United States
Department of
Agriculture
Forest Service
Pacific Northwest
Research Station
Research Paper
PNW-RP-475
December 1994
Curtis and
ary W. Clendenen
Levels-of-growing-stocl< study treatment schedule, showing percent of gross basal
area increment of control plots to be retained in growing stock
Treatment
2
Thinning
3
4
5
6
7
8
Percent
First
·/0
10
30
30
50
50
70
70
Second
10
20
30
40
50
40
70
60
Third
10
30
30
50
50
30
70
50
Fourth
10
40
30
60
50
20
70
40
Fifth
10
50
30
70
50
10
70
30
Public and private agencies are cooperating in a study of eigllt thinning regimes in
young Douglas-fir stands. Regimes differ in ttle amount of basal area allowed to
accrue in growing stocl< at each successive thinning. All regimes start with a common
level of growing stoci< established by a conditioning thinning.
Thinning interval is controlled by height growth of crop trees, and a single type of
thinning is prescribed.
Nine study areas, each involving three completely random replications of each
thinning regime and an unthinned control, have been establislled in western Oregon
and Washington, U.S.A., and on Vancouver Island, British Columbia, Canada. Site
quality of these areas varies from I through IV.
This is a progress report on this cooperative study.
Levels-of G rowing-Stock
Cooperative Study in
Douglas-Fir:
..
Report No.12-The Iron Creek Study: 1966-89.
Robert O. Curtis, Principal Mensurationist
Gary W. Clendenen, Mensurationist
Pacific Northwest Research Station
Forestry Sciences Laboratory
Olympia, Washington
Research Paper PNW-RP-475
U.S. Department of Agriculture,
Forest Service
Pacific Northwest Research Station
Portland, Oregon
December 1994
Abstract
Curtis, Robert 0.; Clendenen, Gary W. 1 994. Levels-of-g rowing-stock cooperative
study in Douglas-fir : report no. 1 2--the Iron Creek study: 1 966-89. Res. Pap.
PNW-RP-475. Portland, OR: U .S. Department of Agriculture, Forest SeNice,
Pacific NortnWest Research Station. 67 p.
Results of the I ron Creek installation of the levels-of-growing-stock study in Douglas­
fir (Pseudotsuga menziesii (Mirb.) Franco) are summarized. To age 42 (planned com­
pletion of the experir:rent) volume growth in this site II Douglas-fir plantation has been
strongly related to level of growing stock, partially offsetting the decrease in volume
growth percent expected with increasing growing stock. Basal area g rowth-growing
stock relations were much weaker than those for volume. Marked differences in tree
size distributions have resulted from thinning. Periodic annual volume increments are
two to three times g reater than mean annual increments at age 42; this stand is far
from culmination. Results in general are similar to those reported for other i nstalla­
tions in the series on medium to good sites.
Keywords: Thinning, growing stock, growth and yield, stand density, Douglas-fir,
Pseudotsuga menziesii, series-Douglas-fir LOGS.
Summary
Results of the I ron Creek installation of the cooperative levels-of-growing-stock study
in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), located in the Randle District
of the G ifford Pinchot National Forest in southern Washington, are summarized
through age 42 (completion of 60 feet of height g rowth, comprising the planned
course of the experiment).
Estimated site index (50-year base) of this plantation is 1 26 (mid-site I I). Contrary to
expectations when the study was established, volume growth has been stro ngly re­
lated to growing stock; basal area growth much less so. There is, a substantial trade­
off between increased individual tree size and value and total cubic volume produc­
tion. Volume growth percentages have been considerably higher than those for basal
area growth. At age 42, growth percentages in merchantable cubic volume are not
strongly related to growing stock. Different growing stock levels have produced
marked differences in tree size distributions and crown dimensions. Periodic annual
cubic volume increments are two to three times greater than mean annual i ncrements
at age 42; the stand is far from culmination. Results have been generally comparable
to those reported from other installations in the study on medium to good sites.
Other LOGS
(Levels-of-Growi n9Stock) Reports
Williamson, R ichard L.; Staebler, George R. 1 965. A cooperative level-of-growing­
stock study in Douglas-fir. Portland, OR: U.S. Department of Agriculture, Forest
Service, Pacific Northwest Forest and Range Experiment Station. 1 2 p.
Describes purpose and scope of a cooperative study investigating the relative merits
of eight different thinning regimes. Main features of six study areas installed between
1 961 and 1 965 in young stands also are summarized .
Williamson, Richard L.; Staebler, George R. 1 971 . Levels-of-growing-stock
cooperative study on Douglas-fir: report no. 1 -'-description of study and existing
study areas. Res. Pap. PNW-11 1 . Portland, OR: U.S. Department of Agriculture,
Forest Service, Pacific Northwest Forest and Range Experiment Station. 1 2 p.
Thinning regimes in young Douglas-fir stands are described. Some characteristics of
individual study areas established by cooperating public and private agencies are
discussed.
Bell, John F.; Berg, Alan B. 1 972. Levels-of-growing-stock cooperative study on
Douglas-fir: report nO. 2-the Hoskins study, 1 963-1 970. Res. Pap. PNW-1 30.
Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest
Forest and Range Experiment Station. 1 9 p.
A calibration thinning and the first treatment thinning in a 20-year-old Douglas-fir
stand at Hoskins, Oregon, are described. Data tabulated for the first 7 years of
management show that growth changes in the thinned stands were greater than
anticipated.
Diggle, P.K. 1 972. The levels-of-growing-stock cooperative study in Douglas-fir in
British Columbia (report no. 3, cooperative L.O.G.S. study series). Inf. Rep.
BC-X-66.Victoria, BC: Canadian Forestry Service, Pacific Forest Research
Centre. 46 p.
Williamson, R ichard L. 1 976. Levels-of-growing-stock cooperative study i n
Douglas-fir: report nO. 4-Rocky Brook, Stampede Creek, and Iron Creek. Res.
Pap. PNW-21 o. Portland, OR: U.S. Department of Agriculture, Forest Service,
Pacific Northwest Forest and Range Experiment Station. 39 p.
The USDA Forest Service maintains three of nine i nstallations in a regional,
cooperative study of influences of levels of growing stock (LOGS) on stand growth.
The effects of calibration thinnings are described for the three areas. Results of first
treatment thinning are described for one area.
Berg, Alan B.; Bell, John F. 1 979. Levels-of-growing-stock cooperative study on
Douglas-fir: report no. 5-the Hoskins study, 1 963-1 975. Res. Pap. PNW-257.
Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest
Forest and Range Experiment Station. 29 p.
The study dramatically demonstrates the capability of young Douglas-fir stands to
transfer the g rowth from many trees to few trees. It also indicates that at least some
of the treatments have the potential to equal or surpass the gross cubic-foot volume
of the controls during the next treatment periods.
Arnott, J.T.; Beddows, D. 1 981 . Levels-of-growing-stock cooperative study in
Douglas-fir: report no. 6-Sayward Forest, Shawnigan Lake. Inf. Rep. B C-X-223.
Victoria, BC: Canadian Forestry Service, Pacific Forest Research Centre. 54 p.
Data are presented for the first 8 and 6 years at Sayward Forest and Shawnigan
Lake, respectively. The effects of the calibration thinnings are described for these two
installations on Vancouver Island, British Columbia. Results of the first treatment
thinning at Sayward Forest for a 4-year response period also are included.
Williamson, R ichard L.; Curtis, Robert 0. 1 984. Levels-of-growing-stock
cooperative study in Douglas-fir: report no. 7-preliminary results; Stampede
Creek, and some comparisons with Iron Creek and Hoskins. Res. Pap. PNW-323.
. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific
Northwest
.
Forest and Range Experiment Station. 42 p.
Results of the Stampede Creek LOGS study i n southwest Oregon are summarized
through the first treatment period, and results are compared with two more advanced
LOG S studies and are generally similar.
Curtis, Robert 0.; Marshall, David D. 1 986. Levels-of-growing-stock cooperative
study in Douglas-fir: report no. 8-the LOGS study: twenty-year results. Res. Pap.
PNW-356. Portland, OR: U.S. ,Department of Agriculture, Forest Service, Pacific
Northwest Research Station. 1 1 3 p.
Reviews history and status of LOGS study and provides new analyses of data, pri­
marily from the site II installations. G rowth is strongly related to growing stock. Thin­
ning treatments have produced marked differences in volume distribution by tree size.
At the fou rth treatment period, current annual increment is still about double mean
annual increment. Differences among treatments are increasing rapidly. There are
considerable differences in productivity among installations, beyond those accounted
for by site differences. The LOGS study design is evaluated.
Curtis, Robert O. 1 987. Levels-of-growing-stock cooperative study in Douglas-fir:
report nO. 9-some comparisons of DFSIM estimates with growth in the levels-of­
growing-stock study. Res. Pap. PNW-RP-376. Portland, OR: U.S. Department of
Agriculture, Forest Service, Pacific Northwest Research Station. 34 p.
Initial stand statistics for the LOGS study i nstallations were projected by the DFSIM
simulation program over the available periods of observation. Estimates were com­
pared with observed volume and basal area growth, diameter change, and mortality.
Overall agreement was reasonably good, although results indicate some biases and
a need for revisions in the DFSIM program.
Marshall, David D.; Bell, John F.; Tappeiner, John C. 1 992. Levels-of-growing­
stock cooperative study in Douglas-fir: report no. 1 0-the Hoskins study, 1 963-83.
Res. Pap. PNW-RP-448. Portland, OR: U.S. Department of Agriculture, Forest
Service, Pacific Northwest Research Station. 65 p.
Results of the Hoskins study are summarized through the fifth and final planned treat­
ment period. To age 40, thinnings in this low site I stand resulted in large increases
in diameter growth with reductions in basal area and cubic volume g rowth and yield.
G rowth was strongly related to level of growing stock. All treatments are still far from
culmination of mean annual increment in cubic feet.
Curtis , Robert O. 1 992. Levels-of-growing stock cooperative study in Douglas-fir:
report no. 1 1 -Stampede Creek: a 20-year progress report. Res. Pap.
PNW-RP-442. Portland, OR: U.S. Department of Agriculture, Forest Service,
Pacific Northwest Research Station. 47 p.
Results of the first 20 years of the Stampede Creek study in southwest Oregon are
summarized. To age 53, growth in this site I I I Douglas-fir stand has been strongly
related to level of growing stock. Marked differences in volume distribution by tree
sizes are developing as a result of thinning. Periodic annual increment is about twice
mean annual i ncrement in all treatments, i ndicating that the stand is still far from
culmination.
Contents
1
Introduction
2
Objectives
2
Methods
2
Description of Study Area
3
Experimental Design
3
Stand Treatments
5
Data Collection and Summarization
5
Analyses
5
Results
5
Analysis of Variance
6
Trends in Live Stand Statistics
9
Relative Density Measures
11
Cumulative Volume Production
16
Volume Distribution by Tree Size Classes
16
Periodic Annual Increment
23
G rowth Percents
23
Crown Development .26
Discussion
26
Analysis of Variance
26
G rowth-Growing Stock Relations
29
G rowth Percents
31
Increasing vs. Fixed vs. Decreasing Treatments
31
Mean Annual Increment and Periodic Annual Increment
32
Stand Damage
32
Volume Production
33
Future Uses of LOGS Study
34
Metric Equivalents
34
L iterature Cited
36
Appendix 1 : Description of Experiment
37
Appendix 2: Tables
67
Appendix 3: The Nine Study Areas
Introduction The I ron Creek levels-of-growing-stock (LOGS) installation is one of nine installations
in a regional thinning study established in young even-aged Douglas-fir (Pseudotsuga
menziesii (Mirb.) Franco) stands according to a common work plan (report no. 1 ­
1
Williamson and Staebler 1 971 ; appendix 1 i n this report; fig. 1 ). This study i s a coop­
e rative effort involving Canadian Forest Service, Oregon State U niversity, USDA For­
est Service, Washington State Department of Natural Resources, and Weyerhaueser
Company. The objective is to compare growth-growing stock relations, cumulative
wood production, and tree size development under eight different thinning regimes
begun before the onset of severe competition. The original study plan was developed
at Weyerhaeuser Company, Centralia, Washington. Procedural details were
developed by the Pacific Northwest Research Station, USDA Forest Service,
Portland, Oregon.
Detailed progress reports on individual installations are contained in the series of
LOGS publications listed at the beginning ofthis report. Curtis and Marshall (1 986)
give an overall summary of results for the first 20 years of the program. Since 1 986,
several of the higher site i nstallations, of which Iron Creek is one, have completed
the full course of the experiment as originally planned.
iRi
:i,SAYWARD
':
VA NCOUV
ISLAND
SHAWNIGAN
LAK
BRITISH
COLUMBIA
._._._.-
",SKYKOMISH
iLEMONS
" ·CenIraJIa
FRANCIS AIRON CREEK
Raymond
WASHINGTON
OREGON
•
Cotvallia
"STAMPEDE CREEK
Figure 1-Locations of the nine installations of
the levels-of- growing-stock cooperative study in
Douglas-fir.
1 Staebler, George R; Williamson, Richard L. 1 962. Plan for
a level-of-growing:stock study In Douglas-fir. Unpublished
study plan. On file with: Forestry Sciences Laboratory,
3 625-:- 93d Avenue SW, Olympia, WA 98512.
1
The I ron Creek LOGS installation was established in 1 966 by the Pacific Northwest
Research Station and the Pacific Northwest Region (Region 6) of the USDA Forest
Service. Some preliminary data were given by Williamson (report no. 4-1 976) and
by Williamson and Curtis (report no. 7-1 984). At the end of the 1 989 growing sea­
son, I ron Creek had completed the fifth and final treatment period of the experiment
as originally planned.
The purposes of this report are to document the quantitative results obtained and to
present and discuss the implications of results through the final treatment period.
Objectives
The LOGS cooperative studies evolved from work in the late 1 950s by Georg e
Staebler (1 959, 1 960). Staebler argued that thinning would transfer increment to the
remaining faster g rowing trees and increase growth percent through reduction in
g rowing stock, while largely eliminating mortality losses. He also recognized that the
impl ied assumption of near-constant gross increment over a wide range of stocking
had not been tested. The objectives of the LOGS studies, as stated i n the 1 962 plan,
were '10 determine how the amount of growing stock retained in repeatedly thinned
stands of Douglas-fir affects cumulative wood production, tree size, and growth­
growing stock ratios." Treatments were designed to include a wide range of growing
stock so that the results would show "how to produce any combination of facto rs
deemed optimum from a management standpoint." The study was not designed as
a test of specific operational thinning regimes but was intended to define the quantita­
tive relations between growth and g rowing stock for a closely controlled initial stand
condition and kind of thinning.
Methods
The I ron Creek LOGS installation was established in 1 966 in a Douglas-fir plantation
located in section 30, T. 1 1 N., R. 7 E., Randle Ranger District, G ifford Pinchot Na­
tional Forest. Stand age was 1 7 years since planting in 1 949; 1 9 years from seed.
Composition at time·of establishment was recorded as nearly pure Douglas-fir; how­
ever, there evidently was abundant natural seeding of western hemlock (Tsuga
heterophylla (Raf.) Sarg.) and redcedar (Thuja plicata Donn ex D. Donn) that had not
yet reached sufficient size to be retained in the calibration cut, as shown by large
n umbers in an understory position now present on the control plots.
Description of Study
Area
The stand is in a midslope position at an elevation of about 2,500 feet. Aspect is
easterly, with slopes averaging about 25 percent. The plant association (Topik and
others 1 986) is western hemlocklswordfern (TSHE/POMU, Tsuga heterophyllal
Polystichum munitum). Estimated site i ndex as of 1 989 (King 1 966) was 1 26 (base
age 50 years breast height [b.h.]), or mid-site I I .
The deep, well-drained soil (series undetermined) is derived from volcanic ash and
lapilli overlying a residual soil developed on fractured volcanic rock. S urface soils
range from sandy loam to loam, with interbedded pumice.
At the time the study was established, many trees had been damaged by bear. About
20 percent of the trees remaining after the calibration thinning had some injury. The
area was then fenced, and further injury was limited to one episode after damage to
the fence in 1 975. By 1 989, few of the remaining trees showed noticeable
evidence
.
of bear damage, although butt scars still could be found.
.
The May 1 980 eruption of Mount St. Helens deposited about 1 inch of ash on the
study area. FOliage was still ash covered the following September.
2
15
25
-*-
C
I
14
o
C\l
o
M
o
Z
13
12
11
23
22
C
21
33
43
53
63
73
X
42
52
62
72
31
41
51
X
71
82
101
111
81
C
\
91
21.3' offset
Figure 2-Arrangement of plots in the Iron Creek LOGS installation.
Several plots have had substantial damage from root rot. One plot (plot 51 in treat­
ment 1 ) has been virtually destroyed by Phellinu5 weirii and has been excluded from
analyses. Redcedar and hemlock reproduction is now abundant in the openings cre­
ated by root rot and as a developing understory in the more heavily thinned
treatments.
Experimental Design
The experiment is a completely randomized design having three replications of eight
thinning treatments, plus control. The 27 plots are one-fifth of an acre, square, without
buffers except that a 30-foot isolation strip was provided around the outer margins of
the experimental area. Physical arrangement is shown in figure 2. Detailed criteria
(appendix 1 ) for area and plot selection provided a high degree of uniformity in initial
conditions.
Stand Treatments
Treatments were rigidly controlled to provide compatibility among installations on
different sites.
Selection of crop trees-Crop trees were selected at the rate of 1 6 per plot (80 per
acre), distributed to provide 4 well-spaced crop trees in each q uarter of a plot. Crop
trees were identified with white paint bands.
Calibration thinning-An initial calibration thinning was made on the 24 plots as­
signed to thinning treatments and was intended to reduce all to as nearly comparable
condition as possible. All t rees less than one-half the initial stand quadratic mean
diameter (QMD) were cut. Additional noncrop trees were cut as needed to meet the
study plan specifications, which called for the stand to be thinned to an initial spacing
based on the equation,
S
=
0 .61 67
x
QMD
+
8,
where S is the average spacing in feet and QMD is quadratic mean diameter of the
leave trees. Marking was controlled by the specifications that QMD of the leave trees
s hou ld be within 1 5 percent of the installation mean, and leave tree basal areas
s hould be within 3 percent. All leave trees on thinned plots were identified with per­
manent n umbered tags. Trees 1 .6 inches diameter at breast height (d.b.h.) and
larger were tagged on the control plots.
3
Treatment thinnings-Treatment thinnings were made in 1 970, 1 973, 1 977, 1 980, and
1 984 (ages 23, 26, 30, 33, and 37, respectively), which corresponded to about 1 0-foot
increments in crop tree height. Thinning intensity was determined as percentages of
gross basal area growth on the control plots, as defined in the table on the inside
front cover. G ross basal area growth of controls was assumed to represent the pro­
ductive potential of the site at full stocking. Basal areas after thinning were calculated
from the equation,
BAn
where BAn
=
BA(n- 1 )+ p x GBAG ,
basal area retained after thinning, BA(n- 1 )
p
=
=
basal area at beginning of preceding treatment period,
p respecified percentage of gross basal area growth of controls to be retained, and =
G BAG
=
average gross basal area growth on controls. The expected trends in basal area created by these specifications are shown in figure 3 . Kind o f thinning was further specified b y t h e following requirements: 1 . No crop trees were to be cut until all noncrop trees had been removed.
2. Average diameter of trees removed in thinning should approximate the average
diameter of trees available for thinning (that is, noncrop trees only until all noncrop
trees had been removed). This resulted in a dID ratio (ratio of diameter of t rees cut
to diameter of stand before thinning) of less than 1 .0 for the stand.
3. Trees removed in thinning were to be distributed across the range of diameters of
trees available forthinning.
:e"
5
D. .
..
:!!
:
I'D
ii
..
I'D
IQ
2
�----Height
Figure 3-ldealized trends in basal area for the eight thinning regimes in the LOGS study.
4
The thinning specifications of the study plan were expected to result in a crown thin­
ning. The diD ratios were calculated for each of the five treatment thinnings. Overall
means were about 0.90 with no clear trends over time or treatment.
Data Collection and
Summarization
Immediately after the calibration thinning, and at all subsequent measurement dates
(that is, 1 966, 1 970, 1 973, i 977, 1 980, 1 984, 1 989), diameters of all tagged trees
were measured to the nearest 0.1 inch. Ingrowth was tagged and measu red on the
control plots only. Heights were measured on a sample of these trees; sample size
differed but was not less than 1 2 trees per plot, and usually more, distributed across
the range of diameters. Beginning with the 1 973 measurement, heights to base of
live crown also were measured.
Constrained height-diameter curves were fit to each measurement on each plot with
an adaptation2 of Hyink and others' (1 988) procedure. Tree vol umes in total cubic feet
i nside bark (CVTS) were calculated by the Bruce and DeMars (1 974) equation, from
actual measured heights when avai lable and from heights predicted by the Clendenen
equations for trees not having measured heights. These were converted to merchant­
able cubic volumes to a 6-inch top (CV6) by using equations from Brackett (1 973).
Stand heights were characterized as average height (H40) of the largest 40 trees (by
d.b.h .) per acre for each plot and were calculated as the mean of the m easured or
estimated heights of all trees in this category.
Analyses
The original study plan specified analysis of variance as the method of analysis. Many
aspects of the experiment are more meani ngfully presented and interpreted, however,
through simple graphic comparisons of means and by regressions of periodic annual
i ncrement in basal area and in volume on basal area at period midpoints, by treat­
ments. Regressions were of the form,
InY
=
a+
blnX + eX ,
as used previously by Curtis and Marshall (report no. 8-1 986). The u nderlying
n umerical values are summarized in a series of tables given in appendix 2.
Results
Analysis of Variance
The analysis of variance is presented in tables 1 and 2 (all tables are in appendix 2).
