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SILVICAL C_HA_RACTERTSTICS ::{ 9RECjON WHITE CMK.Y h_y ROY R. SIL~
"2-­
PACIFIC NORTHWEST FOREST
AN~
'C"'"- s R. W. COWLIN, DIRECTOR
u.s.
EXPERIMENT
"il
DEPARTMENT-OF-AGRICULTURE
7 (U.S. FOREST ~ERVICE:
(q.. PORTLAND) OR.~
~ 1
fo"f.5'i.f<voq_
u~s
~-f1lrfff'l ()f ~
(t.. DECEMBER 1958 STATIO~
~
CONTENTS
Page Habitat Conditions
2
Climatic
2
Edaphic
5
Physiographic .
6
Biotic
6
Life History
6
Seeding Habits
6
Vegetative Reproduction
7
Seedling Development
7
Sapling Stage to Maturity
8
Races and Hybrids
10 Literature Cited
11 SILVICAL CHARACTERISTICS OF OREGON WHITE OAK
by
Roy R ,
~ilen
Division of Forest Management Research
Oregon white oak (Quercus garryana)_!,_/ ranges farther north
than any other species of Quercus in North America. It is the only
native oak in Washington and British Columbia and is the principal
native oak of Oregon. Although its wood compares in quality to that
of the white oaks in the eastern United States, it has never reached
much importance as a timber tree , This is mainly due to its scat­
tered occurrence, small size, and short length of clear bole, and to
the abundance of conifers in the Northwest.
Its wood has been used for flooring, furniture , lumber, fuel,
cooperage staves , cabinet stock, insulator pins, woodenware ,
novelties, baskets , and felling wedges; in the manufacture of agri­
cultural implements and vehicles; and in ship construction (4, 9,
..!.i). !:_/ The greatest consumption of Oregon white oak was 2--: 18S, 000
board-feet (exclusive of fuel) in 1910 (.2_), when it was in demand for
tight cooperage and wagon parts; present annual use is estimated at
less than a million board-feet. Volume is estimated by the U , S .
Forest Service to be about 1 billion board-feet for the species over
its entire range.
Oregon white oak is commonly called Garry or Garry's oak in
Canada (24) , Common names used locally in the United States include
Pacific post oak, Pacific white oak, prairie oak , Oregon oak, west­
ern oak, and western white oak. Compared with its long list of
}:__/ Scientific and common names of trees in this publication
follow: Check list of native and naturalized trees of the Unite d States
(including Alaska) (11 ) ,
2/
Cited.
­
Underscored numbers 1n parentheses r efer to Literat ure
common names, its scientific name has undergone no rev1s1on since
given by David Douglas in 1839 in honor of Nicholas Garry, secretary
of the Hudson's Bay Company . The following synonyms are listed by
Sargent (_!1.): Q. neaei , Lieb . ( 1854); 9: douglasii , Neaei ( 1864);
Q. oerstadiana, R . Brown Campst. (1871 ); 9: jacobi , R . Brown
Campst. (1871); Q. gilberti, Greene (1890).
Oregon white oak is commonly found on drier sites within the
general range of the typical variety of Douglas -fir (Pseudotsuga
menziesii var. menziesii) , These include valleys in the rain shadow
of the Coast Ranges, dry southerly slopes, areas of gravelly soils ,
and table lands.
The range of Oregon white oak extends from British Columbia
to the mountains along the central coast of California (fig. 1 ) . In
British Columbia , it occurs in a narrow belt on the south and east
coast of Vancouver Island as far north as the Courtenay Valley, and
on islands adjacent to the east shore . Existence of more northerly
groves near Quatsino Sound and others in the Fraser Valley (..!_i:) have
since been questioned (24) . The species ranges southward through
Washington and Oregon, generally east of the summit of the Coast
Range and west of the summit of the Cascades. However, its range
extends to the east side of the Cascades in the Yakima and Tygh River
Valleys and includes the Siskiyou Mountains in southern Oregon. In
a few instances it extends nearly to the coast in the valleys of larger
streams of the Coast Range. In California it occurs at elevations up
to 4, 000 feet, principally in the Siskiyou Mountains and the drier
parts of the Coast Range as far south as the Santa Cruz Mountains.
