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Analysis of some factors influencing variation of cellulose in Douglas fir Jaworsky, John Myroslaw 1959

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ANALYSIS OF SOME FACTORS INFLUENCING) VARIATION! OF CELLULOSE IN DOUGLAS F I R by JOHN MYROSLAW JAWORSKY FORESTRY ENGINEER SWISS FEDERAL INSTITUTE OF TECHNOLOGY ZURICH, 1948 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF FORESTRY I n t h e Department o f FORESTRY: We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o t h e r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRITISH COLUMBIA J a n u a r y , 1959 ABSTRACT The aim o f t h i s s t u d y was t o d e t e r m i n e how s e v e r a l g r o w t h f a c t o r s i n f l u e n c e c e l l u l o s e c o n t e n t i n D o u g l a s f i r wood. S t a n d a r d s a m p l e s f r o m e i g h t D o u g l a s f i r t r e e s o r i g i n a t i n g f r o m t h e U. B. C. R e s e a r c h F o r e s t a t Haney, B. C. were s u b m i t t e d t o a s l i g h t l y m o d i f i e d C r o s s and B e v a n e x t r a c t i o n p r o c e d u r e . I n a d d i t i o n , t h e n e w l y - d e v e l o p e d method o f Y u n d t and Bradway was u s e d t o g i v e an i n d e p e n d e n t e s t i m a t e o f c e l l u l o s e f r o m t h e t r e e s w h i c h y i e l d e d e x t r e m e v a l u e s f o r C r o s s and B e v a n c e l l u l o s e . The m a i n f a c t o r s c o n s i d e r e d as i n f l u e n c i n g c e l l u l o s e y i e l d s were crown c l a s s , s i t e and r a d i a l p o s i t i o n w i t h i n t h e same t r e e . I n a d d i t i o n , t h e l a r g e s t t r e e among t h e e i g h t t e s t e d was s t u d i e d t o f u r t h e r d e f i n e t h e e x t e n t o f c e l l u l o s e v a r i a t i o n w i t h i n c r e a s i n g age f r o m t h e p i t h . By a n a l y s i s o f a s i n g l e t r e e l o w e r c e l l u l o s e y i e l d s were o b t a i n e d f o r j u v e n i l e wood as compared w i t h t h e m ature wood i n t h e same t r e e . Most o f t h e v a r i a t i o n i n c e l l u l o s e due t o age was f o u n d i n r i n g s f o r 1-15 y e a r s . D e s p i t e t h e f a c t t h a t two g r o w t h f a c t o r s ( c r o w n c l a s s and s i t e ) were shown t o have a s t a t i s t i c a l l y s i g n i f i c a n t i n f l u e n c e on c e l l u l o s e y i e l d , i t was shown t h a t t h e i r i n f l u e n c e was i n d e p e n d e n t o f r a t e o f g r o w t h . The f o u r l a r g e s t t r e e s had h i g h e r c e l l u l o s e y i e l d s t h a n t h e f o u r s m a l l e s t t r e e s on e a c h p l o t . On t h e a v e r a g e , c e l l u l o s e y i e l d s were h i g h e r f o r t h e p o o r s i t e t h a n t h e good s i t e , y e t t h e v a r i a t i o n s c o u l d n o t be r e l a t e d t o s i z e , g r o w t h r a t e , o r p e r c e n t summerwood. T h e r e was a d e f i n i t e v a r i a t i o n i n c e l l u l o s e c o n t e n t among t h e t r e e s . The h i g h e s t c e l l u l o s e p e r c e n t a g e was f o u n d i n a n i n d i v i d u a l d o m i n a n t t r e e on t h e p o o r s i t e and t h e l o w e s t i n a n i n t e r m e d i a t e t r e e on t h e good s i t e . A c t u a l c a u s e s and c o n t r o l s o f c e l l u l o s e c o n t e n t among i n d i v i d u a l t r e e s r e m a i n t o be e s t a b l i s h e d . However, i t c a n be s t a t e d t h a t t h e r e i s an i m p o r t a n t v a r i a t i o n i n t h e c e l l u l o s e y i e l d s f r o m t r e e t o t r e e , and t h a t i n t h i s sample o f e i g h t t r e e s , y i e l d s o f C r o s s and Bevan c e l l u l o s e r a n g e d f r o m 54 t o 66 p e r c e n t . The d e s i r a b i l i t y o f p r o p a g a t i n g t r e e s w i t h h i g h c e l l u l o s e c o n t e n t i s d i s c u s s e d b r i e f l y . In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f the requirements f o r an advanced degree at the U n i v e r s i t y of B r i t i s h Columbia, I agree t h a t the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and study. I f u r t h e r agree' t h a t permission f o r e xtensive copying of t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by the Head of my Department or by h i s r e p r e s e n t a t i v e s . I t i s understood that copying or p u b l i c a t i o n of t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l not be allowed without my w r i t t e n p e r m i s s i o n . / John M. J*worsky / Department of Forestry The U n i v e r s i t y of B r i t i s h Columbia, Vancouver 3 , Canada, Date February 2, 1959 1 ACKNOWLEDGMENT The author wishes to express his gratitude to Dr. R. W . Wellwood, Dr. J . H. G. Smith and Mr. R. W. Kennedy, of the University of B r i t i s h Columbia, f o r t h e i r d i r e c t i o n and constructive c r i t i c i s m . Dr. B. J . Zobel, Associate Professor of Forest Genetics and Lia i s o n Genetecist, School of Forestry, N. C. State College, Raleigh, N. C , contributed to the experiment by correspondence and by sending copies of his recent publications. Instructions on the procedure f o r determination of water-resistant carbohydrate and alpha-cellulose, sent by Dr. A. P. Yundt, Research Associate, Camp D i v i s i o n , Union Bag-Camp Paper Corporation, Franklin, V i r g i n i a , gave the author a chance to add a valuable supplement to his r e s u l t s . Their response i s g r a t e f u l l y acknowledged. i i TABLE OF CONTENTS Page I. INTRODUCTION! 1 I I . LITERATURE REVIEW 4 I I I . METHOD 10 A . S e l e c t i o n o f T r e e s 10 S. P r e p a r a t i o n o f Samples 11 C. E s t i m a t i o n o f P e r c e n t a g e Summerwood 11 D. P r e p a r a t i o n o f M a t e r i a l f o r E x t r a c t i o n . . . 12 E . E v a l u a t i o n o f M o i s t u r e C o n t e n t 13 F . Removal o f E x t r a c t i v e s 13 Gr. D e t e r m i n a t i o n o f C r o s s and Bevan C e l l u l o s e . 14 Hi D e t e r m i n a t i o n o f W a t e r - R e s 1 s t a n t C a r b o h y d r a t e ( H o l o c e l l u l o s e ) and A l p h a - C e l l u l o s e by Y u n d t and Bradway P r o c e d u r e 16 I . T o t a l Number o f C e l l u l o s e D e t e r m i n a t i o n s . . 17 IV. RESULTS AND S T A T I S T I C A L ANALYSIS 19 A. A n a l y s i s o f E i g h t T r e e s -19 B;. A n a l y s i s o f a S i n g l e T r e e 22 C. A n a l y s i s o f W a t e r - R e s i s t a n t C a r b o h y d r a t e and A l p h a - C e l l u l o s e and I t s C o r r e l a t i o n w i t h C r o s s and Bevan C e l l u l o s e 23 i l l Page V. DISCUSSION 35 A . Determination of Cellulose . 35 EF, F i l t r a t i o n D i f f i c u l t i e s • • 36 C. Results from Cross and Bevan Method . . . . . 38 D. Comments and Results from Yundt and Bradway Method 43 VI. CONCLUSIONS 45 VII. LITERATURE CITED 48 VIII. APPENDIX . . . 1. Summary of Regressions 50 2. Supplementary Analysis of Variance for Eight Trees (Based on Cross and Bevan Cellulose Yields Rounded to the Nearest Whole Percent and on the Inoreased Error Term by the Sum of Squares for Replication. 51 i v L I S T OF TABLES T a b l e Page 1. G e n e r a l D a t a f o r E i g h t T r e e s ( C r o s s and Bevan C e l l u l o s e ) . 25-26 2. T o t a l A n a l y s i s o f V a r i a n c e f o r E i g h t T r e e s ( C r o s s and B e v a n C e l l u l o s e ) , T r e e Term w i t h "A" and "B" R e p l i c a t e s Used 27 3. A n a l y s i s o f V a r i a n c e f o r E i g h t T r e e s and Com-p a r i s o n o f Two E x t r e m e V a l u e s f o r C r o s s and B e v a n C e l l u l o s e Y i e l d s 28 4. C r o s s and Bevan C e l l u l o s e Y i e l d s ( f o r E i g h t T r e e s ) as R e l a t e d t o R a d i a l P o s i t i o n , R a t e o f Growth and P e r c e n t a g e Summerwood . 29 5. C r o s s and Bevan C e l l u l o s e Y i e l d s f o r I n d i v i d u a l T r e e (No. 318) as R e l a t e d t o Age f r o m P i t h . 30 6. W a t e r - R e s i s t a n t C a r b o h y d r a t e (W.R.C.) and A l p h a - C e l l u l o s e Y i e l d s f r o m T r e e s No. 313 and No. 304, A c c o r d i n g t o Method o f Yund t and Bradway 31 7. C o m p a r i s o n o f V a r i a n c e s b e t w e e n C r o s s and B e v a n C e l l u l o s e , W a t e r - R e s i s t a n t C a r b o h y d r a t e (W.R.C.) and A l p h a - C e l l u l o s e f o r T r e e s No. 313 and No. 304 32 8. S a m p l i n g V a r i a t i o n and Time R e c o r d f o r C r o s s and B evan C e l l u l o s e as Compared w i t h W a t e r -Res i s t a n t C a r b o h y d r a t e and A l p h a - C e l l u l o s e f o r T r e e s No. 313 and No. 304 33 V L I S T OF TABLES ( C o n t ' d ) T a b l e Page 9. M o i s t u r e P e r c e n t a g e s as O b t a i n e d by Oven-D r y i n g a t IOO - 105° C and Assumed f o r E a c h o f C o r r e s p o n d i n g R e p l i c a t e s b e f o r e D e t e r m i n a t i o n o f C r o s s and B e v a n C e l l u l o s e 34 L I S T OF FIGURES F i g u r e 1. C h l o r i n a t i o n A p p a r a t u s 47 INTRODUCTION The major chemical constituent of wood i s cellulose, which is recognized as representing roughly 50 per cent of woody substance. Although few other organic compounds have undergone as intensive study as cellulose, l i t t l e research has been done on the variation of cellulose within plants of the same species. Several interesting findings have revealed the interdependence among specific gravity of the wood, tree age, rate of growth and percentage of aummerwood. On the other hand, growth factors related to s o i l type, precipitation, duration of growing seasons, unseasonable frosts, geo-graphical latitude and altitude a l l affect specific gravity. Even inherited features are now suspected as influencing the weight of wood and structure of the tree. Prom the forester's point of view i t i s important to know whether growth conditions results in an increase or deorease in the cellulose content in the wood. It would be of interest to determine whether such factors as s o i l quality and crown class directly, or s i l v i c u l t u r a l treatments indirectly, have any influence on the variation of cellulose in wood. It is known, for Instance, that the amount of cellulose is higher in one species than in another. A variation in cellulose content within the same species might also be expected* Moreover, a variation of cellulose content within individual loblolly pine trees has been shown by Zobel and McElwee ( 2 0 ) . If such variations exist, do they correspond to some sort of pattern which could be established and then used as a tool for the improve-ment of wood quality? The experiment described herein was undertaken in order to investigate the Cross and Bevan cellulose content in wood of Douglas f i r in relation to good and poor forest sites, and in relation to the dominant and Intermediate crown classes. Furthermore, a single tree was analyzed to show whether cellulose content varied from the pith toward the bark. It was hoped that some trends in variation of cellulose content in Douglas f i r , i f established, might suggest a similar variation in other pulping species. Furthermore, positive results from this small experiment could lead to more detailed studies along the