VALUE AND USE
SPECIES: Taxus brevifolia | Pacific Yew 



WOOD PRODUCTS VALUE : 
The nonresinous wood of Pacific yew is fine grained, heavy, hard, and
very strong [5,32,55,62].  It is elastic but very durable, and resists
decay [5,32].  The sapwood is light yellow and thin, and the heartwood
is bright orange or rose red [5].  The wood responds well to finishing
and turns well on lathes [5,30].  This attractive wood has been used to
make canoe paddles, tool handles, poles, and fence posts [32,62].  It is
sometimes used in carving, cabinet-making, and for turned articles
[5,65] but has little or no commercial importance [30,32].

Native Americans traditionally used Pacific yew for constructing
harpoons, spear handles, eating utensils, wedges, paddles, and clubs
used in battle and for hunting seals [5].  Pacific yew is renowned for
its value in making bows and was formerly referred to as "bow plant" by
the Salish people [75].  Bows made from Pacific yew tended to be broad,
short, and flat [80].  Pacific yew is still used to craft some of the
finest archery bows.  The best bows are made from wood which has been
cured for several decades [5] and are, not surprisingly, quite costly.


IMPORTANCE TO LIVESTOCK AND WILDLIFE : 
Pacific yew provides important food and cover for many wildlife species
[34,68].  Old-growth grand fir/Pacific yew forests are often considered
critical moose winter habitat [61].

Browse:  Many wild ungulates feed on Pacific yew including deer, elk,
and moose [14,21,49].  In parts of northern Idaho, it is a preferred
winter moose browse [14].  Although Pacific yew browse may be eaten
during all seasons, use is particularly heavy in fall, winter, and
spring [14,60,61].  In winter, moose eat available forage and bark which
they strip from trees [14].  Plants may be severely hedged in some areas
[60].  Use is typically greatest when other forage is buried by snow
[60].  Moose utilization by season has been documented as follows [60]:

                 percent aggregate use

      May - July           3
      July- September      0
      October - November  42
      December - April    41

In a winter study at a Connecticut nursery, as much as 77.1 percent of
all Pacific yew shoots were browsed by white-tailed deer [12].  Rabbits
and other small herbivores may also browse Pacific yew in many areas
[21].

Pacific yew is reportedly toxic to domestic livestock [65,77], but
conclusive evidence of toxicity is lacking [15,37].  The closely related
English yew (Taxus baccata) is poisonous to cattle, horses, sheep,
rabbits, and man [66].  Some researchers report that Pacific yew is
similarly toxic, particularly when cut, piled, and allowed to rot [32].
However, in many areas livestock appear to browse branches "with
impunity" [70].  Livestock use is generally limited to the winter months
or periods of food scarcity [15].

Fruit:  Fruit of Pacific yew is sweet but reportedly poisonous to some
species [70].  It is readily eaten by many species of songbirds
including the Townsend's solitaire, varied thrush, and hermit thrush
[34].  The ring-tailed cat also feeds on the fruit of Pacific yew [77].

Foraging sites:  Pacific yew snags may be used by foraging woodpeckers
[48].


PALATABILITY : 
Foliage of Pacific yew is at least somewhat palatable to many large
ungulates and is highly palatable to moose, particularly during the fall
and winter [14,60].  Fruit is highly palatable to many species of small
birds and mammals [5,77].


NUTRITIONAL VALUE : 
NO-ENTRY


COVER VALUE : 
Pacific yew commonly forms a dense subcanopy which provides excellent
hiding and thermal cover for large ungulates and other wildlife species
[34,68].  On riparian sites, it provides shade which maintains cool
water temperatures for salmonids and other anadromous fish [68].


VALUE FOR REHABILITATION OF DISTURBED SITES : 
Potential rehabilitation value of Pacific yew is unknown.  However,
plants can be easily propagated from cuttings [5,42] or seed [65].
Cleaned seed averages approximately 17,600 per pound (39/g) [65].
Techniques for propagation from seed have been examined in detail
[21,28,65].  

The fibrous root system of Pacific yew can aid in stabilizing stream
channels [68].


OTHER USES AND VALUES : 
Pacific yew is an attractive ornamental which is frequently used as a
hedge plant [65].  It was first cultivated in 1854 [65].  According to
Kruckeberg [42], only the best foliage forms of Pacific yew can compare
with the much more widely planted English yew.  A shrubby form of
Pacific yew, often associated with serpentine soils, is generally
considered the most desirable ornamental form [42].  Once established in
the garden, Pacific yew grows well in partial shade or full sun [42].

