BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Quercus havardii | Sand Shinnery Oak 



GENERAL BOTANICAL CHARACTERISTICS : 
Sand shinnery oak is a freely branched, clonal, thicket-forming shrub or
small tree [23,27].  Plants generally grow from less than 3 feet to 6
feet (< 1-2 m) in height; they may occasionally reach heights of 13 feet
(4 m) [33].  Individual stems rarely grow to more than 0.8 inch (2 cm)
in diameter [27].  Clones may extend from 9 to more than 49 feet (3-> 15
m) in diameter [27].  Individual stems typically live for 11 to 15
years, although the age of the clone itself may be much older [32].
Clones are continually rejuvenated through new sprouting as aerial stems
senesce [27].

The thick, leathery leaves have toothed or lobed margins [14,33].
Leaves vary in shape from oblong to elliptic, lanceolate to
oblanceolate, or ovate to obovate [14].  The upper surface is lustrous,
grayish or yellowish green, and the lower surface a felty lime green
[32,33].

The fruit is an acorn which varies in size and shape [14].  The broad
cup (up to to 1 inch [2.5 cm] in length) [33] encloses one-third to
one-half of the nut [14].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Seed:  Sand shinnery oak produces good acorn crops an average of 3 out
of every 10 years [32].  Acorns are often damaged or destroyed by late
season frost [32] or by insects.  Seeds are dispersed by gravity, and
birds and mammals.  Seeds of most species within the white oak group
germinate soon after falling to the ground [38].  Root elongation of
sand shinnery oak is generally rapid [32].  Embryological development
has been examined [2].

Seedling establishment:  Seedling establishment of sand shinnery oak is
rare [27,32].  Establishment is generally limited to disturbed sites
that lack competing grasses [27].  Seeds will germinate and seedlings
survive only in years when precipitation from late July to early August
is abundant [32].

Vegetative regeneration:  Sand shinnery oak spreads laterally through
rhizome expansion [33,39].  Rhizomes range from 4 to 39 inches long
(1-10 dm) and elongate vertically toward the soil surface [27].  More
than 60 stems may arise from the same rhizome [32].  Rhizome expansion
and growth is often rapid where competition is slight [28].  Rhizomes
allow sand shinnery oak to expand in areas where conditions are too
severe for seedling establishment [27].

Several sources have also reported that sand shinnery oak sprouts from
roots [37] and underground stems [19,42].  It also spreads slow by
tillers.  In Oklahoma it spread 30 feet (9 m) in 50 years by tillering.
Following disturbance, sand shinnery oak can sprout vigorously from the
stem base [32].


SITE CHARACTERISTICS : 
Sand shinnery oak grows on sandy plains and sand dunes [14] where it
commonly forms dense thickets or shinnery [35].  It grows as a dominant
throughout much of the rolling sandhills of the Great Plains [27].  Sand
shinnery oak is typically associated with dry, sunny sites [43].  

Soil:  Sand shinnery oak grows on shallow to deep sands and, more
rarely, on gypsum [33].  Cover generally declines as soil clay content
increases [32].  Sand shinnery oak forms clumps on sandy loam and dense
stands on deep sand [32].

Climate:  Sand shinnery oak grows under a climatic regime described as
warm temperate and semiarid [47].  Semiarid portions of west Texas and
eastern New Mexico dominated by sand shinnery oak receive an average of
16 inches (41 cm) of annual rainfall [11].  The growing season averages
200 days [11].

Elevation:  Sand shinnery oak grows from 2,300 to 3,400 feet (701-1,036
m) in Trans-Pecos Texas [33] and from 3,634 to 6,896 feet (1,125-2,135
m) in Utah [57].


SUCCESSIONAL STATUS : 
Sand shinnery oak is a constituent of "postclimax" bluestem communities
in the high plains of Texas [35].  It sprouts readily after disturbance
and can rapidly assume prominence in many early seral communities.


SEASONAL DEVELOPMENT : 
In west Texas, vegetative buds of sandy shinnery oak begin to swell in
mid-March [32].  Both male and female flowers begin to form after the
buds develop.  Flowering generally occurs during April in the Great
Plains [14].

Related categories for Species: Quercus havardii | Sand Shinnery Oak