VALUE AND USE
SPECIES: Quercus wislizenii | Interior Live Oak 



WOOD PRODUCTS VALUE : 
Interior live oak is currently highly valued as firewood in many parts
of California, and projections point to ever-increasing demands for oak
(Quercus spp.) fuelwoods [37,47,53,65].  However, cordage per acre
varies widely according to soils and climate [34].  The wood of interior
live oak has little commercial value as lumber [44].  Undesirable
characteristics such as poor durability limit its use [65].


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Interior live oak provides important food and cover for a wide variety
of birds and mammals.  The following species, which occur within the
range of interior live oak, feed on the foliage of oaks:  black-tailed
jackrabbit, Audubon cottontail, brush rabbit, Beechy ground squirrel,
Sonoma chipmunk, beaver, porcupine, and elk [3].  Pocket gophers
occasionally consume the cambium of young oaks [48].  In some areas,
interior live oak is a valuable year-round deer browse [56].  The
evergreen leaves can provide essential winter browse when other
preferred foods are scarce [8].  However, winter utilization by
Columbian black-tailed deer in the Sierra Nevada was reported at
approximately 15 percent, suggesting that this oak is not a preferred
browse species in this area [22].  Oak browse is generally most
important to deer during the early spring when new sprouts are abundant
[22,37].  In some areas deer use oak browse to a limited extent during
the summer [37].  Oak woodlands offer good habitat for mountain lions
because of the relatively large numbers of deer which frequent these
areas [3].

Acorns, which become available by fall, are a valuable dietary
supplement for deer and other wild ungulates [37].  However, acorn
production varies annually, and in some years relatively few acorns are
produced.  Interior live oak does not generally produce acorns in great
quantity [65], but larger crops are usually produced at 5- to 7-year
intervals [43].  More deer move to winter ranges earlier in years of
abundant acorn production than in years of acorn failure [32].  Acorns
are an important food of the black-tailed jackrabbit, brush rabbit,
Beechy ground squirrel, golden-mantled ground squirrel, lodgepole
chipmunk, long-eared chipmunk, Sonoma chipmunk, Merriam chipmunk,
Douglas squirrel, porcupine, red fox, gray fox, black bear, raccoon,
striped skunk, spotted skunk, California ground squirrel, deer mice,
California vole, and harvest mice [3,26].  Acorns represented a
particularly important food source of the California grizzly bear prior
to its extinction [26].  Many birds eat acorns including quails,
ring-necked pheasant, northern flicker, acorn woodpecker, scrub jay,
magpie, Steller's jay, mountain chickadee, California thrasher, western
meadowlark, starling, purple finch, American goldfinch, rufous-sided
towhee, brown towhee, common crow, and band-tailed pigeon [26,66].
Interior live oak provides good foraging sites for Nutall's woodpecker,
white-breasted nuthatch, plain titmouse, ash-throated flycatcher,
black-headed grosbeak, and northern oriole [9].

Livestock:  Cattle and domestic sheep typically utilize interior live
oak browse most during the late spring and summer [55,56].  Young shoots
are particularly favored by cattle during the summer [55].  In some
parts of California, the leaves of interior live oak, along with the
leaves of other oaks, have been found in the diets of 60 percent or more
of the sheep and cattle within the area [37].  Domestic goats apparently
consume oak browse during all seasons [61], although young shoots are
particularly sought in the spring [56].  Domestic and feral pigs consume
large numbers of acorns wherever available [3].



PALATABILITY : 
The acorns and foliage of interior live oak are palatable to many birds
and mammals.  However, overall palatability of the foliage of interior
live oak is described as fair.  New sprouts appear to be much more
palatable to most ungulates than the mature foliage.  Deer eagerly seek
out sprouts up to 2 years in age during all seasons [56].  Specific
palatability ratings are as follows [3,19]:
  
                          mast              foliage
   mule deer              moderate          moderate
   wild boar              heavy             ----
   brush mouse            light             light
   pinyon mouse           light             light
   California mouse       light             light
   deer mouse             light             light
   dusky-footed woodrat   light             light
   western gray squirrel  heavy             ----
   Botta pocket gopher    moderate          moderate


the variety frutescens -
                                         California
          cattle                         poor
          horses                         useless
          domestic sheep                 fair to useless
          domestic goats                 fair to poor
          deer                           excellent to good


