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Plant associations in the Subalpine Mountain Hemlock Zone in Southern British Columbia Peterson, Everett Bruce 1964

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PLANT ASSOCIATIONS IN THE SUBALPINE MOUNTAIN HEMLOCK ZONE IN SOUTHERN BRITISH COLUMBIA by EVERETT BRUCE PETERSON B.S.F., The University of British Columbia, 1 9 5 8 M.F., Yale University, 1 9 5 9 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in the Department of BIOLOGY AND BOTANY We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA January, 1 9 6 4 In presenting this thesis in p a r t i a l fulfilment of the requirements for an advanced degree at the University of British Columbiaj I agree that the Library shall make i t freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the Head of my Department or by his representatives. It i s understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of B i o l o g y and Botany The University of British Columbia, Vancouver 8, Canada. Date January, 1964 The U n i v e r s i t y of B r i t i s h Columbia FACULTY OF GRADUATE STUDIES PROGRAMME OF THE FINAL ORAL EXAMINATION FOR THE DEGREE OF DOCTOR OF PHILOSOPHY B„S„F., The U n i v e r s i t y of B r i t i s h Columbia, 1958 M„F„, Yale U n i v e r s i t y , 1959 IN ROOM 2211, BIOLOGICAL SCIENCES BUILDING, FRIDAY, JANUARY 24, 1964, AT 2:30. P.M. of EVERETT BRUCE PETERSON COMMITTEE IN CHARGE Chairman: F.H. Soward J.E. B i e r V.J. K r a j i n a C A . Rowles W.B. S c h o f i e l d J.K. Stager 0. S z i k l a i T.M.C. Tayl o r D.J. Wort E x t e r n a l Examiner: J.W. Marr D i r e c t o r , I n s t i t u t e of A r c t i c and A l p i n e Research U n i v e r s i t y of Colorado PLANT ASSOCIATIONS IN THE SUBALPINE MOUNTAIN HEMLOCK ZONE IN SOUTHERN BRITISH COLUMBIA ABSTRACT The vegetation of the Subalpine Mountain Hemlock Zone was studied on 130 sample plots with a n a l y t i c and synthetic methods of the Zurich-Montpellier school of phytosociology. This thesis describes 14 plant associations, predominantly of vascular plants, from two a l t i t u d i n a l subzones of the Subalpine. Zone. Published radiosonde temperature data, i n combina-t i o n with thermograph data from Mount Seymour, were used to characterize the climate of the zone. In winter, which i s the season of maximum p r e c i p i t a t i o n , the freezing isotherm most frequently occurs at a l t i -tudes near the lower l i m i t of mountain hemlock. A c l i m a t i c r e s u l t i s the sharp increase i n snow accumu-l a t i o n and duration near the lower l i m i t of t h i s species; an e c o l o g i c a l r e s u l t i s the r e l a t i v e l y sharp boundary between the Subalpine Mountain Hemlock Zone and the Coastal Western Hemlock Zone. Thus, the lower l i m i t of the zone i s indicated by the presence of mountain hemlock as a component of the forests and the upper l i m i t i s marked by the a l t i -t udinal "tree l i m i t " of mountain hemlock. The zonal l i m i t s were placed at 3000 and 5000 feet i n the Seymour - Grouse - Hollyburn - Cathedral Mountain area near the S t r a i t of Georgia, and at 3700 and 5500 feet i n the Paul Ridge - Diamond Head portion of Ga r i b a l d i Park. The lowest 600 to 800 feet of the zone are covered with continuous forest of mountain hemlock, amabilis f i r , yellow cedar and western hem-lock. This continuous forest i s designated as the lower subzone. The upper boundaries of the zone, i n contrast to the lower, are i r r e g u l a r as a re s u l t of topographic influences on snow duration. Snow accumulation increases with a l t i t u d e so that near the tree l i m i t mountain hemlock can grow only on prominences or ridges where snow duration i s l e s s . Most e a r l y s t a g e s o f v e g e t a t i o n appear t o d e v e l o p towards t h e P h y l l o d o c e - C a s s i o p e a s s o c i a t i o n i n the upper subzone. At a l t i t u d e s o f a p p r o x i m a t e l y 5000 f e e t and o v e r ( A l p i n e Zone), t h i s a s s o c i a t i o n o c c u p i e s m e s i c h a b i t a t s where the r e l i e f i s f l a t o r convex and w i t h o u t seepage. I n c o n t r a s t , t h i s same a s s o c i a t i o n o c c u p i e s concave t o p o g r a p h i c p o s i t i o n s , w i t h temporary seepage, i n t h e S u b a l p i n e Zone. Snow d u r a t i o n i s a p p r o x i m a t e l y t h e same on t h i s a s s o c i a t i o n i n b o t h b i o c l i m a t i c zones. However, because o f i t s o c c u r r e n c e on two d i s t i n c t t o p o g r a p h i e s i t i s chionophobous i n the A l p i n e Zone but m o d e r a t e l y c h i o n o p h i l o u s i n t h e S u b a l p i n e Zone, when c o n s i d e r e d i n r e l a t i o n t o a d j a c e n t a s s o c i a t i o n s . The V a c c i n i u m membranaceum - Rhododendron a s s o c i a - . t i o n i s t h e most s u c c e s s i o n a l l y advanced i n the upper subzone. Near i t s lower l i m i t , t h i s a s s o c i a t i o n o c c u p i e s m e s i c h a b i t a t s but a t i t s upper l i m i t i n t h e A l p i n e Zone i t becomes a ' t o p o g r a p h i c c l i m a x ' r e s t r i c t e d t o warmer e x p o s u r e s o r t o r i d g e s between a r e a s o f P h y l l o d o c e and C a s s i o p e . I n t h e l o w e r subzone, the V a c c i n i u m a l a s k a e n s e a s s o c i a t i o n i s s u c c e s s i o n a l l y most advanced. Even i f a d i s t i n c t c l i m a t i c " c l i m a x " a s s o c i a t i o n i s r e c o g n i z e d f o r the l o w e r subzone, t h e r e a r e no t r e e s p e c i e s l i m i t e d s p e c i f i c a l l y t o t h i s a l t i t u d i n a l l e v e l . B o t h subzones a r e u n i f i e d by the same t r e e s p e c i e s i n t o one S u b a l p i n e Zone. W i t h i n t h i s a l t i t u d i n a l b e l t most z o n a l f e a t u r e s o f t h e v e g e t a t i o n a r e r e l a t e d t o t h e i n t e n s i t y , q u a n t i t y and d u r a t i o n o f snow. GRADUATE STUDIES F i e l d o f Study: B o t a n y F o r e s t A u t e c o l o g y F o r e s t S y n e c o l o g y P l a n t P h y s i o l o g y Advanced F o r e s t P a t h o l o g y O t h e r S t u d i e s : V.J. K r a j i n a V.J. K r a j i n a D.J. Wort J.E. B i e r Geomorphology S o i l - P l a n t R e l a t i o n s h i p s F o r e s t r y T r e e Seed Wm.H. Mathews J . B a s a r a b a G.S. A l l e n i i ABSTRACT The vegetation of the Subalpine Mountain Hemlock Zone was studied on 130 sample plots with analytic and synthetic methods of the Zurich - Montpellier school of phytosociology. This thesis describes 14 plant associations, pre-dominantly of vascular plants, from two altitudinal subzones of the Subalpine Zone. Published radiosonde temperature data, in combination with thermo-graph data from Mount Seymour, were used to characterize the climate of the zone. In winter, which is the season of maximum precipitation, the freezing isotherm most frequently occurs at altitudes near the lower limit of mountain hemlock. A climatic result is the sharp increase in snow accumulation and duration near the lower limit of this speciesj an ecological result is the relatively sharp boundary between the Subalpine Mountain Hemlock Zone and the Coastal 'western Hemlock Zone. Thus, the lower limit of the zone is indicated by the presence of mountain hemlock as a component of the forests and the upper limit is marked by the altitudinal 'tree limit' of mountain hemlock. The zonal limits were placed at 3000 and 5000 feet in the Seymour - Grouse - Hollyburn - Cathedral Mountain area near the Strait of Georgia, and at 3700 and 5500 feet in the Paul Ridge -Diamond Head portion of Garibaldi Park. The lowest 600 to 300 feet of the zone are covered with continuous forest of mountain hemlock, amabilis f i r , yellow cedar and western hemlock. This continuous forest is designated as the lower subzone. The upper boundaries of the zone, in contrast to the lower, are i r -regular as a result of topographic influences on snow duration. Snow accum-ulation increases with altitude so that near the tree limit mountain hemlock can grow only on prominences or ridges where snow duration is leas. i i i Most early stages of vegetation appear to develop towards the Phyllo- doce - Gassiope association i n the upper subzone. At altitudes of approximately 5000 feet and over (Alpine Zone), this association occupies mesic habitats where the r e l i e f i s f l a t or convex and without seepage. In contrast, this same as-sociation occupies concave topographic positions, with temporary seepage, i n the Subalpine Zone. Snow duration is-approximately the same on this association in both bioclimatic zones.- However, because of i t s occurrence on two distinct topographies i t i s chionophobous in the Alpine Zone but moderately chionophilous in the Subalpine Zone, when considered i n relation to adjacent associations. The Vaccinium membranaceum - Rhododendron association i s the most successionally advanced i n the upper subzone. Near i t s lower limit, this as-sociation occupies mesic habitats but at i t s upper l i m i t in the Alpine Zone i t becomes a 'topographic climax' restricted to warmer exposures or to ridges be-tween areas of Phyllodoce and Gassiope. In the lower subzone, the Vaccinium alaskaense association i s suc-cessionally most advanced. Even i f a distinct climatic 'climax' association i s recognized for the lower subzone, there are no tree species limited speci-f i c a l l y to this altitudinal level. Both subzones are unified by the same tree species into one Subalpine Zone, Within this altitudinal belt most zonal features of the vegetation are related to the intensity, quantity and duration of snow.' V. J. Krajina iv ACKNOWLEDGEMENT I w i s h t o thank the N a t i o n a l Research C o u n c i l , Ottawa, f o r f i n a n c i n g t h i s s t u d y , and the B r i t i s h Columbia Department of R e c r e a t i o n and C o n s e r v a t i o n f o r the use of p r o v i n c i a l parks f a c i l i t i e s . Dr. V. J . K r a j i n a p r o v i d e d the i n i t i a l s t i m u l a t i o n f o r my i n t e r e s t i n t h i s p r o j e c t , and gave v a l u a b l e a d v i c e from i n c e p t i o n of the study t o completion of the t h e s i s . I am i n d e b t e d t o my Graduate Committee which p r o v i d e d f u r t h e r guidance, and to Dr. T. M. C. T a y l o r f o r the use of study f a c i l i t i e s i n the Department of B i o l o g y and Botany, a t the U n i v e r s i t y o f B r i t i s h Columbia. Dr. W. B. Schofield and Dr. V. J . K r a j i n a h e l p e d w i t h the i d e n t i f i c a t i o n of bryop h y t e s , and l i c h e n s were i d e n t i f i e d w i t h a s s i s t a n c e from Dr. M. Hale of the Smithsonian I n s t i t u t i o n , Washington, D. C. L a s t l y , I am g r a t e f u l t o my f e l l o w - s t u d e n t s , R. C. Brooke and A. C, A r c h e r f o r c o - o p e r a t i o n i n f i e l d work, t o L. O r l o c i f o r h e l p -f u l d i s c u s s i o n s on the problems of e c o l o g i c a l c l a s s i f i c a t i o n , and t o my w i f e f o r her many hours o f h e l p . A s s i s t a n c e and encouragement g i v e n me hy o f f i c i a l s of the Canada Department of F o r e s t r y , F r e d e r i c t o n , ilew Brunswick, i s a l s o acknowledged. V TABLE OF CONTENTS CHAPTER Page I. INTRODUCTION . . . . . 1 II. METHODS . . i 5 A. Fiel d Procedures . . . . . . . . . . . 5 3 . Synthesis and Presentation of F l o r i s t i c Data , 8 0. Synthesis and Presentation of Mensurational Data 11 III. THE SUBALPINE MOUNTAIN HEMLOCK ZONE. 13 A. Definition of the Subalpine Mountain Hemlock Zone. , . . . 13 B. Related. Studies. 15 0 . The Study Area 16 1. Location and Extent, n . . . . . . . . . 16 2. Topography and Geology 18 3 . Climate . . 21 a . Precipitation. . . 22 b. Humidity and Temperature 27 c. Freezing Levels 34 D. The Vegetation AO 1. Zonal and Subzonal F l o r i s t i c Features 4-1-2. Sporadic Species i n the Zone 44 3 . Zonal Influences on the Vegetation 45 a. Patterns in the Vegetation , . 45 b. Altitudinal Influences on Trees. 52 IV. DESCRIPTION OF PLANT ASSOCIATIONS . 65 A. = Lower Subzone 65 a. Dry Habitat 65 (la) Cladothamnus association, l i t h i c sub-association . . „ 6" b. Mesic Habitat. , 63 fe) Vacciniura alaskaense association . . . . 69 c. Moist Habitat. , 71 (lb) Cladothaninus association, hygric sub-association . . 71 (3) §^E§pJopus association . . . 72 (3a) Typical subassociation 72 (3b) Degraded subassociation 75 d. Wet Habitat. 76 (4) Subalpine Oplopanax association. . . . . . 77 (5) Subalpine Lysichitum association 79 e. Moor Habitat , . 82 (6) Eriophoruia - Sphagnum association . . . , 82 B. Upper Subzone . . . . „ . . . , 83 1. Chionophobous Associations . « . . . . . . . . . . . , 83 a. Dry Habitat ....... 83 (la) Cladothaninus association, l i t h i c sub-association . . . 83 b. Mesic Habitat. , 83 (?) Y^5£iBiiiS membranaceum - Rhododendron association , . . 84 v i TABLE OF CONTENTS, continued CHAPTER Page 2. Chionophilous Associations 86 a. Moderately Chionophilous Associations 86 i . Dwarf Tree Association . . . . . . 86 (8) Dwarf Tsuga association 87 (8a) Typical subassociation 87 (8b) Luetkea subassociation. . . . 89 i i . Small Shrub Associations . . . . 89 (9) Vaccinium deliciosum association 90 (10) Phyllodoce - Cassiope association 91 i i i . Herb Association 93 (11) Leptarrhena - Caltha Leptosepala association 93 b. Strongly Chionophilous Associations 94 (12) Saxlfraga t o l n i e i association 94 (13) Carex nigricans association 95 (14) Polytrichum aorvegicum association 96 V. COMPARISONS OF THE ASSOCIATIONS 98 A, Mensuration 98 B. Life-forms 101 VI. RELATIONSHIPS MD SUCCESSIONAL DEVELOPMENT OF ASSOCIATIONS . . 104 A, Upper Subzone 106 B. Lower Subzone 113 VII. SUMMARY AND CONCLUSIONS 115 1. BIBLIOGRAPHY 121 2. BIBLIOGRAPHY OF PUBLICATIONS USED FOR IDENTIFICATION OF VASCULAR PLANTS. . , 128 3. BIBLIOGRAPHY OF PUBLICATIONS USED FOR IDENTIFICATION OF BRYOPHYTES AND.LICHENS. . 129 APPENDIX I 132 Checklist of Vascular Plants from the Subalpine Zone . . . 133 Checklist of Lichens from the Subalpine Zone 138 Checklist of Bryophytes from the Subalpine Zone 139 APPENDIX II 142 Multiple regression analyses of the incidence of basal snow-crook on amabilis f i r , mountain hemlock and yellow cedar. 143 APPENDIX III 145 Table XIII I 4 6 Table XIV I47 Explanation and Legend for Synthesis Tables 148 Synthesis Tables I to IX 150 APPENDIX IV 168 PLATE 1 169 PLATE II 170 PLATE III 171 LIST OF FIGURES Figure To follow page lo Location of sample plots . . . 15 2. General view of the Coastal Subalpine Zone 17 3. View from 6300 feet on Mount Sedgwick 17 A. Approximate distribution of the Coastal Subalpine Zone near' Vancouver, British Columbia , 18 5. Monthly precipitation and stream discharge for Seymour Valley. . . 25 6. Monthly maximum and minimum snow depths for A000 feet and 3200 feet on Mount Seymour 25 7. Hygrothermograph trace for November 24 to December 1, 1961 at 4-000 feet on Mount Seymour 27 8. Hygrothermograph trace for February 17 to 23, 1961 at 4000 feet on Mount Seymour, and for Vancouver Airport 27 9. Composite traces for July 17 to 23, 1961 27 10. Hygrothermograph traces for January 17 to 23, 1962 at 3200 feet on Mount Seymour, and for Vancouver Airport 27 11. Frequency distribution of relative humidity by 10% classes for 3200 feet and 4000 feet on Mount Seymour 28 12. Relationship of accumulated temperature to snow depth for a l t i -tudes of 7 feet, 3200 feet and 4000 feet 34 13a. Frequency of temperatures 32°F. or over at 3200 feet and 4000 feet over Port Hardy . ,. 36 13b. Frequency of temperatures 32°F. or over at 3200 feet and 4000 feet on Mount Seymour 4 . 3 6 14. Cumulative percentage frequency showing occurrence of freezing level at various altitudes 37 15. Percentage increase in the frequency of freezing temperatures for each additional 500-foot rise i n altitude during winter and summer 38 16. Biotic zonation associated with decreasing snoxj duration 45 17. Zonation parallel to a clump of Tsuga mertensiana . . . . . . . . 45 18* Small-scale vegetation patterns controlled by duration of snow . . On page. . 46 t i i i Figure To follow page 19. Dwarf mountain hemlock established on warm southeast slope of ravine where growing season i s longer Cn page . . 47 2 0 . Height-age relationships for mountain hemlock on two "dwarf -hemlock" plots 52 2 1 . Change in diameter - height ratio of mountain hemlock with i n -creasing altitude 52 2 2 . Terminal portions of lower branches from which needles were cut for relative turgidity measurements 58 2 3 . Location of BP 15 and BP 124 i n Mount Seymour Park. 58 2 4 . Seasonal changes of relative turgidity and water/dry weight ratio ^ Abies amabilis and Tsuga mertensiana on Mount Seymour 61 2 5 . Number of trees over 3 inches d.b.h. and gross cubic-foot volume, per acre, by 4 - i n c h diameter classes, for four species in various associations 100 2 6 . Percentage distribution of eight life-forms on each association by number of species 101 27. Percentage distribution of eight life-forms on each association weighted by total cover degree 101 28. Altitudinal distribution of sample plots, by association, for Sey-mour - Grouse - Hollyburn study area and for Garibaldi study area 105 2 9 . Topographic sequence of some associations and their relation to duration of snow cover 105 3 0 . Successional trends in the Coastal Subalpine Zone, southern British Columbia . 105 i x LIST OF TABLES TABLE Page I, Number of freezing cycles at Vancouver Airport and at 3200 feet and 4.000 feet on Mount Seymour . . . . . . . . . . . . . . 20 II. Summary of mean monthly, maximum and minimum temperatures for Vancouver Airport and for 3200 feet and 4000 feet on Mount Seymour . . . . . . . . . . . . . . 30 o _ III. Summary of day-degrees over 43 F 0 and over 32 F. for Vancouver Airport and for 3200 feet and /fiOO feet on Mount Seymour. . . . 32 _ o iV, Summary of hour-degrees over 32 F. for Vancouver Airport and for 3200 feet and 4000 feet on Mount Seymour. . . . . . . . . . 33 V, Frequencies of freezing temperatures at an altitude of 4000 feet over Port Hardy and for the same altitude on Mount Seymour, . , 37 VI. Vegetational characteristics of the Subalpine Zone . . . . . . 40 VII,, Proportion of species, size distribution, and frequency of basal snow-crook on 71 forested plots 42 VIII, Comparison of species in seepage communities by cover degree-abundance values and by characteristic cover degree 50 IX, X^-test of differences i n frequency of basal-snow-crook in three tree species for 10-inch class or less 56 X. Summary of length/thickness ratios i n needles of Tsuga merten- siana and Abies amabilis from 4000 feet and 3200 feet on Mount Seymour 60 XI. Relative turgidity and water/dry weight values for needles of Tsuga mertensiana and Abies amabilis from 4000 feet and 3200 feet on Mount Seymour " . . „ . . . . 62 XII. Averages of gross volume, maximum height and site index for the major species on each association 99 XT.IX-, Life-form distribution by number of species and by total cover degree for each association, with a further breakdown of humicolous bryophytes into growth-forms . . . I46 XIV. Average estimated coverage by each vegetation layer and by rock on the associations and subassociations <».-.. 147 CHAPTER I BTTROUJCTIOH B r i t i s h C o l u m b i a i s p r e d o m i n a n t l y a f o r e s t e d , m o u n t a i n o u s p r o v i n c e . The m o u n t a i n f o r e s t s , b e c a u s e o f t h e i r l o w p r o d u c t i v i t y , h a ve n o t a t t r a c t e d t h e same a t t e n t i o n a s t h e v a l l e y a n d l o w l a n d f o r e s t s . I t i s n a t u r a l t h a t t h i s s h o u l d b e , a s t h e f o r e s t s o f g r e a t e s t c o m m e r c i a l v a l u e o c c u r i n t h e l o w e r e l e v a t i o n s a n d t h e m a i n t r a n s p o r t a t i o n r o u t e s a n d s e t t l e m e n t s a r e f o u n d i n t h e v a l l e y s . When o u r t h o u g h t s a n d a c t i v i t i e s a r e so n e c e s s a r i l y c o n t r o l l e d by t h e e c o n o m i c , s o c i a l a n d p o l i t i c a l a c t i v i t i e s i n t h e s e t t l e d a r e a s o f t h e p r o v i n c e , i t i s e a s y t o o v e r l o o k t h e s i g n i f i c a n c e o f l e s s a c c e s s i b l e a n d l e s s p r o d u c t i v e a r e a s . However, i f t h e p r o v i n c e ' s f o r e s t d i s t r i b u t i o n i s c o n s i d e r e d by a r e a , r e g a r d l e s s o f c o m m e r c i a l v a l u e , an e n t i r e l y d i f -f e r e n t p i c t u r e emerges. The a r e a o f B r i t i s h C o l u m b i a may be d i v i d e d i n t o f i v e m a i n com-p o n e n t s s c o m m e r c i a l f o r e s t c o v e r , 53 p e r c e n t o f t h e t o t a l a r e a ; " r o c k a n d b a r r e n s " , i n c l u d i n g s n o w - f i e l d s , g l a c i e r s a n d a l p i n e t u n d r a , 22 p e r -c e n t j n o n - p r o d u c t i v o t r e e c o v e r ( s u b a l p i n e ) , 16 p e r c e n t j open r a n g e a n d f o r e s t s i n w h i c h c a t t l e g r a z i n g i s p o s s i b l e , 8 p e r c e n t j a n d l e s s t h a n one p e r c e n t i n a g r i c u l t u r a l a n d u r b a n u s e ( B . C. F o r e s t S e r v i c e 1957> H a i g -Brown 1961). On a more l o c a l s c a l e , f o r e s t l a n d o c c u p i e s 42.3 p e r c e n t o f t h e C o a s t a r e a , w i t h n o n - f o r e s t l a n d a n d f r e s h w a t e r a c c o u n t i n g f o r t h e r e -m a i n i n g 57«7 p e r c e n t ( B . C. F o r e s t S e r v i c e 1957). I n c o m p a r i s o n , W h i t f o r d a n d C r a i g (1918) e s t i m a t e d 6 l p e r c e n t o f t h e s o u t h e r n m a i n l a n d c o a s t a r e a t o be above t h e m e r c h a n t a b l e t i m b e r l i n e (10,000 b o a r d f e e t p e r a c r e ) . The l a r g e a r e a o f l e s s p r o d u c t i v e f o r e s t l a n d on t h e u p p e r s l o p e s o f t h e s o u t h e r n C o a s t M o u n t a i n s i s t h e s u b j e c t o f t h e e c o l o g i c a l s t u d y d e s c r i b e d h e r e . T r e e c o v e r on t h i s a r e a i s n o t e n t i r e l y u n m e r c h a n t a b l e a s most o f t h e y e l l o w c e d a r p r o d u c t i o n comes f r o m r e l a t i v e l y h i g h a l t i t u d e s . 2 The main purpose of t h i s t h e s i s i s t o d e s c r i b e the p l a n t a s s o c -i a t i o n s and the z o n a l c l i m a t i c c o n t r o l s i n the southern p o r t i o n of the r e g i o n d e s c r i b e d by Rov/e (1959) as the C o a s t a l S u b a l p i n e S e c t i o n ( S A.3) and by K r a j i n a (1959) as the Suba l p i n e Mountain Hemlock Zone. T h i s ob-j e c t i v e presumes the need f o r c l a s s i f i c a t i o n of n a t u r a l a r e a s . D e s p i t e i t s e a r l y e x i s t e n c e as a s c i e n t i f i c t o o l , c l a s s i f i c a t i o n i s s t i l l e v o l v i n g . Hew d i s c o v e r i e s o f t e n r e q u i r e changes i n systems of c l a s s i f i c a t i o n and, as w i t h o r g a n i c e v o l u t i o n , improvements and i n c r e a s e d d i v e r s i t y a re the r e s u l t . One s h o u l d expect t h a t the need f o r c l a s s i f i -c a t i o n , and the i n t r i c a c i e s of c l a s s i f i c a t i o n , s h o u l d i n c r e a s e as man's knowledge broadens. However, c l a s s i f i c a t i o n has not assumed the same importance i n a l l f i e l d s of i n t e l l e c t u a l endeavor. A p l a n t p h y s i o l o g i s t knows the s p e c i e s w i t h which he works and i s t h e o r e t i c a l l y a b l e t o a p p l y h i s a n a l y -t i c a l r e s u l t s t o t h a t s p e c i e s i n i t s n a t u r a l occurrence. At the other ex-treme i s the f i e l d o f s o i l s c i e n c e i n which te c h n i q u e s of a n a l y s i s are w e l l developed but where s y n t h e s i s i s o n l y b e g i n n i n g (KubiSna i960). In comparison, attempts t o c l a s s i f y n a t u r e e c o l o g i c a l l y have been numerous and date back t o the l a s t c e n t u r y . Yet s o i l s c i e n c e and ecology have a s t a r t l i n g s i m i l a r i t y today i n t h e i r r e l a t i v e l y undeveloped s y n t h e t i c treatment of a n a l y t i c a l data. I t s h o u l d not need emphasis t h a t i n f o r m -a t i o n from f i e l d and l a b o r a t o r y s t u d i e s i s u s u a l l y not a p p l i c a b l e t o a l l s o i l t y p e s , nor to a l l h a b i t a t s . I t i s f o r t h i s reason t h a t KubiBna (i960) a s s e r t e d t h a t the only way t o r a t i o n a l i z e r e s e a r c h i n a n a t u r a l s c i e n c e i s on the b a s i s of broad, e x h a u s t i v e s y s t e m a t i c s . Advances i n ex p e r i m e n t a l technique are negated i f they are not accompanied by c o r -r e s p o n d i n g advances i n a p p l i c a t i o n t o s p e c i f i c h a b i t a t s i n n a t u r e . One of the most c h a l l e n g i n g problems today i n eco l o g y , as i n s o i l s c i e n c e , i s to ensure t h a t the gap between the a n a l y t i c and the s y n t h e t i c ' s y s t e m a t i c ) a s p e c t s of these s c i e n c e s i s .not widened. The s y n t h e s i s of e c o l o g i c a l f i n d i n g s r e q u i r e s an i n c r e a s e d u n d e r s t a n d i n g of n a t u r a l areas and i n c r e a s e d uses of c l a s s i f i c a t i o n of these a r e a s . T h i s p h i l o s o p h y p r o v i d e d the m o t i v a t i o n f o r the present s t u d y , and the f o l l o w i n g t h e s i s i s meant t o complement the e c o l o g i c a l i n f o r m a t i o n p r e v i o u s l y a c q u i r e d through s i m i l a r s t u d i e s i n other p a r t s of B r i t i s h Columbia ( K r a j i n a and S p i l s b u r y 1953? K r a j i n a 19539 A r l i d g e 1955, Brayshaw 1955, McMinn 19575 Mueller-Dombois 1959 5 Lesko I 9 6 I , 3 O r l o c i 196l ? S i s I962&, A r c h e r 1963). T h e s e s t u d i e s , when c o n s i d e r e d c o l l e c t i v e l y , p r o v i d e a c l a s s i f i c a t i o n t h a t may s e r v e a s a b a s i s f o r f o r e s t management a n d p l a n n i n g , f o r a d v i s o r y w o r k , a n d f o r e x p e r i m e n t a l r e s e a r c h . I t i s i m p o r t a n t t o r e a l i z e , t h o u g h , t h a t a c l a s s i f i c a t i o n , w h a t e v e r i t s b a s i s , i s a n a r t i f i c i a l s t r u c t u r e . I t i s a c o n v e n i e n t t o o l u s e d t o e x -p r e s s c u r r e n t i d e a s a b o u t t h e r e l a t i o n s h i p s o f o r g a n i s m s , o r p a r t s o f n a t u r e , t o one a n o t h e r . A s i d e a s c h a n g e , o r a s new f a c t s a c c u m u l a t e , c l a s s i f i c a t i o n s y s t e m s may be r e v i s e d , a n d c o n c l u s i o n s b a s e d on s u c h c l a s s i f i c a t i o n w i l l n e e d t o be a c c o r d i n g l y f l e x i b l e . D e t a i l e d reviews o f t h e d e v e l o p m e n t o f e c o l o g i c a l c l a s s i f i c a t i o n h a v e b e e n p r e s e n t e d b y s e v e r a l a u t h o r s , a n d i t i s u n n e c e s s a r y t o p r e s e n t h e r e a c o m p i l a t i o n o f e a s i l y a c c e s s i b l e r e f e r e n c e s . I t i s i m p o r t a n t o n l y t o d r a w a t t e n t i o n t o some o f t h e m o r e c o m p r e h e n s i v e a n d r e c e n t r e v i e w s f o r t h e i n t e r e s t e d r e a d e r s W h i t t a k e r 1953? P o o r e 1955 a n d 1956, B e c k i n g 1957> C h u r c h i l l a n d H a n s o n 1958, H u s t i c h i960, K r a j i n a i960, Whittaker 1962, a n d P o o r e 1962. I n B r i t i s h C o l u m b i a , e c o l o g i c a l c l a s s i f i c a t i o n h a s a b r i e f h i s t o r y . T h e p r o v i n c e was f i r s t d i v i d e d on a l a r g e r e g i o n a l b a s i s , m a i n l y f o r m e n s u r a t i o n a l p u r p o s e s b y W h i t f o r d a n d C r a i g ( 1Q18) . I n 1937j H a l l i d a y p r e s e n t e d s u b d i v i s i o n s o f a s i m i l a r l y l a r g e s c a l e a s p a r t o f h i s f o r e s t c l a s s i f i c a t i o n f o r Canada. H i s r e g i o n s w e r e f o r m e d on t h e b a s i s o f c l i m a t i c c r i t e r i a a n d t h e y h a v e r e c e n t l y b e e n r e v i s e d b y Rowe (1959). A m o r e d e -t a i l e d , b u t s t i l l v e r y b r o a d , d i v i s i o n o f t h e p r o v i n c e i n t o 12 b i o c l i m a t i c z o n e s was made b y K r a j i n a , (1959) • The w o r k s o f I l v e s s a l o (I929), I C u j a l a (1945) > a n ^ - S p i l s b u r y a n d S m i t h (1947) a r e c o m m o n l y c i t e d a s t h e e a r l i e s t d e t a i l e d p h y t o s o c i o l o g i c a l s t u d i e s i n t h i s p r o v i n c e ( B e l l 1959? O r l o c i I96I). D u r i n g t h e l a s t d e c a d e , e c o s y s t e r n a t i c s t u d i e s w h i c h d e v e l o p e d f r o m a f u s i o n o f p h y t o s o c i o l o g i c a l a n d e n v i r o n m e n t a l c l a s s i f i c a t i o n h a v e b e e n c a r r i e d o u t b y r e s e a r c h e r s ( c i t e d on p a g e 2) u n d e r t h e d i r e c t i o n o f K r a j i n a , a n d b y o t h e r s i n t h e p r o v i n c i a l F o r e s t S e r v i c e ( l l l i n g w o r t h a n d A r l i d g e i960). M o r e r e c e n t l y , t h e F e d e r a l D e p a r t m e n t o f F o r e s t r y h a s i n i t i a t e d r e s e a r c h t o t e s t physiographic s i t e m a p p i n g i n c o a s t a l f o r e s t t y p e s ( L a c a t e 1962). I n t h i s m e t h o d , p l a n t s a r e n o t c o n s i d e r e d u n t i l t h e p h y s i o g r a p h i c u n i t s a r e e s t a b l i s h e d . P u b l i s h e d s o i l s maps a n d r e p o r t s h a v e a l s o p r o v i d e d u s e f u l e n v i r o n m e n t a l i n f o r m a t i o n f o r many p a r t s o f 4 B r i t i s h Columbia, but none i s yet available for subalpine areas. The approach in the present study was primarily phytosociological and followed the analytic and synthetic methods of the Zilirich - Montpellier School (Braun-Blanquet 1932, Becking 1 9 5 7 ) . It was recognized, however, that environmental characteristics are equally as useful as f l o r i s t i c structure for the c l a s s i f i c a t i o n of plant associations. For this reason, modifications of the original Braun-Blanquet methods were made in accord-ance with recommendations by Krajina ( i 9 6 0 ) . The study was carried out in the Department of Biology and Botany, University of .British Columbia, under the direction of Dr. V. J. Krajina and in co-operation with R, C. Brooke. A separate dissertation w i l l discuss the microclimatic and edaphic characteristics in relation to vegetation (Brooke 19&4-) > whereas this thesis concentrates upon phy-tocoenotic characterization with a stress upon some zonal features, es-pecially macroclimate. However, both theses have a single ecosystematic theory as their foundation and they should be considered as a unit. The most important features of the subalpine environment are discussed in Chapter III. In Chapter IV, the plant associations are described in terms of their present composition, and in Chapter VI they are related to one another dynamically where there i s evidence of succession-a l trends. These three chapters are the most important, since they re-present the main findings of this study. 5 CHAPTER I I METHODS Procedures in the f i e l d and the methods of arranging data are, to a large extent, controlled hy the purposes of a particular investiga-tion. Because an ecological study usually involves several related d i s -c i p l i n e s , i t cannot have a single theory around which methods of study can he b u i l t . It i s necessary, therefore, to b r i e f l y outline the f i e l d pro-cedures and the methods of handling and presenting data. A. F i e l d Procedures The methods used in this study do not d i f f e r markedly from those of Krajina ( 1 9 3 3 ) , Brayshaw ( 1 9 5 5 ) , McMinn ( 1 9 5 7 ) , Hueller-Dombois (1959) and Orloci (I96I). This deliberate standardization of methods serves an important purpose by allowing direct comparisons to be made between f l o r -i s t i c descriptions from different bioclimatic zones. Even i f there i s a choice of several available theories to serve as a basis for ecological c l a s s i f i c a t i o n , none of them w i l l explain everything. The main object i s to col l e c t basic ecological information of s u f f i c i e n t accuracy to form an ecosystematic c l a s s i f i c a t i o n and tc allow comparisons for multiple-use land planning. The vegetation was studied by means of sample plots which, on forested areas, ware one chain by two chains ( l / 5 acre), in size. The plots were located in places where the vegetation was uniform over such an area. For non-forested associations, plots l / 2 chain by l / 2 chain ( l / 4 0 acre) were s u f f i c i e n t l y large. It was not only convenient to use these smaller plots, but also necessary in some cases where the assoc-iations were severely limited in area by the topography or the environ-mental gradients, as for example, around late snow-patches or along stream margins. At least one corner of every sample plot was marked by a wooden or steel post and an aluminum tag bearing a record of the plot number, 6 i t s dimensions and i t s orientation. Subsequent v i s i t s to these cornerposts showed many of them leaning or knocked down, especially where snow-creep was pronounced. The four corners of each plot were joined by string to f a c i l i -tate the t a l l y of trees. The diameters, at breast height, of a l l l i v i n g trees over three inches, were measured with a steel tape. Since none of the sample plots was heavily forested, i t was practicable to measure the heights of nearly a l l the trees with an Abney l e v e l . In some cases, heights were estimated by comparison \ 7 i t h adjacent measured trees. A l l of the forested sample plots were in uneven-aged old growth stands of mountain hemlock (Tsuga mertensiana, (Bong.) Carr.), amabilis f i r (Abies amabilis (Dougl.) Forbes), and yellow cedar (Chamaecyparis nootkatensis (D. Don) Spach). Therefore, stand age, as such, could not be determined, but ages were taken over the range of diameters for each species present on a plot. From six to twelve ages were obtained for each plot by increment borings at breast height. F l o r i s t i c analyses were carried out on homogeneous stands by l i s t i n g a l l the vascular plants, bryophytes and lichens on each plot. An area was ocularly judged as homogeneous i f the constituent species appeared uniformly distributed throughout the plot. Species were l i s t e d for each of the following arbitrary stratas Ai - dominant and co-dominant trees ~ intermediate trees A^ - suppressed trees over 30 feet in height B]_ - saplings and shrubs between 6 and 30 feet in height ~2>2 ~ shrubs between 6 inches and 6 feet in height C - herbaceous plants ( a l l ) and small woody plants under 6 inches in height (Note that by this definition subalpine species such as Phyllodoce empetriformis, Cassiope  mertensiana and Vaccinium deliciosum occur in the C layer.) D^  - humicolous bryophytes and lichens The bryophytes and lichens on decayed wood, on rock and on tree trunks were also l i s t e d . Tree or shrub species which occurred in more than one stratum were listed and f l o r i s t i c a l l y evaluated for each. Species significance, s o c i a b i l i t y and vigour were evaluated according to the scales shown in the legend preceding the appended Synthesis Tables, Plants of uncertain identity were collected for l a t e r i d e n t i f i c a t i o n , and were subsequently deposited in the University of 7 B r i t i s h Columbia Herbarium. Microscopic examinations of the bryophytes and lichens often revealed species that were not l i s t e d in the f i e l d notes. In such cases, the extra species were added for the appropriate sample plot to the preliminary synthesis tables, and, as suggested by Dahl ( 1 9 5 6 ) , their f l o r i s t i c ratings were estimated on the basis of the occurrence in other plots of the same association. Detailed microclimatic measurements and edaphic descriptions of the associations are provided by Brooke ( I 9 6 4 ) . Only hygrothermograph data and snow depth measurements from temporary climatic stations at 4000 feet (BP 124) and at 3200 feet (BP 15) are discussed here. Relative turgidity measurements on the needles of mountain hemlock and amabilis f i r were also taken from these two stations to test i f there were d i f -ferences in the internal water balance of needles on a l t i t u d i n a l l y and ecologically d i s t i n c t habitats. F i n a l l y , i t must be emphasized that methods of f l o r i s t i c analysis, as described above, are not s t a t i s t i c a l methods as the term i s otherwise applied in biology. This point was also stressed by Dahl ( 1 9 5 6 ) . S t a t i s t i c a l methods could be more appropriately applied i f every assoc-iati o n had the same chance of occurrence in a zone. Then a random sample would touch a l l habitats about equally. Since this ideal does not exist, s t r a t i f i c a t i o n i s necessary before s t a t i s t i c a l analyses can be carried out. In this particular study, s t r a t i f i c a t i o n was made on the basis of f l o r i s t i c features. This need not imply that the plant association i s the basic unit for ecological studies, but i t i s a useful unit for s t r a t i -f i c a t i o n because i t provides information for studies of habitats and niches. Boundaries between associations are rarely d i s t i n c t , but trans-i t i o n s do not j u s t i f y the annihilation of the units involved. For pre-liminary studies, i t i s best to avoid transitions. I f they are included in association tables, they w i l l reduce the difference between the units because, by d e f i n i t i o n , they represent conditions that are interpolative. It i s better to describe the dis t i n c t and extreme units and to l e t the transitions be mathematically interpolated l a t e r . By this method, i t i s not possible to describe a l l variations of vegetation in an area, but any random point w i l l f a l l into a described vegetation unit or w i l l be readily assigned to an intermediate position between two units (McVean and R a t c l i f f e 1 9 6 2 ) . 