 1994) are currently available for the entire study area. Accordingly, 

decisions about what Section a given borderline mountain range should be placed in was difficult in some 

cases. Thus, when ECOMAP is done for finer-textured 

levels in the Great Basin, the boundaries of higher 

levels will change as well. 

Because these Sections constitute nine coarsely 

different kinds of effective environments across the 

Great Basin (fig. 8), the populations of plant species 

and sub-species of sagebrush within Sections should 

have relatively homogeneous responses compared to 

everywhere else they occur. We have used the recommendations of Kartesz (1994) for Latin names of 

plants. We have used the recommendations of 

Anonymous (1988) for common names, linking the two 

names through the synonymy given in Kartesz (1994). 

Sub-sections have not yet been formalized, except in 

California (Goudey and Smith 1994), and only tentatively for the National Forest lands of the Intermountain Region (Nelson 1994). The Interior Columbia 

River Basin Ecosystem Management group has taken 

watershed boundaries as the basis of Sub-sections of 

the Pacific Northwest (Anonymous 1996). Hydrological boundaries do not appear in the criteria ofECOMAP 

(1993). Thus, there are some issues to be sorted out at 

this level. 

Series are based on the relative cover contributions 

by the various tree species to total tree cover. Use of 

relative cover allows us to compare stands regardless 

of year of data collection, successional status, or site 

potential. Furthermore, the differences in the methods used to assess cover by the different teams using 

the "rapid" and "detailed" methods should be minimized because we are concerned at this level with 

dominance ranking rather than absolute amounts of 

tree cover. This ranking is also easy to do in the field 

by laying out a tape and adding up canopy intercepts. 

The arbitrarily determined Series (table 5) were 

pure stands of Pinus monophylla (designated by the 

acronym, PIMO), strongly (80 to 99 percent relative 

cover) dominated by P. monophylla (designated by the 

acronym, PiMo), weakly (50 to 79 percent) dominated 

by P. monophylla (designated by the acronym, Pimo); 

pure stands of Juniperus osteosperma (100 percent 

relative tree cover, designated by the acronym, JUOS), 

strongly (80 to 99 percent relative cover) dominated by 

J, osteosperma (designated by the acronym, JuOs), 

and weakly (50 to 79 percent relative tree cover) 

dominated by J. osteosperma (designated by the acronym, Juos); and stands strongly (80 to 99 percent) 

dominated by Pinus edulis (designated by the acronym, PiEd), or weakly (50 to 79 percent relative cover) 

dominated by P. edulis (designated by the acronym, 

Pied). Pure stands ofP. edulis were not encounteredin 

this study, apparently because we did not sample 

into eastern Utah where this species is common and 

P. monophylla is not found. Only two stands in which 

Rocky Mountain Juniper (Juniperus scopulorum) dominates were encountered in south central Utah. 

PIMO, PiMo, and Pimo Series (about 55 percent of 

the stands sampled) were primarily found in central 

and western Nevada. PiEd and Pied Series (about 

2 percent of the stands) were found only in southwestern Utah. JUOS, JuOs, and Juos series (about 44 

percent of the stands) dominate geographically in 

western Utah and central and eastern Nevada, but 

also occur locally in western Nevada, and extend to 

lower elevations at the northern and other margins of 

the Great Basin. 

Landtype Associations (LTAs), according to 

ECOMAP (1993), are to be based on geomorphic process and surficial geology, elevation, soil sub-groups, 

families or series, local climate, and potential natural 

communities. No one, to our knowledge, has yet determined how to consistently apply combinations of these 

disparate pieces of factual information and make rules 

for identifying boundaries between LTAs. We await 

examples, particularly for this region. 

The same concern exists for Landtypes and Landtype 

Phases. Until these matters are resolved in a consensual way between the land management, advisory, 

and scientific institutions, we suggest that our simpler, vegetation-based land classification be used. 

The next level ofthe vegetation-based classificational 

hierarchy, the Associations, are designated by the 

dominant shrub present. An alphabetical listing of the 

acronym for each of the 26 shrub taxa used to designate Associations, along with its corresponding Latin 

and common name is found in table 6. 

In order to further differentiate various kinds of 

pinyon-juniper woodlands, we designated Subassociations, based primarily on the dominant native 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Table 4-Relationships between ECOMAP sections and mountain 

ranges. 

Section Mountain Map Code 

Number Name ranges (States) in fig. 2 

322A Northern Mohave Beaver Dam (UT) 46 

Desert McCullough (NV) 2 1 

Panamint (CA) 1 

Sheep (NV) 29 

Spring (NV) 33 

341A Bonneville Basin Burbank Hills (UT) 47 

Canvon (UT) 48 

coniusion (UT) 49 

Cricket (UT) 50 

Mono-WalkerOwens Basins 

Lahontan Basin 

Southeastern 

Great Basin 

Humboldt Basin 

Northern Great 

Basin 

Central Great 

Basin 

Central Great 

Basin 

South-Central 

Utah Highlands 

East Tintic (UT) 52 

House (UT) 54 

Mineral (UT) 55 

Oquirrh (UT) 57 

Pavant (UT) 58 

Pilot (UT-NV) 59 

San Francisco (UT) 6 1 

Sheeprock (UT) 62 

Stansbury (UT) 63 

Wah Wah (UT) 65 

West Tintic (UT) 66 

Excelsior (NV) 12 

P~ne Nut (NV) 24 

Virginia (NV) 41 

Wassuk (NV) 42 

White (CA-NV) 2 

Silver Peak (NV) 3 1 

West Humboldt (NV) 43 

Beryl-Enterprise Hills (UT) 53 

Fortification (NV) 14 

Grant (NV) 16 

Highland (NV) 17 

Kawich (NV) 18 

Needle (UT) 56 

Pine Valley (UT) 60 

Quinn Canyon (NV) 25 

South Egan (NV) 19 

W~lson Creek (NV) 45 

Cherry Creek (NV) 7 

East Humboldt (NV) 11 

Pequop (NV) 23 

Spruce (NV) 34 

Toana (NV) 36 

Albion (ID) 3 

Black Pine (ID) 4 

Goose Creeks (NV-UT) 15 

Sublette (ID) 5 

Bald (NV) 6 

Clan Alpine (NV) 8 

Deep Creek (NV-UT) 5 1 

Desayota (NV) 9 

Diamond (NV) 10 

Fish Creek (NV) 13 

Southern Snake (NV) 20 

Monitor (NV) 22 

North Egan (NV) 39 

Northern Snake (NV) 40 

Roberts Creek (NV) 26 

Ruby (NV) 27 

Schell Creek (NV) 28 

Shoshone (NV) 30 

Simpson Park (NV) 32 

Sulphur Springs (NV) 35 

Toiyabe (NV) 37 

Toquima (NV) 38 

White Pine (NV) 44 

Tushar (UT) 64 

Figure 8-Map of Sections used in this study from 

Bailey and others (1 994). 

perennial grasses, and secondarily, when a native 

perennial grass was not present, on the most abundant native perennial forb. Most of the introduced 

species are annuals. Annuals were ignored because 

their abundance fluctuates greatly from year to year 

(Treshow and Allen 1979) and we sampled over several years (1972 throughl975) with drastically varying weather. Annuals are also usually increased by 

disturbance. We tried to avoid sampling areas of 

recent disturbance. 

An alphabetical listing of the acronyms for each 

species of native perennial grass used to primarily 

designate Sub-associations, alongwithits corresponding Latin and common name is found in table 7. An 

alphabetical listing of the acronyms for each species of 

perennial forbs that were secondarily used to help 

designate Sub-associations appears in table 8. When 

native perennial forbs are used in the absence of a 

native perennial grass to designate a Sub-association, 

the four letter code is surrounded by parentheses to 

alert the user that this has been done. 

Table 9 outlines the hierarchical structure we ended 

up using in the classification presented here. The 

number of units found at each level across the entire 

Great Basin and an example of a named unit are also 

given there. 

Combining the nine Sections with the nine possible 

levels of tree dominance (table 5) creates 81 possible 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 13 
Table 5-Categorization of stands sampled into Series, based on relative cover dominance by tree species. 

Acronym Latin name 

PlMO 

PiMo 

Pimo 

JUOS 

JuOs 

Juos 

PiEd 

Pied 

JUSC 

Pinus monophylla 

Pinus monophylla 

Pinus monophylla 

Juniperus osteosperma 

Juniperus osteosperma 

Juniperus osteosperma 

Pinus edulis 

Pinus edulis 

Juniperus scopulorum 

Common name Relative cover Number of stands 

Singleleaf pinyon 

Singleleaf pinyon 

Singleleaf pinyon 

Utah juniper 

Utah juniper 

Utah juniper 

Colorado pinyon 

Colorado pinyon 

Rocky Mountain juniper 

Percent 

100 

80-99 

50-79 

100 

80-99 

50-79 

80-99 

50-79 

50-79 

Total 426 

Table 6-Shrubs used to designate Associations. The order is alphabetical by acronyms (flrst two letters of genus and first two 

letters of the species names, except for sagebrushes). Corresponding Latin names are those recommended by Kartesz 

(1994), and common names are those recommended by 

Anonymous (1988). 

Code Latin name Common name 

Arnal 

A A 

AN 

Atca 

AT 

AV 

AW 

Cele 

Cemo 

Chna 

Chvi 

Chpa 

Cora 

Epne 

Epvl 

Ermi 

Gusa 

Mare 

Pera 

Pugl 

Pume 

Putr 

Quga 

Rive 

Syal 

Sylo 

Amelanchier alnifolia 

Artemisia arbuscula 

Artemisia nova 

Atriplex canescens 

Arfemisia tridentata ssp. 

tridentata 

Artemisia tridentata ssp. 

vaseyana 

Artemisia tridentata ssp. 

wyomigensis 

Cercocarpus ledifolius 

Cercocarpus montanus 

Chrysothamnus nauseousus 

Chrysothamnus viscidiflorus 

Chrysothamnus paniculatus 

Coleogyne ramosissima 

Ephedra nevadensis 

Ephedra viridis 

Eriogonum microthecum 

Gutierrezia sarothrae 

Mahonia repens 

Peraphyllum ramosissimum 

Purshia glandulosa 

Purshia mexicana 

Purshia tridentata 

Quercus gambelii 

Ribes velutinum 

Symphoricarpos albus 

Symphoricarpos longiflorus 

Saskatoon serviceberry 

Gray low sagebrush 

Black low sagebrush 

Fourwing saltbush 

Basin big sagebrush 

Mountain big sagebrush 

Wyoming b~g sagebrush 

Curlleaf mountaln mahogany 

True mountain mahogany 

Rubber rabbitbrush 

Stickyleaf low rabb~tbrush 

Desert rabbitbrush 

Blackbrush 

Nevada Mormon-tea 

Green Mormon-tea 

Slender buckwheat 

Broom snakeweed 

Oregon-grape 

Squaw-apple 

Desert bitterbrush 

Mexican cliffrose 

Antelope bltterbrush 

Gambel oak 

Desert currant 

Common snowberry 

Longflower snowberry 

Table 7-Native, perennial grasses used to designate Sub-associations. The order isalphabetical by acronyms (first two letters 

of the genus and first two letters of the species names). Latin 

names are those recommended by Kartesz (1994), and 

common names are those recommended by Anonymous 

(1 988). 

Code Latin name Common name 

Arpu Aristida purpurea Purple threeawn 

Bogr Bouteloua gracilis Blue grama 

Brca Bromus carinatus Mountain brome 

Elel Elymus elymoides Bottlebrush squirreltail 

Ella Elymus lanceolatus Thick spike wheatgrass 

Eltr Elymus trachycaulus Slender wheatgrass 

Feid Festuca idahoensis Idaho fescue 

Hija Hilaria jamesii Galleta 

Leci Leymus cinereus Basin wildrye 

Lesa Leymus salinus Salina wlldrye 

Lesi Leymus simplex Bullgrass 

Mumo Muhlenbergia montana Mountain rnuhly 

Orhy Oryzopsis hymenoides lndlan ricegrass 

Pasm Pascopyrum smithii Western wheatgrass 

Pofe Poa fendleriana Muttongrass 

Pose Poasecunda Sandberg's bluegrass 

PsXsa Pseudoelymus X saxicola Foxtail wheatgrass 

Pssp Pseudoroegner~a spicata Bluebunch wheatgrass 

Star Stipa arida Mormon needlegrass 

Stco St~pa comata Needle and thread 

Stoc St~pa occidentalis Western needlegrass 

Stsp St~pa speciosa Desert needlegrass 

Sith Stipa thurber~ana Thurber needlegrass 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Table 8-Native perennial forbs used to designate Sub-associations 

when native perennial grasses were lacking. The order is 

alphabetical by acronyms (first two letters of the genus and 

first two letters of the species names). Latin namesare those 

recommended by Kartesz (1 994), and common names according to Anonymous (1988). 

