FIELD ESTABLISHMENT OF SPINY
HOPSAGE
Nancy L. Shaw
Marshall R. Haferkamp
ABSTRACT
Feasibility of including spiny hopsage (Grayia spinosa
[Hook.] Moq.) in revegetation plantings was examined by
investigating the effect of utricle source, site preparation
technique, planting date, and environmental conditions
on seedling emergence and establishment at two southern
Idaho sites. Seedlings emerged in early March from early
and late fall plantings. Favorable moisture conditions supported high emergence at one site; drought conditions severely impacted emergence at the second site and seedling
establishment at both sites.
INTRODUCTION
A summer deciduous chenopod shrub endemic to the
western United States, spiny hopsage (Grayia spinosa
[Hook.] Moq.) is distributed east of the Cascades and
Sierra Nevadas from central Washington to southern
California and eastward to southwestern Montana and
western Colorado (Hitchcock and Cronquist 1973). In
the northern part of its range, spiny hopsage is commonly
associated with a variety of salt desert shrub communities
and drier portions of Wyoming big sagebrush communities
(Artemisia tridentata ssp. wyomingensis) (Daubenmire
1970; Welsh and others 1987). It often grows intermixed
with other shrubs, rarely occurring in pure stands.
Where abundant, spiny hopsage provides palatable and
nutritious late-winter and spring forage for big game and
livestock, particularly sheep (Blaisdell and Holmgren 1984;
Blauer and others 1976; Daubenmire 1970; McArthur and
others 1978; McCullough 1969). It is also used seasonally
to varying degrees by upland game birds, rodents, and rabbits (Dasmann and Blaisdell1954; Gullion 1964). Krysl
and others (1984) and McCullough (1969) reported crude
protein contents of 11.8 percent in summer and 18 percent
in late winter, respectively. The shrub provides dense,
low-growing cover for birds and other small animals
(USDA Soil Conservation Service 1968), although its
cover value is decreased to some extent following summer
leaf fall.
Spiny hopsage is capable ofresprouting following burning or mechanical damage (Daubenmire 1970; Smith 1974;
Paper presented at the Symposium on Cheatgrass Invasion, Shrub DieOff, and Other Aspects of Shrub Biology and Management, Las Vegas, NV,
April 5-7, 1989.
Nancy L. Shaw is Botanist, Intermountain Research Station, Forest
Service, U.S. Department of Agriculture, Boise, ID 83702. Marshall R.
Haferkamp is Plant Physiologist, Fort Keogh Livestock and Range Research
Laboratory, Agricultural Research Service, U.S. Department of Agriculture,
Miles City, MT 59301.
193
USDA Soil Conservation Service 1968; Wasser 1982) and
is least susceptible to fire during the period of summer dormancy (Rickard and McShane 1984). Both attributes are
desirable for shrubs planted in areas with high wildfire
frequencies. Spiny hopsage is also rated as a useful shrub
for control of wind erosion and an effective soil surface
stabilizer on gentle to moderately steep slopes due to its
dense, low-growing crown and spreading root system
(Dittberner and Olsen 1983; Institute for Land Rehabilitation 1979; USDA Soil Conservation Service 1968).
To date, spiny hopsage has received limited use in
revegetation projects. Early planting failures in Utah
were attributed to placing utricles at excessive depths.
Kay and others (1977) found a 0.4-inch (10-mm) planting
depth provided best emergence from washed plaster. Wood
and others (1976) reported 51 and 48 percent emergence
from bracted and debracted utricles planted 0.2 inches
(5 mm) deep. Surface broadcasting was recommended
by Glazebrook (1941). However, Wood and others (1976)
found few or no seedlings established when debracted
utricles were broadcast on packed, smooth, or rough soil
surfaces or when bracted utricles were broadcast on packed
or smooth surfaces in a greenhouse experiment. Broadcasting bracted utricles on a rough soil surface resulted in
18 percent seedling establishment.