8 In summary, the methods used for this study must he recognized primarily as standardized descriptions of vegetation which permit compari-sons between different associations both intrazonally and interzonally. B. Synthesis and Presentation of F l o r i s t i c Lata The following paragraphs outline the philosophy which i n f l u -enced the organization and descriptions of plant associations in Chapter IV. McVean and R a t c l i f f e (1962) pointed out that vegetation units can be arranged in at least three ways; systematically, or according to a hierarchical c l a s s i f i c a t i o n of the units distinguished^ physiognomically, or according to the life-form of the dominant species5 and ecologically, or according to the main habitat types and a l t i t u d i n a l zonation. The f i r s t alternative, a systematic or hierarchical c l a s s i f i -cation, was inappropriate for the present study, because i t can only be used in later studies which w i l l incorporate the associations described here into higher community units in combination with associations from other bioclimatic zones. The second method i s well suited for the Subalpine Zone since there are great physiognomic differences between the lower forested as-sociations and the upper heath-like and herbaceous associations. This i s in contrast to the associations of the Coastal Western Hemlock Zone most of which are forested and physiognomically more uniform. However, a physiognomic c l a s s i f i c a t i o n by i t s e l f provides only limited information. Studies which y i e l d more.detailed information about the habitat should u t i l i z e such ecological information in the c l a s s i f i c a t i o n scheme, as in the present study. Physiognomic differences were considered only in the comparisons of life-form spectra in each association (Chapter V), and by the grouping into forested and unforested categories in the c l a s s i f i c a t i o n of Chapter IV. The remaining alternative of ecological organization was used ef f e c t i v e l y by Orloci ( 1 9 6 1 ) , in combination with f l o r i s t i c structure, for the forest types in the Coastal Western Hemlock Zone. Descriptions from the Subalpine Zone w i l l be of more value i f they can be dir e c t l y compared with descriptions from lower elevations. Therefore, the or-ganization of Chapter IV closely resembles that used by Orloci ( I 9 6 I ) . 9 The major categories in Chapter IV are two altitudinal subzones, and within each subzone there are habitats ranging from dry or moderately dry to wet. In the upper subzone^ relationships to length of snow cover and physiognomy (forest j kruminholz, small shrub j herb and bryophyte) form the basis for organization, Thusj f lor i s t i c structure is the primary base for classif ication, but i t is organized in alt i tudinal , habitat and phy-siognomic groups. The combination of several cr i ter ia for classification reduces the number of units in any one group. Such organization, in com-bination with descriptions of the associations, should enable the reader to identify the vegetation units of the Subalpine Zone without the aid of a key. Presence, dominance and f ide l i ty are the main cr i ter ia for describing and differentiating the associations. Those species which were present in over 80 per cent of the sample plots in a synthesis table are l is ted as constants. Each constant species whose average cover degree exceeded 10 per cent of the plot area is l i s ted as a constant dominant. Fidelity was determined as outlined by Becking (1957)> and the character-i s t ic species for each association are l isted as follows (Braun-Blanquet 1932)t Fidelity 5 - Exclusive species, ¥/hich are completely or almost completely confined to one community. Fidel i ty 4 - Selective species, which are found most frequently in a certain community. Fidel i ty 3 - Preferential species, present in several communities . more or less abundantly but predominantly or v/ith better v i ta l i ty in one certain community. The choice of exclusive, selective and preferential species was based only on tabular data from plots in th© restricted area of this study. Therefore, a species may be l isted as exclusive to a certain association in the Coastal Subalpine Zone even though i t is known to occur in other associations of the Coastal Western Hemlock Zone or the Alpine Zone. This possibil ity was recognized by Braun-Blanquet (1932) when he pointed out that f idel i ty always refers to the relation of a species to a certain community (within a particular region or zone). Of secondary importance are the social relations which this species has in a l l parts of its range. It is possible for one particular species to be exclusive in different regions to two or more distinct and different communities. The average characteristic species (Fidelity classes 3> 4> and 5) and constant species, taken together, are the characteristic combination 10 of species as used in the Zurich - Montpellier methods of synthesis. The use of dominance as a criterion is recommended for vegetation units con-taining few species (Poore 1955? Dahl 1 9 5 6 ) . Association characteristic species are not plentiful in the Subalpine Zone because the number of species in the associations is small compared to European study areas where' the ZUrich - Montpellier methods were developed. For this reason cr i ter ia such as dominance, environmental features of the habitat, or life-forms should also be used. As pointed out by Krajina ( i 9 6 0 ) , the ideal concept for ecosystem classification is the biogeocoenosis that is composed of an ecotope and a biocoenosis. The ecotope is divided into a climatope and an edaphotope. The biocoenosis is divided into a phytocoenosis, a zoocoenosis and a microbocoenosis (Sukachev, quoted from Krajina i 9 6 0 ) . Most emphasis in this thesis is placed on the phytocoenosis (association), but other factors of the biogeocoenosis are considered, especially for sub-units of the associations. Differential species, which may be non-characteristic, are used to distinguish closely related vegetation units (Braun-Blanquet 1 9 3 2 , Krajina 1933? McVean and Ratcliffe 1 9 6 2 ) . Thus, several subassociations are recognized in Chapter IV by the presence or absence of species, or by differences in the dominance and vigor of certain species. Subassociations reflect edaphic or microclimatic differences (Drees 1 9 5 3 ) ? as in the hygric Cladothamnus subassociation versus the l i th i c Cladothamnus subassociation, whereas variants reflect macroclimatic differences. Only one variant is recognized in Chapter IV, where the subalpine Oplopanax stands are treated as a climatic variant of the Oplopanax - Adiantum forest type described by Orloci ( 1 9 6 2 ) for lower elevations in the Coastal Western Hemlock Zone. Common descriptive names of the vegetation units depicting a dominant species and environmental features are used throughout the text. Names based on the rules by Drees ( 1 9 5 3 ) are also provided because they faci l i tate the systematic grouping of vegetational units into higher categories through standardization of phytosociological nomenclature in different bioclimatic zones. For associations, the suffix -etum was added to the stem of the genus-name of a dominant species. If two generic names were used, the f irst had an -eto ending, and in necessary cases the name of the species in the genitive case was also added. Subassociation 11 names were formed by adding the ending -etosum to the generic stem, and variant names used an -osum suf f i x . Although descriptive prefixes and adjective names are not standardized, the terms nano-, hygric and l i t h i c were used. C. Synthesis and Presentation of Mensurational Data The tree diameter t a l l y was grouped by species into four-inch diameter classes for stand table presentation (Figure 2 5 ) . Height-diameter curves were not constructed as a step in volume determination because actual height measurements were available for nearly a l l individual trees. This wa3 possible because of the r e l a t i v e l y small number of trees on most sample plots, and i t allowed the determination of volume on an i n -dividual tree basis. Gross volume per tree was determined from the Coast Mature Hemlock Tables for both species of.hemlock, from the Coast Mature Cedar Tables for yellow cedar, and from the Coast Balsam Tables for ama-b i l i s f i r (Forestry Handbook for B r i t i s h Columbia 1959)• It v/as impossible to obtain r e l i a b l e site indices for trees of the Subalpine Zone because only old growth stands were available and no s i t e index curves exist for subalpine species. Furthermore, height growth i s usually so slow in the Subalpine Zone (Figure 20) that the conventional expression of height at 100 years i s inappropriate. Despite these weak-nesses, average s i t e index at 100 years ?/as determined where possible to permit comparisons of grovrth rate with lower elevations. A large scale reproduction of the height-age curves published for coastal species at lower elevations (Forestry Handbook for B r i t i s h Columbia 1959» P» 371) served this purpose, but the s i t e indices obtained are not r e l i a b l e (Table X l l ) . For old-growth stands which are slow growing because of a rigorous environment, average height of the t a l l e s t tree regardless of age i s a useful indicator of site productivity. Table XII shows, for each of the four major species, height of the t a l l e s t tree averaged for the number, of plots in each association. These values, when con-sidered together with the gross volumes and the approximate site indices, give a good indication of the p o t e n t i a l i t i e s of each species in the various associations. 12 The synthesis tables (Appendix III) provide per acre values for number of trees, basal area^ and gross volume for each species on every sample plot. These data, excluding basal area, are summarized for five associations and two subassociations by histograms which readily allow a visual comparison of the number of trees per acre and gross volume in cubic feet per acre for each species in each diameter class (Figure 25). 13 CHAPTER III THE SUBALPINE MOUNTAIN HEMLOCK ZONE This chapter defines the study area geographically and a l t i t u -dinally. The topography, geology and climate are described, and the chapter concludes with a discussion of the most important zonal features of the vegetation. A. Definition of the Subalpine Mountain Hemlock Zone It i s well known that climatic and vegetational differences result from increases in altitude in mountainous country. A l t i t u d i n a l zonation i s so obvious that terms such as subalpine, alpine and timberline form part of our regular vocabulary. Increased usage of these terms has, however, lead to indefinite meanings, and for this thesis some definitions are necessary. For the area of his study in Norway, Dahl (1956) drew the upper l i m i t of the subalpine belt "at the timber-line or f o r e s t - l i m i t " . This d e f i n i t i o n , while good in principle, i s inadequate because i t contains within i t poorly defined terms. For example, Hustich (1949) defined the timberline as the l i m i t of timber-sized forests. This definition i s of economic importance but i s misleading as a bi o l o g i c a l boundary. If i t were applied to south coastal B r i t i s h Columbia, timberline would be near the upper l i m i t of western hemlock since the distribution of this species closely approximates the upper li m i t of merchantable forests today. Another definition of timberline, and the more usual one, was given by Dansereau (1957) as the highest elevation at which trees grow. However, i t i s questionable i f coniferous species can be classed as trees near their northern l i m i t or near their a l t i t u d i n a l l i m i t (as for example, krummholz). Where would the timberline be placed in such areas? The designation of three bi o l o g i c a l boundaries, forest l i m i t , tree l i m i t and species l i m i t (Dansereau 1957? Berner 1959) partly solves the problem. 14 These three l i m i t s , when applied to a particular species, make general terms such as montane, suhalpine or alpine more meaningful "by pro-viding a bio l o g i c a l basis for the zonal delineation. For the study area described here, the a l t i t u d i n a l distribution of mountain hemlock in tree form indicates coastal subalpine conditions, and the region may be j u s t i -f i a b l y called the Subalpine Mountain Hemlock Zone, as previously designated by Krajina ( 1 9 5 9 ) . The lower l i m i t of the zone i s represented by the lower l i m i t of mountain hemlock as a dominant component of the forests, and the upper edge of the zone i s placed at the a l t i t u d i n a l tree-limit of mountain hemlock. Thus, the vegetation i s predominantly arborescent, but the trees are often dispersed and smaller than they are at lower elevations (Dan-sereau 1957)• The upper li m i t of trees i s discontinuous and there may be, because of l o c a l l y unfavourable conditions, considerable areas within the subalpine belt not covered by forests or trees. The definition above i s not meant to imply that the Subalpine Zone represents the absolute upper l i m i t of mountain hemlock as a species. The a l t i t u d i n a l species l i m i t occurs higher up in the Alpine Zone (Archer 1 9 6 3 ) . The species does not attain the stature of a tree above the Sub-alpine Zone, however. The term, forest l i m i t , i s useful for subzonal designation because forests are not of uniform continuity from the lower to the upper limits of the zone. In Garibaldi Park, Brink (1959) recognized a "lower subalpine forest" from 3500 to 5000 feet, and noted that the forest was more open above 5000 feet. This upper l i m i t of continuity.in the tree cover, or forest l i m i t , coincides with the a l t i t u d i n a l division of the Subalpine Zone into two subzones in this thesis. The following d i s t r i b u t i o n a l , environmental and f l o r i s t i c features allow a comparison of the original zonal definition (Krajina 1959) with that presented later in this chapter for the specific area of this study. As defined by Krajina ( 1959)> the zone extends along the coastal mountain ranges between altitudes of 3000 and 5500 feet in the south of B r i t i s h Columbia and between 1000 and 2000 feet in the north of the province. Total precipitation varies from 75 to 170 inches per year, with 1 4 . 0 to 15»5 inches in the wettest month and 1.3 to 3 . 3 inches in the driest month. In the southern part of the zone, 30 to 40 per cent of the precipitation occurs in winter or autumn v/ith only 10 to 15 per-cent in the spring or summer. In the northern portion, 30 to 35 Per cent 15 f a l l s in the autumn and 10 to 15 per cent in the summer. Snowfall varies from 170 to 800 inches per year, and i t makes up 20 to 70 per cent of the to t a l precipitation. Krajina (1959) placed the Subalpine Mountain Hemlock Zone in Koppen's Dfc category, and the zonal s o i l was called a coastal subalpine podzol. The Tsuga mertensiana - Abies amabilis - Vaccinium  alaskaense - Vaccinium membranaceum - "Rubus pedatus association was l i s t e d as the climatic climax plant community. B . Related Studies Of the 90 forest sections described for the forest regions of Canada (Rowe 1959)> the briefest description i s given for the Coastal Subalpine Section (SA . 3 ) . This brevity does not mean that the section i s areally or economically unimportant, because there are other forest sections of smaller size or others of equally low forest productivity which are described in greater d e t a i l . Rather, i t r e f l e c t s the paucity of published information on the major tree species and cover types of this section. In the b r i e f l i t e r a t u r e review which follows, l i t t l e attention i s given to suibalpine studies in mountains other than those in coastal B r i t i s h Columbia and in the P a c i f i c Northwest region of the United States. Braun-Blanquet ( 1 9 3 2 ) , Daubenmire ( 1 9 4 3 ) , and McVean and R a t c l i f f e (1962) have a l l stressed that phytosociological studies on different mountain systems are not d i r e c t l y comparable because of i n d i v i d u a l i t y in the en-vironmental conditions of any particular mountain system. For the Olympic Mountains, the history of botanical and ecolo-g i c a l Investigations was reviewed by Jones ( 1 9 3 6 ) . He presented a similar history for Mount Rainier in 1938. A very recent review of subalpine work in the P a c i f i c Northwest i s that by Franklin ( 1 9 6 2 ) . The earliest mountain studies in Coastal B r i t i s h Columbia were mainly botanical explorations. The f i r s t plant collections from higher altitudes were made in 1912 on Grouse Mountain, Hollyburn Ridge and from near Mount Garibaldi (Davidson 1913 to 1915)• Other reports from sub-alpine areas were made by Henry ( 1 9 1 5 ) , Hardy (1927) and Perry ( 1 9 2 8 ) . Further north, McAvoy ( 1 9 2 9 , 1931) described alpine and subalpine con-ditions for the Bella Coola region. Additional references to the Garibaldi area were made by Davidson in 1931, and Taylor ( 1936, 1937) to follow page 15 16 described former forest areas in Saribaldi Park which had been re-covered by a glacier. The recent study by Schmidt (1957) provided valuable information on the. s i l v i c a l characteristics of amabilis f i r , a common species i n the Coastal Subalpine Zone. Brink's report (1959) described successional changes near,the Black Tusk, just north of the present study area. Further reference i s made to his study in later sections. At present, Brink, K&Kay and Mathews of the University of British Columbia (unpublished) are studying alpine and subalpine vegetation in relation to frost, snow and solifluction i n Coastal British Columbia. C. The Study Area 1., Location and Extent The study area i s shown by the distribution of 130 sample plots in Figure 1, The plots were located as follows: Mount Seympur Plots 1-34, 40-51, 123, 124, 129, and 130. Hollyburn Ridge Plots 104-107, 125-123. Grouse Mountain Plots 94-103. Mount Strachan Plot 108. The Lions Plots 109-111 Paul Ridge (Round Mountain) and ) Plots 35-39, 52-93, and Diamond Head area, Garibaldi Park) 112-122. ..Whitford and Craig (1918) classified this area as part of the Coast Forest., It occurs i n Section SA.-3, the Coastal Subalpine Section, of Rowe's (1959) classification, and i t forms part of the Pacific Subalpine Forest referred to by Heusser (i960).. In the 450-square-mile study area, the altitu d i n a l limits of the Subalpine Zone cannot be precisely defined, except locally. Near Burrard Inlet, the lower edge of the zone, as defined by the lower li m i t of mountain hemlock, closely follows the 3000 feet contour. In the triangular physiographic unit bounded by Burrard Inlet on the south, Howe Sound on the west, Stawamus River 17 and Indian River on the northeast, and Indian Arm on the east, very few peaks have areas above the tree l i m i t (except for Cathedral Mountain, 5683 feet, and Sky Pilot Mountain, 6645 feet). Therefore, the area of the Sub'lpine Zone should be closely approximated by the total acreage above the 3000 foot contour. The above physiographic unit, which includes the Seymour - Grouse -Hollyburn study area, h as a total a r e a of approximately 234,000 acres, 87,000 acres of which are above 3000 feet in altitude (determined from planimeter readings on Map sheet 92G, National Topographic Series, 1:250,000-). Thus, approximately 37 per cent of this south coastal area may be classed as sub-alpine (Figure 4)« On Paul Ridge, northeast of Squamish, the lowest mountain hemlock is at 3800 feet and western hemlock i s common to 4000 feet. There i s thus an upward shift of the Subalpine Zone by almost 1000 feet in this part of the study area. Upper and lower al t i t u d i n a l limits of individual associations are also about 1000 feet higher on Paul Ridge than they are on the mountains near Burrard Inlet (Figure 28). The following table summarizes the zonal and subzonal altitudinal limits for this study: Seymour, Grouse, Crown Paul Ridge Hollyburn and Cathedral Mountains (Garibaldi Park) Subalpine zone: 3000 - 5000 feet 3700 - 5500 feet Lower subzone: 3000 - 3600 feet 3700 - 4500 feet Upper subzone: 3600 - 5000 feet 4500 - 5500 feet Alpine zone: over 5000 feet (only over 5500 feet on Cathedral Mountain) With such variation in the altitudinal limits of the zone over a 30-mile distance, comparisons with the altitudinal delineations of this zone in other study areas must be made with caution. In the Black Tusk area, just 15 miles north of Paul Ridge, the limits set by Brink (1959) correspond quite Figure 2 . General view of the Coastal Subalpine Zone, from 54-00 feet on the west Lion. Photograph courtesy of Surveys and Mapping Branch, Province of British Columbia. Figure 3 . View from 6300 feet on Mount Sedgwick shows late snow in the Coastal Subalpine Zone, July 10, 1952. See Figure 1 for vantage point of photograph. Courtesy of Surveys and Mapping Branch, Province of British Columbia. 18 closely. He considered the "lower subalpine forest" to occur from 3500 feet to 5000 feet. Above the 5000-foot contour, the character of the subalpine forest changed markedly but trees 50 feet high were common to 6300 feet. Similar comparisons can be made from studies in other coastal mountain ranges. The Hudsonian Zone of the Olympic Peninsula is similar to the Coastal Sub-alpine Zone in British Columbia in vegetational and climatic characteristics. Altitudinal limits of 3500 feet and 5000 feet were given for the Hudsonian Zone by Jones (1936), and for a similar classification on Mount Rainier (Jones 1938) the limits were placed at 4500 to 6000 feet. Many other examples exist in the literature (see especially Heusser I960, pages 50-75). In the abstracts presented by Franklin (1962), there are 25 direct references to the altitudinal range of mountain hemlock. On the basis of his information, the Co astal Subalpine (Mountain Hemlock) Zone occurs from 6900 to 94°0 feet in the Stanislaus and Lake Tahoe Forest Reserves, California (Sudworth 1900), and from 1200 to 2400 feet in the forests, of southeastern Alaska (Hoffman 1912). This general depression of the zone, from south to north, has many local i r -regularities due to topographic and climatic differences. 2., Topography and Geology The topography of the Coastal Subalpine Zone is best described by the photographs in Figures 2 and 3, The vantage point for Figure 2 is at an altitude of approximately 5400 feet on the most westerly of The Lions. The view is towards the northeast, and subalpine forest covers most of the visible area with the exception of the mid and lower slopes adjacent to Capilano Valley on the right. The latter are part of the Coastal We stern Hemlock Zone (Orloci 1961), On the far horizon, the peaks of Mount Garibaldi, Sky Pilot Mountain and Mamquam Mountain represent the Alpine Zone (Archer 1963). LEGEND TO ACCOMPANY MAP (FIGURE 4) Geological subdivisions are shown only for those areas where sample plots were located (References: Armstrong 1954> Roddick and Armstrong 1956, Mathews 1958). In the Diamond Head - Paul Ridge study area: Quaternary Garibaldi Group G2 - Late glacial and early postglacial Gl - Older d - Dacite b - Andesite and basalt Pre-Upper Cretaceous Older intrusions Oq - Cloudburst quartz diorites (foliated and unfoliated quartz diorite, minor diorite, etc.) Mv - Metavolcanic and metasedimentary rocks (greenstone, slaty a r g i l l i t e , breccia, minor conglomerate, limestone, green schist) In the•Seymour - Grouse - Hollyburn - Lions study areas Triassic (?) and/or later Gambier Group 3 - Tuff, breccia, agglomerate, andesite, slate, a r g i l l i t e , arkose, quartzite, greywacke, conglomerate, minor dacite, trachyte, and basalt Triassic (?) and/or later Bowen Island Group 2b - Banded hornblende-feldspar gneiss, hornblende-biotite-feldspar gneiss, hornblende biotite-quartz schist, d i o r i t i c gneiss, granitoid gneiss, hybrid diorite and granitic rock Plutonic rocks formed at more than one period i n the geological history of the m?.p-area (not an age sequence) H b l l l - Plutonic rocks i n which hornblende forms 50 to 90 per cent and biotite 10 to 50 per cent of mafic mineral content. Quartz diorite ^II,III,M - Plutonic rocks in which hornblende forms 90 per cent or more and biotite 10 per cent or less of mafic mineral content, II-, granodiorite; III, quartz di o r i t e j M. migmatite to follow page 18 See legend opposite for geological subdivisions Coastal Subalpine Zone approximated by the hatched areas over 3000 feet. . • , . J 1 i : ' . • I 1 j Scale 1 i 250,000 I25< Pacific Ocean Index Map Howe Sound Figure 4. Approximate distribution' of H e m l o c k } 7 n n p nr>nr . Y/nnrnnvpr the Coastal Subalpine (Mountain RriHch P.nli imhii-i' 19 The most important geological references for the area are: Heusser (i960) for the Coast Mountains in general and particularly for glacial history? Armstrong (1954.) and Roddick and Armstrong (1956) for the Seymour - Grouse -Hollyburn study area; and Mathews (1958) for the Paul Ridge - Diamond Head study area. Geological subdivisions for the study areas are shown on the dis-tribution map for the Coastal Subalpine Zone (Figure 4.). The most striking features are the occurrence of older intrusive rocks through most of the area and the localized presence of Quaternary volcanic parent materials in parts of Garibaldi Park. The legend accompanying Figure 4. l i s t s the rocks which are prevalent i n each geologic subdivision. Parent material differences i n different parts of the study area do not seem to be correlated with changes in the species composition of the sub-alpine vegetation, except that Cladothamnus pyrolaeflorus i s absent from parent materials of the Garibaldi Group. The study area was glaciated recently, i n both the geologic and anthropomorphic scales of time. For example, near the Opal Cone in Garibaldi Park subalpine forest i s present on slopes above the trim-line of a gla c i a l tongue which has melted back from the valley only i n the last few centuries (Mathews 1958). Naturally the most obvious signs of very recent glaci&tion are near the upper limits of the Subalpine Zone. Glacial striae on rock surfaces are surprisingly few in the mid and lower portions of the zone because of the rapid weathering of rock surfaces since glaciation. The frequency of freezing cycles i s an important factor in the surface weathering and exfoliation of rocks, and the increase i n the number of freezing cycles with increasing altitude (Table I) indicates the potentially greater rate of weathering of rock surfaces i n mountain areas. This phenomenon would be particularly effective i n October, April and May when some rock surfaces would be free of snow. 20 TABLE I Number of freezing cycles at Vancouver Airport (l6 feet) and at 3 2 0 0 feet and: 4 0 0 0 feet on Mount Seymour, Aug. 1, I960 to July 31, 1961* Vancouver Mount Seymour Airport B P l i B P 124 16 f t . 3200 f t . 4 0 0 0 f t . Aug. _ Sept. - - -Oct. 1 7 Nov. 1 3 8 Dec. 12 r 10 Jan. 10' 6 8 Feb, — 6 4 March 1 5 7 Apr. - 10 10 May - 1 2 June - — -July - - -Year 2 4 37 56 * A freezing cycle was a r b i t r a r i l y counted whenever the temperature dropped to 31° F or lower and then rose to 33° F or higher. Parent materials, soil-forming processes, s o i l types, s o i l moisture and s o i l temperature relationships are described for the Subalpine Zone by Brooke (1964). Attention i s drawn here only to the most important zonal features. The high proportion of rock outcrop, particularly i n the upper portions of the zone, i s demonstrated well i n Figure 2. On the ridges, the products of weathering are removed as quickly as they are produced and the s o i l i s consequently very shallow. Slopes and depressions are generally covered with a thin mantle of gla c i a l d r i f t . A l l u v i a l soils are absent from the Subalpine Zone except for small marginal deposits along mountain streams. Wet organic soils are also of very limited occurrence because the r e l i e f i s too steep for bog development. 21 Skeletal disintegration i s the most important weathering process in rock outcrop are as, and podzolization i s the most common soil-forming process. In the subalpine podzols, the elluviated (A ) layer i s not readily visible, however, because of continuous darkening from acidic organic accumu-lations. A high proportion of organic matter i s typical for nearly a l l soils in the Subalpine Zone. The snow cover results i n s o i l temperatures that are far belovr the optimal for bacterial activity and even below their minimal temperatures for much of the year. This leads to the development of a mor, i n which decomposition i s primarily due to fungi. The development of very acid conditions i s partly due to fungal activity (Lutz and Chandler 1957). With decomposition limited to that by fungi, and with a very short season for such a c t i v i t i e s , the amount of unincorporated organic matter increases. As an example, on August 20, 1962, leaves of Vaccinium deliciosum from the previous autumn were s t i l l undecomposed i n well-aerated l i t t e r at an a l t i -tude of A800 feet. In contrast, decomposition by micro-organisms would probably have completely destroyed similar l i t t e r by June in warmer bio-climatic zones. These accumulations can result i n very high percentages of organic matter i n subalpine soils, especially where mineral soils are of limited depth. Freezing cycles, which take place before there i s a snow cover, accelerate the mixing of moist organic matter by heaving, expansion and other physical disturbances i n the uppermost horizons. 3. Climate Increased altitude results i n a general decrease i n air temperature (despite increased insolation), larger differences i n temperature between day and night, and greater precipitation. These three influences, in com-bination with a winter maximum i n precipitation, give the Coast Mountains 2 2 unusual accumulations of snow. The significance of this snow has been i n -sufficiently emphasized i n world classification of climate (Kdppen 195A) and vegetation (Rlibel 1936). Summaries of climatic data from permanently established weather stations are usually presented i n ecological descriptions. In this section, l i t t l e attention i s given to this practice because: (l) climatic records are unavailable for most mountain areas i n British Columbia; ( 2 ) long-term measure-ments taken at lower elevations are not applicable to higher areas. In this thesis, climatic data are discussed from only two temporary stations, one i n the lower subzone at 3 2 0 0 feet on Mount Seymour, and the other i n the upper subzone at 4000 feet (see Map, Figure 23),. The 12-month period from August 1, I960 to July 31, 1961 was chosen to represent snowfall, temperature and humidity conditions at these two locations. Most attention i s given to the development of a method which uses published radiosonde data to indicate the frequency of freezing temperatures at various altitudes. a. Precipitation Landsberg (1958) pointed out that early workers believed precipitation to increase uniformly to the tops of mountains, at least up to 10,000 feet. The increase in total annual precipitation up the slope of the mountain north of Burrard Inlet i s clearly shoxm by the figures below (data from The Climate of British Columbia, Report for I960): Station Altitude, feet Total Prec..., inches North Vancouver (Norgate) 15 68.75 North Vancouver (Hollyrood) 600 7A . 