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Pollen analysis of a post glacial peat deposit in Vancovuer Kiss, Gyula Karoly 1961

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POLLEN ANALYSIS OF A POST GLACIAL PEAT DEPOSIT IN VANCOUVER  by  GYULA KAROLY KISS B.S.F.,  U n i v e r s i t y o f B r i t i s h Columbia, 1959  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in  the  Department of  B i o l o g y and 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  September, 1961  In p r e s e n t i n g t h i s  thesis i n p a r t i a l  o f the requirements f o r an advanced degree a t the o f B r i t i s h Columbia,  fulfilment University  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 reference  and s t u d y .  I f u r t h e r agree  that p e r m i s s i o n f o r e x t e n s i v e copying o f t h i s  thesis for  s c h o l a r l y purposes may be granted by the Head o f my D e p a r t ment or by h i s r e p r e s e n t a t i v e s . i n g or p u b l i c a t i o n o f t h i s  I t i s understood that  thesis for 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 .  Department of B i o l o g y and Botany The U n i v e r s i t y o f B r i t i s h Vancouver 8, Canada. Date September 8,  1961.  copy-  Columbia-  ii  ABSTRACT  The main purpose o f t h i s s t r u c t the Post G l a c i a l v e g e t a t i o n a l  study i s  to r e c o n -  and c l i m a t i c changes  i n d i c a t e d by the p o l l e n g r a i n s and spores preserved i n the Camosun peat bog.  U t i l i z i n g t h i s knowledge an a t -  tempt i s made to d e f i n e  the approximate age of the  earl-  i e s t m i c r o f o s s i l d e p o s i t s o f t h i s bog by comparison of the r e s u l t s w i t h those of Hansen (1947). A single bog.  sample core was taken from the Camosun  The core was d i v i d e d i n t o ten centimetre  specimens, nique.  channel  each o f which was macerated u s i n g a new t e c h -  The macerated m a t e r i a l , i n c l u d i n g the m i c r o f o s -  s i l s were mounted on s l i d e s ,  and percentage  were obtained f o r the m i c r o f o s s i l s  frequencies  i n each specimen.  The  frequency r e s u l t s were i n t e r p r e t e d and c o n c l u s i o n s drawn on the b a s i s of the k i n d and number of m i c r o f o s s i l s It i s  recovered.  concluded t h a t the primary f o r e s t  was  composed mainly of P i n u s , which changed l a t e r i n t o a f o r est  c h a r a c t e r i z e d by Pseudotsuga and Tsuga.  Thus the  cli-  mate appears to have changed from warm and dry to c o o l e r and more m o i s t .  The approximate age o f the f i r s t d e p o s i t s  is  d e f i n e d as r a n g i n g between f o u r and s i x thousand y e a r s . F i n a l l y v a r i o u s suggestions f o r f u t u r e work are presented,  i n c l u d i n g proposals f o r future studies i n  the same bog, and methods f o r the improvement of p a l y n o l o g i c a l techniques  i n general.  iii  TABLE 03? CONTENTS  Abstract  ii  Table o f contents L i s t o f t a b l e s and i l l u s t r a t i o n s  i i i iv  Acknowledgements  v  Introduction  1  Geography, geology and p r e s e n t f l o r a o f the peat bog (i) (ii) (iii)  Geography  4  Geology  5  Present f l o r a  6  Methods  15 Field collection  15  Storage  16  Laboratory methods  16  Results  22  Discussion  28  I n t e r p r e t a t i o n of r e s u l t s  28  Development o f the peat bog  28  S u c c e s s i o n o f the surrounding f o r e s t  52  C l i m a t i c changes  38  Age d e t e r m i n a t i o n  40  Suggestions f o r f u t u r e i n v e s t i g a t i o n s  43  Summary of c o n c l u s i o n s  47  Bibliography  49  iv  LIST OF TABLES AND ILLUSTRATIONS  Text f i g u r e  I: Map showing the peat bog  Table  I: Present f l o r a of the peat bog  Table  9  10  II: Present f l o r a o f the immediate v i c i n i t y of the peat bog  11  Plate I  52  Plate II  54  Chart I  55-56  V ACOOWLEDGEMENTS  At t h i s p l a c e I would l i k e to gratitude  to D r . Glenn Everet Rouse.  ready to g i v e me a h e l p f u l hand.  express my  He was always  H i s encouraging  tude helped me through a l l the d i f f i c u l t i e s p r e p a r a t i o n s f o r and the w r i t i n g o f t h i s My thanks a l s o go to Mr. 1. J.  Krajina,  Orloczi, and  D r . W. H . Mathews,  Mr. G . L . l e s k o ,  atti-  d u r i n g the  thesis. Magasi, D r . V .  D r . R. F . S c a g e l ,  Mr. L . V . H i l l s ,  Mr. L .  Mr. M. B e l l ,  to the r e s t of the people who h e l p e d me d u r i n g the  p r e p a r a t i o n of the present Finally,  text.  I am v e r y g r a t e f u l  to my w i f e ,  Janet E . K i s s , who r e r e a d and a l s o typed t h i s Her moral support was a l s o  invaluable.  thesis.  1  INTRODUCTION  Within the l a s t f i f t y years pollen analysis of p o s t - g l a c i a l peats has become a valuable part of palaeoecological interpretations.  I t has provided information  on climates, environmental changes, and sedimentation, and has become useful i n dating several p o s t - g l a c i a l horizons. Pollen analysis was introduced i n the second decade of t h i s century by Scandinavian workers(e.g. Lagerheim, von Post, etc.), and has become a rapidly growing f i e l d of science. Three names are associated with pollen analysis i n the P a c i f i c North West. the  Hansen (1941, 1947) was one of  e a r l i e s t workers to c o l l e c t useful data along the West  Coast.  Included i n h i s studies are analyses of a bog on  Lulu Island and another one i n New Westminster.  Terasmae  (1958) i s another student who has performed some palynol o g i c a l work on Vancouver Island.  He stresses the consid-  erable importance of pollen analysis i n geological investigations and has been using i t very successfully i n P l e i s tocene studies i n Eastern Canada.  Very recently a compre-  hensive picture of the late-Pleistocene environments of the  North P a c i f i c regions of North America has been con-  tributed by Heusser (i960), a former student of Hansen. He has collected peat samples throughout the West Coast of North America (Alaska, B r i t i s h Columbia,  Washington,  Oregon, and C a l i f o r n i a ) and has used the data obtained from  2  these samples to r e c o n s t r u c t the p o s t - g l a c i a l and v e g e t a t i o n a l  changes o f t h i s  climatic  region.  While these p i o n e e r workers have p r o v i d e d "basic evidence  on p o l l e n d i s t r i b u t i o n and past  climates,  much remains to he accomplished i n Western North America, p a r t i c u l a r l y i n the i n t e r i o r r e g i o n s o f B r i t i s h Previous i n v e s t i g a t o r s  Columbia.  have g i v e n v a l u a b l e i n f o r m a t i o n on  gross c l i m a t i c changes,  but have c o n t r i b u t e d l i t t l e  con-  c e r n i n g more l o c a l i z e d c l i m a t i c and environmental s u c c e s sions.  In a d d i t i o n , almost n o t h i n g has been  about l a n d - w a t e r r e l a t i o n s h i p s at d i f f e r e n t i n the p o s t - g l a c i a l  presented intervals  succession.  As a s m a l l b e g i n n i n g c o n t r i b u t i o n to the l a r g e r problem the present  i n v e s t i g a t i o n was i n i t i a t e d on a bog  i n Vancouver, B . C . , w i t h a t h r e e - f o l d o b j e c t i v e :  (i)  i n v e s t i g a t e the r e c o r d o f p l a n t s i n a l o c a l i z e d peat w i t h the a i d o f p o l l e n a n a l y s i s ;  (ii)  d e p o s i t i o n o f peat;  (iii)  deposit  to i n t e r p r e t from  the g e n e r a l c l i m a t i c changes that have o c c u r r e d s i n c e first  to  to i n v e s t i g a t e the  (i)  the  land-  water r e l a t i o n s a t v a r i o u s stages i n the development  of  the bog. In the p a s t ,  many b o t a n i s t s have not p a i d  much a t t e n t i o n to the mutual r e l a t i o n s h i p s of t r e e and herbaceous p l a n t s . early palaeobotanists  species  This n e g l e c t was probably why d i s r e g a r d e d the importance o f non-  a r b o r e a l p o l l e n g r a i n s and s p o r e s ,  and based t h e i r  p r e t a t i o n s almost completely on t r e e p o l l e n g r a i n s .  inter-  3  However, modern p a l y n o l o g i s t s that  are beginning to  realize  since the environment o f a g i v e n p l a c e i s  charac-  t e r i z e d by the a s s o c i a t i o n tree species alone,  of a l l plants,  and not by  a l l the p o l l e n g r a i n s must be taken  i n t o c o n s i d e r a t i o n i n order to o b t a i n comprehensive sults.  In the present  study,  a l l the spores and p o l l e n  g r a i n s have been c o n s i d e r e d i n the i n t e r p r e t a t i o n o f results,  re-  i n keeping w i t h the modern t r e n d .  4  GEOGRAPHY,  (i)  GEOLOGY AND PRESENT FLORA OF THE PEAT BOG  Geography: The  of  Camosun peat hog i s l o c a t e d i n the  city  Vancouver, B r i t i s h Columbia (123i°W, 4 9 i ° N ) on the  P o i n t Grey p e n i n s u l a , which p r o j e c t s westward and i s bounded by the F r a s e r R i v e r on the south and B u r r a r d I n let  on the n o r t h .  It  is  one o f the n o r t h e r n r e p r e s e n t a -  t i v e s o f the West C o a s t ' s peat d e p o s i t s , extent compared w i t h other bogs to the The  small i n  south.  present boundaries o f the bog cannot be  determined e x a c t l y , have been d i s t u r b e d . occupied by houses, the d r i e r p a r t s .  but i s  because the bog and i t s  entire v i c i n i t y  The south and east boundaries are and gardens are b e i n g c u l t i v a t e d on  A road and h i g h v o l t a g e  lines  cut through  the o r i g i n a l bog, and these d i s t u r b a n c e s r e s t r i c t the i n vestigator less,  i n d e f i n i n g the p r e c i s e l i m i t a t i o n s .  the p o s i t i o n o f the peat bog can be g i v e n by r e f e r -  ence to some g e o g r a p h i c a l b o u n d a r i e s : north;  Crown S t r e e t  the s o u t h ,  However, deposit.  