same line Only one species and one locality were chosen, namely Douglas f i r (Pseudotsuga menziesii (Mirb.) Franco), from the University Research Forest at Haney, B. C. Much useful data on atmospheric conditions, s o i l moisture and growth of Douglas f i r trees at the University Research Forest have been kept during the last decade. A l l the material investigated in this study came from two permanent sample plots whioh are part of a comprehensive study of si t e . Besides being the leading lumber and veneer - 3 -m a t e r i a l i n t h i s p r o v i n c e , D o u g l a s f i r i s o f s e c o n d i m p o r t a n c e as a p u l p i n g s p e c i e s . I n E u r o p e as w e l l as i n N o r t h A m e r i c a , t h e m e c h a n i c a l and a n a t o m i c a l c h a r a c t e r i s t i c s o f t h i s s p e c i e s have b e e n s t u d i e d and a d e q u a t e r e c o r d s a r e a v a i l a b l e . I n -f o r m a t i o n c o n c e r n i n g t h e c e l l u l o s e c o n t e n t o f D o u g l a s f i r i s d e c i d e d l y l i m i t e d , however. A l t h o u g h d i f f e r e n t methods a r e a v a i l a b l e f o r c e l l u l o s e d e t e r m i n a t i o n s , i t was d e c i d e d t o a d o p t t h e C r o s s and B e v a n method, w h i c h I s one o f t h e s t a n d a r d p r o c e d u r e s i n t h e p u l p and p a p e r i n d u s t r y as w e l l as i n f o r e s t p r o d u c t s l a b o r a t o r i e s . However, t h e C r o s s and B evan c e l l u l o s e d e t e r m i n a t i o n r e q u i r e s c o n s i d e r a b l e t i m e f o r c o m p l e t i o n o f a s i n g l e s a m p l e . To a d a p t t h i s method t o t h e l a r g e r number o f s amples o f t h e p r e s e n t s t u d y , and t o t h e a v a i l a b l e l a b o r a t o r y f a c i l i t i e s , c e r t a i n m i n o r m o d i f i c a t i o n s were made. Hence I n t h i s e x p e r i m e n t t h e aim was n o t s o much f o r a b s o l u t e c e l l u l o s e c o n t e n t i n t h e s a m p l e s , as f o r c o m p a r a t i v e v a l u e s o f t h e m o d i f i e d C r o s s and Bevan c e l l u l o s e y i e l d s . As a c h e c k , t h e f o u r wood s a m p l e s t h a t y i e l d e d extreme v a l u e s f o r C r o s s and B e v a n c e l l u l o s e were a n a l y z e d f o r h o l o c e l l u l o s e and a l p h a -c e l l u l o s e a c c o r d i n g l y t o t h e method d e v e l o p e d by Yundt and i B r a d w a y l . D e s c r i b e d i n p e r s o n a l c o r r e s p o n d e n c e w i t h Dr. A. P. Y u n d t , R e s e a r c h A s s o c i a t e , Camp D i v i s i o n , U n i o n Bag-Camp P a p e r C o r p o r a t i o n , F r a n k l i n , V i r g i n i a , June 25, 1958. - 4 -LITERATURE REVIEW The f o l l o w i n g g e n e r a l d e s c r i p t i o n o f t h e c o n s t i t u e n t s Wood c o n t a i n s two m a j o r g r o u p s o f i n g r e d i e n t s . The f i r s t g r o u p , c o m p r i s i n g t h e p r i n c i p a l c o n s t i t u e n t s c e l l u l o s e , h e m i c e l l u l o s e and l i g n i n , i s p r e s e n t i n a l l s p e c i e s o f wood i n r e l a t i v e l y l a r g e q u a n t i t i e s . The s e c o n d g r o u p , c o n s i s t i n g o f t h e m i n o r i n g r e d i e n t s , v a r i e s g r e a t l y b o t h I n t h e n a t u r e o f t h e i n -g r e d i e n t s and t h e amount o f e a c h p r e s e n t I n t h e v a r i o u s s p e c i e s . I n t h i s s e c o n d g r o u p w i l l be f o u n d t a n n i n s , w o o d - c o l o r i n g m a t t e r , r e s i n s , e s s e n t i a l o i l s , o l e o r e s i n s , s u g a r s and o t h e r c a r b o h y d r a t e s , p e c t i n s , gums, n i t r o -gen compounds, f r e e o r g a n i c a c i d s , and m i n e r a l s u b s t a n c e s . . The c h e m i c a l c o m p o s i t i o n o f c o n i f e r o u s s p e c i e s , o r s o f t w o o d s , d i f f e r s f r o m t h a t o f t h e b r o a d -l e a v e d s p e c i e s , o r hardwoods, i n r e s p e c t t o t h e c o m p o s i t i o n o f t h e h e m i c e l l u l o s e and l i g n i n . H e m i c e l l u l o s e o f hardwoods c o n t a i n s more p e n t o s a n s and u r o n l c a c i d s and t h e l i g n i n more m e t h o x y l t h a n c o r r e s p o n d i n g c o n s t i t u e n t s o f s o f t w o o d s . The scheme f o r t h e c h e m i c a l c o m p o s i t i o n o f wood e s t a b l i s h e d by R i t t e r as s t a t e d i n K o l l m a n n (7), i s shown b e l o w as a p e r c e n t o f t h e w e i g h t o f o v e n - d r y wood: o f w o o d / g i v e n by Stamm and H a r r i s ( 1 5 ) : E x t r a c t i v e s L i g n i n H o l o c e l l u l o s e 6% 22% 12% H e m l c e l l u l o s e s C e l l u l o s e E a s i l y h y d r o l y z a b l e 12% I n c e l l u l o s e 22% 38% C r o s s and B e van C e l l u l o s e 60% - 5 -From t h e above d a t a i t f o l l o w s t h a t h e m i c e l l u -l o s e s a r e s u b d i v i d e d i n t o two g r o u p s . The f i r s t g r o u p , a c c o r d i n g t o R i t t e r q u o t e d i n K o l l m a n n (7), c o n t a i n s m o s t l y u r o n i c a c i d g r o u p s and c a n be s e p a r a t e d i n t h e C r o s s and Bevan p r o c e d u r e . The l a r g e r g r o u p o f h e m i c e l l u -l o s e s i s n o t removed by C r o s s and B e v a n i s o l a t i o n t r e a t m e n t s , and h ence i s i n c l u d e d i n C r o s s and Bevan c e l l u l o s e . I t i s c l a i m e d by K o l l m a n n (7) t h a t a l l a n a l y t i c a l p r o c e d u r e s f o r wood have as a common b a s e t h a t t h e r e a c t i v e l i g n i n i s c h e m i c a l l y c h a n g e d , t h u s e n a b l i n g i t t o be s e p a r a t e d f r o m t h e p o l y s a c c h a r i d e s . C o n s i d e r a b l e d i f -f i c u l t i e s i n d e t e r m i n a t i o n o f c e l l u l o s e c o n t e n t i n wood r e s u l t f r o m t h e m a c r o m o l e c u l a r s t r u c t u r e o f c e l l u l o s e . I n c h a i n c o l l o i d s ( e . g . c e l l u l o s e ) , t r a c e s o f r e a c t i v e s u b -s t a n c e s , f o r i n s t a n c e o x y g e n f r o m t h e a i r o r b l e a c h i n g a l k a l i e s , a r e s u f f i c i e n t t o c a u s e a. n o t a b l e d e g r a d a t i o n o f c h a i n m o l e c u l e s . D e s p i t e t h e ext r e m e i m p o r t a n c e o f c e l l u -l o s e m a t e r i a l s i n i n d u s t r y , methods a r e l a c k i n g by w h i c h t h e c e l l u l o s e i n wood may be d e t e r m i n e d p r e c i s e l y . A c c o r d i n g t o H a g g l u n d ( 4 ) , t h e l i g n i n i s c o n n e c t e d w i t h t h e c a r b o h y d r a t e s n o t by a b s o r p t i o n , b u t c h e m i c a l l y by t h e g l u c o s l d i c l i n k a g e . L i g n i n a c t s as a "cement" s u b s t a n c e f o r t h e c e l l u l o s e s k e l e t o n , and a p p a r e n t l y i n some p l a c e s i s d i r e c t l y a t t a c h e d t o t h e c e l l u l o s e c h a i n s . The same a u t h o r f u r t h e r s t a t e s : " i t i s n e v e r p o s s i b l e t o p r e p a r e c o m p l e t e l y p u r e c e l l u l o s e f r o m wood. The r e m o v a l o f t h e p e n t o s a n s i s p a r t i c u l a r l y d i f f i c u l t " . I n h i s o p i n i o n t h e - 6 -i s o l a t i o n o f c e l l u l o s e by t h e C r o s s and B e v a n method does n o t c o m p l e t e l y remove g a l a c t a n . A d i f f e r e n t v i e w on t h e n a t u r e o f l i g n i n - c a r b o -h y d r a t e bonds i s e x p r e s s e d by F r e u d e n b e r g (17), who i n d i c a t e s t h a t a g l u c o s i d i c bond b e t w e e n p o l y s a c c h a r i d e s and l i g n i n i s h i g h l y i m p r o b a b l e , and n o t u n d e r s t a n d a b l e f r o m t h e c h e m i c a l p o i n t o f v i e w , " i f a l i g n i n - c a r b o h y d r a t e c o m b i n a t i o n i s p r e s e n t " , s t a t e s t h e a u t h o r , " t h e q u i n o n e m e t h i d e a d d i t i o n seems t o be t h e o n l y way i n w h i c h i t may be f o r m e d " . D i s c u s s i n g t h e s e c o n d a l t e r n a t i v e , n a m e l y t h e a b s e n c e o f l i g n i n - c a r b o h y d r a t e b o n d s , F r e u d e n b e r g s u g g e s t s : E i t h e r l i g n i n i s so h i g h l y c o n d e n s e d t h a t i t i s i n s o l u b l e i n a l l o r g a n i c s o l v e n t s o r , a l t h o u g h s o l u b l e as s u c h , p h y s i c a l phenomena, f o r e x a m p l e , weak f o r c e s s u c h as h y d r o g e n bonds c a n r e s t r a i n l i g n i n f r o m d i s s o l v i n g u n d e r n o r m a l e x t r a c t i o n c o n d i t i o n s , o r a g a i n , maybe t h e s o l u b l e p a r t s a r e imbedded and c a n n o t d i f f u s e o u t o f t h e t i s s u e . . A c c o r d i n g t o Hawley and Norman (5), t h e h e m l -c e l l u l o s e s i n t h e wood c a n be d i v i d e d i n t o two g r o u p s : t h e f i r s t s t r o n g l y bound t o t h e c e l l u l o s e and r e t a i n e d i n t h e C r o s s and B e van p r o c e d u r e , and t h e s e c o n d s e p a r a b l e f r o m C r o s s and B e v a n c e l l u l o s e . Wise and J a h n (19) a l s o e m p h a s i z e t h e f a c t t h a t C r o s s and B e v a n c e l l u l o s e i s n o t a p u r e c e l l u l o s e s u c h as i s r e p r e s e n t e d by c o t t o n c e l l u l o s e . They m a i n t a i n t h a t C r o s s and B e van c e l l u l o s e c o n t a i n s c o n -s i d e r a b l e q u a n t i t i e s o f r e s i s t a n t h e m i c e l l u l o s e s w h i c h a r e n o t removed by i s o l a t i o n t r e a t m e n t s . A p o r t i o n o f t h e p e n t o s a n s as w e l l as s m a l l t r a c e s o f l i g n i n o r some i n o r g a n i c - 7 -c o n s t i t u e n t s c a n n o t be removed e v e n by p r o l o n g e d c h l o r i n a t i o n . S i m i l a r d i f f i c u l t i e s a r e met i n s e p a r a t i o n o f t h e a c e t y l , f o r m y l and u r o n l c a c i d g r o u p s . They f u r t h e r s u g g e s t t h a t some h y d r o l y s i s and o x i d a t i o n p r o d u c t s o f c e l l u l o s e a r e f o r m e d d u r i n g t h e C r o s s and B e v a n I s o l a t i o n t r e a t m e n t s , a n d p o r t i o n s o f t h e s e r e m a i n i n t h e f i n a l p r o d u c t . Low c e l l u l o s e y i e l d s due t o d e g r a d a t i o n a r e i n t e r -p r e t e d by s e v e r a l r e s e a r c h w o r k e r s i n t h e f o l l o w i n g manner: Wise and J a h n (19) c l a i m t h a t c e l l u l o s e i s o l a t e d by t h e C r o s s and B e van method may g i v e low y i e l d s b e c a u s e o f t h e h i g h c o n c e n t r a t i o n o f h y d r o c h l o r i c a c i d p r o d u c e d d u r i n g c h l o r i n a t i o n . C o p p i c k i n Wise and J a h n (19) s t a t e s t h a t t h e d e g r a d a t i o n o f C r o s s and B e van c e l l u l o s e p r e p a r e d f r o m a s p e n I n c r e a s e s w i t h t h e number o f c h l o r i n a t i o n s , t h e d e g r e e o f p o l y m e r i z a t i o n (DP) f a l l i n g f r o m 4,370 t o 2,730 i n z e r o t o f o u r c h l o r i n a t i o n s . V a n Beckum and R i t t e r s t a t e i n K o l l m a n n (7) t h a t i n t h e a l k a l i t r e a t m e n