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* I _:? * AG "t SILVICAL C_HA_RACTERTSTICS ::{ 9RECjON WHITE CMK.Y

"2-­ h_y ROYR. SIL~

PACIFIC NORTHWEST FOREST AN~ EXPERIMENT STATIO~ ~ 'C"'"- s R. W. COWLIN, DIRECTOR "il u.s. DEPARTMENT-OF-AGRICULTURE 7 (U.S. FOREST ~ERVICE: (t.. (q.. PORTLAND) OR . ~ fo"f.5'i.f

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 United States (including Alaska) (11 ), 2/ ­ Underscored numbers 1n parentheses r efer to Literature Cited. 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 classific ation, the humid z one of the Pacific Coast with pre cipitation- e ff e ctiv eness index e s of 64-127 corresponds roughly to the range of Oregon white oak (_!1) . Throughout this range , the species o ccupie s site s whe r e a v ailable soil moisture is between that require d by grass or ponde rosa pine on one hand and the greater amount required by Douglas-fir on the othe r . Climatic records of w e ather stations (table 1) e mphasize the narrow range of seasonal precipitation in Oregon white oak's natural habitat (i, ~' 18, 20 : 22) .

The geographic range of Oregon white oak lie s within the 25­ t o 4 0 -inch zone of ave rage annual p re c i pitation. Its range is more

- 2 ­ 0....

I - 4<1' \.... AN,.. 0,.. -----­ _...-----u.s\ c.. --­. />..

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----~----\--~ \ __ 41" I 0\ • \.Ou CIIV \ sail ' I .. I ~' \ NEIIAOA \ u1A~"~ \~ 6 I \ • Re no \ I ' \ "'' I\______

Figu re 1.--Range of Oregon white oak.

-3­ Table 1 . --Climatologi cal data for l ocations within the range of Oregon white oakl/

Average : Temperature : Average precipitation : : : annual Location : Elevation . Average : Absolute : frost­ . . free Apr il-Sept . . Annual . Annual .: Jan. ; July ; Max . : Min. : period

Feet ------Inches ------Degrees F. ------aD'------Days

British Columbia : Nanaimo 125 6 . 73 36.40 so 37 65 100+ -10 Victoria 210 4. 08 26.65 so 39 60 95+ 0

Washington : I ~ Seattle 14 6 . 73 31.92 53.2 40 63 98 3 255 I Vancouver 100 7. 64 37.32 52.5 38 67 103 -10 226

Oregon: Corvallis 205 6. 29 39.06 52.4 39 66 106 -14 191 Roseburg 505 5.73 30.50 53.4 41 67 107 - 6 234

California : Weaverville 2,050 5.37 35.78 56.4 37.4 71.4 116 - 5 118 Ukiah 650 3.88 35.35 57.8 45.3 72.4 114 12 208

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 ·near 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/ - Forbes, Robert H. Oregon dendrology. School of For­ estry, Oregon State College. 1945. (Mimeographed 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 {Lithocarpus densiflorus), California black oak {Quercus kelloggii), and California-laurel ( Umbellularia californica) .

LIFE HISTORY

Seeding Habits

Flowering and fruiting. --Flowering of Oregon white oak occurs during April and May, usually later than Douglas-fir and bigleaf maple. Staminate flowe rs appear as long, open, hirsute aments from buds in the leaf axils of the pre vious year's growth. Pistillate flowers are on short stalks that originate from lea 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.--Inter ior 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 compe t i t ion.- -Relative tolerance of Oregon white oak i s listed as intermediate b y Baker (1), but the species is consid­ ered intolerant by some other authoritie~ (I_).i_/ It generally dies quickly when overtopped b y Dougl as-fir, although some particul a r ! y well-established trees m a y live for 20 years after being overtopped (~).

The species 1s us u a lly s ubclimax, developing into climax only on dry, rocky southerl y exposures (..!:_2). The present distribu­ tion of st~nds in the Willamette Valley indicates that there have been general invasions by Douglas -fir into sites previously occupied by Oregon white oak. Some extension of oak stands into valley grass­ lands is also appare nt.

:i_/ K e niston, R. Personal communication. Oregon State College , Corvallis, O reg. 1956.

-9­ 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 conside 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 shoestring 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.

- 10­ LITERATURE CITED

(1 ) Baker, F rede rick S. 1949. A revised tolerance table , Jour . Forestry 47: 179-181.

(2) Boyce, John Shaw 1938. Forest pathology. 600 pp. ) illus . New York and London.

(3) British Columbia Dept. of Agriculture 1945. Climate of British Columbia. (Annual report.) 27 pp . Victoria.

(4) Collingwood, G . H., and Brush, Warren D . 1947. Knowing your trees . 312 pp . , illus. Washington, D . C .

(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. 565 pp . , illus. New York.

(7) Harlow, W . M . , and Harrar, E. S . 1941. Textbook of dendrology, Ed. 2 . 54 2 pp . , illus . New York and London.

(8) Irgens-Moller, H. 1955 . Forest-tree genetics research: Quercus L . Econ. Bot. 9: 53-71 .

(9) Johnson, Herman M . 1933 . Oregon white oak: properties and uses . The Timberman 34(11) : 14-16.

{10) Keen, F. P. 1952. Insect enem1es of western forests. U . S. Dept. Agr . Misc . Pub . 273 (rev. ), 280 pp. , illus .

-11­ {ll) Little ~ ElbertLo, 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

(12) McCulloch ~ W o F o 1940 o Oregon oak- -tree of conflict. Arne r. Forests 46{6): 264-266, 286, 288, illus o

(13) Sargent, Charles Sprague l894o Silva of North America o VoL 8, 190 pp o , illus o Boston and New York.

(14) Schoonover, S o E o 19 51 . American woods . 250 pp o , illus o Santa Monica, Calif.

( 15) Society of American 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 . Amer , Foresters Proc. 1955: 73-76, illus .

( l 8) Thomas , M . K . 19 53 . Climatological atlas of Canada. Meteorological Divo, D e pt. of Transport, 256 pp. Ottawao

(19) Thornthwaite , 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 . Fores t S e r vice 1948. Woody-plant seed manual. 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 . Ashe ville, N , C .

(23) Van Dersal, William R . 1938. Native wood y plants of the Unit e d States , the 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. Fore sts of British Columbia . Canad. Conserv. Comn . 409 pp . , illus . Ottawa.

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