Code Latin name Common name 

Basa 

Cach 

Cacr 

Canu 

Crfl 

Erov 

Erum 

Luse 

Pede 

Pepa 

Phdi 

Stco 

Balsamorhiza saggitata 

Castelleja chromosa 

Caulanthus crassicaulis 

Calochorthus nuttallii 

Cryptantha flavoculata 

Eriogonum ovalifolium 

Eriogonum umbellatum 

Lupinus sericeus 

Penstemon deustus 

Penstemon pachyphyllus 

Phlox diffusa 

Strepthanthus cordatus 

Arrowleaf balsamroot 

Desert Indian paintbrush 

Thickstem wild cabbage 

Sego lily 

Roughseed cryptantha 

Cushion eriogonum 

Sulphur eriogonum 

Silky lupine 

Scobland penstemon 

Thickleaf penstemon 

Diffuse phlox 

Heartshape twist flower 

Series. However, some Series were not found in some 

Sections yielding 45 actual Series. Twenty-six species 

of dominant shrubs were identified (table 6) that when 

combined with the Sections and Series resulted in 183 

Associations. The addition of the 23 dominant grass 

species (not including "no grass") (table 7) resulted in 

a total of 326 Sub-associations. This level of variation 

within such an extensive sample illustrates the large 

variation in the understory communities associated 

with these woodlands over the Great Basin. 

While the level of complexity may superficially seem 

to be more than any manager can consider, please 

keep in mind that at the maximum level of detail 

presented here, the user needs to already know or be 

able to key out only 4 trees, 26 shrubs, and 23 species 

of perennial grasses to use this first level of classification anywhere in the Great Basin. Someone working 

Table 9-Outline of the hierarchical classification used for Great Basin 

pinyon-juniper woodlands. Gradual indenting of each level 

signifies progressively iower entities in the hierarchy. 

Level Number of units Example 

Formation 1 Woodland 

Subformation 1 Conifer Woodland 

Sections 9 Bonneville Basin 

Series 45 PlMO in Section Ill 

Associations 183 PIMOIArno 

Subassociations 326 PIMO/Arno/Elel 

Stands 426 

Macroplots 426 

out of a particular District Office of the USDI Bureau 

of Land Management (BLM) or a Ranger District of 

the USDAForest Service will only need to know or find 

out the identity of less than about half of this list of 

common species. 

A summary of all the Series, Associations, and Subassociations discovered from field sampling so far 

(table 10) indicates how many stands of each Series, 

Association, and Sub-association were sampled in 

each Section. 

While it would be desirable to further subdivide 

pinyon-juniper woodlands beyond Sub-associations 

and relate these lower units to elevation, slope, exposure, topography, soils, ecological site, and so forth, 

this study is not based on a sample that is adequate 

for this level of site specific detail. Thus, indicative, 

not definitive, correlates are listed (when available) 

(tables 11 through 19) as part of the discussion of the 

individual Sections that follow. This information is to 

be regarded as only a starting point for managers and 

scientists to build their own ecological site and stand 

classifications in a local area. 

A stand occupies an area of sufficient homogeneity 

with regard to soils, topography, microclimate, and 

past disturbance history so as to have resulted in 

uniform enough vegetation to be treated as a single 

unit. Although each macroplot used here was sampled 

within a single stand, the spatial extent of those 

stands was not mapped. 

Our data do not make it possible to identify where 

on the landscape finer-textured vegetational classification entities will reliably occur. We also do not 

identify all the environmental factors correlating on a 

landscape basis. Across a region, differing combinations of environmental characteristics can be important in explaining vegetational behavior. The data 

used here also are not close to representing all the 

possible Associations and Sub-associations probably 

present, nor does it adequately portray their relative 

abundances and areal extent. Many of the rarer combinations are probably missing altogether. 

The classification presented here also does not 

necessarily represent an ecological hierarchy. A 

collection of stands now aggregated into particular 

Associations and Sub-associations could represent different degrees of successional status or disturbance 

over several ecological sites. The same classification 

could also represent different community types and 

different responses to management in different Sections. For example, moderately disturbed sites that 

were not detected as such might thus be sampled. 

They could then be initially classified in the same 

Association, but through successional time, may change 

as to both the Association and Sub-association in 

which they would be classified. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12.1998 
Table 10-Summary of occurrences of Series, Associations, and Sub-associations by geographic unit. Numbers indicate stands 

of pinyon-juniper woodland sampled within each category. Sub-associations in parentheses indicate that native 

perennial forbs are used in the absence of a natibe perennial grass. 

PlMO 

1 Seriesa ~ssoc.~ Sub-as so^.^ 

PiMo 

Sections 

322A 1 341A 1 341 D 1 341 E 1 341 F 1 341G / 342B 1 M341A I M341C /~otal 

Amal 

Cele 

Chvi 

Epvi 

Putr 

Rive 

A A 

Feid 

Orhy 

Pssp 

Pose 

Bogr 

Elel 

Feid 

Leci 

Orhy 

Pose 

Pssp 

Stco 

Stoc 

Elel 

Hija 

Orhy 

Pose 

Stoc 

Brca 

Pssp 

Elel 

Orhy 

Pofe 

Pose 

Stoc 

Elel 

Pose 

Pose 

Orhy 

Stth 

Pose 

Elel 

Feid 

Bogr 1 

Elel 

N.G.IN.F.~ 

Orhy 

Pofe 1 

Pose 

Stco 

Stoc 

Hija 

Orhy 

(Pep@ 

Pose 

Stco 

Elel 

Feid 

Leci 

(Luse) 

Orhy 

Pofe 1 

Pose 

(con.) 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Table 10 (Con.) 

PiMo 

Pimo 

Seriesa AOOOC.~ Sub-~OSOC.'. 

Pssp 

Stoc 

Elel 

Hija 

Pose 

Stoc 

Pose 

Pssp 

Elel 

Pofe 

Pose 

Pssp 

Pssp 

Elel 

Elel 

Elel 

Pofe 

Pose 

Brca 

Elel 

Feid 

Pose 

Orhy 

Arpu 

Bogr 

Elel 

Hija 

Orhy 

(Pep4 

Pof e 

Pose 

Pssp 

Stoc 

Elel 

Leci 

Orhy 

Pasm 

Pofe 

Pose 

Stco 

(Stco) 

(CrfI) 

Elel 

(Erum) 

Oihy 

(Pede) 

Pofe 

Pose 

Pssp 

Stoc 

Bogr 

Elel 

(Erum) 

Hija 

Orhy 

Sections 

322A / 341A 1 341 D I 341 E / 341 F 1 341 G 1 3428 1 M341A I M341 C l~otal 

Amal 

Cele 

Gusa 

Mare 

Pugl 

Putr 

Sylo 

(con.) 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Table 10 (Con.) 

I Sections I 

Pimo AW ,I 

Pose 

Star 1 

N.G./N.F.~ 

Pose 

(Basa) 

Elel 

(Erum) 1 

N.G./N.F.~ 

Orhy 

PsXsa 

Bogr 2 

(Cach) 1 

(Pose) 1 

Lesa 

Orhy 

N.G./N.F.~ 

Pose 

Pofe 

PsXsa 

Stco 

Arpu 

Pose 

Pose 

Brca 

Leci 

Orhy 

Pasm 

Pssp 

(Cacr) 

(Canu) 

Elel 

Orhy 

Pasm 

Pose 

Pssp 

Bogr 

(Cacr) 

Elel 

Ella 

Eltr 

Hija 

Leci 

Mumo 

N.G.IN.F.~ 

Orhy 

Pasm 

Pose 

Pssp 

Ella 

Leci 

N.G./N.F.~ 

Orhy 1 

Pasm 

Pose 

Pssp 

Amal (8 

g, Cele 

Cora 

Gusa 

N.s.~ 

N.S. 

Pera 

Pugl 

Pume 

Putr 

JUOS A A g, 

(con.) 

USDA Forest Sewice Gen. Tech. Rep. RMRS-GTR-12. 1998 
Table 10 (Con.) 

JUOS 

Seriesa ASSOC.~ sub-~SSOC.~ 

JuOs 

Sections 

322A 1 341 A 1 341 D 1 341 E / 341 F 1 341 G 1 3428 1 M341A 1 M341 c Total 

Juos 

AW 

Chna 

Chpa 

Chvi 

Cora 

Gusa 

Quga 

Purne 

Putr 

A A 

AN 

AT 

AV 

AW 

Arnal 

Atca 

Cele 

Chpa 

Cora ci 

Epvi 

Purne 

Putr 

Quga 

Bogr 

Elel 1 

Hija 

Leci 

Pose 1 

Pssp 

Pssp 

Arpu 

Pose 

Pssp 

Bogr 1 

Elel 

Orhy 1 

Hija 

Pssp 

Stco 

Elel 

Lesi 

Pasrn 

PsXel 

Pssp 

Hija 

Pasm 

Eltr 

Orhy 

Pasrn 

Pose 

Pssp 

Stco 

Ella 

Hija 

Orhy 

Pose 

Pssp 

Elel 

Orhy 

Pose 

Elel 

Hija 

Pose 

Pssp 

Stco 

Ella 

Orhy 

Elel 

Lesi 

Bogr 1 

Pofe 1 

Stsp 1 

Elel 

Hija 

Pose 

Elel 

Eltr 

(Erurn) 

N.G.JN.F.~ 

Orhy 

Elel 

(Erov) 

Orhy 

1 

1 

1 

1 

1 

1 

1 

1 

1 

2 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

6 

2 

2 

1 

1 

1 

3 

1 5 

1 

5 

3 

1 

1 

1 

3 

1 

3 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

2 

1 1 

1 

1 

1 

1 

1 

1 

2 

(con.) 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Table 10 (Con.) 

Juos 

, 

,I 

JUSC 

JUSC 

Pi Ed 

Pied 

Seriesa ASSOC.~ Sub-assoc: 

AN 

I' 

L 

AT 

AV 

6 

AW 

Cele 

Chvi 

Epvi 

6' 

Ermi 

N.s.~ 

Putr 

, 

AV 

Amal 

AV 

Cemo 

Epne 

Cemo 

Gusa 

Sections 

322A ( 341A / 341 D ( 341 E / 341 F 1 3410 1 3428 / M341A ( M341C l~otal 

Totals 

Series 

Associations 

Sub-associations 

Pose 

Pssp 

Star 

Orhy 

Stco 

Elel 

N.G./N.F.~ 

Orhy 

Pose 

Pssp 

Stth 

Hija 

Pofe 

N.G./N.F.~ 

Orhy 

Pose 

Pose 

Stoc 

(Peps) 

Pssp 

N.G./N.F.~ 

(Erov) 

Pose 

Elel 

Hija 

Orhy 

Bogr 

Pofe 

Bogr 

(Phdi) 

Orhy 

Orhy 

Orhy 

Number of stands 24 82 33 12 95 27 13 133 7 426 

'See table 5 for key to Ser~es acronyms. 

b~ee table 6 for key to Assoclat~on acronyms. 

'See tables 7 and 8 for key to Sub-association acronyms. 

d~.~. = no grass; N.F. = no forb; N S. = no shrub. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12,1998 
Using This Classification 

Now that we have defined all of the hiera'rchical 

levels within our classification and outlined what we 

have already found, we can begin to illustrate the 

structure and utility of this classification using our 

sampled stands. Since the Sections used are approximately equal in size to Ranger Districts of the USDA 

Forest Service and Resource Areas of the USDI Bureau 

of Land Management, the administrative levels where 

most land management decisions are made, we begin 

by illustrating how to use the classification from the 

view of someone working out of one of those offices. 

This report provides the initial classification of the 

Series, Sub-series, Associations, and Sub-associations 

we found present in each Section. The users may well 

find new combinations as they attempt to use this 

material. 

The users need not read all the following text and 

tabular material sequentially. Instead they should 

match up their area of interest with the appropriate 

Section depicted in the map (fig. 8). The mountain 

ranges within each Section are listed in table 4. Their 

geographic locations are shown in figure 2. The reader 

who has determined an area of interest should turn to 

figure 8 to find what Section is involved, and then find 

the following appropriate pages discussing pinyonjuniper woodlands in that Section. We have tried to 

simplify this process by staggering marginal tabs for 

the Sections depicted in figure 8 using the same order 

as they are discussed in the following text. The Sections are covered in a sequential order matching the 

numbering sequence of Bailey and others (1994). 

Note that the first two letters of the generic and 

species Latin name (except for sagebrushes which 

have been further shortened-see table 6) are combined into a four letter acronym in order to shorten the 

text. A complete list of the acronyms, Latin names, 

and common names are given of trees (table 5), of 

shrubs (table 6), of grasses (table 7), and of forbs 

(table 8). 

Occasionally either no shrub, native perennial 

grass, or native perennial forb were encountered in 

the sample. In such cases, 'N.S.' for "no shrub," 'N.G.' 

for "no grass," and 'N.F.' for "no forb" were designated. 

These absences were probably a function of our incomplete sampling of all the individual plants within 

the area of the rectangular 0.1 ha macroplot (fig. 4). 

The user is advised to search throughout the actual 

stand to find the occasional shrub or grass to correct 

these problems. In other words, we don't place significance in classifying by absence of understory. 

In the absence of a native perennial grass, a native 

perennial forb has been used, if possible. When this 

has been done, the forb's acronym is placed within 

parentheses. In a few cases, no vascular plant understory was observed at all and thus the stand could not 

be classified beyond Series. 

The Series within each Section are ordered with 

Pinus monophylla Series first (if present) followed by 

Juniperus osteosperma Series and then Pinus edulis 

Series. 