t o f h o l o c e l l u l o s e , t h e s h o r t c h a i n m o l e c u l e s a r e removed and t h e c e l l u l o s e r e m a i n s u n a f f e c t e d , whereas i n t h e a c i d t r e a t m e n t n o t o n l y t h e s h o r t c h a i n m o l e c u l e s a r e removed, b u t a l s o d e g r a d a t i o n o f c e l l u l o s e t a k e s p l a c e . I t f o l l o w s f r o m t h e s e s t a t e m e n t s t h a t p a r t i c u l a r l y a l p h a - c e l l u l o s e i s e x p o s e d t o h y d r o l y s i s by a c i d s f o r m e d i n t h e s e c o n d a r y r e a c t i o n s o f C r o s s and B e v a n method. However, a s m e n t i o n e d p r e v i o u s l y , t h e m a i n o b j e c t i v e o f t h e p r e s e n t e x p e r i m e n t was t o o b t a i n c o m p a r a t i v e C r o s s and B e van c e l l u l o s e y i e l d s and n o t a b s o l u t e c e l l u l o s e p e r c e n t a g e s f o r e a c h s a m p l e . V a r i a t i o n i n a n a t o m i c a l o r p h y s i c a l s t r u c t u r e o f wood a l s o a f f e c t s t h e y i e l d s o f c e l l u l o s e . W e g e l i u s ( 1 8 ) , a f t e r i n v e s t i g a t i n g t h e a n a t o m i c - s t r u c t u r a l p r o p e r t i e s i n F i n n i s h s p r u c e , f o u n d i n h i s p r e l i m i n a r y e x p e r i m e n t s t h a t t h e y i e l d o f c e l l u l o s e i n c h e m i c a l p u l p i n g was g r e a t e s t when a n n u a l r i n g s were o f n o r m a l w i d t h f o r t h e s p e c i e s . R i t t e r and F l e c k (11) and a l s o B a i l e y q u o t e d i n Wise and J a h n ( 1 9 ) , f i n d h i g h e r c e l l u l o s e y i e l d s f o r summerwood o f D o u g l a s f i r as compared w i t h s p r i n g w o o d . H i g h e r c e l l u l o s e y i e l d s were o b t a i n e d by R i t t e r and F l e c k (10) f o r t h e sapwood o f b a l d c y p r e s s , w h i t e p i n e , y e l l o w c e d a r and i n c e n s e c e d a r t h a n f o r t h e h e a r t w o o d o f t h e same s p e c i e s . S i m i l a r t r e n d s i n c e l l u l o s e r e c o v e r y i n sapwood v e r s u s h e a r t w o o d were c o n f i r m e d by A n d e r s o n (1) i n h i s s t u d y o f w e s t e r n p i n e s . Z o b e l and McElwee ( 2 0 ) , i n v e s t i g a t i n g l o b l o l l y p i n e , m a i n t a i n t h a t t h e t r e e w h i c h has l o w c e l l u l o s e y i e l d s i n i t s J u v e n i l e wood a l s o has l o w y i e l d s i n i t s m a t u r e wood, and where h i g h y i e l d s e x i s t i n J u v e n i l e wood t h e y a r e a s s o c i a t e d w i t h h i g h y i e l d s i n t h e mature wood. They f o u n d t h a t t h e w a t e r - r e s i s t a n t c a r b o h y d r a t e ( h o l o c e l l u l o s e ) was a l w a y s v e r y h i g h l y c o r r e l a t e d w i t h t h e a l p h a - c e l l u l o s e c o n t e n t ( s i g n i f i c a n t a t t h e one p e r c e n t l e v e l ) . I n b o t h t h e J u v e n i l e and ma t u r e wood, w a t e r - r e s i s t a n t c a r b o h y d r a t e y i e l d s were n o t i n f l u e n c e d by s p e c i f i c g r a v i t y when e x p r e s s e d on a u n i t w e i g h t b a s i s . A l p h a - c e l l u l o s e y i e l d s were o n l y s l i g h t l y a f f e c t e d by t h e s p e c i f i c g r a v i t y o f t h e wood. No r e l a t i o n s h i p was f o u n d b e t w e e n c o m p r e s s i o n wood and c e l l u l o s e y i e l d s . - 9 -B l a n d (2) q u o t e s D a d s w e l l and Hawley as r e p o r t i n g t h a t c o m p r e s s i o n wood o f S i t k a s p r u c e and redwood a r e r i c h i n l i g n i n and low i n c e l l u l o s e . S c h w e r i n (12) shows t h e f o l l o w i n g a l p h a - c e l l u l o s e y i e l d s f o r t h e two s p e c i e s l i s t e d b e l o w : F l n u s r a d l a t a N o r m a l wood: 51.0 p e r c e n t ; Compr e s s i o n wood: 45.1 per c e n t E u c a l y p t u s g o n l o c a l y x N o r m a l wood: 42.9 p e r c e n t ; - T e n s i o n wood: 62.1 p e r c e n t Hence i n b o t h s p e c i e s c e l l u l o s e c o n t e n t v a r i e d a c c o r d i n g t o t h e p r e s e n c e o r a b s e n c e o f r e a c t i o n wood. I s e n b e r g (6) s t u d i e d t h e v a r i a t i o n o f c e l l u l o s e w i t h r e s p e c t t o age by s u b d i v i d i n g w h i t e f i r d i s k s i n t o f i v e s u c c e s s i v e z o n e s f r o m p i t h t o b a r k . He f o u n d t h a t c e l l u l o s e c o n t e n t was n e a r l y c o n s t a n t i n t h e f o u r o u t e r z o n e s , b u t showed a c o n s i d e r a b l e d e c r e a s e i n t h e i n n e r h e a r t w o o d ( t h e f i r s t 34 r i n g s f r o m t h e p i t h ) . From t h i s r e v i e w two t h i n g s a r e a p p a r e n t . I s o l a -t i o n o f a b s o l u t e l y p u r e c e l l u l o s e i n t h e wood s u b s t a n c e i s impeded by a number o f o t h e r o r g a n i c compounds c l o s e l y k n i t t e d t o t h e c e l l u l o s e m o l e c u l e s - ; S e c o n d l y , i n many c a s e s t h e changes i n c e l l u l o s e c o n t e n t o f t h e woody s u b -s t a n c e m i g h t be a t t r i b u t e d t o a n a t o m i c a l f e a t u r e s and t o t h e age o f t h e t r e e . . - 10 -METHOD A, Selection of Trees Eight Douglas f i r trees, a l l from two permanent sample plots, were marked and cut at the U.B.C. Research Forest. One sample plot (IS) was located on a good forest site (sword-fern type, site index 180 feet at 100 years), the other (4S) on a poor site (lichen type, site index 80 feet at 100 years). Four sample trees from each plot were to represent the largest and smallest trees on each plot, with two from dominant, and two from the intermediate crown classes. Ages ranged from 70 to 85 years, hence represented second growth. Measurements taken in 1956 were recorded as follows: Site Crown Class Tree No. D.b.h. in Total height inches in feet Good Poor Dominant Intermediate Dominant Intermediate 323 26.5 175 318 30.6 171 326 11.4 313 11.5 304 11.7 79 278 10.1 77 295 5 .7 286 5.0 - 11 -B. P r e p a r a t i o n o f Samples The t r e e s were f e l l e d i n September, 1957. C r o s s s e c t i o n s a p p r o x i m a t e l y 4.5 f e e t above g r o u n d were s e p a r a t e d , m arked, and f o r w a r d e d t o t h e U n i v e r s i t y . P a r t o f t h e i r a s u r f a c e was smoothed w i t h / k n i f e and t r e a t e d w i t h f e r r i c c h l o r i d e s o l u t i o n w h i l e s t i l l f r e s h . T h i s t r e a t m e n t o u t -l i n e d t h e b o u n d a r y b e t w e e n h e a r t w o o d and sapwood, sapwood b e i n g s t a i n e d y e l l o w i s h and h e a r t w o o d g r e e n i s h . G r o w t h r i n g s were c o u n t e d f r o m p i t h t o w a r d t h e b a r k , and e a c h d e c a d a l r i n g m a r ked. S e c t i o n s were s p l i t r a d i a l l y i n t o s l a b s a p p r o x i -m a t e l y one i n c h w ide and two i n c h e s a l o n g t h e g r a i n , i n s u c h a manner t h a t a p a r t o f e a c h g r o w t h r i n g f r o m p i t h t o b a r k was i n c l u d e d . From t h e s e s l a b s i t was s i m p l e t o remove t h e d e s i r e d p o r t i o n s o f t h e wood w i t h a s h a r p k n i f e . Two r a d i a l p o s i t i o n s w i t h i n e a c h t r e e were s e l e c t e d f o r p r e p a r a t i o n o f a n a l y t i c a l s a m p l e s . One p o s i t i o n (16 t o 25 y e a r s ) l a y c o m p l e t e l y i n t h e h e a r t w o o d , w h i l e t h e o t h e r i n c l u d e d t h e f i v e o u t e r g r o w t h r i n g s o f sapwood. M o r e o v e r , a s e p a r a t e c e l l u l o s e d e t e r m i n a t i o n on t h e l a r g e s t sample t r e e i n c l u d e d s a m p l e s w i t h t h e f o l l o w i n g g r o w t h p e r i o d s : one t o f i v e y e a r s , t h e n f o r e a c h d e c a d e f o l l o w i n g t o an age o f 75 y e a r s , and f i n a l l y f o r t h e r e m a i n i n g s i x o u t e r g r o w t h r i n g s . C . E s t i m a t i o n o f P e r c e n t a g e Summerwood As s t a t e d i n t h e p r e v i o u s s e c t i o n , wood sam p l e s r e p r e s e n t e d a h e a r t w o o d d e c a d e , o r f i v e t o s i x o u t e r g r o w t h r i n g s i n t h e sapwood. I n e a c h , p e r c e n t a g e o f summerwood was e s t i m a t e d by c u t t i n g r a d i a l s e c t i o n s 30 m i c r o n s t h i c k , - 12 -staining with phloroglucln-HCl solution, and measuring under an eye-piece micrometer. A 16 mm objective and 10X eye-piece gave a magnification of 160 times. A modified Mork's definition of summerwood was applied to determine the transition from springwood to summerwood. This definition, as interpreted by Smith (13), implies: " A l l tracheids in which the common wall between two c e l l cavities multiplied by two is equal to or greater than the width of the lumen are considered as summerwood; those in which the value is less than the width of a lumen are considered as springwood ( a l l measurements being made in the radial direction)". Further the same author comments: "Mork's definition of summerwood, although originally intended for spruce, has been used as a standard in growth-quality studies by the U. S. Forest Products Laboratory for a l l coniferous woods". How-ever in this experiment somewhat better comparisons were obtained by reducing the proportion between the common c e l l wall thickness and the c e l l lumen. This modification of Mork's definition assumed that summerwood started where the c e l l lumen was narrower than the single common wall (and not double) between two c e l l cavities. D. Preparation of Material for Extraction Samples used for cellulose and moisture content determinations were air-dried, s p l i t into pieces the size of match sticks, and ground In a Wiley m i l l to wood- meal passing a 4o-mesh screen and being retained on a 60-mesh - 13 -s c r e e n . E nough wood mea l was g r o u n d t o p r o d u c e a t l e a s t two r e p l i c a t e s o f 2 g e a c h f o r c e l l u l o s e d e t e r m i n a t i o n s , and 2 g more f o r m o i s t u r e c o n t e n t c a l c u l a t i o n . I n a d d i t i o n , s p a r e m a t e r i a l o f s e v e r a l grams was p r e p a r e d . I n o r d e r t o o b t a i n t h e e q u i l i b r i u m m o i s t u r e c o n t e n t (E.M.C.) f o r t h e s a m p l e s , t h e mea l was s p r e a d on s h e e t s o f p a p e r and l e f t f o r s e v e r a l d a y s a t a room t e m p e r a t u r e o f a p p r o x i m a t e l y 2 0 ° C. E . E v a l u a t i o n o f M o i s t u r e C o n t e n t A p p r o x i m a t e l y 2 g o f c o n d i t i o n e d a i r - d r y wood m e a l was p l a c e d i n a s m a l l t a r e d P e t r i d i s h and k e p t i n a n e l e c t r i c a l l y h e a t e d oven a t a t e m p e r a t u r e o f 1 0 0 - 1 0 5 ° C u n t i l a c o n s t a n t w e i g h t was r e a c h e d (two t o t h r e e d a y s ) . The w e i g h t s o f a i r - d r y and o v e n - d r y wood mea l were s u b s t i t u t e d i n t o t h e c o n v e n t i o n a l f o r m u l a f o r m o i s t u r e c o n t e n t e s t i m a -t i o n : % M.C. = Wt. a i r - d r y - Wt. o v e n - d r y 1 0 Q Wt. o v e n - d r y * The a s s u m p t i o n was made t h a t two r e