and I m p e r i a l Road on the west.  map  The a r e a  approximately 0.25  The shape o f the bog i s  an elongated  about 800 yards and i t s  The o r i e n t a t i o n o f i t  enclosed  square m i l e s .  the edges o f t h i s a r e a are not w i t h i n the  length i s  yards.  16th Avenue on the  on the e a s t ; King Edward Boulevard on  between those f o u r roads i s  Its  Neverthe-  peat  ellipse.  width i s about 200  i s north-south.  A sketch  showing the l o c a t i o n o f the peat-bog i s presented on  5  p . 9 (Text f i g u r e  I).  The present that i t ment.  c o n d i t i o n o f the hog  indicates  i s "being g r a d u a l l y destroyed by man's  encroach-  The east and south ends are d r y i n g o u t .  has been used as a garbage dump. bog i s  f o r b i d d e n at p r e s e n t .  This area  The l a t t e r use o f  the  Some o f the d r i e r peat  has been taken away by the surrounding r e s i d e n t s f o r as a garden f e r t i l i z e r . bog i s  s t i l l active  bog  vegetation.  (ii)  Geology:  However, a l a r g e p a r t o f  and swampy, and i s  The whole area i s a t i o n , which i s i n t e r g l a c i a l .  c l a y or t i l l , but t h i c k e n s  the  occupied by t y p i c a l  p a r t o f the P o i n t Grey formJohnston (1923) d e f i n e d  uppermost l a y e r of t h i s f o r m a t i o n as f o l l o w s : p a r t of the s e c t i o n i s ,  use  i n most p l a c e s ,  the  "The upper  t y p i c a l boulder  which i s u s u a l l y only s i x to ten f e e t towards the i n n e r end of the  thick  peninsula."  T h i s boulder c l a y i s u n d e r l a i n by s t r a t i f i e d  deposits.  "The upper and g r e a t e r p a r t o f these d e p o s i t s c o n s i s t s o f sands and g r a v e l s and some s i l t . . . and without f o s s i l s ,  They are  and are probably g l a c i a l  unweathered outwash."  Armstrong (1956) mapped t h i s a r e a and d e s c r i b e d it  as  " . . . sandy to  up to s i x t y  silty  till  and minor s u b s t r a t i f i e d  f e e t t h i c k but g e n e r a l l y l e s s than twenty f e e t ,  o v e r l a i n i n most p l a c e s by g l a c i o - m a r i n e c l a y e y silty  clay,  drift  and sand, up to t w e n t y - f i v e  silt,  f e e t t h i c k but  6  g e n e r a l l y l e s s than ten  feet."  Thus i t may be concluded t h a t the o r i g i n a l deposition  of peat o c c u r r e d on s i l t y  as a post g l a c i a l marine d e p o s i t .  The sample taken from  the bottom l a y e r s o f the peat bog i s gray s i l t y  composed o f b l u i s h -  c l a y , w i t h v e r y p o o r l y preserved  and o r g a n i c fragments, clay i s  c l a y which o r i g i n a t e d  microfossils  and c o n t a i n s no c a r b o n a t e s .  This  i d e n t i c a l to c l a y from the Burnaby Lake peat bog  which has been found to. c o n t a i n marine  shells.  The h i g h e r surroundings are composed o f outwash o v e r l y i n g t i l l , sands and  with minor amounts o f  glacial  gravelly  sands. A c c o r d i n g to D r . W.H. Mathews (personal  munication,  June, 1961)  p o s i t s occurred i s  the c a v i t y i n which the peat  sheet o f the l a s t g l a c i a t i o n .  e n t a t i o n o f these p a r a l l e l grooves i s g e n e r a l l y  Present  de-  p a r t o f one o f the g l a c i a l grooves  produced by the i c e  (iii)  com-  The o r i -  north-south.  flora:  The present o f peat bog v e g e t a t i o n .  f l o r a o f the bog i s very t y p i c a l In undisturbed areas,  composed o f Pinus c o n t o r t a , representatives  the f l o r a  Tsuga h e t e r o p h y l l a and a few  o f Sorbus s i t c h e n s i s i n the t r e e  layer.  E r i c a c e o u s p l a n t s i n c l u d e Ledum, V a c c i n i u m , K a l m i a , and Gaultheria.  The herbaceous  p l a n t s i n c l u d e Rubus chamae-  morus, P t e r i d i u m a q u i l i n u m , Carex s p p . , g r a s s e s and b r y o phytes.  This vegetation,  however,  has been a l t e r e d  is  7  r a d i c a l l y i n some p l a c e s by the removal o f t r e e s and shrubs, p a r t i c u l a r l y where the h i g h v o l t a g e been b u i l t .  One l i n e  lines  have  extending from 16th Avenue to  south d i v i d e s the bog l e n g t h w i s e ,  approximately i n l i n e  w i t h the p r o j e c t i o n o f Camosun S t r e e t . m i s s i o n l i n e does not a f f e c t  the  The other  trans-  the bog v e r y much, as  it  c u t s a c r o s s the south end o f the Jbog ( p r o j e c t i o n o f King Edward Avenue), and c u t s o f f only a s m a l l p a r t of Since the t r e e s are m i s s i n g ,  it.  the c l e a r e d s t r i p s on the  peat bog dry out v e r y q u i c k l y , and the o r i g i n a l can r e t u r n o n l y very s l o w l y .  vegetation  The p l a n t s growing on these  s t r i p s are mainly Rubus chamaemorus, Ledum groenlandicum, Vaccinium o v a l i f o l i u m , Vaccinium oxycoccus, and b r y o p h y t e s .  At some p l a c e s ,  grows i n s u b s t a n t i a l  stands.  Juncus s p p . ,  Pteridium aquilinum  A complete l i s t  f l o r a i s g i v e n on page 10 (Table  of  the  I).  The f l o r a o f the immediate v i c i n i t y o f bog was a l s o s t u d i e d , presented  and the l i s t  on pages 11-14  (Table  of the p l a n t s  the  is  II).  Although the whole a r e a has been d i s t u r b e d by man, r e g e n e r a t i o n does not f o l l o w the same p a t t e r n i n a l l r e g i o n s of the bog. on the western, borders.  Trees are being  regenerated  southern, and on p a r t o f the n o r t h e r n  The e a s t e r n p a r t p l u s the remainder of  the  n o r t h e r n border i s r e g e n e r a t i n g only shrubs and herbaceous p l a n t s because o f permanent d i s t u r b a n c e s . are composed of Thuja p l i c a t a ,  The f o r e s t s  Tsuga h e t e r o p h y l l a ,  Pseudo-  8  tsuga m e n z i e s i i ,  A b i e s g r a n d i s , A c e r macrophyllum, A l n u s  r u b r a , . P r u n u s emarginata, and S a l i x spp.  Broad-leaved  t r e e s occur i n s u r p r i s i n g l y l a r g e numbers a l l around these young r e g e n e r a t i n g f o r e s t s .  The shrub l a y e r i s  composed  of the s e e d l i n g s o f the above mentioned t r e e s p l u s Rubus spp.,  Gaultheria shallon,  spp.  These shrubs and the herbaceous p l a n t s  Viola,  Pteridium, e t c . ,  tree l a y e r . is  Sambucus pubens,  and Vaccinium Lysichitum,  are not v e r y abundant under the  A p p a r e n t l y t h i s i s because the f o r e s t  q u i t e dense and the  canopy  shade does not a l l o w f o r optimum  growth o f the p l a n t s o f the lower l a y e r s . On the e a s t e r n and p a r t o f the n o r t h e r n s i d e s there are only a few i n d i v i d u a l t r e e s o f A l n u s , and S a l i x . of  The r e s t o f the v e g e t a t i o n  shrubs of Rubus, R i b e s ,  and herbaceous p l a n t s finding i s  (see  is  composed mainly  Sarothamnus, Sambucus, Table I I ) .  etc.,  An i n t e r e s t i n g  t h a t near the garbage dumps, some c u l t i v a t e d  p l a n t s can be found mixed i n w i t h the n a t i v e e.g.  Betula,  Quercus and A e s c u l u s .  plants,  These have been o b v i o u s l y  i n t r o d u c e d by l i t t e r o f parks and gardens.  9  TEXT-FIGURE  I.:  M a p showing  t h e peat b o g .  15 . 16 .17 _I8  University Endowment  Lands  19 _ 2 0 _2I  N  . 2 2 .23 24  O  .25 26  4  27  .29 .30  LEGEND Soale:  one inch equals I 0  i 23  i  i  approximately  IOOO feet  i I 500 yards  Avenues High voltage line City boundary  o  Approximate outlines ot peat bog. Sampling  10  TABLE I Present f l o r a o f the peat hog. Trees: Pinus c o n t o r t a Loud. Isuga h e t e r o p h y l l a  Sarg.  Sorbus s i t c h e n s i s M. Roem. Shrubs and herbaceous  plants:  Ericaceae; Gaultheria shallon Pursh. Kalmia p o l i f o l i a Wangenh. Ledum groenlandicum Oeder Vaccinium m y r t i l l o i d e s  Michx.  Yaccinium o v a l i f o l i u m Bong. Yaccinium oxycoccus v a r . intermedium Gray. Yaccinium p a r v i f o l i u m Smith Yaccinium u l i g i n o s u m L . Juncaceae; Juncus spp. L . Rosaceae; Rubus chamaemorus L . Perns; P t e r i d i u m a q u i l i n u m Kuhn Mosses: Bryum spp. C a l l i e r g o n e l l a schreberi Dicranum scoparium Hedw. Sphagnum spp.  ( B r y . E u r . ) Grout  11  TABLE I I Present f l o r a o f the immediate v i c i n i t y  o f the peat bog.  Trees: Abies grandis  Lindl.  A c e r macrophyllum P u r s h . A l n u s r u b r a Bong. Betula papiryi'era o c c i d e n t a l i s Picea sitchensis  (Bong.)  Prunus emarginata  Carr.  ( D o u g l . ) Walp.  Pseudotsuga m e n z i e s i i S a l i x hookeriana  (Hook.)  ( M i r b . ) Franco  Barratt  S a l i x l a s i a n d r a Benth.  (also  shrub)  Thuja p l i c a t a D. Don. Tsuga h e t e r o p h y l l a Shrubs and herbaceous  Sarg.  plants:  Amaranthaceae; Amaranthus  sp.  Araceae; L y s i c h i t o n camtschatensis ( L . ) Boraginaceae; Myosotis  sp.  Capriioliaceae; Sambucus  sp.  Caryophyllaceae; Saponaria o f f i c i n a l i s S t e l l a r i a media  L.  Cyrill  Schott  Sarg.  12  TABLE I I  (continued)  Compositae; A r t e m i s i a sp.  : Sonchus asper(L.)  Bidens t r i p a r t i t a L . C i r s i u m edule N u t t . Taraxacum o f f i c i n a l e  Webber  Convolvulaceae; Convolvulus  sp.  Cruciferae; Barbaraea sp. Capsella bursa-pastoris  Medic.  Cyperaceae; Carex spp. 2Scirpiialmigji<K;arpua Pre s l .  Ericaceae; Gaultheria shallon Pursh. Vaccinium spp. Geraniaceae; Erodium sp. Gramineae; Agrostis  sp.  Alopecurus p r a t e n s i s L . Bromus sp. D a c t y l i s glomerata L . Elymus s p . Holcus l a n a t u s L .  Hill  13  TABLE I I  (continued) 1.  Lolium perenne Poa annua L . Poa p r a t e n s i s  L.  Guttiierae; Hypericum perforatum L . Juncaceae; Juncus spp. Labiatae; Lamium s p . Mentha s p . Leguminosae; Medicago  sp.  Sarothamnus s c o p a r i u s Wimm. Trifolium  spp.  Onagraceae; Epilobium angustifolium L . Plantaginaceae; Plantago l a n c e o l a t a L . Plantago major L . Polygonaceae; Polygonum s p . Rumex a c e t o s e l l a L . Primulaceae; Anagallis  sp.  