PULP &
PAPER
PULPWOOD \Norld
I A1
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BC PROT!:C EO '( /1
L.a',v (WLE 17, U.S CU l:)
Shelterwood
cutting
studied to see if young-growth hemlock can be
regenerated by series of successive cuttings
About This File: This file was created by scanning the printed
publication. Misscans identified by the software have been
corrected; however, some mistakes may remain.
Ie
S,
-Portland, Ore. A STUDY NOW UNDERWAY at the Hem­
lock Experimental Forest near Grays
Harbor in western Washington is de­
signed to test shelterwood cuttings as
a means of regenerating coastal west­
ern hemlock. Hemlock Experimental A report by
FRANCIS R. HERMAN
Pacific Northwest Forest and
Range Experiment Station
U. S. Forest Service
Portland, Ore.
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•
•
ESTABLISHED REGENERATION
AFTER
THIRD CUT
SHElTERWOOD MANAGEMENT SYSTEM, showing successive stages of regen­
eration in western hemlock forest.
PULP & PAPER - June 11, 1962
Forest is owned by St. Regis Paper
Co. and leased to the U.S. Forest
Service under a cooperative agree­
ment to conduct research aimed at
securing the greatest possible con­
tinuous yield. Logging on the experi­
mental forest is done by St. Regis and
research is conducted by the Pacific
Northwest Forest and Range Experi­
ment Station, Portland, Ore.
In the U.S. Forest Service report,
"Timber Resources for America's Fu­
ture," we are told that more than 18$
of the national pulpwood output is
produced in the Pacific Northwest. To
continue to furnish this proportion of
America's pulpwood requirements in
the year 2000, Pacific Northwest for­
ests must produce perhaps as much
as three and one-half times the pres­
ent output. Even so, an estimated na­
tional demand for 89 million cords of
pulpwood may require the United
States to import nearly 15 million
cords. Successful methods of obtain­
ing quick regeneration and maintain­
ing optimum stocking on all forest
lands will assist in preventing possible
shortages in wood products.
The wood of western hemlock is
admirably suited for producing good
pulp and lumber. Many mills in the
Pacific Northwest look to hemlock to
furnish at least a portion of their
cordwood and sawlogs. Some mills
in western Washington are currently
utilizing hemlock in preference to
other species. Western hemlock is
blessed with many attributes that
make it a good candidate for man61
I'
·
.
.
tics is bci
o[ 2U to :
ou cuttiug
7 acres ea
tcrruption
cuts on ;
shelterwood cutting
complettxl
plan in t
early 2,1
370,000 I
moved in
the shelt.
second an
partments
complete
SEED TRAP makes it possible to estimate amount, viability
and distribution of hemlock seed for any of several shel­
terwood cutting intensities.
agement. It is a prolific producer of
seed and, when provided with its
proper
environmental
condition,
grows rapidly, tall, and straight.
Clear cutting of old-growth
hemlock commonly has been accepted
as the only method that will provide
coilditions conducive to reestablish­
ment of hemlock. Is it certain, how­
ever, that clear-cutting management
of young-growth western hemlock will
provide the best conditions for stand
regeneration? Examination of recently
cutover young-growth hemlock forest
land reveals an abundance of weeds
and brush but only a sparse co\·cr of
new hemlock seedlings. Would some
form of partial cutting, such as the
sheltenvood systcm, prove more suc­
cessful than clear cutting in providing
TRACTOR AND SULKY used for skidding tree-length logs
from shelterwood compartment to roadside landing for
bucking into pulpwood or sawlogs.
quick and abundant regeneration?
Early in this century, logging, for­
est fires, and windstorms in western
Washington left some scattered old
hemlock trees and provided environ­
mental conditions suitable for the es­
tablishment of extensive, even-aged
stands of nearly pure young-growth
hemlock. The exact nature of these
environmental conditions is unknown.
These older trees provided seed and
some degree of shelterwood protec­
tion for the young forest. We cannot
turn back the pages of history and
conveniently look in upon acciden­
tally
created
growing conditions.
!lowever, we can artificially create
varied sets of conditions and measure
resulting
environmental
influences
conducive to establishment of a new
forest.