p l i c a t e s b e i n g w e i g h e d a t t h e same t i m e as 2 g o f wood m e a l f o r o v e n - d r y i n g had t h e same m o i s t u r e c o n t e n t i n t h e a i r - d r y c o n d i t i o n . H a v i n g c a l c u l a t e d t h e m o i s t u r e c o n t e n t o f t h e s i n g l e wood sample a c o r r e s p o n d i n g m o i s t u r e c o n t e n t was a s s i g n e d t o r e p l i c a t e s u s e d f o r c e l l u l o s e d e t e r m i n a t i o n . F . Removal o f E x t r a c t i v e s Two r e p l i c a t e s o f a p p r o x i m a t e l y 2 g o f a i r - d r y wood meal o f e a c h wood sample were s u b m i t t e d f i r s t t o e t h e r and t h e n t o a l c o h o l - b e n z e n e e x t r a c t i o n . The wood m e a l was - 14 -p l a c e d i n 25 m l , m e d i u m - p o r o s i t y , alundum c r u c i b l e s o f known w e i g h t and w e i g h e d t o g e t h e r w i t h t h e c r u c i b l e . A f t e r a s i x -h o u r e x t r a c t i o n p e r i o d i n a S o x h l e t e x t r a c t i o n a p p a r a t u s w i t h e t h y l e t h e r , a n o t h e r e x t r a c t i o n o f s i x h o u r s w i t h a l c o h o l -b e n z e n e m i x t u r e (33 v o l u m e s 95 p e r c e n t e t h y l a l c o h o l and 67 v o l u m e s b e n z e n e ) t o o k p l a c e . A f t e r t h e c o m p l e t i o n o f e x t r a c t i o n t h e wood m e a l was a i r - d r i e d f o r s e v e r a l h o u r s , and washed by s u c t i o n s u c c e s s i v e l y w i t h 50 ml o f 95 p e r c e n t e t h y l a l c o h o l and 50 ml d i s t i l l e d w a t e r . F u r t h e r w a s h i n g s w i t h d i s t i l l e d w a t e r h e l p e d t o remove t h e e x t r a c t e d wood mea l f r o m t h e alundum c r u c i b l e s i n t o w e i g h e d 30-ml Gooch c r u c i b l e s o f medium p o r o s i t y h a v i n g f r i t t e d g l a s s b o t t o m s . G. D e t e r m i n a t i o n o f C r o s s and B e v a n C e l l u l o s e The method a p p l i e d f o r d e t e r m i n a t i o n o f C r o s s and B e v a n c e l l u l o s e a g r e e d e s s e n t i a l l y w i t h t h e i n s t r u c t i o n s i n T.A.P.P.I. S t a n d a r d s , T 17 m-46 (16) and w i t h t h e same p r o -c e d u r e o u t l i n e d by Wise and J a h n (19). However, t h e q u a n t i t i e s o f w a s h i n g s o l u t i o n s were r e d u c e d by h a l f , and i n s t e a d o f u s i n g t h e a p p a r a t u s recommended i n T.A.P.P.I. S t a n d a r d s , a s i m p l i f i e d a p p a r a t u s ( F i g . 1), s i m i l a r t o t h e one u s e d by K u r t h (9) f o r d e t e r m i n a t i o n o f h o l o c e l l u l o s e , was a s s e m b l e d . S m a l l l e c t u r e b o t t l e s o f c o m p r e s s e d c h l o r i n e were u s e d as t h e gas s o u r c e . A f t e r t r a n s f e r l n g t h e e x t r a c t i v e - f r e e wood mea l r e p l i c a t e s i n t o Gooch c r u c i b l e s , e a c h o f them was s e t i n t o a c r u c i b l e h o l d e r . A m o d e r a t e s u c t i o n was a p p l i e d , and t h e - 15 large beaker surrounding the holder was f i l l e d with cold water to a level approximately l/3-inch below the crucible holder. After placing a 60-ml funnel (attached to the chlorine bottle) on top of the crucible, chlorine gas was passed through the wood meal for three to four minutes at a rate of approximately 60 bubbles per minute. Following the removal of the crucible from the apparatus, the chlorinated wood meal was washed successively by suction with 25 ml of d i s t i l l e d cold water, 25 ml of three per cent S0 2 solution, 25 ml of d i s t i l l e d water, and 2 5 ml of freshly prepared two per cent NagSOj solution. The wood material was then transferred to a 250-ml beaker, using a glass rod. The last traces of material were removed from the crucible by washing down with part of a 100-ml portion of two per cent NagSO-*, solution. The beaker containing the sample and solution was covered tightly with folded aluminum f o i l and placed in a boiling water bath for 30 minutes. When boiling was completed, the sample was transferred to a glass crucible and washed with 125 ml of d i s t i l l e d water. The washed material underwent further chlorinations of two to three minutes and, together with the previously described washing procedures, each complete chlorinatlon and washing cycle was usually repeated five to six times. Thereafter the practically delignifled meal showed only a very faint tinge of pink upon addition of Na2S0-j solution. At this stage the sample was washed successively in the G-ooch crucible with 250 ml hot water, then 50 ml 95 per cent ethyl alcohol and 50 ml ethyl ether. Finally the - 16 -crucible containing the delignified product was oven-dried at 100-105° C to a constant weight (24 hours). The percentage of Cross and Bevan cellulose was calculated on the basis of the evaluated oven-dry weight of the wood meal. BJ. Determination of Water-Resist ant Carbohydrate (Holocellulose) and Alpha-Cellulose by Yundt and Bradway^ Procedure In order to have a further comparison, the method for determination of water-resistant carbohydrate and alpha-cellulose, recently developed by Yundt and Bradway, was applied. Only the two trees showing extreme Cross and Bevan cellulose values were selected for testing. The material analyzed was from the same position as that used for Cross and Bevan method. In this new procedure the wood does not have to be pre-extracted, because, according to Yundt, pitch is largely destroyed by the chloriting and the post-wash removes any residual pitch. Sodium chlorite is used as the main delignification agent. the Only 0.7 6 of wood meal was needed for each of/rep-licates. These were submitted to the delignification process in 50-ml Erlenmeyer flasks by placing the flasks in a water bath held at 75° C (* 20) for four hours. The resulting holocellulose was transferred to a 15-ml, coarse, fritted-glass crucible of known weight, washed and sucked dry. The crucible and contents were conditioned to constant weight in a controlled Op. c i t . , p.4. 17 -t e m p e r a t u r e - h u m i d i t y chamber h a v i n g d r y - and w e t - b u l b t e m p e r a t u r e s o f 120° and 109° F r e s p e c t i v e l y . U n der t h e s e c o n d i t i o n s ( r e l a t i v e h u m i d i t y 69 p e r c e n t ) wood c a n be e x p e c t e d t o r e a c h an a p p r o x i m a t e e q u i l i b r i u m m o i s t u r e c o n t e n t o f 11.5 p e r c e n t . T h r e e h o l o c e l l u l o s e s a m p l e s were c o n -d i t i o n e d and t h e n o v e n - d r i e d t o d e t e r m i n e t h e a c t u a l e q u i -l i b r i u m m o i s t u r e c o n t e n t , w h i c h was 11.15 p e r c e n t . Knowing t h e m o i s t u r e c o n t e n t o f t h e s e h o l o c e l l u l o s e s a m p l e s , t h e o v e n - d r y w e i g h t o f t h e r e m a i n i n g s a m p l e s was c a l c u l a t e d by a s s u m i n g a n e q u i v a l e n t m o i s t u r e c o n t e n t . P e r c e n t a g e s o f w a t e r - r e s i s t a n t c a r b o h y d r a t e were e v a l u a t e d on a n o v e n - d r y w e i g h t b a s i s , i n a manner s i m i l a r t o t h e C r o s s and B e v a n d e t e r m i n a t i o n s . A l p h a - c e l l u l o s e was d e t e r m i n e d w i t h o u t r e m o v i n g t h e w a t e r - r e s i s t a n t c a r b o h y d r a t e ( h o l o c e l l u l o s e ) by t r e a t i n g t h e r e m a i n i n g c r u c i b l e s w i t h two 3-ml p o r t i o n s o f 17.5 p e r c e n t NaOH f o r a t o t a l o f 40 m i n u t e s a t 22° C. The I s o l a t e d a l p h a - c e l l u l o s e was o v e n - d r i e d a t a t e m p e r a t u r e o f 100-105° C o v e r n i g h t and i t s p e r c e n t a g e y i e l d was c a l c u l a t e d . I. T o t a l Number o f C e l l u l o s e D e t e r m i n a t i o n s I n a l l , f o u r C r o s s and B e v a n c e l l u l o s e d e t e r m i n a -t i o n s were p e r f o r m e d f o r e a c h o f e i g h t t r e e s , a n d / f u r t h e r e i g h t e e n d e t e r m i n a t i o n s were made f o r t h e s i n g l e , l a r g e s t sample t r e e . W a t e r - r e s i s t a n t c a r b o h y d r a t e and a l p h a - c e l l u l o s e were d e t e r m i n e d i n a d d i t i o n on f o u r s a m p l e s f r o m e a c h o f t h e two t r e e s s h o w i n g maximum and minimum v a l u e s f o r C r o s s and B e van c e l l u l o s e . T h r e e h o l o c e l l u l o s e r e p l i c a t e s were - 18 -o b t a i n e d f o r e a c h o f t h r e e s a m p l e s . The h o l o c e l l u l o s e d e t e r m i n a t i o n i n t h e f o u r t h sample (sapwood o f t h e t r e e N o . 3 1 3 ) , was o n l y d u p l i c a t e d . I s o l a t i o n o f a l p h a - c e l l u l o s e was r e p e a t e d t w i c e f o r e a c h s a m p l e . - 19 -RESULTS OF STATISTICAL ANALYSIS A. Analysis of Eight Trees Eight trees analysed by the Cross and Bevan method yielded results shown in Table 1, There are notable differences in cellulose oontent among samples of Douglas f i r wood, yet i t is d i f f i c u l t to assess to which factors such variation might definitely be attributed. From the i n i t i a l analysis of variance (Table 2) i t seems clear that not only the influences of crown class on cellulose yield (F = 171.52), but also that of Bite (F = 173.79), and of trees nA M and WB" (F = 133.G3), are highly significant when compared with the theoretical F^ of 8.68 at the one per cent level for the 15 degrees of freedom in the error 2. The differences among the means for the three main factors vary from 2.3 to 2.7 per cent. In the case of the dominant (62.34 per cent) versus intermediate (59.70 per cent) crown class, this difference is 2.64 per cent. Lower mean yields are found for the good site (59.69 per cent) as compared with the poor site (62.37 per cent), the difference being 2.68 per cent. A difference of 2.34 per cent exists between the means for the two tree groups "A" and WB", (62.20 per cent versus 59.86 per cent). However several interactions such as site x crown class (F = 11.09), crown class x trees (F » 48.79), and site •'•Snedecor, G.W S t a t i s t i c a l Methods, Applied to Experiments in Agriculture and Biology, The Iowa State College Press, Ames, Iowa, F i f t h Ed., 1957, p. 246. ^In the Supplementary Table (Appendix) cellulose percentages were rounded to the nearest whole percent and analysed statis-t i c a l l y . When the supplementary analysis was compared with the I n i t i a l analysis of variance (p. 27) no significant changes in the main effects were detected. In addition, the site x crown class, crown class x trees, and site x crown class x trees interactic retained their s t a t i s t i c a l significance in both analyses. How-ever, in the supplementary analysis the crown class x location interaction became insignificant, whereas site x location x trees interaction reached significance. - 20 -x crown class x trees (F = 180.06), were found to be highly significant. Presence of such large interactions suggests the existence of components of variance that may render main effects of crown class, site, and trees non-significant. Even the crown class x radial position (location) interaction was significant (F = 