HABITAT CONDITIONS
Climatic
In Thornthwaite 's classifi c ation , the humid z one of the Pacific
Coast with pr e cipitation- e ff e cti v eness index e s of 64-127 corresponds
roughly to th e rang e of Or eg on whit e oak (_!1) . Throughout this range ,
the species o cc upi e s sit e s wh e r e a v ailable soil moistur e is between
that requir e d by grass or ponde rosa pin e on one hand and the greater
amount required by Douglas-fir on th e oth e r . Climatic records of
w e ather stations (tabl e 1) e mphasi ze the narrow range of seasonal
precipitation in Or eg on white oak's natural habitat (i, ~' 18 , 20 : 22) .
Th e geog ra p hic ran ge of Or eg on whit e oak li e s within the 25­
t o 4 0 -inc h zone o f ave rage annual p re c i pitation . Its rang e is more
- 2­
0
....
I
\....
AN,.. 0,..
\
c.. -/>..- ­
_...-----u.s.
-----­
__-\
\
----~----\--~
.
'
\ _ _ 41"
0\ •
I
\
\.Ou CIIV
sail
I
I
\
NEIIAOA
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6
\ • Re no
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Figu r e 1.--Range of Oregon white oak.
-3­
4<1'
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~~,,..
~'
-
I
Table 1 . --Climatol og i cal dat a for l oc at ions within the range of Oregon white oakl/
Location
Fe et
I
~
I
Temperature
: Average
:
: annual
Average
Absolute
frost ­
: Eleva tion .
:
:
free
.
.
Apr il- Sept . .. Annual .. Annual .: Jan. ; July ; Max . : Min. : period
Average
pr ecipitation
------ Inches - -- - --
:
:
-- ------ - - - -- Degrees F . - - ----aD'- --- --
Days
British Columbia :
Nanaimo
Victori a
125
210
6 . 73
4. 08
36.40
26.65
so
so
37
39
65
60
100+
95+
-10
0
Wa shington :
Seattl e
Vancouver
14
100
6 . 73
7 . 64
31.92
37.32
53.2
52.5
40
38
63
67
98
103
3
-10
255
226
Oregon :
Corvallis
Roseburg
205
505
6. 29
5.73
39.06
30.50
52.4
53.4
39
41
66
67
106
107
-14
- 6
191
234
2,050
650
5.37
3.88
35.78
35.35
56.4
57.8
37.4
45.3
71.4
72.4
116
114
- 5
12
118
208
California :
Weaverville
Ukiah
l/
Data from U. S. Wea t her Bureau (20, 11) and British Columbia Dept. of Agriculture (1,
~) .
exactly delineated, however, by rainfall during the growing season
(April through September}, which averages from 4 to 10 inches.
Oregon white oak might grow well on sites with more~ moisture, but
it would not be able to compete successfully with the faster-growing
Douglas -fir.. Extremes of low temperature, early and late frosts,
and snowfall probably are not limiting to Oregon white oak, as it
survives them without serious damage.
Edaphic
Oregon white oak shows little preference as to soil type,]._/
which may vary in texture from stony and gravelly to heavy clay (.!..2_).
It is common on grassy, stony, well-drained slopes that are exces­
sively hot and dry in summer, but it reaches optimum development
in the deep, rich loams of the Cowlitz and Lewis River Valleys in
southwestern Washington and the Willamette Valley in northwestern
Oregon (fig. 2). Stumps 6 feet in diameter have been noted on
Figure 2.--A typical 80­
year-o ld stand of Oregon
white oak adjoining ag­
ricultural land in the
»~llamette Valley near
Albany, Oreg.
Sauvie s Island in the Columbia River ·n ear Portland, Oreg. ( 6).
Oregon white oak is often found in pure groves on both level a-;_d roll­
ing agricultural land of all soil series in major valleys of the Pacific
Northwest. But more often it occurs in scattered groups or as indi­
viduals on less fertile fringes of agricultural soils.
3/
Forb es, Robert H.
estry, Oregon Stat e College.
Oregon dendrology. School of For­
1945. (Mimeograph ed report.)
-5­
Physiographic
Oregon white oak occurs from low elevations in British Co­
lumbia to elevations of 3, 800 feet in Oregon and more than 4, 000 feet
in a few places in California . Over much of its range it grows on the
poorer forest sites , southwest slopes, and areas with thin soils and
frequent rock outcropping s.
