(U t1a<\'"PFRc

INj011l\,rpt.1:( -l< -I <JZ

1'111-

ABSTRACT

Site specific growth data for the 3 yearsfollowing fertilization and thinning are given for theShawnigan research plots. The data base is docu­mented and gross and merchantable volume, andcumulative dbh and height increments are given.Evaluation of treatment response is investigatedusing individual tree increments (dbh, ba, heightand gross volume), stand structure analysis and croptree analysis.

Significant early treatment responses areshown. By using covariance analysis with the 618largest trees/ha as the crop trees, the percent gain ingross volume increment over the adjusted controltreatment was 54, 110 and 188, respectively, forheavy thinning without fertilization, heavy ferti­lization with no thinning, and heavy thinning andheavy fertilization combined.

The analytical approaches used are com­pared and reader feed-back is solicited.

Key words: 3-year growth, individual trees, standstructure, crop trees, Pseudotsugamenziesii

'i-,)r..,K7 l l/,};l )(

RESUME

Les parcelles de recherche aShawnigan antfourni des donnees specifiques de croissance sur desstations pour les 3 annees qui ont suivi leur ferti­lisation et leur eclaircie. Le fichier central est (hoffeet indique I'accroissement des volumes brut et mar­chand, du dhp cumulatif et de la hauteur des arbres.Les auteurs evaluent les facteurs de la reponse auxtraitements en utilisant les accroissements chezchaque arbre (du dhp. de la surface terriere, de lahauteur et du volume brut), I'analyse de la structuredu peuplement et I'analyse des arbres du peuplementfinal.

Des reponses significatives et rap ides sontici presentees. En utilisant une analyse de covariancedes 618 plus gros arbres par hectare comme arbresdu peuplement final, Ie gain en pourcentage d'accrois·sement du volume brut par rapport aux arb res temoins(dont les caracteristiques avaient ete ajustees) fut de54,110 et 188 respectivement pour les parcelles treseclaircies sans fertilisation, fertilisation pronouncesans eclaircies et un traitment combine des parcellestres fertilisees et tres eclaircies.

On fait une comparaison des methodesd'analyse, et a ce sujet les observations du lecteurseront appreciees.

2

TABLE OF CONTENTS

Page

ABSTRACT .

1.0

2.0

INTRODUCTION .......................•......•••.....••...

OOCUMENTATION OF THE DATA BASE ......••.....•......•••.....

5

5

2.1 Units of measurement , , . . . . . . . . . . . . . . . . . . . . . 5

2.2 Measurements on a plot basis , , . . . . . . . . . . . . 5

3.0

2.3

2.4

2.5

3.1

3.2

Measurements on an individual tree basis . ..............•.•....•......•

Volume determination . ..

Data recorded for all plot trees. ......••...................•....

3·YEAR GROWTH RESPONSE...........................•....

Volumes per hectare produced in the first 3 years followingtreatment. . ........................................•......•

Cumulative increment for dbh and height .

6

6

7

8

8

10

4.0 ANALYSIS OF GROWTH RESPONSE OF INDIVIDUAL TREES ........••... 10

4.1

4.2

4.3

4.4

Dbh increment (em/ann) ..

Sa increment (cm 2/annl ..

Height increment (m/ann) . ............•....................••....

Gross volume increment (m3/ann) .

10

13

13

13

5.0 METHODS OF EVALUATING TREATMENT RESPONSE ON APER HECTARE BASIS ...............................••.....•...... 13

5.1

5.2

Stand structure analysis , .

Crop tree analysis .

..........................

..........................

14

19

6.0 COMPARISON OF ANALYTICAL PROCEDURES.........••......••.... 19

7.0 SUMMARY . ............... . . .. " . 20

8.0

9.0

ACKNOWLEDGMENTS....•.........••....•... ..... , .

REFERENCES ..........••...•....•... .....................

21

21

10.0

Appendix I

Appendix II

Appendix III

Appendix IV

Appendix V

Appendix VI

Appendix V II

3

APPENDICES

Plot measurement schedule.

Regression equations for estimating 3-year height increment by treatment . ..

Merchantable volume factor equations. ..

Gross and merchantable volumes by treatments..

Regression equations by treatments for periodic annual increment

(dbh, ba, height and gross vo lume) . . . . . . . . .

Dbh frequency distributions by treatments showing initial condition

and number of trees lost through thinning and mortality . ..

PAl for dbh by dbh classes and treatments.

Page

22

23

24

25

26

29

30

Appendix VIII PAl for ba by dbh classes and treatments. 31

Appendix IX

Appendix X

Appendix XI

Append ix X II

PAl for height by dbh classes and treatments

PAl for volume by dbh classes and treatments.

Tree frequency distributions by dbh class and treatment used

in stand structure analysis. . . . .. . .....

Actual and adjusted PAl for gross volume by covariance analysis

using the 395 and 618 largest trees per hectare. . . .

32

33

34

36

4

LIST OF TABLES

Page

Table 1

Table 2

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Initial mean dbh and height for the 395 and 618 largest trees per hectare.

Table of significance for fertilization, thinning and interaction using the

395 and 618 largest trees per hectare. . . . .....

LIST OF FIGURES

Gross and merchantable volume per hectare by treatments

Cumulative dbh increment by treatments for dbh class 4..

Cumulative height increment by treatments for dbh class 4 .

PAl for dbh by dbh classes and treatments.

PAl for ba by dbh classes and treatments ..

PA I for height by dbh classes and treatments

PAl for gross volume by dbh classes and treatments. ,

Calculated PAl for gross volume of healthy Douglas-fir on a perhectare basis. . . . . . . . . .

18

18

8

9

9

11

11

12

12

14

Figure 9 Treatment response by stand structure 3nalysis using actual treefrequency distributions. . . .....

Figure 10 Treatment response by stand structure analysis using mean treefrequency distribution for each thinning level. . . . . .

Figure 11 Treatment response by stand structure analysis using hypotheticaltree frequency distribution. . .....

Figure 12 Actual and adjusted treatment response by covariance analysis usingthe 395 and 618 largest trees per hectare ..

15

16

17

17

5

1.0 Introduction

Interest in forest fertilization and thinning ishigh in the Pacific Northwest. How best to measureand evaluate treatment response in the most"uniform" of heterogeneous forests is still an openquestion. Attention has recently been focussed onthe development of procedures for handling variationin response (Anon, 1975), and on reporting grossvolume growth (Miller and Pienaar, 1973), Earlyresponses reported have been significant and the dataproduced will be invaluable as input into decision­making models for forest management. As researchprogresses, the need for regionally accepted analysisprocedures will become important if results are to bereadi Iy interpreted.

Details of the site, experimental basis, and themultidisciplinary nature of the project at ShawniganLake, B.C. have been previously reported (Crown,Brett et ai., 1975). The study area was establishedin 1970 in a young 24-year-old Douglas-fir stand, at335 m elevation, on shallow, coarse textured soils(Orthic Dystric BrunisolsL Site index was 21 m at50 years. The basic experiment consisted of a 3 x 3

completely randomized factorial design comprising3 levels of nitrogen fertilization [0 (FO), 224 IF1)and 448 IF2). kg N per ha as urea) applied in thespring, and 3 levels of thinning in which zero (TO),and about 1/3 (Tl) and 2/3 IT21 of the basal areawas removed. Treatments were replicated twicein each of 2 years (1971 and 19721 in plots of 0.04ha surrounded by 10-m·wide buffer zones.

This report is based on only 3 years of growthfollowing fertilization and thinning and results aresite specific. Emphasis, therefore, is placed on thediscussion of analysis procedures rather than onabsolute response values. The report documentsthe data base, gives gross and merchantable volumegrowth on an area basis, cumulative increments fordbh and height, growth of individual trees in respectto dbh, ba, height, and gross volume, and resultsfrom individual trees. Stand Structure (Anon, 1975)and "Crop Tree" analyses are discussed. Manyquestions on analysis procedure are unanswered andreader feed-back is solicited.