Available data from laboratory germination work provide
some guidelines for devising improved field planting strategies for spiny hopsage. King (194 7) reported stratification
promoted germination of utricles harvested at Soap Lake
in eastern Washington. Stratification at 41 °F (5 °C) was
more effective than at 34 °F (1 °C). Maximum germination
of 4-year-old utricles was obtained with a 6-week stratification period while a 2-week treatment released dormancy
of 6-year-old utricles; this suggested a gradual loss of the
prechilling requirement during dry storage. Wallace and
Romney (1972), Wallace and others (1970), and Wood and
others (1976) found utricles from California's Mojave Desert and several sites in Nevada were not dormant and
required no prechilling.
Glazebrook (1941) demonstrated that light had no influence on germination of utricles at 71 to 79 °F (22 to 26 °C)
after being stored for 1 year. Wood and others (1976) obtained highest constant temperature germination of one
California and four Nevada accessions at 50 and 59 °F
(10 and 15 °C). Of 55 alternating temperature combinations tested, a 41 °F (5 °C) low temperature alternating
with high temperatures from 50 to 86 °F (10 to 30 °C)
produced greatest total germination. They suggested these
temperatures reflected the ecological requirements of species native to cold-arid environments that germinate in late
fall or early spring when soil-moisture levels are high.
This file was created by scanning the printed publication.
Errors identified by the software have been corrected;
however, some errors may remain.
Establishment of spiny hopsage from utricles or by transplanting offers a means ofimproving the diversity of native
shrub plantings on adapted sites. Few native woody species occur in many of these areas and commercial sources
of disseminules or planting stock for most are limited. Ability to establish the shrub from utricles would permit its use
in large-scale plantings.
The objective of this study was to investigate the feasibility of establishing spiny hopsage from utricles in the
northern portion of its range. Specific objectives were to
determine the effect of utricle source, planting date, and
site preparation technique on emergence and establishment
of spiny hopsage on two southern Idaho sites.
STUDY SITES
Reynolds Creek-The Reynolds Creek study site is
located in the northern foothills of the Owyhee Mountains
approximately 41 miles (66 km) southwest of Boise, ID.
Elevation is approximately 3,900 ft (1,190 m). Mean annual precipitation is 9.2 inches (234 mm) and mean annual
temperature is 46 to 52 op (8 to 11 °C) (Stephenson 1977).
Soils are fine loamy mixed mesic Typic Haplargids derived
from granitic, basaltic, and rhyolitic alluvium. Wyoming
big sagebrush, shadscale (Atriplex confertifolia), greasewood (Sarcobatus vermiculatus ), spiny hop sage, and bottlebrush squirrel tail (Sitanion hystrix) are major perennial
species. Cheatgrass brome (Bromus tectorum), Russian
thistle (Salsola iberica), and clasping pepperweed (Lepidium perfoliatum) are common annual weeds. The site was
burned in August 1984, and fall seeded to Siberian wheatgrass (Agropyron sibiricum ), nomad alfalfa (Medicago
sativa 'Nomad'), yellow sweet clover (Melilotus officinalis),
and fourwing saltbush (Atriplex canescens) (Mowbray
1990).
Birds of Prey-The Snake River Birds of Prey National
Conservation Area is located on the Snake River Plains
approximately 22 miles (36 km) southwest of Boise in Ada
County, ID. The study site is located at an elevation of
2,790 ft (850 m). Mean annual temperature is 51 °F
(11 °C) and the frost-free season averages 150 days (Collett
1980). Mean annual precipitation at the Kuna 2 Weather
Station, approximately 13 miles (20 km) northwest of the
site is 9.8 inches (248 mm). Soils are well-drained coarse
silty mixed mesic Haplo Xerolic Durorthids formed over
loess on a basalt plain. Depth to the hardpan is 1.6 to
3.3 ft (0.5 to 1.0 m). Major perennial species are Wyoming
big sagebrush, winterfat (Ceratoides lanata), spiny hopsage, Sandberg bluegrass (Poa secunda), and bottlebrush
squirreltail. Common introduced annuals include cheatgrass brome, Russian thistle, and clasping pepperweed.