This follows the p rocedure outlined in the original study plan and used in previous
LOGS reports (report nO. 8-Curtis and Marshall 1 986; report no. 1 0-Marshall and
others 1 992), except for changes made necessary by loss of one plot. This is a
repeated-measures experiment that is computationally similar to a split-plot design
(Snedecor and Cochran 1 980), in which the periodic remeasurements correspond to
subplots. Computations were done with the GLM procedure of BAS (SAS I nstitute
1 988) and used as successive response variables periodic annual gross increment in
cubic volume and corresponding growth percent, periodic annual g ross increment in
basal area and corresponding growth percent, and periodic annual net i ncrement in
q uadratic mean diameter.
The interactions period x (fixed vs. variable), period x (between increasing), and
period x (between decreasing) were in general nonsignificant. The corresponding
main effect fixed vs. variable treatments was nonsignificant, thereby indicating no dif­
ference in overall means. Differences in means between increasing treatments, and
those between decreasing treatments, are significant or nearly so for all variables.
2
Developed by Gary W . Clendenen and David D. Marshall.
5
The interactions period x fixed (linear) and period x (increasing vs. decreasing treat­
ments) were significant in most cases. This indicates that, as would be expected, the·
relations differ over time. Consequently, the corresponding main effects, though statis­
tically significant, are not meaningful. Interpretations are therefore made in terms of
the g raphic comparisons and regressions of growth on g rowing stock, by treatments,
I
presented below.
Trends in Live Stand
Statistics
Height of largest 40 trees per acre (H40)-H40, defined as the average of the
heights of the largest (by d.b.h.) 40 trees per acre, is a useful measure of height
development. This can be calculated objectively for all plots from the data available,
is little affected by thinning, and is now quite commonly used as the basis for site
index estimates in the region.
Excluding plot 51 (severely damaged by root rot), the range in 1 989 heights (age 42)
was from 95 to 1 06 feet. There appeared to be no relation to thinning treatment.
Mean of the thinned plots differed by only 0.2 foot from the mean of the controls
(table 3) .
Figure 4 compares development of H40 over the life of the installation with that
predicted by King (1 966) for site index 1 26. The curves are nearly identical.
Number of trees-Trends over time in trees per acre by thinning treatments are
shown in figure 5. Corresponding numerical values, including those for the controls
(omitted in fig. 5), are given in table 4.
Basal area-Corresponding values of basal area per acre, by treatments, are shown
in figure 6 and in table 5.
100
80
/
60
40
/
/'
v
,."
..
..
20
- - - KIng
_
o
10
20
30
Iron
1966)
Jreek
40
Age (years)
Figure 4-0bserved H40 trend compared to King (1966) predicted heights.
6
50
400
!Y
300
§
..
CD
Co
Iii
E
.0
--
.
-
...... r-.
1-r-t-.l- -----b.-.
....
!-- r-
200
..
:I
Z
100
o
-----
-- H---
1
..
-
1----8
1----4..
==,\- -
- -- 5
F
- ---
-
- 4
==
1:--- --- 6
- --- "
- -- -3
I
-- Fixed
_ -' _ variable
20
25
30
- -
-- -
I
15
7
-I
35
__ .
-
- - 2-1
45
40
Age (years)
Figure 5-Numbers of trees per acre by treatment and age.
300
250
'Q)
1:os
ca
200
.
..
..
..
150
.'
..
..
.'
.'
.'
.'
.
.'
..
.. . .
. . . ..
. ..
. ..
. .. .
..
.. C
.. , .. ..
7
.
�
.
100
..
..
..
..
. '
501-----����-r-----�r---�--�-1
15
- Fixed
- - - Variable
............. Control
20
25
30
35
40
45
Age (years)
Figure 6-Trends of live basal area by treatment and age.
7
18
16
'in
Q)
ti
c:
c
.'C
lii
Q)
E
e
0
::l
0
14·
12
10
8
JIj .....
...L!::; ;-:::.:.::: . ...... ..
6
.
..
__
4
2
O
..
.
.
..
• ..
•. .
•
•• .
....
. ..
.
. ..
.
..
....
.... .
.. .
.
.
.
.....
....
.
.
...
.......
..... Cdt
.. .
...
.
..
. .... C.II
... ....
- , - Fixed
- - - Variable
"""'"'''' Control
15
.
20
__
25
__
30
35
-+
40
__
45
Age (years)
Figure 7-Attained quadratic mean diameters (QMD) by treatment and age.
Quadratic mean diameter (QMD)-Trends in quadratic mean diameter are shown
in figure 7 and table 6. As discussed later, QMD values for the control are strongly
influenced by presence of an understory of small stems of tolerant species. QMD
of Douglas-fir only is a better measure of development relative to the thinned plots
(which are almost pure Douglas-fir) than is QMD of all species.
Other diameter measures-Several other average diameters are sometimes used
to express stand attributes. D40, average diameter of the 40 largest (by d .b.h.) trees
per acre, corresponds to H40 and is useful in expressing effect of treatment on dia­
meter growth of leading dominant trees. Unlike QMD, this is only slightly influenced
by removal of trees through thinning or mortality, because few trees in this category
are cut in the thinning regimes considered, and suppression mortality does not occur.
Trends in development of D40 over time are shown in figure 8 and table 7. Thinning
has had much less effect on D40 than on QMD. Thinning, none the less, has had a
consistent effect on diameter growth of these largest trees.
A second measure of diameter development is D80, quadratic mean diameter of the
largest (by d.b.h.) 80 stems per acre. This is similar to D40, though somewhat smaller
in value, and is sometimes used for similar purposes as a value roughly correspond­
ing to the expected number of surviving trees at harvest age under some commonly
used regimes.
8
l
18 -----
16 -----+----
'fi
c:
e
12 -
.
10 8
.
---
. . . .
...... .
.
.
.
.
.
.
.
.
/:
< : ""
. :.
..... . .
14 i
------r--
.
"
6
4
2
o
- .-- Fixed
(numberedurnlto>
- - - Variable
............. Control
-I
15
.
20
25
35
30
40
45
Age (years)
Figure 8-D40 (average diameter of largest 40 trees per acre) by treatment and age.
A third measure of diameter development is Ocrop, quadratic mean diameter of desig­
nated crop trees, shown in table 7. The study plan envisioned an initial selection of
c rop trees based on a combination of vigor and spacing, with these trees to be fa­
vored during thinning and retained to the end of the experiment. Although there were
80 such trees per acre, diameters were expected to be somewhat less than 080
because of the spacing constraint. Interpretation of this value is somewhat obscured
by substitution of new crop trees for damaged and low-vigor trees, but values are
g iven for comparability with other reports.
Both 080 and Ocrop values become equal to OMO once the number of stems (some
treatments only) has been reduced to 80 per acre.
Total cubic volume (CVTS)-Trends in cubic volume of total stem are shown in
figure 9, with numerical values given in tables 8 and 9.
Merchantable cubic volume (CV6)-Trends in merchantable cubic volume to a
6-inch top diameter inside bark (d. i.b.) are shown .in figure 1 0; numerical values are
in table 1 0.
Relative Density
Measures
Relative density measures are useful in describing thinning regimes, as guides for
density control, as valu es interpretable as measures of competition, and as predictors
of growth. Here, treatments were compared by using two common relative density
measures that are nearly equivalent, except for scale factors. These are Curtis' (1 982)
relative density (RO) and Reineke's (1 933) stand density i ndex (SOl). Relative
density is defined by the equation,
RD=
basal area ,
-VOMD
and is merely a rearrangement of Reineke's equation (with a slight difference in
exponent) into a form that some find easier to use.
9
1 0000
Fixed
- - - Variable
............. Control
_--
9000
8000
7000
I
..,
()
""
6000
" ",
"
...
....
",
"
""
.0
-
",
C
7-�
8
5
' 4_�
5000
4000
3000
2000
1 000
0
15
20
25
30
35
45
40
Age (years)
Figure 9-Total stem volume (CVTS) in live trees, by treatment and age.
7000 �------r---�--�--'
--- Fixed
- - - Variable
............. Control
6000
5000
Qi'
..,
>!:.
l)
(0
4000
-I----t-----+---,--+--+
3000
2000
-I-----4---+--....M
1 000
... �---+---
15
20
25
30
35
40
Age (years)
Figure 1 0-Merchantable volume (CV6) in live trees, by treatment and age.
10
45
Figures 1 1 and 1 2 display trends of RO over time for the various thinning regimes.
The corresponding trends for the control are useful as reference points for thinning
regimes (that is, their relation to "maximum"), and the asymptote represents an esti­
mate oft he maximum attainable density in an unthinned stand at this location. This
d iffers among locations and is not closely related to site index (report no. 8-Curtis
and Marshall 1 986).
The diameter distribution (fig. 1 3) for the I ron Creek control plots illustrates a mensur­
ational problem of common occurrence in western Washington. The main stand con­
sists of Douglas-fir, with an understory of tolerant species-western hemlock and
redcedar. The understory trees contribute little to volume and basal area (1 3 percent
of basal a rea at age 42) and almost nothing to volume or basal area g rowth, and
have negligible effect on growth of the stand; but they do represent a large fraction of
the total number of stems present (47 percent at age 42). This has a considerable
effect on computation of QMO and of density measures, such as RO and SOl , that
i nvolve QMO; and can lead to grossly inflated values that are probably meaningless
as indicators of stand-level competition. Thinned plots had understory removed at
establishment, and ingrowth has not been measured; therefore, they are unaffected.
For the stand structures on the Iron Creek unthinned plots, several methods of adjust­
ment are possible that give values approximating those for a stand with a more or
less symmetrical diameter distribution and equivalent level of competition. One pro­
cedure is to truncate the distribution at a point that excludes most of the understory.
At Iron Creek, a diameter of 040/3 seems a reasonable truncation point for all mea­
surements. An alternative procedure is to calculate RO by using basal area of all
trees (wh ich is little influenced by the understory) and QMO of the Douglas-fir. For
these data, results of the two procedures are nearly identical. The resulting curves
(dashed lines in figs. 1 1 and 1 2) suggest that maximum RO for this stand is in the
range R 080-85. The value of R095 indicated by the calculation using all trees is
almost certainly a gross overestimate of competition level.
Reineke diagram-Figures 1 4 and 1 5 show the trends of number in relation to QMO
of all trees on log-log scales (Reineke 1 933), by treatments. Truncation of the
diameter distribution has no effect on values for thinning treatments but shifts the
curve for the control down and to the right.
Stand density index-Figures 1 6 and 1 7 show the trends of SOl over time for the
various thinning treatments. The trend of SOl for the control plots appears to be
approaching a maximum value in the vicinity of SOl 500. As with RO, inclusion of
small understory stems of a younger age class probably leads to an overestimate.
Cumulative Volume
Production
Total cubic volume-Cumulative total cubic volume production under the various
t reatments is shown in figure 1 8 and table 9. Estimated volume of material cut at the
calibration thinning hgs been added to provide a common origin with the curve for
the control. In the thinned treatments, mortality has been relatively slight and due to
root rot rather than suppression, and g ross production values differ only slightly from
the net values shown.
Although net CVTS production on the control has been higher than on any of the
thinning treatments, with the onset of suppression-related mortality, it is declining
relative to the thinning treatments, and it seems likely that the h igher density thinning
t reatments soon will cross the control curve.
Text continued on page 16
11
100
__ Fixed
80 .
.,
c:
Q)
"0
Q)
.Qi
II:
"........." Control, all trees
- - - Control, truncated
-------t-------r
..
...
..
••
••
•
•
• I'
••
•••
.. . ....
... .
........ .. .... . ...... C I
.I
------
--
. .. ...
...........
.... ...
"
..
.
.
..
.. ..
..
....
...
....
60
. --��-�-�-Ck --
5
40
3
20 0
15
20
25
30
35
45 40
Age (years)
Figure 1 1-Trends in relative density (RO) In relation to age, for fixed treatments
and control.
100
.
..
...
eo
.,
c:
Q)
"0
Q)
>
..,.
II:
...
.....
...
. .... ..
........ . . .. .... .. .. .. C
.II
-- --- Ctr_
60
8
6
40
4
2
20 0
15
20
25 30 35
40 45
Age (years)
Figure 12-Trends in relative density (RO) in relation to age, for variable treatments
and control.
12
I
'I
200
I
150
'U
.5
1 00
\
\
\
\
i
\
\
\
\
\
\
\
\
Q)
....
.s
\
Q)
.c
....
E
:I
Z
50
o
-- oou las-llr
- - - Hem ock and redcedar
o
\
\
\
\
\
\
.-.
.
......
...
.........
4
2
...
6
/I\.
'\
r\t--...
;;........
...< ...
- - .. 12
10
8
16
14
DBH class (one-Inch classes)
Figure 13-Numbers of trees on control in 1 989, by diameter class and species
group.
-=--=•••
.
•
8 .00 -1-----'-"<>0..--•••••••+------+----.:..:...: grl
:..:
7.50
•.. ..---+---------+--c ---------- . ... ..:. .
.. :.;
7.00
... .
×
6.50
..
×
. ..
×
.
.
×
..
.
.
.
6.00
.. ...
. .. 8.50
"--- " '
"
- - ---r-------r----
-_--r-l - - ----.,
xed
a-n- d-l- 00-
...c
-- ..
------ -
---
. .
......
SOl 100
.
g
.s
..
..
. .
.
..
.
..
.
.
..
.
.
.
.
..
..
.
5.50
.
5.00
4.50 -I
______
-----
, -"L3
. ...
..
.
--- ·l--4--- _ _ _-1
·· ··
·
· ··
1
...
.
.. -t-..
........
...
,...
...
--....
.,
..
.. -+
...
4.00 +-...-..,.......
2.00
2.50
1 .50
1 .00
:.:;::..,:.--I
..
3.00
In(QMD)
Figure 14-Reineke plot of In (number of trees) over In(QMD), for fixed treatments
and control.
13
• ••••
- Jarlable
• •••• >r.---+--------1
--- .:..:.: grt���'-a"1"n-"-d""1"'00:-...
B.50
B.OO ..:j--7 .50 7.00 g
.5
. ....
6.00
. ,...
...
c ----------_ ... ..: .. .. .
.....
6.50
. ....
.....
.
. ..
5.50 ... .
.....
. ..
..
'. .. ...
.......... .' \
.....
5.00
" '"
....
..
....
.....
.... '\
••••SOl
600
""
L"--, _
:'"'-I. '- 8
1=:::- 6
... ••••• . I '-- 2
.. ..
. ...
...
-....-_+....
...
.:...,.
...,;. ....
. -..-_I
..
.... .
.
4.50 ...
..,
4.00 +-----...-+-....-....
2.00
1 .00
1 .50
2.50
3.00
In(QMO)
Figure 1 5-Reineke plot of In(number of trees) over In(QMO), for variable treatments
and control.
600
Fixed Control 500
)(
CD
'0
.5
I/)
c
CD
'0
'0
400
300
.
...
...
...
.'
..
... '
.
.'
...
.'.
.'
...
.'.
..'
.
. .. .
.... ...
.. . . ..
. . ..... ... . . . . .. . c
..
7
.
5
3
200
100
15
20
25
30
35
40
45
Age (years)
Figure 16--Stand density Index (SOl) in relation to age, fixed treatments and control.
14
600
Variable
Control
..... ......... .... .. C
"C
.5
. III
5i
"C
"C
·· .
·-·-·4 ------
------- -------+ .
-, ,
-------
500
..
...
.'.
--------1
.'
..'
..
400
..
.
..
..
..
300
.'
.'
.'
..'
.'
..'
...
6
4
200
2
100
20
15
25
35
30
40
45
Age (years)
Figure 17-Stand density index (SDI) in relation to age, variable treatments and
control.
12000
1 0000
..,.----,------,---..,---....__
.,....
--.__---.
-- Fixed - - - Variable ............ Control --------r------
------
o-gr088
.'
------+_---- --+.r· ·· ----- 1
8000
-----_4----+_--_+--���
6ooo
---_4--+_--_+���
--
2000
------+--=::i.illilli"""+_--'___+--_I_---_+_--I
O���-r���
15
20
25
30
35
40
45
Age (years)
Figure 1 8-Cumulative net total volume (CVTS) production in relation to age, and
treatment.
15
Merchantable cubic volume-Cumulative merchantable volume production for the
various treatments is shown in figure 19 and table 9. All values are net. Treatments
5, 7, and 8 have exceeded the control volume, and treatment 4 has produced virtually
the same volume as the control; all thinning treatments have produced considerably
larger diameter trees. As yet suppression-related mortality has had little effect on the
control because mortality has been principally in trees too small to contribute to CV6
totals.
Volume Distribution by
Tree Size Classes
Distribution of CVTS by tree size classes is shown in three g raphs. Figure 20 shows
volumes in live trees 15.6+, 13.6+, 11.6+, 9.6+, 7.6+, and 1.6+ inches d .b.h. at the
end of the fifth treatment period (1989). Figure 21 shows corresponding cumulative
totals-live stand in 1989 plus volumes of trees removed in thinnings. Figure 22
shows distribution at end of fifth treatment period (1989) as percentages of total live
standing volume. Although thinned plots have produced less total volume than the
control, and lower density thinned plots have produced less total volume than h igher
density plots, thinned plots have their volume concentrated on fewer but considerably
larger trees.
Periodic Annual
Increment
Periodic annual increment (PAl) values presented are net. Mortality has bee n negligi­
ble o n most thinned plots. There has been substantial suppression mortality on the
controls, which is not presented here.
PAl in basal area-Time trends of net periodic annual i ncrement in basal a rea are
shown in figures 23 and 24 and in table 11, by treatments. Initially, the control is
much above the others, but falls rapidly through the combination of reduced growth
due to competition and increasing suppression mortality.
8000
7000
- Fixed
- - - - Variable
;;;......, .., Control
6000
W
co
..,
u
--�----�----� --!i
7
5000
4000
3000
2000
1000
0
15
20
25
30
35
40
45
Age (years)
Figure 19-Cumulative net merchantable volume (CV6) production in relation to age
and treatment.
16
10000
Fixed
_ 15.6+
(SSC!j 13.6+
Increasing
Decreasing
Treatment number and group
Il2SI 11.6+
9.6+
Control
c=:J 7.6+
1.6+
Figure 20-Distribution of total volume (CVTS) in live trees by size class and
treatment, 1 989.
9
Fixed
-- 15.6+
(SSC!j 13.6+
Increasing
Decreasing
Control
Treatment number and group
11.6+
9.6+
c=:J 7.6+
1.6+
Figure 2 1-Cumulative production in total volume (CVTS) by tree size class
and treatment, 1 966·89.
17
110
7
FIXed
_ 15.6+
13.6+
InCfeasing
OeCfeasing
Treatment number and group
IZ'lZ'II 11.6+
9.6+
Control
c:=:J 7.6+
B&!lSiIa
1.6+
Figure 22-Percentage distribution of total volume (CVTS) by tree size and
treatment, 1989.
12 �----�-----r--�
••••
••••
•••
• ••
---+--- ----+ .. ..
10
',ro
Q)
>.
N'
I
I
6
.
4
-------
----
------+-------+------ .
----.-- ----- ---+---�:--
��.....;;;::�-7' ----­
I;
3
I---I------i---�- ·
'.
ic
-·
2
Fixed Control 15
20
25
30
35
40
Mldperiod age (years)
Figure 23-Net periodic annual increment in basal area In relation to age, fixed
treatments and control.
18
45
12 .------r---,---,r---.---�
.. .. . .
. . . .....
³..
- - --'-- .
10
".
....
, ........ _""';
"'
"' ... ...
'"
... ,
B
.
'.
- ..
..;...--c------..
":..:'"
.... .y \I•
'" .. c "0 ',
.". .... """
6
2
- - - Variable
""'"'''''' Control
15
20
25
30
35
40
45
Midperlod age (years)
Figure 24-Net periodic annual increment in basal area in relation to age, variable
treatments and control.
PAl in quadratic mean diameter-Time trends of periodic annual increment in QMD
are shown in figures 25 and 26 and in table 12. For thinned plots, values of net
change and of survivor growth are virtually identical, because there has been little
mortality and no ingrowth. These values differ considerably for the control, however.
Survivor growth is the more meaningful expression of actual biological growth (Curtis
and Marshall 1989).
PAl in total cubic v olume-Time trends of periodic annual increment in CVTS are
shown in figures 27 and 28 and in table 13. Note the sharp depression in growth
d u ring the fourth treatment period. This reflects a corresponding depression in height
growth in this period, as well as apparent slight reductions in basal area and diameter
growth. This period represents the second through the fifth growing seasons following
the Mount St. Helens ashfall and could possibly represent an aftereffect of the
eruption.
PAl in merchantable cubic volume-Trends of CV6 PAl over time are shown in
figures 29 and 30 and in table 13. The 6-inch merchantability limit markedly changes
the shape of the cu rves, compared to that for CVTS.
Periodic annual mortality-Periodic annual mortality in number of trees, basal area,
and CVTS is shown in tables 14 and 15. Values are low to negligible in all thinning
treatments but became substantial on the unthinned plots in recent periods.
19
0.50 r--i----:l===::::-r--r---,
0.40
'C'
III
Q)
>.
ffi
C-
1
0.30
!(l
.<:
0
c
cO
:E
0
.!:
...... ....
0.20
0.10
----
t- ---
l----==--j---5
...
:: ::.... : : . :: ==r .-...
---j-----+-==--·t--.
.
"1:,.
.
....
..
I
:::: ::
I
..
.. .
t_-=
----
.
I
. ....... C-survlvors
-- Fixed
"..,,""''' Control
0.00
15.0
20.0
25.0
30.0
35.0
45.0
40.0
Mldperiod age (years)
Figure 25-Periodic annual increment in quadratic mean diameter (QMD) in relation
to age, fixed treatments and control.
0.50
'C'
III
ffi
cI/)
Q)
-fi
c
c-
o
:E
0
.!:
0.40
0.30
..:....
t,
0.20
.......... .
..
.. . .
. .
.
.
0.10
.
