VALUE AND USE
SPECIES: Juniperus monosperma | Oneseed Juniper 



WOOD PRODUCTS VALUE : 
The relatively small stature and multiple stems of oneseed juniper limit
its usefulness as a timber species.  The wood currently has little
commercial value but was formerly used locally for fenceposts, poles,
railroad ties, and mine timbers [16].  Oneseed juniper wood is described
as strong and long-grained [28].


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Pinyon-juniper woodlands provide good habitat for mule deer, bighorn
sheep, bison, wild horses, pronghorns, coyotes, bobcats, badgers,
porcupines, rabbits, mice, voles, woodrats, squirrels, and numerous
birds [16].  The foliage and berries of oneseed juniper provide food for
many species of birds and mammals.

Browse:  The foliage of oneseed juniper appears to be of little value to
domestic livestock.  Sheep and goats may browse this species to a
limited degree in some areas [13,35].  Oneseed juniper browse may induce
abortions in domestic livestock under certain circumstances [73].

Deer utilize the foliage to at least a limited extent [13,35,52].
Mahgoub and others [51] observed fairly heavy utilization in parts of
south-central New Mexico where juniper can represent up to 20 percent of
the annual diet of mule deer.  Oneseed juniper foliage is reported to be
a major mule deer food item from January through March in parts of
southeastern New Mexico [63].  Pronghorns also browse oneseed juniper,
and in some areas, winter use may be fairly heavy [10,74].  Bighorn
sheep and elk consume at least small amounts of juniper browse in
certain locations [63].

Fruit:  The berrylike fruits of oneseed juniper serve as an abundant and
readily available food source for a wide range of wildlife species.  The
bright berries tend to remain on the tree and can provide food
year-round [16].  Fruits are initially plump and juicy but become dry
and leathery by the second winter [65].  Berry ripening usually
corresponds with the arrival of winter residents to the pinyon-juniper
woodlands [64].

Oneseed juniper berries represent an extremely important food source to
a number of bird species.  Berries are abundant, easily acessible, and
nutritious [64].  It is estimated that avian population densities may be
70 percent greater during years with abundant juniper berry crops
(generally every 2 to 5 years) [5].  Studies with captive birds have
revealed that an average Townsend's solitaire can consume approximately
240 berries per day, or 36,000 to 84,000 per winter [5,64].  In some
areas at least 97 percent of the Townsend's solitaire's winter diet may
be made up of oneseed juniper berries [65].  Robins also consume large
numbers of juniper berries.  An individual bird can eat 220 berries per
day or 33,000 per winter [5].  Balda [5] reported 20,000 berries per
cubic meter of juniper foliage in 1973, but by September 1974, birds and
other dispersal agents had reduced berry numbers to 300 per cubic meter.

Birds and mammals serve as important dispersal agents for seeds of
oneseed juniper.  Many bird species disperse seed up to 6.3 miles (10 m)
or more from the seed source [5].  Sheep and domestic cattle can also
facilitate the dispersal of oneseed juniper [40].  A number of the
following species known to consume oneseed juniper are important
dispersal agents [64]:

                                food source     probable role
        northern flicker           berry          disperser
        Steller's jay              berry          disperser
        mountain chickadee         flesh             ---
        plain titmouse             flesh             ---
        sage thrasher              berry          disperser
        American robin             berry          disperser
        Townsend's solitaire       berry          disperser
        western bluebird           berry          disperser
        evening grosbeak           seed           probable
        Cassin's finch             seed           probable
        desert cottontail          berry          disperser
        black-tailed jackrabbit    berry          disperser
        cliff chipmunk             seed           probable
        rock squirrel              seed           probable
        golden mantled ground 
          squirrel                 seed           probable
        deer mice                  seed           probable
        Mexican woodrat            seed           probable
        coyote                     berry          disperser
        gray fox                   berry          disperser
  

Other wildlife species known to consume oneseed juniper berries include:
mule deer, western chipmunk, antelope ground squirrel, squirrels, bear,
javelina, pocket mouse, rabbits, and raccoon [40,63,72,73].


PALATABILITY : 
The fruits of oneseed juniper are sweet tasting and highly palatable to
many birds and mammals [64].  They appear to remain palatable even when
dry.  The foliage is relatively unpalatable to most species, although it
is reported to be somewhat more palatable than most other junipers [13].

