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Morphological and anatomical variation of picea in southwestern British Columbia Scagel, Robert Kevin 1984

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MORPHOLOGICAL AND ANATOMICAL VARIATION OF PICEA IN SOUTHWESTERN BRITISH COLUMBIA. By ROBERT KEVIN SCAGEL B . S c , The U n i v e r s i t y of B r i t i s h Columbia 1977 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (Department of Botany) We accept t h i s t h e s i s as conforming to the r e q u i r e d standard THE UNIVERSITY OF BRITISH COLUMBIA October 1984 (c) Robert Kevin Scagel, 1984 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 of the requirements f o r an advanced degree a t the U n i v e r s i t y o f 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 p e r m i s s i o n f o r e x t e n s i v e 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 o f my department or by h i s or her r e p r e s e n t a t i v e s . I t i s understood t h a t copying or p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l gain 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 . Robert K. Scagel. Department of Botany The U n i v e r s i t y of B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 Date >E-6 (3/81) i i ABSTRACT. R e l a t i o n s between i n d i v i d u a l t r e e s hypothesized to be r e p r e s e n t a t i v e of P i cea enqelmannii and P_j_ s i t c h e n s i s and p u t a t i v e h y b r i d s in southwestern B r i t i s h Columbia were examined using s e v e r a l m o rphological and anatomical v a r i a b l e s measured on cones, needles, and twigs. 36 v a r i a b l e s were s e l e c t e d that had an i n t e r - i n d i v i d u a l v a r i a t i o n that exceeded i n t r a - i n d i v i d u a l v a r i a t i o n . Such r e l a t i v e v a r i a t i o n suggested that the v a r i a b l e s s e l e c t e d were more g e n e t i c a l l y than developmentally v a r i a b l e . These v a r i a b l e s were measured on 640 t r e e s . P a t t e r n s of i n t e r - and i n t r a - i n d i v i d u a l v a r i a t i o n of these v a r i a b l e s were examined with m u l t i v a r i a t e a n a l y s e s . S i m i l a r p a t t e r n s of i n t r a - i n d i v i d u a l v a r i a t i o n with re s p e c t to p o s i t i o n in the canopy were d e t e c t e d r e g a r d l e s s of the age of the t r e e or the s p e c i e s , suggesting that i n t r a - i n d i v i d u a l v a r i a t i o n i n P i c e a i s not n e c e s s a r i l y a f u n c t i o n of the environment e x t r i n s i c to the i n d i v i d u a l . F u r t h e r , the two hypothesized taxa were not e s p e c i a l l y d i f f e r e n t with respect to the p a t t e r n of i n t r a - i n d i v i d u a l v a r i a t i o n . In an i n t e r - i n d i v i d u a l context, the intra-taxonomic v a r i a t i o n was shown to be l a r g e r than inter-taxonomic v a r i a t i o n . I n t e r - i n d i v i d u a l v a r i a t i o n a t t r i b u t e d to the hypothesized taxa was smaller than i n t r a - p o p u l a t i o n v a r i a t i o n . Inter-taxonomic v a r i a t i o n was only 25 percent l a r g e r than i n t r a - i n d i v i d u a l v a r i a t i o n . F u r t h e r , the h ypothesized taxonomic p o l a r i t y of the data was not c o - i n c i d e n t with the a c t u a l p o l a r i t y of the d a ta. What taxonomic s t r u c t u r e emerged was evident only as the extremes of a continuum of i i i v a r i a t i o n over a l a r g e geographic area r e f l e c t i n g l a r g e environmental v a r i a t i o n , suggesting that r e c o g n i t i o n of two taxa of P i c e a i n southwestern B r i t i s h Columbia may not be a p p r o p r i a t e or p r a c t i c a l l y f e a s i b l e . From the evidence a v a i l a b l e here, i t i s not p o s s i b l e to a t t r i b u t e the p a t t e r n of v a r i a t i o n to h y b r i d i z a t i o n f o l l o w e d by i n t r o g r e s s i o n or to the d i f f e r e n t i a t i o n of a s i n g l e , l a r g e polymorphic taxon. The p a t t e r n of i n t e r - i n d i v i d u a l v a r i a t i o n was only p a r t i a l l y c o r r e l a t e d with r e g i o n a l and l o c a l s c a l e s of geographic and environmental v a r i a t i o n . L o c a l p a t t e r n s of v a r i a t i o n were not c o - i n c i d e n t i n 16 separate geographic areas. The r e l a t i o n of the p a t t e r n of v a r i a t i o n in nursery grown t r e e s with re s p e c t to r e g i o n a l s c a l e s of geographic v a r i a t i o n was not c o - i n c i d e n t with the p a t t e r n s of v a r i a t i o n i n n a t u r a l l y grown t r e e s from the same area of o r i g i n . T h i s v a r i a b i l i t y of r e l a t i o n s suggests that i n t e r - i n d i v i d u a l v a r i a t i o n i s probably a t t r i b u t a b l e to processes o p e r a t i n g at an extremely l o c a l s c a l e . I m p l i c a t i o n s from these c o n c l u s i o n s are presented and d i s c u s s e d with re s p e c t to the s y s t e m a t i c s of Picea and the u t i l i z a t i o n of P i c e a in f o r e s t r y and t r e e improvement programmes. i v CONTENTS. ABSTRACT i i CONTENTS i v LIST OF TABLES v i i LIST OF FIGURES. x i i ACKNOWLEDGEMENTS xv PREFACE 1 I. INTRODUCTION 3 I I . MATERIALS AND METHODS 15 1. I n t r o d u c t i o n 15 2. Chara c t e r s 17 2.1 Ch a r a c t e r s and v a r i a b l e s s e l e c t e d • 18 2.2 V a r i a b l e measurement r e p e a t a b i l i t y 22 2.3 V a r i a b l e v a r i a t i o n between i n d i v i d u a l s 26 3. Samples and sampling 31 3 . 1 Study area 31 3.1.1 Climate 35 3.1.2 Edaphic environment 37 3.1.3 A s s o c i a t e d v e g e t a t i o n 39 3.1.4 G e o l o g i c a l , v e g e t a t i o n , and c l i m a t i c frrstory. .. 40 3.1.5 H i s t o r y of Pi c e a i n western North America 42 3.2 T r a n s - i n d i v i d u a l c i r c u m s c r i p t i o n of samples 44 3.2.1 P o p u l a t i o n c i r c u m s c r i p t i o n of samples 44 3.2.2 Taxonomic c i r c u m s c r i p t i o n of samples. 47 3.2.3 L o c a l geographic c i r c u m s c r i p t i o n of samples. ... 48 3.3 S e l e c t i o n o f samples 49 4. Analyses 53 4.1 Mathematical n o t a t i o n and f o r m u l a t i o n 54 4.2 S t a t i s t i c a l techniques 54 4.2.1 Conformity to d i s t r i b u t i o n a l assumptions 56 4.2". 2 Sample s i z e 58 4.2.3 D i s c r e t e v a r i a b l e s 61 4.2.4 U n i v a r i a t e analyses 64 4.2.5 M u l t i v a r i a t e analyses 65 4.3 Computation and t e s t s of s i g n i f i c a n c e 73 I I I . INTRA-INDIVIDUAL VARIATION 74 1. I n t r o d u c t i o n 74 2. M a t e r i a l s and methods 83 2.1 M a t e r i a l s 83 2.2 Analyses 85 V 3. R e s u l t s 89 3.1 A d v e n t i t i o u s versus primary whorl branches 89 3.2 Primary versus secondary whorl branches 90 3.3 Year to year v a r i a t i o n 92 3.4 I n t e r - p o s i t i o n a l v a r i a t i o n 94 3.5 I n t r a - p o s i t i o n a l v a r i a t i o n i n an i n t e r - i n d i v i d u a l context 105 4. D i s c u s s i o n 107 4.1 I m p l i c a t i o n s f o r sampling and i n t e r p r e t a t i o n 110 4.2 Crown form morphogenesis 113 4.3 Furth e r research 116 IV. INTER-INDIVIDUAL VARIATION: TAXONOMIC CIRCUMSCRIPTION. 120 1. I n t r o d u c t i o n 120 2. M a t e r i a l s and methods 123 2.1 M a t e r i a l s 123 2.2 Analyses 124 3. R e s u l t s 127 3.1 P o p u l a t i o n s of standards 127 3.1.1 P_;_ enqelmanni i and P^ s i t c h e n s i s 127 3.1.2 P_j_ enqelmanni i , P. s i t c h e n s i s, and P_^_ g l a u c a . .. 130 3.2 I n d i v i d u a l standards and p u t a t i v e taxonomic r e p r e s e n t a t i v e s 133 3.2.1 P^ enqelmanni i and P_j_ s i t c h e n s i s 133 3.2.2 P\_ enqelmanni i , P. s i t c h e n s i s, and P_^_ g l a u c a . .. 134 3.3 A r t i f i c a l h y b r i d s i n the context of p o p u l a t i o n s of standards. . •. 136 3.4 A r t i f i c i a l and p u t a t i v e h y b r i d s 139 3.5 I n d i v i d u a l standards, p u t a t i v e s , and " h y b r i d s " . .. 140 4. D i s c u s s i o n 144 4.1 I n t r a - p o p u l a t i o n v a r i a t i o n 145 4.2 N a t u r a l h y b r i d s 147 4.3 I n t e r - i n d i v i d u a l v a r i a t i o n i n an i n t e r - i n d i v i d u a l context 150 V. INTER-INDIVIDUAL VARIATION: RELATIONSHIPS OF PATTERNS OF VARIATION 1 52 1. I n t r o d u c t i o n 152 2. M a t e r i a l s and methods 156 2.1 M a t e r i a l s 156 2.2 Analyses . 157 3. R e s u l t s 162 3.1 Geographic v a r i a t i o n 162 • 3.1.1 N a t u r a l v a r i a t i o n 162 3.1.2 Nursery versus n a t u r a l v a r i a t i o n 171 3.2 L o c a l geographic v a r i a t i o n 173 4. D i s c u s s i o n 180 v i 4.1 Inferences from environmental and geographic c o r r e l a t i o n 181 4.2 Inferences from v a r i a b l e s u i t e i n t e r c o r r e l a t i o n . . 186 4.3 H y b r i d i z a t i o n or d i f f e r e n t i a t i o n i n a polymorphic taxon? 190 VI. UNIFYING DISCUSSION 196 1. The nature of Picea in southwestern B r i t i s h Columbia 197 2. R e f l e c t i o n s on the taxonomy of Picea 200 3. Sources of v a r i a t i o n in p o p u l a t i o n s t u d i e s of c o n i f e r s . 205 4. Ontogeny and phylogeny - the i n t e r f a c e 208 V I I . EPILOGUE: IMPLICATIONS AND APPLICATIONS FOR FORESTRY. 213 1. I m p l i c a t i o n s f o r tre e improvement and s i l v i c u l t u r e . . 214 2. I m p l i c a t i o n s f o r Picea f o r e s t r y 219 3. Suggestions f o r independent s t u d i e s and c o l l e c t i o n s . 223 BIBLIOGRAPHY 230 APPENDICES 274 Appendix I. D e s c r i p t i o n of v a r i a b l e s and v a r i a b l e s u i t e s 274 Appendix I I . L o c a t i o n and d i s p o s i t i o n of i n d i v i d u a l t r e e s and p o p u l a t i o n s of t r e e s 281 Appendix I I I . Complete t a b l e s of ANOVAs and PCAs a b b r e v i a t e d i n body of text 293 v i i LIST OF TABLES Table 1. Ch a r a c t e r s used i n pre v i o u s s t u d i e s 21 Table 2. Average v a r i a b l e and v a r i a b l e s u i t e measurement r e p e a t a b i l i t y , i n t e r - i n d i v i d u a l v a r i a b i l i t y , and i n t e r - p o p u l a t i o n v a r i a b i l i t y 24 Table 3. I n t e r - i n d i v i d u a l v a r i a t i o n , r e p e a t a b i l i t y e s t i m a t e s , r e p o r t e d f o r morp h o l o g i c a l c h a r a c t e r s in other c o n i f e r t r e e s p e c i e s 30 Table 4. Summary cf some annual average c l i m a t i c v a r i a b l e s r e p o r t e d f o r the study area and adjacent areas 36 Table 5 D i s t r i b u t i o n of samples with respect to moisture regime. 39 Table 6. D i s t r i b u t i o n of samples with respect to b i o g e o c l i m a t i c zones 41 Table 7. D i s t r i b u t i o n of samples as p o p u l a t i o n s and s i n g l e o c c u r r e n c e s . 46 Table 8. D i s t r i b u t i o n of samples i n t o geographic areas. . 50 Table 9. Summary of samples with complete measurements f o r v a r i o u s v a r i a b l e s u i t e s 53 Table 10. Sample s i z e e stimates f o r i n t r a - i n d i v i d u a l v a r i a t i o n (n) and i n t e r - i n d i v i d u a l v a r i a t i o n (t) 60 Table 11. Summary of H o t e l l i n g ' s T 2 f o r twig morphology based on v a r i a b l e s t a t e f o r d i s c r e t e (presence/ absence) v a r i a b l e : p u l v i n u s pubescence 63 Table 12. ANOVA models used i n a s s e s s i n g v a r i o u s aspects of i n t r a - i n d i v i d u a l v a r i a t i o n 87 Table 13. ANOVA models used i n a s s e s s i n g the c o n t r i b u t i o n of i n t r a - i n d i v i d u a l v a r i a t i o n i n the context of i n t e r - i n d i v i d u a l v a r i a t i o n 88 v i i i Table 14. ANOVAs of i n d i v i d u a l v a r i a b l e s comparing a d v e n t i t i o u s and whorl primary branches of engelmanni i 90 Table 15. M u l t i v a r i a t e apportionment of v a r i a t i o n f o r separate v a r i a b l e s u i t e s due to d i f f e r e n c e s between orders of branches 91 Table 16. ANOVAs comparing year to year v a r i a t i o n of of v a r i a b l e s i n P\_ engelmanni i 93 Table 17. M u l t i v a r i a t e apportionment of v a r i a t i o n f o r separate v a r i a b l e s u i t e s due to d i f f e r e n c e s between p o s i t i o n s of branches 94 Table 18. Mahalanobis' D 2 d i s t a n c e s between a p i c a l - and basal-most branches and cones of engelmanni i and P. s i t c h e n s i s 95 Table 19. Average Mahalanobis's D 2 d i s t a n c e s between i n d i v i d u a l t r e e s i n Table 18 98 Table 20. M u l t i v a r i a t e apportionment of v a r i a t i o n f o r separate v a r i a b l e s u i t e s of separate t r e e s due to whorl p o s i t i o n s . 100 Table 21. C o r r e l a t i o n s amongst component c o r r e l a t i o n s f o r f i r s t components from PCAs i n Table 20 101 Table 22. M u l t i v a r i a t e apportionment of v a r i a t i o n f o r separate v a r i a b l e s u i t e s due to d i f f e r e n c e s between i n d i v i d u a l t r e e s or taxa emphasizing i n t r a - i n d i v i d u a l v a r i a t i o n i n an i n t e r - i n d i v i d u a l context 106 Table 23. M u l t i v a r i a t e apportionment of v a r i a t i o n f o r separate v a r i a b l e s u i t e s due to d i f f e r e n c e s between taxa, p o p u l a t i o n s , and i n d i v i d u a l s of standards of P^ s i t c h e n s i s and P. engelmanni i 128 Table 24. M u l t i v a r i a t e apportionment of v a r i a t i o n f o r separate v a r i a b l e s u i t e s due to d i f f e r e n c e s between taxa, p o p u l a t i o n s , and i n d i v i d u a l s of standards of P_;_ engelmannii, P. gla u c a , and P. s i t c h e n s i s 131 I X Table 25. M u l t i v a r i a t e apportionment of v a r i a t i o n for separate v a r i a b l e s u i t e s due to d i f f e r e n c e s between taxa and i n d i v i d u a l standards and p u t a t i v e s of engelmannii and P. s i t c h e n s i s 133 Table 26. M u l t i v a r i a t e apportionment of v a r i a t i o n f o r separate v a r i a b l e s u i t e s due to d i f f e r e n c e s between taxa and i n d i v i d u a l standards and p u t a t i v e s of engelmanni i , P. glauca, and P_;_ s i t c h e n s i s 136 Table 27. PCAs of separate v a r i a b l e s u i t e s f o r a r t i f i c i a l h y b r i d s and p o p u l a t i o n s of standards of P^ engelmanni i and P. s i t c h e n s i s Table 28. M u l t i v a r i a t e apportionment of v a r i a t i o n f o r separate v a r i a b l e s u i t e s due to d i f f e r e n c e s between a r t i f i c i a l and p u t a t i v e h y b r i d s of P^ engelmanni i and P_j_ s i t c h e n s i s . . 139 Table 29. M u l t i v a r i a t e apportionment of v a r i a t i o n f o r separate v a r i a b l e s u i t e s due to e i t h e r d i f f e r e n c e s between taxa or i n d i v i d u a l s of P_^  engelmanni i , P. s i t c h e n s i s , and p u t a t i v e h y b r i d s 142 Table 30. r 2 v a l u e s f o r i n d i v i d u a l v a r i a b l e s from m u l t i p l e l i n e a r r e g r e s s i o n given i n MODEL 4 164 Table 31. M u l t i v a r i a t e apportionment of v a r i a t i o n f o r separate v a r i a b l e s u i t e s based on p r e d i c t e d and r e s i d u a l values from m u l t i p l e l i n e a r r e g r e s s i o n (MODEL 4) 165 Table 32. C o r r e l a t i o n s among PCAs of o r i g i n a l , p r e d i c t e d , and r e s i d u a l v a l u e s 168 Table 33. I n t e r c o r r e l a t i o n s of v a r i a b l e s u i t e analyses from PCAs of r e s u l t s of r e g r e s s i o n a n a l y s i s 169 Table 34. M u l t i v a r i a t e r e l a t i o n s h i p of v a r i a t i o n f o r separate v a r i a b l e s u i t e s f o r nursery and n a t u r a l l y grown m a t e r i a l s to geographic v a r i a t i o n 171 Table 35. M u l t i v a r i a t e r e l a t i o n s h i p of v a r i a t i o n f o r separate v a r i a b l e s u i t e s f o r separate geographic areas r e l a t e d to the environment 173 Table 36. Ranking of v a r i a b l e s on a d i s p e r s i o n c r i t e r i o n and redundancy a n a l y s i s 224 Table 37. C o e f f i c i e n t s and v a r i a b l e v a l u e s used in v a r i o u s PCAs 226 Table 38. C o r r e l a t i o n amongst PCAs given i n Table XXXVIII. 227 Table 39. ANOVAs and PCAs of separate v a r i a b l e s u i t e s f o r whorl primary and secondary branches of P^ s i t c h e n s i s 293 Table 40. ANOVAs and PCAs of separate v a r i a b l e s u i t e s of whorl branch p o s i t i o n s and mature and immature P^ engelmanni i and P. s i t c h e n s i s 294 Table 41. PCAs of separate v a r i a b l e s u i t e s of whorl branch p o s i t i o n s of i n d i v i d u a l t r e e s of P_j_ engelmanni i and P. s i t c h e n s i s and %SS(mva) f o r each i n d i v i d u a l t r e e . .. 295 Table 42. PCAs of separate v a r i a b l e s u i t e s of i n t r a - i n d i v i d u a l v a r i a t i o n i n the context of i n t e r - i n d i v i d u a l v a r i a t i o n and %SS(mva) 296 Table 43. ANOVAs and PCAs of separate v a r i a b l e s u i t e s f o r sampled p o p u l a t i o n s of standards of P^ engelmanni i and P. s i t c h e n s i s 297 Table 44. ANOVAs and PCAs of separate v a r i a b l e s u i t e s f o r sampled p o p u l a t i o n s of stadards of P_;_ engelmanni i , P. glauca, and P. s i t c h e n s i s 299 Table 45. ANOVAs and PCAs of separate v a r i a b l e s u i t e s f o r sampled i n d i v i d u a l standards and p u t a t i v e s of Pj_ engelmanni i and P. s i t c h e n s i s 301 Table 46. ANOVAs and PCAs of separate v a r i a b l e s u i t e s f o r sampled i n d i v i d u a l standards and p u t a t i v e s of P_^_ engelmanni i , P. g l a u c a , and P_;_ s i t c h e n s i s 303 Table 47. PCAs of separate v a r i a b l e s u i t e s f o r a r t i f i c i a l h y b r i d s and p o p u l a t i o n s of standards of P^ engelmanni i and P. s i t c h e n s i s 305 x i Table 48. ANOVAs and PCAs of separate v a r i a b l e s s u i t e s f o r a l l i n d i v i d u a l s of a r t i f i c i a l h y b r i d s and p u t a t i v e h y b r i d s of P. engelmanni i and P^ s i t c h e n s i s 306 Table 49. ANOVAs and PCAs of separate v a r i a b l e s u i t e s f o r a l l i n d i v i d u a l s of Pj_ engelmanni i , P. s i t c h e n s i s , and p u t a t i v e hybrids. 307 Table 50. ANOVAs and PCAs of separate v a r i a b l e s u i t e s f o r standards, p u t a t i v e s , and " h y b r i d s " of P^ engelmanni i and P. s i t c h e n s i s based on c a l c u l a t e d p r e d i c t e d and r e s i d u a l v a r i a t i o n from m u l t i p l e l i n e a r r e g r e s s i o n with e l e v a t i o n , l a t i t u d e , and l o n g i t u d e 309 Table 51. PCAs of separate v a r i a b l e s u i t e s of standards of P. s i t c h e n s i s comparing n a t u r a l l y o c c u r r i n g t r e e s and t r e e s grown i n the nursery 311 Table 52. PCAs of separate geographic areas f o r separate v a r i a b l e s u i t e s 312 x i i LIST OF FIGURES F i g u r e 1. I l l u s t r a t i o n s of v a r i a b l e s used. 25 F i g u r e 2. Summary of v a r i a b l e v a r i a t i o n based on a l l i n d i v i d u a l s without r e f e r a n c e to taxonomic c i r c u m s c r i p t i o n . 27 F i g u r e 3. I l l u s t r a t i o n of range of v a r i a t i o n encountered for l e a f anatomy 28 F i g u r e 4. Maps of l o c a t i o n of samples and study a r e a . ... 32 F i g u r e 5. E l e v a t i o n a l , l a t i t u d i n a l , and l o n g i t u d i n a l d i s t r i b u t i o n of samples 37 F i g u r e 6. L o c a t i o n of geographic areas c i r c u m s c r i b i n g samples. 49 F i g u r e 7. Schematic r e p r e s e n t a t i o n of sources of i n t r a - i n d i v i d u a l v a r i a t i o n a s s o c i a t e d with branch a r c h i t e c t u r e i n enqelmanni i and s i t c h e n s i s . 52 F i g u r e 8. Schematic r e p r e s e n t a t i o n of i n d i v i d u a l t r e e s of P. enqelmann i i and P^ s i tchens i s from which i n t r a - i n d i v i d u a l sampling conducted 84 F i g u r e 9. O r d i n a t i o n s of f i r s t two components of PCAs of separate v a r i a b l e s u i t e s of whorl primary and secondary branches of P_;_ s i t c h e n s i s 91 F i g u r e 10. O r d i n a t i o n s of f i r s t two components of PCAs of separate v a r i a b l e s u i t e s of whorl branch p o s i t i o n s from P. engelmanni i and P_;_ s i t c h e n s i s 97 F i g u r e 11. Examples of i n t r a - i n d i v i d u a l v a r i a t i o n of l e a f anatomy f o r some t r e e s shown i n F i g u r e 8 102 F i g u r e 12. S c a t t e r s of means and standard d e v i a t i o n s of scores of f i r s t components of PCAs f o r i n d i v i d u a l branches of i n d i v i d u a l t r e e s a g a i n s t whorl branch p o s i t i o n s . ...... 103 F i g u r e 13. O r d i n a t i o n s of f i r s t two components of PCAs of i n d i v i d u a l t r e e s comparing p o s i t i o n of cones 105 F i g u r e 14. O r d i n a t i o n s of f i r s t two components of PCAs of separate v a r i a b l e s u i t e s f o r i n t r a - i n d i v i d u a l variatio-n i n the context of i n t e r - i n d i v i d u a l v a r i a t i o n 108 F i g u r e 15. Summary p a r t i o n i n g o f . s o u r c e s of i n t r a - i n d i v i d u a l v a r i a t i o n . 109 F i g u r e 16. O r d i n a t i o n s of f i r s t two components of PCAs of separate v a r i a b l e s u i t e s f o r p o p u l a t i o n s of standards of P. engelmannii and P_^_ s i t c h e n s i s 129 F i g u r e 17. O r d i n a t i o n s of f i r s t two components of PCAs of separate v a r i a b l e s u i t e s f o r p o p u l a t i o n s of standards of P. engelmanni i , P. g l a u c a , and P_^  s i t c h e n s i s 132 F i g u r e 18. O r d i n a t i o n s of f i r s t two components of PCAs of separate v a r i a b l e s u i t e s f o r a l l standards and p u t a t i v e s of P. engelmannii and P^ s i t c h e n s i s 135 F i g u r e 19. O r d i n a t i o n s of f i r s t two components of PCAs of separate v a r i a b l e s u i t e s f o r a l l standards and p u t a t i v e s of P. engelmanni i , P. glauca , and P_^  s i t c h e n s i s 137 F i g u r e 20. O r d i n a t i o n s of f i r s t two components of PCAs of separate v a r i a b l e s u i t e s f o r sampled p o p u l a t i o n s of standards and a r t i f i c i a l h y b r i d s 138 F i g u r e 21. O r d i n a t i o n s of f i r s t two components of PCAs of separate v a r i a b l e s u i t e s f o r i n d i v i d u a l a r t i f i c i a l h y b r i d s and p u t a t i v e h y b r i d s 141 F i g u r e 22. O r d i n a t i o n s of f i r s t two components of PCAs of separate v a r i a b l e s u i t e s f o r a l l i n d i v i d u a l s of P. engelmanni i , P. s i t c h e n s i s , and " h y b r i d s " 143 F i g u r e 23. O r d i n a t i o n s of means of f i r s t components from PCAs of separate v a r i a b l e s u i t e s f o r standards, p u t a t i v e s , and " h y b r i d s " a g a i n s t e l e v a t i o n , l a t i t u d e , and l o n g i t u d e . . 163 x i v F i g u r e 24. O r d i n a t i o n s of f i r s t two components from PCA of separate v a r i a b l e s u i t e s f o r standards, p u t a t i v e s , and " h y b r i d s " using c a l c u l a t e d p r e d i c t e d and r e s i d u a l values from m u l t i p l e l i n e a r r e g r e s s i o n in MODEL 4 167 F i g u r e 25. Average v e c t o r s of separate v a r i a b l e s u i t e s p l o t t e d i n t o c o - o r d i n a t e s of f i r s t two axes from PCAs of a l l i n d i v i d u a l t r e e s based on o r i g i n a l and p r e d i c t e d and r e s i d u a l v a l u e s from m u l t i p l e r e g r e s s i o n 170 F i g u r e 26. O r d i n a t i o n s of means of component scores f o r i n d i v i d u a l t r e e s from PCAs of separate v a r i a b l e s u i t e s of n a t u r a l l y and nursery grown t r e e s p l o t t e d and re g r e s s e d s e p a r a t e l y a g a i n s t l o n g i t u d e and l a t i t u d e 172 F i g u r e 27. O r d i n a t i o n s of f i r s t two components from PCAS of separate geographic areas and separate v a r i a b l e s u i t e s . 176 F i g u r e 28. P a r t i t i o n i n g of sources of v a r i a t i o n f o r n a t u r a l l y o c c u r r i n g P i c e a i n study area 180 F i g u r e 29. O r d i n a t i o n s of means, standard d e v i a t i o n s , and ranges of f i r s t component scores f o r a p r i o r i i d e n t i f i c a t i o n s and b i o g e o c l i m a t i c zones 229 XV ACKNOWLEDGEMENTS. Thanks and a p p r e c i a t i o n are extended to the f o l l o w i n g people f o r t h e i r time and e f f o r t spent on my behalf during the course of the present study and the r e s e a r c h l e a d i n g up to the f o r m u l a t i o n of the study. Bob G i t t i n s , Jack Maze, Gary B r a d f i e l d , Ned G l i c k , and Yousrey El-Kassaby p r o v i d e d encouragement and c l a r i f i c a t i o n on many aspects of the p h i l o s o p h y , assumptions, and d e t a i l s of v a r i o u s s t a t i s t i c a l a n a l y s e s . John Emanuel, Malcolm G r e i g , and Nancy Reid provided v a l u a b l e advice a s s o c i a t e d with computation. Fred Nuszdorfer and K a r e l K l i n k a p r o v i d e d h e l i c o p t e r time and access through p r e v i o i u s employment to many are a s . Without t h e i r help much of the sampling c o u l d not even have been c o n s i d e r e d . I owe an e s p e c i a l debt to K a r e l K l i n k a who f i r s t i n t r o d u c e d me to t h i s p r i c k l y problem and p r o v i d e d the o r i g i n a l impetus f o r w r i t i n g the f o r e s t r y e p i l o g u e . The WFGA pr o v i d e d the r e s o l v e to w r i t e the e p i l o g u e . U l f B i t t e r l i c k , Reid C a r t e r , Don Fowler, D a n i e l Gagnon,and Helmar Hahn a l l provided samples and expressed continued i n t e r e s t in the study even when r e s u l t s were not immediately forthcoming. Jim Pojar p r o v i d e d comments with respect to many areas o u t s i d e that s t u d i e d here. F i e l d work would have been f a r l e s s e x c i t i n g and m o t i v a t i n g without the h e l p of Paul C o u r t i n , Zong-hi Chen, and Fred Laing Ridge. S p e c i a l thanks are extended to Nelsa and "Buck" Buckingham and Ed T e i c h f o r d i r e c t i n g me to Pat's P r a i r i e p l u s p r o v i d i n g a h o s p i t a b l e atmosphere w h i l s t c o l l e c t i n g on the Olympic P e n i n s u l a . Grant D i c k i n s o n and George Shishkov measured many of the o r i g i n a l samples c o l l e c t e d i n 1979. Anna Scagel w i l l i n g l y p r o v i d e d time that was hers and hers alone by i n d u l g i n g me i n c o l l e c t i n g , b o i l i n g cones, e n t e r i n g data, and back p a t t i n g . She a l s o p r o v i d e d a c l e a r view of the r e a l i t y a s s o c i a t e d with B o t a n i c a l T r i v i a P u r s u i t . 1 PREFACE. There are reasons f o r conducting a s c i e n t i f i c study that go beyond s c i e n c e . Regardless of the o b j e c t i v i t y of any study these reasons i n v a r i a b l y impact on the study. I cannot say what has a t t r a c t e d me to study t r e e s , e s p e c i a l l y spruces. In conducting t h i s research and w r i t i n g the t h e s i s three events oc c u r r e d which e f f e c t i v e l y l i m i t e d or c o l o u r e d the c o n c l u s i o n s that were drawn. As a r e s u l t of s t u d y i n g the consequences of sample s i z e on the r e s u l t s of m u l t i v a r i a t e a n a l y s e s , the number of a n a l y t i c approaches that c o u l d be used i n the study were reduced. Consequently, the p r e s e n t a t i o n of r e s u l t s i s not as parsimonious a summarization as I would have l i k e d . Furthermore, c e r t a i n i s s u e s which, at the o u t s e t , I had wanted to i n v e s t i g a t e , simply c o u l d not be addressed because of d e f i c i e n c y i n sample s i z e . I have t r i e d to i n d i c a t e where such l i m i t a t i o n s have occu r r e d . Second, the r e a l i z a t i o n of the a n a l y t i c and b i o l o g i c a l d e f i c i e n c y r e s u l t i n g from i g n o r i n g i n t r a - i n d i v i d u a l v a r i a t i o n i n the t r a d i t i o n a l approach to t h i s type of study, came too l a t e to be addressed e f f e c t i v e l y . T h i s r e a l i z a t i o n o c c u r r e d d u r i n g the r e f l e c t i v e process of measuring, long a f t e r I had thought data ' c o l l e c t i n g was f i n i s h e d . A quick f i e l d t r i p and some extremely f o r t u i t o u s c o l l e c t i o n s p r o v i d e d some data that proved c r i t i c a l i n p r e s e n t i n g i n s i g h t i n t o the nature of i n t r a - i n d i v i d u a l v a r i a t i o n . The f a i l u r e to c a p i t i l i z e on i n t r a - i n d i v i d u a l v a r i a t i o n as a source of i n f o r m a t i o n r e p r e s e n t s a source of d i s s a t i s f a c t i o n . I have endeavoured to i n d i c a t e a b e t t e r 2 design in sampling and a n a l y i s which would e f f e c t i v e l y i n c o r p o r a t e such i n t r a - i n d i v i d u a l i n f o r m a t i o n in f u t u r e s t u d i e s . The t h i r d event, the one that I am most b i t t e r about, concerns my changing p e r c e p t i o n of the r e l a t i o n of f o r e s t g e n e t i c s to f o r e s t r y and f o r e s t b i o l o g y . In the l a s t few weeks of w r i t i n g the t h e s i s I attended a conference on f o r e s t g e n e t i c s . These meetings were pervaded by a concern f o r the c o n t i n u a t i o n of l e g i s l a t i v e and a d m i n i s t r a t i v e programmes that met p o l i t i c a l and i n d u s t r i a l commitments ra t h e r than s c i e n t i f i c p r i n c i p l e s or the b i o l o g y of the organisms being s t u d i e d . There were few i n s t a n c e s where there was any r e c o g n i t i o n of the problems, s i t u a t i o n s , and o p e r a t i o n a l c o n d i t i o n s under which f o r e s t e r s work and f o r e s t r y i s conducted. It i s as an a n t i t h e s i s to t h i s p e r c e i v e d d i s i n t e r e s t that I o f f e r the e p i l o g u e . For any r e s e a r c h to be of v a l u e , the r e s u l t s and recommendations must be communicated to p o t e n t i a l u s e r s ; otherwise, the r e s e a r c h i s a t o t a l l o s s (Young 1972; S e c r e t a r i a t on F o r e s t r y Research Development 1984). 3 I. INTRODUCTION. Picea A. D i e t , i s a genus of widely d i s t r i b u t e d northern hemisphere c o n i f e r o u s t r e e s that i n c l u d e s between 35 and 40 s p e c i e s that have been v a r i o u s l y grouped i n t o s e v e r a l informal s u p r a s p e c i f i c taxa (Flous 1936; Wright 1955; Gaussen 1966; Bobrov 1971, 1973; Schmidt-Vogt 1977). Most of these species occur at montane and subalpine e l e v a t i o n s . I t i s an a n c i e n t genus d a t i n g from l a t e Cretaceous times in A s i a ( F l o r i n 1963). Species i n the genus have been d i s t i n g u i s h e d t r a d i t i o n a l l y on the b a s i s of three m o r p h o l o g i c a l t r a i t s : nature of the cone s c a l e - s t i f f or f l exuous; needle shape - rhomboid or f l a t t e n e d ; and the presence or absence of pubescence on twigs. A l l p o s s i b l e combinations of these t r a i t s can be used to d e f i n e only nine taxa. Other f e a t u r e s used to d i s t i n g u i s h taxa are cone s i z e , crown form, and geographic or edaphic h a b i t . E v a l u a t i o n of more morphological and anatomical v a r i a b l e s (Wright 1955; C o l l e a u 1968; Sudo 1968) as w e l l as chemical v a r i a b l e s (Wellendorf and Kaufmann 1977; Wellendorf and Simonsen 1979; see review in La Roi and Dugle 1968) have been u t i l i z e d , and these tend to support the r e c o g n i t i o n of s p e c i e s on the b a s i s of the t r a d i t i o n a l v a r i a b l e s . Chromosomal v a r i a t i o n and DNA content vary l i t t l e between the v a r i o u s s p e c i e s (Pravdin, e_t a_l. 1976; Moir and Fox 1977; Burley 1965c; P r i c e , et a l . 1973). E v a l u a t i o n of other v a r i a b l e s i n p a r t i c u l a r groups of s p e c i e s have f u r t h e r s u b s t a n t i a t e d the d i s t i n c t n e s s of taxa and have c l a r i f i e d r e l a t i o n s h i p s i n the genus (Duman 1957; Daubenmire 1968, 1972, 1974; Garman 1957; Marco 1931, 1939; von R u d l o f f 4 1975; T a y l o r and P a t t e r s o n 1980; La Roi and Dugle 1968; Lee and S i h - k i n 1966). As w e l l as attempts to understand r e l a t i o n s h i p s based on these v a r i a b l e s , a l a r g e number of c o n t r o l l e d c r o s s e s between s p e c i e s have been performed (Johnson 1939; Wright 1955; Gordon 1976b, 1978, 1980, 1982; Fowler, et a l . 1980, 1982; Mikkola 1969). Bongarten and Hanover (1982) and Santamour (1967) however, have c a l l e d . a t t e n t i o n to some inadequacies i n the e a r l i e r work on c o n t r o l l e d c r o s s e s owing to the inadequate i s o l a t i o n and i d e n t i f i c a t i o n of parents as w e l l as the small number of parent t r e e s used i n these c r o s s e s . Two groups i n the genus have been su b j e c t e d to i n t e n s i v e systematic i n v e s t i g a t i o n : the P_j_ abies - P_j_ obovata complex i n Europe (Schmidt-Vogt 1977; P r a v d i n , et a l . 1976; L i n d q u i s t 1948; Andersson 1965), and the P^ glauca complex ("Glaucoides", Fowler 1983) of North America. Such i n t e n s i v e r e s e a r c h has been conducted because of the importance of some of these s p e c i e s to f o r e s t r y . I n v e s t i g a t i o n of the the P^ glauca complex has focused on the d i v e r s i t y shown by the s p e c i e s i n western North America: P_j_ s i t c h e n s i s (Bong.) C a r r . ; P\_ glauca (Moench.) Voss; P. engelmanni i Parry ex Engelm. (= P_;_ glauca ssp. engelmanni i (Parry ex Engelm.) T a y l o r ) P^ pungens Engelm.; and, P^ mexicana Martinez (= P_;_ engelmanni i ssp. mexicana (Martinez) T a y l o r and P a t t e r s o n ) . The v a r i o u s taxa of the P_;_ glauca complex are separated from each other p r i m a r i l y on the three morphological c r i t e r i a t r a d i t i o n a l l y used to d i s t i n g u i s h the other s p e c i e s of the genus. P_;_ s i t c h e n s i s i s the only s p e c i e s i n the complex with f l a t t e n e d l e a v e s , P^ engelmannii and P_J_ mexicana are the only s p e c i e s i n the complex with pubescent branches, and 5 P. glauca i s the only s p e c i e s i n the complex with s t i f f cone s c a l e s . The most a n c i e n t f o s s i l s from western North America r e f e r a b l e to P i c e a are of Miocene age ( F l o r i n 1963) and resemble the extant E\ chihuahuana Martinez (Gordon 1968) of the S i e r r a Madre O c c i d e n t a l e of Mexico and P^ breweriana S. Wats..of the Klamath region of Oregon and C a l i f o r n i a . T e r t i a r y and more recent m a c r o f o s s i l s and m i c r o f o s s i l s of P i c e a are widely s c a t t e r e d i n western North America (Crabtree 1983) . These f i n d i n g s suggest the e x i s t e n c e of three major groups of P i c e a i n North America d a t i n g from the l a t e T e r t i a r y to the present.: the P. breweriana - P^ chihuahuana l i n e a g e , the remnants of a more widely d i s t r i b u t e d temperate and montane e l e v a t i o n f o r e s t i n western North America; the P^ mariana - P^ rubens l i n e a g e of a r c t o - b o r e a l l a t i t u d e s i n eastern North America and, the P. glauca complex, widespread at a r c t o - b o r e a l l a t u t u d e s . These three groups are g e n e r a l l y c o n s i d e r e d to have migrated s e p a r a t e l y from A s i a ( T a y l o r and P a t t e r s o n 1980), the P^ glauca complex being the most recent migrant i n the l a t e Cretaceous or e a r l y T e r t i a r y . The r e l a t i o n s h i p s among these three groups of spruces remain obscure as does the r e l a t i o n to f o s s i l s from a l a t e T e r t i a r y P i c e a from the southeastern United S t a t e s ( C r i t c h f i e l d 1984). The s i m i l a r i t y of extant forms of the P^ glauca and P. a b i e s complex to the Miocene P_^  banksi i of a r c t i c North America ( H i l l s and O g i l v i e 1970) lends weight to H u s t i c h ' s (1953) hypothesis concerning a common d e r i v a t i o n of the P^ a b i e s 6 and glauca complexes. O g i l v i e (1972) contends that the extant s p e c i e s of the glauca complex were a l l d i f f e r e n t i a t e d by the P l e i s t o c e n e and that the h y b r i d i z a t i o n , so c h a r a c t e r i s t i c of t h i s l i n e a g e (Wright 1955; Bobrov 1972, 1973), has been a p o s t - g l a c i a l phenomenon (see a l s o C r i t c h f i e l d 1984). Crabtree (1984) c i t i n g La Motte's (1939) c o l l e c t i o n s , suggests that P. s i t c h e n s i s may have been d i f f e r e n t i a t e d much e a r l i e r during the Oligocene. P_;_ engelmanni i appears to have been d i f f e r e n t i a t e d by the m i d - T e r t i a r y f o l l o w i n g mountain b u i l d i n g ( T a y l o r and P a t t e r s o n 1980). Wright (1955) suggests that d i f f e r e n t i a t i o n of these s p e c i e s was by geographic i s o l a t i o n r a t h e r than by the e v o l u t i o n of breeding b a r r i e r s or through strong m o r p h o l o g i c a l d i f f e r e n t i a t i o n . La Roi and Dugle (1968) counter Wright's (1955) comments, and suggest i n s t e a d that Picea has been s u b j e c t e d to l i b e r a l taxonomy ra t h e r than to c o n s e r v a t i v e e v o l u t i o n . Research on the systematics of the taxa i n the western area of the P^ glauca complex reached a h i a t u s d u r i n g 1968 with the c o i n c i d e n t p u b l i c a t i o n of the work of Daubenmire, La Roi and Dugle, and O g i l v i e and von R u d l o f f f o l l o w e d in 1969 by Roche's work. T h i s abundance of r e s e a r c h was an e l a b o r a t i o n on the e a r l i e r work of T a y l o r (1959), Garman (1957), and Horton (1959). More recent r e s e a r c h has been conducted. T h i s recent work has emphasized the r e l a t i o n s of P^ glauca and P_j_ engelmanni i . A l a t e n t assumption of t h i s work i s the r e c o g n i t i o n of P. s i t c h e n s i s as a d i s t i n c t s p e c i e s i n the Pj_ glauca complex. Indeed, t h i s assumption continues a t r a d i t i o n of r e c o g n i z i n g P. s i t c h e n s i s as a d i s t i n c t s p e c i e s i n the genus based on i t s 7 f l a t t e n e d leaves and i t s occurrence at low e l e v a t i o n s . Where hy b r i d s have been observed with e i t h e r P_;_ glauca (Copes and Beckwith 1977; Hanover and W i l k i n s o n 1970; Roche 1969; Daubenmire 1968) or P_^  enqelmanni i ( K l i n k a , e_t a_l. 1982) they have been regarded as a l o c a l phenomenon that does not i n f l u e n c e the v a l i d i t y of the assumed d i s c r e t e n e s s of s i t c h e n s i s from the r e s t of the E\ glauca complex. T h i s p o s i t i o n i s held i n s p i t e of Roche's (1969) o b s e r v a t i o n s concerning the c l i n a l v a r i a t i o n between P^ s i t c h e n s i s and P_;_ enqelmanni i . T h i s presumed d i s c r e t e n e s s of P^ s i t c h e n s i s from the r e s t of the P\_ glauca complex has r e s u l t e d i n i n v e s t i q a t i o n s of p a t t e r n s of v a r i a t i o n w i t h i n P^ s i t c h e n s i s that have g e n e r a l l y proceeded independent of any c o n s i d e r a t i o n f o r other s p e c i e s in the P^ glauca complex. Where other s p e c i e s of the P_;_ glauca complex have been c o n s i d e r e d , they are i d e n t i f i e d merely as a source of comparison ( P o l l a r d , et a l . 1976; von Ru d l o f f 1975). By c o n t r a s t , P_;_ engelmanni i i s g e n e r a l l y f e l t to be subsumed e n t i r e l y i n the v a r i a t i o n demonstrated f o r P^ glauca (Taylor 1959; Hanover and Wilkinson 1970); La Roi and Dugle 1968; Daubenmire 1974; O g i l v i e and von Ru d l o f f 1968; Roche 1969). The nomenclatural conventions remain to be r e s o l v e d : continued r e c o g n i t i o n of P_;_ engelmanni i as a s p e c i e s (Daubenmire 1974; La Roi and Dugle 1968); subsumed as a subspecies of E\ glauca (Taylor 1959; O g i l v i e and von R u d l o f f 1968); or reduced to v a r i e t a l s t a t u s (Hustich 1953; Love and Love 1966). The presumed lack of d i s c r e t e n e s s between P^ engelmannii and P. glauca has been adopted i n f o r e s t r y a p p l i c a t i o n s i n B r i t i s h Columbia where the complex i s r e f e r r e d to as simply " I n t e r i o r 8 spruce" ( K i s s 1976). Contrary to the assumption that s i t c h e n s i s i s d i s c r e t e in the glauca complex are the remarks c i t e d by Garman (1957) that suggest that E\ engelmanni i be c o n s i d e r e d more c l o s e l y r e l a t e d to P^ s i t c h e n s i s than to P_j_ glauca• F r a n k l i n (1961), on the b a s i s of s e e d l i n g morphology, c o r r o b o r a t e s t h i s impression (see however J e f f e r s 1974). A l t e r n a t i v e l y , Moir and Fox (1977) suggest a s i m i l a r i t y of P\_ glauca to P_;_ s i t c h e n s i s on the b a s i s of the presence of a/3-chromosome complement 1. Observations made in c o n j u n c t i o n with work a s s o c i a t e d with that r e p o r t e d i n K l i n k a , et a l . (1982) and other o b s e r v a t i o n s i n areas of the coast mainland of southwestern B r i t i s h Columbia suggested that h y b r i d i z a t i o n of P_j_ s i t c h e n s i s with P. engelmanni i may not have been as l o c a l a phenomenon as p r e v i o u s l y suggested. Although Garman (1957) c a l l e d f o r s p e c i a l a t t e n t i o n to c o l l e c t i n g m a t e r i a l s of P_^  s i t c h e n s i s and P. engelmanni i 2 from t h i s area, the i s o l a t i o n of the area has g e n e r a l l y prevented e x t e n s i v e c o l l e c t i o n (Daubenmire 1968; Falkenhagen and Nash 1978; Roche 1969; others i n Ching and S z i k l a i 1978b). An i n v e s t i g a t i o n of the v a r i a t i o n of P. s i t c h e n s i s and P_^  engelmanni i i n t h i s p a r t i c u l a r area would seem to be necessary to b e t t e r c i r c u m s c r i b e the range of v a r i a t i o n i n the Pj_ glauca complex. The study presented here 1 Guyla K i s s , B r i t i s h Columbia M i n i s t r y of F o r e s t s , Vernon confirms the o b s e r v a t i o n s of Moir and Fox (1977) and o f f e r s the o b s e r v a t i o n t h a t P_;_ engelmannii l a c k s a (b-chromosome complement. 