United States

Department of

Agriculture

Forest Service

Pacific Northwest

Research Station

Research Paper

PNW-RP-543

July 2002

Levels-of-Growing-Stock

Cooperative Study in

Douglas-Fir: Report No. 14–

Stampede Creek: 30-Year Results

Robert O. Curtis and David D. Marshall
Levels-of-growing-stock cooperative study treatment schedule, showing percentage of gross basal area increment of control plot retained 

in growing stock.

Treatment

Thinning 12345678

Percent

First 10 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 eight thinning regimes in

young Douglas-fir stands. Regimes differ in the amount of basal area allowed to accrue

in growing stock at each successive thinning. All regimes started with a common level

of growing stock 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 established in western Oregon and

Washington, U.S.A., and Vancouver Island, British Columbia, Canada. Site quality of

these areas ranges from I to IV.

Robert O. Curtis is a scientist emeritus and David D. Marshall is a forester, Forestry

Sciences Laboratory, 3625 93rd Ave. SW., Olympia, WA 98512-9193.

Background

Authors
Curtis, Robert O.; Marshall, David D. 2002. Levels-of-growing-stock cooperative 

study in Douglas-fir: report no. 14––Stampede Creek: 30-year results. Res. 

Pap. PNW-RP-543. Portland, OR: U.S. Department of Agriculture, Forest Service, 

Pacific Northwest Research Station. 77 p.

Results of the Stampede Creek installation of the levels-of-growing-stock (LOGS) study

in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) are summarized. To age 63

(planned completion of 60 feet of height growth), volume growth on the site III natural

stand has been strongly related to level of growing stock, but basal area growth-growing stock relations were considerably weaker. Marked differences in tree size distributions have resulted from thinning. Periodic annual volume increments at age 63 are two

to three times greater than mean annual increment; this stand is still far from culmination. Results for this southwest Oregon installation are generally similar to those reported from other LOGS installations, although development has been slower than on the

site II installations that make up the majority of the series.

Keywords: Thinning, growing stock, growth and yield, stand density, Douglas-fir,

Pseudotsuga menziesii, series––Douglas-fir LOGS.

Results of the Stampede Creek installation of the cooperative Douglas-fir

(Pseudotsuga menziesii (Mirb.) Franco) levels-of-growing-stock (LOGS) study, located

in the Tiller Ranger District of the Umpqua National Forest in southwest Oregon, are

summarized through age 63 (completion of 60 feet of height growth, comprising the

planned course of the experiment).

Estimated site index (50-year breast height [b.h.] base) of this naturally seeded stand is

111 (site III). The height growth trend differs substantially from widely used older

regional curves, and site estimates have increased by about one full site class during

the period of observation. Volume growth has been strongly related to growing stock;

basal area growth somewhat less so. There is a substantial tradeoff between increased

individual tree size and value and total volume production. Different growing stock levels have produced marked differences in tree size distributions and crown dimensions.

Periodic annual volume increments are two to three times greater than mean annual

increments at age 63, with the differences being greatest for board-foot volumes. The

stand is still far from culmination. Results are generally comparable to those reported

from other LOGS installations, except for the slower development on this medium site

compared to the good sites that make up the majority of LOGS installations.

Williamson, Richard L.; Staebler, George R. 1965. A cooperative level-of-growingstock study in Douglas-fir. Portland, OR: U.S. Department of Agriculture, Forest

Service, Pacific Northwest Forest and Range Experiment Station. 12 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 since 1961

also are summarized.

Williamson, Richard L.; Staebler, George R. 1971. Levels-of-growing-stock cooperative study on Douglas-fir: report no. 1––description of study and existing study areas.

Res. Pap. PNW-111. Portland, OR: U.S. Department of Agriculture, Forest Service,

Pacific Northwest Forest and Range Experiment Station. 12 p.

Abstract

Summary

Other LOGS

(Levels-of-Growing

Stock) Reports
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. 1972. Levels-of-growing-stock cooperative study on

Douglas-fir: report no. 2––the Hoskins study, 1963-70. Res. Pap. PNW-130. Portland,

OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and

Range Experiment Station. 19 p.

A calibration thinning and the first treatment thinning in a 20-year-old Douglas-fir stand

at Hoskins, Oregon, are described. Growth for the first 7 years after thinning was

greater than expected.

Diggle, P.K. 1972. 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.

Describes the establishment and installation of the two LOGS studies established on

Vancouver Island at Shawnigan Lake and Sayward Forest.

Williamson, Richard L. 1976. Levels-of-growing-stock cooperative study in Douglasfir: report no. 4––Rocky Brook, Stampede Creek, and Iron Creek. Res. Pap. PNW-210.

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 installations in a regional cooperative

study of influences of levels of growth 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. 1979. Levels-of-growing-stock cooperative study on

Douglas-fir: report no. 5––the Hoskins study, 1963-75. Res. Pap. PNW-257. Portland,

OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and

Range Experiment Station. 29 p.

Growth data are presented for the first 12 years of management of young Douglas-fir

growing at eight levels of growing stock. The second and third treatment periods are

described.

Young Douglas-fir stands transfer growth from many to few trees. Some of the treatments have the potential to equal the gross cubic-foot volume of the controls during the

next treatment periods.

Arnott, J.T.; Beddows, D. 1981. Levels-of-growing-stock cooperative study in

Douglas-fir: report no. 6––Sayward Forest, Shawnigan Lake. Inf. Rep. BC-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.
Tappeiner, John C.; Bell, John F.; Brodie, J. Douglas. 1982. Response of young

Douglas-fir to 16 years of intensive thinning. Res. Bull. 38. Corvallis, OR: Forest

Research Laboratory, School of Forestry, Oregon State University. 17 p.

Williamson, Richard L.; Curtis, Robert O. 1984. 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 in southwest Oregon are summarized

through the first treatment period, and results are compared with two more advanced

LOGS studies and are generally similar.

Curtis, Robert O.; Marshall, David D. 1986. 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. 113 p.

Reviews history and status of LOGS study and provides new analyses of data, primarily from the site II installations. Growth is strongly related to growing stock. Thinning

treatments have produced marked differences in volume distribution by tree size. At the

fourth treatment period, current annual increment is still about double the 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. 1987. 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 installations were projected by the DFSIM

simulation program over the available periods of observation. Estimates were compared 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 E.; Tappeiner, John C. 1992. Levels-of-growing-stock

cooperative study in Douglas-fir: report no. 10––the Hoskins study, 1963-83. Res. Pap.

PNW-RP-448. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific

Northwest Research Station. 65 p.

Results of the Hoskins LOGS study in western Oregon are summarized and management implications discussed through the fifth and final planned treatment period. To

age 40, thinnings in this low site I Douglas-fir stand resulted in large increases in diameter growth with reductions in basal area and volume growth and yield. Growth was

strongly related to level of growing stock. Culmination of cubic-foot mean annual increment does not appear to be near for any of the treatments.
Curtis, Robert O. 1992. Levels-of-growing-stock cooperative study in Douglas-fir:

report no. 11––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 on this site III 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 increment in all treatments, indicating that the stand is still far

from culmination.

Curtis, Robert O.; Clendenden, Gary W. 1994. Levels-of-growing-stock cooperative

study in Douglas-fir: report no. 12––the Iron Creek study: 1966-89. Res. Pap. PNWRP-475. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific

Northwest Research Station. 67 p.

Results of the Iron Creek study in the Gifford Pinchot National Forest, southern

Washington, are summarized through age 42 (completion of the 60 feet of height

growth comprising the planned course of the experiment). Volume growth of this midsite II plantation has been strongly related to growing stock; basal area growth much

less so. Different growing-stock levels have produced marked differences in the size

distribution and in crown dimensions. Periodic annual volume increment at age 42 is

two to three times mean annual increment in all treatments.

Hoyer, Gerald E.; Andersen, Norman A.; Marshall, David. 1996. Levels-of-growingstock cooperative study in Douglas-fir: report no. 13––the Francis study: 1963-90. Res.

Pap. PNW-RP-488. Portland, OR: U.S. Department of Agriculture, Forest Service,

Pacific Northwest Research Station. 91 p.

Results of the Francis LOGS study, begun at age 15, are summarized together with

results from additional first-thinning treatments started at age 25. To age 42, total cubic

volume growth on this mid-site II plantation has been strongly related to level of growing stock. Close dollar values among several alternatives suggest that diverse stand

structure objectives can be attained at age 42 with little difference in wood productvalue per acre.

Curtis, Robert O.; Marshall, David D.; Bell, John F. 1997. LOGS: a pioneering

example of silvicultural research in coast Douglas-fir. Journal of Forestry. 95(7): 19-25.

Reviews history of LOGS including the reasoning involved in its design and the principal results of the study to date. 

Marshall, David D.; Curtis, Robert O. 2002. Levels-of-growing-stock cooperative

study in Douglas-fir: report no. 15––Hoskins: 35-year results. Res. Pap. PNW-RP-537.

Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest

Research Station. 80 p.

King, James E.; Marshall, David D.; Bell, John F. [In press]. Levels-of-growingstock cooperative studies in Douglas-fir: report no. 17––the Skykomish study, 1961-93;

the Clemons study, 1963-94. Res. Pap. Portland, OR: U.S. Department of Agriculture,

Forest Service, Pacific Northwest Research Station.
1 Introduction 

1 Objectives

2 Methods 

2 Description of Study Area

4 Experimental Design

4 Stand Treatments

7 Data Collection and Summarization

7 Analyses

7 Results

7 Analysis of Variance

10 Trends in Live Stand Statistics

25 Relative Density Measures

26 Crown Development

29 Mortality

29 Cut

29 Cumulative Volume Production

35 Volume Distribution by Log Size Classes

38 Periodic Annual Increment

44 Mean Annual Increment

45 Growth-Growing Stock Relations

47 Growth Percentage

48 Discussion

48 Relation to Results from Other LOGS Installations

50 Growth-Growing Stock Relations

50 Comparative Volume Production

52 MAI Trends and Age of Culmination

52 Management Implications

54 Future Value of the Study

55 Metric Equivalents

56 Literature Cited

58 Appendix

Contents
This page has been left blank intentionally.

Document continues on next page.
The Stampede Creek levels-of-growing-stock (LOGS) installation is one of nine in a

regional study established in young even-aged Douglas-fir (Pseudotsuga menziesii (Mirb.)

Franco) stands according to a common work plan1 (Williamson and Staebler 1971). This

study is a cooperative effort involving the USDA Forest Service, Weyerhaeuser Company,

Oregon State University, Washington Department of Natural Resources, Canadian Forest

Service, and British Columbia Ministry of Forests. The objective is to compare cumulative

wood production, tree size development, and growth-growing stock relations under eight

different thinning regimes that were begun before the onset of severe competition. The

original study plan was developed at Weyerhaeuser Company, Centralia, Washington.

Procedural details to ensure consistency among cooperators were developed by the

Pacific Northwest Research Station, USDA Forest Service, Portland, Oregon.

Descriptions of the program and detailed progress reports on individual installations are

contained in the series of LOGS publications listed. Curtis and Marshall (1986) give an

overall analysis of results for the first 20 years, primarily for the higher site installations,

which then were at or near the end of the planned experiment.

Installations on poorer sites developed more slowly than those on good sites, and the

poorer site installations are only now reaching a point where they can be expected to

show substantial differences among treatments and possible differences in response

compared to stands on good sites. 

The Stampede Creek installation was established in 1968 by the Pacific Northwest

Research Station and the Pacific Northwest Region (Region 6) of the USDA Forest

Service. The installation differs from others in the LOGS series in that it was (1) somewhat taller and older at time of establishment, (2) on a poorer site than the majority of

installations (initially classed as IV but now classed as III), and (3) in an area (southwest Oregon) that is considerably different ecologically from the other installations.

Some preliminary data are given in report no. 4 (Williamson 1976), report no. 7

(Williamson and Curtis 1984), and report no. 11 (Curtis 1992).

This report on the Stampede Creek installation presents summary data and interpretations of results from establishment (1968) through completion of the experiment as

originally planned (1998). It is essentially an update of report no. 11 (Curtis 1992) but

incorporates an additional 10 years of growth and some minor differences in analyses.

The LOGS cooperative study evolved from work in the late 1950s by George Staebler

(1959, 1960). Staebler argued that thinning would transfer increment to the remaining

faster growing trees and increase growth percentage through reduction in growing stock,

while largely eliminating mortality losses. He also recognized that the implied assumption

of near-constant gross increment over a wide range of stocking had not at that time been

tested. The objectives of the LOGS study, as stated in the 1962 plan, were “to 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 results would

show “how to produce any combination of factors deemed optimum from a management

standpoint.” The study was intended to define the quantitative relations between growth

and growing stock for a closely controlled initial stand condition and kind of thinning.

Introduction

Objectives

1 Staebler, George R.; Williamson, Richard L. 1962. Plan for a level-of-growing-stock study in Douglas-fir. Unpublished study plan. On file with:

Forestry Sciences Laboratory, 3625 93rd Avenue SW., Olympia, WA 98512.

1
This report:

• Presents revised data summaries showing development of the Stampede Creek LOGS

installation through age 63 (end of fifth and final treatment period). These tables replace

those in previous publications. They are expected to form part of the basis for one or

more future publications generalizing the overall results of the LOGS installations.

• Compares results of the different treatments.

• Makes some interpretations of these results in relation to results from the higher site

LOGS installations and possible operational stand management regimes.

The Stampede Creek installation is in the Tiller Ranger District, Umpqua National Forest,

near Tiller in southwest Oregon (fig. 1) in sec. 10, T. 31 S., R. 1 W., Willamette Meridian.

It is the only LOGS installation in southwest Oregon (an area often considered ecologically distinct from the Douglas-fir type as found further north) and is within the mixed-conifer

(Pinus-Pseudotsuga-Libocedrus-Abies) zone of Franklin and Dyrness (1973).

The predominantly Douglas-fir stand originated by natural seeding after a 1929 wildfire.

When the study was established in 1968, the stand was older (age as estimated from borings was 33 years total, 25 years b.h. [breast height]) and taller than the initial conditions

of other stands included in the LOGS study. Estimated total ages of dominant and codominant trees ranged from 29 to 36 years. Field notes indicated delayed stand establishment

after the fire, presence of well-developed madrone (Arbutus menziesii Pursh), chinkapin

(Castanopsis chrysophylla (Dougl.) A.DC.), and brush species, and fairly uniform spacing.

Numbers of trees and basal areas before thinning were about 83 percent of normal for the

quadratic mean diameter (QMD) according to table 25 in McArdle and others (1961). This

suggests relatively low early competition and is consistent with the observation that live

crowns extended nearly to breast height at the time of study establishment.

The installation is on a broad minor ridge, at an elevation of 2,700 feet, with an average slope of about 25 percent and a generally north to east aspect. Soils are loam

over clay loam and clay derived from well-weathered volcanic tuffs and breccias.2 Soil

and parent material in the eastern group of plots (fig. 2) contains somewhat more clay

and has higher moisture-holding capacity.3 Average (1972-78) growing season (May to

September) temperature and precipitation were 54.9 oF and 7.71 inches, as determined from weather instruments located at the installation. Present ground cover is

mainly salal (Gaultheria shallon).

The plant association is classified as ABCO/GASH-BENE (Abies concolor/Gaultheria

shallon-Berberis nervosa) except for a small area at the western end of the installation

(plots 21, 32) classified as TSHE/GASH-BENE-SWO (Tsuga heterophylla/Gaultheria

shallon-Berberis nervosa) (Atzet and others 1996).

The area was classified as site IV at time of establishment, but subsequent development has led to a current site index estimate (50 years b.h.) of about 111 feet (site III).

Before study establishment in 1968, about 100 large snags present on the area were felled.

Methods

Description of 

Study Area

2 Herman, Loren D. 1968. Detailed soil survey of LOGS study area on

Stampede Creek, Umpqua N.F. Unpublished report. On file with: Forestry

Sciences Laboratory, 3625 93rd Avenue SW., Olympia, WA 98512.

3 Miller, Richard E. Personal communication. Soil scientist (retired), Pacific

Northwest Research Station, 3625 93rd Ave. SW., Olympia, WA 98512-9193.

2
3

Figure 1––Locations of the nine installations of the levels-of-growing-stock

cooperative study in Douglas-fir.
The experiment is a completely randomized design having three replications of eight

thinning treatments, plus control (treatment 9). 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 given in the study plan for area and plot selection provided a high

degree of uniformity in initial conditions.

Thirty-nine plots were laid out in the stand. Of these, 5 were rejected as unsuitable and

the 27 judged most comparable were selected for use in the study. Of the remaining

seven, two were allocated as spare controls and five as spare thinning plots for use if

major damage to other plots made substitution necessary. The spare plots were measured in 1968 and 1973 only. In 1988, three of the thinned spare plots were remeasured

and the other spares were abandoned. These three plots, not provided for in the original study plan, are designated as treatment 10 and were remeasured in 1988, 1993,

and 1998; the intention was to provide a supplementary comparison with the effects of

a precommercial thinning without subsequent treatment.

Treatments were closely controlled to provide compatibility with installations at other

locations.

Selection of crop trees––Crop trees were selected, before thinning, at the rate of 16

per plot (80 per acre), and distributed to provide three to five well-spaced crop trees in

each quarter of a plot. Crop trees were identified with white paint bands.

Calibration thinning––An initial calibration thinning was made in 1968 (at age 33) on

the 24 plots assigned to thinning treatments plus the spare thinned plots. This was

intended to reduce all plots to as nearly comparable condition as possible. All trees

less than one-half the initial stand QMD were cut. Additional noncrop trees were cut as

Experimental Design

Stand Treatments 

4

Figure 2––Arrangement of plots in the Stampede Creek LOGS installation.

N
needed to meet the study plan specifications, which called for the stand to be thinned

to an initial spacing based on the equation,

S = 0.6167 × QMD + 8 ,

where S is the average spacing in feet and QMD is the quadratic mean diameter of the

leave trees. Marking was controlled by the specifications that QMD of the leave trees

on any plot should be within 15 percent of the installation mean and leave tree basal

areas should be within 3 percent. All leave trees on thinned plots were identified with

permanent numbered tags. Trees 1.6 inches in diameter at breast height (d.b.h.) and

larger were tagged on the control plots.

Treatment thinnings––The eight thinning treatments differ in the amount of basal area

allowed to accumulate in the growing stock. The increase in basal area retained in any

thinning is a predetermined percentage of the gross increase found in the unthinned

plots since the last thinning (inside front cover; table 1). The average residual basal

area for all thinned plots after the calibration thinning is the starting point for calculating

future growing stock accumulation. Growth of controls was assumed to represent the

productive potential of the site at full stocking and can be thought of as providing a

local gross yield table for the study area. 

Following the initial calibration thinning, treatment thinnings were made at intervals of

about 10 feet of growth in crop tree height (approximated in later years by H40, mean

height of the largest 40 stems per acre [8 per plot]).4 Treatment thinnings were made in

1973, 1978, 1983, 1988, and 1993 (ages 38, 43, 48, 53, and 58, respectively). Basal

areas to be left after thinning were calculated from the equation,

BAn = BA(n-1) + p × GBAG ,

where

BAn = basal area retained after thinning,

BA(n-1) = basal area at beginning of preceding treatment period,

p = prespecified percentage of gross basal area growth to be retained, and

GBAG = average gross basal area growth on controls.

The expected trends in basal area created by these specifications are shown schematically in figure 3. Treatments 1, 3, 5, and 7 are hereafter referred to as the “fixed” treatments and 2, 4, 6, and 8 as the “variable” treatments.

Kind of thinning was further specified by the following requirements:

1. No crop trees were to be cut until all noncrop trees had been removed.

2. The QMD of trees removed in thinning should approximate the QMD of trees available for thinning (that is, of noncrop trees only until all noncrop trees had been

removed). This results in a d/D ratio (ratio of diameter of trees cut to diameter of

stand before thinning) of less than 1.0.

4 The original intent was that the initially selected crop trees would be

retained and would form the final stand; however, damage and decline in

vigor of some initially selected trees made numerous substitutions necessary. In effect, the crop tree list was revised at each thinning prior to

marking of trees to be cut.

5
6

Table 1––Treatments defined by percentage of gross basal area increment of

control retained after thinning (calibration thinning excluded)

Thinning

Treatment First Second Third Fourth Fifth

- - - - - - - - - - - - - - - - -Percent retention - - - - - - - - - - - - - - - - - 

Fixed:

1 10 10 10 10 10

3 30 30 30 30 30

5 50 50 50 50 50

7 70 70 70 70 70

Increasing:

2 10 20 30 40 50

4 30 40 50 60 70

Decreasing:

6 50 40 30 20 10

8 70 60 50 40 30

Unthinned:

C – – –– –

Figure 3––Idealized trends in basal area for the eight thinning regimes in the LOGS study.
3. Trees removed in thinning were to be distributed across the range of diameters of

trees available for thinning.

Immediately after the calibration thinning, and at all subsequent measurement dates,

diameters of all tagged trees were measured to the nearest 0.1 inch. Ingrowth was

tagged and measured on the control plots only. Heights were measured on a sample of

trees at each occasion, beginning in 1968; sample size differed at different measurement dates but was never less than 12 trees per plot, and usually more, distributed

across the range of diameters. Heights to base of live crown also were measured,

beginning in 1973. 

Constrained height-diameter curves were fit to each measurement on each plot

(Flewelling and de Jong 1994). Tree volumes in total cubic feet inside bark (CVTS)

were calculated by the Bruce and DeMars (1974) equation, from actual measured

heights when available and from predicted heights for trees not having measured

heights. These were converted to merchantable cubic volumes to a 6-inch top (CV6) by

using equations from Brackett (1973). Scribner volumes for 32-foot logs (SV6)

(Chambers and Foltz 1979), with a minimum top log of 16 feet, were calculated by

using diameter estimates from Flewelling’s (unpublished)5 taper equations.