The palatability of oneseed juniper to livestock and wildlife species in
two western states has been rated as follows [14]:

                      CO       UT
Cattle               poor     poor
Sheep                poor     fair
Horses               poor     poor
Pronghorn            ----     fair
Elk                  ----     fair
Mule deer            ----     fair
Small mammals        ----     good
Small nongame birds  ----     good
Upland game birds    ----     good
Waterfowl            ----     poor


NUTRITIONAL VALUE : 
Oneseed juniper is rated as poor in overall protein and energy value
[14].  However, many species of birds apparently obtain at least
moderate energy value from the berries [5].  These fruits provide a
comparatively rich source of carbohydrates for a number of birds [64].
Caloric value of oneseed juniper berries is as follows [64]:

                size            mg/unit         cal/mg          cal/unit
berries      6.6 mm diameter     107.49           4.57            490.82
seeds        4.9 x 3.6 mm        37.52           4.66            174.85
flesh            ---             69.97           4.52            315.97


COVER VALUE : 
Oneseed juniper provides good cover for a number of birds and mammals
including quail, wild turkeys, deer, and songbirds [63].  The degree to
which oneseed juniper provides environmental protection during one or
more seasons for wildlife species is as follows [14]:

                      CO       UT
Pronghorn            ----     good
Elk                  ----     good
Mule deer            fair     good
White-tailed deer    fair     ----
Small mammals        good     good
Small nongame birds  good     good
Upland game birds    ----     good
Waterfowl            ----     poor


VALUE FOR REHABILITATION OF DISTURBED SITES : 
Oneseed juniper is rated as having low overall value for short-term
rehabilitation but high value for long-term rehabilitation [14].  It has
not been widely used in the past for rehabilitation projects due to
unreliable seed germination caused by inhibitors in the seed coat and
dormancy [21].  Fertilizers, wood chip or straw mulch, plastic mesh for
protection against rodents, and drip irrigation can all contribute to
increased survival on disturbed sites [20,21].  Oneseed juniper has been
successfully planted on a number of surface coal and uranium mines in
the Southwest [20].  Improved techniques have resulted in survival rates
of 70 percent to 99 percent [20,21].

On certain New Mexico sites, drip irrigation is somewhat more effective
than mulch, while triple-superphosphate aids growth more than
slow-release fertilizers [20].  Seed germination can be enhanced by
leaching seeds with water at 68 to 75 degrees Fahrenheit (20-24 deg C)
and cold stratification for 90 days, or seeds should be treated with
water and GA3 or ethephon only, applied 30 days prior to cold
stratification [21].  Planting dates can significantly influence
seedling survival.  On the New Mexico test sites, July planting dates
produced best results at higher elevations, whereas August plantings
were most successful on low-elevation sites [20].  Seedling survival at
several New Mexico sites was as follows [20,21]:

        Raton, NM Site                     Grants, NM Site
planting        % survival              treatment       % survival
 July               73                  mulched             96
 May                55                  non-mulched         89
 August             48

treatment       % survival
May-fertilized      22
May-unfertilized    88
July-fertilized     62
July-unfertilized   86
August-fertilized    3
August-unfertilized 95

        Coal mine site
planting                % survival 2 years after planting
August                                  47
September                               16
November                                14

Transplanting containerized seedlings onto disturbed sites has also been
successful [20,21].  Survival of transplants is apparently dependent on
moisture availability [21].  In New Mexico, survival is best when trees
are planted after the June drought but before the ground freezes
[20,21].  Mulch which aids in water conservation can enhance survival on
dry sites, and on extremely arid sites, drip irrigation may be necessary
[20,21].  Fertilizer may improve survival on some sites particularly
when combined with irrigation [20].  Applications of fertilizer should
be made near the base of the tree but not in the same hole in which the
tree was planted [20].


OTHER USES AND VALUES : 
Native American peoples historically used oneseed juniper for a variety
of purposes.  Wood was used for bows and arrows by the Kiowa, Commanche,
Cheyenne, and Apache [28].  A number of North American peoples ate the
fruit or ground them into flour for bread [73].  Prayer sticks were made
from wood, and a green dye, fibrous mats, and saddles were fashioned
from the bark [73].  Parts of the tree were also used as building
materials and for medicinal purposes [40].

During historic times, oneseed juniper was used as a fuel source, as
fenceposts, charcoal, mine timbers, posts, cellulose, and in a number of
chemical products [40].  Springfield [71] noted that many species of
juniper may have potential value for the production of charcoal, pulp,
particleboard, chip products, fiber, or in certain chemicals.  Oneseed
juniper was first cultivated in 1900 [42].


MANAGEMENT CONSIDERATIONS : 
Pinyon-juniper woodlands have been increasing in extent since settlement
times.  In many parts of Southwest, oneseed juniper and other species
have encroached into adjacent grasslands [35,56,80].  A decrease in fire
frequency has often been cited as the probable cause of this increase
[79], but overgrazing offers another possible explanation.  Past
management efforts have largely focused on halting the juniper invasion
through mechanical or chemical means.  Little regard was given to
possible wildlife use of these areas, or to potential wood products
value of these species.  These factors should be considered when
attempting to devise and implement management strategies in
pinyon-juniper woodlands.  Strategies aimed at preserving wildlife
habitat while allowing carefully managed grazing opportunities should be
favored.  In many cases juniper removal alone does little to increase
long-term forage potential.

Mechanical control:  A number of methods of mechanical removal have been
used with varying success.  Cabling, chaining, bulldozing, and various
means of hand removal have been used in attempts to convert these
woodlands to grasslands.  Generally, cabling or chaining is most
effective on even-terrain sites with approximately 250 trees per acre or
less, and with at least half of those trees greater than 10 feet (3.1 m)
[4,41,71].  Neither the single chaining nor double chaining method
effectively kills trees less than 10 feet (3.1 m) in height [71].