A wildfire removed most woody cover from the site in July
1985 (Pellant 1990). The burn was drill seeded in March
1986, to a mix of Fairway crested wheatgrass (Agropyron
cristatum), Siberian wheatgrass, Russian wildrye (Elymus
junceus), fourwing saltbush, and winterfat. Due to drought
conditions, seeding success was variable.
MATERIALS AND METHODS
Ripe utricles were harvested in May and June 1986, at
Birds of Prey and Reynolds Creek in southwestern Idaho
and at Sponge Springs, Malheur Co., in southeastern Oregon (table 1). Collections were made by beating the shrubs
with a wooden paddle and catching the utricles in a canvas
hopper. Twigs, large leaves, and other coarse material
were removed from air-dried collections using an air screen
machine with a No. 36 top screen and a No.8 bottom
screen. Removal of papery bracts enclosing utricles was
attained with a standard Dybvig seed processor modified
by adding a corrugated plastic liner and corrugated plastic
paddles on a central axle. Threshed utricles were separated from the chaff with an air screen machine fitted with
a 1/12 top screen and a lf21 bottom screen. They were then
stored in sealed plastic containers at approximately 37 to
41 °F (3 to 5 °C).
A grid of 96 plots was established and planted on each
study site in 1986-87. Seedbeds were prepared by rotatilling on August 25 and again on October 14 and 15, 1986,
after heavy rains and emergence of cheatgrass seedlings.
Table 1-Characteristics of spiny hopsage utricle collection sites
Collection site
Sponge
Springs
Reynolds
Creek
Birds of
Prey
Location
Owyhee Co., ID
Malheur Co., OR
Ada Co., ID
Vegetation
Artemisia tridentata
ssp. wyomingensis,
Grayia spinosa,
Bromus tectorum
Artemisia tridentata
ssp. wyomingensis,
Sarcobatus vermiculatus,
Grayia spinosa, Bromus
tectorum
Artemisia tridentata
ssp. wyomingensis,
Ceratoides lanata,
Grayia spinosa,
Poa sandbergii
Elevation (m)
1,220
991
850
234
228
248
Coarse loam
Coarse, silty, mixed,
mesic Haplo Xerotic
Durorthids
Precipitation
(mm)
Soil
Coarse-loamy, mixed,
nonacid, mesic Xeric
Torriorthents
194
in late May, dry conditions prevailed through the spring
and summer months. Moisture content of the upper
1.2 inches (30 mm) of soil was low during much of the
winter. It increased to 14.4 percent in mid-February, but
decreased to 4.0 percent by mid-March and remained low
through most of the growing season, except for brief periods following storms.
Table 2-5eeding dates, 1986-87
Seeding
Early fall
Late fall
Early spring
Late spring
Study site
Reynolds Creek
Birds of Prey
November 12, 1986
December 11, 1986
March 14, 1987
April 12, 1987
November 5, 1986
December 2, 1986
March 11, 1987
April 8, 1987
Fall Plantings-Spiny hopsage seedlings emerged
from early and late fall-planted utricles during an 11-day
period from about March 4 to 15. Precipitation totaling
0.51 inches (13 mm) fell on six days during emergence.
Mean maximum and minimum air temperatures averaged
55 and 35 °F (13 and 2 °C) (fig. 2). Minimum air temperatures were at or below freezing on 32 days after the earliest seedling emergence occurred. The last freeze occurred
onMay22.
Significant utricle source x site preparation and utricle
source X planting date interactions for seedling density
were present on March 22 (table 3). Although there was
Residual rootcrowns of shrubs and perennial grasses
were removed manually. Treatments were utricle source
(table 1), planting date (table 2), and site preparation
(rough or compact surface) arranged in a randomized complete block design with four replications. Individual plots
were 10ft by 5 ft (3.0 m by 1.5 m). Plot surfaces were prepared just prior to planting. Rough surfaces were created
by hand raking. Compact surfaces were prepared by hand
raking followed by twice over compaction with a roller 2 ft
(0. 7 m) wide and 1.5 ft (0.5 m) in diameter, weighing 240 lb
(109 kg).