2 For the sake of b r e v i t y , P^ s i t c h e n s i s and P^ engelmannii w i l l be r e f e r r e d to c o l l e c t i v e l y as P i c e a unless otherwise noted. 9 addresses t h i s i s s u e of v a r i a t i o n of P i c e a . C o n c e p t u a l l y , such a study i n v o l v e s examining and e x p l a i n i n g the v a r i a t i o n i n the t r e e s of the two hypothesized taxa. A n a l y t i c a l l y , such r e s e a r c h i s c a r r i e d out by d e s c r i b i n g and c o r r e l a t i n g p a t t e r n s of v a r i a t i o n at v a r i o u s s c a l e s . There are two s c a l e s of v a r i a t i o n : i n t r a - and i n t e r - i n d i v i d u a l v a r i a t i o n . E f f e c t i v e d e s c r i p t i o n of i n t e r - i n d i v i d u a l v a r i a t i o n must be based on an estimate of i n t r a - i n d i v i d u a l v a r i a t i o n . E x p l a n a t i o n s f o r i n t r a - i n d i v i d u a l v a r i a t i o n i n c o n i f e r s have not commonly been proposed. Where they have been tendered they have been r e l a t e d to the environment, although developmental c o n s i d e r a t i o n s have been made f o r c e r t a i n c o n i f e r s . A n a l y t i c a t t e n t i o n to i n t r a - i n d i v i d u a l v a r i a t i o n has not been c o n s i d e r e d g e n e r a l l y i n c o n i f e r s . Where a n a l y t i c consideration- -has been made i t p r o v i d e s a convenient s c a l e a g a i n s t which i n t e r - i n d i v i d u a l v a r i a t i o n can be compared. A developmental view of i n t r a - i n d i v i d u a l v a r i a t i o n p o t e n t i a l l y o f f e r s f u r t h e r e x p l a n a t i o n s concerning the nature of i n t e r - i n d i v i d u a l v a r i a t i o n i n a d d i t i o n to the r e s u l t s of numerical comparisons. A p l e t h o r a of s p e c i f i c e x p l a n a t i o n s f o r emergent p a t t e r n s of i n t e r - i n d i v i d u a l v a r i a t i o n c o u l d be tendered, but they f a l l under two gen e r a l p r o c e s s e s : h y b r i d i z a t i o n and d i f f e r e n t i a t i o n . N e ither hypothesized process need be mutually e x c l u s i v e . If h y b r i d i z a t i o n c o n s t i t u t e s a v a l i d e x p l a n a t i o n , then the present study w i l l add to our knowledge concerning t h i s p rocess and i t s e v o l u t i o n a r y consequences i n Pi c e a (Wright 1955; Bobrov 1972, 10 1973). If d i f f e r e n t i a t i o n seems a p l a u s i b l e h y p o t h e s i s , then the r e s u l t s of such a study may address e c o l o g i c a l and e v o l u t i o n a r y c o n s i d e r a t i o n s i n P i c e a . The e s s e n t i a l c o n t r a s t and g e n e r a l i z a t i o n s are: s i n g l e s p e c i e s d i f f e r e n t i a t i o n versus two, or more, s p e c i e s merging. Owing to the geographic s c a l e upon which t h i s study i s conducted and, that i n s e x u a l l y reproducing organisms every i n d i v i d u a l i s to some degree unique, one cannot present s p e c i f i c e x p l a n a t i o n s f o r r e l a t i o n s h i p s with respect to immediate parentage and s e l e c t i o n . Only more d i s t a n t a n c e s t r y and l a r g e r s c a l e s e l e c t i o n can be c o n s i d e r e d . Such p a r e n t a g e - s p e c i f i c e x p l a n a t i o n s would r e q u i r e d e t a i l e d sampling and c o n t r o l l e d c r o s s e s - labour i n t e n s i v e procedures that are c o u n t e r - p r o d u c t i v e i n examing the general v a r i a t i o n over such a l a r g e geographic area. Independent p a t t e r n s of v a r i a t i o n have been observed and d e s c r i b e d p r e v i o u s l y i n both taxa f o r s e v e r a l s c a l e s of v a r i a t i o n based on s e v e r a l types of v a r i a b l e s . Over the geographic range of the s p e c i e s s e v e r a l p a t t e r n s have been observed: d i s c o n t i n u o u s v a r i a t i o n (Falkenhagen 1974; Daubenmire 1968; Burley 1965a, 1966c; F o r r e s t I975b,c, 1980b; Mikshe 1971; P o l l a r d , e_t a_l. 1976; Moir and Fox 1977); c l i n a l v a r i a t i o n ( P o l l a r d , et a l . 1976; Burley 1966b,c; O ' D r i s c o l l 1976a; Falkenhagen 1977, 1978; I l l i n g w o r t h 1976; Mergen and T h i e l g e s 1967; El-Kassaby and McLean 1983; Daubenmire 1968); d e v i a t i o n s from c l i n a l v a r i a t i o n (Moir and Fox 1977; F o r r e s t 1980b; Lewis and L i n e s 1976; Daubenmire 1968; Burley 1965b, 1966b; C a n n e l l 11 and W i l l e t t 1975; Falkenhagen 1978; P o l l a r d , et a l . 1975; Hanover and W i l k i n s o n 1970); u n i f o r m i t y (Yen and El-Kassaby 1980; Falkenhagen 1976; Hanover and Wilkinson 1970; Burley 1966a,c; F o r r e s t 1980b). Other o b s e r v a t i o n on v a r i a t i o n are re p o r t e d i n Burley (1966a), H a r r i s (1978); and others i n Ching and S z i k l a i (1978b) and O ' D r i s c o l l (1976b).. E x p l a n a t i o n s f o r these p a t t e r n s invoke s e v e r a l causes: g l a c i a l refugium; m i g r a t i o n ; s e l e c t i o n ; d i f f e r e n t i a t i o n ; h y b r i d i z a t i o n ; i s o l a t i o n and d r i f t ; and, e v o l u t i o n a r y b o t t l e n e c k s . The major source of v a r i a t i o n i n Pj_ s i t c h e n s i s i s c o r r e l a t e d with l a t i t u d e , whereas i n P^ engelmanni i i t i s c o r r e l a t e d with e l e v a t i o n . Most of the e x p l a n a t i o n s f o r the observed p a t t e r n s have been tendered under the assumed v a l i d i t y that n a t u r a l s e l e c t i o n i s the p r i n c i p a l o p e r a t i v e process and the t h e o r e t i c a l e x p e c t a t i o n s taken from the presumed d i s t r i b u t i o n and occurrence of the two s p e c i e s , (Fowells 1965; Hosie 1975; K r a j i n a , et a l 1982; G r i f f i n and C r i t c h f i e l d 1976; L i t t l e 1971). The occurrence of P i c e a i n the study area i s f a r more sporadic than the c o n t i n u i t y suggested by the maps i n these p u b l i c a t i o n s ( K l i n k a , et a_l. 1982). Assumptions need to be r e c o n s i d e r e d when based on the presumption that l a r g e i n t e r - b r e e d i n g p o p u l a t i o n s are continuuous. On a l o c a l s c a l e where o b s e r v a t i o n s have been repo r t e d concerning the nature of p o p u l a t i o n v a r i a t i o n i n these taxa, the l a r g e s t source of v a r i a t i o n i s i n v a r i a b l y c o n t a i n e d w i t h i n the p o p u l a t i o n s . These s t u d i e s of p o p u l a t i o n s have been based on s e e d l i n g p o p u l a t i o n s r a t h e r than mature i n d i v i d u a l s , as have 12 most others s t u d i e s on c o n i f e r s (Falkenhagen 1974). The observed high i n t r a - p o p u l a t i o n v a r i a t i o n i s c o n s i s t a n t with o b s e r v a t i o n s reported f o r the m a j o r i t y of other c o n i f e r o u s s p e c i e s . E x p l a n a t i o n s f o r high i n t r a - p o p u l a t i o n v a r i a t i o n i n P i c e a , as w e l l as other c o n i f e r genera have not been tendered. Furthermore, s p e c i f i c l o c a l e x p l a n a t i o n s cannot be presented here owing to a concern f o r c i r c u m s c r i b i n g the general v a r i a t i o n of P i c e a - however i t may be p o s s i b l e to provide an estimate of the magnitude of i n t r a - p o p u l a t i o n v a r i a t i o n compared to i n t e r - p o p u l a t i o n v a r i a t i o n . S t u d i e s of the v a r i a t i o n serve an economic as w e l l as a systematic purpose. Both s p e c i e s are landscape dominants in v a r i o u s p a r t s of t h e i r range and are important commercial t r e e s p e c i e s . Furthermore, they are p o t e n t i a l l y v a l u a b l e i n r e f o r e s t a t i o n programmes as both s p e c i e s occur as primary s u c c e s s i o n a l s p e c i e s . P_;_ engelmannii i s p a r t i c u l a r y important in r e f o r e s t a t i o n i n the c e n t r a l i n t e r i o r of B r i t i s h Columbia. A d d i t i o n a l l y , both s p e c i e s are used as e x o t i c s i n European r e f o r e s t a t i o n and a f o r e s t a t i o n . I t i s worth n o t i n g that the l a t i t u d e s of t h i s study in southwestern B r i t i s h Columbia are comparable to those of southern B r i t a i n , and that o b s e r v a t i o n s made i n the present study may prove to have relevance to f o r e s t r y i n that part of B r i t a i n . The s i g n i f i c a n c e of P. s i t c h e n s i s to f o r e s t r y has been r e a l i z e d s i n c e i t i s the most widely p l a n t e d commercial s p e c i e s i n B r i t a i n (Pearce 1976). Hybrids between F\_ s i t c h e n s i s and P_j_ glauca are a l s o of i n t e r e s t (Faulkner 1982). D i e t r i c h s o n (1971) suggests that more c o n s i d e r a t i o n be given to P_;_ engelmannii in Norway. Vario u s 13 provenances of engelmanni i a l s o may prove u s e f u l as an e x o t i c in some p l a c e s i n western North America 1 (Shepperd, et a l . 1981). A l t e r n a t i v e e x p l a n a t i o n s f o r s p e c i e s d i f f e r e n t i a t i o n or coalescence may have i m p l i c a t i o n s f o r f o r e s t r y r e l a t i n g to the f e a s a b i l i t y of p r o d u c t i o n and use of " i n t e r - s p e c i f i c " c r o s s e s . Owing to the economic importance of these s p e c i e s , f u r t h e r i n f o r m a t i o n p e r t a i n i n g to the occurrence and ecology of the taxa can be found i n v a r i o u s b i b l i o g r a p h i e s ( K r a j i n a 1969; Fowler and Roche 1977; Roche and Folwer 1975; C h r i s t e n s e n and Hunt 1965; Phelps 1973; H a r r i s and Ruth 1970; Dobbs 1972; K r a j i n a , et a l . 1982). Where r e l e v a n t , s p e c i f i c c o n c l u s i o n s from t h i s corpus of l i t e r a t u r e have been d e t a i l e d i n the succeeding c h a p t e r s . A d d i t i o n a l l y , s p e c i f i c o b s e r v a t i o n s are a l s o given from more recent l i t e r a t u r e and f u r t h e r d i s c u s s i o n i s p r o v i d e d of the conceptual and a n a l y t i c framework. In summary, the present study i s concerned with the nature of v a r i a t i o n i n n a t u r a l l y o c c u r r i n g i n d i v i d u a l s of P. engelmanni i and P_^  s i t c h e n s i s i n a p o r t i o n of the range of these s p e c i e s that has not been d e s c r i b e d p r e v i o u s l y . The hypothesis being t e s t e d i s that there are two taxa: P. s i t c h e n s i s and P^ engelmani i . The i n f e r e n c e d e r i v e d i s : i f t h i s h y p o t h e s i s i s a p p r o p r i a t e then an examination of t r e e s from areas not sampled p r e v i o u s l y w i l l c o ntinue to support the r e c o g n i t i o n of two taxa. Such a study seeks to uncover and 1 Helmar Hahn, B r i t i s h Columbia M i n i s t r y of F o r e s t s ,Vancouver F o r e s t Region, pers. comm. 1 4 d e s c r i b e p a t t e r n s of i n t e r - i n d i v i d u a l v a r i a t i o n at v a r i o u s geographic s c a l e s and o f f e r e x p l a n a t i o n s f o r the p a t t e r n s d e s c r i b e d . To assess i n t e r - i n d i v i d u a l v a r i a t i o n , conceptual and a n a l y t i c a t t e n t i o n must be given to aspects of i n t r a - i n d i v i d u a l v a r i a t i o n . The primary q u e s t i o n being addressed i s whether v a r i a t i o n i s a consequence of the h y b r i d i z a t i o n and subsequent i n t r o g r e s s i o n and d i f f e r e n t i a t i o n of the two taxa, or simply the consequence of the d i f f e r e n t i a t i o n of a s i n g l e polymorphic taxon. The secondary concern i s to present p o s s i b l e e x p l a n a t i o n s f o r these p a t t e r n s of d i f f e r e n t i a t i o n . 15 I I . MATERIALS AND METHODS. 1. I n t r o d u c t i o n . The phenomena r e q u i r i n g e x p l a n a t i o n are v a r i o u s aspects of phenotypic v a r i a t i o n of P i c e a i n southwestern B r i t i s h Columbia. The i d e n t i f i c a t i o n of a given phenomenon re p r e s e n t s a major step towards proposing an e x p l a n a t i o n f o r that phenomenon. Q u a n t i f i c a t i o n and subsequent d e s c r i p t i o n of that phenomenon and the c o n d i t i o n s under which i t i s manifest are r e q u i r e d p r i o r to te n d e r i n g e x p l a n a t i o n s . However, the very a ct of q u a n t i f i c a t i o n focuses a t t e n t i o n on only a p o r t i o n of the p o t e n t i a l information a v a i l a b l e about the s p e c i f i c , phenomenon and the c o n d i t i o n s surrouding i t s occurrence; i n t h i s case, the c h a r a c t e r i s t i c s of an organism. Since, q u a n t i f i c a t i o n i s an estimate of the phenomenon, e x p l a n a t i o n s must be tendered that r e s p e c t the b i a s inherent i n these e s t i m a t e s . T h i s amounts to c a r e f u l l y c o n s i d e r i n g the nature of these c h a r a c t e r s , the nature of sampling, and how the measurement e r r o r a s s o c i a t e d with q u a n t i f y i n g c h a r a c t e r s can be minimized during a n a l y s i s so that e x p l a n a t i o n s are not emburdened by an o b s e r v a t i o n a l b i a s . As one can never d e s c r i b e an organism completely by i t s c h a r a c t e r s , so too i s i t impossible to measure a c h a r a c t e r completely. Indeed, there are probably an i n f i n i t e number of c h a r a c t e r s by which an organism can be d e s c r i b e d - so too are there an i n f i n i t e number of ways to measure a c h a r a c t e r . Measurements or d e s c r i p t i o n s are simply r u l e s used to a s s i g n a number to an o b j e c t (O'Grady 1982). I t i s important to r e a l i z e that c h a r a c t e r s are the m a n i f e s t a t i o n s of i n d i v i d u a l organisms 1 6 by which we d e s c r i b e , communicate, and draw i n f e r e n c e s about i n d i v i d u a l organisms. A c h a r a c t e r does not e x i s t as an independent m a n i f e s t a t i o n of an organism (Davis and Heywood 1973; O'Grady 1982). Although we see organisms, t h e i r p a r t s , and c h a r a c t e r s , i t i s s p e c i f i c v a r i a b l e s i n a l i m i t e d m u l t i v a r i a t e p e r s p e c t i v e that we a c t u a l l y measure. The d i s t i n c t i o n between c h a r a c t e r and v a r i a b l e serves the same e p i s t e m o l o g i c a l purpose as r e c o g n i z i n g the d i f f e r e n c e between p o p u l a t i o n and sample, or estimand and e s t i m a t o r . I t i s c r u c i a l here, as elsewhere, to acknowledge c l e a r l y the m e t h o d o l o g i c a l l y and c o n c e p t u a l l y c o n s t r a i n e d p r e c e p t i o n s of the world around us and how we b r i n g these p e r c e p t i o n s to bear on a s u b j e c t of study. Merely acknowledging the i n t u i t i v e usage of a fundamental concept, such as a c h a r a c t e r (Wiley 1981), does l i t t l e to a l l e v i a t e a m b i g u i t i e s that may a r i s e from such usage. Measuring v a r i a b l e s , c o l l e c t i n g samples, and determining sources of e r r o r a s s o c i a t e d with measuring and c o l l e c t i n g are i n e x t r i c a b l y i n t e r t w i n e d with the s e l e c t i o n of an a p p r o p r i a t e a n a l y t i c s y n t h e s i s . S e v e r a l aspects of sampling are unique to t r e e s , but the a n a l y s i s and conceptual framework used i s that a p p p l i e d i n any systematic i n v e s t i g a t i o n of a b i o l o g i c a l system. An a n a l y t i c technique w e l l s u i t e d to r e s o l v i n g a problem on t h e o r e t i c a l grounds may be inadequate or i n a p p r o p r i a t e with respect to r e s o l v i n g that problem f o r a given c o l l e c t i o n of samples and v a r i a b l e s . Understanding the nature of v a r i a b l e v a r i a t i o n and c o v a r i a t i o n , sampling l i m i t a t i o n s , and a s s o c i a t e d measurement e r r o r f o r a given set of data as w e l l as the caveats f o r a given a n a l y t i c p r o t o c o l allows one to s e l e c t an 1 v a p p r o p r i a t e a n a l y t i c methodology. To t h i s end c o n s i d e r a b l e e f f o r t was spent in d e f i n i n g v a r i a b l e s , sampling, and determining a s s o c i a t e d e r r o r so that an a p p r o p r i a t e a n a l y t i c method c o u l d be employed. In a d d i t i o n to e x p l i c i t l y r e c o g n i z i n g the p e r c e p t i v e c o n s t r a i n t s that are brought to bear on a s u b j e c t of study, i t i s e q u a l l y important to s t a t e c l e a r l y the nature of the i n f e r e n c e s to be drawn from such a study. S p e c i f i c a l l y , the c e n t r a l i n f e r e n c e to be drawn here i s t h a t , besides the e f f e c t of the environment, i n d i v i d u a l s that look a l i k e are assumed to share a l a r g e number of genes in common and are thus capable of i n t e r b r e e d i n g ( S o l b r i g 1968). 2. C h a r a c t e r s . Phenotypic v a r i a b l e s are regarded as an e x p r e s s i o n of g e n e t i c i n f o r m a t i o n and the i n t e r a c t i o n of that i n f o r m a t i o n with the i n t e r n a l environment and the immediate e x t e r n a l environment of the organism, and the surrounding environment. V a r i a b l e s that are more v a r i a b l e w i t h i n an i n d i v i d u a l ( i n t r a - i n d i v i d u a l ) than i n t e r - i n d i v i d u a l l y ( i n t e r - i n d i v i d u a l ) are regarded as being l e s s b u f f e r e d a g a i n s t the l o c a l environment than are those that are more v a r i a b l e between i n d i v i d u a l s . Both types of v a r i a b l e s are g e n e t i c , a l b e i t at d i f f e r e n t extremes of a continuum of the degree of b u f f e r i n g . A s s e s s i n g d i f f e r e n c e s between taxa i s , a n a l y t i c a l l y , a r e l a t i v i s t i c e x e r c i s e . There must be i n f o r m a t i o n about v a r i a t i o n w i t h i n a taxon ( i n t r a - s p e c i f i c ) as w e l l as between 18 taxa ( i n t e r - s p e c i f i c ) . T r a d i t i o n a l l y , i n d e f i n i n g taxa, v a r i a b l e s that have an inter-taxonomic v a r i a t i o n l a r g e r than intra-taxonomic v a r i a t i o n are p r e f e r r e d . However, one must contend with i n d i v i d u a l s , and, a n a l y t i c a l l y , v a r i a b l e v a r i a t i o n and c o - v a r i a t i o n expressed i n t r a - and i n t e r - i n d i v i d u a l l y . If v a r i a b l e s that have a higher i n t e r - i n d i v i d u a l than i n t r a - i n d i v i d u a l v a r i a t i o n are more v a r i a b l e between hypothesized taxa, and these v a r i a b l e s are i n t e r - c o r r e l a t e d i n t h e i r v a r i a t i o n , then, and only then, can an i n f e r e n c e be made concerning taxonomic r e l a t i o n s h i p s (Davis and Heywood 1973). Davis (1983) p r o v i d e s f u r t h e r i n f o r m a t i o n with r e s p e c t to t h i s view and g i v e s an example. S i m i l a r l y , Newhan and Jancey (1983) pr o v i d e an example with respect to p o p u l a t i o n d i f f e r e n t i a t i o n . 2.1 V a r i a b l e s s e l e c t e d . The c e n t r a l aspect of t h i s study i s to p r o v i d e a q u a n t i f i c a t i o n of phenotypic v a r i a t i o n of Picea i n southwestern B r i t i s h Columbia. S p e c i f i c a l l y , i n t e r e s t i s i n d i s t i n g u i s h i n g between i n d i v i d u a l t r e e s . As the o b j e c t i v e i s to understand the r e l a t i o n s h i p s of i n d i v i d u a l t r e e s and a c h a r a c t e r i s the product of the n e c e s s i t y to d e s c r i b e and communicate i n f o r m a t i o n about a p a r t i c u l a r phenomenon, out of an i n f i n i t e number of c h a r a c t e r s by which i t i s p o s s i b l e to d e s c r i b e a given i n d i v i d u a l , only c e r t a i n of these c h a r a c t e r s may be of v a l u e . The c h a r a c t e r s s e l e c t e d f o r t h i s study had to c i r c u m s c r i b e the g e n e r a l form of p a r t s of the organism. The v a r i a b l e s s e l e c t e d had to meet two c r i t e r i a . F i r s t , the accuracy and 19 p r e c i s i o n (Cochran 1977) of the measurement of these v a r i a b l e s was assessed and only those v a r i a b l e s with a high degree of measurement r e p e a t a b i l i t y (= "measurement e r r o r " ) were s e l e c t e d . Second, as i n t e r e s t was i n i n t e r - i n d i v i d u a l v a r i a t i o n , only those v a r i a b l e s d i s p l a y i n g g r e a t e r i n t e r - i n d i v i d u a l than i n t r a - i n d i v i d u a l v a r i a t i o n were used. The c h a r a c t e r s used in t h i s study are morphological and anatomical. M o r p h o l o g i c a l c h a r a c t e r s r e f e r to the e x t e r n a l form of a s t r u c t u r e (e.g. l e a f l e n g t h ) . Anatomical c h a r a c t e r s d e f i n e the i n t e r n a l form of a s t r u c t u r e (e.g. number of endodermal c e l l s i n c r o s s - s e c t i o n ) . The c h a r a c t e r s s e l e c t e d can be regarded as a sample of the genome of the p l a n t . Developmentally, the more c h a r a c t e r s s e l e c t e d from more p o r t i o n s of an i n d i v i d u a l , the b e t t e r the r e p r e s e n t a t i o n of the genome. The s e l e c t i o n c r i t e r i a adopted are fundamentally those adopted by other workers when d e a l i n g with other morphological and chemical v a r i a b l e s . Some workers would a t t a c h more s p e c i f i c g e n e t i c i n t e r p r e t a t i o n s to c e r t a i n of these v a r i a b l e s than o t h e r s , depending upon the o b j e c t i v e s and t h e o r e t i c a l p r e d i s p o s i t i o n of the r e s e a r c h e r . To p r o v i d e a general d e s c r i p t i o n of a l a r g e , a r c h i t e c t u r a l l y complex organism, c h a r a c t e r s were s e l e c t e d that represent the r e p r o d u c t i v e and v e g e t a t i v e p o r t i o n s of the organism. Owing to the s i z e of the organism, v e g e t a t i v e and r e p r o d u c t i v e c h a r a c t e r s c o u l d not be examined from the same p o r t i o n of the canopy. S i m i l a r y the p r e p a r a t o r y techniques employed d i d not allow f o r a one-to-one correspondence to be 20 made between c e r t a i n v e g e t a t i v e v a r i a b l e s . C h a r a c t e r s are grouped together i n "c h a r a c t e r s u i t e s " as there e x i s t s a one-to-one developmental correspondence between the c h a r a c t e r s f o r any given sample. Developmentally, a one-to-one correspondence does not e x i s t between i n d i v i d u a l samples from d i f f e r e n t c h a r a c t e r s u i t e s . For example, although c h a r a c t e r s of cones, cone s c a l e s and b r a c t s , twig morphology, twig anatomy, needle morphology, and needle anatomy a l l c o u l d be examined f o r each i n d i v i d u a l t r e e , they are measured as v a r i a b l e s on separate p a r t s of the same t r e e . Thus one cannot analyze f o r v a r i a b l e i n t e r - c o r r e l a t i o n s between s u i t e s of v a r i a b l e s except as i t a p p l i e s to mean values c a l c u l a t e d f o r these c h a r a c t e r s f o r separate t r e e s . C o r r e l a t i o n between, say, aspects of needle morphology and cones w i t h i n the canopy of a s i n g l e t r e e are a n a l y t i c a l l y p o s s i b l e , but are not meaningful i n a developmental sense. The i n i t i a l s e l e c t i o n of a c h a r a c t e r and d e s c r i p t i o n of v a r i a b l e s was based upon p r e v i o u s work on Pi c e a (see Table 1; Facey 1956; Jansson and Bornmann 1981; Duman 1957; de Laubenfels 1953; Dalgas 1973; J e f f r e e , et a l . 1971; Gordon 1976a; Parker, et a l . 1983; Martinez 1961 i n T a y l o r and P a t t e r s o n 1980; C o l l e a u 1968; Stover 1944) and other c o n i f e r s ( F u l l i n g 1934; Car l s o n and Blake 1969) and examination i n the f i e l d and herbarium (UBC, V, WS; acronyms a c c o r d i n g to Holmgren and Keuken 1974) of many samples. Cone s c a l e p h y l l o t a x i s (Daubenmire, 1968) was not used because of the high e r r o r a s s o c i a t e d with measuring t h i s v a r i a b l e (see a l s o C a n n e l l and Bowler 1978). T a b l e 1 . C h a r a c t e r s u s e d i n p r e v i o u s s t u d i e s . R a t i o v a r i a b l e s e x c l u d e d . S t u d i e s : 1 - D a u b e n m i r e 1 9 6 8 : 2 - D a u b e n m i r e 1 9 7 2 : 3 -D a u b e n m i r e 1 9 7 4 ; 4 - F a l k e n h a g e n a n d N a s h 1 9 7 8 : 5 - F u n s c h 1 9 7 5 : 6 -G a r m a n 1 9 5 7 : 7 - H o r t o n 1 9 5 9 : 8 - K h a l i 1 1 9 7 4 : 9 - K l i n k a , e t a±. 1 9 8 2 : 1 0 - L a R o i a n d D u g l e 1 9 6 8 : 1 1 - M i t t o n a n d A n d a l o r a 1 9 8 1 ; 1 2 -O g i l v i e a n d v o n R u d l o f f 1 9 6 8 ; 1 3 - P a r k e r a n d M c l a c h l a n 1 9 7 8 : 1 4 -R e e d a n d F r e y t a g 1 9 4 9 ; 1 5 - R o c h e 1 9 6 9 ; 1 6 - S t r o n g 1 9 7 8 : 1 7 - T a y l o r a n d P a t t e r s o n 1 9 8 0 : 1 8 - T a y l o r . e _ t a± . 1 9 7 5 : 19 - T a y l o r 1 9 5 9 . V A R I A B L E S C O N E S I Z E . l a r g e s t c o n e l e n g t h m e d i a n c o n e l e n g t h m e d i a n c o n e w i d t h m e a n c o n e l e n g t h m e a n c o n e w i d t h c o n e t e x t u r e c o n e a p e x s h a p e c o n e w e i g t n C O N E S C A L E M E A S U R E M E N T S . s c a l e p h y 1 1 o t a * y s c a l e s h a p e s c a l e m a r g i n t h i c k n e s s s c a l e t e x t u r e s c a l e a p e x s h a p e s c a l e m a r g i n f o r m s e a l e l e n g t h s c a l e w i d t h s c a l e t a p e r s c a l e w i d t h 2 m m b e l o w a p e x f r e e s c a l e s e e d i m p r e s s i o n l e n g t h s e e d i m p r e s s i o n w i d t h B R A C T M E A S U R E M E N T S . b r a c t a p e x s h a p e b r a c t m a r g i n f o r m b r a c t l e n g t h b r a c t w i d t h b r a c t t a p e r S E E D M E A S U R E M E N T S , s e e d w i n g l e n g t h s e e d w i n g w i d t h s e e d l e n g t h s e e d w i d t h T W I G M E A S U R E M E N T S , b r a n c h d i a m e t e r s t e r t g m a t a p r o j e c t i o n s t e r i g m a t a a n g l e p u l v i n u s l e n g t h p u l v i n u s s h a p e p u b e s c e n c e t w i g c o l o u r B U D M E A S U R E M E N T S , b u d s c a l e l e n g t h b u d s c a l e w i d t h b u d s c a l e a p e x s h a p e b u d s c a l e m a r g i n f o r m b u d s c a l e f o r m L E A F M E A S U R E M E N T S , l e a f s h a r p n e s s l o n g e s t l e a f l e n g t h a v e r a g e l e a f l e n g t h s t o m a t a 1 1 l n e s < " d o r s t v e n t r a 1 l t y " 1 r e s i n s a c p o s 1 t i o n r e s i n s a c l e n g t h l e a f w e i g h t l e a f c o l o u r l e a f o r i e n t a t i o n l e a f o d o u r S T U D I E S 1 . 2 . 3 . 6 . 1 0 . 1 7 . 1 8 1 , 2 . 3 . 1 7 . 1 8 1 . 2 . 3 , 1 7 . 18 4 . 5 . 8 . 9 . 1 3 . 1 9 8 . 9 . 1 3 . 1 9 S . 10 6 . 1 0 8 1 . 2 . 3 1 0 1 3 ' 0 7 . 1 0 . 1 3 . 1 9 7 . 1 0 . 1 2 . 1 3 . 1 9 1 . 2 . 3 . 5 . G . 8 . 9 . 1 0 . 1 2 . I S . 1 6 . 1 7 . 1 8 1 . 2 . 3 . 5 , 6 . 8 , 9 . 1 0 . 1 2 , 1 5 , 1 6 . 1 7 , 1 8 2 . 7 . 9 . 1 2 . 1 3 . 1 6 15 2 . 3 . 9 . 1 3 . 1 6 . 1 7 . 1 8 1 5 . 1 6 9 6 . 7 . 1 0 . 1 3 1 0 6 . 9 , 1 3 . 1 5 9 9 4 4 4 4 5 1 . 2 . 3 . 6 . 1 0 1 . 2 . 3 . 6 . 1 0 5 13 1 . 2 . 3 . 5 . 6 . 1 0 . 1 1 . 1 2 . 1 3 . 1 7 . 1 8 . 19 1 3 1 3 1 3 1 3 1 3 1 1 5 . 1 1 . 1 3 1 . 2 . 3 . 1 7 5 . 1 3 . 1 4 . 1 9 I . 2 . 3 . 6 I I . 1 4 1 1 . 1 4 1 3 5 5 5 22 R a t i o v a r i a b l e s c a l c u l a t e d by others were not c a l c u l a t e d because of the poor s t a t i s t i c a l p r o p e r t i e s a s s o c i a t e d with r a t i o s (see review i n P h i l l i p s 1983). The t r a n s l a t i o n of v a r i a b l e s from c h a r a c t e r s may be done i n a number of d i f f e r e n t manners. C h a r a c t e r s can be expressed as continuous, c a t e g o r i c a l , or counts. Continuous v a r i a b l e s o f f e r an a n a l y t i c f l e x i b i l i t y that other types of v a r i a b l e s do not g e n e r a l l y a l l o w . Continuous v a r i a b l e s are a l s o more i n keeping with the continuous nature of v a r i a t i o n of c h a r a c t e r s and the hypothesized g e n e t i c c o n t r o l over t h e i r e x p r e s s i o n (Falconer 1981) 2.2 V a r i a b l e measurement r e p e a t a b i l i t y . Samples used i n determining measurement r e p e a t a b i l i t y were s e l e c t e d randomly from~the t o t a l number of samples a v a i l a b l e (Appendix I I ) . Measurement r e p e a t a b i l i t y i s an estimate of the p r e c i s i o n of measuring. The i n i t i a l assessment of measurement r e p e a t a b i l i t y of these v a r i a b l e s was c a r r i e d out using r e p l i c a t e measurements made by two d i f f e r e n t o b s e r v e r s . Assessment of measurement r e p e a t a b i l i t y was made with an a n a l y s i s of v a r i a n c e model of the form: (MODEL 1.) y = A + e. where y i s a measurement f o r a given v a r i a b l e by a given observer, A i s the hypothesized e f f e c t of an observer, and e i s r e s i d u a l v a r i a t i o n . 23 V a r i a b l e s d i s p l a y i n g g r e a t e r than 10 percent v a r i a t i o n a t t r i b u t e d to observers were su b j e c t e d to r e - s p e c i f i c a t i o n and re-measured on another sample. R e - s p e c i f i c a t i o n sought to make the d e s c r i p t i o n of a v a r i a b l e l e s s ambiguous. Q u a n t i t a t i v e v a r i a b l e s which appeared to be i n v a r i a t e were re-measured on another sample by two observers at a higher m a g n i f i c a t i o n . F o l l o w i n g re-measurement, those v a r i a b l e s s t i l l p o s s e s s i n g gr e a t e r than 10 percent v a r i a t i o n between observers were again r e - s p e c i f i e d and re-examined on yet another sample. V a r i a b l e s proving i n v a r i a t e were re-examined over s e v e r a l samples to determine whether i n f a c t they v a r i e d at a l l . F o l l o w i n g t h i s second re-examination, measurement r e p e a t a b i l i t y was measured at four separate times d u r i n g the course of the year spent i n measuring. Average r e p e a t a b i l i t y estimates over these four estimates are given i n Table 2. Table 2 a l s o g i v e s the average r e p e a t a b i l i t y f o r each v a r i a b l e s u i t e . In g e n e r a l , those v a r i a b l e s with a l a r g e r number of refere n c e p o i n t s and assumed symmetry of form proved to be the v a r i a b l e s that showed the l a r g e s t amount of measurement e r r o r . F i g u r e 1 i l l u s t r a t e s the v a r i a b l e s e v e n t u a l l y s e l e c t e d . Appendix I c o n t a i n s the f u l l d e s c r i p t i o n s f o r the v a r i a b l e s and i n c l u d e s the method of sampling, specimen p r e p a r a t i o n , and measurement technique f o r each v a r i a b l e s u i t e . T a b l e 2 . A v e r a g e v a r i a b l e a n d v a r i a b l e s u i t e m e a s u r e m e n t r e p e a t a b i l i t y i n t e r - i n d i v i d u a l v a r i a b i l i t y , a n d i n t e r - p o p u l a t i o n v a r i a b i l i t y . M e a s u r e m e n t r e p e a t a b i l i t y b a s e d o n A N O v A i n M O D E L 1 . a v e r a g e d o v e r f o u r r e p l i c a t e s p e r f o r m e d d u r i n g t h e c o a r s e o f m e a s u r e m e n t . I n t e r - i n d i v i d u a l a n d p o p u l a t i o n v a r i a b i l i t y b a s e d o n s a m e f o r m o f A N O V A ( M O D E L 1 ) . R e p e a t a b i l i t y a n d v a r i a b i l i t y e x p r e s s e d a s a p e r c e n t a g e o f t h e t o t a l s u m s o f s q u a r e s ( V - S S ^ ) . N o . t a x o n o m i c c i r c u m s c r i p t i o n . V A R I A B L E M E A S U R E M E N T I N T E R - I N T E R -R E P E A T A B I L I T Y I N D I V I D U A L P O P U L A T I O N L E A F M O R P H O L O G Y S U I T E N E E D L E N 4 . 3 7 8 4 7 3 1 . 0 5 A B X S T O M 3 . 2 8 2 3 3 4 1 4 8 A D X S T O M 0 0 € 5 . 0 6 3 8 . 0 3 R E S C V N O 0 0 7 5 . 2 9 4 6 . 6 8 R E S C Y L O C 1 . 8 6 4 . 8 7 4 0 . 2 1 R E S C _ Y L E N 0 8 7 6 6 8 3 8 . 2 3 x 1 . 7 7 2 . 9 4 3 9 . 2 8 T W I G M O R P H O L O G Y S U I T E P U L V L E N 7 . 0 8 9 . 4 7 5 4 . 9 0 T I P W I D 3 . 2 7 6 . 3 3 3 6 . 5 1 T I P D E P 6 . 3 6 6 . 3 6 1 4 . 7 9 P U L V P U B 0 . 0 9 7 . 1 7 7 4 . 1 9 x 4 . 1 8 2 . 3 3 4 5 . 1 0 L E A F A N A T O M Y S U I T E N E E D W I D 1 . 1 9 1 . 2 8 5 6 . 5 1 N E E D E P 7 . 6 9 1 . 6 3 5 8 . 0 6 A B X A N G 2 . 0 8 7 . 2 6 7 3 . 6 9 A D X A N G 3 . 0 7 1 . 2 0 4 4 . 9 2 C E N C ' W I D 7 , 5 9 1 . 0 9 4 6 . 4 0 C E N C Y L A T 2 . 0 9 1 . 3 3 5 9 . 4 6 C E N C Y A B X 1 . 2 9 2 . 9 3 7 3 . 9 1 C E N C Y A D X 1 . 6 8 1 . 7 7 3 8 . 3 6 E N D O N U M 3 . 0 8 4 . 6 8 3 9 . 2 0 P H L E N D 9 . 8 8 8 . 5 3 5 3 . 2 2 X / L E N D 4 . 6 8 5 . 6 8 4 7 . 0 8 x 4 . 0 8 7 . 7 2 5 3 . 7 1 C O N E M O R P H O L O G Y S U I T E C O N L E N 0 . 0 6 6 . 7 5 5 4 . 1 2 C O N W I D 0 . 0 7 2 . 8 2 3 6 . 9 2 S C A L E N 5 . 2 6 2 . 1 8 4 0 . 1 8 S C A L W I D 4 . 3 7 6 . 7 6 4 8 . 3 0 S C A L T A P 9 . 6 5 8 . 7 6 3 5 . 3 8 W I N G W I D 6 . 7 6 9 . 6 1 3 2 . 0 5 W I N G T A P 6 . 2 5 2 . 2 3 1 9 . 9 2 F R E E S C A L 4 . 8 6 7 . 3 1 3 5 . 8 7 B R A C T L E N 9 . 2 7 9 . 2 2 6 7 . 2 1 B R A C T W 1 0 6 . 2 6 7 . 0 2 4 1 . 8 2 B R A C T A P 7 . 7 8 2 . 3 8 6 7 . 9 9 x 5 . 5 6 8 . 6 4 7 4 . 1 9 T W I G A N A T O M Y S U I T E P I T H D I A 8 . 3 3 2 . 1 4 7 0 . 8 4 C O R T H I K 4 . 2 1 3 . 3 5 6 8 . 7 7 P E R I T H I K 2 . 3 3 6 . 4 9 7 9 . 3 3 V B T H I K 6 . 2 3 5 . 7 6 7 7 . 8 3 x 5 . 3 2 9 . 4 4 7 4 . 1 9 C O N E C O L L E C T I O N S U I T E S H C O L E N - - S O . 9 7 S H C O W I D - - 4 4 . 2 3 L O C O L E N - - 5 5 . 9 6 L O C O W I D - - 4 8 . 9 1 x - - 5 0 . 0 2 T O T A L ^ w i t h o u t t w i g a n a t o m y ) 7 4 . 1 6 2 . 1 4 4 6 . 3 4 F i g u r e 1. I l l u s t r a t i o n s o f v a r i a b l e s u s e d . a b b r e v i a t i o n s g i v e n i n A p p e n d i x I . T r i a n g l e s . P . e n g e l m a n n i i : s q u a r e s . P . g l a u c a -= ' r c , « . P j . s i t c h e n s i s . N u m b e r s b e s i d e f i g u r e a r e ~ " s a m p T e ~ n u m b e r s rnZTcZ Znllir, ' ' ' U S " " a ' e a : S H C O L E N . S H C O W I D . L O C O L E N . L O C O W I D . C O N L E N , C O N W I D . L E A F L E N . S c h e m a t i c r e p r e s e n t a t i o n o f leaf c r o s s - s e c t i o n f o l l o w s the c o n v e n t i o n o f C o l l e a u 1 9 6 8 . PUIV LEN CENCYLAT • « o ^ V ^ C E N C Y W | D RESCYLEN RESCYLOC 4 ADXSTOM ABXSTOM ADX ABX PITHDIA SCALEN SCALWID BRACT WID SCALTAP BR AC TAP BRACT LEN .WINGWID FREESCAL W ING TAP B 7O10 26 2.3 V a r i a b l e v a r i a t i o n between i n d i v i d u a l s . The v a r i a b l e s s e l e c t e d were measured on r e p r e s e n t a t i v e samples of the two taxa. The nature of v a r i a b l e v a r i a t i o n was examined with an ANOVA of the same form as given above i n MODEL 1; however, here y i s a measurement f o r a given v a r i a b l e made on a given sample from an i n d i v i d u a l , A i s the hypothesized e f f e c t of the i n d i v i d u a l t r e e ( i n t e r - i n d i v i d u a l v a r i a t i o n ) , and e i s r e s i d u a l v a r i a t i o n or, i n t h i s case, i n t r a - i n d i v i d u a l v a r i a t i o n . Those v a r i a b l e s with an i n t e r - i n d i v i d u a l v a r i a t i o n that exceeded the the i n t r a - i n d i v i d u a l v a r i a t i o n were r e t a i n e d f o r f u r t h e r measurement. A p p l i c a t i o n of t h i s r u l e removed twig anatomy v a r i a b l e s from f u r t h e r c o n s i d e r a t i o n . Table 2 g i v e s the amount of i n t e r - i n d i v i d u a l v a r i a t i o n f o r the v a r i a b l e s s e l e c t e d . F i g u r e 2 summarizes i n t e r - i n d i v i d u a l v a r i a t i o n and i n t e r - p o p u l a t i o n v a r i a t i o n 1 . F i g u r e 3 i l l u s t r a t e s some of the v a r i a t i o n i n l e a f anatomy encountered in t h i s study. Daubenmire (1968, 1972, 1974) and others (Garman 1957; Horton 1959) i l l u s t r a t e some of the v a r i a t i o n encountered i n cone morphology. As an a s i d e , P r a v d i n , et a l . (1978) i l l u s t r a t e the range of v a r i a t i o n f o r the P_;_ abies complex. Estimates of i n t e r - i n d i v i d u a l v a r i a t i o n based on the r e s u l t s of t h i s form of ANOVA are a l s o known as r e p e a t a b i l i t y estimates (Falconer 1981). As a s t a t i s t i c from ANOVA, 1 Between p o p u l a t i o n v a r i a t i o n i s assessed with a model of the same form as i n MODEL 1 given above f o r i n t e r - i n d i v i d u a l v a r i a t i o n , the exce p t i o n here being that "A" i s the e f f e c t of the p o p u l a t i o n ( i n t e r - p o p u l a t i o n v a r i a t i o n ) . 27 F i g u r e 2. Summary of v a r i a b l e v a r i a t i o n based on a l l i n d i v i d u a l s w i t h o u t r e f e r e n c e to taxonomic c i r c u m s c r i p t i o n . %S5'.ndividcui' amount of v a r i a t i o n between i n d i v i d u a l t r e e s . %SS pofuU+ierx amount of v a r i a t i o n between i n d i v i d u a l p o p u l a t i o n s . V a r i a b l e s u i t e s : T - tw i g anatomy; C - cone c o l l e c t i o n ; P - twig morpho logy ; S - cone s c a l e morpho logy ; N - l e a f morpho logy ; A - l e a f anatomy Va lues g i v e n a r e those in T a b l e 2. 100i c o A A P SS o o. 5 A P c. S A N A A C N 0 I I I ' VeSS individual 100 r e p e a t a b i l i t y i s i n t e r p r e t e d as a s a m p l e - s p e c i f i c e s t i m a t e of the h e r i t a b i l i t y o f a t r a i t . As an a p p r o x i m a t i o n o f b r o a d s e n s e h e r i t a b i l i t y , r e p e a t a b i l i t y i s s u b j e c t t o c a u t i o u s i n t e r p r e t a t i o n ( F a l c o n e r 1981; Z o b e l 1961); however, t h i s does not n e g a t e i t s c o m p a r a t i v e u t i l i t y . Owing t o t h e s i z e and p e r e n n i a l n a t u r e o f c o n i f e r s , r e p e a t a b i l i t y i s t h e most p r a c t i c a l means o f e s t i m a t i n g t h e h e r i t a b i l i t y of t r a i t s . I n d e e d , c o n s i d e r i n g t h e s t a t i s t i c a l ( S o k a l and R o h l f 1969), b i o l o g i c a l ( F a l c o n e r 1981; R o b i n s o n 1963; J a c q u a r d 1983) and p h i l o s o p h i c a l (Kempthorne 1978) a s s u m p t i o n s e n g e n d e r e d by t h e "components o f v a r i a n c e " use of ANOVA, r e p e a t a b i l i t y may be t h e o n l y a p p r o p r i a t e means of a s s e s s i n g h e r i t a b i i t y . R a t h e r t h a n s t r e s s i n g t h e s p e c i f i c g e n e t i c a s p e c t s t h a t some r e s e a r c h e r s 28 F i g u r e 3. I l l u s t r a t i o n of range of v a r i a t i o n e n c o u n t e r e d f o r l e a f anatomy. Numbers i d e n t i f y I n d i v i d u a l t r e e s l i s t e d i n Appendix I I . R enqelmonnii |05mm | associate with h e r i t a b i l i t y , r e p e a t a b i l i t y w i l l be used here simply as a r e l a t i v e expression of the amount of in t e r - i n d i v i d u a l v a r i a b i l i t y . The i n t e r - i n d i v i d u a l variation values given in Table 2 are comparable to those given for re p e a t a b i l i t y estimates shown by other morphological characters in other coniferous species 29 (Table 3). These r e p e a t a b i l i t y estimates are g e n e r a l l y l a r g e r than p u b l i s h e d h e r i t a b i l i t i e s f o r other v a r i a b l e s i n t r e e s p e c i e s (Hattemer 1963) and probably r e f l e c t the o v e r - e s t i m a t i o n of h e r i t a b i l i t y c o n s i d e r e d i n the broad sense. However, as h e r i t a b i l i t i e s are most commonly c a l c u l a t e d f o r growth and p h y s i o l o g i c a l v a r i a b l e s i t c o u l d r e f l e c t b a s i c g e n e t i c d i f f e r e n c e s between morphological and p h y s i o l o g i c a l v a r i a b l e s . A d d i t i o n a l l y , the s i z e of the h e r i t a b i l i t y estimate c o u l d be i n t e r p r e t e d as simply the r e s u l t of a more heterogenous sample than other s t u d i e s - the f a c t that hypothesized t r a n s - i n d i v i d u a l e f f e c t s have not been c o n s i d e r e d i n Table 3. Andersson's (1965) r e s u l t s , presented i n Table 3, are p a r t i c u l a r l y l a r g e , but i t should be noted that these samples were from a very l a r g e geographic a r e a . Sorensen's data f o r Pinus e l l i o t t i i Engelm. may be small as a r e s u l t of s e l e c t i o n imposed in sampling (Sorensen 1964). These may serve as a convenient example of Zobel's (1961) remarks concerning the p o p u l a t i o n - s p e c i f i c nature of the g e n e t i c i n t e r p r e t a t i o n of such e s t i m a t e s . As a group, the cone c h a r a c t e r s measured here (Table 2, F i g . 