2.0 Documentationof the data base

Data and analyses included in this reportare based on measurements taken at the time ofinstallation establishment and for the 3 years follow­ing treatment. It is recognized that 3-year resultswill give only initial treatment response. Reportingplanned for 6, 9, 12 and 15 years' post treatment(coincid ing with the measurement schedule inAppendix I) will provide increasingly more reliableestimations of the total response to fertilizationand thinning. Analysis showed no significantdifference between the response for the 1971 and1972 installations and hence the data were pooled,giving 9 treatments each with 4 replications.

A number of initial analyses were also con­ducted using Canadian yard/pound measures.

The measurement of trees involved two dis­tinct strategies, a plot basis and an individual treebasis.

units. In conversion to metricunconventional sizes exist.

i) plot size is 0.0404 ha (1/10 acre).ii) breast height was defined as 1.372 m

(4.5 ftliii) taper steps were at 2.54 cm dob (1 inch)

intervals.ivl diameter class intervals were 2.5 cm

(approximately)v) equations for dbh, basal area, height,

height increment, gross volume and mer­chantable volume use Canadian yard/pound measures.

Canadian yard/poundunits, some ratherExamples are:

Units of Measurement2.1

At the time of inception of this study, metricconversion appeared to be far in the future; conse­quently, the installation was established using

2.2 Measurements on a plot basis

The plot basis is used to evaluate initial plot

condition and to monitor changes at fixed timeintervals through the course of the experiment.

The kind and frequency of measurementstaken are:

aJ dbh over bark (ob) and tree conditionfor all plot and buffer trees were recordedat the time of establishment and annuallyfor the succeeding 3 years; future record­ings wi II be at 3·year intervals; was mea­sured using dbh tapes;

b) height of all plot trees and thinned buffertrees was measured with height poles atthe time of plot establishment. Height ofplot trees will be measured at 3·yearintervals;

6

as defined by Competitive Stress Index (CSll.

Measurements taken were:-

a) dbhob initially and annually thereafter.

b) total height annually from 3 years preced­ing establishment.

e) dob at 0.305 m and at 2.54 em (approx)

stem diameter taper steps measured to a7.62 em minimum dob for larger treesand to half height above dbh for thesmaller trees; these measurements weretaken 3 years after treatment and willbe taken at 3-year intervals until the con­clusion of the study.

2.4 Volume determinationc) height to live crown was measured with

height poles at the time of establishment;subsequent measurement will be made at 6years following establishment and at3-year intervals thereafter;

d) all plot and buffer trees were stem mappedat the time of establishment (prior tothinning). Tree locations were originallymapped using the azimuth-distance methodand later checked using right angledprisms and tapes (now the preferred pro­cedure); and

eJ Competitive Stress Index at dbh (Arney,1973) was calculated for all plot treesfrom dbh measurements and stem maps.

The total number of trees in all plots at plotestablishment was 13,273. The number of plot treescurrently being measured is 3,951.

To determine initial individual tree and initialplot volumes, a local volume equation was developedfor the site. It was derived prior to metrification andhence is in Canadian yard/pound measures. Onehundred and five healthy Douglas-fir trees, selectedto cover the observed range of dbh (2.5 - 32.0 em).

were felled or climbed and measured for dob at2.54-cm taper steps from the butt. Segment volumeswere calculated using Newton's formula (Chapmanand Meyer, 1949), A regression using dbh and heightas independent variables and measured volume asthe dependent variable was fitted, giving the followingvolume equation:

log V = -2.48036 + 1.95882 log D +0.971352log H

where: V = volume in cu ftD = dbhob in inchesH = total height in It

2.3 Measurements on an individual tree basisR2 = 0.999 SEE = 0.031 eu It; No. of obser­

vations= 105

Measurements, taken on an individual treebasis, are designed to provide yearly trends in incre·ment, estimates of volume and form changes andto provide a data base for related investigations.

Individual trees (volume sample trees), 231and 233 for the 1971 and 1972 plots. respectively.

were selected 3 years after treatment on the basis ofinitial dbh and competitive position in the stand

This equation was used to determine individual treevolumes at the time of establishment. However, inthe case of the 1972 plots where tree heights werenot available, it was necessary to estimate initialtree height from data collected on the thinned 1972plot trees.

The regression selected for estimating initialtree height was:

7Height" -14.9985 - 3.27337 0 +

31.152115where 0 " dbhob

where: H = Initial height in feetThis relationship was derived for Douglas-fir,

western red cedar, western hemlock, balsam, western

white pine and lodgepole pine (Appendix III).0= Initial dbhob in inches

R2 = 0.918, SEE" 2.90 It; No. olobserva­tions" 1636

2.5 Data recorded for all plot trees

The data recorded are as follows:

Height increment by treatment was estimatedfrom "1971 plot data. This estimate of height incre­

ment was based on regression analysis of heightincrement against initial height, initial dbh, and dbh

increment. The regression form selected was:

i) plot and tree number

ij) X and Y coordinatesiii) species

iv) treatment

Treatment codes used are;

where a,b, ,b2,b3,b4 and b5 are regressioncoefficients

o = Initial dbhob in inches.

/). 0 = Dbh increment in inches.

Ii H = Height increment in feet.H = Initial height in feet.

Regressions were derived for each of the 9

treatments in the 1971 plot series and applied to thecorresponding treatments for the 1972 plot series.The equations derived are given in Appendix II.

TOFO - CONTROL - No thinning, no fertili-

zation

TOF 1 - No thinning, 224 kg Nlha (urea)

TOF2- No thinning, 448 kg Nlha (urea)

T 1FO - Intermediate thinning, no fertilizer

T1F 1 - Intermediate thinning, 224 kg Nlha(urea)

T1 F2- Intermed iate thinning, 448 kg Nlha(urea)

T 2FO - Heavy thinning, no fertilizer

Diameter class Class mid point (cm) Range cm

Diameter classes used in the analyses are asfollows:

T2F1 - Heavy thinning, 224 kg Nlha (urea)

T 2F2 - Heavy thinning, 448 kg Nlha (urea)

2.50·4.995.00 - 7.497.50 - 9.99

10.00 - 12.4912.50 - 14.9915.00 - 17.49

17.50 - 19.99

3.756.258.75

11.2513.7516.25

18.75

1234

567

v) mortality index records thinned trees,mortality, damage, or disease

vi) CSI at time of establishment, after thinning

and thereafter at 3-year intervals

vii) total height at establishment and thereafter

at 3-year intervalsviii) dbhob at treatment, annually for 3 years

and thereafter at 3-year intervals

To determine tree volume 3 years after treat·ment, it was decided that if no significant change inform quat ient occurred between treatments, the

initial condition volume equation would be used.

The data used to test this hypothesis were taken fromthe detailed measurement of the volume sample treesfor both the 1971 and 1972 plots. Analysis of variance

and paired t tests failed to show any significantdifferences between form quotients for the different

treatments. Consequently, the initial volume equationwas applied to estimate total tree volume 3 years

after treatment.

Merchantab Ie Factor" a+b lID + b2loge 0 + b30

Merchantable tree volume (close utilization)was derived from merchantable volume curves devel·

oped by the B.C. Forest Service (unpublished).Regressions were fitted to these curves to facilitate

determination of merchantable volume values "for

each individual tree. This procedure avoids the

unrealistic merchantable volume increases that occur

when dbh class values are applied to individual

trees, especially where stands are just reaching mer·chantable sizes. Form of the regressions used was;

B

ix) gross and merchantable volume at estab­lishment and thereafter at 3-year intervals

xl height to base of live CrOwn at establish­ment

xi) stem maps before thinning, after thinningand every 3 years thereafter

3.0 3 - year growthresponse

and 3).

3.1 Volumes per hectare produced in the first3 years following treatment

The data presented in this section are basedon the mean treatment response per plot (4 replica·tions per treatment) converted to a per hectare basis.