Stand heights were characterized as H40, the mean height of the 40 stems per acre

with the largest diameters (largest 8 per plot); and as Hcrop, the mean height of designated crop trees. Although Hcrop was originally envisioned as the primary measure,

some initially designated crop trees did not remain reasonable selections as the stand

developed, and substitutions were necessary. H40 is not much different, provides consistent values, and is the principal measure used in this report.

The original study plan specified analysis of variance (ANOVA) as the primary method

of analysis, and ANOVA results are given in many of the other publications listed. A

similar analysis is included here for consistency with the other work. Many aspects of

the experiment are more meaningfully presented and interpreted, however, through

simple graphics and comparisons of treatment means. We devote most of our attention

in subsequent sections to these.

Differences among treatments in periodic gross volume (total stem) growth, gross

basal area growth, survivor QMD growth, and volume growth percentage were tested

by an analysis of variance ANOVA, as specified in the original study plan (see footnote

1) and as shown in table 2. Only the thinned treatments, which were controlled to

achieve a range in growing stock, were included. (Note that for the thinned plots, there

is in most cases little difference between gross and net growth). The results for these

four ANOVAs are summarized in table 3 and discussed below. The specific trends discussed here will be shown graphically in later sections. These results are generally

consistent with those from other LOGS installations at the end of the five treatment

periods (Curtis and Clendenen 1994, Hoyer and others 1996, Marshall and others

1992).

Data Collection and

Summarization

Analyses

Results

Analysis of Variance 

7

5 Using the methodology of Flewelling and Raynes 1993.
All treatments––Over the five treatment periods, growing stock accumulated differently

among the fixed percentage treatments (1, 3, 5, and 7) and among the variable percentage treatments (2, 4, 6, and 8). However, the mean growing stock (average of initial values over the five treatment periods) was nearly the same for the four fixed as for

the mean of four variable treatments (105.9 and 105.5 square feet per acre respectively). This resulted in no significant difference in overall average growth of fixed versus

variable treatments. 

Fixed treatments––The ANOVA tested the fixed percentage treatments (1, 3, 5, and 7)

for linear, quadratic, and cubic trends across the range of growing stock found. In all

cases, growth could be adequately described as linearly related to growing stock (that

is, the squared and cubic terms were not significant) for the five treatment periods.

Basal area and volume growth increased linearly with growing stock, while diameter

growth and volume growth percentage decreased with growing stock. This linear relation also changed significantly between periods (with slope generally decreasing with

age) for all but the volume growth percentage, which stayed similar. One would not

expect these trends to be linear over a wider range of growing stock; growth would

necessarily be zero for zero growing stock, and the ANOVA does not include the much

higher densities of the controls. 

8

Table 2–Analysis of variance

Degrees of freedom

Source of variation (5 treatment periods)

Treatments:

(1) Fixed vs. variable percentage treatments 1

(2) Among levels of fixed percentage treatments – 

Linear effects 1

Quadratic effects 1

Cubic effects 1

(3) Increasing vs. decreasing percentage treatments 1

(4) Between levels of increasing percentage treatments 1

(5) Between levels of decreasing percentage treatments 1

Error (a) for testing treatments 16

Periods (P) 4

Treatment × period interactions:

P × A 4

P × B linear effects 4

P × B quadratic effects 4

P × B cubic effects 4

P × C 4

P × D 4

P × E 4

Error (b) for testing interactions 64

Total 119
Variable treatments––The increasing treatments (2 and 4) accumulated more basal

area in the later treatment periods, and the decreasing treatments (6 and 8) accumulated more basal area in the earlier treatment periods, which resulted in mean growing

stocks (average of initial values of both treatments over the five treatment periods) of

97.8 and 113.1 square feet per acre, respectively. Mean periodic volume growth (over

five treatment periods) was 221.6 for the increasing treatments and 259.8 cubic feet •

acre-1 • year-1 for the decreasing treatments. The corresponding basal area growth was

4.6 and 5.2 square feet • acre-1 • year-1. Both volume and basal area growth were significantly greater for the decreasing treatments. There was no significant difference

among treatments in percentage of diameter growth or volume growth.

For the increasing treatments (2 and 4), with average gross periodic annual increments

in volume of 198.5 and 244.7 cubic feet • acre-1 • year-1, and average gross basal area

periodic annual increments of 4.2 and 5.1 square feet • acre-1 • year-1 respectively,

growth was different between the two levels, with the higher level of growing stock (4)

having greater growth. The differences in average volume and basal area growth

between the decreasing treatment (6 and 8) have generally been significant in the

other LOGS installations, but they were not significantly different here even though

9

Table 3–Analysis of variance results for periodic annual gross volume increment, periodic annual gross basal area increment, survivor quadratic mean

diameter periodic annual increment, and volume growth percentage

P-values and mean square errorsa

Volume (CVTS) Basal area Diameter

Source of variation PAI Growth percent PAI PAI

(A) Fixed vs. variable 0.545 0.288 0.259 0.513

(B) Fixed (linear) 0.000** 0.001** 0.010** 0.000**

(B) Fixed (quadratic) 0.491 0.481 0.741 0.675

(B) Fixed (cubic) 0.356 0.398 0.650 0.787

(C) Increasing vs. decreasing 0.001** 0.962 0.031* 0.715

(D) Between increasing 0.004** 0.863 0.016* 0.235

(E) Between decreasing 0.365 0.003** 0.165 0.060

Error (a) mean square 1,394.126 0.005 0.799 0.465

Periods (P) 0.000** 0.000** 0.000** 0.000**

P × A 0.189 0.671 0.714 0.980

P × B (linear) 0.000** 0.726 0.027* 0.000**

P × B (quadratic) 0.523 0.414 0.835 0.715

P × B (cubic) 0.982 0.675 0.960 0.428

P × C 0.031* 0.776 0.092 0.002**

P × D 0.085 0.721 0.060 0.020*

P × E 0.029* 0.203 0.066 0.003**

Error (b) mean square 183.600 0.095 0.071 0.0002

a P-value is the probability of a larger F-value, given that the null hypothesis of no difference among

means is true. Significance levels: * = 0.01 < p ≤ 0.05 and ** = p ≤ 0.01.
treatment 8 had, on average, nearly 17 percent more growing stock at the start of the

growth periods. Only the volume growth percentage differed significantly between the

two decreasing treatments, with the lower level of growing stock treatment (6) having a

higher growth percentage (6.6 compared to 5.7 percent).

Height of largest 40 trees per acre (H40)––H40, defined as the mean height of the

largest (by d.b.h.) 40 trees per acre (8 per 1/5-acre plot), 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 in the region as the basis

for site estimates. 

The range in 1998 (age 63) values of the treatment means of H40 for thinned plots

was from 114 to 124 feet, with a mean of 118 feet. The data suggest slightly greater

heights for the thinning treatments in higher stocking levels. Mean H40 of the control

plots was 116 feet (table 4).

Figure 4 compares development of H40 over the life of the installation with values predicted by King (1966) and by Hann and Scrivani (1987) for site index 111. The

observed trend is best approximated by the Hann and Scrivani curves, which were

specifically developed for southwestern Oregon. Over the 25 years from establishment

to attainment of age 50 b.h., estimated site index using Kings curves has changed from

98 to 111, whereas the Hann-Scrivani estimates changed only from 108 to 111.

Trends in Live 

Stand Statistics

10

Figure 4––Observed H40 trend (mean of eight thinning treatments and control) compared with trends predicted

by King (1966) and Hann and Scrivani (1987).
11

Table 4–Heights of the 40 largest trees per acre, 1968-98, by treatment, plot, measurement date, and age (in parentheses)

Heights of the 40 largest trees per acre at start of period

Calibration period Treatment period 1 Treatment period 2 Treatment period 3 Treatment period 4 Measurement period 5

1968 1973 1973 1978 1978 1983 1983 1988 1988 1993 1993 1998

Treatment Plot (33) (38) (38) (43) (43) (48) (48) (53) (53) (58) (58) (63)

Feet

Fixed:

1 41 56.5 67.9 67.9 78.0 78.0 89.0 89.0 97.1 97.1 104.8 105.6 114.3

72 58.8 69.5 68.9 80.5 80.5 89.6 89.6 99.0 99.1 110.5 108.3 116.1

126 57.9 70.1 70.1 80.6 80.6 89.0 89.0 101.2 101.2 112.4 112.4 119.1

Avg. 57.7 69.2 69.0 79.7 79.7 89.2 89.2 99.1 99.2 109.2 108.8 116.5

3 51 59.5 69.6 69.6 81.4 81.4 91.1 91.1 99.6 99.6 108.0 108.4 114.9

103 57.6 68.2 68.2 77.9 77.9 88.2 88.2 95.9 95.9 105.9 105.9 111.1121 59.0 68.1 68.1 80.5 80.5 91.8 91.8 101.7 101.0 112.0 112.0 116.5

Avg. 58.7 68.6 68.6 79.9 79.9 90.4 90.4 99.1 98.8 108.6 108.8 114.2

5 92 62.4 74.5 74.5 85.3 85.3 94.4 94.4 104.1 104.1 114.0 114.0 120.6

114 62.8 74.8 74.8 83.5 83.9 92.6 92.6 101.8 101.8 112.1 112.1 118.8

125 61.7 73.4 73.4 82.8 82.9 93.6 93.6 100.9 100.9 111.0 111.0 115.9

Avg. 62.3 74.2 74.2 83.8 84.0 93.5 93.5 102.3 102.3 112.4 112.4 118.4

7 62 61.3 72.0 72.0 81.9 81.9 92.5 92.5 102.1 102.1 110.9 110.9 120.1

106 61.4 72.0 72.0 84.2 84.2 96.1 96.1 106.7 106.7 118.0 118.0 124.7107 60.9 70.1 70.1 79.8 79.8 92.8 92.8 102.3 102.3 113.8 113.8 120.9

Avg. 61.2 71.4 71.4 82.0 82.0 93.8 93.8 103.7 103.7 114.2 114.2 121.9

Increasing:

2 91 58.2 69.5 68.3 78.9 78.9 88.6 88.6 95.1 95.1 104.3 104.3 111.1

112 58.3 70.1 69.6 79.5 79.4 89.3 89.3 97.1 97.1 108.0 108.0 116.0113 61.3 73.9 73.6 84.8 84.8 96.0 96.0 103.0 103.0 112.5 112.5 119.8

Avg. 59.3 71.2 70.5 81.0 81.0 91.3 91.3 98.4 98.4 108.3 108.3 115.6

4 71 57.2 69.7 69.7 78.0 78.0 91.0 91.0 101.4 101.4 111.9 111.9 120.0

82 56.8 67.8 67.5 79.0 79.0 89.9 89.6 99.3 99.3 110.1 110.1 116.8

115 58.6 70.2 70.2 81.1 81.1 89.2 89.2 102.3 102.3 113.1 113.1 116.2

Avg. 57.5 69.3 69.2 79.4 79.4 90.0 90.0 101.0 101.0 111.7 111.7 117.7

Decreasing:

6 32 56.8 66.6 66.6 78.8 78.8 89.9 89.9 99.7 99.7 108.0 108.0 115.9

101 61.0 69.4 69.4 81.7 81.7 92.0 92.0 102.1 102.1 114.0 113.3 119.5102 56.5 67.0 67.0 76.7 75.8 87.1 88.1 96.1 96.1 105.6 105.6 112.4

Avg. 58.1 67.7 67.7 79.1 78.8 89.7 90.0 99.3 99.3 109.2 109.0 115.9

8 96 60.8 73.0 73.0 83.9 83.9 98.0 98.0 107.9 107.9 120.4 120.4 127.7

111 61.2 74.2 74.2 84.3 84.3 95.0 95.0 105.2 105.2 116.0 116.0 123.8

116 59.8 71.7 71.7 80.6 80.6 93.4 93.4 103.7 103.7 115.4 115.4 121.0

Avg. 60.6 73.0 73.0 82.9 82.9 95.4 95.4 105.6 105.6 117.3 117.3 124.2

Unthinned:

C 61 59.5 70.1 70.1 81.0 81.0 90.2 90.2 100.4 100.4 109.5 109.5 117.3

105 60.6 70.8 70.8 81.1 81.1 90.8 90.8 99.6 99.6 109.3 109.3 115.8122 58.0 69.6 69.6 79.6 79.6 86.8 86.8 99.5 99.5 108.3 108.3 114.8

Avg. 59.4 70.2 70.2 80.6 80.6 89.3 89.3 99.8 99.8 109.0 109.0 116.0
Figure 5 compares H40 increment over the 30-year period by treatments. There is

some suggestion that H40 increments on the thinned treatments were slightly greater

than on the control, and that the treatments with higher stocking levels (4, 7, 8) had

slightly better height growth. Treatment 1 is inconsistent with this interpretation, but the

differences could reflect slight differences in site.

Number of trees––Trends over time of trees per acre by treatment are given in table 5.

Distributions by 1-inch diameter classes after calibration (1968) and in 1998 are shown

in table 6 and figure 6.

Basal area––Corresponding values of basal area per acre, by treatments, are shown

in figure 7 and table 7.

Quadratic mean diameter––Trends in QMD by treatment are shown in figure 8 and

table 8. Changes in QMD from 1968 through 1998, by treatments and expressed as

ratios to the corresponding change on control, are shown in figure 9. 

Thinnings have had a strong effect on the 30-year change; the effect has been greatest at the lowest stockings. A considerable part of this change, however, is the result

of the progressive removal of trees of slightly smaller average diameter than that of

the stand as a whole (that is, d/D<1.0). A better expression of the actual effect of

treatments on tree development is survivor diameter growth (Curtis and Marshall

1989), shown in figure 10.

Other diameter measures––Other average diameters are sometimes also used to

express stand attributes. D40, average diameter of the 40 largest (by d.b.h.) trees per

12

Figure 5––Thirty-year increment in H40 expressed as ratios to H40 increment of control, by treatments.
13

Table 5–Trees per acre, 1968-98, by treatment, plot, measurement date, and age (in parentheses)

Trees per acre

Calibration period Treatment period 1 Treatment period 2 Treatment period 3 Treatment period 4 Measurement period 5

1968 1973 1973 1978 1978 1983 1983 1988 1988 1993 1993 1998

Treatment Plot (33) (38) (38) (43) (43) (48) (48) (53) (53) (58) (58) (63)

Number per acre

Fixed:

1 41 300 295 200 195 125 125 75 75 60 60 50 50

72 285 285 175 175 120 120 70 70 55 55 45 40

126 300 300 205 205 150 150 100 100 70 70 55 55

Avg. 295 293 193 192 132 132 82 82 62 62 50 48

3 51 300 300 195 195 150 150 115 115 85 85 75 75

103 295 290 200 200 150 150 125 125 95 95 85 85121 275 275 200 200 155 150 125 125 105 105 85 85

Avg. 290 288 198 198 152 150 122 122 95 95 82 82

5 92 280 275 210 210 175 175 135 135 95 95 80 80

114 280 280 250 250 225 225 205 205 175 170 135 125

125 295 295 250 250 215 215 185 185 175 175 145 140

Avg. 285 283 237 237 205 205 175 175 148 147 120 115

7 62 275 270 250 245 220 215 190 190 175 175 160 150

106 290 290 255 240 225 225 210 210 205 195 185 170107 275 275 275 270 250 250 235 235 215 210 195 195

Avg. 280 278 260 252 232 230 212 212 198 193 180 172

Increasing:

2 91 285 280 195 185 125 125 100 90 90 85 85 75

112 300 300 220 220 140 140 80 80 70 70 65 65113 275 270 155 150 105 105 65 60 60 60 60 55

Avg. 287 283 190 185 123 123 82 77 73 72 70 65

4 71 295 290 175 175 140 135 115 115 100 100 90 90

82 320 315 245 240 175 175 145 145 125 125 125 125

115 275 270 205 200 160 160 145 145 135 135 130 130

Avg. 297 292 208 205 158 157 135 135 120 120 115 115

Decreasing:

6 32 340 335 295 295 220 220 170 170 110 110 85 85

101 290 290 235 235 185 185 130 130 90 90 75 75102 330 325 305 295 250 250 190 185 130 125 100 95

Avg. 320 317 278 275 218 218 163 162 110 108 87 85

8 96 230 230 210 210 175 175 155 150 135 135 110 110

111 280 280 245 245 240 240 205 200 170 170 130 120

116 255 255 250 245 210 210 185 185 155 155 125 125

Avg. 255 255 235 233 208 208 182 178 153 153 122 118

Unthinned:

C 61 1,035 965 965 860 860 675 675 495 495 400 400 345

105 845 830 830 745 745 620 620 470 470 360 360 335122 1,345 1,235 1,235 1,065 1,065 760 760 580 580 470 470 420

Avg. 1,075 1,010 1,010 890 890 685 685 515 515 410 410 367
acre, corresponds to H40 and is useful for expressing effect of treatment on diameter

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 were

cut in the thinning regimes, and suppression mortality was negligible.

The D40 values in 1998 were substantially greater for thinned plots than for the control,

but seem only loosely related to thinning treatment. Thinning treatments have had less

effect on D40 than on QMD. 

14

Figure 6––Frequency distribution of trees per acre, by 1-inch d.b.h. classes for control and combined

thinned plots in 1968 and by treatment in 1998.
15

Table 6––Numbers of trees, by 1-inch class, after calibration and in 1998, by treatment (age in parentheses)

Fixed treatments Increasing treatments Decreasing treatments Unthinned 

1 35 7 2 4 6 8 C

Start End Start End Start End Start End Start End Start End Start End Start End Start End

D.b.h. 1968 1998 1968 1998 1968 1998 1968 1998 1968 1998 1968 1998 1968 1998 1968 1998 1968 1998class (33) (63) (33) (63) (33) (63) (33) (63) (33) (63) (33) (63) (33) (63) (33) (63) (33) (63)Inches - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Number of trees - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 58 03 2 0 0 0 7 0 3 0 2 0 5 0 0 0 5 0 355 134 18 0 13 0 18 0 12 0 35 0 20 2 33 0 30 2 168 135 40 0 40 0 50 3 25 0 52 0 28 0 67 0 13 2 135 106 48 0 43 0 53 3 45 5 42 0 48 2 52 0 32 2 95 277 48 0 50 0 40 3 57 3 43 0 62 0 62 0 40 2 92 208 65 0 73 0 45 0 63 3 42 0 53 3 48 0 57 2 78 359 42 0 32 0 28 7 40 5 27 0 48 2 38 3 33 3 45 2510 23 0 28 0 15 3 18 5 18 2 23 3 10 0 20 2 30 3211 5 0 8 0 10 0 8 12 13 2 8 2 5 0 13 2 12 1312 2 0 0 0 13 5 8 8 5 2 0 2 2 0 8 7 3 2813 2 0 2 5 3 3 0 20 5 0 0 3 3 2 3 3 2 2214 0 0 0 0 2 7 0 17 2 0 0 3 0 2 0 7 2 2815 0 0 0 5 0 10 0 23 2 2 0 13 0 5 0 8 0 2816 0 0 0 12 0 12 0 17 0 5 0 15 0 13 0 12 0 2017 0 8 0 10 0 12 0 17 0 8 0 8 0 8 0 12 0 2018 0 3 0 12 0 7 0 7 0 10 0 17 0 17 0 12 0 2019 0 12 0 15 0 13 0 12 0 3 0 8 0 13 0 15 0 720 0 8 0 13 0 8 0 8 0 7 0 8 0 12 0 12 0 221 0 10 0 3 0 7 0 7 0 10 0 15 0 0 0 10 0 022 0 2 0 5 0 2 0 3 0 8 0 8 0 5 0 3 0 223 0 2 0 2 0 3 0 0 0 2 0 0 0 2 0 2 0 024 0 2 0 0 0 5 0 0 0 0 0 0 0 0 0 0 0 225 0 2 0 2 0 0 0 0 0 2 0 0 0 2 0 0 0 026 0 0 0 3 0 2 0 0 0 3 0 0 0 2 0 2 0 0Total 295 48 290 82 285 115 280 172 287 65 297 115 320 85 255 118 1,075 367
Differences in 30-year change in D40, which take into account differences among treatments in initial D40s, are much more pronounced than differences among 1998 D40s.

Relatively few trees among the largest 40 per acre have been removed in thinning, and

D40 change primarily represents growth even though a few trees were cut. Omitting

treatment 2, which we know was severely impacted by root disease, the changes in

relation to treatment are similar in direction to those for QMD although much smaller in

magnitude.

An alternative measure of diameter development is Dcrop, QMD of designated crop

trees. The original study plan envisioned an initial selection of 80 crop trees per acre,

based on a combination of vigor and spacing, with these trees to be favored during

thinning and retained (in some treatments) to the end of the experiment. Interpretation

of Dcrop is obscured by subsequent substitution of new crop trees for damaged and

low-vigor trees, and we use the closely related value of D40 in preference to Dcrop.

D40 and Dcrop become identical in later years in those treatments where number of

stems was reduced below 80 per acre.

