VALUE AND USE
SPECIES: Quercus dumosa | Nuttall's Scrub Oak 



WOOD PRODUCTS VALUE : 
NO-ENTRY


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Wildlife browse:  Nuttall's scrub oak provides important food and cover
for numerous species in its range.  It is important mule deer browse
[6,60,69].  The evergreen leaves provide important winter browse when
other browse is scarce or unavailable.  The foliage is also an important
dietary component during migration [6].  During the summer, shoots or
sprouts are readily eaten by deer, small rodents, and lagomorphs such as
the brush rabbit [10,37,39].  In southern California chaparral, sprouts
are particularly important food sources for mule deer during the months
of June and July [39].  Oak foliage is an important food of the
California ground squirrel, black-tailed jackrabbit, desert cottontail,
Botta's pocket gopher, brush mouse, dusky-footed woodrat, and deer
mouse, all of which occur within the range of Nuttall's scrub oak [2].
Pocket gophers occasionally feed on the cambium of young oaks [52].

Acorns:  Acorns of Nuttall's scrub oak are eaten by many birds and
mammals including Columbian black-tailed deer, squirrels, California and
mountain quails, and wild turkey [6,10,37,51,69].  The acorns of
California oaks are particularly important food sources for mule deer,
wild boar, brush rabbit, Merriam's chipmunk, western gray squirrel,
California vole, harvest mouse, Botta's pocket gopher, brush mouse,
dusky-footed woodrat, California mouse, deer mouse, gray fox, raccoon,
spotted skunk, and striped skunk [2,19].  Scrub jay, Steller's jay,
magpie, acorn woodpecker, band-tailed pigeon, ring-necked pheasant,
mourning dove, northern flicker, California thrasher, European starling,
western meadowlark, purple finch, American goldfinch, brown towhee,
rufous-sided towhee, and American crow also feed on acorns of California
oaks [19,70].  In years of favorable acorn production, Columbian
black-tailed deer move to winter ranges earlier than in times of acorn
failure [34].  Deer tend to gain weight and "winter" well in years of
acorn abundance [6].  Many small mammals and birds cache acorns for
winter use [74].
   
Livestock:  Nuttall's scrub oak generally provides poor browse for
cattle although sprouts and acorns are frequently eaten [13,59,60,69].
Browse value tends to be higher for domestic sheep and goats.  The low
growth form of Nuttall's scrub oak enhances its value to sheep and goats
[13,60,69], and in some locations, domestic goats appear to prefer oak
browse in all seasons [62].  Domestic or feral pigs feed on large
numbers of acorns whenever available [2].

Nuttall's scrub oak contains relatively high levels of tannin which can
cause illness or death if it is the only food available [60].  Lambs
appear especially vulnerable and can be poisoned if oak browse is eaten
in large quantities [13,69].  Cows, which during gestation consume a
diet made up primarily of acorns, occasionally give birth to calves with
bone abnormalities.  These calves are referred to as "acorn calves" [69].


PALATABILITY : 
The overall palatability of Nuttall's scrub oak browse is described as
fair.  However, early leaves, twigs, sprouts, and shoots are much more
palatable than the mature foliage [60].  Ungulate utilization of the
leaves and stems declines as the foliage become tough with age [66].
Overall palatability of Nuttall's scrub oak is rated as follows [14,60]:
  
deer               good to excellent  
cattle             useless to poor  
horses             useless  
domestic sheep     poor  
domestic goats     poor to good

The sweet-tasting acorns of Nuttall's scrub oak are highly palatable to
many birds, mammals, and insects.  


