A Guide -lo fhe
VOIGHT CREEK EXPERIMENTAL FOREST near Orting, Washington
maintained jointly by the
PACIFIC NORTHWEST FOREST 8 RANGE EXPERIMENT STATION
PUGET SOUND BRANCH
and the
ST. PAUL 8 TACOMA LUMBER COMPANY
U.S. DE PA RTMENT
OF AGRICULTURE
FOREST SERVICE Portland, Oregon 1951
Original
General view of area thinned in 1949--Plot 9, Compt. A-1.
Cu t 1,637 cu. ft. or 27 percen t.
volume 6,176 cu. ft. per acre.
A GUIDE TO THE
VOIGHT CREEK EXPERll ENTAL FOREST
The Voight Creek Experimental Forest is one
of four areas of private forest land dedicated
to cooperative research and demonstration in
the management of second=growth forests of the
Puget Sound regiono
They are called cooperative
experimental forests and are created by lease
agreement between the forest land owner and the
Forest Service
Q
This area has been dedicated to research
by Sto Paul and Tacoma Lumber Company of Tacoma9
Washington9 the owner.
The forest is part of
the company's extensive tree farm system of
1509000 acres situated in eastern Pierce County.
It is representative of the young Douglas-fir
forest that has followed the early logging of
the virgin forest.
In fact.
this area was orig­
inally logged by St. Paul in 1900.
It was
formally activated as a cooperative experimental
forest in December
1947.
under an agreement by
which the Pacific Northwest Forest and Range
Experiment Station,
through its Puget Sound
Branch, prepares the management plan, experiments,
and cutting schedules;
fire protection,
and the company provides
develops the roads, and cuts
and markets the products.
The aims of this experimental forest are
to produce the highest grade products at the
smallest possible cost2
to secure the greatest
possible return per acre,
and to offer practical
aid to timberland owners through demonstrating
sound and feasible forest practices.
"' ' .·
Location and General Characteristics
The forest oonaist:3 of 230 acres located 7 miles east of Orting, (See map on in ide back cover for detailed ·directions.) It is 20 miles from Tacoma and 52 miles from Olympia. It lies on.an upper slope above the Carbon River at an elevation ranging from 830 to'l,l40 r et. Soils are derived from a piedmont glacier from the Cascades and are prlinoipally B rnesto.p. gravelly sandy loam and IndianolEl sandy loam.. The climate is favorable to tree growth
having ample rainfall and moderate temperature.
Records from the nearest weather station (Buckley)
show an annual_ precipitation of 46 inches; 15
inches of this fall during the months April to
·September. Snowfall is rare, very similar to
that at sea level on Puget Sound. Average annual
temperature is 50.4° F.; the April to September
average is 57.8°. The average frost-free growing
season is 161 days.
Research Ob
ctives
·The· general bbjectj_ve of the Voight Creek
Experimental Forest is to conduct st1!ldies and
experiments in m ethods of improved forest manage­
ment e.nd utilization in the forest lands of the
region.. More specifically it i s to study by
mee,.ns .pf experimente,.l cuttings the following
af;lpect of' -f!i.:n.iber management in second-growth
Pouglas..;fi:r.l. !, ( 1) p rtie.l cutting. in the form of
thinnings,_r alvage, and stand improvement;
(2) effect'of partial c uts on the t ree and stand,
particularly as to growth and final yield; ( 3) uses that can be made of the t imb r cut;
(4) how results obtained in these cuttings can
be applied by forest owners to their awn lands.
.
Characteristics of the Forest
The forest, in the spri g of
1949,
was a
37-year even-aged stand of Douglas-fir that
developed following repeated burns over a much
larger clear-cut area.
The Douglas-fir,
80
percent of the stand by volume, is dominant
everywhere except in the drainage bottoms, where
alder and cottonwood are abundant.
Hemlock and
A
cedar are numerous, but as an understory.
few scattered old-growth fir remain near the
northwest corner.
Stooking, which is quite uni­
form, probably was at least partly the result
of seed from outside the forest, since the few
scattered seed trees appear inadequate for such
generally prolific regeneration.
_
Species
14
There are
tree species_growing on the
fore-st, 6 conifers and 8 hardwoods.
The hard­
woods have probably reached their maximum
development, and it is believed they will be
gradually suppressed over the years by.the fir
and hemlock, which are now growing more rapidly
and are apparently more suited to the site.
