DISTRIBUTION AND OCCURRENCE
SPECIES: Juglans californica | Southern California Walnut 



GENERAL DISTRIBUTION : 
Southern California walnut is endemic to California [10].  The current
distribution of southern California walnut-dominated forests and
woodlands is limited to the Santa Clarita River drainage in the vicinity
of Sulphur Mountain, small stands in the Simi Hills and Santa Susana
Mountains, the north slope of the Santa Monica Mountains, and the San
Jose, Puente, and Chino hills.  The best remaining stands are in the San
Jose Hills [8].  Outside of this range, southern California walnut
occurs in Santa Barbara, western San Bernardino, and northern San Diego
counties [25].  It is conspicuously absent from the coastal foothills of
the Santa Ana Mountains, San Diego County [33]. 

Southern california walnut is cultivated in Hawaii [38].


ECOSYSTEMS : 
   FRES28  Western hardwoods
   FRES34  Chaparral - mountain shrub


STATES : 
     CA  HI


ADMINISTRATIVE UNITS : 
     DEVA  SAMO


BLM PHYSIOGRAPHIC REGIONS : 
    3  Southern Pacific Border
    7  Lower Basin and Range


KUCHLER PLANT ASSOCIATIONS : 
   K030  California oakwoods
   K033  Chaparral
   K035  Coastal sagebrush


SAF COVER TYPES : 
   246  California black oak
   248  Knobcone pine
   249  Canyon live oak
   250  Blue oak - Digger pine
   255  California coast live oak


SRM (RANGELAND) COVER TYPES : 
NO-ENTRY


HABITAT TYPES AND PLANT COMMUNITIES : 
Southern California walnut woodland may be monospecific or mixed.  Coast
live oak (Quercus agrifolia) frequently codominants in the walnut
woodland [13].  Between Santa Barbara and Orange counties, southern
California walnut is locally dominant or codominant in the coast live
oak phase of oak woodland [1,8].  Narrow, isolated stands of southern
California walnut sometimes occur in chaparral [29].  Occasionally,
southern California walnut is found in coastal sage scrub [9].

Classifications naming southern California walnut as a dominant or
indicator species are as follows:

Community ecology and distribution of California hardwood forests and
   woodlands [1]
Californian evergreen forest and woodland [5]
Oak woodland [8]
Vegetation types of the San Gabriel Mountains [9]
Demographic structure of California black walnut (Juglans californica;
   Juglandaceae) woodlands in southern California [13]
An introduction to the plant communities of the Santa Ana and San
   Jacinto Mountains [33].  

Associated species not previously mentioned include arroyo willow (Salix
lasiolepis), California sycamore (Platanus racemosa), white alder (Alnus
rhombifolia), California bay (Umbellularia californica), laurel sumac
(Malosma laurina), sugar sumac (Rhus ovata), toyon (Heteromeles
arbutifolia), Mexican elder (Sambucus mexicana), redberry (Rhamnus
crocea), coffeeberry (R. californica), hollyleaf cherry (Prunus
ilicifolia), birchleaf mountain-mahogany (Cercocarpus betuloides),
California scrub oak (Quercus dumosa), poison-oak (Toxicodendron
diversilobum), spiny ceanothus (Ceanothus spinosus), bigpod ceanothus
(C. megacarpus), California sagebrush (Artemisia californica),
California buckwheat (Eriogonum fasciculatum), black sage (Salvia
mellifera), fuschia-flower gooseberry (Ribes speciosum), brome (Bromus
spp.), wild oat (Avena fatua), sweetscented bedstraw (Galium triflorum),
rape mustard (Brassica rapa), wildrye (Elymus spp.), and Mexican whorled
milkweed (Asclepias fascicularis) [9,13,14,18,24,28].

Related categories for Species: Juglans californica | Southern California Walnut