. .......... .. · ..........· . . · c1 .net ..
....
.
.. ...
..
- - - Variable "''''''',,'' Control 15.0
20.0
25.0
30.0
35.0
L
---
. . ..... . . C-survlvors 40.0
45.0
Mldperiod age (years)
Figure 2 6-Periodic annual increment in quadratic mean diameter (QMD) in relation
to age, variable treatments and control.
20
'I
I
,I
------
500
••
••
300 ' ---+---
.... . . , ..
:
•.
••
.
.
•
.
.
to
"
------
----
---
fi/IJ
• ••
•
"
;
,
.. ...
,'-"', ",
'"
... .. ... ..
"'...;:;':""-"\o:".
" ...
.
7
.
g
--�-
1
- t--- -�
----
I
... ... ... ..... .. .. .. - -- --- ..
;-- ..
/1
..
..
.. _
7._�
c
_ _ _ _ • -- ....
_
,
. . . . .. . . . . . . .
..
7,
....
-
.
;
41'
,'",; .,'
...
+"",'
#.
" ... ... "!
.. ...
...
- ---,--I.... _,,:=:::
--- -
200
.
-------r------
- --- -- :
400 · 1 -
1 00
1
----
-- MAl, fixed
- - - PAl, fixed
.".""",,. MAl and PAl control
...::;:
.
••
•• ••
..
..
•• ••
•• • •
.. .
×..
...
5
_3
O +-----�----�--+_--_+--�
15
20
25
30
35
45
40
Age (years)
Figure 27-Mean annual increment and periodic annual increment in net volume
(CVTS) in relation to age, fixed treatments and control.
500
400
----
I
.1
------
-----r------r-----'------,
-- MAt, varlabte
- - - PAl, variable
"" ..".... . MAl and PAl, control
---- --
f---- 7:
.
.
,0
.
. . .
×····:· ;:--->
.
,.
, ... ..·1.. ""',...... ....
I
,.
?::.7":'1-- ',
. . . .. . . .
.
.
.
. -- - -
,',. ... _
- t-----
2..
--
_
... ....
.... '
"
.-
.
.
• •••
••
. . . ..
.
.
... . ..
.. ..
.
-l-. .
--..
.. .
.
.
+----�
I
_ ,8
••
.-":;,1,,"",
----. C4
...
_ __
.".
.
100
�---
:: -:.:;-::t---
, ." ,,; ."., - -- ..--- - - - - -- - - -
--+
,.. - -=-
200
..
.
,0
'
0
,
300
.
:
C
:: :::;:: :--
....
-
O +-----�----�---+--�
15
20
25
30
35
40
45
Age (years)
Figure 2 8-Mean annual increment and periodic annual increment in net volume
(CVTS) in relation to age, variable treatments and control.
21
450 400
;;;
,
.
350
.
.
'
,; ;".
300
250
200
150
c --���=-r- .l-.
100
50
o +---����--+---�--�--�
45
40
30
15
20
35
25
--
.
'i
III
Q)
>III
()
", '
;S
c
III
"
:;
,
"
..-
7
5
3
-----
Age (years)
Figure 29 Mean annual increment and periodic annual Increment in net
mechantable volume (CV6) in relation to age, fixed treatments and control.
450
---- --------- 1 ---- ---1
1
l
- MAl , variab le
lab le
••
vard
•
: l an p.'Al, contrOl :::.. ...•...•••••. . . . . .. . . . . .. I.,'C
..:..
:
.
.. . . ..
400O +--- -- - .....
.-""-',"; ...... .... .. .. ..-. 48
.r..:...
..
;
"r
"
.tI.
;
;
- - -_+ 300 +--- -- - 4_-
--
.------ 6.--.
....
I
.
''l rl'.;...=-------=-F- -"'-'-"'- _t
-y:2--__I
250 +----I----f
ill .
...
fl ---- ---- ------ ---200 +------+-- /I
. lIlIl .""
......
..
I
......
1 50 1l----r /1. : r_--- - ==j;
62 ·-_1
: _1
.
1 °0 1----r Io/lfl-:-j_.. .
=t
f
'
·· +_---4_--- -50 +---- --......
C
0 +------4----- -- ---15
30
35 45
20 40
25
...
..
•
Age (years)
Figure 30-Mean annual Increment and periodic annual increment in het
merchantable volume (CV6) In elation to age, variable treatments and control.
22
I I
I
Growth Percents
G rowth percentage is one method of expressing g rowth rates. The arg ument that one
should seek maximum return on growing stock, one expression of which is growth
percent, had an important place in the thinking that led to the LOGS study. G rowth
percents used here are calculated as,
growth percent
where
X1
and
X2
=
1 00
[(X :�2)/2]
1
are growing stock at beginning and end of the growth period.
Trends over time of growth percents for basal area of all trees, for CVTS, and for CV6
are shown in figures 3 1 , 32, and 33 and in table 1 6.
Basal area growth percent-A consistent pattern has occurred, as expected, of
growth percent declining over time. The higher density treatments have lower growth
percents at a given age, because higher density means a larger divisor. The control
falls much below the thinned treatments, both because of its larger divisor and be­
cause it has substantial suppression mortality.
CVTS growth percent Patterns are similar but the spread between treatments is
less, compared to basal area growth percent. Suppression mortality on the control
represents proportionally much less volume than does basal area because of the
small size of trees involved. In thinned treatments, although lower stocking reduces
the divisor and is expected to result in higher growth percent, this is partially offset
by the reduction in PAl associated with low stocking (further discussion below) .
-
CV6 growth percent-The plots are in a stage of development where ratios of
merchantable to total cubic volume are changing rapidly, and this has a considerable
effect on the trends shown. Initial growth percents are very high because of the small
values of CV6 used as the divisor. Ratios of merchantable volume to total volume
increase faster on the lower stocked plots because of the larger trees; this tends to
offset the relative i ncrease in growth percent expected from lower total volume of
growing stock. The net effect over the age range represented here is to reduce the
differences in growth percent among treatments.
Comparisons at age 42-G rowth percents in basal area, CVTS, and CV4 in relation
to basal area stocking at age 42 (the most recent growth period available) are com­
pared in figure 34. Volume growth percents are considerably higher than basal area
growth percents, which in part represents the effect of rapid height growth. G rowth
percents in CV6 are somewhat higher than in CVTS and, at this stage in stand de­
velopment, do not differ much among treatments. Because value increases with tree
size, presumably value growth percents are higher than shown and might have some­
what different relations to level of growing stock and age.
Crown Development
For the 1 989 data (age 42), height to live crown (HLC) measurements were plotted
over d.b.h., by treatment. With the possible exception of a few of the smallest trees,
the relation was in. all cases well represented by a horizontal line. Similar plots of live
crown ratio (LCR) generally showed a positive slope, as would be expected, because
total height increases with diameter. Therefore, although HLC treatment values can
be expressed as simple means, LCR cannot. It seems reasonable to c haracterize
treatment values of LCR by the LCR corresponding to average dimensions of the 40
largest (by d.b.h.) trees per acre. This is readily obtained as (H40-mean H LC)/H40.
23
1 4 ,-------��--_r--�--__,
12
10
B
6
4
- - -- ---­ -----j
2
-
----
. . . ..
'
"
.
-- Fixed
(numbered units)
- - - Variable
""""",,. Control
15
..
.
. . .-"
'------'-----+------
20
25
c__---
35
30
----
40
45
/.Ige (years)
Figure 31-Net basal area growth percent in relation to age and treatment.
20
16
c:
Ql
.e,
.t::
Cl
- . _ ._--
12
- .:.
--- --
B
Q)
z
. ,
4
15
.. . ...
.
.. . .
__:..I
"
"
------- -
-- Fixed (numbered
- - - Variable
"""""". Control
lines)
20
25
s
. . .. . . .
. .
.
. ... I
....
.;;::-._
30
c---. ···..-.-;--!c
35
40
Age (years)
Figure 32-Net volume (CVTS) growth percent in relation to age and treatment.
24
45
50 �------�r---�--�--�
?
c:
Q)
e
Q)
So
Ol
40
30
---1--- -- .------
20
Qj
z
--I--""'IIIIliI�-_�
--I
-- Flxed;---
10
- - - Variable
'"'''''''''' Control
15
25
20
30
35
45
40
Age (years)
Figure 33-Net merchantable volume (CV6) growth percent in relation to age and
treatment.
10 ,------,--�--_,--.---_r--_.
8
I
•
X
..
>a<
"
•
----.-­ .- ------.- �.�-.X-+------t.---­
6
4 •
. ____
°
0.,....
c1)
____ _
-+
°
2
0
._-- ._.-
o Basal area
X CVTS 0
•
F. V
50
6
100
150
200
250
300
Mldperiod basal area (1t2/acre)
Figure 34-Comparison of g rowth percents in basal area, total volume, and
merchantable volume in most recent growth period, 1 984-89,
25
The resulting values at age 42 are shown in figure 35. Note that HLC values are al­
most identical for treatments 2;'3, and 6 and for treatments 7, 4, and 8. This corre­
sponds to the expected equality of basal area at the end of the experiment, as shown in figure 3. LCR40 values are strongly related to basal area (and, similarly, to RD), as shown in figure 36. A question not addressed in this report, but worthy of examination, is that of consistency of these relations over time and among installations. Because total height within a treatment decreases with decreasing diameter, while HLC remains constant, the differences in live crown ratio associated with different stocking levels will be greater for smaller trees. D iscussi on
Results from the Iron Creek LOGS installation are qualitatively similar to those from other site II installations, as reported by Curtis and Marshall (report no. 8-1 986) and Marshall and others (report no. 1 0-1 992). Although there are some quantitative differences related to site and stand peculiarities, results generally are consistent with and reinforce conclusions previously drawn from other installations. Two basic ideas played a major role in conception and design of the LOGS study. The first of these was a concept sometimes termed the "Langsaeter hypothesis" (Langsaeter 1 941 , as quoted by Braathe 1 957; Staebler 1 960), widely believed to have been demonstrated by European experience (Mar:Molier 1 954) and stated in standard silviculture textbooks (for example, Smith 1 962: 43). According to this hy­
pothesis, the main effect of thinning, over a wide range of residual densities, is to redistribute a near-constant gross increment across various n umbers of trees. If true, this would greatly simplify construction of yield tables and prediction of thinning effects. This hypothesis had never been tested, however, for young Douglas-fir and was still controversial in Europe in the late 1 950s (Holmsgaard 1 958). A second related idea (Staebler 1 959) was that, for financial efficiency, one should retai n the minimum amount of growing stock feasible without major loss in growth. If the "Langsaeter hypothesis" is assumed to hold, then growth percent should be in direct inverse relation to growing stock over a considerable range in growing stock . . The LOGS study was designed to test these two concepts. It also includes a specific additional comparison among fixed, increasing, and decreasing trends in growing stock, and it was recognized that it would provide much concomitant information. A nalysis of Variance
Results from the ANOVA were much the same as those previously reported for other LOG S installations and were consistent with the graphic comparisons of means that form most of this report. Growth-Growing Stock
Relations
Except where specifically indicated, the discussion refers to net growth rather than gross growth. (For the various thinning treatments gross and net growth are almost identical; however, they differ considerably for the control, where suppression mortal­
ity has become important in the last two g rowth periods.) Regressions for gross basal area growth in relation to midperiod basal area (fig. 37) show PAl increasing with stocking, although the curves become flatter with advancing age. The curves form a consistent series, with elevation decreasing uniformly with advancing age. Those for net basal area (fig. 38) show, from the third period on, an apparent maximum near the highest stocking in the thinned treatments. This maxi­
mum is due almost entirely to the effect of mortality on the control and would not appear were the control omitted. 26
T-1 T - 3 T-5 T - 7
Constant
T - 2 T-4
C
T-6 T-8
IncreasIng
Decreasing
Control
Treatment number and group
- Live crown
Height to live crown
Figure 35-1 989 heights and heights to live crown of 40
largest trees per acre, by treatment.
0.70
0.6Q ·
._ --
0.50
!
0
c:
(.)
Q)
0.40 ·
--j
_
_
- ---
--
------
-
-
----jl-----
- -- ---
rJ
--
--.-_t----_+_---
:
4-____ __ _____
0
__
___
- - ------
•
g----
- -----­
o
----jf--.-- - ---.
----I--- ----+----+--
0.30
0.20
-
- ---
•
0. 1 0 ·
. -
-�-+----__t---_+_---___\---+-- --
• Largest 4 0 :l All -------------+----11--\--- --+-- --
0.00 -t----.....+
.- -...--+---1I....-+...
....-+--....--I
..
300
o
50
250
100
1 50
200
Basal area (ft 2/acre)
Figure 36-1 989 (age 42) live crown ratios of largest 40 stems per acre and of all
stems In relation to basal area.
27
1 4 ,----,--�--_r--_,
+---c-.-� ------ ---
12
___ TP.2
10
-_-)( TP·3
xt---+------f -----
8
l_.-JU--t----€l TP.4
1 . Tp.5 -----
6
--------
4
2
-+----+---- --+------+--------
---- ------
O ����-r����--�+_�
50
100
150
200
250
300
Mldperiod basal area (ft 2/acre)
Figure 37-Gross basal area periodic annual increment In relation to midperiod
basal area, by periods.
14
- - ------- -----
12
,
III
Q)
>.
10
"Q)
l:;
III
8
", '
:!:.
'"
'"
iil
II)
'"
.0
Qi
z
-----f -------
6
4
----+ ----------+--1
--+----
2
0
50
1 00
150
200
250
300
Mldperiod basal area (ft2/acre) ,
Figure 3 a-Net basal area periodic annual increment in relation to mldperiod basal
area, by periods.
28
Compared to the basal area increment regressions, similar regressions for g ross and
net CVTS PAl (figs. 39 and 40) have considerably steeper slopes, stil l present in the
most recent period. This reflects rapid and continued height growth (report no. 8­
Curtis and Marshall 1 986: 80). No maximum is present for gross increment; for net,
an apparent maximum occurs in the last two growth periods, arising entirely from
mortality in the control.
Elevations decrease with advancing age, but the trend is somewhat irregular. This
corresponds to irregularities in estimated height increments, which may or may not
be real.
The corresponding net i ncrement regressions for CV6 (fig. 41 ) strongly resemble the
gross increment curves for CVTS. No maximum is present; mortality on the control
is, so far, in small trees having little or no effect on the CV6 curve.
The above comparisons demonstrate that both net and gross volume increment are
in fact strongly related to growing stock. The relation is considerably weaker for
basal area increment; the difference is d ue to the height g rowth component of volume
increment. Like other LOGS installations, Iron Creek clearly demonstrates that the
"Langsaeter hypothesis" does not hold for young Douglas-fir stands making rapid
height growth. The increased individual tree sizes and values associated with lower
growing stock levels are bought at the cost of decreased total cubic volume
production.
Growth Percents
As expected, growth percents decline over time and with increasing stocking. Trends
differ with the variable i nvolved. Greatest differences between treatments occur with
basal area growth percent (fig. 3 1 ). Differences are less for CVTS (fig. 32) and least
for CV6 (fig . 33) . Differences between basal area and CVTS growth percents arise
because CVTS growth is more strongly related to stocking than is basal area growth;
hence, a decrease in the denominator (midperiod CVTS) is associated with a de­
crease in the numerator (PAl) and reduces differences in growth percent. This is also
true for CV6, but an additional factor involved is the small volume in CV6 present in
small-diameter stands (higher density treatments).
A clear relation exists between growth percent in basal area and basal area, and be­
tween growth percent in CVTS and basal area stocking, but only a very weak one
exists between growth percent in CV6 and basal area stocking (fig. 34). The latter
relation is expected to become stronger as trees in all thinning treatm nts pass into
diameter classes having most of their volume in CV6.
At age 42, growth percents in both CVTS and CV6 do not differ g reatly among thin­
ning treatments and are much higher than those in basal area (fig. 34). This again
reflects th!3 effect of rapid height increment and emphasizes the fact that basal area
growth is not a surrogate for volume growth.
Although the general direction of the trends of growth percent in relation to growing
stock is as expected, the magnitude of differences "in volume growth percents among
treatments is considerably less than anticipated when the study was established.
Again, this is a consequence of failure of the "Langsaeter hypothesis."
29
500 �------,---,--r---r--,
50
1 00
1 50
200
300
250
Midperiod basal area (ft 2/acre)
Figure 39-Periodic annual increment in net volume (CVTS) in relation to midperiod
basal area, by periods.
500
•
.
III
Ql
>.
' Ql
t;
III
TP·5
400
300
", '
:E.
200
u
fJ)
fJ)
e
(!)
--I
--+----+
I-----
1 00
--
--
0
50
1 00
1 50
200
250
Midperiod basal area (ft2/acre)
Figure 40-Periodic annual increment in gross volume (CVTS) in relation to
midperiod basal area, by periods.
30
300
500 T-------�--_.--_r����--_,
400
"i"(ij
Cl>
>-
'7';'
300
1 00
.
50
------
100
1 50
200
250
300
Midperiod basal area (ft 2{acre)
Figure 41-Periodic annual increment in net merchantable volume (eV6) in relation
to mid period basal area, by periods.
I ncreasing vs. Fixed vs.
Decreasing Treatments
The original plan called for comparison of increasing vs. fixed vs. decreasing treat­
ments at each of two final basal area levels (see inside front cover). Namely, T-4
(increasing) vs. T-5 vs. T-8 (decreasing), and T-2 (increasing) vs. T-3 vs. T-6 (de­
creasing). In each g roup, the order of cumulative volume production (table 9) is
decreasing > fixed > increasing, while that of attained QMD at the final measure­
ment is the reverse.
The goal of equal final basal areas within each treatment group was not completely
attained. Differences were not large-1 65 vs. 1 70 vs. 1 74 square feet per acre for
the higher level, and 1 22 vs. 1 31 vs. 1 35 square feet per acre for the lower level
group. But these differences were sufficient to cast some doubt on the reality of ob­
served differences in volumes and diameters. The graphs of volume distribution by
size classes (figs. 2 1 , 22, and 23) do, however, strongly suggest that the Increasing
treatments have more volume and a larger fraction of their volume in the largest tree
size class than do the fixed and decreasing treatments.
Mean Annual Increment
and Periodic Annual
I ncrement
Mean annual increment (MAl) and PAl values in eVTS have been superimposed in
figures 27 and 28, and those of MAl and PAl in eV6 in figures 29 and 30.
The jog in the PAl values for the period 1 980-84 represents the second through the
fifth growing seasons after the Mount St. Helens ashfa". It is tempting to consider this
as a delayed effect (primarily on height increment) of the eruption; however, this is
speculative and there could be quite a different cause.
31
The MAl and PAl curves shown bring out an important point, which is consistent with
results to date from other LOGS installations and pertinent to current forest manage­
ment controversies: at age 42, PAl is roughly twice MAl in total cubic volume (CVTS)
and three times greater than MAl in merchantable volume (CV6) (tables 1 3, 1 7). All
treatments are still far from culmination. It is clear that harvest at this age-not un­
common in the region today-'--w ould involve large losses in productivity relative to the
potential.
Stand Damage
Bear damage was striking when the Iron Creek installation was first established, but
further damage was eliminated by fencing and little evidence of damage is visible
today. Effect on the experiment has been negligible.
Root disease has had a considerable and increasing effect on stand development. I n
1 989, existing root rot pockets were mapped. One plot (plot 5 1 in treatment 1 ) had
been virtually destroyed and was eliminated from analyses. Three plots (52, 9 1 , 1 01 )
contained holes comprising less than 25 percent of the plot area. Two others (53 and
63) contained holes or scattered root rot trees not considered to have had much ef­
fect as yet. But because declining trees were removed in the frequent light thinnings,
mortality and loss from this cause, as shown in the record, is considerably less than
would have occurred under operational thinning on a longer cycle.
Except for loss of plot 51 , the main effect of root rot on the experiment to date has
been disruption of the initial choice of crop trees. Excluding plot 5 1 , on which the loss
was almost total, 1 3 percent of the initial crop trees had been replaced by substitutes
by 1 989. In most cases suitable sUbstitutes were available, and the effect on stand
growth has probably been minor.
A secondary effect of root disease is accelerated development of an understory of
tolerant species-redcedar and hemlock. Plot 51 is a particularly striking example and
now is occupied by dense and vigorous redcedar. Development here (and also at the
Rocky Brook LOGS installation) suggests that root disease is often a major factor in
natural conversion of initially homogeneous and nearly pure Douglas-fir stands to con­
siderably less uniform stands with a substantial redcedar component.
The Mount St. Helens ashfall, though spectacular at the time, has had only a
transitory effect.
Volume Production
Cumulative totals-Cumulative net CVTS production to age 42 is still higher on the
control than on any of the thinning treatments (fig. 1 8); although, with the o nset of
suppression mortality, the curves for the control and for treatment 7 appear to be con­
verging. (When the LOGS study was planned, treatment 7 was designed as a treat­
ment expected to do little more than forestall suppression-related mortality). I n con­
trast, four treatments (5, 7, 6, and 8) exceed the control in cumulative net eV6 pro­
duction (fig. 1 9). Treatment 1 ranks lowest in both CVTS and CV6.
Volume distribution by tree size-Figures 20 and 21 show distribution of total vol­
ume (CVTS) by tree size classes at age 42 and for cumulative production to age 42.
From these it is clear that all thinning treatments except treatment 1 have p roduced
substantially larger volumes than the control in the largest size classes, and that the
proportions of volume in the larger size classes are much higher. This implies a con­
siderably higher future value per cubic foot because of both lower logging cost and
the much higher value of large trees, which are now moving into sizes where log
grades will be changing rapidly.
32
At age 42, thinning treatments 5, 7, 6, and a-the higher density treatments-appear
to have produced the most favorable results in terms of the combination of relatively
high CV6 and concentration of this volume on relatively large trees. Treatment 1
clearly has too few trees for a timber production objective and was i n fact intended
as an extreme treatment "designed to fail."