Five rows 10ft (3m) long and 1ft (0.3 m) apart were
planted in each plot with a single-row small plot seeder.
Viable utricles were planted at a rate of 20 per linear foot
(66/linear meter) equivalent to 20 per ft 2 (217/m2). Calculations of viability were based on results oftetrazolium
staining tests. Planting depth was approximately 0.1 to
0.2 inches (2.5 to 5 mm).
Both sites were fenced to exclude livestock. Weeds
were removed manually during the 1987 growing season.
Precipitation, air temperature, and 0.0- to 0.8-inch (0- to
20-mm) soil temperature were monitored at Birds of Prey.
Precipitation was monitored at the Reynolds Creek site.
Air temperature was measured at the Reynolds Weather
Station approximately 2 miles (3.2 km) south of the
Reynolds Creek study site. Soil moisture for the 0- to
1.2-inch (0- to 30-mm) depth at each site was determined
gravimetrically on 12 samples collected on selected dates
from November 1986, to June 1987.
Seedling emergence and establishment at each site were
monitored on selected dates throughout the first growing
season. Seedling density was measured on three 6.6-ft
(2-m) transects, and frequency of distribution was determined on twelve 1.65-ft (0.5-m) transects placed within
rows in the interior of each plot.
Effect of utricle source, planting date, and seedbed preparation were test&d for each site using analysis of variance
for a randomized complete block design. Mean separation
tests were made using FLSD0_05 (Peterson 1985). Frequency data were transformed for analysis with arcsin {ji
using the correction for small sample size recommended
by Snedecor and Cochran (1980).
10 Precipitation CmmJ
D
1111-11
10 ..... 17 .,. ., ,.,.,....
40
80
20
OCT
NOV
1988
DEC
JAN
FEB
MAR
APR
MAY
JUN
JUL
1887
Figure 1-Monthly precipitation at the Reynolds
Creek study site.
RESULTS
Reynolds Creek
~0~---------------------------------------NOV
DEC
JAN
FEB
MAR
APR
WAY
JUN
JUL
September through January precipitation was 36 percent
of normal (fig. 1). With the exceptions of above-average
rainfall in February and early March and record rainfall
195
1986
1987
Figure 2-Mean weekly maximum and minimum air
temperatures at the Reynolds Creek study site.
Table 3-Spiny hopsage seedling density (No./m2) on fall-seeded plots at Reynolds Creek,
March 22, 1987
Site
preparation
Planting
date
Reynolds Creek
Utricle source
Sponge Springs
Birds of Prey
- - - - - - - - - - - - - - - - - - Seedlings/rrf - - - - - - - - - - - - - - - - 133.oa1
107.]8-1
137.3a1
1,289.1b1
ss.ob 1
Rough
Compact
Early fall
Late fall
8s.ob 1
69.ob 1
103.5a2
62.8c1
58.9b1
11.ob1
50.]C1
1Within rows, means followed by the same letter do not differ (p ~ 0.05).
2Means for site preparation or planting date in the same column followed by the same number
do not differ (p ~ 0.05).
43.2 percent for the Sponge Springs to 31.3 percent for
the Reynolds Creek source. Significant differences again
existed among density means for utricle source and site
preparation technique. However, among utricle sources,
only the means for the Sponge Springs and Birds of Prey
sources differed significantly.
Final seedling counts were completed on July 13 as
leaves were beginning to dry prior to abscission and 'summer dormancy. Overall density decreased only slightly
between May 24 and July 13 (table 4). Emergence of new
seedlings and minor increases in density for late-fall plantings and the Reynolds Creek and Sponge Springs utricle
sources may have occurred in response to unusually heavy
rains in late May (fig. 1). Difficulty in distinguishing all
recently emerged seedlings prevented determination of
actual seedling losses and gains since the previous sampling date. Few Melanotrichus nymphs were noted, but
drought effects continued to impact seedling survival
and vigor. Significant differences in density existed only
among utricle sources with density of Sponge Springs seedlings significantly exceeding that of Birds of Prey seedlings
(table 4).