The discussions for each Section are presented as 

stand alone entities. Thus, a manager may read only 

the treatment for each Section in which they are 

interested. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Section 322A: Pinyon-Juniper Woodlands 

of the Northern Mohave Desert 

The first geographic grouping of pinyon-juniper 

woodlands that was considered occurs in the northernmost portion of Section 322A(fig. 8), commonly known 

as the Mohave Desert. We sampled woodlands on only 

five mountain ranges there: McCullough, Sheep, and 

Spring in Nevada, the Panamint Range in California, 

and the Beaver Dam Mountains of extreme southwestern Utah (table 5). Only "rapid" sampling was 

done on these mountain ranges. The field teams 

working this area did not obtain adequate soil descriptions to reliably classify to Great Group level at all 

stands, hence the missing information in the two far 

right columns of table 11. Because our coverage of 

this Section is spatially limited, the land manager or 

scientist should expect to encounter many other kinds 

of pinyon-juniper woodlands when working in that 

section. 

Section 322Ahad five Series (table 11); PiMo, Pimo, 

JUOS, JuOs, and Juos. 

The PiMo Series in this Section has two Associations 

and three Sub-associations (table 11). The Associations are PiMoIAN and PiMoIAV. The PiMoIAN Association is represented by the PiMo/AN/Bogr and PiMoI 

ANPofe Sub-associations. The PiMoIAV Association 

had only a PiMoIAVPofe Sub-association. 

The Pimo Series in this Section is divided among 

five Associations. The PimoIAN Association had 

Pimo/AN/Elel and PimoIANlHija Sub-associations. 

The PimoIAV Association had but the PimoIAVl 

(Erum) Sub-association. The PimoIAW Association 

had three Sub-associations: Pimo/AW/Bogr, PimoIAWl 

Elel, and PimoIAWlStar. The PimoICele Association 

had but one Sub-association, PimolCelel(Erum). The 

PimoICora Association had the Pimo/Cora/Bogr, Pimol 

Cord(Cach), and Pimo/Cora/Pose Sub-associations 

(table 11). 

The JUOS Series in this Section was represented by 

five stands divided into three Associations (table 11). 

The Associations are JUOSIAV, JUOSIAW, and JUOSI 

Cora. The JUOSIAV Association had the JUOSIAVI 

Orhy Sub-association. The JUOSIAW Association was 

divided into JUOS/AW/Elel and JUOSIAWPose Subassociations. The JUOSICora Association was split 

between JUOSICoralBogr and JUOSICordOrhy Subassociations. 

The JuOs Series in Section 322A has two Associations (table ll), so far. These are JuOsIChpa and JuOsI 

Corarepresented by JuOsIChpalBogr, JuOs/CoraPofe, 

and JuOsICordStsp Sub-associations, respectively. 

The Juos Series in this Section is represented by 

only one stand of the JuosIANlStar Sub-association. 

Table 11-Summary of Pinyon-Juniper Woodland Series, Associations, and Sub-associations in Section 322A. Parentheses lndicate that native 

perennial forbs are used to des~gnate a Sub-association in the absence of a native perennial grass. 

Soils Soils 

Seriesa ~ssoc.~ sub-assocnc Mtn. range Elev. (m) Aspect Slope Geol, form. (great group) (subgroup) 

PIMO AN Bogr Spring 2,200 E 08 Granitic 

Pofe Panarnint 2,000 N 62 Granitic Haploxerolls 

AV Panamint 2,200 W 38 Granitic 

Pimo AN Elel Sheep 1,800 E 16 Granitic Haploxerolls 

Hija Panarnint 2,000 S 24 Gran~tic Haploxerolls 

AV (E rum) Spring 2,000 W 28 Granitic 

AW Bogr Spring 2,000 E 05 Granitic 

Sheep 1,800 S 10 Shale 

Elel Sheep 1,600 N 32 Basaltic Haploxerolls 

Star Spring 1,800 S 32 Granitic 

Cele (Erurn) Sprlng 2,200 W 2 1 Granitic 

Cora Bogr Beaver Dam 1,400 S 27 Quartzite 

McCullough 1,600 E 16 Granitic 

(Cac h) Spring 1,800 N 10 Granitic 

Pose Beaver Dam 1,400 W 38 Quartzite 

JUOS AV Orhy Beaver Dam 1,400 E 14 Quartzite 

AW Elel Beaver Dam 1,400 N 2 1 Quartzite 

Pose Beaver Dam 1,200 N 21 Quartzite Haploxerolls 

Cora Bogr Spring 1,800 E 10 Granitic 

Orhy Sprlng 1,600 S 16 Granitic 

JuOs Chpa Bogr McCullough 1,600 N 10 Granitic Haploxerolls 

Cora Pofe Panarnint 1,800 W 20 Granitic 

Stsp McCuliough 1,600 S 09 Granitic 

Juos AN Star Sheep 2,000 W 14 Granitic Haploxerolls 

aSee table 5 for key to Series acronyms. 

'see table 6 for key to Assoc~atlon acronyms. 'See tables 7 and 8 for key to Sub-association acronyms. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Section 341 A: Pinyon-Juniper Woodlands 

of the Bonneville Basin 

This Section comprises a large area of land in western Utah and extreme eastern Nevada (fig. 8). This 

area does not drain to the ocean and was covered by a 

large freshwater lake (Bonneville) during the Pleistocene. The remnants are the Great Salt Lake, Utah 

Lake, Sevier Dry Lake, and numerous salt pans in all 

the low spots. Pinyon-juniper woodlands, however, 

occupy intermediate elevations on most of the mountains within and bordering this basin. 

Fifteen mountain ranges were sampled from Section 341Ain this study (tables 5 and 12). Since some of 

the Associations and Sub-associations were found on 

more than one mountain range (table 12), some redundancy was encountered and accordingly more confidence can be placed in these classificational entities 

than in other Sections where given Associations or 

Sub-associations are found only once. 

Section 341A had seven Series (table 12); PiMo, 

Pimo, JUOS, JuOs, Juos, PiEd, and Pied. 

The PiMo Series in this Section had four Associations (table 12). The PiMoIAN Association had but the 

PiMoIANlStco Sub-association. The PiMoIAT Association also had only the PiMoIATlStco Sub-association. 

The PiMoIGusa Association had only the PiMoIGusd 

Pssp Sub-associa-tion. The PiMoIPutr Association had 

but the PiMoPutrPofe Sub-association. 

The Pimo Series in Section 341A had seven Associations (table 12). The PimoIAN Association had four 

Sub-associations. These were the PimoIANlArpu, Pimol 

ANElel, Pimo/AN/(Pepa), and PimoIANPofe. The 

PimoIAT Association had two Sub-associations. These 

were the PimoIATlOrhy and Pimo/AT/Pasm Subassociations (table 12). The PimoIAV Association had 

only the PimoIAVPssp Sub-association. The Pimol 

AW Association had but the PimoIAWlOrhy Sub-association. The PimoICele Association had two Sub-associations, the Pimo/Cele/(Basa) and Pimo/Cele/N.G./ 

N.F. The PimoIGusa Association had but the Pimol 

Gusaesa Sub-association. The PimoPugl Association had but the PimoPugl/Stco Sub-association. 

The JUOS Series in Section 341A had eight Associations (table 12). The JUOSIAA Association had two 

Sub-associations; JUOSIAPJOrhy and JUOSIAAPasm. 

The JUOSIAN Association had four Sub-associations; 

JUOS/AN/(Canu), JUOSIANlElel, JUOSIANlOrhy , and JUOSIANPasm. The JUOSIAT Association had 

nine Sub-associations; JUOSIATBogr, JUOS/AT/Ella, 

JUOSIATlHija, JUOS/AT/Mumo, JUOS/AT/N.G./N.F., 

JUOSIATlOrhy, JUOSIATIPasm, JUOSIATPose, and 

JUOS/AT/Pssp. The JUOSIAV Association had four 

Sub-associations; JUOS/AV/N.G.lN.F., JUOSIAVI 

Pasm, JUOSIAVPose, and JUOSIAVPssp. The JUOSI 

Chna Association had only the JUOS/Chna/Pssp Subassociation. The JUOSIGusa Association had two Subassociations; JUOSIGusdHija and JUOS/GusdStco. 

The JUOSPume Association had two Sub-associations; JUOSPumePasm and JUOS/Pume/PsXsa. The 

JUOSIQuga Association had but the JUOS/Quga/ 

Elel Sub-association. 

The JuOs Series in this Section had nine Associations (table 12). The JuOsIAAAssociation had but the 

JuOs/AA/Pasm Sub-association. The JuOsIAN Association had the JuOs/AN/Orhy and JuOs/ANPasm 

Sub-associations. The JuOsIAT Association had four 

Sub-associations; the JuOs/AT/Ella, JuOsIATlHija, 

JuOsIATlOrhy, and JuOsIATPssp. The JuOsIAV Association had but the JuOs/AT/Elel Sub-association. 

The JuOsIAW Association had the JuOsIAWElel and 

JuOsIAWPssp Sub-associations. The JuOsIAmal Association had only the JuOs/Amal/Ella Sub-association. The JuOsIAtca Association had but the JuOsI 

AtcdOrhy Sub-association. The JuOsICele Association had two Sub-associations; the JuOs/Cele/Elel and 

JuOs/Cele/Lesi. The JuOsIQuga Association had the 

JuOs/Quga/Eltr, JuOs/Qugd(Erum), JuOs/Quga/N. G.1 

N.F., and JuOs/QugdOrhy Sub-associations. 

The Juos Series in Section 341A had four Associations (table 12). The JuosIAN Association had Juosl 

ANIOrhy and JuosIANPssp Sub-associations. The 

JuosIAW Association had but the JuosIAWlHija Subassociation. The JuosICele Association had the Juosl 

Ce1elN.G.N.F. and Juos/CelePose Sub-associations. 

The JuosPutr Association had only the JuosPutrI 

Orhy Sub-association (table 12). 

The PiEd Series in this Section had but the PiEd1 

EpneIOrhy Sub-association. 

The Pied Series in Section 341A had but the Pied1 

GusdOrhy Sub-association, 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12.1998 
Table 12-Summary of Pinyon-Juniper Woodland Series, Associations, and Sub-associations in Section 341A. Parentheses indicate that native 

perennial forbs are used in the absence of a native perennial grass to designate Sub-Association. See table 2 for key to abbreviations 

for geological formations. 

PiMo 

Pimo 

JUOS 

JUOS 

JuOs 

AN 

AT 

Gusa 

Putr 

AN 

AT 

AV 

AW 

Cele 

Gusa 

Pugl 

A A 

AN 

AT 

AV 

Chna 

Gusa 

Pume 

Quga 

A A 

AN 

AT 

Stco 

Pssp 

Pofe 

Arpu 

Elel 

(Pep4 

Pofe 

Orhy 

Pasm 

Pssp 

Orhy 

(Basa) 

N.G.IN.F.~ 

Lesa 

Stco 

Orhy 

Pasm 

(Canu) 

Elel 

Orhy 

Pasm 

Bogr 

Ella 

Hrja 

Mumo 

N.G./N.F.~ 

Orhy 

Pasm 

Pose 

Pssp 

N.G.IN.F.~ 

Pasm 

Pose 

Pssp 

Hija 

Stco 

Pasm 

PsXsa 

Elel 

Pasm 

Orhy 

Pasm 

Ella 

H~ja 

Orhy 

Mtn. range 

Pll0t 

Pilot 

Wah Wah 

Pilot 

Wah Wah 

House 

House 

Confus~on 

San Franc~sco 

Oquirrh 

San Francrsco 

Confusion 

Prlot 

Mrneral 

Confus~on 

Pilot 

Stansbury 

East T~nt~c 

Sheeprock 

Pavant 

Burbank H~lls 

West Tint~c 

Canyon 

Mineral 

West Trnt~c 

Mineral 

Cricket 

Cricket 

Mineral 

Mineral 

Stansbury 

East Trnt~c 

Wah Wah 

West Tintic 

Canyon 

Cr~cket 

Cr~cket 

Mrneral 

East T~ntrc 

East Tintic 

Canyon 

Stansbury 

Mineral 

M~neral 

House 

San Francisco 

Wah Wah 

Stansbury 

Sheeprock 

Pavant 

East Tlntic 

P1lot 

Oqu~rrh 

Oqu~rrh 

Oquirrh 

West Trnt~c 

Wah Wah 

Wah Wah 

San Franc~sco 

Elev. (m) 

2,000 

2,000 

2,000 

2,000 

1,800 

2,000 

2,200 

2,200 

2,000 

1,800 

2,200 

2,200 

2,200 

2,200 

2,000 

1,800 

2,000 

2,000 

2,000 

1,600 

2,000 

1,800 

1,600 

2,000 

1,800 

1,800 

1,800 

1,800 

1,800 

1,800 

1,800 

1,800 

1,800 

1,800 

1,600 

1,800 

1,800 

1,800 

1,800 

2,000 

1,800 

2,000 

1,800 

2,000 

1,800 

1,800 

1,800 

1,800 

2,000 

1,800 

1,800 

1,800 

1,600 

1,600 

1,800 

2,000 

1,800 

2,000 

2,000 

Aspect 

W 

s 

N 

E 

S 

S 

s 

E 

s 

W 

N 

W 

w 

E 

W 

N 

N 

E 

W 

W 

E 

S 

N 

W 

E 

N 

N 

E 

s 

E 

E 

W 

W 

W 

W 

S 

W 

W 

S 

W 

E 

E 

S 

N 

E 

W 

N 

S 

E 

N 

N 

W 

E 

N 

s 

N 

E 

s 

N 

Slope 

11 

36 

2 1 

40 

3 1 

05 

03 

2 1 

2 1 

25 

23 

18 

53 

31 

49 

49 

06 

25 

11 

19 

05 

04 

09 

16 

09 

12 

09 

12 

09 

07 

05 

09 

07 

25 

11 

2 1 

09 

05 

18 

2 1 

25 

14 

3 1 

2 1 

0 

12 

2 1 

45 

18 

14 

17 

07 

07 

25 

16 

09 

18 

04 

18 

Geol. form. 