Some Native American peoples traditionally associated Pacific yew with
death and bereavement [32,75].  The fragrant foliage was used as a
deodorant and cleaning agent [75].  Tonics made from Pacific yew were
used medicinally by many peoples of the Pacific Northwest [75].
Although seeds are poisonous, the fleshy portions surrounding them were
sometimes eaten [75].  The supple, stringy underbark was sometimes used
for braiding and weaving various items [32].

Taxol, a substance obtained from the bark of Pacific yew [33], has
inhibited the growth of various types of cancer cells in experimental
tests [1,44].  Clinical trials indicate that taxol produces a definite
but limited activity against metastatic melanoma and some types of
leukemia [44].  It may also be useful in treating ovarian cancer and in
inhibiting the growth of carcinosarcoma cells [11,44,38].  Taxol
inhibits the replication of Trypanosoma cruzi, a pathogenic protozoan
which causes Chagas disease [11], as well as the disease-causing
flagellate Trichomonas vaginalis [35].

Researchers are currently working on methods to synthesize taxol in the
laboratory, but efforts to date have been only partially successful
[39].  Pacific yew yields more taxol than any other species of yew
(Taxus spp.) and remains the primary source of this substance [11].
Recent experiments suggest that it may soon be possible to obtain taxol
from the leaves rather than from the bark [39].


MANAGEMENT CONSIDERATIONS : 
Timber harvest:  Pacific yew is uncommon on most recently harvested
sites [81].  It is sensitive to drastic changes in light and temperature
and can be severely harmed by increasing exposure to heat after tree
canopy removal [34].  Sensitivity to frost may also cause decreases in
yew after overstory removal [11].  Plants commonly turn orange or brown,
and the foliage dies back after clearcutting [5,11,49].  However,
Pacific yew often adapts to unshaded conditions through changes in twig
distribution and leaf morphology [11].  In a northern Idaho study,
approximately 78 percent of individual plants survived overstory removal
[11].

Reductions in the cover of Pacific yew are often dramatic.  Antos [2]
reported 1.4 percent cover after grand fir types were clearcut in
western Montana.  Prior to timber harvest, Pacific yew represented
nearly 20 percent cover.  The effects of timber harvest have been
examined in a number of studies [4,18,19].  Uneven-aged individual tree
removal or group selection is much less damaging to yew than
clearcutting [34].  Broadcast burning also greatly reduces the cover of
Pacific yew [61].

Wildlife:  In parts of northern Idaho, moose browse Pacific yew heavily
during winter.  Browse in clearcuts is generally covered by deep snow
and inaccessible to moose.  However, plants within the understory of
old-growth forests are readily accessible and heavily utilized [60].
Clearcutting in these areas does not favor moose.  For best moose
habitat, timber harvest should be avoided in old-growth grand
fir/Pacific yew communities [61].  To protect Pacific yew and maintain
adequate moose browse, whole tree removal should be used where possible
to lessen the need for slash disposal [61].  Slash should be piled and
then burned rather than broadcast burned.  Natural grand fir and
Engelmann spruce (Picea engelmannii) regeneration can be supplemented by
planting Douglas-fir (Pseudotsuga menziesii) in small clearings [61].

Damage:  Pacific yew may be severely damaged by rabbits and deer [21].
Moose occasionally kill trees by girdling the trunk [14].  In some
locations ungulates can hedge or even remove Pacific yew from springs
and seeps [14].  In parts of northern Idaho, heavy moose browsing can
prevent Pacific yew dominance on ridges and south aspects [14]. In some
areas, yew regeneration can be significantly impacted by moose [14].

Pacific yew is resistant to damage from sulfur dioxide pollution [11]
and is resistant to insects and disease [50].

Allelopathy:  Seedlings of other species are rarely found beneath yews
[49].  Pacific yew has exhibited inhibition both in laboratory
experiments and in the field [16,64].  Allelopathic compounds may be
concentrated in senescent leaves and leached into the litter [64].

Bark collection:  Approximately 20,000 pounds (9,080 kg) of bark is
required to produce 2.2 pounds (1 kg) of taxol [1].  In some locations,
populations of Pacific yew are threatened by collectors gathering bark
for its anticancer properties [68].  If this demand continues, this
important species could become scarce in many areas [11].

Old growth indicator:  Scher and Jimerson [68] noted that long-lived
temperature-sensitive species such as Pacific yew may serve as useful
indicators of old-growth forests.

Related categories for Species: Taxus brevifolia | Pacific Yew