The LOGS study was not intended as a comparison of operationally feasible thinning
regimes. It was designed as (1 ) a test of hypotheses on relations between growth and
growing stock, and growth percent and growing stock, and (2) a means of developing
information on the nature and quantitative values of growth-growing stock relations
that would aid in predicting the results of possible thinning regimes. These aims have
been met.
The very short thinning cycle used (10 feet of height growth = 3-5 years) is clearly
impractical operationally. However, several studies have indicated that-within limits­
thinning cycle has only a minor influence on production. Essentially the same results
probably could have been achieved by initial precommercial thinning to the numbers
left in the first treatment thinning, followed by one or two entries (rather than the five
actually made) designed to give a similar trend in average g rowing stock over time.
Future Uses of LOGS
Study
This report summarizes the principal stand statistics for the Iron Creek installation to
age 42 and represents completion of the study as originally planned. It also presents
the principal analyses called for in the original study plan. This follows the pattern
established by reports on other installations. There are a number of aspects not
addressed, however, that should receive attention in the future.
Continuation of installations-Future development of these stands should be
followed. Interpretation of the results and desirability of the stGlcking levels compared
will be heavily influenced by the way they develop over the next few years. Early
stocking levels that appeared relatively undesirable may change ranking with ad­
vancing age as densities, log grades, and values change. Further treatment is not
feasible because of the relatively small plot sizes; there simply are too few trees left
to allow reasonable thinning.
The members of the LOGS cooperative have agreed to continue remeasurement of
these installations for at least 1 0 years after completion of the planned experiment.
Value development-To date, almost all analyses of LOGS installations (and all
those presented for Iron Creek) have been in terms of volume and basal area rather
than value production. This could be q uite misleading, because value is strongly
related to tree size. Interpretations could be very different and probably would be
strongly influenced by choice of alternative harvest ages.
Iron Creek, and other LOGS installations, are now in a stage where values are
changing rapidly. Further measurements soon will be available, and it should be pos­
sible, by using available simulators, to project present stand characteristics and size
distributions for some distance into the future with a high degree of confidence.
Calculation and analyses of value development should provide much information on
the value consequences of alternative growing stock levels and alternative harvest
ages. These questions are highly pertinent to current controversies over forest man­
. agement practices.
33
Understory development-To date, no quantitative descriptions o r measurements
have been made of the herbaceous vegetation, shrubs, and developing understory of
hemlock and redcedar. Yet it is evident from casual inspection that strong relations
exist among treatment, composition, and vigor of this secondary vegetation. At I ron
Creek, the more heavily thinned treatments are developing a pronounced understory
of hemlock and cedar that eventually will lead to a two storied stand with distinctly
different height and diameter distributions for Douglas-fir vs. the tolerant hemlock and
cedar. Observation of other LOGS installations indicates that these relations differ
markedly among sites. There is a need for examination and comparison of these
relations across the various LOGS installations, for which long-term and very detailed
records of development and treatment of the overstory are available. Again , these
relations and differences are pertinent to current concerns about effects of thinning
and stocking levels on development of wildlife habitat and biodiversity in young
stands.
Crown development-Present crown dimensions and live crown ratios at Iron Creek
(figs. 35, 36) are closely related to current basal area stocking (and to relative den­
sity). C rown measurements also exist for most of the past measurement dates at I ron
Creek and for some of the other LOGS installations. An analysis of trends over time
of crown dimensions in relation to tree dimensions, position, and stand density, and
of the consistency of such relations across installations, would be highly desirable.
Such i nformation is an important component of a number of widely used stand de­
velopment models, and good data are scarce.
Metric Equivalents
1 inch
1 foot
=
=
2.54 centimeters
0.3048 meter
1 square foot
=
0.09290 square meter
1 cubic foot = 0.028 cubic meter
1 acre
=
0.4047 hectare
1 square foot per acre
1 cubic foot per acre
1 mile
Literature C ited
=
=
=
0.2296 square meter per hectare
0.06997 cubic meter per hectare
1 .609 kilometers
Braathe, Peder. 1 957. Thinnings in even-aged stands: a summary of European
literature. New Brunswick, NS: University of New Brunswick, Faculty of Forestry.
92 p .
Brackett, Michael. 1 973. Notes o n tarif tree volume computation. Resour. Mgmt.
Rep. 24. Olympia, WA: Washington Department of Natural Resources. 26 p.
Bruce, David; DeMars, Donald J. 1 974. Volume equations for second-growth
Douglas-fir. Res. Note PNW-239. Portland, OR: U.S. Department of Agriculture,
Forest Service, Pacific Northwest Forest and Range Experiment Station. 5 p.
Curtis, Robert O. 1 982. A simple i ndex of stand density for Douglas-fir. Forest
Science. 28(1 ): 92-94.
Curtis, Robert 0.; Marshall, David D. 1 989. On the definition of stand diameter
growth for remeasured plots. Western Journal of Applied Forestry. 4(3): 1 02-1 03.
34
Holmsgaard, Erik. 1 958. Comments on some German and Swedish thinning experi­
ments in Norway spruce. Forest Science. 4(1 ) : 54-60.
Hyink, D.M.; Scott, W.; Leon, R.M. 1 988. Some important aspects in the develop­
ment of a managed stand growth model for western hemlock. In: Ek, A.L.; Shifley,
S. R . ; Burk, T.E. , eds. Forest growth modelling and prediction: Proceedings of
IUFRO conference; 1 987 August 23-27; Minneapolis, MN. Gen. Tech. Rep.
NC-1 20. Minneapolis, MN: U.S. Department of Agriculture, Forest Service, North
Central Forest Experiment Station: 9-2 1 . King, James E. 1 966. Site index curves for Douglas-fir in the Pacific Northwest. For.
Pap. 8. Centralia, WA: Weyerhaeuser Forestry Research Center. 49 p.
Langsaeter, A. 1 941 . Om tynning i enaldret gran-og furskog = Thinning of even-aged
spruce and pine forests. Referat: Produktionsuntersuchungen von Fichtenwald.
Meddelelser fra det Norske Skogforsoeksvesen. 8 : 1 31 -2 1 6.
Mar:Moller, Carl. 1 954. The influence of thinning on volume increment. In: Thinning
problems and practices in Denmark. Tech. Publ. 76. Syracuse, NY: State
University of New York, College of Forestry at Syracuse: 5-44.
Reineke, L.H. 1 933. Perfecting a stand-density index for even-aged forests. Journal
of Agricultural Research. 46: 627-638.
SAS Institute. 1 988. SAS/STAT user's guide, Release 6.03 edition. Cary, NC: SAS
Institute, Inc. 1 028 p .
Smith, David M . 1 962. The practice of silviculture. 7th ed. New York: John Wiley
and Sons. 578 p.
Snedecor, George W.; Cochran, William G. 1 980. Statistical methods. 7th ed.
Ames, IA: Iowa State University Press. 507 p .
Staebler, George R. 1 959. Optimum levels of g rowing stock for managed stands.
Proceedings, Society of American Foresters: 1 1 0-1 1 3.
Staebler, George R. 1 960. Theoretical derivation of numerical thinning schedules for
Douglas-fir. Forest Science. 6(2): 98- 1 09.
Topik, Christopher; Halverson, Nancy M.; Brockway, Dale G. 1 986. Plant
association and management guide for the western hemlock zone . '
R6-ECOL-230A-1 986. Portland, OR: U.S. Department of Agriculture, Forest
Service, Pacific Northwest Region. 1 32 p.
35
Appendix 1 :
Description of
Experim ent
The following information is excerpted (and paraphrased) from Williamson and
Staebler (report no. 1 -1 97 1 ) .
The experiment is designed t o test a number of thinning regimes beginning i n young
stands made alike at the start through a calibration thinning. Thereafter, through the
time required for 60 feet of height growth, growing stock is controlled by allowing a
specified addition to the growing stock between successive thinnings. Any extra
growth is cut and is one of the measured effects of the thinning regime.
Experimental Design
A single experiment consists of eight thinning regimes plus unthinned plots whose
growth is the basis for treatment in these regimes. There are three plots per treatment
arranged in a completely randomized design for a total of 27 plots of one-fifth acre
each.
Crop Tree Selection
Well-formed, uniformly spaced, dominant trees at the rate of 80 per acre, or 1 6 per
plot, are designated as crop trees before initial thinning. Each quarter of a plot must
have no fewer than three suitable crop trees or no more than five-another criterion
for stand uniformity.
Initial or "Calibration"
Thinning
All 24 treated plots are thinned initially to the same density to minimize the effect of
variations in original density on stand growth. Density of residual trees is controlled
by quadratic mean diameter (diameter of tree of average basal area) of the residual
stand according to the formula,
Average spacing in feet
=
(0.61 67 x QMD)
+
8.
If one concentrates on leaving a certain amount of basal area corresponding to an
estimated overall quadratic mean d.b.h. ...[QMD], then the residual number of trees
may vary freely and the actual...[QMDs] may differ among plots . . . plus or minus 1 0
percent. Alternatively, if emphasis is on leaving a certain number of trees to corre­
spond to an estimated overall . . . [QMD], then the basal areas differ among plots and
the actuaL .. [QMDs] may vary ... plus or minus 1 5 percent between plots.
Treatments
Control of Thinning
I nterval
Control of Type of
Thinning
The eight tested thinning regimes differ in the amount of basal area allowed to ac­
cumulate in the growing stock. The amount of growth retained in any thinning is a
predetermined percentage of the gross increase found in the unthinned plots since
the last thinning . . . (table inside front cover). The average residual basal area for all
thinned plots after the calibration thinning is the foundation upon which all future
growing stock accumulation is based. As used ih the study, control plots may be
thought of as providing a "local gross yield table" for the study area.
,
Thinnings will be made (after the calibration thinning) whenever average height
growth of crop trees . . .comes closest to each multiple of 1 0 feet [above the initial
height].
As far as possible, type of thinning is eliminated as a variable in the treatment thin­
nings through several specifications.
1 . No crop tree may be cut until all noncrop trees have been cut (another tree may be
substituted for a crop tree damaged by logging or killed by natural agents).
2. The quadratic mean diameter of cut trees should approximate that of trees avail­
able for cutting.
3. The diameters of cut trees should be distributed across the full diameter range of
trees available for cutting.
36
Appendix 2: Tables
Table 1-Analysis of variance
Source of variation
Treatments:
A. Fixed vs. variable percentage treatments
B. Among levels of fixed percentage treatments­
Linear effects
Quadratic effects
Cubic effects
C. Increasing percentage treatments
D. Between levels of increasing percentage treatments
E. Between levels of decreasing percentage treatments
Error a for testing treatments
P periods
Treatments x period interactions:
PxA
P x B linear effects
P x B quadratic effects
P x B cubic effects
PxC
PxD
PxE
E rror b for testing interactions
Total
Degrees of freedom
(5 treatment periods)
(7)
1
1
1
1
1
1
1
15
4
4
4
4
4
4
4
4
60
115
37
Table 2-Analysis of variance results for periodic annual gross growth and
gross growth percent in volume (CVTS) and basal area, and net periodic annual
growth in quadratic mean diameter
P-valuesa and mean square errors
PAl
Source of variation
%
Treatments:
A. Fixed vs. variable
B. Fixed (linear)
B. Fixed (quadratic)
B. Fixed (cubic)
C. Increasing vs. decreasing
D. Between increasing
E. Between decreasing
Error a mean square
0.00"
.66
.00"
.14
.85
.00"
.00"
.00"
841 .39
0.00"
.38
.00"
.33
.20
.00"
.00"
.00"
.290
P periods:
PxA
P x B (linear)
P x B (quadratic)
P x B (cubic)
PxC
PxD
PxE
Error b mean square
.00"
.66
.00"
.05'
.77
.02'
.06
.13
290.72
.00"
.74
.10
.52
.76
.26
.41
.17
.310
a
Basal area
PAl
Growth
0.00"
.29
.00"
.17
.71
.00"
.00"
.16
.423
.00"
.41
.08
.00"
.22
.00"
.26
.12
.0668
%
0.00"
.96
.00"
.13
.41
.00"
.00"
.00"
. 1 90
.00"
.07
.00"
.04'
.70
.00"
.99
.00"
.0376
Diameter
PAl
0.00"
.83
.00"
.37
.60
.00"
.07
.05
.00244
.00"
.37
.00"
.50
.52
.04'
.06
.15
.000301
P is the probability of a larger F. given that the null hypothesis of no difference among means is true.
Significance levels:
38
Volume
Growth
• =
0.01 <p<0.05;
•• =
0.00<p<0.01.
Table 3a-Treatment mean heig hts (H40) of 40 largest d iameter trees per acre
and of crop trees (Hcrop) by treatment, period, and year
Before cut
After cut
Treatment
1 966
( 1 9) a
1 970
(23)
1 973
(26)
1 977
(30)
1 980
(33)
1 984
(37)
1 989
(42)
Feet
Fixed:
b
1 H40
Hcrop
3 H40
Hcrop
5 H40
Hcrop
7 H40
Hcrop
Increasing:
2 H40
Hcrop
4 H40
Hcrop
Decreasing:
6 H40
Hcrop
8 H40
Hcrop
Unthinned:
C H40
Hcrop
a
b
39.9
35.2
37.3
35.2
38.4
37.0
38.5
36.3
50. 1
46.0
49. 1
46.8
50.3
48.7
49.3
47. 1
59.0
53.3
56.4
54.4
59.4
57.6
58.6
55.8
68.9
64.0
67.6
65.0
69.7
67.8
69.9
66.8
78.7
72.9
75.5
73.2
78.3
76.9
78.5
75.9
85.3
81 .0
84.4
82. 1
87.8
85.5
87.8
84.4
97.3
94.4
97.8
94.8
1 02.0
98.5
1 00.6
96.4
40.1
38.2
40.8
39.4
50.7
48.9
52.8
50.4
57.8
57.3
59.6
57.8
67.3
66.4
68.6
67.3
75.7
74.6
77.5
76.3
85.5
83.7
87.4
85.6
99.4
95.3
99.7
96.9
36.9
35.6
40.4
38.4
47.6
46. 1
51 .0
48.8
55.7
53.8
60.0
57.4
67.2
64.6
69.0
66.4
75.3
73.2
79.2
79.2
83.7
82.2
85.8
83.4
96.9
94.3
99.2
96.6
36.6
35.4
48.5
46.9
57. 1
55.6
67.7
65.4
76.5
74.7
85.9
83.5
98.1
95.3
Stand age in parentheses. Plot 51 omitted from mean of treatment 1 because of root rot. 39
Table 3b-Treatment mean heights (H40) of 1 00 largest diameter trees per
hectare and of crop trees, by treatment, period, and year
Before cut
After cut
Treatment
1 966
(1 9) 8
1 970
(23)
1 973
(26)
1 977
(30)
1 980
(33)
1 984
(37)
1 989
(42)
Meters
Fixed:
b
1 H40
Herop
3 H40
Hcrop
5 H40
Hcrop
7 H40
Hcrop
Increasing:
2 H40
Hcrop
4 H40
Hcrop
Decreasing:
6 H40
Hcrop
8 H40
Hcrop
Unthinned:
C H40
Hcrop
a
b
40
1 2.2
1 0.7
1 1 .4
1 0.7
1 1 .7
1 1 .3
1 1 .7
1 1 .1
1 5.3
1 4.0
1 5.0
1 4.3
1 5.3
1 4.8
1 5.0
1 4.4
1 8.0
1 6.2
1 7.2
1 6.6
1 8. 1
1 7.6
1 7.9
1 7.0
21 .0
1 9.5
20.6
1 9.8
2 1 .2
20.7
21 .3
20.4
24.0
22.2
23.0
22.3
23.9
23.4
23.9
23. 1
26.0
24.7
25.7
25.0
26.8
26. 1
26.8
25.7
29.6
28.8
29.8
28.9
31 . 1
30.0
30.7
29.4
1 2.2
1 1 .6
1 2.4
1 2.0
1 5.5
1 4.9
1 6. 1
1 5.4
1 7.6
1 7.5
1 8.2
1 7.6
20.5
20.2
20.9
20.5
23. 1
22.7
23.6
23.3
26. 1
25.5
26.6
26. 1
30.3
29.0
30.4
29.5
1 1 .2
1 0.8
1 2.3
1 1 .7
1 4.5
1 4.0
1 5.6
1 4.9
1 7.0
1 6.4
1 8.3
1 7.5
20.5
1 9.7
2 1 .0
20.2
22.9
22.3
24. 1
24. 1
25.5
25. 1
26.2
25.4
29.5
28.8
30.2
29.4
1 1 .1
1 0.8
1 4.8
1 4.3
1 7.4
1 7.0
20.6
1 9.9
23.3
22.8
26.2
25.5
29.9
29.0
Stand age in parentheses. Plot 51 omitted from mean of treatment 1 because of root rot. Table 4a-Number of trees per acre by treatment, plot, period, year and age
Calibration
Treatment
Plot
After cut Before cut
1 966
1 970
(1 9)a
(23)
Period 1
After cut
1 970
(23)
Period 2
Before cut After cut
1 973
1 973
(26)
(26)
Period 3
Before cut
1 977
(30)
After cut
1 977
(30)
Period 4
Before cut
1 980
(33)
After cut
1 980
(33)
Period 5
Before cut
1 984
(37)
After cut
1 984
(37)
1 989
(42)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - Number of Trees - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Fixed:
b
1
3
5
7
Increasing:
2
4
Decreasing:
6
8
Unthinned:
C
a
21
33
51
31
42
52
12
41
72
11
23
63
350
360
355
355
335
355
345
335
360
345
355
380
345
355
330
350
335
335
335
330
350
340
345
355
205
225
240
275
215
255
275
255
300
305
340
355
205
215
21 0
270
210
230
275
255
290
305
335
31 0
1 40
1 55
1 60
225
1 65
1 90
230
220
275
280
325
310
1 40
1 50
1 45
220
1 65
1 80
230
220
260
280
31 0
300
95
110
95
1 85
1 45
1 55
215
205
260
280
31 0
300
95
1 10
85
1 85
1 45
1 50
215
205
260
280
31 0
290
75
80
75
1 60
1 25
1 50
1 95
1 85
250
265
305
290
75
80
75
1 60
1 25
1 50
1 95
1 85
240
265
300
285
55
65
65
1 35
1 00
110
1 65
1 60
210
235
270
275
55
65
65
1 35
1 00
1 05
1 65
1 60
210
230
270
265
82
91
1 01
13
62
111
360
370
350
335
400
355
355
350
335
330
390
345
200
215
1 80
200
285
245
1 95
1 90
1 80
1 90
265
230
1 50
1 75
1 40
1 55
235
200
1 50
1 75
1 35
1 55
230
1 90
1 25
1 35
1 20
1 50
21 5
1 75
1 25
1 30
1 20
1 45
215
1 75
1 10
1 30
1 05
1 40
1 90
1 65
110
1 30
1 00
1 40
1 90
1 65
95
1 10
85
1 30
1 80
1 50
95
110
85
1 30
1 75
1 50
15
43
81
14
53
73
350
370
360
340
360
355
335
350
345
330
350
355
290
315
315
290
345
305
285
290
310
290
315
270
240
255
· 260
245
310
270
235
250
255
245
305
270
205
1 95
21 0
225
285
260
200
1 95
210
220
275
255
1 70
1 70
1 75
1 95
270
21 0
1 65
1 70
1 75
1 90
265
210
1 30
1 30
1 25
1 50
230
1 80
1 30
1 30
1 25
1 50
225
1 80
22
25
71
1 345
1 385
1 085
1 390
1 400
1 1 40
1 390
1 400
1 1 40
1 325
1 395
1 1 60
1 325
1 395
1 1 60
1 260
1 320
1110
1 260
1 320 .
1110
1 1 80
1 1 80
1 025
1 1 80
1 1 80
1 025
1 1 05
1 035
890
1 1 05
1 035
890
920
830
785
Stand age in parentheses.
b Plot 51 abandoned 1 989 because of severe root rot.
./:>.
