BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Quercus grisea | Gray Oak 



GENERAL BOTANICAL CHARACTERISTICS : 
Gray oak is a native medium-sized tree from 20 to 65 feet (6-20 m) tall
[12,32,35].  Its growth form varies from a tree with one trunk to a
clonal shrub [1].  Gray oak is many branched.  It may be low growing and
less than 18 inches (45.7 cm) in diameter [12].  Gray oak leaves are
evergreen or drought-deciduous, depending upon the amount of winter
precipitation received [1,50].  The leaves are leathery and small, 0.8
to 3 inches (2-7.5 cm) long [17].  Pistillate catkins have one to six
flowers; staminate catkins are loosely flowered.  Acorns are solitary or
paired and are about 0.5 inch (1.2 cm) long [11,60].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Gray oak reproduces asexually and sexually.  Shrubby gray oak puts out
many ramets [1].  Gray oak is monoecious.  Acorns are produced annually
[11,60].  No information on gray oak acorn germination was found in the
literature.  However, the other southwestern oaks, such as Arizona white
oak and Emory oak (Q. emoryi), have no seed dormancy.  Most germination
occurs within 30 days after acorns drop from the trees [39].  Acorn
consumption by animals may substantially depress gray oak establishment
rates.


SITE CHARACTERISTICS : 
Gray oak occurs along drainages, arroyos, rocky slopes, foothills,
bajadas, stream sides, and terraces [16,19,41,50].  It is a facultative
riparian species [40].  Gray oak has a low-growing form in open savannas
[16].  It reaches tree size in mesic canyons [12,17].  Gray oak occurs
in semiarid climates characterized by mild winters, hot summers, and dry
springs [14,37,52].  It is found on shallow, rocky soils with textures
that range from clays to sandy loams. The soils often are derived from
igneous or dolomitic parent materials [13,41,44,50].

Gray oak can be found from lower slopes to ridgetops [20].  It occurs
from 4,000 to 9,000 feet (1,219-2,743 m) throughout its range
[17,37,50].  Gray oak predominantly occurs on north-facing exposures on
lower slopes, but it has been reported from all aspects [12,20,22,41].
At higher elevations, it may be restricted to sun-exposed or
southeastern aspects [1,20].



SUCCESSIONAL STATUS : 
Facultative Seral Species

Gray oak is a seral or climax understory species in pinyon-juniper
woodlands [49].  Following cabling or fire in pinyon-juniper woodlands,
gray oak and other oaks begin to establish after about 4 years, during
the grass and forb stage [30,49].  Gray oak is a seral species in
Douglas-fir and ponderosa pine forests, and a climax understory species
in ponderosa pine and Chihuahuan pine (Pinus leiophylla var.
chihuahuana) forests [12,14,34].  Gray oak is a climax species in
Madrean evergreen oak and encinal communities [25,34].


SEASONAL DEVELOPMENT : 
Gray oak flowers as new leaves emerge [17].  Acorns mature during the
autumn [60].  Leaves may remain throughout the winter until new leaves
are produced in mid-March through April [1].

Related categories for Species: Quercus grisea | Gray Oak