2) are more v a r i a b l e w i t h i n an i n d i v i d u a l than are v e g e t a t i v e v a r i a b l e s . The i n f e r e n c e drawn i s t h a t , i n Picea of southwestern B r i t i s h Columbia, the r e p r o d u c t i v e c h a r a c t e r s s e l e c t e d are s u b j e c t to l e s s g e n e t i c c o n t r o l than are the v e g e t a t i v e c h a r a c t e r s . T h i s c o n c l u s i o n i s c o n t r a d i c t o r y to the general e x p e c t a t i o n that r e p r o d u c t i v e c h a r a c t e r s are l e s s s u b j e c t to environmental p e r t u r b a t i o n than are v e g e t a t i v e 30 T a b l e 3. I n t e r - i n d i v i d u a l v a r i a t i o n , r e p e a t a b i l i t y e s t i m a t e s , r e p o r t e d f o r m o r p h o l o g i c a l c h a r a c t e r s in o t h e r c o n i f e r o u s t r e e s p e c i e s . V a l u e s r e p o r t e d i n the t a b l e a r e p e r c e n t a g e of t o t a l v a r i a t i o n due to d i f f e r e n c e s between i n d i v i d u a l t r e e s . V a l u e s a r e c a l c u l a t e d from c i t e d a u t h o r i t i e s and r e f e r to the t o t a l i n t e r - i n d i v i d u a 1 v a r i a t i o n w i t h o u t r e s p e c t to h y p o t h e s i z e d t r a n s - i n d i v i d u a 1 s o u r c e s or va r i at i on . P i c e a g l a u c a ( K h a l i l 1974) cone weight cone l e n g t h cone w i d t h s c a l e l e n g t h s c a l e w i d t h 86 . 16 95 .07 7 1 . 33 78 . 74 62 . 78.68 1 1 A b i e s ba l samea ( L e s t e r 1968) cone l e n g t h s c a l e l e n g t h seed l e n g t h b r a c t l e n g t h s t a l k l e n g t h 70.00 85.00 77 .00 85.00 76 .00 77 . 80 P i c e a mar i ana ( P a r k e r e t aj_ . 1983) cone l e n g t h 67 . 30 cone d i a m e t e r 68 . 70 s c a l e l e n g t h 70 . 90 s c a l e w i d t h 71 .90 s c a l e c o n c a v i t y 61 . 40 dark band w i d t h 70 .00 1 i g h t band w i d t h 67 . 60 s eed l e n g t h 73 .80 seed+wing l e n g t h 70 .60 l e a f w i d t h 48 . 40 l e a f t h i c k n e s s 49 . 20 t w i g p u b e s c e n c e 60 .'60 l e a f apex shape 30 . 30 r e s i n c a n a l s e p a r a t i on 70 00 v a s c u l a r b u n d l e d i a m e t e r 36 . 80 l o n g e s t bud s c a l e l e n g t h 75 . 80 l a t e r a l bud 1ength 71 . 30 x 62 .59 P s e u d o t s u g a menz i e s i i (Chen, e t a [ . , u n p u b l . ) x n e e d l e anatomy 86.32 P i cea ab i es (Ander s son 1965) cone weight 90.01 cone 1ength 91.67 .•'seeds/ cone 81.22 seed we i gh t / cone 85.29 x 86 . 17 P i n u s e l 1 i o t t i i ( So rensen 1964) l e a f l e n g t h 48 .67 f a s i c l e volume 54 .95 l e a f d i v e r g e n c e 41 . 83 shea th l e n g t h 78 . 74 bud s c a l e l e n g t h 77 83 ~ 60 . 40 P i nus kes i ya ( B u r l e y and Barrow 1972) l e a f l e n g t h 76.84 % 3 - l e a f f a s i c l e 67.96 l e a f / f a s i c l e 67.88 "x 70.89 P i c ea mar i ana ( K h a l i l 1975) cone l e n g t h 65.93 cone w i d t h 64.91 "x 65.42 31 (Stebbins 1950; Davis and Heywood 1973). T h i s a l s o c o n t r a d i c t s the o b s e r v a t i o n s of Parker et a l . (1983) (see Table 3) and T a y l o r (1959). The general trend in Table 3 of cone morphology v a r i a b l e s i s that they have a l a r g e r i n t e r - i n d i v i d u a l v a r i a t i o n than v e g e t a t i v e v a r i a b l e s . 3. Samples and sampling. Once v a r i a b l e s were s e l e c t e d , i t was necessary to d i r e c t a t t e n t i o n to the o r i g i n of the samples and how these samples r e l a t e to the v a r i o u s a p r i o r i t r a n s - i n d i v i d u a l l e v e l s of o r g a n i z a t i o n that have been hypothesized, i . e . p o p u l a t i o n s and taxa. 3.1 Study a r e a . The main area of study i s mainland southwestern B r i t i s h Columbia i n c l u d i n g both the Coast and Cascade Mountain Ranges ( F i g . 4A). The area i n c l u d e d i n the study was expanded to address s p e c i f i c s i t u a t i o n s a r i s i n g i n the main p o r t i o n of the study area. These supplemental areas were s e l e c t e d to c i r c u m s c r i b e b e t t e r the v a r i a t i o n of both s p e c i e s and to c o n s i d e r the e x i s t e n c e and e f f e c t of a p o s s i b l e t h i r d s p e c i e s , P. g l a u c a . Such supplemental sampling permits a b e t t e r understanding of the v a r i a t i o n in the study a r e a . S p e c i f i c a l l y , the i n c l u s i o n of samples from these a d d i t i o n a l areas sought t o : i d e n t i f y the r e l a t i o n between 32 Figure 4. Maps of locations of samples arid study area. A - study area; B - common garden samples of s i tchens i s ; C - naturally growing c o l l e c t i o n s from southern portion of range of P_^  s i tchens i s ; D -samples of engelmanni i outside of study area. Tree and population numbers correspond to those given in Appendix II. A B C D p. enqelmanni i and Pj_ glauca; i d e n t i f y the re l a t i o n between P. enqelmanni i in the study area to that reported for a disjunct location of the P^ enqelmanni i on the Olympic Peninisula (Sharpe 1970; Hitchcock, et a l . 1969) (Fig. 4D); identify the relation between E\ enqelmanni i in the study area to that in the wettest and d r i e s t portions of the i n t e r i o r of B r i t i s h Columbia (Fig. 4D); and, identif y the rel a t i o n between sitchensis in the study area and that in more southerly locations (Fig. 4B, C) 33 The p o s s i b i l i t y of the occurrence and/ or i n t r o g r e s s i o n of P. glauca Knight I n l e t c o u l d not be denied a p r i o r i . As such i t was necessary to examine the r e l a t i o n between engelmanni i and P. glauca, a l b e i t s u p e r f i c i a l l y . The suspected occurrence of P. glauca i n Knight I n l e t i s based on the crown form and cone morphology f o r t r e e s east of Remote Creek along the K l i n k a k l i n i R i v e r . A d d i t i o n a l l y , p e r s o n a l reconnaissance d u r i n g previous r e s e a r c h 1 west of T a t l a Lake i n d i c a t e d the presence of P_^  glauca in the r e l a t i v e l y low e l e v a t i o n pass to Knight I n l e t along the K l i n a k l i n a R i v e r . Such an occurrence i s not unexpected s i n c e s i m i l a r s i t u a t i o n s have been r e p o r t e d f o r more n o r t h e r l y i n l e t s : Skeena River (Daubenmire 1968; Garman 1957; Roche 1969; Coupe, et a l . 1982; Hanover and Wil k i n s o n 1970; Copes and Beckwith 1977; Falkenhagen and Nash 1978); Dean River ( P o j a r 2 ) ; B e l l a Coola River ( P o j a r 2 ) ; Nass River (Garman 1957; Roche 1969); and Bu l k l e y R i v e r (Roche 1969). S e v e r a l s p e c i f i c c o l l e c t i o n s were made to d e s c r i b e the nature of i n t r a - i n d i v i d u a l v a r i a t i o n . These are d e s c r i b e d more f u l l y i n Chapter I I I . Samples were c o l l e c t e d under n a t u r a l s i t u a t i o n s as w e l l as from a v a r i e t y of common garden s i t u a t i o n s . F i r s t , r e p r e s e n t a t i v e s of P^ s i t c h e n s i s from throughout the n a t u r a l range of the s p e c i e s were sampled i n a common garden s i t u a t i o n 34 in the C h i l l i w a c k V a l l e y 3 ( F i g . 4B). The t r e e s had been grown from seed. Comparison of n a t u r a l l y o c c u r r i n g t r e e s to nursery grown t r e e s may provide i n s i g h t i n t o the f a c t o r s surrounding p o p u l a t i o n d i f f e r e n t i a t i o n . F u r t h e r , t h i s comparison may prove u s e f u l in r e l a t i n g the r e s u l t s r e p o r t e d from other common garden r e s e a r c h to the r e s u l t s presented here based on p l a n t s c o l l e c t e d under n a t u r a l c o n d i t i o n s . More exact l o c a t i o n s and inf o r m a t i o n are given i n Appendix I I . Two other common gardens were sampled; one at Red Rock, south of P r i n c e George, B r i t i s h Columbia 1 and the other at F r e d e r i c t o n , New Brunswick 2. In both of these n u r s e r i e s , i n d i v i d u a l s of known h y b r i d parentage were sampled. Such c o l l e c t i o n s p r o v i d e i n f o r m a t i o n concerning the d e s c r i p t i o n of h y b r i d s . Secondly these c o l l e c t i o n s provide i n f o r m a t i o n r e g a r d i n g the p r a c t i c a l i t y of r e c o g n i z i n g n a t u r a l l y o c c u r r i n g h y b r i d s . More s p e c i f i c i n f o r m a t i o n about the parentage of these t r e e s i s provided i n Appendix I I . In a d d i t i o n to the t r e e s s p e c i f i c a l l y sampled f o r t h i s study, data from specimens sampled p r e v i o u s l y i n K l i n k a , et a l . (1982) were a l s o u s e d 3 . 1 B r i t i s h Columbia M i n i s t r y of F o r e s t s , Vancouver F o r e s t Region, Research Branch - Vancouver 1981. 2 B r i t i s h Columbia M i n i s t r y of F o r e s t s , P r i n c e Rupert F o r e s t Region, Smithers. 3 U l f B i t t e r l i c k ; B r i t i s h Columbia M i n i s t r y of F o r e s t s 1 Gyula K i s h ; B r i t i s h Columbia M i n i s t r y of F o r e s t s . 2 Dan Fowler; Canadian F o r e s t r y S e r v i c e . 3 p e r m i s s i o n of K a r e l K l i n k a ; B r i t i s h Columbia M i n i s t r y of F o r e s t s . 35 3.1.1 C l i m a t e . In the study area samples came from e l e v a t i o n s between sea l e v e l and 2100 m ASL. Some of the range of c l i m a t i c c o n d i t i o n s r e p o r t e d w i t h i n the study area are i n d i c a t e d i n Table 4. Owing to the extreme topographic v a r i a t i o n and l o c a l c l i m a t i c a l t e r a t i o n a s s o c i a t e d with such topography, a c t u a l c l i m a t i c values can w e l l be expected to d i f f e r s u b s t a n t i a l l y from those r e p o r t e d . The v a l u e s presented i n Table 4 give an impression of c l i m a t i c v a r i a t i o n r a t h e r than p r o v i d i n g an accurate d e s c r i p t i o n of the c l i m a t e at any given sample l o c a t i o n . However these c l i m a t i c v a r i a b l e s should not be i n t e r p r e t e d as being the only f a c t o r s r e s p o n s i b l e f o r l i m i t i n g growth and s u r v i v a l of P i c e a at a given s i t e . F u r t h e r , the v a r i a t i o n of the c l i m a t e corresponds roughly with e l e v a t i o n , l a t i t u d e , and l o n g i t u d e . Climate i n the range of P.? s i t c h e n s i s i s summarized b r i e f l y by F l e t c h e r (1976). S c h a e f f e r (1978a,b) and O ' D r i s c o l l (1976b) pr o v i d e a g e n e r a l overview of c l i m a t i c v a r i a t i o n f o r the study a r e a . F i g u r e 5 i l l u s t r a t e s the range of d i s t r i b u t i o n of samples with respect to l o n g i t u d e , l a t i t u d e , and e l e v a t i o n . These f i g u r e s serve to c o r r o b o r a t e the impression from the l i t e r a t u r e that P_j_ s i t c h e n s i s i s a low e l e v a t i o n , c o a s t a l s p e c i e s whereas P. engelmani i i s a h i g h e l e v a t i o n , i n t e r i o r s p e c i e s ; however, any edaphic d i s c o n t i n u i t y (Wright 1955; Daubenmire 1968) i s not apparent. P r e d i c t a b l y , the " h y b r i d s " occur i n i n t e r m e d i a t e areas. I t should be noted that the c o l l e c t i o n s of F\ s i t c h e n s i s from the h i g h e s t e l e v a t i o n s came from more n o r t h e r l y areas - an o b s e r v a t i o n that c o r r o b o r a t e s Daubenmire's (1968) r e p o r t that T a b l e 4. Summary of some annua l a ve rage c l i m a t i c v a r i a b l e s r e p o r t e d f o r the S tudy a r e a and a d j a c e n t a r e a s . SSS - s t a n d a r d P_^  s i t chens i s; SSP - p u t a t i v e P. s i t chens t s; SXE - " h y b r i d " ; ESP - p u t a t i v e P_^  enge1mann i i ; ESS -s t a n d a r d P_^  enge 1 mann i i ; WSS - s t a n d a r d g 1 auca . - no d a t a a v a i l a b l e . S o u r c e s : U.S. Dep t . of Commerce (1975 ) ; Env i ronment Canada (1973; 1975a, 1975b). STATION ID ELEV RAIN SNOW X T min T maxT FROST (m) (mm t (C ) (C ) (C ) ( day ) STUDY AREA BRITTANIA BEACH SSS 50 1985 782 10 .0 6 4 13 5 43 PORT ALICE 20 3152 587 9 . 4 5 . 7 13 . 1 33 PORT HARDY 25 1660 706 7 . 9 4 . 7 1 1 . 2 67 RIVER JORDAN 5 1962 2 18 9 .0 5. 2 12 .8 44 SOUAMISH 2 1916 1455 8 .9. 4 7 13 . 3 84 TOFINO 30 3020 4 17 9 . 2 5 . 7 12 . 7 49 VANCOUVER - UBC 95 1258 490 9 . 8 6 6 13 . 1 33 CHILLIWACK SSP 10 1636 1029 10 . 2 5 . 7 14 .8 57 HANEY RESEARCH FOR. 190 f 101 1 107 8 . 9 4 . 7 13 . 2 80 HOPE 50 1448 162 1 9 . 7 5 . 1 14 . 3 77 ALTA LAKE SXE 730 837 5936 5 . 7 0. 4 10 .9 176 PEMBERTON MEADOWS ESP 240 742 2825 7 . 2 2 . 1 12 . 3 128 SKAGIT RIVER 560 802 3228 7 .8 1 . 9 13 8 165 ALLISON PASS ESS 1470 486 9652 1 .8 -3 . 7 7 . 5 255 OUTSIDE STUDY AREA HEDLEY ESP 570 218 • 752 7 .9 1 . 7 14 . 1 158 KEREMEOS 470 189 602 9 . 7 4 . 2 15 . 1 1 14 KLEENA KLEENE 980 204 1669 1 . 8 -5 . 8 9 . 5 258 MICA DAM 6 30 7 17 7364 4 . 2 - 0 . 9 9 . 3 184 REVELSTOKE 500 703 4 115 7 . 2 1 . 7 12 . 6 150 CHUTE LAKE ESS 1305 302 3106 3 . 2 -3 . 3 9 6 228 HEDLEY MINE 1930 2 14 3297 2 . 2 -3 . 4 7 , 7 231 SEOUIM, WASH. SSS 60 - - 9 . 8 7 3 17 . 1 _ ELWHA STATION. WASH. 120 14 13 - -BROOKINGS. ORE. SSS 30 2056 - 1 1 . 8 8 . 3 15 3 -BANDON. ORE. 30 15 19 - 10 . 8 7 . 4 14 , 3 -CANARY. ORE. 30 2097 - 1 1 . 2 6 . 3 16 . 3 -OTTAWA, ONTARIO WSS - 663 193 5 8 0. 8 10. 8 162 CHILLIWACK RIVER NURSERY SAMPLES KODIAK IS. ALASKA SSS 10 1440 - 4 8 - 1 . 2 12 . 7 -CORDOVA BAY 15 2350 - 3 4 -5 . 0 1 1 . 9 -JUNEAU 10 1389 - 6 .0 -2 . 6 14 . 1 -TERRACE. B .C. 70 917 1816 6 . 7 2 . 7 10. 8 137 SANDSPIT 10 1 182 785 7 . 9 5 . 1 10. 6 63 BELLA COOLA 20 1358 1750 7 . 4 2 . 8 12 . 0 1 24 CHILLIWACK < SEE ABOVE > FORKS, WASH. 120 2956 - 9 5 3 . 6 15 . 6 -CLOVERDALE . ORE . 5 2 147 - 10 9 5 . 9 15 . 7 -CANARY BROOKINGS < SEE ABOVE < SEE ABOVE 37 F i g u r e 5. E l e v a t i o n a l , l a t i t u d i n a l , and l o n g i t u d i n a l d i s t r i b u t i o n of samples. SSS - s t a n d a r d s i tchens i s ; SSP - p u t a t i v e P_^  s i tchens i s ; SXE - " h y b r i d " ; ESP - p u t a t i v e P_^  enge I mann i i ; ESS - s t a n d a r d P . enge 1 mann i i ; IESP - p u t a t i v e P_^  enge 1 mann i i i n t e r i o r ; IESS -s t a n d a r d enge 1 mann 1 i i n t e r i o r . ELEVATION 2100 I JJlTflfJI tr) <0 Of it/ <(/ ty ty LATITUDE 52 2 4 8 0 LONGITUDE 128 2 I I I I I I 115 B t h i s species occupies a wider e l e v a t i o n range at higher l a t i t u d e s . 3.1.2 Edaphic environment. Parent m a t e r i a l s i n the study area are p r i m a r i l y coarse textured quartz- and g r a n o - d i o r i t e s (Holland 1976). Notable exceptions are the limestone and sedimentary parent m a t e r i a l s of the C h i l l i w a c k V a l l e y and some of i t s a s s o c i a t e d drainages. In a l l areas these parent m a t e r i a l s are o v e r l a i n , to various degrees, by an accumulation of g l a c i a l t i l l s and c o l l u v i a l m a t e r i a l s (Ryder 1978). S o i l s where Picea occur are p r i m a r i l y those associated with f l u v i a l and a l l u v i a l landforms. Well aerated and pervious cumulic regosols and l e s s aerated and saturated g l e y s o l s are the most frequent. On the outer coast, Picea may occur i n brackish c o n d i t i o n s a s s o c i a t e d with sandy s o i l s of advancing beach f r o n t s (Cordes 1972). 38 Picea occurs on a v a r i e t y of s o i l types on more upland s i t e s . In the n o r t h e r l y c o a s t a l p o r t i o n of the study area, P i c e a occurs on v a r i o u s degrees of humified podsols and " f o l i s o l s " (Pojar 1982). In the i n t e r i o r p o r t i o n of the study area, P i c e a may be found on v a r i o u s degrees of i l l u v i a t e d l u v i s o l s . With i n c r e a s i n g e l e v a t i o n on both the coast and the i n t e r i o r , P i c ea i s found on p o o r l y developed podsols and b r u n i s o l s . L i k e c l i m a t e , edaphic v a r i a t i o n corresponds roughly with geographic l o c a t i o n . F u r t h e r , the d e s c r i p t i o n s of the edaphic environment given here are not meant to be accurate f o r any given s i t e - they simply serve to d e s c r i b e the p o s s i b l e v a r i a t i o n i n the study a r e a . An approximation of the edaphic environment i s provided by an i n d i c a t i o n of the r e l a t i v e a v a i l a b i t y of moisture for each c o l l e c t i o n s i t e . Such q u a n t i f i c a t i o n i s provided by the c l a s s i f i c a t i o n o u t l i n e d i n Walmsley, et a l . (1980). B r i e f l y , t h i s c l a s s i f i c a t i o n of moisture a v a i l a b i l i t y i s a landscape c l a s s i f i c a t i o n with secondary a t t e n t i o n p a i d to t e x t u r a l p r o p e r t i e s of the s p e c i f i c s o i l . The d i s p o s i t i o n of samples with respect to moisture regime i s given i n Table 5. The d i s p o s i t i o n of i n d i v i d u a l samples with respect to moisture regime i s given i n Appendix I I . Table 5 serves to i l l u s t r a t e the wider edaphic amplitude of P^ _ enqelmanni i and " h y b r i d s " compared with E\ s i t c h e n s i s . I t should be noted that t h i s moisture index i s not e n t i r e l y independent of l o c a l c l i m a t e . For example, what c o n s t i t u t e s a s u b x e r i c s i t e on the outer coast 3 9 T a b l e 5. D i s t r i b u t i o n o f samples w i t h r e s p e c t to m o i s t u r e reg ime. M o i s t u r e reg ime scheme f o l l o w s Walms ley, e t al_. (1980) . IDENTIFICATION P. s i t c h e n s i s XERIC SUB- SUB- MESIC SUB- HYGRIC TOTAL XERIC MESIC HYGRIC STANDARDS PUTATIVES "HYBRIDS' P. enge1mann i i STANDARDS PUTATIVES SELKIRK MTNS. STANDARDS PUTATIVES 16 10 10 10 10 27 4 13 25 51 18 27 36 38 51 10 36 12 21 8 44 15 62 65 133 71 105 10 69 515 might w e l l be subhygric i n the i n t e r i o r . A d e s c r i p t i o n of the edaphic environment present today does not n e c e s s a r i l y r e f l e c t the edaphic environment that was c r i t i c a l to the establishment and e a r l y growth of the t r e e s sampled f o r t h i s study. A d d i t i o n a l l y , the l a t e r a l v a r i a b i l i t y of edaphic v a r i a b l e s i s such ( C o u r t i n , e_t a_l. 1983) that more d e t a i l e d d e s c r i p t i o n besides that given here i s l i a b l e to be subj e c t to a l a r g e measurement e r r o r . 3.1.3 A s s o c i a t e d v e g e t a t i o n . In a d d i t i o n to c l i m a t i c and edaphic v a r i a t i o n , there are many documented d e s c r i p t i o n s of v e g e t a t i o n found growing with P i c e a . References s p e c i f i c to the study area and a u x i l i a r y sample s i t e s can be found i n : K r a j i n a , et a_l. ( 1978); K r a j i n a , et a l . (1982); K r a j i n a (1969); K r a j i n a (1965); K l i n k a , et a l . (1982); K l i n k a , et a l . (1980); K l i n k a , et a l . (1979); Jones 40 and Annas (1978); F r a n k l i n and Dyrness (1973); Rowe (1977). As with c l i m a t e there i s a strong interdependence of ve g e t a t i o n and e l e v a t i o n , l o n g i t u d e , and l a t i t u d e . An approximation of a s s o c i a t e d f o r e s t v e g e t a t i o n , p r i m a r i l y f o r e s t t r e e s , i s pr o v i d e d i n t h i s study by a s s i g n i n g each sample to a " b i o g e o c l i m a t i c zone" ( K r a j i n a 1969). More p r e c i s e b i o g e o c l i m a t i c c i r c u m s c r i p t i o n i s p o s s i b l e ( M i t c h e l l , et a l . 1981a, b; U t z i g , et a l . 1983; C o u r t i n , et a l . 1981; K l i n k a , e_t a l . 1979), however the wide geographic d i s t r i b u t i o n of the samples makes assignment to these a e r i a l l y smaller syntaxa i m p r a c t i c a l . The b i o g e o c l i m a t i c d i s p o s i t i o n of samples i s i n d i c a t e d i n Table 6. The d i s p o s i t i o n of i n d i v i d u a l samples i s given i n Appendix I I . L i k e the edaphic environment, contemporary a s s o c i a t e d v e g e t a t i o n may not be n e c e s s a r i l y that c o n t r i b u t i n g to the s u r v i v a l and c h a r a c t e r i s t i c s of the i n d i v i d u a l today. The e f f e c t of a given herb s p e c i e s on a l a r g e t r e e may be v a s t l y d i f f e r e n t from the e f f e c t of the same herb s p e c i e s upon the establishment and development of s e e d l i n g s . 3.1.4 G e o l o g i c a l , v e g e t a t i o n , and c l i m a t i c h i s t o r y . Evidence of recent g l a c i a t i o n i s p e r v a s i v e throughout the study area. The m a j o r i t y of upland s o i l s have developed from g l a c i a l t i l l s and the landscape i s dominated by the e f f e c t s of g l a c i a t i o n (Ryder 1978). H o l l a n d (1976) and Ryder (1978) pr o v i d e a review and summary of the geomorphic h i s t o r y of the study area. With the exception of the t r e e s sampled i n Oregon 41 T a b l e G. D i s t r i b u t i o n of samples w i t h r e s p e c t to b i o g e o c l i m a t i c zone s . CDF - c o a s t a l d o u g l a s - f i r zone ; CWH - c o a s t a l wes te rn hemlock zone : MH -mounta in hemlock zone ; ESSF - engelmann s p r u c e s u b a l p i n e f i r zone ; IDF -i n t e r i o r d o u g l a s - f i r zone ; IWH - i n t e r i o r wes te rn hemlock zone . Ass i gnment to b i o g e o c l i m a t i c zone based on C o u r t e n , e_t aj_. (1981) ; K l i n k a , et a±. ( 1979, 1980); M i t c h e l l , e t a]_. (1981a, b ) ; and, U t z i g , et al_. ( 1983). BIOGEOCLIMATIC ZONES IDENTIFICATION CDF CWH MH ESSF IDF IWH s i t c h e n s i s STANDARDS 13 49 PUTATIVES 1 64 "HYBRIDS" 116 15 P. enge lmanni i STANDARDS 71 PUTATIVES 7 7 56 35 SELKIRK MTNS. STANDARDS 10 PUTATIVES 50 5 14 and C a l i f o r n i a , a l l t r e e s sampled came from an area covered by i c e d u r i n g the l a s t c o n t i n e n t a l g l a c i a t i o n (Ryder 1978). Daubenmire (1978) and Wolfe (1969) provide reviews and summary of the pre-Quaternary v e g e t a t i o n of the a r e a . Hebda (1983) p r o v i d e s a summary of the p o s t - g l a c i a l v e g e t a t i o n change for the c o a s t . Mack, et a l . (1976), Hansen (1955), and Hebda (1982) pr o v i d e summaries of v e g e t a t i o n changes f o r the i n t e r i o r . F o l l o w i n g the most recent g l a c i a t i o n the c l i m a t e i s assumed to have become warmer and d r i e r than at present. T h i s xerothermic or hypsithermal p e r i o d occurred around 6000 yBp and was most pronounced i n the i n t e r i o r ( A l l e y 1976; Mack, et a l . 1976; Hansen 1955; Daubenmire 1975; Hebda 1982) and in the rainshadow areas of the coast (Barnosky 1981). The hypothesis 4 2 of the e x i s t e n c e of the xerothermic p e r i o d remains enigmatic f o r more c o a s t a l areas (Mathewes 1973). The v e g e t a t i o n and r e - v e g e t a t i v e h i s t o r y of the study area has been d i s c u s s e d by numerous workers. The v e g e t a t i o n h i s t o r y c o n s t i t u t e s the b a s i s f o r d e r i v e d i n f e r e n c e s concerning c l i m a t i c h i s t o r y . The accounts d i f f e r i n respect to a c t u a l dates but the trends reported are s i m i l a r . 3.1.5 H i s t o r y of Picea i n western North America. In examining the v a r i a t i o n of the two hypo t h e s i z e d taxa i n the study area i t i s necessary to pl a c e the occurrence of Picea today i n t o some s o r t of h i s t o r i c a l p e r s p e c t i v e , e s p e c i a l l y i f i n f e r e n c e s regarding r e l a t i o n s h i p s are to be forthcoming. P a r t i c u l a r l y important i n c o n s i d e r i n g the Quaternary h i s t o r y of Picea i n the study area, i s the p o s t - g l a c i a l p e r i o d . These i n t e r p r e t a t i o n s are g e n e r a l l y based on p a l y n o l o g i c evidence. As se p a r a t i o n of P\_ s i t c h e n s i s and P_;_ enqelmanni i on p o l l e n s i z e i s tenuous (Mathewes 1973; Wilson 1963), i t i s imp o s s i b l e to r e t r a c e the h i s t o r y of both taxa d u r i n g t h i s p e r i o d . I t i s g e n e r a l l y agreed that these s p e c i e s , l i k e many o t h e r s , r e t r e a t e d south d u r i n g g l a c i a l episodes and that more montane sp e c i e s descended to lower e l e v a t i o n s . For the c o a s t a l area where i n v e s t i g a t i o n s have been made p r i m a r i l y at low e l e v a t i o n s , P i c e a p o l l e n has been assumed to be that of P^ s i t c h e n s i s . In the i n t e r i o r , P i c e a p o l l e n has been assumed to be e i t h e r P. engelmanni i or P^ glauca, depending upon the p r o x i m i t y of contemporary s p e c i e s . The s a n c t i t y of these i n t e r p r e t a t i o n s has 43 been c h a l l e n g e d by the recent f i n d i n g s of m a c r o f o s s i l s in the Puget lowlands i d e n t i f i e d as P_;_ enqelmanni i (Barnosky 1981). Daubenmire (1968) p r o v i d e s a f u r t h e r review of the nature of Pi c e a i n the Puget lowlands. An important i s s u e i n the Quaternary h i s t o r y of P i c e a i n western North America concerns the hypothesis of a g l a c i a l r e f u g i a of the s p e c i e s . Such an hypothesis has been tendered for P_^  s i t c h e n s i s (reviewed i n Daubenmire 1968) and P^ glauca (reviewed i n C r i t c h f i e l d 1984). In both cases c o n c l u s i o n s concerning t h i s h y p o thesis remains enigmatic. The hypothesis i s f r e q u e n t l y invoked to e x p l a i n apparent d i s c o n t i n u i t i e s in the v a r i a t i o n of P_;_ s i t c h e n s i s . A s i m i l a r h y p othesis has been tendered by P o r s i l d ( i n Garman 1957) f o r P^ enqelmanni i . A r e l a t e d i s s u e i s the hypothesized i n t r a - g l a c i a l g e n e t i c d e p a u p e r i z a t i o n of P_;_ s i t c h e n s i s (Yeh and El-Kassaby 1980) and subsequent d i f f e r e n t i a t i o n d u r i n g p o s t - g l a c i a l m i g r a t i o n ( I l l i n g w o r t h 1976). P o s t - g l a c i a l d i f f e r e n t i a t i o n of P. enqelmanni i d u r i n g m i g r a t i o n has a l s o been hypothesized by Daubenmire (1974). For the coast and i n t e r i o r , P i c e a p o l l e n i s g e n e r a l l y present and abundant i n the o l d e s t sequences. For the c o a s t a l areas, P i c e a p o l l e n d e c l i n e s g r a d u a l l y to the pr e s e n t . In the i n t e r i o r and r a i n sha.dow areas, Picea i n i t i a l l y d e c l i n e s and then i n c r e a s e s a f t e r 5000 yBP, tending to support the hypothesized occurrence of a hypsith e r m a l i n t e r v a l . 44 3.2 T r a n s - i n d i v i d u a l c i r c u m s c r i p t i o n of samples Regardless of the hypothesized sources of t r a n s - i n d i v i d u a l v a r i a t i o n , o f t e n s t i p u l a t e d by t h e o r e t i c a l c o n s i d e r a t i o n s or convention r a t h e r than b i o l o g i c a l r e a l i t y , the nature of the occurrence of P i c e a i n southwestern B r i t i s h Columbia i s such that systematic and balanced sampling for a l l sources of t r a n s - i n d i v i d u a l v a r i a t i o n was not p o s s i b l e . 3.2.1 P o p u l a t i o n c i r c u m s c r i p t i o n of samples. Where there were a number of i n d i v i d u a l t r e e s at a p a r t i c u l a r l o c a t i o n a p o p u l a t i o n was d e f i n e d i f i n d i v i d u a l s were w i t h i n 30m of each other, approximately the same age (+/- 10 y e a r s ) , and were growing in s i m i l a r p h y s i o g r a p h i c and edaphic c o n d i t i o n s . T h i s s p a t i a l part of t h i s d e f i n i t i o n of a p o p u l a t i o n i s based upon the a v a i l a b l e l i t e r a t u r e p e r t a i n i n g to p o l l e n (Wright 1953; C o l w e l l 1951; Ibe 1983; S i l e n 1962; Wang, et a l . 1969) and seed d i s p e r s a l (Mair 1973; Stern and Roche 1974) i n f o r e s t t r e e s . T h i s s p a t i a l r e s t r i c t i o n minimizes long d i s t a n c e p o l l i n a t i o n and d i s p e r s a l . Trees were cored as a check that o b v i o u s l y d i f f e r e n t aged i n d i v i d u a l s had not been sampled. Under c o l l e c t i o n s i t u a t i o n s where increment c o r i n g was not p o s s i b l e , diameter at breast height was used as an age e s t i m a t o r . Such sampling reduces the p o t e n t i a l h e t e r o g e n e i t y i n the data r e l a t e d to d i f f e r e n t ages and meso-topographic environmental c o n d i t i o n s . The r e s t r i c t e d d i s t a n c e between t r e e s a l s o c o n f i n e s the d e f i n i t i o n of p o p u l a t i o n to those i n d i v i d u a l s that are p o t e n t i a l l y able to 45 c r o s s - p o l l i n a t e with each other ("neighbourhood s i z e " - Ledig 1974) and probably represent the progeny from a r e s t r i c t e d p a r e n t a l g e n e r a t i o n . As a consequence of adopting such a narrow d e f i n i t i o n of a p o p u l a t i o n , i n t r a - p o p u l a t i o n v a r i a t i o n i s expected to be lower than that observed f o r s t u d i e s with broader o p e r a t i o n a l d e f i n i t i o n s of a p o p u l a t i o n . As a r e s u l t of such s t r i n g e n t d e f i n i t i o n s of a p o p u l a t i o n , the p o p u l a t i o n s sampled c o u l d be represented by two or more i n d i v i d u a l s . In some areas there were, p o t e n t i a l l y , a l a r g e number of t r e e s that c o u l d be assigned c l e a r l y to a s i n g l e p o p u l a t i o n . Under such c o n d i t i o n s where there were such l a r g e numbers of i n d i v i d u a l s , samples from f i v e to ten t r e e s were made. A l a r g e r number of i n d i v i d u a l t r e e s c o u l d have been sampled in such p o p u l a t i o n s , but only at the expense of a l a r g e investment of time spent i n sampling. Such p o p u l a t i o n - i n t e n s i v e sampling would have r e s u l t e d i n a concomitant d e c l i n e i n the d i s t r i b u t i o n of sampling over the geographic extent of the study area. As a r e s u l t , sampling at a p o p u l a t i o n l e v e l was unbalanced thereby c o m p l i c a t i n g a n a l y s i s . The d i s t r i b u t i o n of samples i n t o p o p u l a t i o n s i s i n d i c a t e d i n Table 7. S p e c i f i c d i s t r i b u t i o n of i n d i v i d u a l samples i s given i n Appendix I I . In most cases p o p u l a t i o n s were even-aged and l a c k e d a complex stand a g e - s t r u c t u r e such as found in Abies a m a b i l i s stands ( H e r r i n g and E t h e r i d g e 1976). S i m i l a r l y the edaphic and p h y s i o g r a p h i c environment were w e l l c i r c u m s c r i b e d - i n d i v i d u a l s were l a c k i n g on adjacent p h y s i o g r a p h i c a l l y or e d a p h i c a l l y d i f f e r e n t s i t e s . In some s i t u a t i o n s i t was p o s s i b l e to d e f i n e 46 T a b l e 7 . D i s t r i b u t i o n o f s a m p l e s a s p o p u l a t i o n s a n d s i n g l e o c c u r r e n c e s . P o p u l a t i o n s - t o t a l n u m b e r o f s a m p l e s : t o t a l H p o p u l a t i o n s {0 p o p u l a t i o n s * H s a m p l e s p e r p o p u l a t i o n ) . I D E N T I F I C A T I O N POPULAT IONS S I N G L E S P. s i t c h e n s i s STANDARDS 4 4 : 6 ( 1 6 ; 2 * 1 0 : 2 * 3 : 2 } 18 P U T A T I V E S 2 1 : 7 { 6 : 4 ; 3 ; 4 * 2 > 44 " H Y B R I D S " 8 2 : 1 3{ 16: 1 5 : 1 3 : 1 0 ; 7 ; 5 ; 2 * 3 ; 5 * 2 > 51 P. e n g e1m a n n i i STANDARDS 6 6 : 7 { 2 1 ; 1 1 ; 1 0 ; 2 * 7 ; 2 *5 } 5 P U T A T I V E S 8 4 : 1 3 { 2 2 : 15 ; 1 3 : 2 * 6 ; 6 * 3 ; 2 * 2) 21 S E L K I R K MTNS. STANDARDS 10 : 2 * 5 P U T A T I V E S 6 6 : 1 9 { 1 0 : 2 * 5 : 4 : 1 2 * 3 ; 3 * 2 ) 3 TOTAL 3 7 3 : 6 7 { 2 2 ; 2 1 ; 2 * 1 6 ; 2 * 1 5 ; 2 * 1 3 ; 142 1 1 ; 5 * 1 0 ; 3 * 7 ; 3 * 6 ; 7 * 5 ; 2 * 4 ; 2 3 * 3 ; 1 5 * 2 ) p o p u l a t i o n s and c o l l e c t samples from s p a t i a l l y adjacent s i t e s where there were obvious environmental d i f f e r e n c e s or age d i f f e r e n c e s . Stand age d i f f e r e n c e s ( i . e . comparing mature and s a p l i n g s ) were a s s o c i a t e d with obvious edaphic p e r t u r b a t i o n of one form or another. S e e d l i n g and s a p l i n g samples c o l l e c t e d were growing in r e c e n t l y exposed mineral s o i l , agreeing with the general o b s e r v a t i o n s by Dobbs (1972) and o t h e r s . Along the c o a s t , p o p u l a t i o n s , i n the sense d e f i n e d above, were d i f f i c u l t to f i n d as a consequence of l o g g i n g or simply edaphic c o n d i t i o n s ( i . e . r e l a t i v e l y r e s t r i c t e d edaphic amplitude of P i c e a c o u p l e d with i t s e a r l y s u c c e s s i o n a l o c c u r r e n c e ) . Approximatly 40 percent of the c o l l e c t i o n s made were sampled from lone t r e e s . Indeed, t h i s i n a b i l i t y to s a t i s f y the hypothesized p o p u l a t i o n a l l e v e l of t r a n s - i n d i v i d u a l v a r i a t i o n causes q u e s t i o n s to be asked as whether or not a " p o p u l a t i o n " i s 4 7 indeed a v i a b l e , n a t u r a l l y o c c u r r i n g s u b j e c t worthy of study i n c o a s t a l P i cea c o l l e c t e d in t h i s study. 3.2.2 Taxonomic c i r c u m s c r i p t i o n of samples. A p r e - r e q u i s i t e f o r i n v e s t i g a t i n g the s i m i l a r i t y of taxa i s that r e f e r e n c e samples, des i g n a t e d as "standards", are r e q u i r e d . For the purposes of t h i s study three groups of standards were choosen: standards, p u t a t i v e s , and h y b r i d s . Trees growing along the immediate coast and coast-mainland that o c c u r r e d below 100m ASL and were growing i n a l l u v i a l s i t e s , f l u v i a l t e r r a c e s , L y s i c h i t o n swamps, or beach f r o n t s were d e c l a r e d as standards r e p r e s e n t i n g P^ s i t c h e n s i s . I n d i v i d u a l t r e e s growing at the t r e e - l i n e and w i t h i n 500m of t r e e l i n e i n the Cascade Range and the more e a s t e r l y mountain ranges were, r e g a r d l e s s of edaphic h a b i t a t , c o n s i d e r e d as standards of P. engelmann i i . Owing to the taxonomic c o n f u s i o n between P. engelmanni i and P^ glauca i n B r i t i s h Columbia (Garman 1957; Daubenmire 1974; Roche 1969; T a y l o r 1959) standards r e p r e s e n t a t i v e of P_^  glauca were o b t a i n e d from the Ottawa V a l l e y 1 . Trees which were growing at in t e r m e d i a t e e l e v a t i o n s and d i s p l a y e d " c h a r a c t e r i s t i c " crown and mo r p h o l o g i c a l c h a r a c t e r s of the two taxa were d e c l a r e d to be p u t a t i v e r e p r e s e n t a t i v e s of the taxa being i n v e s t i g a t e d . The d e s c r i p t i o n of " h y b r i d s " was 1 Samples c o l l e c t e d c o u r t esy of D a n i e l Gagnon, U n i v e r s i t e du Quebec a Montreal. \ 48 a p p l i e d to those t r e e s that had an " i n t e r m e d i a t e " crown form and morphological c h a r a c t e r s . Such an i d e n t i f i c a t i o n of h y b r i d i n d i v i d u a l s separated, as a group, t r e e s found growing at intermediate e l e v a t i o n s on the c o a s t a l s i d e of the Cascades and Coast Mountains along a l l u v i a l fans, f l u v i a l t e r r a n c e s , and along steep c o l l u v i a l s lopes with seepage. T h i s c h a r a c t e r i z a t i o n of the " h y b r i d " h a b i t a t c o i n c i d e s with that expected to favour h y b r i d i z a t i o n and s u r v i v a l of h y b r i d s . The d i s p o s i t i o n of samples as standards, p u t a t i v e s , and h y b r i d s i s given i n Table 5. The l a t i t u d i n a l , l o n g i t u d i n a l , and e l e v a t i o n of s e p a r a t i o n of standards of the two taxa should be noted i n F i g u r e 5. More s p e c i f i c d i s p o s i t i o n of i n d i v i d u a l samples i s given i n Appendix I I . 3.2.3 L o c a l geographic c i r c u m s c r i p t i o n of samples. In examining the r e l a t i o n s h i p between morphological and anatomical v a r i a t i o n with l o c a l geographic v a r i a t i o n i t was necessary to a s s i g n samples, somewhat a r b i t r a r i l y , to 16 geographic a r e a s . The general l o c a t i o n of these geographic areas are given i n F i g u r e 6. The d i s t r i b u t i o n of samples i n t o the geographic areas i n given i n Table 8. The d i s t r u b i t i o n of i n d i v i d u a l t r e e s i s given i n Appendix I I . These geographic areas c i r c u m s c r i b e the occurrence of samples and can be d i v i d e d i n t o three broad areas: c o a s t , t r a n s i t i o n , and i n t e r i o r . These broad areas roughly correspond to the physiography of the study area (Holland 1976). The 16 geographic areas are not meant to r e f l e c t c l i m a t i c , e c o l o g i c a l , 49 F i g u r e 6. L o c a t i o n of g e o g r a p h i c a r e a s c i r c u m s c r i b i n g samples . Genera l g e o g r a p h i c a r e a s : C - c o a s t ; T - t r a n s i t i o n ; I - i n t e r i o r . S p e c i f i c g e o g r a p h i c l o c a t i o n s : 1 - s o u t h e r n Vancouver Is. and O lympic P e n n i n s u l a ( SV IOLY) ; 2 - Howe Sd. and W h i s t l e r (HOWHIS); 3 - lower F r a s e r V a l l e y (LOFRAV); 4 - Toba I n l e t (TOBA ) ; 5 - Bute I n l e t (BUTE); 6 - K n i g h t I n l e t (KNIGHT); 7 - n o r t h e r n Vancouver Is. (NVANCI); 8 -C h i l l i w a c k V a l l e y ( C H I L L I ) ; 9 - F r a s e r Canyon (HOPLYT); 10 - upper L i l l o o e t t R i v e r (PEMBRA); 11 - Sumalo and Skag i t R i v e r s (HOPMAN) ; 12 - S i m i l k a m e e n R i v e r (MANPRI ) : 13 - Okanagan (OKAN); 14 - Mt. R e v e l s t o k e (MTREV); 15 - R o g e r s ' Pass (ROGPAS 1 ; 16 - M ica Creek (MICA ) . edaphic, or taxonomic groups. They simply group together samples i n a given geographic area and are g e n e r a l l y c i r c u m s c r i b e d by a major drainage and attempt to i l l u s t r a t e the l o c a l m o r p h o l o g i c a l and environmental v a r i a t i o n that might be encountered i n such an a r e a . Table 8 i l l u s t r a t e s the v a r i e t y of i d e n t i f i c a t i o n s that can be found i n a narrowly d e f i n e d area. 3.3 S e l e c t i o n of samples. The arbo rescent h a b i t of P i c e a made for s p e c i f i c problems in s ystematic sampling of f o l i a g e , branches, and cones. F o l i a g e and branches were of t e n not e a s i l y obtained even with a 3m long pole pruner. The lowest whorl branches were o f t e n over 6m above the ground. Cones i n the two s p e c i e s are u s u a l l y r e s t r i c t e d to 50 T a b l e 8. D i s t r i b u t i o n of samples i n t o g e o g r a p h i c a r e a s . Numbers and a b b r e v i a t i o n s f o r g e o g r a p h i c a r e a s g i v e n i n c a p t i o n to F i g u r e 6. SSS - s i t chens i s s t a n d a r d : SSP - P^ s i t chens i s p u t a t i v e ; SXE -" h y b r i d " : ESP - P^ enge lmanni i p u t a t i v e ; ESS - P^ . engelmanni i s t a n d a r d ; IESP - S e l k i r k Mtns. P_^  engelmanni i p u t a t i v e ; IESS -S e l k i r k Mtns. P_^_ enge lmanni i s t a n d a r d . Note , not a l l t r e e s c o l l e c t e d were a s s i g n e d to a g e o g r a p h i c a r e a . GEOGRAPHIC IDENTIFICATION AREA U ) SSS SSP SXE ESP ESS IESP IESS TOTAL SVIOLY 1 9 15 24 HOWHIS 2 38 2 47 2 89 LOFRAV 3 5 6 1 1 TOBA 4 1 14 1 16 BUTE 5 3 5 8 KNIGHT 6 18 30 2 50 NVANCI 7 7 1 1 18 CHILLI 8 • 3 21 24 HOPLYT 9 2 8 10 PEMBRA 10 66 66 HOPMAN 1 1 14 4 18 MANPRI 12 28 44 72 OKAN 13 1 27 28 MTREV 14 5 24 29 ROGPAS 15 24 24 MICA 16 5 16 21 * * 508 * * the top t h i r d of the canopy of the t r e e (Owens and Molder 1976b; H a r r i s o n and Owens 1983) and c o l l e c t i o n s of cones u s u a l l y had to be made from cones that had f a l l e n to the ground. Cones were not always a v a i l a b l e as a r e s u l t of poor or sporadic cone-set, i n s e c t damage, or s q u i r r e l p r e d a t i o n . Those t r e e s f i v e years o l d or younger were not sampled owing to the d i m i n u t i v e s i z e of the f o l i a g e and problems encountered with the manipulation of such small s t r u c t u r e s d u r i n g measurement. As w e l l , such young t r e e s appear to d i s p l a y j u v e n i l l e f o l i a g e that i s d i s t i n c t from mature t r e e s ( J e f f e r s 1974). S i m i l a r r e l a t i o n s between age and s i z e have been reported by Funsch (1975), although he c l a i m s that the e f f e c t of age i s most pronounced f o r t r e e s younger than 15 years. Another aspect of immature t r e e s that was observed regards pubescence. 51 I t appears that young t r e e s may lack pubescence whereas the mature t r e e s i n the same stand have pubescence. Based on o b s e r v a t i o n s at the C h i l l i w a c k River Nursery, s p e c i e s that are d e s c r i b e d as pubescent, are glabrous when young. L i n d q u i s t (1948) r e p o r t s s i m i l a r o b s e r v a t i o n s f o r P_;_ a b i e s . For these reasons twig morphology was not recorded f o r immature t r e e s . Wherever p o s s i b l e , v e g e t a t i v e and r e p r o d u c t i v e m a t e r i a l s were c o l l e c t e d from each i n d i v i d u a l . Cones were c o l l e c t e d from around the base of the i n d i v i d u a l i n such a manner that p o s s i b l e contamination by cones from neighbouring t r e e s was minimized. I t was assumed that t h i s manner of c o l l e c t i n g cones represented a random sample from the canopy. Cone c o l l e c t i o n s made d i r e c t l y from the upper canopy of t r e e s were made by c l i m b i n g , or sampling standing t r e e s from a h e l i c o p t e r or from f a l l e n t r e e s . F o l l o w i n g c o l l e c t i o n , the cones were examined and, on the b a s i s of the amount of decomposition, only those cones o b v i o u s l y belonging to the most recent cone crop were r e t a i n e d f o r measurement. Branch and f o l i a g e c o l l e c t i o n s were made from the lowermost whorl primary branches ( F i g . 