In many areas, junipers and pinyons start to resume dominance as soon as
28 years after cabling [69].  Oneseed juniper seeds remain viable buried
in the soil on-site or are dispersed from off-site by birds and mammals
[69].  In many areas, particularly with many young tree prior to
treatment, reinvasion is rapid, and results do not appear to justify
these relatively expensive attempts at control [61].  Junipers may
become dominant particularly rapidly on sites with deeper soils [68].
Poor results have also been obtained on rocky soils, which seldom
produce good graminoid cover after juniper removal [67].  Stands should
have few young trees and at least 15 percent residual grass cover for
these mechanical treatments to be effective in promoting increases in
forage [67].  Some researchers recommend using fire or herbicides as a
second treatment approximately 5 years after cabling to increase tree
kill [67].

Bulldozing is most effective on sites with small- to medium-sized trees
and tree densities of 100 to 150 per acre [41,71].  Severson [70]
reported poor results after pinyon-juniper woodlands in New Mexico were
thinned and bulldozed.  Differences in densities between most treated
and untreated areas were not detectable 13 to 18 years later [70].  No
significant differences were observed between bulldozed and
untreated/thinned treatments [70].

Crushing even-aged mature stands and hand removal of individual trees
have been tested, although both methods are expensive and have somewhat
limited utility [3,41].  Mechanical removal of oneseed juniper has not
produced increased water yields in experiments [19].

Chemical control:  The foliage of junipers tends to be resistant to
herbicides, and leaves have little surface area for absorption [41].
Junipers can reportedly be killed by chemicals such as arsenite,
ammonium sulfate, esters of 2,4-D, and 2,4,5-T, polychlorobenzoic acid,
and picloram.  See Springfield [71] and Johnsen [41] for details.

Range condition:  Many pinyon-juniper ranges are now in relatively poor
condition.  The following species are indicative of range condition on
certain Arizona oneseed juniper sites [32,33]:

excellent:  black gama (Bouteloua eriopoda), Indian ricegrass (Oryzopsis
            hymenoides), blue grama (B. gracilis), winterfat (Eurotia
            lanata), cliffrose (Cowania spp.), and fourwing saltbush (Atriplex
            canescens).

good:       Indian ricegrass, black grama, blue grama, needlegrass
            (Stipa spp.), and spike muhly (Muhlenbergia wrightii).

fair:       blue grama, bare soil.

poor:       broom snakeweed (Gutierrezia sarothrae), ringgrass
            (Muhlenbergia torreyi), often much erosion.

Production:  Herbage production values are variable in pinyon-juniper
woodlands.  Springfield [71] reported an inverse relationship between
tree canopy and average herbage production as follows:

        tree canopy             average herbage production
             0%                         600 lbs per acre
            20%                         300 lbs per acre
            80%                          50 lbs per acre

Several studies have examined the influence of oneseed juniper canopy on
understory vegetation.  Results suggest fairly distinct vegetative zones
surrounding oneseed junipers.  Relatively little vegetation grows
closest to the tree where litter accumulation is greatest and shading
most extreme [1,66].  Generally such species as blue grama, sand muhly
(Muhlenbergia arenicoloides), skunkbush sumac (Rhus trilobata), and
algerita (Berberis trifoliata) occur here [1].  The second zone, which
extends outward beneath the canopy, is represented by creeping muhly
(Muhlenberiga repens), broom snakeweed, galleta (Hilaria jamesii),
sideoats grama (Bouteloua curtipendula), blue grama , and western
wheatgrass (Pascopyrum smithii) [1].  Production here was found to be
approximately 293 pounds air-dry herbage per acre [2].  Blue grama,
galleta , wolftail (Lycurus phleoides), mat muhly (Muhlenbergia
richardsonis), scarlet globemallow (Sphaeralcea coccinea), dropseed
(Aristida spp.), and hairy grama (Bouteloua hirsuta) are often most
prevalent in the outer zone or in tree interspaces [1].  In some areas,
western wheatgrass and broom snakeweed are well represented in
interspaces which receive full sunlight [2].  Generally, cool-season
grasses such as prairie junegrass (Koeleria cristata), western
wheatgrass, bottlebrush squirreltail (Sitanion hystrix), and mutton
bluegrass (Poa fendleriana) occur more abundantly under the canopy of
oneseed juniper than in the interspaces [1,17].  Schott and Pieper [66]
reported that oneseed juniper canopy crown diameter is negatively
correlated with the basal area of grasses.  Such factors as shading,
decreased soil moisture due to absorption by oneseed juniper roots, and
possible chemical properties of oneseed juniper litter, all effect the
composition of understory vegetation [2,38,66].

Fertilization:  The diameter of oneseed juniper was found to be largely
unaffected by the addition of nitrogen fertilizer in a New Mexico study,
although the growth of lateral branches and the apex was enhanced [63].

Related categories for Species: Juniperus monosperma | Oneseed Juniper