16

Figure 7––Trends of live basal area over time, by treatment.
17

Table 7–Basal area of all live trees per acre, 1968-98, by treatment, plot, measurement date, and age (in parentheses)

Basal area

Calibration period Treatment period 1 Treatment period 2 Treatment period 3 Treatment period 4 Measurement period 5

1968 1973 1973 1978 1978 1983 1983 1988 1988 1993 1993 1998

Treatment Plot (33) (38) (38) (43) (43) (48) (48) (53) (53) (58) (58) (63)

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Square feet per acre - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Fixed:

1 41 67.6 98.5 72.6 101.8 75.2 102.7 75.5 95.3 78.5 96.5 82.1 98.4

72 71.8 103.8 75.5 104.3 78.0 102.9 76.7 95.6 79.3 97.8 81.5 87.8

126 67.2 93.6 72.1 96.4 76.2 97.1 78.8 97.6 79.8 98.0 84.9 101.3

Avg. 68.9 98.6 73.4 100.8 76.5 100.9 77.0 96.2 79.2 97.4 82.9 95.8

3 51 72.8 103.7 80.8 111.2 90.9 120.5 100.6 122.5 105.0 127.3 114.6 134.4

103 69.6 98.0 79.3 108.8 90.2 113.8 96.6 117.9 104.8 125.3 114.1 132.8121 68.3 96.9 78.1 104.1 87.5 112.5 96.8 119.0 104.4 125.2 112.7 131.4

Avg. 70.2 99.5 79.4 108.0 89.6 115.6 98.0 119.8 104.7 126.0 113.8 132.9

5 92 72.2 104.1 85.8 117.1 102.5 135.4 117.1 145.6 129.1 155.0 141.5 164.6

114 64.9 92.3 86.1 113.3 103.4 128.1 116.0 137.2 129.7 148.5 141.9 146.5

125 69.7 96.6 87.7 114.0 99.8 122.8 114.6 134.2 129.6 151.0 142.6 161.6

Avg. 68.9 97.7 86.5 114.8 101.9 128.8 115.9 139.0 129.5 151.5 142.0 157.6

7 62 68.9 98.7 92.8 123.4 113.5 143.3 134.4 159.1 154.3 179.7 172.1 194.9

106 70.5 100.1 92.2 121.0 114.0 140.7 133.7 157.7 154.8 169.7 159.8 177.2107 68.7 96.1 96.1 124.5 117.9 144.3 138.9 162.3 154.7 177.1 172.9 194.5

Avg. 69.4 98.3 93.7 123.0 115.1 142.8 135.7 159.7 154.6 175.5 168.3 188.9

Increasing:

2 91 67.9 92.8 72.0 93.8 73.7 94.7 86.9 94.3 94.3 110.8 110.8 118.5

112 64.6 94.6 72.0 101.3 77.7 103.4 85.7 107.1 97.2 117.0 110.7 130.1113 70.1 100.5 71.4 95.8 81.6 105.1 84.3 91.1 91.1 109.1 109.1 116.6

Avg. 67.5 96.0 71.8 97.0 77.6 101.0 85.6 97.5 94.2 112.3 110.2 121.7

4 71 70.8 102.4 78.5 109.5 90.6 117.5 105.3 130.6 121.8 147.8 139.9 162.6

82 67.1 97.5 80.9 109.9 90.7 120.3 106.3 129.8 121.4 148.1 148.1 174.2

115 71.2 97.8 80.6 103.3 87.3 109.6 105.1 125.8 121.6 143.1 140.2 160.6

Avg. 69.7 99.2 80.0 107.6 89.5 115.8 105.6 128.7 121.6 146.3 142.7 165.8

Decreasing:

6 32 66.7 95.3 86.5 119.4 98.9 130.8 106.8 132.5 112.2 138.1 116.7 139.6

101 66.6 98.4 85.3 120.3 99.1 128.7 106.5 131.8 112.3 135.7 120.7 142.2102 60.7 89.7 85.7 117.3 100.6 130.4 106.8 130.8 111.7 130.7 115.6 135.1

Avg. 64.7 94.4 85.8 119.0 99.6 129.9 106.7 131.7 112.0 134.8 117.7 138.9

8 96 68.6 96.4 91.8 120.3 109.9 136.6 123.6 143.6 134.7 156.4 145.8 166.8

111 62.3 90.9 85.4 114.8 111.4 138.3 126.1 149.6 137.9 160.7 144.5 158.7

116 70.5 98.1 96.8 124.1 110.9 138.9 126.2 150.5 137.6 162.8 146.1 169.5

Avg. 67.1 95.1 91.3 119.7 110.8 137.9 125.3 147.9 136.7 160.0 145.4 165.0

Unthinned:

C 61 121.7 153.6 153.6 186.2 186.2 212.0 212.0 232.1 232.1 247.0 247.0 271.0

105 107.7 138.3 138.3 165.9 165.9 187.3 187.3 200.0 200.0 207.7 207.7 222.7122 133.0 164.1 164.1 191.1 191.1 207.2 207.2 224.1 224.1 239.3 239.3 258.4

Avg. 120.8 152.0 152.0 181.1 181.1 202.2 202.2 218.7 218.7 231.3 231.3 250.7
Figure 8––Trends of quadratic mean diameter over time, by treatment.

Figure 9––Thirty-year diameter increments (QMD and D40) by treatment, expressed as ratios to

corresponding change on control.

18
19

Table 8–Quadratic mean diameter of all live trees, 1968-98, by treatment, plot, measurement date, and age (in parentheses)

Quadratic mean diameter

Calibration period Treatment period 1 Treatment period 2 Treatment period 3 Treatment period 4 Measurement period 5

1968 1973 1973 1978 1978 1983 1983 1988 1988 1993 1993 1998

Treatment Plot (33) (38) (38) (43) (43) (48) (48) (53) (53) (58) (58) (63)

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Inches - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Fixed:

1 41 6.4 7.8 8.2 9.8 10.5 12.3 13.6 15.3 15.5 17.2 17.4 19.0

72 6.8 8.2 8.9 10.5 10.9 12.5 14.2 15.8 16.3 18.1 18.2 20.1

126 6.4 7.6 8.0 9.3 9.7 10.9 12.0 13.4 14.5 16.0 16.8 18.4

Avg. 6.5 7.9 8.4 9.8 10.4 11.9 13.3 14.8 15.4 17.1 17.5 19.1

3 51 6.7 8.0 8.7 10.2 10.5 12.1 12.7 14.0 15.0 16.6 16.7 18.1

103 6.6 7.9 8.5 10.0 10.5 11.8 11.9 13.1 14.2 15.6 15.7 16.9121 6.7 8.0 8.5 9.8 10.2 11.7 11.9 13.2 13.5 14.8 15.6 16.8

Avg. 6.7 8.0 8.6 10.0 10.4 11.9 12.2 13.4 14.3 15.6 16.0 17.3

5 92 6.9 8.3 8.7 10.1 10.4 11.9 12.6 14.1 15.8 17.3 18.0 19.4

114 6.5 7.8 7.9 9.1 9.2 10.2 10.2 11.1 11.7 12.7 13.9 14.7

125 6.6 7.7 8.0 9.1 9.2 10.2 10.7 11.5 11.7 12.6 13.4 14.5

Avg. 6.7 8.0 8.2 9.5 9.6 10.8 11.1 12.2 13.0 14.2 15.1 16.2

7 62 6.8 8.2 8.3 9.6 9.7 11.1 11.4 12.4 12.7 13.7 14.0 15.4

106 6.7 8.0 8.1 9.6 9.6 10.7 10.8 11.7 11.8 12.6 12.6 13.8107 6.8 8.0 8.0 9.2 9.3 10.3 10.4 11.3 11.5 12.4 12.8 13.5

Avg. 6.7 8.0 8.1 9.5 9.6 10.7 10.9 11.8 12.0 12.9 13.1 14.3

Increasing:2 91 6.6 7.8 8.2 9.6 10.4 11.8 12.6 13.9 13.9 15.5 15.5 17.0

112 6.3 7.6 7.7 9.2 10.1 11.6 14.0 15.7 16.0 17.5 17.7 19.2113 6.8 8.3 9.2 10.8 11.9 13.5 15.4 16.7 16.7 18.3 18.3 19.7

Avg. 6.6 7.9 8.4 9.9 10.8 12.3 14.0 15.4 15.5 17.1 17.1 18.6

4 71 6.6 8.0 9.1 10.7 10.9 12.6 13.0 14.4 14.9 16.5 16.9 18.2

82 6.2 7.5 7.8 9.2 9.8 11.2 11.6 12.8 13.3 14.7 14.7 16.0

115 6.9 8.1 8.5 9.7 10.0 11.2 11.5 12.6 12.8 13.9 14.1 15.0

Avg. 6.6 7.9 8.4 9.9 10.2 11.7 12.0 13.3 13.7 15.0 15.2 16.4

Decreasing:6 32 6.0 7.2 7.3 8.6 9.1 10.4 10.7 12.0 13.7 15.2 15.9 17.4

101 6.5 7.9 8.2 9.7 9.9 11.3 12.3 13.6 15.1 16.6 17.2 18.6102 5.8 7.1 7.2 8.5 8.6 9.8 10.1 11.4 12.5 13.8 14.6 16.1

Avg. 6.1 7.4 7.6 8.9 9.2 10.5 11.0 12.3 13.8 15.2 15.9 17.4

8 96 7.4 8.8 9.0 10.2 10.7 12.0 12.1 13.2 13.5 14.6 15.6 16.7

111 6.4 7.7 8.0 9.3 9.2 10.3 10.6 11.7 12.2 13.2 14.3 15.6

116 7.1 8.4 8.4 9.6 9.8 11.0 11.2 12.2 12.8 13.9 14.6 15.8

Avg. 7.0 8.3 8.5 9.7 9.9 11.1 11.3 12.4 12.8 13.9 14.8 16.0

Unthinned:C 61 4.6 5.4 5.4 6.3 6.3 7.6 7.6 9.3 9.3 10.6 10.6 12.0

105 4.8 5.5 5.5 6.4 6.4 7.4 7.4 8.8 8.8 10.3 10.3 11.0122 4.3 4.9 4.9 5.7 5.7 7.1 7.1 8.4 8.4 9.7 9.7 10.6

Avg. 4.6 5.3 5.3 6.1 6.1 7.4 7.4 8.8 8.8 10.2 10.2 11.2
20

Figure 10––Survivor diameter growth by treatment and midperiod age.

Figure 11––Trends of total cubic volume (CVTS) per acre over time, by treatments.
21

Table 9–Total cubic volume (CVTS) of all live trees per acre, 1968-98, by treatment, plot, measurement date, and age (in parentheses)

Volume-total stem

Calibration period Treatment period 1 Treatment period 2 Treatment period 3 Treatment period 4 Measurement period 5

1968 1973 1973 1978 1978 1983 1983 1988 1988 1993 1993 1998

Treatment Plot (33) (38) (38) (43) (43) (48) (48) (53) (53) (58) (58) (63)

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Cubic feet per acre - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Fixed:1 41 1,447 2,515 1,880 3,031 2,267 3,476 2,605 3,577 2,927 3,816 3,249 4,134

72 1,572 2,661 1,978 3,122 2,361 3,453 2,617 3,527 2,958 3,953 3,293 3,763

126 1,421 2,358 1,858 2,808 2,251 3,151 2,636 3,658 3,063 4,100 3,604 4,464

Avg. 1,480 2,511 1,905 2,987 2,293 3,360 2,619 3,588 2,983 3,956 3,382 4,120

3 51 1,544 2,578 2,075 3,337 2,753 4,084 3,440 4,558 3,955 5,141 4,633 5,732

103 1,448 2,399 1,994 3,131 2,623 3,713 3,162 4,198 3,787 4,959 4,526 5,479121 1,452 2,402 1,974 3,043 2,599 3,785 3,271 4,422 3,900 5,116 4,658 5,583

Avg. 1,481 2,460 2,015 3,171 2,658 3,861 3,291 4,393 3,881 5,072 4,605 5,598

5 92 1,589 2,715 2,274 3,533 3,111 4,573 3,998 5,439 4,902 6,394 5,861 7,074

114 1,406 2,361 2,222 3,314 3,031 4,188 3,776 4,882 4,675 5,808 5,647 6,130

125 1,500 2,461 2,267 3,363 2,955 4,087 3,848 4,883 4,731 6,029 5,765 6,797

Avg. 1,498 2,512 2,254 3,403 3,032 4,282 3,874 5,068 4,770 6,077 5,758 6,667

7 62 1,559 2,619 2,471 3,722 3,428 4,938 4,662 6,047 5,880 7,432 7,138 8,645

106 1,585 2,637 2,445 3,656 3,448 4,891 4,662 6,069 5,964 7,148 6,731 7,919107 1,577 2,544 2,544 3,741 3,555 5,001 4,829 6,181 5,926 7,424 7,291 8,653

Avg. 1,574 2,600 2,486 3,706 3,477 4,943 4,718 6,099 5,923 7,335 7,053 8,406

Increasing:2 91 1,400 2,267 1,786 2,633 2,102 3,035 2,829 3,336 3,336 4,259 4,259 4,791

112 1,327 2,321 1,784 2,829 2,239 3,316 2,876 3,898 3,524 4,663 4,396 5,443113 1,513 2,598 1,918 2,933 2,549 3,641 3,013 3,465 3,465 4,488 4,488 5,012

Avg. 1,413 2,395 1,829 2,798 2,296 3,331 2,906 3,567 3,442 4,470 4,381 5,082

4 71 1,470 2,576 2,060 3,268 2,712 3,990 3,583 4,834 4,534 5,908 5,612 6,857

82 1,363 2,387 1,992 3,126 2,633 3,959 3,523 4,705 4,431 5,913 5,913 7,273

115 1,506 2,470 2,077 3,013 2,585 3,575 3,461 4,608 4,480 5,734 5,633 6,651

Avg. 1,446 2,477 2,043 3,136 2,643 3,841 3,522 4,716 4,482 5,852 5,719 6,927

Decreasing: 6 32 1,343 2,257 2,066 3,290 2,784 4,222 3,492 4,749 4,128 5,462 4,655 5,879

101 1,424 2,405 2,111 3,441 2,860 4,189 3,540 4,807 4,195 5,581 5,000 6,144102 1,213 2,120 2,036 3,182 2,718 4,076 3,377 4,518 3,930 5,040 4,480 5,527

Avg. 1,327 2,261 2,071 3,304 2,787 4,163 3,470 4,691 4,084 5,361 4,712 5,850

8 96 1,545 2,585 2,480 3,702 3,411 4,920 4,466 5,678 5,360 6,873 6,487 7,773

111 1,352 2,347 2,231 3,372 3,267 4,609 4,245 5,520 5,148 6,579 6,011 6,954

116 1,567 2,575 2,545 3,663 3,300 4,784 4,372 5,684 5,260 6,883 6,242 7,524

Avg. 1,488 2,502 2,419 3,579 3,326 4,771 4,361 5,627 5,256 6,778 6,247 7,417

Unthinned:C 61 2,455 3,654 3,654 5,175 5,175 6,780 6,780 8,415 8,415 9,823 9,823 11,493

105 2,211 3,316 3,316 4,609 4,609 5,917 5,917 7,088 7,088 8,136 8,136 9,206122 2,587 3,774 3,774 5,099 5,099 6,301 6,301 7,835 7,835 9,205 9,205 10,555

Avg. 2,417 3,581 3,581 4,961 4,961 6,333 6,333 7,779 7,779 9,055 9,055 10,418
22

Figure 12––Trends of merchantable cubic volume to a 6-inch top (CV6) over time, by treatments.

Total cubic volume (CVTS)––Trends in standing cubic volume of total stem inside

bark, by treatment, are shown in figure 11, with numerical values given in table 9.

Merchantable cubic volume––Trends in standing merchantable cubic volume (CV6)

to a 6-inch top diameter inside bark (d.i.b.), by treatment, are shown in figure 12;

numerical values are in table 10. 

Board-foot volume (SV6)––General trends are more or less similar to those in CV6

(table 11), and we do not emphasize board feet in this report; we will later point out

some comparisons of interest. Where shown, volumes are for 32-foot logs, with a

minimum top log length of 16 feet, to a 6-inch top.
23

Table 10–Merchantable cubic volume (CV6) of all live trees per acre, 1968-98, by treatment, plot, measurement date, and age (inparentheses)

Volume to a 6-inch top

Calibration period Treatment period 1 Treatment period 2 Treatment period 3 Treatment period 4 Measurement period 5

1968 1973 1973 1978 1978 1983 1983 1988 1988 1993 1993 1998

Treatment Plot (33) (38) (38) (43) (43) (48) (48) (53) (53) (58) (58) (63)

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Cubic feet per acre - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 

Fixed:1 41 504 1,496 1,179 2,349 1,854 3,094 2,396 3,361 2,755 3,626 3,088 3,948

72 746 1,758 1,414 2,564 1,995 3,084 2,430 3,329 2,801 3,768 3,140 3,600

126 506 1,292 1,114 2,060 1,720 2,627 2,321 3,331 2,851 3,871 3,423 4,259

Avg. 586 1,515 1,236 2,325 1,856 2,935 2,382 3,340 2,802 3,755 3,217 3,935

3 51 627 1,561 1,396 2,660 2,254 3,601 3,074 4,186 3,703 4,868 4,392 5,460

103 576 1,459 1,318 2,464 2,138 3,239 2,767 3,795 3,518 4,668 4,266 5,199121 608 1,484 1,294 2,363 2,086 3,282 2,860 4,007 3,559 4,756 4,382 5,292

Avg. 604 1,501 1,336 2,496 2,160 3,374 2,900 3,996 3,593 4,764 4,346 5,317

5 92 755 1,747 1,547 2,770 2,494 3,953 3,551 4,979 4,603 6,061 5,575 6,753

114 740 1,573 1,525 2,540 2,361 3,465 3,129 4,187 4,115 5,237 5,184 5,677

125 684 1,505 1,467 2,489 2,217 3,300 3,171 4,184 4,076 5,353 5,235 6,287

Avg. 726 1,608 1,513 2,600 2,357 3,572 3,284 4,450 4,265 5,550 5,332 6,239

7 62 656 1,635 1,560 2,836 2,647 4,152 3,985 5,362 5,254 6,784 6,563 8,089

106 663 1,621 1,546 2,791 2,642 4,054 3,892 5,278 5,193 6,385 6,003 7,218107 626 1,532 1,532 2,736 2,629 4,052 3,942 5,292 5,135 6,633 6,555 7,903

Avg. 648 1,596 1,546 2,788 2,639 4,086 3,939 5,310 5,194 6,601 6,374 7,737

Increasing:2 91 624 1,358 1,124 1,977 1,687 2,616 2,522 3,049 3,049 3,976 3,976 4,521

112 573 1,389 1,119 2,098 1,797 2,869 2,654 3,667 3,322 4,433 4,182 5,198113 861 1,830 1,485 2,509 2,259 3,336 2,834 3,287 3,287 4,279 4,279 4,791

Avg. 686 1,526 1,243 2,195 1,914 2,940 2,670 3,334 3,219 4,229 4,145 4,836

4 71 593 1,609 1,475 2,723 2,295 3,597 3,255 4,498 4,257 5,601 5,337 6,544

82 500 1,392 1,171 2,294 2,042 3,379 3,070 4,258 4,044 5,511 5,511 6,849

115 639 1,499 1,362 2,318 2,039 3,034 2,988 4,124 4,039 5,270 5,188 6,189

Avg. 577 1,500 1,336 2,445 2,125 3,337 3,104 4,293 4,113 5,461 5,345 6,528

Decreasing:6 32 380 1,109 1,053 2,218 2,011 3,434 2,906 4,154 3,787 5,111 4,390 5,588

101 621 1,451 1,331 2,629 2,243 3,552 3,115 4,368 3,918 5,275 4,746 5,860102 423 1,169 1,144 2,210 1,908 3,199 2,703 3,860 3,490 4,604 4,151 5,203

Avg. 474 1,243 1,176 2,352 2,054 3,395 2,908 4,127 3,732 4,997 4,429 5,550

8 96 803 1,795 1,756 2,979 2,833 4,310 3,931 5,146 4,886 6,364 6,085 7,337

111 693 1,590 1,557 2,654 2,565 3,852 3,585 4,853 4,607 6,002 5,578 6,517

116 693 1,670 1,661 2,826 2,576 4,040 3,730 5,039 4,755 6,350 5,805 7,069

Avg. 729 1,685 1,658 2,820 2,658 4,067 3,749 5,013 4,750 6,239 5,823 6,974

Unthinned:C 61 688 1,687 1,687 3,122 3,122 4,863 4,863 6,651 6,651 8,386 8,386 10,195

105 797 1,662 1,662 2,847 2,847 4,146 4,146 5,421 5,421 6,709 6,709 7,861122 856 1,790 1,790 3,005 3,005 4,280 4,280 5,903 5,903 7,470 7,470 8,952

Avg. 780 1,713 1,713 2,991 2,991 4,430 4,430 5,992 5,992 7,522 7,522 9,003
24Table 11–Scribner board-foot volume (SV6) of all live trees per acre, 1968-98, by treatment, plot, measurement date, and age (in

parentheses)

Volume to a 6-inch top, 32-foot logs

Calibration period Treatment period 1 Treatment period 2 Treatment period 3 Treatment period 4 Measurement period 5

1968 1973 1973 1978 1978 1983 1983 1988 1988 1993 1993 1998

Treatment Plot (33) (38) (38) (43) (43) (48) (48) (53) (53) (58) (58) (63)

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Scribner board feet per acre - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Fixed:

1 41 838 5,880 4,656 8,626 6,533 12,485 9,652 13,765 11,180 14,903 12,759 17,861

72 2,131 6,453 5,159 9,255 7,130 12,246 9,551 13,744 11,539 15,600 13,328 16,670

126 1,424 4,293 3,712 7,608 6,307 10,608 9,199 13,544 11,591 17,042 15,173 19,240

Avg. 1,464 5,542 4,509 8,496 6,657 11,780 9,467 13,684 11,437 15,848 13,753 17,924

3 51 1,794 5,277 4,903 10,166 8,542 14,303 12,265 16,981 14,950 20,469 18,681 24,922

103 1,511 5,270 4,826 8,672 7,506 12,175 10,443 15,410 14,328 19,633 17,910 22,520121 1,474 5,456 4,751 9,094 7,896 13,139 11,578 16,645 14,728 20,927 19,180 23,863