Shelterwood cutting system
is being tested on the Hemlock Ex­
perimental Forest, 15 miles north of
Hoquiam, Wash.-an "experimental
island" within a large area of young­
growth western hemlock. The original
forest was logged near the tum of the
century, and the bulk of the present
stand is now about 60 years old. A
few scattered, older western hemlocks
that escaped the early logging are
found throughout the area. The stand
averages 270 stems per acre in trees
6 to 30 in. in diameter, and volumes
exceed 43,000 bd. ft. per acre. Here
on 68 acres in this nearly pure stand
of young-growth western hemlock, ef­
fects of a wide range of shelterwood
cuttings on regeneration are being
studied.
Comparison of 12 cutting intensi­
Shelten
from clen
the time \
cut over.
moved b}
ings inste.
a new cn
surviving
nifies, sh<
ter or pre
trees shat
teet new
light an.
extremes.
light also
undesirab
might dt
young fOl
Shelter
esters to
trees for
and gro\\
providin
seed, the
their rat.
in quanl
rotations.
and sele.
tained t
managen
Unlike
health b
cure all a
ment is'
undoubt.
ciated \'
shelterw.
poses of
Foremos
damage
ing succ.
establish
damage<
subs QU'
should I
of timb
measurc
tivc abl
seedling
Facto
dance (
quality
RESIDUAL SHELTERWOOD stand after initial cutting has
23 trees per acre. Research will show if this is lighter
shelterwood stand than is desirable.
62
AFTER INITIAL CUTTING this stand has 54 trees per acre.
Second cut in 5 years will leave half these trees to pro­
vide seed and soil protection.
PULP & PAPER - June 11,
need to
thev ar'
scale 0
vironml
PULP &
ties is being made in residual stands
of 20 to 200 trees per acre. Logging
on cutting compartments of from 5 to
7 acres each began in 1960. After in­
terruption by winter weather, initial
cuts on all 12 compartments were
completed according to prescribed
plan in the late summer of 196!.
Nearly 2,000 cords of pulpwood and
370,000 bd. ft. of sawlogs were re­
moved in Ulis first cut. Accordin g to
the shelterwood management plan,
second and third cuttings on all com­
pmtments at intervals of 5 years will
complete thc cutting schedule.
09s
for
em
Exof
Ital
ng­
nal
Ule
ent
A
cks
are
md
oos
nes
ere
l1ld
ef­
lod
'ng
Isi­
,.
I
\
r
e.
)-
Shelterwood management differs
from clear cutting in that it delays
the time when the forest is completely
cut over. Seed-bearing trees are re­
moved by two or more successive fell­
ings instead of by single cutting. Thus
a new crop establishes itself from the
survivin g seed trees. As the term sig­
nifies, shelterwood also provides shel­
ter or protection. Crowns of retained
trees shade the forest Aoor and pro­
tect new seedlings from bright sun­
light and detrimental temperature
extremes. The limited intensity of sun­
light also controls the development of
undesirable brush and weeds that
might delay the establishment of a
young forest.
Shelterwood cutting permits for­
esters to select and retain certain
trees for their seed-bearing ability
and growth potential. In addition to
' providing an abundant supply of
seed, the released trees win increase
their rate of wood production-both
in quantity and quality. Shortened
rotations, improved yield volumes,
and selected auality all may be ob­
tained through careful shelterwood
management.
Unlike the claims made for many
health tonic elixirs that purportedly
cure all ailments. sheltenvood manage­
ment is not said to be perfect. There
undoubtedly will be problems asso­
ciated with the apolication of the
shelterwood system. One of the pur­
poses of the studv is to evaluate these.
'
Foremost is the possihility of logj:(ing
damage to established seedlings dur­
ing successive cuttin)!s. Young growth
established after a first cut may be
damaged by felling and skidding in
subsequent cuts. Amount of damage
should be associated with the amount
of timbl'r cut ea ch time. The final
IlwaSUl"(' of sncce ss will hc the rela­
tivc abundance of healthy hemlock
secdIinl!s.
Fad rs conh'ibnting to an abun­
dance of well-distributed and high­
quality western hemlock seedlings
need to he' known and evaluated if
the'v an' to 1)(' C'ncol1raged in large­
scal(, operations. These include en­
yironn1C'nt:ll innucnees sllch as compcPULP & PAPER
­
June 11, 1962
tition from other plant species, light
intensity, aspect, slope, and seedbed
as well as the factors of seed fall,
germinative capacity, and seedling
survival.