Ranunculaceae; - Ranunculus repens L .  14  TABLE I I  (continued)  Rosaceae; Rubus p a r v i f l o r u s  Nutt.  Rubus s p e c t a b i l i s PursJa. Spiraea douglasii  Hook.  Saxifragaceae; Ribes Perns and f e r n  spp.  allies:  Athyrium f i l i x Equisetum  femina  ( L . ) Roth.  spp.  P t e r i d i u m a q u i l i n u m Kuhn Mosses: Gamptothecium l u t e s c e n s (Huds.) Dicranum spp. Eurhynchium s p . Hypnum s p . Mnium spp. Polytrichum  sp.  Rhytidiadelphus  sp.  Bry. Eur.  15  METHODS  Field  collection: In c o l l e c t i n g the peat samples, i t was con-  sidered important to choose an appropriate time of year to avoid p o l l e n and spore contamination from the a i r . Late autumn seemed to be a very good time because no p l a n t s appeared to be producing p o l l e n or spores.  Ac-  c o r d i n g l y , the middle of November, 1959, was chosen f o r t a k i n g samples. The sampling s i t e was chosen to a f f o r d both ease of approach and supposedly good r e p r e s e n t a t i o n of the peat i n the bog.  A s a t i s f a c t o r y s i t e was found ap-  proximately 175 yards west-northwest of the corner of Crown Street and King Edward Avenue.  The s i t e i s un-  disturbed, and i s s u f f i c i e n t l y d i s t a n t from the road and the small i n t e r m i t t e n t stream to escape any major contamination. The sample was taken with the a i d of a peat borer.  This peat borer, made by Djos company of Sweden,  i s composed of a boring head, a sampler (50 centimetres l o n g ) , and a handle.  The length of the borer i s 150  centimetres and i t has three extensions, g i v i n g a t o t a l l e n g t h of 600 centimetres. Every 50 centimetre length i s marked on the extensions. In- u s i n g the borer, one has to bore down to the 50 centimetre mark.  The sampler i s then  opened by t u r n i n g the borer i n the opposite d i r e c t i o n .  16  This a c t i o n p e e l s o f f a s t r i p of peat from the edges o f the hore h o l e .  The b o r e r i s p u l l e d from the h o l e , and  the core i s removed, c a t a l o g u e d ,  and s t o r e d .  The same  procedure i s repeated at i n t e r v a l s o f 50 centimetres and the samples are kept i n c o n s e c u t i v e  order.  Twelve 50 centimetre cores were taken which r e p r e s e n t 600 centimetres  i n depth.  The i n d i v i d u a l  cores  were s t o r e d i n a wooden box and were separated from each o t h e r by means o f wood.  The tops and bottoms o f  the  samples were marked so they would not be c o n f u s e d .  The  box was then covered to a v o i d l a t e r c o n t a m i n a t i o n .  Storage; The c o l l e c t e d peat was not used f o r s e v e r a l months and was p l a c e d i n a dry room f o r s t o r a g e . storage,  the peat d r i e d and shrank from 600  to 400 centimetres  (2/3  of o r i g i n a l length).  During  centimetres This  s h r i n k i n g was c o n s i d e r e d when d i v i s i o n s of the core were made f o r m a c e r a t i o n .  Laboratory methods: The maceration o f the m a t e r i a l was c a r r i e d out d u r i n g the summer o f I960.  The l a b o r a t o r y techniques  s t a r t e d w i t h the d i v i s i o n o f the o r i g i n a l 50 centimetre cores i n t o specimens.  Since there were no s t r u c t u r a l  l a y e r s to f o l l o w i n d i v i d i n g the c o r e s , divided a r b i t r a r i l y .  they were  The l e n g t h s e l e c t e d  f o r the  indi-  17  victual specimens was chosen at 10 c e n t i m e t r e s . because the peat of men  shrank d u r i n g d r y i n g ,  However,  the f i n a l  each specimen was about 6.6 c e n t i m e t r e s .  length  Each s p e c i -  r e c e i v e d the core symbol K-j_ and a number showing  p l a c e i n the s u c c e s s i v e o r d e r ( e . g . second l a y e r ; e t c . ) .  K]_-l;  its  top l a y e r ; K i ~ 2 ,  F i n a l l y the specimens were cut  i n t o two h a l v e s v e r t i c a l l y , and one o f the h a l v e s  was  used f o r m a c e r a t i o n . The  maceration was i n i t i a t e d by b r e a k i n g the  peat i n t o approximately one m i l l i m e t r e p i e c e s . ken  peat was t r a n s f e r r e d to p l a s t i c b e a k e r s .  beakers were p l a c e d i n b o i l i n g water so t h e i r c o u l d be kept at a constant  The b r o These contents  temperature ( 2 1 2 ° F ) .  Usually  f o u r samples were macerated a t the same time, and a l l beakers were c a r e f u l l y l a b e l l e d to a v o i d mixing o f  the  spe-  cimens. The m a c e r a t i o n was performed by the combina t i o n o f two methods; the a c e t o l y s i s ,  and S c h u l z e ' s  s o l u t i o n methods. The  acetolysis  Erdtman (1943, p . 2 9 ) .  method was f i r s t d e s c r i b e d by  The macerating s o l u t i o n i s com-  posed o f concentrated s u l f u r i c a c i d (one u n i t ) and a c e t i c anhydride  (nine u n i t s ) .  Fifty  c c . of t h i s  s o l u t i o n are  a p p l i e d to each sample and the beakers are kept i n b o i l ing  water f o r t h i r t y m i n u t e s .  material i s  A f t e r t h i s treatment  the  c e n t r i f u g e d , washed i n water three times and  t r e a t e d w i t h a 5f° s o l u t i o n o f potassium h y d r o x i d e .  The  18  alkali ial.  i s a p p l i e d to d i s s o l v e Then the m a t e r i a l i s  three times i n hot water.  the o x i d i z e d o r g a n i c mater-  c e n t r i f u g e d a g a i n and washed After a f i n a l  centrifuging,  samples are mounted on microscope s l i d e s .  The s t a i n i n g  i s done with s a f r a n i n , and c o r n syrup i s used to the m a t e r i a l to the s l i d e s .  The r e s t  affix  of the samples  are  saved f o r r e f e r e n c e m a t e r i a l i n case repeated maceration becomes  necessary. A f t e r checking the prepared s l i d e s under the  microscope i t was found t h a t the s l i d e s c o n t a i n e d a l a r g e amount of o r g a n i c d e b r i s , and a great number o f the m i c r o f o s s i l s were s t i l l  covered w i t h o r g a n i c a t t r i t u s .  There-  fore another method had to be sought i n order to better r e s u l t s .  The method f i n a l l y s e l e c t e d was one em-  ploying Schulze's  solution  potassium c h l o r a t e )  (concentrated n i t r i c a c i d and  as the o x i d i z i n g agent.  dure has been used by former i n v e s t i g a t o r s coal, to  obtain  but to the a u t h o r ' s knowledge,  This proceto  macerate  has not been a p p l i e d  peat. In t h i s m o d i f i e d p r o c e s s ,  Schulze's  solution  was a p p l i e d to peat which had been p r e v i o u s l y macerated by the a c e t o l y s i s method. mixture o f f i v e  The S c h u l z e ' s  solution is  a  grams o f potassium c h l o r a t e and 50 c c .  o f concentrated n i t r i c a c i d made up to 100 c c . w i t h d i s t i l l e d water.  F i f t y cc. of Schulze's  a p p l i e d to the samples f o r two h o u r s . ment the m a t e r i a l v/as washed,  s o l u t i o n was After this  treat-  and potassium hydroxide  19  was a p p l i e d to d i s s o l v e A f t e r a f i n a l washing,  the o x i d i z e d o r g a n i c m a t e r i a l . the samples v/ere a g a i n c e n t r i f u g e d ,  and the m i c r o f o s s i l sediment was mounted on microscope slides.  The r e s u l t s were much b e t t e r than the  method a l o n e .  acetolysis  The c o n c e n t r a t i o n of m i c r o f o s s i l s  was  much h i g h e r and the s l i d e s were c l e a r e r . At a depth of 54-0 centimetres  siliceous  matter and c l a y appeared to be mixed w i t h the  peat.  Therefore the samples were t r e a t e d w i t h h y d r o f l u o r i c a c i d f o r about twelve hours to d i s s o l v e ter.  the m i n e r a l mat-  A f t e r the a c i d had been d i s c a r d e d , the sample was  washed s e v e r a l times w i t h water, c a t i o n of the a c e t o l y s i s  followed by the  appli-  and n i t r i c a c i d methods.  M i c r o f o s s i l s recovered from each macerated sample were mounted on three o r f o u r s l i d e s and the were l a b e l l e d .  slides  The l a b e l s r e c e i v e d the core symbol K]_,  the sequence number ( e . g . to mark the s l i d e .  1,  2, e t c . )  and a small  letter  The s l i d e s were then p l a c e d i n a  c a b i n e t to await i d e n t i f i c a t i o n and frequency  counts.  The next step o f the l a b o r a t o r y work was  the  i d e n t i f i c a t i o n and frequency counts o f the p o l l e n g r a i n s and s p o r e s .  I d e n t i f i c a t i o n r e q u i r e d p r e l i m i n a r y study  o f the p o l l e n g r a i n s o f the p r e s e n t l y growing s p e c i e s , and p o l l e n on modern r e f e r e n c e identifications  s l i d e s provided p o s i t i v e  f o r most g e n e r a .  In some cases i t  i m p o s s i b l e to i d e n t i f y the genus due to the of s e v e r a l genera.  was  similarities  These p o l l e n g r a i n s and spores  20  r e c e i v e d only t h e i r f a m i l y names ( e . g . osae,  etc.)  E r i c a c e a e , Legumin-  Species were seldom i d e n t i f i e d due to  resemblance o f s e v e r a l s p e c i e s . made as f o l l o w s : growing p l a n t s ;  (i) (ii)  were checked; ( i i i )  Identifications  a l i s t was made of the slides  close  were  presently  o f p o l l e n of extant general  notes on the morphology and a draw-  i n g o f the g e n e r a l appearance were made f o r each s p e c i e s of p o l l e n . A f t e r the p r e l i m i n a r y s t u d i e s were f i n i s h e d , a systematic  frequency count was made of each 10 c e n t i -  metre specimen.  Approximately two hundred m i c r o f o s s i l s  were counted and i d e n t i f i e d from each sample. were performed u s i n g the h i g h - d r y o b j e c t i v e  The counts  (x45),  t r a v e r s i n g the l e n g t h and breadth of each s l i d e . l e a s t two s l i d e s  and by At  o f each sample were used f o r each f r e -  quency count i n o r d e r to i n c r e a s e the p r o b a b i l i t y o f i n tercepting a l l species present.  