Biotic
Oregon white oak occurs to some extent in pure, dense stands
in the open valleys between the Coast and Cascade Ranges . In parts
of western Washington, western Oregon, and California, it frequently
grows as an oak savanna where the forest meets valley grasslands.
Elsewhere it merges into several other types through complex transi­
tions .
It is a component of the oak-madrone type, which covers
about 400, 000 acres in Oregon and Washington. Good stands occupy
only a small part of this acreage; the majority of the type is noncom­
mercial scrub oak . In southern Oregon, California black oak replaces
Oregon white oak as the principal component of the oak-madrone type.
Oregon white oak is also common in the Pacific ponderosa pine­
Douglas -fir and Pacific Douglas -fir types (.!:..2_) .
The most common associate throughout its range 1s Douglas­
fir, which often comes in as an understory if the oak stand is not too
dense. The fir quickly overtops the oak and frequently chokes it out,
Other associated trees include Pacific madrone {Arbutus menziesii),
ponderosa pine {Pinus ponderosa), bigleaf maple {Acer macrophyllum),
Oregon ash {Fraxinus latifolia), Pacific dogwood (Cornus nuttallii),
tanoak {Litho carpus densiflorus), California black oak {Quercus
kelloggii), and California-laurel ( Umbellularia californica) .
LIFE HISTORY
Seeding Habits
Flowering and fruiting. --Flowe ring of Oregon white oak occurs
during April and May, usually later than Douglas-fir and bigleaf maple.
Staminate flow e rs appear as long, open, hirsute aments from buds in
the leaf axils of the pr e vious year's growth . Pistillate flowers are on
short stalks that originate from le a f axils of the current year's
growth{~_) .
-6 ­
Seed production . --Large crops of acorns are produced every
few years (_~_). The effects of weather on pollination and the reasons
for periodicity of seed crops are not known.
During development, acorns are attacked by the filbertworm
(Melissopus latiferreanus) and the filbert weevil (Curculio uniformis)
(l...Q_). When mature, they are a preferred food of pocket gophers
(Thomomys spp. ), black-tailed deer (Odocoileus hemionus
columbianus), mice (Peromyscus maniculatus and Microtus spp.),
chipmunks (Tamias townsendii), and squirrels (Tamiasciurus
douglasii and Citellus beecheyi douglasii) . The entire crop is con­
sumed some years . Consumption of acorns oy cattle, which is con­
sidered to cause digestive and other disturbances; occurs when other
forage is scarce (z) . Steller jays (Cyanocitta stelleri sp . ) and wood
ducks (Aix sponsa) also feed on acorns (g) .
Seed dissemination . - -Acorns mature 1n one season and fall
in September or October (Q) . Dissemination of the heavy acorns is
usually within a short distance of the tree. Animals that gather and
store the acorns are believed mainly responsible for long-distance
dissemination and migration .
Vegetative Reproduction
Vegetative propagation of all oaks is considered difficult and
no instances of layering , rooting of cuttings, or grafting have been
reported for Oregon white oak. In other species of white oak, cuttings
from older trees are impossible to root, but cuttings frorn the basal
part of 3- to 4-year-old plants have been rooted with success . Graft­
ing has been successful on many white oaks (~_) and vegetative propa­
gation of Oregon white oak by this means appears possible. Stumps
of Oregon white oak sprout vigorously and provide the surest means
of natural regeneration (~_) .
Seedling Development
Establishment, --Although large crops of acorns are produced
every few years, natural reproduction by seed is usually poor, owing
in part to the inability of germinating seeds to penetrate the heavy
sods upon which they are so frequently disseminated C~). Destruction
of acorns by insects ) rodents, birds, and deer is another important
contributing cause .
-7­
The best natural seedbed for Oregon white oak is moist, well­
aerated soil with an inch or more of leaf litter. Germination is
hypogeous and the species requires no pretreatment to break dormancy.
Germination occurs in the late fall or early spring, with percentage of
germination usually high (~) . The juvenile root is adapted to pene­
trate quickly and deeply before the onset of summertime drought, but
seedlings sometimes succumb to lack of moisture. Other causes of
mortality are competition from other plants, grazing, trampling , and
grass fire (~) ,
The tree 1s easily killed in its early years by fire, but with
the development of thicker bark at maturity it can withstand light
grass fires . Foliage of Oregon white oak is high in protein content
and is browsed by cattle and deer . However, the mature tree is re­
garded as resistant to heavy grazing {~). Oak is subject to much
animal injury of all types because it is often the predominating tree
of forest borders , where animal activity is greatest {~) . Pocket
gophers and ground squirrels injure roots of smaller trees by chew­
ing .