5 2 North Vancouver (North Lonsdale) 950 81.58 North Vancouver (Mosquito Creek) 1130 99.01 Mount Seymour 2700 103.66 Hollyburn Ridge 3120 106.66 23 The relationship between annual precipitation at the foot of a mountain (P Q) to that at an elevation, h, (measured in 100-foot units) was expressed empirically by Landsberg (1958) as follows: P h = P Q + 0.72 h •If Norgate data are applied to this formula, Hollyburn Ridge should have a tota.1 annual precipitation of about 91 inches. The discrepancy with actual measurements indicates that there may be anomalies due to topographic config-uration and, more importantly, that there i s not a straight-line relationship with increasing altitude. Walker (l96l) discussed the limitations of upward extrapolation from stations at relatively low levels (as in Spilsbury and Tisdale's work, 1944-). Spreen (19A7) described a s t a t i s t i c a l method of re-lating precipitation to the slope and other characteristics of the terrain. However, this method requires a well distributed network of stations that i s not available i n British Columbia. The main findings of a study by Walker (l96l) are outlined i n the following paragraphs because they represent the best information available for the Coastal Subalpine Zone. Specific estimates of precipitation over mountains were obtained by calculating the orographic component of precipitation along ac t u a l cross sections. These sections were used as interpolative guides and precipitation data were calculated from synoptic analyses which showed the amount of precipitation contributed by air-flows from different directions. Walker's studies on the mechanism of precipitation indicated that the greatest precipitation occurs at cloud b ase. Frontal cloud systems give the bulk of the cold season precipitation and cloud bases during the heaviest rains average £000 feet in coastal regions. In summer, convective precipita-tion i s more important than precipitation from frontal systems. Again,-maximum precipitation i s probably ne ar the base of cumuliform clouds, and Walker generalized by placing the summer level-.of maximum precipitation near 24 6000 feet on the southern coast of British Columbia. On the northern British Columbia coast, where frontal activity i s frequent even i n summer, the a l t i -tude of maximum summer precipitation i s nearer 4OOO feet. There i s a similar south to north gradient in the winter level of maximum precipitation. Since much of this winter precipitation occurs as snow, the altitude of heavy snow accumulation w i l l be lo\rer tov/ards the north. This north-south gradient correlates with the northward altitudinal depression of mountain hemlock (Sudworth 1900, Hoffman 1912). The Coastal Subalpine Zone, which i s defined by the altitudinal distribution of this species, i s therefore similarly correlated with changes i n the altitudinal level of heavy snow ac-cumulations. Comparisons of the altitude at which maximum precipitation occurs on coastal and interior mountains also explain why timberline i s lower on the coast. Walker (p. 93) took into consideration that most precipitation f e l l from frontal cloud systems and placed the level of maximum precipitation at 4OOO feet on the Coast for the whole year, but at 6000 feet i n the Interior of the province. On the Coast there i s a winter maximum i n the precipitation regime so that much of the annual precipitation at the altitude of maximum occurrence w i l l be i n the form of snow. The result i s an accumulation of snow at lower altitudes on the Coast than could be possible i n the Interior, and the upper limit of forests i s depressed. Over the Coast Mountains, total annual precipitation i n excess of 160 inches was calculated by Walker (l96l) for 1956. Measuring stations are so scarce that similar amounts have not been actually recorded i n the moun-tains. Walker (p. 90) gave the following monthly measurements at 3000 feet on Hollyburn Ridge, for a yearly total of 114.2 inches: J F M A M J J A S O N D Total ppt. 10.2 8.9 11.3 6.6 4.2 7..3 4.9 3.2 8.6 13.4 20.2 15.4 inche s 25 The regime above shows the winter concentration of precipitation which i s largely i n the form of snow. At 3120 feet on Hollyburn Ridge, the 7-yeor average for annual winter snowfall i s 302.8 inches (Climate of British Columbia I 9 6 0 ) . Winter totals from the Cascade Mountains where vegetation i s similar to that i n the Coastal Subalpine Zone show similarly large accumulations of snow. Freeman and M artin (1954) l i s t e d average winter totals of 400 inches at 3000 feet on Snoqualmie P ass, and 492 inches at 4400 feet near Mount Baker, both i n the State of Washington. The maximum average snowfall recorded i n the United States (575 inches) i s from Paradise Ranger Station (5550 feet) i n Mount Rainier National Park (Landsberg 1958). In the present study, snow depth was recorded on upright graduated poles at weekly intervals. These weekly values of snow depth would not be the same a s cumulative daily totals as recorded i n permanent climatic stations. In the winter of 1960-61, maximum recorded snow depth was 175 inches at an altitude of 4000 feet on Mount Seymour but only 56 inches at 3200 feet (Figure 6 ) . As expected, there i s also a difference i n duration of snow cover between the two stations. At 3200 feet the f i r s t snow was recorded on November 12, I960, and, except for some snow-free patches i n the last half of December and late January, there was complete snow cover u n t i l April 29. The last patches of snow were gone by May 29, to give a total of 199 days of snow cover. At 4000 feet a trace of snow on October 8 disappeared and the f i r s t permanent snow of the season was on October 29, I960. The last patches disappeared by June 19, 1961 making the duration 234 days. These two examples are considered representative for the lower and upper subzones of this bioclimatic zone. Data were used from laboratory information i n Geology 412 at the University of Br i t i s h Columbia to show the relationships between seasonal pre-cipitation, snow accumulation and stream discharge. The precipitation curve (Figure 5) i s based on 33 years of measurements at an altitude of 583 feet i n to foljqw page 25 14 12 'SZ ^ 1 0 10" snow = l" roin M A M J N Figure 5. Monthly precipitation, including snow,at 583 ft. in Seymour Valley. Discharge is. in equivalent inches for 47 sq.mile watershed. Stippling.] shows season of net increose in snow depth - . . 160 ' 140 ' 120 XZ . .£ 100 a> 5 o c 80 .60 40 20 •J1V K'.K ID.' m 1 00 ro. a — 8 O O CO ro mn — M a x . during month •—M(n. during month — ' 1 s ; 0 : N M M J J A S 0 Figure 6.. Monthly .maximum and minimum snow depths for BPI24 (4000ft) and BPI5 (3200ft.)'''on Mount. Seymour. ' 1960-61." 26 Seymour Valley. Average monthly stream discharge (cubic feat per second) for the Seymour River was theoretically converted to a uniform distribution over the entire area of the drainage basin by the formula: Equivalent depth _ Cu. ft./sec, x 60 x 60 x 24 x 30 x 12 in inches ~ 5280 x 5280 x area i n sq, mi. For this particular watershed, months throughout a year may be placed i n three categories: (l) months when there i s a net increase i n snow depth -November to March inclusivej (2) months when there i s a net decrease i n snow depth - April, May and June^ and (3) months when l i t t l e or no snow remains -July to October inclusive. These three periods are closely correlated with the monthly changes i n stream discharge (Figures 5 and 6), During the wettest months of the year most of the precipitation occurs as snow, and during the months when there i s a net increase i n snow there i s an excess of precipitation over runoff because most of the snow i s stored i n the drainage basin (Figure 5). At the time of spring runoff, stream discharge i n equivalent inches far exceeds precipitation. The excess of discharge over pre-cipitation i n July results from the melting of late snow-patches i n the Sub-alpine Zone, even though the two stations represented i n Figure 6 show no snow remaining i n July, 1961. The f i n a l feature of importance i s the similarity i n slope of the precipitation and discharge curves when snow i s not involved as a storage factor. The normal increase i n precipitation from August onwards i s followed by a proportionate increase i n stream discharge, u n t i l freezing temperatures and snow again hinder runoff. The secondary December peak in discharge i s a result of heavy rains i n the levels of the watershed which are below snow-line at that time of year. The relationships described above indicate the necessity for knowledge of subalpine climatic and ecological conditions i f water production and run-27 off control are to be considered i n land management. b. Humidity and Temperature Stevenson screens were placed near ground level with the sensitive portion of the hygrothermographs 25 centimeters above the s o i l surface. During winter, the screens were mounted on trees so that they could be readily moved up or down with fluctuating snow levels. The station near 3200 feet (BP 15) was i n a shaded mesic Vaccinium alaskaense association of the lower subzone. The station at 4000 feet (BP 124) was more exposed and was located i n a l i t h i c Gladothamnus association. There are three distinct diurnal patterns of relative humidity throughout the year i n the Subalpine Zone (Figures 7 to 10 inclusive). The f i r s t i s the typical winter trace as shown by the f i r s t four days in Figure 7 and the entire week in Figure 8 . During this season relative humidity may remain above 90 per cent for days at a time especially i f cloud base i s below the altitude of the measuring station. Eis (1962b) observed similar traces i n lower elevations of the Western Hemlock Zone. Relative humidity i n the Stev-enson screen was often between 90 and 95 per cent even when i t was raining. It rose to 100 per cent only i n time of heavy dew or fog. The second diurnal pattern of relative humidity occurs during clear summer weather. It i s characterized by a very marked difference between day and night, as shown i n the top trace of Figure 9. The daily range of relative humidity i s greatest on the more exposed station at 4000 feet. The third pattern i s characterized by continuously low humidities and i s associated with temperature inversions during the winter. The trace i n Figure 10 shows humidities which are unknown at lower altitudes. Vancouver reported relative humidities of 100 per cent when they were as low as 10 per to follow page 27 to follow page to follow page 27 28 cent at 3200 feet on Mount Seymour. Prom the evening of January 18 u n t i l January 23 i t was foggy at Vancouver Airport, but continuously clear at higher altitudes on the mountains. Turner (1953) described similar periods of low humidity for south coastal British Columbia. They occur mainly when warm, dry tropical a i r overrides several hundred feet of cooler maritime air. The great diurnal variations of relative humidity, particularly i n the summer months, make average values relatively meaningless. To characterize humidity conditions at the two subalpine stations, a frequency distribution for 10 per cent humidity-classes was used (Figure l l ) . The original hygrothermo-graph sheets from a 12-month period were sampled by two-hour intervals. The humidity shown at every two-hour intersection along the trace was t a l l i e d i n the appropriate 10 per cent class. By this method, 2504 readings were t a l l i e d for station BP 124 and 2687 for station BP 15 over the one-year period. The results were plotted on logarithmic paper so that the small frequency of low humidities could be shown. Figure 11 indicates the relative occurrence of the humidity features discussed i n the preceding paragraphs. For example, humid-i t i e s between 90 and 100 per cent occur more th an 50 per cent of the time,- and humidities less than 20 per cent occur approximately one per cent of the time; As expected, the shaded station showed a smaller frequency of humidities i n the lower classes than the exposed station (BP 124). During the periods of uniformly high relative humidity, temperatures do not vary more than three or four degrees daily and these uniform temperatures are common during much of the winter (Figures 7 and 8). In clear summer weather, the diurnal variation of temperature i s much greater on the relatively exposed station at 4000 feet (BP 124) than at sea level (Figure 9) . Diurnal variation i s much less i n the shaded station at 3200 feet and i t i s a few degrees cooler than the sea level station at a l l times of the day. On a cloudy summer day (July 23, Figure 9) the great to follow page 28 90 50 10 u c cu 3 CU 0 . 5 -0.1 I -/// / / / /// / / / //I / / / /// /// '// / / * '// / / / '// / / / '// /// * / / / / V ' / / / /f ' / / /// * / / /// '// /•/ '// /S/ '/' ' / / / / / • // / / / ' / / ' / / / / / ' / / / / / • // ' / / /// ' / / '// '// /// '// • / / /// * / / /// '// '// ' / / / / / ' / / '// ' / / ' / / '// '// ' / / • // '// '/J '// /// '// ' / / '// / / / ' / / /// '// '// '// ' / / ' / / ' / / '// ' / / ' // ' s / '// ' / / '// ' / / ' / / '// '// 'J / ' / / '// '// '// ' • / / '// '// // '// / / // '// '// '// '// '// '// ' / / ' / / '// ' // '// '// ' / / '// '// • / / ' / V '// '// • '/* f/t '// • // '// '// • / / /// '/* • / / /// f / / •// / / / ' / / ' / / ' / / ' / / • // '// t / / '// /// '/i '// '// / /1 • // '// ' / / '// '// • // 'SS ' / / ' / / '// / / / '// 'S/ f f / ' / / / / / '// '// ' / / '// '/s t// '// '// '// '// ' s / '// / / / / / / '// '// s / / '// '// ' / / / / / '// '// /// / / / '// "/ '// '// f// '// f/l '// '// / / / '// '/S / / * '// 'S/ '// '// / / / '// s / / '// / /1 ' / / '/s / s * ' // '// / / / '// / •/ '// '// ' / s • // //•/ f /' //, '// '// / / J '// '// / • < ' / / • // f / / ' / / '/' /// '// > / / //I ' / / ' / s /'t '// '// /' / f// '// /// '// '// / ' ' / / '// s / > ' / / '// / s * ' / / '// / / / '// //* ' / / '// '// '// '/S ' / / f // ' / / '// '// 'S' '// ' / / / / / ' / V ' / / /// ' / f '// 'S/ '// '// '// '// //* t// f// /// /// '// /// " / '// /// '// '// /// ! '/S I f// • r// >// '// '// '// '// : '// '// f// tss '// '// '// ff/ /// '// /// s// s// ff/ /// /// /// /// /// '// /// '// '// /// '// >// ' / / '// '// '// '// '// '// '// '// '// ' / / r / / '// '// >// '// '// '// '// ' / / '// '// r// '// '// '// "( '// / / / ' / / '// ' / / >// '// '// ' / / '// ' / / '// ' / / ' / / f / / '// / / ' / / ' / / ' / / ' / / ' / s '// / / // / / / / >// 90 50 10 0.5 25 35- 45 55 65 Midpoint of 10% relative humidity 75 85 classes 95 0.1 Figure l l . . Frequency distribution of relative humidity by 10% classes for BP 124 (4000 ft.) and BP 15 (3200 ff.) on Mount Seymour. Aug. I, I960 to" July. 31 ,-.1961, 29 differences i n diurnal range between the shaded and unshaded subalpine stations are eliminated, and both of them are 10 to 15 degrees cooler than the station ne ar sea level. The altitudinal gradient in temperature i s best revealed during cloudy weather i n winterj temperatures at 4OOO feet are usually 15 degrees lower than those near sea level at this time of year (Figure 8). During an inversion from January 18 to 23, 1962, temperatures at 3200 feet on the mountain were as much as 26 degrees warmer than those at Vancouver Airport (Figure 10). The freezing level at this time was over 11,000 feet which i s a common summer position (compare to freezing levels for July 21 to 23, Figure 9). Such conditions arc not common, but one or two invasions of warm, dry tropical a i r may be expected every winter. I f the warm a i r mass re-mains over the mountains for several consecutive days, snow levels may be greatly reduced. The decrease i n snow depth during December I960 (Figure 6) resulted from a prolonged temperature inversion. There can also be inversions when there are outbreaks of continental Arctic air from the east. However, these are of shorter duration because of heating from below by water surfaces. In a l l months, the mean temperatures are lower for mountain stations than for Vancouver Airport (Table II). The mean monthly temperature for January was less than the mean temperature for February at Vancouver Airport. In contrast, the January mean was considerably higher than the February mean at the mountain stations. This reflects the importance of temperature inver-sions during January. On the two mountain stations, the mean monthly minimum temperature was always lower at the relatively exposed station (4OOO feet). The mean monthly maximum was higher at the 4OOO feet station from June to October inclusive but the mean monthly temperature i s higher at the upper station only during July, August and September. Schmidt (i960) stressed that conventional methods of compiling meteor-ological data are of l i t t l e use i n relating climate to growth of trees, nor do TABLE II Suirauary of mean monthly, maximum and minimum temperatures for Vancouver Airport and for 3200 f t . and 4OOO f t . on Mount Seymour. Aug. 1, I960 to July 31, 1961 Vancouver Airport ( 16 f t . ) : Aug. Sept. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Mean monthly max. 68.5 6 3 . 1 56.7 4 8 . 3 4 4 . 3 4 5 . 5 .47.9 51 .6 54.3 61 .5 70 .4 7 3 . 9 Mean monthly min. 55.4 49 .6 4 7 . 1 3 8 . 5 3 4 - 3 3 6 . 1 3 9 . 3 4 0 . 1 4 3 . 1 4 8 . 4 54.2 57.3 Mean monthly temp. 6 I . 4 5 6 . 5 51.8 4 3 . 4 3 9 . 2 40.3 4 3 . 5 45 .0 4 8 . 7 5 5 . 0 62.3 6 6 . 1 Mount Seymour (3200 f t . ) BP15: Mean monthly max. 54-3 54.4 45.9 3 5 . 1 3 6 . 7 39 .9 33.4 3 4 . 0 3 6 . 7 4 6 . 2 5 8 . 6 6 2 . 1 Mean monthly min. 4 7 . 2 4 6 . 9 4 0 . 2 3 1 . 4 3 1 . 3 3 3 . 7 2 9 . 0 23.9 3 1 . 7 3 9 . 0 4 3 . 6 53 .1 Mean monthly temp. 5 0 . 7 5 0 . 1 4 3 . 0 3 3 . 2 3 4 . 0 36.8 3 1 . 2 31 .4 34*2 4 2 . 3 5 3 . 6 5 7 . 6 Mount Seymour (4OOO f t . ) BP124 Msan monthly max. 59.8 62.6 4 7 . 6 3 4 . 6 3 6 . 3 3 9 . 0 31 .3 3 2 . 2 3 5 . 3 4 4 . 6 6 1 . 5 7 2 . 4 Mean monthly min. 4 3 . 5 4 0 . 5 3 7 . 0 28 .2 29 .0 31.8 27 .3 27 .0 29 .5 36.9 4 4 - 0 4 8 , 4 Mean monthly temp. 51.5 51.5 4 2 . 3 31.4 3 2 . 4 3 5 . 4 2 9 . 3 29 .6 3 2 . 4 4 0 . 7 52.7 6 O . 4 31 they provide a means of describing and classifying altitudinal climatic grad-ients. He recommended the use of accumulated temperatures on an hour-degree basis i n relation to various threshold values. Summaries of accumulated temperatures are presented in Table III to allow comparisons with other bioclimatic zones (Krajina 1959). Day-degrees above 43° F. were calculated from the difference between the daily mean temp-erature and 43° F., when the former was more than the threshold value. The annual number of day-degrees over 43° F. was i486 at the shaded station (3200 feet), I642 at the more exposed station (4000 feet), and 3264 at Vancouver Airport (16 feet). These compare with 1500-3000 for the Coastal Western Hem-lock Zone and 2500-3500 for the Coastal Douglas-fir Zone (Krajina 1963). In this same table, the number of days with a mean temperature over 32° F. and the accumulated day-degrees over 32° F. are also shown. With 32° F. as the threshold value, the shaded station at 3200 feet was slightly warmer than the higher station, whereas the opposite was true when 43° F. was used as a thresh-old value. Hour-degrees as recommended by Schmidt (i960) may be measured by a planimeter on thermograph sheets, or by taking direct hourly readings from the trace and relating i t to the threshold value. The latter method was used here but readings were taken only every two hours as recommended by Landsberg (1958, p. 149). Because of i t s direct relationship to snow accumulation, 32° F. was chosen as the threshold value. The results are presented i n Table IV as hour-degrees over 32° F. for each month. The monthly values would not be directly comparable because the months vary i n length and correction factors to obtain a standard month were applied. The magnitude of temperature decrease with increased altitude i s shown by the station at 4000 feet which has less than half the hour-degrees over 32° F. recorded for Vancouver Airport. By this method, the 4000-foot station i s cooler than that TABLE III Summary of day-degrees over 43oF. and over 32°F. for Vancouver Airport and for 3200 f t . and 4000 f t . on Mount Seymour. Aug. 1, I960 to July 31, 1961 Vancouver Airport ( l 6 f t . ) : No, days with mean temp, over 43°F. Dav-degrees over 43°F. Aug. Sept. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Year 31 4£7 30 4 0 1 31 268 15 42 8 2 0 12 44 15 4 6 23 119 27 168 31 380 3 0 581 31 708 284 3264 No. days v/ith mean temp, over 32°F. Day-degrees over 32°F. 31 828 30 731 31 609 30 400 3 0 180 31 351 28 321 31 429 30 496 31 721 30 31 911 1049 364 7026 Mount Seymour (3200 f t . ) BP15: No. days v/ith mean temp, over 43°F. Day-degrees over 43°F. 28 249 29 231 16 85 2 6 2 2 5 38 0 0 0 0 0 0 14 97 27 324 31 4 5 4 154 i486 No. days with mean temp, over 32°F. Day-degrees over 32°F. 31 587 30 560 31 342 2 0 70 22 96 23 170 1 1 3 0 16 50 23 88 30 330 30 650 31 794 298 3767 Mount Seymour (4.OOO ft. ) BP124.: No. days with mean temp, over 43°F. Day-degrees over 43°F. 22 292 26 265 14 94 2 11 2 4 4 37 0 0 0 0 0 0 1 0 80 2 6 317 31 540 137 I642 No. days with mean temp, over 32°F. Day-degrees over 32°F. 31 609 30 587 31 312 13 51 15 65 19 144 4 13 U 30 17 60 29 274 30 637 31 880 264 3642 TABLE IV Summary of hour-degrees over 32°F. for Vancouver Airport and for 3200 f t . and 4.000 f t . on Mount Seymour. Aug. 1, I960 to July 31, 1961 Aug. Sept. Oct, Nov. Dec. Jan. Feb. Mar. Apr. May June July Year Vancouver Airport (l6 f t . ) ; Hour-degrees over 32°F. * Corrected to std. month % of hrs. i n month 3 2 ° or more 21874 21458 100 17631 1 4 7 3 4 17878 I 4 4 5 4 100 100 8250 8366 100 5527 5 4 2 2 90.6 6773 6644 93.4 5979 6493 100 9679 11757 9495 11922 93.9 1 0 0 16966 I 6 6 4 4 100 21750 2 2 0 5 5 100 25088 2 4 . 6 1 1 100 166,008 Mount Seymour ( 3 2 0 0 f t . ) BP15: Hour-degrees over 32°F. * Corrected to std. month % of hrs. i n month 3 2 ° or more 13744 13483 100 13008 13190 100 7840 7691 99.7 1650 1673 6 4 . 4 2 L 4 6 2105 70.2 4092 4 0 L 4 75.0 860 934 35.1 1476 1 4 4 8 53.2 2236 2267 73.1 7836 7687 93.1 15502 15719 100 18679 13324 100 89,069 Mount Seymour (4000 f t . ) BP124: Hour-degrees over 3 2°F. * Corrected to std. month % of hrs. i n month 3 2 ° or more 13554 13296 100 12298 12470 100 5918 5806 96.0 1186 1 2 0 3 39.4-2116 2076 48*6 3702 3632 58.1 388 4 2 1 21.7 814 798 39.8 1 4 2 4 1444 58.1 6470 6347 94 . 4 14222 I 4 4 2 I 100 1 9 3 5 2 13984 100 81,444 * Standard month taken as 365/12 = 30.417 days. Correction factor for 28-day month = 30.417/28 = 1.086; for 30-day month = 1.014; for 31-day month = 0,981 34 at 3200 feet during every month except July, whereas in other methods of cal-culating accumulated temperature (Table III) this relationship was not always revealed so clearly. There i s l i t t l e doubt that the expression of data by accumulated hour-degrees i s more accurate, although more time consuming. When accumulated hour-degrees are related to snow accumulation at various altitudes, a lag i n early spring warming i s noted at the two subalpine stations (Figure 12). Particularly i n March and April, the high albedo of snow surface prevents i t from absorbing much heat. These relationships result in a marked reduction of the growing season at higher altitude. . Scologists have used temperature data i n many different ways i n attempts to correlate i t with plant l i f e . Daubenmire (1938) and Kramer and Kozlowski (i960) c r i t i c i z e d methods of correlating temperature summations with biotic features because i t requires the assumption that each degree of temper-ature has the same significance. A further weakness i s that interacting phases of climate tend to make isotherms impractical as guides to the distribution of vegetation (Kramer and iiozlowski I960). Degrees along a temperature scale may ordinarily be considered as a continuum as far as their direct influence on plant l i f e i s concerned.. How-ever, the physical changes which occur at the freezing point of water disrupt the temperature continuum at this point. This i s especially significant in areas of high precipitation where freezing temperatures of a certain frequency w i l l cause snow accumulations that greatly shorten the growing season for plants. For this reason, the remainder of this section i s devoted to a determination of the frequency of freezing temperatures at various altitudes i n the zone. c. Freezing Levels The hypothesis t h a t radiosonde freezing level data could be used in c o o CM ro > o 24 22 20 •18 U 6 14 . 12 .10 8 at o I 2 • ft ft -r • • • •: • • • I • • • ft ft ft •• • • • I. ft ft * •-• • » ^ O C - 50 -100 • • • c • • « «-• • • -~ • • • •! • • • -• • • «I • • <-« • • *-• • • v • • •. -••••«: • • . . — -o. T 3 S o <= cn -150 -200 • • • » • • • » • i-• • « — i « « «— « « ft iZ i • ft ft— ft ft ft > I ft ft ft— • 9 • n (960: A Figure 12 oirport -• • • i • • • • • • I • • • » • • • • • • • • • > • • * • • • • • • •— • • ft • ft ft-7 • ft ft ft ft ft d ft » ft I ft ft • ft ft • •-ft ft • 1 • ft ft-• • • 4 • * • • • * • • • c • • • -• • • r ; • • •• • • » z i • • •" • • •— • • • c • • ft— ft ft ft ; . ft • * • « •: • * * : •« • • • • : > • » •-• • • -• • • -• • • z » ft ft • • • : • • • * • « «i « • « r i • • ft-« # « i i • « #-• • •* • • c ft ••• T M M Relationship of accumulated temperature to snow depth for altitudes of vertical bars), 3200 ft. (BPI5-dots), and 4000 ft. ( BP 124-horizontal bars) J J 1961 V 7 ft. (Vancouver o S o 35 to determine the frequency of freezing temperatures on a mountain slope was tested i n several ways. The nearest station from which readings were available v/as Port Hardy (Latitude 50°14' N, Longitude 127°22' VI) 225 miles northwest of the study area. Daily readings at 4 P«m. (00:00 Greenwich Mean Time) and 4- a.m. (12:00 Greenwich Mean Time), obtained from a balloon ascent which records the altitude at which a freezing temperature i s f i r s t encountered, are published as geopotential kilometers above saa level i n the Monthly Bulletin Canadian Radiosonde Data. Radiosonde readings were converted to altitude i n feet and the values were plotted on the hygrothermograph sheets for the days shown i n Figures 7 to 10 inclusive. Figures 7 and 8 are stippled when the freezing level was at 4.000 feet or less on the basis of radiosonde readings. This stippling re-presents the time when the temperature should also be 32° F. or less at the same altitude (4000 feet) on a mountain slope i f temperature measurement by atmospheric radiosonde methods are comparable with those obtained from a thermograph at a ground station. From November 24. to 28, 1961, when the freezing level was below 4.000 feet at Port Hardy (stippled area, Figure 7) temperatures were also below freezing at 4-000 feet on Mount Seymour. When the level rose ahove 4000 feet over Port Hardy, a corresponding rise above freezing was shown at the 4000-foot mountain station. Even small fluctuations i n the freezing level over Port Hardy coincide with changes in the thermograph trace on Mount Seymour, 225 miles away (see Figure 7, 4 a.m., November 30, 196l). Further relation-ships can be observed by study of the graphs i n Figures 7 and 8, and even closer correlations could be expected i f radiosonde data were available more frequently than every 12 hours. For comparison, the freezing levels for one week i n the summer are shown in Figure 9 , and the great change in freezing 3 6 level during a winter temperature inversion i s shown i n Figure 10. The selected examples (Figures 7 to 10) do not necessarily prove that the radiosonde readings can be used to characterize freezing levels on a mountain slope. For example, a weather front between Port Hardy and the local study area could disrupt freezing levels. Therefore, i t was necessary to test the relationship over a period of time. The monthly frequencies of temperature 32° F. or over at altitudes of 3200 feet and 4OOO feet over Port Hardy, based only on radiosonde data, show a remarkable similarity to the same information for the same 12-month period based on thermograph data from stations at 3200 feet and 4OOO feet on Mount Seymour (Figures 13a and 13b). To test the relationship further, a Chi-square test of the frequency of freezing temperatures at 4OOO feet or less over Port Hardy and at 4OOO feet on Mount Seymour was carried out for the season when freezing levels could be expected to intersect the mountain-side (Table V). At the .05 level of prob-ab i l i t y , there i s no significant difference i n the frequency of freezing temperatures at 4.p.m. when the radiosonde, and thermograph methods are com-pared. At 4 a.m. there i s a significant difference because the daily minimum at the ground station occurs i n the early morning as a result of nocturnal cooling. But this lack of agreement for the early morning readings i s a result of the morning heat balance near the ground and i s not necessarily dependent upon the atmospheric freezing level, nor does i t reflect a fault of the proposed use of atmospheric radiosonde data. Both a.m. and p.m. radio-sonde readings could be used, and the only weakness would be an underestimate of the frequency of freezing temperatures at ground level in the early morning. The evidence above indicates that over a period of time the freezing isotherm w i l l intersect a mountain-side at an altitude similar to that measured • • 1 I • • ft ft • I • • ft ft « I • ft ft ft < > ft • • • • ' ft ft • • * > ft ft ft ft 4 I • • • ft 4 I ft « • ft 4 • ft ft ft « » ft ft • ft « I ft « ft ft I I ft < ft ft » ft 4 Mount Seymour B.C. * • * • ft ft 4 ft ft • • 1 ft • « * ft ft ft « ft • 4 . ft ft ft ft « I ft I ft • i ft < ft • » ft t ft • • • 4 ft ft » ft ft > ft 41 ft ft I ft • • ft I ft • ft ft • • • • • • ft 4 41 ft ft ft 4 ft ft ft ft 4 ft • • ft ft ft ft I ft ft ft ft * ft ft ft ft • • '* I ft » ft ft 100 9 0 8 0 7 0 6 0 5 0 4 0 30 - 20 - 10 0 N M M I 9 6 0 1961 Figure 13b. Frequency of temperatures 32°F or over for 3200 ft.(BP 15) and 4 0 0 0 ft. (BPI24) on Mount Seymour, based on 4380 readings for each altitude. io s o I d 3 7 T A B L E V Frequencies of freezing temperatures (4 a.m. and 4 p.m.) at an altitude of 4OOO feet over Port Hardy and for the same altitude on Mount Seymour. Sept. 1 , I 9 6 0 to May 3 1 , 1 9 6 1 ..4OOO feet over Port Hardy 4000 feet on Mount Seymour 4 p.m.-' 4 a.m. 4 p.m. 4 a.m. Freezing level 4OOO feet or less 8 9 9 8 Temp. 3 1 - 5 ° F . or less at 4000 feet 9 9 123 Freezing level over 4OOO feet 1 8 4 1 7 5 Temp. 3 1 . 5 * F . or over at 4000 feet 1 7 4 1 5 0 Total 2 7 3 2 7 3 2 7 3 2 7 3 Tests of significance: (P.05 F O R 1 D' F* = 3 . 8 4 ) at 4 p.ia.' 0 . 8 1 = no significant difference at 4 a.m. 4 « 7 5 = significant difference some distance away. This w i l l apply especially for relatively cold a i r masses, which are more affected by obstructing mountain ranges than are warm a i r masses^ stable cold a i r may be slowed or even stopped i n i t s movement by intercepting high mountains (Davis 1 9 5 9 , p. 1 3 8 ) . Periodic discrepancies can be expected because i t i s known that during f l i g h t over mountains i n cloudy weather, icing may occur at lower levels than i n the same a i r mass over level country (World-Met. Organ. I 9 6 0 ) , and the presence of a weather front between the radiosonde station and the mountain in question could influence the altitude of the freezing level. Furthermore, evapotranspiration and other vegetational i n -fluences could affect the freezing isotherm. The forest cover on the 3200-foot station, i n contrast to the openness at the 4-000-foot station, would have some influence on the frequency of freezing temperatures (Figure 13b), but apparently none of these influences wa-s'J important enough i n the com-parisons betwsen Fort Hardy and Mount Seymour to disrupt the close relationships 1 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 Altitude, in thousands of feet Figure 14. Cumulative percentage frequency showing occurrence of freezing level at various altitudes. Data from Port Hardy, B.C. , Jan.1,1959 to - May 31,1962. • 38 shown above. Therefore, i t should be possible to determine from radiosonde data the frequency of freezing temperature for any period of the year for any altitude on a mountain-side. Accordingly, a cumulative percentage frequency (ogive) curve was constructed for altitudes up to 17,000 feet (Figure 14). These curves are based on approximately 24.OO published radiosonde readings from January 1, 1959 to May 31, 1962. In cases where the temperature was below freezing throughout the sounding, freezing level was t a l l i e d at the surface. In cases when there was a temperature inversion, the free zing level was not t a l l i e d at the ground level but at the altitude where a freezing temperature was again recorded. The results were plotted by months, but where two or more months shov/ed a similar frequency distribution they were grouped. The curves are similar to those published by the U. S. Navy (1956) and have a number of useful appli-cations. They allow determination of the frequency of occurrence of the 32° F. isotherm above or below any given altitude. There are two ways to read the graph: i f freezing level i s equal to or less than 3000 feet i n 32 per cent of the observations during November, then obviously i t i s above 3000 feet during 68 per cent of the observations. There i s a great altitudinal lowering of the freezing isotherm from November to May inclusive (Figure 14), The curves also rise more sharply during these months, particularly within the altitudinal limits of the lower subzone. This means that a small increase i n altitude i n the lower half of the Subalpine Zone w i l l be associated with a relatively large increase i n the frequency of freezing temperatures during the winter months (Figure 15a). To construct the histograms i n Figure 15, an altitudinal range which would include a l l mountains i n the study area was selected (0 to 11,000 feet). From a large-scale reproduction of Figure 14, the frequency of freezing temp-eratures for each month were t a l l i e d for every 500-foot altitudinal class. ! to follow page 5§ 10 9 8 7 6 5 c e 4 CL 3 h 2 (a) Oct.I.to May 31, average of 1959, 60,6 I ; S 62./ , o m tv-o o o o o m m m m m N s w s N . — — CM CM fO o IT) •rO O o O O O O O O O O . O S f > i n m m m i n i r > i n m m m W N N h- CM , F- CM f"- CM CM in in - io • ( O S N oo co cn o CD CM o o' 10 9 -8 -7 6 ••' 5 3 . 