Avg. 1,593 5,334 4,826 9,311 7,981 13,206 11,429 16,345 14,669 20,343 18,590 23,768

5 92 1,997 5,799 5,056 10,194 9,217 15,406 13,703 21,134 19,416 26,589 24,444 31,592

114 2,302 5,381 5,238 9,118 8,472 13,418 12,025 16,670 16,370 22,841 22,598 25,744

125 1,995 5,005 5,005 9,600 8,428 13,115 12,612 17,378 16,877 22,999 22,496 27,967

Avg. 2,098 5,395 5,100 9,637 8,706 13,979 12,780 18,394 17,554 24,143 23,179 28,434

7 62 1,720 5,835 5,505 10,603 9,850 17,464 16,774 22,857 22,355 29,197 28,231 37,208

106 1,670 5,919 5,607 10,817 10,315 16,788 16,074 23,440 23,040 29,554 27,879 34,037107 1,339 5,904 5,904 10,977 10,445 16,693 16,299 23,266 22,590 29,587 29,229 36,452

Avg. 1,576 5,886 5,672 10,799 10,203 16,982 16,382 23,188 22,661 29,446 28,446 35,899

Increasing:2 91 1,753 4,480 3,772 6,982 5,785 10,077 9,759 12,074 12,074 16,822 16,822 19,619

112 1,507 4,988 4,037 7,174 6,197 10,891 10,121 14,607 13,113 19,435 18,364 23,898113 2,602 6,419 5,311 9,208 8,241 13,158 11,404 13,501 13,501 18,996 18,996 22,094

Avg. 1,954 5,296 4,374 7,788 6,741 11,375 10,428 13,394 12,896 18,418 18,061 21,870

4 71 1,724 5,048 4,936 9,570 8,044 14,075 12,785 17,986 16,946 24,034 22,993 29,527

82 1,199 5,104 4,235 8,357 7,411 13,027 11,716 17,306 16,409 24,189 24,189 30,430

115 1,905 5,340 4,865 8,604 7,458 12,108 11,896 16,875 16,462 22,477 22,189 27,467

Avg. 1,609 5,164 4,679 8,844 7,638 13,070 12,132 17,389 16,606 23,567 23,124 29,141

Decreasing:6 32 1,076 3,711 3,593 7,941 7,335 13,125 11,104 17,790 16,285 22,014 18,854 24,994

101 1,694 4,793 4,469 9,410 7,920 13,814 12,136 18,445 16,640 22,907 20,663 26,918102 1,244 3,833 3,833 7,788 6,784 12,405 10,437 15,553 13,937 19,617 17,507 22,523

Avg. 1,338 4,112 3,965 8,379 7,346 13,115 11,225 17,263 15,621 21,513 19,008 24,812

8 96 2,538 5,999 5,874 11,493 10,974 17,891 16,380 21,703 20,674 28,978 27,722 34,186

111 2,003 5,729 5,579 9,788 9,500 15,193 14,125 20,662 19,716 26,957 25,033 30,353

116 1,844 6,048 6,048 10,976 9,842 17,179 15,815 21,596 20,204 28,037 25,707 32,760

Avg. 2,128 5,925 5,833 10,753 10,105 16,754 15,440 21,321 20,198 27,990 26,154 32,433

Unthinned:C 61 1,874 6,385 6,385 11,974 11,974 20,266 20,266 28,682 28,682 37,400 37,400 45,825

105 2,388 5,141 5,141 10,754 10,754 16,661 16,661 23,353 23,353 30,330 30,330 35,735122 2,730 6,296 6,296 10,880 10,880 17,173 17,173 25,796 25,796 33,404 33,404 40,300

Avg. 2,331 5,941 5,941 11,203 11,203 18,033 18,033 25,943 25,943 33,711 33,711 40,620
Relative density measures are useful in describing thinning regimes, as guides for 

density control, as values interpretable as measures of competition, and as predictors

of growth. Here, treatments are compared by using two common relative density

measures that are nearly equivalent, except for scale factors.These are Curtis'

(1982) relative density (RD) and Reineke’s (1933) stand density index (SDI). 

Relative density––Relative density (RD) is defined by the equation,

RD = basal area / √QMD ,

and is merely a rearrangement of Reineke’s equation (with a slight difference in exponent) into a form that some find easier to use.

Figure 13 displays trends of RD 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 estimate of the maximum attainable density in an unthinned stand at this location. 

Because the stand is nearly pure Douglas-fir and lacks the understory of tolerant

species found at some other LOGS sites, RD values are unaffected by the biases introduced when such an understory is present, as at the Iron Creek LOGS installation

(Curtis and Clendenen 1994).

Relative Density 

Measures

25

Figure 13––Trends of relative density (Curtis 1982) over time, by treatments.
Stand density index––Figure 14 shows trends of SDI over time for the various thinning treatments. The control plots appear to be approaching a maximum in the vicinity

of SDI 500.

From regressions of live crown ratio on d.b.h. fit separately for each treatment and

measurement date, live crown ratios were estimated corresponding to (1) D40, mean

diameter of the largest 40 trees per acre; and (2) QMD, the quadratic mean diameter 

of all trees. From these values and corresponding estimated heights, values also were

calculated for live crown length and height to live crown. The resulting values for the

most recent measurement, 1998, are shown in figures 15, 16, and 17.

Estimates of crown ratio and crown length are inherently imprecise, primarily because

of the difficulty in defining base of live crown in a way that gives consistent successive

measurements. Despite considerable resulting variation, the general trends shown are

clear. Within each treatment category (fixed, increasing, decreasing) crown ratios and

live crown lengths decline and heights to live crown increase as stocking level increases with lighter thinning. Crown ratios and crown lengths are consistently greater for the

largest 40 trees per acre than for all trees, but the corresponding differences in heights

to live crown are slight.

Crown Development

26

Figure 14––Trends of stand density index (Reineke 1933) over time, by treatments.
27

Figure 15––Live crown ratios, 1998, by treatments; means of 40 largest trees per acre and of all trees.

Figure 16––Live crown lengths, 1998, by treatments; means of 40 largest trees per acre and of all trees.
28

Figure 17––Heights to live crown, 1998, by treatments; means of 40 largest trees per acre and of all trees.

Figure 18––Live crown ratios in relation to relative density, 1998, by treatments, for 40 largest trees per acre

and for all trees.
Crown ratios are likewise strongly related to relative density (fig. 18), with values for the

40 largest trees per acre and for all trees diverging sharply as stand density increases.

There are similar relations (not shown) with basal area. Elevations of these curves differ at successive measurements. Thus, neither relative density nor basal area, considered alone, is an adequate predictor of crown ratio across measurement dates.

The stand was initially of rather low density, and although the control is now well within

the zone of competition-related mortality (figs. 14 and 15), relative density still is not

extremely high. Although the control has had appreciable mortality in number of stems

and basal area (table 12) and in volume (table 13), most of this has been fairly uniform

over time and confined mainly to the smallest trees, whose loss has not had a major

effect on volume and volume increment statistics.

All thinning treatments are well below densities at which competition-related mortality

would be expected. There has been fairly severe episodic mortality in plots 91 and

113 in treatment 2 in 1983-88 and 1993-98, and in plot 114 in treatment 5 in 1993-

98. This was due mostly to root rot and root rot-related windthrow, which removed a

few large trees. On these small plots, loss of even a single large tree introduces

large fluctuations in estimates of net periodic annual increment in basal area and in

volume. This is a major contributor to the somewhat erratic variations in trends in

graphs to be presented.

Statistics for cut trees, by treatment, period, and unit of measure, are given in tables 

14 and 15. The mean of d/D (ratio of diameter of cut trees to diameter of all trees

before cutting), over all thinning treatments and periods, was 0.81, with no clear trends

over time or treatment. This value is considerably less than in other LOGS installations;

reasons for this difference are unclear. It may be related to the fact that the initial stand

was relatively open, of natural origin, and considerably taller than other LOGS installations and therefore might have had a wider initial range of diameters.

Net total cubic volume––Trends of cumulative net total cubic volume (CVTS) are

shown in figure 19. This is the sum of 1998 CVTS + CVTS removed in thinnings and

does not include mortality (which was small except on treatment 2 and in the control).

The values shown do not include the volume removed in the calibration cut, which––

estimated as the difference between mean of controls and mean postcalibration value

of thinned plots––was 954 cubic feet per acre. If this is included, there is little 

difference in cumulative CVTS production between treatments 7, 8, and the control.

The apparent greater production of treatment 1 compared to treatment 2 is the reverse

of the relation observed in other LOGS installations, where treatment 2 consistently

has given somewhat higher production than treatment 1. The anomalous position of

treatment 2 in this and other graphs apparently was caused by mortality, principally

root disease and root disease-related windfall.

Mortality

Cut

Cumulative Volume

Production 

29
Table 12–Number, diameter, and basal area of trees recorded as dead at end of

each period, by treatment, measurement date, and age (in parentheses)

End of period:

1973 1978 1983 1988 1993 1998

Treatment (38) (43) (48) (53) (58) (63) Total

Trees per acre

Fixed:

1 2 2 0 0026

3 2 0 2 0004

5 2 0 0 0259

7 2 8 2 0 5 8 25

Increasing:

2 3 5 0 5 2 5 20

4 5 3 2 0 0 0 10

Decreasing:

6 3 3 0 2 2 2 12

8 0 2 0 3038

Unthinned: 

C 65 118 205 170 105 43 706

Quadratic mean diameter

Inches

Fixed:

1 5.74 2.65 0.00 0.00 0.00 15.61 9.72

3 5.74 0.00 3.13 0.00 0.00 0.00 4.62

5 3.36 0.00 0.00 0.00 6.21 12.90 10.18

7 2.82 4.48 4.39 0.00 10.93 6.87 6.90

Increasing:

2 6.76 7.51 0.00 15.66 7.31 14.84 11.94

4 4.69 7.54 9.40 0.00 0.00 0.00 6.76

Decreasing:

6 3.78 3.75 0.00 8.03 11.23 6.75 6.82

8 0.00 6.21 0.00 5.97 0.00 10.05 7.80

Unthinned:

C 2.36 2.63 2.89 3.33 5.01 5.25 3.49

Basal area

Square feet per acre 

Fixed:

1 0.36 0.08 0.00 0.00 0.00 2.66 3.09

3 0.36 0.00 0.11 0.00 0.00 0.00 0.47

5 0.12 0.00 0.00 0.00 0.42 4.54 5.08

7 0.09 0.88 0.21 0.00 3.26 2.06 6.49

Increasing:

2 0.75 1.54 0.00 6.69 0.58 6.01 15.56

4 0.60 0.93 0.96 0.00 0.00 0.00 2.49

Decreasing:

6 0.23 0.23 0.00 0.70 1.38 0.50 3.04

8 0.00 0.42 0.00 0.58 0.00 1.65 2.66

Unthinned:

C 1.97 4.45 9.35 10.27 14.36 6.47 46.86

30
Table 13–Volume of trees recorded as dead at end of each period, by treatment,

measurement date, and age (in parentheses)

End of period:

1973 1978 1983 1988 1993 1998

Treatment (38) (43) (48) (53) (58) (63) Total

Volume

Cubic feet per acre

Fixed:

1 8.1 0.7 0.0 0.0 0.0 113.2 122.0

3 7.6 0.0 1.5 0.0 0.0 0.0 9.1

5 1.7 0.0 0.0 0.0 12.1 185.0 198.8

7 1.3 17.3 4.6 0.0 132.8 64.5 220.5

Increasing:

2 18.0 35.5 0.0 260.1 16.6 257.5 587.7

4 11.0 24.8 30.25 0.0 0.0 0.0 66.0

Decreasing:

6 3.4 3.5 0.0 21.9 50.9 13.8 93.5

8 0.0 10.0 0.0 13.3 0.0 65.8 89.0

Unthinned:

C 22.4 63.4 149.5 192.4 386.4 186.2 1,000.4

Volume to a 6-inch top

Cubic feet per acre

Fixed:

1 0.8 0.0 0.0 0.0 0.0 107.7 108.5

3 0.8 0.0 0.0 0.0 0.0 0.0 0.8

5 0.0 0.0 0.0 0.0 3.0 166.3 169.3

7 0.0 0.0 0.0 0.0 116.4 30.6 147.1

Increasing:

2 11.2 15.8 0.0 243.6 8.8 239.3 518.7

4 0.8 17.7 24.3 0.0 0.0 0.0 42.7

Decreasing:

6 0.0 0.0 0.0 14.4 45.7 5.6 65.6

8 0.0 2.5 0.0 0.3 0.0 58.8 61.6

Unthinned:

C 0.0 10.6 6.4 13.7 100.2 58.9 189.8

Volume

Scribner board feet per acre

Fixed:

1 0.0 0.0 0.0 0.0 0.0 453.5 453.5

3 0.0 0.0 0.0 0.0 0.0 0.0 0.0

5 0.0 0.0 0.0 0.0 0.0 714.6 714.6

7 0.0 0.0 0.0 0.0 537.9 144.1 682.0

Increasing:

2 50.0 35.4 0.0 1,029.4 45.8 1,059.1 2,219.7

4 0.0 83.7 96.0 0.0 0.0 0.0 179.7

Decreasing:

6 0.0 0.0 0.0 83.7 210.9 0.0 294.6

8 0.0 0.0 0.0 0.0 0.0 250.7 250.7

Unthinned:

C 0.0 52.0 0.0 43.7 463.5 265.6 824.9

31
Table 14–Number, diameter, and basal area of trees cut, by treatment, period,

measurement date, and age (in parentheses)

End of period:

1973 1978 1983 1988 1993

Treatment (38) (43) (48) (53) (58) Total

Trees per acre

Fixed:

1 100 60 50 20 12 242

3 90 47 28 27 13 205

5 47 32 30 27 27 163

7 18 20 18 13 13 82

Increasing:

2 93 62 42 3 2 202

4 83 47 22 15 5 172

Decreasing:

6 38 57 55 52 22 224

8 20 25 27 25 32 129

Unthinned:

C 000000

Quadratic mean diameter

Inches

Fixed:

1 6.8 8.6 9.4 12.5 14.9 8.9

3 6.4 8.5 10.7 10.1 13.1 8.6

5 6.6 8.6 8.9 8.1 8.0 7.9

7 6.8 8.5 8.5 8.5 10.1 8.4

Increasing:

2 6.9 7.6 8.2 14.2 13.8 7.6

4 6.5 8.4 9.2 9.4 11.5 7.9

Decreasing:

6 6.4 7.9 8.8 8.3 12.0 8.5

8 5.9 8.1 9.3 9.0 9.1 8.5

Unthinned:

C 0.0 0.0 0.0 0.0 0.0 0.0

Basal area

Square feet per acre

Fixed:

1 25.2 24.4 23.9 17.0 14.6 105.0

3 20.1 18.5 17.6 15.0 12.2 83.4

5 11.1 12.9 12.9 9.5 9.5 56.0

7 4.6 7.9 7.1 5.1 7.2 31.9

Increasing:

2 24.1 19.3 15.4 3.3 2.1 64.2

4 19.3 18.0 10.2 7.2 3.6 58.3

Decreasing:

6 8.6 19.4 23.3 19.6 17.2 88.1

8 3.8 9.0 12.7 11.1 14.5 51.0

Unthinned:

C 0.0 0.0 0.0 0.0 0.0 0.0

32
Table 15–Volume of trees cut, by treatment, period, measurement date, and age

(in parentheses)

End of period:

1973 1978 1983 1988 1993

Treatment (38) (43) (48) (53) (58) Total

Volume

Cubic feet per acre

Fixed:

1 606 694 741 605 574 3,220

3 445 512 570 512 466 2,506

5 258 371 408 298 320 1,655

7 113 229 225 176 281 1,025

Increasing:

2 566 502 424 125 89 1,706

4 434 492 319 234 132 1,612

Decreasing:

6 189 517 693 607 649 2,656

8 84 253 410 371 532 1,649

Unthinned:

C 0 0 0000

Volume to a 6-inch top

Cubic feet per acre

Fixed:

1 280 468 553 538 538 2,377

3 165 336 474 403 418 1,796

5 95 242 289 185 219 1,030

7 50 148 147 117 227 689

Increasing:

2 283 280 270 115 84 1,032

4 164 320 233 180 115 1,012

Decreasing:

6 67 298 487 395 568 1,816

8 27 162 319 263 416 1,186

Unthinned:

C 0 0 0000

Volume

Scribner board feet per acre

Fixed:

1 1,033 1,839 2,312 2,248 2,095 9,527

3 508 1,330 1,777 1,677 1,752 7,043

5 296 931 1,199 839 964 4,230

7 214 596 599 526 1,000 2,936

Increasing:

2 922 1,047 948 498 357 3,772

4 485 1,206 938 783 443 3,855

Decreasing:

6 148 1,033 1,889 1,642 2,505 7,217

8 92 647 1,314 1,122 1,836 5,012

Unthinned:

C 0 0 0000

33
Net merchantable cubic volume––Trends of cumulative net merchantable cubic volume (CV6) are shown in figure 20. Values are the sum of 1998 CV6 + CV6 removed in

thinnings and do not include mortality (which was substantial in treatment 2). Average

CV6 removed in the calibration cut was small (151 cubic feet per acre) and is not

included. The general pattern of relations among treatments is similar to that for CVTS.

Ratios of thinning volumes to cumulative net production––Cumulative volumes cut

in thinnings (excluding calibration), expressed as ratios to cumulative net yield as of

1998, are shown for CVTS and CV6 in the following tabulation:

Treatment CVTS CV6

_________________________________

Fixed:

1 0.44 0.38

3 0.31 0.25

5 0.20 0.14

7 0.11 0.08

Increasing:

2 0.25 0.18

4 0.19 0.13

Decreasing:

6 0.31 0.25

8 0.18 0.14

34

Figure 19––Trends of cumulative net total cubic volume (CVTS) production (standing volume + past 

thinnings) over time, by treatments.
Distributions of CV6 by log size classes are shown in figure 21 and table 16 as percentages of standing volume in live trees by 2-inch log diameter classes as of the end

of the fifth treatment period (1998). Table 17 shows percentages of cumulative thinning

volumes by 2-inch log diameter classes. Tables 18 and 19 give corresponding values

for board-foot volumes (SV6). 

Volume Distribution 

by Log Size Classes 

35

Figure 20––Trends of cumulative net merchantable cubic volume (CV6) production (standing volume + past

thinnings) over time, by treatments.
36

Figure 21––Percentage distribution of live merchantable cubic volume (CV6) in 1998, by log diameter

classes for fixed treatments and control.

Table 16–Percentage of merchantable cubic volume (CV6) of live trees, 1998, in

logs with scaling diameters larger than indicated value

Scaling diameter (inches): Total live

Treatment 6 8 10 12 14 16 18 CV6

- - - - - - - - - - - - - - - - - - - - Percent - - - - - - - - - - - - - - - - - - - Ft3/acre

Fixed:

1 100 89.8 82.9 64.1 35.0 8.8 0 3,935

3 100 87.6 75.2 48.7 23.3 2.1 0 5,317

5 100 85.3 72.3 47.8 23.3 10.8 2.1 6,239

7 100 79.8 58.1 32.1 11.4 3.0 0 7,737

Increasing:

2 100 88.7 79.1 61.1 36.9 12.2 5.5 4,836

4 100 83.7 73.5 45.7 25.1 1.6 0 6,528

Decreasing:

6 100 87.5 74.1 52.0 23.8 6.8 2.5 5,550

8 100 85.3 71.2 47.9 22.1 5.4 1.9 6,974

Unthinned:

C 100 71.7 41.7 21.2 3.2 1.4 0 9,003
37

Table 17–Percentage of merchantable cubic volume (CV6) of trees removed in

thinnings, in logs with scaling diameters larger than indicated value

Scaling diameter (inches):

Treatment 6 8 10 12 14 16 18 Total cut CV6

- - - - - - - - - - - - - - - - - - - - - - Percent - - - - - - - - - - - - - - - Ft 3/acre

Fixed:

1 100 54.5 33.2 15.6 6.1 0 0 2,377

3 100 53.2 25.5 10.0 2.3 0 0 1,796

5 100 53.7 22.5 13.2 3.0 1.6 0 1,030

7 100 41.7 22.8 10.6 2.5 0 0 689

Increasing:

2 100 67.2 50.3 28.4 21.3 3.9 2.8 1,032

4 100 54.8 38.3 19.3 8.2 0 0 1,012

Decreasing:

6 100 50.5 30.9 20.3 8.1 5.3 0 1,816

8 100 57.2 26.1 9.5 3.3 1.8 0 1,186

Unthinned:

C 100 0 0 0 0 0 0 0

Table 18–Percentage of merchantable board-foot volume (SV6) of live trees, 1998,

in logs with scaling diameters larger than indicated value 

Scaling diameter (inches): Total live 

Treatments 6 8 10 12 14 16 18 SV6

- - - - - - - - - - - - - - - - - - - - - Percent - - - - - - - - - - - - - - - - - Bd. ft./acre

Fixed:

1 100 92.4 85.8 64.9 36.0 9.6 0 17,934

3 100 89.7 77.6 49.0 24.2 2.2 0 23,768

5 100 87.8 75.5 49.7 25.2 11.8 2.3 28,434

7 100 81.4 60.4 33.6 12.4 4.0 0 35,899

Increasing:

2 100 91.5 82.6 63.0 40.0 13.5 6.2 21,870

4 100 86.3 76.4 47.3 27.1 1.8 0 29,141

Decreasing:

6 100 89.7 76.7 53.0 25.9 7.5 2.9 24,812

8 100 87.5 73.7 49.1 24.2 6.7 2.1 32,433

Unthinned:

C 100 73.5 45.0 23.67 4.1 2.1 0 40,620
Periodic annual increment (PAI) values presented are net unless otherwise specified

and calculated as the difference between values at start of the period (after thinning)

and those at end of the period (before thinning), divided by years in the period. Gross

PAI values (which include mortality) also are presented for comparative purposes.