-"
"""
I\)
Table 4b-Number of trees per hectare by treatment, plot, period, year and age
Treatment
Fixed:
b
1
3
5
7
Increasing:
2
4
Decreasing:
6
8
Unthinned:
C
a
b
Plot
Afte(cut
1 966
a
( 1 9)
Before cut
1 970
(23)
Period 2
Period 1
Calibration
After cut
1 970
(23)
Before cut After cut
1 973
1 973
(26)
(26)
Period 3
Before cut
1 977
(30)
After cut
1 977
(30)
Period 4
Before cut
1 980
(33)
After cut
1 980
(33)
Period 5
Before cut
1 984
(37)
After cut
1 984
(37)
1 989
(42)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - Numb er of Trees - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
21
33
51
31
42
52
12
41
72
11
23
63
865
890
877
877
828
877
853
828
890
853
877
939
853
877
815
865
828
828
828
815
865
840
853
877
507
556
593
680
531
630
680
630
741
754
840
877
507
531
519
667
519
568
680
630
717
754
828
766
346
383
395
556
408
469
568
544
680
692
803
766
346
371
358
544
408
445
568
544
642
692
766
741
235
272
235
457
358
383
531
507
642
692
766
741
235
272
210
457
358
371
531
507
642
692
766
717
1 85
1 98
1 85
395
309
371
482
457
618
655
754
71 7
1 85
1 98
1 85
395
309
371
482
457
593
655
741
704
1 36
1 61
1 61
334
247
272
408
395
519
581
667
680
1 36
1 61
1 61
334
247
259
408
395
519
568
667
655
82
91
1 01
13
62
111
890
914
865
828
988
877
877
865
828
815
964
853
494
531
445
494
704
605
482
469
445
469
655
568
371
432
346
383
581
494
371
432
334
383
568
469
309
334
297
371
531
432
309
321
297
358
531
432
272
321
259
346
469
408
272
321
247
346
469
408
235
272
210
321
445
371
235
272
210
321
432
371
15
43
81
14
53
73
865
91 4
890
840
890
877
828
865
853
815
865
877
71 7
778
778
717
853
754
704
717
766
71 7
778
667
593
630
642
605
766
667
581
618
630
605
754
667
507
482
519
556
704
642
494
482
519
544
680
630
420
420
432
482
667
519
408
420
432
469
655
519
321
321
309
371
568
445
321
321
309
371
556
445
22
25
71
3324
3422
2681
3435
3459
281 7
3435
3459
281 7
3274
3447
2866
3274
3447
2866
31 1 4
3262
2743
31 1 4
3262
2743
291 6
291 6
2533
291 6
291 6
2533
2731
2558
2 1 99
2731
2558
2 1 99
2273
2051
1 940
Stand age in parentheses. Plot 51 abandoned 1 989 because of severe root rot. Table Sa-Basal area ·per acre by treatment, plot, period, year and age
Period 1
Calibration
Treatment
Fixed:
b
1
3
5
7
Increasing:
2
4
Plot
8
Unthinned:
C
a
b
.j::>.
cu
After cut
1 970
(23)
Before cut
1 973
(26)
After cut
1 973
(26)
Before cut
1 977
(30)
Period 4
Period 3
After cut
1 977
(30)
Before cut
1 980
(33)
After cut
1 980
(33)
Before cut
1 984
(37)
Period 5
After cut
1 984
(37)
1 989
(42)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Square feet - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
21
33
51
31
42
52
12
·
41
72
11
23
63
45.0
44.0
41 .3
43.9
51 .0
43.9
48.2
51 . 1
46.5
52.2
46.8
48.7
78.1
79.5
70.5
75.0
88.7
75.9
82.5
85.8
79.4
88.5
8 1 .3
8 1 .4
52.9
53.1
52.8
6 1 .9
62.2
61 .6
71 .4
71 .3
71 .3
8 1 .3
79.5
81 .4
77.7
77.9
69.8
87.1
86.8
84.2
1 0 1 .6
1 02.3
95.3
1 1 4.6
1 09.6
1 02.7
57.8 57.1
56.5
73.9
69.3
72.8
92.3
91 .0
90.6
1 07.6
1 07.5
1 02.7
85.4
84.9
77.9
1 05.8
1 00.6
1 00.0
1 29. 1
1 28.7
1 1 8. 1
1 47.3
1 44.0
1 36.4
62.5
64.5
55.8
92.6
92.9
86.7
1 22. 1
1 21 .9
1 1 8. 1
1 47.3
1 44.0
1 36.4
79.2
82.0
63.0
1 1 5.2
1 1 4.5
1 04.7
1 47.5
1 48.3
1 40.2
1 73. 1
1 70.5
1 58. 1
64.6
63.0
59. 1
1 00.4
1 00.6
1 04.7
1 34.2
1 35.1
1 35.4
1 69.4
1 69.1
1 58.1
83.3
8 1 .0
74.5
1 25.3
1 22.0
1 30.2
1 60.0
1 61 .5
1 57.0
1 98.9
1 95.1
1 83.8
65.9
68.0
67.7
1 1 0.5
1 04.6
1 04.4
1 41 . 1
1 42.2
1 41 .8
1 79.5
1 79.5
1 78.6
82.2
86.6
85.6
1 36.4
1 29.5
1 27.6
1 69.2
1 71 .1
1 68.6
209. 1
208.6
206.0
82
91
1 01
13
62
111
49.3
45.0
52.1
5 1 .7
47.2
50. 1
88.1
77.2
88.0
90.6
83.5
85.3
52.5
51 .2
51 . 1
6 1 .8
64.8
64.0
74.5
67.1
75.0
85.4
90.0
85.9
60.0
6 1 .7
60.7
74.6
82.1
76.3
89.1
92.8
87.7
1 08.4
1 1 5.9
1 09.0
77.9
74.5
80.2
1 06.0
1 07.2
1 02.9
97.2
89.2
98.9
1 25.5
1 30.6
1 26.7
88.3
89.2
89.2
1 23.0
1 1 8.6
1 20.7
1 09.7
1 1 2.4
1 07.1
1 47.3
1 44.6
1 48.1
99.2
98.7
95.8
1 35.9
1 38.4
1 37.0
1 23.3
1 23.5
1 1 8. 1
1 63.6
1 66.7
1 64.2
15
43
81
14
53
73
46.3
45.9
43.9
51 .7
46.4
49.5
80.6
79.1
77.5
89.7
82.9
87.6
72.0
71 .5
72.1
80.8
81 .6
80.4
1 02.3
96.1
1 01 .7
1 1 5.7
1 02.9
1 02.3
86.8
87.9
86.8
1 04.0
1 01 .7
1 02.3
1 21 .7
1 25.4
1 22.2
1 44.5
1 37.2
1 41 . 1
1 05.6
99.6
1 04.7
1 35.9
1 27.8
1 37.9
1 26. 1
1 22.9
1 28.9
1 59.6
1 48.4
1 61 .4
1 1 0.8
1 09.5
1 1 2.5
1 44.9
1 44.8
1 44.5
1 3 1 .7
1 34.6
1 37.6
1 7 1 .0
1 67.5
1 66.6
1 1 0.3
1 09.5
1 09.4
1 46.9
1 46.5
1 46.8
1 35.5
1 36.0
1 34.8
1 76.9
1 71 .9
1 73.4
22
25
71
97.8
90.9
70.2
1 47.8
1 41 .2
1 1 4.3
1 47.8
1 41 .2
1 1 4.3
1 83.1
1 81 .6
1 49.9
1 83.1
1 81 .6
1 49.9
224. 1
225.9
1 81 .9
224.1
225.9
1 81 .9
245.6
242.6
201 .5
245.6
242.6
201 .9
267.9
261 .0
2 1 6.4
267.9
261 .0
21 6.4
272.9
272.9
232.2
Decreasing:
6
After cut Before cut
1 970
1 966
( 1 9)a
(23)
Period 2
Stand age in parentheses.
Plot 51 abandoned 1 989 because of severe root rot.
Table 5b-Basal area per hectare by treatment, plot, period, year, and age
Period 1
Calibration
Treatment
Fixed:
b
1
3
5
7
Increasing:
2
4
Decreasing:
6
8
Unthinned:
C
a
b
Plot
After cut Before cut
1 966
1 970
a
(23)
( 1 9)
After cut
1 970
(23)
Period 3
Period 2
Before cut
1 973
(26)
After cut
1 973
(26)
Before cut
1 977
(30)
After cut
1 977
(30)
Before cut
1 980
(33)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Square meters - - -
-
Period 5
Period 4
After cut
1 980
(33)
Before cut
1 984
(37)
After cut
1 984
(37)
------------------------
1 989
(42)
- -
---
21
33
51
31
42
52
12
41
72
11
23
63
1 0.3
1 0. 1
9.5
1 0. 1
1 1 .7
1 0. 1
1 1 .1
1 1 .7
1 0.7
1 2.0
1 0.7
1 1 .2
1 7.9
1 8.3
1 6.2
1 7.2
20.4
1 7.4
1 8.9
1 9.7
1 8.2
20.3
1 8.7
1 8.7
1 2. 1
1 2.2
1 2. 1
1 4.2
1 4.3
1 4.2
1 6.4
1 6.4
1 6.4
1 8.7
1 8.3
1 8.7
1 7.8
1 7.9
1 6.0
20.0
1 9.9
1 9.3
23.3
23.5
21 .9
26.3
25.2
23.6
1 3.3
1 3.1
1 3.0
1 7.0
1 5.9
1 6.7
2 1 .2
20.9
20.8
24.7
24.7
23.6
1 9.6
1 9.5
1 7.9
24.3
23.1
22.9
29.6
29.6
27. 1
33.8
33.1
3 1 .3
1 4.3
1 4.8
1 2.8
2 1 .3
2 1 .3
1 9.9
28.0
28.0
27. 1
33.8
33. 1
3 1 .3
1 8.2
1 8.8
1 4.5
26.4
26.3
24.0
33.9
34.0
32.2
39.7
39.2
36.3
1 4.8
1 4.5
1 3.6
23.1
23.1
24.0
30.8
3 1 .0
31.1
38.9
38.8
36.3
1 9. 1
1 8.6
1 7. 1
28.8
28.0
29.9
36.7
37.1
36.0
45.7
44.8
42.2
1 5. 1
1 5.6
1 5.5
25.4
24.0
24.0
32.4
32.6
32.6
41 .2
41 .2
41 .0
1 8.9
1 9.9
1 9.7
3 1 .3
29.7
29.3
38.8
39.3
38.7
48.0
47.9
47.3
82
91
1 01
13
62
111
1 1 .3
1 0.3
1 2.0
1 1 .9
1 0.8
1 1 .5
20.2
1 7.7
20.2
20.8
1 9.2
1 9.6
1 2. 1
1 1 .8
1 1 .7
1 4.2
1 4.9
1 4.7
1 7.1
1 5.4
1 7.2
1 9.6
20.7
1 9.7
1 3.8
1 4.2
1 3.9
1 7. 1
1 8.8
1 7.5
20.5
2 1 .3
20.1
24,9
26.6
25.0
1 7.9
1 7. 1
1 8.4
24.3
24.6
23.6
22.3
20.5
22.7
28.8
30.0
29.1
20.3
20.5
20.5
28.2
27.2
27.7
25.2
25.8
24.6
33.8
33.2
34.0
22.8
22.7
22.0
3 1 .2
3 1 .8
3 1 .5
28.3
28.3
27.1
37.6
38.3
37.7
15
43
81
14
53
73
1 0.6
1 0.5
1 0. 1
1 1 .9
1 0.6
1 1 .4
1 8.5
1 8.2
1 7.8
20.6
1 9.0
20.1
1 6.5
1 6.4
1 6.5
1 8.5
1 8.7
1 8.5
23.5
22.1
23.4
26.6
23.6
23.5
1 9.9
20.2
1 9.9
23.9
23.3
23.5
27.9
28.8
28. 1
33.2
31 .5
32.4
24.2
22.9
24.0
3 1 .2
29.3
3 1 .7
28.9
28.2
29.6
36.6
34.1
37.0
25.4
25. 1
25.8
33.3
33.2
33.2
30.2
30.9
31 .6
39.3
38.4
38.2
25.3
25.1
25. 1
33.7
33.6
33.7
31.1
3 1 .2
30.9
40.6
39.5
39.8
22
25
71
22.5
20.9
1 6. 1
33.9
32.4
26.2
33.9
32.4
26.2
42.0
41 .7
34.4
42.0
41 .7
34.4
51 .4
51 .9
41 .8
5 1 .4
51 .9
41.8
56.4
55.7
46.3
56.4
55.7
46.3
6 1 .5
59.9
49.7
61 .5
59.9
49.7
62.6
62.6
53.3
Stand age in parentheses. Plot ?1 abandoned 1 989 because of severe root rot. Table Sa-Quadratic mean diameter of all live trees by treatment, plot, period, year and age
Calibration
Treatment
Fixed:
b
1
3
5
7
Increasing:
2
4
Decreasing:
6
8
Unthinned:
C
a
b
01
Plot
After cut Before cut
1 966
1 970
a
(23)
( 1 9)
Period 1
After cut
1 970
(23)
Period 2
Before cut
1 973
(26)
After cut
1 973
(26)
Period 3
Before cut
1 977
(30)
After cut
1 977
(30)
Period 4
Before cut
1 980
(33)
After cut
1 980
(33)
Period 5
Before cut
1 984
(37)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Inches - - - - - - - - - - - - - - - - - - -
-
After cut
1 984
(37)
1 989
(42)
---------------
21
33
51
31
42
52
12
41
72
11
23
63
4.9
4.7
4.6
4.8
5.3
4.8
5.1
5.3
4.9
5.3
4.9
4.8
6.4
6.4
6.3
6.3
7.0
6.4
6.7
6.9
6.5
6.9
6.6
6.5
6.9
6.6
6.3
6.4
7.3
6.7
6.9
7.2
6.6
7.0
6.5
6.5
8.3
8. 1
7.8
7.7
8.7
8.2
8.2
8.6
7.8
8.3
7.7
7.8
8.7
8.2
8.0
7.8
8.8
8.4
8.6
8.7
7.8
8.4
7.8
7.8
1 0.6
1 0.2
9.9
9.4
1 0.6
1 0. 1
1 0. 1
1 0.4
9.1
9.8
9.2
9. 1
1 1 .0
1 0.4
1 0.4
9.6
1 0.8
1 0. 1
1 0.2
1 0.4
9.1
9.8
9.2
9.1
1 2.4
1 1 .7
1 1 .7
1 0.7
1 2.0
1 1 .3
1 1 .2
1 1 .5
9.9
1 0.6
1 0.0
1 0.0
1 2.6
1 2.0
1 2.0
1 0.7
1 2. 1
1 1 .3
1 1 .2
1 1 .6
1 0.0
1 0.8
1 0. 1
1 0.0
1 4.3
1 3.6
1 3.5
1 2.0
1 3.4
1 2.6
1 2.3
12.7
1 1 .0
1 1 .7
1 0.9
1 0.9
1 4.8 ·
1 3.9
1 3.8
1 2.3
1 3.9
1 3.2
1 2.5
1 2.8
1 1 .1
1 1 .8
1 1 .0
1 0.9
1 6.6
1 5.6
1 5.5
1 3.6
1 5.4
1 4.9
1 3.7
1 4.0
1 2. 1
1 2.9
1 1 .9
1 1 .9
82
91
1 01
13
62
111
5.0
4.7
5.2
5.3
4.7
5.1
6.7
6.4
6.9
7. 1
6.3
6.7
6.9
6.6
7.2
7.5
6.5
6.9
8.4
8.0
8.7
9. 1
7.9
8.3
8.6
8.0
8.9
9.4
8.0
8.4
1 0.4
9.9
1 0.9
1 1 .3
9.6
1 0.3
1 0.7
1 0. 1
1 1 .1
1 1 .4
9.6
1 0.4
1,1 .9
1 1 .2
1 2.3
1 2.6
1 0.6
1 1 .5
1 2. 1
1 1 .2
1 2.5
1 2.7
1 0.7
1 1 .6
1 3.5
1 2.6
1 4.0
1 3.9
1 1 .8
1 2.8
1 3.8
1 2.8
1 4.4
1 3.8
1 1 .9
1 2.9
1 5.4
1 4.3
1 6.0
1 5.2
1 3.2
1 4.2
15
43
81
14
53
73
4.9
4.8
4.7
5.3
4.9
5.1
6.6
6.4
6.4
7. 1
6.6
6.7
6.7
6.5
6.5
7.1
6.6
7.0
8. 1
7.8
7.8
8.6
7.7
8.3
8.1
8.0
7.8
8.8
7.8
8.3
9.7
9.6
9.4
1 0.4
9.1
9.8
9.7
9.7
9.6
1 0.5
9. 1
9.9 .
1 0.8
1 0.7
1 0.6
1 1 .5
9.9
1 0.8
1 0.9
1 0.9
1 0.9
1 1 .7
9.9
1 1 .2
1 2. 1
1 2.0
1 2.0
1 2.8
1 0.8
1 2. 1
1 2.5
1 2.4
1 2.7
1 3.4
1 0.8
1 2.2
1 3.8
1 3.9
1 4.1
1 4.7
1 1 .8
1 3.3
22
25
71
3.7
3.5
3.4
4.4
4.3
4.3
4.4
4.3
4.3
5.0
4.9
4.9
5.0
4.9
4.9
5.7
5.6
5.5
5.7
5.6
5.5
6.2
6. 1
6.0
6.2
6.1
6.0
6.7
6.8
6.7
6.7
6.8
6.7
7.4
7.8
7.4
Stand age in parentheses. Plot 51 abandoned 1989 because of severe root rot. 0)
Table Sb-Ouadratic mean diameter of all live trees by treatment, plot, period, year and age
Period 1
Calibration
Treatment
Fixed:
b
1
3
5
7
After cut Before cut
1 966
1 970
a
Plot
(23)
( 1 9)
4
8
Unthinned:
C
a
b
After cut
1 973
(26)
Before cut
1 977
(30)
After cut
1 977
(30)
Before cut
1 980
(33)
- -
After cut
1 980
(33)
Period 5
Before cut
1 984
(37)
After cut
1 984
(37)
1 989
(42)
-------------------------
21
33
51
31
42
52
12
41
72
11
23
63
1 2.4
1 1 .9
1 1 .7
1 2.2
1 3.5
1 2.2
1 3.0
1 3.5
1 2.4
1 3.5
1 2.4
1 2.2
1 6.3
1 6.3
1 6.0
1 6.0
1 7.8
1 6.3
1 7.0
1 7.5
1 6.5
1 7.5
1 6.8
1 6.5
1 7.5
1 6.8
1 6.0
1 6.3
1 8.5
1 7.0
1 7.5
1 8.3
1 6.8
1 7.8
1 6.5
1 6.5
21.1
20.6
1 9.8
1 9.6
22.1
20.8
20.8
21 .8
1 9.8
21.1
1 9.6
1 9.8
22. 1
20.8
20.3
1 9.8
22.4
2 1 .3
2 1 .8
22.1
1 9.8
2 1 .3
1 9.8
1 9.8
26.9
25.9
25.1
23.9
26.9
25.7
25.7
26.4
23. 1
24.9
23.4
23.1
27.9
26.4
26.4
24.4
27.4
25.7
25.9
26.4
23. 1
24.9
23.4
23. 1
31 .5
29.7
29.7
27.2
30.5
28.7
28.4
29.2
25.1
26.9
25.4
25.4
32.0
30.5
30.5
27.2
30.7
28.7
28.4
29.5
25.4
27.4
25.7
25.4
36.3
34.5
34.3
30.5
34.0
32.0
3 1 .2
32.3
27.9
29.7
27.7
27.7
37.6
35.3
35. 1
3 1 .2
35.3
33.5
31 .8
32.5
28.2
30.0
27.9
27.7
42.2
39.6
39.4
34.5
39. 1
37.8
34.8
35.6
30.7
32.8
30.2
30.2
82
91
1 01
13
62
111
1 2.7
1 1 .9
1 3.2
1 3.5
1 1 .9
1 3.0
1 7.0
1 6.3
1 7.5
1 8.0
1 6.0
1 7.0
1 7.5
1 6.8
1 8.3
1 9. 1
1 6.5
1 7.5
21 .3
20.3
22.1
23.1
20.1
21 .1
2 1 .8
20.3
22.6
23.9
20.3
21 .3
26.4
25.1
27.7
28.7
24.4
26.2
27.2
25.7
28.2
29.0
24.4
26.4
30.2
28.4
3 1 .2
32.0
26.9
29.2
30.7
28.4
31 .8
32.3
27.2
29.5
34.3
32.0
35.6
35.3
30.0
32.5
35.1
32.5
36.6
35. 1
30.2
32.8
39.1
36.3
40.6
38.6
33.5
36. 1
15
81
14
53
73
1 2.4
1 2.2
1 1 .9
1 3.5
1 2.4
1 3.0
1 6.8
1 6.3
1 6.3
1 8.0
1 6.8
1 7.0
1 7.0
1 6.5
1 6.5
1 8.0
1 6.8
1 7.8
20.6
1 9.8
1 9.8
21 .8
1 9.6
21.1
20.6
20.3
1 9.8
22.4
1 9.8
21.1
24.6
24.4
23.9
26.4
23.1
24.9
24.6
24.6
24.4
26.7
23.1
25. 1
27.4
27.2
26.9
29.2
25. 1
27.4
27.7
27.7
27.7
29.7
25.1
28.4
30.7
30.5
30.5
32.5
27.4
30.7
3 1 .8
3 1 .5
32.3
34.0
27.4
3 1 .0
35.1
35.3
35.8
37.3
30.0
33.8
22
25
71
9.4
8.9
8.6
1 1 .2
1 0.9
1 0.9
1 1 .2
1 0.9
1 0.9
1 2.7
1 2.4
1 2.4
1 2.7
1 2.4
1 2.4
1 4.5
1 4.2
1 4.0
1 4.5
1 4.2
1 4.0
1 5.7
1 5.5
1 5.2
1 5.7
1 5.5
1 5.2
1 7.0
1 7.3
1 7.0
1 7.0
1 7.3
1 7.0
1 8.8
1 9.8
1 8.8
Decreasing:
6
Before cut
1 973
(26)
Period 4
Period 3
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Centimeters - - - -
Increasing:
2
After cut
1 970
(23)
Period 2
43
Stand age in parentheses. Plot 51 abandoned 1 989 because of severe root rot. Table 7a-Quadratic mean diameters of largest 40 trees per acre, crop trees,
and largest 80 trees per acre by treatment, period, and year
Before cut
After cut
Treatment
QMD
1 966
a
(1 9)
1 970
(23)
1 973
(26)
1 977
(30)
- - - - - - - - - - - - - -
Fixed:
b
1
3
5
7
Increasing:
2
4
Decreasing:
6
8
Unthinned:
C
1 980
(33)
1 984
(37)
1 989
(42)
- - - - - - - - - - - - - -
largest 40 crop trees
largest 80 largest 40
crop trees
largest 80
largest 40
crop trees
largest 80
largest 40
crop trees
largest 80 6.5
5.6
6.1
6.6
5.9
6.3
6.8
6.1
6.4
6.7
5.7
6.3
8.6
7.4
8.0
8.6
7.8
8.2
8.8
8.0
8.3
8.7
7.5
8.2
1 0.2
9.0
9.5
1 0. 1
9.2
9.6
1 0.3
9.5
9.8
1 0.3 ·
9.0
9.7
1 2.2
1 1 .1
1 1 .5
1 2.0
1 1 .0
1 1 .4
1 2.2
1 1 .2
1 1 .5
1 2.0
1 0.5
1 1 .4
1 3.6
1 2.5
1 2.6
1 3.3
1 2.3
1 2.6
1 3.3
1 2.3
1 2.6
1 3.2
1 1 .5
1 2.4
1 5.2
1 4.2
1 3.9
1 4.8
1 3.6
1 3.9
1 4.6
1 3.5
1 3.8
1 4.4
1 2.6
1 3.6
1 6.5
1 5. 1
1 5.5
1 6. 1
1 4.8
1 5. 1
1 5.7
1 3.7
1 4.8
largest 40
crop trees
largest 80
largest 40
crop trees
largest 80 6.6
5.8
6.2
6.5
5.9
6.3
8.5
7.7
8. 1
8.5
7.8
8.2
9.9
9.3
9.5
1 0. 1
9.3
9.7
1 1 .9
11.1
1 1 .3 ,.