2 Mid-point, of altitudinal class ,'feet.' (b) June I to Sept. 30, average ! :. of 1959,60 a 61. . Figure 15. Percentage increase in the frequency of freezing temperatures for each additional 500 ft. rise in altitude from 500 to 11,000 ft. . above, m.s.l., for (a) "winter" and (b) "summer". Data from Port . Hardy, B.C. 39 Months during which snowfall normally occurs i n the Subalpine Zone were grouped as "winter11 months (October to May inclusive) and the remainder were grouped as "summer" months. Freezing temperatures which were recorded at zero altitude i n Figure 14 were excluded i n the computation for Figure 15 because they \-rere mainly ground frosts and were not directly related to an altitudinal analysis of freezing levels. Therefore, the 500 to 1000 f t . altitudinal class i s the f i r s t one shown i n Figure 15. The bars are plotted at the mid-points of the classes, and each bar shows the percentage increase i n the frequency of freez-ing temperatures that could be expected for each additional 500-foot rise up a mountain-side. The bars are additive to 100 per cent, but this does not mean that the freezing level i s below 11,000 feet 100 per cent of the time (Figure L4 shows that i t i s not). Percentages refer only to the particular altitudinal range that was <;hosen. The summer values are presented only for comparison and are of l i t t l e importance since the freezing level i s usually above the Subal-pine Zone during these months. The 32° F. isotherm most frequently occurs between 2250 and 4250 feet i n the period from October 1 to May 31 (Figure 15a), and i n many individual months the modal occurrence of the freezing level was observed to be i n the 3250-foot altitudinal class. The concentration of winter freezing levels i n this altitudinal range coincides with the sharp increase i n snow accumulation §t this level on the mountains of the study area. At 3000 feet approximately 33 per cent of the observations from October 1 to May 31 indicate temperatures at or below freezing (summation of the f i r s t five bars i n Figure 15). This i s sufficient to maintain a snow cover'that greatly shortens the growing season. The rapid increase i n the frequency of freezing' temperatures up to the 4250-foot class accounts for the 117-inch difference in maximum snow depth between the 3200 and 4000-foot stations (Figure 6). This i s the main climatic d i f f e r -ence of the two f l o r i s t i c a l l y distinct subzones of the Subalpine Zone. 4-0 D. The Vegetation In this section, the f l o r i s t i c features which identify the Sub-alpine Mountain Hemlock Zone and which distinguish within i t two altitudinal TABLE VI Vegetational characteristics of the Subalpine Zone Differentiating species for lower subzone ON MESIC HABITATS Tsuga heterophylla  Menziesia ferruginea Differentiating species for upper subzone ON MESIC HABITATS Vaccinium deliciosum  Cassiope mertensiana Character species for entire zone ON MESIC HABITATS Abies amabilis (low vigour) Tsuga mertensiana  Vaccinium membranaceum  Rhododendron albiflorum Sorbus occidentalis  Rubus pedatus  Rhytidiopsis robusta  Kiaeria b l y t t i i  Orthocaulis f l o e r k i i ON WET EDAPHIC HABITATS Abies amabilis (high vigour) Chamaecyparis nootkatensis Valeriana sitchensis  Veratrum eschscholtzii ON DRY EDAPHIC HABITATS Cladothamnus pyrolaeflorus  Lescuraea baileyi  Pilophoron h a l l i i Vaccinium alaskaense  Vaccinium ovalifolium Blechnum spicant  Lysichitum americanum Mnium spinulosum Scapania bolanderi  Plagiothecium undulatum ON DRY EDAPHIC HABITATS Goodyera oblongifolia Phyllodoce empetriformis Gaultheria huraifusa Leptarrhena p y r o l i f o l i a  Parnassia fimbriata Polytrichum norvegicum ON DRY EDAPHIC HABITATS Saxifraga ferruginea  Luzula wahlenbergii  Lycopodium sitchense  Cetraria islandica  Cetraria stenophylla  Crocvnia merabranacea  Andreaea rupestris  Grimmia alpestris  Oligotrichum hercynicum  Umbilicaria torrefacta Streptopus amplexifolius Tofieldia glutinosa  Streptopus roseus Juncus mertensianus Tiare l l a t r i f o l i a t a Andreaea nivalis T i a r e l l a unifoliata Gymnomitrium varians Pyrola secunda Luetkea pectinate Cornus canadensis Saxifraga tolmiei Clintonia uniflora Deschampsia atropurpurea Listera caurina Hieracium gracile  Listera cordata Streptopus streptopoides ON WET EDAPHIC HABITATS Hypnum circinale Salix comrautata Rhytidiadelphus loreus Carex nigricans Lophocolea heterophylla Carex spectabilis Caltha leptosepala ON WET EDAPHIC HABITATS Erigeron peregrinus Rubus spectabilis Hippuris montana Athyrium f i l i x - f emina Juncus drummondii subzones a r e discussed. There i s also an enumeration of species which occur sporadically within the zone, and f i n a l l y some of the more important zonal influences on the vegetation are presented. The latter section deals with vegetation patterns, height growth of trees and relations of ti-ee height to diameter with increasing altitude, the influence of snow on basal crook in tree stems, and relative turgidity measurements of amabilis f i r and mountain hemlock needles from trees i n the upper and lower subzones. 1. Zonal and Subzonal F l o r i s t i c Features The low forest productivity and the relative inaccessibility have helped to keep the vegetation undisturbed. There are no anthropogenous com-munities i n the zone end few introduced species. The zonal character species are shown for mesic, wet and dry habitats i n the f i r s t column of Table VI. In addition, there i s a tabulation of differentiating species for the lower and upper subzones. Many of the differentiating species for the lower subzone occur also i n the Coastal Western Hemlock Zone at lower altitudes. But when they occur i n combination with the zonal subalpine species of column one i n Table VI, they can be used for differentiation of lower subalpine conditions. Mountain hemlock i s the most common large trees i n the zone (Table VII). Of a l l trees measured'on 71 forested sample plots, 46.7 per cent of the trees larger than the 10-inch diameter class were mountain hemlock, 38.4 per cent were amabilis f i r and only 14.9 per cent were yellow cedar. Con-versely, amabilis f i r was the most abundant tree i n the 10-inch class or less, followed by mountain hemlock and. yellow cedar. Almost 70 per cent of the amabilis f i r on the sample plots were i n the 10-inch class or less, 67.0 per cent of the cedar, and 53.3 per cent of the mountain hemlock (Table VII). S i l v i c a l characteristics of mountain hemlock were summarized by 42 TABL3 VII P r o p o r t i o n of species, s i z e d i s t r i b u t i o n , and frequency of b a s a l snow-crook on 71 f o r e s t e d p l o t s i n the Subalpine Zone. Am a b i l i s f i r Yellow cedar Mountain hemlock T o t a l No. % No. % No. % Trees 10" c l a s s or l e s s % of t o t a l f o r species 1054 51.4 69.7 360 17 . 6 67.0 634 3 1 . 0 53.3 2048 Trees over 10" c l a s s % of t o t a l f o r species 457 3 8 . 4 3 0 . 3 177 14.9 3 3 . 0 556 46.7 4 6 . 7 1190 T o t a l 1511 537 1190 3238 Trees 10" c l a s s or l e s s w i t h snow-crook % of t o t a l p o s s i b l e 222 21 .1 133 36 .9 255 4 0 . 2 610 Trees over 10" c l a s s w i t h snow-crook % of t o t a l p o s s i b l e 18 3 . 9 3 1.7 53 9 . 5 74 Dahms (1958) and the 1962 review by F r a n k l i n c o l l e c t s many a d d i t i o n a l r e f e r e n -ces f o r the species. Heusser's (i960) range map f o r mountain hemlock i s the best a v a i l a b l e . Schmidt (1957) di s c u s s e d the s i l v i c s and d i s t r i b u t i o n o f a m a b i l i s f i r i n d e t a i l , Dimock (1958) reviewed the s i l v i c a l c h a r a c t e r i s t i c s of the species, and Haddock ( l 9 6 l ) r e c e n t l y p u b l i s h e d new i n f o r m a t i o n on the d i s t r i b u t i o n o f a m a b i l i s f i r . S i l v i c a l c h a r a c t e r i s t i c s of y e l l o w cedar were discussed by Sudworth (1908), B e t t s (1953) and Andersen (1959). As the zonal species i n the study area, mountain hemlock grows on a wide v a r i e t y of h a b i t a t s . I t can regenerate i n dense shade, on decayed wood, or on humus. Mhen i t occurs i n seepage h a b i t a t s a t lower l e v e l s of the zone, i t i s o f t e n confined to humps created by i r r e g u l a r i t i e s i n the topography or by accumulation of organic matter j the species t h r i v e s on eminences of i t s own making. I n the upper p o r t i o n s of the Subalpine Zone, r i d g e s are the most 43 p o d z o l i z e d areas and mountain hemlock i s the most s u c c e s s f u l t r e e species there. Even on r e l a t i v e l y bare areas, such as morainal surfaces, i t w i l l germinate and grow s u c c e s s f u l l y . I t i s a l s o the f i r s t t r e e species to invade the P h y l l o - doce - Gassiope heaths (see P l a t e I , F and P l a t e I I , C), as discussed by B r i n k (1959). The s p a r s e l y d i s t r i b u t e d t r e e s on the upper slope i n Figure 3 and i n P l a t e I , G are a l l mountain hemlock. I t i s c l e a r l y the zonal species f o r the area, A m a b i l i s f i r and y e l l o w cedar, which are both t y p i c a l P a c i f i c Coast elements ( P o r s i l d 1958), are s t r o n g l y c o n t r o l l e d by edaphic c o n d i t i o n s . The most productive f o r e s t stands are on warm southwest slopes near the lower l i m i t s of the zone, and a m a b i l i s f i r c o n t r i b u t e s the gr e a t e s t volume on such stands (see Figure 25A - the t y p i c a l s u b a s s o c i a t i o n of the Streptopus a s s o c i a t i o n , and P l a t e I , A). A m a b i l i s f i r i s abundant i n a l l l a y e r s because i t i s the most shade t o l e r a n t t r e e on the coast of B r i t i s h Columbia, and i t s best development i s i n seepage h a b i t a t s where i t even grows i n depressions, 'when raw humus i s t h i c k , a m a b i l i s f i r r e g e n e r a t i o n i s f a r l e s s s u c c e s s f u l than mountain hemlock. Yellow cedar has a d i s t r i b u t i o n a l range s i m i l a r to mountain hemlock except t h a t i t i s very uncommon i n the I n t e r i o r o f B r i t i s h Columbia. However, on a l o c a l scale the two species have l i t t l e i n commoni where mountain hemlock grows w e l l , y e l l o w cedar does not, and v i c e - v e r s a . Yellow cedar has some f e a t u r e s which adapt i t w e l l to subalpine c l i m a t e c o n d i t i o n s . For example, the drooping and v e r t i c a l l y - d i s p o s e d b r a n c h l e t s prevent great accumulations of snow i n the crowns of t h i s species.. Nevertheless, i t i s a t a disadvantage be..-cause i t does not grow w e l l on the very a c i d raw humus which covers so much of t h i s zone. I t s best development i s on seepage slopes, o f t e n i n combination w i t h l a r g e a m a b i l i s f i r (see Figure 25B, the degraded s u b a s s o c i a t i o n of the Streptopus a s s o c i a t i o n ) . . The o l d e s t tree found i n t h i s study was a r e c e n t l y -f e l l e d y ellow cedar a t 3500 f e e t on Mount Seymour. A count of r i n g s on i t s 44 stump showed that i t was at least 800 years old, an indication that yellow cedar i s highly resistant to decay. In the upper subzone, yellow cedar occurs as a gnarled shrub around isolated clumps of mountain hemlock (Plate I, D) or marginal to seepage and moor areas (Plato II, A). A common feature of subalpine vegetation i s the substitution of different species i n a genus that i s common In lower bioclimatic zones: as examples, Tsuga heterophylla i s replaced by Tsuga mertensiana i n the Subalpine Zonej Sorbus sitchensis by Sprbus occidentalis; and Vaccinium parvifolium by Vaccinium alaskaense. 2. Sporadic Species i n the Zone Western hemlock (Tsuga heterophylla) i s common up to 3200 feet on Mount Seymour and up to 4000 feet on Paul Ridge. It i s the most common low-elevation tree species i n the zone. Tolerance to podzolization and raw humus allows i t s growth i n subalpine areas i n contrast to Douglas-fir (Pseudotsuga  menziesii) or western red-cedar (Thu.ja plicata). The latter species i s re-stricted to moist edaphic habitats at lower altitudes, and i n comparable sub-alpine habitats i t i s replaced by yellow cedar. Western red-cedar shows l i t t l e frost resistance so i t s occurrence i n the study area was limited to the lower Lysichitum sites at 2900 feet on Hollyburn Ridge. Taxus brevifolia. another sporadic species i n the Subalpine Zone, occurred with western red-cedar on the same site. Western white pine (Pinus monticola) i s very sporadic in the zone and the largest tree was found i n a moist Lysichitum association. Stunted i n -dividuals of white pine occur on exposed rock outcrops but the species i s rapid-l y being reduced i n abundance, mostly through the action of white pine b l i s t e r rust. Dead trees of the species are common. On Hollyburn Ridge at 3200 feet, 14 dead standing white pines were counted on a l/2-acre portion of a Cladothamnus ridge. 4 5 Lodgepole pine (Pinus contorta) occurs on exposed rock outcrops near The Lions and has been reported on the top of Crown Mountain ( K r a j i n a , personal conraunication), but i t i s otherwise very r a r e i n the zone. Whitebark pine (Pinus a l b i c a u l i s ) was seen at G a r i b a l d i Lake, n o r t h of the study area. A l p i n e f i r (Abies l a s i o c a r p a ) occurs a t the t r e e - l i n e near Diamond Head and i n the Eeno-stuck Meadows. These l o c a t i o n s extend the range of a l p i n e f i r to the west slopes of the Coast Mountains where i t had not p r e v i o u s l y been mapped by Alex-ander (1958). The o n l y other sporadic t r e e species i n the zone i s S i t k a spruce (Picea s i t c h e n s i s ) on the subalpine Oplopanax a s s o c i a t i o n a t 3760 f e e t above sea l e v e l (Paul Badge). This i s an important e x t e n s i o n of i t s recorded a l t i -t u d i n a l range since Ruth (1958) s t a t e d that i t was not recorded above 2 5 0 0 f e e t i n southern B r i t i s h Columbia. As expected, many of the low e l e v a t i o n species which reach t h e i r upper l i m i t i n the Subalpine Zone occur there i n much reduced v i g o r (see s i t e i n d i c e s f o r western hemlock i n Table X I I , Chapter V I ) , L o n i c e r a u t a h e n s i s , which i s a common shrub a t lower e l e v a t i o n s i n the I n t e r i o r o f B r i t i s h Columbia, occurs a t 3700 f e e t on Paul Ridge, and L e t h a r i a v u l p i n a , a l i c h e n commonly a s s o c i a t e d w i t h the I n t e r i o r D o u g l a s - f i r Zone (Bray-shaw 1955), was found on dead branches of y e l l o w cedar a t 4.600 f e e t on the same mountain. Other i n t e r i o r species which were c o l l e c t e d i n the C o a s t a l Subalpine Zone are S a x i f r a g a l y a l l i i and Habenaria d i l a t a t a . The most important A r c t i c -A l pine elements ( P o r s i l d 1958) s p o r a d i c a l l y present are: Empetrum nigrum, Vaccinium u l i g i n o s u i a . Epilobium l a t i f o l i u m , and Oxyria digyna. Cladonia  p a c i f i c a . which A h t i ( l 9 6 l ) d e s c r i b e d as a lowland species, was c o l l e c t e d f a r above i t s normal a l t i t u d i n a l range a t 4390 f e e t near The L i o n s , 3, Zonal Influences on the Vegetation a. P a t t e r n s i n the V e g e t a t i o n Two l e v e l s of v e g e t a t i o n a l zonation must be recognized, Bioclimati.c to follow page 4-5. Figure 16. Biotic zonation associated, with decreasing snow duration from A to E. The dominant species i n each band are; A, Carex nigricans; B , Phyllo- doce enpetrifornis and Gassiope mertensiana; C, Vacciniura deliciosum; D, Vaccinium membranaceum; E, Rhododendron albiflorum and Tsuga. mertensiana. Figure 17. Closer view of zonation parallel to a clump of Tsuga mertensiana. kt Vaccinium membranaceum; B, Vaccinium deliciosum; C, Phyllodoce empetri- formis and Cassiope mertensiana. 46 Figure 18, Snail-scale vegetation patterns controlled by duration of snow, Phyllodoce eapetriformis and Cassiope mertensiana occur beneath these late snow-banks, 4400 feet, July 13, 1961. z o n a t i o n has a l r e a d y been discussed; i t i s the basis for tha recognition of a d i s t i n c t C o a s t a l Subalpine Zone, However, within the zone, vegetation patterns are i n f l u e n c e d by emlroiiiaental gradients to give snail scale biotic zonation, ar. shc-.tL i n F i g u r e s 16 and 17. Irregular topography allows uneven accumulation of snow an'1, i n F i g u r e 16 the snow remains longest i n the depression at the r i g h t , -he sequence of decreasing snow duration from the depression to the edge of the t r e e s on the slope results i n biotic zonation. Each zone has d i s t i n c t dominant species and the boundaries are sharp. Figure 17 i s a closer view of t h i s zonation parallel to a group of trees. Proof that these snail-scale v e g e t a t i o n patterns are closely correlated with the duration of snow ir. given i n F i g u r e s 18 and 19. Note how closely the dark green patches of Phyllodoce empetriformis and Cassiope mertensiana match the la s t patches of snow i n Figure 18, The aspect of a slope may cause similar differences i n vegetation through differences i n snow duration. In Figure 19, snow had dis-appeared from the warmer southeast slope of a ravine by July 13. A distinct a s s o c i a t i o n of dwarf moun'vain hemlock was established on this slope. On the 4 7 east slope of ravine where growing season i s longer. One to three f e e t o f snow r e n a i n over the Phyllodoce - Gassiooe area on northwest slope, J u l y 13, 1961, 4300 f e e t . opposite northwest slope, where one to three f e e t o f snow remained, an assoc-i a t i o n of Phyllodoce and Cassiope was present. On c e r t a i n aspects, the steep-ness of the slope nay also i n f l u e n c e snow d u r a t i o n and ve g e t a t i o n . The w e l l developed Phyllodoce - Cassiope a s s o c i a t i o n shown i n P l a t e I I , D was on a 14 degree southeast slope, but not f a r below where the slope steepened to 36 degrees clumps of mountain hemlock surrounded by Vaccinium membranaceun were developed. The steeper slope was more a t r i g h t angles to the sun's rays and the increased i n s o l a t i o n would lengthen the- growing season s u f f i c i e n t l y to a l l o w the establishment o f mountain hemlock. The more h e a v i l y f o r e s t e d slope i n the center o f P l a t e I I I , A (Appendix IV) shows a s i m i l a r phenomenon. Snow measurements showed t h a t t h i s southwest slope was f r e e o f snow a month before the surrounding Phyllodoce - Cassiope areas where t r e e s are much more sparse. These examples c l e a r l y i n d i c a t e the i n f l u e n c e s of topography, slope and aspect. The d i s t i n g u i s h a b l e v e g e t a t i o n u n i t s shown i n Figur e s 16 and 17 do not occur o n l y as narrow bands along sharp environmental g r a d i e n t s . I n places 48 where changes i n snow duration are more gradual, the units may cover larger areas. It was i n such areas that sample plots were located for f l o r i s t i c analyses. The zones shown i n the photographs above were too narrow for sampling by plot but their relative position along an obvious gradient of snow duration provided use-f u l information which would have heen less detectable where the associations cover broader areas. A characteristic of the upper subalpine region i s the isolated clumps of trees. Shaw (1909) recorded similar features i n the Selkirk Mountains, where the groups were mostly confined to spots where, from local contours, the snow had not accumulated so deeply. This i s a possible explanation for the origin of such clumps. At present, many clumps ar© on ground no higher than the sur-rounding heath-like areas, but i n i t i a l l y the trees must have established on higher points of morainal material which were the f i r s t to be free of snow. Subsequent smoothing of morainal surfaces by organic accumulations or by erosion could mask the small prominences on which the trees originally developed. Mountain hemlock i s known to be a successful pioneer species on glacial moraines (Lutz 1930), and once i t grew to a height greater than the winter snow level i t could hasten the melting snow around the clump. Evergreen trees r e f l e c t only 7 per cent of the radiant energy which f a l l s on them, whereas a fresh snow surface reflects from 80 to 90 per cent (L andsberg 1958, p. 122). A result i s increased melting of snow near the isolated clumpj this i s i n contrast to conditions under a closed forest canopy where shading delays snow melt. This influence on the ecoclimate i s aided by interception of some snow by the tree's crown. When this snow melts and when i t rains, the dripping also helps to melt the snow around the tree or clump of trees. The combination of these three factors creates openings as shown in Plate I, D. Thus the growing season may be one month longer i n this band near the clump than i t i s just a few yards away i n the heath-like area. As a result, zonation similar to that shown i n Figure 17 occurs around every tree clump. The 49 lengthening of the growing season near the tree clump also means that this i s the only place where mountain hemlock has a chance to germinate; thus the clumps are self-perpetuating. Wind i s not a control of tree-line i n this zone as i t i s i n the Rockies (Daubenmire 1943). Mountain hemlock and alpine f i r at their tree limit near L i t t l e Diamond Head i n Garibaldi Park did not have asymmetric tops and they reached their greatest altitude on ridges where snow accumulation was less. Daubenmire (1943) and Shaw (1909) gave these as c r i t e r i a of a snow-controlled upper l i m i t . In contrast, where wind controls timberline the upper parts of the trees are asymmetrical and the highest occurrence i s i n the lee of obstructions or i n sheltered valleys (Daubenmire 1943). In sharp contrast to lower altitudes, the short subalpine growing season allows only two clearly marked seasonal aspects - a hibernal and an aestival. The seepage communities which have the highest number of herbaceous plants naturally have species with different antheses: for example, in the Lysichitum association Coptis asplenifolia flowers before any other species; and at higher elevations Caltha leptosepala and Leptarrhena p y r o l i f o l i a flower in late June but Parnassia fimbriata not u n t i l late August. However, the d i f -ferences are insufficient to distinguish separate vernal and aestival aspects. Along the margins of mountain streams or on slopes of abundant seepage certain species may transcend their usual altitudinal range (Table VIII). Alpine and subalpine species, such as Valeriana sitchensis, Parnassia  fimbriata. and Senecio triangularis reach their lowest limits at 3000 feet on a very wet Lvsichitua area and the low elevation species Thu.ja plicata, Taxus  brevifolia and Maianthemum dilatatum reach their highest limits on the same area to give an unusual combination of species (Tabic VIII). These examples show that certain edaphic conditions can over-ride the influences of macroclimate and a l -titude. It i s for similar reasons that large areas of "alpine meadows" extend TableVIIlcomparison of species in seepage communities by cover degree-abundance values and by characteristic cover degree. Plots are listed in order of increasing altitude from;.700 feet in the Western Hemlock Zone to 4800 feet in the Subalpine Mountain Hemlock Zone. Values for plots E-95. E-58 and B-10 taken from 0r loc i . l96l . See legend at bottom of next page. Vaccinium alaskaense - Lysichitum forest type WeBt. Hemlock Zone  Subalpine Mountain Hemlock Zone Leptarrhena - Qaltha non-forest type of the Subalpine-Alpine trans-itlon Zone  Plot Number S- S~ E-95 58 10 BP- BP- BP- BP- BP- BP- BP-49 126 127 128 18 4 l 89 BP- BP- BP- BP- BP-"88 9? 79 73 70 Locality «J Elevation (ft.) - hundreds Exposure Slope (degrees) Snow Cover (weeks)>estimate SO H SM 7 11 29 E t SE 4 ? 15 0 0 26 SM H H H SM SH RH 29 29 29 JO JO JO 40 SE SW SW K IU 9 I 15 8 7 20 27 25 10 26 26 26 26 29 29 34 RM Q RM RH BH 40 42 45 47 48 SW SE SW SW IM 2 14 10 9 4 34 56 36 37 37 % Cover, Layer A B C D 75 50 50 50 65 40 95 55 80 65 60 60 80 30 75 60 80 45 55 50 65 35 55 65 45 40 60 65 65 65 65 75 70 - 1 15 - -90 95 98 85 85 i LIST OF PLANTS , 3 V Ihar. 3har 3iar. Layer A« m a cov. cov cov. dap;. deg dee. Picea sitchensis 1 + + 4 Alnus rubra 2 3 15 n n 3 4 ^Pinus jnonti coia 1 + _ 4 -Thuja plicata 1 8' 4 5« 50 n n 2 8 5 5 1 1 3 4 3 4 Tsuga heterophylla 1 5 28 6 5 4 4 24 N B 2 5 3 + 5 + • 4 n a 5 5 5 + 7 <2 r + 5 1 1 Abies amabilis 1 2 4 L 19 II B 2 3 4 5 4 r a 0 3 4 4 4 3 5 4 3 Tsuga mertensiana 1 4 - 2 + 4 4 4 >2 8 n 1 2 2 )„ 4 4 r ) 2 4 n n .3 J 2 4_ 4 Chamaecyparis nootkatensis 1 + - 6 5 ' J i Ji" 30 n n 2 4 5 1 r P B 0 5 5 4 3 5 Layer Bt Gaultheria shallon 2 5 1 12 Alnus rubra 1 3 5 Oplopanax horridus 1 4 1 10 0 1 2 4 4 Sambucus pubens i 1 n n 2 4 2 Thuja plicata i i 7 1 — 0 1 2 1 Taxus brevifolia n n 1 0 "5 5 2 1 Ribes bracteosum p n 1 O 4 -4 -Rubus spectabilis eL 1 + 4 29 4 a n 2 8 2 1 2 4 1 Tsuga heterophylla 1 4 3 3 7 4 2 1 3 2 1 4 D B 2 4 5 1 1 1 1 1 Abies amabilis 1 3: + + 5 2 4 5 4 3 4 3 13 1  n 2 4 2 4 3 5 2 3 2 1 Vaccinium ovalifolium 2 2 + 4 4 1 1 2 5 1 Vaccinium alaskaense 1 23 1 18 a a .2 6 4 _4 5 5 4 7 4 l Menziesia ferruginea 1 5 5 n a 2 2 4 2 4 1 5 2 Vaccinium membranaceum 2 4 1 2 2 -Cladothamnus pyrolaeflorus 1 4 4 2 n n 2 1 + 5 _ Sorbus occidentalis 1 + 4 _ n n 2 -+ 1 2 Tsuga mertensiana 1 4 - 4 1 2 4 2 4 5" fl B 2 2 4 1 2 2 2 4- _ Chamaecyparis nootkatensis 1' + - 4 1 1 1 1 2 5 5 4 B B 2 1 1 1 4 1 5 3 Rhododendron albiflorum 2 i — 1 Salix commutata 2 1 Vaccinium deliciosum 2 .... Cont'd. TableVII]P°ivM.nued. E- S- E- C !har BP- BP- BP- BP- BP- BP- BP- t JharBP- BP- BP- BP- BP- Ohai 95 58 10 c .d. 4 9 126 127 128 18 41 89 < 88 ?? TP . H . 7° 6 f4 l Layer Cl Lycopodium selago 1 + -Circaea alpina 2 1 Luzula parviflora + ' -Oarex bolanderi + 1 3 2 Dryopteris austriaca 2 2 + 1 Moneses uniflora 1 Maianthemum dilatatum 5~ T 15 • 1 1 -Viola glabella .1. - 4 2 ...,3.._ .5. Linnaea borealis 4" - 3 + 2 Galium triflorum 1 - 1 -Polystichum munitum 4 -Goodyera oblongifolia • a*. Rubus spectabilis 4 + + — Boykinla elata . .* -Athyrium filix-femina 2 1 1 4 2 • • 2 + • 4 5 3 Tsuga mertensiana + 2 2 ...1. . 1 . .1 Listera cordata + 1 - + + + + + + -Tiarella unifoliata + 1 5 + 2 1 Tiarella t r i f o l i a t a ¥ ~2 3 5 1 1 3 1 + 1 Gymnocarpium dryopteris 1 + - 2 _.3_. 2 4 „_3 Blechnum spicant 3 4 4 " 8 ~~z 5 2 2 "4 1 5 Cornus canadensis 2 2 2 1 1 2 -Streptopus amplexifolius + +• 2 — "l" + + 1 3 1 2 i Rubus pedatus 2 4 4 4 4 4 4 2 4 3 1 7 4 -Lysichitum americanum ;? 7 7 ) 65 ( 4 5 7 7 6 7 5 J 58 Streptopus roseus 1 2 2 5 3 2 2 Streptopus streptopoides • 2q 1 2 1 2 -Coptis asplenifolia 4 _ 4 3. . 2 . 2 5 Oarex laeviculmis 1 + • + + <5 5 Abies amabilis 2 2 2 1 1 1 2 -Veratrum eschschoitzii 2 1 2 1 • 1 1 -3- - 4 - "5 3 4 " • 5 - 4 4 Habenaria saccata .3 5 + + + 1 2 - 1 -Clintonia uniflora 4 - io 4 4 T 2 3 3 2 5 Vaccinium sp. 3 1 1 1 1 2 1 1 Menziesla ferruginea 4 1 + + 2 4 -Chamaecyparis nootkatensis 4 i i 1 1 . .JL - 1 4.._ ... Pyrola secunda 4 " - 1 4 Osmorhiza purpurea + 1 -Trientalis arctica i -Lycopodium clavatum . + + -Nephrophyllidium criata-galli 2 2 1 Epilobium alpinum + - 4 5 2 3 1 2 1 1 Melica smithii 4 4 -Saxifraga arguta .1 1 -Oaltha l e D t o a e n a l a 5 25 6 5 4 6 5 25 Leotarrhena pyrolifolia .. 1. .5 12 6 .7. 35_. Juncus mertensianus 5 25 2 1 2 1 Bfcbenaria dilatata _ 4 _ 1 -Equisetum palustre 5 25 5 7 27 Arnica l a t i f o l i a 1 — 1 -4_. Senecio triangularis 1 1 5 1 "4 7 Erigeron peregrinus i 5 2 3 5 6 4 7 24 Oarex spectabilis . . . . . " " l 4 3 4 4 Hippuris montane. 1 - 1 2 . -Parnaasia fimbriata 1 1 4 3 5 3 "3 ' 5 15 Mitella pentandra 1 4 1 1 1 1 _1 . Valeriana sitchensis 4 4 2 7 1 4 2 2 -Agrostis aequivalvis 4 ,"2 1 5 1 8 Petasltes frigidus 3 4 2 Viola palustris 5 2 13. Tofieldia glutinosa 3 1 2 Oarex nigricans 2 7 2 "? •7 20 O&lamagrostis canadensis 5 2 5 Veronica serpyllifolia 1 1 .__ Deschampsia atropurpurea 2 i 4 -Hordeum brachyantherum 3 •j Agrostis thurberiana 1 4 Salix commutata 4 10 Carex i l l o t a 2 4 Juncus drummondii 1 1 -®Legend 1 SC - Seymour Creek Valley; H - Hollyburn Mountain; SM - Seymour Mountain; RM - Round Mountain, Garibaldi Park; G - Grouse Mountain. W Tabular values refer to the cover degree-abundance symbols of the Domin/iCrajina scale ( + , 1 , 2 , 10.) 98ft Characteristic cover degree • total cover degree value divided by the number of plots on which species i s present, expressed in percent. 52 well down into the Subalpine Zone, especially i n moist edaphic habitats. For example, plot BP89 at 4000 feet (Table VIII),' even though i t i s p a r t i a l l y forest-ed, i s f l o r i s t i c & l l y closer to the Lsptarrhena •- Caltha leptosepala than to the Lysichitum associations of lower altitudes. This transitional plot i s a good example to show that the Lysichitum habitat i s occupied in the upper subzone of the Subalpine Zone by the Leptarrhena - Caltha association. b, Altitudinal Influences on Trees In this section there i s a discussion of changes i n height/diameter relationships v/ith increasing altitude. An analysis of basal snow-crook i n subalpine species i s presented because of i t s possible applications to so l i f l u c -tion and snow-creep studies i n the Subalpine Zone (Mathews and MacKay 1962). In the f i n a l part of the section, relative turgidity measurements which were taken on two altit u d i n a l l y and ecologically distinct habitats are discussed. Average maximum height of mountain hemlock i s as great as 139 feet at the lower l i m i t of the zone and as low as 71 feet near the upper tree limit' (Table X l l ) , In extreme cases height growth i s only five feet i n 100 years (Figure 20). For larger trees i t was noted that the reduction of maximum height with increasing altitude was not accompanied by a proportionate reduction i n maximum diameter at breast height. The result i s a marked increase i n taper of tree trunks. One way to express i t i s with an index that relates diameter and height (maxima) to one another. Indices were calculated for the t a l l e s t mountain hemlock with an un-broken top on each of 44 sample plots on Hollyburn, Seymour and Grouse Mountains, with the following formula; Index = % max. x 100 W . x 12 where, % n i a x < = d.b.h. of tal l e s t tree, i n inches H = height of t a l l e s t tree, i n feet j to fol[ow page 52 I I I ' 1 1 J I I 1 1 1 1 1 1 1 1 1 , 1 50 ; - • -• _ 40 -« • 0 Y, 30 • » • 0 • • • 2 0 9 • • • 'a • - , . — 10 Elevation, hundreds of feet — 29 30 31 1 I I 32 J 33 34 35 36 37 38 39 1 I I 1 1 4f> 4 , 4? 4 ? 44 4 ? 4,6 , ! ' Figure 21. ; Change in * diameter-heights-ratio (growth-form index) of ., mountain- hem lock "withincreasing altitude. Based on 44 plots. 53 Mountain hemlock was chosen because i t extended over the widest altitudinal range of the three subalpine species. It also showed the lowest percentage of wind-broken tops, even i f i t i s the most common species i n exposed habitats. To analyse the influence of altitude on the index, i t was necessary to re-strict the sample to the Seymour - Grouse - Hollyburn areas where the alti t u d i n a l range of mountain hemlock i s similar. On Paul Ridge, the lower limit of mountain hemlock was nearly 1000 feet higher than i n the Seymour area. Obvious-l y samples from these two l o c a l i t i e s would need to be treated separately i f elevation i s being considered as an independent variable. An increase i n diameter-height index i s shown for increasing a l t i -tude i n Figure 21. The regression equation was calculated with elevation ex-pressed i n units of one hundred feet so that the index value on the y-axis has been increased by a factor of 10. The increased index value with increasing altitude i s pa r t i a l l y explained by characteristics of diameter growth i n ex-posed trees. Baker (1950) stated that i n exposed trees annual rings increase in thickness from the base of the crown downward, and i n a study of wind sway Jacobs (1954) found that sway increased diameter growth of roots near the trunk and increased eccentric trunk development along the line of the main winds. Although winds are less frequent i n coastal subalpine areas than i n interior mountains (Daubenmire 194-3), exposed trees at higher altitudes may have good diameter growth from the base of the cro\m downwards. Even near their upper limit, trees can have a large diameter at breast height far out of proportion to the total height of the tree. Studies of environmental and altitudinal i n -fluences on auxin balances within the trees would probably explain some of these relationships. The weight and movement of snow on subalpine slopes greatly depresses the stems of shrubs and small trees. Plate III, B shows the force exerted on dwarf mountain hemlock by snow creep as late as July 7, 1962. These small trees 54 can return to an upright position for only a short time each year, When they are t a l l enough to exceed the maximum winter snow depth, the upper trunk and crown w i l l usually be upright, but a distinct basal snow crook remains as evi-dence of the great force of snow creep. Basal snow crook has been mentioned only rarely i n the literature, even i f i t i s a common feature of subalpine trees., Sudworth (1918) recorded the phenomenon i n mountain hemlock and Kienholz (1930) discussed anatomical features of wood from the base of "pistol-butted" trees. When trees were measured i n the present study, snow crook was re-corded i f i t was noticeable. A summary of i t s occurrence on 71 forested sample plots i s given i n Table VII, page 42. For trees larger than the 10-inch diameter class, 9.5 per cent of the mountain hemlock had basal crook, 1.7 per cent of the yellow cedar, and 3.9 per cent of the amabilis f i r . In the 10-inch class or less, 40.2 per cent of the mountain hemlock were affected, 36.9 per cent of the yellow cedar, and 21.1 per cent of the amabilis f i r . As Sudworth (1918) pointed out, subsequent growth f a i l s to straight-en entirely the bent stems, but the figures above show that the phenomenon i s much less noticeable in older and larger trees. The frequency of snow crook i s especially reduced for yellow cedar larger than the 10-inch diameter class. There are two probable reasons for this. Firs t , the characteristic butt-swell at the base of large yellow cedar trees would obscure the earlier effects of snow crook, and secondly, most of the 177 trees measured i n the larger diameter classes occurred in associations near the lower limit of the subalpine zone where the force of snovr-creep would be less. Conversely, yellow cedar i n the small diameter classes extends to higher elevations and a marked increase i n the frequency of snow-crook i s evident. When the three subalpine species uere compared, there was a very highly significant difference i n the frequency of snow-crook. However, when 55 only yellow cedar and mountain hemlock were compared there was no significant difference (Table IX). These relationships were examined further i n an attempt to learn more about differences i n species responses to great accumulations of snow. The Alwac III-E computer was used for a multiple regression analysis of seven independent variables on the percentage of trees exhibiting snow-crook. Details of the analyses are provided i n Appendix II, but the main findings are summarized below. The regression analyses were carried out with the standard S-7.1 programme which provided a stepwise reduction analysis. This gave an indica-tion of the relative importance of each independent variable. Amabilis f i r was treated separately since i t showed the effects of snow-creep much less than the other two species. The independent variables i n decreasing order of im-portance for amabilis f i r xreres steepness of slope, total basal area on plot, length of slope above, percentage cover by the tree layer (crown closure), snow duration, altitude and aspect. The coefficient of determination (100 R2) for a i l variables was 53.9 per cent,,. Only the f i r s t two variables were sig-nificantly correlated with the percentage of trees showing snow crook; steep-ness of slope at the .01 level of probability, and total basal area at the .05 level. For mountain hemlock and jellov cedar, decreasing order of import-ance for the same variables wass steepness of slope, elevation, length of slope above, aspect, percentage cover by the tree layer, snow duration, and basal area. In this case the coefficient of determination for a l l variables was only 42.3 per cent, and steepness of slope was the only variable s i g n i f i -cantly correlated with the percentage of snow crook (.01 level of probability). The results indicate some weaknesses of such a multiple regression stepwise analysis. One fault i n the above analysis i s that some independent variables were inter-related (snow duration, aspect and elevation; or basal 56 TABLE IX X 2-test of differences i n frequency of basal snow-crook i n three tree species for 10-inch class or less on 71 sample plots. Amabilis f i r Yellow cedar Mountain hemlock Total Trees with crook Trees without crook 222 832 133 227 255 379 610 1438 Total 1054 360 634 2048 X2 = 99.77 = very highly sigrri (for 2 degrees of freedom, X2 .ficant. = 5.99 at the 5% level) Trees with crook Trees without crook 133 227 255 379 388 606 Total 360 634 994 X2 = 1.04 - not significant. (for 1 degree of freedom, X2 = 3.84 at the 5% level) area and per cent coverage by the tree layer). When a regression i s applied to such a complex of factors, the variance due to the complex i s attributed to several factors, none of which can appear significant precisely because of the intercorrelations within the group of factors (Canada Department of Forestry 1961). In addition, the relationships between many variables are non-linear. For example, the length of slope i n the analysis above should probably not be forced into a linearly additive model. Snow creep and i t s influences on trees should be negligible at the crest of a ridge but would increase i n importance on the shoulder of the ridge. However, a maximum rate w i l l be reached some-where on the slope beyond which increased le-ngth of slope above w i l l have l i t t l e or no effect. (W. H. Mathews, personal communication). 