VALUE AND USE
SPECIES: Juglans californica | Southern California Walnut 



WOOD PRODUCTS VALUE : 
NO-ENTRY


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Southern California walnut forests and woodlands provide favorable
habitat for a number of vertebrates and invertebrates.  A 2-year survey
in a southern California walnut woodland in the San Jose Hills found 29
species of diurnal birds [25].  Many rodents, including California
ground squirrels and western gray squirrels, eat the nuts [11,25].  The
nuts are rarely eaten by deer [25].


PALATABILITY : 
NO-ENTRY


NUTRITIONAL VALUE : 
NO-ENTRY


COVER VALUE : 
Larger southern California walnut trees provide excellent cover for
deer, nesting birds, and rodents [25].  Raptors such as owls use the
upper reaches of trees as roosts and nesting places.  California ground
squirrels dig burrows at the bases of old trees [25].


VALUE FOR REHABILITATION OF DISTURBED SITES : 
Southern California walnut has been successfully planted for erosion
control on road slopes with deep soil at elevations below 3,500 feet
(1,066 m).  Best growth is achieved in partial shade [11].  In Los
Angeles County, southern California walnut was planted in brush wattles
during construction of a road fill.  Trees reached heights of 12 feet
(3.7 m) in 10 years [11].  


OTHER USES AND VALUES : 
Humans eat the nuts of southern California walnut, but the nuts are not
grown commercially [25].  Chumash Indians ate the walnuts and used the
nutshells for dice.  They used the bark for making baskets [31].
Southern California walnut is suitable for ornamental landscaping and is
widely planted in urban forestry projects [11,13].


MANAGEMENT CONSIDERATIONS : 
Southern California walnut communities are in decline [5,10].  Threats
include urban and rural development, overgrazing, and increased
recreational use of walnut woodlands [14,25].  In Aliso Creek, Chino
Hills State Park, cattle grazing initiated dry conditions, which were
worsened by a 5-year drought.  The resulting very dry environment
hindered survival of walnut seedlings [14].  Grazing has been the
principal economic activity in California walnut forests and woodlands
for 200 years.  The species composition of the southern California
walnut woodland understory in the Puente and San Jose hills is
attributed to overgrazing by cattle [25].

Pathogens:  Southern California walnut is highly susceptible to crown
(Phytophthora spp.) rots.  Walnuts planted in soil infested with P.
citricola and flooded for 48 hours biweekly showed reduced growth and
high rates of mortality [17].

In the San Jose Hills, southern California walnut develop heart rot
between 20 to 30 years of age.  Portions of the trunk and older limbs
subsequently become infested with termites and wood-boring beetles.
Older multistemmed trees often have some stems that are healthy, some
with heart rot, and others that are dead [25].

Related categories for Species: Juglans californica | Southern California Walnut