.
12.1
1 1 .2
1 1 .6
1 3.2
1 2.2
1 2.6
1 3.3
1 2.4
1 2.8
1 4.7
1 3.7
1 4. 0
1 4.7
1 3.7
1 4. 1
1 6.5
1 5.3
1 5.6
1 6.2
1 5.0
1 5.5
largest 40
crop trees
largest 80
largest 40 crop trees
largest 80 6.4
5.7
6.1
6.7
5.9
6.4
8.4
7.6
8.0
8.8
8.0
8.4
9.9
9.0
9.5
1 0.4
9.6
1 0.0
1 1 .7
1 0. 8
1 1 .3
1 2.2
1 1.1
1 1 .7
1 3.0
1 2.0
1 2.4
1 3.4
1 2. 1
1 2.8
1 4.3
1 3.3
1 3.8
1 4.7
1 3.2
1 3.7
1 5.9
1 5.0
1 5.2
1 6. 1
1 4. 6
1 5.3
largest 40 crop trees
largest 80
6.5
5.8
6.1
8.3
7.4
7.8
9.5
8.6
9.0
1 0.9
9.7
1 0.4
1 1 .7
1 0.5
1 1 .2
1 2.7
1 1 .2
1 2. 1
1 3.8
1 2.2
1 3.2
8
Stand age in parentheses. C
Number per acre <BO. 1 7.0
1 6. 1
c
b Treatment 1 mean omits plot 51 , because of severe root rot. 47
Table 7b-Quadratic mean diameters of largest 1 00 trees per hectare, crop
trees, and largest 200 trees per hectare by treatment, period, and year
Before cut
After cut
Treatment
QMD
1 966
( 1 9) a
1 970
(23)
1 973
(26)
------------
Fixed:
b
1
3
5
7
Increasing:
2
4
Decreasing:
6
8
Unthinned:
C
a
b
C
48
1 977
(30)
n
e
1 980
(33)
1 984
(37)
1 989
(42)
------------
largest 1 00
crop trees
largest 200
largest 1 00
crop trees
largest 200
largest 1 00
crop trees
largest 200
largest 1 00
crop trees
largest 200
1 6.5
1 4.2
1 5.5
1 6.8
1 5.0
1 6.0
1 7.2
1 5.5
1 6.3
1 7. 1
1 4.5
1 6. 1
21 .7
1 8.8
20.4
21 .8
1 9.8
20.8
22.3
20.3
21.1
22.1
1 9.1
20.8
25.8
22.9
24.2
25.7
23.4
24.5
26.2
24.1
25.0
26. 1
22.9
24.6
31.0
28.2
29. 1
30.5
27.9
29.0
30.9
28.4
29. 1
30.6
26.7
28.9
34.4
31 .8
32. 1
33.7
31 .2
32.0
33.8
31 .2
31 .9
33.4
29.2
31 .6
38.5
36. 1
35.2
37.6
34.5
35.4
37.0
34.3
35.0
36.5
32.0
34.5
41 .8
38.4
39.4
40.9
37.6
38.4
39.8
34.8
37.6
largest 1 00
crop trees
largest 200
largest 1 00
crop trees
largest 200
1 6.7
1 4.7
1 5.8
1 6.6
1 5.0
1 5.9
21 .6
1 9.6
20.7
21 .5
1 9.8
20.8
25. 1
23.6
24.0
25.7
23.6
24.6
30.2
28.2
28.7
30.6
28.4
29.5
33.5
31 .0
32.0
33.8
31 .5
32.5
37.4
34.8
35.6
37.3
34.8
35.8
4 1 .9
38.9
39.7
41 . 1
38. 1
39.3
largest 1 00
crop trees
largest 200
largest 1 00
crop trees
largest 200
1 6.3
1 4.5
1 5.4
1 7.1
1 5.0
1 6.2
21 .3
1 9.3
20.3
22.3
20.3
21 .3
25. 1
22.9
24.2
26.3
24.4
25.3
29.7
27.4
28.7
31.1
28.2
29.8
32.9
30.5
31 .6
34.0
30.7
32.5
36.4
33.8
35.0
37.3
33.5
34.7
40.5
38. 1
38.7
41 .0
37. 1
38.8
largest 1 00
crop trees
largest 200
1 6.5
1 4.7
1 5.5
21.1
1 8.8
1 9.8
24.1
21 .8
22.9
26.9
24.6
26.4
29.7
26.7
28.4
32.3
28.4
30.7
35.0
31 .0
33.5
Stand age in parentheses. Treatment 1 mean omits plot 51 because of severe root rot. Number per hectare <200. 43. 1
40.9
c
Table 8a-Total cubic volume (CVTS) per acre by treatment, plot, period, year and age
Calibration
Treatment
Fixed:
b
1
3
5
7
Increasing:
2
4
Decreasing:
6
8
Unthinned:
C
a
Plot
After cut Before cut
1 966
1970
(23)
( 1 9) a
Period 1
After cut
1 970
(23)
Before cut After cut
1 973
1 973
(26)
(26)
Before cut
1 977
(30)
Period 4
Period 3
After cut
1 977
(30)
Before cut
1 980
(33)
After cut
1 980
(33)
Before cut
1 984
(37)
Period 5
After cut
1 984
(37)
1 989
(42)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Cubic feet - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
21
33
51
31
42
52
12
41
72
11
23
63
614
644
551
609
739
607
740
768
697
788
667
744
1 390
1 491
1 281
1 321
1 730
1 392
1 61 8
1 679
1 492
1 690
1 51 9
1 590
959
1 006
960
1 1 00
1 225
1 1 45
1 407
1 41 1
1 347
1 554
1 485
1 590
1 590
1 698
1 435
1 849
1 923
1 767
2320
2344
2093
2590
2380
2362
1 201
1 252
1 1 70
1 574
1 535
1 536
21 30
2094
1 991
2438
2336
2362
2124
2143
1 862
2686
2637
2522
3503
3378
3079
3948
3777
3623
1 564
1 646
1 359
2355
2436
21 78
331 6
3204
3079
3948
3777
3623
2228
2366
1 685
3295
3344
2927
4485
4380
4084
5320
5035
4704
1 822
1 828
1 600
2879
2928
2927
4079
3989
3947
521 1
4992
4704
261 2
2524
2204
4004
3967
4052
5324
5295
521 5
6647
6302
6153
2087
2134
201 0
3546
3406
3267
471 4
4672
4728
601 1
5801
5984
2969
3090
2870
4993
4860
4540
6452
6476
6369
7884
7751
7822
82
91
1 01
13
62
111
773
648
821
822
687
826
1 743
1 489
1 724
1 774
1 603
1 806
1 049
998
1 01 3
1 235
1 260
1 365
1 766
1 51 1
1 691
1 979
1 928
2088
1 438
1 389
1 371
1 733
1 765
1 859
2430
2359
231 5
281 4
2969
3045
2131
1 864
2131
2748
2734
2874
2878
2581
291 0
3680
3754
3981
2625
2581
2630
361 8
341 9
3798
3653
3642
351 7
4785
4655
5226
3327
3 1 96
3151
441 7
4449
4838
4693
4477
4365
5978
6101
6460
15
43
81
14
53
73
686
605
628
824
673
81 9
1 487
1 397
1 443
1 71 6
1 579
1 751
1 333
1 266
1 347
1 552
1 554
1 627
2171
1 930
2258
2604
21 92
2367
1 844
1 778
1 931
2353
2166
2367
3066
3 1 08
3 1 34
3665
3389
3829
2653
2471
2698
3461
3 1 55
3746
3561
3433
3798
4560
4121
4847
3121
3068
3329
4153
4020
4373
4160
41 87
4454
5543
5202
5564
3496
3454
3564
4795
4559
491 9
4891
491 5
4984
6645
6191
6667
22
25
71
1 324
1 206
942
2697
2496
2086
2697
2496
2086
3998
3806
3 1 96
3998
3806
3 1 96
5730
5625
451 2
5730
5625
451 2
7291
6853
561 6
7291
6853
561 6
8651
8289
6980
8651
8289
6980
1 0000
9983
8527
Stand are in parentheses. b Plot 51 abandoned 1 989 because of severe root rot. ""'"
co
Period 2
_
(1J
0
Table 8b-Total cubic volume (CVTS) per hectare by treatment, plot, period, year and age
Calibration
Treatment
Fixed:
b
1
3
5
7
Increasing:
2
4
Decreasing:
6
8
Unthinned:
C
a
Plot
After cut Before cut
1 970
1 966
a
(23)
( 1 9)
Period 1
After cut
1 970
(23)
'11
Before cut
1 973
(26)
After cut
1 973
(26)
Period 4
Period 3
Period 2
Before cut
1 977
(30)
After cut
1 977
(30)
Before cut
1 980
(33)
After cut
1 980
(33)
Period 5
Before cut
1 984
(37)
After cut
1 984
(37)
1 989
(42)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Cubic meters - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
52
42
52
54
49
55
47
52
97
1 04
90
92
1 21
97
1 13
1 17
1 04
1 18
1 06
111
67
70
67
77
86
80
98
99
94
1 09
1 04
111
111
1 19
1 00
1 29
1 35
1 24
1 62
1 64
1 46
1 81
1 67
1 65
84
88
82
1 10
1 07
1 07
1 49
1 46
1 39
1 71
1 63
1 65
1 49
1 50
1 30
1 88
1 84
1 76
245
236
215
276
264
254
1 09
1 15
95
1 65
1 70
1 52
232
224
215
276
264
254
1 56
1 66
1 18
231
234
205
314
306
286
372
352
329
1 27
1 28
1 12
201
205
205
285
279
276
365
349
329
1 83
1 77
1 54
280
278
283
372
371
365
465
441
431
1 46
1 49
1 41
248
238
229
330
327
331
421
406
41 9
208
21 6
201
349
340
318
451
453
446
552
542
547
82
91
1 01
13
62
111
54
45
57
57
48
58
1 22
1 04
1 21
1 24
1 12
1 26
73
70
71
86
88
95
1 24
1 06
1 18
1 38
1 35
1 46
1 01
97
96
1 21
1 23
1 30
1 70
1 65
1 62
1 97
208
213
1 49
1 30
1 49
1 92
1 91
201
201
1 81
204
257
263
279
1 84
1 81
1 84
253
239
266
256
255
246
335
326
366
233
224
220
309
31 1
339
328
313
305
41 8
427
452
15
81
14
53
73
48
42
44
58
47
57
1 04
98
1 01
1 20
1 10
1 22
93
89
94
1 09
1 09
1 14
1 52
1 35
1 58
1 82
1 53
1 66
1 29
1 24
1 35
1 65
1 52
1 66
21 5
21 7
219
256
237
268
1 86
1 73
1 89
242
221
262
249
240
266
319
288
339
218
215
233
291
281
306
291
293
312
388
364
389
245
242
249
335
319
344
342
344
349
465
433
466
22
25
71
93
84
66
1 89
1 75
1 46
1 89
1 75
1 46
280
266
224
280
266
224
401
394
316
401
394
316
51 0
480
393
510
480
393
605
580
488
605
580
488
700
699
597
21
33
51
31
42
52
12
41
72
11
23
63
43
43
45
39
43
Stand age in parentheses. b Plot 51 abandoned 1 989 because of severe root rot. Table 9a-Average per acre stand statistics, by treatment, year, and age
Removed in thinning
After thinning
Treatment
Fixed:
a
1
3
5
7
I ncreasing:
2
01
......
Year
Age
Period
H40
Trees
left
Ft
QMD
all
QMD
crop
- - Inches - -
Basal
area
CVTS
Ff
Fr
37
42
0
1
2
3
4
5
6
0
1
2
3
4
5
6
0
1
2
3
4
5
6
0
1
2
3
4
5
6
40
50
59
69
79
85
97
37
49
56
68
76
84
98
38
50
59
70
78
88
1 02
38
49
59
70
78
88
1 01
355
215
1 48
1 02
78
60
60
348
248
1 93
1 62
1 45
115
1 13
347
277
242
227
21 0
1 78
1 78
360
333
305
297
287
260
255
4.8
6.8
8.5
1 0.7
1 2.3
1 4.4
1 6.1
5.0
6.8
8.3
1 0.2
1 1 .4
1 3.1
1 4.6
5.1
6.9
8.4
9.9
1 0.9
1 2.1
1 3.3
5.0
6.7
8.0
9.4
1 0.3
1 1 .2
12.2
5.6
7.4
9.1
1 1 .1
1 2.5
1 4.3
1 6.1
5.9
7.8
9.2
1 1 .0
1 2.3
1 3.6
1 5. 1
6.1
8.0
9.5
1 1 .2
1 2.3
1 3.5
1 4.8
5.7
7.5
8.9
1 0.5
1 1 .5
1 2.6
1 3.7
44.5
53.0
57.4
63.5
63.8
67.0
84.4
46.3
61 .9
72.0
90.7
1 0 1 .9
1 06.5
1 3 1 .1
48.6
71 .3
91 .3
1 20.7
1 34.9
1 41 .7
1 69.6
49.2
80.7
1 05.9
1 42.6
1 65.6
1 79.2
207.9
629
982
1 226
1 605
1 824
21 1 0
3029
652
1 1 56
1 548
2323
291 1
3406
4798
735
1 388
2072
3200
4005
4705
6432
733
1 543
2378
3782
4969
5932
781 9
19
23
26
30
33
37
42
0
1
2
3
4
5
6
40
51
58
67
76
86
99
360
1 98
1 55
127
115
97
97
5.0
6.9
8.5
.6
1 .9
3.7
5.2
5.8
7.7
9.3
1 1 .1
1 2.2
1 3.7
15.3
48.8
51 .6
60.8
77.5
88.9
97.9
1 21 .6
747
1 020
1 399
2042
2612
3224
451 1
1 966
1 970
1 973
1 977
1 980
1 984
1 989
1 966
1 970
1 973
1 977
1 980
1 984
1 989
1 966
1 970
1 973
1 977
1 980
1 984
1 989
1 966
1 970
1 973
1 977
1 980
1 984
1 989
19
23
26
30
33
37
42
19
23
26
30
33
37
42
19
23
26
30
33
37
42
19
23
26
30
1 966
1 970
1 973
1 977
1 980
1 984
1 989
33
Trees
cut
QMD
In
Basal
area
Ff
CVTS
Mortality
CV6
diD
Trees
dead
In
- Cubic feet -
1 35
65
43
25
18
0
5.9
7.6
9.7
1 1 .2
1 2.6
0
25.8
20.4'
21 .7
1 6.8
1 5.2
0
92
43
27
15
30
0
5.9
7.7
8.9
1 0.9
1 0.9
0
1 8.0
1 4. 1
1 1 .4
9.6
1 9.3
0
62
32
10
17
28
0
5.8
7.1
9.2
1 0.5
1 0.8
0
1 1 .2
8.4
4.6
1 0.5
1 7.8
0
13
12
0
7
23
0
4.0
4.6
0
4.3
1 2. 1
0
3.0
3.0
0
1 .8
1 3.4
0
b
450
458
41 8
528
472
458
0
450
325
298
292
277
601
0
450
208
1 81
1 20
31 1
573
0
450
57
65
0
51
435
0
1 48
33
27
10
17
0
6.3
8.0
9.3
10.7
1 1 .4
0
32.8
1 1 .5
1 2.3
6.2
1 1 .8
0
632
257
326
1 78
379
0
QMD
Cum Yield
Basal
area
CVTS
Ff
Fr
29
92
62
41
19
34
0
230
905
1 893
2594
3345
4246
4
31 3
1 032
2148
3058
4155
5537
10
347
1 1 88
2557
3706
5001
6705
13
306
1215
2694
3955
5367
7255
36
73
7
34
35
0
1 1 97
21 02
2738
3707
4454
5446
6733
1 1 97
2138
2847
3823
4604
5631
691 8
0
350
1 066
2131
2900
3902
5170
5.0
2.5
2.5
0
0
0
3.8
7.7
6.1
0
0
0
0.4
.8
.5
0
0
0
4
16
11
0
0
0
22
1 38
1 85
230
497
0
.92
.94
.86
.88
.85
1 1 .7
1 1 .7
5.0
1 .7
0
1 .7
3.8
6.6
8.3
8.7
0
1 0.4
.9
2.8
1 .9
.7
0
1 .0
13
55
47
18
0
33
.88
.90
.85
.96
.86
8.3
3.3
5.0
0
3.3
0
4.9
8.2
7.4
0
6.7
0
1 .1
1 .2
1 .5
0
.8
0
18
27
38
0
23
0
.99
.88
1 3.3
1 6.7
8.3
3.3
3.3
5.0
4.7
6.7
7.4
8.8
6.2
6.4
1 .6
4.1
2.5
1 .4
.7
1 .1
5.0
7.8
5.7
1 1 .3
1 1 .2
0
.5
1 .1
.1
.4
.3
0
6
24
0
19
338
0
122
118
224
1 41
327
0
0
0
.78
.90
0
.95
.95
.89
.88
.86
0
3.75
3.33
.42
.56
.42
0
- - - Cubic feet- - -
1 079
1 894
2571
3489
4181
4924
5843
1 1 02
1 944
2689
3802
4686
5782
7207
1 1 85
2064
2955
4241
5357
6653
8381
1 1 83
2078
3071
4536
5815
7233
9 1 53
0.92
.92
.94
.93
.90
0
6
60
78
258
466
0
Net
CV6
1 079
1 890
2551
3458
4150
4893
581 2
1 1 02
1 931
2621
3687
4553
5649
7040
1 1 85
2046
291 0
4158
5274
6547
8275
1 1 83
2050
2950
4354
5592
6990
8877
29
1 63
391
391
41 1
0
0
NE:lt G ross
CVTS CVTS
en
I\J
Table 9a-Average per acre stand statistics, by treatment, year, and age (continued)
Treatment
Year
Age
Period
H40
Trees
left
Ft
4
Decreasing:
6
8
Control:
C
a
QMD
all
QMD
crop
- - Inches - -
Mortality
Removed in thinning
After thinning
Basal
area
CVTS
Ff
Ft3
1 966
1 970
1 973
1 977
1 980
1 984
1 989
19
23
26
30
33
37
42
0
1
2
3
4
5
6
41
53
60
69
78
87
1 00
363
243
1 97
1 80
1 65
1 53
1 52
5,0
7.0
8.6
.5
1 .7
2.9
1 4.2
5.9
7.8
9.4
1 1 .2
1 2.4
1 3.7
1 5.0
49.7
63.5
77.7
1 05.4
1 20.8
1 37.1
1 64.8
778
1 286
1 786
2785
361 2
4568
6 1 80
1 966
1 970
1 973
1 977
1 980
1 984
1 989
1 966
1 970
1 973
1 977
1 980
1 984
1 989
19
23
26
30
33
37
42
19
23
26
30
33
37
42
0
1
2
3
4
5
6
0
1
2
3
4
5
6
37
48
56
67
75
84
97
40
51
60
69
79
86
99
360
307
252
203
1 72
1 28
1 28
352
313
275
257
225
1 87
1 85
4.8
6.6
8.0
9.7
1 0.9
1 2.5
1 3.9
5.1
6.9
8.3
9.8
1 0.9
1 2.1
1 3.3
5.7
7.6
9.0
1 0.8
1 2.0
1 3.3
1 5.0
5.9
8.0
9.6
1 1 .1
1 2. 1
1 3.2
1 4.6
45.4
71.9
87.2
1 03.3
1 1 1 .0
1 09.7
1 35.4
49.2
80.9
1 02.6
1 33.9
1 44.8
1 46.7
1 74.1
639
1315
1 851
2607
3172
3504
4930
772
1 578
2295
3454
41 82
4757
6501
1 966
1 970
1 973
1 977
1 980
1 984
1 989
19
23
26
30
33
37
42
0
1
2
3
4
5
6
37
49
57
68
77
86
98
1 272
1 31 0
1 293
1 230
1 1 28
1010
845
3.5
4.3
4.9
5.6
6.1
6.7
7.5
5.8
7.4
8.6
9.7
1 0.5
1 1 .2
1 2.2
86.3
1 34.4
1 71 .5
21 0.6
229.9
248.4
259.3
1 1 57
2426
3667
5289
6586
7973
9503
Plot in treatment 1 omitted because of root rot. b Estimated 450 cubic feet per acre removed in calibration is included in total yield. Trees
cut
QMD
Basal '
area CVTS
CV6
diD
Trees
dead
QMD
Cum Yield
Basal
area
CVTS
Ff
Ft3
- - - Cubic feet - - -
1 228
2178
2889
4046
5066
6343
7955
1 228
2196
2994
41 68
5230
6507
8127
4
387
1 1 90
2473
3534
481 5
6414
1 089
1 892
2696
3948
4938
6032
7457
1 222
2132
2941
4274
5329
6583
8326
1 089
1 91 7
2771
4049
5055
6 1 87
7612
1 222
2144
31 04
5534
6822
8581
0
238
1 021
2344
3376
4479
5895
6
439
1 337
2727
3827
5096
6808
1 1 57 1 1 57
2426 2439
3667 3715
5289 5438
6586 6895
7972 8505
9503 1 06 1 6
5
1 73
741
2022
3203
4634
6496
In
Ff
112
32
12
13
12
0
6.1
7.4
9.4
9.8