The following list gives common anq scientific
names:
Conifers
Common name·
Scientific name
Douglas-fir
Western hemlock
Western redcedar
Sitka spruce
Western white pine
Pacific yew
Pseudotsuga taxifolia
Tsuga heterophylla
Thuja plicata
Picea sitchensis
Pinus monticola
Taxus brevifolia
-3-
..•:'.",
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Forest-wide Volume by Species
·
Cubic foot
6 in.+ d.b.,h ..
to' 4-in. to
·s���cies-.l�::;•r
1 10 in.+
Board-foot mill tallY
12 in.+
d b.h.
_i;o_�-in..__top
d.boho
to__2-i!l._.__top
Inches
.
•I
+.
.
Douglas-fir
2-
2 . 2·64
2-
Hemlock
. Cedar
!'·
Alder
Cottonwood
·-
Misc. Hdwd ..
Tot l
.
Per acre
•
812l'728
54,418
26 28 18 20. 28
12
•
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•
...0
0
G
0
0
0
•
•
•O
-0
-- -·--·
49;036
20 470
17,641
24Jd+9
1,826,200
142,600
24,150
149,261
85,523
5,740
2 712,160
' 211 761
35,863
200,000.
95,000
9,000
978,742
4 .. 256.
2,233,474 9,711
3,263,78 4
14,190
.
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Hardwoods
Scientific name
Common name
""
Red alder
Black cottonwood
,Bigleaf maple
Paci.fic willow
Biglea.f Paci.fic willow
Cascara
Bitter. cherry
Paci.fic dogwood
Alnu rubra
·Populus trichocarpa
Acer macrophyllum
Salix lasiandra
S. lasiandra lyallii
Rhamnus purshiana
Prunus emarginata
Cornus nuttalli
Volume·
A forest-wide cruise, ·completed in January
1949, r vealed for the 37-year-old stand on land
rated site index 144 (site III) the volumes by
species shown on page 4.
Growth
Mean annual growth thus far has been 115
cubic feet and 262 board feet (12 inches +to
an 8-inch top) per acre per year. However, this
young stand is at the beginning · of its most
productive period
Increment studies indicate
that the growth of the conifers alone over .the
next 10-year period will excee 160 cubic feet
and 935 feet board-measure annuallyo To deter­
mine a method o.f growth prediction for managed
stands o.f young· Douglas-fir timber is one o.f
the objectives of the research program. Judi­
cious salvage and thinning cuts are expected to
raise the rate of net growth of the existing
growing stock substantially over its present
rate.
•
.
-5­
Administration
The cutting
d marketing are done by the
company in the areas sele cted by the station as
agreed in the research plan. All timber to be
cut is marked by the station except salvage
material, which is left to the judgment of-the
cutting crew. ·By e xperimentation and improvisa­
tion, the company has arrived at economical
methods to handle s mal l timber and at the same
time reduce logging damage to a minim . A 4-·
man crew has proved the most efficient, and a
single horse use d in skidding was found to be
cheaper than tractors. Trees are felled with a
1-man power saw, skidded to the landing, and
loaded on trucks by a homemade portable loa er.
All work is by a company crew.
An al l-weather road system of 1 63 miles
makes all parts of the area easily accessible.
Short, ungraded truck trails are built to
shorten horse skidding when needed. Cutting and
hau_ling can be carrie d on at any time of the
year.
All timber cut is for immediate use, and no
nonmerchantable trees are cut·. The timlber is
'
sold in the round form except for split cedar
posts. Products cut in first-cycle thinnings
have been:
Cubic-foot volume
Percent
Product
Total·
Per acre
of total
..
Smelter and
·
standard poles
Saw timber
Car stake s
Mine props and
fence posts
63,355'
603
47 ($9
11,127
449
·106
9&520
131,131
91
1,249
-6­
4B
36
9
100
The smelter poles. used in the smelting of
copper,
are cut from trees
8
inches d.b.h. and
12
l arger.
Saw timber comes _from trees
inches
..
d.b.h. and l arger, cut to a 9-inch minimum top
and later sawn into small dimension lumber by a
small sawmill operator nearby.
in shipping bulk product
and mine props come from trees
and larger
Car stakes1
used
on railroad flat cars.