Gross Volume

Gross volume (G. Vol) and merchantablevolume (M. Vol) per hectare are reported along withcumulative increment for dbh and height (Figs. 1,2

The 3-year gross volume and the percent gainor loss in 3-year increment compared to control aregiven in Fig. 1a. The maximum 3-year gross volumeincrement of 70.67 m3/ha occurred with the TOF2

a) Gross volume

'00

:3 YR. GROSS VOL.GROWTH FOLLOWINGTREATMENT

GROSS VOL.AT TREATMENT

} TREATMENTS--T2-­

Fa FI F2

43

b-il3+-~"...-+;,<,/--~.••.••.3.••.6,.-- ~"--~ _-+-_~_i_iA_WT_~_~E_R~_~_HL_L_~_~L_'N_Gm MERCH.VOLAT TREATMENT

--T,-­

Fa FJ F2

8058l\< 54

--To-­Fa F1 F2

o

50

50

50

c~,~

E

w 100

":::>..J0>

'50

50

o

b) Merchantable volume- percentage gain or loss over control

Figure 1. Gross and merchantable volume per hectare by treatments.

Figure 2. Cumulativedbh increment by treat­ments for dbh class 4.

'.0

~I

2.0...z~

'"~'"0;!;

or~

0

~

>;:::~J 1.0"'""0

'.0

9

./"-'./" ,"0'.. ....-::.,~ ._..... CO""'­.' -:;:;: ....

~.:.. ,

;;;;.::::',:::~

2

YEARS SINCE TREATMENT

TREATMENTS

... ToFo

Figure 3. Cumulativeheight increment by treat·ments for dbh class 4.

2.0

1.0

TREATMENTS

I 2

YEARS SINCE TREATMENT

10

4.0 Analysis ofgrowth response ofindividual trees

The PAl for control trees is compared tothat of treated trees which had the same initial dbh(Figs. 4 through 7). Within treatments, trees of differ­ing initial dbh are compared to provide someinsight into changes in stand dynamics associatedwith treatment.

Examination of the gain in dbh incrementover that of the control indicates that increasingthe levels of both fertilization and thinning resultedin increased increment (Fig. 4 and Appendix VII).In general, the greatest response for each fertilizationlevel was associated with the heavy thinning treat­ments.

In this analysis, individual tree PeriodicAnnual increment (PAl) Of is used throughout.Comparison of the growth responses of individualtrees between and within treatments provides a goodbasis for the evaluation of response to fertilizationand thinning. It provides for a better understanding ofplot response data and is input data for stand models.To make the comparisons, regressions using healthyDouglas-fir trees were fitted for dbh, ba, heightand gross volume increment against initial dbh(Appendix V). These equations were solved for 6.25,8.75. 11.25 and 13.75 em initial dbh, the midpointsof the dbh classes 2 through 5. Insufficient dataprecluded use of dbh classes 1 and 6 through 11.

Dbh increment (em/a)4.1

treatment, and the smallest increment of 22.20m 3/haoccurred with the T2FO treatment (Appendix IV).Fertilization has given a marked increase in GrossVolume increment. As might be expected, thinningalone has reduced the Gross Volume but this incre·ment has accrued on a smaller number of largertrees. Fertilization with thinning has offset the volumeincrement reduction that resulted from thinning.

Merchantable Volume

Fertilization increased growth at all thinninglevels (Fig. 1bl. Thinning alone reduced the responsedue to the reduction in number of trees. Fertilizationof intermediate thinnings compensated for the incre­ment reduction associated with thinning and resultedin increments similar to the unthinned treatments.Fertilization of heavy thinning treatments resulted ina substantial increase in increment that more· thancompensated for the thinning effect.

Initial stand differences (Appendix VI andFig. 1) have profound and confounding effects ongrowth response. For example, the marked differencein number of trees and dbh distribution in theunthinned plots explains the higher initial volumesin the TOFO (Control) as compared to the TOF2treatment. Also, the higher initial merchantablevolume of the TOF 1 treatment results from thepresence of a few larger trees (see Table 11.

The maximum 3-year merchantable volumeincrement of 58.81 m3/ha occurred in the T lF2treatment, and the smallest increment of 20.76 m3/haoccurred with the T2FO treatment (Appendix IVI.

3.2 Cumulative increment for dbh and height

Graphs of cumulative dbh and height incre­ment against years since treatment are given fordbh class 4 to provide insight into annual changesin response (Figs. 2 and 3). These data were takenfrom the volume sample trees and hence do notcoincide exactly with individual tree response deter­mined by regression (Figs. 4 and 5).

Comparisons of response to fertilization andthinning indicate a positive treatment interaction.For example, in dbh class 4, the dbh incrementfor control (TOFOI was 0.39 em. The gain abovecontrol for heavy fertilization alone (TOF2) was 0.38cm; for heavy thinning alone (T2FO) was 0.25 cm,and for heavy fertilization and thinning combined(T2F2) was 0.83, indicating a positive interactionof 0.20 em.

The similarity of the dbh growth trends forthe T2F2 and T2F, treatments after 3 years isworthy of note, and future trends for these treat­ments will be of considerable interest. 0 ivergenceof height increment between fertilized and unfer­tilized treatments in these early measurements isvery distinct and will be monitored closely in future.

In all cases, total dbh increment for a giventreatment increased with increasing initial dbh(Appendix VII). When examining gain over controlincrement for a given treatment, the small dbh

* For the first 3 years following treatment.

11

TREATMENTS

----T,---­

"

----T,----

2 3 4 5 2 :3 .. 5 2 3 4 5 , , , , 2 3 4 5 , , , , , , , , , , , , , , 4 ,INITIAL DBH CLASS

Figure 4. PAl for dbh by dbh classes and treatments. (em/a)

TREATMENTS

T,

'0 " "

0

00

00 0 :=

:~ 0

0

0 0

" " " 0

0 0

0

~ ~

0

0

::0

0

000000

:;

~~

zou

~o••

*~z8~

"•,8x~

~o

rc

I? ~: JI~0

CONTROL I~ 0

c- o t/.

~L 0 L L ,

00

"" 00

0 000

-----TO-----

-1+~

zou

~

"•,8x~

~•o

"~~

zou~

>oo•

....

2 3 4 52 3 4 52 3 4 52 3 4 5

"

~ 0

~ ~0

~

~~

0.!:<

L~::

~0t::' 00

0

'" 0~

2 3 4 5

INITIAL OBH CLASS

2 3 4 5

----- T, -----

""

2 3 4 5

"

2 3 4 5

'0

2 :3 4 5

'0

"

0 '0,N

~

'"'" ,~

0

,

00

Figure 5. PAl for ba by dbh classes and treatments. (cm2 /al

Note: - Total increment = Growth equal to control + Gain above control.

12

TREATMENTS

----TO---- -----T, ----- T,-----

~0­Zovw>g•

2 3 4 5

F,

2 3 4 :5

FO

2 :3 4 :52 :3 4 5

F,

2 :3 4 5

FO

2 :3 4 52 3 -4 5

::

, , ,- ,:::

, , ., :::: :: : :

: :: : :: : :: :: ::::

:: :::: :

:: ::

F,

2 :3 4 :>2 :3 4 ~

FO0'

0'0,

CONTROLE

° ~0-~ :'" :W ::~ 0':

:

0' :

INITIAL OBH CLASS , ,t_~ GROWTH LESS THAN CONTROL

Figure 6. PAl for height by dbh classes and treatments.(m/al

TREATMENTS

To T, T,

FO F, F, FO F, F, Fo F, F2

"00"

• Gain above control as a percentage of control growth.

"0 179

92 ::.. : "0'0 '" 2~0

• '"~., z

~~ ~:: 08 ~:: v

: 78

'" '" "o~ : ww : >~ 00' " 97 :;

:: : :: 09' : ~

~

" :: 23 '50 •~

0.48 :: :: IF ~

:

t> r 7 rCONTROL 46 .

