VALUE AND USE
SPECIES: Yucca brevifolia | Joshua Tree 



WOOD PRODUCTS VALUE : 
Joshua tree wood is light, pliable, porous, durable, and has a unique
and attractive grain [26].  It is used in novelty products such as
picture frames, book covers, postcards, napkin rings, and boxes [26,43].
Joshua tree veneer, which is available in parts of southern California,
is attractive, provides good insulation, and improves acoustics [43].


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Joshua tree provides food and shelter for many animals of the Mohave
Desert.  The foliage provides some browse for bighorn sheep [35] and
other wild ungulates.  The Mexican woodrat, rabbits, and other small
mammals consume the young succulent leaves [25,26,43], as do domestic
sheep and goats in drier parts of the Mohave.  Deer, squirrels, and
small birds consume the young blossoms and fruit [20,21].  Cattle,
burros, and wild horses also eat the fruit [10].  The antelope ground
squirrel, and presumably other rodents, cache dried Joshua tree seed for
winter use [20].


PALATABILITY : 
The sweet blossoms and fleshy fruits of the Joshua tree are highly
palatable [20,21].  Dried seeds are particularly relished by the
antelope ground squirrel in winter [20,21].  Leaves are most palatable
to wild ungulates, small mammals, and domestic livestock when young and
succulent [25,26].  The palatability of Joshua tree to livestock and
wildlife in Utah has been rated as follows [11]:

                           UT
Cattle                    poor
Sheep                     poor
Horses                    poor
Pronghorn                 poor
Elk                       poor
Mule deer                 poor
Small mammals             poor
Upland game birds         ---- 


NUTRITIONAL VALUE : 
Joshua tree is rated as poor in both energy and protein value [11].
Specific food values of various parts of Joshua tree (var. jaegeriana)
are as follows [43]:

                oil   water   n-free   crude     fat   fiber   ash
                              extract  protein     
see            34.4%   5.9%    34.8%    10.2%    3.2%   9.9%   1.6%
pods           ----    7.6%    60.0%     6.7%    2.0%  16.8%   6.9%
seed meal      ----    9%      53%      15.5%    5%    ----    2.5%


COVER VALUE : 
Joshua tree provides much-needed shade and cover for numerous
desert-dwelling animals.  Arborescent plants are rare in the Mohave
Desert, and the branches of this tall yucca provide perching sites for
predatory birds such as the sparrow hawk and loggerhead shrike [21].

This tall, shaggy, irregularly shaped yucca lends itself to favorable
nesting or resting sites for many small birds and reptiles.  Studies
have shown that at least 25 species of birds nest in the Joshua tree.
Some, such as the Scott's oriole, nest in shady leaf clusters, while
others, such as the flicker and ladder-backed woodpecker, excavate nest
holes in the corky trunks [20,21].  The yucca night lizard usually
exists in close proximity to Joshua trees, inhabiting dark rotting
hollows where available [21] and feeding on the abundance of insects
associated with this tree [25].  Woodrats frequently build nests in the
fallen trunks of Joshua trees [25].  The Mexican woodrat often uses the
leaves as nesting material [26].

Domestic livestock seek out shade provided by Joshua trees [16].  The
degree to which Joshua tree provides environmental protection during one
or more seasons for wildlife in Utah has been rated as follows [11]:

                      UT
Pronghorn            poor
Elk                  poor
Mule deer            poor
Small mammals        fair
Small nongame birds  fair
Upland game birds    good
Waterfowl            poor


VALUE FOR REHABILITATION OF DISTURBED SITES : 
Joshua tree woodlands are extremely fragile and can take centuries to
recover from disturbance [41].  Joshua tree can be used in
rehabilitation, although its potential value for both long- and
short-term revegetation is rated as low.  It has moderate value for
erosion control [11].  Seedlings can be transplanted onto disturbed
sites, but it is is important not to overwater young plants [43].


OTHER USES AND VALUES : 
Historical uses:  Wood - Ancient Cliff Dwellers of the Southwest often
incorporated Joshua tree beams into their living structures [43].  Early
ranchers built fences from the cork trunks [20,21].  The pulp was made
into fine paper and for a time a London newspaper was printed on
newsprint made from Joshua tree pulp [26].  High processing and
transportation costs eventually put an end to its use in the paper
industry.  Other - Native Americans used the rootlets to make a red dye,
and made rope, sandals, mats, and baskets from fibers obtained from the
leaves [20,21,25].  They roasted and ate the flower buds, and used the
ground seeds to make meal and mush [25,26].  They produced an alcoholic
beverage from the fermented buds and flowers [25].

Modern uses:  The clear, tasteless, and nearly odorless oil obtained
from seeds and pods, and sapogenins derived mainly from Joshua tree
roots, may someday have commercial value [34,43].  Chemicals obtained
from the Joshua tree have been used in the synthesis of vanillin, as a
fertilizer, and as a carbon dioxide stabilizer used in controlling oil
fires [43].  The Joshua tree's unique appearance makes it well suited
for use as an ornamental [35].  It has been transplanted successfully
outside of its natural range in Nevada and Utah [10].


MANAGEMENT CONSIDERATIONS : 
Grazing:  Many Joshua tree woodlands have been heavily grazed by
livestock in the past.  Grazing systems have little or no effect on
improving range conditions because of the extreme aridity and harshness
of these areas.  Efforts to improve these ranges tend to be expensive
and yield few beneficial results [15].

Biomass:  Joshua biomass is difficult to determine accurately.  Bostick
and Tueller [5] reported that biomass ranged from 449 pounds per acre
(504 kg/ha) on poor sites to 2,483 pounds per acre (2,790 kg/ha) on
excellent sites; biomass averaged 1,369 pounds per acre (1,538 kg/ha).

Damage:  Extensive vandalism has occurred in many Joshua tree woodlands
in California [43].  Larger trees have been burned or defaced, and many
trees have been dug up for planting in urban or residential areas.
Survival of trees removed in this manner is believed to be extremely
rare.

Related categories for Species: Yucca brevifolia | Joshua Tree