In most c a s e s , however,  there were more than enough m i c r o f o s s i l s on one s l i d e  to  complete the 2 0 0 - g r a i n q u o t a . A r e p r e s e n t a t i v e p o l l e n g r a i n o r spore o f each s p e c i e s was photographed and the c o - o r d i n a t e s r e corded.  These were chosen as r e p r e s e n t a t i v e  future reference. Plate  types  for  These photographs are presented i n  I. I t was found t h a t 57 samples c o u l d be used  f o r frequency counts; the lowest three samples contained no i d e n t i f i a b l e m i c r o f o s s i l s .  21  Frequencies o f genera—or f a m i l i e s , cases—are  expressed as percentages,  p o l l e n diagram (Chartl(). i n centimetres percentages  i n some  and recorded on a  The o r d i n a t e g i v e s the depth  and the a b s c i s s a  expresses the  o f the v a r i o u s m i c r o f o s s i l s .  relative  Frequencies o f  some genera are not r e c o r d e d on t h i s diagram because they occur i n very low percentages list  (Ufa o r l e s s ) .  The  o f genera o c c u r r i n g i n low numbers i s presented on  the same pages as the p o l l e n diagram (Chart  I).  22  RESULTS  In p r e s e n t i n g the r e s u l t s i t  should be  emphasized t h a t t h i s study i s based upon one sample c o r e . Therefore n e i t h e r the r e s u l t s n o r the caji be used as r e p r e s e n t a t i v e  interpretations  f o r the whole bog u n t i l  some a d d i t i o n a l c o r e s are taken from v a r i o u s p a r t s of the peat bog.  I f the a n a l y s i s o f o t h e r cores should  g i v e s i m i l a r r e s u l t s the c o n c l u s i o n s c o u l d be expanded, and a f a i r l y complete p i c t u r e f o r the f l o r a l obtained.  Therefore the r e s u l t s and the  sequences  conclusions  g i v e n i n t h i s d i s s e r t a t i o n are v a l i d o n l y f o r t h a t  par-  t i c u l a r p a r t o f the peat bog which i s r e p r e s e n t e d by the core.  Nevertheless,  the v e g e t a t i o n o f the surrounding  f o r e s t s i s p r o b a b l y r e p r e s e n t e d as w e l l i n t h i s  spot  as  anywhere e l s e i n the bog. The r e s u l t s o f the a n a l y s i s show a c l e a r p i c t u r e o f the v a r i o u s occurrences a n d . f r e q u e n c i e s o f the d i f f e r e n t genera or f a m i l i e s  (Chart I ) .  The bottom  l a y e r o f the sample a t a depth o f 570 centimetres was composed mainly o f s i l t y c l a y , w i t h some peat mixed i n t o it.  T h i s l a y e r contained the f i r s t i d e n t i f i a b l e m i c r o -  fossils.  As the c h a r t shows, the most abundant s p e c i e s  i s P i n u s , f o l l o w e d by A l n u s , ages o f A b i e s and Quercus.  P i c e a , and s m a l l e r p e r c e n t Only one herbaceous p l a n t ,  Typha, appears i n n o t i c e a b l e p e r c e n t a g e . the complete absence o f Pseudotsuga,  Noteworthy  is  Isuga, E r i c a c e a e ,  23  and a l l but one of the herbaceous p l a n t s . At approximately the 540 centimetre l e v e l , L a r i x enters the spectrum, but never reaches a h i g h frequency; i t a l t e r n a t e l y disappears and reappears a t higher l e v e l s i n the core.  Nymphaeaceae, Juncaceae, and  Cyperaceae are also represented a t t h i s depth.  Tsuga  shows a low percentage but soon disappears again. Except f o r some minor changes, such as the l i m i t e d appearance o f Gramineae and Leguminosae, essent i a l l y the same p o l l e n occurs up to 480 centimetres. At the 480 centimetre l e v e l some r a d i c a l changes completely a l t e r the f l o r a l p i c t u r e .  The absence  of Pinus, P i c e a , and Abies i s s t r i k i n g l y obvious.  Twenty  centimetres higher, a t the 460 centimetre l e v e l Pinus and Picea reappear but i n much lower percentages, while the reappearance  of Abies does not occur u n t i l l a t e r a t  approximately 430 centimetres. At approximately the 470 centimetre l e v e l , Pseudotsuga and Tsuga appear f o r the f i r s t time.  Both  species are i n very low percentages a t the beginning (470 centimetres) but Pseudotsuga r a p i d l y increases (maximum a t 370 centimetres) u n t i l a t higher l e v e l s i t begins to decrease.  The most recent l e v e l s of the core  have y i e l d e d a very low percentage of Pseudotsugaj approximately 5$. Tsuga shows a d i f f e r e n t p i c t u r e , s t a r t i n g w i t h a low percentage and slowly i n c r e a s i n g , u n t i l a t the present time i t i s quite abundant, approx-  24  i m a t e l y 11%.  In b r i e f ,  been d e c r e a s i n g while  i t appears that Pseudotsuga  has  Tsuga has been i n c r e a s i n g i n f r e -  quency d u r i n g the l a t e s t p e r i o d s o f  deposition.  E r i c a c e a e f i r s t appear at the 480  centimetre  l e v e l and continue w i t h only one i n t e r r u p t i o n throughout the r e s t  o f the core It i s  sample.  significant  to note the v e r y h i g h p e r -  centage of nymphaeaceous p o l l e n at the 460 level.  This i s  centimetre  f o l l o w e d by a g r e a t r e d u c t i o n o f both  typhaceous and nymphaeaceous p o l l e n u n t i l the 260 timetre l e v e l  is  cen-  reached.  The l a s t r e c o r d of Quercus was o b t a i n e d at the 430 centimetre l e v e l .  At the same time  Pseudotsuga  was i n c r e a s i n g f a i r l y r a p i d l y , to become a co-dominant w i t h Alnus at the 410 centimetre l e v e l .  The same r e l a -  t i v e percentages e x i s t to about 270 c e n t i m e t r e s , o n l y minor changes;  e.g.  with  the sudden occurrence o f r e l a -  t i v e l y l a r g e amounts o f P t e r i d i u m and Sphagnum between the 380 and 350 centimetre  levels.  At h i g h e r l e v e l s i n the c o r e , change i s  the f i r s t major  the appearance o f a l a r g e amount o f Lycopodium  a t 270 c e n t i m e t r e s .  This i s  followed  large frequencies  o f Typha a t 260,  240 c e n t i m e t r e s .  Lycopodium i n c r e a s e s  centimetres)  s h o r t l y by f a i r l y  and Nymphaeaceae i n one l a y e r  c l o s e to 20%, but soon d i s a p p e a r s ;  l a y e r to c o n t a i n more than 1% i s  the  the 230 centimetre  at (240 last level.  At about t h i s l e v e l Pinus becomes more abundant at h i g h e r  25  l e v e l s i n the  core.  The next important change i s the complete and final is  disappearance o f Typha at 180 c e n t i m e t r e s .  This  f o l l o w e d by the disappearance o f Nymphaeaceae a t  centimetres.  130  In the same l a y e r , E r i c a c e a e begin to i n -  crease and from there up remain at a r e l a t i v e l y h i g h frequency i n c l u d i n g the most r e c e n t peat  specimen.  There are a few genera which must be d i s c u s s e d s e p a r a t e l y because they c o u l d not e a s i l y be f i t t e d the above d i s c u s s i o n . Betula,  into  These .'genera-, are A l n u s , A b i e s ,  Juncus-Carex group, Sphagnum, and A r t e m i s i a . Alnus i s i n r e l a t i v e l y v e r y h i g h  percentages  throughout the e n t i r e c o r e , and the changes from h i g h to low f r e q u e n c i e s are v e r y sudden. (570 to 520 c e n t i m e t r e s ) dant.  It increases,  In the bottom l a y e r s  Alnus i s not c o n s p i c u o u s l y abun-  however,  to 66$ a t 470  centimetres,  and decreases r a t h e r s t e a d i l y to a low o f 12$ at centimetres.  From t h e r e ,  i t r a p i d l y increases  370  again,  and reaches the h i g h e s t o f a l l the r e c o r d e d m i c r o f o s s i l percentages o f over 80$ a t 330 c e n t i m e t r e s .  This  is  f o l l o w e d by a g r a d u a l decrease to a minimum o f 15% at 220 to 230 c e n t i m e t r e s , centimetres,  another i n c r e a s e to 55$ at 180  and a f i n a l decrease toward the 20$ i n the  most r e c e n t l a y e r . A b i e s does not show any s i g n i f i c a n t i n the p r o f i l e . percentage,  It  trends  s t a r t s i n the bottom l a y e r i n a low  occurs i n low frequency from 480 to  430  26  centimetres,  and a g a i n from 250 to 150 c e n t i m e t r e s .  l a s t t r a c e of i t  The  can be noted a t 140 c e n t i m e t r e s .  h i g h e s t percentage  The  reached by A b i e s never exceeds 6fo,  B e t u l a i s r e p r e s e n t e d o n l y i n v e r y low p e r centages o f mostly l e s s than one p e r c e n t . l a y e r , however,  its  frequency i s c l o s e to  In the  last  2$.  The Juncus-Carex combination c o u l d not be separated because the p o l l e n g r a i n s o f Juncus s h r i v e l and crumple d u r i n g a c e t o l y s i s ,  and thus become  to d i s t i n g u i s h from those o f Carex. i n h a b i t the same g e n e r a l h a b i t a t s ,  difficult  Because both genera the i n a b i l i t y to  dis-  t i n g u i s h g r a i n s o f each does not d e t r a c t from u s i n g them for ecological centimetres  interpretations.  They f i r s t appear at  and, except f o r the i n t e r v a l between 470  420 c e n t i m e t r e s ,  they i n c r e a s e metres,  to  they appear c o n t i n u o u s l y throughout  sample at approximately 10$ f r e q u e n c y .  the  The o n l y time  c o n s p i c u o u s l y i s between 120 to 70  centi-  where t h e i r h i g h e s t frequency. exceeds 30$  approximately 100  540  (at  centimetres).  Sphagnum does not seem to be v e r y important in this  c o r e , and i t I s . p o s s l b l e r  not a Sphagnum-peat bog.  t h a t the Camosun bog  However,  Sphagnum i n some areas  produces sporangia v e r y i n f r e q u e n t l y , bogs (Dr. W.B. S c h o f i e l d , e i t h e r case,  it  is  even i n e x t e n s i v e  p e r s o n a l communication).  