1 2.3
0
22.9
9.4
5.7
6.8
9.6
0
441
213
1 57
1 94
321
0
51
98
1 15
1 46
285
0
.91
.88
.91
.85
.95
0
2.08 4.7
5.00
7.0
1 .25
5.6
.56 1 0.0
0
0
.33
5.7
.3
1 .3
.2
.3
0
.1
18
87
17
26
0
8
37
43
43
30
42
0
6.0
7.3
9.2
9.6
1 0.5
0
7.0
1 0.1
1 2.3
1 6.1
23.1
0
1 27
269
496
425
762
0
13
86
333
309
614
0
.93
.93
.96
.89
.87
0
4.17 4.2
3.89
6.3
1 .25
6.4
.56
8.4
.42 1 1 .3
0
0
.4
.9
.3
.2
.3
0
25
50
26
17
37
0
32
17
17
25
35
0
6.1
6.9
8.6
1 0.0
1 0.7
0
5.8
4.3
7.0
1 1 .7
21 .6
0
1 04
92
1 74
327
679
0
21
34
1 98
222
556
0
.90
.85
.88
.94
.90
0
1 .67
7.22
.42
2.22
.83
.33
4.4
7.7
5.7
6.5
8.0
7.7
.2
2.3
.1
.5
.3
.1
12
151
7
36
33
16
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2.7
2.8
3.0
3.4
3.7
4.7
.9
2.0
4.9
7.1
9.0
1 9.0
14
35
1 00
1 60
1 087
581
0
0
0
0
0
0
0
•
In
Cubic feet ·
0
0
0
0
0
0
0
26.7
43.3
93.3
1 1 3.3
1 23.3
1 63.3
Net Gross
CVTS CVTS
4444
Net
CV6
Table 9b-Average per hectare stand statistics, by treatment, year, and age
Removed in thinning
After thinning
Treatment
Year
Age
Period
H40
Trees
left
m
QMD
all
QMD
crop
Centimeters
Basal
area
CVTS
2
m
3
m
Trees
cut
QMD
Basal
area
Cm
2
m
1 5.0
5.9
32.0
CVTS
la
3
5
7
Trees
dead
31 .5
QMD
Basal
area
CVTS
Cm
2
m
3
m
b
19
0
1 2.2
877
1 2.2
1 4.2
1 0.2
44
1 970
23
1
1 5.3
531
1 7.3
1 8.8
1 2.2
69
333
1 973
26
2
1 8.0
366
4.7
21 .0
252
1 4.6
86
112
1 9.3
3
23.1
28.2
. 1 61
30
21 .6
27.2
1 3.2
1 977
1 06
24.6
5.0
1 980
33
4
24.0
1 93
31 .2
31 .8
1 4.6
1 28
62
28.4
1 984
37
5
26.0
1 48
36.6
36.3
1 5.4
1 48
44
32.0
1 989
42
6
29.6
1 48
40.9
40.9
1 9.4
21 2
0
1 966
1 970
19
23
0
1
1 1 .4
1 5.0
860
613
1 2.7
1 7.3
1 5.0
1 9.8
1 0.6
1 4.2
46
1 973
1 977
26
30
2
3
1 7.2
20.6
477
400
21 .1
25.9
23.4
27.9
1 980
1 984
33
4
31 .2
204
5
358
284
29.0
37
23.0
25.7
1 6.5
20.8
23.4
33.3
34.5
24.4
238
1 989
1 966
42
19
6
0
29.8
1 1 .7
279
857
37.1
1 3.0
38.4
1 5.5
30.1
1 1 .2
336
51
0
1 970
23
1
1 5.3
684
1 7.5
20.3
1 6.4
97
1 53
1 4.7
2.6
1 4.6
.4
.88
20
1 2.4
.2
1 973
1 977
26
30
2
1 8. 1
21 .2
598
q61
21 .3
25.1
24.1
28.4
21 .0
27.7
1 45
224
79
3
1 8.0
23.4
1 .9
1 .1
1 2.7
8.4
4.2
5.5
.90
.85
8
12
20.8
1 8.8
1 980
1 984
33
4
· 23.9
2.4
4.1
1 8 .0
0
40.1
32.6
.96
.86
0
32.5
26.7
27.4
21 .8
30.7
280
329
42
26.8
31 .2
34.3
31 .0
5
519
440
27.7
37
8
1 7.0
1 989
42
6
31 .1
440
0
889
0
31 .5
0
1 1 .7
450
51
0
0
38.9
1 1 .3
0
19
37.6
1 4.5
0
1 966
33.8
1 2.7
1 970
23
1
1 5.0
822
1 7.0
1 9.0
1 8.5
1 08
32
1 0.2
1 973
1 977
26
2
1 7.9
21 .3
20.3
23.9
22.6
26.7
24.3
32.7
1 66
265
1 1 .7
3
753
734
30
30
1 980
33
4
23.9
709
26.2
29.2
38.0
348
17
1 0.9
.4
3.6
1 .3
1 984
37
5
26.8
642
28.4
32.0
41 .1
415
57
30.7
3.1
30.4
23.6
1 989
42
6
30.7
630
31 .0
34.8
47.7
547
0
0
0
0
1 966
19
0
1 2.2
889
1 2.7
1 4.7
1 1 .2
52
1 970
23
1
1 5.5
489
1 7.5
1 9.6
1 1 .8
71
366
1 6.0
7.5
8.5
0.95
9.3
0
75
75
0
12
9.6
0.1
0.3
1 32
1 32
16
29.2
1 1 .4
.92
6
.94
6
1 .1
.8
1 78
27.4
1 9.6
1 5.5
.2
36.9
242
1 80
244
1 32
3.9
33.0
27.4
.93
0
0
0
293
1 82
32.0
28.8
.90
0
0
0
0
0
290
3.5
342
234
0
0
0
0
0
0
407
344
409
77
0
0
227
1 5.0
4.1
1 08
1 06
67
1 9.6
22.6
3.2
2.6
20.8
20.4
37
74
27.7
2.2
1 9.4
1 6.1
27.7
4.4
42.0
34.8
0
0
31 .5
0
25
69
0
0
0
0
- - Cubic meters - -
0.92
81
0
Net
CV6
2.0
31 .5
22.7
1 62
Net Gross
CVTS CVTS
1 88
266
72
1 50
.0
31 9
395
328
405
214
291
2.3
493
504
387
83
83
1 .3
1 43
1 44
1
24
.3
.3
1 .9
2.7
204
291
207
297
83
1 79
0
1 .6
369
458
375
466
259
.2
0
579
586
469
83
83
1
2.0
1 43
1 45
21
.2
9.7
1 2.9
.94
29
12
1 6.8
21 .1
.6
3.8
.86
.4
3.3
4
22.1
.0
.2
1 .3
0
.0
4
26.4
.2
0
.4
.7
4.5
0
1 .7
0
44.2
1 83
258
9.6
4.0
0
0
22
29
0
297
1 36
.92
.88
.85
63
77
1 35
1 .5
.7
0
.1
0
0
.9
350
.99
33
1 1 .9
.88
41
20
1 7.0
.9
6.4
206
21 5
1 8.8
.6
4.3
305
317
1 85
1 88
.78
8
22.4
.3
2.9
391
407
277
.90
8
1 5.7
.2
1 .3
489
506
376
12
1 6.3
.2
2.4
621
640
508
84
84
0
1 2.7
0.1 .
2.5
1 47
1 50
24
.2
5.1
1 92
1 99
75
.1
259
268
1 49
203
0
.4
1 973
26
2
1 7.6
383
21 .6
23.6
1 4.0
98
82
20.3
2.6
1 8 .0
8.2
.95
8.2
1 9.8
1 977
30
3
20.5
314
26.9
28.2
1 7.8
1 43
67
23.6
2.8
22.8
1 5.7
.89
1 .0
1 4.5
1 980
33
4
23.1
284
30.2
31 .0
20.4
1 83
25
27.2
1 .4
1 2.4
9.9
.88
1 .4
28.7
.1
2.4
312
322
1 984
37
42
5
26.1
240
34.8
34.8
22.5
226
42
29.0
2.7
26.5
22.9
1 .0
28.4
.1
2.4
381
394
273
6
30.3
240
38.6
38.9
27.9
31 6
0
0
0
86
.00
0
471
484
362
1 989
01
t.:I
diD
1 966
Increasing:
2
CV6
Cubic meters
Fixed:
Cum Yield
Mortality
0
0
0
0
0
0
C.l1
Table 9b-Average per hectare stand statistics, by treatment, year, and age (continued)
Removed in thinning After thinning
Treatment
Year
Age
Period
H40
Trees
left
m
Basal
area
CVTS
Centimeters
2
m
3
m
QMD
all
QMD
crop
Trees
cut
QMD
Basal
area
2
CVTS
Cum Yield
Mortality
CV6
Cm
m
1 5.5
5.3
30.9
3.6
diD
Trees
dead
Cubic meters QMD
Basal
area
CVTS
Cm
2
m
3
m
1 1 .9
0.1
1 .3
Net G ross
CVTS CVTS
Net
CV6
- - Cubic meters - -
Fixed:
4
Decreasing:
6
1 966
19
0
1 2.4
897
1 2.7
1 5.0
1 1 .4
54
1 970
23
1
1 6.1
600
1 7.8
1 9.8
1 4.6 ·
90
277
1 973
26
2
1 8.2
487
21 .8
23.9
1 7.8
1 25
79
1 8.8
2.2
1 4.9
1 977
30
3
20.9
445
26.7
28.4
24.2
1 95
30
23.9
1 .3
1 1 .0
24.9
31 .2
1 .6
2.2
0
0
0
8.9
Control:
C
a
b
1 2.4
1 7.8
.3
6.1
202
209
83
.91
3.1
1 4.2
.1
1 .2
283
292
1 73
1 3.6
1 0.2
.85
1 .4
25.4
.1
22.5
1 9.9
.95
0
0
0
1 .8
0
354
444
366
455
247
337
.8
1 4.5
0
.6
557
569
449
76
76
0
4.2
9.6
1 0.7
1 6.0
.1
.2
1 .7
3.5
1 32
6.0
.93
.93
1 89
1 34
1 94
17
71
23.3
.96
1 6.3
21 .6
.89
3.1
1 .4
.1
.1
1 .8
1 .2
276
346
283
354
236
.1
2.6
422
0
522
433
533
31 3
41 2
4
5
23.6
408
29.7
31 .5
32
26.6
378
32.8
34.8
27.7
31 .5
253
37
320
30
1 989
42
6
30.4
375
36.1
38.1
37.8
432
0
1 966
19
0
1 1 .2
889
1 2.2
1 4.5
1 0.4
45
1 970
1 973
23
26
1
2
1 4.5
1 6.8
20.3
1 9.3
22.9
1 6.5
20.0
92
1 30
91
1 06
1 5.2
1 7.0
758
622
1 8.5
1 .6
2.3
1 8.8
1 977
1 980
30
3
4
20.5
22.9
501
425
24.6
27.7
27.4
30.5
23.7
25.5
1 82
222
1 06
74
23.4
24.4
2.8
3.7
34.7
29.7
37
42
5
25.5
29.5
31 6
316
31 .8
35.3
33.8
38.1
25.2
31 . 1
245
345
1 04
0
26.7
0
5.3
6
53.3
0
43.0
0
79
42
1 5.5
1 .3
7.3
1 7.5
1 .0
6.4
1 .5
2.4
.90
.85
1 7.8
1 9.6
21 .8
1 .6
1 2.2
1 3.8
.88
1 .0
1 4.5
1 989
8
.88
8.0
33
1 984
1 966
19
0
1 2.3
869
1 3.0
1 5.0
1 1 .3
54
1 970
1 973
23
1
2
1 5.6
773
679
1 7.5
20.3
1 8.6
110
1 977
30
21 .0
26
1 8.3
21 . 1
24.4
23.6
161
24.9
28.2
30.7
42
0
0
27
6.9
1 980
33
86
1 54
5.1
1 984
0
86
1 52
0.91
0
.2
.87
0
21 .3
1 .0
0
28.7
0
0
4.1
1 1 .2
0
1 64
86
86
0
.8
1 49
31
.5
1 0.6
206
1 50
21 7
299
94
1 91
1 980
33
3
4
24.1
635
556
27.7
30.7
33.1
242
292
62
25.4
2.7
22.9
1 5.5
.94
5.5
1 6.5
.1
.5
2.5
373
31 1
387
1 984
37
5
26.2
462
30.7
33.5
33.7
333
86
27.2
5.0
47.5
38.9
.90
2.0
20.3
.1
2.3
461
477
357
1 989
42
6
30.2
457
33.8
37.1
40.0
455
0
0
0
0
0
0
.8
1 9.6
1 .1
583
600
476
1 966
19
0
1 1 .2
1 4.7
1 9.8
81
0
0
0
0
0
0
81
23
1
1 4.8
31 42
4298
8.9
1 970
1 0.9
1 8.8
30.8
1 70
0
0
0
0
0
0
65.9
6.8
.2
1 .0
1 70
81
1 71
0
12
1 973
1 977
26
2
1 7.4
4242
1 2.4
21 .8
39.4
257
0
0
0
0
1 4.2
24.6
48.3
370
0
0
0
0
0
1 .1
2.4
7.0
260
4035
7.1
7.6
257
20.6
1 07.0
230.4
.5
3
0
0
0
30
370
381
52
1 41
0
0
268
1 980
33
4
23.3
3701
1 5.5
26.7
52.8
461
0
0
0
0
0
0
279.8
8.6
1 .6
1 1 .2
461
482
224
1 984
37
5
26.2
3314
1 7.0
28.4
57.0
558
0
0
0
0
0
0
304.6
9.4
2.1
76.1
558
595
324
1 989
42
6
29.9
2772
1 9.0
31 .0
59.5
665
0
0
0
0
0
0
403.4
1 1 .9
4.4
40.6
665
743
454
Plot 51 in treatment 1 omitted because of root rot. Estimated 31 .5 cubic meters per hectare (CVTS) removed in calibration is included in total yield. Table 1 0a-Merchantable cubic volume (CV6) per acre by treatment, plot, period, year and age
Period 1
Calibration
Treatment
Fix'bd :
1
3
5
7
Plot
4
8
Unthinned:
C
a
b
en
en
After cut
1 970
(23)
Before cut
1 973
(26)
After cut
1 973
(26)
Before cut
1 977
(30)
After cut
1 977
(30)
21
33
51
31
42
52
12
41
72
11
23
63
0
0
0
0
12
0
18
12
0
26
13
0
248
21 1
206
204
420
316
352
456
233
445
302
1 71
229
1 72
1 80
204
374
297
352
440
233
445
284
1 71
898
854
718
908
1 1 97
925
1 282
1 334
932
1 520
1 09 1
1 01 6
751
676
670
796
970
851
1 2$2
1 230
905
1 448
1 091
1 01 6
1 725
1 679
1 429
1 908
21 1 5
1 945
2701
2685
2088
2985
2604
2403
1314
1 308
1 1 04
1 71 5
2005
1 694
2586
2564
2088
2985
2604
2403
82
91
1 01
13
62
111
0
0
0
0
0
13
369
1 63
518
668
1 22
372
217
1 19
349
552
1 22
335
1 027
770
1 036
1 31 6
920
1 1 83
883
702
893
1 209
852
1 062
1 967
1 772
1 935
2392
21 68
241 2
15
43
81
14
53
73
0
0
0
0
0
18
290
239
1 86
615
319
382
273
21 7
1 86
551
319
382
1 1 96
829
999
1 565
1 033
1 350
1 044
829
893
1 463
1 033
1 350
22
25
71
0
0
16
1 53
246
1 20
1 53
246
1 20
734
807
683
734
807
683
Decreasing:
6
Before cut
1 970
(23)
Period 3
Before cut
1 980
(33)
Period 4
After cut
1 980
(33)
Before cut
1 984
(37)
Period 5
After cut
1 984
(37)
1 989
(42)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Cubic feet - - - - - - - - - - - - - - - - - - - - - - - :- - - - - - - - - -
Increasing:
2
After cut
1 966
( 1 9) a
Period 2
Stand age in parentheses. Plot 51 abandoned 1 989 because of severe root rot. 1 986
2036
1 462
2706
2944
2493
3798
3776
31 1 1
4331
3806
3577
1 634
1 607
1 41 1
2369
2590
2493
3453
3446
301 2
4273
3806
3577
2424
2320
2021
3491
3624
3629
471 8
4757
4320
5734
5 1 57
5062
1 953
1 968
1 851
3 1 33
3 1 48
2973
421 1
4209
3976
5221
4783
4934
281 3
291 0
2698
4584
4574
4243
591 5
5981
561 4
7093
6690
6821
1 762
1 443
1 797
2344
1 979
2304
2524
2191
2593
3307
3064
3439
2333
2191
2359
3260
2822
3291
3360
3270
3259
441 9
4071
4726
3081
2889
2938
4075
3900
4387
4422
41 63
4127
5606
5562
5989
2291
2275
2 1 68
2898
2248
2870
1 973
1 829
1 933
2769
2075
2845
291 4
2827
3091
3897
3126
3967
2588
2559
2760
3582
3039
3703
361 9
3698
3899
4976
4257
4895
3086
3091
3 1 97
4370
3738
4351
4480
4539
4600
6 1 72
5374
6050
2241
2038
1 787
2241
2038
1 787
3564
3132
291 3
3564
3132
291 3
4955
4655
4293
4955
4655
4293
6839
6657
5992
,
c.n
0)
Table 1 0b-Merchantable cubic volume (CV6) per hectare by treatment, plot, period, year and age
Period 1
Calibration
Treatment
Plot
After cut
1 966
(1 9)a
Before cut
1 970
(23)
After cut
1 970
(23)
Period 2
Before cut
1 973
(26)
After cut
1 973
(26)
Period 3
Before cut
1 977
(30)
After cut
1 977
(30)
Before cut
1 980
(33)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Cubic feet - - - -
Fixed:
1
b
3
5
7
Increasing:
2
4
8
Unthinned: C
a
b
-
--
-
--
After cut
1 980
(33)
-
Period 5
Before cut
1 984
(37)
-------
After cut
1 984
(37)
- - - - -
------
1 989
(42)
- - - -
21
33
51
31
42
52
12
41
72
11
23
63
0
0
0
0
1
0
1
1
0
2
1
0
17
15
14
14
29
22
25
32
16
31
21
12
16
12
13
14
26
21
25
31
16
31
20
12
63
60
50
64
84
65
90
93
65
1 06
76
71
53
47
47
56
68
60
86
86
63
1 01
76
71
1 21
1 17
1 00
1 34
1 48
1 36
1 89
1 88
1 46
209
1 82
1 68
92
91
77
1 20
1 40
119
1 81
1 79
1 46
209
1 82
1 68
1 39
1 42
1 02
1 89
206
1 74
266
264
218
303
266
250
1 14
1 12
99
1 66
1 81
1 74
242
241
21 1
299
266
250
1 70
1 62
1 41
244
254
254
330 333
302
401
361
354
1 37
1 38
1 30
21 9
220
208
295
295
278
365
335
345
1 97
204
1 89
321
320
297
414
41 9
393
496
468
477
82
91
1 01
13
62
111
0
0
0
0
0
1
26
11
36
47
9
26
15
8
24
39
9
23
72
54
73
92
64
83
62
49
63
85
60
74
1 38
1 24
1 35
1 67
1 52
1 69
1 23
1 01
1 26
1 64
1 38
1 61
1 77
1 53
1 81
231
214
241
1 63
1 53
1 65
228
1 97
230
235
229
228
309
285
331
21 6
202
206
285
273
307
309
291
289
392
389
41 9
15
43
81
14
53
73
0
0
0
0
0
1
20
17
13
43
22
27
19
15
13
39
22
27
84
58
70
1 09
72
94
73
58
62
1 02
72
94
1 60
1 59
1 52
203
1 57
201
1 38
1 28
1 35
1 94
1 45
1 99
204
1 98
216
273
219
278
1 81
1 79
1 93
251
21 3
259
253
259
273
348
298
343
216
216
224
306
262
304
313
318
322
432
376
423
22
25
71
0
11
17
8
11
17
8
51
56
48
51
56
48
1 57
1 43
1 25
1 57
1 43
1 25
249
219
204
249
219
204
347
326
300
347 326
300
479
466
41 9
Decreasing:
6
Period 4
0
1
Stand age in parentheses.
Plot 51 abandoned 1989 because of severe root rot.
Table 1 1 a-Periodic annual increment in net basal area per acre, by treatment
and period
Treatment
Fixed:
18
3
5
7
Increasing:
2
4
Decreasing:
6
8
Unthinned:
C
a
Calibration;
midperiod
age 21 .0
Period 1 ;
midperiod
age 24.5
Period 2;
midperiod
age 28.0
Period 3;
midperiod
age 31 .5
Period 4;
midperiod
age 35.0
Period 5;
midperiod
age 39.5
Square feet
8.6
8.4
8.5
8.6
8.3
8.0
9.5
9.4
6.9
7.5
8.5
9.2
5.7
6.9
8.2
8.2
4.6
6.0
6.2
6.8
3.5
4.9
5.6
5.7
8.9
9.2
6.9
7.9
7.3
8.4
5.9
7.4
5.2
6.5
4.7
5.5
8.4
9.4
9.4
8.7
9.0
9.6
7.6
7.5
5.9
5.9
5. 1
5.5
1 0.7
1 1 .2
9.2
7.4
5.2
3.3
Plot 51 omitted from treatment 1 rneans because of root rot.
Table 1 1 b-Periodic annual increment in net basal area per hectare, by
treatment and period
Treatment
Fixed:
18
3
5
7
Increasing:
2
4
Decreasing:
6
8
Unthinned:
C
a
Calibration;
midperiod
age 21 .0
Period 1 ;
midperiod
age 24.5
Period 2;
midperiod
age 28.0
Period 3;
midperiod
age 31 .5
Period 4;
midperiod
age 35.0
Period 5;
midperiod
age 39.5
Square meters
1 .97
1 .93
1 .95
1 .98 .