57 The non-linaar relationships of some variables impose limitations upon such methods of analysis. The necessary precautions are well expressed below (Canada Department of Forestry 196l): "A multiple regression analysis i s only a tool to be used as a guide i n preliminary work on construction of more r e a l i s t i c models. At best, this procedure w i l l yield the researcher a rough idea as to which variables are accounting for a signif-icant proportion of the variance i n the system. At worst, blind application of multiple regression analysis leads to erroneous conclusions. A significant regression coefficient may not mean that a factor i s important; rather, the factor may be highly correlated with some factor which i s important but i s not included i n the regression analysis." These limitations account for the low coefficients of determination above (53.9 per cent for amabilis f i r , and 42.3 per cent for mountain hemlock and yellow cedar). But even i f some important factors were omitted from the regression analyses, steepness of slope i s indicated as the most important con-t r o l of snow-crook. However, i t was noted i n the f i e l d that snow-deformed stems were also common on the small trees which grew around groups of larger trees. These groups, mainly of mountain hemlock, often occurred on distinct prominences on plots that were otherwise of gentle slope. Data from such plots were not used i n the regression analyses because i t was impossible to quantitatively ex-press steepness of the slope vrhen the elevated clumps of trees made the topo-graphy irregular. Only sample plots of uniform slope were used in the analyses but this neglected the influence of snow cascading down from the crowns of larger trees onto the smaller trees around the group. Mountain hemlock and yellow cedar are the usual species around these elevated groups of mountain hemlock, whereas small amabilis f i r trees often occur in the depression be-tween the humps. Therefore, mountain hemlock and yellow cedar would be most subject to deformation by cascading snow from the larger tree crowns. Failure to include this fts a variable i n the regression analyses resulted i n a lower coefficient of determination for these two species than for amabilis f i r . 58 Persistence of lower branches can also influence the incidence of snow-crook. Dahms (1958) observed that natural pruning was poor i n mountain hemlock, and i n this study branches persisted almost to the ground i n both mountain hemlock and yellow cedar. This would provide more surface area against which the forces of snow creep could act. Conversely, amabilis f i r prunes i t -self better and should be less subject to deformation by the down-slope forces of snow. These species differences are reflected i n the lowest incidence of snow-crook in amabilis f i r for trees of the 10-inch diameter class or less (Table VII). The omission of lower branching habit as an independent variable could also account for some of the unexplained portion of variation i n snow-crook for mountain hemlock and yellow cedar. Altitude was not significantly correlated with the percentage of trees with basal snow-crook in either analysis because samples were taken from the Subalpine Zone only. If some samples had been taken from below the levels of heavy winter snow accumulation, altitude would have been more important as a variable. This would have been possible only with amabilis f i r because i t i s the only species whose range extends downwards into a relatively snow-free bioclimatic region. Mountain hemlock and yellow cedar are restricted to an altitudinal range which i s influenced by the forces of snow accumulation throughout. Even near the lower li m i t of these species there i s enough snow to deform the stems of small tress so that increasing amounts of snow v/ith increasing altitude do not result i n a significant correlation with the oc-currence of basal snow-crook. In conclusion, some of the variation of this particular phenomenon i s related to s i l v i c a l characteristics of the species involved, but unless more r e a l i s t i c regression models can be constructed, i t i s unwise to attempt to f i t a multiple regression to such a complex natural phenomenon. Influences of altitude and exposure were clearly shown by needle to follow page 5& Figure 22. Te rmina l p o r t i o n s o f l o w e r b r a n c h e s f r o m w h i c h n e e d l e s w e r e cut for r e l a t i v e t u r g i d i t y m e a s u r e m e n t s : A . A b i e s a m a b i l i s ; B. Tsuga m e r t e n s i a n a . In b o t h c a s e s , t h e l o w e r s a m p l e is f r o m n e a r B P 1 5 , a n d t h e u p p e r f r o m n e a r B P 124. F i g u r e 25, L o c a t i o n of B P 1 5 a n d B P 1 2 4 in Mount S e y m o u r P a r k . 59 mprphology of amabilis f i r and mountain hemlock collected, at different levels i n the Subalpine Zone. The dense, s t i f f needles of open-grown trees are shown i n the upper portion of Figure 2 2 . They were collected from an altitude of 4000 feet i n the upper subzone (see Figure 2 3 ) . The lower portion of Figure 22 shows the more sparsely distributed needles on terminal branches collected from shaded subalpine forest of the lower subzone (near BP 15, 3200 feet). ' Four l / 2-inch lengths of twig were sampled from each of the terminal portions of lower branches shown i n Figure 22, and the measurements are sum-marized i n Table X. The branches from more exposed trees i n the upper subzone had approximately twice as many needles on a given length of twig i n both species. Average length of needle was not markedly different i n either species from the two altitudes, but average thickness was much greater on the needles from the higher altitude. This xrould be a result of the well-known difference between sun and shade foliage where there i s a much thicker layer of palisade ce l l s i n foliage exposed to f u l l sunlight. The resulting differences i n length/ thickness ratio are clearly shown for the four branch collections i n Table X. These morphological differences occurred on two l o c a l i t i e s which were altitudinally and environmentally distinct. Because of such distinct differences, these l o c a l i t i e s were good sampling points at which to test the sensitivity of a measure of the internal water balance. Kramer and Kozlowski ( i 9 6 0 ) stressed that a l l other phenomena or factors related to s o i l moisture are important chiefly because they affect the internal water relations of trees and thereby modify the physiological processes and conditions which aff«ct growth. A measure of relative turgidity which describes the actual water con-tent of plant tissues relative to what i t would be i f the tissues were f u l l y hydrated was proposed by Weatherley (1950) and has been used for tree species i n British Columbia by Bier (1959) and Baranyay ( l 9 6 l ) . Similar methods were used here with some modifications as discussed below. 60 TABLE X Summary of length/thickness ratios i n needles of Tsuga  mertensiana and Abies amabilis from 1+000 feet and 3200 feet on Mount Seymour (values i n inches).* Tsuga mertensiana Abies amabilis Sample Needles on Av. Av. L / T Needles on Av. Av. L/T No. i i n . twig Length Thick. Ratio -g- i n . twig Length Thick. Ratio A. Expos sed, open-grown trees, elevation 4000 f t l : ( B P 1 2 4 ) 1 2 8 . 5 3 2 . 0 2 9 1 8 . 3 3 7 . 6 3 2 .024 2 6 . 3 2 2 9 .541 . 0 3 2 1 6 . 9 36 . 7 6 5 . 0 2 7 2 8 . 3 3 2 5 . 5 1 0 . 0 2 8 1 8 . 2 3 2 . 8 4 1 . 0 2 6 3 2 . 4 4 3 3 . 5 2 3 . 0 2 7 1 9 . 4 3 1 . 8 0 8 . 0 2 7 2 9 . 9 Average 2 8 1 8 . 2 3 4 2 9 . 2 B. Shaded trees beneath forest canopy, elevation 3200 f t . : ( B P 1 5 ) 1 1 5 . 6 2 3 . 0 1 0 6 2 . 3 1 6 , 8 5 0 . 0 1 6 5 3 . 1 2 1 7 . 5 3 8 . 0 1 0 5 3 . 8 1 5 . 6 9 7 . 0 1 6 4 3 . 6 3 1 4 . 5 6 1 . 0 1 0 5 6 . 1 1 7 . 7 9 1 . 0 1 5 5 2 . 7 4 2 0 . 5 8 2 . 0 1 0 5 8 . 2 1 6 . 7 5 6 . 0 1 6 47.2 Average 1 6 5 7 . 6 1 6 4 9 . 2 *A11 needles on a standard l / 2-inch length of twig were measured as one sample. Leaf thickness was measured to the nearest one one-thousandth of an inch with a STARRETT Comparator. Leaf length was measured only to the nearest twentieth of an inch, but the average for each sample was carried to three decimal places to correspond with the thickness readings. There were two objectives i n the study of relative turgidity: (l) to compare the water content i n two different tree species i n different months on the same habitat j and (2) to compare the results from two distinct habitats which varied i n altitude and i n density of tree cover. Amabilis f i r and mountain hemlock were sampled from an exposed l i t h i c Cladothamnus association at 4000 feet (near 3 P 124) and from a shaded, mesic Vaccinium alaskaense association i n the lower subzone at 3200 feet (near B P 1 5 ) . A terminal portion of branch (Figure 22) was cut from each species 61 at each l o c a l i t y at approximately one-month intervals from February 23, 1962 to August 30, 1962. The branch tips were always collected i n the early morning to reduce the effects of diurnal variation, and they were always cut at eye lev e l from the north side of the same tree. They were placed i n plastic bags and taken to the laboratory for weighing on a Mettler precision balance. Three samples of 15 needles each were cut from every branch. Needles from 1961 were used for the entire six-month period of this study. These cut needles were weighed immediately for fresh weights and then placed i n d i s t i l l e d water to bring them to saturation. During this period, the needles were held upright i n a small v i a l by a folded piece of paper towel. The cut ends of the o needles stood in the water at 10 C. and after 24- hours they were removed and surface dried on paper towels. A second weighing at this stage gave the sat-o urated weight, and a f i n a l weighing after 4 hours of oven-drying at 90 C. gave the dry weight of the sample. Relative turgidity was calculated for each sample from the formula; Relative turgidity = fresh weight - oven dry weight x IQO. saturated weight - oven dry weight The data are shown in Table XI and averages of the three replications are plotted i n Figure 24. Moisture as a percentage of dry weights v^ as calculated only for comparison. The great differences in tissue density (see Table X) are reflected i n the bottom portion of Figure 24 where the thin needles from the low station have a consistently higher water/dry weight ratio than the thick needles from the exposed location. These great differences show the importance of a measure such as relative turgidity which eliminates veJJiationa due to varying tissue density. with the methods described above, no consistent difference i n rela-tive turgidity was revealed for mountain hemlock on the different habitats, but at the upper station species differences were detectable by this method ! to _ J o Mow page 61 .0-1 > a OJ 0 0 9 0 80 70 HIGH STATION (14000 ) Abies . amabilis 1; : 0 0 Tsuga mertensiana + + LOW STATION (3200') f Abies amabilis o o. Tsuga •• mertensiana' +• •+ 1 1962 ' I r o CM' JX u. . 2 4 0 r -CM O r o o . < / \ OJ Z3 r o . O r o < 2 0 0 CD Q O 5 6 0 20 Figure 24. Seasonal changes of relative turgidity and water1 dry •" weight ratio'in Abies amabilis and Tsuga mertensiana from 2 localities on Mount Seymour. 62 TABLE XI Relative turgidity and water/dry weight values for needles of Tsuga mertensiana and Abies amabilis from 4OOO feet and 3200 feet on Mount Seymour (values i n per cent). Cladothamnus, l i t h i c subassociation Vaccinium alaskaense association Exposed Trees - 4OOO f t . - BP124 Shaded Trees - 3200 f t . - BP15 Tsuga Abies Tsuga Abies Date R. T.IWater/DU' R. T.i Water/DU R. T. Water/DW R. T. Water/DW Feb. 23 1 1 81.5 127.3 1 81.2 80.9 82.4 124.3 121.4 123.4 71.3 70.4 j 74.0 140.8 142.7 152.3 68.5 68.9 70.3 150.5 177.6 179.7 Avge. 81.5 127.3 : 81.5 123.0 71.9 L45.6 69.2 ] 169.3 Mch. 26 88.5 88.0 85.3 147.9 142.0 137.1 86.7 ! 91.3 87.6 126.5 125.4 127.6 8 I . 4 78.3 34.6 200.0 189.8 176.3 85.4 84.8 82.7 169.2 172.1 174.1 Avge. 87.3 142.4 88.5 126.5 81.6 188.7 34.3 171.8 Apr. 30 90.4 87.9 90.7 154.3 147.0 159.9 96.1 94.1 94.3 135.4 131.4 132.9 92.1 92.6 93.1 218.7 240.4 232.7 90.7 85.6 86.2 139.2 217.1 206.2 Avge. 89.7 153.7 94.8 133.2 92.6 230.6 87.6 204.2 June 5 88.7 84.2 81.0 131.5 139.0 143.6 94.2 93.3 92.1 139.9 123.0 128.3 36.6 89.0 92.6 156.7 162.9 158.9 89.7 88.5 89.9 148.1 166.4 150.7 Avge,. 84.6 138.0 93.2 130.4 39.4 159.5 89.4 155.1 July 7 88.3 90.4 92.5 134.2 137.3 134.4 97.6 97.1 95.1 137.3 130.4 132.6 89.9 87.3 80.1 156.5 142.3 141.9 92.3 93.4 93.0 129.7 153'. 1 144.5 Avge. 90.4 135.3 96.6 133.4 85.7 146.9 92.9 142.4 July 31 92,9 87.1 95.9 165.3 I64 .4 155.2 95.5 97.0 94.7 141.4 133.0 126.6 87.6 86.8 85.6 229.0 176.8 171.2 89.9 89.0 92.9 183.6 187.0 168.7 Avge-. 92.0 161.6 95.8 133.7 36.7 192.3 90.6 ' 179.8 Aug. 30 81.2 88.3 86.0 153.1 171.0 178.5 93.0 93.3 94-4 138.6 134.3 133.7 88.4 37.6 90.8 202.0 194.1 93.6 89.9 35.6 155.9 179.7 163.7 Avge. 85.2 167.5 93.5 135.5 89.0 198.0 89.7 168.1 63 because amabilis f i r showed a higher relative turgidity than mountain hemlock throughout the study period. The most meaningful results were obtained from a comparison of amabilis f i r on the two habitats (Figure 24). On the basis that a f u l l y turgid plant i s i n the most satisfactory condition for growth and other physiological responses (Kramer and Kozlowski I960), amabilis f i r growing on the exposed site at 4000 feet i s more vigorous than that i n a more heavily forested site at a lower elevation (Figure 24). In the Coastal Subalpine Zone of British Columbia, precipitation i s frequent enough so that even trees growing on shallow soils of sites without seepage can main-tain a high relative turgidity. The results may have been different i f samples had been taken from the top of. mature dominant trees, because at the lower station shading of the low branches probably influenced their relative turgidity. Trees in the shaded forest stands at lower elevations are often suppressed and greater root competition may result i n relative turgidity values lower than those shown in open-grown trees on supposedly drier sites. Another reason for the lower relative turgidity rates i n amabilis f i r on the shaded, mesic Vaccinium alaskaense association might be the reduction of absorptive surfaces by the great mortality of roots and rootlets i n the acid subalpine raw humus. The high percentage of dead roots i n subalpine humus was observed, but no actual measurements were made to determine i f there were differences i n growth and abundance of roots on different habitats. It i s possible that roots are better developed on trees which occur on exposed rock outcrop areas where competition i s less, and this could explain the more favourable water balance on such sites. Unfortunately the measurements were not continued long enough to show distinct seasonal trends. A winter minimum was indicated i n both species at both altitudes. Freezing of the s o i l i s not severe beneath the snow cover in the Subalpine Zone but i t may be sufficient to reduce the amount of water 64 available to the roots i n mid-winter. It i s unlikely that a minimum would occur near the end of the growing season, as reported i n other studies, because the late snow provides neltwater at least u n t i l the end of July, and precipitation during the remainder of the growing season i s sufficient to maintain high rela-tive turgidity on even the "driest" habitats in the Subalpine Zone. Relative turgidity i s a simple and reliable measurement that w i l l reflect species and habitat differences. As a symptom which integrates various factors such as s o i l moisture, temperature, root vigour and crown closure, i t i s of practical use. • A weakness i s that even though i t may provide a relative measure of tree vigour, i t does not explain the cause of good or poor tree vigour. 65 CHAPTER IV DESCRIPTION OF PLANT ASSOCIATIONS The appended synthesis tables provide f u l l details of th© f lorist ic analyses. Therefore, only the main f lorist ic and. environmental features of each vegetation unit ar© outlined in this chapter. Mensurational data and l i f e -form spectra are presented separately in Chapter V, and estimated average cover-age by each vegetation layer is shown in Table XIV, Appendix III. Figure 28 indicates the altitudinal distribution of associations described below, A. Lower Subzone A l l associations described for the lower subzone are forested, except for those which occur on moor habitats. The variations in predominant tree species and other f loristic features are described for dry, mesic, moist, wet, and moor habitats below. a. Dry Habitat Rock outcrop habitats with very shallow soils occur in both the upper and lower subzones. Such areas are well drained and are usually topographically situated so that there is no opportunity for supplementary seepage water. (la) Cladothamnus association, l i th ic subassociation (Tsugeto -Cladothamneturn subassoc. lithicum) Reference: Synthesis Table I Characteristic combination of species Constant dominants Constants, not dominant T.suga mertensiana Menzie sia ferruginea Cladothamnus pyrolaeflorus Vaccinium ovalifolium 66 Constant dominants, cont'd. Constants, not dominant, cont'd. Vaccinium membranacoum  Chamaecyparis nootkatensis Vaccinium alaskaense Abies a m a b i l i s Dicranum fuscescens R h y t i d i o p s i s robusta Selectives Cladothamnus p y r o l a e f l o r u s Sorbus o c c i d e n t a l i s Rubus pedatus Phyllodoce empetriformis O r t h o c a u l i s f l o e r k i i  C l adonia b e l l i d i f l o r a P r e f e r e n t s Menziesia f e r r u g i n e a  Sorbus o c c i d e n t a l i s  G a u l t h e r i a humifusa  Lescuraea b a i l e y i C ladonia r a n g i f e r i n a Pleurozium s c h r e b e r i The l i t h i c s u b a s s o c i a t i o n of the Cladothamnus a s s o c i a t i o n i s the subalpine e q u i v a l e n t of the Vaccinium - G a u l t h e r i a f o r e s t type described by O r l o c i (1961) and Lesko ( l 9 6 l ) f o r the C o a s t a l Western Hemlock Zone. The equivalence i s both edaphic and m i c r o c l i m a t i c f o r , i n both cases, these as-s o c i a t i o n s occur on r i d g e s o r on the upper p o r t i o n s of exposed convex slopes. The most important environmental f e a t u r e i s the shallowness of the s o i l . Bare rock was estimated to cover between 10 and 15 per cent o f the sur-face area, and o n l y a t h i n mantle of organic s o i l covers the rock i n the r e -maining p o r t i o n s . Most o f the s p a r s e l y f o r e s t e d r i d g e s i n Figure 2 belong to the l i t h i c s u b a s s o c i a t i o n o f the Cladothamnus a s s o c i a t i o n . The extreme exposure, the l a c k of seepage and the shallow s o i l s r e s u l t i n an average gross volume o f o n l y 2,647 cubic f e e t per acre, 73 per cent of which i s mountain hemlock. Trees were estimated to cover o n l y 24 per cent o f the t o t a l area and t h e i r tops are so o f t e n broken that the average height o f the t a l l e s t a m a b i l i s f i r i s o n l y 45 f e e t and of y e l l o w cedar, 44 f e e t . Mountain hemlock crowns are more r e s i s t a n t to wind, snow and i c e break-age and the t a l l e s t t r e e o f t h i s species averages 71 f e e t , on the b a s i s o f 12 sample p l o t s . 67 The trees usually occur in clusters. Very few of them are without • decay and most have broken or dead tops. In most cases, the groups of trees grow on emminences created by their own l i t ter or on humps made by underlying boulders. Such prominences, whioh are the f irst spots to be clear of snow in the spring, are the most favourable places for tree species to regenerate. It is for this reason that on this association the best regeneration can be found under existing clumps of trees. The sparse tree cover allows a dense shrub layer to develop because shading is negligible. These shrubs also confine re-generation because they cover the area completely except immediately around the clusters .of trees. The shrub layer, with an estimated average cover of 75 per cent, is made up mostly of Cladothamnus pyrolaeflorus, Vaccinium membranaceum and sap-lings of the three major tree species. Greater amounts of Phyllodoce empetriformis, Cassiope mertensiana, Vaccinium deliciosum, Luetkea pectinata, Carex nigricans. Lycopodium sitchense and Deschampsia atropurpurea differentiate the C layer of this subassociation from that which occurs on hygric habitats in the lower subzone, Dicranum fuscescens, Rhytidiopsis robusta, Dicranum scoparium and Rhytidiadelphus loreus are the most important humicolous bryophytes. Cladonia  gracilis, Cladonia pleurota and Crocynia membranacea on this subassociation distinguish the ground layer from the hygric counterpart. There are also greater quantities of Rhacomitrium heterostichum, Cladonia rangiferina and Cladonia squamosa on this drier subassociation. The estimated average amount of rock outcrop is 12 per cent of the plot area. Whenever there is a thin humus cover over rock surfaces the same species of humicolous bryophytes occur. Pleurozium schreberi is another im-portant species i n such cases, particularly as a raw humus builder. On bare rock surfaces Diplophyllum taxifolium, j). obtusjfolium, Rhacomitrium hetero-68 s t i c h u m and P i l o p h o r o n h a l l i i are common. P t i l i d i u m p u l c h e r r i m u m and L e s c u r a e a b a i l a y i a r e the main s p e c i e s on decayed wood, a s i d e from t h e h u m i c o l o u s s p e c i e s t h a t a l s o d e v e l o p t h e r e . An i m p o r t a n t f l o r i s t i c f e a t u r e o f t h i s a s s o c i a t i o n i s the abundant L e s c u r a e a b a i l e y i on t w i g s and stems o f e r i c a c e o u s s h r u b s near ground l e v e l . C e t r a r i a  s t e n o p h y l l a a c c u r s o# l o w - l y i n g - t w i g s i n g r e a t e r amounts t h a n i n t h e h y g r i c s u b a s s o c i a t i o n . A m a b i l i s f i r and m o u n t a i n hemlock t r u n k s s u p p o r t m a i n l y P t i l i d i u m  p u l c h e r r i m u m , A l e c t o r i a s a r m e n t o s a , P a r m e l i a e n t e r o p y r p h a and C e t r a r i a g l a u c a . On y e l l o w c e d a r , L e s c u r a e a b a i l e y i and R a d u l a c o m p l a n a t a predominate^ and n e a r t h e base o f t h e t r e e R h y t i d i o p s i s r o b u s t a , L o b a r i a l i n a t a and 1Mnium s p i n u l o s u m a r e more common. The v e g e t a t i o n a l s i m i l a r i t i e s o f t h e Cladothamnus a s s o c i a t i o n on two d i f f e r e n t h a b i t a t s i n t h e Seymour - Grouse - H o l l y b u r n a r e a i n d i c a t e t h a t e c o system d i f f e r e n c e s do ^not a l w a y s c o i n c i d e w i t h d i s t i n c t v e g e t a t i o n a l d i f f -e r e n c e s . Because- Cladothamnus p y r o l a e f l o r u s i s n o t p r e s e n t i n t h e P a u l R i d g e -Diamond Head p o r t i o n o f G a r i b a l d i P a r k , S y n t h e s i s T a b l e I i n c l u d e s no sample p l o t s from t h e r e . A s p e c i a l v a r i a n t o f t h e Cladothamnus a s s o c i a t i o n , c h a r -a c t e r i z e d m a i n l y by V a c c i n i u m membranaceum, would o c c u p y s i m i l a r h a b i t a t s i n t h a t p a r t o f t h e s t u d y a r e a . b. M e s i c H a b i t a t T h i s h a b i t a t i s p r e d o m i n a n t l y on g l a c i a l t i l l s u b s t r a t e and l a c k s thee exposed r o c k o u t c r o p s t h a t are c h a r a c t e r i s t i c f o r t h e x e r i c h a b i t a t des-c r i b e d above. M e s i c h a b i t a t s u s u a l l y o c c u r on t h e upper p o r t i o n s o f g e n t l e s l o p e s and t h e i n f l u e n c e o f seepage d u r i n g t h e d r i e s t p a r t o f t h e summer i s n e g l i g i b l e (Brooke 1964). 69 (2) Vaccinium alaskaense association (Abieteto - Tsugetum mertensianae) Reference} Synthesis Table II Characteristic combination of species: Constant dominants Constants, not dominant Tsuga mertensiana Abies amabilis Vaccinium membranaceum  Rubus pedatus Vaccinium alaskaense  Rhytidiopsis robusta Exclusive, selective and preferential species, none. Broad areas i n the lower subzone, i n which there i s only temporary seepage during the early summer, are covered by this association. It i s topo-graphically and successionally similar to the Vaccinium alaskaense - Plagio-thecium - Clintonia forest type of the Western Hemlock Zone (Orloci 196l). However, much greater snow accumulations in the Subalpine Zone make the two associations mensurationally and f l o r i s t i c a l l y distinct. The most obvious difference i s that western hemlock i s largely replaced by mountain hemlock in this association. Average gross volume i s 12,081 cubic feet, made up mostly of mountain hemlock (Table XII). Average height of the t a l l e s t tree i s 109 feet for mountain hem-lock, 98 feet for western hemlock, 87 feet for amabilis f i r , and 78 feet for yellow cedar. An indication of the low productivity i n the Subalpine Zone i s shown by the average site index of only 65 feet for amabilis f i r j on the mesic zonal forest type between altitudes of 700 and 2700 feet, the some species had an average site index of 97 feet (Orloci 196l). A l l diameter classes are well represented by the four tree species which i s an indication that the habitat i s representative of "climax" conditions (Figure 25). Invasion by other species i s d i f f i c u l t under these circumstances, as shown by the absence of sporadic tree species i n this association. Trees are largely confined to humps which rise The tree layer has an estimated average coverage of 69 per cent. 70 three or four feet above general ground level, except f o r amabilis f i r which may also occur on the lower ground between the prominences. Estimated average coverage for the shrub (B) layer i s 59 per cent. It i s often l o c a l l y sparse where the tree canopy i s dense. Vaccinium alask-aense and Abies amabilis provide the largest degree of cover, but Tsuga mer-tensiana and Vaccinium membranaceum are also constant species i n this layer. The average coverage of the C layer i s only eight per cent, mainly a result of the dense shading by the tree and shrub layers. Blechnum spicant and Streptopus streptopoi.des indicate the presence of some temporary seepage on this association even i f these species are present with low sociability and vigour. Rubus pedatus and Clintonia uniflora are the most important non-woody species i n this layer, but regeneration of Vaccinium and amabilis f i r also pro-vide small coverage. Rhytidiopsis robusta, Dicranum scoparium, D. fuscescens and Rhytid-iadelphus loreus are the main humicolous species. More moisture and shade on this mesic association allow Blepharostoma trichophyllum, Cephalozia media, Calypogeia neesiana, Lophocolea heterophylla and Lepidozia reptans to occur on 60 to 80 per cent of the plots. Amabilis f i r germinants are constant and plentiful in the D layer. Bryophytes and lichens on rock surfaces are not noticeably different from those on the Cladothamnus association. There i s a greater amount of de-cayed wood on the Vaccinium alaskaense association and i t contains a greater variety of bryophytes. Most of the mosses and liverworts from the humus spread to decaying logs, vhere they form a mixture vith Bazzania ambigua, Lophozia  porphyroleuca and Hypnum circinale. Lescuraea baileyi occurs rarely on Vaccinium stems in this assoc-iation, although Ptilidium pulcherrimum commonly does. Bryophytes and lichens epiphytic on tree trunks include those of the 71 Cladothamnus association, with the following additions? Hypnum circinale, Parmeliopsis hyperopia, Sphaerophorus globosus and Cladonia squamosa. c. Moist Habitat This category includes areas with temporary or irregular seepage. Slopes that have shallow soils become mesic toward the end of the growing season and support the hygric (moist) subassociation of the Cladothamnus association. On moist habitats that have deeper soils the Streptopus assoc-iation, with i t s luxuriant herbaceous layer, occurs. Although both of these vegetation units occur on moist habitats, individual tree size i s far greater on the Streptopus association. It i s not known i f the poor tree growth on the Cladothamnus association i s due to some factor other than the shallow s o i l . (lb) Cladothamnus association, hygric subassociation (Tsugeto -Cladothamneturn subassoc. hygricum) Reference: Synthesis Table I Characteristic combination of species: as i n l i t h i c subassoc-iation with differentiating features as described below. This subassociation represents an ecosystematic variation of the Cladothamnus association. F l o r i s t i c features of this subassociation on moist, but shallow, soils are not markedly different from those of the l i t h i c counter-part. The tree layer, predominantly of mountain hemlock, has an estimated average cover of only 43 per cent. Average gross volume i s 5,4-66 cubic feet per acre, and the average height of the tallest tree i s 84 feet for mountain hemlock, 76 feet for amabilis f i r and 73 feet for yellow cedar. Site indices at 100 years are between 40 and 50 feet for a l l three species. Mountain hem-lock has the greatest number of trees and the greatest gro?" volume of the three species i n a l l diameter classes except the smallest (5-inch class), 72 where amabilis f i r i s the predominant species. The shrub layer on this subassociation i s the most dense i n the en-tir e zone. The estimated 90 per cent coverage i s of Cladothamnus pyrolaeflorus, Vaccinium alaskaense and V. membranaceum. Where there i s occasional coniferous regeneration amongst the shrubs i t appears to stagnate at approximately four or five, inches in diameter and at 10 to L4 feet i n height. This stagnation may be a result of the weight and movement of snow which depresses and deforms shrubs and small trees. but i t i s not abundant and i s of poor vigour. Cassiope mertensiana and Vac- cinium deliciosum are poorly represented when compared to the l i t h i c subassoc-iation. Rhytidiadelphus loreus are the most common mosses on humus. Lichens occur very sparingly on this subassociation. (3) Streptopus association (Abieteto - Streptopetum) Reference: Synthesis T able III and Plate I, A. ' Two subassociations are recognized and described below for this association. Phyllodoce empetriformis i s a constant species i n this subassociation Dicranum fuscescens, Rhytidiopsis robusta, Dicranum scoparium and (3a) Typical subassociation (subassoc. abietetoso - streptopetosum) Characteristic combination of species: Constant dominants Constants, not dominant Menziesia ferruginea  Blechnum 'spicant Streptopus roseus Veratrum eschscholtzii Preferents Exclusives and selectives, none Blechnum spicant  Streptopus roseus  Streptopus streptopoides Plagiothecium denticulatum 73 This association i s closely related to the orthic Blechnum forest type at lower elevations i n the Coastal VJestern Hemlock Zone. The most obvious f l o r i s t i c difference i s the low species significance, sociability and vigour of Blechnum spicant in the Subalpine Zone. The greater accumulations of humus and the shorter growing season i n the Subalpine Zone probably hinder the oc-currence of Blechnum, but the presence of i t s usual associates, such as Streptopus spp. and Tiarella spp. suggests edaphic similarities i n the two associations of the two bioclimatic zones. The typical subassociation usually occurs on middle portions of slopes and often there are steep rock faces exposed above. A l l precipitation runs off from the rock surfaces to ensure a plentiful supply of seepage below. The s o i l on this association i s usually deeper than 70 cm., therefore seepage i s not confined to the surface. It was frequently noted that these habitats are free of snow in June when portions of the slope both above and below are s t i l l covered by two to three feet of snow. In many instances this i s due to a relatively warmer west or southwest exposure. Furthermore, this association frequently occurs on slopes as steep as 30 degrees where occasional small snow-slides are possible. These factors combine to lessen snow accumulation, and the consequent increase in length of growing season allows greater decomposition of humus. The break-down of humus i s further enhanced by seepage water which l a t e r a l l y translocates nutrients required for the process of decomposition. The f i n a l result i s ex-cellent tree growth for such an altitude; at 3700 feet on Grouse Mountain a 20-year radial increment of three inches was noted for amabilis f i r . The greatest heights and diameters recorded in this study were on this association (total height 170 feet and d.b.h. 64.5 inches for amabilis f i r ; 171 feet and 58.9 inches for mountain hemlock). The ta l l e s t yellow cedar (130 feet) also occurred here and the greatest diameter for the species (70.0 inches) was on 74 a degraded subassociation of the Streptopus association.' The highest average volume i n the zone, 17,951 cubic feet per acre, i s on this association and 55 per cent of i t i s amabilis f i r . Average height of the t a l l e s t tree i s 142 feet for amabilis f i r , 135 for mountain hemlock, 114 for yellow cedar and 102 for western hemlock. Amabilis f i r i s more numer-ous than other species in a l l diameter classes. Yellow cedar i s rarely present in diameter classes less than 20 inches, and above this size i t averages only one tree per acre i n each diameter class. Both species of hemlock are repres-ented i n a l l diameter classes. Constant dominant shrubs are not noticeably different from those on the mesic Vaccinium alaskaense association; Vaccinium alaskaense and Abies. amabilis dominate the B layer i n both cases... The sporadic occurrence of Oplopanax horridus indicates that there i s at least temporary seepage on this habitat. Rubus pedatus, Blechnum spicant, Streptopus roseus, Veratrum  eschscholtzii, Clintonia uniflora and Tiarella spp, dominate the herbaceous layer. Lysichitum americanum occurs with low vigour and only on the wettest parts of the association. There are no distinctive bryophytes on the humus; they are a combin-ation of mesophytic species such as Dicranum fuseescens and Rhytidiopsis  robusta and hydrophytic ones such as Mnium nudum and Plagiothecium undulatum.. Lignicolous species are mainly Hypnum circinale, Dicranum scoparium, Rhytidiadelphus loreus, Scapania bolanderi, Plagiothecium elegans, Tsuga hetero-phylla and patches of mixed liverworts. The latter are usually Cephalozia media,  Blephai-ostoma trichophyllum, Lepidozia reptans and Lophocolea heterophylla. Yellow cedar bark i s par t i a l l y covered with Heterocladium procurrens,  Radula complanata, Plagiothecium elegans, Hypnum circinale and Lobaria linata. On a recent yellow cedar windfall Antitrichia curtipendula, Parmelia entero-75 morpha, Ptilidium pulcherrimum and Sphaerophorus globo.sus were noted on the upper sides of branches i n the upper half of the tree crown; Amabilis f i r and both species of hemlock support species on their lower trunks distinct from those on yellow cedar. Parmelia enteromorpha, Sphaerophorus globosus, Parmeliopsis hyperopta, Alectoria sarmentosa, Ptilidium  pulcherrimum, Hypnum circinale and Dicranum fuscescens are a l l common. (3b) Degraded subassociation (subassoc. chamae cypare to sum) Reference: Synthesis Table III Characteristic combination of species: as i n typical subassoc-iation, with differentiating species as described below. In the shrub layer Cladothamnus pyrolaeflorus and Rhododendron a l b i -florum distinguish this from the typical subassociation. The absence of Rubus  spectabilis i n the degraded subassociation i s a further difference c In the subordinate layers, Gymnocarpium dryopteris and Bryum sand-bergii are absent from this subassociation, and species such as Streptopus streptopoides, T i a r e l l a t r i f o l i a t a , T. unifoliata and Athyrium filix-femina occur i n less than 20 per cent of the plots. Conversely, Listera caurina and Plagiochila asplenioides have a higher presence rating than on the typical subas sociation. The degraded subassociation i s further distinguishable by the following features of i t s tree layer: (l) amabilis f i r i s exceeded by mountain hemlock, both i n number of trees and i n gross volume, for most diameter classes; (2) western hemlock i s only sporadically present, most often as large trees over 4-0 inches i n diameter; and (3) yellow cedar i s more numerous, but s t i l l absent from some of the smaller diameter classes. As the typical Streptopus association develops towards this degraded subassociation there i s a poorer representation of the low altitude species, western hemlock and amabilis f i r , 76 and an increased number of yellow cedar and mountain hemlock (Figure 2 5 ) . Yellow cedar entirely dominates i n the diameter classes over 37 inches. For this species there i s an average of 12 trees per acre over 39 inches i n diameter; i t i s not surprising that over 4-0 per cent of the gross volume on the subassociation i s from yellow cedar alone. Average gross volume per acre i s approximately 3000 cubic feet less than on the typical subassociation. Average height of the t a l l e s t tree i s 24 feet less i n the two species of hem-lock, 25 feet less i n amabilis f i r , but 2 feet greater i n yellow cedar on the degraded subassociation. Another noticeable feature i s the reduction i n average coverage by the herbaceous layer to only 16 per cent. This indicates a marked development towards the mesic Vaccinium alaskaense association where increased shade, great-er depth to seepage, and more raw humus limit coverage of the G layer. A distinct concentration of Mnium spinulosum, Plagiochila asplen- ioides and Barbilophozia lycopodiodes near the base of large.yellow cedar trees are additional differentiating f l o r i s t i c features of this subassociation. On the two occasions when Polystichum muniturn was observed in the Subalpine Zone, i t grew in close contact with yellow cedar. The bark of this tree may provide nutritional benefits to species growing at i t s base and, for Polystichum^ the required moisture would be provided by the portion of intercepted precipitation which reaches the forest floor as stem-flow on these large trees. d. Wet Habitat This habitat i s characterized by permanent seepage which i s often near the surface. Where these seepage habitats occur adjacent to mountain streams, tree growth i s good, as on the subalpine Oplopanax association. In other cases, tree growth may be hindered by slow-moving water and poor aeration near the surface, as on the subalpine Lysichitum association. 