As a result of extremely active emergence in March,
seedling frequency was high throughout the growing
season, ranging from 98.4 percent on March 27 to 86.3
percent on May 27. Seedling distribution was uniform
and similar among all treatments on each sampling date.
a trend toward greater emergence on rough compared to
compact surfaces, differences were not significant. Greater
early fall compared to late-fall densities were significant
only for the Sponge Springs source. Significantly more
seedlings emerged from Sponge Springs utricles compared
to the other two sources for each site preparation technique
and planting date. Total Reynolds Creek emergence was
significantly greater than Birds of Prey emergence on
rough surfaces and from late-fall plantings, but not from
compact surfaces nor from early fall plantings.
Seedling densities for all fall-planted plots decreased
considerably by April 23 (table 4). Many seedlings were
withered or stressed by dry conditions. A small percentage
of seedlings were damaged or killed by Melanotrichus spp.
nymphs. Decrease in seedling density from all causes varied from 49.2 percent for the Sponge Springs to 41.7 percent for the Birds of Prey utricle source. Significant differences in density of remaining seedlings resulted from
utricle source and site preparation technique. Seedling
density was greatest for the Sponge Springs followed by
the Reynolds Creek and Birds of Prey utricle sources.
Densities on rough surfaces were significantly greater
than on smooth surfaces (table 4).
Drought conditions combined with increased predation
by Melanotrichus nymphs resulted in further declines in
seedling numbers by May 24 (table 4). Shoots of a small
number of seedlings were damaged or broken by a hail
storm. Mean decrease in seedling density ranged from
Ta.ble 4-Spiny hopsage seedling density (No .1m2) on fall-seeded plots at Reynolds Creek on
selected dates in 1987
Date
Site preparation
Rough
Compact
Reynolds
Creek
Utricle source
Sponge
Springs
Birds of
Prey
-----------------------Seedfings/rrf---------------------April23
May 24
July 13
41.4b
2s.P
42.5b
29.2ab
29.4ab
35.5c
23.6b
21.P
1Within site preparation methods and utricle sources, means in the same row followed by the same letter
do not differ (p ~ 0.05).
196
.w
Spring Plantings-Seedlings were observed on springplanted plots only after record late-May rainfall. Four seedlings emerged from early spring and four from late-springplanted plots. These eight seedlings included emergents of
all three accessions and both site preparation techniques.
2.0
Birds of Prey
10
October to January precipitation at the Birds of Prey site
totaled only 1.38 inches (35 mm) (fig. 3), an amount similar
to that received at Reynolds Creek over the same period.
Early February precipitation was high, but drought conditions returned by mid-February. Spring precipitation
patterns were also similar at both sites. March, April,
and much of May were quite dry with heavy rains falling
in late May.
Moisture content in the surface 1.2 inches (30 mm) of
soil was low throughout much of the winter, increasing
from 3.1 percent in mid-November to 15 percent in midFebruary and decreasing to 1. 7 percent by April 23.
30
0
-10
-20
DEC
NOV
FEB
JAN
1988
50
WAR
APR
NAY
APR
t.CAY
1987
B
Soli
Temperature (Oc)
40
Fall Plantings-Most spiny hopsage seedling emergence
occurred from approximately March 1 to 10. Mean maximum and minimum air temperatures were 59 and 37 °F
(15 and 3 °C) (fig. 4). Mean maximum and minimum temperatures for the surface 0.8 inches (20 mm) of soil were
53 and 36 °F (12 and 2 °C) (fig. 4). Twenty-three days with
minimum air temperatures at or below freezing occurred
after emergence began, the last occurring on May 3.
Initial seedling counts on March 25 revealed emergence
of 2.8 seedlings/m2 for the Reynolds Creek and Sponge
Springs utricle sources and 1.6 seedlings/m2 for the Birds
of Prey source. Seedling density varied significantly among
utricle sources; density of Birds of Prey seedlings was significantly lower than density of the other two accessions.
Withering and dead seedlings were observed.