~" [(0:-~ ;;: : ::~ °

~0 Ii L : L L :: L ::~ ::'" :: :

: ::a :: : 0-

: z~ :: : : : 0.00' :: v

:: : 00-

"•,0

.010 w~0-•, , , , 2 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , 0z0

INITIAL aSH CLASS

Figure 7. PAl for gross volume by dbh classes and treatments. (m3/a)

Note: . Total increment = Growth equal to control + Gain above control.

classes occasionally exhibit a greater gain than thelarge dbh classes (i.e., T lFOI and with little or nodifference between classes 4 and 5.

13

(T 2F2) was 0.0127 m3, indicating a positive inter­action of 0.0047 m3.

Sa response is essentially identical to dbhresponse (Fig. 5 and Appendix VillI. The onlymarked difference is that there is a more consistentincrease in ba gain with increasing initial dbh. Treat·ment responses for dbh class 4 are as follows: Saincrement for control 1TOFOI was 7.19 cm2 Thegain above control for heavy fertilization alone (TOF2)was 7.66 cm 2; for heavy thinning alone (T2FOI was4.95 cm2, and for heavy fertilization and heavythinning oombined was 17.75 cm2, indicating apositive treatment interaction of 5.14 cm 2.

4.2

4.3

Sa increment (cm 2/a)

Height increment (m/a)

Total volume increment and increment gainabove control increased markedly for a given treat­ment with increasing initial tree size. However, it isinteresting to note that gain above control expressedas a percentage of control growth for a given dbhclass is inversely related to tree size, as shown by thepercentage values in Fig. 7.

5.0 Methods ofevaluating treat­ment response on aper hectare basis

Height increment response differs markedlyfrom dbh and ba response. The most strikingfeature was the decrease in height increment associatedwith increasing thinning intensity when no fertilizerwas added. This is commonly termed "thinning shock"and is well illustrated in Fig. 6.

Fig. 6 and Appendix IX show that:

1) for those treatments having no fertilizerapplication, the periodic annual incrementin height was less than that of the control,and decreased as thinning intensity increased

(T 1FO, T 2FOI2) for those treatments having no thinning,

the periodic annual increment in heightincreased with fertilization (TOF1' TOF21.

3) fertilization reduces the degree of thinningshock; the heavier the fertilizer applica·tion, the less the shock.

4.4 Gross volume increment (m3/a)

The gain in gross volume increment over thatof the control provides the measure of the effectof fertilization and thinning. Increasing levels ofboth fertilization and thinning increased volume gainfor all dbh classes (Fig. 7 and Appendix XI.

Comparison of the volume increment responseindicates a positive treatment interaction. Forexample, in dbh class 4, volume increment for control(TOFOI was 0.0071 m3. Gain above control for heavy

fertilization alone (T OF21 was 0.0062 m3; for heavythinning alone (T2F01 was 0.001S m3; and forheavy fertilization and heavy thinning combined

How best to evaluate treatment response ona per hectare basis is still an open question. The verymarked variation in the response of trees of differentdbh class within treatments (F ig. 7) points up theimportance of tree frequency distribution by dbhclass when per hectare response is being considered.

Gross differences in tree frequency distribu­tion result from the removal of trees in thinning.Other less obvious but important tree frequencydistribution differences within thinning treatmentsresult from variations in site, initial stand conditionand mortality. The effect of the tree frequencydistribution differences on the evaluation of treat­ment response (fha) can be demonstrated, ingeneral, by comparing the actual 3-year volumeincrement given in Fig. 1 with the results of theindividual tree PAl for gross volume in Fig. 7.In Fig. 1, thinning within fertilization treatmentsshows a loss in 3·year volume increment, whereasin Fig. 7, a net gain in gross volume increment isshown. The large differences in tree frequencydistribution created by the removal of trees inthinning (Appendix VI) mask the treatmentresponse on a per hectare basis. Therefore, toevaluate treatment response, these important treefrequency distribution differences must be accountedfor.

Two approaches are examined: 1) standstructure analysis, and 2) crop tree analysis.

Stand structure analysis was used on theShawnigan Lake data to evaluate gross volumeresponse to treatment. The concept was describedby the Regional Forest Nutrition Research Project(Anon., 1975).

5.1 Stand structure analysis

14

mined (3) to the dbh frequency distri·

but ions for each treatment (2)5) the difference between the total gross

volume increment and the gross volumeincrement for control image (41 was taken

to represent treatment response6) treatment response was then expressed as

a percentage of the control image

Treatment responses were calculated as

follows:

1) total gross volume increment was deter­mined for each treatment

2) dbh frequency distributions were deter­mined for each treatment

3) gross volume increments were determinedfor midpoints of each dbh class for controltreatment

4) a 'control image' was created by applyingcontrol gross volume increments deter-

Regression equations on healthy Douglas-fir(Appendix V) were used to define the control andtreatment increment values for dbh classes 1-7. Classes8 through 11 were not included because, in the initialstand condition, these dbh classes were not represen­ted in all treatments. Using the tree frequency distri­bution for the healthy Douglas-fir as they exist foreach treatment, the percentage of gain or loss in grossvolume increment by treatment was calculated and isgiven in Fig. 8. Results from stand structure analysis

can be compared to Fig. 8.

FO10

5

0,0~,

0'"E

w

"::>-'~ 5

'"'"0a:

'"10..

"-

15

--TO-­

Fe F1 F2

50

TREATMENTS

---T,--

Fe F1 F2

46

'4-2.....; I

•••••• i::t:.

---T2---

F1 F2

• Percentage gain or loss over control.

GAIN ABOVECONTROL

GROWTH EaUALTO CONTROL

, ,~ _ ~ GROWTH LESS THAN CONTROL

Figure 8. Calculated PAl for gross volume of healthy Douglas-fir on a per hectare basis.

15

The concept was applied using three sets offrequency distributions by dbh class as follows:

ments.

1) Actual tree frequency distributions

1) The actual tree frequency distributionsby treatments as they occurred (AppendixXla).

2) The mean tree frequency distribution foreach thinning level (Appendix Xl b).

3) A hypothetical tree frequency distribu­tion equivalent to the individual plotthat had the smallest number of treesafter thinning (Appendix X1c).

The last two were tested in order to removestand structure differences among thinning treat-

In this analysis, comparisons were made usingthe actual tree frequency distributions as theyoccurred.

Figure 9 shows the treatment response (volumeincrement gain above control image) determined bystand structure analysis. This method of analysisgives a good estimation of both fertilization andthinning response. However, evaluation of the resultsis still confounded by different numbers of trees,both within and between thinning levels.

TREATMENTS

--TO--

Fa F, F2

--T2-­

Fo F1 F2

1591

178

II.

.. Treatment response as a percentage of control image growth.15

10

c,c

5~,'"E TREATMENT

w 10 RESPONSE

'"::> 0~~~.J

0> ,,,,, CONTROL

U> ~(IMAGE GROWTH

U>0 :~:a:: ,'" 5 ,,,,

'" {a. ,.,

:::::;,

10,,,,,

Figure 9. Treatment response by stand structure analysis using actual tree frequencydistributions.

16

2) Mean tree frequency distribution for eachthinning level

was applied to a hypothetical distribution whichcoincided with that of the individual plot having theleast number of trees (F ig. 11).

The use of mean tree frequency distributioncalculated for each thinning level removes differencesand gives a better basis for the evaluation of fenilizereffects within thinning levels (Fig. 10). This treatmentof the data made little or no difference to the per·centage calculations. However, it did affect treatmentresponse; e.g. positive adjustment of the controlimage for the TOF2 treatment caused an increase inthe treatment response.

Use of the hypothetical distribution has theadvantage of removing stand structure differencesassociated with thinning effects and initial standconditions. The order of treatment response dupli·cates that found for individual tree gross volumegain (Fig. 7). The order of response, from highest

to lowest, was as follows: T2F2' T2Fl' T1F2' TOF2'T 1F1, TOF 1, T2FO' T1FO and TOFO'

3) Hypothetical tree frequency distribution

To oompare results of both thinning and fer·tilization on the same basis, stand structure analysis

While the stand structure analysis providesa good base for evaluating response, it is somewhatlimited in that it is not possible to include the largertrees because they do not exist in all treatments.