1 .90
1 .85
2.17
2. 1 6
1 .59
1 .73
1 .95
2. 1 0
1 .31
1 .59
1 .89
1 .89
1 .05
1 .37
1 .41
1 .56
0.80
1 .13
1 .28
1 .32
2.05
2.1 1
1 .58
1 .80
1 .67
1 .92
1 .34
1 .70
1 .20
1 .49
1 .09
1 .27
1 .93
2. 1 5
2. 1 6
1 .99
2.06
2.20
1 .73
1 .73
1 .36
1 .36
1.18
1 .26
2.46
2.58
2. 1 0
1 .70
1 .20
0.75
Plot 51 omitted from treatment 1 means because of root rot.
57 Table 1 2a-Periodic annual net increment in quadratic mean diameter of all
trees and of survivors (control only, in parentheses), by treatment and period
Treatment
Calibration;
midperiod
age 2 1 . 0
Period 2;
midperiod
age 28.0
Period 3;
midperiod
age 3 1 . 5
Period 4;
midperiod
age 35.0
Period 5;
midperiod
age 39.5
Inches
Fixed:
1a
3
5
7
Increasing:
2
4
Decreasing:
6
8
Unthinned:
C
a
Period 1 ;
midperiod
age 24.5
0.41
.41
.40
.41
0.49
.47
.43
.43
0.48
.43
.38
.35
0.45
.39
.32
.28
0.42
.32
.26
.22
0.36
.31
.23
.20
.42
.42
.49
.48
.47
.45
.41
.37
.36
.30
.31
.26
.42
.43
.44
.44
.40
.36
.35
.31
.29
.24
.28
.23
.21
b
(.21 )
.20
(.20)
.17
( . 1 5)
.17
( . 1 2)
.15
(. 1 0)
.16
(.09)
Plot 51 omitted from treatment 1 means because of root rot.
b Survivor growth.
Table 1 2b-Periodic annual net increment in quadratic mean diameter of all
trees and of survivors (control only, in parentheses), by treatment and period
Treatment
Calibration;
midperiod
age 21 .0
Fixed:
1a
3
5
7
Increasing:
2
4
Decreasing:
6
8
Unthinned:
C
a
Period 2;
midperiod
age 28.0
Period 3;
midperiod
age 3 1 . 5
Period 4;
midperiod
age 35.0
Period 5;
midperiod
age 39.5
Centimeters
1 .04
1 .04
1 .02
1 .04
1 .24
1 .1 9
1 .09
1 .09
1 .22
1 .09
.96
.89
1 .14
.99
.81
.71
1 .07
.82
.66
.56
0.91
.79
.58
.51
1 .07
1 .07
1 .24
1 .22
1 .1 9
1 .14
1 .04
.94
.91
.76
.79
.66
1 .07
1 .09
1.12
1 .12
1 .02
.91
.89
.79
.74
.61
.71
.58
.53
b
(.53)
.51
(.51 )
.43
(.38)
.43
( .30)
. . 38
(.25)
.41
(.23)
Plot 51 omitted from treatment 1 means because of root rot.
b Survivor growth.
58
Period 1 ;
midperiod
age 24.5
Table 1 3a-Periodic annual increment in net total cubic volume (CVTS) and
merchantable volume (CV6) per acre, by treatment and period
Treatment
Calibration;
midperiod
age 21 .0
Period 1 ;
midperiod
age 24.5
Period 2;
midperiod
age 28.0
Period 3;
midperiod
age 31 .5
Period 4;
midperiod
age 35.0
Period 5;
midperiod
age 39.5
Cubic feet
Fixed:
1 a eVTS
eV6
3
eVTS
eV6
5
eVTS
eV6
7
eVTS
eV6
Increasing:
2
eVTS
eV6
eVTS
4
eV6
Decreasing:
6
eVTS
eV6
eVTS
8
eV6
Unthinned:
e eVTS
eV6
a
203
57
207
77
217
84
217
73
220
225
230
239
288
280
300
303
227
247
267
279
312
342
351
370
231
234
289
303
372
383
412
414
1 86
1 88
274
274
318
324
350
358
1 84
1 80
278
276
346
341
377
378
226
88
237
96
212
239
237
268
242
266
289
321
249
256
340
354
248
251
319
320
257
254
322
320
201
60
229
1 08
268
261
270
300
313
331
333
347
330
344
352
367
274
276
314
317
285
283
349
342
317
42
41 4
41 9
406
320
432
394
347
358
332
372
Plot 51 omitted from treatment 1 means because of root rot.
59
Table 1 3b-Periodic annual increment in net total cubic volume (CVTS) and
merchantable volume (CV6) per hectare, by treatment and period
Treatment
Calibration;
midperiod
age 21 .0
Period 1 ;
midperiod
age 24.5
Period 2;
midperiod
age 28.0
Period 3;
midperiod
age 3 1 . 5
Period 4;
mid period
age 35.0
Period 5;
midperiod
age 39.5
Cubic meters
Fixed:
1 a CVTS
CV6
CVTS
3
CV6
5
CVTS
CV6
CVTS
CV6
Increasing:
CVTS
2
CV6
CVTS
4
CV6
Decreasing:
6
CVTS
CV6
8
CVTS
CV6
Unthinned:
C CVTS
CV6
a
60
1 4.2
4.0
1 4. 5
5.4
1 5.2
5.9
1 5.2
5.1
1 5.4
1 5.7
1 6. 1
1 6.7
20.2
1 9.6
21 .0
21 .2
1 5.9
1 7.3
1 8.7
1 9.5
21 .8
23.9
24.6
25.9
1 6.2
1 6.4
20.2
21 ..2
26.0
26.8
· 28.8
29.0
1 3.0
1 3.2
1 9.2
1 9.2
22.2
22.7
24.5
25.0
1 2.9
1 2.6
1 9.4
1 9.3
24.2
23.9
26.4
26.4
1 5.8
6.2
1 6.6
6.7
1 4.8
1 6.7
1 6.6
1 8.8
1 6.9
1 8. 6
20.2
22.5
1 7.4
1 7. 9
23.8
24.8
1 7.4
1 7.6
22.3
22.4
1 8.0
1 7.8
22.5
22.4
1 4. 1
4.2
1 6.0
7.6
1 8.8
1 8.3
1 8.9
21 .0
21 .9
23.2
23.3
24.3
23. 1
24.1
24.6
25.7
1 9.2
1 9.3
22.0
22.2
1 9.9
1 9.8
24.4
23.9
22.2
2.9
29.0
29.3
28.4
22.4
30.2
27.6
24.3
25.0
23.2
26.0
Plot 51 omitted from treatment 1 means because of root rot.
Table 1 4a-Periodic annual mortality in number of trees and in basal area, per
acre, by treatment and period
. Treatment
Calibration;
midperiod
age 2 1 . 0
Period 1 ;
midperiod
age 24.5
Period 2;
midperiod
age 28.0
Period 3;
midperiod
age 31 .5
Period 4;
midperiod
age 35.0
Period 5;
midperiod
age 39.5
Number per a cre
Fixed:
18
3
5
7
Increasing:
2
4
Decreasing:
6
8
Control:
C
Fixed:
18
3
5
7
Increasing:
2
4
Decreasing:
6
8
Control:
C
a
1 .25
2.08
2.08
3.33
0.84
3.89
.1 1
5.56
0.63
1 .25
1 .25
2.08
0
.56
0
1.11
0
0
.83
.83
0*
.33
0
1 .00
3.75
2.08
3.33
5.00
.42
1 .25
.56
.56
.42
0
0
.33
4. 1 7
1 .67
3.89
7.22
1 .25
.42
.56
2.22
.42
.83
0
.33
6.67
1 4.44
23.33
37.78
24. 1 7
32.67
Basal area, square feet per acre
.09
.22
.27
.18
.25
.92
.41
.30
.13
.47
.38
.54
0
.23
0
.1 1
0
0
.21
.10
.20
0
.09
.51
.27
1 .07
1 .30
.07
.20
.39
.30
.28
0
0
.06
.41
.18
.87
2.34
.29
.07
.21
.51
.29
.29
0
.1 1
.23
.67
1 .22
2.38
1 .75
3.81
0
Plot 51 in treatment 1 excluded because of root rot.
61
Table 1 4b-Periodic annual mortality in number of trees and in basal area, per
hectare, by treatment and period
Treatment
Calibration;
midperiod
age 21 .0
Period 1 ;
midperiod
age 24.5
Period 2;
midperiod
age 28.0
Period 3;
midperiod
age 31 .5
Period 4;
midperiod
age 35.0
Period 5;
midperiod
age 39.5
Number per hectare
Fixed:
1a
3
5
7
Increasing
2
4
Decreasing
6
8
Control
C
3. 1 0
5. 1 0
5. 1 0
8.20
2.10
9.60
.30
1 3.70
1 .60
3. 1 0
3. 1 0
5. 1 0
0
1 .40
0
2.70
0
.00
2.00
2.00
0
.80
0
2.50
9.30
5. 1 0
8.20
1 2.40
1 .00
3. 1 0
1 .40
1 .40
1 .00
0
0
.80
1 0.30
4. 1 0
9.60
1 7.80
3. 1 0
1 .00
1 .40
5.50
1 .00
2.00
0
.80
1 6.50
35.70
57.60
93.30
59.70
80.70
Basal area, square meters
Fixed:
1a
3
5
7
Increasing
2
4
Decreasing
6
8
Control
C
a
62
.02
.05
.06
.04
.06
.21
.09
.07
.03
.11
.09
.12
0
.05
.00
.02
0
0
.05
.02
0
.05
0
. 02
.12
.06
.25
.30
.02
.06
. 09
.07
.06
0
0
.01
.09
.04
.20
.54
.07
.02
.05
.12
.07
.07
0
.02
.05
.15
.28
.55
.40
.87
Plot 51 in treatment 1 excluded because of root rot.
Table 1 5a-Periodic annual mortality in total cubic volume (CVTS) per acre, by
treatment and period
Treatment
Fixed:
a
1
3
5
7
Increasing
2
4
Decreasing
6
8
Control
C
a
Calibration;
midperiod
age 2 1 . 0
Period 1 ;
midperiod
age 24.5
Period 2;
midperiod
age 28.0
Period 3;
midperiod
age 3 1 .5
Period 4;
midperiod
age 35.0
Period 5;
midperiod
age 39.5
Cubic feet p er acre
1 .1
3.3
4.5
7.2
5.4
1 8.3
9.0
30.6
2.8
1 1 .7
9.5
1 5.4
0
6.1
0
1 3.8
0
.0
5.8
4.8
0
6.7
0
6.7
9.1
4.5
24.3
29.0
1 .7
4.2
1 1 .3
8.5
8.8
0
0
1 .6
6.3
3.0
1 6.6
50.4
6.5
1 .6
5.6
1 2.0
9.3
8.2
0
3.2
3.4
1 1 .6
25.0
53.2
56.0
1 1 6. 1
Plot 5 1 I n treatment 1 excluded because of root rot. CV6 mortality has been negligible . .
Table 1 5b-Periodic annual mortality i n total cubic volume (CVTS) per hectare,
by treatment and period
Treatment
Fixed:
a
1
3
5
7
Increasing:
2
4
Decreasing:
6
8
Control:
C
a
Calibration;
midperiod
age 21 .0
Period 1 ;
midperiod
age 24.5
Period 2;
midperiod
age 28.0
Period 3;
midperiod
age 31 .5
Period 4;
midperiod
age 35.0
Period 5;
midperiod
age 39.5
Cubic meters
0.07
.23
.31
.50
0.38
1 .28
.63
2.14
0.20
.82
.66
1 .08
0
.64
.31
1 .70
2.03
.12
.29
.79
.59
.44
.21
1 .16
3.53
.45
.1 1
.24
.81
1 .75
.42
0
0
0
.40
.34
0
.62
0
.39
.84
.65
.57
0
3.72
3.92
0
.96
0
.47
.47
.11
.22
8. 1 2
Plot 5 1 I n treatment 1 excluded because of root rot. CV6 mortality has been negligible.
63
Table 1 6-Net basal area (BA) growth percent, net cubic volume (CVTS) growth
percent, and net merchantable volume (CV6) groWth percent (based on
midperiod values), by treatment and period
Period
Treatment
Unit
TP-1
Calibration
1 970-73
1 966-70
age 2 1 .0 age 24.5
TP-2
1 973-77
age 28.0
TP-3
1 977-80
age 3 1 .5
TP-4
1 980-84
age 35.0
TP-5
1 984-89
age 39.5
- - - - - - - - - - - - - - - Percent - - - - - - - - - - - - - -
Fixed:
18
3
5
7
Increasing:
2
4
Decreasing:
6
8
Unthinned:
C
a
64
-
SA
CVTS
CV6
SA
CVTS
CV6
SA
CVTS
CV6
SA
CVTS
CV6
1 3. 9
1 9.6
50.0
1 3.3
1 9.4
49. 1
1 3.0
1 8.5
47.6
1 3.0
1 8.6
46.8
1 2.6
1 6.8
41 .9
1 0.9
1 5.3
37. 1
1 1 .1
1 5.8
37.2
9.9
1 5.0
41 .0
9.7
1 3.5
20.5
8.7
1 2.8
1 9.6
7.8
1 1 .5
1 9.0
7.4
1 1 .4
1 9.4
7.9
1 1 .8
1 4. 1
6.8
1 0.4
1 3.4
6.2
9.9
1 2.8
5.3
9.3
1 2.6
6.3
8.5
9.4
5.2
7.9
9.1
4.2
6.9
8.2
3.8
6.2
7.8
4.6
7.1
7.3
4. 1
6.8
7.3
3.6
6.2
6.8
3.0
5.5
6.4
SA
CVTS
CV6
SA
CVTS
CV6
1 3.4
1 8.9
50.0
1 3.5
1 9.0
48.9
1 1 .0
1 5.8
41 .8
1 0.4
1 4.5
38.5
9.7
1 2.9
1 9.7
8.9
1 2.2
1 9.2
6.8
1 0.3
1 2.6
6.4
1 0. 1
1 3.0
5.2
8.0
9.0
4.8
7.5
8.5
4.3
6.7
7.0
3.7
6.0
6.5
SA
CVTS
CV6
SA
CVTS
CV6
1 3.5
1 9.3
49. 1
1 3.8
1 8.6
48.5
1 0.9
1 5.5
40.9
9.2
1 3.5
34.8
8.5
1 2.6
1 9.4
7.9
1 1 .2
1 7.7 .
6.6
1 0.6
1 3.6
5.2
8.6
1 1 .9
4.8
7.4
8.4
3.8
6.5
7.8
4.2
6.8
7.3
3.4
6.2
6.9
SA
CVTS
CV6
1 1 .0
1 7.8
46. 1
8.1
1 3.6
42.0
5.1
9.0
23. 1
2.9
7.3
1 5. 1
1 .9
4.8
9.2
.9
3.5
6.7
Treatment 1 mean omits plot 5 1 , because of root rot.
Table 1 7a-Net mean annual increment in total cubic feet (CVTS) and
merchantable cubic feet (CV6) per acre, by treatment, year, and age
Treatment
Fixed:
1c
3
5
7
Increasing:
2
4
Decreasing:
6
8
Control:
C
Unit
1 966
a
(1 9)
1 970
(23)
1 973
(26)
1 977
(30)
1 980
(33)
- - - - - - - - - Cubic feet p er acre per yea
1 984
(37)
f--
-
-
1 989
(42)
-
-
- - -
eVTS
eV6
eVTS
eV6
eVTS
eV6
eVTS
eV6
57
0
58
0
62
0
62
9
82
10
84
14
89
15
89
20
98
35
1 01
40
112
46
1 14
52
1 15
63
1 23
72
1 39
85
1 45
95
1 26
79
1 38
93
1 60
112
1 69
1 24
1 32
90
1 53
112
1 77
1 35
1 89
1 49
1 38
1 01
1 68
1 32
1 97
1 60
21 1
1 76
eVTS
eV6
eVTS
eV6
63
0
65
0
91
15
95
17
1 05
41
111
46
1 24
71
1 35
82
1 35
88
1 54
1 07
1 47
1 06
1 71
1 30
1 60
1 23
1 89
1 53
CVTS
eV6
eVTS
CV6
57
0
64
0
82
10
93
19
1 04
39
1 13
51
1 32
78
1 42
91
1 50
1 02
1 61
1 16
1 63
121
1 78
1 38
1 78
1 40
1 98
1 62
CVTS
CV6
61
1 05
8
141
28
1 76
67
200
97
215
1 25
226
1 55
0
a
Stand age in parentheses. Estimated cut of 450 cubic feet per acre has been included in totals for CVTS. c Plot 51 in treatment 1 excluded because of root rot. b
65
Table 1 7b-Net mean annual increment in total cubic volume (CVTS) and
merchantable cubic volume (CV6) per hectare, by treatment, year, and age
Treatment
Unit
1 966
a
(1 9)
1 970
(23)
1 973
(26)
1 977
(30)
1 980
(33)
- - - - - - - - - - - - - Cubic metersb -
Fixed:
1c
3
5
7
Increasing:
2
4
Decreasing:
6
8
Control:
e
a
b
c
66
-
--
1 989
(42)
1 984
(37)
- -
--
-
---
-
eVTS
eV6
eVTS
eV6
eVTS
eV6
eVTS
eV6
4.0
0
4.1
0
4.3
0
4.3
.6
5.7
.7
5.9
1 .0
6.2
1 .0
6.2
1 .4
6.9
2.4
7.1
2.8
7.8
3.2
8.0
3.6
8.0
4.4
8.6
5.0
9.7
5.9
1 0. 1
6.6
8.8
5.5
9.7
6.5
1 1 .2
7.8
1 1 .8
8.7
9.2
6.3
1 0.7
7.8
1 2.4
9.4
1 3.2
1 0.4
9.7
7. 1
1 1 .8
9.2
1 3.8
1 1 .2
1 4.8
1 2.3
eVTS
eV6
eVTS
eV6
4.4
0
4.5
0
6.4
1 .0
6.6
1 .2
7.3
2.9
7.8
3.2
8.7
5.0
9.4
5.7
9.4
6.2
1 0.8
7.5
1 0.3
7.4
1 2.0
9.1
1 1 .2
8.6
1 3.2
1 0.7
eVTS
eV6
eVTS
eV6
4.0
0
4.5
0
5.7
.7
6.5
1 .3
7.3
2.7
7.9
3.6
9.2
5.5
9.9
6.4
1 0.5
7. 1
1 1 .3
8.1
1 1 .4
8.5
1 2. 5
9.7
1 2.5
9.8
1 3.8
1 1 .3
eVTS
eV6
4.3
0
7.3
8.0
9.9
2.0
1 2.3
4.7
1 4.0
6.8
1 5. 0
8.7
1 5.8
1 0.8
Stand age in parentheses
..
Estimated calibration cut of 31 .5 cubic meters per hectare has been included in totals for CVTS. Plot 51 in treatment 1 excluded because of root rot. Appendix 3: The
N in e Study Areas
Study Area
Cooperator
Skykomish
Clemons
Western Forestry Research Department
Weyerhaeuser Company
Tacoma, WA
Hoskins
College of Forestry
O regon State University
Corvallis, OR
USDA Forest Service
Rocky Brook
Stampede Creek Pacific Northwest Research Station and
Pacific Northwest Region
I ron Creek
Portland, OR
Francis
State of Washington
Department of Natural Resources
Olympia, WA
Sayward Forest Canadian Forest Service
Shawnigan Lake Pacific and Yukon Region
Pacific Forest Research Centre
Victoria, BC
*u.s. GOVERNMENT PRINTING
OFFICE: 1 994
-
689-313/01001
67
Curtis, Robert 0.; Clendenen, Gary W. 1 994. Levels-of-growing-stocl< cooperative
sludy in Douglas-fir: report no. 1 2-lhe I ron Creel study: '1966-89. Res. Pap.
PNW-RP-475. Portland, OR: U . S . Department of Agriculture, Forest Service,
Pacific Northwest Research Station. 67 p.
Results of Ihe I ron Creel< installation of the levels-of-growing-stocl< study in Douglas­
fir (Pseudotsuga menziesii (Mirb.) Franco) are summarized. To age 42 (planned com­
pletion of the experiment) volume g rowth in this site " Douglas-fir plantation has been
strongly related 10 level of growing stock, partially offsetting the decrease in volume
growth percent expected with increasing growing sloci . Basal area growth-growing
sioci< relations were much weaker than those for volume. Marked differences in tree
size distributions have resulted from thinning. Periodic annual volume increments are
two to three times greater than mean annual increments at age 42; this stand is far
from culmination. Results in general are similar to those reported for other installa­
tions in the series on medium to good sites.
Keywords: Thinning, growing stocl<, growth and yield, stand density, Douglas-fir,
Pseudotsuga menziesii, series-Douglas-fir LOGS.
The Forest Sen/ice of the U.S. Department of
Agriculture is dedicated to the principle of multiple
use management of the Nation's forest resources
for sustained yields of wood, water, forage, wildlife,
and recreation. Through forestry research,
cooperation with the States and private forest
owners, and management of the National Forests
and National G rasslands, it strives-as directed by
Congress-to provide increasingly greater setvice
to a growing Nation.
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Forest Service is a diverse organization committed
to equal opportunity in employment and program
delivery. USDA prohibits discrimination on the
basis of race, color, national origin, sex, relig ion,
age, disability, political affil iation, and familial
status. Persons believing that they have been
discriminated against should contact the Secretary,
U.S. Department of Agriculture, Washington, DC 20250,
or cali 202-720-7327 (voice), or 202-720- 1 1 27 (TOO).
Pacific Northwest Research Station
333 S.W. First Avenue
P.O. Box 3890
Portland, Oregon 97208-3890
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Pacific No rthwest Rese arch Station
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