Oregon white oak apparently can be successfully regenerated
from stump sprouts without benefit of special silvicultural measures
during harvesting and slash disposaL Also, establishment of plan­
tations from seed on prepared seedbeds should not be difficult , al­
though no instances of deliberate establishment of plantations are
known. Numerous small pure stands of all age classes, which have
established naturally, can be found on fringes of agricultural zones .
Early growth . --Height growth , except in the seedling stage,
is considered slow (~_} . Tolerance to shade in its youth is greater
than at maturity {~) .
Sapling Stage to Maturity
Growth and yield. --Growth from sapling stage to maturity is
very slow {~ , 2_) , At best , the trees do not reach 100 feet in height
and seldom average more than 70 feet on their best sites in a life
span that may reach 500 years (~) . Diameters at 250 years of age
are seldom more than 3 feet.
Volumes per acre in pure stands at various ages and sites are
not known . The 80-year-old stand shown in figure 3, which averages
160 trees 3 . 6 inches and larger in diameter at breast height ~ would
yield about 15 cords per acre .
-8­
Figure 3.--Int e r i or view
of 80-year old s t and
shown in figure 2 . Es­
timated yield i s abo ut
15 cords per acre.
R e action to comp e t i t ion.- -Relative tolerance of Oregon white
oak i s listed as intermediat e b y Baker (1), but the species is consid ­
ered intolerant by som e other authoritie~ (I_).i_/ It generally dies
quickly when overtopp ed b y Do ug l as-fir, although some particul a r ! y
well-established tre es m a y li ve for 20 years after being overtopped
(~).
The species 1s us u a lly s ubclimax, developing into climax
only on dry, rocky south er l y exposures (..!:_2). The present distribu­
tion of st~nds in the Willamette Valley indicates that there have been
general invasions by Dou glas -fir into sites previously occupied by
Oregon white oak. Som e extension of oak stands into valley grass­
lands is also appar e nt.
:i_/ K e nist on, R.
Personal communication.
Coll ege , Cor vallis, O reg. 1956.
-9­
Or egon Stat e
Damaging agents . - -Oregon white oak is subject to damage
from a number of insects . The western oak looper (Lambdina
fiscellaria somniaria) may become epidemic and defoliate oaks over
a wide area . No permanent damage is done , however, since the tree
is able to leaf out again the following year (l...Q_) . The California tent
caterpillar {Malacosoma californicum} and the blue- sided tent cater­
pillar {M. constricta) also cause defoliation . Numerous cynipids
(gall wasps) attack the twigs and leaves of white oak, each causing
galls of characteristic sizes and shapes. Some cause conspicuous
twig killing by forming masses of galls between the bark and the wood,
thus blocking circulation . None of the insect pests of this oak are
con side red serious, however, and loss of trees by insect attack is
not believed common.
The present list of pathogens attacking Oregon white oak in­
cludes 31 species . Of these, all but six are considered saprophytic.~/
A pest that is common south of latitude 45 o 20 ' , but rare or absent
farther north, is the hairy mistletoe (Phoradendron villosum), which
is thought to inhibit tree growth . This conspicuous mistletoe-­
favored as a Christmas decoration-- can become so thick as to reduce
vigor to the point of killing the tree . The two major wood decays are
shoe string root rot , caused by the fungus Armillaria mellea , and a
trunk rot caused by Polyporus dryophilus . Oak mildew, caused by
Microsphaera alni, is a common foliage disease .
RACES AND HYBRIDS
A single natural hybrid, Quercus X eplingii {..9..: douglasii X
garryana) , is recognized (~_} . Racial variations within the species
have been observed by Sargent (.!.i_}, who describes a shrub-like form
of Quercus garryana on the shores and islands of Puget Sound and in
an area near Klamath Falls , Oreg . Acorns and leaves of Brewer oak
(Q . oerstediana), a small to large spreading shrub occurring on the
west slopes of the Sierra Mountains in California , are similar to
those of Oregon white oak . It is listed as a variety of Q . garryana
by Van Dersal (Q) but is maintained as a distinct species by Sargent
and Sudworth {_!__2, ..!....§_).