TREATMENTS

--TO--

Fe FI F2

--T,

Fo F,

--T2--

Fe Fl F2

1591

176

• Treatment response as a percentage of control image growth.

II.

15

10

c

"c~ 5",.,E

TREATMENTw RESPONSE

":::> 0...J0 CONTROL>U) IMAGE GROWTHU)

0a:

5'";;"-

10

Figure 10. Treatment response by stand structure analysis using mean tree frequency distri­bution for each thinning level.

17

TREATMENTS

--TO-­

Fa F1 F2 FO

--T2-­

Fa F1 F2

.. Treatment response as a percentage of control image growth.'0

c,C

L,'" 5E

w:E:::>--'0> 0UlUl0a:

'".. 5a.

'08

89

-'o'"I-Zou

17'

TREATMENTRESPONSE

CONTROLIMAGE GROWTH

Figure 11. Treatment response by stand structure analYsis using hypothetical tree frequencydistribution.

GROWTH EQUALTO CONTROL

TREATMENTRESPONSE

GROWTH EQUALTO CONTROL

TREATMENTRESPONSE

'BB

".

TZFZ - TREATMENTS

A

AAA

39

itA A

'0.

A

A

A

618 LARGEST TREES I ho

395 LARGEST TREES I ha

A

• •

11A A

110

AAA

CONTROL

CONTROl

PA

,

,

0

0,0 ,~,~

E

w:>

'0"-'0>

'"'"0'" ,'"....

0

A - ACTUAL

B - ADJUSTED .. Treatment response as a percentage of control.

Figure 12. Actual and adjusted treatment response by covariance analysis using the 395and 618 largest trees per hectare.

18

Table 1 - Initial mean dbh and height for the 395 and 618 largest trees per hectare.

Treatment

TOFO TOF 1 TOF2 T1 FO T 1F1 T 1F2 T2 FO T2F1 T2F2 GeneralMean

lal 395 largest trees/ha.

Initialdbh(eml 13.40 14.76 12.53 13.49 13.50 13.19 12.56 12.40 12.65 13.16

Initialheight (m) 12.03 12.30 11.02 11.92 11.62 11.40 10.99 11.31 11.11 11.52

(b) 618 largest trees/ha

Initialdbh (em) 12.74 13.67 11.93 12.70 12.76 12.48 11.59 11.62 11.71 12.36

Initialheight (ml 11.77 11.83 10.70 11.54 11.36 11.03 10.60 10.98 10.67 11.16

Table 2· Table of significance for fertilization, thinning and interaction using the 395 largest trees per

hectare

395 largest trees/ha

618 largest trees/ha

Dbh Sa Height Volume

Thinning •• • ••• ns •••Fertilization *... ••• ••• •••Interaction •• * • ••• •

Thinning ••• ••• ns •••Fertilization ••• ••• ••• •••Interaction • • •• ns

where ,.. = significant at the 5 percent level

** = significant at the 1 percent level,..,..,.. = sign ificant at the 0.1 percent level

and os = non significant.

5.2 Crop tree analysis

19

using:

The primary management objective in ferti·lizing and thinning is to speed up the growth of thecrop trees. Therefore, evaluation of treatment responseof the potential crop trees would seem to be a logicalanalytical approach that would probably appeal topracticing foresters and that would appear to havesome distinct advantages, e.g.:

1) the analysis is not complicated by themany small tfees that will have little orno merchantable value.

2) it eliminates the problems associatedwith the variation in stand structure.

3) the analysis is based on trees that have ahigh probability of being harvested.

The 395 and 618 largest trees per hectare(160 and 250 trees per acre, respectively) wereselected as representing the lower and upper limitsof the range of density of potential crop trees (com­mercial thinning and final crop) for managed standson sites similar to Shawnigan Lake. The response issimilar to that shown for individual trees and standstructure, except where the trees are considerablysmaller or larger than the general mean T 2FO andTOF1 treatments (Table 1, Fig. 12),

The difference in initial mean dbh and heightnecessitated the use of covariance analysis to evaluatethe differences in response to fertilization and thin­ning. The analysis was based on individual trees,using initial dbh and initial height as covariates.

The results of the analyses (Fig. 12 andAppendix XII) generally confirm the results obtainedfrom the individual tree and stand structure analyses.

The parameters showing statistical significanceover control for fertilization and thinning and theirinteraction are given in Table 2.

6.0 Comparison ofanalyticalapproaches

The response of Douglas-fir at ShawniganLake to fertilization and thinning has been evaluated

1) response on hectare basis; 2) growthresponse of individual trees; 3) stand structureanalysis, and 4) crop tree analysis.

With the exception of the response on ahectare basis, the analyses gave generally similarresults. However, we feel that all of the approacheshave application, albeit for different purposes. Someof the potentials and limitations of the approachesare listed below:

1) Response on a Hectare Basis

al Potentials

i) provides a real measure of totalvolume and volume increment.

bl Limitations

i) growth response is confounded bydiffering number of stems withindbh classes, especially among thin­ning treatments.

2) Growth Response of Individual Trees

a) Potentials

i) provides a basis for elucidatingstand dynamics and evaluating theeffects of competition.

H) allows comparison of growth re­sponse of essentially identical in­dividual trees.

iii) provides an excellent basis forinput into stand models.

b) Limitations

j) does not provide information ontotal stand response (area response)

unless used in conjunction with thestand table, as in stand structureanalysis.

3) Stand Structure Analysis

a) Potentials

i) has the greatest potential for deter­

mining response to thinning and fert­

lization in the mid-range diameters.

iil is easily adaptable for application indeveloping managed stand tables.

iii) provides an excellent base forevaluat­ing fertilization effects within (or inthe absence of) thinning treatments.

b) Limitations

i) it is of restricted value at the upperand lower diameter limits becauseof few or missing trees.

4) Crop Trees Analysis

a) Potentials

il has the g-eatest potential appli·cation for forest management, webelieve, as it relates to that partof the stand that is of the greatesteconomic importance.

b) Limitations

i) ignores the large component ofsmall trees.

7.0 Summary

The principal purpose of this paper is topresent the 3-year fertilization and thinning responseof a young stand of Douglas-fir at Shawnigan Lakeand to compare analytical approaches to the evalua­tion of response.

The study area and experimental layout aredescribed briefly and a detailed description of thedata base, including the units of measurement,measurement on a plot basis, measurement on anindividual tree basis and a description of the datacurrently being recorded, is given.

Regression equations are derived to estimatetotal tree volume and merchantable volume andinitial height and dbh, ba, height and gross volumeincrement by treatments. Analysis of form quotientshowed no significant differences between treatments.

3-year-treatment response is reported interms of:

20

1) volume increment (gross and merchantable)on a hectare basis

2) cumulative increment for dbh and height3) growth response of individual trees (dbh,

ba, height and volume)4) stand structure analysis using three dbh

frequency distributions5) crop tree response for the 395 and 618

largest trees per hectare (160 and 250largest trees per acre).

1) Evaluation of treatment response, usingvolume increment on a per hectare basis indicatedthat fertilization within thinning levels resulted inincreased increment, while thinning caused a reduc­tion in increment. The reduction in response asso­ciated with thinning is attributable to fewer numbersof trees on the thinned plots. The different numbersof trees within thinning treatments distorted themagnitude of response to fertilization. The use ofvolume response on a per hectare basis is thoughtto be unsatisfactory for determining both the mag­nitude and order of response, because of differencesin initial stand condition and differences in the treefrequency distributions by dbh class.

2) Examination of annual dbh and heightincrement trends provided some interesting indica­tions of response. Obh increment responded wellto both fertilization and thinning over the 3-yearperiod and appears to be maintaining the differen­tial rates of increment. The similarity of growthresponse to the T2F2 and T 2F 1 treatments shouldbe of special interest to the forest manager becauseof the high cost of fertilizer. The differential ratesof height increment also appear to be continuing.