Limest./Dolo. 

PhylliteIQu. 

Granitoid 

Limestone 

Limestone 

Limest./Dolo. 

Limest./Dolo. 

Limest./Dolo. 

Haploxerolls 

Lrmest./Dolo. 

Tuff-Weld. 

Tuff 

Quartzite 

Shale 

Alluvium 

Haploxerolls 

Alluvium 

Alluvium 

Quartz~te 

Haplargids 

Alluvium 

Tuff 

Alluvium 

Alluvium 

Lrrnestone 

Tuff 

Limestone 

Alluvium 

Granitoid 

Limestone 

Quartzite 

Alluvium 

Tuff 

Tuff-Weld. 

Alluvium 

Soils 

(great group) 

Calcixerolls 

Haploxerolls 

Haplargids 

Calciorthids 

Argixerolls 

Haploxerolls 

Calciorthids 

Soils 

(subgroup) 

aridic 

xerollic 

lithic xerollic 

lithic 

lithic 

lithic 

xerollic 

aridic 

xerollic 

Hapioxerolls 

(con.) 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Table 12 (Con.) 

Soils Soils 

Seriesa ~ssoc.~ Sub-assocc Mtn. range Elev. (m) Aspect Slope Geol. form. (great group) (subgroup) 

JuOs AT Orhy San Francisco 2,000 E 09 , Pssp Pilot 1,800 E 25 Quartzite Calcixerolls aridic 

AV Elel Mineral 1,800 N 05 Argixerolls aridic calcic 

Mineral 1,800 E 07 Calciorthids xerollic 

AW Mineral 1,800 W 11 Torrifluvents xeric 

Pssp Mineral 2,000 W 34 Alluvium 

Amal Ella West Tintic 2,000 E 16 Alluvium 

Atca Orhy Pavant 1,800 E 18 Tuff 

Cele Elel Mineral 2,000 S 23 SiltISand 

Lesi Confusion 2,000 E 58 Limest./Dolo. Calciorthids lithic xerollic 

Quga Eltr Mineral 2,000 N 12 Haploxerolls aridic )I (Erum) Pavant 2,000 S 33 Alluvium 

N.G./N.F.~ Mineral 2,000 S 47 Haploxerolls aridic 

Orhy Canyon 1,800 S 12 

Juos AN Burbank Hills 2,000 N 27 L./Dolo.-Silt Calciorthids xerollic 

Pssp Mineral 2,000 E 23 SiltISand 

House 2,000 E 27 Limestone 

AW Hija Wah Wah 2,000 E 09 

Cele N.G./N.F.~ pilot 2,200 S 40 Limest./Dolo. Haploxerolls lithic 

Pose Pilot 2,000 N 53 Limest./Dolo. Calcixerolls ar~dic 

Putr Orhy Mineral 2,000 E 11 Calciorthids xerollic 

PiEd Epne Pavant 2,000 E 18 

Pied Gusa Wah Wah 2,000 W 05 

'See table 5 for key to Series acronyms. 

'see table 6 for key to Association acronyms. 

'See tables 7 and 8 for key to Sub-associat~on acronyms. 

d~.~. = no grass; N.F. = no forb; N.S. = no shrub encountered 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12.1998 
Section 341 D: Pinyon-Juniper Woodlands Sub-associations. The PIMOIAW Association had the 

of the MO~O-~alker-~wens Basins of PIMOIAWlHija, PIMOIAWlOrhy, PIMOlAWPose, and 

Extreme Western Nevada and Adjacent the PIMOIAWlStco Sub-associations. The PIMOIChvil 

Pose Sub-association was the only one found for the California PIMOIChvi Association. The PIMOPutr Association 

Section 341D is the smallest of the nine Sections 

sampled in this study (fig. 8). The Washoe, Mason, 

Owens, and Deep Springs Valleys are involved, but 

most of the pinyon-juniper woodlands are found on the 

mountains directly next to the eastern slope of the 

Sierra Nevada. The mountain ranges sampled in this 

study were the Pine Nut, Wassuk, Excelsior, and 

Virginia Ranges wholly in Nevada and the White 

Mountains that straddle the border with California 

(table 4, fig. 2). 

This Section had four Series (table 13); PIMO, PiMo, 

Pimo, and Juos. 

The PIMO Series in Section 341D had seven Associations and 15 Sub-associations (table 13). The 

PIMOIAN Association had but the PIMOIANlOrhy 

Sub-association. The PIMOIAT Association had but 

the PIMOIATPose Sub-association. The PIMOIAV 

Association had the PIMOIAVlElel, PIMOIAVPose, 

PIMO/AV/Pssp, PIMOIAVlStco, and PIMOIAVlStoc 

had the PIMOPutrIOrhy and PIMOPutrIStth Subassociations. The PIMO/Rive/Pose Sub-association 

was the sole Sub-association within the PIMOIRive 

Association. 

The PiMo Series had PiMoIAV, PiMoIAW, and PiMoI 

Sylo Associations. The PiMo AVAssociation had PiMoI 

AVIElel, PiMoIAVlLeci, PiMo/AV/(Luse), and PiMoI 

AVPose Sub-associations. The PiMoIAW Association 

had but the PiMoIAWlElel Sub-association. The 

PiMoISylo Association had only the PiMoISyloPose 

Sub-association. 

The PimoIAN Association had a lone PimoIANlElel 

Sub-association. The PimoIAT Association had the 

PimoIATlOrhy and the Pimo/AT/Stoc Sub-associations 

(table 13). 

The Juos Series had only a JuosIAVlStth Subassociation on a 33 percent southerly slope at 1,800 m 

on the Pine Nut Mountains, indicating how rare 

juniper-dominated woodlands are in this Section. 

Table 13-Summary of Pinyon-Juniper Woodland Series, Associations, and Sub-associations in Section 341 D. Parentheses indicate that native 

perennial forbs are used in the absence of a native perennial grass to designate Sub-Association. 

Soils Soils 

Seriesa ~ssoc.~ Sub-assoc.' Mtn, range Elev. (m) Aspect Slope Geol. form. (great group) (subgroup) 

PI MO 

PIMO 

PiMo 

Pimo 

Juos 

AN 

AT 

AV 

AW 

Chvi 

Putr 

Putr 

Rive 

AV 

A W 

Sylo 

AN 

AT 

AV 

Orhy 

Pose 

Elel 

Pose 

Pssp 

Stco 

Stoc 

Hija 

Orhy 

Pose 

Stco 

Pose 

Orhy 

Stth 

Pose 

Elel 

Leci 

(Luse) 

Pose 

Elel 

Pose 

Elel 

Orhy 

Stoc 

Stth 

White 

Wassuk 

White 

White 

Excelsior 

Wassuk 

White 

Excelsior 

White 

Wassuk 

Wassuk 

Wassuk 

Wassuk 

Excelsior 

Wassuk 

Pine Nut 

Excelsior 

Pine Nut 

Virginia Range 

Virginia Range 

Pine Nut 

Pine Nut 

Pine Nut 

Pine Nut 

Virginia Range 

Virginia Range 

Virginia Range 

Wassuk 

White 

White 

Wassuk 

Pine Nut 

Pine Nut 

Granitic 

Granitic 

Granitic 

Rhyolitic 

Granitic 

Rhyolitic 

Granitic 

Granitic 

Granitic 

Granitic 

Granitic 

Granitic 

Granitic 

Granitic 

Basaltic 

Granitic 

Granitic 

Basaltic 

Basaltic 

Basaltic 

Granitic 

Granitic 

Granitic 

Granitic 

Granitic 

Basaltic 

Granitic 

Granitic 

Granitic 

Haploborolls 

Haploborolls 

Haploborolls 

Cambiorthids 

Cambiorthids 

Argiborolls 

Cambiorthids 

Cambiorthids 

Cambiorthids 

Paleorthids 

aridic 

aridic 

aridic 

lithic xerollic 

xerollic 

aridic 

lithic xerollic 

lithic xerollic 

xerollic 

xerollic 

aSee table 5 for key to Series acronyms. 

b~ee table 6 for key to Association acronyms. 

'See tables 7 and 8 for key to Sub-association acronyms 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Section 341 E: Pinyon-Juniper Woodlands 

of the Lahontan Basin of Western Nevada 

Section 341E occupies most of western Nevadafrom 

the Santa Rosa Mountains near the Oregon border 

to Pahute Mesa on the border of the Mohave Desert 

(fig. 8). The lowlands of the central part of this unit 

were once occupied by glacial Lake Lahontan. Of 

the approximately 20 separate mountain ranges in 

this "sea" of desert terrain, our random sample draw 

only led to two; the West Humboldt and Silver Peak 

Ranges (table 5). The mountains in the north largely 

lack pinyon juniper woodlands (fig. 3). The southernmost mountains have considerable woodland acreage that was not sampled in this effort. The team 

working this set of mountains was too sparing in their 

efforts at soil descriptions for us to be able to conclude 

much about soils there. We thus must caution that 

the classification presented here is only a beginning. 

Section 341E had four Series; PIMO, PiMo, Pimo, 

and JUOS (table 14). 

The PIMO Series is represented by but one stand in 

the PIMOJAWh3lel Sub-association. 

The PiMo Series had two Associations; PiMoIAN 

and PiMoJAT. PiMolANJElel and PiMoJANIOrhy 

were the two Sub-associations representing the 

PiMoJAN Association. The only Sub-association in the 

PiMo/AT Association was PiMolATJOrhy. 

The Pimo Series had PimoJAA and PimoIAN Associations, both with Orhy as their leading understory 

perennial grass and thus only Sub-associations. 

The JUOS Series in this Section had JUQSIAA, 

JUOSJAT, and JUOSJAV Associations. JUOSJAAArca 

and JUOSlAAneci Sub-associations were sampled 

here. JUOSJATIElel was the only Sub-association 

found within the JUOSJAT Association. The JUOSJ 

AVPose Sub-association was the only one found 

within the JUOSJAV Association. 

Table 14-Summary of Pinyon-Juniper Woodland Series, Associations, and Sub-associations in Section 341 E. See table 2 for key to abbreviations 

of geological formations. 

Soils Soils 

Seriesa ~ssoc? Sub-assocc Mtn. range Elev. (rn) Aspect Slope Geol. form. (great group) (subgroup) 

PlMO AN f lel Silver Peak 2,400 W 09 

PiMo AN Elel Silver Peak 2,400 S 05 

Orhy Silver Peak 2,200 W 05 

AT Orhy Silver Peak 2,200 E 40 

Pimo AA Orhy Silver Peak 2,200 N 07 

AN Orhy Silver Peak 2,200 S 21 Limestone 

JWOS AA Brca West Humboldt 2,000 E 36 

Leci West Hurnboldt 2,000 W 45 Limest./Dolo. Calcixerolls 

West Humboldt 1,800 E 51 Lirnest.JDolo. Calcixerolls 

AT Elel West Humboldt 2,000 S 36 Quartzite 

West Humboldt 1,800 S 05 Quartzite 

AV Pose West Murnboldt 1,800 W 36 Limest.lDolo. Galcixerolls 

'See table 5 for key to Series acronyms. 

'see table 6 for key to Assocration acronyms. 

'See 'tables 7 and 8 for key to Sub-assocratlon acronyms. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12.1998 
Section 341 F: Pinyon-Juniper Woodlands 

of the Southeastern Great Basin 

Section 341F occurs in southeastern Nevada and a 

smaller portion in adjacent southwestern Utah (fig. 8). 

Even though this Section is smaller than Section 

341E, it was sampled more thoroughly because of the 

random selection of mountain ranges used. Ten mountain ranges were visited in this study (tables 5 and 15). 

Data from the South Egan, Quinn Canyon, Highland, 

Wilson Creek, Grant, Fortification, and Kawich Ranges 

of Nevada are used here, as is data from the Needle 

and Pine Valley Mountains and Beryl-Enterprise Hills 

of Utah. The elevations of the valleys between the 

mountains in this Section are often high enough that 

pinyon-juniper woodlands cover much mid-valley terrain as well as the lower hill systems and lower flanks 

of the mountains. 

Section 341F had eight Series; PIMO, PiMo, Pimo, 

JUOS, JuOs, Juos, Jusc (Juniperus scopulorum), and 

PiEd (table 15). 

There were three Associations in the PIMO Series; 

PIMOIAV, PIMOICele, and PIMOIChvi. The PIMOI 

AV Association had PIMOIAVBogr, PIMOIAVlOrhy, 

PIMOIAVlPose, and PIMOIAVPssp Sub-associations. 

The PIMOICelePofe and PIMO/Cele/Pose were the 

two Sub-associations in the PIMOICele Association. 

The PIMOIChvi Association had but the PIMOIChvil 

Elel Sub-association. 