PAI in basal area––Time trends of net and gross periodic annual increment in basal

area are shown in figure 22, by treatments. Initially the control is much above the others,

but net PAI decreases rapidly because of the combination of reduced growth due to

competition and increasing suppression-related mortality. Trends of gross PAI (fig. 23)

are considerably more regular than those of net PAI, because of the effects of mortality.

Although the control has low net PAI due to mortality, gross PAI of the control is generally

higher than in any of the other treatments. This is consistent with the idea that gross

growth of the control represents the productive capacity of the site. The thinning treatments with lowest stocking (treatments 1 and 2) are well below the others.

Periodic Annual

Increment

38

Table 19–Percentage of merchantable board-foot volume (SV6) of trees removed

in thinnings, in logs with scaling diameters larger than indicated value

Scaling diameter (inches) Total cut 

Treatment 6 8 10 12 14 16 18 SV6

- - - - - - - - - - - - - - - - - - - - Percent - - - - - - - - - - - - - - - - - Bd. ft./acre

Fixed:

1 100 61.5 44.3 27.6 14.4 0 0 9,527

3 100 60.8 38.4 17.7 5.4 0 0 7,043

5 100 65.3 38.6 23.1 6.6 3.9 0 4,230

7 100 51.8 35.6 22.3 5.5 0 0 2,936

Increasing:

2 100 79.9 68.3 49.6 41.0 8.9 6.5 3,772

4 100 68.0 55.5 34.8 16.4 0 0 3,855

Decreasing:

6 100 61.8 44.3 32.0 18.7 13.3 0 7,217

8 100 63.8 39.6 17.3 7.4 4.3 0 5,012

Unthinned:

C 100 0 0 0 0 0 0 0
39

Figure 22––Net basal area periodic annual increment in relation to age, by treatments: (A) fixed treatments

and control, and (B) variable treatments and control.
40

Figure 23––Gross basal area periodic annual increment in relation to age, by treatments: (A) fixed treatments

and control, and (B) variable treatments and control.
PAI in volume––Time trends of net PAI in CVTS, CV6, and SV6 (Scribner) are shown

in figures 24, 25, and 26.

Unlike basal area, where there was little difference in PAI among treatments other than

the two lowest stockings (1 and 2), there are marked differences in volume PAI. The

treatments that retain higher stocking levels have consistently greater volume PAIs. 

41

Figure 24––Mean annual increment and periodic annual increment in net total volume (CVTS) in relation to

age and treatment: (A) fixed treatments and control, and (B) variable treatments and control.
42

Figure 25––Mean annual increment and periodic annual increment in net merchantable cubic volume (CV6)

in relation to age and treatment: (A) fixed treatments and control, and (B) variable treatments and control.
43

Figure 26––Mean annual increment and periodic annual increment in Scribner board feet (SV6) in relation to

age and treatment: (A) fixed treatments and control, and (B) variable treatments and control.
There also are differences in trends for the different volume measures. SV6 shows a

lesser decrease with increasing age; this is expected, because board-foot to cubic-foot

ratios increase with increasing tree size. 

Mean annual increment (MAI) is the quotient of cumulative net production up to a given

age divided by that age; that is, the mean production rate over the period from age

zero to the given age.

Mean annual increments in net CVTS, net CV6, and net SV6 are shown superimposed

on the corresponding PAI curves in figures 25, 26, and 27.

Again, there are evident differences in curve shape with different measures of volume.

The curves become more nearly linear as one progresses from CVTS to CV6 to SV6.

Mean Annual 

Increment

44

Figure 27––Net basal area periodic annual increment in relation to midperiod basal area, by periods.
Figures 27 and 28 show observed trends of net and gross PAI in basal area in relation

to midperiod basal area, by growth periods. Figures 29 and 30 make a similar comparison for CVTS.

Compared to net increment, the fluctuations arising from mortality on these small plots

are markedly reduced when gross increment is used. In general, gross increment

increases with basal area stocking and declines over successive growth periods. The

relative rate of increase is greater, and the decline over successive periods less, for

cubic volume than for basal area.

Similar differences appear for net increment, although they are somewhat obscured by

mortality-related variation. Net basal area increment is nearly independent of stocking

except at the lowest stocking levels, whereas gross basal area increment increases

with stocking up to the maximum in the data. Net volume increment shows a maximum

in the vicinity of the most heavily stocked thinning treatments, namely treatments 7 and

8; whereas gross increment continues to increase with stocking. Greater gross growth

on the control is offset by increased mortality.

Relations of net volume increment to relative density and SDI, which are not shown,

are similar to those shown for the relation to basal area, although the difference in

scales produces a lateral shift in the positions of the curves for successive periods. 

Growth-Growing 

Stock Relations

45

Figure 28––Gross basal area periodic annual increment in relation to midperiod basal area, by periods.
46

Figure 29––Net total cubic volume periodic annual increment in relation to midperiod basal area, by periods.

Figure 30––Gross total cubic volume periodic annual increment in relation to midperiod basal area, by 

periods.
Growth percentage is one method of expressing growth rates. The argument that one

should seek maximum return on growing stock, one expression of which is growth percentage, had an important place in the thinking that led to the LOGS study. Growth

percentages used here are calculated as,

growth percent = 100 {PAI / [(X1 + X2) / 2]} ,

where X1 and X2 are growing stock at the beginning and end of the growth period.

CV6 growth percentage––Trends over time of growth percentage in CV6 are shown

in figure 31. Initial growth percentages are very high because of the small values of

CV6 in 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

increase in growth percentage expected from lower total volume of growing stock. The

net effect is to reduce the differences in growth percentage among treatments.

Ratios of merchantable to total cubic volume change with increase in diameter, and this

has a considerable effect on the trends. Compared to CV6, the trend for CVTS starts at

a lower value and declines less rapidly; that for SV6 starts at a higher value and

declines more steeply in the early years. Otherwise the general trends and comparative positions of the treatments are similar.

Growth Percentage

47

Figure 31––Trends of net merchantable volume growth percentage over time, all treatments.
Comparisons for most recent period––Growth percentages in basal area, CVTS,

CV6, and SV6 in relation to midperiod basal area stocking are compared in figure 32

for the most recent growth period. Figure 33 similarly compares growth percentages by

units of measure and treatments (for fixed treatments and control for 1993-98 only). 

Volume growth percentage is higher than basal area growth percentage, a difference

representing the effect of continuing height growth. Growth percentages in CV6 are

somewhat higher than in CVTS and, at this stage in stand development, do not differ

much among treatments. In turn, growth percentages in SV6 are higher than those in

CV6. Because value per unit of volume generally increases with tree size, presumably

value growth percentages are higher than shown and might have somewhat different

relations to level of growing stock and age.

The numerous statistics discussed above are consolidated in tables 20-29 in the

appendix, as means of values for the three plots in each treatment and measurement

date, in both English and metric units. We anticipate that these detailed data will form

the basis for additional comparisons and analyses in the future.

Results from the Stampede Creek LOGS installation in general are qualitatively similar

to those from other LOGS installations as of completion of the planned 60 feet of

height growth, as reported in Curtis and Marshall (1986) and various subsequent individual installation reports. Although there are some quantitative differences related to

site and stand peculiarities, results generally are consistent with and reinforce conclusions drawn previously from the other installations.

Stampede Creek was somewhat older and taller at establishment than other installations in the LOGS series and is on a poorer site than most installations. Therefore,

although it is one of the oldest in terms of stand age, it is not now as far along in

development as the higher site installations. As of 1998 it had just completed the

planned 60 feet of height growth after calibration. In contrast, several of the higher

site installations have had an additional 20 or 30 feet of height growth and a corresponding buildup in stocking subsequent to the final thinning; in some instances

(Hoskins, Iron Creek), this is reflected in markedly increased mortality on the control

and an increase in the ratio of production on the various thinning treatments to that

of controls.

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 1941, as quoted by Braathe 1957; Staebler 1960), widely believed to have

been demonstrated by European experience (Mar:Moller 1954) and stated in standard

silviculture textbooks (for example, Smith 1962: 43). According to this hypothesis, the

main effect of thinning, over a wide range of stand densities, is to redistribute a nearconstant gross increment across various numbers of trees. If true, this would greatly

simplify construction of yield tables and prediction of thinning effects. This hypothesis

had never been tested for young Douglas-fir and was somewhat controversial in

Europe in the late 1950s (Assman 1970, Holmsgaard 1958).

A second related idea (Staebler 1959) was that, for financial efficiency, one should

retain the minimum amount of growing stock feasible without major loss in growth. If

the Langsaeter hypothesis is assumed to hold, then growth percentage should be in

direct inverse relation to growing stock over a considerable range in growing stock.

Discussion

Relation to Results

from Other LOGS

Installations

48
49

Figure 32––Net growth percentages in basal area, CVTS, CV6, and SV6 in the 1993-98 growth period, in

relation to midperiod basal area.

Figure 33––Net growth percentages in basal area, CVTS, CV6, and SV6 in the 1993-98 growth period, by

treatments (fixed treatments and control only).
The LOGS study was designed to test these two concepts and to develop quantitative

relations that could be used to design density control regimes. It also included specific

additional comparisons between fixed, increasing, and decreasing trends in growing

stock. And it was expected to provide much concomitant information.

Except where specifically indicated, the following discussion refers to net rather than to

gross growth. (For thinned plots, gross and net growth are little different with the

exception of treatment 2 and one plot in treatment 5; differences are somewhat greater

for the control.) 

The curves for net basal area PAI in relation to midperiod basal area (fig. 27) show an

apparent maximum near the highest stocking in the thinned treatments. (This maximum

is probably due to the effect of mortality on the control and would not appear were the

control omitted.) Those for gross basal area growth (fig. 28) show PAI increasing with

stocking, although the curves become flatter with advancing age. The curves form a

consistent series, with elevation decreasing uniformly with advancing age. 

Compared to the basal area increment trends, similar trends for gross and net CVTS

increment (figs. 29 and 30) have considerably steeper slopes, still present in the most

recent period. This reflects continuing height growth (Curtis and Marshall 1986: 80). No

maximum is present for gross increment. For net increment, an apparent maximum

occurs in the vicinity of the greatest basal area present on thinned plots and reflects

mortality on the control.

These comparisons demonstrate that, in this comparatively young Douglas-fir stand,

both net and gross volume increment are in fact strongly related to growing stock. This

result is consistent with results from other LOGS installations (Curtis and Clendenen

1994, Curtis and Marshall 1986, Hoyer and others 1996, Marshall and others 1992).

The relation is considerably weaker for basal area increment than for volume increment. We attribute the difference to the height growth component of volume increment.

Like the other LOGS installations, Stampede 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.

Ranking by treatments––Figure 34 compares 1998 cumulative CV6 production by

treatments and is expressed as percentages of CV6 production of the control. In general, production increases with stocking within each of the treatment groups (fixed,

increasing, decreasing). The control currently exceeds all thinning treatments, although

treatments 7 and 8 are very close. The rankings by CV6 are of course in inverse order

to rankings by 1998 attained diameters.

The relatively low positions of treatments 2 and 5 relative to the general trends reflect

in part the effect of mortality among large trees, primarily due to root disease and related

windthrow.

Comparison of the relative density trends shown in figures 13 and 14 shows that treatments 1, 2, and 3 produce relative densities that are not only low but also declining

over time. Given the demonstrated relation between volume production and stocking,

Growth-Growing 

Stock Relations

Comparative Volume

Production

50
the low production on these treatments is to be expected. Production comparisons

(tables 17 to 25 and fig. 34) are consistent with the rule-of-thumb that commercial thinning regimes having timber production as their primary objective should generally aim

to maintain relative densities in the range of RD35 to RD55 except in juvenile stands

(QMD < ca. 6 inches), and somewhat higher as stands approach final harvest (Curtis

and others 1981: 72). Aesthetic and wildlife enhancement objectives could of course

modify this recommendation, as would premiums for rapid diameter growth.

Thinning removals––As would be expected, relative removals are much higher in the

lower density treatments (tables 20 through 27), ranging from 44 percent of total net

CVTS yield in treatment 1 to 12 percent in treatment 7 and 18 percent in treatment 8.

Increasing vs. decreasing treatments––The basal area trends projected in the original study plan (fig. 3) were expected to converge at the end of 60 feet of height growth

at one point for treatments 2, 3, and 6 and at another and higher point for treatments 4,

5, and 8. In actuality, in the first group, basal areas for treatments 3 and 6 are nearly

the same and that for 2 is considerably lower, probably reflecting mortality; and in the

second group, basal areas for treatments 4 and 8 are almost identical and 5 is slightly

lower, again probably reflecting mortality.

Among treatments 2, 3, and 6, treatment 6 (decreasing) has a slight advantage in CV6

production. Among treatments 4, 5, and 8, treatment 8 (decreasing) is superior, and the

difference between 4 and 5 is small. 

51

Figure 34––Cumulative net CV6 production by thinning treatment expressed as a percentage of net

production on control.
Spare plots––Three of the original spare plots were resurrected in 1983 and have

been remeasured along with the others since then. It was thought that these would

provide a measure of the development of a stand receiving an initial precommercial

thinning and no subsequent treatment. The spare plots had somewhat lower H40 in

1998 than others (table 29), which suggests that there were reasons why these were

not used and that they are somewhat lower sites. Hence, a direct comparison at the

same ages is questionable. A comparison of trends in relation to attained H40, however,

suggests that cubic volume production of the spares is in the general vicinity of that of

treatments 7 and 8 at equivalent H40. Similarly, 1998 live crown ratio is similar to that

of treatments 7 and 8 and substantially greater than for the control. Relative density in

1998 was 59 and live crown ratio (all trees) was about 0.36, indicating that the spares

are at or somewhat beyond the stage where commercial thinning would be clearly

appropriate and will soon enter the zone of suppression-related mortality. 

Mean annual increment (MAI) at any point in time is the quotient of cumulative net production divided by age; that is, average production rate achieved as of the specified

age. Culmination age is the age when this attains a maximum, and this is also the age

at which the PAI curve intersects the MAI curve. 

Figures 24, 25, and 26 show observed trends of PAI and MAI for net volume in,

respectively, CVTS, CV6, and SV6. Several points stand out:

1. The erratic PAI curve for treatment 2 and the decline in PAI of treatments 2 and 5 in

the most recent growth period are partly the result of mortality and unrelated to

stand density or thinning regime.

2. The decline in PAI in recent periods for treatments 1, 2, and 3 is associated with the

very low and decreasing relative density in these treatments.

3. For most treatments, current PAI is still two to three times greater than MAI, indicating that the stands are not yet close to culmination.

4. Shape and relative position of the PAI and MAI curves are influenced by the unit of

measure. PAI curves decline less sharply and MAI curves become more nearly linear as one goes from CVTS to CV6 to SV6. This is a consequence of the change in

the ratio of merchantable to total volume that occurs as trees become larger.

LOGS was designed to determine relations among levels of growing stock, increment,

and other stand attributes. The light and very frequent thinnings adopted to maintain

close control of growing stock may not be operationally feasible or desirable in many

situations. We believe, however, that much the same results could be achieved with

considerably longer intervals between entries and correspondingly heavier removals.

LOGS provides information useful in designing alternative regimes.

1. One pertinent result is that the Langsaeter hypothesis of equal production over a

wide range of stand densities does not generally hold for young Douglas-fir. Volume

production is in fact strongly related to growing stock and increases up to or through

treatment 7, which was intended as the maximum level of growing stock thought

consistent with avoidance of suppression mortality and maintenance of stand stability.

In LOGS, through the planned 60 feet of height growth after initial thinning, thinned

treatments have consistently produced less total volume than the control.

MAI Trends and Age 

of Culmination

Management 

Implications

52
Current trends on several installations (Curtis and Clendenen 1994, Hoyer and others 1996, Marshall and Curtis 2002) strongly suggest that this will change in stands

held for some time after the last planned thinning, as stands increase in density and

as the controls are increasingly impacted by suppression-related mortality. 

2. An associated result is that thinning does not automatically increase growth percentage in inverse relation to growing stock. Although heavy thinning does increase

growth percentage, the anticipated increase is to a considerable extent offset by the

decrease in growth associated with smaller growing stock. And, growth percentage

for board feet is higher than for merchantable cubic volume, which in turn is higher

than for total volume

3. LOGS installations were placed in areas carefully selected for full and uniform stocking. Thinned stand conditions after the calibration cut were little different from those

existing on thousands of precommercially thinned acres. The unthinned controls,

however, were and are denser and more uniform than many unthinned stands and

relatively free from hardwoods. One might expect higher volume production from the

controls in early life than from typical unthinned stands, and potential volume gains

from operational thinning are probably underestimated by simple comparisons of

LOGS thinned plots with LOGS control plots (Curtis and others 1997). There is also

the possibility of a slight upward bias in growth estimates for the controls, because

they are unbuffered plots surrounded by thinned plots of much lower density.

Comparison of thinned vs. control in LOGS does not justify a generalization that volume production cannot be increased by thinning. 

4. It is clear, however, from both LOGS and other existing long-term thinning studies,

that the main benefits of thinning are not increased cubic volume production per se,

but larger and more valuable trees, enhanced stand stability, the ability to provide

timber and timber-related employment while maintaining forest cover for extended

periods, and enhancement of visual and wildlife values.

5. A further result, largely unanticipated but which has become increasingly important,

is the definition of the PAI and MAI curves and their implications for culmination age,

growth and yield, and rotations. There are increasing pressures for forms of management that minimize the visual impacts of harvest operations and provide a range

of stand ages with features favorable to wildlife. One option is the combination of

extended rotations with repeated thinning. 

These results, together with other analyses of long-term studies (Curtis 1995) indicate that considerable extension of rotations combined with repeated thinning need

not reduce and would probably increase long-term production, income, and employment. The associated higher growing stocks also would increase carbon sequestration (Haswell 2000). It is clear from figures 24, 25, and 26 and similar graphs from

other LOGS studies that harvest on the very short rotations used by some owners

ultimately must produce drastic reductions in production and employment; short-rotation harvest also creates large areas in early regeneration stages, the appearance of

which generates much public opposition to forestry. 

6. The LOGS data constitute a major portion of the database now available for simulation models. The original study plan (see footnote 1) stated the objective was “...to

53
determine how the amount of growing stock retained...affects cumulative

wood production, tree size, and growth-growing stock ratios. The treatments are planned to cover a broad enough range in growing stock levels

so that the findings will tell how to produce any combination of factors

deemed optimum from a management standpoint.”

The above was a very ambitious objective, and LOGS does not in itself provide such

an answer. But, it has produced much information on trends in attainable diameter

and volume growth under contrasting regimes and is still producing data that form a

valuable part of the information needed. In 1962, modern simulation models were

unknown to forestry, and the authors of the study plan could not have foreseen the

developments in methodology that have occurred since then. LOGS represents

probably the most extensive, most detailed, most tightly controlled, and highest quality thinning data set existing in the region. We anticipate continuing reliance on these

data as an important component of future modeling efforts.

Overall summaries of results for all the individual installations are now or soon will be

available. The general similarity of results across installations has been pointed out

(Curtis and Marshall 1986), but as yet there is no overall analysis of the combined

data.

The most effective way to do this probably will be to use the LOGS data in combination

with high-quality data from other sources as the basis for an overall growth model. This

already has been done with the earlier LOGS data by Hann and others (1997), but the

LOGS data available to them were incomplete, and considerable additional data from

other sources are becoming available. This would necessarily be a major effort, beyond

the scope and capabilities of the LOGS committee as presently constituted and possibly best handled through the Stand Management Cooperative.

There also are a number of subsidiary analyses that should be much more manageable and could produce reports in a fairly short time. These might include:

1. Combined data analyses of MAI and PAI trends. To date these have been discussed

in connection with individual installations, but it may be possible to reduce these to a

form representing the overall trends across installations, in a way that would provide

a compact and readily interpretable presentation. 

2. Examination of possible expression of crown length and crown ratio as functions of

stand density and height. It is clear that fairly close relations exist within an individual

installation. Can these be generalized across installations?

3. Evaluation of possible biases arising from the absence of buffers between plots.

Although we believe such biases are minor, we cannot be certain in the absence of

quantitative measures. Some LOGS installations have been stem-mapped, and a

few installations have separate tree records for an interior 0.1-acre subplot. An evaluation would be useful both to enhance confidence in our results and to guide

design of future experiments.

Future Value 

of the Study 

54
High-quality data from long-term permanent plot experiments such as LOGS provide

an essential basis for development of growth and yield models and for predictions of

the results of alternative management regimes. They also provide on-the-ground examples of the effect of management that can have important educational value. They have

a credibility that no amount of short-term measurements and model assumptions can

provide. And in the past, they often have produced results contradicting the accepted

wisdom of the moment and have provided needed corrections.

Stampede Creek has reached the end of the planned thinning sequence, and further

thinning is not feasible because of the small plot sizes. Possible edge effects associated with the lack of buffers may become more important as trees become fewer and

larger; however, conditions on either side of a thinned plot boundary are in most cases

not drastically different, and it seems unlikely that edge effects have materially affected

results thus far. We believe that continued maintenance and measurement are important.

With the buildup of growing stock over time, trends may develop that are considerably

different from those observed to date. This is already happening on some other installations, such as Iron Creek, Francis, and Hoskins, where some thinned-plot productioncurves are crossing those of the controls, and where competition-related mortality on

the controls is increasing rapidly and appears likely to produce earlier culmination in

the control than in the thinned stands. 