10.00), although radial position by i t s e l f was not significant (F = 5.42). Similarly, comparing the means for heartwood (61.29 per cent) and sapwood (60.77 per cent), only slightly higher cellulose yield was found for the former (0.52 per cent). This might indicate that in some trees, such as the four dominants and one intermediate (Nos. 323, 318, 304, 278 and 326, Table 1), the Cross and Bevan cellulose yield is likely to be higher within the 16 - 25 year period than in the five outer growth rings. In the remaining intermediate trees (Nos. 313, 295 and 286, Table 1) an opposite trend was noticed. When these factors are combined, growth rate might be suspected as a chief source of cellulose variation. Nevertheless the regression of cellulose on rate of growth, as represented by the width of the cores submitted to analysis, was not s t a t i s t i c a l l y significant, showing a M t " value of only 0.38 (Appendix A) which is much lower than the 2.145 theoretical " t " 1 required for significance at the five per cent level with 14 degrees of freedom. Ibid. p. 46. - 21 -In compliance with the multifactorial design of the i n i t i a l s t a t i s t i c a l analysis (Table 2), the "tree" term was based on total of replicates "A" and "B". However for the purpose of further interpretation the eight trees of the study may be grouped and designed as a new "tree" term. This "tree" term would then Include crown class, site, the "A" and "B" tree groups, as well as their interactions. The analysis summarized in Table 3 shows that the new "tree" term is a very highly significant source of variation, giving an F of 42.95 as compared with 3.50 for theoretical F^ at the one per cent level and ,seven and twenty-four degrees of freedom. Also a very high F (274.01) is evaluated at the bottom of Table 3 for the comparison between the two extremes in cellulose yields, (trees Nos. 313 and 304). Differences between high and low values may then suggest the range in cellulose content to be expected among Douglas f i r in general. The regression of cellulose on percentage summerwood (Appendix Bi) could not be proven significant, since i t had a " t " of 0.10 as compared with the theoretical value of 2.145 for " t " 2 at the five per cent level with 14 degrees of freedom. By interpreting these results the following conclusion can be drawn: 1) There is a variation in cellulose yields from tree to tree and, 2) the differences have to be attributed to some unaccounted factor which is d i f f i c u l t to discover by 1 I b i d . p. 246 2 I b i d . p. 46 - 22 -the extraction method applied, or to d i s t i n g u i s h by-s t a t i s t i c a l a n a l y s i s . This w i l l be discussed more f u l l y i n the following section. B. Analysis of a Single Tree The regression analysis of the largest i n d i v i d u a l tree (No. 318), Table 4, showed one i n t e r e s t i n g feature. Namely, c e l l u l o s e y i e l d s increased r a p i d l y within the growth period of one to 25 years, at the growth period of 36 - 45 years some sort of l e v e l l i n g could be noticed, then c e l l u l o s e percentages again rose, reaching a maximum value i n the outer zone. The calculated data for the 1 - 2 6 years growth period, Appendix C, gave a regression c o e f f i c i e n t b = 0.24, with the sample standard deviation of the regression c o e f f i c i e n t s^ = 0.029. These two values gave an F = 68.81, over three times as large as t h e o r e t i c a l F l at the one per cent l e v e l with one and four degrees of freedom. F i t t i n g the regression l i n e f o r the growth period between 16 - 81 years, Appendix C, b = 0 . 0 6 and s^ = 0.023 rendered an F value s i g n i f i c a n t only at the f i v e per cent l e v e l . For t h i s second regression l i n e supposedly representing mature wood, calculated F= 7.04 exceeded t h e o r e t i c a l F l = 4 . 9 6 at one and ten degrees of freedom and the f i v e per cent l e v e l of confidence. Although the r e s u l t s obtained from analyzing a single tree cannot be regarded as conclusive, at least they strengthen the Ibid. p. 246. - 23 -argument t h a t c e l l u l o s e y i e l d s a r e h i g h e r i n t h e mature wood as compared w i t h t h e J u v e n i l e wood. 0. A n a l y s i s o f W a t e r - R e s i s t a n t C a r b o h y d r a t e and A l p h a -C e l l u l o s e and I t s C o r r e l a t i o n w i t h C r o s s and B e v a n C e l l u l o s e D e t e r m i n a t i o n o f w a t e r - r e s i s t a n t c a r b o h y d r a t e ( h o l o c e l l u l o s e ) a c c o r d i n g t o t h e method o f Y u n d t and Bradway, i n t h e sample t r e e s h a v i n g t h e e x t r e m e s o f c e l l u l o s e y i e l d s (Nos. 313 and 304, T a b l e 6), s t r e n g t h e n e d t h e e v i d e n c e g a i n e d by t h e C r o s s and Bevan method. T r e e No. 304, w h i c h showed h i g h e r c e l l u l o s e y i e l d s f o r t h e C r o s s and B e v a n method ( T a b l e 1), a l s o gave h i g h e r h o l o c e l l u l o s e and a l p h a -c e l l u l o s e y i e l d s t h a n t r e e No. 313 ( T a b l e 6). However, t h e d i f f e r e n c e s b e t w e e n t h e means f o r t h e t r e e s , amounted t o r o u g h l y f i v e p e r c e n t ( T a b l e 6), f o r b o t h w a t e r - r e s i s t a n t c a r b o h y d r a t e and a l p h a - c e l l u l o s e , as compared w i t h e l e v e n p e r c e n t f o r C r o s s and Bevan c e l l u l o s e ( T a b l e 3). V a r i a n c e r a t i o s ( T a b l e 7) f o r b o t h methods r e v e a l e d s i g n i f i c a n t d i f f e r e n c e s a t t h e one p e r c e n t l e v e l b e t w e e n t r e e s 304 and 313, f o r C r o s s and Bevan c e l l u l o s e , h o l o c e l l u l o s e , and a l p h a -c e l l u l o s e . F o r C r o s s and Bevan c e l l u l o s e , t h i s F had a v a l u e o f 451.10, f o r h o l o c e l l u l o s e 57.64, whereas f o r a l p h a -c e l l u l o s e a c o r r e s p o n d i n g F o f 46.60 was o b t a i n e d . I n a l l t h r e e c a s e s t h e F v a l u e e x c e e d e d t h e 34.12 f o r t h e t h e o r e t i c a l F ^ a t t h e one p e r c e n t l e v e l w i t h t h r e e d e g r e e s o f f r e e d o m . I b i d . p . 246 24 F i n a l l y , t h e s a m p l i n g v a r i a t i o n ( T a b l e 8) shows t h e h i g h e s t a c c u r a c y i n c e l l u l o s e d e t e r m i n a t i o n f o r t h e G r o s s and Bevan method. Y e t t h e t i m e s p e n t on d e t e r m i n a t i o n o f e i t h e r w a t e r - r e s i s t a n t c a r b o h y d r a t e o r a l p h a - c e l l u l o s e b y t h e Yundt and Bradway method, was r o u g h l y o n e - e i g h t h o f t h a t r e q u i r e d f o r d e t e r m i n a t i o n o f C r o s s and Bevan c e l l u l o s e . - 25 -T A B L E 1 GENERAL DATA. FOR E I G H T TREES (CROSS AND BEVAN CELLULOSE) Cellulose (per cent) Sums Sums Crown Radial of dry weight for for Site Class Tree No* Position of Sample Sample 1 Sample 2 Locations Trees Domi-nant 325(A) 1 3 1 8 ( B ) 1 I? a. 8* 5 9 . 9 8 5 9 . 3 5 6 2 . 7 4 6 2 * 1 0 61*56 60*46 63.18 61.50 1 2 1 * 5 4 1 1 9 . 8 1 1 2 5 . 9 2 123.60 2 4 1 . 3 5 249*52 Good 326 (A) Q . s* 6 1 . 5 7 5 9 . 9 4 62.99 60.08 1 2 4 , 5 6 1 2 0 . 0 2 2 4 4 . 5 8 Inter-mediate 313(B) h. 9* 5 4 . 7 6 5 4 . 9 7 53.88 55.99 1 0 8 . 6 4 1 1 0 . 9 6 2 1 9 . 6 0 4 3 0 4 ( A ) h. s* 65.45 64*86 66.27 6 4 . 6 4 131*72 1 2 9 . 5 0 2 6 1 . 2 2 ^ Domi-nant 2 7 8 ( B ) h. s* 62*15 60.33 6 2 * 0 4 6 1 . 1 4 1 2 4 . 1 9 1 2 1 . 4 7 2 4 5 . 6 6 Poor Inter-mediate 2 9 5 ( A ) 2 8 6 ( B ) a* s. h* s* 6 0 . 9 2 62*82 60*68 60*86 6 2 . 2 5 62*07 6 0 . 1 9 61*22 123.17 124*89 1 2 0 . 8 7 122*08 248*06 242*95 Totals 9 7 3 . 4 8 9 7 9 . 4 6 1 , 9 5 2 . 9 4 1*952 .94 1* For convenience eight trees were subdivided into two groups: (A) and (B ) . 2* Heartwood 3* Sapwood 4* Tree with the lowest cellulose content 5* Tree with the highest cellulose content - 26 -TABLE 1 (Cont»d) GENERAL DATA FOR EIGHT TREES (CROSS AND BEVAN CELLULOSE) Totals and Means for Sites Totals and Means for Crown Classes Totals and Means for Replications Totals and Means for Radial Position Totals and Means f o r Tree Groups Good 955.05 (59 .6?) Sample 1 973.48 (60.84) Heartwood Trees (A) 995*21 (62.20) Dominant 997.75 (62.34) 980.61 (61.29) Poor 997*89 (62*37) Inter-mediate 955*19 (59*70) Sample 2 979.46 (61.22) Sapwood 972.33 (60.77) Trees ( B ) 957.73 (59*86) 1,952*94 1 ,952.94 1 ,952.94 1 ,952,94 1,952*94 - 27 -TABLE 2 TOTAL ANALYSIS OF VARIANCE FOR EIGHT TREES (CROSS AND BEVAN CELLULOSE) TREE TERM WITH "A" AND "B" REPLICATES USED. S o u r c e o f V a r i a t i o n D e g r e e s o f F r e e -dom. Sum o f S q u a r e s Mean S q u a r e F T e s t Crown C l a s s 1 56.60 56.60 171.52* S i t e 1 57.35 57.35 173.79* T r e e s 1 43.90 43.90 133.03* R a d i a l P o s i t i o n 1 1.79 1.79 5.42 R e p l i c a t i o n 1 1.12 1.12 3.39 I n t e r a c t i o n s : S x C r . C I . 1 3.66 3.66 11.09* S x T r . 1 0.46 0.46 1.39 C r . C I . x T r . 1 16.10 16.10 48.49* S x L 1 0.92 0.92 2.79 C r . C I . x L 1 3.30 3.30 10.00* L x T r . 1 0.96 0.96 2.91 S x C r . C I . x L 1 0.78 0.78 2.36 S x C r . C I . x T r . 1 59.42 59.42 180.06* S x L x T r . 1 1.57 1.57 4.76 C r . C I . x L x T r . 1 1.63 1.63 4.94 S x C r . C'L x L x T r , 1 1.82 1.82 5.52 R e s i d u a l ( E r r o r ) 15 5.00 0.33 TOTAL 31 256.36 ^ C a l c u l a t e d F g r e a t e r t h a n t h e o r e t i c a l F o f 8,68 a t t h e one p e r c e n t l e v e l , (one and 15 d e g r e e s o f f r e e d o m ) h e n c e t h e s e r e s u l t s a r e h i g h l y s i g n i f i c a n t . - 28 -TABLE 3 ANALYSIS OF VARIANCE FOR EIGHT TREES AND COMPARISON OF TWO EXTREME VALUES FOR CROSS AND BEVAN CELLULOSE Y I E L D S . (A COMBINED "TREE" TERM USED.) S o u r c e o f D e g r e e s V a r i a t i o n o f Freedom Sum o f Mean F S q u a r e s S q u a r e s T e s t T o t a l 31 256.36 T r e e s 7 237.49 33.93 42.95* R e s i d u a l 24 18.87 0.79 * T h e o r e t i c a l F f o r s e v e n and 24 d e g r e e s o f f r e e d o m a t one p e r c e n t l e v e l = 3.50. C o m p a r i s o n b e t w e e n c e l l u l o s e y i e l d s f o r t r e e s Nos. 313 and 304: (219.60)2 - (261.22)2 - (219.60 - 261.22)2 = 216.53 8~ 216.53 / 0.79 = 274.01* F f o r 3 and 24 d e g r e e s o f f r e e d o m a t one p e r c e n t l e v e l : 4.72 Mean C e l l u l o s e y i e l d s f o r t r e e s : No. 313: 54.90 p e r c e n t ; No. 304: 65.25 p e r c e n t . - 29 -TABLE 4 CROSS AND BEVAN CELLULOSE YIELDS (FOR EIGHT TREES) AS RELATED TO RADIAL POSITION (LOCATION), RATE OF GROWTH AND PERCENTAGE SUMMERWOOD. T r e e Nd. L o c a -t i o n W i d t h 1 o f C o r e mm P e r c e n -t a g e Sum-merwood Means f o r C e l l u l o s e 323 H 2 67.50 34 .0 60 .77 318 H 66.00 43 .0 62.96 326 H 48 .50 37 .0 62 .28 313 H 34.00 47 .0 54.32 304 H 18.00 4 3 . 5 65 .86 ' 278 H 17.20 4 7 . 5 62 .10 295 H 17.30 39 .0 61 .58 286 H 13.60 51.0 60 .44 323 S 3 12.00 30 .0 59.90 318 S 25.60 39 .0 61 .80 326 S 2.40 21 .0 60 .01 313 s 4 .00 21.0 55.48 304 s 17 .00 35 .0 64 .75 278 s 14.60 4 7 . 0 60 .74 295 s 3 .00 34 .0 62 .44 286 s 1.60 39 .5 61 .04 1. R a t e o f g r o w t h , e q u i v a l e n t t o t h e measured c o r e w i d t h f o r t h e f i v e o u t e r g r o w t h r i n g s i n t h e sapwood and t e n g r o w t h r i n g s i n t h e h e a r t w o o d (16-25 y e a r s ) . 