Woodwatch Profile

Species: Sitka Spruce (Picea sitchensis)

Characteristics in the Living Environment (Silvics)

Size: 125 – 180 feet in height (up to 300ft.) and 3 – 5 feet in diameter (up to 25ft.) and is the

largest Spruce species.

Lifespan: 700 – 800 years old. Due to rapid growth in favorable conditions, large size may not

indicate exceptional age.

Range: Narrow strip along north Pacific at low elevations with maritime climate and abundant

moisture throughout the year. Its northwest limit is on Kodiak Island, Alaska and its southwest

limit is near Fort Bragg, California. In the southern portion of its range (including Oregon), it

principally grows within 4 miles of the coast, with inland extensions along larger rivers.

Tolerances: Deep, full canopy; ocean spray.

Seed & Reproduction: Sitka Spruce is monecious, with male and female reproductive organs

occurring on the same tree. Female (seed) cones are usually produced at the ends of primary

branches near the tops of trees. Male (pollen) cones are usually produced at the ends of

secondary branches lower in trees. However, both may occur on the same branch. Cone bearing

usually begins between the tree’s 20th and 40th year. Like Douglas Fir, the cones hang down from

the branches, but Sitka Spruce cones do not have forked bracts, and the cone scales are paper

thin.

Ecology: Sitka Spruce is a vigorous, fast growing tree usually dominant in the forest canopy, and

often associated with Western Hemlock. The dense Spruce Hemlock stands of the Northwest

Coast have some of the highest growth rates of North America. Best development is on deep,

well aerated soils. Drainage is important, and growth is poor on swampy sites. Mature trees in

tidal swamps will appear much younger than actual age. Commonly occupies alluvial soils along

streams, sandy or coarse textured soils, or soils having a thick accumulation of organic material.

Often occupies a prominent position on exposed headlands and beaches. Often a significant

component of healthy estuaries, with roots stabilizing banks and fallen trees providing hydrology

calming structure and sanctuary for wildlife.

Current Status: In 1989 the volume (International ¼ inch rule) of Sitka Spruce sawtimber on

commercial forest land in Washington, Oregon, and California was measured as 7,848 million

board feet; in Alaska, the volume was 63,493 million board feet. The species remains

widespread, although old growth Sitka Spruce forests are nearly gone. Native pathogens such as

white pine weevil and spruce bud worm not currently a major threat.

Places to visit and see Sitka Spruce in its living environment

At Cape Meares State Scenic Viewpoint, a massive Sitka Spruce over 250 years old has branches

growing like giant tentacles from a 50 foot base. Known as the Octopus or Council Tree, its

branches were deliberately shaped by early Tillamook peoples after being chosen to become a

site of ceremonies and elder councils.

Almost any trail along the Oregon coast will pass through Sitka Spruce stands. Near Otis,

Oregon you can hike a steep 4.2 mile out-and-back trail through young and mature (150 plus

year old) Sika Spruce forest to an open coastal headland in a 270 acre United Nations Biosphere

Reserve managed by the Nature Conservancy.

Just south of Seaside, Oregon a 364 acre coastal wetland and flood plain restoration project in

the upper reaches of the Necanicum River estuary system and along Circle Creek has protected

and enhanced one of the largest remaining coastal Spruce swamps on the Oregon Coast.

Thousands of Sitka Spruce trees have been planted by volunteers to restore Spruce swamp

converted to pasture land in the 19th century. Contact the North Coast Land Conservancy in

Seaside for access.

Did you know?

Sitka Spruce is named for Sitka Island (now known as Baranof Island) in southeast Alaska where

it was first named by Europeans in 1832.

By the time WWI broke out in Europe, Sitka Spruce was recognized as the best of all materials

for aeroplane construction due to its high strength to weight ratio and the fact that the length and

toughness of its fibers meant it would not splinter when hit with a bullet. However, a woods

labor general strike and market manipulations by mill owners meant wartime demand could not

be met. In 1917, to increase production of aircraft-quality Sitka Spruce, the U.S. Army Signal

Corps established a Spruce Production Division of some 30,000 “spruce soldiers” to work

alongside civilian loggers and millwrights. As a result, production rose 5,000 per cent in a little

more than a year, with a total of 143 million board feet harvested (including almost 54 million

board feet from Oregon) in the final year of the war. After the war, logging companies adopted

labor policies and working conditions similar to those of the division and utilized the division

built logging roads and railroads to access large tracts of otherwise inaccessible forest.

The wooden Hughes HK-4 Hercules aircraft, the largest flying boat ever built with the largest

wingspan of any aircraft in history, was nicknamed “the spruce goose”. Currently on display at

the Evergreen Aviation Museum in McMinnville, Oregon, the plane is actually made of

laminated panels consisting primarily of birch, with some spruce.

