|
Wildlife, Animals, and Plants
|
|
VALUE AND USE
SPECIES: Lithocarpus densiflora | Tanoak
WOOD PRODUCTS VALUE :
Tanoak compares favorably with eastern hardwoods in strength, hardness,
and machining characteristics [31]. Manufacture of tanoak wood products
has been limited, however, due to an inconsistent supply of quality raw
materials. When processed properly, upper grades exhibit excellent
strength and an oaklike appearance, and produce a good grade of veneer
and plywood. Tanoak flooring, panelling, and decking have also been
manufactured [43]. Where stength, not appearance, is of primary concern,
lower grades have been used to make pallets, crossties, mine timbers,
baseball bats, and garden tool handles [7,31,43]. The wood has also
been chipped for particle board and pulp manufacture. Besides being
widely used as a source of domestic fuelwood [7], tanoak is currently
under consideration for use in waferboard, as a sports equipment
laminate, and for the cogeneration of electricity [31].
IMPORTANCE TO LIVESTOCK AND WILDLIFE :
Livestock: Although tanoak is generally considered of little browse
value to the majority of livestock [6,45], acorns and young seedlings
are highly preferred by hogs and cattle [43]. The leaves of shrub
tanoak (var. echinoides) provide some forage for domestic goats; use
typically corresponds to a lack of other more palatable forage and is an
indication of overgrazing on many sites [45].
Wildlife: Tanoak provides important habitat for numerous wildlife
species [2]. Because it tends to grow in mixtures with hardwoods and
conifers, tanoak is often a component of communities which are
structurally and compositionally diverse [31]. Tanoak habitats supply
food and nesting sites for the northern flying squirrel, Allen's
chipmunk, and dusky-footed woodrat [39]. Mammals which feed on tanoak
acorns include the black bear, black-tailed deer, Townsend chipmunk,
California ground squirrel, and redwood chickaree. Acorns are also a
source of food for birds such as the band-tailed pigeon, California
woodpecker, and varied thrush [39,42,53]. Cavity nesters known to use
tanoak include the downy woodpecker, northern flicker, red-breasted
nuthatch, white-breasted nuthatch, brown creeper, and house wren [40].
PALATABILITY :
Tanoak is of low palatability to most livestock and wildlife [6,45].
Utilization occurs primarily when other more preferred species are
unavailable. Mule deer readily consume both the leaves and acorns of
shrub tanoak (var. echinoides) in Yosemite National Park [45].
NUTRITIONAL VALUE :
Nutritional content of acorns produced by a number of West Coast
hardwoods including tanoak, California black oak (Quercus kelloggii),
valley oak (Q. lobata), blue oak (Q. douglasii), interior live oak (Q.
wislizenii), canyon live oak (Q. chrysolepis), and California live oak
(Q. agrifolia) are presented below [24].
carbohydrate 42 - 52%
protein 3 - 5%
fat 4 - 14%
COVER VALUE :
The multilayered structure of mature tanoak stands provides hiding cover
for a variety of birds and small mammals [39]. The northern flying
squirrel, Allen's chipmunk, and dusky-footed woodrat all rely heavily on
tanoak habitats for hiding, thermal, and nesting cover. Tanoak logs are
utilized as resting and hiding cover by a number of salamanders
including the ensatina, Del Norte salamander, and black salamander.
VALUE FOR REHABILITATION OF DISTURBED SITES :
Tanoak may be useful for controlling erosion since plants reestablish
rapidly through vigorous sprouting following disturbance [43].
OTHER USES AND VALUES :
Tannin produced from tanoak bark is used commercially to cure leathers
[31,42,53]; the tannin is particularly well suited for the curing of
heavy leathers such as soles of shoes and saddles [42]. Tanoak tannin
also possesses some medicinal properties. Ground acorns have been used
as chicken feed. Tanoaks are occasionally cultivated as ornamentals
[23]. The current year's growth exhibits a fuzzy covering of
reddish-brown hairs which often irritates the eyes and skin and may
cause coughing and sneezing [4,42].
Historically, tanoak acorns provided a dietary staple for indigenous
peoples throughout the California Coast Ranges. The tannins were
leached out, and then the acorns were either pounded into a mush or
dried and ground into flour for baking [22,43]. Apparently tanoak
acorns were much preferred over other types due to their high oil
content [42].
MANAGEMENT CONSIDERATIONS :
Competition: Tanoak represents a significant source of competition to
conifers [4,29,38]. Even though plants do not resprout as aggressively
as many associated species such as bigleaf maple (Acer macrophyllum),
madrone (Arbutus menzeisii), or Oregon white oak (Quercus garryana),
tanoak is much more abundant in conifer understories [21,42,48]. After
release from heavy shade, suppressed tanoak develops with remarkable
speed, often forming a dense cover [31]. Prolonged tanoak competition
typically results in lost conifer growth, extended rotations, and
inadequate conifer stocking on many sites [31]. Tanoak competition may
be particularly severe in new plantations, causing slow growth and high
conifer seedling mortality. To maintain plantations, tanoak must be
suppressed to the point where conifers can gain dominance. Herbicides
can be effective in temporarily reducing tanoak [5,8,12,20]. Possible
nonchemical control methods include mechanical means of site preparation
such as uprooting stumps or stump grinding [32]. Preharvest burning or
brush slashing used in conjunction with either preharvest or postharvest
burning are also potential methods of control [15,18,26]. Nonchemical
treatments are most successful when applied within a few years of
planting. Postplanting, follow-up treatments may be necessary on many
sites. Biotic control agents have received some attention. The
uncommon development of stunted and chlorotic tanoak sprouts on logged
areas in northern California could not be linked to either pathogens or
viruses [32].
Prediction equations have been developed which reliably estimate the
postdisturbance sprouting potential of tanoak from preharvest inventory
data [48]. Since these equations predict cover by age group and
diameter class, it may be possible to identify that segment of the
tanoak understory contributing most to postdisturbance coverages,
thereby aiding in the selection of an appropriate control method on a
site by site basis.
Tanoak management: Tanoak has often been considered a "weed" tree with
respect to conifer management. Since it is a highly persistant species
on many sites, intensive management of tanoak for hardwood timber
production may be a logical management option on some sites [28,31].
Management potential is highest on sites where extensive, even-aged
stands have developed following clearcutting or fire. Clearcut
harvesting and manipulation of subsequent sprout stands is the
recommended silvicultural treatment [30]. Sprouting from burls may be
encouraged by cutting stumps to less than 8 inches (20 cm); basal
sprouts have a low incidence of rot bridging from stump to sprout pith.
Leaving higher stumps encourages stool sprouts and increases the
likelihood of heart rot in young stands [30,31]. Tanoak grows better
and with better form if crowns are all in codominant position. As the
number of sprouts per clump declines over time, stem density becomes a
significant factor in maintaining the mutual shading so necessary for
optimal growth. Consequently, best development tends to occur where
stands are composed of both high densities of tanoak sprout clumps and
multiple stems per clump [31]. Initial thinnings are most effective
after the age of 20, at which time growth has been concentrated into a
few dominant stems; thinning prior to this time causes the production of
numerous resprouts. In northern California, best growth is
obtained when thrifty, 20-year-old stands are thinned to basal areas of
approximately 90 square ft/acre (21 square m/ha). McDonald and
Tappeiner [31] suggest interplanting thinned stands of tanoak with
Douglas-fir. Tanoak could then be harvested earlier in the rotation,
thereby increasing the growth and yield of Douglas-fir.
Related categories for Species: Lithocarpus densiflora
| Tanoak
|
 |