6
inches d.b.h.
Standard poles are cut from the
Fence posts are
better saw- timber size trees.
•
.
produced from the dead and down ced r snags
scattered thro ughout the area.
Skidding smelter poles with horse.
-7-
Protection
Fire protection for the area is through the
company's regular.fire protection plan, based
upon pri:ma.ry state ·re.sponsibility supplemented
by additional help from the company's tree farm
organization. A cqnt nuous and . closed canopy
l.(eaps wind circul tion to a minimum, tending to
preserve soil oisture and prevent excessive
desiccation. The partial c').lts in progr,ess are
believed to incr ase fire hazard but sTight;t.y,
as the slash is closely lopped in ·cutti,ng. Specif­
ic study of this faotor .is needed.
The easy·
accessibility d'!le to.the road system and the
'close proximity.of·a suppression crew afford ex­
cellent fire. suppression 10pportunities.
Thus far no insect problems have developed
in connection with cutting. Considerable :r9ot
rot (Poria. weirii ) is evl.dent· throughout the
ta.nd and presents a real problem in salvage and
control. Nq easy detection of the disease l:las
been found to ·date; it is only immediately prior
to dea'tn that the fo.liage shows evidence of·
infect:Lqn.
Trespass is negligible because of.con rolled
entrance to the forest.
Grazing by stock or lbrowsing by game is no
problem: forage is at a 1rninimum because· of
dense stocking. As C'\ltt Jtlg opens the s.tand more
forage or browse can be expected.
- 8-
Research Program
Commercial-thinning of natural Douglas-fir
stands is being studied thro;gh an intensive
permanent plot system. Mortality and logging
injury data are also being gathered on the
plots.
Other research_proj cts include;
pruning studiesj studies on the financial as­
pects of young-growth manageme t; observation
on Poria weirii detection and control; studies
of the effect of soil on growth and yield; ef
fects of management practices on the soil; and
a comprehensive experiment to learn more of the
producti on of Douglas-fir seed as affected by
age and thinningo
Commercial Thinnin·g Experiments
Most of t he work in progress on the.
Voight Creek Experimental Forest is directed
toward testing a number of hypotheses regarding
the thinning of second-growth Douglas-fir.
Three intensities of thinning with three in­
tervals between cuts are being studied. Al.so
there are check areas on which no thinning will
be done.
Answers are sought to these ·questions:
What is the optimum gro,Ying stock to carry?
.What is the best volume to remove in any· one
cut?
How long should the interval be between
cuts for the best results? What is the best
balance between volume of yield removed in the
intermediate cuts and that left for the final
harvest if we are to obtain maximum volume.and
v lue production? Which are the best trees to
take and to leave in each cut?
-9-
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NW V4 a S lf2 SW lf4, Sec.6, T.l8 N., R.6 E., W.M.
VOIGHT CI?EEK
EXPERIMENTAL
FOREST ®
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MEDIUM
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B-2
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8-1
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SCALE
400
IN
CHECK
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C-4 LIGHT
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em
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r::,.'". VY BLOCK A, COMP. I A-I H.c;;
HEAVY THINNING
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I/5A. SAMPLE PLOT·
TREATMENT. EXAMPLE: ·
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TEMPORARY PLOT
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s
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BLOCK BOUNDARY
COMPARTMENT
-BOUNDARY
@
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@ C-3 CtfECK
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LEGEND­
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FEET
0
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800
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Thinning Data
I Intensity
of cut
·j
A-1
A-2
A-3
.A-4
B-1
B-2
B-3
before
B-4
cuttin
f't.,
3,589
3,087
3,738
Heavy
Check
.Light
4,:1,92
Medium
Heavy Check First Cut
'Volume
Cu.
I
1-'
[\)
I
-
Light
.Average
d.b.h..
and
In.
Cu. ft.;
8.3
7 3
7·7
1 475
0
657
.•
0 r.
u.c.
9 .6
9'.2
Average
d.p.h. .
'In
.•
I
Percent
removed
8.3
41
0
., 429
7·9
7.5
1-8
13.2
. 39
.,
10o4
9.1
4,116'
8.8
1,208.
'
""'
B
'Voltime
.removed
1,780
0
578
1,328
4,874
Medium
I Average·
A
3,698
5 239
4,514
·
on Blocks
.