The Trident I submarine-launched ballistic missile, deployed by the U. S. Navy and the British

Royal Navy between 1979 and 2005, had nose cone fairings made of Sitka Spruce. The fairings

shielded the multiple independent reentry vehicle warheads as the missile accelerated up through

the atmosphere.

Native Peoples consider the sharp needles of Sitka Spruce to provide special powers of

protection and to guard against evil thoughts. The inner bark and pitch are used as food and

medicine. The boiled roots are used in making tightly woven waterproof baskets and hats.

Remarkable Traits: Sitka Spruce is the 5th largest and 3rd tallest conifer species in the world. In

Oregon, Sitka Spruce is highly dependent on the moisture of the coastal fog belt, and was once

known as tideland spruce. It is an impressive, tall, straight tree with an evenly tapering trunk and

a shallow root system with long lateral roots and few branchings. Mature trees often develop

enlarged, swollen, and buttressed bases and open conical crowns. Trunks sometimes develop

large swollen burls, possibly due to early bud damage. Both Sitka Spruce and Hemlock have

adapted to high windthrow mortality with seedlings that have evolved to germinate and thrive on

a substrate of decaying conifer wood or “nurse logs”.

Species Puzzler: What are the two identifying field characteristics that would allow positive

identification, even in the dark? (the stiffest and sharpest needles of any tree in the region that

bristle out on all sides of the branch, and the scaly, jigsaw puzzle bark.)

The values and qualities of its wood

The sapwood of Sitka Spruce is creamy white to light yellow and blends gradually into the

heartwood, which is pinkish yellow to brown. Sapwood in mature trees may be 3 to 6 inches

wide, and wider in young trees. The wood has a fine, uniform texture, generally straight grain, no

distinct taste or odor, and relatively few resin ducts. The annual rings are distinct, with a band of

lighter colored earlywood shading gradually into a narrower band of darker latewood.

Wood from Sitka Spruce is considered moderate in weight, stiffness, hardness, resistance to

shock, shrinkage, bending, and compressive strength. It has a low resistance to decay. However,

Sitka Spruce has the highest strength to weight ratio of any wood. This ratio makes Sitka Spruce

valuable for light aircraft components and oars, planking, masts and spars for boats. Thin panels

of slow growth Sitka Spruce are highly resonant, and are often used as sounding boards for high

quality pianos and faces for fine stringed instruments.

The wood is kiln dried easily and can be worked easily when free of knots. Sharp cutting edges

are required to produce a good planed finish. Glues and finishes well, although it can give

blotchy and inconsistent results when stained due to its closed pore structure. This can be

avoided by the use of sanding sealers. Severe reactions are uncommon, but Sitka Spruce has

been reported as a sensitizer, resulting in skin irritation and or respiratory discomfort.

Sitka Spruce is preferred (along with Hemlock) for paper pulp because of its long strong fibers

and the ease with which it can be processed. Even lower grade Sitka Spruce logs provide high

grade fibers. It is also used to make high grade chemical pulps for rayon and plastics.

Places to visit and see uses of harvested Sitka Spruce

The Western Antique Aeroplane and Automobile Museum, Hood River, Oregon. Many original

and replica aeroplanes from the Golden Age of Aviation (1903-1941) with Sitka Spruce

airframes, including an original 1917 Curtiss JN-4D Jenny.

Evergreen Aviation & Space Museum, McMinnville, Oregon. The museum’s general aviation

collection has several replicas of early airplanes with Sitka Spruce airframes, including the

Wright 1903 Flyer.

Information Sources for Sitka Spruce

“Trees to Know in Oregon”, Charles R. Ross. Extension Bulletin 697. Published by Oregon State

University Extension Service and the State Department of Forestry.

“Plants of the Pacific Northwest Coast”, Jim Pojar and Andy Mackinnon, editors. Published by

Lone Pine Publishing, Vancouver, B. C.

“Information on Oregon Wood Species”, Oregon Wood Innovation Center, Oregon State

University: owic.oregonstate.edu/information-oregon-wood-species

“Picea sitchensis (Bong.) Carr.” A.S. Harris. U.S. Forest Service Silvics Manual:

na.fs.fed.us/spfo/pubs/silvics_manual/Volume_1/picea/sitchensis.htm

“The Gymnosperm Database”, edited by Christopher J. Earle: conifers.org

“The Wood Database”, edited by Eric Meier: wood-database.com

“The Spruce Production Division”, Gerald Williams. Forest History Today, Spring, 1999:

foresthistory.org/Publications/FHT/FHTSpring1999/fhtspruce.pdf

To find Build Local Alliance members who produce, sell, and work with Sitka Spruce, Go to the

following link and type “sitka spruce” in the search window:

http://www.buildlocalalliance.org/member-products-services/