77 (4.) Subalpine Oplopanax a s s o c i a t i o n (Thujeto - Oplopanacetum abiet-eto sum amabilis) Reference: Synthesis Table V and Plate I, b The c h a r a c t e r i s t i c combination of species below i s tentative be-cause synthesis was based on only four sample p l o t s . Presence classes could not be accurately assigned to the constituent species f o r such a small number of samples. Constant dominants Constants; not dominant Tsuga heterophylla Vaccinium o v a l i f o l i u m Abies amabilis Vaccinium membranaceum Oplopanax horridus Lonicera utahensis Vaccinium alaskaense T i a r e l l a u n i f o l i a t a Athyrium f i l i x - f e m i n a C l i n t o n i a u n i f l o r a Gymnocarpium dryopteris V i o l a g l a b e l l a Streptopus roseus Streptopus amplexifolius R h y t i d i o p s i s robusta Rubus pedatus Veratrum e s c h s c h c l t z i i Exclusives Pyrola secunda Osmorhiza purpurea Oplopanax horridus T i a r e l l a t r i f o l i a t a Lonicera utahensis Streptopus streptopoides Ribes bracteosum L i s t e r a caurina Dicranum fuscescens S e l e c t i v e s Hypnum c i r c i n a l e Scapania bolanderi Picea s i t c h e n s i s Preferents,. continued Preferents V i o l a g l a b e l l a Thuja p l i c a t a Streptopus amplexifolius Vaccinium o v a l i f o l i u m Osmorhiza purpurea Rubus s p e c t a b i l i s Lycopodium clavatum Athyrium f i l i x - f e m i n a Ribes lacustre Gymnocarpium dryopteris Scapania bolanderi T i a r e l l a u n i f o l i a t a Bryum sandbergii This vegetation u n i t i s considered a subalpine c l i m a t i c v a r i a n t of the Oplopanax - Adiantum f o r e s t type described by O r l o c i ( l 9 6 l ) 0 Edaphic con-d i t i o n s of the two appear very s i m i l a r ; both occur marginal to mountain streams where there i s abundant and r a p i d l y moving seepage near the surface. R e s t r i c t i o n to t h i s p a r t i c u l a r habitat severely l i m i t s the d i s t r i b u t i o n of t h i s f o r e s t type and i t s subalpine v a r i a n t . F l o r i s t i c d i f f e r e n c e s are not great between the two, 73 except that Thuja plicata i s rare or lacking i n the subalpine variant and amabilis f i r i s much more common. In the herbaceous layer,, Adiantum pedatum i s replaced by Gyrahocarpium dryopteris in the Subalpine Zone. Lonicera utah-ensis in the subalpine variant further distinguishes i t from the related assoc-iation at lower altitudes, i t i s important to distinguish the subalpine Oplo-panax sites from the Oplopanax forest type of flood-plains at lower elevations (Piceeto - Oplopanacetum, Orloci 196l). The latter develops on an entirely different habitat, and i t s origin, development and s t a b i l i t y are unlike the association under discussion here. Insufficient mensurational data were available to obtain reliable stand table and diameter-class volume data. Average coverage by the tree layer was estimated to be only 51 per cent. Many openings are present because of frequent windfall. The abundant moisture supply in the association may en-courage shallow-rootedness which, in turn, could explain the high incidence of windfall. Despite the relatively sparse tree cover, gross volumes per aero are high because of large individual tree volumes. The four 1/5-acre plots average 15,688 cubic feet per acre, with western hemlock and amabilis f i r con-tributing most of the volume. Yellow cedar i s not abundant because some of the sample plots occurred below the lower altitudinal limit of this species on Paul Ridge. Sitka spruce are few i n number on this association but contribute a large volume. A spruce 158 feet t a l l and 43.7 inches at breast height was recorded on one of these plots at an altitude of 3760 feet.. Average height of the t a l l e s t tree i s 139 feet for mountain hemlockj 138 for balsam fir-, 128 for western red cedar and 127 for western hemlock. Amabilis f i r has the greatest site index of 101 feet, western hemlock 9 5 , western red cedar 9 5 , and mountain hemlock only 78. On this association mountain hemlock i s clearly confined to higher portions of the habitat where drainage i s better, whereas amabilis f i r occurs throughout. 79 Large openings i n the upper canopy encourage a dense shrub layer. It i s dominated by Oplopanax horridus (Plate I, B), Vaccinium alaskaense and Abies amabilis. The constant species that provide most coverage i n the C layer are Athyrium filix-femina, Gymnocarpium dryopteris, and Streptopus roseus. Mnium nudum i s the most significant moss in the ground layer, and other species that characterize the moist conditions of this habitat are: Hypnum circinale, Scapania bolanderi, Bryum sandbergii, Eurhynchium stokesii, Moerckia b l y t t i i and Plagiothecium undulatum. Hookeria lucens, which occurs only sporadically, also indicates abundant seepage at or near the surface. There are usually no rocks exposed on this association, and decayed wood i s occupied by many of the bryophytes l i s t e d above. Lepidozia reptans,  Cephalozia media? Blepharostoma trichophyllum and Ptilidium pulcherrimum are also widespread on decaying \</indfalls. Corticolous bryophytes were not studied i n sufficient detail to detect differences from those on trees of the mesic Vaccinium alaskaense association which often occurs adjacent to the moist Oplopanax ravines. (5) Subalpine Lysichitum association (Chamaecypareto - Lysichitetum) Reference: Synthesis Table V Characteristic combination of species: Constant dominants Constants, not dominant Chamaecyparis nootkatensis Tsuga mertensiana Tsuga heterophylla Menziesia ferruginea Abies amabilis Rubus pedatus Vaccinium alaskaense Clintonia uniflora Lysichitum americanum Carex laeviculmis Mnium nudum Veratrum eschscholtzii Rhytidiadelphus loreus Blechnum spicant Athyrium filix-femina Exclusives Streptopus roseus Streptopus amplexifolius  Coptis asplenifolia Cornus canadensis Listera cordata  Rhytidiopsis robusta  Plagiothecium undulatum 80 Constants, not dominant, cont'd. Lysichitum americanum Sphagnum squarrosum Selectives Sphagnum squarrosum  Dicranum fuseescens  Pellia epiphylla Preferents, continued Preferents Carex laeviculmis  Veratrum eschscholtzii  Listera cordata Habenaria saccata Pellia epiphylla  Mnium spinulosum Conocephalum conicum  Sphagnum girgensohnii Hypnum dieckii Nephrophillidium crista-galli  Mnium nudum  Rhytidiadelphus loreus Plagiothecium undulatum Lysichitum americanum occurs in a number of different bioclimatic zones because i t grows on habitats in which edaphic controls prevail over climatic influences. The coastal subalpine Lysichitum association differs f lorist ical ly from others previously described by a similar name for the Douglas-fir zone on the east coast of Vancouver Island, for the Interior Western Hemlock Zone, or for the Coastal Western Hemlock Zone (Forestry Hand-book for British Columbia 1959, Orloci 196l). It is most closely related to "^ne Vaccinium alaskaense - Lysichitum forest type of the Coastal Western Hemlock Zone (see Table VIII), but Picea sitchensis and Thu.ja plicata are 'replaced by Chamaecyparis nootkatensis in the subalpine counterpart. restricted to areas where seepage is abundant, permanent and near the surface. Therefore, i t is most common on concave, lower slopes. The impeded drainage and poor aeration result in a low total volume of only 8,345 cubic feet per acre. For volume, decreasing order of importance for the tree species is western hemlock, yellow cedar, mountain hemlock and balsam f i r . Western hemlock has an average maximum height of 111 feet, followed by mountain hemlock. When age is considered, mountain hemlock shows the highest site index It occurs only near the lower limits of the Subalpine Zone and is Average coverage by the tree layer was estimated at 66 per cent. 81 of 71 feet, western hemlock 65 feet, yellow cedar 61 feet and amabilis f i r only 57 feet. Amabilis f i r i s the most numerous tree i n the small diameter.classes but i s rarely larger than the 21-inch class. Most of the volume in large diam-eter classes i s from yellow cedar and western hemlock. Western white pine and western red-cedar are sporadic trees i n this association. Vaccinium alaskaense i s the most important species i n the shrub layer., and regeneration of the four common tree species make up the most of the re-maining cover. On such habitats there are groupings of herbaceous species in the wettest portions quite distinct from the combination of species which occurs on the elevated, more acid humps. Sample plots as large as l/5-acre have the dis-advantage of covering both microhabitats and an unusual combination of species may result i n the synthesis tables unless previous stratification i s made in the l i s t of species. In the wettest portions of this association Lysichitum americanum? Clintonia uniflora and Veratrum eschscholtzii typify the success of geophytes. Most of the remaining species i n Synthesis Table V are assoc-iated with Lysichitum in the moist depressions, but the following are more common near the clumps of trees where there i s some raw humus development and where depth to seepage i s greater: Rubus pedatus, Pyrola secunda, Streptopus  streptopoides, Cornus canadensis, Maianthemum dilatatum, Vaccinium spp., Menziesia ferruginea, Goodyera oblongifolia and Sorbus oecidentalis. On moist depressions.Mnium nudum. Sphagnum squarrosum, P e l l i a  epiphylla and Plagiothecium undulatum predominate, but Rhytidiadelphus loreus,  Rhytidiopsis robusta and Dicranum fuscescens are l o c a l l y abundant on drier prominences. The primary lignicolous bryophytes are Dicranum fuscescens, Hypnum  circinale, Ptilidium pulcherrimum, Rhytidiadelphus loreus, Scapania bolanderi. 82 Lophocolea heterophylla and Rhytidiopsis robusta. On very moist logs and rocks Hypnum dieckii differentiates this wet association from those which are moist, mesic or dry, Corticolous bryophytes and lichens are similar to those described for the Streptopus association. e. Moor Habijjat Areas with stagnant water are included here and only one association is described for this category. (6) Eriophorura - Sphagnum association (Eriophoreto - Sphagnetum) References: Synthesis Table IV and Plate II, B Characteristic combination of species: Constants, none Preferents Exclusives Scjrpus caespitosus Sphagnum plumulosum Eriophorum angustifolium Scapania uliginosa Carex aquatilis Sphagnum mendocinum Calliergonella cuspidata Selectives, none Polytrichum commune The characteristic combination of species above is very tentative because this association was not studied in sufficient detail. It occurs sporadically in the Subalpine Zone and there was great f lorist ic variation in the five plots that were analysed. This association is most frequent in the lower subzone, but i t may sometimes occur in the upper subzone and even frag-mentarily in the Alpine Zone. This association begins to develop in open stagnant water or on slopes where drainage is severely impeded. Carex aquatilis and Drepanocladus exan- nulatus characterize the f irst stage of development (Plate II, B), and later stages are dominated by Eriophorum angustifolium, Sphagnum plumulosum and S. mendocinum. 83 On one of these moor areas there was a slight slope of four degrees, which was sufficient to improve drainage, and common species of the Leptarrhena -Caltha leptosepala association were associated with Eriophorum angustifolium ^ Carex aquatilis. This association requires further study for an understand-ing of its ecological and phytosociological features. B, Upper Subzone In this part of the Subalpine Zone trees grow only on dry and mesic habitats which have a relatively short duration of snow. Wet and moist habitats, often because of their topographic position, have such a long duration of snow that trees are unable to develop. 1, Chionophobous Associations Chionophobous communities are those which are relatively intolerant to great accumulations and long duration of snow. In the upper subzone, the two associations which contain trees are placed in this category. a. Dry Habitat The l i th ic subassociation of the Cladothamnus association occupies dry habitats in both the upper and lower subzones. Floristic features are not markedly different in the upper subzone from those described for the subassoc-iation at lower elevations. Total volume is usually less than 2 0 0 0 cubic feet per acre and species such as Phyllodoce empetriformis, Cassiope mertensiana, Vaccinium deliciosum and Luetkea pectinata are much more prominent on this sub-association in the upper subzone. b* Mesic Habitat This habitat may have a considerable amount of rock outcrop but i t always occurs on a slope position and the soils are generally deeper than in 84 the drier l i t h i c habitat of the upper subzone (Brooke 1 9 6 4 ) . (?) Vaccinium membranaceum - Rhododendron association (Tsugeto -Vaccinieturn membranacei) Reference: Synthesis Table VI, Plates I, E and III, C Characteristic combination of species: Constant dominants Constants, not dominant Tsuga mertensiana Phyllodoce empetriformis Abies amabilis Vaccinium deliciosum Vaccinium membranaceum Orthocaulis f l o e r k i i Rhytidiopsis robusta Preferents Exclusives, none Vaccinium membranaceum Selectives Rhododendron albiflorum This association i s f l o r i s t i c a l l y similar to the Engelmann Spruce -Alpine F i r - Black Huckleberry association of the Interior Subalpine Zone (Arlidge 1 9 5 5 ) and i s related to vegetation types described by Daubenmire ( 1 9 5 2 ) i n northern Idaho, Tsuga mertensiana, Rhododendron albiflorum and Vaccinium  membranaceum are amongst the climax dominants in subalpine areas of inland mountains, and. in this study the Vaccinium membranaceum - Rhododendron assoc-iation was best developed i n the portions of Garibaldi Park which were furthest from the Strait of Georgia. This association may develop on somewhat different habitats depending upon altitude. Its optimal development, at an altitude of 3 9 0 0 feet, i s shown in Plate III, 0 . At the altitudinal tree l i m i t (near 6 0 0 0 feet i n this study), the same association develops as a topographic climax only on drier, more ex-posed ridges (Plate I, E). -When this association was confined to a narrow ridge i t was often impossible to establish a sample plot as large as l/5-acre. Only the five sample plots that were of standard l/5-acre size were used in the summaries 85 of mensurational data (Figure 25 and Table XII). Average gross volume i s 6,4-51 cubic feet per acre, with mountain hemlock accounting for 67 per cent. Average height of the tal l e s t tree i s 86 feet for mountain hemlock, 71 feet for amabilis f i r and 53 feet for yellow cedar. Site indices could not be accurately calculated, but for each species i t i s less than 4-0 feet at 100 years. Mountain hemlock i s the only species represented in a l l diameter classes. Yellow cedar has a very low average number of trees in the smallest diameter class, i n contrast to i t s abundance at this size in the l i t h i c sub-association of the Cladothamnus association. Both yellow cedar and amabilis f i r are only sporadically present i n diameter classes over 13 inches. Basal snow-crook i s common on tree trunks, particularly where the slope i s great, and the stems of t a l l shrubs are permanently appressed by the weight of snow. Vaccinium membranaceum, Rhododendron albiflorum and Tsuga  mertensiana are the main species i n the shrub layer. As in the mesic Vaccinium alaskaense association of the lower sub-zone, the herbaceous layer i s poorly developed. There are only a few chamae-phytes and small woody phonerophytes in the C layer. The constant occurrence of Rhytidiopsis robusta on humus clearly differentiates the ground layer of this association from that on non-forested associations i n the upper subzone, whereas Orthocaulis f l o e r k i i as a constant species distinguishes the humicolous layer from that i n forested associations at lower altitudes. Lichens are numerous by species but provide l i t t l e sur-face coverage, and species of Rhacomitrium are uncommon on humus. When this association occurs near i t s upper l i m i t on ridges, the humicolous bryophyte layer i s very sparse with the result that average coverage by bryophytes i s the lowest of any multi-layered association in the Subalpine Zone. Rock surfaces support Andreaea rupestris, Rhacomitrium heterostichum 86 Diplophylluin taxifolium, Kiaeria falcate, Cladonia b e l l i d i f l o r a , Pilophoron  h a l l i i and Lecidea spp. Decayed wood i s not plenti f u l but i s mainly covered by Dicranum  ecoparium, Ptilidium pulcherrimum, Rhytidiopsis robusta and Cladonia b e l l i d i -f l o r a . Cetraria stenophylla and Ptilidium pulcherrimum occur on both Rhodo-dendron and Vaccinium stems but are more abundant on the latter. At the lower altitudinal limits of this association, Lescuraea baileyi also occurs on the stems of Vaccinium. Corticolous species are few; Parmeliopsis hyperopta, Ptilidium  pulcherrimum and Dicranum fuscescens are the main species below average winter snow level on the trunks of mountain hemlock. Alectoria sarmentosa and Sphaerophorous globosus occur higher up on the tree trunks. The only recorded occurrence of Letharia vulpina i n this study was on the bark-free dead branches of yellow cedar of this association. 2. Chionophilous Associations Those associations that develop i n habitats of relatively long snow duration are described below. Trees, as such, are lacking but tree species may be present in dwarf form (Figure 20), Two categories, moderately and strongly chionophilous associations, are discussed below. a. Moderately Chionophilous Associations Habitats with snow duration intermediate between that on forested areas and that i n late snow-patch areas would be similar to 'early snow-patch' habitats as described by Dahl ( 1 9 5 6 ) . The vegetation on these areas of medium snow duration i s considered to be moderately chionophilous in the present classification. i . Dwarf Tree Association Tree species i n this association are rarely over ten feet t a l l . -87 They are often leaning (Plate III, 3) and usually have a snow-crook at the base of the stem. Although dwarfed and somewhat deformed from the forces of snow, tree species are not so severely misshapen as in true krummholz of alpine areas. A more or less erect stem can develop in tree species of the association described below, whereas krummholz of higher altitudes is more closely appressed to the ground, probably as a result of greater exposure to wind. (8) Dwarf Tsuga association (Nano-Tsugetum mertensianae) Reference: Synthesis Table VII and Plate I, F Two subassociations are recognized and described below for this association. (8a) Typical subassociation (subassoc. nano-tsugetosum mertensianae) Characteristic combination of species: Constant dominants Constants, not dominant Tsuga mertensiana Vaccinium deliciosum Phyllodoce empetriformis Deschampsia atropurpurea Cassiope mertensiana Dicranum fuseescens  Luetkea pectinata Orthooaulis f lberkil Preferents Selectives Luetkea pectinata Hippurls montana Deschampsia atropurpurea Ths most important environmental feature distinguishing the two subassociations here is the relative lack of seepage in the typical subassoc-iation. Successional relationships of this association were discussed by Brink ( 1 9 5 9 ) but i t s f lorist ic details have not been previously elaborated.. The typical subassociation occurs on warmer exposures or on elevated areas where snow duration is less than on the adjacent Phyllodoce - Cassiope assoc-iation (Figure 1 9 and Plate I, F) . Conversely, near its lower limit this association occurs on topography that favours longer snow duration than in 88 the surrounding l i t h i c subassociation of the Cladothamnus association. Even i n the lower subzone, collection of cold a i r i n depressions and ravines can create conditions which maintain a dwarf Tsuga association. This association was sampled at an altitude as low as 3300 feet on Mount Seymour; mountain hemlock there was only five feet t a l i at an age of 93 years. The dominance of mountain hemlock physiognomically distinguishes this vegetation unit from the surrounding small shrub associations of the upper subzone. Some hemlocks were over six feet t a l l i n every plot sampled, but height growth i s extremely slow. At an altitude of 4OOO feet mountain hemlock was 12 feet t a l l at 50 years of age, and at 4750 feet i t was only four feet t a l l at 100 years of age (Figure 20). The combined coverage by dwarf Tsuga mertensiana, Phyllodoce empet-riformis and Cassiope mertensiana allows l i t t l e room for other shrubs. Neither Vaccinium deliciosum nor V. membranaceum are well represented i n this assoc-iation. Deschampsia atropurpurea, always with a low species significance and sociability, i s a selective species. The a b i l i t y of mountain hemlock to occur as a pioneer on relatively bare s o i l allows this association to develop i n some places without much prev-ious humus accumulation. The high presence values of pioneers such as Ly-copodium sitchense and Crocynia membranacea indicate that this i s a relatively early stage i n vegetational development. By contrast, on the Vaccinium d e l i - ciosum association organic accumulations are deeper, and Lycopodium and Crocynia are already eliminated or infrequent. Rhacomitrium heterostichum, R. canescens, Orthocaulis f l o e r k i i , Dicranum fuscescens, Kiaerkia falcata, Crocynia membranacea and Cladonia  squamosa are the most important humicolous bryophytes and lichens. Rhacomitrium heterostichum i s also the dominant moss on rock surfaces but Rhizocarpon geographicum, Andreaea rupestris, Grimmia apocarpa and various ! 89 unidentified crustose lichens are also common. No mosses develop on trunks of the dwarf Tsuga i n this association. (8b) Luetkea subassociation (subassoc' luetkaetosum pectinatae) Reference; Synthesis Table VII Characteristic combination of species, as i n typical sub-association, with differentiating species as below. The two subassociations described here are good examples of similar vegetation types developing on quite different habitats. The typical subassoc-iation occurs on a variety of topographic positions and i s often well developed on prominences where there i s no benefit from seepage (Plate I, F). In con-trast, the Luetkea subassociation i s restricted to concave areas where seepage i s available through a l l of the short growing season. Physiognomic differences are slight between the two subassociations and there are few species differences. The presence of Hippuris montani and Carex nigricans, and the better develop-ment of Luetkea pectinata reflect the more abundant moisture of the Luetkea subassociationj the absence of Crocynia, membranacea and Cladonia squamosa further differentiates i t from the typical subassociation. In both cases, humus i s very shallow and poorly developed, but the improved moisture supply allows the increased occurrence of P e l l i a neesiana and. Lophozia porphyroleuca on the Luetkea subassociation. Rock surfaces in the typical subassociation are covered with species similar to those on rocks of the Phyllodoce - Cassiope association. On the Luetkea subassociation the main coverage on rocks i s by Gymnomitrium concinnatum, Rhacomitrium heterostichum, Diplophyllum taxifolium, Xiaeria falcata and Andreaea nivalis . i i . Small Shrub Associations The two associations described below are also considered to be moderately chionophilous. They are usually on habitats which are moist because 90 of melting snow u n t i l about mid-July, but they become mesic toward the end of the summer. Tree species, even i n dwarf form, are very uncommon on these as-sociations. (/) Vaccinium deliciosum association (Vaccinietum deliciosi) References Synthesis Table VIII Characteristic combination of species: Constant dominants Constants, not dominant .Vaccinium deliciosum Tsuga mertensiana Phyllodoce empetrifprmis Vaccinium membranaceum Cassiope mertensiana ' Luetkea pectinata Dicranum fusee scejis Cetraria islandica  Orthocaulis f l o e r k i i Rhytidiopsis robusTa Preferents Selectives Vaccinium deliciosum Cetraria islandica Relatively pure patches of Vaccinium deliciosum occur adjacent to areas of Phyllodoce empetriformis and Cassiope mertensiana but Vaccinium appears unable to tolerate such a long snow duration as these low evergreen shrubs. The Vaccinium deliciosum association has f l o r i s t i c characteristics transitional towards the Vaccinium membranaceum - Rhododendron association, which i s an i n -dication that i t i s less chionophilous than the Phyllodoce - Cassiope assoc-iation in the Subalpine Zone. The zonation and distribution of Vaccinium  deliciosum are often a result of differences i n the length of growing season, and i t s frequent concentration along small temporary streams also indicates that this species i s less xerophytic than Phyllodoce or Cassiope. The relatively deep s o i l and the well developed humus layer on this association provide improved moisture conditions. Even though tree species are not abundant, the deep humus layer, the lack of pioneer species such as Lycopodium sitchense, and the constant occurrence of Rhytidiopsis robusta and Vaccinium membranaceum indicate that vegetational development i s well advanced 91 here,, This association i s more closely related, f l o r i s t i c ally, to forested communities than i t i s to the Phyllodoce - Cassiope association, and for this reason i s not found at higher altitudes i n the Alpine Zone. It i s a character-i s t i c association of the upper subzone of the Subalpine Mountain Hemlock Zone. There i s a well-developed shrub layer which i s dominated by Vaccinium  deliciosum. The layer less than six inches in height (C) i s occupied largely by this same species and by Phyllodoce empetriformis. Cassiope mertensiana i s reduced in total cover degree by the increased shading of Vaccinium over six inches t a l l . Lycopodium sitchense i s entirely absent, in contrast to the other small shrub association at this altitude. Dicranum fuseescens and Orthocaulis f l o e r k i i are the dominant humi-colous species but the occurrence of Rhytidiopsis robusta and Cetraria islandica differentiate this layer from that i n the Phyllodoce - Cassiope association. Cladonia b e l l i d i f l o r a i s the only prominent lichen i n the humus layer, and Cetraria stenophylla i s abundant on the stems of Vaccinium deliciosum near ground, level. Bryophytes and lichens on rock surfaces are similar to those on the Phyllodoce - Cassiope association. ( 1 0 ) Phyllodoce - Cassiope association (Phyllodoceto - Cassiopeturn  mertensianae) Reference: Synthesis Table IX and Plate II, D Characteristic combination of species: Constant dominants Constants, not dominant Phyllodoce empetriformis Luetkea pectinata Cassiope mertensiana Vaccinium deliciosum Preferents Dicranum fuscescens Orthocaulis f l o e r k i i Phyllodoce empetriformis Cassiope mertensiana Exclusives and Selectives, none Lycopodium sitchense' Gymnomitrium varians  Kiaeria falcata  Crocynia membranacea 92 T h i s v e g e t a t i o n u n i t was p r e v i o u s l y s t u d i e d b y McAvoy (1929, 1931 ).• ... . B r i n k (1959) a n d A r c h e r (1963). I t i s t h e me s i c a s s o c i a t i o n i n t h e A l p i n e Zone ( A r c h e r 1963)., b u t i n t h e S u b a l p i n e Zone i t o c c u r s o n m o i s t h a b i t a t s . I t s o c c u p a t i o n o f c o n c a v e t o p o g r a p h i c p o s i t i o n s w i t h t e m p o r a r y seepage i n t h e S u b a l p i n e Zone i s i n s h a r p c o n t r a s t t o i t s d e v e l o p m e n t i n t h e A l p i n e Zone o n c o n v e x o r f l a t r e l i e f w i t h o u t s e e p a g e . The two t o p o g r a p h i c a l l y d i s t i n c t h a b i t a t s o n w h i c h t h i s a s s o c i a t i o n o c c u r s i n t h e two b i o c l i m a t i c z o n e s i n f l u e n c e n o t o n l y t h e m o i s t u r e r e l a t i o n - . s h i p s b u t a l s o snow d u r a t i o n . On b o t h h a b i t a t s i n t h e two d i f f e r e n t z o n e s t h e snow r e m a i n s f o r n i n e t o t e n months o f t h e y e a r . H o w e v e r , r e l a t i v e t o o t h e r t o p o g r a p h i c p o s i t i o n s a n d v e g e t a t i o n u n i t s , t h e P h y l l o d o c e - C a s s i o p e a s s o c i a t i o n i s c h i o n o p h o b o u s i n t h e A l p i n e Zone b u t m o d e r a t e l y c h i o n o p h i l o u s i n t h e S u b a l p i n e Z o n a . I n t h e A l p i n e Z o n e , P h y l l o d o c e e m p e t r i f o r m i s a n d C a s s i o p e m e r t e n s i a n a a r e t h e d o m i n a n t s p e c i e s o f t h i s a s s o c i a t i o n ; i n t h e S u b a l p i n e Z o n e , t h e a s s o c -i a t i o n becomes more d i v e r s i f i e d b y t h e i n v a s i o n o f t a l l e r s h r u b s o r t r e e s p e c i e s T h e r e i s a g r e a t e r p r o p o r t i o n o f V a c c i n i u m d e l i c i o s u m a n d T s u g a m e r t e n s i a n a , a n d l e s s e r amounts o f C a s s i o p e m e r t e n s i a n a when t h i s a s s o c i a t i o n o c c u r s w i t h i n t h e S u b a l p i n e Z o n e . I f t h e r e i s a B l a y e r d e v e l o p e d , m o u n t a i n h e m l o c k i s t h e d o m i n a n t s p e c i e s , b u t C h a m a e c y p a r i s n o o t k a t e n s i s , V a c c i n i u m d e l i c i o s u m , V . membranaceum a n d S o r b u s o c c i d e n t a l i s may a l s o o c c u r o v e r s i x i n c h e s i n h e i g h t . I n i t s e a r l y p h a s e s t h i s a s s o c i a t i o n c o n t a i n s a h i g h p r o p o r t i o n o f L u e t k e a p e c t i n a t a , L y c o p o d i u m s i t c h e n s e , C r o c y n i a m e m b r a n a c e a , K i a e r i a f a l c a t a , a n d G y m n o m i t r i u m v a r i a n s . The c o n s t a n t d o m i n a n t b r y o p h y t e s , D i c r a n u m f u s c e s c e n s a n d O r t h o c a u l i s f l o e r k i i , a r e l a c k i n g o n l y d u r i n g t h e i n i t i a l p h a s e o f d e v e l o p -m e n t . 