3) Both fertilization and thinning resultedin increased PAl for dbh, ba and volume on individ·ual trees. Fertilization caused an increase in heightincrement regardless of thinning level, whileincreased levels of thinning reduced height incre·ment. While the analysis of individual tree responsecannot be used directly in determining response on ahectare basis, it provides a good basis for comparisonof treatment response by diameter classes and hasconsiderable promise for application in modelling.

4) The stand structure approach providedan excellent base for determining response to fer­tilization and thinning in the mid-range diameters,but has limited application for projecting final cropvolumes because it is not possible to include the very

large trees.

5) The crop tree approach, which evaluatestreatment response on the potential crop trees, isprobably the most appealing to practicing foresters.However, it ignores a large component of small trees.

On the basis of the analyses conducted, itwould appear that the magnitude of response recor­ded for fertilization and thinning depends to a largedegree on the type of analysis used. Our intent hasbeen to present a number of differing proceduresand to solicit reader response to their application.

21

9.0 REFERENCES

Anon, 1975. Washington State University, Seattle.College of Forest Resources, Regional forestnutrition research project. Biennial Report1972-74.

Arney, J.D. 1973. Tables for quantifying competitivestress on individual trees. Can. Dept. Environ.,Can. For. Serv., Pac. For. Res. Centre, Victoria.Information Rept_ BC-X-7B_ 15 pp_

Chapman, H.H_, and W.H. Meyer. 1949_ ForestMensuration. McGraw-HilI. New Yrok. 1949.

The authors thank John F. Dronzek for histechnical assistance in the field, Jack Rudd for pro·gramming assistance, Donald W. Whitney for deri·vation of merchantable volume factors, and JohnC. Wiens for the illustration of this report.

8.0 ACKNOWLEDGMENTS

Crown, M., Brett, C.P. et al. 1975. Fertilization andthinning effects on a Douglas-fir ecosystemat Shawnigan Lake: An establishment report.Canadian Forestry Service, Pacific ForestResearch Centre. Victoria, B.C. ReportBC-X-l10, January 1975_

Miller, R.E., and L.V. Pienaar. 1973. Seven-yearresponse of 35·year-old Douglas-fir to nitrogenfertilizer_ USDA For. Serv. Res. Pap. PNW-165,24 p., illus. Pacific Northwest Forest andRange Experiment Station, Portland, Oregon.

22

10.0 Appendices

Appendix I. Plot Measurement Schedule

Date to be Kind of measurement

measured 1971 plots 1972 plots

Spring '76 3

Fall '76 1,3& 4 2&5

Fall '77 2&5 1,3& 4

Fall '78 2&5 2 & 5

Fall '79 1,3& 4 2 & 5

Fall '80 2&5 1,3& 4

Fall '81 2&5 2&5

Fall '82 1,3& 4 2&5

Fall '83 2&5 1,3& 4

Fall '84 2&5 2& 5

Fall '85 1,3& 4 2& 5

Fall '86 1,3& 4

Kind of measurement:

1 = Dbh all trees in the plots.

2 = Dbh all volume sample trees.

3 = Original height or height every 3 years on all trees in the plots.

4 = Volume sample tree measurement (dbh, dab at taper steps, and height).

5 = Dbh all trees used in study PC·23·006 not measured in 1 or 2.

Ap

pen

dix

II.

Reg

ress

ion

equ

atio

ns

for

esti

mat

ing

3-ye

arh

eig

ht

incr

emen

t(b

,H)

by

trea

tmen

t

R2

SE

Elm

las

s

TOFO

/lH

=-1

.97

48

2+

2.47

792

D-.

55

14

74

D2

+.3

1257

9E-Q

1D

3+

5.22

529/

1D+

.495

936E

-01

H0.

866

0.70

235

7

T1F

OIl

H=

3.97

355

-.8

77

77

4D

+.3

7219

5D

2-.

30

21

47

E-0

1D

3+

3.22

7511

D-

.597

534E

-01

H0.

607

0.90

915

4

T2

F Oll

H=

-2.0

37

94

+.9

2164

5D

-.1

03

13

D2

+.2

0602

7E-Q

2D

3+3

.619

1311

D+

.192

91E

-Q1

H0.

705

0.71

972

TOF

1II

H=

-3.9

02

45

+4.

5855

5D

-.9

67

55

8D

2+

.604

633E

-01

D3

+4.7

0053

11D

+.2

60

4E

-01

H0.

899

0.80

226

7

T1F

1ll

H=

-5.7

05

65

+7.

1371

7D

-1.

5805

4D

2+

.115

326

D3

+2.

4503

711

D-.

63

57

79

E-Q

2H

0.68

90.

985

139

'"w

T2

F1

llH

=28

.518

5-

19.0

712

D+

5.05

678

D2

-.4

09

21

8D

3+2

.046

811D

..10

6627

H0.

660

1.06

071

TO

F2ll

H=

-5.0

03

03

+7.

1718

9D

-1.9

91

35

D2

+.1

70

11

D3

+5.

2419

411D

+.8

86

62

E-0

2H

0.84

41.

078

301

T1

F2

IIH

=-2

.88

09

+6.

59D

-1.

3041

5D

2+

.883

537E

-01

D3

+2.

1791

311D

-.9

96

32

9E

-01

H0.

706

0.90

116

1

T2

F2

llH

=1

5.6

89

3-7

.29

26

5D

+1

.71

63

8D

2_

.12

80

68

D3

+4.

0161

411D

-.1

20

22

H0.

382

1.39

669

Wh

ere

0=

Init

ial

db

ho

bin

inch

es

60

=3-

year

db

hin

crem

ent

inin

ches

H=

init

ial

hei

gh

tin

feet

6H=

3·ye

arhe

ight

incr

emen

tin

feet

Ap

pen

dix

III.

Mer

chan

tabl

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olum

eF

acto

rE

quat

ions

Do

ug

las-

fir:

Wes

tern

Red

Ced

ar:

Wes

tern

Hem

lock

:

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sam

:

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tern

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teP

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R2

SEE

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38

15

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06

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60.

003

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MV

F=

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43

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/0-0

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03

110

900

+0.

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201.

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MV

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whe

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(75

cm),

the

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sd

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app

ly

Ap

pen

dix

IV.

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gros

san

dm

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bytr

eatm

ents

.

Tre

atm

ents

TOFO

TO

FlT

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T1

F OT

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lF2

T2

F OT

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(G.

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).

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ter

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plot

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284.

013.

483.

413.

361.

811.

931.

84

(197

1&

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72

llm

3 /ha

)14

0.11

130.

4799

.09

85.9

984

.26

83.0

244

.73

47.6

945

.47

Ibl

G.

Vol

.3

yrs

afte

rtr

eatm

ent

1197

3&

1974

)(m

3 /pl

ot)

7.66

7.96

6.87

4.90

5.74

6.17

2.71

3.53

3.82

1197

3&

1974

l1m

i3/h

al18

9.28

196.

7016

9.76

121.

0814

1.84

152.

4666

.97

87.2

394

.39

lei

3·yr

.G

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ol.

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t(m

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l49

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66.2

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35.0

957

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69.4

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23.5

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=0.

910

R2

=0.

962

R2

=0.

899

R2

=0.

976

SEE

=0.

170

cm

SEE

=2.

778

cm2

SE

E=

0.1

88

m

SEE

=0.

0023

8m

3

db

hin

crem

ent

=.2

3600

9+

.60

58

29

E-0

10

+.6

64

38

5E

-02

02

-.2

3991

4E-Q

30

3

bain

crem

ent

:2.

8584

1-1

.14

99

20

+.3

7026

60

2-.

70

21

78

E-0

20

3

htin

crem

ent

=.1

3318

7+

.244

382

E-0

10

+.2

72

32

3/0

g.vo

l.inc

rem

ent

=.1

3546

7E-0

1-.