NUTRITIONAL VALUE : 
Acorns:  Acorns are generally rated as relatively high in carbohydrates,
fats, and crude fiber, but low in protein and ash [37,56].  The
nutritional value of interior live oak acorns is as follows [1,19]:

  moisture    crude    crude    fat    N-free    ash    Ca    tannins   P
  (%)         protein  fiber    (%)    extract   (%)    (%)   (%)       (%)
              (%)      (%)
  29.80       3.08     11.24    14.47   40.40    1.01   0.09   4.60     0.05
      
Foliage:  Oak browse is relatively high in protein and carbohydrates.
However, tannins present in oak browse may reduce protein digestibility
[37].  The composition of leafy branches is as follows [56]:

     total ash (%)   silica (%)   silica-free     Ca      P      K            
                                  ash (%)         (%)    (%)    (%)
          2.27         0.34          2.93        0.707   0.069  0.335

Protein levels of interior live oak browse vary seasonally as follows
[56]:

           April and May       17.5%
           June - August       10.5%
           September - March    8.0%


COVER VALUE : 
Interior live oak provides good thermal, escape, and resting cover for
many birds and mammals.  Larger California oaks (Quercus spp.) offer
shade for livestock and good hiding cover for deer [56].  Dense oak
chaparral made up of smaller shrublike oaks provides excellent thermal
cover for animals such as the gray fox and bobcat.  Raccoons use hollow
oaks for dens, and black bears occasionally den at the base of trees.
Fallen oaks serve as hiding locations for deer mice, striped skunks,
gray squirrels, and fox squirrels.  Interior live oak provides hiding,
resting, or nesting cover for the following species:  black-tailed
jackrabbit, Audubon cottontail, brush rabbit, Beechy ground squirrel,
golden-mantled ground squirrel, lodgepole chipmunk, long-eared chipmunk,
Sonoma chipmunk, Merriam chipmunk, Douglas squirrel, San Joaquin pocket
mouse, San Diego pocket mouse, spiny pocket mouse, Stephens kangaroo
rat, San Joaquin kangaroo rat, giant kangaroo rat, desert woodrat,
common opossum, shrews, bats, beaver, pinyon mouse, brush mouse,
California mouse, deer mouse, cactus mouse, muskrat, Pacific jumping
mouse, dusky-footed woodrat, Botta pocket gopher, western gray squirrel,
porcupine, red fox, gray fox, island fox, black bear, ringtail, raccoon,
spotted skunk, striped skunk, wild boar, mountain lion, mule deer, and
elk [3].  Many birds use California oaks for perching and nesting sites.
Some larger, older interior live oaks are well-suited for excavation by
various cavity nesters [66].


VALUE FOR REHABILITATION OF DISTURBED SITES : 
Interior live oak has been used to a limited extent in revegetating
certain riparian areas of California.  Little sprouting was observed
after acorns were planted onto riparian sites in the Santa Clara Valley
of southern California, and viability may have been much reduced or lost
while seeds were in storage [23].


OTHER USES AND VALUES : 
After leaching away the bitter tannins, Native Americans used the acorns
of many oaks (Quercus spp.) for cooking oils, soups, stews, or breads
[1].  Some California oaks were historically used locally as fenceposts
or mine timbers.  Many are currently used for landscaping purposes [56].
Interior live oak was first cultivated in 1874 [43].


MANAGEMENT CONSIDERATIONS : 
Wildlife management:  For maintaining optimum wildlife value in
California oak woodlands, managers recommend the following [3]:

        1) maintain 25 to 50 percent canopy cover in oaks.
        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 [52].

Harvesting:  Interior live oak may be well-suited for periodic
harvesting for energy generation because of its high rate of biomass
production and net primary productivity [50].

Chemical control:  Interior live oak is resistant to most herbicides.
Two or three treatments are often required for a complete kill [7].

Grazing:  Biswell [6] reports that in areas dominated by interior live
oak which are managed primarily for livestock production, deferred
grazing may be undesirable.  Browsing here serves as the main
controlling factor in brush suppression.

Related categories for Species: Quercus wislizenii | Interior Live Oak