50
A
Air
Temperature (Oc)
30
2.0
10
0
-10
-2.0
DEC
NOV
1986
JAN
FU
MAR
1987
Figure 4-Mean weekly maximum and minimum air
(A) and soil (B) temperatures at the Birds of Prey
study site.
Precipitation (mm)
By April 22, most seedlings had succumbed, apparently
as a result of drought conditions. A few seedlings were
damaged or destroyed by seed harvester ants (Pogonomyrmex salinus). Only eight seedlings remained on the
grid. No seedlings survived on May 23.
Frequency of seedling distribution reflected the poor
seedling emergence and averaged 27.2 percent in March.
Frequency of Sponge Springs seedlings (34.2 percent) was
significantly greater than that of Birds of Prey seedlings
(20.2 percent), with that of Reynolds Creek intermediate
(27.1 percent). By April22, frequency decreased to 5.6
percent with no significant differences among treatments.
"0
30
20
10
o~--~----~----~--~----~----~--~----~
OCT
NOV
1888
DEC
JAN
FEB
MAR
APR
Spring Planting-No seedlings were observed on
early or late spring-planted plots on any observation date.
Lack of emergence following heavy precipitation in late
May may be attributed to inadequate spring stratification
or the very transient improvement in surface soil moisture following the storms. Undetected seedlings may
have emerged and died between observation dates.
MAY
1887
Figure 3-Monthly precipitation at the Birds of
Prey study site.
197
DISCUSSION
Spiny hopsage can be established by planting utricles
on southern Idaho rangelands. Contrasting results at two
study sites during a drought year indicate a need for further work to define requirements for germination and seedling establishment, develop technology to enhance planting
success, and determine the economic feasibility of adding
the species to revegetation projects in low-precipitation
areas.
Fall plantings appear to be essential to provide sufficient
stratification for release of dormancy. In the present
study, adequate stratification evidently occurred at both
sites for fall plantings even though the soil was quite dry
throughout much of the winter. Laboratory work indicated
all three seedlots required a 45- to 60-day stratification at
2 to 5 °C to release dormancy (Shaw 1990). The significant
two-way interaction between fall planting date and utricle
source at Reynolds Creek in March may be indicative of
variability in stratification requirements among utricle
sources. Decreased dormancy may persist into the summer
in at least some ungerminated seed as indicated by the
emergence that occurred following May rains at Reynolds
Creek.
Emergence of fall-planted utricles occurred rapidly and
fairly uniformly at both sites as the soil surface began
thawing. Young seedlings were capable of surviving subsequent periods of below-freezing minimal air temperatures. Glazebrook (1941) commented that spiny hopsage
seedlings could be frozen solid "while still very young" and
yet survive. Early emergence maximizes ability of seedlings to compete with cheatgrass and other winter and
summer annuals (Vallentine 1980). It also permits maximal seedling growth prior to soil moisture depletion and
onset of summer dormancy. Larger seedlings were noted
to retain leaves and continue growth longer than smaller
ones.
The apparently greater germinability and vigor of the
Sponge Springs utricles have not been examined. Differences could be genetic or environmental in nature, the
latter relating to factors impacting utricle maturation,
harvest date, or utricle handling. Utricle weights of all
three accessions differed significantly (Shaw 1990). Sponge
Springs utricles were heaviest followed by Reynolds Creek
and Birds of Prey. Disseminule weight can be used as a
predictor of seed vigor for some species (Bewley and Black
1983), but the relationship has not been examined for spiny
hopsage. Long-term adaptability of the Sponge Springs
accession to either study site is not known.
The surface compaction treatment was designed to increase uniformity of seeding depth. Soil was compacted
directly o'ver the utricles by the press wheel of the drill
on both rough and compact surfaces. Greater survival on
rough surfaces through the May evaluation at Reynolds
Creek indicates that average planting depth in these plots
was not excessive and roughness may have provided more
varied microsites within and adjacent to the furrows, improving shading and water catchment.