7). Twig and needles were sampled from the middle of a two year o l d increment. Such c o l l e c t i o n s were not always a v a i l a b l e and other orders of branches from d i f f e r e n t canopy p o s i t i o n s had to be c o l l e c t e d . The true order of branching was o f t e n d i f f i c u l t to i d e n t i f y owing to previous damage to branches c o l l e c t e d . For t r e e s growing at t r e e l i n e , where annual e x t e n s i o n growth was very s m a l l , i t was not p o s s i b l e to measure c h a r a c t e r s a s s o c i a t e d with twig morphology. 52 F i g u r e 7. S c h e m a t i c r e p r e s e n t a t i o n of s o u r c e s of i n t r a - i n d i v i d u a 1 v a r i a t i o n a s s o c i a t e d w i t h b r a n c h a r c h i t e c t u r e in enge1mann i i and P. s i t c h e n s 1 s . A) F o u r - y e a r o l d stem (O) w i t h whorl (W) and i n t e r w h o r l ( I ) p r i m a r y (1) b r a n c h e s . B) T h r e e - y e a r o l d whorl p r i m a r y b r a n c h w i t h whor l and i n t e r w h o r l s econda ry (2) b r a n c h e s . C i r c l e s r e p r e s e n t whorl nodes . O r d e r i n g scheme i s a c r o p e t a l . G e n e r a l l y , v e g e t a t i v e m a t e r i a l s were more d i f f i c u l t to o b t a i n than were r e p r o d u c t i v e m a t e r i a l s (Table 9). More complete c o l l e c t i o n s c o u l d be made in the i n t e r i o r where the t r e e s were smaller and had narrower crown forms.. The p a t c h i n e s s of the sampling from i n d i v i d u a l s c r e a t e d unbalanced v a r i a b l e s u i t e s f o r separate t r e e s ( i . e . not a l l t r e e s c o u l d have the same number of v a r i a b l e s u i t e s measured). Such an unbalanced a v a i l a b i l i t y of samples complicates any pure s t a t i s t i c a l e v a l u a t i o n of the da t a . A general summary of the number of complete v a r i a b l e s u i t e s i s given i n Table 9. S p e c i f i c d i s p o s i t i o n of i n d i v i d u a l s with respect to v a r i a b l e s u i t e s i s given i n Appendix I I . 53 T a b l e 9. Summary of samples w i t h c o m p l e t e measurements f o r v a r i o u s v a r i a b l e s u i t e s . p - tt v a r i a b l e s per v a r i a b l e s u i t e . No te , cone morphology i n c l u d e s cone c o l l e c t i o n v a r i a b l e s . IDENTIFICATION VARIABLE SUITES MORPHOLOGY ANATOMY TOTAL TOTAL CONE TWIG LEAF LEAF AVAI LABI (p=15) (P = 4) (p = 6) (p=11) (p=36) P. s i t c h e n s i s STANDARDS 42 46 46 44 24 62 PUTATIVES 59 35 35 19 16 65 "HYBRIDS" 102 99 100 77 50 133 P . enge1mann i i STANDARDS 45 53 53 65 37 7 1 PUTATIVES 63 60 52 7 1 38 105 SELKIRK MTNS. STANDARDS 10 10 10 10 10 10 PUTATIVES 55 45 45 4 1 29 69 4. Analyses. The data analyses conducted here are p r i m a r i l y e x p l o r a t o r y rather than c o n f i r m a t o r y in nature ( M o s t e l l e r and Tukey 1977). P r e c i s e s t a t i s t i c a l i n f e r e n c e s , a l t h o u g h an experimental i d e a l , are f r e q u e n t l y d i f f i c u l t to make owing to the n e c e s s i t y of s a t i s f y i n g attendant assumptions. Such an approach focuses more on the u t i l i z a t i o n of s t a t i s t i c a l techniques f o r purposes of general i n d i c a t i o n and de t e r m i n a t i o n r a t h e r than p r e c i s e s t a t i s t i c a l i n f e r e n c e s . The a n a l y t i c and b i o l o g i c a l assumptions a s s o c i a t e d with such h e u r i s t i c approaches are l e s s s t r i n g e n t than those a s s o c i a t e d with p u r e l y c o n f i r m a t o r y s t a t i s t i c a l approaches. I t i s worth n o t i n g t h a t e x p l o r a t o r y data a n a l y s i s i s an i n t e g r a l p a r t of a c o n f i r m a t o r y d a t a - a n a l y t i c p r o t o c o l . F u r t h e r , t h i s approach i n b i o l o g y and sys t e m a t i c s i s not new, merely a r e p h r a s i n g of the inf o r m a l d a t a - a n a l y t i c methodology of Anderson (1941, 1949, 1956). 54 4.1 Mathematical n o t a t i o n and f o r m u l a t i o n The mathematical n o t a t i o n and f o r m u l a t i o n given here has been i n t e n t i o n a l l y s i m p l i f i e d and minimized to allow f o r an a p p r e c i a t i o n of the t r a n s l a t i o n of the b i o l o g i c a l s i t u a t i o n under i n v e s t i g a t i o n i n t o the a c t u a l a n a l y t i c model employed i n the i n v e s t i g a t i o n . Such b r e v i t y a l l o w s fo r the communication of a n a l y t i c i n t u i t i o n , and does not encumber the reader with the complexity and d e t a i l of the a n a l y s i s . S i m i l a r l y , owing to the l e n g t h of v a r i o u s a n a l y t i c r e s u l t s , the n o t a t i o n and d e t a i l presented i n the body of the t e x t i s i n t e n t i o n a l l y minimized. However, as the d i s c u s s i o n of many of the r e s u l t s are based upon d e t a i l s excluded in these t a b l e s i n the t e x t , the complete t a b l e s are presented in Appendix I I I . 4.2 S t a t i s t i c a l techniques. Data were subjected to a v a r i e t y of u n i v a r i a t e ( a n a l y s i s of v a r i a n c e (ANOVA), r e g r e s s i o n , and c o r r e l a t i o n ) and m u l t i v a r i a t e techniques ( p r i n c i p a l components a n a l y s i s (PCA)). U n i v a r i a t e techniques (UVA) estimate v a r i o u s p o p u l a t i o n parameters from the data whereas m u l t i v a r i a t e techniques (MVA) are t y p i c a l l y used to maximize v a r i o u s parameters and minimize the d i m e n s i o n a l i t y of the d ata. MVAs produce summary s t a t i s t i c s and v a r i a b l e s which are l i n e a r composites of the o r i g i n a l v a r i a b l e s and are used to e x p l o r e f u r t h e r the r e l a t i o n s among samples where the o r i g i n a l v a r i a b l e s would not o r d i n a r i l y permit such e x p l o r a t i o n because of v a r i a b l e i n t e r - c o r r e l a t i o n s . 55 MVA methods have been used most commonly as the b a s i s f o r t e n d e r i n g e v o l u t i o n a r y i n f e r e n c e s . Making more d i r e c t g e n e t i c i n f e r e n c e s , a s i d e from c o n t r o l l e d h y b r i d i z a t i o n (Sharik and Barnes 1971; T a i and Tarn 1980; T a i and De Jong 1980; Williamson 1977; Goodman 1967; Neff and Smith 1979), are comparatively r a r e and recent (Lande 1979; Leamy 1977; Morishima and Oka 1968; Oka and Morishima 1968; Smith, et a l . 1962; Wright 1954; H a s h i g u i c h i and Morishima 1969; A t c h l e y , et a l . 1982; Chevrud, e_t a l . 1983). Most g e n e t i c i n f e r e n c e s have been based on UVA (see however Becker 1967, regarding " s e l e c t i o n i n d i c e s " ) . Although g e n e t i c i n f e r e n c e d e r i v e d from UVA are o f t e n a p p r o p r i a t e f o r s p e c i f i c breeding purposes, they g e n e r a l l y ignore the m u l t i v a r i a t e nature of c h a r a c t e r v a r i a t i o n and c o v a r i a t i o n (Arnold 1981; Sterns 1984). To ignore such aspects of g e n e t i c v a r i a t i o n i g n o r e s , f o r example, the p o t e n t i a l e f f e c t of intra-chromosomal l i n k a g e , inter-chromosomal e f f e c t s , m u l t i - g e n i c e f f e c t s , and c y t o p l a s m i c e f f e c t s i n accounting f o r observed p a t t e r n s of phenotypic v a r i a t i o n . I t i s the i n t e r - r e l a t i o n of v a r i a b l e s that i s fundamental to s t u d i e s of b i o l o g i c a l systems. Development and e v o l u t i o n can be viewed as changing v a r i a b l e i n t e r - r e l a t i o n s with r e s p e c t to d i f f e r e n t time s c a l e s . Maze, et a_l. ( 1984) and S c a g e l , et a l . (1984) demonstrate such changes f o r ovule development of Nothofagus a n t a r c t i c a . M i t t o n , et a l . (1980) demonstrate s i m i l a r changes between p o p u l a t i o n s of Pinus ponderosa. Maze (1983) demonstrates such changes between p o p u l a t i o n and s p e c i e s of Abies. Most s t r u c t u r e d m u l t i v a r i a t e systematic s t u d i e s r e l y on these v a r i a b l e i n t e r - c o r r e l a t i o n s (Adams 1982; Campbell and 56 Dearn 1980; Scagel and Maze 1984). MVA methods are used throughout the study as they provide fo r simultaneous q u a n t i f i c a t i o n of v a r i a t i o n and l i n e a r inter-independance of v a r i a b l e s . By c o n t r a s t , UVA methods pro v i d e for q u a n t i f i c a t i o n of only s i n g l e v a r i a b l e s one at a time and n e g l e c t the inter-dependance of v a r i a b l e s . Q u a n t i f i c a t i o n and s t a t i s t i c a l a t t e n t i o n to v a r i a b l e inter-dependance r e s p e c t s the i n t e g r a t e d nature of b i o l o g i c a l systems. In the case of whole organisms, developmental and e v o l u t i o n a r y interdependance. 4.2.1 Conformity to d i s t r i b u t i o n a l assumptions. U t i l i z a t i o n of UVA and MVA o f t e n r e q u i r e s a t i s f a c t i o n of s p e c i f i c sampling and d i s t r i b u t i o n a l assumptions about the data. A common d i s t r i b u t i o n a l assumption i s that the data be normally d i s t r i b u t e d . In a s s e s s i n g n o r m a l i t y of v a r i a b l e d i s t r i b u t i o n s D'Agostino's t e s t of n o r m a l i t y (Zar 1974) was used. V a r i a b l e s not f a l l i n g w i t h i n the s p e c i f i e d c o n f i d e n c e l i m i t s c a l c u l a t e d f o r D'Agostino's D were f u r t h e r c h a r a c t e r i z e d u sing cumulative frequency d i s t r i b u t i o n p l o t s (CFDs, Univ. of Michigan, S t a t i s t i c a l Research Lab. 1976), measures of skewness (gt) and k u r t o s i s ( g ^ ) . Such c h a r a c t e r i z a t i o n allows i n f e r e n c e s to be drawn concerning the nature of the d i s t r i b u t i o n (Bock 1975), suggests t r a n s f o r m a t i o n s a p p r o p r i a t e to minimize departures from n o r m a l i t y , and a i d s i n the d e t e c t i o n of o u t l i e r s (Barnett and Lewis 1978). Transforming data to approximate n o r m a l i t y or symmetrize the data (Tukey 1977), although u s e f u l f o r drawing 57 s t a t i s t i c a l c o n c l u s i o n s , may make i n t e r p r e t a t i o n d i f f i c u l t . For the v a r i o u s data s e t s examined the v a r i a b l e s d i d not have to be transformed. Most v a r i a b l e s appeared to be s l i g h t l y skewed to the r i g h t from that expected f o r normally d i s t r i b u t e d d a t a . T h i s i s the same s i t u a t i o n r e p o r t e d by Barkworth, e_t a l . jj_979). Such skewed d i s t r i b u t i o n s may be a t t r i b u t e d e i t h e r to the consequence of i n c r e a s e d developmental v a r i a b i l i t y at l a r g e r s i z e s or to i n c r e a s e d measurement e r r o r . M u l t i v a r i a t e n o r m a l i t y i s assumed f o r s t a t i s t i c a l a p p l i c a t i o n s of MVA. The assessment of m u l t i v a r i a t e n o r m a l i t y i s most e a s i l y approached by a s s u r i n g that the marginal d i s t r i b u t i o n s of the v a r i a b l e s are normally d i s t r i b u t e d (Bock 1975; Pimentel 1979). G e n e r a l l y , i f the marginal d i s t r i b u t i o n s approximate n o r m a l i t y , so w i l l the c o n d i t i o n a l and component d i s t r i b u t i o n s , thereby approximating m u l t i v a r i a t e n o r m a l i t y (Pimentel 1979). However, marginal n o r m a l i t y by i t s e l f i s not s u f f i c i e n t to i n d i c a t e m u l t i v a r i a t e n o r m a l i t y . P u r e l y s t a t i s t i c a l assessments of m u l t i v a i a t e n o r m a l i t y are a v a i l a b l e (Mardia 1970, 1974; Wagle 1968; Day 1969; Mardia and Zemrock 1975; Machado 1983; Malmgren 1979; Reyment 1971; Cox and Small 1978; Andrews, e_t §JL. 1972) ,however s t a t i s t i c a l elegance i s achi e v e d at the expense of computational cost and r e s t r i c t i o n to d i m e n s i o n a l l y small s e t s of data. An h e u r i s t i c assessment of the conformity to m u l t i v a r i a t e n o r m a l i t y i s p r o v i d e d by the CFD technique proposed by Campbell (1980). Gnanadesikan (1977) p r o v i d e s many examples of the use of CFD techniques f o r c h a r a c t e r i z i n g m u l t i v a r i a t e data p r i o r to MVA. 58 For most h e u r i s t i c a p p l i c a t i o n s of MVA, m u l t i v a r i a t e n o r m a l i t y does not have to be assumed, merely that the data not c o n t a i n w i l d o u t l i e r s or groups of o u t l i e r s . Some MVA, such as c a n o n i c a l v a r i a t e s a n a l y s i s (CVA), may be s e n s i t i v e to departures from m u l t i v a r i a t e n o r m a l i t y , e s p e c i a l l y with repect to i n d i v i d u a l group c o v a r i a n c e m a t r i c e s (Gower 1972). The data s e t s examined here were a l l i n d i c a t e d as being m u l t i v a r i a t e normally d i s t r i b u t e d . S i n g l e or groups of o u t l i e r s were a p p a r a n t l y n o n - e x i s t e n t , and there was l i t t l e i n the way of departure from the curve expected f o r a m u l t i v a r i a t e normal d i s t r i b u t i o n . 4.2.2 Sample s i z e . Fundamental to any study of v a r i a t i o n i s the establishment of an adequate sample s i z e (n) f o r a s p e c i f i c purpose. Such concerns r e f e r to the sample accuracy. Previous i n v e s t i g a t i o n s in' Picea have g e n e r a l l y used an n based on c r i t e r i a r e l a t i n g more to the economics of the study r a t h e r than r e s p e c t i n g the v a r i a b i l i t y of the organism. No i n f o r m a t i o n i s p r o v i d e d i n any of these s t u d i e s as to the adequacy of the sample s i z e s used (see Table 1 f o r c i t a t i o n of s p e c i f i c s t u d i e s ) . Concern f o r the economics of conducting r e s e a r c h may w e l l c o n s t i t u t e a v a l i d c r i t e r i o n f o r d e c i d i n g upon a given n. However, without some in f o r m a t i o n c o n c e r n i n g the adequacy of n in e s t i m a t i n g a d e s i r e d p o p u l a t i o n parameter there can be l i t t l e c o nfidence p l a c e d i n the value of the sample s t a t i s t i c . Sample 59 s i z e d i r e c t l y i n f l u e n c e s the sample s t a t i s t i c - the l a r g e r n i s the more r e l i a b l e i s the s t a t i s t i c that estimates the parameter. Any estimate of n i s , by d e f i n i t i o n , sample s p e c i f i c . The more v a r i a b l e a c o l l e c t i o n of samples, the l a r g e r an n w i l l be r e q u i r e d to estimate r e l i a b l y a given parameter. The sample s i z e e s t i m a t i o n technique employed here i s based upon the methodology o u t l i n e d i n Scagel, e_t a_l. (1984). T h i s approach seeks to s e l e c t an n at which the determinant of the c o r r e l a t i o n matrix (|R|) s t a b i l i z e s , thereby p r o v i d i n g a s t a b l e n f o r MVA. A s i m i l a r sample s i z e e s t i m a t i o n methodology i s used f o r i n d i v i d u a l v a r i a b l e s where one s e l e c t s an n at which the standard e r r o r of the mean i s l e s s than the accuracy of the measuring d e v i c e . During the i n i t i a l sampling f o r t h i s study a u n i v a r i a t e sample s i z e e s t i m a t i o n technique i l l u s t r a t e d by Green (1972) i n concert with a g r a p h i c a l technique i l l u s t r a t e d by Wood (1972) was used. The technique i l l u s t r a t e d by Green (1972) r e q u i r e s that an estimate of the p o p u l a t i o n c o e f f i c i e n t of v a r i a t i o n be made. In c o n t r a s t , Wood's (1972) technique i s a s e q u e n t i a l , s a m p l e - s p e c i f i c g r a p h i c a l technique. Sample s i z e s suggested by these techniques were used as the b a s i s f o r s e l e c t i n g sample s i z e f o r separate v a r i a b l e s u i t e s . However, u t i l i z i n g the l e s s parameter- and s a m p l e - s p e c i f i c methodology of S c a g e l , et a l . (1984) i n d i c a t e d that these i n i t i a l sample s i z e estimates were g e n e r a l l y too small (Table 10). In a r r i v i n g at the m u l t i v a r i a t e e x t e n s i o n of the sample-size e s t i m a t i o n a s i m i l a r u nderestimation of m u l t i v a r i a t e sample s i z e was observed f o r the 60 T a b l e 1 0 . S a m p l e s i z e e s t i m a t e s f o r m t r a - i n d i v i d u a 1 v a r i a t i o n ( n ) a n d i n t e r - i n d i v i d u a l v a r i a t i o n ( t ) . E s t i m a t e s b a s e d o n s t a n d a r d s o f b o t h t a x a . U n i v a r i a t e e s t i m a t e s b a s e d u p o n t r i e n o r t a t w h i c h s e . d e c l i n e s b e l o w m e a s u r e m e n t a c c u r a c y . M u l t i v a r i a t e e s t i m a t e s b a s e d u p o n n o r t a t w h i c h | R ( o r D • s t a b i l i z e i n t e r - i n d i v i d u a l v a r i a t i o n b a s e d o n a v e r a g i n g n b a s e d o n s a m p l e - s i z e e s t i m a t i o n o f G r e e n ( 1 9 7 2 ) a n d W o o d ( 1 9 7 2 ) ( n / t U S E D t - n b a s e d o n l a r g e r o f G r e e n o r W o o d ' s t e c h n i q u e . p - n u m b e r o f v a r i a b l e s p e r v a r i a b l e s u i t e . n n / t U S E D t V A R I A B L E 'neftt ' — s i t c h e n s i s P . e n g e 1 m a n n i i P . s ' t c h e n s i s P e n g e 1 m a n n ; i N E E D L E N ( 8 » 1 0 5 5 2 0 1 5 4 B X S T 0 M ( 9 1 5 5 2 5 2 0 4 D X S T 0 M ( 7 ) 1 0 5 1 0 1 0 R E S C Y N O ( 3 5 ) 1 1 1 1 R E S C Y L O C 1 1 9 ) 1 0 2 0 1 0 2 0 R E S C Y L E N ( 4 7 ) 1 0 2 0 1 0 1 5 P U L V L E N 1 8 ) 2 0 3 0 5 4 0 4 0 T I P W I O ( 2 ) 7 1 5 2 0 1 0 T I P O E P ( 2 ) 5 1 0 15 2 0 P U L V P U B ( 1 ) 1 1 1 1 N E E D W I D ( 2 ) 2 5 3 0 5 5 0 4 5 N E E D E P ( 1 I 2 0 3 0 4 5 4 0 4 B X 4 N G < 1 ) 5 1 0 1 0 2 0 4 D X 4 N G ( 3 ) 8 2 0 2 0 1 5 C E N C Y W I D ( 1 ) 2 0 3 0 4 5 4 5 C E N C Y L 4 T ( 2 1 2 5 3 5 7 0 5 0 C E N C V 4 B X ( 2 ) 2 0 3 5 3 0 4 0 C E N C Y 4 D X 1 8 ) 2 5 3 5 5 0 4 5 E N D O N U M ( 2 1 5 1 0 5 2 5 P H L E N D ( 4 ) 2 0 4 0 5 0 4 5 X V L E N D ( 1 1 ) 2 5 3 0 4 5 3 0 C O N L E N ( 3 ) 3 0 2 0 5 2 5 2 5 C Q N W I D ( 2 ) 2 0 1 5 . 1 0 1 0 S C 4 L E N ( 7 1 1 5 1 0 5 1 0 S C 4 L W I D ( 6 ) 2 0 2 5 " 2 0 3 0 S C 4 L T 4 P I 1 2 ) 2 5 3 0 2 5 3 5 W I N G W I D ( 8 ) 3 0 3 0 2 0 3 0 W I N G T A P ( 1 0 ) 2 0 3 0 2 0 2 0 F R E E S C 4 L ( 2 8 ) 1 5 3 5 2 5 3 5 B R A C T L E N ( 2 0 ) 2 5 2 5 3 0 3 5 B R A C T W 1 D ( 1 2 ) 1 0 5 1 0 1 5 B R 4 C T T 4 P ( 3 0 ) 2 5 1 0 2 5 2 0 S H C O L E N ( 3 ) - - >5 2 5 2 5 S H C O W I D ( 2 ) - - 1 5 1 0 L O C O L E N ( 3 ) - 2 5 2 0 L O C O W I D I 2 ) - 5 1 0 V A R I 4 B L E S U I T E L E A F 4 N 4 T 0 M Y : | R | 3 0 3 5 5 4 0 3 0 ( p = 1 1 > D ' 2 5 3 0 3 0 2 0 C O N E C O L L E C T I O N : 1*1 - _ 1 3 0 3 5 ( p » 1 1 ) D ' - - 2 5 2 0 L E A F M O R P H O L O G Y : l«l 3 0 2 5 5 3 0 4 0 < p = 6 1 D ' 2 0 1 0 9 1 5 T W I G M O R P H O L O G Y : | R | 1 0 2 5 5 2 5 2 0 ( p = 4 ) 0 ' 2 0 1 5 1 2 1 0 C O N E M O R P H O L O G Y : lei 3 5 3 0 1 0 3 5 3 5 ( p = 4 ) D 1 1 5 2 5 2 0 2 0 61 technique proposed by Newhan and Jancey (1981). In a d d i t i o n to the s t a b i l i z a t i o n of the determinant of the c o r r e l a t i o n m a t r i c , the s t a b i l i z a t i o n of Mahalanobis' D 2 was a l s o examined. The determinant of the c o r r e l a t i o n matrix i s an e s s e n t i a l s t a t i s t i c f o r the m u l t i v a r i a t e a p p l i c a t i o n of MVA. Mahalanobis' D 2 i s an e s s e n t i a l s t a t i s t i c i n the s t a t i s t i c a l a p p l i c a t i o n of a s t r u c t u r e d MVA such as m u l t i v a r i a t e a n a l y s i s of v a r i a n c e (MANOVA) and i t s f u r t h e r e x t e n s i o n to CVA and d i s c r i m i n a n t f u n c t i o n a n a l y s i s (DFA). Assessment of the s t a b i l i z a t i o n of Mahalanobis' D 2 i s a p r e - r e q u i s i t e to performing a s t r u c t u r e d MVA. U n i v a r i a t e and m u l t i v a r i a t e sample s i z e estimates are given f o r a l l v a r i a b l e s and v a r i a b l e s u i t e s i n Table 10. The sample s i z e s r e p o r t e d here f o r both i n t r a - and i n t e r - i n d i v i d u a l l e v e l s of v a r i a t i o n are based upon standards of each s p e c i e s . Sample s i z e s (n or t) and degrees of freedom <df) have been given e x p l i c i t l y i n a l l t a b l e s and f i g u r e s . The a c t u a l sample s i z e s employed were smaller than those i n d i c a t e d by Table 10 as the t e s t s were performed a f t e r sampling was completed. 4.2.3 D i s c r e t e v a r i a b l e s . P u l v i n u s pubescence, u n l i k e the other v a r i a b l e s i s a q u a l i t a t i v e r a t h e r than q u a n t i t a t i v e v a r i a b l e (Appendix I ) . The i n c l u s i o n of such a v a r i a b l e along with q u a n t i t a t i v e continuous v a r i a b l e s i n a m u l t i v a r i a t e a n a l y s i s may c o n t r i b u t e more to inter-sample d i f f e r e n c e s than the q u a n t i t a t i v e v a r i a b l e s , even when s t a n d a r d i z e d (Barkworth, et a_l. 1979; Sneath and Sokal 62 1973). R e a l i z i n g that the i n c l u s i o n of such a q u a l i t a t i v e v a r i a b l e may bi a s the r e s u l t s of a m u l t i v a r i a t e a n a l y s i s , i t i s c r i t i c a l to determine the degree that such a v a r i a b l e may be a s s o i c a t e d with other v a r i a b l e s p r i o r to being submitted to an a n a l y s i s . I f the v a r i a t i o n of such a v a r i a b l e i s s i m i l a r to that of the other v a r i a b l e s then i t i s permissable to i n c l u d e the two types of v a r i a b l e s i n the same a n a l y s i s . A measure of p a r t i a l c o r r e l a t i o n c o u l d address the problem of the c o n t r i b u t i o n of the c a t e g o r i c a l v a r i a b l e i n a b i v a r i a t e s i t u a t i o n ; however, i t does not address the m u l t i v a r i a t e nature of the s i t u a t i o n nor does i t address the que s t i o n of whether the q u a l i t a t i v e v a r i a b l e - s t a t e i s a s s o c i a t e d with the q u a n t i t a t i v e v a r i a b l e s . Rephrasing, a b i v a r i a t e approach does not allow one to determine i f , assuming a q u a n t i t a t i v e v a r i a b l e i s ta x o n o m i c a l l y s i g n i f i c a n t , the q u a l i t a t i v e v a r i a b l e i s s i m i l a r i l y s i g n i f i c a n t . Barkworth, et a_l. (1979) addressed t h i s problem by way of MANOVA. B r i e f l y , the groups of samples they submitted to MANOVA were determined by the s t a t e of a q u a l i t a t i v e c h a r a c t e r and only q u a n t i t a t i v e c h a r a c t e r s were employed. Employing Wilk's A to t e s t the m u l t i v a r i a t e d i f f e r e n c e s between the group c e n t r o i d s enabled them to determine whether a s p e c i f i c q u a l i t a t i v e v a r i a b l e - s t a t e used to c a l i b r a t e the groups was indeed t a x o n o m i c a l l y s i g n i f i c a n t ( i . e . shared v a r i a t i o n with q u a n t i t a t i v e v a r i a b l e s ) . Such an approach to the e v a l u a t i o n of the c o n t r i b u t i o n of the q u a l i t a t i v e v a r i a b l e to the r e l a t i o n s h i p s amongst the two sp e c i e s was taken here. I t should 63 be p o i n t e d out that as only two v a r i a b l e s t a t e s were i n v o l v e d here (pubescence: present or absen t ) , the MANOVA approach employeed by Barkworth, et aJL. (1979) s i m p l i f i e s to H o t e l l i n g ' s T 2 t e s t of the d i f f e r e n c e between two c e n t r o i d s (Morrison 1976). A summary of the T 2 s performed i s given in Tables 11. In T a b l e 11. Summary of H o t e l l i n g ' s T ' f o r tw i g morphology based on v a r i a b l e s t a t e f o r d i s c r e t e ( p r e s e n c e / absence ) v a r i a b l e : p u l v i n u s p u b e s c e n c e . * , T ! s i g n i f i c a n t 9 p < 0 . 0 1 ; D 7 v a l u e s g i v e n i n body of t a b l e . P.s - P_^  s i t chens i s ; P . g - g l a u c a ; P . e - P_^  engelmanni i . COMPARISON df 13,x) INTRA-INDIVIDUAL ADVENTITIOUS v s . WHORL 8 PRIMARY v s . SECONDARY 98 1979 V S . 1981 9 INTERWHORL P^ s i t c h e n s i s 52 INTERWHORL P^ enge lmanni i 58 i nvar i a t e i nvar i a t e i nvar i a t e 2 . 97 i nvar i a t e INTER-INDIVIDUAL P. s i t chens i s  P. enge1mann i i  P. g l a u c a 530 385 6 1 1 . 97 0. 37 1 1 . 50 INTER-SPECIF IC P.s x P.e x P g P.s x P.e 984 919 1 . 14* 1 . 59* only two i n s t a n c e s were the continuous v a r i a b l e s of twig morphology i n d i c a t e d as showing s i g n i f i c a n t d i f f e r e n c e s between the groups being compared. For those comparisons where the v a r i a b l e was e i t h e r i n v a r i a t e or the a t t a i n e d T 2 was not s i g n i f i c a n t , the v a r i a b l e was excluded from f u r t h e r a n a l y s i s f o r that source of v a r i a t i o n . 64 4.2.4 U n i v a r i a t e a n a l y s e s . ANOVA was used both as a means of t e s t i n g the d i f f e r e n c e s between means as w e l l as examining the s t r u c t u r e of the data. ANOVA was used as a means of p a r t i t i o n i n g the v a r i a t i o n on the ba s i s of the percentage of the t o t a l sums of squares i n t o v a r i o u s hypothesized sources (%SS 5 0 w R C,e. ( u v a ) ) . The use of ANOVA f o r both h e u r i s t i c and s t a t i s t i c a l purposes i s c o n s i s t a n t with the d a t a - e x p l o r a t i v e purpose of ANOVA (Tukey 1962; Tukey and Wilk 1966; Kempthorne 1978; Wilkinson 1978; O'Grady 1982). B a r t l e t t ' s t e s t (Zar 1974) was used in t e s t i n g the e q u a l i t y of the group v a r i a n c e s when the ANOVA model employed was balanced or near-balanced. The s p e c i f i c forms of the ANOVA models used are given e x p l i c i t l y i n the t e x t as "nude" models (Nooney 1965). The p a r t i t i o n i n g of v a r i a t i o n on the b a s i s of sums of squares i s , i n comparison with the "variance component a n a l y s i s " (Sokal and Rohlf 1969), l e s s dependent upon the assumptions of the homogeneity of group v a r i a n c e s . A d d i t i o n a l l y , p a r t i t i o n i n g by a sums of square c r i t e r i o n r a t h e r than a mean square c r i t e r i o n a l l o w s one to compare the v a r i a t i o n of i n d i v i d u a l groups f o r a s p e c i f i c h y p o t h e s i z e d source of v a r i a t i o n . At the time of completion of t h i s study i t was observed that the two methods of p a r t i t i o n i n g v a r i a n c e from an hypothesized source gave approximately equal r e s u l t s . For most of the MVAs performed, UVAs of the i n d i v i d u a l v a r i a b l e s i n v o l v e d were a l s o performed and the r e s u l t s presented along with the MVA. Although these UVAs are o f t e n unneccessary for the purpose of the p o i n t s r a i s e d here, they are a v a l u a b l e 65 adjunct f o r two reasons. F i r s t , under s i t u a t i o n s where a reader may not be f a m i l i a r with the MVA techniques used, such UVA w i l l a l low an a p p r e c i a t i o n f o r the s i t u a t i o n being d e s c r i b e d . Secondly, f o r readers i n t e r e s t e d i n extending the r e s u l t s given here to independent r e s e a r c h , such UVA may be u s e f u l i n d e s i g n i n g a sampling technique and c o n s i d e r i n g , s p e c i f i c v a r i a b l e s ( i . e . Newman and Jancey 1983). 4.2.5 M u l t i v a r i a t e a n a l y s e s . PCA was the p r i n c i p a l MVA technique used. The summary v a r i a b l e s provide the b a s i s f o r most of the UVA. PCA maximizes the between sample v a r i a n c e i n the data and a l l o w s a comparison of the i n d i v i d u a l samples without a p r i o r i s t r a t i f i c a t i o n of v a r i a b l e s (as i n c a n o n i c a l c o r r e l a t i o n a n a l y s i s ) or samples (as i n c a n o n i c a l v a r i a t e s a n a l y s i s (CCA)). In a l l cases PCA was performed upon a c o r r e l a t i o n matrix, R, of some p v a r i a b l e s . The c o r r e l a t i o n matrix was p r e f e r r e d r a t h e r than the d i s p e r s i o n matrix, or v a r i a n c e - c o v a r i a n c e matrix, as i n t e r e s t was i n r e l a t i v e r a t h e r than a b s o l u t e v a r i a t i o n . As many v a r i a b l e s were not commensurable, R p r o v i d e s a scale-independent means of examining c h a r a c t e r v a r i a t i o n and c o v a r i a t i o n (see a l s o Noy-Meir 1973; Noy-Meir, e_t a l . 1975 f o r s u c c i n c t d i s c u s s i o n on the nature of the d i s p e r s i o n matrix to be submitted to an e i g e n v a l u e - e i g e n v e c t o r e x t r a c t i o n t e c h n i q u e ) . I n d i v i d u a l elements of R, c o r r e l a t i o n coef f i c e n t s , rjk , are i n t u i t i v e l y more meaningful i n the context of morphological v a r i a t i o n than other measures of d i s p e r s i o n , such as v a r i a n c e and c o v a r i a n c e . C o n s i d e r a b l e d e t a i l and d i s c u s s i o n of PCA i s p r o v i d e d here as i t 66 i s the most g e n e r a l i z e d of the e i g e n v e c t o r - e i g e n v a l u e e x t r a c t i o n techniques used and the i n t e r p r e t a t i v e techniques are r e a d i l y extended to the other MVA used. PCA, l i k e other MVA e i g e n v e c t o r - e i g e n v a l u e e x t r a c t i o n techniques r e s u l t s in i_ v e c t o r - v a r i a b l e s . These v e c t o r - v a r i a b l e s are l i n e a r composites of the o r i g i n a l v a r i a b l e s and are independent or orthogonal with respect to each other. These v e c t o r - v a r i a b l e s are r e f e r r e d to as components ( = " p r i n c i p a l v a r i a b l e s " , Dempster 1969) or, more c o l l o q u i a l l y , "axes". A s s o c i a t e d with each component i s an eigenvalue (X, ) and e i g e n v e c t o r ( v - ) . X-, i s the v a r i a n c e of samples f o r that component. y_j i s a v e c t o r of c o e f f i c i e n t s r e l a t i n g the o r i g i n a l v a r i a b l e values to the new v e c t o r - v a r i a b l e . For a " s t a b l e " PCA s o l u t i o n the number of samples, n, must exceed the number of o r i g i n a l v a r i a b l e s , p, forming R (see a l s o remarks above with respect to sample s i z e ; Karr and M a r t i n 1981; S c a g e l , et a l . 1984). PCA maximizes the v a r i a n c e of the n samples on which the p v a r i a b l e s have been measured. The value of each sample for each component i s r e f e r r e d to as the component score f o r that sample. The l i n e a r independence of the i n d i v i d u a l components i s shown in that the c o r r e l a t i o n of the scores from separate components i s 0.0. Cooley and Lohnes (1971) pr o v i d e a readable account of the c a l c u l a t i o n of component scores f o r a p a r t i c u l a r PCA. The component scores serve as a summarization of the i n i t i a l data. As each of the o r i g i n a l p v a r i a b l e s c o n t r i b u t e s to each component, the component scores have the d e s i r a b l e 67 p r o p e r t y of p r o v i d i n g a r e d u c t i o n in d i m e n s i o n a l i t y of the o r i g i n a l d a ta. For the same reason component scores are a l s o more normally d i s t r i b u t e d than the o r i g i n a l p v a r i a b l e s on the same sample (Morrison 1976; Pimentel 1979; C h a t f i e l d and C o l l i n s 1980; the " c e n t r a l l i m i t theorem"). S t a t i s t i c a l i n f e r e n c e based on PCA assumes m u l t i v a r i a t e n o r m a l i t y of the o r i g i n a l data and that R i s d e r i v e d from a s i n g l e p o p u l a t i o n . However, C h a t f i e l d and C o l l i n s (1980) and M orrison (1976) provide evidence f o r the s t a t i s t i c a l robustness of PCA and a s s o c i a t e d i n t e r p r e t a t i v e techniques under non-normal s i t u a t i o n s . S a t i s f a c t i o n of m u l t i v a r i a t e n o r m a l i t y i s seen as being important where r e s u l t s are marginal in t h e i r s i g n i f i c a n c e . PCA can be used f o r h e u r i s t i c a p p r e c i a t i o n of the v a r i a t i o n i n the data even i f the d i s t r i b u t i o n a l caveats cannot be s a t i s f i e d p r o v i d e d the data do not c o n t a i n r a d i c a l o u t l i e r s (Ruymgaart 1981). It i s the h e u r i s t i c a p p l i c a t i o n of PCA ( o r d i n a t i o n , c l u s t e r i n g , and UVA or MVA s t a t i s t i c a l analyses of component scores) that the method i s most f r e q u e n t l y encountered. The reader i s r e f e r r e d to Pimentel (1979), G i t t i n s (1969), and Isebrands and Crow (1975) f o r a more d e t a i l e d d i s c u s s i o n of the caveats a s s o c i a t e d with the method and a p p l i c a t i o n to b i o l o g i c a l s i t u a t i o n s . P r i o r to performing PCA, the c o r r e l a t i o n matrix to be f a c t o r e d was e v a l u a t e d to determine whether in f a c t PCA was necessary. Estimates of the o v e r a l l s t r u c t u r e of R are provided by t e s t of e q u i c o r r e l a t i o n ( B a r t l e t t ' s or Lawley's t e s t of e q u a l i t y , C h a t f i e l d and C o l l i n s 1980) and independence 68 (Anderson's t e s t of s p h e r i c i t y , C h a t f i e l d and C o l l i n s 1980) of rjk of R. I f the r ^ are equal but non-zero there i s no unique component p o s s i b l e to e x t r a c t . I f the o r i g i n a l v a r i a b l e s are independent ( i . e . a l l r j ^ are s t a t i s t i c a l l y equal to zero) there i s no reason to perform a PCA as the o r i g i n a l v a r i a b l e s a l r e a d y can be c o n s i d e r e d l i n e a r l y independent and r e d u c t i o n of d i m e n s i o n a l i t y i s not necessary. Unless otherwise noted, a l l PCAs r e p o r t e d here have been based upon an R where the rjk were s t a t i s t i c a l l y n e i t h e r the same nor equal to z e r o . • The i n t e r p r e t a t i o n of the r e s u l t s of PCA has been made with a number of techniques. Component-specific i n t e r p r e t a t i o n s of R are based upon c o n s i d e r i n g the p o r p o r t i o n of the t o t a l v a r i a t i o n ( = i n t r a - s e t redundancy, G i t t i n s 1979) of the data a t t r i b u t e d to the component (%var.), and a t e s t of the independence of the e x t r a c t e d component from r e s i d u a l s t r u c t u r e i n R (Anderson's t e s t of e q u a l i t y , Morrison 1976; Cooley and Lohnes 1971). Unless otherwise noted a l l components from PCAs r e p o r t e d here are s i g n i f i c a n t l y d i f f e r e n t from r e s i d u a l v a r i a t i o n and have an eigenvalue g r e a t e r than 1.0. E i g e n v a l u e s have not been presented i n the t a b l e s of the r e s u l t s of the PCAs as the percent v a r i a n c e i s j u s t as meaningful p r o v i d e d that the PCA i s d e r i v e d from a c o r r e l a t i o n m atrix. For a c o r r e l a t i o n m a t r i x : 69 The e i g e n v e c t o r v a l u e s , a;| , (=component l o a d i n g s ) of the o r i g i n a l v a r i a b l e s provide an estimate of the s i g n i f i c a n c e of the c o n t r i b u t i o n of each of the o r i g i n a l v a r i a b l e s to a p a r t i c u l a r component. An a l t e r n a t e , and more s t a b l e ( G i t t i n s 1979), way to i n t e r p r e t the c o n t r i b u t i o n of the o r i g i n a l v a r i a b l e s to the scores of the separate components i s to c a l c u l a t e product-moment c o r r e l a t i o n s between the o r i g i n a l v a r i a b l e s and the component scores ("component c o r r e l a t i o n s " , Pimentel 1979; "component s t r u c t u r e " , Cooley and Lohnes 1971). For a c o r r e l a t i o n matrix the r e l a t i o n s h i p of the component c o r r e l a t i o n s to the e igenvalue of that component i s the average square of the component c o r r e l a t i o n s f o r a given component equals the percentage of the t o t a l v a r i a n c e e x t r a c t e d by that component. The r e l i a n c e upon component c o r r e l a t i o n i s e s p e c i a l l y necessary under c o n d i t i o n s where the o r i g i n a l data may have been transformed. A d d i t i o n a l l y , such product-moment c o r r e l a t i o n s have an advantage over e i g e n v e c t o r v a l u e s in that t h e i r s i g n i f i c a n c e can be t e s t e d . An a d d i t i o n a l i n f e r e n c e d e r i v e d from the r e l a t i v e s i z e s and signs of e i g e n v e c t o r values concerns the form of v a r i a t i o n d e s c r i b e d by a given component (Pimental 1979). If the e i g envector v a l u e s are approximately the same s i z e and s i g n ( i . e . approximating a v e c t o r of isometry, Pimentel 1979), then the form of v a r i a t i o n f o r t h a t component i s s a i d to r e f l e c t , p r i m a r i l y , d i f f e r e n c e s in s i z e among samples. If the e i g envector v a l u e s are markedly d i f f e r e n t i n magnitude and are of opposite s i g n s , then the component r e f l e c t s s i z e and shape d i f f e r e n c e s . The d i s t i n c t i o n between these two forms of 70 v a r i a t i o n i s important as i t serves to r e f l e c t , r e s p e c t i v e l y , the d i f f e r e n c e s between simple and complex v a r i a b l e v a r i a t i o n and i n t e r - c o r r e l a t i o n . C o r r e l a t i o n among eige n v e c t o r v a l u e s of separate PCAs (A t c h l e y , et a l . 1982; Pimentel 1979, " t h e o r e t i c a l v e c t o r s " ; B l a c k i t h and Reyment 1971) p r o v i d e s an assessment of the s i m i l a r i t y between these PCAs. Such comparisons are v a l i d only where the PCAs share the same v a r i a b l e s but not n e c e s s a r i l y the same samples. The c o r r e l a t i o n of c o r r e l a t i o n m a t rices or comparisons of |R| may a l s o s u f f i c e as an a l t e r n a t i v e means of comparing R (Newman and Jancey 1981; Scagel and Maze 1984; S c a g e l , et a l . 1984) . The component scores can be used to provide o r d i n a t i o n s that i l l u s t r a t e the p a t t e r n of v a r i a t i o n of samples. Unless otherwise i n d i c a t e d a l l o r d i n a t i o n s presented here are drawn i n such a manner that the s c a l e s of the c o - o r d i n a t e axes are equal. The l e n g t h of the axes correspond to the maximum d i s p e r s i o n of sample submitted to the a n a l y s i s f o r the f i r s t component. T h i s g r a p h i c a l convention emphasizes the d e c r e a s i n g v a r i a n c e e x t r a c t e d by succeeding components. Where means of s e v e r a l samples are i l l u s t r a t e d , the s c a l e of the o r d i n a t i o n emphasizes the d i s p e r s i o n of the means i n the space of the o r i g i n a l samples from which the means were c a l c u l a t e d . In a l l o r d i n a t i o n s the amount of v a r i a t i o n accounted f o r by a given component i s given p a r e n t h e t i c a l l y to emphasize the d e c r e a s i n g v a r i a n c e a s s o c i a t e d with s e q u e n t i a l l y smaller e i g e n v e c t o r s . In a d d i t i o n to o r d i n a t i o n , component scores are a l s o 71 u t i l i z e d i n subsequent u n i v a r i a t e a n a l y s e s . U n i v a r i a t e techniques allow a component-specific i n t e r p r e t a t i o n and provide a f u r t h e r method of a s s e s s i n g the s i g n i f i c a n c e of a component. U t i l i z i n g component scores i n c o r r e l a t i o n and r e g r e s s i o n a n a l y s e s i s a common p r a c t i s e . ANOVA of component scores has not r e c e i v e d the same a t t e n t i o n (but see Moore 1965; Pimentel 1979; Maze and Parker 1983; Scagel and Maze 1984; Wheeler and Guires 1979). T o t a l m u l t i v a r i a t e v a r i a t i o n i s r e f e r r e d to here as " % S S S o u R c £ (mva)". Owing to the a d d i t i v e nature of the components from PCA, the u t i l i z a t i o n of ANOVA may p r o v i d e an assessment of the t o t a l m u l t i v a r i a t e v a r i a t i o n over some p components (Scagel and Maze 1984; Wheeler and G u i r e s 1979). Although t e s t s of s i g n i f i c a n c e a s s o c i a t e d with %SS (uva) are given, no s i m i l a r t e s t s of s i g n i f i c a n c e are p r o v i d e d f o r %SS (mva). During the completion of t h i s study i t was observed that the value o b t a i n e d f o r t o t a l m u l t i v a r i a t e v a r i a t i o n (v c , Scagel and Maze 1984) of a given source i s equal to the average v a r i a t i o n of each v a r i a b l e f o r the same hypothesized source. For example, given a simple s i t u a t i o n where v a r i a t i o n i s hypothesized to be due to a s i n g l e source, A, and samples have been measured f o r three v a r i a b l e s , x-. : x, , x 2 , x 3 . 