Stampede Creek is unique among the LOGS installations in its location and site characteristics. We therefore believe it is important that the installation be maintained and

measured periodically over at least the next decade, and preferably longer.

1 inch = 2.54 centimeters

1 foot = 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 = 0.2296 square meter per hectare

1 cubic foot per acre = 0.06997 cubic meter per hectare

oF = 1.8 × oC + 32

Metric Equivalents

55
Assman, E. 1970. The principles of forest yield study. Oxford: Pergamon Press. 506 p.

Atzet, T.; White, D.E.; McCrimmon, L.A. [and others], tech. coords. 1996. Field 

guide to the forested plant associations of southwest Oregon. Tech. Pap. R6-NRECOL-TP-17-96. Portland, OR: U.S. Department of Agriculture, Forest Service,

Pacific Northwest Region. 372 p.

Braathe, P. 1957. Thinnings in even-aged stands: a summary of European literature. 

Fredericton, NB: University of New Brunswick, Faculty of Forestry. 92 p.

Brackett, M. 1973. Notes on tarif tree volume computation. Resour. Mgmt. Rep. 24. 

Olympia, WA: Washington Department of Natural Resources. 26 p.

Bruce, D.; DeMars, D.J. 1974. 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.

Chambers, C.J., Jr.; Foltz, B.W. 1979. The tarif system-revisions and additions. DNR 

Note 27. Olympia, WA: Washington Department of Natural Resources. 8 p.

Curtis, R.O. 1982. A simple index of stand density for Douglas-fir. Forest Science. 

28(1): 92-94.

Curtis, R.O. 1995. Extended rotations and culmination age of coast Douglas-fir: old 

studies speak to current issues. Res. Pap. PNW-RP-485. Portland, OR: U.S.

Department of Agriculture, Forest Service, Pacific Northwest Research Station. 49 p.

Curtis, R.O.; Clendenen, G.W.; DeMars, D.J. 1981. A new stand simulator for coast 

Douglas-fir: DFSIM user’s guide. Gen. Tech. Rep. PNW-128. Portland, OR: U.S.

Department of Agriculture, Forest Service, Pacific Northwest Forest and Range

Experiment Station. 79 p.

Curtis, R.O.; Marshall, D.D. 1989. On the definition of stand diameter growth for 

remeasured plots. Western Journal of Applied Forestry. 4(3): 102-103.

Curtis, R.O.; Marshall, D.D.; Bell, J.F. 1997. LOGS––a pioneering example of silvicultural research in coast Douglas-fir. Journal of Forestry. 95(7): 19-25.

Flewelling, J.W.; de Jong, R. 1994. Considerations in simultaneous curve fitting for 

repeated height-diameter measurements. Canadian Journal of Forest Research. 24:

1408-1414.

Flewelling, J.W.; Raynes, L.M. 1993. Variable-shape stem-profile predictions for western hemlock. Part I: Predictions from DBH and total height. Canadian Journal of

Forest Research. 23: 520-536.

Literature Cited6

56

6 Some text references are for previous LOGS reports, which are

given in the front matter and not repeated here.
Franklin, J.F.; Dyrness, C.T. 1973. Natural vegetation of Oregon and Washington. 

Gen. Tech. Rep. PNW-8. Portland, OR: U.S. Department of Agriculture, Forest 

Service, Pacific Northwest Forest and Range Experiment Station. 417 p.

Hann, D.W.; Hester, A.S.; Olsen, C.L. 1997. ORGANON users manual. Version 6.0. 

Corvallis, OR: Department of Forest Resources, Oregon State University. 167 p.

Hann, D.W.; Scrivani, J.A. 1987. Dominant height growth and site index equations for 

Douglas-fir and ponderosa pine in southwest Oregon. Res. Bull. 59. Corvallis, OR: 

Forest Research Laboratory, Oregon State University. 13 p.

Haswell, W.T., III. 2000. Techniques for estimating forest carbon. Journal of Forestry. 

98(9): FOCUS, 1-3.

Holmsgaard, E. 1958. Comments on some German and Swedish thinning experiments in Norway spruce. Forest Science. 4(1): 54-60.

King, J.E. 1966. Site index curves for Douglas-fir in the Pacific Northwest. For. Pap. 8. 

Centralia, WA: Weyerhaeuser Forestry Research Center. 49 p.

Langsaeter, A. 1941. Om tynning i enaldret gran-og furskog: Thinning of even-aged 

spruce and pine forests. Meddelelser fra det Norske Skogforsoeksvesen. 8: 131-216.

Mar:Moller, C. 1954. 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.

McArdle, R.E.; Meyer, W.H.; Bruce, D. 1961. The yield of Douglas-fir in the Pacific 

Northwest. Tech. Bull. 201. Rev. Washington, DC: U.S. Department of Agriculture. 72 p.

Reineke, L.H. 1933. Perfecting a stand-density index for even-aged forests. Journal of 

Agricultural Research. 46: 627-638.

Smith, D.M. 1962. The practice of silviculture. 7th ed. New York: John Wiley and Sons. 

578 p.

Staebler, G.R. 1959. Optimum levels of growing stock for managed stands. 

Proceedings, Society of American Foresters: 110-113.

Staebler, G.R. 1960. Theoretical derivation of numerical thinning schedules for 

Douglas-fir. Forest Science. 6(2): 98-109.

57
Appendix

58

Table 20a–Stand development table for treatment 1 (plots 41, 72, and 126), by year, per acre basis 

After thinning Removed in thinning Mortality 

40 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Feet Inches No. Inches Ft 2 - -Cubic feet - - No. Inches Ft 2 - - - - - - - - - -Cubic feet - - - - - - - - - No. Inches Ft2 - - Ft3 - -

1968 33 58 9.2 295 6.5 68.9 1,480 586 0 0.0 0.0 0 0 0.0 0.0 0.00 0 0.0 0.0 0 01973 38 69 10.9 193 8.4 73.4 1,905 1,236 100 6.8 25.2 606 280 6.1 5.3 0.87 2 6.3 0.4 8 11978 43 80 12.7 132 10.4 76.5 2,293 1,856 60 8.6 24.4 694 468 11.6 9.4 0.88 2 2.9 0.1 1 01983 48 89 14.6 82 13.3 77.0 2,619 2,382 50 9.4 23.9 741 553 14.8 12.3 0.79 0 0.0 0.0 0 01988 53 99 16.4 62 15.4 79.2 2,983 2,802 20 12.5 17.0 605 538 30.3 26.9 0.85 0 0.0 0.0 0 01993 58 109 18.1 50 17.5 82.9 3,382 3,217 12 15.1 14.6 574 538 47.8 44.8 0.89 0 0.0 0.0 0 01998 63 116 19.6 48 19.1 95.8 4,120 3,935 0 0.0 0.0 0 0 0.0 0.0 0.00 2 17.1 2.7 113 108

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - - Cubic feet - - - - - - - - - - - -Inches- - - Square feet - - - - - - - - - - - - - - - - Cubic feet - - - - - - - - - - - - - - - - - -

1968 33 1,480 1,480 586 586 0.00 0.00 0.0 0.0 0 45 0 18 0 45 0 181973 38 2,511 2,520 1,515 1,516 0.26 0.26 5.9 6.0 206 66 186 40 208 66 186 401978 43 3,593 3,602 2,604 2,605 0.30 0.29 5.5 5.5 216 84 218 61 217 84 218 611983 48 4,660 4,669 3,683 3,684 0.31 0.31 4.9 4.9 213 97 216 77 213 97 216 771988 53 5,628 5,637 4,641 4,642 0.31 0.31 3.8 3.8 194 106 192 88 194 106 192 881993 58 6,602 6,611 5,594 5,595 0.34 0.34 3.6 3.6 195 114 191 96 195 114 191 961998 63 7,340 7,462 6,313 6,421 0.33 0.33 2.6 3.1 148 117 144 100 170 118 165 102

a Average height and d.b.h. of the 40 largest trees per acre (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 6-inch top diameter (CV6), inside bark.d Only trees 7.6 inches d.b.h. and larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 3,220 cubic feet 

(49 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 122 cubic feet (2 percent of the total gross yield).
Table 20b––Stand development table for treatment 1 (plots 41, 72, and 126), by year, per hectare basis

After thinning Removed in thinning Mortality 

100 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal 

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Meters cm No. cm m2 Cubic meters No. cm m2 - - - - - - - - Cubic meters- - - - - - - - - No. cm m2 - - m3 - -

1968 33 18.1 23.3 729 16.6 15.8 104.1 41.5 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0 0.0 0.0 0.0 0.01973 38 21.6 27.8 478 21.3 16.9 133.9 87.0 247 17.3 5.8 42.9 20.1 0.2 0.2 0.87 4 16.0 0.1 1.1 0.61978 43 24.8 32.3 325 26.3 17.6 161.0 130.4 148 21.9 5.6 49.1 33.3 0.3 0.3 0.88 4 7.4 0.0 0.6 0.51983 48 27.7 37.2 202 33.7 17.7 183.9 167.3 124 23.8 5.5 52.3 39.2 0.4 0.4 0.79 0 0.0 0.0 0.0 0.01988 53 30.7 41.5 152 39.2 18.2 209.3 196.7 49 31.7 3.9 42.8 38.2 0.9 0.8 0.85 0 0.0 0.0 0.0 0.01993 58 33.8 46.0 124 44.4 19.1 237.2 225.7 29 38.5 3.4 40.7 38.2 1.4 1.3 0.89 0 0.0 0.0 0.0 0.01998 63 36.0 49.9 119 48.7 22.0 288.9 276.0 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 4 43.5 0.6 8.4 8.0

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - Cubic meters - - - - - Centimeters - - - m2 - - - - - - - - - - - - - - - - - - Cubic meters - - - - - - - - - - - - - - -

1968 33 104.1 104.1 41.5 41.5 0.00 0.00 0.0 0.0 0.0 3.6 0.0 1.7 0.0 3.6 0.0 1.71973 38 176.3 176.9 106.6 106.6 0.67 0.66 1.4 1.4 14.9 5.1 13.5 3.3 15.1 5.1 13.5 3.31978 43 252.0 252.7 182.8 182.8 0.75 0.74 1.3 1.3 15.6 6.3 15.7 4.7 15.7 6.4 15.7 4.71983 48 326.7 327.3 258.3 258.4 0.79 0.79 1.1 1.1 15.4 7.3 15.6 5.9 15.4 7.3 15.6 5.91988 53 394.5 395.1 325.4 325.5 0.79 0.79 0.9 0.9 14.1 7.9 13.9 6.6 14.1 7.9 13.9 6.61993 58 462.6 463.2 392.1 392.2 0.85 0.85 0.8 0.8 14.1 8.5 13.8 7.3 14.1 8.5 13.8 7.31998 63 514.3 522.8 442.4 450.0 0.85 0.83 0.6 0.7 10.8 8.7 10.6 7.5 12.4 8.8 12.1 7.6

a Average height and d.b.h. of the 100 largest trees per hectare (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 15.25-cm top diameter (CV6), inside bark.d Only trees 19.3 cm d.b.h. and larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 225.4 cubic meters

(49 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 8.5 cubic meters (2 percent of the total gross yield).

59
Table 21a––Stand development table for treatment 2 (plots 91, 112, and 113), by year, per acre basis

After thinning Removed in thinning Mortality 

40 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Feet Inches No. Inches Ft 2 - -Cubic feet - - No. Inches Ft 2 - - - - - - - - - -Cubic feet - - - - - - - - - No. Inches Ft2 - - Ft3 - -

1968 33 59 10.4 287 6.6 67.5 1,413 686 0 0.0 0.0 0 0 0 0.0 0.00 0 0.0 0.0 0 01973 38 71 12.3 190 8.4 71.8 1,829 1,243 93 6.9 24.1 566 283 6.1 5.9 0.87 3 6.4 0.7 18 111978 43 81 14.1 123 10.8 77.6 2,296 1,914 62 7.6 19.3 502 280 8.1 6.2 0.77 5 7.5 1.5 36 161983 48 91 15.8 82 14.0 85.6 2,916 2,670 42 8.2 15.4 424 270 10.1 8.2 0.67 0 0.0 0.0 0 01988 53 98 17.2 73 15.5 94.2 3,442 3,219 3 13.4 3.3 125 115 41.7 38.3 0.88 5 15.7 6.7 260 2441993 58 108 18.9 70 17.1 110.2 4,381 4,145 2 15.1 2.1 89 84 44.5 42.0 0.89 2 8.0 0.6 17 91998 63 116 20.4 65 18.6 121.7 5,082 4,836 0 0.0 0.0 0 0 0.0 0.0 0.00 5 14.8 6.0 258 239

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - - Cubic feet - - - - - - - - - - - -Inches - - - Square feet - - - - - - - - - - - - - - - - Cubic feet - - - - - - - - - - - - - - - - - -

1968 33 1,413 1,413 686 686 0.00 0.00 0.0 0.0 0 43 0 21 0 43 0 211973 38 2,395 2,413 1,526 1,537 0.26 0.26 5.7 5.8 196 63 168 40 200 64 170 401978 43 3,364 3,418 2,478 2,505 0.30 0.29 5.0 5.3 194 78 190 58 201 79 194 581983 48 4,398 4,452 3,504 3,531 0.30 0.30 4.7 4.7 207 92 205 73 207 93 205 741988 53 5,059 5,373 4,168 4,439 0.28 0.31 2.4 3.7 132 95 133 79 184 101 182 841993 58 6,087 6,417 5,178 5,457 0.31 0.30 3.6 3.7 206 105 202 89 209 111 204 941998 63 6,788 7,376 5,869 6,388 0.30 0.28 2.3 3.5 140 108 138 93 192 117 186 101aAverage height and d.b.h. of the 40 largest trees per acre (estimated from d.b.h. and HT-d.b.h. curves).bQuadratic mean diameter at breast height.cAll volumes are total stem cubic (CVTS) or merchantable cubic to a 6-inch top diameter (CV6), inside bark.d Only trees 7.6 inches d.b.h. and larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 1,706 cubic feet 

(27 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 588 cubic feet (8 percent of the total gross yield).

60
Table 21b––Stand development table for treatment 2 (plots 91, 112, and 113), by year, per hectare basis

After thinning Removed in thinning Mortality 

100 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Meters cm No. cm m2 Cubic meters No. cm m2 - - - - - - - Cubic meters- - - - - - - - - No. cm m2 - - m3 - -

1968 33 18.6 26.4 708 16.7 15.5 99.4 48.5 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0 0.0 0.0 0.0 0.01973 38 22.2 31.3 469 21.3 16.5 128.6 87.5 231 17.5 5.6 40.1 20.3 0.2 0.2 0.87 8 16.3 0.2 1.8 1.31978 43 25.2 35.7 305 27.5 17.9 161.3 134.5 152 19.3 4.4 35.6 20.1 0.2 0.2 0.77 12 19.1 0.4 3.0 1.61983 48 28.3 40.2 202 35.6 19.7 203.9 187.4 103 20.9 3.5 30.2 19.4 0.3 0.2 0.67 0 0.0 0.0 0.0 0.01988 53 30.5 43.7 181 39.4 21.7 241.4 225.9 8 34.2 0.8 9.2 8.5 1.1 1.0 0.88 12 39.8 1.5 18.7 17.61993 58 33.5 47.9 173 43.6 25.3 307.2 290.7 4 38.4 0.5 6.7 6.4 1.5 1.5 0.89 4 20.4 0.1 1.7 1.11998 63 35.8 51.7 161 47.4 28.0 356.2 339.1 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 12 37.7 1.4 18.5 17.3

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - - Cubic meters - - - - - - - - - cm - - - Square meters - - - - - - - - - - - - - - - Cubic meters - - - - - - - - - - - - - - -

1968 33 99.4 99.4 48.5 48.5 0.00 0.00 0.0 0.0 0.0 3.5 0.0 2.0 0.0 3.5 0.0 2.01973 38 168.2 169.4 107.3 108.1 0.67 0.66 1.3 1.3 14.2 4.9 12.3 3.3 14.5 4.9 12.4 3.31978 43 236.0 239.8 173.9 175.8 0.76 0.75 1.2 1.2 14.1 6.0 13.8 4.5 14.6 6.1 14.1 4.61983 48 308.4 312.1 245.8 247.7 0.77 0.77 1.1 1.1 15.0 6.9 14.9 5.6 15.0 7.0 14.9 5.61988 53 354.6 376.6 292.3 311.2 0.70 0.79 0.5 0.9 9.7 7.2 9.8 6.0 13.4 7.6 13.2 6.41993 58 426.6 449.7 362.9 382.5 0.80 0.75 0.8 0.9 14.9 7.8 14.6 6.7 15.1 8.2 14.8 7.11998 63 475.7 516.8 411.3 447.6 0.76 0.71 0.5 0.8 10.3 8.0 10.2 7.0 13.9 8.7 13.5 7.6

a Average height and d.b.h. of the 100 largest trees per hectare (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 15.25-cm top diameter (CV6), inside bark.d Only trees 19.3 cm d.b.h. and larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 119.4 cubic meters 

(27 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 41.1 cubic meters (8 percent of the total gross yield).

61
Table 22a––Stand development table for treatment 3 (plots 51, 103, and 121), by year, per acre basis

After thinning Removed in thinning Mortality 

40 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal 

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Feet Inches No. Inches Ft 2 - -Cubic feet - - No. Inches Ft 2 - - - - - - - - - -Cubic feet - - - - - - - - - No. Inches Ft2 - - Ft3 - -

1968 33 59 9.4 290 6.7 70.2 1,481 604 0 0.0 0.0 0 0 0.0 0.0 0.00 0 0.0 0.0 0 01973 38 69 11.2 198 8.6 79.4 2,015 1,336 90 6.4 20.1 445 165 4.9 3.7 0.80 2 6.3 0.4 8 11978 43 80 12.9 152 10.4 89.6 2,658 2,160 47 8.5 18.5 512 336 10.9 8.0 0.85 0 0.0 0.0 0 01983 48 90 14.6 122 12.2 98.0 3,291 2,900 28 10.7 17.6 570 474 20.4 17.6 0.90 2 3.4 0.1 2 01988 53 99 16.2 95 14.3 104.7 3,881 3,593 27 10.2 15.0 512 403 19.0 14.9 0.76 0 0.0 0.0 0 01993 58 109 17.6 82 16.0 113.8 4,605 4,346 13 12.9 12.2 466 418 35.8 32.2 0.83 0 0.0 0.0 0 01998 63 114 19.0 82 17.3 132.9 5,598 5,317 0 0.0 0.0 0 0 0.0 0.0 0.00 0 0.0 0.0 0 0

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - - Cubic feet - - - - - - - - - - - - Inches - - - Square feet - - - - - - - - - - - - - - - - Cubic feet - - - - - - - - - - - - - - - - - -

1968 33 1,481 1,481 604 604 0.00 0.00 0.0 0.0 0 45 0 18 0 45 0 181973 38 2,460 2,467 1,501 1,502 0.26 0.26 5.9 5.9 196 65 179 40 197 65 180 401978 43 3,616 3,623 2,661 2,662 0.28 0.28 5.7 5.7 231 84 232 62 231 84 232 621983 48 4,818 4,827 3,875 3,876 0.30 0.29 5.2 5.2 241 100 243 81 241 101 243 811988 53 5,920 5,929 4,971 4,972 0.26 0.26 4.4 4.4 220 112 219 94 220 112 219 941993 58 7,112 7,121 6,142 6,143 0.28 0.28 4.2 4.2 238 123 234 106 238 123 234 1061998 63 8,104 8,113 7,112 7,113 0.26 0.26 3.8 3.8 198 129 194 113 198 129 194 113a Average height and d.b.h. of the 40 largest trees per acre (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 6-inch top diameter (CV6), inside bark.d Only trees 7.6 inches d.b.h. and larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 2,506 cubic feet 

(35 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 9 cubic feet (0.1 percent of the total gross yield).

62
Table 22b––Stand development table for treatment 3 (plots 51, 103, and 121), by year, per hectare basis

After thinning Removed in thinning Mortality 

100 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Meters cm No. cm m2 Cubic meters No. cm m2 - - - - - - - - Cubic meters- - - - - - - - - No. cm m2 - - m3 - -

1968 33 18.4 23.9 716 16.9 16.2 104.2 42.8 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0 0.0 0.0 0.0 0.01973 38 21.4 28.3 490 21.8 18.3 141.5 94.0 222 16.3 4.6 31.6 12.1 0.1 0.1 0.80 4 16.0 0.1 1.0 0.61978 43 24.9 32.8 375 26.5 20.6 186.6 151.7 115 21.7 4.2 36.4 24.0 0.3 0.2 0.85 0 0.0 0.0 0.0 0.01983 48 28.1 37.2 301 30.9 22.5 230.9 203.5 70 27.2 4.1 40.4 33.6 0.6 0.5 0.90 4 8.7 0.0 0.6 0.51988 53 30.7 41.1 235 36.3 24.1 272.1 252.0 66 25.9 3.5 36.4 28.7 0.5 0.4 0.76 0 0.0 0.0 0.0 0.01993 58 33.6 44.8 202 40.7 26.2 322.9 304.8 33 32.9 2.8 33.2 29.7 1.0 0.9 0.83 0 0.0 0.0 0.0 0.01998 63 35.3 48.2 202 44.0 30.6 392.4 372.7 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0 0.0 0.0 0.0 0.0

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - Cubic meters - - - - - - - - - cm - - - - Square meters - - - - - - - - - - - - - - - Cubic meters - - - - - - - - - - - - - - -

1968 33 104.2 104.2 42.8 42.8 0.00 0.00 0.0 0.0 0.0 3.6 0.0 1.8 0.0 3.6 0.0 1.81973 38 172.7 173.2 105.6 105.6 0.66 0.66 1.3 1.4 14.2 5.0 13.1 3.3 14.3 5.0 13.1 3.31978 43 253.6 254.1 186.8 186.8 0.72 0.72 1.3 1.3 16.7 6.4 16.7 4.8 16.7 6.4 16.7 4.81983 48 337.8 338.4 271.8 271.8 0.75 0.73 1.2 1.2 17.3 7.5 17.5 6.2 17.4 7.5 17.5 6.21988 53 414.9 415.5 348.5 348.5 0.65 0.65 1.0 1.0 15.9 8.3 15.8 7.1 15.9 8.3 15.8 7.11993 58 498.3 498.9 430.4 430.5 0.70 0.70 1.0 1.0 17.2 9.1 16.9 7.9 17.2 9.1 16.9 7.91998 63 567.8 568.4 498.4 498.4 0.66 0.66 0.9 0.9 14.4 9.5 14.1 8.4 14.4 9.5 14.1 8.4

a Average height and d.b.h. of the 100 largest trees per hectare (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 15.25-cm top diameter (CV6), inside bark.d Only trees 19.3 cm d.b.h. and larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 175.4 cubic 

meters (35 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 0.6 cubic meters (0.1 percent of the total gross yield).