2 . H e a r t w o o d . 3. Sapwood. - 30 -TABLE 5 CROSS AND BEVAN CELLULOSE YIELDS FOR INDIVIDUAL TREE (NO. 318) AS RELATED TO AGE FROM P I T H . L o c a - G r o w t h A v e r -t i o n P e r i o d s age ( Y e a r s ) Age 1-5 2.5 Hi 6-15 10 ff 16-25 20 Hi 26-35 30 Hi 36-45 40 H 46-55 50 S - H 1 56-65 60 S 66-75 70 S 76-81 78 R e p l i c a t i o n s Means f o r 1 2 C e l l u l o s e 56.72 58.01 57.36 58.99 58.80 58.90 61.75 61.36 61.56 61.08 61.38 61.23 61.91 58.53 60.22 59.89 62.95 61.42 63.58 63.29 63.44 62.03 63.74 62.88 63.19 63.47 63.33 1 Sapwood-zone r e c o r d e d as s t a r t i n g a t t h e t r e e age o f 58 y e a r s . TABLE 6 WATER-RESISTANT CARBOHYDRATE (W.R.C.) AND ALPHA-CELLULOSE YIELDS FROM TREES (NO. 313 AND NO. 304) ACCORDING TO METHOD OF YUNDT AND BRADWAY Tree NO. Location or Radial P o s i t i o n W.R.C, as percentage of oven»dry wood Alpha-Cel-l u l o s e as percentage of oven-dry wood Grand Averages f o r trees, i W.R.C* Averages f o r heart-wood vs* sapwood i W.R.C. Grand Averages f o r trees, % Alpha-c e l l u l o s e Averages f o r sap-wood vs. heartwood Alpha-cel-l u l o s e % 513 Heartwood n n 69*8? 69*48 f t 70.73* 43*80 42.48 71.17 70.02 45.64 4 3 i 14 Sapwood 11 72.54 73.21 47i83 48.44 72*88 48.13 304 Heartwood n 11 77.47 77^ 73 77.91* 5 1 . 4 4 5L*89 a* 76.56 77.70 50.93 51*66 Sapwood n it 76.12 7 3 i 8 l 7 6 . 3 3 * 51*51 4 8 . 8 6 75.42 50.19 Jr. Replicates oven-dried f o r evaluating moisture content of remaining h o l o c e l l u l o s e samples* - 32 -TABLE 7 COMPARISON OF VARIANCES BETWEEN CROSS AND BEVAN (CR. & B:.) CELLULOSE WATER RESISTANT CARBOHYDRATE (W.R.C.) AND ALPHA-CELLULOSE FOR TREES (NO. 313 AND NO. 304). Sum o f S q u a r e s D e g r e e s C r . & B, o f F r eedom C e l l u l o s e S o u r c e s o f V a r i a t i o n T r e e s (T) 1 L o c a t i o n ( L ) 1 T x L ( i n t e r - ( T x L ) a c t i o n ) 1 R e p l i c a t i o n (R) 1 E r r o r (E) 3 T o t a l ( T ) 7 C r . &.B. C e l l u l o s e 216.53 (T) 50.15 (L) (T x L) (R) (E) 0.4 (T) 0.87 216.53 0 2.58 0 . 0 7 1.20 220.38 W.R.C. A l p h a -C e l l u l o s e 50.15 55.92 0.16 6.18 17.02 20.96 0.39 1.06 2.62 3 .61 70.34 87.73 Mean S q u a r e s F - T e s t s W.R.C. A l p h a - CFT&~W. W.R.C. A l p h a -C e l l u l o s e C e l l u l o s e C e l l u l o s e 55.92 451.10* 57.64* 46 .60* 1.20 * S i g n i f i c a n t a t one p e r c e n t l e v e l , t h e o r e t i c a l F = 34.12, t h r e e d e g r e e s o f f r e e d o m . TABLE 8 SAMPLING VARIATION AND TIME RECORD FOR CROSS AND BEVAN CELLULOSE AS COMPARED WITH WATER RESISTANT CARBOHYDRATE AND ALPHA-CELLULOSE FOR TREES (NOS. 313 AND 304) C r o s s & Bevan C e l l u l o s e Water R e s i s t a n t C a r b o -h y d r a t e A l p h a -C e l l u l o s e Mean p e r c e n t -ages f o r t h r e e t y p e s o f c e l l u -l o s e 60.10 T h r e e p e r c e n t o f t h e mean 1.80 S t a n d a r d D e v i a t i o n ( s q u a r e d ) 0.64 S E 2 = (jL0|M)2 0 > 2 4 N - 3D 2 — 2.67* V Time 100 h r s , 73.86 2.22 3.36 0.36 9.33 12 h r s 48.28 1.45 5.30 0.16 33.12 12 h r s , II +. it' t f o r s i x d e g r e e s o f f r e e d o m and one p e r c e n t l e v e l = 3.707 N = number o f samples r e q u i r e d t o o b t a i n a mean e s t i m a t e w i t h i n t h r e e p e r c e n t o f t h e t r u e mean. * I f t h e e r r o r v a r i a n c e w i t h t h r e e d e g r e e s o f f r e e d o m i n T a b l e 7 were u s e d , N would be r e d u c e d t o 1.67, 2.42. and 7.5 r e s p e c t i v e l y . TABLE 9 MOISTURE PERCENTAGES AS OBTAINED BY OVEN-DRYING AT 100-105° C AND ASSUMED FOR EACH OF CORRESPONDING REPLICATES BEFORE DETERMINATION OF CROSS AND BEVAN CELLULOSE T r e e No.. M o i s t u r e P e r c e n t a g e Heartwood Sapwood 323 9.01 6.49 318 8.62 10.22 326 7.56 8.50 313 6.94 11.06 304 10.45 7.20 278 6.28 6.26 295 6.17 7.76 286 6.48 7.77 T r e e No. 318 R a d i a l P o s i t i o n G r owth P e r i o d s ( Y e a r s ) M o i s t u r e P e r c e n t a g e Heartwood w H ft Heartwood-Sapwood Sapwood w 1-5 6-15 16-25 26-35 36-45 46-55 56-65 66-75 76-81 7.22 8.68 8.67 8.79 8.82 8.86 9.26 9.60 9.75 DISCUSSION! A. D e t e r m i n a t i o n o f C e l l u l o s e D i f f i c u l t i e s e n c o u n t e r e d i n t h e d e t e r m i n a t i o n o f c e l l u l o s e c o n t e n t i n wood have a l r e a d y b e e n d i s c u s s e d . A l -t h o u g h a number o f d e t a i l e d methods a r e a v a i l a b l e t h e r e i s no s t r o n g c o r r e l a t i o n among them, and t h e y i e l d s o b t a i n e d by use o f d i f f e r e n t methods v a r y c o n s i d e r a b l y . A p p a r e n t l y , e v e n m i n o r c hanges i n t h e same method may c a u s e v a r y i n g r e s u l t s i n t h e amounts o f c e l l u l o s e r e c o v e r e d . A c c o r d i n g t o K o l l m a n n (7) t h e v a r i a t i o n i n c e l l u l o s e y i e l d s f o r s p r u c e wood may r a n g e f r o m 37.2 t o 64.6 p e r c e n t d e p e n d i n g on t h e method a p p l i e d . I n t h e c a s e o f t h e C r o s s and Beva.n e x t r a c t i o n method, c e l l u l o s e c o n t e n t i n t h e wood may r e a c h a v a l u e o f 64.6 p e r c e n t a f t e r t h r e e c h l o r i n a t i o n s and 60.6 p e r c e n t a f t e r s i x c h l o r i n a t i o n s (7). Many o f t h e s e v a r i a t i o n s may be e x p l a i n e d by t h e f a c t t h a t wood i s n o t a s i m p l e c h e m i c a l compound. I t d i f f e r s w i d e l y w i t h s p e c i e s and w i t h e c o l o g i c a l and g e n e t i c f a c t o r s c o n t r o l l i n g g r o w t h o f i n d i v i d u a l t r e e s . I n a d d i t i o n t o c e l l u l o s e , l i g n i n , and h e m i c e l l u l o s e s , most woods c o n t a i n a number o f e x t r a c t i v e s , s u c h as r e s i n s , t e r p e n e s , f a t s , waxes and t a n n i n s , as w e l l as a s m a l l p e r c e n t a g e o f i n o r g a n i c s u b s t a n c e s . A p p a r e n t l y p e n t o s a n s a r e p a r t i c u l a r l y d i f f i c u l t t o remove f r o m c e l l u l o s e , and t h e i r c o m p l e t e s e p a r a t i o n i s l i k e l y t o c a u s e a n a d d i t i o n a l l o s s o f c e l l u l o s e . - 36 -B. F i l t r a t i o n D i f f i c u l t i e s A l t h o u g h t h e c h l o r i n a t i o n t i m e i n t h e C r o s s and Be v a n method, as a p p l i e d h e r e , c o i n c i d e d w i t h t h a t recommended i n t h e i n s t r u c t i o n s , t h e p r e c i s e volume o f c h l o r i n e gas a g r e e d o n l y a p p r o x i m a t e l y w i t h t h e q u a n t i t i e s p r e s c r i b e d . I n c e r t a i n s amples i t was n o t i c e d t h a t wood m e a l underwent f a s t e r and more i n t e n s i v e C h l o r i n a t i o n t h a n i n t h e o t h e r s . U s u a l l y a f t e r t h e t h i r d c h l o r l n a t i o n - a n d - b o i l i n g i n NagSOj s o l u t i o n , wood mea l had l o s t i t s o r i g i n a l s h a p e , and s m a l l , d i s i n t e g r a t e d p a r t i c l e s o f t e n p l u g g e d t h e f r i t t e d b o t t o m o f t h e e x t r a c t i o n c r u c i b l e . The c h l o r i n a t e d l i g n i n i n c l u d e d I n t h e Na 2SG-j s o l u t i o n a l s o s l o w e d down t h e r a t e o f f i l t r a t i o n b e c a u s e i t s v i s c o s i t y i n c r e a s e d as t h e s o l u t i o n was f i l t e r e d . N o n - u n i f o r m p o r o s i t y , d u r a b i l i t y o f t h e f r i t t e d g l a s s b o t t o m , o r c l e a n i n g c a p a c i t y o f t h e e x t r a c t i o n c r u c i b l e s i n t e r f e r e d o c c a s i o n a l l y . A f t e r t h e c o m p l e t i o n o f f i n a l f i l t r a t i o n and w e i g h i n g , c r u c i b l e s u s u a l l y underwent two o r more d a y s s t o r a g e i n c l e a n i n g s o l u t i o n , t h e n were r e p e a t e d l y b o i l e d i n n i t r i c a c i d , s u l f u r i c a c i d , and d i s t i l l e d w a t e r . A f t e r t h i s t r e a t m e n t t h e f i l t r a t i o n s p e e d o f a n a v e r a g e c r u c i b l e was i n t h e r a n g e o f t e n t o t h i r t y s e c o n d s p e r 30 ml o f w a t e r . Wood meal u s e d f o r e x t r a c t i o n had p a s s e d t h r o u g h a 40-mesh s c r e e n o f t h e W i l e y m i l l , and was r e t a i n e d , on a 60-mesh s c r e e n . I n s e v e r a l e x t r a r e p l i c a t e s , w h i c h were n o t s u b -m i t t e d t o s t a t i s t i c a l a n a l y s i s , i t was n o t i c e d t h a t 60-mesh - 3 7 -wood meal underwent much easier chlorination and ex-traction than 40-mesh wood meal. Therefore i t is rec-ommended that, in future experiments of a similar type, 60-mesh rather than 40-mesh wood meal be used. In cases where yields were suspected of being faulty because of technique errors made in the cellulose determination, one or more additional samples were treated un t i l confidence in the accuracy of the results was obtained. As an example, hydrolysis could be one of the reasons for inaccurate cellulose yields. On the average, i t took two days per sample to accomplish the isolation of cellulose. However, due to the minor differences in porosity of Gooch-crucible bottoms, in certain cases i t took over a week to accomplish a similar isolation. Obviously the prolonged exposure to the traces of hydro-chloric acid formed during the treatment could cause an excessive degradation of cellulose. Due to the differences in penetration and diffusion rate of the chlorine gas through the material, while suction was applied, over-chlorination might have decreased the polymerization degree of the cellulose chains. Other miscellaneous sources of error were prevalent. Sometimes i t was suspected that a small amount of the material had been lost while handling through an extraction and isolation cycle. While some samples showed a negative Maule reaction after the completion of five or six cycles, they turned yellowish upon oven-drying, - 38 -i n d i c a t i n g t h a t a s m a l l amount o f l i g n i n m i g h t have r e m a i n e d i n t h e s a m p l e . T h e s e s h o r t c o m i n g s were c a r e f u l l y r e c o r d e d , and t h e r e p e t i t i o n s o f c e l l u l o s e d e t e r m i n a t i o n s were deemed n e c e s s a r y i n some c a s e s . C. R e s u l t s f r o m C r o s s and Bevan Method I t c a n be s e e n f r o m T a b l e 1 t h a t t h e d i f f e r e n c e s i n c e l l u l o s e y i e l d s b etween r e p l i c a t e s l i e w i t h i n t h e r a n g e o f p l u s o r minus one p e r c e n t . When t h i s e x p e r i m e n t was u n d e r t a k e n i t was hoped t h a t t h e two l a r g e s t and two s m a l l e s t t r e e s on e a c h p l o t w ould be a d e q u a t e t o a s s e s s t h e i m p o r t a n c e o f g r o w t h r a t e i n c e l l u l o s e v a r i a t i o n . From T a b l e 1 i t s h o u l d be n o t i c e d t h a t t h e d i f f e r e n c e s i n C r o s s and B e v a n c e l l u l o s e y i e l d s between t o t a l s f o r s i t e and c rown c l a s s a r e p r a c t i c a l l y t h e same as t h a t b e t w e e n i n d i v i d u a l t r e e s . T h i s phenomena p u t s one