VALUE AND USE
SPECIES: Quercus chrysolepis | Canyon Live Oak 



WOOD PRODUCTS VALUE : 
Canyon live oak is, by volume, one of the most important California
hardwoods and represents an estimated 2,033 million cubic feet of
growing stock [8,74].  The wood is hard, stiff, and strong [72] and
appears to have some commercial value [97].  It can be used to make
furniture, pallets, and attractive multi-colored paneling or veneer
[74,91], but utilization of canyon live oak wood appears to be
best-suited to small, cottage industry [74].

Canyon live oak is a valuable firewood species in many parts of
California [74], and projections point to increasing demands for
California oak (Quercus spp.) fuelwoods [56].  


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Canyon live oak provides important habitat for many animal species.
Large oaks serve as perching, nesting, resting, or foraging sites for
numerous species of birds and provide shade and cover for both large and
small mammals.  Small oaks provide cover and readily available browse.
California oaks are important to shrews, bats, moles, rabbits, ground
squirrels, tree squirrels, woodrats, mice, voles, chipmunks, pocket
gophers, kangaroo rats, pocket mice, foxes, porcupines, bear, beaver,
ringtail, raccoon, skunks, elk, deer, bighorn sheep, and jumping mice.
Canyon live oak woodlands serve as excellent mountain lion habitat
because of the large number of deer frequenting these areas [5].

Browse:  In many areas deer browse canyon live oak throughout the year
[83].  However, it is most commonly used in trace amounts or when other
more preferred forage is lacking [46].  Mule deer occasionally feed on
the foliage and twigs of canyon live oak [5,83], but its overall value
is relatively low [97].  The following wildlife species, which occur
within the range of canyon live oak, feed on oak foliage:  black-tailed
jackrabbit, beaver, Audubon cottontail, brush rabbit, pinyon mouse,
red-backed vole, Beechy ground squirrel, Sonoma chipmunk, Botta pocket
gopher, cactus mouse, deer mouse, and porcupine [5].  Pocket gophers
frequently eat the cambium of young canyon live oaks [73].  Cattle and
domestic sheep browse canyon live oak when other more preferred forage
is scarce or unavailable [19].

Mast:  Canyon live oak is a fairly consistent acorn producer which
enhances its value to wildlife species which rely on mast.  Many small
birds and mammals, including jays and woodpeckers, cache acorns from
various California oaks [13].  Acorns of canyon live oak are important
dietary components of many birds including acorn woodpecker, band-tailed
pigeon, scrub jay, Stellers jay, common crow, and magpie [13,27,91,98].
Many mammals such as deer, mice, black-tailed jackrabbit, brush mouse,
western gray squirrel, pocket gophers, California ground squirrel,
dusky-footed woodrat, and harvest mouse also consume canyon live oak
acorns [13,27,91].  Prior to its extinction, the California grizzly fed
extensively on the acorns of live oaks [27].  The following mammals
consume large numbers of acorns from many species of oak:  common
opossum, Audubon cottontail, Belding ground squirrel, pinyon mouse,
Beechy ground squirrel, golden-mantled ground squirrel, Townsend
chipmunk, long-eared chipmunk, Sonoma chipmunk, northern flying
squirrel, Botta pocket gopher, California mouse, deer mouse, porcupine,
gray fox, black bear, ringtail, spotted skunk, raccoon, elk, and mule
deer [5].  Birds such as quails, pheasant, turkey, mourning dove,
woodpeckers, jays, mountain chickadee, California thrasher, starling,
western meadowlark, purple finch, American goldfinch, rufous-sided
towhee, and brown towhee also eat acorns of many California oaks [98].

Canyon live oak often provides excellent foraging sites for many small
birds including the Nutt's woodpecker, acorn woodpecker, white-breasted
nuthatch, plain titmouse, and northern oriole [7].


PALATABILITY : 
Overall palatability of canyon live oak browse is low.  Foliage tends to
be less palatable than that of scrub oak (Quercus dumosa) or interior
live oak (Q. wislizenii) [83].  The tender sprouts of most oaks are much
more palatable than tougher mature foliage.

Acorns of canyon live oak are highly palatable to many birds, insects,
and mammals [73,83].


NUTRITIONAL VALUE : 
Oak browse is relatively high in both protein and carbohydrates,
although values vary seasonally.  However, tannins present in oak browse
may reduce protein digestibility [56].  Crude protein values of canyon
live oak browse in California averaged 11.6 percent in October but
declined to 5.2 percent by November [83].

Acorns provide a good source of crude fiber, fats, and carbohydrates but
are generally low in protein and ash [56,83].  The nutritional value of
canyon live oak acorns is as follows [3,43]:

     water (%)     protein (%)     fat (%)     carbohydrates (%)
        9.0           4.13          8.65            63.52

        stored acorns      4.51 kcal/g
        kcal/stored acorn  5.08
        total caloric content of stored acorns  12.400 kcal


COVER VALUE : 
Canyon live oak provides cover for many species of birds and mammals.
The specific growth form of this variable tree or shrub largely
determines the type and quality of cover.  This oak frequently grows in
dense thickets [17] which can serve as good hiding or nesting cover for
many smaller birds and mammals.  Large, single-stemmed canyon live oaks
furnish shade for domestic livestock and cover for large wild ungulates
such as deer [83].  The western screech owl, mountain chickadee,
chestnut-backed chickadee, and other cavity nesters frequently use nests
in older canyon live oaks [75].  Many species of birds use this oak for
perching, resting, or foraging sites [98].