Poor emergence at Birds of Prey and high attrition of
seedlings at both sites was not unexpected given the generally dry conditions. Native spiny hopsage seedlings are
rarely observed in southern Idaho or eastern Oregon, but
198
are most common in high-moisture years. They generally
emerge under the densest portions of nurse plant canopies
where competition with other species is reduced and temperature and moisture conditions are ameliorated by shading and litter. These conditions contrast strongly with
seedbed conditions provided on the test plots.
This initial work indicates that successful inclusion
of spiny hopsage in rangeland seedings requires shallow
planting in fall or winter. Emergence and establishment
can vary among utricle sources. Emergence may be quite
high if adequate soil moisture is present. Measures to provide water catchment and shading might enhance establishment. Ability of seedlings to compete with weeds or
other planted species is largely unknown.
ACKNOWLEDGMENTS
We wish to thank the U.S. Department of the Interior,
Bureau of Land Management, Boise District and Snake
River Birds of Prey National Conservation Area, Boise, ID,
for providing study sites; the U.S. Department of Agriculture, Agricultural Research Service, Northwest Watershed
Research Center, Boise, ID, for providing precipitation data
for the Reynolds Creek site; William Clark, Orma J. Smith
Museum of Natural History, College of Idaho, Caldwell, ID,
and Adam Asquith, Department of Entomology, Oregon
State University, Corvallis, OR, for insect identification;
and volunteers Stephanie Carlson, Emerenciana Hurd,
and David Shaw for assistance with field work.
REFERENCES
Bewley, J. D.; Black, M. 1983. Physiology and biochemistry
of seeds in relation to germination. vol. 1. Development,
germination, and growth. New York: Springer-Verlag.
306p.
Blaisdell, J.P.; Holmgren, R. C. 1984. Managing intermountain rangelands-salt-desert shrub ranges. Gen.
Tech. Rep. INT-163. Ogden, UT: U.S. Department of
Agriculture, Forest Service, Intermountain Forest and
Range Experiment Station. 52 p.
Blauer, A. C.; Plummer, A. P.; McArthur, E. D.; Stevens,
R.; Giunta, B. C. 1976. Characteristics and hybridization
of important intermountain shrubs. II. Chenopod family.
Res. Pap. INT-177. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range
Experiment Station. 42 p.
Collett, R. A. 1980. Soil survey of Ada County area, Idaho.
Washington, DC: U.S. Department of Agriculture, Soil
Conservation Service. 327 p. Maps.
Dasmann, W. P.; Blaisdell, J. A. 1954. Deer and forage
relationships on the Lassen-Washoe interstate winter
deer range California Fish & Game. 40(3): 215-234.
Daubenmire, R. 1970. Steppe vegetation of Washington.
Tech. Bull. 62. Pullman, WA: Washington State University, College of Agriculture, Washington Agricultural
Experiment Station: 64-65.
Dittberner, P. L.; Olsen, M. R. 1983. The plant information
network (PIN) data base: Colorado, Montana, North
Dakota, Utah, and Wyoming. FWS/OBS-83-36.
Washington, DC: U.S. Department of the Interior, Fish
Shaw, N. 1990. Data on file at: U.S. Department of Agriculture, Forest Service, Intermountain Research Station,
Forestry Sciences Laboratory, Boise, ID.
Smith, J. G. 1974. Grayia H. & A. hopsage. In: Shopmeyer,
C. S., tech. coord. Seeds of woody plants in the United
States. Agric. Handb. 450. Washington, DC: U.S. Department of Agriculture, Forest Service: 434-436.
Snedecor, G. W.; Cochran, W. G. 1980. Statistical methods.
7th ed. Ames, lA: The Iowa State University Press.
507p.
Stephenson, G. R. 1977. Soil-geology-vegetation inventories
for Reynolds Creek Watershed. Moscow, ID: University
of Idaho, College of Agriculture, Agricultural Experiment
Station in cooperation with U.S. Department of Agriculture, Agricultural Research Service and Soil Conservation Service. 66 p. Maps.
U.S. Department of Agriculture, Soil Conservation Service.
1968. Management and uses of spiny hopsage in the
state of Washington. State of Washington, Plant Science
Handbook. Spokane, WA: U.S. Department of Agriculture, Soil Conservation Service, Plant Materials Section.
n.p.