5/
Wright , E . , and Childs , T .
Personal communication.
Pac . NW . Forest and Range Expt. Sta ., Portland , Oreg . 1956 .
- 1 0­
LITERATURE CITED
(1 )
(2)
(3)
(4)
Baker , F red e rick S.
1949.
A revised tolerance table ,
179-181.
Boyce, John Shaw
1938.
Forest pathology .
London .
Jour . Forestry 47:
600 pp. ) illus .
British Columbia Dept. of Agriculture
1945 .
Climate of British Columbia .
27 pp . Victoria.
New York and
(Annual report.)
Collingwood, G . H., and Brush, Warren D .
1947.
Knowing your trees . 312 pp . , illus.
D. C.
Washington,
(5)
Dayton, William A .
1931.
Important western browse plants . U . S. Dept.
Agr . Misc . Pub . 101 . 214 pp . , illus.
(6)
Eliot, Willard Ayres
1938 .
Forest trees of the Pacific Coast.
New York .
(7)
(8)
(9)
{10)
Harlow, W . M . , and Harrar, E. S .
1941.
Textbook of dendrology ,
New York and London.
Ed . 2 .
Irgens-Moller , H.
1955 .
Forest-tree genetics research:
Econ. Bot. 9: 53-71 .
565 pp . , illus.
5 4 2 pp . , ill us .
Quercus L .
Johnson, Herman M .
1933 .
Oregon white oak: properties and uses .
Timberman 34(11) : 14-16 .
The
Keen, F. P.
1952 .
Insect enem1es of western forests. U . S. Dept.
Agr . Misc . Pub . 273 (rev . ), 280 pp . , illus .
-11­
{ll)
Little ~
(12)
McCulloch ~
ElbertL o, Jr .
19 53 o Check list of native and naturalized trees of the
United States (including Alaska) . U . S. Dept. Agr o
Handb . 4l o 472 pp o
1940 o
(13)
(14)
Wo F o
Oregon oak- -tree of conflict. Arne r. Forests
46{6): 264-266, 286, 288 , illus o
Sargent , Charles Sprague
l894 o Silva of North America o
Boston and New York.
Schoonover, S o E o
19 51 .
American woods .
Calif .
VoL 8, 190 pp o , ill us o
250 pp o , ill us o Santa Monica ,
( 15)
Society of Amer ic an Foresters
1954 .
Forest cover types of North America (exclusive
of Mexico) . 67 pp . Washington , D o C o
(16)
Sudworth . George B o
1908 .
Forest trees of the Pacific slope o 441 pp . , illus ,
Washington , D o C .
{l 7)
Tarrant , Robert F .
1956 .
Forest soils of the Pacific Northwest. Soc .
Am er , Foresters Proc . 1955: 73-76 , illus .
( l 8)
Thomas , M . K .
19 53 .
Climatological atlas of Canada. Meteorological
Div o, D e pt . of Transport , 256 pp . Ottawa o
(19)
Thornthwait e , C o W .
1941 o Atlas of climatic types in the United States ~ 1900­
1939 . U . S o Dept. Agr . Mis e Pub. 421 , 7 pp . >
96 maps o
(20)
U , S . D epartment of Agriculture
1941 ,
Climate and man , yearbook of agriculture o
1248 pp ., illus o
- 12­
( 21 )
U . S . Fore s t S e r vic e
1948 .
Woody-plant seed manua l. U . S . Dept. A g r .
Misc . Pub . 654 , 416 pp . , illus .
(22) U . S . Weather Bureau
1955 .
Climatological data . (Annual Summary 1954 . )
Washington, vol. 58; California, voL 58; and
Oregon , vol. 60 .
Ash e ville, N , C .
(23) Van Dersal , William R .
1938. Native woo d y plants of the Unit e d States , th e ir
erosion- c ontrol and wildlife values . U. S . Dept.
Agr . Misc . Pub . 303 , 362 pp . , illus .
(24) Whitford } H . N .; and Craig , R . D .
1918 .
For e sts of British Columbia . Canad . Conserv .
Comn . 409 pp . , illus . Ottawa .
-13­