51

67

87

E-0

20

+.6

93

54

7E

-03

02

-.1

38

21

8E

-Q4

03

Tre

atm

ent

3·

Hea

vyth

inni

ng,

nofe

rtil

izer

(T2F

01

R2

=0.

782

SEE

=0.

250

cm

R2

=0.

928

SEE

=4.

571

cm2

'" 0-R

2=

0.63

8SE

E=

0.22

5m

R2

=0.

962

SEE

=0.

0035

2m

3

dbh

incr

emen

t=

.660

648

+.3

6288

1E

-01

0+

.94

63

52

E-0

20

2-.

26

11

8E

-03

03

bain

crem

ent

=6.

7874

7-

1.46

103

0+

.421

625

02

-.5

11

77

0E

-02

03

htin

crem

ent

=-1

.99

30

5-.

99

39

87

E-Q

10

+1

.24

96

31

0

g.vo

l.in

crem

ent

=.2

41

98

6E

-04

-.8

34

81

3E

-03

0+

.26

25

10

E-0

30

2+

.19

83

66

E-0

50

3

Wh

ere

0=

init

ial

db

h

11F

or

hea

lth

yD

ou

gla

s-fi

rtr

ees

on

ly,

du

rin

gth

efir

st3

year

sfo

llow

ing

trea

tmen

t.

R2

=0.

735

R2

=0.

910

R2

=0.

704

R2

:0.

937

SEE

=0.

298

cm

SEE

=6.

374

cm2

SEE

=0.

196

m

SEE

=0.

0052

0m

3

Ap

pe

nd

ixV

.-

(Con

tinue

d)

Tre

atm

en

t4

-No

thin

nin

g,

224

kgN

lha

(UR

EA

)IT

OF

1)

dbh

incr

emen

t=

-.5

40

65

7+

.171

747

0+

.59

02

09

E-0

20

2-.

32

65

19

E-Q

30

3

bain

crem

ent

=.2

1195

5-

1.78

341

0+

.535

733

02

-.1

13

17

7E

-01

03

ht

incr

emen

t=

-3.6

11

50

-.3

26

04

00

+2

.78

18

5/0

g.vo

l.in

crem

ent

=-.

20

47

21

E-0

2-.

74

64

80

E-0

30

+.3

27

69

3E

-03

02

-.5

43

60

8E

-06

03

Tre

atm

ent

5-

Inte

rmed

iate

thin

nin

g,

224

kgN

lha

(UR

EA

)T

1F1)

R2

=0.

902

R2

=0.

956

R2

=0.

904

R2

=0.

970

SE

E=

0.2

84

em

SE

E=

5.19

6cm

2

SE

E=

0.24

1m

SE

E=

0.0

04

78

m3

db

hin

crem

ent

=-1

.68

01

9+

.694

618

0-.

43

66

68

E-Q

l0

2+

.112

432E

-02

03

bain

crem

ent

=-1

3.5

42

5+

3.54

797

0+

.120

953

02

+.8

50

34

4E

-03

03

hti

ncr

em

en

t=

-3.4

13

47

-.3

83

01

20

+2

.93

12

0/0

g.vo

l.in

crem

ent

=-.

80

65

77

E-0

2+

.12

35

82

E-0

20

+.2

18

78

4E

-03

02

+.3

002

E-0

50

3

Tre

atm

en

t6

-H

eavy

thin

nin

g,

224

kgN

lha

(UR

EA

)IT

2F

1)

R2

=0.

842

SEE

=8.

300

em

R2

=0.

948

SE

E=

5.52

6cm

2

R2

=0.

750

"S

EE

=0

.22

6m

.....

R2

=0

.97

0SE

E=

0.00

430

m3

db

hin

crem

ent

=-.

44

07

1O

E-0

1+

.37

52

56

0-.

80

59

25

E-Q

20

2-.

59

96

18

E-0

40

3

bain

crem

ent

=6.

4107

1-2

.04

27

50

+.9

0091

00

2-.

24

98

76

E-O

l0

3

ht

incr

emen

t=

-2.3

40

37

-.1

90

15

50

+1

.89

76

4/0

g.vo

l.in

crem

ent

=.8

43

27

3E

-Ol

-.2

78

38

9E

-Q1

0+

.32

35

14

E-Q

20

2-.

92

07

28

E-0

40

3

Whe

re0

=In

itia

ldb

h

R2

=0.

663

R2

=0.

882

R2

=0

.60

1

R2

=0

.92

8

SE

E=

0.42

0em

SE

E=

9.29

2cm

2

SE

E=

0.28

2m

SE

E=

0.00

731

m3

App

endi

xV..

(Con

tinue

d)

Tre

atm

ent

7-

No

thin

nin

g,

448

kgN

lha

(UR

EA

)IT

OF

2)

db

hin

crem

ent

=-.

68

97

23

+.2

8893

0+

.18

83

79

E-0

20

2-.

35

25

6E

-03

03

bain

crem

ent

=.3

05

58

5-

1.85

377

0-

.699

177

02

-.1

64

24

7E

-01

03

ht

incr

emen

t=

-2.9

56

91

-.2

83

62

00

+2.

5470

9vD

g.vo

l.in

crem

ent

=-.

30

91

93

E-0

2+

.16

69

63

E-0

30

+.2

09

03

6E

-03

02

+.1

02

81

9E

-04

03

Tre

atm

ent8

·In

term

edia

teth

inn

ing

,44

8kg

Nlh

a(U

RE

A)

1T2F

2)

R2

=0

.87

6

R2

=0.

948

R2

=0.

806

R2

=0.

969

SE

E=

0.3

54

cm

SE

E=

5.67

9cm

2

SE

E=

0.3

50

m

SE

E=

0.0

04

48

m3

db

hin

crem

ent

=-1

.37

51

6+

.64

13

72

0-.

30

75

90

E-Q

l0

2+

.55

07

62

E-0

30

3

bain

crem

ent

=-1

4.6

54

5+

3.46

806

0+

.324

712

02

-.8

00

92

2E

-02

03

ht

incr

emen

t=

-2.7

73

89

-.3

54

94

80

+2

.68

46

91

0

g.vo

l.in

crem

ent

=-.

11

26

84

E-Q

l+

.18

60

60

E-Q

20

+.2

82

22

7E

-Q3

02

_.3

70

68

5E

-07

03

Tre

atm

ent

9·

Hea

vyth

inn

ing

,44

8kg

Nlh

a(U

RE

A)

(T2

F2

)

R2

=0.

758

SEE

=0

.45

6cm

R2

=0

.91

2S

EE

=8

.51

8cm

2IV ex

>

R2

=0

.69

4S

EE

=0.

240

m

R2

=0.

952

SE

E=

0.0

06

26

m3

db

hin

crem

ent

=-1

.76

03

0+

1.08

279

0-.

74

80

73

E-Q

10

2+

.18

87

95

E-0

20

3

bain

crem

ent

=-5

2.0

51

2+

16.9

697

0-.

76

72

95

02

+.2

32

24

3E

-01

03

ht

incr

emen

t=

.917

45-.

95

81

32

E-Q

l0

+.7

29

25

21

5

g.vo

l.in

crem

ent

=-.

20

30

59

E-0

2-.

56

71

97

E-0

30

+.7

07

37

4E

-03

02

-.1

52

30

8E

-04

03

Whe

re0

=In

itia

ld

bh

R2

=0.

564

R2

=0.

874

R2

=0.

043

R2

=0

.91

1

SE

E=

0.49

4cm

SE

E=

11.4

60cm

2

SE

E=

0.3

83

m

SE

E=

0.00

989

m3

29

Appendix VI. Dbh frequency distributions by treatments showing initial condition and number oftrees lost through thinning and mortality (cross hatched).