Vallentine, J. F. 1980. Range development and improvements. 2d ed. Provo, UT: Brigham Young University
Press. 545 p.
Wallace, A.; Romney, E. M. 1972. Radioecology and ecophysiology of desert plants at the Nevada Test Site.
USAEC Rep. TID-25954. Riverside, CA: Environmental
Radiation Division, Laboratory of Nuclear Medicine and
Radiation Biology and Agricultural Science, Los Angeles
Soil Science and Agricultural Engineering. 439 p.
Wallace, A.; Romney, E. M.; Ashcroft, R. T. 1970. Soil temperature effects on growth of seedlings of some shrub
species which grow in the transitional area between
the Mojave and Great Basin Deserts. Bioscience. 20(21):
1158-1159.
Wasser, C. H. 1982. Ecology and culture of selected species
useful in revegetating disturbed lands in the west. FWS/
OBS-82/56. Washington, DC: U.S. Department of the
Interior, Fish and Wildlife Service, Office of Biological
Services, Western Energy and Land Use Team. 347 p.
Welsh, S. L.; Atwood, N.D.; Goodrich, S.; Higgins, L. C.,
eds. 1987. A Utah flora. Great Basin Naturalist Memoirs. 9. 894 p.
Wood, M. K.; Knight, R. W.; Young, J. A. 1976. Spiny
hopsage germination. Journal of Range Management.
29(1): 53-56.
and Wildlife Service, Division of Biological Services,
Research and Development, Western Energy and Land
Use Team. 786 p.
Glazebrook, T. B. 1941. Overcoming delayed germination
in the seed of plants valuable for erosion control and
wildlife utilization. Moscow, ID: University of Idaho.
97 p. Thesis.
Gullion, G. W. 1964. Wildlife uses of Nevada plants. In:
Contributions toward a flora of Nevada. Washington,
DC: U.S. National Arboretum, Herbarium: 49-170.
Hitchcock, C. L.; Cronquist, A 1973. Flora of the Pacific
Northwest. Seattle, WA: University ofWashington Press.
730p.
Institute for Land Rehabilitation. 1979. Selection, propagation, and field establishment of native plant species on
disturbed arid lands. Bull. 500. Logan, UT: Utah State
University, Agricultural Experiment Station. 49 p.
Kay, B. L.; Ross, C. M.; Graves, W. L. 1977. Hop-sage.
Mojave Revegetation Notes 6. Davis, CA: University
of California. 5 p.
King, J. E. 1947. The effect of various treatments to induce
germination of seed of some plants valuable for soil conservation and wildlife. Moscow, ID: University of Idaho.
97 p. Thesis.
Krysl, L. J.; Sowell, B. F.; Hubbert, M. E.; Plumb, G. E.;
Jewett, T. K.; Smith, M.A.; Waggoner, J. W. 1984.
Horses and cattle grazing in the Wyoming Red Desert. II.
Dietary quality. Journal of Range Management. 37(3):
252-256.
McArthur, E. D.; Plummer, A. P.; Davis, J. N. 1978. Rehabilitation of game r~nge in the salt desert. In: Wyoming
shrublands, proceedings of the seventh Wyoming shrub
ecology workshop. Laramie, WY: University of Wyoming,
Range Management Division: 23-50.
McCullough, D. R. 1969. The Tule elk-its history, behavior, and ecology. Publications in zoology. Berkeley, CA:
University of California Press. 88: 1-191.
Mowbray, J. 1990. [Personal communication]. Boise, ID:
U.S. Department of Agriculture, Agricultural Research
Service, Northwest Watershed Research Center.
Pellant, M. 1990. [Personal communication]. Boise, ID:
U.S. Department of the Interior, Bureau of Land Management, Idaho State Office.
Peterson, R. G. 1985. Design and analysis of experiments.
New York: Marcel Dekker. 429 p.
Rickard, W. H.; McShane, M. C. 1984. Demise of spiny
hopsage shrubs following summer wildfire: an authentic
record. Northwest Science. 58(4): 282-285.
199