In  i s v v e r y apparent t h a t Sphagnum spores  are not found i n l a r g e amounts. they appear i n s i g n i f i c a n t  At only three p l a c e s do  amounts,  at 380 to 350  centi-  27  metres,  a s h o r t i n t e r v a l from 230 to 220  centimetres,  and a t 20 centimetres w i t h a very h i g h frequency o f over 20$. A r t e m i s i a o c c u r s s p o r a d i c a l l y only i n lower l e v e l s and at low f r e q u e n c i e s , 440 centimetres where i t five  except f o r one l e v e l  at  reaches a v a l u e o f approximately  percent. During the frequency count i t was n o t i c e d  that coal.  some o f the specimens contained fragments o f c h a r These specimens were at l e v e l s 190,  200 and 290  centimetres. Another noteworthy d i s c o v e r y was the appearance o f l a r g e amounts of f i n e centimetres.  sand i n specimens from 240 to  During m a c e r a t i o n , the sand s e t t l e d  bottom o f the c e n t r i f u g e  to  270  the  tubes before c e n t r i f u g i n g , and  hence was easy to remove. F i n a l l y the occurrence o f diatom s h e l l s should be mentioned.  Diatom s h e l l s d i d not occur i n the bottom  l a y e r s up to 540 c e n t i m e t r e s ,  probably because  the  spe-  cimens had been macerated w i t h h y d r o f l u o r i c a c i d which would d i s s o l v e  these s h e l l s .  to 130 centimetres  contained many diatom s h e l l s .  13Q centimetre l e v e l , a g a i n reappeared.  However, specimens from 540 At the  diatom s h e l l s disappeared and never  28  DISCUSSION  I n t e r p r e t a t i o n of  results:  From the r e s u l t s bog i t  i s possible  the development its  o f the a n a l y s i s o f the peat  to make s e v e r a l  suggestions concerning  of the bog, the v e g e t a t i o n a l  changes of  s u r r o u n d i n g s , and the approximate time o f the  occurrence o f  first  microfossils.  Development o f the peat bog: C o n s i d e r i n g the p o l l e n data o f the peat it  sample,  i s very l i k e l y that the peat bog has developed from a  lake.  Many f a c t s seem to support t h i s The f i r s t  possibility.  and v e r y i n t e r e s t i n g  a t t e n t i v e study of the p o l l e n p r o f i l e s  i m p r e s s i o n on  (Chart I) i s  l a c k o f p o l l e n g r a i n s o f herbaceous p l a n t s i n the p a r t of the p r o f i l e . — i n small amounts—is  i n g i n the  early  The only herbaceous genus o c c u r r i n g Typha.  the f a c t t h a t the l a k e i t s e l f vegetation  The e x p l a n a t i o n o f t h i s  is  p r o b a b l y d i d not have any  except f o r a few i n d i v i d u a l s o f Typha growshallows. C o n s i d e r i n g Soo's (1953) c l a s s i f i c a t i o n  lakes,  the  t h i s l a k e c o u l d have been i n the e u t r o p h i c  T h i s stage i s  of  stage.  c h a r a c t e r i z e d by the ample p o p u l a t i o n s  a l g a e and p l a n k t o n due to r i c h n e s s i n n u t r i e n t s . water o f such l a k e s i s u s u a l l y t u r b i d , neutral or s l i g h t l y basic.  greenish,  of  The and  When the depth o f the v/ater  29  becomes s u f f i c i e n t a l a r g e number of water-plants the l a k e .  inhabit  These p l a n t s are u s u a l l y c e r t a i n members of  Typhaceae followed by Nymphaeaceae, Haloragidaceae, Najadaceae and some of the Cyperaceae (Carex). A l l these h y p o t h e t i c a l requirements are s a t i s f i e d i n the Camosun bog, as shown by the chart and r e s u l t s which were discussed p r e v i o u s l y .  the  The presence  of l a r g e amounts of diatom s h e l l s (page 27) suggests that there was a prosperous population of plankton. ding to Dr. R.F.  Scagel  Accor-  (personal communication,  1961)  the presence of diatoms i n d i c a t e s n e u t r a l or s l i g h t l y basic chemical c o n d i t i o n s and also the presence of l i g h t . This type of environment i s a l s o very favourable f o r water-plants. The lake hypothesis  i s f u r t h e r supported  by the appearance of representatives of Nymphaeaceae a nd by the expansion of Typha at 530 centimetres.  The  f i l l i n g up of the lake appears to have proceeded r a p i d l y w i t h the a i d of organic m a t e r i a l from such p l a n t s . Typha g r a d u a l l y disappears and f o r a p e r i o d , members of Nymphaeaceae dominate, but the s i t u a t i o n suddenly changes at the 440 centimetre l e v e l . p l a n t s completely two t h i n g s :  At t h i s l e v e l the water-  disappeared, which could mean one  of  one i s that the l a k e became a peat bog,  w i t h an accompanying change from water to t e r r e s t r i a l plants.  This i s most l i k e l y a wrong conclusion, as the  samples are s t i l l f u l l of remains of diatom s h e l l s .  30  Also,  the i n c r e a s e i n the percentage o f t e r r e s t r i a l bog  p l a n t s i s not e x t e n s i v e ,  and hence does not support t h i s  conclusion. The o t h e r , and more p l a u s i b l e , e x p l a n a t i o n i s that f o r some reason the water l e v e l o f the l a k e rose c o n s i d e r a b l y , which prevented the w a t e r - p l a n t s from c o n tinuing t h e i r existence.  T h i s r i s i n g o f the water l e v e l  could have been caused by a change i n the course o f a stream.  Such a s h i f t o f stream course would have sup-  p l i e d the l a k e w i t h a d d i t i o n a l water.  Another p o s s i b i l i t y  i s t h a t a stream which had served f o r c a r r y i n g away the excess water o f the l a k e was blocked by some o b s t a c l e . The t h i r d p o s s i b i l i t y i s a combination o f the two, which c o u l d cause an enormous change i n the water l e v e l o f  the  lake. This second deep-water c o n d i t i o n o f the l a k e probably e x i s t e d f o r q u i t e a l o n g t i m e , as the suggest.  results  A few i n d i v i d u a l s o f Typha were s t i l l growing  i n the shallows but otherwise the l a k e was without vegetation. This c o n d i t i o n changed q u i t e r a p i d l y at a p p r o x i m a t e l y 270 c e n t i m e t r e s .  The sediments o f sand  r e p o r t e d on page 27) hastened the f i l l i n g  (as  of the l a k e .  The presence o f a l a r g e number o f Lycopodium spores can probably be e x p l a i n e d by t h i s  same phenomenon.  p o s s i b l e that a stream, p r e v i o u s l y n o n - e x i s t e n t ,  It  is  started  f e e d i n g the l a k e c a r r y i n g sand and o r g a n i c m a t e r i a l i n t o  31  it.  T h i s stream c o u l d have been the t r a n s p o r t i n g agent  f o r the lycopodium s p o r e s . on the banks o f the  These p l a n t s probably grew  stream.  At any r a t e the depth o f the l a k e became sufficient  f o r w a t e r - p l a n t s a g a i n at approximately the  260 centimetre l e v e l , i n h a b i t e d i t s waters  and Typha f o l l o w e d by Wymphaeaceae again.  The f i l l i n g thereafter.  o f the l a k e proceeded r a p i d l y  The l a k e remained as a l a k e f o r a p e r i o d  o f t i m e , and a p p a r e n t l y became swampy at about 130  cent-  imetres as evidenced by the prevalence of J u n c u s - C a r e x . Ericaceae also land  s t a r t e d to take over the newly  exposed  surface. T h i s stage of l a k e s ,  peat bogs,  is  j u s t before they become  c a l l e d the d y s t r o p h i c stage (Soo,  1953).  Such l a k e s are u s u a l l y developed from e u t r o p h i c l a k e s by the accumulation o f o r g a n i c a c i d s . accumulation,  this  the water becomes poor i n c a l c i u m and o t h e r  mineral n u t r i e n t s , humus, i s  As a, r e s u l t o f  c o n t a i n s a l a r g e amount of c o l l o i d a l  brown, and a c i d i c .  Por these reasons,  p l a n k t o n p o p u l a t i o n and the algae of d y s t r o p h i c are l i m i t e d i n number.  the lakes  The l a k e s r a p i d l y t u r n i n t o  and soon t h e r e a f t e r become peat  bogs.  T h i s theory can very w e l l be a p p l i e d to Camosun peat bog.  swamps  At approximately 130  the  centimetres,  Nymphaeaceae completely d i s a p p e a r s from the p r o f i l e and the amount of p o l l e n g r a i n s of E r i c a c e a e and the Juncus-  32  Carex grcmp i n c r e a s e s .  The s h e l l s  o f diatoms are completely  l a c k i n g from about t h i s same l e v e l , which i s a l s o an i n d i c a t i o n o f the change of the l a k e .  Naturally,  the  trees  Pinus and Tsuga d i d not i n h a b i t the bog u n t i l l a t e r when the swampy c o n d i t i o n s became l e s s wet and more a p p r o p r i a t e f o r these t r e e s . crease  There i s ,  however,  a very i m p r e s s i v e i n -  i n the p o l l e n g r a i n s o f these t r e e s l a t e r , which  suggests t h e i r presence on the bog. s u p p o s i t i o n cannot be proved; i t the b a s i s of present c o n d i t i o n s .  Unfortunately t h i s  can only be suggested on At the present  time,  Tsuga and E r i c a c e a e occur i n other than the peat e n v i r o n ment, but a l a r g e number o f them grow a l s o on the bog.  Therefore i t  peat  i s p o s s i b l e t h a t the i n c r e a s e o f Tsuga  and E r i c a c e a e p o l l e n was due to t h e i r i n v a s i o n o f the bog.  peat  On the o t h e r hand, Pinus c o n t o r t a p r e s e n t l y grows  only on peat i n t h i s a r e a .  It i s quite l i k e l y ,  therefore,  that the i n c r e a s e o f Pinus p o l l e n percentage o c c u r r e d when t h i s t r e e s p e c i e s had begun to occupy the peat bog. In b r i e f ,  the p l a n t m i c r o f o s s i l s and other  combined f a c t o r s i n d i c a t e t h a t the peat bog developed from a l a k e through a n a t u r a l  succession.  S u c c e s s i o n o f the surrounding f o r e s t : The s u c c e s s i o n  of the f o r e s t  i n this region,  a c c o r d i n g to the r e s u l t s o f t h i s i n v e s t i g a t i o n , with an abundance o f P i n u s .  I t appears that the  began forest  around the l a k e was composed of Pinus w i t h some P i c e a and  33  Abies intermixed.  While Pinus c o n t o r t a i s  of Pinus growing on the bog today, that  the f o s s i l ,  is  extremely  e n t i a t e the v a r i o u s s p e c i e s .  