i n d o u b t as t o w h e t h e r t h e c e l l u l o s e v a r i a b i l i t y c a n be a s c r i b e d t o s i t e and crown c l a s s f a c t o r s , o r s i m p l y t o t h e d i f f e r e n c e s b e t w e e n i n d i v i d u a l t r e e s r e p r e s e n t e d i n t h e s e f a c t o r s by c h a n c e . A n a l y s i s o f v a r i a n c e and a v e r a g e s f o r e i g h t t r e e s r e v e a l e d h i g h e r y i e l d s f o r t h e p o o r s i t e as compared w i t h t h e good s i t e . H i g h e r y i e l d s were o b t a i n e d f o r d o m i n a n t t r e e s as compared w i t h t h e i n t e r m e d i a t e o n e s . The i n t e r p r e t a t i o n i n a s t a t i s t i c a l s e n s e may be w e l l o vershadowed by t h e s i g n i f i c a n c e o f b e t w e e n - t r e e v a r i a t i o n . More c e l l u l o s e was o b t a i n e d f o r t h e s l o w e r r a t e o f g r o w t h r e p r e s e n t e d by t h e p o o r s i t e . On - 39 -t h e o t h e r hand l e s s c e l l u l o s e was e s t a b l i s h e d f o r t h e s l o w e r r a t e o f g r o w t h when r e l a t e d t o t h e i n t e r m e d i a t e crown c l a s s . F o t h s i t e and crown c l a s s a r e c l o s e l y r e l a t e d t o t h e r a t e o f g r o w t h , and no r e g r e s s i o n o f c e l l u l o s e on r a t e o f g r o w t h c o u l d be p r o v e n i n t h i s e x p e r i m e n t . E r l c k s o n (3) r e c e n t l y i n v e s t i -g a t e d t h e e f f e c t s o f f e r t i l i z a t i o n and t h i n n i n g on wood o f 3 0 - y e a r - o l d D o u g l a s f i r s t a n d , and compared i t w i t h t h e wood f o r m e d on t h e same t r e e i n t h e f o u r y e a r s b e f o r e t r e a t m e n t . A c c o r d i n g t o h i s r e s u l t s n e i t h e r h o l o c e l l u l s e nofc a l p h a - c e l l u -l o s e y i e l d s were s i g n i f i c a n t l y a f f e c t e d b y t h e t r e a t m e n t s . O n l y s l i g h t l y l o w e r c e l l u l o s e y i e l d s were o b t a i n e d f o r t h e wood fo r m e d a f t e r t r e a t m e n t s . The i n c r e a s e d r a t e o f g r o w t h , r e s u l t e d I n a volume i n c r e a s e b u t n o t i n a h i g h e r c e l l u l o s e c o n t e n t . B e t w e e n - t r e e v a r i a t i o n e x t e n d e d f r o m a minimum o f a p p r o x i m a t e l y 54 p e r c e n t t o a maximum o f 66 p e r c e n t , o r a r a n g e o f r o u g h l y 12 p e r c e n t . The v e r y h i g h s i g n i f i c a n c e o f t r e e x crown c l a s s x s i t e i n t e r a c t i o n i n d i c a t e s t h a t t h e com-b i n a t i o n o f a l l t h r e e f a c t o r s , i . e . i n d i v i d u a l t r e e d i f f e r e n c e s , a r e r e s p o n s i b l e f o r t h e v a r i a t i o n i n c e l l u l o s e c o n t e n t among t h e sample t r e e s . Z o b e l and McElwee (20) r e c e n t l y i n v e s t i g a t e d l o b l o l l y p i n e i n o r d e r t o d e t e r m i n e t h e v a r i a b i l i t y I n c e l l u l o s e c o n t e n t as r e l a t e d t o t r e e s , s i t e s and g e o g r a p h i c a l r e g i o n s . They f o u n d a r a n g e o f s e v e n and 13 p e r c e n t i n y i e l d o f a l p h a - c e l l u l o s e and h o l o c e l l u l o s e r e s p e c t i v e l y . They c o n -c l u d e d t h a t due t o t h e l i m i t e d p o p u l a t i o n s t u d i e d "no s p e c u l a t i o n i s y e t p o s s i b l e as t o g e n e t i c i m p l i c a t i o n s o r t o - 40 -t h e d e g r e e o f c e l l u l o s e h e r i t a b i l l t y " . The more d e t a i l e d s t u d y o f a s i n g l e t r e e ( T a b l e 5) was p l a n n e d t o p e r m i t a s s e s s m e n t o f t r e n d s w i t h i n a t r e e . T h e s e may be ev e n more i m p o r t a n t t h a n t h e i n f l u e n c e o f s i t e , b e t w e e n - t r e e v a r i a t i o n , and crown c l a s s . O b v i o u s l y t h e r e s u l t s o b t a i n e d f r o m a n a l y s i s o f t h e s i n g l e l a r g e s t sample t r e e do n o t by t h e m s e l v e s p e r m i t any g e n e r a l i z a t i o n . N e v e r t h e l e s s , l o w e r c e l l u l o s e y i e l d f o r t h e j u v e n i l e a r e a ( T a b l e 5), t o g e t h e r w i t h t h e s t a t i s t i c a l l y s i g n i f i c a n t r e g r e s s i o n o f c e l l u l o s e y i e l d on age f r o m one t o 25 y e a r s ( A p p e n d i x C ) , e s s e n t i a l l y a g r e e d w i t h t h e r e s u l t s o f Z o b e l and McElwee (20). They f o u n d t h a t w i t h i n t h e same l o b l o l l y p i n e t r e e , m ature wood p r o d u c e s a h i g h e r amount o f c e l l u l o s e t h a n J u v e n i l e wood. F u r t h e r , t h e y s t a t e t h a t a t r e e w h i c h has a low c e l l u l o s e y i e l d i n i t s j u v e n i l e wood a l s o has low c e l l u l o s e c o n t e n t i n i t s mature wood, and a h i g h y i e l d i n i t s j u v e n i l e wood i n d i c a t e s h i g h y i e l d i n mature wood. I s e n b e r g (6), i n v e s t i g a t i n g 160 y e a r - o l d w h i t e f i r , f o u n d t h a t c e l l u l o s e c o n t e n t was n e a r l y c o n s t a n t a f t e r an age o f 34 y e a r s b u t showed a c o n s i d e r a b l e d e c r e a s e b e l o w t h a t a g e . I n c a s e o f t r e e No. 318, t h e d i f f e r e n c e b e t w e e n t h e means i n c e l l u l o s e c o n t e n t f o r j u v e n i l e v e r s u s mature wood was r o u g h l y t h r e e p e r c e n t . The r e g r e s s i o n o f c e l l u l o s e y i e l d on age was b a r e l y s i g n i f i c a n t a t t h e f i v e p e r c e n t l e v e l f o r t h e g r o w t h p e r i o d between 16 and 81 y e a r s , whereas b e l o w 15 y e a r s o f age t h e c o r r e s p o n d i n g r e g r e s s i o n was - 4 1 -s i g n i f i c a n t e v e n a t t h e one p e r c e n t l e v e l . O n l y s m a l l , s t a t i s t i c a l l y i n s i g n i f i c a n t , d i f f e r e n c e s i n y i e l d s b e t w e e n h e a r t w o o d (16-25 y e a r s ) and t h e o u t e r f i v e g r o w t h r i n g s were o b s e r v e d i n t h e p r e s e n t e x p e r i m e n t . S i n c e t h e o u t e r f i v e g r o w t h r i n g s i n e a c h t r e e r e p r e s e n t e d t h e sapwood, t h e r e s u l t s o f t h i s s t u d y d i s a g r e e d w i t h t h o s e o b t a i n e d by o t h e r I n v e s t i g a t o r s . R i t t e r and F l e c k (10), s t u d y i n g b a l d c y p r e s s , y e l l o w c e d a r , w h i t e c e d a r , i n c e n s e c e d a r and w h i t e p i n e , f o u n d h i g h e r c e l l u l o s e y i e l d s i n t h e sapwood t h a n i n t h e h e a r t w o o d . A n d e r s o n (1), a f t e r a n a l y s i n g w e s t e r n w h i t e p i n e , came t o t h e c o n c l u s i o n t h a t sapwood c o n t a i n s more c e l l u l o s e t h a n h e a r t w o o d . A somewhat d i f f e r e n t p a t t e r n i n w e s t e r n h e m l o c k was e s t a b l i s h e d by K r u g ( 8 ) , who d i v i d e d t h e wood d i s k s i n t o t h r e e u n i f o r m s e c t i o n s , r e p r e s e n t i n g t h e sapwood, mlddlewood and h e a r t -wood. A d e c r e a s e i n c e l l u l o s e c o n t e n t was n o t e d f r o m t h e sapwood t o t h e m l d dlewood and t h e n a n I n c r e a s e t o t h e h e a r t w o o d . When c o m p a r i n g t h e means f o r c e l l u l o s e y i e l d s o b t a i n e d i n t h i s e x p e r i m e n t , s l i g h t l y h i g h e r y i e l d s were f o u n d f o r t h e h e a r t w o o d o f d o m i n a n t t r e e s t h a n f o r t h e o u t e r f i v e g r o w t h r i n g s . What c o u l d be r e s p o n s i b l e f o r t h e e v i d e n t l y h i g h e r y i e l d s i n t h e h e a r t w o o d o f d o m i n a n t t r e e s o t h e r t h a n c e l l u l o s e i t s e l f ? I n T a b l e 9 i t i s shown t h a t t h e r e was a l o s s o f 9.01 p e r c e n t i n w e i g h t a f t e r o v e n -d r y i n g t h e h e a r t w o o d meal f r o m t h e t r e e No. 323 and 10.45 - 42 -per cent for the tree No. 304. Both values represented the moisture content assumed for the replicates under analysis. These percentages are on the average two to three units higher than the moisture content of about eight per cent found in the majority of samples. The apparently higher moisture content established for the heartwood might have been caused by volatIzation of certain extractives during oven-drying. If heartwood extractives were removed with the water, the calculated oven-dry weight of the heartwood samples used for analysis were In error. The higher cellulose yields for heartwood could therefore be due to the lower-than-actual values used for oven-dry weight of the heartwood meal, since cellulose yields were calculated as a percentage of this weight. No correlation between cellulose yield and percentage summerwood could be proven. In the samples analysed summerwood represented 21 to 51 per cent of the total growth ring (Table 4). Usually a higher portion of summerwood for the same speoies means also an increased specific gravity of the wood. It might be mentioned that Zobel and McElwee (20), investigating l o b l o l l y pine, found Insignificant effect of specific gravity on alpha-cellulose y i e l d . On the other hand, Bailey, quoted in Wise and Jahn (19), olaims that a higher percentage of lignin is present In the springwood than in the summerwood of Douglas f i r . Ritter and Fleck (11) maintain the same, and suggest that Douglas f i r springwood is higher in lignin than the summer-- 43 -wood, presumably because the middle lamella, which is largely lignin, forms a larger portion of the total in the springwood. D. Comments and Results from Yundt and Bradway Method The method recently developed by Yundt and Bradway was tested on only eight replicates representing two trees. However, even this small scale test Indicated good correla-tion between the water-resistant carbohydrate as well as alpha-cellulose on the one hand, and the Cross and Bevan cellulose on the other. Although the differences between the two trees measured by the Cross and Bevan method were more pronounced than corresponding yields of holocellulose or alpha-cellulose, in a l l cases the differences between trees were significant at the one per cent level. A corresponding relationship was even established for the yields of heartwood as compared with the sapwood in the same tree. For instance, in tree No. 313 the cellulose yield was slightly higher in the sapwood than in the heartwood, and the opposite relationship was established for tree No, 304, regardless of the method applied. It should be added that the alpha-cellulose content ranged from 42.5 to 51.9 per cent. These values are rather low when compared with the 52.1 to 62.5 per cent yield for loblolly pine investi-gated by Zobel and McElwee (20). In contrast, Cross and Bevan cellulose yields in tree No. 304 were high (65.86 per cent), and only about ten per cent lower than holo-_ 44 -c e l l u l o s e y i e l d s . C r o s s and B evan c e l l u l o s e c o n t a i n s a s u b s t a n t i a l amount o f n o n - r e m o v a b l e h e m i c e l l u l o s e s . Q u i t e l i k e l y t h e s e h e m i c e l l u l o s e s c a u s e d t h e d i f f e r e n c e b e t w