Morphological and anatomical variation of picea in southwestern British Columbia

Scagel, Robert Kevin
doi:10.14288/1.0096121
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Morphological and anatomical variation of picea in southwestern British Columbia Scagel, Robert Kevin 1984

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Title	Morphological and anatomical variation of picea in southwestern British Columbia
Creator	Scagel, Robert Kevin
Publisher	University of British Columbia
Date Issued	1984
Description	Relations between individual trees hypothesized to be representative of Picea enqelmannii and P. sitchensis and putative hybrids in southwestern British Columbia were examined using several morphological and anatomical variables measured on cones, needles, and twigs. 36 variables were selected that had an inter-individual variation that exceeded intra-individual variation. Such relative variation suggested that the variables selected were more genetically than developmentally variable. These variables were measured on 640 trees. Patterns of inter- and intra-individual variation of these variables were examined with multivariate analyses. Similar patterns of intra-individual variation with respect to position in the canopy were detected regardless of the age of the tree or the species, suggesting that intra-individual variation in Picea is not necessarily a function of the environment extrinsic to the individual. Further, the two hypothesized taxa were not especially different with respect to the pattern of intra-individual variation. In an inter-individual context, the intra-taxonomic variation was shown to be larger than inter-taxonomic variation. Inter-individual variation attributed to the hypothesized taxa was smaller than intra-population variation. Inter-taxonomic variation was only 25 percent larger than intra-individual variation. Further, the hypothesized taxonomic polarity of the data was not co-incident with the actual polarity of the data. What taxonomic structure emerged was evident only as the extremes of a continuum of variation over a large geographic area reflecting large environmental variation, suggesting that recognition of two taxa of Picea in southwestern British Columbia may not be appropriate or practically feasible. From the evidence available here, it is not possible to attribute the pattern of variation to hybridization followed by introgression or to the differentiation of a single, large polymorphic taxon. The pattern of inter-individual variation was only partially correlated with regional and local scales of geographic and environmental variation. Local patterns of variation were not co-incident in 16 separate geographic areas. The relation of the pattern of variation in nursery grown trees with respect to regional scales of geographic variation was not co-incident with the patterns of variation in naturally grown trees from the same area of origin. This variability of relations suggests that inter-individual variation is probably attributable to processes operating at an extremely local scale. Implications from these conclusions are presented and discussed with respect to the systematics of Picea and the utilization of Picea in forestry and tree improvement programmes.
Genre	Thesis/Dissertation
Type	Text
Language	eng
Date Available	2010-05-16
Provider	Vancouver : University of British Columbia Library
Rights	For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
DOI	10.14288/1.0096121
URI	http://hdl.handle.net/2429/24766
Degree	Master of Science - MSc
Program	Botany
Affiliation	Science, Faculty of Botany, Department of
Degree Grantor	University of British Columbia
Campus	UBCV
Scholarly Level	Graduate
AggregatedSourceRepository	DSpace
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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
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Morphological and anatomical variation of picea in southwestern British Columbia Scagel, Robert Kevin 1984

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