ing,  i s quite  found i n the e a r l y h o r i z o n s ,  some o t h e r s p e c i e s as i t  indicate,  it  the only  difficult  Of c o u r s e ,  as the  possible represents to  there were q u i t e a few i n d i v i d u a l s o f Alnus grow-  position,  Because  Alnus p r o b a b l y d i d not have to be very  numerous to g i v e a h i g h percentage drier,  differ-  resitlts  probably mostly on the shores o f the l a k e .  of i t s  species  of pollen g r a i n s .  The  more exposed s i t e s probably bore some Quercus s p e c i e s .  Alternatively,  Quercus p o l l e n could have come from Van-  couver I s l a n d , which was probably d r i e r and warmer, and hence more s u i t a b l e  f o r Quercus.  was e n t i r e l y d i f f e r e n t  At any r a t e the  from the present  forest  f o r e s t s of  this  area. The v e g e t a t i o n under the f o r e s t p o s s i b l y r i c h e r than i s  t r e e s was  i n d i c a t e d by the p o l l e n r e c o r d .  However, the p o l l e n p r o d u c t i o n of u n d e r s t o r y p l a n t s  was  unable to compete with the r e l a t i v e l y h i g h p r o d u c t i o n o f coniferous  trees,  s i n c e the former are  insect-pollinated,  i n most c a s e s , and hence would stand l e s s chance o f represented plants  as w e l l .  The other f a c t o r r e s t r i c t i n g  from r e p r e s e n t a t i o n  being these  i n the bog was probably the  l a c k of wind under the f o r e s t  trees.  Without wind there  would be no major t r a n s p o r t i n g agent f o r the p o l l e n g r a i n s . These c o n d i t i o n s were r a d i c a l l y changed by some k i n d o f c a t a s t r o p h e .  For 20 c e n t i m e t r e s (480  to  34  460 centimetres)  a l l the c o n i f e r o u s  tree p o l l e n grains  are m i s s i n g from the p o l l e n p r o f i l e , with only Alnus and Quercus r e p r e s e n t i n g the t r e e s p e c i e s . p l a n a t i o n f o r t h i s phenomenon i s t r o y e d the former f o r e s t ceased to e x i s t .  A possible  t h a t a huge f i r e  and the sources of p o l l e n g r a i n s  especially  a b l e to produce flowers ten y e a r s or l e s s .  around l a k e s .  This t r e e  is  and hence p o l l e n g r a i n s w i t h i n  Hence i t  i s understandable that  o f the p o l l e n g r a i n s would be those of Alnus soon  after  des-  I t i s known t h a t Alnus regenerates v e r y  soon a f t e r a f i r e ,  the f i r e .  ex-  most  after  The continuous occurrence o f Quercus p o l l e n  the f i r e can a l s o be e x p l a i n e d i f i t  i s assumed  that  oak t r e e s were growing i n areas separated from c o n i f e r o u s t r e e s i n i s o l a t e d groups before the f i r e .  Also,  the  fire  resistance  of Quercus i s much g r e a t e r than t h a t o f most  conifers.  I f the p o l l e n of Quercus came from Vancouver  I s l a n d then the e x p l a n a t i o n i s o b v i o u s :  the f i r e would  not expand t h a t f a r and the source of p o l l e n g r a i n s would remain.  This l a t t e r case c o u l d only be t r u e i f there were  no c o n i f e r s present conifers,  on Vancouver I s l a n d .  I f there were  t h e i r p o l l e n would have come over here along  w i t h Quercus. A f t e r the f i r e a n a t u r a l r e g e n e r a t i o n would r e p l a c e the burnt c o n i f e r o u s  forest.  F o l l o w i n g the  re-  g e n e r a t i o n there would s t i l l be a l o n g time u n t i l the new coniferous In t h i s  t r e e s c o u l d s t a r t to produce p o l l e n g r a i n s .  i n t e r v a l , Alnus would be producing r e l a t i v e l y  35  l a r g e numbers o f g r a i n s , w h i c h w o u l d a c c o u n t f o r t h e frequencies  o f A l n u s p o l l e n f o l l o w i n g the The  est  record  changed a f t e r  the  t r e e s , e.g.  Pinus  nant  species, of the  e.g.  and  the  d i d not  composition and  Tsuga.  This  species probably  changes  one  (page 3 8 ) .  t h i n g to add:  change s u d d e n l y .  the  Por  change b e c a u s e t h e  Pinus  species erate  C o l u m b i a , page 5 5 8 ) .  1 1  It  as  i t occurred  centimetres), indicating  necessary  gradually.  gradual  This  latter  f o l l o w i n g the  probably  but  that  and  not  s p e c i e s had  Pinus  dominant.  shade  (480  a climax to  Picea also regenerated  climax  a s s o c i a t i o n with Pseudotsuga  fire  to  tree,  Pseudotsuga. later  i n much s m a l l e r numbers t h a n  the  regen-  fire.  f o l l o w i n g the  T s u g a was  to  British  freedom from  i n s m a l l numbers r e l a t i v e  Pinus  with  probably  f o r e s t s would  ( F o r e s t r y Handbook f o r  appears that  centimetres),  ginal  present  this  of Pseudotsuga.  The  would have been r e a l i z e d  470  the  " . . . r e q u i r e s f r e e d o m f r o m shade i n o r d e r  successfully....  This  connection  changed  reflect  new  changes.  environment  However, t h e v e g e t a t i o n w o u l d n o t  regeneration  by  domi-  indicates  in  I t more l i k e l y  still-existing  for-  replacement  environment, mostly c l i m a t i c  climatic  s u p p r e s s the  o f the  the p r e v i o u s l y  i s d i s c u s s e d more t h o r o u g h l y  i s only  fire.  P i c e a were r e p l a c e d  p r e v i o u s l y dominant  possibility  there  catastrophe  P s e u d o t s u g a and  changes i n the  with  shows t h e  high  (460  before,  changed; the  ori-  d o m i n a n t became a n a s s o c i a t i o n ,  36  The environmental c o n d i t i o n s were probably good f o r t h i s new composition of f o r e s t time,  f o r quite a long  f o r the c h a r t shows only minor changes u n t i l  recently.  These minor changes i n the percentages  have been caused by v a r i o u s f a c t o r s , destroyed the f o r e s t  such a s :  quite could  f i r e s which  i n p a r t o r i n whole; m a t u r a t i o n and  r e g e n e r a t i o n o f some o f the t r e e  s p e c i e s ; and the  invasion  o f some o f the herbaceous s p e c i e s i n t o the v i c i n i t y o f the sample, a t times i n overwhelming q u a n t i t i e s . ever the causes,  What-  the r e l a t i v e percentage o f the p o l l e n  g r a i n s o f the f o r e s t  t r e e s changed only r e c e n t l y ,  p r o x i m a t e l y the l e v e l o f 30 c e n t i m e t r e s .  At t h i s  at aplevel,  Pseudotsuga decreases to a v e r y low percentage o f a p p r o x i m a t e l y 5fo.  Even the present v e g e t a t i o n a l  i n d i c a t e s a very low percentage, o f Pseudotsuga, h i g h e r number o f A l n u s ,  Thuja and Tsuga.  structure and much  Unfortunately,  the p o l l e n g r a i n s o f Thuja do not p r e s e r v e i n most Other i n v e s t i g a t o r s have a l s o found the l a c k of p o l l e n v e r y c h a r a c t e r i s t i c i n peat d e p o s i t s 1940).  cases.  Thuja  (Hansen,  T h i s problem w i l l be d i s c u s s d l a t e r i n connection e  w i t h f u t u r e work s u g g e s t i o n s . The e x p l a n a t i o n o f .the decrease o f Pseudotsuga can be g i v e n as man's s e l e c t i v e  encroachment.  Pseudotsuga was probably growing r e l a t i v e l y w e l l , o f the l a r g e o l d t r e e s i n d i c a t e . timber,  as some  Man, i n need o f nearby  cut the l a r g e r ones, l e a v i n g the l e s s v a l u a b l e  and s m a l l e r t r e e s i n p l a c e .  37  Another p o s s i b l e n a t u r a l cause.  e x p l a n a t i o n i s l i n k e d to a  A c c o r d i n g to t h i s  explanation,  the  has been t r e n d i n g towards c o o l e r and more moist  climate  conditions.  T h i s would probably cause a change from the present C o a s t a l Douglas f i r a s s o c i a t i o n to the C o a s t a l V/estern hemlock association.  This i s ,  of course,  only t h e o r e t i c a l at  present and more p r o o f would be necessary conclusions.  the  to draw f i n a l  The i n c r e a s e o f Tsuga c o u l d have been caused  p u r e l y by l o c a l i n v a s i o n of t h i s  s p e c i e s i n t o the peat bog,  r a t h e r than by a major change i n the f o r e s t  associations.  The r e l a t i v e l y h i g h frequency of P i c e a c o u l d be e x p l a i n e d by the f a c t t h a t i t s and hence i t  p o l l e n i s q u i t e buoyant,  can t r a v e l f a r t h e r d i s t a n c e s  species.  It i s also possible  tivity is  quite high.  than some other  that Picea p o l l e n produc-  At p r e s e n t ,  P i c e a appears very  s p a r s e l y i n the P o i n t Grey a r e a , and probably was not important at any time i n the s u c c e s s i o n  of the  vegetation.  The other t r e e s p e c i e s are not very common i n the c o r e , and o c c u r r e d only i n s m a l l e r The problem o f the f o r e s t summarized as f o l l o w s : content  frequencies.  succession  the e a r l y d e p o s i t s had a p o l l e n  i n d i c a t i n g an abundance o f P i n u s .  This changed  i n t o another a s s o c i a t i o n i n which Pseudotsuga was dominant s p e c i e s . times,  the  The p o s s i b i l i t y i s t h a t i n present  this association is  i n which Tsuga w i l l  can be  changing a g a i n i n t o a new one  be a co-dominant s p e c i e s w i t h T h u j a .  38  Climatic  t  changes: The suggestions o f c l i m a t i c changes are a l s o  based on the r e s u l t s because the whole s u b j e c t i s upon the v e g e t a t i o n a l  changes.  built  Ecological studies  suggest  t h a t one o f the most important environmental f a c t o r s the climate-.  I f the c l i m a t e changes the  usually reflects  is  vegetation  t h i s change, p r o v i d e d the change i s on  a more o r l e s s permanent b a s i s has time to take p l a c e .  so that the  Of c o u r s e ,  succession  the same c l i m a t e does  not alv/ays develop the same v e g e t a t i o n because o f e f f e c t o f other f a c t o r s .  Nevertheless,  the  one can draw  reasonable c o n c l u s i o n s concerning the c l i m a t e from the vegetation. As the r e s u l t s i n d i c a t e the f i r s t  forest  was composed o f Pinus with some P i c e a and A b i e s . probably grew on the more exposed,  Quercus  d r i e r and warmer s i t e s .  