TREATMENTS

Fa

---TO---

Fa

---T,---

Fa

---T2---

FI

CONDITION

24624624635 35 35

24624624635 35 35

THINNING ANa {D}MORTALITY 0 INITIAL

24624624635 35 35

200

1200

1400

w 1000

'"..>-"WI'"W0- 800u>ww'">-~

0

'" 600w<D:>=>z

400

DBH CLASSES

Ap

pen

dix

VII

I.PA

lfo

'ba

by

db

hcl

asse

san

dt'

eatm

ents

Init

ial

db

hT

reat

men

ts

Cla

ssM

idpo

int

lem

}TO

FOTO

F1T

OF2

T1F

OT1

Fl

T1F

2T

2F

OT

2F

lT

2F

2

Co

ntr

ol

a)T

otal

bain

crem

ent/

tree

*(c

m2 )

26.

251.

662.

414.

012.

814.

525.

924.

297.

589.

90

38.

753.

966.

018.

875.

489.

1111

.73

7.62

13.5

917

.75

411

.25

7.19

10.6

114

.85

8.93

14.3

018

.02

12.1

420

.62

24.9

4

513

.75

11.2

315

.85

21.4

312

.93

20.1

124

.53

17.7

027

.90

32.2

0

b)B

ain

crem

ent

gain

abov

eco

ntr

ol

(cm

2)

~2

6.25

0.00

0.75

2.35

1.15

2.86

4.26

2.63

5.92

8.24

38.

750.

002.

054.

911.

525.

157.

773.

669.

6313

.79

411

.25

0.00

3.43

7.66

1.74

7.11

10.8

34.

9513

.44

17.7

5

513

.75

0.00

4.62

10.2

01.

708.

8813

.30

6.47

16.6

720

.97

·Oe

riv

ed

fro

mre

gres

sion

equ

atio

ns

Ap

pen

dix

V.

Ap

pen

dix

IX.

PAl

for

heig

htby

dbh

clas

ses

and

trea

tmen

ts

Init

ial

dbh

Tre

atm

ents

Cla

ssM

idpo

int

lem

}TO

FO

TO

F1

TO

F2

T,F

OT

1F1

T1F

2T

2F

OT

2F1

T2

F2

Con

trol a}

Tot

alhe

ight

iner

emen

t!tr

ee(m

)'

26.

250.

360.

440.

550.

320.

510.

570.

170.

410.

71

38.

750.

460.

590.

700.

380.

640.

690.

280.

540.

75

411

.25

0.52

0.68

0.80

0.44

0.70

0.74

0.36

0.63

0.76

513

.75

0.55

0.74

0.86

0.49

0.73

0.77

0.42

0.69

0.77

b)H

eigh

tin

crem

ent

gain

abov

eco

ntro

l1m

)w '"

26.

250.

000.

080.

19-0

.04

0.15

0.21

-0.1

90.

050.

36

38.

750.

000.

130.

24-0

.07

0.18

0.23

-0.1

8-.

08

0.29

411

.25

0.00

0.17

0.28

-0.0

80.

190.

23-0

.16

0.11

0.25

513

.75

0.00

0.19

0.31

-0.0

60.

180.

22-0

.12

0.14

0.22

*D

eriv

edfr

om

regr

essi

oneq

uat

ion

sA

pp

en

dix

V.

Ap

pen

dix

X.

PAl

for

gros

svo

lum

eb

ydb

hcl

asse

san

dtr

eatm

ents

.

Init

iald

bh

Tre

atm

ents

Cla

ssM

idp

oin

t(e

ml

TOFO

TOF

1T

OF2

T1

FO

T1F

1T

1F

2T

2F

OT

2F

lT

2F2

Co

ntr

ol a)

To

tal

gros

svo

lum

ein

crem

ent/

tree

(m3

)*

26.

250.

0014

0.00

200.

0029

0.00

170.

0030

0.00

380.

0018

0.00

470.

0061

38.

750.

0036

0.00

540.

0071

0.00

410.

0072

0.00

890.

0047

0.00

890

.01

23

411

.25

0.00

710.

0101

0.01

330.

0078

0.01

260.

0151

0.00

890.

0165

0.0

19

8

513

.75

0.01

170.

0161

0.02

180.

0126

0.01

940.

0225

0.01

440.

0261

0.02

81

bl

Gro

ssvo

lum

ein

crem

ent

gain

abov

eco

ntr

ol

(m3

)w w

26.

260.

0000

0.00

060.

0015

0.00

030.

0016

0.00

240.

0005

0.00

340.

0048

38.

750.

0000

0.00

170.

0034

0.00

040.

0035

0.00

520.

0011

0.00

530.

0087

411

.25

0.00

000.

0030

0.00

620.

0007

0.00

550.

0080

0.00

180.

0094

0.01

27

513

.75

0.00

000.

0044

0.01

010.

0009

0.00

770,

0108

0.00

270.

0129

0.01

64

...D

eriv

edfr

om

regr

essi

oneq

uat

ion

sA

pp

end

ixV

.

Ap

pen

dix

XI.

Tre

efr

eque

ncy

dist

ribu

tion

sby

dbh

clas

san

dtr

eatm

ent

used

inst

and

stru

ctur

ean

alys

is.

(a)

Act

ualt

ree

freq

uenc

ydi

stri

buti

ons

bytr

eatm

ents

asth

eyoc

cur.

Init

iald

bh

Num

ber

oftr

ees

bytr

eatm

ent

Cla

ssM

idp

oin

tle

m)

TOFO

TO

Fl

TO

F2

T1F

OT1

F1

T1F

2T

2F

OT

2F

lT

2F

2

3.75

3620

242

23

00

0

26.

2558

3540

1414

151

23

38

.75

5644

4727

2432

16

1112

411

.25

3430

2726

2424

1317

15

51

3.7

59

105

89

75

55

616

.25

12

22

22

11

2

w7

18.7

51

20

00

00

00

l>-

(b)

Mea

ntr

eefr

eque

ncy

dist

ribu

tion

sfo

rea

chth

inni

ngle

vel.

Init

iald

bh

Num

ber

oftr

ees

bytr

eatm

ent

Cla

ssM

idp

oin

tle

m)

TOF

OT

OF

1T

OF

2T

1FO

T1F

1T

1F2

T2

FO

T2

F1

T2

F2

3.75

2626

262

22

00

0

26.

254

44

444

1414

142

22

38

.75

49

49

4928

2828

131

313

411

.25

3030

3024

2424

1515

15

513

.75

88

88

88

55

5

616

.25

22

22

22

718

.75

11

10

00

00

0

Ap

pe

nd

ixX

I(C

ontin

ued)

(c)

Hyp

oth

etic

altr

eefr

equ

ency

dis

trib

uti

on

.

Init

iald

bh

Num

ber

of

tree

sb

ytr

eatm

ent

Cla

ssM

idp

oin

t(e

m)

TOF

OTO

F1T

OF

2T

1FO

T1F

1T

1F

2T

2F

OT

2F

1T

2F

2

3.75

00

00

00

00

0

26.

253

33

33

33

33

w '"3

8.75

1010

1010

1010

1010

10

411

.25

1414

1414

1414

1414

14

513

.75

55

55

55

55

5

616

.25

22

22

22

22

2

718

.75

00

00

00

00

0

App

endi

xX

II.

Act

ual

and

adju

sted

PA

lfo

rgr

oss

volu

me

by

cova

rian

cean

alys

isus

ing

the

39

5an

d6

18

larg

est

tree

sp

erh

ecta

re(m

3)

Tre

atm

ent

Act

ual

Gai

no

ver

%G

ain

abov

eA

dju

sted

Gai

no

ver

%G

ain

abov

eA

ctua

lA

ctua

lA

djus

ted

Adj

uste

dC

on

tro

lC

on

tro

lC

ontr

olC

on

tro

l

a)39

5la

rges

ttr

ees/

ha

TO

FO

(con

trol

)4.

525

00

4.04

00

0

TO

F1

7.69

13.

165

70.0

5.48

31.

443

35.7

TO

F26.

958

2.43

353

.87.

875

3.83

594

.9

T1

FO4.

817

0.29

26.

54.

270

0.23

05.

7

T1F

17.

724

3.19

970

.77.

286

3.24

680

.3

T1F

28.

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