34
13.1·
11.3
0
11 27
10.5
.29
Scattered throughout the forest in a
systematic, replicated pattern are more than
200 tem porary . and permanent ,p1ulti-sized
circular sample plots of 1/80-, 1/20-, and
1/5-acre. Th se plots wil.l provide data for
determining the effect of the cutting treat­
ments appli d
The forest is qivided into
three blocks (see map on pages lO-ll) ·to p r-. ·
mit replicat on and into four io partments to
.of thinning
p e rmi t use of t4e three intensities
.
and a cnec ar a.
•
.
.Generally speaking, the first trees marked
for cutting are the deformed, broken, seriously
injured or dyin g trees; next, ·rough dominants.
to release trees of bett r form; then, trees in subordinate positions not expected to survive to the next cutting·. Lastly, some trees are removed to improve the spacing and release · more promising trees. How far these categories are drawn upon is determined by the amount of out and the stand character·.
Thus far thinnings have been completed
for six compartments, as shown on page 12,
for trees 6 inches d.b.h. and larger, acre
basis.
Studies of mortality and how it is af­
fected by the various types of thinning are
maintained along with the growth studies.
· Pruning Studies
Pruning plots ar e set up on all the thinn ed
plots to test various methods, tools, and costs.
Production of merchantable.cl ar wood in,less
than 100 years is seldom possible under natural
·
. - 13­
stand conditions. Trees that show possibilities
of increa d growth are pruned, t a rate of 100­
125 per acre. Studias indicate tnat pruning the
first 16-foot log can produQa clear lumber within
50-60 years at an added cost of less than $15
perM.
Financial Aspects of
Thinning
Determining the costs and r eturns
of
thin­
ning young Douglas-fir is another res arch ob­
jective.
The intention is to make these first
cuttings at least selfpporting if possibl .
Experience is showing th t an o tput of 12.0
cubic feet
per
man-hour w:tll be necessary to
realize this objeotiv ,
Thi goal has been
exceeded in the .l st twct compartment out. $ub­
sequent cuts s'hou1.d 'be more profitable· since
.initial developm nt has b een .c.ompleted, trees
will be larger, and the ni..unber_of steins less,
.
Some information has already -been obtained, and data of increasing value wil accumulate in the years ahead. Thus f r 105 acres have been thinned, remov­
ing 29 percent of the growing stock, or 1,208
The value of this harvest
cubic feet per acre.
per acre, loaded on the truck in
averaged
the woods, At this samEI rate the product value
of the growing stock left for future increment
would be
per acre,
Actually the residual
!Stand is worth more beceluse the poorer trees were
out, the better ones reserved for future growth.
The employment possibilities of such fully pro­
ducing s econd growth, assuming an estimated annual
growth of 160 cubic feet, would be 12.8 man-hours
per acre per year in harvesting alone.
It wo uld
such acre§ to employ yearlong one
take but
$175
$425
140
woods worker in harvesting the annual growth,
Typical 18-foot pruning using
a 14-foot pole saw.
·
-15­
· ·
Poria weirii Studies
( se
page
8}
Comprehensive·studies of root rot ( Poria
weirii)
aye been started by the Division of
Forest Pathology ( Bureau of :Plant Indlilstry).
Centers of infection have been surveyed to de- ·
termine the effects of th{nning on spre
of the
rot and to tudy its incidence in connection
th soil types, topography, and pure or mix d
stands.
Soil Studies
Site quality is under study in relation to
the·soil types which have been locate d on a de­
tailed soils map.
Continuing s udies·are planned
of the effects of repeated thinning on the soil
and of humus C9 ition and soil ferti ity under
Douglas-fir and ald r stands occurring on si
soil typeso
lar
Seed Production Studies
A
study has been started to gather over a
period of year , .. information on seed production
of yo.ung Douglas-fir that will be use.:t;ul in
planning the thinningi harvesting, and r egenera­
tion of this species.
To date 4o seed. traps
·. have been installed in·.block A, 10 in . ea c h of
he 3 thinning.trea ents and 10 in ·the check to
determine the:. effects of thinning on the volume
of seed pro4ucticm .. · seeq . ycles a nd s ed bearing
. age are ·a1so beii1g observ·ed in the test areas.