63
Table 23a––Stand development table for treatment 4 (plots 71, 82, and 115), by year, per acre basis

After thinning Removed in thinning Mortality 

40 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Feet Inches No. Inches Ft 2 - -Cubic feet - - No. Inches Ft 2 - - - - - - - - - -Cubic feet - - - - - - - - - No. Inches Ft2 - - Ft3 - -

1968 33 58 9.1 297 6.6 69.7 1,446 577 0 0.0 0.0 0 0 0.0 0.0 0.00 0 0.0 0.0 0 01973 38 69 10.9 208 8.4 80.0 2,043 1,336 83 6.5 19.3 434 164 5.2 3.4 0.82 5 4.7 0.6 11 11978 43 79 12.8 158 10.2 89.5 2,643 2,125 47 8.4 18.0 492 320 10.5 8.4 0.86 3 7.2 0.9 25 181983 48 90 14.6 135 12.0 105.6 3,522 3,104 22 9.3 10.2 319 233 14.5 12.9 0.80 2 10.3 1.0 30 241988 53 101 16.1 120 13.7 121.6 4,482 4,113 15 9.4 7.2 234 180 15.6 15.0 0.71 0 0.0 0.0 0 01993 58 112 17.9 115 15.2 142.7 5,719 5,345 5 11.5 3.6 132 115 26.4 23.0 0.77 0 0.0 0.0 0 01998 63 118 19.4 115 16.4 165.8 6,927 6,528 0 0.0 0.0 0 0 0.0 0.0 0.00 0 0.0 0.0 0 0

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - - Cubic feet - - - - - - - - - - - - -Inches- - - Square feet - - - - - - - - - - - - - - - - Cubic feet - - - - - - - - - - - - - - - - - -

1968 33 1,446 1,446 577 577 0.00 0.00 0.0 0.0 0 44 0 17 0 44 0 171973 38 2,477 2,488 1,500 1501 0.27 0.26 5.9 6.0 206 65 184 39 208 65 185 391978 43 3,570 3,606 2,609 2,627 0.28 0.28 5.5 5.7 218 83 222 61 223 84 225 611983 48 4,768 4,834 3,821 3,863 0.30 0.29 5.3 5.5 240 99 242 80 246 101 247 801988 53 5,961 6,027 5,010 5,053 0.25 0.25 4.6 4.6 239 112 238 95 239 114 238 951993 58 7,331 7,397 6,357 6,400 0.27 0.27 5.0 5.0 274 126 269 110 274 128 269 1101998 63 8,539 8,605 7,539 7,582 0.24 0.24 4.6 4.6 242 136 236 120 242 137 236 120a Average height and d.b.h. of the 40 largest trees per acre (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 6-inch top diameter (CV6), inside bark.d Only trees 7.6 inches d.b.h. and larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 1,612 cubic feet 

(22 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 66 cubic feet (1 percent of the total gross yield).

64
Table 23b––Stand development table for treatment 4 (plots 71, 82, and 115), by year, per hectare basis

After thinning Removed in thinning Mortality 

100 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Meters cm No. cm m2 Cubic meters No. cm m2 - - - - - - - - Cubic meters- - - - - - - - - No. cm m2 - - m3 - -

1968 33 18.0 23.2 733 16.7 16.0 101.7 40.9 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0 0.0 0.0 0.0 0.01973 38 21.6 27.8 515 21.5 18.4 143.5 94.0 206 16.6 4.4 30.9 12.0 0.1 0.1 0.82 12 11.9 0.1 1.3 0.61978 43 24.7 32.4 391 26.0 20.6 185.5 149.3 115 21.4 4.1 35.0 22.9 0.3 0.2 0.86 8 18.2 0.2 2.2 1.71983 48 28.0 37.2 333 30.6 24.3 247.1 217.8 54 23.7 2.4 22.8 16.8 0.4 0.4 0.80 4 26.2 0.2 2.6 2.21988 53 31.3 41.0 296 34.9 28.0 314.2 288.4 37 23.8 1.6 16.9 13.1 0.4 0.4 0.71 0 0.0 0.0 0.0 0.01993 58 34.6 45.4 284 38.7 32.8 400.8 374.7 12 29.3 0.8 9.8 8.6 0.8 0.7 0.77 0 0.0 0.0 0.0 0.01998 63 36.4 49.3 284 41.7 38.1 485.4 457.4 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0 0.0 0.0 0.0 0.0

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - - Cubic meters - - - - - - - - cm - - - Square meters - - - - - - - - - - - - - - - Cubic meters - - - - - - - - - - - - - - -

1968 33 101.7 101.7 40.9 40.9 0.00 0.00 0.0 0.0 0.0 3.6 0.0 1.7 0.0 3.6 0.0 1.71973 38 173.9 174.7 105.5 105.5 0.68 0.66 1.4 1.4 14.9 5.1 13.4 3.3 15.1 5.1 13.4 3.31978 43 250.4 252.9 183.1 184.4 0.72 0.72 1.3 1.3 15.8 6.3 16.0 4.7 16.1 6.4 16.3 4.81983 48 334.3 338.9 267.9 270.9 0.75 0.75 1.2 1.3 17.3 7.5 17.5 6.1 17.7 7.5 17.8 6.11988 53 417.8 422.4 351.2 354.2 0.64 0.64 1.1 1.1 17.2 8.4 17.1 7.1 17.2 8.5 17.1 7.21993 58 513.7 518.3 445.5 448.5 0.68 0.68 1.1 1.1 19.7 9.3 19.4 8.2 19.7 9.4 19.4 8.21998 63 598.2 602.8 528.3 531.3 0.60 0.60 1.1 1.1 17.4 10.0 17.1 8.9 17.4 10.1 17.1 8.9

a Average height and d.b.h. of the 100 largest trees per hectare (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 15.25-cm top diameter (CV6), inside bark.d Only trees 19.3 cm d.b.h. and larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 112.8 cubic 

meters (22 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 4.6 cubic meters (1 percent of the total gross yield).

65
Table 24a––Stand development table for treatment 5 (plots 92, 114, and 125), by year, per acre basis

After thinning Removed in thinning Mortality 

40 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years FeetI nches No. Inches Ft 2 - -Cubic feet - - No. Inches Ft 2 - - - - - - - - - -Cubic feet - - - - - - - - - No. Inches Ft2 - - Ft3 - -

1968 33 62 10.4 285 6.7 68.9 1,498 726 0 0.0 0.0 0 0 0.0 0.0 0.00 0 0.0 0.0 0 0

1973 38 74 12.3 237 8.2 86.5 2,254 1,513 47 6.6 11.1 258 95 5.5 3.2 0.83 2 3.7 0.1 2 0

1978 43 84 14.1 205 9.6 101.9 3,032 2,357 32 8.6 12.9 371 242 11.6 8.6 0.92 0 0.0 0.0 0 0

1983 48 94 15.8 175 11.1 115.9 3,874 3,284 30 8.9 12.9 408 289 13.6 10.7 0.83 0 0.0 0.0 0 0

1988 53 102 17.2 148 13.0 129.5 4,770 4,265 27 8.1 9.5 298 185 11.0 10.3 0.67 0 0.0 0.0 0 0

1993 58 112 18.6 120 15.1 142.0 5,758 5,332 27 8.1 9.5 320 219 11.9 12.9 0.59 2 6.8 0.4 12 3

1998 63 118 19.9 115 16.2 157.6 6,667 6,239 0 0.0 0.0 0 0 0.0 0.0 0.00 5 12.9 4.5 185 166

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - - Cubic feet - - - - - - - - - - - -Inches - - - Square feet - - - - - - - - - - - - - - - - Cubic feet - - - - - - - - - - - - - - - - - 

1968 33 1,498 1,498 726 726 0.00 0.00 0.0 0.0 0 45 0 22 0 45 0 22

1973 38 2,512 2,514 1,608 1,608 0.26 0.26 5.8 5.8 203 66 176 42 203 66 176 42

1978 43 3,661 3,663 2,695 2,695 0.25 0.25 5.7 5.7 230 85 217 63 230 85 217 63

1983 48 4,911 4,913 3,910 3,910 0.24 0.24 5.4 5.4 250 102 243 81 250 102 243 81

1988 53 6,105 6,107 5,077 5,077 0.22 0.22 4.6 4.6 239 115 233 96 239 115 233 96

1993 58 7,412 7,426 6,362 6,365 0.23 0.22 4.4 4.5 262 128 257 110 264 128 258 110

1998 63 8,322 8,521 7,269 7,439 0.22 0.22 3.1 4.0 182 132 181 115 219 135 215 118

a Average height and d.b.h. of the 40 largest trees per acre (estimated from d.b.h. and HT-d.b.h. curves).

b Quadratic mean diameter at breast height.

c All volumes are total stem cubic (CVTS) or merchantable cubic to a 6-inch top diameter (CV6), inside bark.

d Only trees 7.6 inches d.b.h. or larger.

e QMD cut ÷ QMD before thinning.

f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 1,655 cubic feet 

(22 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 199 cubic feet (2 percent of the total gross yield).

66
Table 24b––Stand development table for treatment 5 (plots 92, 114, and 125), by year, per hectare basis

After thinning Removed in thinning Mortality 

100 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Meters cm No. cm m2 Cubic meters No. cm m2 - - - - - - - - Cubic meters- - - - - - - - - No. cm m2 - - m3 - -

1968 33 19.5 26.5 704 16.9 15.9 105.4 51.3 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0 0.0 0.0 0.0 0.01973 38 23.1 31.3 585 20.9 19.9 158.3 106.4 115 16.8 2.6 18.5 7.2 0.2 0.1 0.83 4 9.4 0.0 0.6 0.51978 43 26.1 35.8 506 24.4 23.4 212.8 165.5 78 22.0 3.0 26.5 17.5 0.3 0.2 0.92 0 0.0 0.0 0.0 0.01983 48 29.0 40.1 432 28.4 26.6 271.7 230.3 74 22.6 3.0 29.1 20.7 0.4 0.3 0.83 0 0.0 0.0 0.0 0.01988 53 31.7 43.8 366 33.1 29.8 334.4 299.0 66 20.6 2.2 21.4 13.4 0.3 0.3 0.67 0 0.0 0.0 0.0 0.01993 58 34.8 47.4 296 38.4 32.7 403.5 373.7 66 20.5 2.2 22.9 15.8 0.3 0.4 0.59 4 17.3 0.1 1.3 0.71998 63 36.6 50.5 284 41.2 36.2 467.2 437.2 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 12 32.8 1.0 13.5 12.1

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - - Cubic meters - - - - - - - - - cm - - - Square meters - - - - - - - - - - - - - - - Cubic meters - - - - - - - - - - - - - - -

1968 33 105.4 105.4 51.3 51.3 0.00 0.00 0.0 0.0 0.0 3.7 0.0 2.0 0.0 3.7 0.0 2.01973 38 176.4 176.5 113.1 113.1 0.66 0.65 1.3 1.3 14.7 5.1 12.8 3.5 14.7 5.1 12.8 3.51978 43 256.8 256.9 189.1 189.1 0.64 0.64 1.3 1.3 16.6 6.5 15.7 4.9 16.6 6.5 15.7 4.91983 48 344.3 344.4 274.2 274.2 0.61 0.61 1.2 1.2 18.0 7.7 17.5 6.2 18.0 7.7 17.5 6.21988 53 427.8 428.0 355.9 355.9 0.55 0.55 1.1 1.1 17.2 8.6 16.8 7.2 17.2 8.6 16.8 7.21993 58 519.4 520.3 445.8 446.0 0.58 0.56 1.0 1.0 18.8 9.4 18.5 8.2 19.0 9.5 18.5 8.21998 63 583.0 597.0 509.3 521.2 0.56 0.55 0.7 0.9 13.2 9.7 13.2 8.6 15.8 10.0 15.5 8.8

a Average height and d.b.h. of the 100 largest trees per hectare (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 15.25-cm top diameter (CV6), inside bark.d Only trees 19.3 cm d.b.h. and larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 115.8 cubic 

meters (22 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 13.9 cubic meters (2 percent of the total gross yield).

67
Table 25a––Stand development table for treatment 6 (plots 32, 101, and 102), by year, per acre basis

After thinning Removed in thinning Mortality 40 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Feet Inches No. Inches Ft 2 - -Cubic feet - - No. Inches Ft 2 - - - - - - - - - -Cubic feet - - - - - - - - - No. Inches Ft2 - - Ft3 - -

1968 33 58 9.1 320 6.1 64.7 1,327 474 0 0.0 0.0 0 0 0.0 0.0 0.00 0 0.0 0.0 0 0

1973 38 68 10.9 278 7.6 85.8 2,071 1,176 38 6.4 8.6 189 67 5.0 3.3 0.87 3 3.6 0.2 3 0

1978 43 79 12.8 218 9.2 99.6 2,787 2,054 57 7.9 19.4 517 298 9.1 6.2 0.89 3 3.6 0.2 3 0

1983 48 90 14.6 163 11.0 1,06.7 3,470 2,908 55 8.8 23.3 693 487 12.6 11.3 0.84 0 0.0 0.0 0 0

1988 53 99 16.3 110 13.8 1,12.0 4,084 3,732 52 8.3 19.6 607 395 11.7 10.7 0.68 2 8.8 0.7 22 14

1993 58 109 17.9 87 15.9 1,17.7 4,712 4,429 22 12.1 17.2 649 568 29.5 25.8 0.80 2 12.3 1.4 51 46

1998 63 116 19.4 85 17.4 1,38.9 5,850 5,550 0 0.0 0.0 0 0 0.0 0.0 0.00 2 7.4 0.5 14 6

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - - Cubic feet - - - - - - - - - - - -Inches- - - - Square feet - - - - - - - - - - - - - - - - Cubic feet - - - - - - - - - - - - - - - - - -

1968 33 1,327 1,327 474 474 0.00 0.00 0.0 0.0 0 40 0 14 0 40 0 14

1973 38 2,261 2,264 1,243 1,243 0.26 0.26 6.0 6.0 187 59 154 33 187 60 154 33

1978 43 3,494 3,501 2,419 2,419 0.28 0.27 6.6 6.7 247 81 235 56 247 81 235 56

1983 48 4,869 4,876 3,760 3,760 0.26 0.26 6.1 6.1 275 101 268 78 275 102 268 78

1988 53 6,090 6,119 4,980 4,994 0.26 0.25 5.0 5.1 244 115 244 94 249 115 247 94

1993 58 7,367 7,447 6,245 6,305 0.29 0.29 4.6 4.8 255 127 253 108 266 128 262 109

1998 63 8,506 8,599 7,366 7,431 0.30 0.28 4.3 4.4 228 135 224 117 230 136 225 118

a Average height and d.b.h. of the 40 largest trees per acre (estimated from d.b.h. and HT-d.b.h. curves).

b Quadratic mean diameter at breast height.

c All volumes are total stem cubic (CVTS) or merchantable cubic to a 6-inch top diameter (CV6), inside bark.

d Only trees 7.6 inches d.b.h. or larger.

e QMD cut ÷ QMD before thinning.

f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 2,656 cubic feet 

(36 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 93 cubic feet (1 percent of the total gross yield).

68
Table 25b––Stand development table for treatment 6 (plots 32, 101, and 102), by year, per hectare basis

After thinning Removed in thinning Mortality 

100 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Meters cm No. cm m 2 Cubic meters No. cm m2 - - - - - - - - Cubic meters- - - - - - - - - No. cm m2 - - m3 - -

1968 33 18.2 23.1 790 15.5 14.9 93.4 33.7 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0 0.0 0.0 0.0 0.01973 38 21.1 27.8 687 19.2 19.7 145.5 82.8 95 16.3 2.0 13.8 5.2 0.1 0.1 0.87 8 9.1 0.1 0.7 0.51978 43 24.6 32.5 539 23.4 22.9 195.6 144.3 140 20.2 4.5 36.7 21.4 0.3 0.2 0.89 8 9.0 0.1 0.7 0.51983 48 27.8 37.1 403 28.1 24.5 243.4 204.0 136 22.4 5.3 49.0 34.6 0.4 0.3 0.84 0 0.0 0.0 0.0 0.01988 53 30.8 41.3 272 35.0 25.8 286.4 261.7 128 21.2 4.5 43.0 28.2 0.3 0.3 0.68 4 22.4 0.2 2.0 1.51993 58 33.8 45.5 214 40.3 27.1 330.3 310.5 54 30.7 4.0 46.0 40.3 0.8 0.7 0.80 4 31.3 0.3 4.1 3.71998 63 35.9 49.3 210 44.2 32.0 410.0 389.0 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 4 18.8 0.1 1.5 0.9

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - - Cubic meters - - - - - - - - - cm - - - Square meters - - - - - - - - - - - - - - - Cubic meters - - - - - - - - - - - - - - -

1968 33 93.4 93.4 33.7 33.7 0.00 0.00 0.0 0.0 0.0 3.3 0.0 1.5 0.0 3.3 0.0 1.51973 38 158.7 159.0 87.5 87.5 0.67 0.66 1.4 1.4 13.6 4.7 11.3 2.8 13.6 4.7 11.3 2.81978 43 245.1 245.5 169.8 169.8 0.71 0.69 1.5 1.5 17.8 6.2 17.0 4.4 17.8 6.2 17.0 4.41983 48 341.3 341.8 263.7 263.7 0.67 0.67 1.4 1.4 19.8 7.6 19.3 6.0 19.8 7.6 19.3 6.01988 53 426.8 428.8 349.1 350.1 0.65 0.64 1.1 1.2 17.6 8.5 17.6 7.1 17.9 8.6 17.8 7.11993 58 516.2 521.8 437.6 441.8 0.73 0.73 1.0 1.1 18.4 9.4 18.2 8.0 19.1 9.5 18.8 8.11998 63 595.9 602.4 516.1 520.7 0.77 0.72 1.0 1.0 16.4 10.0 16.2 8.7 16.6 10.1 16.3 8.8

a Average height and d.b.h. of the 100 largest trees per hectare (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 15.25-cm top diameter (CV6), inside bark.d Only trees 19.3 cm d.b.h. or larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 185.9 cubic 

meters (36 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 6.5 cubic meters (1 percent of the total gross yield).

69
Table 26a––Stand development table for treatment 7 (plots 62, 106, and 107), by year, per acre basis

After thinning Removed in thinning Mortality 

40 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Feet Inches No. Inches Ft 2 - -Cubic feet - - No. Inches Ft 2 - - - - - - - - - -Cubic feet - - - - - - - - - No. Inches Ft2 - - Ft3 - -

1968 33 61 9.5 280 6.7 69.4 1,574 648 0 0.0 0.0 0 0 0.0 0.0 0.00 0 0.0 0.0 0 01973 38 71 11.3 260 8.1 93.7 2,486 1,546 18 6.8 4.6 113 50 6.3 6.3 0.84 2 3.1 0.1 1 01978 43 82 13.0 232 9.6 115.1 3,477 2,639 20 8.5 7.9 229 148 11.4 8.7 0.90 8 4.4 0.9 17 01983 48 94 14.5 212 10.9 135.7 4,718 3,939 18 8.4 7.1 225 147 12.5 11.3 0.79 2 4.8 0.2 5 01988 53 104 15.8 198 12.0 154.6 5,923 5,194 13 8.4 5.1 176 117 13.5 9.8 0.71 0 0.0 0.0 0 01993 58 114 17.1 180 13.1 168.3 7,053 6,374 13 10.0 7.2 281 227 21.6 18.9 0.77 5 10.9 3.3 133 1161998 63 122 18.3 172 14.3 188.9 8,406 7,737 0 0.0 0.0 0 0 0.0 0.0 0.00 8 6.7 2.1 65 31

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - - Cubic feet - - - - - - - - - - - - -Inches- - - Square feet - - - - - - - - - - - - - - - - Cubic feet - - - - - - - - - - - - - - - - - -

1968 33 1,574 1,574 648 648 0.00 0.00 0.0 0.0 0 48 0 20 0 48 0 201973 38 2,600 2,601 1,596 1,596 0.26 0.26 5.8 5.8 205 68 190 42 206 68 190 421978 43 3,820 3,839 2,838 2,838 0.27 0.25 5.9 6.0 244 89 248 66 247 89 248 661983 48 5,286 5,309 4,285 4,285 0.23 0.22 5.5 5.6 293 110 289 89 294 111 289 891988 53 6,667 6,690 5,656 5,656 0.19 0.19 4.8 4.8 276 126 274 107 276 126 274 1071993 58 8,079 8,235 7,062 7,179 0.19 0.19 4.2 4.8 282 139 281 122 309 142 305 1241998 63 9,431 9,652 8,425 8,573 0.23 0.18 4.1 4.5 271 150 273 134 283 153 279 136a Average height and d.b.h. of the 40 largest trees per acre (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 6-inch top diameter (CV6), inside bark.d Only trees 7.6 inches d.b.h. or larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 1,025 cubic feet 

(12 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 221 cubic feet (2 percent of the total gross yield).