72 The c a l c u l a t i o n of t o t a l m u l t i v a r i a t e v a r i a t i o n due to source A would be ( sensu Scagel and Maze 1984): Th i s r e l a t i o n s i m p l i f i e s the a n a l y t i c steps necessary to c a l c u l a t e %SS (mva). Indeed, t h i s r e l a t i o n p r o v i d e s a means by which m u l t i v a r i a t e v a r i a t i o n can be c a l c u l a t e d when a PCA cannot be performed owing to e i t h e r the s t r u c t u r e of R or d i m e n s i o n a l i t y of the data. I t a l s o p r o v i d e s a way that p r e v i o u s u n i v a r i a t e s t u d i e s can be compared to m u l t i v a r i a t e s t u d i e s . A d d i t i o n a l l y , the same e m p i r i c a l r e l a t i o n e x i s t s f o r r 2 values from r e g r e s s i o n of i n d i v i d u a l v a r i a b l e s and r 2 values from r e g r e s s i o n of component s c o r e s . T h i s r e l a t i o n between m u l t i v a r i a t e and u n i v a r i a t e v a r i a t i o n serves to f u r t h e r j u s t i f y the i n c l u s i o n of UVA r e s u l t s with the r e s u l t s of MVA and in c r e a s e s the u t i l i t y of these r e s u l t s f o r f u t u r e independent a n a l y s e s . Although r e d u c t i o n of d i m e n s i o n a l i t y i s an e s s e n t i a l f e a t u r e of PCA, O r l o c i (1973, 1975, 1978) p r o v i d e s an independent means of a s s e s s i n g d i m e n s i o n a l i t y . O r l o c i ' s technique of ranking v a r i a b l e s on a sums of squares c r i t e r i o n and s p e c i f i c v a r i a n c e (=redundancy) was employed here as a means vc can a l s o be c a l c u l a t e d by: 73 of p r o v i d i n g a summarization of the data used and to suggest a reduced c h a r a c t e r set f o r u t i l i z a t i o n i f f u r t h e r sampling i s undertaken ( i . e . an independent c o r r o b o r a t o r y s t u d y ) . B e s h i r (1975) p r o v i d e s an i l l u s t r a t i o n of the use of t h i s technique with re s p e c t to Pinus banksiana. 4.3 Computation and t e s t s of s i g n i f i c a n c e . Mention has been made of v a r i o u s t e s t s of s t a t i s t i c a l s i g n i f i c a n c e employed i n d i f f e r e n t a n a l y s e s . Unless otherwise s t a t e d i n the t e x t , a l l t e s t s i n d i c a t e d as being s i g n i f i c a n t are judged to be so at a p r o b a b i l i t y of p < 0.01. L e v e l s of s i g n i f i c a n c e are e x p l i c i t l y r e f e r e n c e d i n a l l t a b l e s and f i g u r e s . A l l a n a l y s e s were performed using the computing f a c i l i t i e s a v a i l a b l e at the U n i v e r s i t y of B r i t i s h Columbia. S t a t i s t i c a l programmes used were: ANOVAR (Greig and O s t e r l i n 1978); GENLIN (Greig and B j e r r i n g 1980); MIDAS (Fox and Guire 1976); and, NTSYS (Rohlf, e_t a l . 1980). M u l t i v a r i a t e and u n i v a r i a t e sample s i z e e s t i m a t i o n and O r l o c i ' s ranking of c h a r a c t e r s by a d i s p e r s i o n c r i t e r i o n were performed using a programme developed by John Emanuel of the F a c u l t y of F o r e s t r y at the U n i v e r s i t y of B r i t i s h Columbia. Gary B r a d f i e l d of the Botany Department at the U n i v e r s i t y of B r i t i s h Columbia p r o v i d e d a two-dimensional p l o t t i n g r o u t i n e which accommodated i d e n t i f i c a t i o n of p l o t t e d p o i n t s . As w e l l , s e v e r a l programmes developed as system s u b - r o u t i n e s at the U n i v e r s i t y of B r i t i s h Columbia were used. 74 I I I . INTRA-INDIVIDUAL VARIATION. 1. I n t r o d u c t i o n . In m o r p h o l o g i c a l l y small and simple organisms, the p e r c e p t i o n and assessment of i n t r a - i n d i v i d u a l and i n t e r - i n d i v i d u a l v a r i a t i o n i s , f o r systematic purposes, o f t e n r e a d i l y apparent. In m o r p h o l o g i c a l l y l a r g e and a n a t o m i c a l l y complex organsims, such as spruce t r e e s , i n t r a - i n d i v i d u a l v a r i a t i o n i s not as apparent nor, as a r e s u l t , i s i n t e r - i n d i v i d u a l v a r i a t i o n as easy to a s s e s s . I n t r a - i n d i v i d u a l v a r i a t i o n of t r e e s i s most commonly c o n s i d e r e d with re s p e c t to s t a t i s t i c a l accuracy (Zobel and T a l b e r t 1984). As i n t r a - i n d i v i d u a l v a r i a t i o n i s , by c l a s s i c a l d e f i n i t i o n (Falconer 1981), not a r e s u l t of g e n e t i c v a r i a t i o n but l o c a l i z e d environmental and developmental v a r i a t i o n , such variation-'srerves as a comparative y a r d s t i c k a g a i n s t which suspected g e n e t i c v a r i a t i o n can be compared. I m p l i c i t i n the r e c o g n i t i o n of g e n e t i c and developmental sources of v a r i a t i o n i s the assumption that h e r i t a b l e d i f f e r e n c e s between i n d i v i d u a l s are g e n e t i c , whereas d i f f e r e n c e s amongst p a r t s of an i n d i v i d u a l are the r e s u l t of somatic* mutations, or other "non-genetic" causes or the r e s u l t of genotype-environment i n t e r a c t i o n . However, such assumptions ignore the g e n e t i c b a s i s of development. As mentioned e a r l i e r (Chapt. I I ) , developmental v a r i a t i o n i s b e t t e r c o n s i d e r e d as simply another l e v e l of g e n e t i c v a r i a t i o n , a l b e i t a l e s s e n v i r o n m e n t a l l y b u f f e r e d one. The nature of i n t r a - i n d i v i d u a l v a r i a t i o n i n an 75 i n t e r - i n d i v i d u a l context i s important to c o n s i d e r f o r the reasons o u t l i n e d here. Having been s a t i s f i e d that the v a r i a b l e s being used i n t h i s study have a l a r g e r i n t e r - i n d i v i d u a l than i n t r a - i n d i v i d u a l v a r i a t i o n (Table 2) one c o u l d ignore i n t r a - i n d i v i d u a l v a r i a t i o n , or i n the words of M o s t e l l e r and Tukey (1977), "sweep i t under the rug". However, to ignore i n t r a - i n d i v i d u a l v a r i a t i o n assumes random i n t r a - i n d i v i d u a l v a r i a t i o n . That i n t r a - i n d i v i d u a l v a r i a t i o n may not be random suggests that sampling and i n t e r p r e t a t i o n c o u l d be i n f l u e n c e d by developmental v a r i a t i o n . I_n P. s i t c h e n s i s , these p o i n t s and others have been emphasized by F o r r e s t (1975b, 1980a). Reference has been made e a r l i e r t o the sampling problems n e c e s s i t a t e d by the s i z e , form, and occurrence of i n d i v i d u a l t r e e s . As w e l l , the attendant s t r u c t u r a l complexity in. even those p o s i t i o n s of the t r e e that c o u l d be e a s i l y sampled, n e c e s s i t a t e d very s p e c i f i c sampling s t r a t e g i e s . Evidence in the l i t e r a t u r e a v a i l a b l e on Picea s u b s t a n t i a t e s the impressions based on f i e l d o b s e r v a t i o n s of d i f f e r e n c e s between ord e r s , p o s i t i o n s , and ages i n the canopy. Addressing the i s s u e of i n t r a - i n d i v i d u a l v a r i a t i o n of the s e l e c t e d v a r i a b l e s avoids c r i t s i c m s such as those d i r e c t e d at P a r k e r , _ e t _ a l . (1981) by Hunt and von R u d l o f f (1983). A number of m orphological and anatomical s t u d i e s of i n t r a - i n d i v i d u a l v a r i a t i o n of P i c e a have been conducted. Denne (1979) and France and Mexal (1980) have r e l a t e d the v a r i a b i l i t y of wood anatomy i n P_;_ s i t c h e n s i s to p o s i t i o n i n the canopy and b o l e . Garman (1957) r e l a t e d v a r i a t i o n of s c a l e morphology to 76 p o s i t i o n i n the cone. T h i s v a r i a t i o n i s seen r e a d i l y i n l o n g i t u d i n a l cone s e c t i o n s . T a y l o r (1959) r e p o r t e d on cone and needle morphology w i t h i n the canopy. Ewers (1982) and S i f t o n (1965) have r e p o r t e d on a g e - r e l a t e d v a r i a t i o n of needle anatomy in P_j_ a b i e s (L.) K r a s t . and P^ pungens. In a d d i t i o n to p o s i t i o n a l v a r i a b i l i t y of morphological v a r i a b l e s , Funsch (1975) a l s o examined i n t r a - i n d i v i d u a l v a r i a b i l i t y r e l a t e d to compass d i r e c t i o n i n the canopy of P_;_ enqelmanni i . Wilson (1963) re p o r t e d on the v a r i a b i l i t y of p o l l e n of E"\ g l a u c a . G e n e r a l l y , the most a p i c a l and lowest orders of branches have the l a r g e s t s t r u c t u r e s ; they a l s o develop more q u i c k l y ( H a r r i s o n and Owens 1983). T a y l o r (1959) c o u l d not dete c t i n t r a - i n d i v i d u a l v a r i a t i o n i n Rocky Mountain P_^  englmannii. S i m i l a r l y , Funsch (1975) c o u l d not d e t e c t i n t r a - i n d i v i d u a l v a r i a t i o n r e l a t e d to compass d i r e c t i o n of the canopy. V a r i a t i o n that has been observed in s i t c h e n s i s has been a t t r i b u t e d to com p e t i t i o n f o r n u t r i e n t s and l i g h t , growth r e g u l a t i o n a s s o c i a t e d with a p i c a l dominance, and the e x t e r n a l environment (Larsen 1927; Stover 1944; Wardle 1968; Leverenz and J a r v i s 1980a,b; Grace, et a l . 1975). More r e c e n t l y i n t e r e s t has focused on the i n t r a - i n d i v i d u a l v a r i a b i l i t y of p h y s i o l o g i c a l and growth v a r i a b l e s i n P i c e a . S t r u c t u r a l v a r i a t i o n sometimes has been r e p o r t e d i n c o n j u n c t i o n with these p h y s i o l o g i c a l s t u d i e s (Leverenz and J a r v i s 1980a,b; Lewandowska and J a r v i s 1978).' I n t r a - i n d i v i d u a l p h y s i o l o g i c a l v a r i a t i o n has been r e l a t e d to order of branching (Norman and J a r v i s 1974), p o s i t i o n (Baxter and C a n n e l l 1978; F r a s e r , et 77 a l . 1964; Leverenz and J a r v i s 1979, I980a,b; Lewandowska and J a r v i s 1978), and age ( F r e e l a n d 1952; Fry and P h i l l i p s 1977; S o i k k e l i 1978). Schulze, e_t a_l. (1977) working on P^ a b i e s and Leverenz and J a r v i s (1980a) working on P_^  s i t c h e n s i s have rep o r t e d v a r i a t i o n w i t h i n a s i n g l e increment of growth. I n t r a - i n d i v i d u a l p h y s i o l o g i c a l v a r i a t i o n , l i k e s t r u c t u r a l v a r i a t i o n , has been hypothesized to be e f f e c t e d by c o m p e t i t i o n f o r l i g h t and n u t r i e n t s , growth r e g u l a t o r s , the micro-environment surrounding the s t r u c t u r e , and the environment of the t r e e . Of s p e c i a l i n t e r e s t has been the r e l a t i o n of i n t r a - i n d i v i d u a l v a r i a t i o n to i n c i d e n t s u n l i g h t ("sun and shade" p o s i t i o n s , Kramer and K o z l o s k i 1979; Zimmerman and Brown 1971) as r e p o r t e d by Leverenz and J a r v i s (I980a,b) i n P_;_ s i t c h e n s i s , and Fuchs, et a l . (1977) and Schulze, et a l . (1977) in E\ a b i e s . With the advent of commercial s c a l e g r a f t i n g programmes a t t e n t i o n has a l s o been d i r e c t e d to c y c l o - , p e r i - , and t o pophysis. Some of the most elegant s t u d i e s of i n t r a - i n d i v i d u a l v a r i a t i o n i n c o n i f e r s and P i c e a i n p a r t i c u l a r are the c o n t r i b u t i o n s of H r u t f i o r d , et a l . (1974), F o r r e s t (1975a,b; 1980a), von R u d l o f f (1967, 1975), O g i l v i e and von R u d l o f f (1968), and Kaufmann, et a_l. (1974). These s t u d i e s have emphasized both the s p a t i a l and temporal v a r i a t i o n of v o l a t i l e chemical compounds. I t should be noted that i n t r a - i n d i v i d u a l v a r i a b i l i t y , at l e a s t i n P^ s i t c h e n s i s , i s not r e s t r i c t e d to the a e r i a l p o r t i o n s of the t r e e , but a l s o occurs i n the root system (Ford and Deans 1977; E i s and Long 1972). 78 In the present study there are s e v e r a l obvious sources of i n t r a - i n d i v i d u a l v a r i a t i o n that can be q u a n t i f i e d . These r e l a t e to the age of the increment of growth, the p o s i t i o n , and order of branches. These sources of v a r i a t i o n are common in other c o n i f e r o u s s p e c i e s owing to the s i m i l a r a r c h i t e c t u r e (Tomlinson, 1983: "Massart's model"). Indeed, s t u d i e s of i n t r a - i n d i v i d u a l v a r i a t i o n of s i t c h e n s i s have formed the b a s i s f o r e n t i r e s t u d i e s (Denne 1979; France and Mexal 1980; Schulze, et a l . 1977; F r a s e r , et a l . 1964; von Ru d l o f f 1967; F o r r e s t 1975a, b, 1980a). Since i n t e r e s t here i s i n the v a r i a t i o n a s s o c i a t e d with m a t e r i a l from a v a r i e t y of p o s i t i o n s that are commonly encountered d u r i n g c o l l e c t i n g , emphasis has been placed on a s s e s s i n g v a r i a t i o n i n v e g e t a t i v e m a t e r i a l s a s s o c i a t e d with: a d v e n t i t i o u s and whorl primary branches of the same age from the lowest primary branch ( F i g . 7); primary and secondary whorl primary branches of the same age from the lowest primary branches ( F i g . 7); the year of c o l l e c t i o n of primary whorl branches from the lowest whorl primary branches; and, whorl primary branches from d i f f e r e n t p o s i t i o n s in the canopy. The v a r i a t i o n of cone morphology with r e s p e c t to p o s i t i o n s i n the canopy was a l s o examined. Although a d d r e s s i n g these sources of i n t r a - i n d i v i d u a l v a r i a t i o n may not allow the assignment of s t a t i s t i c a l c o n f i d e n c e l i m i t s to i n t e r - i n d i v i d u a l v a r i a t i o n due to the unbalanced nature of sampling, i t w i l l permit an h e u r i s t i c a p p r e c i a t i o n of t h i s source of v a r i a t i o n . A d v e n t i t i o u s branching i n s i t c h e n s i s i s thought to be a r e s u l t of environmental inducement by e i t h e r p h y s i c a l damage to 79 the t r e e (Herman 1964) or stand damage (Issac 1940). Based on o b s e r v a t i o n s made i n the f i e l d , the same would appear to be the case f o r engelmanni i although there has not been e x p l i c i t c i t a t i o n to t h i s e f f e c t i n the l i t e r a t u r e . There i s a l s o no l i t e r a t u r e i n d i c a t i n g whether there are morphological or anatomical d i f f e r e n c e s between the two p o s i t i o n s . As these two p o s i t i o n s of branches are o f t e n i n markedly d i f f e r e n t environments, i t would be reasonable to expect the e x i s t e n c e of morphological and anatomical d i f f e r e n c e s . A d v e n t i t i o u s branches, although not un i f o r m l y present, are e a s i e r to sample than whorl branches. Orders of branches have been more i n t e n s i v e l y i n v e s t i g a t e d by a number of workers. I t i s an obvious source of v a r i a t i o n . The nature of branching of the t r e e i s i n t e r p r e t e d as a determinant of the form of the t r e e . Some re s e a r c h has suggested s i g n i f i c a n t d i f f e r e n c e s between orders of branching. Where these d i f f e r e n c e s are observed they are a t t r i b u t e d i n v a r i a b l y to growth r e g u l a t i o n a s s o c i a t e d with a p i c a l dominance. With re s p e c t to temporal v a r i a t i o n i n c o n i f e r s , the l i t e r a t u r e i s very e x t e n s i v e with both o b s e r v a t i o n s and tendered e x p l a n a t i o n s f o r such v a r i a t i o n (Stover 1944; Andersson 1965). E x p l a n a t i o n s f o r t h i s source of v a r i a t i o n have been a t t r i b u t e d to e x t r i n s i c f a c t o r s ( c l i m a t i c changes, pathogen i n f e s t a t i o n , p h y s i c a l damage) and i n t r i n s i c c o n t r o l s (mast seeding, S i l v e r t o n 1980). As sampling was c a r r i e d out over s e v e r a l years i t would appear that t h i s source of v a r i a t i o n c o u l d e a s i l y i n f l u e n c e the 80 r e s u l t s . By temporal v a r i a t i o n r e f e r e n c e i s made to v a r i a t i o n between two year o l d twigs and needles i n i t i a t e d and e l o n g a t i n g d u r i n g separate years. For example, a two year o l d v e g e t a t i v e c o l l e c t i o n made i n 1979 would have been i n i t i a t e d at the end of 1977 and elongated d u r i n g 1978. Such m a t e r i a l may d i f f e r from two year o l d m a t e r i a l c o l l e c t e d d u r i n g 1980 owing to the s p e c i f i c e x t r i n s i c and i n t r i n s i c c o n d i t i o n s surrounding i n i t i a t i o n and e l o n g a t i o n d u r i n g 1978 and 1979 (see H a r r i s o n and Owens 1983; Owens and Molder 1976a, 1976b, 1977, 1979,1980; Owens, et al.. 1977; Singh and Owens 1981, re g a r d i n g sequence and timing of v e g e t a t i v e and r e p r o d u c t i v e e v e n t s ) . I t should be noted that because of the p e r e n n i a l h a b i t of the organism that there i s a temporal component a s s o c i a t e d with whorl, p o s i t i o n , and order of branching ( F r a s e r 1976). A d d i t i o n a l l y the temporal v a r i a t i o n c o u l d be assessed f o r e i g h t years growth i n Picea because the leaves p e r s i s t that long. • Perhaps the s i n g l e most obvious source of v a r i a t i o n i n la r g e a r b o r e s c e nt organisms i s that a s s o c i a t e d with the p o s i t i o n in the canopy from which a sample comes. Indeed, i t i s height that most c h a r a c t e r i z e s t r e e a r c h i t e c t u r e . C e r t a i n l y t h i s i s the most e x t e n s i v e l y documented source of i n t r a - i n d i v i d u a l v a r i a t i o n . E x p l a n a t i o n s f o r within-canopy v a r i a t i o n , " h e t e r o p h y l l y " , are a t t r i b u t e d to environmental ("sun and shade" l e a f morphology) and developmental ( " j u v e n i l e and mature" f o l i a g e , " v e g e t a t i v e and f e r t i l e " p o s i t i o n s ) causes. Q u a n t i f y i n g i n t r a - i n d i v i d u a l v a r i a t i o n i n P^ engelmannii 81 and P_^  s i t c h e n s i s p r o v i d e s a d e s c r i p t i o n of t h i s v a r i a t i o n f o r more taxa. Addressing aspects of t h i s v a r i a t i o n i n mature and immature i n d i v i d u a l s may allow f o r e x p l a n a t i o n s of t h i s v a r i a t i o n with respect to v a r i o u s competing hypotheses concerning environmental or developmental c o n t r o l . In a d d i t i o n , such i n f o r m a t i o n may be of value i n t r e e - b r e e d i n g programmes where g r a f t i n g and r o o t i n g p r o j e c t s are being c a r r i e d out (Klaehn 1963; Rouland 1973), although g r a f t i n c o m p a t i b i l i t y problems have not been r e p o r t e d f o r P_^  s i t c h e n s i s or P. enqelmanni i (Bower 1982). Furt h e r such i n v e s t i g a t i o n s may be u s e f u l i n understanding the i n t e r a c t i o n of t r e e s with v a r i o u s pathogens (Whitham 1981). A t t e n t i o n to i n t r a - i n d i v i d u a l v a r i a t i o n serves more than j u s t the pragmatic o b j e c t i v e s demanded by a systematic study and s i l v i c u l t u r a l p r a c t i s e s . I t i s e s s e n t i a l f o r an understanding of the development and f u n c t i o n i n g of m o r p h o l o g i c a l l y and an a t o m i c a l l y complex organisms. For t h i s reason i n t r a - i n d i v i d u a l v a r i a t i o n i n t r e e s has been r e l a t e d to crown form. Although crown form i s p o o r l y understood and q u a n t i f i e d , i t has been assumed to be important based on the demonstration of p a t t e r n s of i n t r a - i n d i v i d u a l v a r i a t i a t i o n . Crown form i s r e p o r t e d l y under g e n e t i c c o n t r o l i n many sp e c i e s of Pi c e a (Grant and Mi t t o n 1976, 1977; Alexandrov 1971; Roche 1965; L i n d q u i s t 1948; Jankiewicz and S t e c k i 1976) although there i s a d i v e r s i t y of o p i n i o n as to the degree of ge n e t i c c o n t r o l . Some have a t t r i b u t e d taxonomic s i g n i f i c a n c e to crown form i n P i c e a (Schmidt-Vogt 1977; Jones and Bernard 1977) and 82 have speculated on a d a p t a t i o n of v a r i o u s crown forms of P^ a b i e s to heavy snow packs (Alexandrov 1971; L i n d q u i s t 1948). Other r e s e a r c h e r s have emphasized the a d a p t a t i o n of the crown of P. s i t c h e n s i s to the i n t e r c e p t i o n of p r e c i p a t a t i o n and l i g h t (Ford and Deans 1978; Cochrane and Ford 1976; Ford and Di g g l e 1980), competition f o r n u t r i e n t s , c o m p e t i t i o n with other t r e e s (Ford 1976), and o p t i m i z a t i o n of mechanical p r o p e r t i e s a s s o c i a t e d with support (McMahon and Konauer 1976). Both i n t r i n s i c ( Cannell 1974) and e x t r i n s i c ( C a n n e l l , e_t §_1. 1976; P o l l a r d and Logan 1979) c o n t r o l s have been proposed. The most f r e q u e n t l y tendered s p e c u l a t i o n concerns a d a p a t a t i o n for o p t i m i z a t i o n of p h o t o s y n t h e t i c e f f i c i e n c y (Leverenz and J a r v i s 1980a,b; Norman and J a r v i s 1974; Horn 1971; F i s h e r and Honda 1979a,b; F i s h e r and Hibbs 1982). Regardless of the hypothesized a d a p t a t i o n , crown form i s g e n e r a l l y agreed to i n f l u e n c e stand s t r u c t u r e , composition, r e g e n e r a t i o n , and r e p r o d u c t i o n (Brunig 1976; Jankiewicz and S t e c k i 1976). Crown form i s r e c o g n i z e d t o c o n s i s t of a h i e r a r c h y of u n i t s ( F r a s e r , et a l . 1964; Cochrane and Ford 1978) in which s l i g h t i n t e r n a l and e x t e r n a l changes d u r i n g development may r e s u l t i n s u b s t a n t i a l a l t e r a t i o n s to the crown form (Pearce and Moore 1962; Honda 1971; Tomlinson 1982), which, i n turn may a f f e c t the stand c h a r a c t e r i s t i c s mentioned above. These e x p l a n a t i o n s of crown form respect the development of i n d i v i d u a l t r e e s and p h y s i c a l i n t e r a c t i o n amongst t r e e s i n the stand. 83 2. M a t e r i a l s and methods. 2.1 M a t e r i a l s . A l l i n v e s t i g a t i o n s were r e s t r i c t e d to i n d i v i d u a l s c o n s i d e r e d to be standards f o r the two s p e c i e s (see Chapt. I I ) . Such a l i m i t a t i o n s i m p l i f i e s the nature and expected degree of i n t e r - i n d i v i d u a l v a r i a t i o n , p e r m i t t i n g a more c o n s t r a i n e d s i t u a t i o n under which i n t r a - i n d i v i d u a l v a r i a t i o n can be examined. A l l the sources of i n t r a - i n d i v i d u a l v a r i a t i o n being c o n s i d e r e d c o u l d not be assessed f o r any s i n g l e t r e e or at any one s i t e encountered during the course of t h e . f i e l d c o l l e c t i o n s . To do so would have n e c e s s i t a t e d whole t r e e sampling. A d v e n t i t i o u s and whorl primary branches were compared from an i n d i v i d u a l of P_j_ engelmanni i (Tree 218, Appendix I I ) . Primary and secondary whorl branches were compared from an i n d i v i d u a l r e p r e s e n t a t i v e of P^ s i t c h e n s i s (Tree 527, Appendix I I ) . Year to year comparisons were made f o r an i n d i v i d u a l r e p r e s e n t a t i v e of P_^_ engelmann i i (Tree 60705, Appendix I I ) . I n t e r - p o s i t i o n a l v a r i a t i o n was compared under three c o n d i t i o n s . S i n g l e , mature t r e e s r e p r e s e n t a t i v e f o r both of the taxa were sampled at r e g u l a r l y spaced i n t e r v a l s throughout the crown ( F i g . 8). T h i s sampling was p o s s i b l e s i n c e the t r e e s had been e i t h e r blown over dur i n g a storm (Tree 221, Appendix II) or s t r u c k down by a truck (Tree 557, Appendix I I ) . S i x , eleven year o l d s a p l i n g s r e p r e s e n t i n g a s i n g l e h a l f - s i b f a m i l y 1 of P. s i t c h e n s i s were sampled at each whorl in t h e i r canopies where weevi l damage had not obscured the o r d e r i n g of branches. 84 F i g u r e 8. S c h e m a t i c r e p r e s e n t a t i n of I n d i v i d u a l t r e e s of P_^  enge1manni i and s i t c h e n s i s f rom which i n t r a - i n d i v i d u a l s a m p l i n g c o n d u c t e d T1 - T6, 11 -year o l d immature P_^  s i t chens i s from n u r s e r y : l a t e r a l b r a n c h Increments shown a r e a v e r a g e d per w h o r l , c i r c l e s r e p r e s e n t whor l nodes . T7 , mature P_^  s i t chens i s (SXP 221 ) . T8. mature P• enge lmanni1 (SXP 527 ) . T r i a n g l e s mark p o s i t i o n at which samples t aken f rom mature t r e e s . Not a l l whorl p r i m a r y b r a n c h e s marked f o r immature t r e e s due to measurement p rob lems a s s o c i a t e d w i t h weev i l damage. * , p o s i t i o n s cones c o l l e c t e d f rom. I n c l u d i n g immature t r e e s allows a t e s t of whether i n t e r - p o s i t i o n a l v a r i a t i o n may be environmental or developmental. I f v a r i a t i o n i s a r e s u l t of environmental causes, then mature and immature t r e e s would not be expected to d i s p l a y s i m i l a r p a t t e r n s of i n t r a - i n d i v i d u a l v a r i a t i o n . I n c l u d i n g immature i n d i v i d u a l s a l s o allows a comparison of t h e i r morphology and anatomy with that of mature t r e e s and t e s t whether, w i t h i n the c i r c u m s c r i p t i o n of a given taxon, there are s u b s t a n t i a l d i f f e r e n c e s that c o u l d r e s u l t from the age of the 1 p e r s . comm., U l f B i t t e r l i c k ; B r i t s h Columbia M i n i s t y of F o r e s t s , C h i l l i w a c k River Nursery 85 t r e e s . The mature t r e e s c o l l e c t e d appeared s i m i l a r i n age, form, and edaphic d i s p o s i t i o n to neighbouring t r e e s i n the p o p u l a t i o n s . The t r e e s were sampled i n l a t e autumn before t h e r e had been severe l o s s of the c u r r e n t year's cone crop. The s a p l i n g s sampled were growing at the C h i l l i w a c k R i v e r Nursery of the B r i t i s h Columbia M i n i s t r y of F o r e s t s (Appendix I I : t r e e s 71601, 71602, 71603, 71604, 71605, 71606). Relevant i n f o r m a t i o n concerning the height, age, form, and sampling p o s i t i o n s of the i n d i v i d u a l s i s given i n F i g u r e 8. For examining the nature of i n t r a - i n d i v i d u a l v a r i a t i o n i n the context of i n t e r - i n d i v i d u a l v a r i a t i o n , i n d i v i d u a l t r e e s were in c l u d e d that were standards of engelmanni i and P_;_ s i t c h e n s i s . 2.2 Analyses. PCAs based upon c o r r e l a t i o n m a t r i c e s of separate s u i t e s of v a r i a b l e s were performed. Owing to the r e s t r i c t e d number of samples a v a i l a b l e , combining separate s u i t e s of v a r i a b l e s by averaging c o u l d not be used without i n v a l i d a t i n g the d i m e n s i o n a l i t y c o n s t r a i n t s of PCA. A l l data submitted to PCA were f i r s t t e s t e d f o r independence of c o r r e l a t i o n c o e f f i c i e n t s . Where independence was accepted and PCA t h e r e f o r e not necessary, u n i v a r i a t e analyses of the i n d i v i d u a l v a r i a b l e s was performed. E v a l u a t i n g d i f f e r e n c e s between v a r i o u s p o s i t i o n s was based upon ANOVAs of o r i g i n a l v a r i a b l e s or component s c o r e s . The 86 ANOVA models used are given in Table 12. I t should be noted that owing to the p a u c i t y of m a t e r i a l s , that there i s no term that r e f e r s to d i f f e r e n c e s among taxa. The lack of samples prevented a s t r u c t u r e d MVA, such as MANOVA and subsequent CVA, from being performed; although such a s t r u c t u r e d MVA would have been a n a l y t i c a l l y a p p r o p r i a t e . D i f f e r e n c e s between p o s i t i o n s i n the canopy were examined i n two manners. Mahalanobis' D 2 d i s t a n c e s between a p i c a l - and basal-most p o s i t i o n s were c a l c u l a t e d as a means of comparing these p o s i t i o n s in the v a r i o u s t r e e s . Although the sample s i z e s a v a i l a b l e per p o s i t i o n are suboptimal (Table 10), the behavior of the sample s i z e e s t i m a t i o n of D 2 was such that such a u t i l i z a t i o n of D 2 may s u f f i c e i n g i v i n g an impression of the gen e r a l t r e n d rather than s p e c i f i c d e t a i l . P r e l i m i n a r y i n s p e c t i o n s of s c a t t e r p l o t s of component scores a g a i n s t whorl or p o s i t i o n were a l s o made to determine whether a general t r e n d were present i n the data. I f a t r e n d were apparent, r e g r e s s i o n was performed provided that d i s p e r s i o n of samples around the r e g r e s s i o n l i n e c o u l d be c o n s i d e r e d normally d i s t r i b u t e d ( C h a t t e r j e e and P r i c e 1977). Mahalanobis' D 2 d i s t a n c e s were a l s o c a l c u l a t e d as a means of det e r m i n i n g o v e r a l l s i m i l a r i t y of the i n d i v i d u a l t r e e s sampled f o r i n t e r - p o s i t i o n a l v a r i a t i o n . The sample s i z e s a v a i l a b l e per i n d i v i d u a l t r e e appeared (Table 10) to be adequate f o r a l l o w i n g such use D 2. I t was impossible to q u a n t i f y i n t r a - i n d i v i d u a l v a r i a t i o n i n an i n t e r - i n d i v i d u a l or inter-taxonmic context u s i n g a s i n g l e T a b l e 12. ANOVA models used i n a s s e s s i n g v a r i o u s a s p e c t s of i n t r a - i n d i v i d u a l v a r i a t i o n . y -v a r i a b l e v a l u e s or component s c o r e s f o r a g i v e n sample: e - r e s i d u a l v a r i a t i o n . SOURCE ADVENTITIOUS/ WHORL MODEL y = A + e. TERMS b r a n c h p o s i t i o n : advent i t i ous whor 1 VARIABLE SUITE TWIG MORPHOLOGY LEAF MORPHOLOGY LEAF ANATOMY PRIMARY/ SECONDARY y = A + B(A) + e. A - b r a n c h o r d e r : pr i mary seconda ry B(A) - b r a n c h w i t h i n o r d e r . TWIG MORPHOLOGY LEAF MORPHOLOGY LEAF ANATOMY YEAR/ YEAR y = A + e. c o11e c t i on year TWIG MORPHOLOGY LEAF MORPHOLOGY LEAF ANATOMY INTER-POSITIONAL y = A + B ( A ) + e . A - t r e e B(A) - p o s i t i o n in t r e e TWIG MORPHOLOGY LEAF MORPHOLOGY LEAF ANATOMY A + B(A) + C(AB) + e. A - t r e e B(A) - p o s i t i o n in t r e e C(AB) - cone i n p o s i t i o n CONE MORPHOLOGY 88 ANOVA as systematic sampling of a l l i n d i v i d u a l s c o u l d not be undertaken. A comparison was made between two d i f f e r e n t ANOVAs based on component scores from PCAs i n c l u d i n g and e x c l u d i n g the source of i n t r a - i n d i v i d u a l v a r i a t i o n of i n t e r e s t . D i f f e r e n c e s between these ANOVAs were assessed on the b a s i s of the change i n the sums of squares. The exact nature of the ANOVAs are given i s Table 13. Without respect to the taxonomic c i r c u m s c r i p t i o n of the i n d i v i d u a l t r e e s , s u i t e s of v a r i a b l e s whose i n t r a - i n d i v i d u a l v a r i a t i o n d i d not markedly decrease the amount of i n t e r - i n d i v i d u a l v a r i a t i o n were to be p r e f e r r e d to those s u i t e s that were d r a s t i c a l l y a l t e r e d by the i n t e r - i n d i v i d u a l v a r i a t i o n . I t would be p r e d i c t e d that adding sources of T a b l e 13. ANOVA models u sed i n a s s e s s i n g the c o n t r i b u t i o n of i n t r a - i n d i v i d u a l v a r i a t i o n i n the c o n t e x t of i n t e r - i n d i v i d u a 1 v a r i a t i o n . y - v a r i a b l e v a l u e f o r component s c o r e f o r a g i v e n samp le : e - r e s i d u a l v a r i a t i o n . MODEL TERMS VARIABLE SUITES y = A + e. A - i n d i v i d u a l TWIG MORPHOLOGY LEAF MORPHOLOGY or CONE MORPHOLOGY LEAF ANATOMY A - t a x a : P. s i t c h e n s i s P. enqe1mann i i i n t r a - i n d i v i d u a l v a r i a t i o n should decrease the amount of v a r i a t i o n due to hypothesized i n t e r - i n d i v i d u a l s o urces. Where p o s s i b l e , s p e c i f y i n g the ANOVA in terms of i n d i v i d u a l s , r a t h e r than taxa, prevented the unwarranted i m p o s i t i o n and r e i f i c a t i o n of a p r i o r i taxonomic hypotheses. 89 To serve as an h e u r i s t i c a p p r e c i a t i o n of i n t r a - i n d i v i d u a l v a r i a t i o n , o r d i n a t i o n s of component scores were made to provide an h e u r i s t i c a p p r e c i a t i o n f o r the i n t r a - i n d i v i d u a l v a r i a t i o n i n such an i n t e r - i n d i v i d u a l c o n t e x t . In those analyses that compared separate PCAs of separate t r e e s , the s c a l e s of the o r d i n a t e and the a b s c i s s a were determined by the l a r g e s t d i s p e r s i o n of samples over a l l separate a n a l y s e s . Such o r d i n a t i o n f a c i l i t a t e s comparison among i n d i v i d u a l a n a l y s e s . 3. R e s u l t s . 3.1 A d v e n t i t i o u s versus whorl primary branches. The sample s i z e s (Table 10) were not s u f f i c i e n t to perform a r e l i a b l e PCA. F u r t h e r , t e s t s of the independence of c o r r e l a t i o n c o e f f i c i e n t s i n d i c a t e d that there was no s i g n i f i c a n t c o - v a r i a t i o n among the groups of v a r i a b l e s i n the v a r i o u s Rs, i n d i c a t i n g that a l l v a r i a b l e s c o u l d be co n s i d e r e d independent, thus making PCA unnecessary. ANOVAs, Table 14, i n d i c a t e d that only the average l e n g t h of the r e s i n c y s t s (RESCYLEN) c o u l d be co n s i d e r e d s i g n i f i c a n t l y d i f f e r e n t between whorl and a d v e n t i t i o u s branches - those of the whorl branches being longer (2.6 mm) than those of the a d v e n t i t i o u s branches (1.2 mm). B a r t l e t t ' s t e s t of the e q u a l i t y Of v a r i a n c e s d i d not i n d i c a t e h e t e r o s c e d a c i t y of v a r i a n c e s among the two p o s i t i o n s . With the e x c e p t i o n of the s i n g l e s i g n i f i c a n t d i f f e r e n c e , 90 T a b l e 14. ANOVAs of I n d i v i d u a l v a r i a b l e s compar ing a d v e n t i t i o u s and whorl p r i m a r y b r a n c h e s of e n g e l m a n n i1 . * . s i g n i f i c a n t F - v a l u e s @ p < 0 . 0 1 . O ther symbology g i v e n i n T a b l e 12. VARIABLES SUITE %SS- VARIABLE SUITE %SSc LEAF MORPHOLOGY (n -10 ) NEEDLEN 38.38 ABXSTOM 0 .50 ADXSTOM 0.67 RESCYNO 9.09 RESCYLOC 0.58 RESCYLEN 53 .68* x 17.58 TWIG MORPHOLOGY PULVLEN TIPWID TIPDEP PULVPUB (n = 10) 1 .45 0 .00 2 . 44 i nvar i a t e 1 . 30 LEAF ANATOMY (n=10) NEEDWID 7.93 NEEDEP 7 4 9 ABXANG 20.41 ADXANG 2.11 CENCYWID 2.14 CENCYLAT 22.17 CENCYABX 2.72 CENCYADX 20.29 ENDONUM 26.60 PHLENO 18.55 XYLEND 9.35 ~ 12.71 TOTAL x 10.. 53 the average amount of v a r i a t i o n r e s u l t i n g from d i f f e r e n c e s between the two orders of branches f o r a l l s u i t e s of v a r i a b l e s accounted f o r only about 10 percent of the t o t a l i n t r a - i n d i v i d u a l v a r i a t i o n - twice as l a r g e as the measurement r e p e a t a b i l i t y (Table 2). As a group, l e a f morphology v a r i a b l e s provided the best s e p a r a t i o n of the two p o s i t i o n s of branches. Twig morphology appeared to vary l i t t l e with r e s p e c t to branch p o s i t i o n . 3.2 Primary versus secondary whorl branches. ANOVAs, Table 15, i n d i c a t e d that d i f f e r e n c e s between orders of branches, although s i g n i f i c a n t , c o n s i s t e n t l y accounted f o r l e s s v a r i a t i o n i n the data than d i f f e r e n c e s between i n d i v i d u a l branches. The v a r i a t i o n a t t r i b u t e d to d i f f e r e n c e s between orders of branches was e x t r a c t e d p r i m a r l y by the f i r s t component of the PCAs, an i n t e r p r e t a t i o n supported by o r d i n a t i o n s i n T a b l e 15. M u l t i v a r i a t e a p p o r t i o n m e n t of v a r i a t i o n f o r s e p a r a t e v a r i a b l e s u i t e s due to d i f f e r e n c e s between o r d e r s of b r a n c h e s . A b b r e v i a t i o n of PCAs and ANOVAs i n T a b l e 39, Appendix I I I . Symbols g i v e n i n T a b l e 12. O r d i n a t i o n of r e s u l t a n t component s c o r e s g i v e n i n F i g u r e 9. %SS (mva) VARIABLE SUITE A B(A) E LEAF ANATOMY 18.37 35.32 46.31 LEAF MORPHOLOGY 7.67 36.97 55.36 TWIG MORPHOLOGY 33.42 44.95 21.65 x VEGETATIVE 19.82 39.08 41.11 F i g u r e 9. Component c o r r e l a t i o n s and mean values suggest that v a r i a b l e s measured on primary whorl branches were c o n s i s t e n t l y l a r g e r than those of the secondary branches. However, l e a f anatomy appears to vary i n more than j u s t s i z e of v a r i a b l e s as evidenced by the very low and negative component c o r r e l a t i o n s f o r angles of the l e a f s u r f a c e (ABXANG, ADXANG). D i f f e r e n c e s between the two orders of branches was most emphasized by twig morphology. F i g u r e 9. O r d i n a t i o n s of f i r s t two components of PCAs of s e p a r a t e v a r i a b l e s u i t e s of whorl p r i m a r y and seconda ry b ranches of P. S i t c h e n s i s . S co re s from PCA g i v e n in T a b l e 39. Appendix I I I. Open c i r c l e s - whorl p r i m a r y b r a n c h ; f i l l e d c i r c l e s - whorl s econdary b r a n c h . G l y p h s r e p r e s e n t i n d i v i d u a l samples . TWIG MORPHOLOGY LEAF ANATOMY K> O cP • O CD * «D •O • c0* o CD 8° LEAF MORPHOLOGY • O ° O The t o t a l v a r i a t i o n f o r a l l v a r i a b l e s over a l l s u i t e s of 92 v a r i a b l e s as a r e s u l t of d i f f e r e n c e s between branch orders was about 20 percent and that a t t r i b u t e d to d i f f e r e n c e s between branches w i t h i n an order was n e a r l y twice ( i . e . 40%) as l a r g e . The d i f f e r e n c e between orders was twice as l a r g e as the mean d i f f e r e n c e between a d v e n t i t i o u s and whorl branches (Table 14). With the exc e p t i o n of the twig morphology v a r i a b l e s u i t e , i n t r a - b r a n c h ( r e s i d u a l ) v a r i a t i o n accounted f o r a much l a r g e r p r o p o r t i o n of the t o t a l v a r i a t i o n than any other hypothesized source of v a r i a t i o n . O r d i n a t i o n s of i n d i v i d u a l branch means ( F i g . 9) showed no c o n s i s t e n t r e l a t i o n between the secondary branch subtending a given primary ( i . e . primary and secondary branches from the same whorl primary branch d i d not appear more s i m i l a r than secondaries from other branches). The o r d i n a t i o n s r e - i n f o r c e the r e s u l t s o b t a i n e d from ANOVAs of component scores (Table 15) that there was l i t t l e s e p a r a t i o n between the two orders of branches, except i n the case of twig morphology. F i g u r e 9 a l s o emphasizes t h a t the v a r i a t i o n among samples from secondary branches based on twig morphology were more v a r i a b l e than samples from primary branches. 3.3 Year to year v a r i a t i o n . The sample s i z e s were i n s u f f i c i e n t to allow a PCA (Table 10). A d d i t i o n a l l y , t e s t s of the independence of c o r r e l a t i o n c o e f f i c i e n t s of R i n d i c a t e d that the p u l v i n u s , l e a f morphology, and cone morphology v a r i a b l e s u i t e s had no s i g n i f i c a n t o v e r a l l v a r i a t i o n i n the data, suggesting that 93 v a r i a b l e s in these groups were independent. One-way ANOVA (Table 16) t e s t e d whether some of the v a r i a b l e s d i s t i n g u i s h e d between the two d i f f e r e n t y e a r s . The r e s u l t s i n d i c a t e that there were s i g n i f i c a n t d i f f e r e n c e s between the years for only 7 v a r i a b l e s : RESCYNO, PULVLEN, TIPWID, NEEDWID, CENCYLAT, CONWID, AND SCALEN. The average amount of T a b l e 16. ANOVAs compar ing year to year v a r i a t i o n of v a r i a b l e s i n P. enge1mann i i . VARIABLES SUITE %SSfl VARIABLE SUITE %SS A LEAF MORPHOLOGY (n=10) LEAF ANATOMY (n= 10) NEEDLEN 12 .90 NEEDWID 59 . 37* ABXSTOM 10 . 1 1 NEEDEP 13 . 45 ADXSTOM 4 OO ABXANG 3 , 80 RESCYNO 51 .02* ADXANG 7 . 40 RESCYLOC 38 . 33 CENCYWID 0. . 38 RESCYLEN 3 .82 CENCYLAT 73 . 35* X 20.03 CENCYABX 0. . 26 CENCYADX 26 .44 TWIG MORPHOLOGY (n=10) ENDONUM 0 OO PULVLEN 81 .09* PHLEND 1 1 . . 36 TIPWID 55 . 17* XYLEND 5 . 77 TIPDEP 7 .44 ~ 18 . 33 PULVPUB 1nvar i a t e X 47 . 90 CONE MORPHOLOGY <n = 34 ) CONLEN 1 .50 CONWID 46 .04* SCALEN 27 . 54* SCALWID 2 . 35 SCALTAP 2 . 1 1 WINGWID 2 . 82 WINGTAP 1 . 34 FREESCAL 3 . 27 BRACTLEN 0 . 84 BRACTWID 3 . 10 BRACTAP 0 . 17 31.01 TOTAL X 29.34 v a r i a t i o n between years accounted f o r 30 percent of the t o t a l i n t r a - i n d i v i d u a l v a r i a t i o n . T h i s amount of i n t r a - i n d i v i d u a l v a r i a t i o n i s , i n comparison with measurement r e p e a t a b i l i t y , branch p o s i t i o n (11%), and branch order (20%) a l a r g e source of 94 v a r i a t i o n . However, i t i s n o t as l a r g e a s o u r c e o f i n t r a - i n d i v i d u a l v a r i a t i o n a s w i t h i n i n c r e m e n t v a r i a t i o n ( T a b l e 15). E x a m i n a t i o n of mean v a r i a b l e v a l u e s f o r t h e two y e a r s o f growth s u g g e s t e d t h a t t h e r e were no c o n s i s t e n t t r e n d s ( i . e . one y e a r d i d not have c o n s i s t e n t l y l a r g e r v a r i a b l e v a l u e s t h a n t h e o t h e r , even t h o s e v a r i a b l e s w h i c h were s i g n i f i c a n t l y d i f f e r e n t o v e r t h e two y e a r s ) . 3.4 I n t e r - p o s i t i o n a l v a r i a t i o n . O v e r a l l e i g e n - s t r u c t u r e i n d i c a t e d s i g n i f i c a n t v a r i a t i o n amongst a l l v a r i a b l e s i n e a c h v a r i a b l e s u i t e . ANOVA of component s c o r e s i n d i c a t e d t h a t t h e l a r g e s t s i n g l e s o u r c e of v a r i a t i o n was a t t r i b u t e d t o i n t e r - i n d i v i d u a l d i f f e r e n c e s ( T a b l e 17). However, c o n s i d e r i n g a l l i n t r a - i n d i v i d u a l s o u r c e s o f T a b l e 17. M u l t i v a r i a t e a p p o r t i o n m e n t of v a r i a t i o n f o r s e p a r a t e v a r i a b l e s u i t e s due to d i f f e r e n c e s between p o s i t i o n s of b r a n c h e s . A b b r e v i a t i o n of PCAs and ANOVAs i n T a b l e 40, Appendix I I I. Symbols g i v e n i n T a b l e 12. O r d i n a t i o n s of r e s u l t a n t component s c o r e s g i v e n i n F i g u r e 10.. %SS (mva) VARIABLE SUITE A B ( A ) C U B ) E LEAF ANATOMY 55 . 