'When T s u g a m e r t e n s i a n a a n d V a c c i n i u m d e l i c i o s u m o c c u r o n t h i s a s s o c -i a t i o n , R h y t i d i o p s i s r o b u s t a may a l s o d e v e l o p b e n e a t h t h e m . R o c k s u r f a c e s a r e p a r t i a l l y c o v e r e d w i t h R h a c o m i t r i u m h e t e r o s t i c h u m , R . c a n e s c e n s , A n d r e a e a 93 rupestris, Rhizocarpon geographicum, Lecidea sp., Harsupella ustulata, Umbil-i c a r i a torrefacta and Gyronomitrium concinnatumc. Cetraria stenophylla, which i s very common on twigs of Vaccinium  deliciosum, rarely occurs in the Phyllodoce -- Cassiope association. i i i : , Herb Association Only one association i s placed in this group,* It occurs where water i s permanently at or near the surface. Where there i s a surface flow of water snow melt i s hastened. Thus, a slightly longer growing season separates this association from nearby strongly chionophilous associations. ( l l ) Leptarrhena - Caltha leptosepala association (Leptarrheneto -Calthetun leptosepalae) References Synthesis Table IV, Plate II, A Characteristic combination of species: Constant dominants Constants, not dominant Leptarrhena pyrolifolia Carex spectabilis Erigeron peregrinus Caltha leptosepala Parnassia fimbriata Rhytidiadelphus squarrosus Drepanocladus exannulatus Philonotis fontana Exclusives Preferents Caltha leptosepala Carex spectabilis Mitelia pentandra Selectives Juncus mertensianus Arnica l a t i f o l i a Salix commutata Tofieldia glutinosa Leptarrhena p y r o l i f o l i a Veronica serpyl1 i f o l i a Erigeron peregrinus Cratoneuron commutatun Parnassia fimbriata Campyliu^ stellatum Epilobium alpinum Equisetum palustre Petasites frigidus Rhytidiadelphus squarrosus Drepanocladus exannulatus Philonotis fontana 94 Leptarrhena - Galtha a s s o c i a t i o n i s f l o r i s t i c a l l y s i m i l a r to the a l p i n e f o r b meadow described by B r i n k (1959) f o r the- Black Tusk area o f G a r i -b a l d i Park, and the hygrophytic a s s o c i a t i o n s d e s c r i b e d by Archer (1963) f o r the A l p i n e Zone. The f l o r i s t i c s i m i l a r i t i e s of t h i s seepage a s s o c i a t i o n w i t h the Lysic h i t u m seepage a s s o c i a t i o n s a t lower a l t i t u d e s i n d i c a t e the predominance of edaphic c o n t r o l s over m i c r o c l i m a t i c i n f l u e n c e i n such h a b i t a t s (Table V I I I , Chapter I I I ) . When t h i s a s s o c i a t i o n occurs on the margins of a stream d i f f e r e n t combinations of species occur i n bands p a r a l l e l to the open water. P e t a s i t e s f r i g i d u s and Drepanocladus exannulatus represent very e a r l y stages i n the de-velopment of t h i s a s s o c i a t i o n c l o s e s t to the stream ( P l a t e I I I , D)j Leptarrhena  p y r o l i f o l i a , E r i g e r o n peregrinus, C a l t h a l e p t o s e p a l a , P a r n a s s i a f i n b r i a t a ,  Rhytidiadelphus squarrosus and Mnium nudum c h a r a c t e r i z e the l a t e stages of the a s s o c i a t i o n a f t e r organic accumulations have r a i s e d the surface f u r t h e r above stream l e v e l . Sphagnum plunulosum occurs i n t h i s a s s o c i a t i o n i f seepage i s impeded. Luetkea p e c t i n a t a , Phyllodoce empetriformis, Cassiope mertensiana, G a u l t h e r i a humifusa, and Chamaecyparis nootkatensis are the f i r s t species from other a s s o c i a t i o n s to invade the margins of the Leptarrhena - Ca l t h a a s s o c i a t i o n . b. S t r o n g l y Chionophilous A s s o c i a t i o n s This category includes le.%0 snow-patch a s s o c i a t i o n s of the Subalpine Zone where snow may remain as l a t e as the f i r s t week i n August. The assoc-i a t i o n s of t h i s group are c h a r a c t e r i z e d by t h e i r physiognomic s i m p l i c i t y and by t h e i r small number of c o n s t i t u e n t species. (12) S a x i f r a g a t o l m i e i a s s o c i a t i o n (Saxifrageturn t o l m i e i ) References Synthesis Table V I I I , P l a t e s I I I , E and II, F 95 The characteristic combination of species was not determined, because this association i s more typical oi alpine conditions and was insufficiently sampled in the Subalpine Zone. It was observed only loc a l l y on Paul Ridge and on a recently glaciated colluvial talus slope near The Lions. This association i s the f i r s t to occur on unstable colluvial slopes, with coarse-textured so i l s . The sparse C layer i s dominated by Saxifraga  tolmiei and Luzula wahlenbergii i n the earliest stages of development. Phyllo-doce empetriformis may occur sporadically as a pioneer in portions of the slope which are l o c a l l y stable. In later stages of development, Juncus drummondii, Carex spectabilis, Luetkea pectinata, Cryptogramma crispa, Athyrium alpestre and Saxifraga ferruginea occur. The ground layer i s dominated during a l l stages by Gyrinomitrium  varians (Plate II, F), and Oligotrichum hercynicua i s a constant .species. Polytrichum norvegicurn, Kiaeria b l y t t i i and Pohlia drummondii were also re-corded. If rocks became stabilized on these slopes, they are occupied mostly by Andreaea niv a l i s . The occurrence of species such as Athyrium alpestre, Carex spectabilis,  Luetkea pectin ata, Gymnomitriua varians, Polytrichum norvegicurn, Pohlia drum- mondii and Andreaea nivalis indicate that the long snow cover provides plenti-f u l moisture to the habitat during the short growing season. They also indicate the f l o r i s t i c similarities to other snow-patoh associations discussed below. (13) Carex nigricans association (Caricetum nigricantis) Reference: Synthesis Table VIII Characteristic combination of species: Constant dominants Constants, not dominant Carex nigricans Deschampsia atropurpurea Polytrichum norvegicurn Exclusives Polytrichum norvegicurn 96 Selectives Preferents Carex nigricans Juncus drummondii Kiaeria b l y t t i i Saxifrage, tolmiei. This association reaches i t s optimal development in the Alpine Zone but i t i s b r i e f l y mentioned here because of i t s presence in upper portions of the Subalpine Zone, It occupies depressions where the snow remains between 9 and 10 months of the year. So i l depth i s usually over 50 cm. because i n many cases this association occupies former ponds which are now f i l l e d by deep accumu-lations of fine-textured soils. The short growing season limits the number of species, and vegetational development i s extremely slow on such habitats. In the Subalpine Zone, the most important species of this association are Carex nigricans, Deschampsia atropurpurea, Juncus drummondii and Carex  spectabilis. -Luetkea pectinata, Phyllodoce empetriforais and Cassiope  mertensiana are the earliest invaders. The latter species would be absent on well developed examples of this association in the Alpine Zone (Archer 1963). In the ground layer, Polytrichum norvegicum, Kiaeria b l y t t i i and Pohlia drummondii are the main species. ( I 4 ) Polytrichum norvegicum association (Polytrichetum norvegici) Reference: Synthesis Table VIII The characteristic combination of species was not determined because this i s a typically alpine association which occurs only fragmentarily i n the Subalpine Zone. F l o r i s t i c data from two sample plots are shown in Synthesis Table VIII to indicate environmental and phytosociological similarities of this association with the Carex nigricans association. Depressions with the extreme maximum of snow duration (at least u n t i l the f i r s t week of August) are dominated by Polytrichum norvegicum. 97 However, i n the Subalpine Zone t h i s a s s o c i a t i o n o f t e n occurs i n a mosaic w i t h the Oarex n i g r i c a n s a s s o c i a t i o n on moist h a b i t a t s v / i t h f i n e - t e x t u r e d s o i l s . S i m i l a r l a t e snow-patches have been stud i e d i n d e t a i l by European s c i e n t i s t s (Braun-Blanquet 1932, K r a j i n a 1933, G j a e r e v o l l 1950), and i n B r i t i s h Columbia; Shaw (1916) and McAvoy (1929, 1931) have discussed s u c c e s s i o n a l r e l a t i o n s h i p s between P o l y t r i c h u n norvegicum and Carex n i g r i c a n s . Archer (1963) als o discussed a s s o c i a t i o n s f o r these species« However, these references per-t a i n to areas w i t h a l t i t u d e s u s u a l l y greater than the Subalpine Zone o f t h i s study. 98 CHAPTER V COMPARISONS OF THE ASSOCIATIONS This chapter presents basic men sura t'ional data grouped according to the associations just described. Comparisons of life-forms on each assoc-iation are also presented in tabular and graphic form. The data are not dis-cussed in detail since their main purpose is to complement the descriptions of the associations, and to allow comparisons with similar data from other bioclimatic zones. A, Mensuration The greatest average volume occurs on the typical subassociation of the Streptopus association with nearly 18,000 cubic feet per acre, and the least on the l i th ic subassociation of the Cladothamnus association with less than 3,000 cubic feet per acre. The largest individual tree volumes occur on the subalpine Oplopanax association but the total volume per acre is reduced on this site by the high number of windfall (Table XII). The association of optimum development for each tree species is: the mesic Vaccinium alaskaense association for mountain henlpckj the typical subassociation of the Streptopus association for amabilis f i r ; the degraded subassociation of the Streptopus association for yelloxj cedar j and the subalpine Oplopanax association for western hemlock. The relative importance of each tree species in every association is indicated by the total volumes.. Mountain hemlock is the major species in the TABLE XII Averages of gross volume, maximum height and s i t e index f o r the major species on each a s s o c i a t i o n en M o CO 1-3 X o o CO O a, to CO t=> Tj* PM CD O T J E H d PH. Sort CD E H O C O t3 re O En • H O in « tG O CO !=> I t a • H O -P 5 ri j-3 1-3 O O O £3 o O o No. of Plots 6 4 13 6 9 5 12 5 Avge. Gross V o l . cu. f t . / a c r e : A l l species i n c l . sporadics '8 ,345 15,688 17,951 15,OL4 12,081 5 ,466 2 ,657 6 ,451 mountain hemlock 1,820 1 ,850 4 ,131 4 , 4 8 3 5,910 3 ,004 1,931 4,236 amabilis f i r 890 4 ,053 9 ,903 3 ,753 2 ,809 890 357 1 ,619 yellow cedar 2,172 323 1 ,055 6,006 1,366 1 ,459 344 40 6 western hemlock 2,273 6,991 2 ,646 289 1,996 To t a l f o r major species 7 ,155 13,217 17 ,735 14 ,536 •12,081 5 ,353 2 ,632 6,311 T o t a l f o r sporadic species 1 ,190 2,471 216 478 . — 113 25 140 Avge. ht. t a l l e s t tree on p l o t mountain hemlock 102 139 135 111 109 84 71 86 amahilis f i r 83 138 142 117 87 76 45 71 yellow cedar 97 91 114 116 78 73 44 58 western hemlock 111 127 102 78 98 - -Avge. s i t e index, at 100 y r s . mountain hemlock 71 78 76 67 65 46 44 40 amabilis f i r 57 101 93 74 65 49 40 40 yellow cedar 61 1 72 66 45 44 40 40 western hemlock 65 95 69 1 54 "•- -100 Vacciniua alaskaense, the Cladothamnus and the Vaccinium meabranaoeun -Rhododendron associations,* araabilis f i r predominates in the typical Streptopus •aubassociationj amabilis f i r predominates in the typical Streptopus subassoc-iation; yellow cedar shows the highest volume of the four species i n the de-graded _Sjtrep_topus subassociation; and western hemlock i s the main species in the subalpine Lysichitum and Oplopanax associations. The sporadic species which account for the extra volume on some associations are as follows: on the Lysichitum association, western white pine and western red-cedar; on the subalpine Oplopanax association, Sitka spruce and Douglas-fir; on the Streptopus association, western red-cedar; on the Cladothamnus association, western hemlock; and on the Vaccinium membranaceum - Rhododendron association, alpine f i r , western white pine and western hemlock. Eis (1962a) showed that there was a f a i r l y constant decrease i n site index with increasing altitude on associations that have a wide altitudinal range. Consequently,' site indices of subalpine species are very low. Only with amabilis f i r on the Oplopanax association i s site index over 100 feet at 100 years, and in many cases i t i s less than 50 for a l l species (Table XII.). The number of trees and the gross volume in cubic feet per acre are shown for the various diameter classes of each species i n Figure 25*". The important features from these graphs were already discussed i n the association descriptions of Chapter IV. •'•Some changes in nomenclature and organization were made after Figure 25 was reproduced. C. Mesic Vaccinium should read C. Vacciniun alaskaense; E. Vaccinium memfoyanaceum - Rhododendron. F.. Cladothamnus i s based on the five sample plots shown for the hygric subassociation in Synthesis Table I plus five sample plots (101, 104, 43, 19 and 21) that were later grouped in" the l i t h i c subassociation. G. Lithosolic CJadothamnus should read Lithic Clado- thamnus and, as shown in Figure 25, the data for this group are based only on the seven sample plots originally classified as l i t h i c . t o f o l l o w page 100 Figure 25. Number of trees over 3 inches d.b.h. and gross cubic-foot volume, per acre, by 4-inch diameter classes, for 4 species in various associations. Figure continued next page. t . t. . NO..OF .TREES GROSS .VOLUME, Cubic feet I II 1 i I I ' 1  M i l l ! I I I I I I I I I I II 1 I I I I l 1 1—I I I I I 11 1 1—I I I I I I ! i '• i' I '. 5 I.,..., ' • E. RHODODENDRON —I—I 1 1 l l l l i l — i 1 I_J 1 i i i i i 1 i i i i i i 11 i Figure 25. continued 101 B. Life-forms Raunlciaer's life-form system, as modified by Krajina (1933) and used by Orloci (l96l), served to group the species of the study area as follows: Macrophanerophytes (Pn) Chamaephytes (Ch) Lichens (L) Deciduous nanbphanerophytes (Pnd) Henicryptophytes (li) Bryophytes (B) Evergreen nanophanerophytes (Pne) Geophytes (G) Life-forms were weighted by total cover degree v/ith the same scale as used by Orloci (l96l), and the results are directly comparable to those i n the Coastal Western Hemlock Zone (Table XIII, Figures 26 and 27). The nost striking feature when one considers the number of species i n each life-form i s the absence of therophytes (T) i n a l l associations of the zone. In the comparison of associations, henicryptophytes are most numerous on the four wettest associations. Geophytes are few throughout the whole zone and are absent on the Carex nigricans association where the growing season i s too short for the successful growth of species which must rejuvenate from below ground surface every year, The number of lichens i s greatest in the dry and mesic associations of the upper subzone (Figure 26). The physiognomy of each association i s more clearly portrayed when life-forms are weighted by total cover degree (Figure 27). Macrophanerophytes have an obvious concentration in the associations near the lower limits of the zone. Deciduous shrubs are nost abundant on the Cladothamnus, Vacciniun mem-branaceum - Rhododendron and Vacciniun alaskaense associations, and evergreen nanophanerophytes are important only on the chionophilous associations of the upper subzone. Based on cover degree, geophytes are important only on the sub-alpine Lysichitum and Oplopanax associations where there i s abundant seepage. The high proportion of henicryptophytes on the moist and wet Carex nigricans,  Leptarrhena - Caltha, and Eriophorum - Sphagnum associations sharply d i f f e r -entiates them from adjacent associations on drier habitats. to follow page 101 40 h-30 20 10 I \Lysichitum\ 50 40 30 20 50 40 30 20 10 50 40 30 20 10 & £ £ 5 o i m \Vacc. alaskaense\ |_ • \b*iarf "Tsuga, I ; Carex nigricans*. \Oplopanax\ 1 Cladothamnus Wa'cc' deliciosum: •\ Leptarrhena • \Streptopus\ \yacc~~ memaranaceum;: I Rhododendron] Phyllodoce - Cassiope \^iophdrumj, Figure 26. Percentage distribution of 8 life-forms on each association, by number of species.. • to follow page 101 40 30 20 10 . 50 40 30 20 - 10 a> a it CL 50 40 30 20 10 50 -40 -30 20 10 \ Lysichitum] \Oplopanax\ £ £ O O I CO _l \Vocc, alaskdense \ iC/odothamn'us' i Voce, deliciosum I Dwarf Tsuga, .56.6 \ 7-i — I Carex nigricans I Leptarrhena] \St rept opus: | /ocir. membranaceum] SRhododendron \ ~Pp/Jl£^ce^jCassiope\ |55. J! \Erio~phorum Figure 27. Percentage, distribution of 8, life-forms on. each association, weighted, by, total cover degree^,.-102 When bryophytes are considered collectively as one life-form, there are no great differences between associations (Table XIII). Therefore, humicol-ous bryophytes were further categorized into growth-forms i n an attempt to re-veal further f l o r i s t i c differences i n the habitats. Closeness of the entire moss plant to the habitat surface i s consid-ered to give bryophytes high sensitivity to changes i n substrate or microcli-mate. This has been recognized by ecologists for some time, but bryophytes have usually been considered on an individual species basis. Only recently have there been demonstrations of correlations between growth-forms and habitat (Gimingham and Birse 1957). A l l species identified from the Coastal Subalpine Zone were grouped into the following growth-forms (see Checklist, Appendix I ) . (1) Cushions (Cu) - compact, dome-shaped groups. (2) T a l l turfs, branches erect (Te) - parallel, upright shoots over 2 cm. (3) T a l l turfs, divergent branches (Td) - laterals whorled or scattered. (4) Short turfs (t) - as ( 2 ) , but under 2 ca. (5) Mats (M) - horizontally interwoven shoots. (6) Thread-like forms (Mt) - as (5), but delicate and sparsely branched. (7) Thalloid mats (Th) - as i n thalloid liverworts. (8) Wefts (W) - Luxuriant and loosely intertwined shoots. The growth-forns of humicolous bryophytes are presented for each association i n Table XIII. There was no s t a t i s t i c a l evaluation of differences, but some correlations of growth-form with habitat are distinguishable. Cushions are absent from the table because only humicolous species were classified. The amount of exposed rock increases with altitude and the proportion of cushions, as represented by the genera Andreaea and Grimmia, i s greater in the upper sub-zone because they are restricted to rock surfaces. Mats, xtfhich are abundant in shaded habitats at lower altitudes, are unimportant i n the Subalpine Zone and are absent from late snow-patch associations. There are few species classed 103 as wefts, but the widespread occurrence of Rhytidiopsis robusta gives this group a high total cover degree i n the forested associations of the lower sub-zone. There i s a marked increase i n the total cover by short turfs with i n -creasing altitude, and the group i s best represented by Polytriehum norvegicurn beneath late snow-patches. Thalloid mats are restricted to moist seepage assoc-iations, and the t a l l turfs with divergent branches occur only on areas of plentiful seepage or poor drainage. The correlations of growth-form with habitat, even i f subjective,, are in agreement with those reported by Horikawa and Ando (1952) and Gimingham and Birse (1957). If the ecological significance of growth-forms were more carefully examined, i t may be possible to use bryophytes as ecological i n d i -cators without requiring precise species identification. This would encourage their use i n practical ecological investigations. 164 CHAPTER VI'. RELATIONSHIPS AND SUCCESSIONAL DEVELOPMENT OF ASSOCIATIONS The development and t r a n s f o r m a t i o n of p l a n t a s s o c i a t i o n s can be most c l e a r l y understood from long-term observations of s p e c i f i c v e g e t a t i o n a l u n i t s . In the absence of t h i s i d e a l , much must depend upon c i r c u m s t a n t i a l evidence such as the presence of i n v a d i n g species. F o r t u n a t e l y , i n subalpine and a l -pine areas there are more bare i n i t i a than a t lower a l t i t u d e s and i n the upper subzone i t i s p o s s i b l e to observe the o r i g i n and e a r l y development of assoc-i a t i o n s on a v a r i e t y of h a b i t a t s . A problem i n the upper p o r t i o n s of the Sub-a l p i n e Zone i s t h a t the time since g l a c i a t i o n i s so short t h a t development towards a 'vegetational climax' i s probably not very w e l l advanced. In the lower subzone, there has been greater development towards a uniform f o r e s t on mesic h a b i t a t s , w i t h the r e s u l t t h a t e a r l i e r stages of development are already obscured. This chapter proposes h y p o t h e t i c a l developmental changes which may be expected i n the a s s o c i a t i o n s of the upper and lower subzones. The upper subzone i s discussed f i r s t to provide d e t a i l s of e a r l y stages which are l e s s c l e a r l y r e v e a l e d a t lower e l e v a t i o n s i n the zone. I n t h i s chapter, a 'climax' a s s o c i a t i o n i s depicted f o r each subzone as the s u c c e s s i o n a l l y most advanced type of v e g e t a t i o n now e x i s t i n g under mesic c o n d i t i o n s . The e a r l i e s t steps i n succession, which were not s t u d i e d i n de-t a i l , are r e f e r r e d to as 'stages', and w i t h i n the l i m i t s of some a s s o c i a t i o n s developmental 'phases' are recognized (Braun-Blanquet 1 9 3 2 ) . Present a l t i t u d i n a l d i s t r i b u t i o n of the v a r i o u s a s s o c i a t i o n s provides i n d i r e c t i n f o r m a t i o n on a c t u a l and p o t e n t i a l s u c c e s s i o n a l trends w i t h i n the Subalpine Zone,, As a guide to the d i s c u s s i o n which f o l l o w s , the a l t i t u d i n a l 105 range of each association, based on the distribution of sample plots i n this study, i s shown in Figure 28. Associations which are known to occur above or below the altitudes sampled by plot are extended by broken lines. The occur-rence of associations at lower altitudes in the Seymour - Grouse -- Hollyburn study area than in Garibaldi Park i s clearly shown (Figure 28). Present topographic position of various associations i n relation to one another also gives circumstantial evidence of developmental trends i n the vegetation. A topographic sequence of the main associations i n the upper sub-zone and their relation to duration of snow cover i s shown In Figure 29. Vege-tational differences associated with the environmental gradient of decreasing snow duration in Figure 29 indicate potential successional changes i f there should be, for example, macroclimatic changes that would cause a decrease in average annual snow duration. The proposed successional trends are diagramatically summarized in Figure 30. This figure should not be interpreted too l i t e r a l l y . In some cases, the length of the lines separating units imply only typographical con-venience, and where the lines are accompanied by a question mark one or more unknown developmental stages have been omitted. Increasing elevation i s implied from l e f t to right i n the figure, and increased vegetational develop-ment i s indicated from bottom to top. The various i n i t i a and the pioneer associations on them are placed near the bottom of the page, whereas the most successionally advanced associations for the two subzones and for the Alpine Zone appear as 'climaxes5 near the top. Altitudinal ranges of the 'climax' associations are shown separately for the portion of the study area which i n -cludes Seymour, Grouse, Hollyburn and Cathedral Mountains and for that which includes Paul Ridge and Diamond Head in Garibaldi Park. Convex glacial d r i f t i n i t i a are afforded the highest position i n the chart because vegetational development i s most rapid there. For example, mountain hemlock may grow I to follow page 10J? 6 0 0 0 5 0 0 0 4 0 0 0 -3000 -• I I I I TTTTTTI I ! n •t: «0: t I; Jo, nTrm i i ! o 6! I I I I ' L . QJjJ mo If i t ;<3: '8: • • § ' 1^! IS! : v. i < : : •Si :-J Association Figure 2 8 . Altitudinal distribution of sample plots, by association, for Seymour-Grouse-Hollyburn study area (lined bars) and for Garibaldi study area(open bars) I . tyocc. membronoceumj 2. Vaccinium deliciosum 3. Dwarf Tsuga 4 . Phyllodoce-Cassiope 5 . ,Carex nigricans 6 . Polytrichum norvegicurn Snow level. on : A. June 10. D. July 30. B. July I . E. Aug. 10. C July 15, Figure 29, Topographic sequence of some associations and their relation to duration of • snow cover. Vaccinium alaskaense assoc. climox from 3000 - 3 6 0 0 feet (Cathedral MU 3 7 0 0 - 4 5 0 0 feet (Garibaldi Park) Vaccinium membranaceum- Rhododendron assoc. climax from 3 6 0 0 - 5 0 0 0 feet (Cathedral Mt.) 4500 -5500 feet (Garibaldi Park).-Streptopus assoc., degroded subossoc . Streptopus assoc.. typical subossoc, Cladothamnus assoc., | hygric subassoc . Cladothamnus assoc., ;;1ith'1c subassoc. -Subalpine Oplopanax assoc. Subalpine Lysichitum assoc . At lower-elevations CONVEX GLACIAL DRIFT INITIA See Orloci, I96I Seepage slopes Dwarf Tsuga assoc., typicol subassoc. Vocciniunv-deliciosum assoc. Dwarf Tsuga assoc., Luetkea subassoc. See Archer, I963 Phyllodoce - Cassiope assoc., climax over 5000 feet (Cathedral Mt.) 5500 feet(Garibaldi PorkO Leptarrheno-Caltha leptosepala (Petasites-, Philonotis stage ) Streams — Seepage slopes .At lower-elevations CONCAVE GLACIAL DRIFT - A * hiqher-INITIA elevations (Dreponoclodus-Scopania uliginosa stoge ) Eriophor urn-Sphagnum assoc . Luetkeo-Lycopodium phase ( Cladonia-Rhacomitrium stage ) (Andreaea stage) (Lichen stage) •' Mainly at higher elevations \ / -Streams (Drepanocladus stage) r / Polytrichum fGymn^mifrTurn \ norvegicum -assoc^. * varians phase CONCAVE ROCK OUTCROP INITIA . \ CONVEX ROCK OUTCROP 8 TALUS INITIA Mainly at — higher -elevations Early -bryophytic stages See Orlo I96I ci. Lakes 8 — ponds Lakes a ponds — -(Nuphar stage) L \ Late snow - patch associations Figure 30. Successional trends in the Coastal Subalpine Zone, Southern British Columbia. 106 directly as a pioneer on morainal material and a multi-layered association may develop i n a short time. Concave i n i t i a , i f covered by water, pass through a much longer period of development before they are occupied by complex ter-r e s t r i a l associations and are, therefore, placed near the bottom of the page.-This generalization does not apply, of course, to concave glacial d r i f t seep-age slopes where vegetational colonization and development nay be relatively rapid. Because rock outcrop i n i t i a are more widespread at higher elevations, they are placed to the right of the chart. Development i s extremely slow there, especially i n concave areas where the greater snow accumulation allows a growing season of only a few weeks. A. Upper Subzone Non-forested associe„tions outnumber those with trees i n the upper subzone because of the short time since glaciation and because of the high annual accumulation of snow which prevents forest development. This allows ready recognition of several distinct i n i t i a . On convex rock outcrop and talus i n i t i a , early stages of development are indicated by Rhizocarpon geographicun, Pilophoron h a l l i i , Cetraria hepati-Unbilicaria phaea, JJ. torrefacta and Lecidea spp. especially on the most exposed rock surfaces. These exposed rock surfaces are the most xeric habitats in the Subalpine Zone. Rocks which are covered with snow for 9 to 10 months of the year are less xeric and are colonized by bryophytes rather than lichens. Andreaea nivalis i s the most abundant species i n such cases. Weathering prod-ucts from the rock surfaces and organic accumulations from bryophytes and lichens allow colonization by additional species, and when Cladonia and Rhacomitrium species are well established on such surfaces, chamaephytic species are able to invade. Surface accumulations of wind-borne mineral and organic matter on 107 late snow-banks result i n the formation of deeper s o i l profiles i n depressions. On side slopes of the depressions, soils are shallower and are composed very largely of organic matter. These s o i l differences correlate strongly v/ith vegetation differences but one does not necessarily explain the other. Major (1961) stressed that both vegetation and s o i l differences can be correlated with environmental variables of the ecosystem. In concave areas of the upper subzone, snow duration i s the most important environmental variable controlling the vegetation, and i t s relation to the present distribution of some assoc-iations i s shown in Figure 29. Gjaerevoll (1950), Dahl (1956), and Churchill and Hanson (1958) warned that the dynamic approach to vegetation problems i s unpromising in stable com-munities where autogenic influences are limited by a factor such as snow dur-ation. Dahl (1956) pointed out that no succession can take place between vegetation zones around such snow-patches because the climate i s relatively constant and because developmental changes i n the vegetation w i l l not alter the over-riding ecological factor, the effect of snow cover. He suggested that the problem should be attacked by describing the vegetation in different zones and relating the differences to environmental factors. If the important environmental factors can be influenced by the activity of the plants, dynamic relationships w i l l emerge. These precautions apply more to the Alpine Zone (Archer 1963) where the controls by snow are strongest. In the Subalpine Zone, most snow patches disappear early enough to allow Carex nigricans to develop, and purely bryo-phytic associations are absent. Marginal invasion of chamaephytes such as Luetkea pectinata and Lycopodium sitchense can be observed in Carex nigricans associations. These chamaephytes are recognized as an early phase of the Phyllodoce - Cassiope association, and their creeping habit allows them to expand into areas of Carex without any particular preparatory change in the 108 h a b i t a t . M a r g i n a l c l u m p s o f P h y l l o d o c e and C a s s i o p e a r e a l s o a b l e t o i n v a d e C a r e x a r e a s p r o v i d i n g t h e r e i s n o t a s h a r p e n v i r o n m e n t a l g r a d i e n t o f i n c r e a s -i n g snow d u r a t i o n ( s e e P l a t e I I , E ) . A t h i r d l i n e o f d e v e l o p m e n t t a k e s p l a c e a t h i g h e r e l e v a t i o n s o n c o n v e x s l o p e s o f u n c o n s o l i d a t e d m a t e r i a l . C o l l u v i a l movement and e r o s i o n may h i n d e r t h e s u c c e s s o f p i o n e e r s p e c i e s o n s u c h a r e a s , b u t s p e c i e s o f h i g h s o c i a b i l i t y s u c h a s G y m n o n i i t r i u a v a r i a n s c a n w i t h s t a n d t h e i n s t a b i l i t y b y m o v i n g d o w n s l o p e w i t h t h e s o i l ( P l a t e I I , F)» L a r g e r s t o n e s , w h i c h have a s l o w e r r a t e o f movement o n s u c h s l o p e s , p r o v i d e a s m a l l a r e a o f g r e a t e r s t a b i l i t y o n t h e i r l o w e r s i d e . S a x i f r a g a t o l m i e i , L u z u l a w a h l e n b e r g i i , a n d o c c a s i o n a l l y T s u g a m e r t e n s i a n a o r P h y l l o d o c e e m p e t r i f o r n i s , c a n e s t a b l i s h o n t h e l o w e r s i d e o f s u c h o b s t r u c t i o n s ( P l a t e I I I , E ) , b u t o r i e n t a t i o n o f t h e v e g e t a t i o n i n a c l u s t e r e d d o w n s l o p e p a t t e r n , r a t h e r t h a n a c o n t i n u o u s p a t t e r n , t e s t i f i e s t o t h e a c t i v e downward movement o f t h e s u r f a c e s o i l . The p i o n e e r s p e c i e s o n s u c h a r e a s have a n a u t o g e n i c i n f l u e n c e i n t h e c o n s o l i d a t i n g , r a t h e r t h a n c o n s t r u c t i v e , s e n s e ( B r a u n - B l a n q u e t 1932)° S m a l l s u b a l p i n e ponds w i l l g r a d u a l l y c l o s e i n a s a r e s u l t o f s i l t a c c u m u l a t i o n o r f r o m m a r g i n a l o r g a n i c a c c u m u l a t i o n s . D i - e p a n o c l a d u s e x a z m u - l a t u s a n d C a r e x a q u a t i l j s a r e t h e f i r s t i m p o r t a n t c o n s t r u c t i v e s p e c i e s b e -c a u s e t h e y a r e a b l e t o grow s u c c e s s f u l l y b e l o w w a t e r ( P l a t e I I , B ) . A n a e r o b i c c o n d i t i o n s r e t a r d d e c o m p o s i t i o n w i t h t h e r e s u l t t h a t o r g a n i c m a t t e r a n d o r -g a n i c a c i d s a c c u m u l a t e here . , T h i s a l l o w s t h e i n v a s i o n o f Sphagnum and o t h e r moor s p e c i e s . O n l y f i v e E r i o p h o r u m - Sphagnum a r e a s w e r e e n c o u n t e r e d I n t h i s s t u d y , and t h e y w e r e so f l o r i s t i c a l l y v a r i a b l e t h a t a p r o p e r s y n t h e s i s was i m p o s s i b l e * S p e c i e s c o m p o s i t i o n i n d i c a t e d a t r a n s i t i o n t o t h e L e p t a r r h e n a -C a l t h a a s s o c i a t i o n i n one c a s e , a n d t o w a r d s C a r e x s p e c t a b i l i s i n o t h e r c a s e s . D a l i l (1956) d e n i e d t h e d e v e l o p m e n t o f s i m i l a r moors i n t o c o m m u n i t i e s o f d r y -l a n d s u c c e s s i o n . He s t a t e d t h a t a n e q u i l i b r i u m s t a g e i s r e a c h e d a t a c e r t a i n 109 thickness of peat which i s determined by climate. Successional relationships of this moor association are unclear for this study area without further i n -vestigations. A distinct association develops on the margins of subalpine streams and on areas of abundant seepage. Drepanocladus exannulatus and Scapania  uliginosa grow submersed in streams, and on the immediate margins of the streams Philonotis fontana and Petasites frigidus predominate. These are early stages which w i l l develop towards a moist, herbaceous Leptarrhena -Caltha association, as organic matter accumulates and raises the surface of the habitat further above the level of the stream. This development w i l l be favoured in sluggish streams with low erosive power. There are small ravines in the Subalpine Zone which were formerly drained by temporary surface streams and which are now occupied by a platform of Leptarrhena pyro l i f o l i a , Caltha  leptosepala and other herbs. Seepage i s abundant but there i s no surface movement or accumulation of water after Leptarrhena pyr o l i f o l i a i s established. This association i s flanked by the same chamaephytes which invade other early associations. The foregoing paragraphs and the lines i n Figure 30 indicate at least four avenues by which early associations may hypothetically develop towards the Luetkea - Lycopodium phase of the Phyllodoce - Cassiope association. In a l l cases, development i s extremely slow. This i s clearly shown in Plate III, F where secondary succession has covered only half of the bare ground surface 16 years after the Carex nigricans sod was removed for roofing material. A l l of the associations discussed to this point are more typically alpine, but they form an important part of the subalpine mosaic of vegetation and must be considered as preliminary stages in the development of the more complex subalpine associations. At altitudes of approximately 5000 feet and over (5500 feet i n 110 G a r i b a l d i Park), mesic h a b i t a t s are occupied by the Phyllodoce - Cassiope a s s o c i a t i o n . This i s a good example of an a s s o c i a t i o n which assumes d i s -t i n c t l y d i f f e r e n t p o s i t i o n s i n the-developmental sequence i n the two d i f f e r -ent b i o c l i m a t i c zones.. I n the A l p i n e Zone, succession w i l l not advance beyond t h i s a s s o c i a t i o n cn mesic h a b i t a t s ; i n the Subalpine Zone i t i s o n l y an i n t e r -mediate stage i n the development towards f o r e s t e d a s s o c i a t i o n s * This d i f f e r -ence i s r e l a t e d to the occurrence of t h i s a s s o c i a t i o n on two d i s t i n c t topo-graphies i n the two b i o c l i m a t i c zones, as discussed i n Chapter IV, The remaining a s s o c i a t i o n s i n the upper subzone are d i s t r i b u t e d i n narrow b i o t i c zones as shown i n F i g u r e 16, 17, 18, 19 and 29. or over broader areas where there are d i f f e r e n c e s i n snow d u r a t i o n as a r e s u l t of exposure or topographic c o n f i g u r a t i o n - The Vaccinium d e l i c i o s u m a s s o c i a t i o n occurs i n an intermediate p o s i t i o n between the Phyllodoce - 0assiope_ a s s o c i a t i o n and the more h i g h l y developed a s s o c i a t i o n s along g r a d i e n t s of snow d u r a t i o n (Figure .17), but i t i s u s u a l l y very r e s t r i c t e d i n s i z e and d i s t r i b u t i o n . This e n v i r -onmentally c o n t r o l l e d zonation need not imply t h a t Vaccinium d e l i c i o s u m i s a necessary s u c c e s s i o n a l stage a f t e r Phyllodoce and Cassiope. Autogenic changes i n the PJiyllodoce - J^s_siope_ a s s o c i a t i o n do not n e c e s s a r i l y make the h a b i t a t more s u i t a b l e f o r Vaccinium de l i c i o s u m ; i f they d i d , t h i s species would be more widespread i n the upper subzone„ Environmental i n f l u e n c e s t h a t would l e s s e n snow d u r a t i o n are the main p o t e n t i a l changes t h a t would favour Vaccin-ium deliciosum.