70
Table 26b––Stand development table for treatment 7 (plots 62, 106, and 107), by year, per hectare basis

After thinning Removed in thinning Mortality 

100 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Meters cm No. cm m2 Cubic meters No. cm m2 - - - - - - - - Cubic meters- - - - - - - - - No. cm m2 - - m3 - -

1968 33 19.2 24.2 692 17.1 16.0 110.6 45.9 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0 0.0 0.0 0.0 0.01973 38 22.3 28.8 642 20.7 21.6 174.6 108.7 45 17.2 1.0 8.4 4.0 0.2 0.2 0.84 4 7.9 0.0 0.6 0.51978 43 25.5 33.0 572 24.3 26.5 243.9 185.2 49 21.6 1.8 16.5 10.9 0.3 0.2 0.90 21 11.2 0.2 1.7 0.51983 48 29.1 36.9 523 27.6 31.2 330.7 276.3 45 21.4 1.6 16.3 10.8 0.4 0.3 0.79 4 12.2 0.0 0.8 0.51988 53 32.1 40.2 490 30.5 35.6 415.1 364.1 33 21.4 1.2 12.8 8.7 0.4 0.3 0.71 0 0.0 0.0 0.0 0.01993 58 35.3 43.3 445 33.4 38.7 494.2 446.7 33 25.3 1.7 20.2 16.4 0.6 0.6 0.77 12 27.8 0.7 9.8 8.71998 63 37.7 46.5 424 36.3 43.4 588.9 542.1 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 21 17.1 0.5 5.0 2.6

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - Cubic meters - - - - - - - - - cm - - - Square meters - - - - - - - - - - - - - - - Cubic meters - - - - - - - - - - - - - - -

1968 33 110.6 110.6 45.9 45.9 0.00 0.00 0.0 0.0 0.0 3.8 0.0 1.9 0.0 3.8 0.0 1.91973 38 182.5 182.6 112.2 112.2 0.66 0.66 1.3 1.3 14.9 5.3 13.8 3.4 14.9 5.3 13.8 3.41978 43 267.9 269.2 199.1 199.1 0.68 0.63 1.3 1.4 17.6 6.7 17.9 5.1 17.8 6.7 17.9 5.11983 48 370.5 372.1 300.4 300.4 0.57 0.56 1.3 1.3 21.0 8.2 20.8 6.7 21.1 8.2 20.8 6.71988 53 467.2 468.8 396.4 396.4 0.47 0.47 1.1 1.1 19.8 9.3 19.7 8.0 19.8 9.3 19.7 8.01993 58 566.0 576.9 494.9 503.0 0.48 0.47 1.0 1.1 20.3 10.3 20.2 9.0 22.1 10.4 21.8 9.21998 63 660.7 676.1 590.3 600.6 0.58 0.45 0.9 1.0 19.4 11.0 19.6 9.9 20.3 11.2 20.0 10.0

a Average height and d.b.h. of the 100 largest trees per hectare (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 15.25-cm top diameter (CV6), inside bark.d Only trees 19.3 cm d.b.h. or larger.eQMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 71.8 cubic 

meters (12 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 15.4 cubic meters (2 percent of the total gross yield).

71
Table 27a––Stand development table for treatment 8 (plots 96, 111, and 116), by year, per acre basis

After thinning Removed in thinning Mortality 

40 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Feet Inches No. Inches Ft 2 - -Cubic feet - - No. Inches Ft 2 - - - - - - - - - -Cubic feet - - - - - - - - - No. Inches Ft2 - - Ft3 - -

1968 33 61 10.1 255 7.0 67.1 1,488 729 0 0.0 0.0 0 0 0.0 0.0 0.00 0 0.0 0.0 0 01973 38 73 12.1 235 8.5 91.3 2,419 1,658 20 5.9 3.8 84 27 4.2 3.9 0.71 0 0.0 0.0 0 01978 43 83 13.8 208 9.9 110.8 3,326 2,658 25 8.1 9.0 253 162 10.1 8.1 0.83 2 6.8 0.4 10 31983 48 95 15.4 182 11.3 125.3 4,361 3,749 27 9.3 12.7 410 319 15.2 15.9 0.85 0 0.0 0.0 0 01988 53 106 16.8 153 12.8 136.7 5,256 4,750 25 9.0 11.1 371 263 14.8 12.0 0.73 3 5.7 0.6 13 01993 58 117 18.2 122 14.8 145.4 6,247 5,823 32 9.2 14.5 532 416 16.6 20.8 0.66 0 0.0 0.0 0 01998 63 124 19.5 118 16.0 165.0 7,417 6,974 0 0.0 0.0 0 0 0.0 0.0 0.00 3 9.5 1.7 66 59

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - Cubic feet - - - - - - - - - - - -Inches- - - Square feet - - - - - - - - - - - - - - - - Cubic feet - - - - - - - - - - - - - - - - - -

1968 33 1,488 1,488 729 729 0.00 0.00 0.0 0.0 0 45 0 22 0 45 0 221973 38 2,502 2,502 1,685 1,685 0.27 0.27 5.6 5.6 203 66 191 44 203 66 191 441978 43 3,662 3,672 2,846 2,849 0.25 0.25 5.7 5.8 232 85 232 66 234 85 233 661983 48 5,107 5,117 4,256 4,258 0.23 0.23 5.4 5.4 289 106 282 89 289 107 282 891988 53 6,374 6,397 5,520 5,522 0.22 0.20 4.5 4.6 253 120 253 104 256 121 253 1041993 58 7,896 7,919 7,009 7,011 0.21 0.21 4.6 4.6 304 136 298 121 304 137 298 1211998 63 9,066 9,155 8,160 8,222 0.23 0.21 3.9 4.2 234 144 230 130 247 145 242 131a Average height and d.b.h. of the 40 largest trees per acre (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 6-inch top diameter (CV6), inside bark.d Only trees 7.6 inches d.b.h or larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 1,649 cubic feet 

(21 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 89 cubic feet (1 percent of the total gross yield).

72
Table 27b––Stand development table for treatment 8 (plots 96, 111, and 116), by year, per hectare basis

After thinning Removed in thinning Mortality 

100 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Meters cm No. cm m2 Cubic meters No. cm m2 - - - - - - - - Cubic meters- - - - - - - - - No. cm m2 - - m3 - -

1968 33 19.0 25.8 630 17.7 15.4 104.7 51.6 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0 0.0 0.0 0.0 0.0

1973 38 22.8 30.6 580 21.5 21.0 169.8 116.6 49 15.0 0.9 6.4 2.4 0.1 0.1 0.71 0 0.0 0.0 0.0 0.0

1978 43 25.8 34.9 515 25.3 25.5 233.3 186.6 62 20.6 2.1 18.2 11.8 0.3 0.2 0.84 4 17.3 0.1 1.2 0.7

1983 48 29.6 39.2 449 28.7 28.8 305.8 262.9 66 23.7 2.9 29.2 22.8 0.4 0.4 0.85 0 0.0 0.0 0.0 0.0

1988 53 32.7 42.7 379 32.6 31.5 368.4 333.0 62 23.0 2.6 26.5 18.9 0.4 0.3 0.73 8 14.4 0.1 1.4 0.5

1993 58 36.3 46.2 301 37.7 33.5 437.8 408.1 78 23.3 3.3 37.7 29.6 0.5 0.6 0.66 0 0.0 0.0 0.0 0.0

1998 63 38.4 49.6 292 40.7 37.9 519.7 488.7 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 8 24.2 0.4 5.1 4.6

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - Cubic meters - - - - - - - - cm - - - Square meters - - - - - - - - - - - - - - - Cubic meters - - - - - - - - - - - - - - -

1968 33 104.7 104.7 51.6 51.6 0.00 0.00 0.0 0.0 0.0 3.7 0.0 2.0 0.0 3.7 0.0 2.0

1973 38 175.7 175.7 118.4 118.4 0.67 0.67 1.3 1.3 14.7 5.1 13.9 3.6 14.7 5.1 13.9 3.6

1978 43 256.9 257.6 199.7 199.9 0.64 0.64 1.3 1.3 16.7 6.5 16.8 5.1 16.9 6.5 16.8 5.1

1983 48 358.0 358.7 298.4 298.6 0.59 0.59 1.3 1.3 20.7 7.9 20.2 6.7 20.7 8.0 20.2 6.7

1988 53 446.7 448.3 386.9 387.1 0.56 0.51 1.0 1.1 18.2 8.9 18.2 7.8 18.4 8.9 18.2 7.8

1993 58 553.2 554.9 491.1 491.3 0.53 0.53 1.1 1.1 21.8 10.0 21.3 9.0 21.8 10.1 21.3 9.0

1998 63 635.1 641.4 571.7 576.0 0.60 0.54 0.9 1.0 16.9 10.6 16.6 9.6 17.8 10.7 17.4 9.6

a Average height and d.b.h. of the 100 largest trees per hectare (estimated from d.b.h. and HT-d.b.h. curves).

b Quadratic mean diameter at breast height.

c All volumes are total stem cubic (CVTS) or merchantable cubic to a 15.25-cm top diameter (CV6), inside bark.

d Only trees 19.3 cm d.b.h. or larger.

e QMD cut ÷ QMD before thinning.

f Net = standing + thinning; gross = standing + thinning + mortality. Yield does not include any volume removed in the calibration cut. Volume (CVTS) removed in thinnings = 115.5 cubic 

meters (21 percent of the total gross yield at the last thinning). Volume (CVTS) in mortality = 6.2 cubic meters (1 percent of the total gross yield).

73
Table 28a––Stand development table for treatment 9, unthinned control (plots 61, 105, and 122), by year, per acre basis

After thinning Removed in thinning Mortality 

40 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Feet Inches No. Inches Ft 2 - -Cubic feet - - No. Inches Ft 2 - - - - - - - - - -Cubic feet - - - - - - - - - No. Inches Ft2 - - Ft3 - -

1968 33 59 9.7 1,075 4.6 120.8 2,417 780 0 0.0 0.0 0 0 0.0 0.0 0.00 0 0.0 0.0 0 01973 38 70 11.2 1,010 5.3 152.0 3,581 1,713 0 0.0 0.0 0 0 0.0 0.0 0.00 65 2.4 2.0 22 01978 43 81 12.6 890 6.1 181.1 4,961 2,991 0 0.0 0.0 0 0 0.0 0.0 0.00 118 2.6 4.4 63 111983 48 89 14.0 685 7.4 202.2 6,333 4,430 0 0.0 0.0 0 0 0.0 0.0 0.00 205 2.9 9.3 149 61988 53 100 15.3 515 8.8 218.7 7,779 5,992 0 0.0 0.0 0 0 0.0 0.0 0.00 170 3.3 10.3 192 141993 58 109 16.4 410 10.2 231.3 9,055 7,522 0 0.0 0.0 0 0 0.0 0.0 0.00 105 5.0 14.4 386 1001998 63 116 17.6 367 11.2 250.7 10,418 9,003 0 0.0 0.0 0 0 0.0 0.0 0.00 43 5.2 6.5 186 59

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - - Cubic feet - - - - - - - - - - - -Inches- - - - Square feet - - - - - - - - - - - - - - - - Cubic feet - - - - - - - - - - - - - - - - - -

1968 33 2,417 2,417 780 780 0.00 0.00 0.0 0.0 0 73 0 24 0 73 0 241973 38 3,581 3,604 1,713 1,713 0.14 0.12 6.2 6.6 233 94 187 45 237 95 187 451978 43 4,961 5,047 2,991 3,002 0.17 0.12 5.8 6.7 276 115 256 70 289 117 258 701983 48 6,333 6,568 4,430 4,447 0.24 0.12 4.2 6.1 274 132 288 92 304 137 289 931988 53 7,779 8,207 5,992 6,022 0.29 0.11 3.3 5.4 289 147 312 113 328 155 315 1141993 58 9,055 9,869 7,522 7,653 0.27 0.12 2.5 5.4 255 156 306 130 332 170 326 1321998 63 10,418 11,418 9,003 9,192 0.20 0.12 3.9 5.2 273 165 296 143 310 181 308 146a Average height and d.b.h. of the 40 largest trees per acre (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 6-inch top diameter (CV6), inside bark.d Only trees 7.6 inches d.b.h. or larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Volume (CVTS) in mortality = 1,000 cubic feet (9 percent of the total gross yield).

74
Table 28b––Stand development table for treatment 9, unthinned control (plots 61, 105, and 122), by year, per hectare basis

After thinning Removed in thinning Mortality 

100 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Meters cm No. cm m2 Cubic meters No. cm m2 - - - - - - - Cubic meters- - - - - - - - No. cm m2 - - m3 - -

1968 33 18.6 24.6 2,655 11.6 27.8 169.7 55.1 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0 0.0 0.0 0.0 0.01973 38 21.9 28.4 2,495 13.4 35.0 251.2 120.4 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 161 6.0 0.5 2.1 0.51978 43 25.1 32.1 2,198 15.6 41.6 347.8 209.9 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 292 6.7 1.0 4.9 1.21983 48 27.7 35.7 1,692 18.7 46.5 443.8 310.6 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 506 7.4 2.1 11.0 0.91988 53 30.9 38.8 1,272 22.5 50.3 545.0 419.9 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 420 8.5 2.4 14.0 1.51993 58 33.8 41.8 1,013 25.9 53.2 634.3 527.0 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 259 12.7 3.3 27.5 7.51998 63 35.9 44.6 906 28.5 57.7 729.7 630.7 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 107 13.3 1.5 13.5 4.6

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - Cubic meters - - - - - - - - cm - - - Square meters - - - - - - - - - - - - - - - Cubic meters - - - - - - - - - - - - - - -

1968 33 169.7 169.7 55.1 55.1 0.00 0.00 0.0 0.0 0.0 5.6 0.0 2.2 0.0 5.6 0.0 2.21973 38 251.2 252.8 120.4 120.4 0.36 0.31 1.4 1.5 16.8 7.1 13.6 3.7 17.1 7.1 13.6 3.71978 43 347.8 353.8 209.9 210.6 0.43 0.31 1.3 1.5 19.8 8.6 18.4 5.4 20.7 8.7 18.5 5.41983 48 443.8 460.3 310.6 311.8 0.62 0.29 1.0 1.4 19.7 9.7 20.6 7.0 21.8 10.1 20.7 7.01988 53 545.0 575.0 419.9 422.1 0.75 0.28 0.8 1.2 20.8 10.8 22.4 8.4 23.4 11.3 22.6 8.51993 58 634.3 691.3 527.0 536.2 0.69 0.31 0.6 1.2 18.4 11.4 21.9 9.6 23.8 12.4 23.3 9.71998 63 729.7 799.8 630.7 644.0 0.52 0.30 0.9 1.2 19.6 12.1 21.2 10.5 22.2 13.2 22.1 10.7

a Average height and d.b.h. of the 100 largest trees per hectare (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 15.25-cm top diameter (CV6), inside bark.d Only trees 19.3 cm d.b.h. or larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Volume (CVTS) in mortality = 70.0 cubic meters (9 percent of the total gross yield).

75
Table 29a––Stand development table for treatment 10, spares (plots 21, 81, and 123), by year, per acre basis

After thinning Removed in thinning Mortality 

40 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Feet Inches No. Inches Ft 2 - -Cubic feet - - No. Inches Ft 2 - - - - - - - - - -Cubic feet - - - - - - - - - No. Inches Ft2 - - Ft3 - -

1968 33 50 8.5 330 5.8 60.7 1,131 341 0 0.0 0.0 0 0 0.0 0.0 0.00 0 0.0 0.0 0 01973 38 62 10.0 323 6.9 84.5 1,897 939 0 0.0 0.0 0 0 0.0 0.0 0.00 8 5.5 1.4 29 141988 53 93 14.5 302 10.0 162.4 5,413 4,344 0 0.0 0.0 0 0 0.0 0.0 0.00 23 5.0 3.1 70 71993 58 102 15.9 277 11.1 183.2 6,639 5,645 0 0.0 0.0 0 0 0.0 0.0 0.00 25 6.4 5.7 161 701998 63 110 17.2 263 12.0 205.0 7,959 7,001 0 0.0 0.0 0 0 0.0 0.0 0.00 13 6.6 3.2 93 43

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - - Cubic feet - - - - - - - - - - -Inches- - - Square feet - - - - - - - - - - - - - - - Cubic feet - - - - - - - - - - - - - - - - - -

1968 33 1,131 1,131 341 341 0.00 0.00 0.0 0.0 0 34 0 10 0 34 0 101973 38 1,897 1,926 939 953 0.22 0.22 4.8 5.0 153 50 120 25 159 51 122 251988 53 5,413 5,512 4,344 4,365 0.20 0.20 5.2 5.4 234 102 227 82 239 104 227 821993 58 6,639 6,899 5,645 5,736 0.22 0.17 4.1 5.3 245 114 260 97 277 119 274 991998 63 7,959 8,311 7,001 7,135 0.19 0.15 4.4 5.0 264 126 271 111 283 132 280 113a Average height and d.b.h. of the 40 largest trees per acre (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 6-inch top diameter (CV6), inside bark.d Only trees 7.6 inches d.b.h. or larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Volume (CVTS) in mortality = 352 cubic feet (4 percent of the total gross yield).

76
Table 29b––Stand development table for treatment 10, spares (plots 21, 81, and 123), by year, per hectare basis

After thinning Removed in thinning Mortality 

100 largest treesa Volumec Volume Volume/tree Volume

Stand Basal Basal Basal

Year age HT D.b.h. Trees QMDb area CVTS CV6d Trees QMD area CVTS CV6d CVTS CV6d d/De Trees QMD area CVTS CV6d

Years Meters cm No. cm m2 Cubic meters No. cm m2 - - - - - - - - Cubic meters- - - - - - - - - No. cm m2 - - m3 - -

1968 33 15.8 21.6 815 14.8 14.0 79.7 24.3 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0 0.0 0.0 0.0 0.01973 38 19.4 25.5 799 17.7 19.4 133.3 66.2 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 21 14.0 0.3 2.5 1.51988 53 28.9 36.9 745 25.5 37.4 379.4 304.6 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 58 12.6 0.7 5.4 1.01993 58 31.6 40.4 683 28.2 42.1 465.3 395.7 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 62 16.4 1.3 11.7 5.41998 63 34.1 43.7 650 30.6 47.1 557.6 490.6 0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 33 16.8 0.7 7.0 3.5

Cumulative yieldf QMD growth BA growth Net volume growth Gross volume growth 

Net Gross Net Gross Net Surv. Net Gross CVTS CVTS CV6 CV6 CVTS CVTS CV6 CV6

CVTS CVTS CV6 CV6 PAI PAI PAI PAI PAI MAI PAI MAI PAI MAI PAI MAI

- - - - - - Cubic meters - - - - - - - - - cm - - - Square meters - - - - - - - - - - - - - - - Cubic meters - - - - - - - - - - - - - - -

1968 33 79.7 79.7 24.3 24.3 0.00 0.00 0.0 0.0 0.0 2.9 0.0 1.2 0.0 2.9 0.0 1.21973 38 133.3 135.3 66.2 67.2 0.57 0.57 1.1 1.2 11.2 4.0 8.9 2.2 11.6 4.0 9.1 2.31988 53 379.4 386.3 304.6 306.0 0.52 0.50 1.2 1.2 16.9 7.6 16.4 6.2 17.2 7.8 16.4 6.31993 58 465.3 483.4 395.7 402.0 0.55 0.42 1.0 1.2 17.7 8.5 18.7 7.3 19.9 8.8 19.7 7.41998 63 557.6 582.3 490.6 500.0 0.48 0.38 1.0 1.2 19.0 9.3 19.5 8.3 20.3 9.7 20.1 8.4

a Average height and d.b.h. of the 100 largest trees per hectare (estimated from d.b.h. and HT-d.b.h. curves).b Quadratic mean diameter at breast height.c All volumes are total stem cubic (CVTS) or merchantable cubic to a 15.25-cm top diameter (CV6), inside bark.d Only trees 19.3 cm d.b.h. or larger.e QMD cut ÷ QMD before thinning.f Net = standing + thinning; gross = standing + thinning + mortality. Volume (CVTS) in mortality = 24.7 cubic meters (4 percent of the total gross yield).

77
This page has been left blank intentionally.
The Forest Service 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 Grasslands, it strives––as directed by

Congress––to provide increasingly greater service to a growing Nation.

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, gender, religion,

age, disability, political beliefs, sexual orientation, or marital or family status. (Not

all prohibited bases apply to all programs.) Persons with disabilities who require

alternative means for communication of program information (Braille, large print,

audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600

(voice and TDD).

To file a complaint of discrimination, write USDA, Director, Office of Civil Rights,

Room 326-W, Whitten Building, 14th and Independence Avenue, SW,

Washington, DC 20250-9410 or call (202) 720-5964 (voice and TDD). USDA is

an equal opportunity provider and employer.

Pacific Northwest Research Station

Web site http://www.fs.fed.us/pnw

Telephone (503) 808-2592

Publication requests (503) 808-2138

FAX (503) 808-2130

E-mail pnw_pnwpubs@fs.fed.us

Mailing address Publications Distribution

Pacific Northwest Research Station

P.O. Box 3890

Portland, OR 97208-3890
U.S. Department of Agriculture

Pacific Northwest Research Station

333 S.W. First Avenue

P.O. Box 3890

Portland, Oregon 97208-3890

Official Business

Penalty for Private Use, $300