Carnivores, such as the gray fox and bobcat, use California oaks for
thermal or escape cover, and black bear occasionally den at the base of
trees.  Raccoons den in hollow oaks, and deer mice, striped skunks, and
gray squirrels use fallen logs for shelter.  Oaks are known to provide
cover for the following mammals which occur within the range of canyon
live oak: common opossum, brush rabbit, Beechy ground squirrel, northern
flying squirrel, Botta pocket gopher, Douglas squirrel, California
mouse, deer mouse, gray fox, black bear, ringtail, raccoon, western
red-backed vole, pinyon mouse, wild boar, and mule deer [5].  

Usage of canyon live oak cover during one or more seasons is as follows
[5]:

     black-tailed jackrabbit           light
     dusky-footed woodrat              moderate
     brush mouse                       light   
     western gray squirrel             moderate
     mountain lion                     light


VALUE FOR REHABILITATION OF DISTURBED SITES : 
Many species of California oaks (Quercus spp.) are valued for preventing
soil erosion [83].  Canyon live oak grows well on steep slopes which are
prone to erosion and is an excellent soil stabilizer [91].


OTHER USES AND VALUES : 
During the era of westward expansion, settlers used the wood of canyon
live oak for many purposes.  The wood is particularly hard, hence the
origin of the common names "rock oak" or "maul oak."  Its hardness made
it particularly well-suited for axles, tool handles, mauls, wagon
tongues, plow beams, ship frames, and wheels [45,80].  Wedges made from
this oak were used to split redwood into railroad ties [46].  Many
California oaks were used locally for mine timbers or fenceposts [83].
Oak wood was also used to make charcoal [80].

Native Americans traditionally used the acorns of canyon live oak to
make mush or flour which was baked into cakes after the bitter tannins
were removed [45].  Results of modern-day tests indicate that the meal
derived from acorns of canyon live oak makes a nutritious and flavorful
supplement to ordinary wheat flour used in breads and cookies [20].

A number of California oaks have been widely used in landscaping [83]
and canyon live oak was first cultivated in 1877 [66].  It is
particularly well-suited for use in urban plantings.  The foliage of
canyon live oak turns an attractive golden color in the fall which
enhances its value as an ornamental [91].


MANAGEMENT CONSIDERATIONS : 
Chemical control:  Research indicates that herbicides such as 2,4-D or
trichlopyr (Garlon) can be fairly effective in reducing canyon live oak
[12,91].  The herbicide 2,4-D appears to be somewhat more effective than
2,4,5-T, but repeated applications are generally necessary to achieve
total control.  Treated plants often sprout from the base or, less
commonly from the stem, even after they are subsequently burned [25].
Hundreds of sprouts often develop in place of the one or two original
stems.  Gratkowski [25] observed that two applications of herbicides
were insufficient to reduce resprouts by 50 percent.  However, in a
study conducted in the Klamath Mountains of northern California, Garlon,
when applied to recently cut stem sprouts, killed approximately 90
percent of all sprout clumps [P. McDonald, pers. comm. 1990].

Competition:  Stump-sprouts of canyon live oak provide vigorous
competition for conifer seedlings [25,90].  This oak forms a prominent
part of brushfields which develop after timber harvest and adversely
impact conifer growth and establishment [85,87].  Growth rates of
Douglas-fir seedlings can be significantly reduced by the presence of
canyon live oak sprouts which can readily shade the seedlings [89].
Tesch and Hobbs [89] found that after the third growing season, conifer
seedling losses increased as oak sprout growth increased.  Longer
rotations are likely where even moderate levels of sprouts provide
competition for newly planted Douglas-fir seedlings.  Evidence suggests
that sprout growth of canyon live oak tends to be more vigorous in
clearcuts than in thinned stands [15].  Average numbers of canyon live
oak and height development by timber treatment were documented as
follows [15]:

             treatment       height (cm)      # sprouts/ stump
             clearcut         24                     41
             thinned          14                     17

Biomass:  Because of its high rate of biomass production and net primary
productivity, canyon live oak may be suitable for periodic harvesting
for energy generation [77].  Maximum biomass production for fuel wood
can be obtained in closed canopy stands [91].

Timber management:  Canyon live oak is best managed in even-aged stands
intermixed with conifers, where primary management objectives focus on
sawtimber production.  Trees tend to exhibit poor form and excessive
crown development when grown in open stands.  The growth form most
suited for use as sawtimber, is attained in closed canopy stands.  Stand
management guidelines, as well as detailed information on growth and
yield, have been documented [91].

Wildlife management:  The following guidelines have been developed for
maintaining optimum wildlife value of California oak woodlands [5]:

           1)  maintain 25 to 50 percent canopy cover
           2)  maintain basal area of 200 to 2,000 ft. sq. per 40 acres
           3)  maintain a mixture of age classes
           4)  disperse oaks in 0.5 to 5 acre aggregations

Avian diversity may be enhanced by retaining large patches of oak,
leaving adequate travel corridors between patches, and keeping
structural diversity within the patches [78].

Related categories for Species: Quercus chrysolepis | Canyon Live Oak