In an effort to discover the quantity
of seed that falls under each intensity
of cutting, simple but effective seed
traps made of wire screen fitted into
a wood frame are placed within each
shelterwood-cutting compartment. A
number of these traps scattered over
a known area give an estimate of the
available seed supply per acre. Con­
tents of Ule traps are collected and
examined several times a year.
Logging costs and returns
for the entire shelterwood manag
ment cutting period are being kept.
Because work is less concentrated
under shelterwood than under clear­
cutting management, logging costs
may be somewhat higher. Even extra
cost may be justified if healthy re­
generation can be obtained more
quickly under one Ulan under an­
other cutting treatment.
On other portions of the Hemlock
Experimental Forest, periodic tbin­
nings have been carried out since
1950. These thinnings are designed
to remove the least desirable mem­
bers of the stand and promote d
velopment of the better members of
the crop. The thinnings are stimulat­
ing good crown development that will
produce good seed crops later on.
These stands are being groomed for
application of the best management
-be it she1terwood or some other r
generation cutting method.
It is from thinning experiments that
we get an inkling of the growth ca­
pacity of young-growth western hem­
lock. The net mean annual increment
to date has been 158 cu. ft. or 828
bd. ft. per acre. The experimental for­
est is growing rapidly, however, and
the thinned stands show a current net
periodic yearly increment of 179 cu.
ft. or 1,490 bd. ft. per acre.
Time is not far off when young­
growth westell1 hemlock stands will
be called upon to bear a major por­
tion of the rapidly increasing demand
for cellulose. Some of these stands,
though only 40 to 60 years old, even
now furnish pulpwood to the ever­
increasing capacity of pulp and paper
mills. Foresters must learn to man­
agc this young crop of wood to main­
taill wood growth at least cqual to
that of demand. Studies at Hemlock
Experiment:ll Forest are designed to
provide foresters with management
guides. If shc1terwood management
provides the key to quick, adequate
regeneration of w estern hem lock, a
shelterwood l'utting guide will be
available for :lpplication hy the end
•
of tIl{' stl1dy period.
APA
release
reviews
For further information on publications
described below, write:
M1ElUCAN PULPWOOD ASSOCIATION
220 E. 42nd St., New York 17, N.Y.
(Please identify by number in brackets)
Experimental tractor
designed by a forest engineer at
Catawba Timber Co. (Bowaters Caro­
lina) is a four-wheel, rubber-tired
unit for hauling pulpwood. Basic
chassis is a Massey Ferguson model 65
diesel farm tractor, from which the
front wheels have been removed. An
integral pallet cart is attached to this
unit with a "wasp-waist" universal
hjtch. A "Big Stick" mast and boom
loader (TR 59-R-30) have been fitted
on the basic unit.
In operation, a cable is fastened to
pulpwood bolts, then moved by re­
mote control to a position near the
machine, at which point wood is
manually controlled onto the pallet.
Pallets that are carried to unloading
area, dumped and reloaded on the
unit, can carry up to n cords of pulp­
wood. Release is illustrated. (TR-62­
R-9)
"Ergonomics"
in forestry is defined as measur
ment of work in terms of the quantity
of heat to which it is equivalent. In
Swedish forestry, for the past 20 years,
a basic tool for determining labor
capability has been physiological re­
search. This release states what differ­
ent ergonomic methods can do, how
they do it and results from their ap­
plication. Although ilie Swedish find­
ings are spelled out in word and by
graph, the APA comments that "the
need for determining physiological
and psychological demands on forest
workers seem very remote." (TR 62­
R-I0)
Nylon safety pads
for knees of work pants have been
demonstrated to cut lost-time acci­
dents from chain-saw injuries 10-20%
at one company, while reducing them
almost 35% at another, according to
this release. Chain saw "ccidcnts ;\rL'
rep ort ed to have increasc>cJ from ] 6
of all injuries in 1957 to 31% last year.
Many companies report that chain
saw accidents are primarily in the
klH.'e :lrca.
An Eastern Canadian company is
marketing tlwse knee pads at a r ea ­
sonable price; a U.S. l'ompany is
contemplating their manufacture if
there is illterest shown. (TR 62-H-12)
63