The ericaceous p l a n t s were p r o b a b l y completely l a c k i n g at t h i s t i m e .  The v e g e t a t i o n as a whole i n d i c a t e s a  warmer, d r i e r p e r i o d than at p r e s e n t .  But i t  is  possible  that t h i s c l i m a t e was a l r e a d y changing i n t o a more m o i s t , cooler.one  soon a f t e r the f i r s t m i c r o f o s s i l  T h i s suggestion i s  deposits.  supported by the f a c t that the  forest  d e v e l o p i n g a f t e r the f i r e was composed o f new s p e c i e s which found the d i f f e r e n t c o n d i t i o n s more s u i t a b l e themselves  than they were f o r the p r e v i o u s  for  trees.  T h i s changed c l i m a t e was probably c o o l e r and wetter than the p r e c e d i n g one,  f o r the new s p e c i e s were  39  Pseudotsuga and Tsuga.  Both, o f these genera r e q u i r e  r e l a t i v e l y h i g h e r amounts of p r e c i p i t a t i o n and can stand c o o l e r c o n d i t i o n s than Pinus and P i c e a . v e r y common as the r e s u l t s q u i r e s moist  show; t h i s  Alnus was a l s o  species also  re-  soil. Another s i g n of the c o o l e r c l i m a t e a f t e r  fire  the  i s the disappearance of the p o l l e n g r a i n s of Quercus  from the p r o f i l e .  These t r e e s probably were not destroyed  a t the same time by the f i r e but were destroyed l a t e r , p o s s i b l y e i t h e r by another f i r e or by n a t u r a l d e a t h . Because o f unfavourable c o n d i t i o n s they c o u l d not r e g e n erate.  One of these unfavourable c o n d i t i o n s was the  climate,  and the o t h e r was the f a c t t h a t the  cooler  conditions  were more s u i t e d to new s p e c i e s which h i n d e r e d the  regen-  e r a t i o n o f Quercus. The c l i m a t e d i d not change much f o l l o w i n g the advent of the c o o l e r and w e t t e r p e r i o d a f t e r the except t h a t i t  fire,  probably was becoming p r o g r e s s i v e l y  and more moist as time passed.  At present i t  cooler  seems to be  even wetter and c o o l e r than f o l l o w i n g the f i r e and the appearance o f Pseudotsuga and Tsuga.  This hypothesis  based on the f a c t that pseudotsuga seems to be l o s i n g importance to Tsuga and probably a l s o to T h u j a . tunately,  is its  Unfor-  the p o l l e n g r a i n s of the l a t t e r cannot be found  i n peat; t h i s  suggestion,  therefore,  can o n l y be supported  by the present a s s o c i a t i o n of the two s p e c i e s .  Nowadays  Thuja i s abundant i n the c l o s e v i c i n i t y o f the peat bog.  40  Pseudotsuga appears to be g i v i n g way to Tsuga and Thuja.  This may be e i t h e r n a t u r a l occurrence  or caused s o l e l y by man's encroachment.  In the former  case, the statement may stand that the climate has gradu a l l y been grov/ing c o o l e r and wetter since a t l e a s t the f i r s t appearance of Pseudotsuga and Tsuga. In summary, there was probably only one major change i n climate since the f i r s t p o l l e n deposits, v i z . from a warmer and d r i e r climate i n d i c a t e d by Pinus to a c o o l e r and more moist climate c h a r a c t e r i z e d by Pseudotsuga and Tsuga.  This change was i n progress a t  the time of the deposits of the f i r s t specimens or s h o r t l y t h e r e a f t e r . There i s a l s o a suggestion that t h i s climate i s a t the present becoming s t i l l c o o l e r and wetter.  This i s suggested by the decrease o f Pseudo-  tsuga and increase o f Tsuga and probably also Thuja.  Age  determination: The age determination of the bottom l a y e r s  of the sample creates a problem.  The e a s i e s t and most  dependable determination would be the carbon-dating method but t h i s i s a very c o s t l y process.  Therefore a  comparative method had to be used to achieve a reasonable conclusion regarding the age o f the f i r s t d e p o s i t s . The comparison was made with Hansen's (1947) results.  According to h i s conclusions there were three  c l i m a t i c periods i n the P a c i f i c Northwest i n p o s t - g l a c i a l  41  time.  The f i r s t p e r i o d , which showed a tendency  i n c r e a s i n g warmth and dryness began i n time,  about f i f t e e n  towards  late-glacial  thousand years ago,  reaching  its  maximum approximately eight thousand y e a r s ago. second p e r i o d , more p e r t i n e n t to t h i s  The  study, was a stage  o i maximum warmth and dryness f o r about f o u r thousand years  ( e i g h t to f o u r thousand years a g o ) .  period,  The next  from f o u r thousand y e a r s to the p r e s e n t ,  a tendency to a c o o l e r and more moist  shows  climate.  As was shown p r e v i o u s l y (page 38) the o f the samples i n d i c a t e s  a warm and dry c l i m a t e .  i t was a l s o shown t h a t t h i s soon,  climate started,  first But  probably  to change i n t o one t h a t was c o o l e r and w e t t e r .  This f i n d i n g l i m i t s the time of the f i r s t  microfossil  d e p o s i t s to w i t h i n e i g h t to f o u r thousand years  ago.  But Hansen a l s o found a w e l l d e f i n e d l a y e r of v o l c a n i c ash i n most of h i s  samples from the West Coast which  was d e p o s i t e d approximately s i x thousand years  ago.  This l a y e r v/as searched f o r but lias not been found i n the sample taken by the w r i t e r ,  i n s p i t e of the  that h i s a t t e n t i o n was c a l l e d to i t s rence.  Therefore i t  possible  can be s t a t e d s a f e l y  deposited  not be t r a c e d .  This  identified microfossils  l e s s than s i x thousand years ago.  dep ths contained s i l t y  occur-  that the v o l -  canic ash l a y e r was m i s s i n g from the c o r e . suggests that the f i r s t  fact  fact were  The lower  c l a y i n which an ash l a y e r c o u l d  42  This layers  o f the  sand y e a r s . can  conclusion  core This  s e t s the  age  o f the  sample b e t w e e n s i x and seems t o be  give without using  the  the  four  bottom thou-  closest limitation  r e s u l t s of the  one  carbon-dating  method. If vicinity  the  vegetation  o f t h i s p e a t bog  as  was  the  i n the  same i n  vicinities  bogs s t u d i e d by  Hansen  Lulu  comparison would probably  I s l a n d the  easier,  discussed  Camosun b o g .  t o r s i n f l u e n c i n g the large On  changes can  the  other  hand the  factor i s that  climatic in his  Pacific  only  be  The  b a s e d on  Northwest The  present  the  For  age  of the  f o r the  sample  Another the  these  same cen-  differ-  the  given  on  deduced  by  Hansen  interpretation, therefore, results for  the  1947). first  deposits  a b l y younger than s i x thousand but sand y e a r s  distances.  b a s e d on  more g e n e r a l i z e d  (Hansen,  that  I s l a n d : 500  i n t e r p r e t a t i o n s , w h i c h were n o t  t o be  so many f a c -  s a m p l e s were  Lulu  centimetres).  comparison could  studies.  presently  b o g s were n o t  centimetres;  and  vegetation  even i n such s h o r t  depths of the  the  been  (25-centimetre d i v i s i o n s ) .  Camosun: 570  e n c e s , any  the  are  d i v i s i o n s of h i s  W e s t m i n s t e r : 425  timetres;  had  the  have  c l o s e to  However, t h e r e  occur  of  Westminster  development o f the  a much l a r g e r s c a l e  (Hew  (1940) i n New  f o r t h e s e b o g s were v e r y  the  area.  then i s prob-  o l d e r than four  thou-  43  Suggestions  for future  investigations:  The present i n v e s t i g a t i o n of the Camosun peat bog can be considered only as a p r e l i m i n a r y study "because only one sample was t a k e n .  T h e r e f o r e , as was  mentioned p r e v i o u s l y , these r e s u l t s  cannot be a p p l i e d  to the whole bog. The i c e  cover o f the l a s t  glaciation re-  t r e a t e d from t h i s area approximately 10,500 years ago (Dr. W.H. Mathews, p e r s o n a l communication, 1961).  The  s t u d i e d sample r e p r e s e n t s a maximum age o f s i x thousand years.  Therefore i t  i s p o s s i b l e .that the  may have s t a r t e d e a r l i e r than the present  vegetation sample  indicates.  I t could have been t h a t the d e p o s i t i o n l a y e r s reached this level  of the l a k e at approximately s i x to f o u r t h o u -  sand years ago.  Some p a r t s of the bog may be deeper and  may c o n t a i n m i c r o f o s s i l s of g r e a t e r ages. For t h i s reason the f i r s t  step i n f u r t h e r  study should be to take a s e r i e s of t e s t samples v a r i o u s s i t e s i n the bog.  The l o n g e s t of the  at  cores  obtained should then be d i v i d e d and macerated, as was done w i t h the core o f t h i s present  study,  of the two cores should be compared. would serve as r e f e r e n c e  and the  The other  results  samples  samples and at c e r t a i n depths  a specimen of each should be macerated to check w i t h the o r i g i n a l r e s u l t s . by these l a t e r c o r e s ,  I f the r e s u l t s were c o r r o b o r a t e d they c o u l d then be g e n e r a l i z e d .  By t a k i n g s e v e r a l  samples from the peat bog  44  at v a r i o u s p l a c e s an o p p o r t u n i t y would "be g i v e n to investigator  the  to map the bog more a c c u r a t e l y h o r i z o n -  t a l l y at each l e v e l .  A l s o knowledge  c o u l d be obtained  of the v e r t i c a l s e c t i o n of the peat bog based on these new core  samples. The next important step would be a more  accurate age d e t e r m i n a t i o n , which should be done at l e a s t f o r the bottom l a y e r (the would a l s o be v e r y u s e f u l  deepest l a y e r ) .  It  to determine the age of  those  succeeding l a y e r s which i n d i c a t e c l i m a t i c changes.  