The PiMo Series had eight Associations; PiMoIAN, 

PiMoIAT, PiMoIAV, PiMoIAW, PiMoIAmal, PiMoICele, 

PiMo/Mare, and PiMoISylo. The PiMoIANlOrhy Subassociation was the only such unit in PiMoIAN. The 

PiMoIAT Association was divided into PiMoIATlHija 

and PiMoIATPose Sub-associations. The PiMoIAV 

Association was divided into PiMoIAVIElel, PiMoIAVl 

Orhy, PiMoIAVlPose, and PiMoIAVPssp Sub-associations. There was only the PiMo/AW/Hija Sub-association within the PiMoIAW Association (table 15). The 

PiMoIAmal Association was divided into PiMo/Amal/ 

Pose and PiMo/Amal/Pssp Sub-associations. The PiMoI 

Cele Association was only represented by the PiMoI 

CelePofe Sub-association. The PiMoIMare Association had but the PiMo/Mare/Elel Sub-association. The 

PiMoISylo Association was split into the PiMoISylol 

Brca and PiMo/Sylo/Elel Sub-associations. 

The Pimo Series in Section 341F had PimoIAN, Pimol 

AT, PimoIAV, PimoIAW, PimoIAmal, PimoICele, Pimol 

Gusa, Pimo/N.S., Pimopera, PimoPugl, and Pimol 

Pume Associations. The PimoIAN Association had Pimol 

ANBogr, Pimo/AN/Elel, Pimo/AN/Pofe, and PimoIANl 

Pose Sub-associations. The PimoIAT Association had 

PimoIATlOrhy and PimoIATPofe Sub-associations. 

The PimoIAV Association had the PimoIAVIElel, Pimol 

AVIOrhy, and PimoIAVPose Sub-associations. The 

PimoIAW Association had representation in Pimol 

AWIElel, Pimo/AW/(Erum), and PimoIAWlHija Subassociations. The PimoIAmal Association had but the 

Pimo/Amal/N.G./N.F. Sub-association. 

The PimoICele Association was divided into Pimo/ 

CeleIOrhy and PimoICelePsXsa Sub-associations. The 

PimoIGusa Association had but the Pimo/GusalOrhy 

Sub-association. There was also a Pimo/N.S./N.G./ 

N.F. Sub-association. The PimoPera Association had 

but the PimoPera/Pofe Sub-association. The Pimol 

Pug1 Association had but the Pimo/Pugl/PsXsa Subassociation. The PimoPume Association had Pimol 

PumeIArpu and PimoPumePose Sub-associations. 

The JUOS Series in Section 341F had eight Associations; JUOSIAN, JUOSIAT, JUOSIAV, JUOSIAW, 

JUOSIChpa, JUOSIChvi, JUOSICora, and JUOSPume 

(table 15). The JUOSIAN Association had but the 

JUOSIANlOrhy Sub-association. The JUOSIAT Association had but the JUOSIATlPose Sub-association. 

The JUOSIAV Association had but the JUOSIAVlElla 

Sub-association, whereas the JUOSIAW Association 

had JUOSIAWBogr and JUOSIAWlHija Sub-associations. The JUOSIChpa Association had only the JUOSI 

ChpaIArpu Sub-association. The JUOSIChvi Association had only the JUOS/Chvi/Pssp Sub-association. 

The JUOSICora Association was represented by only 

the JUOSICoralElel Sub-association. The JUOS/ 

Pume Association had but the JUOSPume/Lesi Subassociation (table 15). 

The JuOs Series in this Section had six Associations 

(table 15); the JuOsIAA, JuOsIAN, JuOsIAT, JuOs/ 

AV, JuOsIAW, and JuOsPume. The JuOs/AAAssociation had only the JuOs/AA/Hija Sub-association. The 

JuOsIAN Association was split into JuOs/AN/Eltr, 

JuOs/AN/Orhy, and JuOs/AN/Stco Sub-associations. 

The JuOsIAT Association had the JuOs/AT/Hija and 

JuOsIATlOrhy Sub-associations. The JuOsIAV Association had only the JuOsIAVlOrhy Sub-association, The 

JuOsIAW Association was divided between JuOsIAWl 

Hija, JuOs/AW/Pose, and JuOsIAWlStco Sub-associations. The JuOsPume Association had only the JuOsI 

Pume/Hija Sub-association. 

The Juos Series in Section 341F had nine Associations; JuosIAN, JuosIAT, JuosIAV, JuosIAW, Juosl 

Chvi, JuosIEpvi, JuosIErmi, Juos/N.S., and JuosPutr, 

each represented by only one Sub-association except 

the JuosIAN Association that was split into Juosl 

ANIElel and Juos/AN/(Erov) Sub-associations. The 

JuosIAV Association was divided into Juos/AV/N.G./ 

N.F. and Juos/AV/Orhy Sub-associations; and Juosl 

Putr which had Juos/Putr/Elel and Juos/Putr/Hija 

Sub-associations (table 15). 

The PiEd Series in this Section was represented 

only once as a PiEd/Cemo/(Phdi) Sub-association at 

1,800 m elevation on a 25 percent northerly slope on 

the Pine Valley Mountains. 

The only place in Section 341F where we encountered woodland dominated by the Jusc Series was at 

2,000 m elevation on a 2 percent N slope of the Pine 

Valley mountains. In this instance the dominant understory shrub was Amal and the dominant grass 

was Pofe. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Table 15-Summary of Pinyon-Juniper Woodland Series, Associations, and Sub-associations in Section 341 F. Parentheses indicate that native 

perennial forbs are used in the absence of a native perennial grass to designate a Sub-association, See table 2 for key to abbreviations 

for geological formations. 

PlMO 

PiMo 

Pimo 

AV 

(2 

Cele 

Chvi 

AN 

AT 

AV 

AV 

AW 

Amal 

Cele 

Mare 

Sylo 

AN 

AT 

AV 

AW 

Amal 

Cele 

Gusa 

N.s.~ 

Pera 

Pugl 

Pume 

Sub-assocc Mtn. range Elev. (m) 

Bogr Needle 2,400 

Orhy Needle 2,400 

Pose Quinn Canyon 2,000 

Needle 2,400 

Quinn Canyon 2,200 

Pssp Kawich 2,200 

Pofe Highland 2,400 

Pose Needle 2,400 

Elel Needle 2,400 

Orhy Needle 2,200 

Grant 2,000 

Grant 2,000 

Hija Kawich 2,000 

Pose Enterprise-Beryl Hills 2,200 

Quinn Canyon 2,000 

Elel Needle 2,200 

Needle 2,400 

Orhy Needle 2,200 

Needle 2,200 

Pose Quinn Canyon 2,200 

Pssp Quinn Canyon 2,000 

Pssp Kawich 2,000 

Hija Grant 2,000 

Pose Needle 2,200 

Quinn Canyon 2,200 

Pssp Quinn Canyon 2,200 

Pofe Highland 2,400 

Highland 2,400 

Elel Needle 2,200 

Brca Quinn Canyon 2,200 

Elel Highland 2,600 

Bogr Wilson Creek 2,000 

Elel South Egan 2,200 

Pofe Highland 2,200 

Pose Quinn Canyon 2,000 

Orhy Needle 2,200 

Quinn Canyon 1,800 

Pofe Highland 2,200 

Elel Needle 2,400 

Needle 2,400 

Orhy Needle 2,200 

Pose Kawich 2,000 

Elel Wilson Creek 2,000 

Elel Fortif~cation 2,000 

(Erum) Fortification 2,000 

Hija Highland 2,000 

Highland 1,800 

N.G./N.F.~ Needle 2,200 

Orhy Needle 2,400 

Highland 2,400 

PsXsa Highland 2,200 

Orhy Needle 2,400 

N.G.IN.F.~ Needle 2,200 

Pofe Highland 2,200 

PsXsa South Egan 2,200 

Arpu Needle 2,000 

Aspect 

W 

W 

N 

N 

W 

E 

E 

E 

N 

E 

N 

W 

S 

N 

S 

N 

E 

S 

W 

E 

W 

E 

S 

N 

S 

N 

N 

W 

N 

W 

E 

W 

E 

W 

E 

N 

E 

N 

E 

E 

S 

N 

S 

E 

W 

S 

W 

E 

S 

S 

S 

S 

W 

E 

W 

S 

Slope 

25 

11 

48 

16 

35 

56 

25 

27 

18 

04 

11 

27 

14 

07 

13 

21 

42 

16 

09 

42 

09 

11 

35 

36 

11 

45 

31 

31 

21 

35 

107 

13 

07 

55 

34 

25 

28 

2 1 

49 

5 1 

32 

47 

02 

11 

05 

38 

05 

18 

60 

36 

40 

62 

05 

27 

12 

16 

Geol, form. 

Granitic 

Granitic 

Granitic 

Limest./Dolo. 

AndesiticIRh. 

Basaltic 

Granitic 

AndesiticIRh. 

Granitic 

AndesiticIRh. 

AndesiticIRh. 

Granitic 

Granitic 

Granitic 

Granitic 

Granitic 

Limest.1Dolo. 

Limest./Dolo. 

Granitic 

Limest./Dolo. 

Granitic 

Limest.1Dolo. 

Granitic 

Granitic 

Limest./Dolo. 

Granitic 

Granitic 

Alluvium 

Alluvium 

Alluvium 

Alluvium 

Limest.1Dolo. 

Soils 

(great group) 

Haploborolls 

Haploborolls 

Haploborolls 

Agriborolls 

Haploborolls 

Haploxerolls 

Haploxerolls 

Haploborolls 

Haploxerolls 

Haploxerolls ' 

Haploxerolls 

Haploxerolls 

Haploborolls 

Haploxerolls 

Argiborolls 

Haploxerolls 

Haploxerolls 

Haploxerolls 

Haploborolls 

Argiborolls 

Haplargids 

Calciorthids 

Calciorthids 

Argixerolls 

Cambiorthids 

Camborthids 

Cambiorthids 

Cambiorthids 

Haplargids 

Calcixerolls 

Argixerolls 

Soils 

(subgroup) 

lithic 

aridic 

lithic 

lithic 

lithic 

aridic 

lithic 

lithic 

aridic 

aridic 

lithic 

lithic 

lithic 

lithic 

lithic 

lithic 

lithic 

lithic 

aridic 

lithic 

lithic xerollic 

xerollic 

xerollic 

aridic 

lithic xerollic 

lithic xerollic 

lithic xerollic 

lithic xerollic 

xerollic 

aridic 

aridic calcic 

(con:) 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12.1998 
Table 15 (Con.) 

Pimo 

JUOS 

duos 

Juos 

JUSC 

PiEd 

Pume 

AN 

AT 

AV 

AW 

Chpa 

Chvi 

Cora 

Pume 

A A 

AN 

AT 

AV 

AW 

Pume 

AN 

AT 

AV 

AW 

Chvi 

Epvi 

Ermi 

N.s.~ 

Putr 

Amal 

Cemo 

Sub-as so^.^ Mtn, range Elev. (m) 

Pose Enterprise-Beryl Hills 2,200 

Orhy South Egan 2,000 

Pose Pine Valley 1,800 

Ella Pine Valley 2,000 

Bogr Plne Valley 1,800 

Hija Plne Valley 2,000 

Arpu Highland 1,800 

Pssp Needle 2,000 

Elel Pine Valley 1,200 

Lesl Pine Valley 2,000 

Hija Needle 2,000 

Eltr Highland 2,000 

Orhy Needle 2,000 

Wilson Creek 2,000 

Grant 2,000 

Stco Fortlflcation 2,000 

Hija Kawich 2,000 

Orhy Needle 1,800 

Orhy Quinn Canyon 2,000 

Hija Enterprise-Beryl Hills 1,800 

Enterprise-Beryl H~lls 2,000 

Fortification 2,000 

Pose Enterpr~se-Beryl Hills 1,800 

Stco W~lson Creek 2,000 

Hija Enterpr~se-Beryl Hills 2,000 

Elel Needle 2,000 

(Erov) Needle 2,000 

Stco Highland 2,000 

N.G./N.F.~ Needle 2,200 

Orhy Needle 2,200 

Pofe Highland 2,000 

Stoc Needle 2,200 

(Pepa) Needle 2,000 

N.G.IN.F.~ Needle 2,000 

(Erov) Needle 2,000 

Elel Needle 2,200 

Hija Enterprise-Beryl Hills 2,000 

Pofe Plne Valley 2,000 

(Phdl) Pine Valley 1,800 

Aspect 

E 

W 

S 

W 

W 

S 

S 

N 

E 

E 

W 

E 

W 

N 

k 

W 

S 

S 

N 

S 

S 

W 

E 

E 

E 

S 

W 

W 

S 

N 

E 

s 

N 

s 

W 

N 

N 

N 

Slope 

07 

02 

14 

19 

12 

14 

23 

11 

0 

16 

05 

05 

04 

05 

11 

02 

14 

02 

23 

04 

29 

13 

05 

08 

2 1 

05 

2 1 

07 

18 

45 

09 

21 

27 

11 

16 

16 

18 

02 

25 

Geol, form. 

Alluvium 

Shale 

Alluvium 

Alluvium 

Rhyolitic 

Gran~tic 

Alluvium 

Granitic 

AndesiticIRh. 

Andesitic/Rh. 

Andes~ticiRh. 

Rhyol~tlc 

Andesitic/Rh. 

Alluvium 

Alluvium 

AndesitlclRh. 

AndesltlclRh. 