30 22 .90 2 1 . 57 LEAF MORPHOLOGY 44 . 96 23 . 90 31.14 TWIG MORPHOLOGY 46 . 23 46 .59 7.18 CONE MORPHOLOGY 27 .64 11.91 42 .97 17 .49 x VEGETATIVE 48.91 31.13 19 . 96 x TOTAL 43 . 59 26 . 33 30.09 v a r i a t i o n , o n l y l e a f anatomy had an i n t e r - i n d i v i d u a l v a r i a t i o n t h a t e x c e e d e d i n t r a - i n d i v i d u a l . The l a r g e s t v a r i a t i o n was h y p o t h e s i z e d t o be t h e r e s u l t of i n t e r - p o s i t i o n a l e f f e c t s 95 manifest by twig morphology. The l a r g e s t source of v a r i a t i o n of cone morphology (Table 17) was a t t r i b u t e d to d i f f e r e n c e s between cones at a s i n g l e p o s i t i o n i n the canopy. D i f f e r e n c e s between cones from d i f f e r e n t whorls provided the second l a r g e s t source of v a r i a t i o n . Mahalanobis' D 2 d i s t a n c e s between a p i c a l - and basal-most branches (Table 18) i n d i c a t e that there were grea t e r d i f f e r e n c e s i n l e a f anatomy w i t h i n mature t r e e s than immature t r e e s . The T a b l e 18. M a h a l a n o b i s ' D 1 d i s t a n c e s between a p i c a l - and b a s a l - m o s t b r a n c h e s and cones of P_^  enge 1 mann i i and P_^  s i t chens i s . D i a gona l e l e m e n t s (+), i n t r a - i n d i v i d u a l d i s t a n c e s between a p i c a l - and b a s a l - m o s t b r a n c h e s . Lower o f f - d i a g o n a l e l e m e n t s , d i s t a n c e s between b a s a l b r a n c h e s . Upper o f f - d i a g o n a l e l e m e n t s , d i s t a n c e s between a p i c a l b r a n c h e s . Is, immature s i t chens i s (T1 - TG) ; Ms, mature p. s i t c h e n s i s ( T 7 ) : Me, mature P_^  enge1manni i ( T 8 ) . P.enge1mann i i and P_^  s i t c h e n s i s. No te : D ! v a l u e s c o u l d not be c a l c u l a t e d f o r tw i g morpho logy due to m a t r i x s i n g u l a r i t y . LEAF ANATOMY LEAF MORPHOLOGY Is Ms Me Is Ms Me Is 3 . 10 34 . 50 77 . 82 10.81 18.82 18 .04 Ms 5 . 23 41 . 98 44 . 23 2 .89 20. 53 19 . 28 Me 205.92 199 . 4 1 . 7 3.90 20. 12 1 1 .83 2 . 39 CONE MORPHOLOGY Ms Me Ms 43.76 65.30 + Me 43.47 8.80 i n d i v i d u a l of E\ enqelmanni i was d e c i d e d l y d i f f e r e n t from both the mature and immature I\ s i t c h e n s i s , but only with respect to 96 l e a f anatomy. These d i s t a n c e s a l s o i n d i c a t e that there were gre a t e r d i f f e r e n c e s between the bas a l branches than between the a p i c a l branches. Leaves from the b a s a l most branches of engelmannii were l e s s s i m i l a r to those of s i t c h e n s i s than were leaves from the a p i c a l most b r a n c h e s . D i f f e r e n c e s between the two taxa were most emphasized by comparing l e a f anatomy of b a s a l branches. I n t e r - i n d i v i d u a l d i f f e r e n c e s of both taxa were most conspicuous when apical-most p o s i t i o n s were compared on the b a s i s of l e a f and cone morphology. I n t e r - i n d i v i d u a l d i f f e r e n c e s in P_z_ s i t c h e n s i s are most obvious when comparing a p i c a l branches. F i g u r e 10, i n d i c a t e s that there e x i s t s a d i s c r e t e d i f f e r e n c e between the a p i c a l - and basal-most branches. F u r t h e r , F i g u r e 10 i n d i c a t e s that there i s c o n s i s t e n t l y a gre a t e r d i s p e r s i o n amongst the apical-most needles than among the basal-most needles. T h i s p a t t e r n i s evident i n both mature and immature t r e e s . The o v e r a l l assessment of d i f f e r e n c e s based on Mahalanobis' D 2 i s given i n Table 19. These r e s u l t s i n d i c a t e that the l a r g e s t i n t e r - i n d i v i d u a l d i f f e r e n c e s e x i s t between the s i n g l e i n d i v i d u a l of P^ engelmanni i and a l l i n d i v i d u a l s of P. s i t c h e n s i s . By c o n t r a s t , the d i f f e r e n c e s among i n d i v i d u a l s of P^ s i t c h e n s i s are t r i v i a l and there appears to be no d i f f e r e n c e r e s u l t i n g from the age except, perhaps, i n c o n s i d e r i n g l e a f morphology. That i s , the mature i n d i v i d u a l of P. s i t c h e n s i s i s no l e s s d i f f e r e n t from immature t r e e s than 97 F i g u r e 10. O r d i n a t i o n s of f i r s t two components of PCAs o f s e p a r a t e v a r i a b l e s u i t e s of whor l b r a n c h p o s i t i o n s from P_^  engelmanni i and P_^  s i t c h e n s i s S c o r e s from PCAs g i v e n in T a b l e 40, Appendix I I I. Open g l y p h s , a p i c a l - m o s t b r a n c h e s ; f i l l e d g l y p h s , b a s a l - m o s t p o s i t i o n s . C i r c l e s - P^ s i t chens i s; t r i a n g l e s - P^ engelmanni i . I n t e r v e n i n g sampled p o s i t i o n s o m i t t e d from o r d i n a t i o n to emphas ize p o l a r i t y . G l y p h s r e p r e s e n t i n d i v i d u a l samples . LEAF ANATOMY ^ TWIG MORPHOLOGY d i f f e r e n c e s between i n d i v i d u a l immature t r e e s . With r e s p e c t to branch pubescence, i t was observed that the apical-most branches of the sampled mature i n d i v i d u a l of p. s i t c h e n s i s had pubescent p u l v i n i i . T h i s same s i t u a t i o n e x i s t e d f o r the apical-most branches from a p u t a t i v e P. s i t c h e n s i s (Tree 532, Appendix I I ) . S i m i l a r l y , pubescent branches were a l s o observed on an i n d i v i d u a l of P_;_ glauca (Tree 70301, Appendix II) from the Ottawa V a l l e y . Observations made on f a l l e n branches from other t r e e s i n the study area suggested that t h i s s i t u a t i o n was more frequent than the samples a v a i l a b l e 98 T a b l e 19. Average M a h a l a n o b i s ' D! d i s t a n c e s between i n d i v i d u a l t r e e s in T a b l e 18. D! v a l u e s below d i a g o n a l ( . - - ) - d i s t a n c e s between i n d i v i d u a l t r e e s . Symbols g i v e n i n F i g u r e 8 and T a b l e 18. LEAF ANATOMY Is T1 T2 3 .06 T3 5 . 61 4 . 22 T4 7 . 66 3 .59 7 .61 T5 6 . 88 2 .85 9 . 42 2 . 39 --T6 10. .01 6 . 33 1 1 . 69 1 1 . 94 7 . 18 Ms T7 G . 99 5 . 74 13 . 23 1 1 .61 5 . 81 8 . 55 Me T8 56 . 38 51 .49 47 .06 G6 . 23 56 . 28 59. 18 53 . 77 LEAF MORPHOLOGY Is T 1 T2 5 . 88 T3 0 . 95 6 .08 T4 2 . 18 6 .02 T5 3 . 77 3 . 37 T6 1 1 . .66 6 .88 Ms T7 20. . 77 19 .84 Me T8 38 . 05 25 .65 0. 87 . - -4 .20 2.69 . - -9.4 1 6.62 7.68 22 . 40 22 . 24 15.14 39.73 39.39 31.54 TWIG MORPHOLOGY Is T1 T2 3 .67 T3 3 . 16 0. 56 T4 0 . 32 3 . 76 3 . 72 T5 1 . 24 2 . 83 1 . 59 1 . 38 T6 8 . 54 1 . 97 1 . 87 9 . 87 6 . 85 __ Ms T7 4 .81 2.14 2 . 1 1 4 . 02 2 . 26 6.12 Me T8 88 .95 90.4 1 87 .61 88 .02 83 . 54 95.99 7 1 . 46 . -T 1 T2 T3 T4 T5 T6 T7 T8 99 would suggest. In these s i t u a t i o n s where the a p i c a l branches were pubescent, the bas a l branches appeared gl a b r o u s . As the PCA of a l l t r e e s may have convoluted p a t t e r n s of i n t r a - i n d i v i d u a l v a r i a t i o n , and the ANOVAs suggested s i g n i f i c a n t d i f f e r e n c e s between i n d i v i d u a l t r e e s , separate PCAs were performed f o r each tr e e f o r each v a r i a b l e s u i t e . The component scores from these PCAs were then examined by ANOVA (Table 20). The f i r s t component from each of these PCAs i n d i c a t e s that the l a r g e s t source of v a r i a t i o n was a t t r i b u t e d to d i f f e r e n c e s between whorl p o s i t i o n s f o r twig morphology, l e a f anatomy, and l e a f morphology (averaging 74%, 53%, and 51% r e s p e c t i v e l y over a l l t r e e s ) . I n t e r - p o s i t i o n a l d i f f e r e n c e s were l e s s than i n t r a - p o s i t i o n a l d i f f e r e n c e s f o r cone morphology, averaging 17 percent over a l l t r e e s . I n t r a - p o s i t i o n cone morphology v a r i a t i o n was much l a r g e r (83%) than i n t e r - p o s i t i o n a l v a r i a t i o n f o r any other v a r i a b l e s u i t e . The r e l a t i v e magnitude of the component c o r r e l a t i o n s (Table 21) suggested that the f i r s t components were r e f l e c t i n g s i z e and shape d i f f e r e n c e s between samples. ANOVAs suggested that i n t e r - b r a n c h d i f f e r e n c e s g e n e r a l l y exceeded i n t r a - b r a n c h v a r i a t i o n only f o r the f i r s t components. Examples of the type of v a r i a t i o n shown by l e a f anatomy are given i n F i g u r e 11 which emphasizes the s t r i k i n g v a r i a t i o n w i t h i n and between t r e e s . An i n i t i a l s c a t t e r of component scores a g a i n s t p o s i t i o n or whorl suggested a common trend f o r each t r e e ( F i g . 12). However as the v a r i a n c e s of component scores f o r each p o s i t i o n c o u l d not be co n s i d e r e d equal, based on B a r t l e t t ' s t e s t , r e g r e s s i o n and T a b l e 20. M u l t i v a r i a t e appor t i onment of v a r i a t i o n f o r s e p a r a t e v a r i a b l e s u i t e s of s e p a r a t e t r e e s due to whor l p o s i t i o n s . A b b r e v i a t i o n of T a b l e 41 in Appendix I I I. Symbols g i v e n in T a b l e 12 and F i g u r e 8. O r d i n a t i o n s of r e s u l t a n t component s c o r e s g i v e n i n F i g u r e s 12 and 13. %SS (mva) Is Ms Me X T 1 T2 T3 T4 T5 T6 T7 T8 VARIABLE SUITE LEAF ANATOMY A 67 . 89 53 . 39 60. 72 67 . 82 53.21 35 . 16 59 . 05 29 ,90 53 . 39 e 32 . 1 1 46.61 39 . 28 32 . 20 46 . 79 64 . 84 40. 95 70 . 10 46 .61 LEAF MORPHOLOGY A 43 . 01 41 .89 42 .93 42 . 92 7 2 . 89 52 47 82 . 79 27 . 30 50 78 e 56 . 69 58 . 1 1 57 .07 57 . 08 27.11 47 .53 17 . 21 72 . 70 49 . 23 TWIG MORPHOLOGY A 94 . 25 96. 55 74 . 84 30. 90 74 . 14 e 5 . 75 3 . 45 25. 16 69. 10 25 . 87 CONE MORPHOLOGY A 24 . 85 8. 92 16 .89 B( A) 62 . 72 63 . 87 63 . 30 e 12 . 42 27 . 21 19 . 82 x VEGETATIVE A 68 . 38 69 . 10 72 . 22 29 . 07 59 . 44 e 31 . 62 30. 90 27 . 87 70. 93 40 . 56 x TOTA 1 A e 60. 39 . 38 63 24 . 75 . 03 97 48 51 .80 . 20 101 T a b l e 21. C o r r e l a t i o n s amongst component c o r r e l a t i o n s f o r f i r s t components f rom PCAs i n T a b l e 20. * . c o r r e l a t i o n s s i g n i f i c a n t p < 0 . 0 1 . Other symbols as i n F i g u r e 8. LEAF ANATOMY IS T1 T2 T3 T4 T5 T6 . 599 . 726* .749* ' . 389 . 509 .912* .905* .849* . 863* . 967* . 754* . 722 . 704 . 78 1 * .7 19 Ms T7 .435 .808* . 827 . 702 .847* .516 Me T8 . 709 .689 .829 . 847* . 550 . 377 .611 LEAF MORPHOLOGY Is T1 T2 T3 T4 T5 T6 - .671 . 688 . 924* . 790 . 975* - . 490 - .878 - . 323 - . 594 . 562 . 884 . 751 . 563 . 877 .831 Ms T7 . 955* - . 713 . 763 .909 .837 .955* Me T8 .938* - . 774 .693 .941* . 758 .928* .991* T1 T2 T3 T4 T5 T6 T7 T8 TWIG MORPHOLOGY Is T1 T4 Ms T7 Me T8 . 574 .519 .438 .519 .438 .438 T1 T4 T7 T8 102 F i g u r e 11. Examples of i n t r a - i n d i v i d u a l v a r i a t i o n of l ea f anatomy f o r some t r e e s shown i n F i g u r e 8. s t a t i s t i c a l comparison of slopes was not c o n s i d e r e d a p p r o p r i a t e . These diagrams ( F i g . 12) f u r t h e r emphasize the continuous nature of v a r i a t i o n i n the t r e e s . The diagrams a l s o emphasize the s i m i l a r i t y of i n t r a - i n d i v i d u a l v a r i a t i o n of a l l the i n d i v i d u a l s r e g a r d l e s s of age with the exception of the n e c r o t i c and stunted i n d i v i d u a l s ( F i g . 8: T5, T6). Table 21 presents c o r r e l a t i o n s among the e i g e n v e c t o r - v a l u e s from separate PCAs i n d i c a t i n g a s t r i k i n g s i m i l a r i t y i n the c o n t r i b u t i o n of l e a f anatomy v a r i a b l e s to the p a t t e r n of i n t r a - i n d i v i d u a l p a t t e r n . PCAs of i n d i v i d u a l t r e e s and subsequent s c a t t e r s of component scores i n d i c a t e d that v a r i a t i o n i n t e r - p o s i t i o n a l v a r i a t i o n was the l a r g e s t source of v a r i a t i o n i n each t r e e , except f o r P^ engelmannii. C o r r e l a t i o n s amongst component c o r r e l a t i o n s (Table 21) from PCAs i n Table 20, suggest a general s i m i l a r i t y of the v a r i a b l e s c o n t r i b u t i n g to the p a t t e r n of 103 F i g u r e 1 2 . S c a t t e r s o f m e a n s a n d s t a n d a r d d e v i a t i o n s o f s c o r e s o f f i r s t c o m p o n e n t s o f P C A s f o r i n d i v i d u a l b r a n c h e s o f i n d i v i d u a l t r e e s a g a i n s t w h o r l b r a n c h p o s i t i o n s . S c o r e s b a s e d o n P C A s g i v e n i n T a b 1e 4 1 , A p p e n d i x I I I . S y m b o I s a s i n F i g u r e 8 . A l l f i r s t c o m p o n e n t s d r a w n t o s a m e s e a I e . L E A F A N A T O M Y L E A F M O R P H O L O G Y T W I G M O R P H O L O G Y TB 104 i n t r a - i n d i v i d u a l v a r i a t i o n amongst a l l t r e e s . The component c o r r e l a t i o n s i n d i c a t e d that the p a t t e r n of i n t e r - p o s i t i o n a l v a r i a t i o n of l e a f anatomy of i n d i v i d a l s of F\ s i t c h e n s i s was, r e g a r d l e s s of m a t u r i t y , a r e s u l t of the a p i c a l leaves being wider (NEEDWID) and deeper (NEEDEP) and having l a r g e r c e n t r a l c y l i n d e r s (or measurements a s s o c i a t e d with the l o c a t i o n of the c e n t r a l c y l i n d e r ; CENCY.^.) than the more ba s a l l e a v e s . V a r i a t i o n among leaves of the i n d i v i d u a l of P^ engelmanni i was more dependent upon aspects of the c e n t r a l c y l i n d e r and v a s c u l a r bundle than the v a r i a b l e s c o n t r i b u t i n g to the v a r i a t i o n i n P_^_ s i t c h e n s i s . U n l i k e l e a f anatomy, l e a f and twig morphology, although showing s i g n i f i c a n t d i f f e r e n c e s between p o s i t i o n s , d i d not show a c o n s i s t e n t t r e n d that was h i g h l y c o r r e l a t e d with p o s i t i o n i n the canopy. There was no c o n s i s t e n t t r e n d in i n t e r - w h o r l v a r i a t i o n , except f o r l e a f anatomy, that suggested that the more a p i c a l l y disposed l e a v e s were more v a r i a b l e . Of the v a r i a b l e s u i t e s that were examined with PCA, twig morphology showed the l e a s t i n t r a - p o s i t i o n v a r i a t i o n . PCAs of cone morphology v a r i a t i o n w i t h i n the canopy of i n d i v i d u a l t r e e s were a l s o performed (Table 20). Although there was s i g n i f i c a n t v a r i a t i o n i n the data, p r e l i m i n a r y s c a t t e r s of PCA component scores a g a i n s t p o s i t i o n i n the canopy d i d not appear to be r e l a t e d l i n e a r l y as in the case of l e a f anatomy. F i g u r e 13 p r e s e n t s an o r d i n a t i o n of the f i r s t two components from these separate PCAs, and i n d i c a t e s a v i r t u a l o v e r l a p amongst cones of a p i c a l - and basal-most cone b e a r i n g branches. 1 05 F i g u r e 13. O r d i n a t i o n s of f i r s t two components of PCAs of i n d i v i d u a l t r e e s c o m p a r i n g p o s i t i o n s of c o n e s . S co re s from PCAs g i v e n in T a b l e -4 1. Append ix I I I. G l y p h s as in F i g u r e 10. I n t e r v e n i n g sample p o s i t i o n s o m i t t e d from o r d i n a t i o n to emphas ize p o l a r i t y A l l components drawn to the same s c a l e . G l yphs r e p r e s e n t i n d i v i d u a l sea 1es. (51.69 •..) <4&'" *'•> L i k e twig and l e a f morphology, cone morphology v a r i a t i o n of the two t r e e s were not s i g n i f i c a n t l y c o r r e l a t e d (r=0.345). 3.5 I n t r a - i n d i v i d u a l v a r i a t i o n in the context of i n t e r - i n d i v i d u a l v a r i a t i o n . Without i n c l u d i n g sources of s p e c i f i c i n t r a - i n d i v i d u a l v a r i a t i o n , a l l e v a l u a t i o n of c o r r e l a t i o n matrices i n d i c a t e d that there was s i g n i f i c a n t v a r i a t i o n i n the data (Table 22). ANOVAs (Table 22) suggested that the l a r g e s t source of v a r i a t i o n was a t t r i b u t e d to d i f f e r e n c e s between i n d i v i d u a l s . E i g e n - v e c t o r values f o r the components of the separate PCAs suggested that the p a t t e r n s of v a r i a t i o n were s i g n i f i c a n t l y c o r r e l a t e d . I n t e r j e c t i n g i n t r a - i n d i v i d u a l v a r i a t i o n only m inimally a l t e r e d the r e s u l t s of ANOVA, suggesting that these i n t r a - i n d i v i d u a l sources of v a r i a t i o n were not h i g h l y s i g n i f i c a n t i n an i n t e r - i n d i v i d u a l c o n t e x t , thereby c o r r o b o r a t i n g the c o n c l u s i o n from e a r l i e r a n a l y s e s . Adding 106 T a b l e 22. M u l t i v a r i a t e a p p o r t i o n m e n t of v a r i a t i o n f o r s e p a r a t e v a r i a b l e s u i t e s due to d i f f e r e n c e s between i n d i v i d u a l t r e e s or t a x a , e m p h a s i z i n g d i f f e r e n t s o u r c e s of i n t r a -1nd1v1dua1 v a r i a t i o n i n an i n t e r - i n d i v i d u a 1 c o n t e x t . A b b r e v i a t i o n of the PCAs and ANOVAs i n T a b l e 42, Appendix I I I. WO - w i t h o u t any o t h e r i n t r a - i n d i v i d u a l v a r i a t i o n b e s i d e s i n t r a - i n c r e m e n t ; 1°/2° - w i t h p r i m a r y and s e c o n d a r y o r d e r s of b r a n c h i n g and b ranches w i t h i n o r d e r ; POS -w i t h i n t e r - p o s i t i o n a l v a r i a t i o n ; %W0 - change from %SS WO. Other symbols g i v e n m T a b l e 13. O r d i n a t i o n of r e s u l t a n t component s c o r e s g i v e n i n F i g u r e 14. %SS (mva) TAXA INDIVIDUAL VARIABLE SUITE A E %WO A E %W0 LEAF ANATOMY WO 31 .87 68 . 13 0 .0 87 . 72 12 . 82 0 .0 1 °/2° 36 .49 63 .51 -4 .62 86 .96 13 .04 0 .02 POS 30 . 27 69 . 27 1 . 14 79 . 89 20 . 1 1 7 . 29 LEAF MORPHOLOGY WO 26 .58 73 . 42 0 .0 79 .60 20 .40 0 .0 1 °/2° 21 .80 78 .20 4 . 78 75 . 52 24 .48 4 .08 POS 23 .00 77 .00 3 .58 77 .09 22 .91 2 , .51 TWIG MORPHOLOGY WO 35 . 42 64 , 58 0. .0 93 .68 6 , 32 0 .0 1 °/2° 35 .05 64 . 95 0. . 37 90. .63 9 , 37 3 . 05 POS 31 .27 68 .73 4 . 15 87 .41 12 .59 6 . 27 CONE MORPHOLOGY WO 19. ,02 80. .98 0. 0 67. . 73 32 . 27 0. 0 POS 17 . 87 82 . 13 1 . . 15 63. .50 35 . 50 3. 23 x VEGETATIVE WO 31 . 29 68. 71 0. 0 87. 00 13. 00 0. 0 1 °/2° 31 . . 1 1 68 . .89 0. 18 84 .  37 15 . 63 2 . 63 POS 28 . 18 7 1 . 82 -3 . 1 1 81 . .46 18 . 54 5 . 54 x TOTAL WO 28 . 22 7 1 . 78 0. 0 82 . 18 17 . 82 0. 0 POS 25 . 60 74 . 40 2 . 62 76. 97 23 . 03 5 . 18 i n t r a - i n d i v i d u a l sources of v a r i a t i o n g e n e r a l l y decreased the amount of v a r i a t i o n between i n d i v i d u a l s . Such a decrease i s expected. However, f o r l e a f anatomy the v a r i a t i o n between hypothesized taxa i n c r e a s e d suggesting that the i n c l u s i o n of i n t r a - i n d i v i d u a l sources of v a r i a t i o n c o u l d a l t e r a taxonomic h y p o t h e s i s . These ANOVAs suggest that d i f f e r e n c e s between taxa are much l e s s than d i f f e r e n c e s between i n d i v i d u a l s . F u r t h e r , the i n t e r - i n d i v i d u a l and inter-taxonomic d i f f e r e n t i a t i o n was lower f o r cone morphology than f o r the other v a r i a b l e s u i t e s . O r d i n a t i o n s , F i g u r e 14, c o r r o b o r a t e the impression of small 1 07 inter-taxonomic d i f f e r e n c e s . Indeed, b e a r i n g i n mind that the open glyphs represent means of i n d i v i d u a l t r e e s ( i . e . on average 18% of the t o t a l v a r i t i o n i n the data has been removed from the o r d i n a t i o n d u r i n g the c a l c u l a t i o n s of means) there i s a l a r g e degree of o v e r l a p between point-swarms a s s i g n a b l e to the two taxa. The r e s u l t s presented i n Tables 14 to 17 have been averaged and summarized in F i g u r e 15. T h i s summarization assumes that the three hypothesized sources of v a r i a t i o n are independent. Compared to the other h y p o t h e s i z e d sources, of i n t r a - i n d i v i d u a l v a r i a t i o n , the v a r i a t i o n w i t h i n a s i n g l e increment i s i n d i c a t e d as being l a r g e r than both the s p e c i f i e d i n t e r - i n c r e m e n t sources of v a r i a t i o n . 4. D i s c u s s i o n . Other sources of i n t r a - i n d i v i d u a l v a r i a t i o n are p o s s i b l e to i n v e s t i g a t e and, perhaps, should have been i n v e s t i g a t e d . C o n s i d e r a t i o n of the s i z e and p a t t e r n of j u s t these few sources of i n t r a - i n d i v i d u a l v a r i a t i o n leads to c o n s i d e r a t i o n s concerning how these p a t t e r n s may a f f e c t the understanding and i n t e r p r e t a t i o n of p a t t e r n s of i n t e r - i n d i v i d u a l v a r i a t i o n . Such c o n s i d e r a t i o n of the p a t t e r n s of i n t r a - i n d i v i d u a l v a r i a t i o n c a l l s i n t o q u e s t i o n the assumed e f f i c a c y of e x t r i n s i c processes i n accounting f o r intra-crown p a t t e r n s of v a r i a t i o n and the development of crown form. As these r e s u l t s are based on only a few t r e e s and a few p o s i t i o n s , the c o n c l u s i o n s must be regarded as being more F i g u r e 1 4 . O r d i n a t i o n s o f f i r s t t w o c o m p o n e n t s o f P C A s o f s e p a r a t e v a r i a b l e s u i t e s f o r i n t r a - i n d i v i d u a l v a r i a t i o n i n t h e c o n t e x t o f i n t e r - i n d i v i d u a 1 v a r i a t i o n . S c o r e s b a s e d o n P C A s g i v e n i n T a b l e 4 2 . A p p e n d i x i l l . O p e n g l y p h s r e p r e s e n t m e a n s o f i n d i v i d u a l t r e e s ; s o l i d g l y p h s a r e i n d i v i d u a l s a m p l e s f r o m a s i n g l e t r e e f o r t h e s o u r c e o f v a r i a t i o n i n d i c a t e d . O t h e r g l y p h s a s i n F i g u r e 1 0 . LEAF MORPHOLOGY MLB O CP , £ 0 oS?»* o OA& A A A A H VI2' tt int«r-positional ,o O O O •O O A A TWIG MORPHOLOGY VIV inter-post tional O L E A F ANATOMY f i i . 3 f , . l I49.76-'.) It3.se-.) CONE MORPHOLOGY 109 F i g u r e 15. Summary of p a r t i o n i n g of s o u r c e s of i n t r a - i n d i v i d u a l v a r i a t i o n . Summary based on t o t a l '/SS (mva) Ta b l e s 14 to 17 S t i p l e d b o r d e r of p i e i n d i c a t e s r e g i o n that i s r e f e r r e d to i n a l l subsequent a n a l y s e s as " i n t r a - i n d i v i d u a l v a r i a t i o n " . t e n t a t i v e than c o n c l u s i v e i n nature. Regardless, these r e s u l t s suggest the need f o r new r e s e a r c h d i r e c t i o n s and approaches to res e a r c h in seeking to understand the i n t e g r a t i o n of developmental, e c o l o g i c a l and e v o l u t i o n a r y p r o c e s s e s . As f o r e s t r y i n t e r e s t s become i n c r e a s i n g l y concerned with p h y s i o l o g i c a l and y i e l d v a r i a b l e s (Campbell 1975), p a r t i c u l a r l y phenology ( D i e t r i c h s o n 1964), i n v e s t i g a t i o n s of the developmental assumptions u n d e r l y i n g these v a r i a b l e s (Burley 1965; Campbell 1974; R e h f e l d t and L e s t e r 1969; Re h f e l d t 1983; and C a n n e l l , et a l . 1976) should be undertaken. 110 4.1 Sampling i m p l i c a t i o n s . These r e s u l t s suggest t h a t , i n P i c e a , p r o v i d e d that the sampling of v e g e t a t i v e m a t e r i a l s i s r e s t r i c t e d to the lower branches of i n d i v i d u a l s , t here should not be a great deal of d i f f e r e n c e as to whether a whorl or a d v e n t i t i o u s branch i s sampled. F u r t h e r , the order of branching and year of c o l l e c t i o n may be unimportant to understanding i n t e r - i n d i v i d u a l v a r i a t i o n . However, as these estimates are sample and v a r i a b l e s p e c i f i c , i t seems a p p r o p r i a t e to suggest that extending sampling and i n c r e a s i n g the present sample s i z e s and making c r i t i c a l o b s e r v a t i o n s on other aspects of crown form may w e l l uncover p r e v i o u s l y unreported and s i g n i f i c a n t sources and p a t t e r n s of i n t r a - i n d i v i d u a l v a r i a t i o n . Where obvious environmental and developmental d i f f e r e n c e s between p o s i t i o n s i n the canopy appear to e x i s t , i t would seem a d v i s a b l e to note these f e a t u r e s and to take them i n t o c o n s i d e r a t i o n when making i n t e r p r e t a t i o n s . The r e s u l t s suggest three s p e c i f i c s i t u a t i o n s i n which sources of i n t r a - i n d i v i d u a l v a r i a t i o n should be taken i n t o c o n s i d e r a t i o n when examining p a t t e r n s of i n t e r - i n d i v i d u a l v a r i a t i o n and d e r i v i n g i n f e r e n c e s . F i r s t , where p a t t e r n s of i n t e r - i n d i v i d u a l v a r i a t i o n based on l e a f morphology are s t r o n g l y c o r r e l a t e d with r e s i n c y s t l e n g t h s (RESCYLEN), then the d i s p o s i t i o n of samples with r e s p e c t to whorl or a d v e n t i t i o u s branches should be taken i n t o c o n s i d e r a t i o n . Second, anomalies i n i n t e r - i n d i v i d u a l v a r i a t i o n based on twig morphology might be e x p l a i n a b l e by the order of branch sampled. T h i r d , where c o l l e c t i o n s have been made over s e v e r a l years, i n t e r - i n d i v i d u a l 111 v a r i a t i o n of twig morphology c o u l d r e f l e c t d i f f e r e n c e s i n the year of c o l l e c t i o n . S i m i l a r l y , p a t t e r n s of i n t e r - i n d i v i d u a l v a r i a t i o n based on cone morphology that are s t r o n g l y c o r r e l a t e d with cone width (CONWID) should be examined f o r a r t i f a c t s c r e a t e d by the year of c o l l e c t i o n s . The lack of d i s c r e t e d i f f e r e n c e s between j u v e n i l e and mature i n d i v i d u a l s of s i t c h e n s i s (Table 21) suggests t h a t , f o r the ages and environmental c o n d i t i o n s sampled here, a l l ages of i n d i v i d u a l s c o u l d be used when examining p a t t e r n s of i n t e r - i n d i v i d u a l v a r i a t i o n . The s i t u a t i o n remains unclear with respect to P_;_ engelmanni i owing to a l a c k of immature samples. Not withstanding the o b s e r v a t i o n s of a g e - r e l a t e d v a r i a t i o n demonstrated i n other s p e c i e s of Picea ( L i n d q u i s t 1948; Funsch 1975) and the o b s e r v a t i o n s r e p o r t e d i n Chapter II with respect to pubescence and needle morphology, the a n a l y s e s presented here i n d i c a t e that a g e - r e l a t e d d i f f e r e n c e s are not e s p e c i a l l y l a r g e . However they do d i f f e r i n i n t r a - i n d i v i d u a l v a r i a t i o n - mature t r e e s are more v a r i a b l e than immature. With r e s p e c t to the v a r i a b l e s examined here, i n an i n t e r - i n d i v i d u a l c o n t e x t , a g e - r e l a t e d v a r i a t i o n appears to be a t r i v i a l source of var i a t i o n . The demonstrated lack of i d e n t i f i a b l e p a t t e r n of i n t r a - i n d i v i d u a l v a r i a t i o n of cone morphology suggests that the assumption (Chapt. II) that cone c o l l e c t i o n s represent a random c o l l e c t i o n from the crown i s not necessary. The data presented suggest that d i s p o s i t i o n of cones in the t r e e w i l l probably not be of s e r i o u s consequence i n understanding p a t t e r n s of 1 1 2 i n t e r - i n d i v i d u a l v a r i a t i o n . On an i n t e r - i n d i v i d u a l note, c o n s i d e r i n g that the t r e e s used i n t h i s a n a l y s i s represent standards of the two taxa, and probably represent the most m o r p h o l o g i c a l l y and a n a t o m i c a l l y p o l a r i z e d data a v a i l a b l e , the d i s c r e t e n e s s of the two taxa r e q u i r e s comment. That i n t r a - i n d i v i d u a l sources of v a r i a t i o n g e n e r a l l y exceed i n t e r - i n d i v i d u a l sources of v a r i a t i o n (Table 17) i s a somewhat unexpected r e s u l t c o n s i d e r i n g that these i n d i v i d u a l s supposedly represent two tax a . The i n d i v i d u a l s i n que s t i o n are separated by 6° lo n g i t u d e and 1400m e l e v a t i o n . F u r t h e r , i n t e r - s p e c i f i c v a r i a t i o n i s much l e s s than i n t e r - i n d i v i d u a l v a r i a t i o n (Table 22) sugges t i n g that the p o i n t s r a i s e d here with respect to the p a t t e r n and degree of i n t r a - i n d i v i d u a l v a r i a t i o n should be taken i n t o c a r e f u l c o n s i d e r a t i o n when e x p l o r i n g p a t t e r n s of i n t e r - i n d i v i d u a l v a r i a t i o n . T h i s o p i n i o n i s f u r t h e r r e - i n f o r c e d upon c o n s i d e r i n g the spread of samples from i n d i v i d u a l t r e e s i n these o r d i n a t i o n s ( F i g . 14). These r e s u l t s q u e s t i o n the p a l e o b o t a n i c a l s i g n i f i c a n c e of the f i n d i n g s of m a c r o f o s s i l s of IP^ engelmannii i n the Puget lowlands (Barnosky 1981). T h i s r e p o r t e d f i n d i n g of P. engelmannii c o u l d simply be of needles from the upper canopy of Pj_ s i t c h e n s i s r a t h e r than needles of P_^  engelmanni i . Other f i n d i n g s of P i c e a m a c r o - f o s s i l s (e.g. H i l l s and O g i l v i e 1970; see a l s o c i t a t i o n s i n C r i t c h f i e l d 1984) should be c a r e f u l l y re-examined i n l i g h t of these f i n d i n g s . Wilson (1963) echoes these same remarks with respect to m i c r o f o s s i l s . 1 1 3 These r e s u l t s on i n t e r - s p e c i f i c v a r i a t i o n c o n t r a d i c t those of other r e s e a r c h e r s (Garman 1957; Roche 1969; Daubenmire 1968; K l i n k a , et a l . 1982). The values presented in Table 22 suggest that i n t r a - i n d i v i d u a l v a r i a t i o n may be as l a r g e as i n t e r - s p e c i f i c v a r i a t i o n . T h i s o b s e r v a t i o n of the r e l a t i v e s i z e of i n t e r - s p e c i f i c and i n t r a - i n d i v i d u a l v a r i a t i o n lends support to the i n c o r p o r a t i o n of i n f o r m a t i o n about i n t r a - i n d i v i d u a l v a r i a t i o n i n t o r e s e a r c h on t r a n s - i n d i v i d u a l sources of v a r i a t i o n . The demonstration of s m a l l e r d i f f e r e n c e s between taxa based on cone morphology as compared to v e g e t a t i v e v a r i a b l e s (Table 22) suggests that the c o n c l u s i o n of p revious work r e l y i n g p r i m a r i l y on a spects of cone morphology (Coupe, et a l . 1982; Strong 1978; Roche 1969; C r i t c h f i e l d 1984; Horton 1959) should be r e - c o n s i d e r e d . These c o n c l u s i o n s and c o n s i d e r a t i o n s have been i n t e g r a t e d i n t o subsequent i n t e r p r e t a t i o n s of p a t t e r n s of i n t e r - i n d i v i d u a l v a r i a t i o n . 4.2 Crown form morphogenesis. The r e s u l t s presented here support those of p revious r e p o r t s with re s p e c t to the s i g n i f i c a n c e between orders and p o s i t i o n s of branches in the canopy. If p h y s i o l o g i c a l c h a r a c t e r i s t i c s are s t r o n g l y r e l a t e d to the p a t t e r n s of m o r p h o l o g i c a l v a r i a t i o n shown here, then, even i f they are as s l i g h t as r e p o r t e d here, when e x t r a p o l a t e d f o r the e n t i r e volume of the l i v i n g canopy of an i n d i v i d u a l t r e e these d i f f e r e n c e s c o u l d prove to be h i g h l y s i g n i f i c a n t and e s p e c i a l l y r e l e v a n t in understanding the p h y s i o l o g i c a l maintenance of i n d i v i d u a l t r e e s . 1 1 4 The m o r p h o l o g i c a l and anatomical v a r i a t i o n shown here may a l s o be important i n understanding the nature of s e l e c t i v e i n s e c t and fungal i n f e s t a t i o n . E x p l a n a t i o n s f o r the observed c o n s i s t e n c y of l a r g e r v a r i a b l e values on primary branches and apical-most canopy p o s i t i o n s c o u l d be a s c r i b e d to growth r e g u l a t i o n a s s o c i a t e d with a p i c a l dominance. The high degree of v a r i a t i o n a t t r i b u t e d to d i f f e r e n c e s between branches w i t h i n an order c o u l d r e s u l t from the l o c a l environment ( i . e . d i r e c t i o n , shading, surrounding v e g e t a t i o n , i n s e c t or p h y s i c a l damage). The o b s e r v a t i o n of d i s c r e t e d i f f e r e n c e s between the a p i c a l - and basal-most branches suggests the m a n i f e s t a t i o n of environmental v a r i a t i o n d e s c r i b e d as "sun and shade" morphology. However, both mature and immature t r e e s show the same p a t t e r n of c l i n a l intra-canopy v a r i a t i o n , thus suggesting that the p a t t e r n may not be caused by environmental f a c t o r s . In t h i s regard i t i s worth p o i n t i n g out t h a t , owing to the p e r e n n i a l d u r a t i o n of the leaves i n P i c e a , that the l e a f that appears today i n the sun w i l l , e v e n t u a l l y , be i n the shade. The d i s c r e t e d i f f e r e n c e s between a p i c a l - and basal-most branches must be regarded as a sampling a r t i f a c t caused by sampling opposite p o l e s of a continuum. F i g u r e 12 and Table 20 i n d i c a t e a high degree of s i m i l a r i t y of p a t t e r n s of i n t r a - i n d i v i d u a l v a r i a t i o n over a small but d i v e r s e group of i n d i v i d a u l t r e e s i n markedly d i f f e r e n t environments. Such an o b s e r v a t i o n i s unexpected i f e x t r i n s i c c o n t r o l s are regarded as being important to t r e e form and intra-crown v a r i a t i o n . F u r t h e r the u n i f o r m i t y of the p a t t e r n of 1 1 5 i n t r a - i n d i v i d u a l v a r i a t i o n suggests s i m i l a r c o n t r o l s . I t i s i n t e r e s t i n g to note that the maintenance of t h i s u n i f o r m i t y i n p a t t e r n appears to be a f f e c t e d by the vigour of the i n d i v i d u a l t r e e . These r e s u l t s suggest t h a t , i n s i t c h e n s i s and P• enqelmanni i , crown form and intra-crown v a r i a t i o n may be the r e s u l t , p r i m a r i l y , of developmental as opposed to environmental pro c e s s e s . These r e s u l t s suqgest that growth and development of s a p l i n g s i s under the same s o r t of developmental c o n t r o l as i n mature t r e e s although not to the same degree of intra-crown d i f f e r e n t i a t i o n . Such suggestions l e a d d i r e c t l y to c o n s i d e r i n g how known p h y s i o l o g i c a l processes a s s o c i a t e d with growth r e g u l a t i o n can account f o r the continued c o - o r d i n a t e d and p r e d i c t a b l e growth, p h y s i o l o g y , and development i n such l a r g e , a r c h i t e c t u r a l l y complex organisms as P i c e a . The known p h y s i o l o g i c a l processes may be adequate i n a d d r e s s i n g the development of young t r e e s , however the c o - o r d i n a t i o n of growth and development i n t r e e s reaching over 30m i n height remains enigmatic. In support of the aforementioned n e c e s s i t y f o r an i n t e g r a t i o n of developmental and e v o l u t i o n a r y s t u d i e s , are the r e s u l t s d e a l i n g with the assessment of i n t e r - i n d i v i d u a l s i m i l a r i t y based upon whether samples from a p i c a l or b a s a l branches are examined. S i m i l a r o b s e r v a t i o n s have been made by O g i l v i e and von Ru d l o f f (1968) concerning the s i m i l a r i t y of intra-crown v a r i a t i o n of P_;_ engelmannii to e l e v a t i o n a l v a r i a t i o n . Stover (1944) c i t e s a s i m i l a r i t y of intra-crown v a r i a t i o n of E"\ enqelamnni i t h a t corresponds to edaphic v a r i a t i o n . The same a p p l i e s f o r the o b s e r v a t i o n made here and 1 1 6 r e p o r t e d elsewhere by Daubenmire (1968, 1974) with r e s p e c t to the appearance of pubescent and glabrous branches on the same i n d i v i d u a l s w e l l removed from p o s s i b l e sympatry with other pubescent s p e c i e s of P i c e a (e.g. P_;_ engelmannii, P. mariana, or P. rubens). These r e s u l t s h i n t at shared and d e r i v e d developmental d i f f e r e n c e s between taxa t h a t , i n s t e a d of being expressed throughout the growth and development of an i n d i v i d u a l , are only manifest at p a r t i c u l a r stages d u r i n g growth and then only at given p o s i t i o n s . I t i s worth n o t i n g the s i m i l a r i t y of the s i t u a t i o n r e p o r t e d here with that r e p o r t e d for P. a b i e s by L i n d q u i s t (1948). 4.3 F u r t h e r r e s e a r c h . Having presented a thumbnail sketch of p a t t e r n s of i n t r a - i n d i v i d u a l v a r i a t i o n i n P i c e a i t seems a p p r o p r i a t e to suggest some d i r e c t i o n f o r f u t u r e r e s e a r c h d e a l i n g with i n t r a - i n d i v i d u a l v a r i a t i o n . S p e c i f i c a l l y : r e s e a r c h d i r e c t e d at e x p l o r i n g the dynamics and i n t e r - r e l a t i o n s of these sources of v a r i a t i o n through the development and growth of i n d i v i d u a l t r e e s ; and, systematic sampling of these sources of i n t r a - i n d i v i d u a l v a r i a t i o n i n an i n t e r - i n d i v i d u a l and inter-taxonomic context. Tomlinson (1982) suggests such an approach i s e s s e n t i a l f o r understanding the form and v a r i a b i l i t y of form i n t r e e s . T h i s same suggestion has been made by Norman and J a r v i s (1974) with respect to p h y s i o l o g i c a l v a r i a t i o n . R i d i n g (1976) p r o v i d e s an example with p r a c t i c a l a p p l i c a t i o n i n g r a f t i n g programmes. 1 17 Dea l i n g f i r s t with the dynamics of i n t r a - i n d i v i d u a l v a r i a t i o n , one would p r e d i c t i n c r e a s e d v a r i a b i l i t y f o r more r e c e n t l y d e r i v e d p o r t i o n s of the canopy than i n o l d e r p o r t i o n s (Maze, et a_l. 1984). In f a c t , t h i s hypothesis appears to have been upheld here, at l e a s t f o r l e a f anatomy ( F i g . 10) where there i s i n c r e a s i n g i n t r a - i n d i v i d u a l v a r i a t i o n with the age of the t r e e . E s p e c i a l l y important i n t h i s regard would be r e s e a r c h d i r e c t e d at u n r a v e l l i n g the inter-dependence of p o s i t i o n , age, and order with respect to growth and development of the canopy of i n d i v i d u a l t r e e s . Such a study would address d i r e c t l y the growth and development of crown form v a r i a t i o n and would p r o v i d e a v a l u a b l e e x t e n s i o n of the dynamics d e s c r i b e d by M a i l l e t t e (1982) and o t h e r s , (Rehfeldt and Wykoff 1981; Namkoong, et a l . 1972; Namkoong and Conkle 1976; N i c h o l l s 1967) and the s t a t i c d e s c r i p t i o n s of F r a s e r ( F r a s e r , et_ a l . 1964; F r a s e r and McGuire 1969; F r a s e r 1976). The changing p r o p o r t i o n of sources of i n t r a - i n d i v i d u a l v a r i a t i o n over the course of development might be important to understanding the c o n t r o l s of t h i s p r o c e s s . Such a study would r e q u i r e whole t r e e , systematic sampling with c a r e f u l mapping of sampling l o c a t i o n s , ages, and o r d e r s . Extending a study, such as that o u t l i n e d above, to s e v e r a l d i f f e r e n t p o p u l a t i o n s of, say, s e v e r a l taxa, c o u l d be used to d e r i v e i n f e r e n c e s concerning the i n t e g r a t i o n of development i n e v o l u t i o n a r y p r o c e s s e s . A d d i t i o n a l l y , as i n t e r e s t i n such a study would be i n i n t r a - i n d i v i d u a l v a r i a t i o n , v a r i a b l e s i n a d d i t i o n to those measured here might a l s o be c o n s i d e r e d . 1 18 Another area of re s e a r c h , p a r t i a l l y a l l i e d to that d i s c u s s e d above, i s the matter of a g e - r e l a t e d v a r i a t i o n . The iss u e of a g e - r e l a t e d v a r i a t i o n i s c e n t r a l to the i n f e r e n c e s made concerning the p h y s i o l o g y of e s t a b l i s h i n g s e e d l i n g s and any r e s u l t a n t s e l e c t i o n . Age r e l a t e d v a r i a t i o n has been addressed in s e v e r a l s p e c i e s of Abies i n the context of the d i f f e r e n t i a t i o n of j u v e n i l e from mature p o p u l a t i o n s (Maze, et a l . 1981; Maze and Parker 1983). However, i t should be p o i n t e d out that i n these s t u d i e s the e f f e c t of a g e - r e l a t e d v a r i a t i o n and s e l e c t i o n may not have been adequately separated. The apparently anomalous r e s u l t s of these s t u d i e s of i n c r e a s i n g v a r i a b i l i t y with age c o u l d be simply a consequence of a g e - r e l a t e d v a r i a t i o n r a t h e r than g e n e t i c d i f f e r e n t i a t i o n between g e n e r a t i o n s . A g e - r e l a t e d v a r i a t i o n i s w e l l known i n Juniperus (e.g. Juniperus scopulorum Sarg.) as w e l l as i n other woody p l a n t s (Wareing and P h i l l i p s 1981; Zimmerman and Brown 1971; Kramer and Kozlowski 1979) and a t r u l y morphogenetic study of a g e - r e l a t e d v a r i a t i o n would have to i n v o l v e s e q u e n t i a l sampling of the same i n d i v i d u a l s over the course of development through to sexual maturity of the organism. In P i c e a such a study would r e q u i r e many y e a r s . The development i n c o n i f e r s and Picea have a l l been based on s t a t i c a n a l y s i s of crown form, a dynamic study may prove u s e f u l i n understanding the p e r c e p t i o n s of p a t t e r n s of v a r i a t i o n , as w e l l i t would pr o v i d e i n f o r m a t i o n regarding the morphogenetic e x p l a n a t i o n f o r these p a t t e r n s . Such a study may be e s p e c i a l l y important i n understanding the degree that cumulative e f f e c t s are r e s p o n s i b l e f o r crown form and examine the conformity of these d e s c r i p t i o n s with respect to 1 19 hypothesized models (Honda 1971; McMahon and Kroneuer 1976; F i s h e r and Honda 1979a; Baker, et al. 1973) and rep o r t e d v a r i a t i o n s ( F i s h e r and Hibbs 1982; Hibbs 1981). 