For  t h i s age d e t e r m i n a t i o n the c a r b o n - d a t i n g method would be most  reliable. Knowing these ages one c o u l d s a f e l y  state  the approximate age of the peat bog and a l s o c o u l d g i v e very accurate dates of the v e g e t a t i o n a l would be r e f l e c t i n g  c l i m a t i c changes.  would only be r e l i a b l e i f most of the ilar  changes which Of course,  it  samples gave sim-  results. The a b o v e - d e s c r i b e d suggestions concern  the Camosun peat bog s p e c i f i c a l l y .  However, a s i m i l a r  procedure could be a p p l i c a b l e to any peat At the p r e s e n t ,  deposit.  some o f the r e s u l t s  p a l y n o l o g i c a l s t u d i e s must be i n t e r p r e t i v e ,  of  f o r we do  not have enough i n f o r m a t i o n on v a r i o u s f a c t o r s  influ-  encing p o l l e n and spore a n a l y s i s ,  pollen  p r o d u c t i v i t y of d i f f e r e n t  such a s :  the  plants; migration distances  of these g r a i n s ; and the degree of p r e s e r v a t i o n of  45  different  s p e c i e s i n v a r i o u s media.  would g r e a t l y  influence  These  the p r o f i l e .  factors  Tor example,  if  there are a few i n d i v i d u a l s o f h i g h - p o l l e n - p r o d u c i n g s p e c i e s growing among low-producing s p e c i e s which are more numerous, i n the r e l a t i v e  the d i f f e r e n c e percentages.  probably w i l l not be shown The h i g h p o l l e n produc-  t i v i t y would compensate f o r the number. To e l i m i n a t e  these d i s t o r t i o n s  be some i n v e s t i g a t i o n s o f the r e l a t i v e t i v i t y of d i f f e r e n t various grains,  species,  there  should  pollen-produc-  the m i g r a t i o n d i s t a n c e  and p r e s e r v a t i o n s t u d i e s i n  media of the g r a i n s of v a r i o u s s p e c i e s .  of  different  Some p r e l i m -  i n a r y s t u d i e s a l r e a d y have been done on each  subject  but no systematic r e s u l t s have been g i v e n to d a t e . • Naturally,  the frequency o f a g i v e n  i n a sample would be l i m i t e d by the c o l l e c t i v e of the above-mentioned ever,  f a c t o r s upon i t s  exactly  collectively,  conclusions  influence  grains.  i f these f a c t o r s were s t u d i e d f i r s t  and secondly  species  How-  individually,  could be more  drawn concerning the d i s t r i b u t i o n and frequency  of p l a n t s ,  and e c o l o g i c a l  conditions.  Branches of t r e e s c o u l d be i s o l a t e d p o l l i n a t i o n to study the p o l l e n p r o d u c t i v i t y . r e s u l t s could only be used i f the r e l a t i v e of p o l l e n m i g r a t i o n were a l s o s t u d i e d .  before But these  distances  For t h i s  s t a t i o n s would have to be used f o r c o l l e c t i n g  study,  pollen  g r a i n s from the a i r , w i t h notes as to the d i f f e r e n t  wind  46  directions.  When t h i s  f o l l o w ; namely,  study i s done another has  to  the d e f i n i t i o n of the percentage  of  different  s p e c i e s i n the a s s o c i a t i o n s  collected  g r a i n s came.  from where  Knowing these f a c t s  the  the  conclusions  could be drawn concerning the r e l a t i v e p o l l e n  content  from w e l l d e s c r i b e d a s s o c i a t i o n s  distances.  at d i f f e r e n t  These data c o u l d be used i n p a l y n o l o g i c a l s t u d i e s to g i v e more s t a n d a r d i z e d  results.  Furthermore, there i s  one 'other f a c t o r which  should be c a l c u l a t e d , v i z . the p r e s e r v a t i o n The p r e s e r v a t i o n percentage g i s t s with the p e r c e n t i l e different  percentage.  would supply the p a l y n o l o -  p r e s e r v a t i o n of the p o l l e n o f  p l a n t s p e c i e s i n v a r i o u s media.  w i l l o b v i o u s l y be a f f e c t e d  by t h i s  More s p e c i f i c a l l y ,  Any r e s u l t s  factor.  there  should be a c o r -  r e c t i o n f a c t o r a p p l i e d to each s p e c i e s i n  different  media which would be d e r i v e d through the study o f three above d e s c r i b e d f a c t o r s ; tivity,  migration distance,  the  namely, r e l a t i v e p r o d u c -  and degree of p r e s e r v a t i o n .  For some s p e c i e s the l a t t e r would be p r a c t i c a l l y zero and t h e r e f o r e zero.  the whole f a c t o r would be p r a c t i c a l l y  In some cases, however,  s e v e r a l g r a i n s might  be p r e s e r v e d , which could d i s p r o p o r t i o n a t e  representation.  This would a p p l y , f o r i n s t a n c e ,  The s o l u t i o n  to Thuja,.  f o r t h i s problem would be to determine which s p e c i e s have zero p r e s e r v a t i o n r a t i n g s , i n palynological studies,  and to d i s r e g a r d them  even i f they should happen to  47  occur i n some samples. These suggested i n v e s t i g a t i o n s would need time, hard work, and f i n a n c i a l s u p p o r t .  The r e s u l t s ,  however, would he worth the work and money spent on the studies  f o r they would enable f u t u r e p a l y n o l o g i s t s  to  produce f a r b e t t e r and more r e l i a b l e c o n c l u s i o n s .  Summary o f  conclusions: The a u t h o r ' s c o n c l u s i o n s , based on the r e -  s u l t s o f the p o l l e n a n a l y s i s o f the Camosun peat bog, can be summarized b r i e f l y as 1.  follows:  The peat bog appears to have developed  from a p o s t - g l a c i a l l a k e as a n a t u r a l T h i s theory i s  succession.,  supported by the p o l l e n p r o f i l e c o n -  t a i n i n g t y p i c a l l a k e and peat bog v e g e t a t i o n and a l s o by the presence and disappearance of diatoms. 2. sylvan.  The v e g e t a t i o n o f the surroundings was  The f o r e s t s have d e f i n i t e l y changed at  once from Pinus f o r e s t s  least  i n t o Pseudotsuga f o r e s t s and  probably they are now changing i n t o f o r e s t s  characterized  by Tsuga and q u i t e l i k e l y T h u j a . 3.  The c l i m a t e has changed at l e a s t  as i n d i c a t e d by v e g e t a t i o n a l forests.  changes of the surrounding  This change was a change from a warmer and  d r i e r c l i m a t e to a c o o l e r and more moist There i s  once,  climate.  s p e c u l a t i o n that t h i s c l i m a t e i s  c o o l e r and more moist i n present times,  turning  but t h i s  even cannot  48  be proved c o n c l u s i v e l y by the r e s u l t s . 4.  The approximate age d e t e r m i n a t i o n , based  on a comparison o f t h e p r e s e n t r e s u l t s w i t h those o f Hansen (1947), i n d i c a t e s an approximate 3,ge o f between s i x to f o u r thousand y e a r s .  T h i s age i s w i t h r e f e r e n c e  to the f i r s t m i c r o f o s s i l d e p o s i t s o b t a i n e d from -the c o r e sample.  49  LITERATURE CITED  Armstrong, J.E.  1956.  S u r f i c i a l g e o l o g y o f Vancouver  a r e a , B r i t i s h Columbia. o f Canada, paper Hansen, H.P.  1940.  G e o l o g i c a l Survey  55-40.  P a l a e o e c o l o g y o f two peat bogs  i n s o u t h w e s t e r n B r i t i s h Columbia. J o u r n a l o f Botany, March, Hansen, H.P.  1947.  American  1940.  Postglacial forest  succession,  c l i m a t e , and c h r o n o l o g y i n the P a c i f i c N o r t h west.  T r a n s a c t i o n o f the American P h i l o -  s o p h i c a l S o c i e t y , V o l . 3 7 , P a r t 1. Heusser, C.J.  I960.  Late-Pleistocene  of north P a c i f i c  environments  North America.  American  G e o g r a p h i c a l S o c i e t y , Broadway a t 156th S t r e e t , New York, J o h n s t o n , W.A.  1923.  Map-area. logical Soo, R.  1953.  N.Y. Geology o f F r a s e r R i v e r D e l t a No. 116 G e o l o g i c a l S e r i e s , Geo-  Survey.  Novenyfoldrajz.  Tankonyvkiado, Buda-  pest. Terasmae, J .  1958.  C o n t r i b u t i o n to Canadian p a l y n o l o g y .  G e o l o g i c a l Survey o f Canada, B u l l e t i n  46,  Ottawa. Terasmae, J . and F y l e s , J.G. of l a t e - g l a c i a l  1959. P a l a e o b o t a n i c a l s t u d y d e p o s i t s from Vancouver I s l a n d ,  B r i t i s h Columbia.  Canadian J o u r n a l o f Botany,  50  v o l . 37. Terasmae, J . and Hughes, 0. L.  I960.  G l a c i a l retreat  i n the North Bay area, Ontario.  Science, v o l .  131, No. 3411. 1959. Columbia.  Forestry handbook f o r B r i t i s h The Forest Club of U.B.C., Vancouver.  51  PLATE I  Arboreal pollen  All  grains  f i g u r e s c a . x500  1  Alnus sp.  (Tourn.) L .  2  Pseudotsuga m e n z i e s i i .  3  Tsuga h e t e r o p h y l l a .  4  Pinus sp. L .  5  A b i e s sp.  (Tourn.) L .  6  Picea  Link.  7  L a r i x sp.  ^  Quercus g a r r y a n a .  9  B e t u l a sp.  sp.  10  Salix  sp.  11  Acer sp.  ( M i r b . ) Franco  Sarg.  Tourn. ex Adana. Dougl.  ( T o u r n . ) L. (Tourn.) L .  ( T o u r n . ) L.  LATE I  I  1  3  to 8  g  o1 I l  I ! I ?OM  53  PLATE I I  Non a r b o r e a l p o l l e n  All  figures ca.  grains  x500.  1  Oarex-Juncus  group.  14  A c h i l l e a sp. L .  2  Carex-Juncus group.  15  Caryophyllaceae.  3  Ericaceae.  16  Chenopodium s p .  4  P t e r i d i u m sp.  17  Drosera sp. L .  5  Sphagnum  18  Dryopteris sp.  6  Gramineae.  19  Desmidiospora  7  Nymphaeaceae.  20  Helianthus  8  Nymphaeaceae.  21  I l e x sp.  9  Lycopodium sp. L .  22  M y r i c a sp. L .  23  Polypodium s p . L .  24  Plantago  10  Scop.  sp.  .Typha sp. L .  (Tourn.) L .  Typha l a t i f o l i a .  12  A r t e m i s i a sp. L .  25  Saxifraga  13  Leguminosae.  26  S p i r a e a sp. L . -  Leguminosae.  Adans.  sp. L .  11  27  L.  (Tourn;) L .  sp. L . sp. L .  54  CHART I  POLLEN  PROFILE  OF CAMOSUN  PEAT  <V N.B.  5T  BOG.  A l s o o c c u r r e d in t r a c e s  and w e r e c o u n t e d but recorded on g r a p h s  not  ARBOREAL ACER SALIX NON-ARBOREAL ACHILLEA CARYOPHYLLACEAE CHENOPODIUM DROSERA DRYOPTERIS FUNGAL  SP.  SP  HELIANTHUS  ?  ILEX? MOSS  SP  MYRICA MYRIOPHYLLUM PLANTAGO POLYPODIUM SAXIFRAGA SPIRAEA i  ARBOREA L  i ii  w o zooio  0 10  N 0 N - AR B 0 R E A L O  30  o zo o zo o\o o  i  TRIFOLIUM  ?  

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