Soils 

(great group) 

Haploxerolls 

Paleorthids 

Argixerolls 

Paleorthids 

Calcixerolls 

Haplargids 

Haploxerolls 

Cambiorthids 

Argixerolls 

Calcixerolls 

Cambiorthids 

Calcixerolls 

Argixerolls 

Argixerolls 

Cambiorthids 

Argixerolls 

Cambiorthids 

Soils 

(subgroup) 

aridic 

xerollic 

aridic calcic 

xerollic 

aridic 

xerollic 

aridic 

xerollic 

arid~c 

aridic 

lithic xerollic 

aridic 

aridic 

aridic 

xerollic 

aridic 

lithic xerollic 

aSee table 5 for key to Ser~es acronyms 

b~ee table 6 for key to Assoc~ation acronyms. 

'See tables 7 and 8 for key to Sub-assoc~at~on acronyms. 

d~ G. = no grass, N.F. = no forb; N S. = no shrubs encountered. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Section 341 G: Humboldt Basin of 

Northeastern Nevada 

Section 341G corresponds to most of the lower 

elevations within the drainage of the Humboldt River 

situated in northeastern Nevada and a small part of 

Utahnorth of the Deep Creek Range. Even though this 

is smaller than Section 341E, we randomly drew five 

mountain ranges; the Cherry Creek, East Humboldt, 

Spruce, Pequop, and Toana, all in Nevada. Most of the 

sampling was, however, "rapid" and some of the soils 

and geological information was inadequate for reporting here, 

Five Series are represented in this Section; PiMo, 

Pimo, JUOS, JuOs, and Juos (table 16). 

The PiMo Series in Section 341G has four Associations; PiMoIAN, PiMoIAV, PiMoICele, and PiMoPutr. 

The PiMoIAN Association was split into PiMoIANl 

N.G./N.F. and PiMoIANlOrhy. The PiMoIAV Association had only the PiMoIAVPssp Sub-association. The 

PiMoICele Association had only the PiMoICelePssp 

Sub-association. The PiMoPutr Association had only 

the PiMoPutrPose Sub-association. 

The Pimo Series in this Section had six Associations; 

PimoIAN, PimoIAT, PimoIAV, PimoIAW, Pimo/N.S., 

and PimoPutr. The PimoIAN Association had but the 

Pimo/AN/Pssp Sub-association. The PimoIAT Association had the PimoIATlOrhy and Pimo/AT/Stco Subassociations. The PimoIAV Association had only the 

PimoIAVPssp Sub-association. The PimoIAW Association had only the PimoIAWPose Sub-association. 

The Pim0IN.S. Association had only the PimoLN.S.1 

Pose Sub-association. PimoPutr Association had only 

the PimoPutrPose Sub-association. 

The JUOS Series in Section 341G'had three ~ssociations; JUOSIAN, JUOSIAT, and JUOSIChvi. The 

JUOSIAN Association was represented only by the 

JUOS/AN/(Cacr) Sub-association. The JUOSIAT Association had only the JUOSIATlOrhy Sub-association. The JUOSIChvi Association was split into JUOSI 

Chvi/Pose and JUOS/Chvi/Pssp Sub-associations. 

The JuOs Series in this Section had three Associations; JuOsIAT, JuOsIAW, and JuOsPutr. The JuOsI 

AT Association had only the JuOsIATlPssp Subassociation. The JuOsIAW Association had but the 

JuOsIAWPssp Sub-association. The JuOsPutr Association had only the JuOsPutrPose Sub-association. 

The Juos Series in Section 341G had two Associations; JuosIAN, and Ju0sIN.S. (table 16). The JuosIAN 

Association had only the JuosIANlPssp Sub-association. Only the Juos/N.S.Pose Sub-association was 

found in the JuosLN.S. Association in this Section 

(table 16). 

Table 16-Summary of Pinyon-Juniper Woodland Series, Associations, and Sub-associations in Section 341 G. Parentheses indicate that native 

perennial forbs are used in the absence of a native perennial grass to designate Sub-association. Also see table 2 for key to 

abbreviations for geological formations. 

PiMo 

Pimo 

JUOS 

JuOs 

Juos 

~ssoc.~ Sub-assocc Mtn. range Elev. (m) Aspect Slope 

AN N.G.IN.F.~ 

Orhy 

AV Pssp 

Cele Pssp 

Putr Pose 

AN Pssp 

AT Orhy 

Stco 

AV Pssp 

AW Pose 

N.s.~ Pose 

Putr Pose 

AN (Cacr) 

AT Orhy 

Chvi Pose 

Pssp 

AT Pssp 

AW Pssp 

Putr Pose 

AN Pssp 

N.s.~ Pose 

Pequop 

Cherry Creek 

Spruce Mountain 

Cherry Creek 

East Humboldt 

Cherry Creek 

Cherry Creek 

Pequop 

Toana 

Spruce Mountain 

Spruce Mountain 

Toana 

Pequop 

East Humboldt 

Toana 

Spruce Mountain 

Cherry Creek 

East Humboldt 

Toana 

East Humboldt 

Pequop 

Spruce Mountain 

Spruce Mountain 

East Humboldt 

East Humboldt 

Cherry Creek 

Toana 

Geol. form. 

Granitic 

Granitic 

Limest./Dolo. silt 

Alluvium 

Siltisand. 

Granitic 

Limest./Dolo. Silt. 

Limest./Dolo. Silt. 

Tuff-Weld. 

Soils 

(great group) 

Cambiorthids 

Calciorthids 

Paleoxerolls 

Cambiorthids 

Paleorthids 

Cambiorthids 

Soils 

(subgroup) 

lithic xerollic 

xerollic 

lithic 

aridic 

lithic xerollic 

xerollic 

xerollic 

aridic 

:See table 5 for key to Ser~es acronyms. 

See table 6 for key to Association acronyms. 

:See tables 7 and 8 for key to Sub-association acronyms. 

N.G. = no grass; N.F. =no forb; N.S. = no shrub encountered. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Section 342B: Pinyon-Juniper Woodlands 

of the Northern Great Basin in Northern 

Nevada, Extreme northwestern Utah, and 

Adjacent Idaho and Oregon 

Section 342B is a unit that has a western lobe 

extending from the flanks of the Sierra Nevada across 

the northern part of the Lahontan Basin of Nevada 

and independent lake basins of southeastern Oregon 

to a restricted corridor across the Leonard Creek and 

Trout Creek Mountains near the Nevada-Oregon 

border to an elongated easterly lobe across extreme 

northeastern Nevada, extreme northwestern Utah, 

and part of southern Idaho (fig. 8). The northwestern 

lobe holds only western juniper (Juniperus occidentalis), a sub-type not within our study area boundaries (fig. 1). We randomly drew no mountain ranges 

in the southwestern part of this Section. Therefore, 

our information only derives from the four mountain 

ranges sampled in the eastern lobe; the Goose Creeks 

along the Nevada-Utah border, and the Albion, Black 

Pine, and Sublette Ranges in southern Idaho. 

Only one Series was found in this Section; JUOS 

(table 17). That is, only woodlands dominated solely by 

Utah juniper were sampled. We know that Pinus 

monophylla extends northward to the Cache Peak 

Range, near the Silent City of Rocks in southern 

Idaho, and also on the north, south, and easterly 

slopes of the Raft River Mountains in the extreme 

northwestern Utah. However, our random selections 

did not lead us there. If other work expands our 

efforts, other Series are expected to emerge. 

The JUOS Series in Section 342B had six Associations; JUOSIAA, JUOSIAN, JUOSIAT, JUOSIAV, 

JUOSIGusa, and JUOSPutr (table 17). The JUOSIAA 

Association had but the JUOSIAAPssp Sub-association. The JUOSIAN Association was split into JUOSI 

ANE'ose and JUOSIANPssp Sub-associations. The 

JUOSIAT Association was divided into the JUOSIATI 

Eltr, JUOSIATE'ose, and JUOSIATE'ssp Sub-associations. The JUOSIAV Association was split into JUOSI 

AVPose and JUOSIAVPssp Sub-associations. The 

JUOSIGusa Association had but the JUOS/Gusa/Pssp 

Sub-association. The JUOSPutr Association had only 

the JUOSPutrPssp Sub-association (table 17). 

Table 17-Summary of Pinyon-Juniper Woodland Series, Associations, and Sub-associations in Section 342B. See table 2 for key to abbreviations 

for geological formations. 

Soils Soils 

Seriesa ~ssoc.~ sub-a~soc.~ Mtn. range Elev. (m) Aspect Slope Geol. form, (great group) (subgroup) 

JUOS AA Pssp Goose Creek 1,800 W 25 AndesiticJRh. Calciorthids xerollic 

AN Pose Albion 1,600 S 05 

Pssp Black Pine 1,800 E 07 Qu./Lime. Calciorthids xerollic 

Black Pine 1,800 S 11 Qu./Lime. Calciorthids xerollic 

AT Eltr Goose Creek 1,800 E 19 Alluvium Haploxerolls aridic 

Pose Albion 1,600 W 07 

Black Pine 1,800 W 09 SiltISand. Haploxerolls Calciorthidic 

Pssp Black Pine 1,600 S 05 Qu./Lime. Calciorthids xerollic 

AV Pose Sublett 1,600 N 

Pssp Goose Creek 1,800 S 49 AndesiticIRh. Cambiorthids xerollic 

Goose Creek 2,000 S 18 AndesiticJRh. Haploxerolls aridic 

Gusa Pssp Black Pine 1,600 E 05 Qu./Lime. Calcixerolls aridlc 

Putr Pssp Sublett 1,600 W 

'See table 5 for key to Series acronyms. 

b~ee table 6 for key to Association acronyms. 

'See tables 7 and 8 for key to Sub-association acronyms. 

32 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Section M341 A: Pinyon-Juniper 

Woodlands of the Central Great Basin 

Most of Section M341A occurs in central Nevada, 

with a lobe extending easterly to the Deep Creek 

Mountains along the Nevada-Utah border about 100 

miles south of Wendover (fig. 8). This is the region 

of highest average elevation within the Great Basin. 

Although there are higher points elsewhere in our 

study area (for example, White Mountains), even the 

valley bottoms in this Section have elevations generally exceeding 5,000 feet. Because this Section, on 

average, is higher and thus wetter and cooler (and has 

mostly calcareous parent materials, Cronquist and 

others 1972), it has much actual and potential woodland habitat. 

Our random selection of 19 mountain ranges in 

this Section (table 5) yielded the densest set of data 

(table 18) we have for any Section. Even so, we do not 

pretend that we encountered all possibilities here; 

however, we did have greater redundancies and thus 

have more confidence in discussing the woodlands of 

this Section than any other (table 18). 

Six woodland Series were found in Section M341A; 

PIMO, PiMo, Pimo, JUOS, JuOs, and Juos (table 18). 

The PIMO Series was represented by eight Associations; PIMOIAA, PIMOIAN, PIMOIAT, PIMOIAV, 

PIMOIAW, PIMOIAmal, PIMOICele, and PIMOiEpvi. 

The PIMOIAA Association had only the PIMOIM 

Feid Sub-association. The PIMOIAN Association also 

had solely the PIMO/AN/Pssp Sub-association. The 

PIMOIAT Association had the single PIMOIATPose 

Sub-association. The PIMOIAV Association, however, 

had PIMOIAVlF'eid, PIMOIAVLeci, and PIMOIAVI 

Pose Sub-associations. The PIMOIAWAssociationhad 

only the PIMOIAWlStoc Sub-association. The PIMOI 

Amal Association had the PIMO/AmaVBrca and PIMOI 

AmayPssp Sub-associations. The PIMOICele Association had the PIMOICeleiElel, PIMO/Cele/Orhy, PIMOI 

CelePose, and PIMO/Cele/Stoc Sub-associations. The 

PIMOEpvi Association had only the PIMO/Epvi/Pose 

Sub-association. 

The PiMo Series in Section M341AhadnineAssociations; PiMolAA, PiMoIAN, PiMOIAT, PiMoIAV, PiMoI 

AW, PiMoICele, PiMoPugl, PiMoPutr, and PiMoI 

Sylo. The PiMolAA Association was split into the PiMoI 

AAIElel and PiMoIAAFeid Sub-associations. The PiMoI 

AN Association was divided into the PiMoIANlN.G.1 

N.F., PiMoIANlOrhy, PiMoIANPose, and PiMoIANl 

Stoc Sub-associations. The PiMoIAT Association was 

sorted into the PiMoIATlOrhy, PiMo/AT/(Pepa), and 

PiMoIATPose Sub-associations. The PiMolAVAssociation was further segregated into PiMoIAViElel, PiMoI 

AVmeid, PiMoIAVlOrhy, PiMoIAVPose, PiMoIAVlPssp, 

and PiMoIAVlStoc Sub-associations. The PiMoIAW 

Association was split into the PiMoIAWlHija, PiMoIAWl 

Pose, and PiMoIAWlStoc Sub-associations. The PiMoI 

Cele Association was divided into the PiMo/Cele/Elel 

and PiMoICelePose Sub-associations. The PiMoIPugl 

Association had but the PiMoPugliElel Sub-association. The PiMoPutr Association also had only the 

PiMoPutr/Elel Sub-association. The PiMoISylo Association was split into the PiMo/Sylo/Feid and PiMol 

SyloPose Sub-associations. 