1 20 IV. INTER-INDIVIDUAL VARIATION: TAXONOMIC CIRCUMSCRIPTION. 1. I n t r o d u c t i o n . As P_;_ enqelmanni i and P^ s i t c h e n s i s do not g e n e r a l l y e x h i b i t n a t u r a l c l o n i n g (however see Cooper (1931) regarding l a y e r i n g i n P^ s i t c h e n s i s ), phenotypic d i f f e r e n c e s between i n d i v i d u a l s are a f u n c t i o n of g e n e t i c d i f f e r e n c e s as we l l as developmental and environmental d i f f e r e n c e s . Except f o r i d e n t i c a l twins, a l l i n d i v i d u a l s are g e n e t i c a l l y unique. S p e c i f i c a l l y , we are i n t e r e s t e d i n whether there are a n a l y t i c a l l y emergent, t r a n s - i n d i v i d u a l l e v e l s of v a r i a t i o n that correspond to a p r i o r i g e n e c o l o g i c a l , p o p u l a t i o n a l , or taxonomic hypotheses: g e n e r a t i o n s , ecotypes, p o p u l a t i o n s , and s p e c i e s -P. engelmanni i and P_^  s i t c h e n s i s. By a n a l y t i c a l l y emergent, r e f e r e n c e i s here made to examining f o r and d e t e c t i n g hypothesized sources of v a r i a t i o n r a t h e r than a p r i o r i i m p o s i t i o n of these hypotheses on the data. Good examples of the a n a l y t i c emergence of a t r a n s - i n d i v i d u a l source of v a r i a t i o n are p r o v i d e d by Campbell and Dearn (1980) and Wells, et a l . (1977). If the emergence of t r a n s - i n d i v i d u a l sources of v a r i a t i o n can be demonstrated, then they r e q u i r e q u a n t i f i c a t i o n and subsequent e x p l a n a t i o n . Q u a n t i f i c a t i o n and e x p l a n a t i o n f o r hypothesized sources of v a r i a t i o n without examining the v a l i d i t y of these hypotheses may b i a s c o n c l u s i o n s r e g a r d i n g these l e v e l s of v a r i a t i o n . Indeed, t e n d e r i n g e x p l a n a t i o n s f o r sources of v a r i a t i o n more conceptual than r e a l may le a d to unwarranted 121 r e i f i c a t i o n and m i s r e p r e s e n t a t i o n of b i o l o g i c a l r e a l i t y . Burley (1965a) and L a n g l e t t (1959,1962,1963) p o i n t out that a name ( i . e . a taxonomic hypothesis) c o n f e r s a f a l s e sense of importance on a named taxonomic group (hypothesis) and a u t o m a t i c a l l y imparls an impression of homogeneity w i t h i n and h e t e r o g e n e i t y between groups, or that there i s more v a r i a b i l i t y between than w i t h i n groups. I n t r a - i n d i v i d u a l , or developmental, v a r i a t i o n p r o v i d e s the s c a l e a g a i n s t which p a t t e r n s and s c a l e s of t r a n s - i n d i v i d u a l v a r i a t i o n are compared. The i n t e n t of t h i s chapter i s to examine the v a l i d i t y of the taxonomic hypothesis of two taxa, as the acceptance of such a taxonomy w i l l determine the c i r c u m s c r i p t i o n of the s u b s p e c i f i c l e v e l s of i n t e r - i n d i v i d u a l v a r i a t i o n . For example, q u a n t i f i c a t i o n and e x p l a n a t i o n f o r p o p u l a t i o n v a r i a t i o n i n a taxon that l a c k s g e n e c o l o g i c a l s t r u c t u r e of p r e v a l e n t , s e l e c t e d genotype(s) may l e a d to erroneous c o n c l u s i o n s r e g a r d i n g e x p l a n a t i o n f o r the observed v a r i a t i o n between groups of sympatric i n d i v i d u a l s . F u r t h e r , i n a s p e c i e s where a l a r g e number of i n d i v i d u a l s are not part of i d e n t i f i a b l e p o p u l a t i o n s , such as P_;_ s i t c h e n s i s , the t e n d e r i n g of e x p l a n a t i o n s based on p o p u l a t i o n a l assumptions would be i n a p p r o p r i a t e . S i m i l a r l y , q u a n t i f i c a t i o n and e x p l a n a t i o n s f o r p o p u l a t i o n v a r i a t i o n i n a p o o r l y d e f i n e d or polymorphic taxon that has been s u b j e c t e d to a r b i t r a r y nomenclatural s p l i t t i n g may l e a d to erroneous c o n c l u s i o n s about that taxon unless the nature of p o p u l a t i o n v a r i a t i o n i n g e o g r a p h i c a l l y juxtaposed and sympatric "taxa" i s a l s o c o n s i d e r e d . 1 22 Such examples are e s p e c i a l l y easy to envisage f o r the two taxa being i n v e s t i g a t e d here. The r e p o r t e d lack of a pronounced l a t i t u d i n a l t r e n d i n p o p u l a t i o n s of s i t c h e n s i s (Lewis and Lines 1976) may serve as a convenient case i n p o i n t . The p e r c e i v e d narrow edaphic and geographic range of P_j_ s i t c h e n s i s along a lengthy l a t i t u d i n a l range suggests that there should be a pronounced l a t i t u d i n a l v a r i a t i o n (Wright 1976). Such l a t i t u d i n a l v a r i a t i o n has been demonstrated by a number of workers (see Ching and S z i k l a i 1978b; O ' D r i s c o l l 1976b). However, as mentioned in p r e v i o u s c h a p t e r s , the a c t u a l nature of " p o p u l a t i o n s " are somewhat d i f f e r e n t from e x p e c t a t i o n s - perhaps accounting f o r the lack of a pronounced t r e n d . A d d i t i o n a l l y , the r e p o r t e d h y b r i d i z a t i o n of P_j_ s i t c h e n s i s with P^ glauca ( L i t t l e 1953 1 ; Daubenmire 1968; Roche 1969; Copes and Beckwith 1977), may serve to obscure the expected trend i n v a r i a t i o n or suggest d i s c o n t i n u i t i e s i n v a r i a t i o n . By comparison the v a r i a t i o n of P_^_ engelmanni i has g e n e r a l l y been r e l a t e d to e l e v a t i o n (Habeck and Weaver 1969; O g i l v i e and von R u d l o f f 1968; Horton 1959; Garman 1957; La Roi and Dugle 1968). If t r a n s - i n d i v i d u a l sources of v a r i a t i o n corresponding to the two hypothesized taxa are indeed emergent, then the q u e s t i o n of p o t e n t i a l n a t u r a l h y b r i d i z a t i o n needs to be addressed. The r e s u l t s presented i n Chapter III (Table 22) i n d i c a t e d t h at the r e c o g n i t i o n of h y b r i d s may be d i f f i c u l t as d i f f e r e n c e s between the two taxa are smaller than d i f f e r e n c e s between t r e e s . 1 Hulten (1968) c o n s i d e r s t h i s r e p o r t to be based on a h y b r i d between s i t c h e n s i s and P_^_ mariana r a t h e r than P^ g l a u c a . 1 23 S i m i l a r l y , i f these hypothesized t r a n s - i n d i v i d u a l sources of v a r i a t i o n are not manifest i n an emergent manner, then the p e r c e i v e d d i s c r e t e n e s s of these taxa may be c a l l e d i n t o q u e s t i o n . F u r t h e r , such f i n d i n g s may i n d i c a t e areas i n which p r e v i o u s c o n c l u s i o n s may have been d e f i c i e n t owing to acceptance of the q u e s t i o n a b l e p e r c e p t i o n of d i s c r e t e n e s s of the two taxa. E s t a b l i s h i n g whether there are such t r a n s - i n d i v i d u a l l e v e l s of v a r i a t i o n as g e n e r a t i o n s , p o p u l a t i o n s , d i s c r e t e taxa, and h y b r i d s between these taxa may, i n themselves, o f f e r e x p l a n a t i o n s f o r the r e p o r t e d i n c o n s i s t a n c y between expected and a c t u a l v a r i a t i o n . Often p o p u l a t i o n s and provenances are simply a r b i t r a r i l y e r e c t e d as being r e p r e s e n t a t i v e of i n d i v i d u a l s from a p a r t i c u l a r geographic area without r e f e r e n c e to the edaphic and microgeographic v a r i a t i o n or the a c t u a l phylogeny. E s t a b l i s h i n g the nature of these sources of v a r i a t i o n p r o v i d e s a v i t a l c i r c u m s c r i p t i o n f o r the f u r t h e r d e t a i l e d q u a n t i f i c a t i o n and subsequent e x p l a n a t i o n . From a more p r a c t i c a l viewpoint, documentation of such l e v e l s of v a r i a t i o n may suggest a l t e r n a t e p r e s c r i p t i o n s and o b j e c t i v e s i n s i l v i c u l t u r a l and t r e e - b r e e d i n g programmes. 2. M a t e r i a l s and methods. 2.1 M a t e r i a l s . A l l of the t r e e s sampled were used in examining t r a n s - i n d i v i d u a l sources of v a r i a t i o n ( t h i s i n c l u d e d the samples of s i t c h e n s i s from the C h i l l i w a c k R i v e r N u r s e r y ) . Both 1 24 mature and immature t r e e s were used as p r e v i o u s analyses (Table 19) i n d i c a t e d l i t t l e d i f f e r e n c e between the d i f f e r e n t ages. In p r o v i d i n g f u r t h e r inter-taxonomic comparison, i n d i v i d u a l s of P_^  glauca were i n c l u d e d in some a n a l y s e s . To assess the a b i l i t y to recognize n a t u r a l h y b r i d s , samples of known a r t i f i c a l h y b r i d i z a t i o n were i n c l u d e d i n some a n a l y s e s . A d d i t i o n a l l y , a r t i f i c i a l h y b r i d s and samples of t h e i r maternal parent were a l s o compared. 2.2 Analyses. The primary a n a l y t i c technqiue was PCA. PCA r e s p e c t s the u n s t r u c t u r e d form of the hypothesis being t e s t e d (Burley and Barrow 1972) and the a v a i l a b l e sample s i z e (Table 10). T h i s a n a l y t i c approach allows any t r a n s - i n d i v i d u a l sources of v a r i a t i o n to be emergent r a t h e r than imposed a p r i o r i . I n c l u d i n g i n t r a - i n d i v i d u a l v a r i a t i o n i n these analyses allows any emergent t r a n s - i n d i v i d u a l source of v a r i a t i o n to be assessed r e l a t i v e to v a r i a t i o n that i s more i n t r a - i n d i v i d u a l in nature ( i . e . developmental r a t h e r than g e n e t i c ) . P r a g m a t i c a l l y , i f t r a n s - i n d i v i d u a l sources of v a r i a t i o n are indeed emergent, then i t would be worthwhile to be able to a s s i g n i n d i v i d u a l s to these sources. The assignment of a given i n d i v i d u a l to a hypothesized taxon i s dependent upon i n t r a - i n d i v i d u a l v a r i a t i o n . Although the i n c l u s i o n of i n t r a - i n d i v i d u a l v a r i a t i o n c o u l d be accommodated and would be a p p r o p r i a t e f o r a s t r u c t u r e d MVA, the a v a i l a b l e sample s i z e s m i t i g a t e a g a i n s t such an approach (Table 10). 1 25 In q u a n t i f y i n g t r a n s - i n d i v i d u a l l e v e l s of v a r i a t i o n of po p u l a t i o n s and taxa, ANOVA of PCAs based on separate v a r i a b l e s u i t e s of p o p u l a t i o n s of standards were performed that used the nested d e s i g n : (MODEL 2.) y = A + B(A) + C(AB) + e. where A i s an e f f e c t based on d i f f e r e n t taxa, B i s the e f f e c t a t t r i b u t e d to p a r t i c u l a r p o p u l a t i o n i n A, C i s the e f f e c t of an i n d i v i d u a l i n B, and e i s i n t r a - i n d i v i d u a l v a r i a t i o n . T h i s ANOVA was used i n e v a l u a t i n g PCAs of E\ engelmanni i and P. s i t c h e n s i s , as w e l l as i n e v a l u a t i n g PCAs that i n c l u d e d p o p u l a t i o n s of standards of P^ gl a u c a . The i n c l u s i o n of a term for hypothesized p o p u l a t i o n s serves a comparative purpose rather than a t e s t on the d i f f e r e n t i a t i o n among p o p u l a t i o n s . It should be remembered t h a t i n t r a - i n d i v i d u a l v a r i a t i o n r e f e r s to in t r a - i n c r e m e n t v a r i a t i o n , and that some of the p o p u l a t i o n s are comparatively s m a l l . Using j u s t those standard samples that o c c u r r e d i n po p u l a t i o n s may unduly p o l a r i z e the data l e a d i n g to an i n a p p r o p r i a t e assessment of r e l a t i o n s h i p s of the two taxa. A d d i t i o n a l l y , i t ignores a major source of v a r i a t i o n i n the data as a l a r g e number of t r e e s are not present i n r e c o g n i z e a b l e p o p u l a t i o n s (Table 7 ) . I n c r e a s i n g the number of samples r e p r e s e n t a t i v e of the two taxa without b e n e f i t of the c i r c u m s c r i p t i o n by a p o p u l a t i o n or r e s t r i c t i o n to extreme environmental and geographic l o c a t i o n s may allow a l e s s b i a s e d assessment of the d i f f e r e n c e s between the two taxa. 1 26 A nested ANOVA: (MODEL 3.) Y = A + B(A) + e. a p p l i e d to PCAs of such data and compared to the pr e v i o u s ANOVAs on j u s t p o p u l a t i o n s of standards w i l l i n d i c a t e the degree of b i a s caused by d e a l i n g with r e c o g n i z a b l e m o r p h o l o g i c a l and environmental extremes. In t h i s ANOVA, A i s the e f f e c t a t t r i b u t e d to d i f f e r e n t taxa, B the e f f e c t of d i f f e r e n t i n d i v i d u a l s i n the taxa, and e i s the i n t r a - i n d i v i d u a l v a r i a t i o n . As with p o p u l a t i o n s of standards, t h i s a n a l y s i s was performed f o r P_j_ enqelmanni i , P. s i t c h e n s i s , and P^ g l a u c a . P r i o r to ad d r e s s i n g the q u e s t i o n of n a t u r a l l y o c c u r r i n g h y b r i d s , an e v a l u a t i o n of the morphology of known h y b r i d s i n the context of standards of both taxa was performed to determine whether the d e t e c t i o n of n a t u r a l h y b r i d i z a t i o n was p r a c t i c a l . T h i s e v a l u a t i o n was made using an o r d i n a t i o n from PCAs i n c l u d i n g p o p u l a t i o n s of standards of P^ engelmanni i and P_^_ s i t c h e n s i s along with samples of known a r t i f i c i a l h y b r i d s . A f u r t h e r comparison of a r t i f i c i a l h y b r i d s and the p u t a t i v e h y b r i d s was performed to determine the r e l a t i o n among h y b r i d s without r e f e r e n c e to parent taxa. These comparisons c o u l d be made only for the v e g e t a t i v e v a r i a b l e s u i t e s as the a r t i f i c i a l h y b r i d s were s t i l l immature and lac k e d cones. In t h i s comparison between a r t i f i c i a l and p u t a t i v e h y b r i d s , the ANOVA used was that given i n MODEL 3, except that A was the e f f e c t a t t r i b u t e d to the d i f f e r e n t groups of h y b r i d s : a r t i f i c i a l or p u t a t i v e . 1 27 PCAs of separate v a r i a b l e s u i t e s f o r a l l t r e e s were a l s o performed. As w e l l a PCA based on a l l 36 v a r i a b l e s was a l s o performed. For the a n a l y s i s that used the a r t i f i c i a l h y b r i d s , a l l 21 v e g e t a t i v e v a r i a b l e s were used. For those PCAs of a l l v a r i a b l e s or a l l v e g e t a t i v e v a r i a b l e s , values were averaged f o r each t r e e , thus i g n o r i n g i n t r a - i n d i v i d u a l v a r i a t i o n . Such averaging was necessary owing to the lack of an i n t r a - i n d i v i d u a l one-to-one correspondance between v a r i a b l e s of separate v a r i a b l e s u i t e s . The sample s i z e was c o n s i d e r e d adequate to perform these PCAs on the b a s i s of the sample s i z e e s t i m a t i o n technique o u t l i n e d i n Chapter I I . ANOVAs based on these a n a l y s e s had the hypothesized term a t t r i b u t e d to i n d i v i d u a l s i n MODEL 2 and MODEL 3 subsumed by the r e s i d u a l term as a r e s u l t of averaging per t r e e . 3. R e s u l t s . 3.1 P o p u l a t i o n s of standards. 3.1.1 P_^  engelmanni i and P^ s i t c h e n s i s . P o l a r i z i n g the r e l a t i o n between P_^  engelmanni i and P. s i t c h e n s i s by examing only p o p u l a t i o n s of standards i n d i c a t e d that there were s i g n i f i c a n t , but small d i f f e r e n c e s between the two taxa (Table 23). F i g u r e 16 c o r r o b o r a t e s t h i s impression of s l i g h t d i f f e r e n c e between the two taxa. For a l l v a r i a b l e s u i t e s , the amount of intra-taxonomic v a r i a t i o n exceeds the inter-taxonomic v a r i a t i o n . With the exception of cone morphology, i n t e r - p o p u l a t i o n v a r i a t i o n accounts f o r l e s s v a r i a t i o n than i n t e r - i n d i v i d u a l v a r i a t i o n w i t h i n p o p u l a t i o n s . I t should be noted (Table 23), that the l a r g e s t amount of 1 28 T a b l e 23. M u l t i v a r i a t e a p p o r t i o n m e n t of v a r i a t i o n f o r s e p a r a t e v a r i a b l e s u i t e s due to d i f f e r e n c e s between t a x a , p o p u l a t i o n s , and i n d i v i d u a l s t a n d a r d s of P_^  enqe lmanni i and P_^  s i t chens i s . A b b r e v i a t i o n of PCAs and ANOVAs i n T a b l e 43, Appendix I I I. Symbols g i v e n i n MODEL 2. O r d i n a t i o n of r e s u l t a n t component s c o r e s g i v e n i n F i gure 16. %SS (mva) VARIABLE SUITE A B (A ) C( AB) E LEAF ANATOMY 29.21 24.49 33 .61 12 .69 LEAF MORPHOLOGY 29 .09 16 . 16 33.50 21 . 26 TWIG MORPHOLOGY 41.81 16 . 74 36.84 4 .62 CONE MORPHOLOGY 20. 79 27 .70 20.35 31.14 TOTAL 31 .54 27 . 14 - 41 .32 x VEGETATIVE 33 . 37 19.13 34 .65 12 . 86 i n t r a - i n d i v i d u a l v a r i a t i o n i s a t t r i b u t e d to cone morphology and l e a f morphology and exceeds the corresponding v a r i a t i o n between taxa. The s m a l l e s t amount of i n t r a - i n d i v i d u a l v a r i a t i o n i s a t t r i b u t e d to twig morphology. G e n e r a l l y , there i s more v a r i a t i o n between i n d i v i d u a l t r e e s w i t h i n a p o p u l a t i o n than between p o p u l a t i o n s or between hypothesized taxa. ANOVAs of separate v a r i a b l e s in Table 23 i n d i c a t e d that there were only s i x v a r i a b l e s that had an inter-taxonomic v a r i a t i o n that exceeded intra-taxonomic v a r i a t i o n (ABXANG, CENCYABX, ADXSTOM, PULVPUB, BRACTLEN, BRACTAP). The d i v e r s i t y of c l i m a t i c , environmental, and geographic v a r i a t i o n of these samples should be c o n s i d e r e d i n a p p r e c i a t i n g these r e s u l t s . Ignoring i n t r a - i n d i v i d u a l v a r i a t i o n f o r a l l 36 v a r i a b l e s emphasized the d i s t i n c t i o n between the two taxa ( F i g . 16). However, i t should be noted that as a r e s u l t of the averaging by tr e e that 17 percent of the t o t a l v a r i a t i o n has been removed. As F i g u r e 16 i l l u s t r a t e s , the primary d i f f e r e n c e between o r d i n a t i o n s of separate v a r i a b l e s u i t e s and that based on a l l v a r i a b l e s i s one of r o t a t i o n of c o - o r d i n a t e axes r a t h e r than the t F i g u r e 16. O r d i n a t i o n s of f i r s t two components of PCAs of s e p a r a t e v a r i a b l e s u i t e s f o r p o p u l a t i o n s of s t a n d a r d s of P_^  enge1manni1 and P. s 1 t c h e n s i s. S co re s based on PCAs g i v e n i n T a b l e 43. Appendix III G l yphs r e p r e s e n t means f o r i n d i v i d u a l t r e e s . G l y p h s as in F i g u r e 10. Not a l l i n d i v i d u a l t r e e s c o u l d be p l o t t e d . L E A F ANATOMY A A ^ LEAF MORPHOLOGY O O oo' ft O O _ A iO O 'A A A ^ A A CONE MORPHOLOGY TWIG MORPHOLOGY o TOTAL . v . \ A A > AS' o o 1 30 emergence of any fundamental new p a t t e r n . Based upon the component c o r r e l a t i o n s of the components which account f o r the l a r g e s t d i f f e r e n c e between the hypo t h e s i z e d taxa i t appears that ABXANG, ADXANG, CENCYABX, SCALWID, BRACTAP, ADXSTOM, RESCYNO, RESCYLOC, PULVPUB, and TIPWID are the v a r i a b l e s that best d e s c r i b e the p o l a r i t y i n the data. F u r t h e r , the s i z e and s i g n of these component c o r r e l a t i o n s suggest that p o l a r i t y i s not s t r i c t l y a r e f l e c t i o n of s i z e d i f f e r e n c e s . These are not a l l the same v a r i a b l e s that account f o r the l a r g e s t d i f f e r e n c e s between hypothesized taxa. These r e s u l t s suggest that the hypothesized taxonomic p o l a r i t y i s not c o - i n c i d e n t with the p o l a r i t y of the data. 3.1.2 P_;_ engelmanni i , P. s i t c h e n s i s , and Pj_ g l a u c a . Adding the p o p u l a t i o n s of P_^  glauca from western Quebec f u r t h e r p o l a r i z e s the data, however there i s s t i l l a l a r g e r intra-taxonomic v a r i a t i o n than inter-taxonomic v a r i a t i o n (Table 24). In a d d i t i o n to the s i x i n d i v i d u a l v a r i a b l e s i n d i c a t e d that had an inter-taxonomic v a r i a t i o n that exceeded intra-taxonomic v a r i a t i o n , NEEDEP and FREESCAL were a l s o c o n s i d e r e d important to d i s t i n g u i s h i n g between the taxa. Component c o r r e l a t i o n s suggest that the a d d i t i o n of two p o p u l a t i o n s of glauca r e a l l y only e f f e c t e d the f i r s t component, other components remained approximately the same with resp e c t to s i g n and magnitude of component c o r r e l a t i o n s and the v a r i a t i o n accounted f o r . The a d d i t i o n of the two p o p u l a t i o n s of 131 Table 24. Multivariate apportionment of v a r i a t i o n for separate variable suites due to differences between taxa, populations, and individuals of standard engelmanni i , P. glauca, and F\ sitchensis. Abbreviation of PCAs and ANOVAs given in Table 44, Appendix III. Symbols given in MODEL 2. Ordinations of resultant component scores given in Figure 17. %SS (mva) VARIABLE SUITE A B (A) C( AB) E LEAF ANATOMY 35.68 27 . 39 20. 75 16.18 LEAF MORPHOLOGY 29 . 98 13 . 90 32 .68 2 1 . 78 TWIG MORPHOLOGY 4 1 . 70 16 . 48 35.92 5.91 CONE MORPHOLOGY 35.39 19 . 39 18 .64 26.02 TOTAL 38 .90 24 . 15 - 36 . 95 x VEGETATIVE 35 . 79 .19 . 26 29 . 78 13.17 p. glauca i n c r e a s e d the v a r i a b i l i t y as a r e s u l t of p o p u l a t i o n s from that given i n Table 23, but only f o r l e a f anatomy and twig morphology. L i k e the r e s u l t s in Table 23, i n t e r - i n d i v i d u a l v a r i a t i o n based on v e g e t a t i v e v a r i a b l e s were gre a t e r than that based on r e p r o d u c t i v e v a r i a b l e s . The p o l a r i z i n g v a r i a b l e s remained as above, with the s u b s t i t u t i o n of BRACTLEN f o r BRACTAP and the a d d i t i o n of CENCYLAT. Again, there appears to be a lack of c o - i n c i d e n c e between taxonomic and data p o l a r i t y . O r d i n a t i o n s ( F i g . 17) emphasize the s t r i k i n g s i m i l a r i t y among the three taxa. P ^ engelmann i i i s intermediate to the other two taxa with respect to l e a f anatomy and cone morphology. p. glauca appears intermediate to the other two taxa f o r l e a f morphology and twig morphology. The o r d i n a t i o n of a l l 36 v a r i a b l e s , l i k e that i n F i g u r e 16, f u r t h e r emphasized the d i s t i n c t i o n between E \ engelmanni i and P _ ^ s i t c h e n s i s. P . glauca however c o n s t i t u t e s only a p o l a r p o s i t i o n with respect to the second component of v a r i a t i o n and the samples f a l l w i t h i n the range of v a r i a t i o n shown f o r standards of F\_ enqelmannii. It should be remembered that the standards of E*\ glauca and F i g u r e 17. O r d i n a t i o n s of f i r s t two components of PCAs of s e p a r a t e v a r i a b l e s u i t e s f o r p o p u l a t i o n s of s t a n d a r d s of P_^  enge1manni i , P. g l a u c a . and P_^  s i t chens i s S co res based on PCAs g i v e n in T a b l e 44, Appendix I I I . G l yphs r e p r e s e n t means of i n d i v i d u a l t r e e s and a r e as in F i g u r e 16 excep t squares r e p r e s e n t i n d v i d u a l s of P. g1auca . Not a l l i n d i v i d u a l t r e e s c o u l d be p l o t t e d due to o v e r l a p . LEAF ANATOMY ft A ' . ^ V A LEAF MORPHOLOGY O OO o o <9 o o O A A'/TS. CONE MORPHOLOGY A TWIG MORPHOLOGY 1#° o° TOTAL A A I . A A\ o o o o ax o oo o° o o o 9> o C O ro 133 P. enqelmanni i came from p o p u l a t i o n s on d i f f e r e n t s i d e s of the cont i nent. 3.2 I n d i v i d u a l standards and p u t a t i v e taxonomic r e p r e s e n t a t i v e s . 3.2.1 E"\ enqelmanni i and P^ s i t c h e n s i s . The decreased m o r p h o l o g i c a l and anatomical p o l a r i t y c r e a t e d by c o n s i d e r i n g more than j u s t p o p u l a t i o n s of standards was r e f l e c t e d i n the amount of v a r i a t i o n accounted f o r by the f i r s t few axes (Table 25) compared to those in Table 23. In s p i t e of T a b l e 25. M u l t i v a r i a t e a p p o r t i o n m e n t of v a r i a t i o n f o r s e p a r a t e v a r i a b l e s u i t e s due to d i f f e r e n c e s between taxa and i n d i v i d u a l s of s t a n d a r d and p u t a t i v e P^ enge lmanni i and P_^  s i t chens i s. A b b r e v i a t i o n of PCAs and ANOVAs g i v e n i n T a b l e 45, Append ix I I I . Symbols g i v e n i n MODEL 3. O r d i n a t i o n s of r e s u l t a n t component s c o r e s g i v e n i n F i gu re 18. %SS (mva) VARIABLE SUITE A B( A) E LEAF ANATOMY 31 .84 51 .47 16 .69 LEAF MORPHOLOGY 20 . 93 56 . 73 22 .43 TWIG MORPHOLOGY 24 .61 67 . 16 8 . 24 CONE MORPHOLOGY 36.44 23 . 28 29 .03 TOTAL 28 .01 - 7 1 .97 x VEGETATIVE 25 . 79 58 . 45 15 . 76 t h i s decreased p o l a r i t y , the component c o r r e l a t i o n s were s i g n i f i c a n t l y c o r r e l a t e d with those given i n ' T a b l e 23, implying that fundamentally new sources of v a r i a t i o n have not been added. The amount of v a r i a t i o n a t t r i b u t e d to taxa i n Table 25 i s only 3 percent l e s s than that given i n Table 23. F i g u r e 18 f u r t h e r c o r r o b o r a t e s that new sources of 1 34 v a r i a t i o n have not been added. However, compared with F i g u r e 16, the d i f f e r e n c e s between the hypothesized taxa have been obscured. On i n s p e c t i n g the component scores f o r d i f f e r e n t t r e e s i t was observed that the samples of P_;_ engelmannii from the Cascade Mountains and S e l k i r k s are c o - i n c i d e n t . S i m i l a r l y c o - i n c i d e n t were the samples of s i t c h e n s i s from southern Oregon and the study area. The apportionment of v a r i a t i o n i n d i c a t e d that there was s u b s t a n t i a l l y more intra-taxonomic v a r i a t i o n than inter-taxonomic v a r i a t i o n . Further (Table 23), only f i v e v a r i a b l e s (NEEDEP, ABXANG, CENCYABX, ADXSTOM, PULVPUB) had an inter-taxonomic v a r i a b i l i t y that exceeded intra-taxonomic. A l l r e p r o d u c t i v e v a r i a b l e s had an intra-taxonomic v a r i a b i l i t y that exceeded the inter-taxonomic v a r i a b i l i t y . F i g u r e 18 f o r the separate v a r i a b l e s u i t e s f u r t h e r s u b s t a n t i a t e s the impression of p o o r l y separated taxa r e p o r t e d above i n Table 22. 3.2.2 E\_ engelmannii , P. s i t c h e n s i s , and P_j_ g l a u c a . As with the a n a l y s i s i n Table 25, the p o l a r i t y of the data decreased, component c o r r e l a t i o n s remained v i r t u a l l y unchanged, and the inter-taxonomic v a r i a t i o n was l e s s than intra-taxonomic v a r i a t i o n (Table 26). The a d d i t i o n of more i n d i v i d u a l s decreased the d i f f e r e n c e s between taxa by 8 percent compared to Table 24. L i k e Table 25, the removal of the hypothesized e f f e c t of -populations i n c r e a s e d the i n t e r - i n d i v i d u a l v a r i a b i l i t y . I n t e r - p o p u l a t i o n v a r i a t i o n , such as i t was ( i . e . approximately 25% of the i n t e r - i n d i v i d u a l v a r i a t i o n ) , was obscured by F i g u r e 18. O r d i n a t i o n s of f i r s t two components of PCAs of s e p a r a t e v a r i a b l e s u i t e s f o r a l l s t a n d a r d s and p u t a t i v e s of P_^  engeImann i i and P. s i t chens i s. S co re s based on PCAs g i v e n in T a b l e 45. Append ix I I I . G l yphs as in F i g u r e 16. LEAF ANATOMY LEAF MORPHOLOGY CONE MORPHOLOGY TWIG MORPHOLOGY (40 5O •/.) TOTAL w A A V ' A A O O o o oi 1 36 T a b l e 26. M u l t i v a r i a t e a p p o r t i o n m e n t of v a r i a t i o n f o r s e p a r a t e v a r i a b l e s u i t e s due to d i f f e r e n c e s between taxa and i n d i v i d u a l s of s t a n d a r d and p u t a t i v e P_;_ enge 1 mann i i . P . g l a u c a . and P_^  s i t chens i s . A b b r e v i a t i o n of PCAs and ANOVAs g i v e n in T a b l e 46, Appendix I I I. Symbols g i v e n in MODEL 3. O r d i n a t i o n s of r e s u l t a n t component s c o r e s g i v e n in F i g u r e 19. %SS (mva) VARIABLE SUITE A B (A ) E LEAF ANATOMY 32 . 10 51 .03 16 . 90 LEAF MORPHOLOGY 2 1 . 50 54 . 32 22 . 53 TWIG MORPHOLOGY 25 . 00 66 . 48 8 . 52 CONE MORPHOLOGY 13 . 73 65 .72 20. 55 TOTAL 30. 88 - 69 . 12 x VEGETATIVE 26 . 20 57 . 28 16 . 52 i n t e r - i n d i v i d u a l v a r i a t i o n . F i g u r e 19 f u r t h e r c o r r o b o r a t e s t h i s impression of p o o r l y separated taxa. The o r d i n a t i o n based on a l l 36 v a r i a b l e s f u r t h e r emphasized the p o l a r i t y of glauca w i t h i n the v a r i a t i o n of P^ engelmanni i . 3.3 A r t i f i c i a l h y b r i d s i n the context of p o p u l a t i o n s of standards. The amount of v a r i a t i o n accounted for by the separate PCAs (Table 40, Appendix III = Table 27) are s i m i l a r to those given in Table 23. The o r d i n a t i o n s ( F i g . 20) suggested l i t t l e in the way of intermediacy f o r these known h y b r i d s , even though there was a tendency f o r the two taxa to occupy opposite p o l e s of the o r d i n a t i o n . P a r t i c u l a r l y important was the o b s e r v a t i o n that the maternal "P^ engelmannii" f o r the New Brunswick h y b r i d s was c l o s e r to s i t c h e n s i s than were i t s progeny based on the separate v a r i a b l e s u i t e s . Examination of the v a r i a n c e of component scores f o r i n d i v i d u a l t r e e s d i d not i n d i c a t e t h a t , as a group, the h y b r i d s were any more v a r i a b l e than the standards. F i g u r e 19. O r d i n a t i o n s of f i r s t two components of PCAs of s e p a r a t e v a r i a b l e s u i t e s f o r a l l i n i d i v i d u a l s t a n d a r d s and p u t a t i v e s of P . enge 1 mann i i . P . g l auca . and P_^  s i t chens i s . S co re s ba sed on PCAs g i v e n in T a b l e 46, Appendix I I I. G l y p h s as in F i g u r e 17. LEAF ANATOMY LEAF MORPHOLOGY CONE MORPHOLOGY TWIG MORPHOLOGY F i g u r e 20. O r d i n a t i o n s of f i r s t two components of PCAs of s e p a r a t e v a r i a b l e s u i t e s f o r sampled p o p u l a t i o n s of s t a n d a r d s and a r t i f i c a l h y b r i d s . S co re s based on PCAs g i v e n in T a b l e 47, Append ix III G l y p h s as in F i g u r e 16. F i l l e d t r i a n g l e - materna l P_^  enge1mann i i f o r New Brunswick h y b r i d s . H a l f - f i l l e d g l y p h s - a r t i f i c a l h y b r i d s upper h a l f f i l l e d - New Brunswick h y b r i d s ; lower h a l f f i l l e d - Red Rock hybr i ds . LEAF ANATOMY LEAF MORPHOLOGY TWIG MORPHOLOGY VEGETATIVE 00 co 139 The o r d i n a t i o n of the PCA based on a l l 21 v e g e t a t i v e v a r i a b l e s ( F i g . 20) c o r r o b o r a t e s the impression that the a r t i f i c i a l h y b r i d s are more l i k e the maternal taxon than the p a t e r n a l taxon. The p o l a r i t y of the h y b r i d s on the second component suggests a s i m i l a r i t y to the d i s p o s i t i o n of Pj_ glauca standards in F i g u r e s 16 and 18. 3.4 A r t i f i c i a l and p u t a t i v e h y b r i d s . ANOVAs of PCAs of j u s t the a r t i f i c i a l and p u t a t i v e h y b r i d s (Table 28) suggested that there were small but s i g n i f i c a n t d i f f e r e n c e s between the two groups. Most of the v a r i a t i o n i s T a b l e 28. M u l t i v a r i a t e a p p o r t i o n m e n t of v a r i a t i o n f o r s e p a r a t e v a r i a b l e s u i t e s due to d i f f e r e n c e s between a r t i f i c a l and p u t a t i v e h y b r i d s of P. enge1mann i i and P_^  s i t c h e n s i s. A b b r e v i a t i o n of PCAs and ANOVAs g i v e n i n T a b l e 48, Append ix I I I. Symbols g i v e n i n MODEL 3. O r d i n a t i o n s of r e s u l t a n t component s c o r e s g i v e n in F i g u r e 21. %SS (mva) VARIABLE SUITE A B(A) E LEAF ANATOMY 3.67 76.28 20.05 LEAF MORPHOLOGY 14.06 70.17 15.77 TWIG MORPHOLOGY 1.15 90.09 8.76 VEGETATIVE 8.82 - 91.18 between i n d i v i d u a l t r e e s and the amount of i n t r a - i n d i v i d u a l v a r i a t i o n remains s i m i l a r to that presented i n Tables 23 and 24. Fi g u r e 21 i n d i c a t e s a v i r t u a l o v e r l a p of the v a r i a t i o n of the two groups, an impression c o r r o b o r a t e d by the high i n t e r - i n d i v i d u a l v a r i a t i o n (Table 28). The p u t a t i v e h y b r i d s 140 c o n s t i t u t e a s i g n i f i c a n t l y more heterogenous group of i n d i v i d u a l s than the a r t i f i c i a l h y b r i d s . As evidenced by the amount of v a r i a t i o n accounted f o r the f i r s t few components of these PCAs, the p o l a r i t y i n these data are not as pronounced as those i n Table 27 (= Table 40, Appendix I I I ) . However, the component-correlations were r a d i c a l l y d i f f e r e n t suggesting that p r e v i o u s l y undescribed p a t t e r n s of v a r i a t i o n were being d e s c r i b e d . None of the i n d i v i d u a l v a r i a b l e s had a v a r i a t i o n between the two types of h y b r i d s that exceeded the v a r i a t i o n w i t h i n a group of h y b r i d s . The l a r g e s t source of v a r i a t i o n was between t r e e s . 3.5 I n d i v i d u a l standards, p u t a t i v e s , and " h y b r i d s " . Adding the hypothesized h y b r i d s to the samples of standards and'putatives of the two taxa (Table 29) decreased only s l i g h t l y the p o l a r i t y of the data compared to Table 23 and 24, and d i d not a l t e r component c o r r e l a t i o n s . To i t e r a t e , the v a r i a b l e s most r e s p o n s i b l e f o r the p o l a r i z a t i o n of the p a t t e r n of v a r i a t i o n of the i n d i v i d u a l v a r i a b l e s u i t e s a r e : NEEDEP, PHLEND, XYLEND, ADXSTOM, RESCYNO, TIPWID, and SCALEN. If only i n t e r - i n d i v i d u a l v a r i a t i o n i s c o n s i d e r e d , the v a r i a b l e s r e s p o n s i b l e f o r p o l a r i z a t i o n are: NEEDEP, ABXANG, CENCYABX, BRACTLEN, and BRACTAP. F i g u r e 22 i n d i c a t e s that what s e p a r a t i o n appears to e x i s t between the two taxa, i s v i r t u a l l y obscured when the " h y b r i d s " were a l s o examined. The c o - i n c i d e n c e of the v e c t o r s of v a r i a b l e s that best d e s c r i b e the h y p o t h e s i z e d taxonomic p o l a r i t y or a c t u a l p o l a r i t y of the data are at an F i g u r e 21. O r d i n a t i o n of f i r s t two components of PCAs of s e p a r a t e v a r i a b l e s u i t e s f o r i n d i v i d u a l a r t i f i c i a l h y b r i d s and p u t a t i v e h y b r i d s . S co re s ba sed on PCAs g i v e n in Tab le 48, Appendix I I I. H a l f - f i l l e d g l y p h s - a r t i f i c i a l h y b r i d s . Open c i r c l e s - p u t a t i v e h y b r i d s . G l yphs r e p r e s e n t means of I n d i v i d u a l t r e e s . LEAF ANATOMY LEAF MORPHOLOGY TWIG MORPHOLOGY VEGETATIVE 1 42 T a b l e 29. M u l t i v a r i a t e a p p o r t i o n m e n t of v a r i a t i o n f o r s e p a r a t e v a r i a b l e s u i t e s due t o e i t h e r d i f f e r e n c e s between taxa or i n d i v i d u a l s of P. enge lmanni i , P. s i t chens i s, o r t h e i r p u t a t i v e h y b r i d . A b b r e v i a t i o n of PCAs and ANOVAs i n T a b l e 49, Appendix I I I. %SS (mva) f o r t a x a ba sed on o n l y s t a n d a r d s and p u t a t i v e s of the two t a x a . O r d i n a t i o n s of r e s u l t a n t component s c o r e s g i v e n in F i g u r e s 22 and 23. %SS (mva) TAXA INDIVIDUAL VARIABLE SUITE A E A E LEAF ANATOMY 35 . 70 64 . 30 83.00 17 .00 LEAF MORPHOLOGY 25 . 37 75 . 63 78.92 21 .08 TWIG MORPHOLOGY 22 . 20 77 .80 93 .90 6 . 10 CONE MORPHOLOGY 17 . 95 82 .05 66 . 1 1 33 . 89 TOTAL 28 . 07 71 .99 "x 80.48 19 . 52 x VEGETATIVE 27 . 76 72 . 24 85 . 27 14 .93 angle of about 22° to each other. T h i s would suggest p a r t i a l c o - i n c i d e n c e of hypothesis and data. Without c o n s i d e r i n g taxonomic c i r c u m s c r i p t i o n , the d i f f e r e n c e s between i n d i v i d u a l s was emphasized. Based on these values, the r e l a t i v e d i f f e r e n c e s between taxa accounts f o r l e s s than h a l f of the v a r i a t i o n between i n d i v i d u a l s . A n a l y t i c a l l y , i g n o r i n g i n t r a - i n d i v i d u a l v a r i a t i o n and using a l l 36. v a r i a b l e s does l i t t l e to a l t e r the impression of a continuum of morphological and anatomical v a r i a t i o n . F u r t h e r , the r e l a t i o n of the p u t a t i v e hybrids suggest intermediacy rather than c o n f u s i o n with engelmanni i or s i t c h e n s i s as i n d i c a t e d i n F i g u r e 20 f o r the a r t i f i c i a l h y b r i d s . Owing to the p r o x i m i t y and o v e r l a p of the p o i n t swarms of standards, no p o p u l a t i o n s c o u l d be i d e n t i f i e d that c o n t a i n e d examples of both hypothesized p a r e n t a l taxa and h y b r i d s . I n d i v i d u a l p u t a t i v e h y b r i d p o p u l a t i o n s were no more v a r i a b l e than some of the i n d i v i d u a l p o p u l a t i o n s of standards, although as a group they were F i g u r e 22. O r d i n a t i o n s of f i r s t two components of PCAs of s e p a r a t e v a r i a b l e s u i t e s f o r a l l i n d i v i d u a l s of P_^  enge1mann i i , P. s i t chens i s. and " h y b r i d s " . S co re s based on PCA ' s g i v e n in T a b l e 49, Append ix I I I. G l yphs r e p r e s e n t means of i n d i v i d u a l t r e e s as i n F i g u r e 16. Ha 1 f - f 1 11ed g l y p h s r e p r e s e n t " h y b r i d s " . Not a l l i n d i v i d u a l t r e e s c o u l d be p l o t t e d . 1 44 s i g n i f i c a n t l y l a r g e r . 4. D i s c u s s i o n . The m o r p h o l o g i c a l and anatomical v a r i a t i o n of Picea sampled in southwestern B r i t i s h Columbia suggest that there e x i s t s a continuum of v a r i a t i o n r a t h e r than a d i s c r e t e p a t t e r n of t r a n s - i n d i v i d u a l v a r i a t i o n such,as t h a t suggested by the two hypothesized t a x a . The r e s u l t s f u r t h e r the c o n c l u s i o n that P. glauca and P_;_ engelmanni i r e p r e s e n t l i t t l e more than nomenclatural exaggerations of prominent p o p u l a t i o n a l or i n t r a - p o p u l a t i o n a l morphological f e a t u r e s . The v a r i a b l e s that support the taxonomic p o l a r i t y between P_^  engelmannii and P. s i t c h e n s i s a r e , with the e x c e p t i o n of the p r e v i o u s l y unreported l e a f anatomy v a r i a b l e s , the same as have been used by others - yet they are not the only v a r i a b l e s that determine the p o l a r i t y of the data. The d i f f e r e n c e i n c o n c l u s i o n s r e g a r d i n g the a p p r o p r i a t e n e s s of the h y p o t h e s i z e d taxa i s a t t r i b u t a b l e to the method of a n a l y s i s (no i p s a t i v e measures, no r a t i o v a r i a b l e s ) , the i n c l u s i o n of i n t r a - i n d i v i d u a l sources of v a r i a t i o n a g a i n s t which i n t e r - i n d i v i d u a l sources of v a r i a t i o n c o u l d be compared, and l a r g e number of samples from areas not sampled p r e v i o u s l y . I t i s i n s t r u c t i v e t o compare these r e s u l t s with those of Gordon (1976) d e a l i n g w i t h the "P^ mariana - rubens" complex and the r e s u l t s of Parker and McLachlan (1978) d e a l i n g with the r e l a t i o n of P^ glauca to P^ mariana. C l e a r l y the r e l a t i o n shown 1 45 here between s i t c h e n s i s and P_;_ engelmanni i i s not as d i s c r e t e as that reported f o r mariana and E\_ rubens, nor P. glauca, and P^ mariana. However, n e i t h e r i s i t as con v o l u t e d as the r e l a t i o n shown here between P^ glauca and P^ engelmanni i (see a l s o La Roi and Dugle 1968), nor P^ engelmanni i and P. pungens (Mitton and Andalora 1981). Regardless of the nomenclatural c o n s i d e r a t i o n s , the r e s u l t s presented here suggest that P_;_ s i t c h e n s i s should not be excluded from i n v e s t i g a t i o n s of the P^ glauca complex. 