·
-16­
Traps used
for
the seed study are
21x3'x511•
The larger trees removed in thinning are
as 8-foot logs and are cut into
rough lumber at a local mill,
.
-17-
2x4•s
and
sold'
King Creek E
·
riment
A!l ex:peT.iment supplementing the V?ight Creek
tudies· has· been s ta,rted on a, 25-acre tract·lo­
cated on the.King Creek divi ion of.St, Paul and Tacoma. Lumber Company. P.oldtngs.
This pxperiment is designed to CQIIlpare \;he :results of f)election thinning with those· of crown thinning. The ·
Douglas-fir s tan growing on this low site III
land of coarse· gravel vm.:s 27 years old, in the
ti< conditions ahd eleva"':'
spping of 1949. Cl
tions are· s imilar to tho e at Yoig t Creek, which
lies six miles to the northeast. <J;he area was
first cut in 1917 and wa::; burned at le!;lst once
prior to 1923, after whi<:h a scattered catbh of'
s eedlings developed. In 1932 the area was cut
extenstvely for Christma1s trees. Gradually,
s ince the burn, the s tand has filled up with
seedlings until now it is 95 percent stocked by
cubic vol e. The stand is not s trictly even­
aged, as it has a considerable number f' hemlock
and cedar tree::; less than 6 inches in iameter.
In the so-called s election thinning, only the
larger, rougher, poorly formed trees or the stand
are cut providing their removal does not release
more than one side of the re ining tre.es at any
one tiine·o Trees removed. average about l. inch or
so· larger in d.b.h. than the average fpr.the
entire stand before thim1ing. Such a method is
believed well sui ted to <mtting .in you g stands
that must. pay its way, a$ it may be applied much
earlier.in the life'of the stand than bther methods.
·The f'irial crop s hould be of high·qu 1ity since the
cleanest and best-forin.ed·trees have been
favored
I
from the. s tart. Trees . in the final crop probably
will be larger than those in the unthi¥ned stand,
but smaller than thos e developed by crown thinning.
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Conversely, in crown thinning the most promis­
ing trees in the dominant and codominant classes
are favored by gradually releasing them from com­
peting, but poorer trees in the same crown class.
-18··
/
Trees removed average about 1 2 to 1 inch smaller
in d.b.h. than the average f or the en tire stand
before thinning.
Trees iu the final c rop should
be larger than those developed b y sele ction thin­
ning.
A test o f this system was started in
October
1950.
A third area, which will not be
thinned, has been established ·to serve as a c heck .
The first cut under the s election me thod.was
made in the e arly spring of
removed 213 cubic
1949•
eet per acre,
The thinning
whic h is
19
cent of the original volume in trees 6 inche
per­
s
The average t ree cut was·8.8
d.b.h. and larger.
inches in diameter, compared to 7.5 inches for
all trees 6 inches and over. All timber cut was
converted to smelt er poles and saw timber.
This
first thinning was done at a· slight profit.
The second cut for the sele ction method and
the first for tlB
in the fall of
crown thinning were completed.
1950.
Selection thinning removed
123 cubic feet per acre;
feet per acre.
crown thinning, 83 cubic
The diameter of t he average tree
cut was 8.9 inches and 7.3 inches respectivelyo
The smaller t rees cu t on_the crown thinning plots
were made into corral poles and car stakes.
The
value of the products c ut on the selecti on plots
was sufficient to cover costs, but the c rown
thi n ning was made a t a loss beca use of the lighter
cut and the smaller t ree
r..
handled.
Thinni gs will be 'repeated at 2-year inter­
vals for both the selection and crown thinning
areas.
Later thinnings should be less costly
and the prodUcts obtained more v aluable because
the trees to
be cut will be l arger.
Records of
growth and material r emoved in the various cut­
tings will make i t possible t o compare the
merits of the t wo methods over a longer p eriod.
-19­
I
1\)
0
i
Cedar fence posts salvaged from snags and old windfalls,
Compartment A l.
I.
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K/Nfi CREEl< fiATE
1/2
SCALE IN
0
MILES
I
2
Local Roag. Map
Voight Creek Experimental Fqrest a nd King Creek P lots
Photographs by Lee Merril l - Courtesy St. Paul & Tacor,
Lumber Company- front cover and
page ·17.
U. S. Forest Service photographs - pages 7, 15 and 20,