e e n C r o s s and Bevan c e l l u l o s e and a l p h a - c e l l u l o s e . The a t t r a c t i v e n e s s o f t h e Y u n d t and Bradway method l i e s n o t o n l y i n t h e s m a l l amount o f t i m e i n v o l v e d , b u t a l s o i n t h e p o s s i b i l i t y o f d e t e r m i n i n g b o t h h o l o c e l l u l o s e and a l p h a - c e l l u l o s e on t h e same s a m p l e . S m a l l s a m p l e s c a n be u s e d i n t h i s method, so t h a t s m a l l i n c r e m e n t c o r e s c a n be a n a l y s e d . O b v i o u s l y t h i s e x t r a c t i o n p r o c e d u r e c a n be v e r y u s e f u l t o t h e wood t e c h n o l o g i s t . A l t h o u g h i t i s c l a i m e d by Y u n d t t h a t t h i s s t r i c t l y e m p i r i c a l method does n o t g i v e answers i d e n t i c a l w i t h o t h e r methods d i f f e r i n g i n d e t a i l , n e v e r t h e l e s s , he s u g g e s t s , and t h e s e d a t a c o n f i r m , t h a t y i e l d s s h o u l d be v a l i d f o r c o m p a r a t i v e p u r p o s e s . - 45 -CONCLUSIONS E a s e d on t h e r e s u l t s f r o m a n a l y s e s o f e i g h t D o u g l a s f i r t r e e s , no f u l l y s a t i s f a c t o r y e x p l a n a t i o n f o r t h e v a r i a t i o n o f c e l l u l o s e y i e l d s c o u l d be f o u n d . However, i t i s r e a s o n a b l e t o s u g g e s t t h a t most o f t h e v a r i a t i o n i n c e l l u l o s e c o n t e n t c o u l d be a t t r i b u t e d t o c h a r a c t e r i s t i c s o f t h e I n d i v i d u a l t r e e s . The work o f Z o b e l and McElwee (20), and t h e r e s u l t s o f t h i s e x p e r i m e n t , i n d i c a t e t h a t c e r t a i n s t e p s m i g h t be t a k e n t o i m prove t h e q u a l i t y o f p u l p w o o d . S t u d y o f a s i n g l e t r e e r e v e a l e d l o w e r c e l l u l o s e y i e l d s f o r t h e e a r l y g r o w t h r i n g s as compared w i t h t h e m a i n p o r t i o n o f t h e s t e m, I n c l u d i n g t h e o u t e r g r o w t h r i n g s i n t h e sapwood z o n e . I f i t i s assumed t h a t c e l l u l o s e c o n t e n t i n t h e wood v a r i e s f r o m t r e e t o t r e e , b u t i n c r e a s e s f r o m p i t h t o w a r d t h e b a r k I n t h e same t r e e , i t s h o u l d be p o s s i b l e t o r e c o g n i z e t r e e s w i t h r e l a t i v e l y h i g h c e l l u l o s e c o n t e n t e a r l y i n t h e l i f e o f t h e t r e e . By a n a l y s i n g a s m a l l c o r e f r o m t h e y o u n g t r e e , f u t u r e c e l l u l o s e y i e l d s m i g h t be p r e d i c t e d . C l e a r l y , t h e i m p o r t a n c e o f b e t w e e n - t r e e v a r i a t i o n i n c e l l u l o s e c o n t e n t s u g g e s t s t h e a d v a n t a g e s o f s e l e c t i n g t r e e s w i t h d e s i r e d pulpwood q u a l i t i e s f o r b r e e d i n g p u r p o s e s . However, t h i s o b j e c t i v e must be r e a c h e d w i t h o u t n e g l e c t i n g o t h e r f a c t o r s o f wood and t r e e q u a l i t y , s u c h as f i b r e p r o p e r t i e s , v o l u m e , s p e c i f i c g r a v i t y , s e l f - p r u n i n g a b i l i t y , - 46 s h a p e , and r e s i s t a n c e t o d i s e a s e . The u l t i m a t e s o l u t i o n o f t h i s p r o b l e m p r o b a b l y l i e s i n more i n t e n s i v e s t u d i e s on t h e c o r r e l a t i o n among t h e I n h e r i t e d t r e e c h a r a c t e r i s t i c s and t h e most d e s i r a b l e wood p r o p e r t i e s , as w e l l as on a s s e s s m e n t o f t h e r e l a t i v e i m p o r t a n c e o f e a c h v a r i a b l e . I n t h e p r e c e d i n g e x p e r i m e n t t h e e x t r e m e s i n C r o s s and B e v a n c e l l u l o s e r a n g e d o v e r t w e l v e p e r c e n t . I f t h e two e x t r e m e t r e e s were o m i t t e d t h i s d i f f e r e n c e c o u l d be r e d u c e d t o o n l y two o r t h r e e p e r c e n t . B r e e d i n g f o r s u c h a s l i g h t i n c r e a s e i n c e l l u l o s e c o n t e n t a t t h e e x p e n s e o f some o t h e r v a l u a b l e wood p r o p e r t i e s w o u l d h a r d l y be f e a s i b l e . The o n l y j u s t i f i a b l e p l a n w o u l d be t o b r e e d t r e e s w i t h as many v a l u a b l e c h a r a c t e r i s t i c s as p o s s i b l e . D e p e n d i n g on demands and s p e c i e s , s u c h c h a r a c t e r i s t i c s w o u l d p r o b a b l y i n c l u d e : h i g h c e l l u l o s e c o n t e n t , good f i b r e p r o p e r t i e s , d e s i r a b l e s p e c i f i c g r a v i t y , w e l l - b a l a n c e d s t r e n g t h p r o p e r t i e s , and r e s i s t a n c e t o d e c a y . I n t h e c a s e o f D o u g l a s f i r , t h e d e s i r a b i l i t y o f s u c h c o m b i n a t i o n i s p r o b a b l y more i m p o r t a n t t h a n f o r many o t h e r s p e c i e s , f o r i n t h e f o r e s e e a b l e f u t u r e , t h i s s p e c i e s w i l l c o n t i n u e t o be v a l u a b l e f o r v e n e e r , l u m b e r , and p u l p . - 4 7 -FIGURE I CHLORINATION APPARATUS •Suction A — Funnel B — Gooch Crucible C — Crucible Holder 0 — Beaker filled with water E — Suction Flask - 48 -LITERATURE CITED 1. A n d e r s o n , A. B. 1944. C h e m i s t r y o f w e s t e r n p i n e s . I n d u s t r . and E n g n g . Chem. 36: 662-663. 2. B l a n d , D.E. 1958. The c h e m i s t r y o f r e a c t i o n wood. The l i g n i n s o f E u c a l y p t u s g o n l o c a l y x and P i n u s r a d l a t a . H o l z f o r s c h u n g 12(2): 36-43. 3. E r i c k s o n , H.D., and G.M.G. L a m b e r t , 1958. E f f e c t s o f f e r t i l i z a t i o n and t h i n n i n g on c h e m i c a l c o m p o s i t i o n , g r o w t h , a n d s p e c i f i c g r a v i t y o f y o u n g D o u g l a s f i r . F o r . S c i . 4(4): 307-315. 4. H a g g l u n d , E . 1951. C h e m i s t r y o f wood. A c a d . P r e s s I n c . , New Y o r k . 631 PP. 5. Hawley, L . F . , and A.G. Norman, 1932. The d i f f e r e n t i a t i o n o f h e m i c e l l u l o s e s . I n d u s t r . and Engng. Chem. 24: 1190-1194. 6. I s e n b e r g , I.H. 1936. Age and c h e m i c a l c o m p o s i t i o n o f w h i t e f i r wood. J . Am. Chem. S o c . 5.8: 2231-2233. 7. K a l l m a n n , F . 1951. T e c h n o l o g i e des H o l z e s , V o l . 1. Second e d . S p r i n g i e r P u b l . , Munchen. 1050 p p . 8. K r u g , W.H. 1902. C h e m i c a l s t u d i e s o f some f o r e s t p r o d u c t s o f e c o n o m i c i m p o r t a n c e . U.S. D e p t . A g r . Y e a r b o o k : 321-332. 9. K u r t h , E . F . 1948. C h e m i c a l a n a l y s i s o f w e s t e r n woods. Pap. T r a d e J . 126(6): 56-57. 10. R i t t e r , G.J., and L.C. F l e c k . 1923. The r e s u l t s o f a n a l y s i s o f h e a r t w o o d and sapwood o f some A m e r i c a n woods. I n d u s t r . and E n g n g . Chem. 15.: 1055-1056. 11. . 1926. C h e m i s t r y o f wood. S p r i n g w o o d and summerwood. I n d u s t r . and Engng.Chem. 18: 608-609. ~* 12. S c h w e r i n , G. 1958. The c h e m i s t r y o f r e a c t i o n wood. The p o l y s a c c h a r i d e s o f E u c a l y p t u s g o n l o c a l y x and P i n u s r a d l a t a . H o l z f o r s c h u n g 12(2): 43-48. 13. S m i t h , D.M. 1955. C o m p a r i s o n o f methods o f e s t i m a t i n g summerwood p e r c e n t a g e i n w i d e - r i n g e d , s e c o n d - g r o w t h D o u g l a s f i r . U.S. F o r . P r o d . L a b . R e p t . No. 2035. 8 p p . 14. S n e d e c o r , G.W. 1957. S t a t i s t i c a l methods, a p p l i e d t o e x p e r i m e n t s i n a g r i c u l t u r e and b i o l o g y . F i f t h e d . Iowa S t a t e C o l l . P r e s s , Ames, Iowa. 534 p p . - 49 -15. Stamm, A . J . and E . E . H a r r i s . 1953. C h e m i c a l p r o c e s s i n g o f wood. Chem. P u b l . Co., New Y o r k . 595 PP. 16. T e c h n i c a l A s s o c i a t i o n o f t h e P u l p and P a p e r I n d u s t r y . 1953. T e s t i n g methods, recommended p r a c t i c e s , s p e c i f i c a t i o n s . New Y o r k . 17. U n i t e d N a t i o n s F o o d and A g r i c u l t u r e O r g a n i z a t i o n . 1957. P r o b l e m s i n wood c h e m i s t r y . Weizmann P r e s s , J e r u s a l e m . 136 pp. 18. W e g e l i u s , T. 1946. Det f i n s k a g r a n v i r k e t s e g e n s k a p e r o c h k v a l i t e t s v a r i a t i o n e r . S v e n s k P a p p e r s t i d . 4g: 51-61. 19. W i s e , L . E . , and E.C. J a h n . 1952. Wood c h e m i s t r y . V o l s . I and I I . R e i n h o l d P u b l . Corp.,. New Y o r k . 1347 p p . 20. Z o b e l , B3.J., and R.L. McElwee. 1958. V a r i a t i o n o f c e l l u l o s e i n l o b l o l l y p i n e . T a p p i 4l(4): 167-171. - 50 -SUMMARY OF REGRESSIONS A. R e g r e s s i o n o f C r o s s and B e v a n C e l l u l o s e y i e l d ( e i g h t t r e e s ) o n R a t e o f Gr o w t h : b = 0.028; s D s 0.073; t = b / s ^ = o.38 ( n o t s i g n i f i c a n t ; t h e o r e t i c a l t f o r 14 d . f . and 5$ l e v e l = 2.145) B. R e g r e s s i o n o f C r o s s and Bevan C e l l u l o s e y i e l d ( e i g h t t r e e s ) on P e r c e n t a g e Summerwood: b = 0.018; s D = 0.176; t = b / s D = 0.10 ( n o t s i g n i f i c a n t ; t h e o r e t i c a l t f o r 14 d . f . and 5% l e v e l = 2.145) C. R e g r e s s i o n o f C r o s s and Bevan C e l l u l o s e y i e l d on Age, i n t h e L a r g e s t S i n g l e T r e e , No. 318 1-26 y e a r s g r o w t h p e r i o d : b = 0.24; s b = 0.029; F = 68.81* ( s i g n i f i c a n t a t 1% l e v e l ; t h e o r e t i c a l F , f o r 1 and 4 d . f . and 1% l e v e l = 21.20) 16-81 y e a r s g r o w t h p e r i o d : h = 0.06; s D = 0.023; F = 7.04* ( s i g n i f i c a n t a t 5% l e v e l , t h e o r e t i c a l F f o r 1 and 10 d . f . and 5% l e v e l = 4.96). Symbols u s e d : b = r e g r e s s i o n c o e f f i c i e n t s D = sample s t a n d a r d d e v i a t i o n o f t h e r e g r e s s i o n c o e f f i c i e n t t = d e v i a t i o n o f t h e e s t i m a t e d mean f r o m t h a t o f t h e p o p u l a t i o n F = v a r i a n c e r a t i o M = mean SD = s t a n d a r d d e v i a t i o n d . f . = d e g r e e s o f f r e e d o m . - 51 -APPENDIX-SUPPLEMENTARY ANALYSIS OF VARIANCE FOR EIGHT TREES (BASED ON"CROSS AND BEVAN CELLULOSE YIELDS ROUNDED TO THE NEAREST WHOLE PERCENT AND ON THE INCREASED ERROR TERM BY THE SUM OF SQUARES FOR REPLICATION) Source of Degrees Sum of Mean F Variation of Free- Squares Square Test dom. Crown Class 1 52.53 52.53 128.12* Site 1 52.53 52.53 128.12* Trees (Groups "A" '*MB^ 1 42.78 42.78 104.34* Radial Position 1 2.53 2.53 6.17, Interactions: S S x Cr. CI. 1 3.79 3.79 9.24* S x Tr. 1 0.78 0.78 1.90 Cr. 01. x Tr. 1 16.54 16.54 40.34* 3 x L 1 1.53 1.53 3.73 Cr. CI. x L 1 2.53 2.53 6.17 L x Tr. 1 0.78 0.78 1.90 S x Gr. .01. x L 1 0.78 0.78 1.90. S x Gr. 01. x Tr. 1 63.27 63.27 154.32* S x L x Tr. 1 3.79 3.79 9.24* Cr. 01. x L x Tr. 1 1.53 1.53 3.73 3 x Gr. 01. x Lx Tr. 1 0.78 0.78 1.90 Residual (Error) 16 6.50 0.41 TOTAL 31 252.97 #»F" obtained greater than theoretical "F" of 8.68 (for one and 15 degrees of freedom at one percent level) 

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