The Pimo Series in Section M341A had six Associations (table 18); PimoIAN, PimoIAT, PimoIAV, 

PimoIAW, PimoIAmal, and PimoICele. The PimoIAN 

Association had the Pimo/AN/Elel, PimoIANlOrhy, 

PimoIANPose, and Pimo/AN/Stoc Sub-associations. 

The PimoIAT Association was divided into the Pimol 

ATLElel, PimoIATLeci, PimoIATlPasm, PimoIATlPose, 

and Pimo/AT/(Stco) Sub-associations. The PimoIAV 

Association was divided into Pimo/AV/(Crfl), Pimol 

AVIOrhy, Pimo/AV/(Pede), PimoIAVPofe, PimoIAVl 

Pose, Pimo/AV/Pssp, and Pimo/AV/Stoc Sub-associations. The PimoIAW Association was divided into the 

PimoIAWiElel and Pimo/AWPose Sub-associations. 

The Pimo/Amal Association had but a single Pimol 

AmayPose Sub-association. The PimoICele Association had only the Pimo/CeleiElel Sub-association. 

The JUOS Series in this Section had four Associations; JUOSIAN, JUOSIAT, JUOSIAV, and JUOSI 

AW. The JUOSIAN Association was divided into the 

JUOSIANlOrhy and JUOSIANlPose Sub-associations. 

The JUOSIAT Association had JUOS/AT/(Cacr) and 

the JUOSIATLeci Sub-associations. The JUOSIAV 

Association was split into the JUOSIAVlElla, JUOSI 

AVLeci, JUOSIAVlOrhy, and JUOSIAVPose Subassociations. The JUOSIAW Association was divided 

into the JUOSIAWlLeci and the JUOSIAWPssp 

Sub-associations. 

The JuOs Series in Section M341A was divided into 

four Associations; JuOsIAN, JuOsIAT, JuOsIAV, and 

JuOs/Epvi. The JuOsIAN Association was split 

among the JuOs/AN/Orhy, JuOs/AN/Pose, and the 

JuOs/AN/Pssp Sub-associations. The JuOsIAT Association had the JuOs/AT/Orhy, JuOs/ATPose, and JuOsI 

ATPssp Sub-associations. The JuOsIAV Association 

was divided between the JuOs/AV/Elel and JuOsIAVl 

Pose Sub-associations. The JuOsiEpvi Association had 

but the JuOsiEpvi/Elel Sub-association (table 18). 

The Juos Series in Section M341A had seven Associations; JuosIAN, JuosIAT, JuosIAV, JuosICele, Juosl 

Chvi, JuosiEpvi, and JuoslPutr. The JuosIAN Association was divided into the Juos/AN/Orhy and the Juosl 

ANJPose Sub-associations. The JuosIAT Association 

had only the Juos/AT/Orhy Sub-association. The Juosl 

AV Association was split between the Juos/AV/Elel, 

Juos/AVlPose and the JuosIAVPssp Sub-associations. 

The JuosICele Association was divided between the 

Juos/Cele/Orhy and the JuosICelePose Sub-associations. The JuosIChvi Association had but the Juosl 

ChviIPose Sub-association. The JuosiEpvi Association 

had only the Juos/Epvi/Pssp Sub-association. The Juosl 

Putr Association had only the JuoslPutrlOrhy Subassociation (table 18). 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Table 18-Summary of Pinyon-Juniper Woodland Series, Associations, and Sub-associations in Section M341A. Parentheses indicate that native 

perennial forbs are used in the absence of a native perennial grass todesignate Sub-association. Alsosee table 2 for key to abbreviations 

of geological formations. 

Soils Soils 

Seriesa ~ssoc.~ Sub-as so^.^ Mtn. range Elev. (m) Aspect Slope Geol. form. (great group) (subgroup) 

PlMO AA Feid Shoshone 2,400 N 55 Tuff-Weld. Haploborolls aridic 

AN Pssp White Pine 2,200 E 16 

AT Pose Desayota 2,000 W 36 

AV Feid Shoshone 2,400 N 49 Tuff-Weld. Haploborolls aridic 

Leci Shoshone 2,600 E 45 Rhyolitic Haploborolls aridic 

Pose Shoshone 2,200 N 36 Alluvium Argixerolls aridic 

Shoshone 2,600 N 42 Tuff-Weld. Haploborolls aridic 

Shoshone 2,400 S 40 Conglom. Cambiorthids xerollic 

Shoshone 2,400 S 51 Conglom Argiborolls aridic 

Shoshone 2,600 S 53 Rhyolitic Argiborolls aridic 

Shoshone 2,400 W 49 Conglom Durargids xerollic 

AW Stoc North Egan 2,400 W 73 

Amal Brca Southern Snake 2,200 E 03 Granitic 

Pssp Ruby 2,000 N 52 

Cele Elel Monitor 2,600 S 31 Tuff-Weld. Haploborolls aridic 

Orhy Toiyabe 2,400 S 27 AndesiticIRh. Haploborolls aridic 

Pose Shoshone 2,600 E 32 Tuff-Weld. Argiborolls aridic 

Shoshone 2,600 S 60 Tuff-Weld. Argiborolls aridic 

Shoshone 2,600 W 60 Tuff-Weld. Haploborolls aridic 

Stoc Monitor 2,600 W 40 Tuff-Weld. Haploborolls lithic 

Epvi Pose Shoshone 2,400 E 70 Tuff-Weld. Haploborolls aridic 

PiMo A A Elel North Egan 2,400 N 14 

Feid Shoshone 2,200 N 47 Tuff-Weld. Argixerolls aridic 

AN N.G./N.F.~ Northern Snake 2,200 W 40 

Orhy Simpson Park 2,000 E 17 

Simpson Park 2,000 W 30 

Pose Toiyabe 2,000 E 29 Granitic Paleorthids xerollic 

Toiyabe 2,000 W 25 Alluvium Paleorthids xerollic 

Desayota 2,000 N 18 

Stoc Schell Creek 2,000 N 14 Rhyolitic Cambiorthids xerollic 

AT Orhy Deep Creek 2,000 S 21 

(Peps) Northern Snake 2,400 W 60 

Pose Shoshone 2,200 W 45 Tuff-Weld. Haplargids lithic xerollic 

Southern Snake 2,000 N 09 Granitic 

Clan Alpine 1,800 N 56 

Clan Alpine 1,800 N 28 

Clan Alpine 2,000 E 19 

AV Elel Schell Creek 2,400 E 51 Shale Haploborolls aridic 

North Egan 2,200 S 05 

Feid Toiyabe 2,400 W 51 Limest.1Dolo. 

Simpson Park 2,000 N 39 

Desayota 2,200 E 49 

Feid Sulphur Springs 2,200 N 55 Granitic 

Orhy Desayota 2,200 S 19 

Fish Creek 2,200 W 07 

Pose Shoshone 2,200 N 27 Basaltic Argixerolls aridic 

Shoshone 2,200 E 14 Alluvium Argixerolls aridic 

Shoshone 2,200 E Tuff -Weld. 

Shoshone 2,400 E 60 Tuff-Weld. Argiborolls aridic 

Shoshone 2,200 S 21 Tuff-Weld. Haploxerolls aridic 

Shoshone 2,200 W 55 Tuff-Weld. Haploxerolls aridic 

Monitor 2,400 N 29 Tuff-Weld. 

Desayota 2,000 S 32 

Desayota 2,200 W 30 

Pssp Southern Snake 2,200 W 19 Basaltic 

White Pine 2,400 S 

Stoc North Egan 2,400 E 36 

AW Hija Simpson Park 2,000 S 28 

Pose Deep Creek 2,200 S 34 

Shoshone 2,200 E 07 Alluvium Haploxerolls aridic 

Stoc Northern Snake 2,000 E 18 

Cele Elel Monitor 2,400 E 12 Tuff-Weld. Durargids xerollic , Monitor 2,600 E 38 Tuff-Weld. Haploborolls aridic 

Pose Toiyabe 2,400 E 70 Limest./Dolo. Cambiorthids xerollic 

Pugl Elel Toiyabe 2,200 S 21 Tuff-Weld. Haploxerolls aridic 

Putr Elel Monitor 2,200 E 04 Tuff-Weld. Argixerolls aridic 

Sylo Feid Toiyabe 2,200 W 40 Limest./Dolo. Haploxeroils aridic 

Pose Monitor 2,200 N 02 Tuff-Weld. Haploxerolls lithic (con.) 

34 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Table 18 (Con.) 

Seriesa 

Pimo 

I 

LC 

L' 

6, 

I 

6, 

~ssoc.~ 

AN 

L/ 

AT 

6' 

L/ 

AV 

AW 

Amal 

Cele 

AN 

AT 

AV 

AW 

AN 

AT 

AV 

Epvi 

AN 

AT 

AV 

Cele 

Cele 

Cele 

Chvi 

Epvi 

Putr 

Sub-~SSOC.~ 

Elel 

Orhy 

Pose I 

Stoc 

Elel 

Leci 

Pasm 

Pose 

(Stco) 

(CrfI) 

Orhy 

(Pede) 

Pofe 

Pose 

Pssp 

Soils 

(great group) 

Soils 

Mtn. range Elev. (m) Aspect Slope Geol. form. (subgroup) 

Basaltic 

Granitic 

Northern Snake 

Southern Snake 

Deep Creek 

Sulphur Spring 

Fish Creek 

Northern Snake 

Schell Creek 

Mon~tor 

Roberts Creek 

White Pine 

Deep Creek 

Deep Creek 

Schell Creek 

Ruby 

Bald 

Shoshone 

Shoshone 

Toquirna 

North Egan 

Toquirna 

White Pine 

Northern Snake 

Roberts Creek 

Toquima 

Toquirna 

Monitor 

Shoshone 

Southern Snake 

Roberts Creek 

Monitor 

Diamond 

Diamond 

Sulphur Springs 

Roberts Creek 

Ruby 

Diamond 

Diamond 

Shoshone 

Bald 

Fish Creek 

Diamond 

Fish Creek 

White Pine 

Ruby 

Roberts Creek 

Sulphur Springs 

Deep Creek 

Schell Creek 

Sulphur Springs 

Deep Creek 

Deep Creek 

Schell Creek 

Toiyabe 

Southern Snake 

Fish Creek 

Sulphur Springs 

Bald 

Fish Creek 

North Egan 

Bald 

Schell Creek 

Bald 

Schell Creek 

Toiyabe 

Shoshone 

Schell Creek 

Bald 

AndesiticlRh. 

Tuff-Weld. 

Haploxerolls 

Haplargids 

aridic 

xerollic 

Shale Haploxerolls aridic 

aridic 

xerollic 

Tuff-Weld. 

Alluvium 

Argixerolls 

Durargids 

Tuff-Weld. 

Basaltic 

Granitic 

Cambiorthids 

Haplargids 

xerollic 

xerollic 

Stoc 

Elel 

Pose 

Pose 

Elel 

Orhy 

Pose 

(Cacr) 

Leci 

Ella 

Leci 

Orhy 

Pose 

Leci 

Pssp 

Orhy 

Pose 

Pssp 

Orhy 

Pose 

Pssp 

Elel 

Pose 

Elel 

Orhy 

Pose 

Orhy 

Elel 

Pose 

Pssp 

Orhy 

Pssp 

Orhy 

Pose 

Pose 

Pssp 

Orhy 

Tuff-Weld. Argiborolls aridic 

JUOS 

Granitic 

Basaltic Haploxerolls aridic 

Granitic 

Quartzite 

Granitic 

Haploxerolls 

Cambiorthids 

aridic 

lithic xerollic 

Limest.1Dolo. 

Alluvium 

Basaltic 

Juos 

Granitic 

Lirnest.lDolo. 

Tuff-Weld. 

Tuff-Weld. 

Lirnest.lDolo. 

xerollic 

aridic 

Haplargids 

Argixerolls 

'See table 5 for key to Series acronyms. 

b~ee table 6 for key to Association acronyms. 

'See tables 7 and 8 for key to Sub-association acronyms. d~.~. = no grass; N.F. = no forb; N.S. = no shrub encountered. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Section M341 C: Pinyon-Juniper 

Woodlands in the High Plateaus and 

Mountains of South Central Utah 

Our study area (fig. 1) overlapped slightly with 

Section M341C (fig. 8). We didnot sample the Wasatch, 

Markagunt, and Paunsagunt Plateaus that make up 

most of this unit, but only randomly drew only the 

Tushar Range (table 19). We encountered five Series 

there; JuOs, Juos, PiEd, Pied, and JUSC. 

The JuOs Series in Section M341C had only the 

JuOsIQuga Association and JuOs/Quga/Elel Subassociation (table 19). 

The Juos Series in this Section had the JuosIAT 

and JuosIAV Associations. The JuosIAT Association 

had only the Juos/AT/Orhy Sub-association. The 

JuoslAV Association was divided into Juos/AV/Elel 

and Juos/AV/Orhy Sub-associations. 

The PiEd Series in Section M341C was represented 

by only the PiEdIAV Association and PiEd/AV/Bogr 

Sub-association. 

The Pied Series in this Section had only the PiedICemo 

Association and Pied/Cemo/Orhy Sub-association. 

The JUSC Series appeared only when sampling 

Sections M341C and M341F. It was represented only 

by the JUSCIAV Association and JUSClAV/Bogr Subassociation (table 19) in Section M341C. 

Table 19-Summary of Pinyon-Juniper Woodland Series, Associations, and Sub-associations in Section M341 C. See table 2for key to abbreviations 

of geological formations. 

