DISTRIBUTION AND OCCURRENCE
SPECIES: Quercus douglasii | Blue Oak 



GENERAL DISTRIBUTION : 
Blue oak is endemic to California.  It occurs in valleys and lower
slopes of the Coast Ranges and in lower foothills of the Sierra Nevada.
Its distribution almost completely encircles the Central Valley [30,53].


ECOSYSTEMS : 
   FRES21  Ponderosa pine
   FRES28  Western hardwoods
   FRES34  Chaparral - mountain shrub
   FRES35  Pinyon - juniper
   FRES42  Annual grasslands


STATES : 
     CA


ADMINISTRATIVE UNITS : 
     KICA  PINN  SEQU  WHIS  YOSE


BLM PHYSIOGRAPHIC REGIONS : 
   3  Southern Pacific Border
   4  Sierra Mountains


KUCHLER PLANT ASSOCIATIONS : 
   K010  Ponderosa shrub forest
   K011  Western ponderosa forest
   K023  Juniper - pinyon woodland
   K030  California oakwoods
   K033  Chaparral
   K035  Coastal sagebrush
   K038  Great Basin sagebrush
   K048  California steppe


SAF COVER TYPES : 
   239  Pinyon - juniper
   245  Pacific ponderosa pine
   246  California black oak
   248  Knobcone pine
   249  Canyon live oak
   250  Blue oak - gray pine
   255  California coast live oak


SRM (RANGELAND) COVER TYPES : 
   201  Blue oak woodland
   202  Coast live oak woodland
   203  Riparian woodland
   204  North coastal shrub
   205  Coastal sage shrub
   206  Chamise chaparral
   207  Scrub oak mixed chaparral
   208  Ceanothus mixed chaparral
   422  Riparian


HABITAT TYPES AND PLANT COMMUNITIES : 
Blue oak-dominated communities are highly variable in composition.  Blue
oak frequently associates with gray pine (Pinus sabiniana).  It also
occurs in monospecific stands or codominates with several other oak
species.  Oak codominants not listed in previous frames include interior
live (Q. wislizenii) and valley (Q. lobata) oaks.  The blue oak
community ranges in physiognomy from open savanna to farily dense
woodland with a shrubby understory.  It merges or forms a mosaic with
annual grassland at low elevation and with chaparral, other oak woodland
phases, or singleleaf pinyon-California juniper (Pinus
monophylla-Juniperus californica) woodland at higher elevation [26].

The following publications name blue oak as a dominant species:

Blue oak communities in California [3]
Association types in the North Coast Ranges of California [18]
Oak woodland [26]
Valley grassland [29]
Terrestrial natural communities of California [30]
The vascular plant communities of California [62]

Plant associations:  Overstory associates not previously listed include
Coulter pine (Pinus coulteri) and California buckeye (Aesculus
californica).  Shrub associates include leather oak (Q. durata),
California scrub oak (Q. dumosa), buckbrush (Ceanothus cuneatus),
California coffeeberry (Rhamnus californica), chamise (Adenostoma
fasciculatum), manzanita (Arctostaphylos spp.), poison-oak
(Toxicodendron diversilobum), and toyon (Heteromeles arbutifolia).  Some
common ground cover associates are annual bluegrass (Poa annua), annual
fescues (Vulpia spp.), annual ryegrass (Lolium multiflorum), medusahead
(Taeniatherum caput-medusae), ripgut brome (Bromus rubens), wild oat
(Avena fatua), bur clover (Medicago polymorpha), filaree (Erodium spp.),
star thistle (Centaurea spp.), and tarweed (Hemizonia, Holocarpha, and
Madia spp.) [5,6,16].

Related categories for Species: Quercus douglasii | Blue Oak