NUTRITIONAL VALUE : 
Browse:  Oak browse tends to be relatively high in both protein and
carbohydrates [37], although values vary seasonally.  The crude protein
content of Nuttall's scrub oak sprouts in California averaged 16 to 23
percent during May and June but declined to only 8 percent by late
summer [60].  Tannins present in oak browse may reduce protein
digestibility [37].

          leaves  -
     N (%)     cellulose (%)     lignin (%)     crude fiber (%)
     1.30         18.2             11.7             29.9

Acorns:  Acorns provide a good source of crude fiber, fats, and
carbohydrates but tend to be relatively low in protein and ash [37,60].
Specific nutritional value of Nuttall's scrub live oak acorns is as
follows [1,14,58]:

          acorns -
 water (%)     protein (%)     fat (%)     carbohydrates (%)     tannin (%)
  44.58           2.29          3.42           40.65                5.15

 crude fiber (%)     N-free extract (%)     ash (%)     Ca (%)     P (%)
  7.96                     40.65             1.10        0.09       0.05     


COVER VALUE : 
Nuttall's scrub oak provides thermal, hiding, and escape cover for many
birds and mammals, including mule deer and black-tailed jackrabbit
[2,60].  California oaks provide much sought-after shade for domestic
livestock [60], and perching and nesting sites for many birds [70].
Dense oak chaparral, which is sometimes dominated by Nuttall's scrub
oak, provides excellent thermal cover for animals such as the gray fox
and bobcat.  Fallen oaks provide excellent cover for deer mouse, skunk,
and squirrel.  Raccoon frequently use hollow oaks for den sites [2].

The following mammals occur within the range of Nuttall's scrub oak and
are known to utilize oaks to satisfy cover requirements:  California
ground squirrel, common opossum, brush rabbit, western gray squirrel,
Botta's pocket gopher, brush mouse, dusky-footed woodrat, California
mouse, deer mouse, gray fox, raccoon, mountain lion, bobcat, wild boar,
gray shrew, California leaf-nosed bat, big free-tailed bat, western
mastiff bat, San Diego pocket mouse, desert woodrat, Pacific kangaroo
rat, California meadow mouse, and long-tailed meadow mouse [2].


VALUE FOR REHABILITATION OF DISTURBED SITES : 
Nuttall's scrub oak, because of its dense, extensive root system, can
aid in preventing soil erosion on some sites [13].  It has been used
successfully in revegetating disturbed riparian sites in parts of
California [17].


OTHER USES AND VALUES : 
The acorns of Nuttall's scrub oak were once a staple in the diet of
Native Americans living in parts of present-day California [10].  After
leaching away the bitter tannins, Native Americans used the acorns in
soups and stews, or pressed them to make cooking oil [1].  Medicinal
preparations, dyes, and tanning agents were made from the bark [10].

Nuttall's scrub oak is used for landscaping [23].


MANAGEMENT CONSIDERATIONS : 
Chemical control:  Nuttall'scrub oak appears to be relatively resistant
to many types of herbicides.  Up to 3 applications of 2,4-D or 2,4,5-T
may be required to completely kill the plants [26].  However, picloram
appears to be somewhat more effective.  Approximately 25 to 50 percent
of picloram-treated Nuttall's scrub oaks were killed within 8 months of
application [51].  Helicopter spraying may be an effective option in
certain locations where Nuttall's scrub oak forms a dense, unbroken
canopy [72].  The comparative effectiveness of various herbicides for
control of Nuttall's scrub oak is well documented [51,72].
  
Livestock:  Nuttall's scrub oak appears to be relatively resistant to
most types of livestock browsing [8,42,40].  It is particularly tolerant
of sheep browsing and recovers quickly after sheep are removed despite
serious damage to the plants.  Badly hedged plants made significant
recoveries within 3 years after sheep browsing was discontinued [8,7].

Deferred grazing may be detrimental in certain oak chaparral communities
managed primarily for livestock production [5].  Browsing here can
function as the primary means of brush suppression [6].

Wildlife:  The following guidelines have been developed for maintaining
optimum wildlife value of California oak woodlands [2]:
      
          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
               
Productivity:  Nuttall's scrub oak accumulated biomass at an average
annual rate of 0.53 MT per hectare -1 over a 35-year period in southern
California chaparral.  First year biomass accumulation was approximately
5.3 times greater than the overall average [56], suggesting rapid early
growth after disturbance.

Related categories for Species: Quercus dumosa | Nuttall's Scrub Oak