4.1 I n t r a - p o p u l a t i o n v a r i a t i o n . The l a r g e s t source of i n t e r - i n d i v i d u a l v a r i a t i o n was a t t r i b u t e d to v a r i a t i o n between i n d i v i d u a l t r e e s w i t h i n a p o p u l a t i o n . T h i s c o r r o b o r a t e s the f i n d i n g s made by other r e s e a r c h e r s working with P i c e a , as w e l l as the m a j o r i t y of other c o n i f e r s . S i m i l a r r e s u l t s are r e p o r t e d f o r morp h o l o g i c a l and anatomical v a r i a b l e s , as w e l l as f o r growth and y i e l d v a r i a b l e s , isoenzymes and other chemicals, and p h y s i o l o g i c a l v a r i a b l e s . These r e s u l t s are based on n a t u r a l l y o c c u r r i n g m a t e r i a l s as w e l l as nursery grown provenances, progeny, and f a m i l y t r i a l s . Some re s e a r c h e r s have proposed that t h i s high w i t h i n - p o p u l a t i o n v a r i a t i o n i s r e l a t e d to the s u c c e s s i o n a l s t a t u s of the s p e c i e s (Rehfeldt and L e s t e r 1969), however the l a r g e v a r i a b i l i t y c o n s i s t e n t l y shown f o r many s p e c i e s i r r e s p e c t i v e of t h e i r s u c c e s s i o n a l s t a t u s (Guires 1984) suggests that t h i s h ypothesized r e l a t i o n may be erroneous. There i s no independent i n f o r m a t i o n c o n s i s t a n t l y a v a i a l b l e 1 46 in t h i s study that would permit the systematic e x p l o r a t i o n concerning the source of t h i s i n t r a - i n d i v i d u a l v a r i a t i o n . Research i n t o t h i s aspect of v a r i a t i o n of c o n i f e r s g e n e r a l l y has not been addressed (Adams 1981). Where such s t u d i e s have been undertaken or hypotheses advanced the proposed e x p l a n a t i o n s have most f r e q u e n t l y been tendered with r e s p e c t to n a t u r a l s e l e c t i o n by the environment (Shaw and A l l a r d 1981; L i n h a r t , et a l . 1981a,b; E h r l i c h and Raven 1969; M i t t o n , et a l . 1977; Grant and M i t t o n 1976, 1977; Hamrick 1976) in agreement with the w e l l known microgeographic and edaphic v a r i a t i o n shown in herbs. M i t t o n (1983) tendered other e x p l a n a t i o n s based on the presumed an c i e n t nature of the c o n i f e r l i n e a g e , l a r g e p o p u l a t i o n s i z e s , l o n g e v i t y of the t r e e s , and the a s s o c i a t e d high f e c u n d i t y over such a long l i f e span. R e h f e l d t (1979a) has tendered e x p l a n a t i o n s based on phenotypi'c p l a s t i c i t y . Stern (1972) suggested that the l a c k of s e l e c t i o n and frequent mutatiqn~were I e x p l a n a t i o n s f o r the high w i t h i n p o p u l a t i o n v a r i a t i o n The demonstration of f a m i l y s t r u c t u r e i n f o r e s t stands ( L i n h a r t , et a l . 1981a,b; Rehfe l d t 1978, 1983; Coles and Fowler 1976; M i t t o n , e_t a l . 1977; Shaw and A l l a r d 1981) and y e a r l y v a g r a n c i e s of breeding s t r u c t u r e (King and Dancik 1984) as w e l l as the demonstrated i n e f f i c i e n c y of e x t r i n s i c sources of v a r i a t i o n to account f o r w i t h i n - p o p u l a t i o n v a r i a t i o n (Maze 1984) suggests that r e p r o d u c t i o n alone may be the p r i n c i p a l v a r i a t i o n - g e n e r a t i n g and o r d e r i n g process i n n a t u r a l l y o c c u r r i n g stands. A d d i t i o n a l l y , Rowe's (1961) comments and those of others (Falkenhagen 1977; King 1979; Burgar 1964; B j o r n s t a d 1981) concerning environmental p r e c o n d i t i o n i n g ( i n c l u d i n g 1 47 maternal e f f e c t s ) a l s o should be c o n s i d e r e d i n such explanat i o n s . These o b s e r v a t i o n s on i n t e r - i n d i v i d u a l v a r i a t i o n and s p e c u l a t i o n s concerning the l a r g e s i z e of t h i s component suggest that the major e v o l u t i o n a r y and e c o l o g i c a l processes may be o c c u r r i n g at an extremely l o c a l s c a l e . F u r t h e r , these r e s u l t s suggest that r e p r o d u c t i o n and d i s p e r s a l may be the primary f a c t o r s by which e v o l u t i o n a r y n o v e l t i e s u l t i m a t e l y become emergent from an a n c e s t r a l taxon. If n a t u r a l s e l e c t i o n mediated p o p u l a t i o n d i f f e r e n t i a t i o n i s to be accepted as the c a u s a l mechanism i n e v o l u t i o n , these r e s u l t s and those of many others would appear to c o n t r a d i c t t h i s h y p o t h e s i s (see a l s o Mitton 1983) f o r c o n i f e r s . N a t u r a l s e l e c t i o n may w e l l be o p e r a t i v e , but i t s e f f e c t s and o p e r a t i v e s c a l e would appear to be . c o n d i t i o n a l upon the s p e c i f i c l i n e a g e e v o l v i n g (Rehfeldt 1984b). 4.2 N a t u r a l h y b r i d i z a t i o n . The r e s u l t s from the comparison of c o n t r o l l e d h y b r i d s and standards suggest that the h y b r i d s are d i f f i c u l t to recognize as i n t e r m e d i a t e s both i n r e s p e c t to form and v a r i a b i l i t y . T h i s may be the r e s u l t of pronounced maternal e f f e c t s . These r e s u l t s are at v a r i a n c e with other m u l t i v a r i a t e analyses of c o n t r o l l e d h y b r i d s where such l a r g e maternal e f f e c t s have not been as pronounced. The p o l a r d i s p o s i t i o n of the a r t i f i c i a l h y b r i d s and the a v a i l a b l e maternal parent c o u l d a l s o suggest a more P. glauca - l i k e maternal parent r a t h e r than E\ engelmannii. Indeed, based on the i n f o r m a t i o n p r o v i d e d f o r the o r i g i n of at 1 48 l e a s t the maternal parent of the New Brunswick h y b r i d i z a t i o n (Tree 70418, Appendix I I ) , t h i s i s a l i k e l y e x p l a n a t i o n . T h i s s i t u a t i o n i s not as obvious f o r the Red Rock h y b r i d i z a t i o n as the maternal parents were from a v a r i e t y of comparatively high e l e v a t i o n o r i g i n s . Other e x p l a n a t i o n s f o r the appearance of the a r t i f i c i a l h y b r i d s are p o s s i b l e , but are p r i m a r i l y experimental (e.g. inadequate i s o l a t i o n ..during p o l l i n a t i o n 1 ) . Regardless of the hypothesized e f f e c t s of maternal parent or exprimental e r r o r , the poor d i s t i n c t i o n between the two hypothesized taxa would suggest t h a t , at best, i t would be d i f f i c u l t to i d e n t i f y a h y b r i d . F u r t h e r , the appearance of the a r t i f i c i a l h y b r i d s f a l l s e a s i l y w i t h i n the range of v a r i a b i l i t y of the two s p e c i e s without suggesting new p a t t e r n s of v a r i a t i o n or i n c r e a s e d v a r i a b i l i t y . I f expermental causes can be r u l e d out, then r e s u l t s presented here f o r the h y b r i d s suggest that glauca shares the same r e l a t i o n to engelmanni i and P^ s i t c h e n s i s as the h y b r i d P^ engelmanni i x P^ s i t c h e n s i s . T h i s c o n t r a d i c t s Roche's (1969) suggestions that P_^  engelmanni i appears intermediate between P_j_ s i t c h e n s i s and P_;_ glauca ; however, Roche's data were based on only cone morphology. The r e l a t i o n of the p u t a t i v e h y b r i d s to the a r t i f i c i a l h y b r i d s remains enigmatic with r e s p e c t to the data presented so f a r . The higher h e t e r o g e n e i t y of the p u t a t i v e h y b r i d s 1 T h i s e x p l a n a t i o n i s not adequate f o r the Red Rock m a t e r i a l as the maternal parents were p o l l i n a t e d i n mid-winter in Vernon, where there were no other t r e e s present that were c o n t r i b u t i n g p o l l e n , p e r s . comm., Guyla K i s s , B r i t i s h Columbia M i n i s t r y of F o r e s t s , Vernon. 1 49 ( F i g . 20, 21) c o u l d r e f l e c t : the c o n t r i b u t i o n of a g r e a t e r number of parent t r e e s than the a r t i f i c i a l h y b r i d s ; g r e a t e r environmental v a r i a b i l i t y among the p u t a t i v e h y b r i d s than the common garden c o n d i t i o n s of the a r t i f i c i a l h y b r i d s ; the consequence of i n t r o g r e s s i v e h y b r i d i z a t i o n ; or, an i n a p p r o p r i a t e assignment of i n d i v i d u a l t r e e s as p u t a t i v e h y b r i d s based on a group of v a r i a b l e s that were only p a r t i a l l y c o - i n c i d e n t with the p a t t e r n s of v a r i a t i o n shown here. Owing to the appearance of the a r t i f i c i a l h y b r i d s i t i s suggested that the p u t a t i v e h y b r i d s i n southwestern B r i t i s h Columbia are not the r e s u l t o f, at l e a s t , contemporaneous, h y b r i d i z a t i o n between two taxa. T h i s does not r u l e out h i s t o r i c a l h y b r i d i z a t i o n or subsequent i n t r o g r e s s i o n or s e l e c t i o n as e x p l a n a t i o n s f o r the observed v a r i a t i o n . U n t i l f u r t h e r e x p l o r a t i o n s of the p a t t e r n of v a r i a t i o n encountered here are conducted, t e n d e r i n g e x p l a n a t i o n s based on e i t h e r i n t r o g r e s s i v e h y b r i d i z a t i o n or d i f f e r e n t i a t i o n w i t h i n a s i n g l e polymorphic taxon must remain enigmatic. Regardless of the outcome of such r e s e a r c h i t i s important to note that the r e l a t i o n s h i p of engelmannii to glauca appears fundamentally d i f f e r e n t from that with P_^_ s i t c h e n s i s - t h i s alone r e q u i r e s f u r t h e r e l a b o r a t i o n . 1 50 4.3 I n t r a - i n d i v i d u a l v a r i a t i o n i n an i n t e r - i n d i v i d u a l c o n t e x t . The r e s u l t s presented emphasize the importance i n systematic s t u d i e s of c o n s i d e r i n g and q u a n t i f y i n g i n t r a - i n d i v i d u a l v a r i a t i o n . These r e s u l t s i n d i c a t e that the d i f f i c u l t y inherent in the i d e n t i f i c a t i o n of i n d i v i d u a l t r e e s to one of the a p r i o r i taxa on the b a s i s of s i n g l e c h a r a c t e r s and s i n g l e values r e s u l t s from d e a l i n g with tendencies r a t h e r than a c t u a l i t i e s . In t h i s c o n t e x t , i t i s worth p o i n t i n g out that f o r every s t a t i s t i c of l o c a t i o n ( i . e . a mean) there i s a s t a t i s t i c of spread ( i . e . a standard d e v i a t i o n ) . If i t can be demonstrated that the v a r i a b i l i t y among v a r i a b l e v a l u e s i s e n t i r e l y experimental i n nature, then the spread or v a r i a b i l i t y of o b s e r v a t i o n s can be ignored. If the v a r i a b i l i t y r e s u l t s , i n p a r t , from causes independent of experimental e r r o r , then t h i s spread can be ignored only at the expense of m i s r e p r e s e n t i n g the nature of the s i t u a t i o n being d e s c r i b e d . A s t a t i s t i c of l o c a t i o n i s only as meaningful as the accompanying s t a t i s t i c of spread and the sample s i z e upon which both are based. As was demonstrated i n Chapter I I , i n t r a - i n d i v i d u a l m o rphological and anatomical v a r i a t i o n , whatever i t s cause, occurs and i s not random and thus should not be ignored. The c o n c l u s i o n s reached here suggest that i n southwestern B r i t i s h Columbia f u r t h e r r e s e a r c h aimed at e x p l a n a t i o n s of v a r i a t i o n need not c o n s i d e r p r e v i o u s l y hypothesized taxonomic c i r c u m s c r i p t i o n . Thus, i n v e s t i g a t i o n s of say, p o p u l a t i o n d i f f e r e n t i a t i o n , c o u l d be a p p l i e d over the complete range of v a r i a t i o n i l l u s t r a t e d here without having to c o n s i d e r the 151 "taxon" to which the p o p u l a t i o n may be a s s i g n e d . E x p l a n a t i o n s f o r p o p u l a t i o n v a r i a t i o n thus c o u l d be addressed, say i n the context of geographic v a r i a t i o n i n v e s t i g a t e d by others concerned with d i f f e r e n t i a t i o n between marginal and c e n t r a l p o p u l a t i o n s ( T i g e r s t e d t 1973; Soule 1973; Yeh and Layton 1979). Regardless of how the problem i s approached, the r e s u l t s presented here suggest a more complex s i t u a t i o n c o n cerning P i c e a in western North America than p r e v i o u s l y c o n s i d e r e d . 152 V. INTER-INDIVIDUAL VARIATION: RELATIONSHIPS OF PATTERNS OF VARIATION. 1 . I n t r o d u c t i o n . Having demonstrated i n Chapter IV that there e x i s t s i n southwestern B r i t i s h Columbia a complex c l i n a l p a t t e r n of morph o l o g i c a l and anatomical v a r i a t i o n between P^ engelmanni i and P_;_ s i t c h e n s i s , e x p l a n a t i o n s are r e q u i r e d to i n t e r p r e t t h i s p a t t e r n of v a r i a t i o n i r r e s p e c t i v e of hypothesized c i r c u m s c r i b i n g taxa. Indeed, the c l i n a l p a t t e r n of v a r i a t i o n suggests that the i m p o s i t i o n of taxonomic c i r c u m s c r i p t i o n i s unwarranted i n proposing e x p l a n a t i o n s f o r v a r i a t i o n . Two g e n e r a l hypotheses can be o f f e r e d to e x p l a i n p a t t e r n s of v a r i a t i o n . These can be tendered as the r e s u l t of e i t h e r c o r r e l a t i n g m o r p h o l o g i c a l and anatomical v a r i a t i o n with i n t r i n s i c and/ or e x t r i n s i c v a r i a t i o n or a p p o r t i o n i n g v a r i a t i o n to these sources of v a r i a t i o n . Strong c o r r e l a t i o n s more s t r o n g l y suggest of p o s s i b l e causes than poor c o r r e l a t e s . Larger sources of v a r i a t i o n more s t r o n g l y i n d i c a t e p o s s i b l e causes than do smaller sources of v a r i a t i o n . These hypotheses are o f t e n tendered as i f they were mutually e x c l u s i v e or that only the e x t r i n s i c e x p l a n a t i o n s are a c c e p t a b l e . A p r i o r i d i s p o s i t i o n s toward e x t r i n s i c or i n t r i n s i c e x p l a n a t i o n s i s inappropr i a t e . E x t r i n s i c e x p l a n a t i o n s are o f f e r e d more f r e q u e n t l y than are i n t r i n s i c . Such e x p l a n a t i o n s r e s u l t from c o r r e l a t i n g p a t t e r n s of phenotypic v a r i a t i o n with the environment from which the 1 53 samples are taken. D i s c o n t i n u i t i e s i n geographic d i s t r i b u t i o n are expected to be accompanied by d i s c o n t i n u i t i e s i n pheotypic v a r i a t i o n . In s p i t e of the emphasis on e x t r i n s i c e x p l a n a t i o n s , ( i . e . e x t r i n s i c c o r r e l a t e s r e f l e c t s e l e c t i o n p r e s s u r e s , Thorpe 1976) there i s a continuum of both e x t r i n s i c and i n t r i n s i c f a c t o r s that i s hypothesized to a f f e c t the observed phenotypic v a r i a t i o n . T h i s continuum can be d i v i d e d i n t o s e v e r a l s c a l e s : broad geographic environmental v a r i a t i o n , such as c l i m a t e , a s s o c i a t e d with l o n g i t u d e , l a t i t u d e , and e l e v a t i o n ; l o c a l c l i m a t i c and topo-edaphic v a r i a t i o n ; and, w i t h i n i n d i v i d u a l v a r i a t i o n . E x p l a n a t i o n s based on the c o r r e l a t i o n s between the e x t e r n a l environment and i n t e r - i n d i v i d u a l v a r i a t i o n are formulated under arguments of n a t u r a l s e l e c t i o n . I n t r a - i n d i v i d u a l v a r i a t i o n that i s c o r r e l a t e d with the environment i s r e f e r r e d to under "phenotypic p l a s t i c i t y " . In ge n e r a l , speci.es that are widely d i s t r i b u t e d are expected to show c o r r e l a t i o n between phenotype and geography. Large i n d i v i d u a l p l a n t s are expected to show c o r r e l a t i o n between phenotype of organs and p o s i t i o n i n the pl a n t with r e s p e c t to the surrounding environment. I n t r i n s i c e x p l a n a t i o n s are based on c o r r e l a t i o n s of the p a t t e r n of morphological and anatomical v a r i a t i o n with ancestor-descendant r e l a t i o n s of v a r i o u s ages or ontogeny. As with e x t r i n s i c c o r r e l a t e s , there i s a continuum of i n t r i n s i c v a r i a t i o n that can be d i v i d e d i n t o i n t e r v a l s of v a r i a b l e d u r a t i o n with respect to the l i f e of the organism: long-term r e l a t i o n s amongst i n d i v i d u a l s r e f l e c t i n g d i s t a n t a n c e s t o r s ; p a r e n t - o f f s p r i n g r e l a t i o n s ; and, i n t r a - i n d i v i d u a l v a r i a t i o n 1 54 between separate organs or c h a r a c t e r s . I n t e r - i n d i v i d u a l e x p l a n a t i o n s are formulated under p h y l o g e n e t i c s and g e n e t i c s , whereas i n t r a - i n d i v i d u a l v a r i a t i o n e x p l a n a t i o n s are formulated with respect to development. E x p l a n a t i o n s of i n t e r - i n d i v i d u a l v a r i a t i o n , r e g a r d l e s s of t h e i r e x t r i n s i c or i n t r i n s i c nature, are e v o l u t i o n a r y in nature. E x p l a n a t i o n s of i n t r a - i n d i v i d u a l v a r i a t i o n are o n t o g e n e t i c . There i s an approximate one-to-one r e l a t i o n between the geographic s c a l e s of v a r i a t i o n and the h i s t o r i c a l s c a l e s of v a r i a t i o n . A n c e s t r a l r e l a t i o n s are r e f l e c t e d i n broad geographic v a r i a t i o n . S i m i l a r l y , l o c a l environmental v a r i a t i o n i s complexed with p a r e n t ^ o f f s p r i n g r e l a t i o n s i n that more widely separated i n d i v i d u a l s are assumed to be more d i s t a n t l y r e l a t e d than are i n d i i v i d u a l s t h a t are c l o s e r to each other. In s t u d i e s , such as those r e p o r t e d here, that are based on a l i m i t e d i n t r a - i n d i v i d u a l sampling under n a t u r a l l y o c c u r r i n g s i t u a t i o n s , i t i s impossible to e f f e c t i v e l y d i s c r i m i n a t e or a p p o r t i o n v a r i a t i o n i n t o e x t r i n s i c or i n t r i n s i c . However, i t i s p o s s i b l e to a p p o r t i o n v a r i a t i o n i n t o these v a r i o u s s c a l e s of v a r i a t i o n . For example, apportionment of v a r i a t i o n i n t o i n t e r - i n d i v i d u a l versus i n t r a - i n d i v i d u a l sources of v a r i a t i o n and subsequent c o r r e l a t i o n s with these s c a l e s of v a r i a t i o n serves as a means of a d d r e s s i n g the apportionment of v a r i a t i o n . Such an apportionment of v a r i a t i o n serves as a f i r s t approximation for f u r t h e r r e s e a r c h conducted under common garden c o n d i t i o n s with c o n t r o l l e d mating aimed at i s o l a t i n g the s p e c i f i c i n t r i n s i c and e x t r i n s i c f a c t o r s o p e r a t i v e at a s c a l e 155 that accounts for the l a r g e s t source of v a r i a t i o n i n the data. Indeed, an i n v e s t i g a t i o n of the apportionment of n a t u r a l l y o c c u r r i n g v a r i a t i o n i s e s s e n t i a l to the i n i t i a t i o n of a b i o l o g i c a l l y sound s i l v i c u l t u r a l or t r e e improvement programme. Such programmes should be guided by the n a t u r a l v a r i a t i o n of the organism being s t u d i e d r a t h e r than by t h e o r e t i c a l or economic p r e d i s p o s i t i o n to a p a r t i c u l a r s c a l e of v a r i a t i o n f o r a g e n e r a l i z e d organism. An important aspect to c o n s i d e r with respect to the i n t e r - i n d i v i d u a l v a r i a t i o n i s the i n t e r - r e l a t i o n s h i p of v a r i o u s v a r i a b l e s and groups of v a r i a b l e s . The demonstration of i n t e r - r e l a t i o n s h i p s between groups of v a r i a b l e s are important fo r more than j u s t a n a l y t i c purposes (Small, et a_l. 1982). Such i n t e r - r e l a t i o n s h i p s suggest developmental inter-dependence between d i v e r s e groups of v a r i a b l e s (Morishima and Oka 1968). Falkenhagen (1974) p o i n t s out that an organism grows and s u r v i v e s only i f adequate r e l a t i o n s between organs, s t r u c t u r e s , and p h y s i o l o g y are maintained. Such i n t e r c o r r e l a t i o n s a l s o c a r r y e v o l u t i o n a r y i m p l i c a t i o n s (Maze 1983)^ V a r i a b l e i n t e r - c o r r e l a t i o n s a l s o c a r r y important g e n e t i c i n f e r e n c e s under the r u b r i c of " l i n k a g e d i s e q u i l i b r i u m " ( M i t t o n , e_t a_l. 1980). Such a t t e n t i o n to the i n t e r - r e l a t i o n s h i p s between groups of v a r i a b l e s a i d i n understanding the developmental nature of the v a r i a b l e s and the e v o l u t i o n a r y s t a t u s of the taxon being examined. As w e l l , they p r o v i d e an a l t e r n a t e view of m o r p h o l o g i c a l v a r i a t i o n : v a r i a t i o n i s not n e c e s s a r i l y a d a p t i v e , simply the r e s u l t of m o r p h o l o g i c a l dependency. 1 56 In a d d i t i o n to p r o v i d i n g e x p l a n a t i o n s f o r observed p a t t e r n s of v a r i a t i o n , there i s a l s o a need to r e l a t e the observed v a r i a t i o n to that r e p o r t e d i n the l i t e r a t u r e . Comparison with s t u d i e s based on n a t u r a l l y o c c u r r i n g t r e e s i s s t r a i g h t f o r w a r d ; however, comparisons with the r e s u l t s based on common garden s i t u a t i o n s i s not as d i r e c t . Comparison of p a t t e r n s of v a r i a t i o n based on t r e e s from a common garden to the n a t u r a l l y o c c u r r i n g p a t t e r n would f a c i l i a t e such a comparison. 2. M a t e r i a l s and methods. 2 . 1 M a t e r i a l s . Except f o r the a r t i f i c i a l h y b r i d s and the standards of P. glauca, a l l the t r e e s sampled and used i n the pr e v i o u s chapters were used i n c o r r e l a t i n g with the v a r i o u s s c a l e s of v a r i a t i o n . Owing to l i m i t a t i o n s of the number of provenances grown i n the nursery, comparison between n a t u r a l l y o c c u r r i n g and nursery grown t r e e s c o u l d be made only f o r standards of P. s i t c h e n s i s . S i m i l a r l y , as the nursery grown t r e e s were s t i l l immature, comparisons with n a t u r a l l y grown t r e e s c o u l d be made using only v e g e t a t i v e v a r i a b l e s . The l a c k of inf o r m a t i o n p e r t a i n i n g to c o r r e l a t e s f o r i n t r a - i n d i v i d u a l v a r i a t i o n ( i . e . exact p o s i t i o n w i t h i n the t r e e and r e q u i s i t e r e p l i c a t i o n w i t h i n p o s i t i o n s ) n e c e s s i t a t e d that averages of v a r i a b l e s per t r e e be used. Such averaging removes about 20 percent of the t o t a l v a r i a t i o n . T h i s a v e r a g i n g s i m p l i f i e s a n a l y s i s c o n s i d e r a b l y but any c o r r e l a t e s p e r t a i n only 157 to the i n t e r - i n d i v i d u a l p o r t i o n of the t o t a l v a r i a t i o n of the data. T h i s assumes that there i s no i n t e r a c t i o n between i n t e r - i n d i v i d u a l v a r i a t i o n and i n t r a - i n d i v i d u a l v a r i a t i o n . Although p o p u l a t i o n s of Picea do occur (Table 7) t h i s l e v e l of o r g a n i z a t i o n cannot be addressed d i r e c t l y as a l a r g e number of t r e e s , e s p e c i a l l y on the c o a s t , d i d not occur i n p o p u l a t i o n s . Where t r e e s do occur i n p o p u l a t i o n s , the p o p u l a t i o n s i z e s a v a i l a b l e are extremely v a r i a b l e making a n a l y s i s d i f f i c u l t . T h i s does not mean that the c o n t r i b u t i o n of p o p u l a t i o n d i f f e r e n t i a t i o n to the p a t t e r n of morphological and anatomical v a r i a t i o n i s r e j e c t e d , merely that the nature of the study and the samples a v a i l a b l e does not permit such an a n a l y s i s , or at l e a s t an a n a l y s i s which w i l l y i e l d r e p r o d u c i b l e r e s u l t s . For example, the r e g u l a r occurrence of d e f i n e d p o p u l a t i o n s i n the i n t e r i o r may w e l l c o n s t i t u t e an important d i f f e r e n c e between the extremes of the morphological continuum i d e n t i f i e d i n t h i s study. Table 23 suggests that a p p o r t i o n i n g 25 percent of the t o t a l i n t e r - i n d i v i d u a l v a r i a t i o n to i n t e r - p o p u l a t i o n v a r i a t i o n i s worth remembering when c o n s i d e r i n g the r e s u l t s to be presented i n t h i s c h a pter. 2.2 Analyses. In examining the r e l a t i o n s h i p s of p a t t e r n s of v a r i a t i o n to broad geographic v a r i a t i o n , the r e s u l t s from the PCAs i n Table 29 and F i g u r e 22 were p l o t t e d s e p a r a t e l y a g a i n s t l a t i t u d e , l o n g i t u d e , and e l e v a t i o n to assess the g e n e r a l form of the hypothesized r e l a t i o n . 1 58 Using means of each of the o r i g i n a l v a r i a b l e s per t r e e , a m u l t i p l e l i n e a r r e g r e s s i o n of the form: (MODEL 4.) y = e l e v a t i o n + l o n g i t u d e + l a t i t u d e + e. was performed and r e s i d u a l and p r e d i c t e d values were c a l c u l a t e d f o r each t r e e f o r each v a r i a b l e . Such a r e g r e s s i o n c o n s i d e r s a l l t r e e s e q u a l l y , r e g a r d l e s s of p o p u l a t i o n a l d i s p o s i t i o n . The r e s i d u a l and p r e d i c t e d v a l u e s were su b j e c t e d to separate PCAs fo r each v a r i a b l e s u i t e and the components of these PCAs were examined by the ANOVA model: (MODEL 5.) y = A + e. were A i s the e f f e c t of the hypothesized taxa. Although the PCAs upon which t h i s ANOVA was based used a l l the a v a i l a b l e t r e e s , only the scores f o r the standards and p u t a t i v e s of the taxa were used i n the ANOVA. Such an a n a l y s i s has been used i n examining s u b s p e c i f i c v a r i a t i o n i n Pseudotsuga m e n z i e s i i (Chen, et a l . 1984). Based on such an a n a l y s i s of r e s i d u a l and p r e d i c t e d values, i f the hypo t h e s i z e d taxa are indeed m o r p h o l o g i c a l l y and a n a t o m i c a l l y d i s c r e t e then removing the e f f e c t s of a l l o p a t r y of taxa and c l i m a t i c v a r i a t i o n a s s o c i a t e d with l o n g i t u d e , l a t i t u d e , and e l e v a t i o n should not a f f e c t the apportionment of v a r i a t i o n r e s u l t i n g from r e c o g n i t i o n of taxa. T h i s approach e f f e c t i v e l y s t a n d a r d i z e s the g e o g r a p h i c a l and h i s t o r i c a l d i f f e r e n t i a t i o n of 1 59 p o p u l a t i o n s . S u b s t a n t i a l re-arrangement of the apportionment of v a r i a t i o n r e s u l t i n g from r e c o g n i t i o n of taxa and the p a t t e r n of v a r i a t i o n as a r e s u l t of removing the e f f e c t s of geography would suggest that the taxa are more g e o g r a p h i c a l l y than m o r p h o l o g i c a l l y d i s c r e t e . Such a c o n c l u s i o n would suggest that i n d i v i d u a l s are more g e n e t i c a l l y s i m i l a r than geographic s e p a r a t i o n alone might suggest. In examining the r e l a t i o n s h i p between p a t t e r n s of morphological and anatomical v a r i a t i o n with l o c a l geographic environmental v a r i a t i o n PCAs were performed on each separate v a r i a b l e s u i t e f o r each of the 16 a r b i t r a r i l y e r e c t e d geographic areas (Table 7, F i g . 6). Average component scores were c a l c u l a t e d f o r each t r e e f o r each PCA and the scores from each PCA c o r r e l a t e d s e p a r a t e l y a g a i n s t e l e v a t i o n and r e l a t i v e moisture a v a i l a b i l i t y . E l e v a t i o n has been suggested p r e v i o u s l y by Roche (1969) and others (Falkenhagen 1974, 1978; La Roi and Dugle 1968; Horton 1959; O g i l v i e and von Rudloff 1968) as being the major determinant of l o c a l geographic v a r i a t i o n . Singh and Owens (1981) and H a r r i s o n and Owens (1983) have concluded that e l e v a t i o n may a f f e c t the time of i n i t i a t i o n of morphogenesis and other aspects of morphogenesis i n P_^  engelmannii. As w e l l , a m u l t i p l e l i n e a r r e g r e s s i o n of mean component scores a g a i n s t moisture and e l e v a t i o n was performed. I t should be emphasized that these geographic areas simply group together samples i n a given geographic area and attempt to i l l u s t r a t e the l o c a l m o rphological and environmental v a r i a t i o n that might be encountered i n such an area. Although t r e a t e d independently of the broad p a t t e r n s of geographic v a r i a t i o n , t h i s i s an a n a l y t i c 160 convenience r a t h e r than a t e s t e d assumption. T e s t i n g f o r the i n t e r a c t i o n of the v a r i o u s s c a l e s of p a t t e r n would r e q u i r e more e x t e n s i v e l o c a l i z e d sampling than were a v a i l a b l e here. Comparing n a t u r a l l y and nursery grown P_;_ s i t c h e n s i s was made by performing separate PCAs on each group f o r each v a r i a b l e s u i t e , averaging component scores f o r each t r e e , and then r e g r e s s i n g the scores s e p a r a t e l y a g a i n s t l a t i t u d e and l o n g i t u d e . The nursery grown m a t e r i a l s represented P^ s i t c h e n s i s from throughout i t s range ( F i g . 4B). As with the separate geographic areas, the mean scores were submitted to m u l t i p l e l i n e a r r e g r e s s i o n a g a i n s t l o n g i t u d e and l a t i t u d e . Using only n a t u r a l l y o c c u r r i n g standards of P_;_ s i t c h e n s i s was necessary to r e s t r i c t the p o s s i b l e e f f e c t s of e l e v a t i o n . If the e x t e r n a l environment, or at l e a s t the s c a l e of environment a s s o c i a t e d with geography, i s an important aspect of morp h o l o g i c a l v a r i a t i o n then the c o r r e l a t i o n with the environment should be stronger f o r the n a t u r a l l y grown t r e e s than the nursery grown t r e e s . The o b s e r v a t i o n of a l a r g e i n t r a - p o p u l a t i o n v a r i a t i o n (Table 23) suggests that the converse may be expected; i . e . the n a t u r a l l y grown t r e e s would be expected to be l e s s s t r o n g l y c o r r e l a t e d with geography than the nursery grown t r e e s as a consequence of the gre a t e r l o c a l edaphic v a r i a t i o n and, p o t e n t i a l l y , l a r g e r number of parents c o n t r i b u t i n g to the t r e e s c o l l e c t e d at any one s i t e . To examine the i n t e r - r e l a t i o n s h i p s among the p a t t e r n s of v a r i a t i o n of separate s u i t e s of v a r i a b l e s , average component scores f o r each t r e e i n the separate PCAs were c a l c u l a t e d . T h i s 161 averaging assumes that i n t r a - t r e e v a r i a t i o n of r e p r o d u c t i v e and v e g e t a t i v e v a r i a b l e s are independent. Such independence i s suggested i n F i g u r e s 12 and 13. Departures from independence of v e g e t a t i v e and r e p r o d u c t i v e v a r i a b l e s based on i n t e r - i n d i v i d u a l v a r i a t i o n suggests that e v o l u t i o n i n t h i s l i n e a g e has r e s u l t e d in the emergence of developmental interdependence. The appearance of such interdependence suggests e i t h e r p a r a l l e l s e l e c t i o n f o r r e p r o d u c t i v e and v e g e t a t i v e t r a i t s , or simply the consequences of e v o l u t i o n being a v a r i a t i o n g e n e r a t i n g process (Wiley and Brooks 1982; Maze 1983). Owing to the sampling c o n s t r a i n t s given i n Chapter I I , there are s e v e r a l s u i t e s of v a r i a b l e s . These v a r i a b l e s u i t e s are not a l l expected to be independent. Based on the common d e r i v a t i o n of some the s u i t e s of v a r i a b l e s , i t would be p r e d i c t e d that some s u i t e s of v a r i a b l e s would be expected to be more h i g h l y i n t e r - c o r r e l a t e d than o t h e r s . That i s , they would show a s i m i l a r development. As a consequence, s u i t e s of v a r i a b l e s that are s p a t i a l l y adjacent or developmentally s e q u e n t i a l would be expected to be more c l o s e l y i n t e r - c o r r e l a t e d than those on more removed p a r t s or d e r i v e d from d i f f e r e n t a p i c e s (Morishima and Oka 1968; Scagel and Maze 1983). For the d i f f e r e n t s u i t e s of v e g e t a t i v e v a r i a b l e s measured here i t would be p r e d i c t e d that the twig morphology s u i t e should be the l e a s t i n t e r - r e l a t e d , f o l l o w e d then by the l e a f morphology and l e a f anatomy. T h i s sequence i s p r e d i c t e d on the b a s i s of the work of Owens (1968) d e a l i n g with the development of D o u g l a s - f i r needles and that of Owens and Molder (1976a) and H a r r i s o n and Owens (1983) d e a l i n g with development of the shoots of s i t c h e n s i s 1 62 and Pj_ engelmanni i . In a l l a n a l y s e s , the i d e n t i f i c a t i o n of a l l i n d i v i d u a l s was r e t a i n e d i n order to- permit comparison with the r e s u l t s presented i n e a r l i e r c h a p t e r s . The r e t e n t i o n of these i d e n t i f i c a t i o n s a l s o a i d s the i n t e r p r e t a t i o n of the r e s u l t s based more on the convention of r e c o g n i z i n g the two taxa rather than supporting the continued r e c o g n i t i o n of separate taxa i n southwestern B r i t i s h Columbia. 3. R e s u l t s . 3.1 Geographic v a r i a t i o n . 3.1.1 N a t u r a l v a r i a t i o n . Table 29 and F i g u r e 22 i l l u s t r a t e the r e l a t i o n between a l l the t r e e s . F i g u r e 23 d e p i c t s the s c a t t e r s of the scores from these PCAs a g a i n s t l a t i t u d e , l o n g i t u d e , and e l e v a t i o n . The s i g n i f i c a n t r 2 v a l u e s i n c l u d e d i n the f i g u r e are g e n e r a l l y s m a l l . Over a l l v a r i a b l e s , l o n g i t u d e and e l e v a t i o n account fo r the l a r g e s t source of i n t e r - i n d i v i d u a l v a r i a t i o n . L a t i t u d i n a l v a r i a t i o n was much s m a l l e r . There was l i t t l e i n the way of a n o n - l i n e a r t r e n d i n the geographic v a r i a t i o n of m o r p h o l o g i c a l and anatomical v a r i a t i o n . The p u t a t i v e h y b r i d s were intermediate appearing with r e s p e c t to l o n g i t u d e and e l e v a t i o n -emphasizing the c o n t i n u i t y between coast and i n t e r i o r as w e l l as high and low e l e v a t i o n . I t should be noted that there appeared to be an e l e v a t i o n a l d i s c o n t i n u i t y of about 200m between the F i g u r e 2 3 . O r d i n a t i o n s o f m e a n s o f f i r s t c o m p o n e n t s f r o m P C A o f s e p a r a t e v a r i a b l e s u i t e s f o r s t a n d a r d s , p u t a t i v e s . a n d " h y b r i d s " a g a i n s t e l e v a t i o n , l a t i t u d e , a n d l o n g i t u d e . S c o r e s b a s e d o n P C A s g i v e n i n T a b l e 49. A p p e n d i x 1 1 1 . G l y p h s a s i n F i g u r e 2 2 . F i r s t c o m p o n e n t t h a t f r o m P C A s i n F i g u r e 2 2 . " . r ' v a l u e s s i g n i f i c a n t 0 p < 0 . 0 1 . CONE MORPHOLOGY LEAF ANATOMY TWIG MORPHOLOGY r =0 093* r' .-OO0B r' ;007< TOTAL 9 L7ZS.'. r =0577' O o f-? c r = 0158* r'=0 573* 1 64 r e p r e s e n t a t i v e s of P_;_ s i t c h e n s i s and the p u t a t i v e h y b r i d s and P• engelmann i i from 300 to 500m ASL. F i g u r e 23 emphasizes the co - i n c i d e n c e of Cascade and S e l k i r k Mountain F*\_ engelmanni i as we l l as the Oregon and B r i t i s h Columbia P^ s i t c h e n s i s . I t i s worthwhile n o t i n g that the P^ engelmanni i p o p u l a t i o n s are 400 km apart spanning 3° l o n g i t u d e and 2° l a t i t u d e . The d i s t a n c e s s e p a r a t i n g the P^ s i tchens i s are even l a r g e r : 500 to 1000 km over 10 to 15° l a t i t u d e . Table 30 gives the r 2 values a s s o c i a t e d with each v a r i a b l e for the m u l t i p l e l i n e a r r e g r e s i o n given i n MODEL 4. As a group, T a b l e 30. r ! v a l u e s f o r i n d i v i d u a l v a r i a b l e s from m u l t i p l e l inear -r e g r e s s i o n g i v e n i n MODEL 4. r' v a l u e s e x p r e s s e d as a t o t a l of i n t e r - i n d i v i d u a 1 v a r i a t i o n . P r e d i c t e d and r e s i d u a l v a l u e s c a l c u l a t e d on the b a s i s of the r e g r e s s i o n s . * . r ' v a l u e s s i g n i f i c a n t <a p < 0.01 . VARIABLES r . t VARIABLES r 1 NEEDWID 5 . 29* NEEDLEN 4 .64* NEEDEP 47 . 68* ADXSTOM 44 . 4 1 * ABXANG 35 . 40* ABXSTOM 33 .46* ADXANG 20. 89* RESCYN0 23 .92* CENCYWID 9 . 12* RESCYLOC 23 .73* CENCYLAT 10. 32* RESCYLEN 1 . 98 CENCYABX 60. 01 * X 22 .02 CENCYADX 36 . 99* ENDONUM 16 . 56* C0NLEN 21 .04 * PHLEND 28 . 73* C0NWID 20 .90* XYLEND 21 . 66* SCALEN 13.71* X 26.60 SCALWID 34.22* SCALTAP 9.44* WINGWID 16.74* PULVLEN 2 1 . 25* WINGTAP 6.66* TIPWID 16 . 66* FREE SCAL 15.60* TIPDEP 1 . 65 BRACTLEN 54 .46* PULVPUB 52 . 45* BRACTWID 18.92* 23 .00 BRACTAP 53 .27* x 22.60 TOTAL x 23.56 l e a f anatomy v a r i a b l e s are the most s t r o n g l y a s s o c i a t e d with geography. On the average, v e g e t a t i v e v a r i a b l e s are only 1 65 s l i g h t l y more c o r r e l a t e d with the geography than are the r e p r o d u c t i v e . The v a r i a b l e s which are the most s t r o n g l y c o r r e l a t e d ( i . e . r 2 > 50%) with the geographic v a r i a b l e s a r e : NEEDEP, CENCYABX, PULVPUB, BRACTLEN, AND BRACTAP. Nearly a l l v a r i a b l e s were r e l a t e d s i g n i f i c a n t l y to the geographic v a r i a b l e s . Over a l l v a r i a b l e s , the average r 2 f o r t h i s m u l t i p l e l i n e a r r e g r e s s i o n i s 24 percent of the t o t a l i n t e r - i n d i v i d u a l v a r i a t i o n . Table 31 g i v e s the r e s u l t s of the PCAs based on the r e s i d u a l and p r e d i c t e d values from the m u l t i p l e l i n e a r r e g r e s s i o n s given i n MODEL 4. The amount of v a r i a t i o n accounted T a b l e 3 1 . M u l t i v a r i a t e a p p o r t i o n m e n t of v a r i a t i o n f o r s e p a r a t e v a r i a b l e s u i t e s b a s e d on p r e d i c t e d and r e s i d u a l v a l u e s from m u l t i p l e l i n e a r r e g r e s s i o n (MODEL 4 ) . O r i g i n a l v a l u e s based on PCAs and ANOVAs g i v e n i n T a b l e 2 9 . A b b r e v i a t i o n of PCAs and ANOVAs g i v e n i n T a b l e 4 9 and 5 0 , Append ix I I I . O r d i n a t i o n s of r e s u l t a n t component s c o r e s g i v e n in F i g u r e s 2 2 . 2 3 , and 2 4 . % S S A (mva) V A R I A B L E S U I T E O R I G I N A L P R E D I C T E D R E S I D U A L L E A F ANATOMY 3 5 . 7 0 7 1.59 5 . 2 2 L E A F MORPHOLOGY 2 5 . 3 7 5 9 . 2 6 2 . 6 9 TW I G MORPHOLOGY 2 2 . 2 0 6 3 . 4 0 1.45 CONE MORPHOLOGY 2 4 . 9 8 5 3 . 2 2 1.44 T O T A L 2 7 . 0 6 6 1.87 2 . 7 0 x V E G E T A T I V E 2 7 . 7 6 6 4 7 5 3 . 1 2 f o r by the PCAs and the component c o r r e l a t i o n s should be compared with those given in Table 29. The PCAs based on the p r e d i c t e d v a l u e s were the most p o l a r . F i g u r e 24 i l l u s t r a t e s the r e l a t i o n among the t r e e s based on the r e s i d u a l and p r e d i c t e d v a l u e s , these should be compared with those i n F i g u r e 22. I t should be emphasized the PCA based on p r e d i c t e d scores from the 1 66 m u l t i p l e l i n e a r r e g r e s s i o n s only accounts f o r 24 percent of the t o t a l v a r i a t i o n i n the data. ANOVAs of component scores (Tables 29 and 31) i n d i c a t e that removing the e f f e c t of geography by r e g r e s s i o n a l s o removes a l a r g e p o r t i o n of the inter-taxonomic v a r i a t i o n ; the o r d i n a t i o n based on r e s i d u a l s ( F i g . 24) emphasizes t h i s l a c k of taxonomic p o l a r i t y . As important as the demonstration of the d e c l i n e i n v a r i a t i o n caused by r e c o g n i t i o n of hypothesized taxa r e s u l t s from the a n a l y s i s of r e s i d u a l v a l u e s , i s the demonstration of the i n c r e a s e d v a r i a t i o n caused by taxon r e c o g n i t i o n r e s u l t i n g from the a n a l y s i s of p r e d i c t e d v a l u e s . The o r d i n a t i o n s of p r e d i c t e d v a l u e s a l s o emphasize the intermediate appearance of the p u t a t i v e h y b r i d s . Based on the p r e d i c t e d v a l u e s from the r e g r e s s i o n , only 8 v a r i a b l e s (NEEDWID, NEEDLEN, TIPDEP, CONWID, SCALEN, SCALTAP, FREESCAL, and LOCOWID) d i s p l a y e d an inter-taxonomic v a r i a t i o n that exceeded inter-taxonomic v a r i a t i o n . Those v a r i a b l e s with the l a r g e s t r 2 v a l u e s (Table 30) g e n e r a l l y had the l a r g e s t %SS^ (uva) a t t r i b u t e d to taxon r e c o g n i t i o n (Table 31) based on p r e d i c t e d v a l u e s . The l a r g e s t %SS A(uva) as a r e s u l t of taxon r e c o g n i t i o n f o r v a r i a b l e s i n Table 29 are those with the l a r g e s t %SS^(uva) a t t r i b u t e d to taxa i n Table 31 f o r r e s i d u a l v a l u e s . The p o l a r i t y of the data based on p r e d i c t e d v a l u e s emphasizes BRACTLEN, BRACTAP, ABXANG, ADXSTOM, CENCYABX, NEEDEP, and CENCYADX. By c o n t r a s t the p o l a r i t y of the data based on r e s i d u a l v a l u e s emphasizes TIPDEP, TIPWID, CENCYWID, and SCALEN. Table 32 p r e s e n t s the c o r r e l a t i o n between the PCAs based on 1 67 F i g u r e 2 4 . O r d i n a t i o n s o f f i r s t t w o c o m p o n e n t s f r o m P C A s o f s e p a r a t e v a r 1 a b 1 e s u 1 t e s f o r s t a n d a r d s . p u t a t i v e s . a n d " h y b r i d s " u s i n g c a l c u l a t e d p r e d i c t e d a n d r e s i d u a l v a l u e s f r o m m u l t i p l e l i n e a r r e g r e s s i o n i n M O D E L 4 . G l y p h s a s i n F i g u r e 2 2 . S c o r e s b a s e d o n P C A S g i v e n i n T a b l e 5 0 , A p p e n d i x I I I . L E A F A N A T O M Y f