JuOs 

Juos 

PiEd 

Pied 

JUSC 

~ssoc.~ Sub-assocnc Mtn, range 

Quga Elel Tushar 

AT Orhy Tushar 

AV Elel Tushar 

Orhy Tushar 

AV Bogr Tushar 

Cerno Orhy Tushar 

AV Bogr Tushar 

Elev. (m) 

2,000 

2,000 

2,200 

2,000 

2,000 

2,200 

2,200 

Aspect 

W 

E 

N 

N 

s 

E 

S 

Slope 

04 

27 

16 

18 

31 

27 

21 

Geol, form. 

AndesiticIRh. 

Conglom 

AndesiticIRh. 

Conglom 

AndesiticIRh. 

Conglom 

AndesiticIRh. 

Soils 

(great group) 

Argixerolls 

Calcixerolls 

Durorthids 

Argixerolls 

Haploxerolls 

Haploxerolls 

Haploxerolls 

Soils 

(subgroup) 

aridic calcic 

aridic 

typic 

aridic 

aridic 

aridic 

lithic 

'See table 5 for key to Series acronyms. 

b~ee table 6 for key to Association acronyms. 

'See tables 7 and 8 for key to Sub-association acronyms. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
Comparison of Groupings Between 

Sections 

This completes the presentation of findings at the 

Section level. We now turn to comparison of Series, 

Associations, and Sub-Associations between Sections 

to see where overlaps occur and whether any larger 

generalizations are possible. To do this, consult 

table 10 where we have listed all ofthe Series, Associations, and Sub-Associations identified in this initial 

classification along the three far left columns. Into 

the columns to the right, we have listed the number of 

stands sampled in each of the nine Sections and totals 

for the samples in each. On the last few lines of 

table 10 are the total numbers of sampled stands for 

each Series, Association, and Sub-association in each 

Section and for the total study. 

Plant species within the Great Basin pinyon-juniper 

woodlands are not randomly intermingled; there are 

definite latitudinal, longitudinal, and elevational patterns. For instance, Pinus monophylla dominates in 

the west and south and occurs mostly at the higher 

elevations there. The leading understory shrubs under Pinus monophylla dominated woodlands are more 

often those associated with more mesic environments 

than occurs with juniper (table 10). The PiMo Series is 

the only one that was found in eight out of nine 

Sections, while the PIMO Series is found in four Sections (table 10). Juniperus osteosperma is much more 

widespread than the two pinyon species and thus has 

a much wider array of leading understory shrubs 

(table 10). Afew grasses arevery widespread (table 7). 

For instance, Indian ricegrass (Oryzopsis hymenoides) 

is a dominant found in every Section and Series 

(table 10). Blue grama (Bouteloua gracilis), while 

found as an understory dominant in nearly all the 

Series, is found only in the more southerly or lower 

elevation Sections (table 10). Thus, Boutelouagracilis 

(Bogr) and the other major warm season perennial 

grass, Hilaria jamesii (Hija), are indicators of relatively warmer and drier conditions wherever they are 

found. 

Putting the indicator value of shrubs together with 

the indicator value of the leading dominant grasses 

(table 8) shows that cool season grasses are definitely 

more common under the tall sagebrushes and other 

shrubs associated with generally higher elevations, 

more northerly latitudes, northerly slopes in the 

south, or otherwise more mesic conditions. Warm 

season grasses have an affinity for low sagebrushes 

and other shrubs that are associatedwithmore desertlike conditions. 

There are some general relationships between vegetational Series and soil Orders related to elevation 

and temperature (fig. 7). Argiborolls and Haploborolls 

are confined to the pinyon dominated vegetational 

Series, and Calciorthids and Calcixerolls are found 

predominately with Utah juniper dominated Series. 

Camborthids and Haploxerolls are found in all Series 

(table 20). 

Topographic and soils influences within the Sections cannot be reliably identified from this initial 

attempt at classification. We found the landform descriptors used in the field were too vague to be consistently applied by field crews not trained in geomorphology. More detailed analysis within the Shoshone 

and Needle Ranges incorporating topography and 

soils will be reported on in subsequent publications. 

Table PO-Relationship of vegetational series to soil orders. Numbers in cells indicate number of stands where adequate soil 

descriptions were made to allow the correspondence to be expressed here. 

Vegetational Seriesa 

Soil order PlMO PiMo Pimo JUOS JuOs Juos JUSC PiEd Pied 

Argiboroll 6 2 2 

Argixeroll 1 4 4 3 6 

Calciorthid 4 5 2 2 

Calcixeroll 1 1 4 2 6 

Camborthid 5 4 5 1 3 4 

Durargid 1 1 1 

Durorthid 1 

Haplargid 2 4 1 1 1 

Haploboroll 16 4 1 

Haploxeroll 15 11 6 6 2 1 1 1 

Palorthid 2 1 3 

Palexeroll 1 

Torrifluvent 1 

aSee table 5 for key to Series acronyms. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 37 
Validation 

We now need to consider how complete the classification presented herein is, as well as its reliability. 

The ultimate answers to these questions require practical attempts to use our classification. We can, however, report some preliminary testing. 

Because we sampled the Shoshone and Needle 

Ranges more intensively, yet excluded the data from 

intervening elevations and exposures in developing 

the classification presented here, we can now bring 

those data forward and see how much overlap there 

is with the initial identifications within the hierarchy of the classification and speculate on how many 

new Associations and Sub-associations need to be 

identified. 

Basin-wide classification identified only about half 

(28 out of 45) of the Sub-associations sampled on the 

Shoshone Range (table 21). Only three out of 31 Subassociations were identified elsewhere in Section 341E. 

This again illustrates the great variability in dominant plant species combinations within pinyonjuniper woodlands. 

Sampling of woodlands on the Needle Range by the 

two teams involved greatly different intensities of 

sampling (table 22). Team A looked at 48 stands 

whereas Team B looked at only 10 stands. It was, 

therefore, inevitable that their work would differ in 

the resulting classification categories. In fact, only one 

(PiMo/ArtrvalOrhy) out of 46 Sub-associations was 

sampled by both teams. This points out the degree to 

which initial sample size and the guidelines used, plus 

Table 21-Comparison of pinyon-juniper woodland stand placement on the Shoshone Range, Nevada, using abbreviated 

(200 m elevation increments) versus full (each 100 m elevation) sampling. Numbers are the number of stands 

observed in each hierarchial level. 

Number of stands 

Seriesa ~ssociation~ Sub-associationc Abbreviated Full Total Predicted 

PlMO 

PiMo 

I 

cr 

<( 

< 

< 

6 

,' 

Pimo 

L< 

rc 

8 

JUOS 

JuOs 

Juos 

'I 

Total 

A A 

AV 

Cele 

E pvi 

Pugl 

A A 

AN 

AT 

AV 

AW 6 

Cele 

Epvi 

Pugl 

Putr 

Sylo 

A A 

AT 

AV 

AW 

Pugl 

Putr 

AV 

AW 

AW 

Cele 

Chvi 

Feid 

Pose 

Pose 

Pose 

Pose 

Pose 

Feid 

Pose 

Pose 

Pose 

Feid 

Pose 

Elel 

Pose 

Pose 

Pose 

Pose 

Pose 

Feid 

Pose 

Pose 

Pose 

Elel 

Pose 

Elel 

Pose 

PsXsa 

Pose 

Pose 

Leci 

Elel 

No 

N 0 

Yes 

Yes 

N 0 

N 0 

No 

No 

Yes 

Yes 

Yes 

Yes 

N 0 

Yes 

Yes 

Yes 

N 0 

No 

Yes 

N 0 

No 

No 

Yes 

Yes 

No 

Yes 

Yes 

Yes 

No 

No 

Yes 

1 6 yes 

15 no 

aSee table 5 for key to Series acronyms. 

b~ee table 6 for key to Associat~ons acronyms. 

'See tables 7 and 8 for key to Sub-associations acronyms. 

38 USDA Forest Service Gen. Tech. Rep, RMRS-GTR-12. 1998 
Table 22-Comparison of pinyon-juniperwoodland standplacement on the Needle Range, Utah, using abbreviated (200 m elevation 

increments) vs. full (each 100 m elevation) sampling. The findings of the two teams are designated A or B. Numbers are 

of stands sampled within that hierarchial level. Y = yes, was predicted, N = not predicted, I = Sub-association that was 

identified in Section 341A. 

Seriesa ~ssociation~ Sub-associationc 

PlMO A A Elel 'L AN Bogr 66 AV Bogr (1 61 Pose 66 , Pssp 6, Cele Pose 6, Chvi Elel 

PiMo AN Orhy , AT N.G.~ '6 AV Elel ,c (C N.G. (6 ,c Orhy 66 Orhy L Amal Pose 66 Pssp 66 Mare Elel (C Syor N.G./N.F.~ 

Pimo AN Bogr 'I (( Elel rc 66 Pose 66 AV Elel 66 ,, Orhy ,L 6, Stco (1 AW Orhy ,c Amal N.G. 

Cele Orhy L Chvi Elel 6 Gusa Orhy 

Mare Elel 'L N.S. N.G./N.F.~ 'I Pume Arpu 

JUOS Chvi Pssp 

JuOs A A Hija 66 AN Orhy 66 AW Orhy 

Chvi Elel 

Gusa Hija 

Juos AN Arpu (6 66 Elel , 66 N.G./N.F.~ 

(6 AV Elel 66 LL N.G./N.F.~ 

6, 6' Orhy ,c Cele Arpu (6 Chvi Stoc (6 Epvi N.G./N.F.~ '6 Erum N.G./N.F.~ 66 Putr Elel 

Totals 

Abbreviated Full Total Team Predicted 

N 

N 

Y/I 

Y/I 

Y/O 

Y/I 

Y/I 

Y/I 

Y/I 

Y/I 

Y/O 

Y/I 

Y/I 

Y/I 

Y/I 

N 

A 

Y/I 

Y/I 

Y/I 

Y/I 

Y/I 

N 

Y/I 

N 

Y/I 

N 

N 

N 

N 

N 

Y/I 

Y/I 

Y/I 

Y/I 

N 

aSee table 5 for key to Series acronyms. 

b~ee table 6 for key to Associations acronyms. 

'See tables 7 and 8 for key to Sub-associations acronyms. 

d~.~. = no grass; N.F. = no forbs encountered. 

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12.1998 
Table 23-Comparison of classification of the pinyon-juniperwoodlands of the Mineral Range, Utah, 

by two teams using the "rapid" approach. 

Seriesa ~ssociation~ Sub-associationc Number of stands Team 

Pimo Cele 

JUOS AT 

JuOs 

Cele 

Quga 

Juos AN 

Putr 

N.G./N.F.~ 

Ella 

Mumo 

N.G./N.F.~ 

Bogr 

N.G./N.F.~ 

Pssp 

Elel 

Elel 

Pssp 

Elel 

Eltr 

N.G./N.F.~ 

Pssp 

Orhy 

aSee table 5 for key to Series acronyms. 

b~ee table 6 for key to Associations acronyms. 

'See tables 7 and 8 for key to Sub-associations acronyms. 

d~.~. = no grass; N.F. = no forbs encountered. 

the choices made by different crews for locating sampling sites influence the outcome. It also illustrates 

the requirement for a classification hierarchy to be 

simple, open-ended, and adaptable to be useable in 

Great Basin woodlands. 

The sampling of the Mineral Range by two different 

teams, both working in the "rapid" mode had no 

overlap at the Sub-association level (table 23). Even at 

the Association level, there was only three out of nine 

Associations in common (table 23). Only three of the 

four Series were even sampled by both teams. 

The above should demonstrate that the classification presented constitutes only the first outline, a 

skeleton on which to build. Users should be prepared 

to at least add their own additional units at the 

Association, Sub-association, and finer grained (local) 

levels. Everywhere this classification is used, it will 

need to be expanded to the more site specific Landtype 

Association and Landtype levels. Between the Association and Sub-association levels, and possibly between other levels as well, additional environmental 

factors will possibly need to be included. This is probably most true where Landtype Association and 

Landtype levels are involved. Nevertheless, the methods proposed to expand this classification are easy and 

open ended enough so that adding to the system 

should be routine. The authors would appreciate receiving feedback from readers on additions and modifications they find necessary in practice. 

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42 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-12. 1998 
West, Neil E.; Tausch, Robin J.; Tuelle'r, Paul T. 1998. A management-oriented classification 

of pinyon-juniper woodlands of the Great Basin. Gen. Tech. Rep. RMRS-GTR-12. Ogden, 

UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 

42 p. 

A hierarchical framework for the classification of Great Basin pinyon-juniper woodlands 

was based on a systematic sample of 426 stands from a random selection of 66 of the 

11 0 mountain ranges in the region. That is, mountain ranges were randomly selected, but 

stands were systematically located on mountain ranges. The National Hierarchical Framework of Ecological Units (ECOMAP) was used for the highest levels of classification, 

subdividing the Great Basin into nine relatively environmentally homogeneous Sections. The 

remaining levels are vegetation-based, focusing on the relative composition and dominance 

of pinyon and juniper and the dominant shrub and perennial grass species present. This 

approach will allow managers to better relate the results of previous, as well as new studies 

and management experiences. 

Keywords: pinyon, juniper, vegetation classification, ECOMAP, Ecoregions, management 

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