VALUE AND USE
SPECIES: Picea sitchensis | Sitka Spruce 



WOOD PRODUCTS VALUE : 
Sitka spruce is the most important timber species in Alaska [5].  The
wood, with its high strength to weight ratio, is valuable for use as
turbine blades for wind-driven electrical generators, masts for sail
boats, ladders, oars [24], boats, and racing sculls [55].  Sitka
spruce's high resonant quality makes it valuable in the manufacture of
piano sounding boards and guitars.  The wood from Sitka spruce is also
used in saw timber, high-grade wood pulp, and plywood [30,55].


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Sitka spruce forests in various phases of succession provide habitat, in
many cases critical habitat, for a large variety of mammals, game and
nongame birds, reptiles, and amphibians [7,19,43].  Its value as a
browse species for large ungulates is poor [11], while it has fair to
good value for some game birds [42].


PALATABILITY : 
Sitka spruce is slightly palatable to large ungulates.  It is browsed
only in the spring, and then only the new growth [5,11].  In Alaska and
British Columbia the needles comprise up to 90 percent of the winter
diet of blue grouse [42].


NUTRITIONAL VALUE : 
NO-ENTRY


COVER VALUE : 
Sitka spruce forests provide hiding and thermal cover for a large
variety of mammals.  Old-growth Stika spruce forests in Alaska and
British Columbia are critical winter habitat for the Sitka deer.  Old
growth provides thermal cover and acts as a snow screen, allowing easier
access to browse species [25,51].  Sitka deer require large blocks of
old growth from sea level to the alpine and subalpine environments for
migrational movements from summer to winter range [51].  Sitka spruce
forests also provide habitat for Roosevelt elk, woodland caribou [19],
Alaskan brown bear, and mountain goat [42].

Sitka spruce provides good nesting and roosting habitat for avifauna
[52,56].  Snags and live trees with broken tops provide nesting habitat
for primary and secondary cavity nesters [27].  The bald eagle uses
primarily (greater than 90 percent) Sitka spruce for nesting trees on
Admiralty Island [42], and also uses them as roosting trees to survey
the incoming breakers for food [5].  The peregrine falcon in coastal
British Columbia uses Stika spruce for platform nesting and secondary
cavity nesting [9].


VALUE FOR REHABILITATION OF DISTURBED SITES : 
Sitka spruce is a pioneer species which colonizes glacial moraines as
the glaciers retreat.  On the Juneau Icefield, Sitka spruce has
colonized "nunatacks" (rocky peaks) protruding through the icefield [6].
Sitka spruce also acted as an aggressive pioneer on uplifted terrain
from the 1964 earthquake [4].


OTHER USES AND VALUES : 
Native Americans have used Sitka spruce for various purposes.  The roots
can be woven to produce baskets and rain hats.  The pitch was used for
calking canoes [5], for chewing, and medicinal purposes [47].

Pioneers split Stika spruce into shakes for roofing and siding [5].

Sitka spruce also has limited food value for humans, for the inner bark
and young shoots may be eaten as emergency food.  Tea can be made from
the young shoots [47].

In the first half of this century Sitka spruce provided most of the wood
for stuctural components of World War I and II aircraft [5,55].  More
recently it has been used as the nose cones for missiles and space craft
[50].


MANAGEMENT CONSIDERATIONS : 
Sitka spruce, as one of the most important timber species and components
of old-growth habitat, has recently been the center of many management
concerns.  Proposals for changes in timber harvest areas and methods
have been explored by Nyberg and others [43] and Schoen and Kirchhoff
[51].  They provide in-depth information and management alternatives.

Wildlife habitat:  Even-aged management of the species results in
reduced habitat for the black-tailed deer.  Shrub fields created after
clearcutting are of limited use to deer in the winter.  The depth of
snow accumulation is greater, and snow persists longer in the clearcuts,
reducing the time available for browsing.  The forage in clearcuts is
less digestible than that grown in the shade of the preharvest stands.
Also, the large amount of slash resulting from clearcutting old-growth
Sitka spruce impedes movement of large ungulates, especially during
winter migration.  Lastly, once the regeneration has reached canopy
closure (20 to 30 years), the understory production is greatly reduced
for at least the next 100 years, compared to old-growth stands with
their various stages of regeneration [19,25].

Alaback [2] studied ways to reduce the negative impact of clearcutting
on Sitka deer.  Thinning the stands prior to canopy closure (less than
25 years) seems to be the best method for areas already cut.  Thinning
to 12 x 12 feet (3.5 x 3.5 m) spacing results in the most diverse
vegetation.  Once canopy closure has occurred (greater than 30 years),
uneven-aged management practices can result in the creation of gaps in
the canopy, which in turn will allow for a more diverse understory [3].

Damaging agents:  Sitka spruce is susceptible to Sitka spruce weevil, or
white pine weevil (Pissodes strobi)), spruce aphid (Elatobium
abietinum), spruce beetle (Dendroctonus rufipennis), and root rot by
Armillaria millea and Heterobasidian annosum [24].

The Sitka spruce weevil has such a detrimental effect on Sitka spruce in
the lower portion of its range, from southern British Columbia to
northern California, that Sitka spruce is not actively managed for
regeneration there.  The F1 generation of the hybrid, Lutz spuce, yields
a tree 100 percent resistant to weevil attack, but growth rate is
sacrificed.  Back-crossing the F1 generation with Sitka spruce increases
the growth rate, but up to 50 percent of the progeny are susceptible to
weevil attack [41].  Also, although Lutz spruce is less susceptible to
the Sitka spruce weevil, it is more susceptible than Sitka spruce to the
spruce beetle [29].

Sitka spruce is susceptible to wind throw, which can account for up to
80 percent of the mortality within stands.  Regeneration from gap phase
replacement, however, is rapid [15].

Control:  Chemical shrub control is often required to regenerate Sitka
spruce successfully following harvest [18,36].

Related categories for Species: Picea sitchensis | Sitka Spruce