-Development from the Phyllodoce - Cassiope a s s o c i a t i o n towards one w i t h l a r g e r l i f e - f o r m s and w i t h a greater d i v e r s i t y of species i s o c c u r r i n g i n many p a r t s of the upper subzone ( P l a t e s I , F and I I , C). This p a r t i c u l a r stage of subalpine succession has a l r e a d y been discussed i n d e t a i l by B r i n k (1959) and s i m i l a r development was noted by Vechten (i960) i n the C e n t r a l Oregon Cascades where mountain hemlock f o r e s t i s advancing sl o w l y i n t o meadows I l l and some other areas. Brink (1959) discounted the influence of warming from larger trees because i n many areas where dwarf mountain hemlock i s invading the nearest mature trees are several hundred yards away and the short hemlock has l i t t l e or no influence on snow duration u n t i l tree height exceeds late spring snow depths (5 to 10 feet). Both of the above authors considered the establishment of short trees i n the subalpine heath to be a reflection of climatic moderation over the last one or two centuries. There i s no reason to doubt this hypothesis on the basis of observations i n the present study. The invasion of mountain hemlock into Phyllodoce - Cassiope areas marks an important stage i n development, Tree species, even i f extremely slow-growing, can create conditions detrimental to pre-existing species. Cassiope mertensiana i s strongly shade intolerant and w i l l decrease i n significance and vigour as mountain hemlock increases. Conversely, the increased protection w i l l encourage species such as Rhytidiopsis robusta, Vaccinium membranaceum and occasionally Rubus pedatus. Mountain hemlock i s the f i r s t species i n the successional sequence with the a b i l i t y to influence microclimate by hastening snow-melt i n late May and June. This influence encourages Vaccinium membran-aceum and allows the invasion of Rhododendron albiflorum. Vaccinium membran- aceum i s the most successful of these two species i n places where the humus remains relatively undeveloped. This species was observed on a few occasions, especially i n the Luetkea subassociation of the dwarf Tsuga association where moisture i s abundant, to survive even on bare mineral s o i l . Rhododendron a l b i -florum requires a deep, acid raw humus and i t grows best on the large humps of organic matter which occur around clumps of trees i n the upper subzone. The unusual restriction of the Vaccinium membranaceum - Rhododendron association (Plate I, E) suggests that i t i s a topographic climax (Daubenmire 194.3) near i t s upper limit, whereas at lower elevations i n the upper subzone this assoc-iation i s the most mature type of vegetation on mesic habitats (Plate III, C). 112 It i s not well distributed yet in the higher limits of the upper subzone be-cause the great snow accumulation restricts i t to certain topographic situation? there. On Mount Seymour, .the Vaccinium membranaceum - Rhododendron assoc-iation contains l i t t l e or no Rhododendron albiflorum, because this i s more typically an interior subalpine species. It i s noticeably more abundant in the Garibaldi Park area which i s further inland. To some extent, the same applies to Vaccinium membranaceum which i s a frequent species of interior sub-alpine areas (Arlidge 1 9 5 5 ) , but i t i s more frequent i n coastal areas than i s Rhododendron albiflorum. The pattern of vegetation i n the upper subzone on Mount Seymour i s a mosaic of the l i t h i c Cladothamnus subassociation which occurs on topographic prominences, fragments of the Vaccinium membranaceum - Rhododendron association, and the Phyllodoce - Cassiope and dwarf Tsuga associations, The abundant dwarf mountain hemlock in this part of the study area i s -an indication that, with time, forested associations w i l l be more widespread i n the upper part of the Subalpine Zone. The l i t h i c Cladothamnus subassociation, which was described as a dry edaphic component of both subzones, i s mainly restricted to the Seymour -Grouse - Hollyburn study area. It i s not present on the Quaternary dacitic volcanics or on the older metavolcanic rocks of Paul Ridge and Diamond Head (Figure 4). This may reflect a parent material influence on the distribution of Cladothamnus pyrolaeflorus, because Paul Ridge i s not beyond the range of this coastal species; i t was encountered again on the Cloudburst quartz diorite 1" (Mathews 1958) further inland near Mamquam Lake in Garibaldi Park. The high proportion of Phyllodoce, Cassiope, Vaccinium deliciosum and lichens on the l i t h i c Cladothamnus subassociation indicates i t s a f f i n i t i e s to earlier stages of development in the upper subzone. However, further 113 development of this subassociation i s hindered by i t s confinement to exposed, dry ridges or prominences. B0 Lower Subzone During Pleistocene' glacial recession when some portions of the Sub-alpine Zone were s t i l l covered with mountain glaciers, early successional stages similar to those described above were probably evident in the lower subzone. Important differences would have been a thicker mantle of d r i f t , more extensive areas of d r i f t i n i t i a , and fewer bare rock i n i t i a i n the lower subzone. These differences, combined with presently smaller annual accumula-tions of snow and a longer time since glacial recession, have allowed more complex associations to develop here than i n the upper subzonee On dry habitats,which are now occupied by the l i t h i c Cladothamnus subassociation, successional changes towards the hygric Cladothamnus sub-association and the Vaccinium alaskaense association occur as organic accumu-lations and continuing weathering processes deepen the s o i l . Because of the restriction of the l i t h i c Cle.dothpj.inus subassociation to upper portions of con-vex slopes, moisture from late r a l seepage i s not plentiful but the development of an impervious layer i n the s o i l profile makes moisture from precipitation more effective. Early stages of development in seepage habitats are now obscure. However, the presence of subalpine and alpine species (Senecio triangularis, Parnassia fimbriate and Valeriana sitchensis) in Lysichitum sites of the lower subzone indicates that this association i s a more highly developed and forest-ed counterpart of the wet Leptarrhena - Caltha association of the upper sub-zone (Table VIII). The associations on seepage slopes or adjacent to open streams contain the greatest numbers of species, but such associations i n the lower subzone are much richer i n species than their upper subzone counterparts. 114 This i s partly a result of climatic differences, but there are probably also edaphic changes with altitude on such habitats. Wilcox et a l . (1957) found for both stream water and seepage water that i t had a higher pH and a higher salt content than did water i n the same drainage basin at higher elevations. These chemical changes would encourage additional species of autogenic im-portance i n seepage habitats at lower elevations. In moist and wet habitats there i s a progressive trend towards better drainage similar to that described by Orloci (l96l) and Lesko (l96l), and de-velopment in the lower subzone leads towards the mesic Vaccinium alaskaense association (Figure 30). With increased humus accumulation and greater s o i l maturation the lower subzonal climax association may be able to develop at higher altitudes within the zone in the future. However, such an altitudinal extension would probably also require macroclimatic changes because1 snow ac-cumulations at present impose strong altitudinal limitations on certain species and associations. 115 CHAPTER VII SUMMARY AND CONCLUSIONS Of the 90 forest sections described for the forest regions of Canada (Rove 19$9)f "the briefest .description is given for the Coastal Subalpine section of British Columbia, This brevity reflects the paucity of published information on tree species and cover types of the section. The strong climatic and topo-graphic controls of vegetation patterns and succession, the great physiognomic variety of associations and the undisturbed natural vegetation make the Sub-alpine Mountain Hemlock Zone an excellent area for studies of land, vegetation and climatic relationships. The main purposes of this thesis were to describe the vegetation and to determine the most important climatic controls of zonal limits, tree distribution, biotic zonation and vegetational development. Most of the data presented wi l l serve as basic information for future detailed studies and wi l l allow f lorist ic and climatic comparisons to be made with other bio-climatic zones. The main findings of the study are summarized and discussed below. (1) The Subalpine Mountain Hemlock Zone in southern British Columbia eannot be precisely defined altitudinally beoause i t s upper and lower limits may vary as much as 1000 feet through topographic and climatic influences. In this study, the zonal limits were plaoed at 3000 feet and 5000 feet in the Seymour - Grouse - Hollyburn - Cathedral Mountain area near the Strait of Georgia, and at 3700 feet and 5500 feet in the Paul Ridge - Diamond Head portion of Garibaldi Park. Thirty-seven per cent of the land area may be classed as subalpine in the physiographic unit between Howe Sound, Burrard Inlet and the Indian River. (2) Various biological limits of mountain hemlock may be used to delineate and subdivide the zone. The sharp lower limit of this species is 116 considered the lover limit of the Subalpine Zone. The lowest 600 to 800 feet of the zone are covered with continuous forest of mountain hemlock, amabilis f i r , yellow cedar and western hemlock. This continuous forest i s designated as the lower subzone; thus, the upper 'forest limit' i s a criterion for sub-zonal delineation. The upper l i m i t of the zone i s marked by the altitu d i n a l 'tree l i m i t ' of mountain hemlock. This definition makes cartographic desig-nation of the upper l i m i t d i f f i c u l t because trees extend upward into the Alpine Zone in an inte r d i g i t a l pattern on favourable exposures. The irregular upper li m i t to the Subalpine Zone i s i n distinct contrast to i t s relatively sharp lower lim i t . (3) Temperature characteristics for various altitudinal levels were determined, in part, from analyses of radiosonde data xjhich give the altitude of the freezing isotherm (Chapter III). From such data i t i s possible to de-termine the frequency of freezing temperatures for any period of the year, and the approximate length of the frost-free season, for any altitude on a mountain-side (Figure I 4 ) . To obtain equivalent information by conventional methods would require an expensive network of instruments closely spaced over a broad altitudinal range„ If published radiosonde temperature data are used i n com-bination with recently developed methods of synoptic precipitation analysis (Walker 196l), i t i s possible to obtain reliable temperature and precipitation data for inaccessible mountain areas, (4) Degrees along a temperature scale may ordinarily be considered as a continuum as far as their direct influence on plant l i f e i s concerned. However, the physical changes that occur at the freezing point of water disrupt the temperature continuum at this point. This i s especially significant in areas of high precipitation where freezing temperatures of a certain frequency w i l l cause snow accumulations that greatly shorten the growing season for plants. Radiosonde data from Port Hardy, British Columbia, indicate that in winter the 117 f r e e z i n g isotherm most f r e q u e n t l y occurs at a l t i t u d e s w i t h i n the lower h a l f of the Subalpine Zone (Chapter I I I ) . A c l i m a t i c r e s u l t i s a sharp increase i n snow d u r a t i o n near the a l t i t u d i n a l lower l i m i t of mountain hemlock; an e c o l o -g i c a l r e s u l t i s the r e l a t i v e l y sharp d e l i n e a t i o n between the Subalpine Mountain Hemlock Zone and the C o a s t a l Western Hemlock zone 0 (5) Temperature i s more r e l i a b l e here as a c o n t r o l of zonal boundaries than i t i s i n other b i o c l i m a t i c zones of B r i t i s h Columbia, because of the phys-i c a l changes t h a t occur at f r e e z i n g p o i n t and because of the modal co n c e n t r a t i o n of the f r e e z i n g isotherm i n a c e r t a i n a l t i t u d i n a l band on a mountain-side (Figure 15)0 (6) The i r r e g u l a r upper boundaries of the zone are a r e s u l t of topo-graphic i n f l u e n c e s on snow accumulation and d u r a t i o n . Snow accumulation i n c r e a s -es w i t h a l t i t u d e so that near the tree l i m i t mountain hemlock can grow o n l y on prominences or r i d g e s where snow accumulation i s l e s s , or on warmer exposures where the snow melts more q u i c k l y . (7) Most of the zonal f e a t u r e s of the v e g e t a t i o n can be r e l a t e d to the i n t e n s i t y , q u a n t i t y and d u r a t i o n of snow* Sm a l l - s c a l e b i o t i c .conation and d i s t r i b u t i o n of a s s o c i a t i o n s are c l o s e l y r e l a t e d to topography through i t s i n f l u e n c e on snow d u r a t i o n (Figures 16, 17 and 29)» (8) On the unforested a s s o c i a t i o n s i n the upper subzone where snow i s the dominant environmental i n f l u e n c e , autogenic changes are s l i g h t . Only when mountain hemlock reaches a hoight greater than the May and June snow l e v e l s (5 to 10 f e e t ) can t h i s species have an i n f l u e n c e by hastening snow melt and lengthening the growing season. This i n f l u e n c e i s best developed around the sporadic clumps of l a r g e r t r e e s i n the upper subzone. The combined i n f l u e n c e s of snow i n t e r c e p t i o n by the crowns and greater melting near the clumps because of greater heat absorption r e s u l t i n an important lengthening of the growing season around these clumps ( P l a t e I , D). Subalpine species which r e q u i r e a 118 snow-free season of at least three months, such as Vaccinium membranaceum and Rhododendron albiflo_runi, are largely confined to such b i o t i c a l l y created open-ings i n the snow cover or to exposures which favour early melting of the snow. (9) There are strong altit u d i n a l influences on tree growth in the Subalpine Zone. Site index i s nearly always less than 100 feet at 100 years, and i s often less than 50. Although tree heights are much reduced with i n -creasing altitude, diameters at breast height do not show a proportionate de-crease. The result i s a marked increase in taper of tree trunks with increas-ing altitude (Chapter IIl)„ (10) Snow creep, particularly on steep slopes, causes many trees i n the small diameter classes to have a basal snow-crook. Mountain hemlock and yellow cedar are most strongly affected by this deformation probably because they retain more branches near the ground than amabilis f i r does. These lower branches provide a greater surface area against which the forces of snow can act (Chapter III). (11) On the basis that a f u l l y turgid plant i s in the most satis-factory condition for growth ancl other physiological responses (Kramer and Kozlowski I960), amabilis f i r growing on an exposed rock outcrop area at 4OOO feet i n the upper subzone i s more vigorous than that in a more heavily forested site at a lower elevation (Figure 2 4 ) . This statement i s based on relative turgidity readings of needles from branches near ground level. In the coastal Subalpine Zone, melting snow jorovides s o i l moisture often into July and pre-cipitation i s sufficient during the remainder of the growing season so that even trees growing on shallow soils of sites with no permanent seepage can maintain a high relative turgidity. By contrast, root competition may be such for trees i n a shaded forest stand that they actually have relative turgidity values lower than open-grown trees on supposedly drier sites (Chapter III). These relationships should be tested further by measurements from the upper 119 tree crown where the influences of suppression and'shading could he eliminated,, (12) Early stages of vegetational development are s t i l l evident on several types of i n i t i a i n the upper subzone because of the relatively short time since glaciation and because of limitations i n vegetational development imposed by the long annual duration of snow. (13) Most early stages of vegetation appear to develop towards the Phyllodoce - Cassiope association. At rltitudes of 5000 or 5500 feet and over (Alpine Zone) this w i l l remain as the successionally most advanced association on mesic habitats where the r e l i e f i s f l a t or convex and xd.thout seepage. In contrast, this same association occupies concave topographic positions with temporary seepage i n the Subalpine Zone. As a result of i t s occurrence on two distinct topographies i n the two bioclimatic zones, the Phyllodoce - Cassiope association i s chionophobous in the Alpine Zone but moderately chionophilous i n the Subalpine Zone., when considered i n relation to adjacent associations-However, i n the two different zones snow duration i s actually approximately the same for the association because of the different topographic positions which i t occupies- These differences indicate that topography i s not always reliable as a basis for ecological classification unless the influences of macroclimate are also taken into account. (14) The Vaccinium membraryaceum - Rhododendron association most closely approximates 'climax' conditions in the upper subzone (Figure 30)*, In altitudes where i t i s best developed i t occupies mesic habitats (Plate III, C), but near i t s upper li m i t i n the Alpine Zone this association becomes a 'topographic climax' (Daubenmire 1943) restricted to warmer exposures or to ridges betxreen the areas of Phyllodoce and Cassiope (Plate I, E)* (15) Some species from the Coastal Western Hemlock Zone occur i n the lower subzone in combination with characteristic subalpine species. This combination of species f l o r i s t i c a l l y differentiates the lower subzone from the 120 adjacent Western Hemlock Zone and from the upper subzone (Table VI). The mesic Vaccinium alaskaense association i s the most representative of 'climax' develop-ment for the lower subzone. However, even i f a d i s t i n c t 'climax' association i s recognized for the lower portions of the Subalpine Zone, there are no tree species l i m i t e d s p e c i f i c a l l y to t h i s subzone so that i t cannot be e a s i l y desig-nated as a separate bioclimatic zone. (16) In the lower subzone, early successional stages which have lead to the Vaccinium alaskaense association are more obscure than are early stages i n the upper subzone. The presence of subalpine and alpine herbaceous species i n Lysichitum s i t e s of the lower subzone indicate that t h i s association i s a more highly developed and forested counterpart of the wet Leptarrhena - Caltha association of the upper subzone (Table V I I I ) . (17) The a b i l i t y of certain species to transcend the i r usual a l t i -t u dinal range along mountain streams or o n slopes of abundant seepage (Table VIII) indicates that edaphic controls may sometimes over-ride the influences of macroclimate and a l t i t u d e , This i s also one reason why much of the Sub-alpine Zone i s a mosaic of subalpine and alpine associations. (18) F l o r i s t i c data collected i n t h i s study are presented i n the appended synthesis tables. As suggested by Moore (1962) these tables, as pre-sently organized, are merely working hypotheses to be tested by further work, (19) Mensurational data indicate that subalpine areas i n south coastal B r i t i s h Columbia are of l i m i t e d use for wood production. Extreme i n -a c c e s s i b i l i t y further l i m i t s u t i l i z a t i o n , with the r e s u l t that recreation and watershed management are the p r i n c i p l e land-uses for the area. 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Bot. Gaz. 61: 477-494. 127 Snedecor, G. W , 1956. S t a t i s t i c a l methods. 5 ed. Iowa St a t e College Press, Ames, Iowa. 534 PP" S p i l s b u r y , R . H., and D. S, Smith. 1947. F o r e s t s i t e types of the P a c i f i c Northwest. B e C. For. Serv, Tech. B u l l . T . 3 0 . 4 6 pp. , and £•, W. T i s d a l e , 1944. S o i l p l a n t r e l a t i o n s h i p s and v e r t i c a l summer temperature and p r e c i p i t a t i o n changes w i t h height. S c i . A g r i c . 2 4 ; 3 9 5 - 4 3 6 . Spreen, W . C. 1947* Determination of the e f f e c t of topography on p r e c i p i -t a t i o n . Transactions of Am. Geophy. Union 28: 285-290. Sudworth, G. B. 1900. S t a n i s l a u s and Lake Tahoe F o r e s t Reserves, C a l i f o r n i a and adjacent t e r r i t o r y . U a S. Geol, Surv. 21. Ann. Report, 1899-1900, In: F r a n k l i n , J. F. 1962. P a c i f . Nthwest. For. Range Expt. Sta. Res. Paper 51. . . 1908. F o r e s t t r e e s of the P a c i f i c slope. U, S. For. 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W, van, I I I , I960, The ecology of the t i m b e r l i n e and a l p i n e v e g e t a t i o n o f the Three S i s t e r s , Oregon, Thesis D i s s e r t , quoted from: F o r e s t r y A b s t r a c t s , 1961, 22: 220. Walker, E. R. 1961, A synoptic c l i m a t o l o g y f o r p a r t s of the western C o r d i l l e r a , A r c t i c Meteor. Res. Grqup, M c G i l l Univ. S c i e n . Report No*. 3, P u b l , i n Meteor. No. 35, 218 pp. Weatheriey, P. E. 1950. Studies i n the water r e l a t i o n s of the c o t t o n p l a n t , I . "The f i e l d measurement of water d e f i c i t s i n l e a v e s . New P h y t o l . 4 9 : 81-97. Wh i t f o r d , H. N., and R. D. C r a i g , 1918. F o r e s t s of B r i t i s h Columbia,, Canada, Comm. of Conserv. 409 pp. Whittaker, R, H. 1953. A c o n s i d e r a t i o n of the climax theory: The climax as a p o p u l a t i o n and p a t t e r n . E c o l . Monog . '23s 41-78* 128 Whittaker, R. H. 1962. Classification of natural communities. Bot. Rev, 28: 1-239. Wilcox, J. C., W. D. Holland and J. M. McDougald. 1957. Relation of elevation of a mountain stream to reaction and salt content of water and s a i l . Canad. J. Soil Sci. 37s 11-20. World Meteor. Organ. I 9 6 0 , The airflow over mountains. Geneva, Secretariat of the W. M! 0 . Tech. Note 34 . 135 pp. 2. BIBLIOGRAPHY OF PUBLICATIONS USED FOR IDENTIFICATION OF VASCULAR PLANTS Ahrams, L. 1955. Illustrated flora of the Pacific States. Vols, I, II and III. Stanford Univ. Press. 538, 635, 866 pp. respectively. , and R. S. Ferris. 1959. Illustrated f l o r a of the Pacific States. Volume IV. Stanford Univ. Press. 732 pp. Davis, R. J. 1952. Flora of Idaho. W. C. Brown Co., Dubuque, Idaho. 828 pp. Eastham, J. W. 1947. Supplement to 'Flora of Southern British Columbia' ( j . K. Henry). Special Publication No. 1. B. C. Prov. Mus., Victoria, B. C. 119 pp. Flett, J. B. 1922. Features of the flora of Mount Rainier National Park. Nat. Parks Service, U. S. Dept. of Interior. 50 pp. Henry, J. K. 1915. Flora of southern British Columbia and Vancouver Island. W. J. Gage & Co., Toronto. 363 pp. Hitchcock, C. L. (No date). Grasses and grass like plants of Montana, Idaho, Washington and Alberta and British Columbia. Univ. of Wash. Publ. 60 pp. , A. Cronquist, M. Cwenby, and d". W. Thompson. 1955. Vascular plants of the Pacific Northwest. Part 5s Compositae. Univ. of Wash. Press. 353 pp. ; . 19 59. Va scular plants of the Pacific Northwest. Part 4: Ericaceae through Campanulaceae.-Univ. of Wash. Press. 510 pp. _______ . __• 1961. Vascular plants of the Pacific Northwest. Part 3% Saxifragaceae to Ericaceae. Univ. of Wash. Press. 614 pp. Hubbard, W. A. 1955. The grasses of British Columbia. B. C. Prov. Mus., Dept. of Educ, Handbook No. 9 . Victoria, B. C. 205 pp. Hulten, E. 1941-1950. Flora of Alaska and Yukon. Parts 1 to 10. Lunds Univ. Arsskr. N. F. Avd. 2 . 1902 pp. Mueller-Dombois, D. 1956. A literature and herbarium study of the members of the Vacciniaceae (The huckleberry family) occurring in British Columbia. Typed Report, Dept. of Bi o l . & Bot., Univ. of B. C. 129 Munz., P. A, 1959. A California f l o r a . Univ. of Calif; Press. Berkeley. 1681 pp. Peck, M. E. 1941. A manual of the higher plants of Oregon. Binfords & Mort. Portland, Oregon. 866 pp. Piper, C. V. 1906. Flora of the State of Washington, Cont'rib. from U. S, Nat; Herb. Vol. XI. Smithsonian Inst.^ U. S„ Nat. Mus., Washington, D. C. 637 pp. Szczawinski, A. F. 1959. The orchids of British Columbia. B. C, Prov. Mus;, Dept. of Rec, & Cons,, Handbook No. 16. Victoria, B. C. 124 PP« . 1962, The heather family (Ericaceae) of British Columbia.-B. C. Prov. Mas., Dept. of Rec. & Cons., Handbook No, 19. Victoria, B, C, 205 pp. Taylor, T. M. C, 1956. The ferns and fern-allies of British Columbia. B. C. Prov. Mus., Dept. of Educ, Handbook No. 12, Victoria, B. C. . 1959. Notes for f i e l d t r i p No. 1 (British Columbia). IX International Botanical Congress, Canada, 1959, Mimeo. Pamphlet, Univ. of B. C , Vancouver. 99 pp. (Used as a checklist for Tracheophyta). 3. BIBLIOGRAPHY OF PUBLICATIONS USED FOR IDENTIFICATION OF BRYOPHYTES AND LICHENS Ahti, T. 1961. Taxonomic studies on reindeer lichens (Cladonia, sub-genus Cladina). Societas Zoologica Botanica Formica 'Vanamo'. Helsinki. 160 pp. & plates. Andrews, A, L. 1913. North American flora. Sphagnales. New York Bot. Garden. Vol. 15 ( i ) . 75 pp. . 1940. Li s t of the North American species of Sphagnum. The Bryologist 43: 132. Arnell, S. 1956. Illustrated moss flora of fennoscandia. I. Hepaticae. The Bot. Soc. of Lund. C W K Gleerups Publ., Lund, Sweden. 308 pp. Blomquist, H. L. 1938. Peatmosses of the southeastern States, Jour, of the Elisha Mitchell Sci. Soc. Vol. 54 ( l ) . 21 pp. Clark, Lv, and T. C. Frye. . 1928. The liverworts of the northwest. Puget Sound B i o l . Stn., Univ. of Wash. Vol. 6. 194 PP» Erichsen, C. F. E. 1957. Flechtenflora von Nordvrestdeutschland. Gustav Fischer Verlag Stuttgart. 411 pp. (Used for Cladonia, pp. 191-194). Evans, A. W. 1940. Li s t of Hepaticae found i n the United States, Canada, and Arctic America. The Bryologist 43: 133-138. 130 Frye, T. ,G. 1918, Illustrated key to the western Sphagnaceae. The Bryologist 21: 37-48. • and L. Clark. 1937.-1947. Hepaticae of North America. Univ, of Wash. Publ. in Biol. Vol. 6 (i-5). 1022 pp. Galloe, 0, 1954. Natural history of the Danish lichens^ Original Investi-gations based upon new principles. Part IX. Cladonia. Ejnar Munksgaard. Copenhagen. 74 PP» & 194 plates. Grout, A. J. 1903. Mosses with the hand-lens and microscope. A non-technical handbook of the more common mosses of the northeastern United States. Publ, by the Author. Brooklyn. 416 pp. . 1928-1939. Moss flora of North America, north of Mexico. Vols. I, II, & III. Publ, by the Author. Newfane, Vermont. 264, 285, 277 pp. respectively. . 1940. L i s t of mosses of North America north of Mexico. The Bryologist 43: 117-131. Hale, M. E. Jr., and W. L, Culberson. I960. A second checklist of the lichens of the continental United States and Canada, The Bryologist 63: 137-172. Howard, G. E. 1950. Lichens of the State of Washington. Univ. of Wash. Press; 191 pp. Imshaug, H. 1957. Alpine lichens of western United States and adjacent Canada. I. The macrolichens. The Bryologist 60: 177-272. Lamb, I. M. 1951. On the morphology, phylogeny and taxonomy of the lichen genus Stereocaulon. Can. Jour. Bot. 29: 522-584. Lawton, E. 1957. A revision of the genus Lescuraea i n Europe and North ' America. Bull. Torrey Bot. Club 84: 281-307. . (No date). Key for the identification of mosses of Washington and Oregon. Unpublished manuscript. MacVicar, S. M. I960. The students' handbook of Bri t i s h Hepatics, Reprint of the Second Edition (1926). Weldon and Wesley, Ltd., Codicbte, Herts. 464 pp. Schuster, R. M. 1949. The ecology and distribution of Hepaticae in central and western New York. Amer. Midi. Nat. 42: 513-712. ,. 1951. Notes on neoarctic Hepaticae. III. A conspectus of the family Lophoziaceae with a revision of the genera and sub-genera, Amer. Midi. Nat. 45: 1-117. . 1953. Boreal Hepaticae. A manual of the liverworts of Minnesota and adjacent regions. Amer. Midi. Nat. 49: 257-684. . 1958. Annotated key to the orders, families and genera of Hepaticae of America north of Mexico. The Bryologist 61: 1-66. 131 Taylor, T, M. C. -1959. Notes for f ield trip No. 1 (British Columbia). IX International Botanical Congress, Canada, 1959. Mimeo. Pamphlet, Univ. of B. C, Vancouver, 99 PP« (Pages 14-19, A,.F. Szczawinski and V. J, Krajina, used/as a checklist for liohens, and pages 20-31> V, J. Krajina, used as a checklist for bryophytes). APPENDIX I Checklist of Vascular Plants from the Subalpine Zone Checklist of Lichens from the Subalpine Zone Checklist of Bryophytes from the Subalpine Zone 133 Checklist of Vascular Plants from the Subalpine Zone, (collected from 2900 feet to 6000 feet above sea level, between latitude 49°22' and 49°56' and longitude 122°56' to 123012', north of Vancouver, B, C.) Species are grouped into major life-form categories for three approximate altitudinal levels: (l) Species of lower elevations that occur also in the iower portions of the subalpine zone; (2) subalpine speciesj and (3) species of the subalpine-alpine transition. These three categories are not precisely de-fined, so that the placing of a species in one does not necessarily preclude i t s occurrence in another. Nomenclature and authorities for the names are those given in the manuals that were used for identification. Publications that were used for this purpose are l i s t e d i n a separate section of the bibliography. (l) Species of lower elevations that occur also in the subalpine zone: I'-'IACROPHANEROPHYTES (MP) Abies amabilis (Dougl.) Forbes Picea sitchensis (Bongi) Carri Pinus contorta Dougl. ex Loud. Pinus monticola Dougl. Pseudotsuga menziesii (Mirb«) Franco Sambucus pubens Michx, Taxus brevifolia Nutt. Thuja plicata D. Don. Tsuga heterophylla (Raf.) Sarg. NAN0PHANER0PHYTES - deciduous (NPd) Alnus crispa (Ait.) Pursh. ssp. sinuata (Regel) Hult. Amelanchier a l n i f o l i a (Nutt.) Nutt. Lonicera utahensis S. Wats. Menziesia ferruginea Smith Oplopanax horridus (Smith) Miq» Ribes braeteosum Dougl. Ribes lacustre (Pers.) Poir. Rubus spectabilis Pursh Vaccinium alaskaense Howell Vaccinium membranaceum Dougl, ex Hook. Vaccinium ovalifolium Smith Vaccinium parvifolium Smith CHAMAEPHYTES (CH) Cornus canadensis L. Gaultheria o v a l i f o l i a Gray Kalmia p o l i f o l i a Wang, Linnaea borealis L. Lycopodium clavatum L. Lycopodium selago L. Moneses uniflora (L.) A, Gray Pyrola secunda L. Rubus pedatus J . E, Smith SelagineUa wallacei HIeron. Vaccinium uliginosun L. HEMICRYPTOPHYTES (H) Adenocaulon bicolor Hook. Adiantum pedatum L. Agrostis aequivalvis Trin. Agrostis alba L . Agrostis exarata Trin. Agrostis idahoensis Nash Agrostis scabra Willd. var. germinata (Trin.) Swallen Agrostis thurberiana Hitchc. Anaphalis margaritacea ( L . ) B. & H. Athyrium filix-femina (L.) Roth. Blechnum spicant (L.) Roth. Botrychium multifidum (Gmel.) Rupr* Boylcinia elata (Nutt.) Greene Calamagrostis canadensis (Michx.) Beauv. Campanula rotundifolia L. Carex ablata Bailey Carex aquatilis Wahl. Carex hoodii Boott. Carex laeviculmis Meinsh. Carex physocarpa Presi. Claytonia s i b i r i c a Pursh Coptis asplenifolia Salisb. Dryopteris austriaca (Jacq.) Woynar Elymus glaucus Buckl. Epilobium angustifolium L. Galium triflorum Michx. Goodyera oblongifolia Raf. Heuchera glabra Willd. Hordeum brachyantherum Nevski Juncus effusus L. Juncus f i l i f o r m i s L. Luzula parviflora (Ehrh.) Desv. Melica smithii (Porter) Vasey Mimulus guttatus DC. var. depauperatus (Gray) Grant Mitella breweri Gray Mitella pentandra Hook. Osmorhiza chilensis H. 2: A. Petasites frigidus ( L . ) Fries var. palmatus (Ait.) Cronq. Pleuropogon refractus (Gray) Benth. Polypodium vulgare L . ssp. columbianum Gilbert Polystichum munitum (iCiulf.) Pre s i . S t e llaria crispa Cham. & Schl. Tiarella laciniata Hook. Tiarella t r i f o l i a t a L. Tiarella unifoliata Hook. Tofieldia glutinosa (Michx.) Pers. Trisetum cernuum Trin. Viola glabella Nutt. Viola orbiculata Geyer Viola palustris L. GEOPHYTES (G) Clintonia uniflora (Schult;) Kunth; Corallorhiza mertensiana Bongard. Dicentra formosa (Andr,') Walpi Equisetum arvense L, Equisetum palustre L«, Gymnocarpium dryopteris (Li) Newm. Habenaria dilatata (Pursh.) Hoolc. Habenaria saccata Greene Liliura columbianum Hanson Listera caurina Piper Listera cordata (L.) R. Bri Lysichitum americanum Hult. & St. John Maianthemum dilatatum (Wood) Nels. <k McB.-Nuphar polysepalum Engeln. Streptopus amplexifolius (L.) DC; Streptopus roseus Michx, Streptopus streptopoides (Ledeb.) Fi & R; Veratrum eschscholtzii A. Gray (2) Subalpine species: MACROPHANEROPHYTES (l_?) Abies lasiocarpa (Hook.) Nutt. Chamaecyparis nootkatensis (D. Doni) Spachi Pinus albicaulis Engelm. Tsuga mertensiana (Bong.) Carr. NANOPHANKROEHYTES A deciduous (NPd) Cladothamnus pyrolaeflorus Bong, Rhododendron albiflorum Hook. Ribes acerifolium Howell Sorbus occidentalis (S, Wats.) Greene Spiraea densiflora Nutt, Vaccinium deliciosum Piper CHAMAEPHYTES (CH) Gaultheria humifusa (Grali.) Rydb, Lycopodium sitchense Rupr. HEMICRYPTOPHYTES (H) Agrostis rossae Vasey Caltha leptosepala DC. Carex i l l o t a Bailey Carex mertensii Prescott Carex phaeocephala Piper Carex r o s s i i Boott. Carex spectabilis Desv, Cheilanthes gracillima D. C. Eaton 136 Cryptogramma crispa (L.) R. Br. Epilobium latifolium L. Eriophorum angustifolium Roth. Hippuris montana Ledeb. Juncus drummondii E. Meyer Juncus mertensianus Bong. Nephrophyllidium c r i s t a - g a l l i (Menzies) Gilg, Osmorhiza purpurea (Coult. & Rose) Suksd. Polystichum lonchitis (L.) Roth. Saxifraga mertensiana Bong, Scirpus caespitosus L. var. collosus Bigel. Senecio triangularis Hook. Trientalis arctica Fisch. Veronica s e r p y l l i f o l i a L." var. humifusa (Dickson) Vahl. (3) Species of the Subalpine-alpine transition; NANOPHANEROPHYTES - deciluous (NPd) Salix commutata Bebb. NANOPHANEROPHYTES - evergreen (NPe) Cassiope mertensiana (Bong.) G. Don. Juniperus communis L. var. montana Ait. Phyllodoce empetriformis (Smith) D, Don. Phyllodoce glanduliflora (Hook.) Coville CHAMAEPHYTES (CH) Antennaria alpina (L.) Gaertn. var. media (Greene) Jeps. Empetrum nigrum L. Luetkea pectinata (Pursh.) Kuntze Penstemon davidsonii Greene var. menziesii (Keck) Cronq. Penstemon procerus Dougl. var, tolmiei (Hook.) Cronq. Phlox douglasii Hook. Saxifraga tolmiei T. ik G. Sedum divergens S. Wats. Sibbaldia procumbens L. Vaccinium caespitosum Michx. HEMICRYPTOPHYTES (H) Anemone occidentalis Wats. Athyrium alpestre (Hoppe) Rylands Arnica l a t i f o l i a Bong. var. g r a c i l i s (Rydb.) Cronq. Arnica l a t i f o l i a Bongo var, l a t i f o l i a Cronq. Carex nigricans C. A. Meyer Carex p r e s l i i Steud. Carex pyrenaica Wahl. Castilleja hispida Benth. Castilleja parviflora Bong. var. albida (Penn.) Owenby Deschampsia atropurpurea (Wahl,) Scheele. Epilobium clavatum Trel, Erigeron peregrinus (Pursh.) Greene ssp, callianthemus (Greene) Cronq. var. angustifolius (Gray) Cronq. 137 Erigeron peregrinus (Pursh.) Greene ssp. callianthenus (Greene) Cronq, var, scaposus (T; & G;] Crdnq^ Hieracium gracile Hook. Juncus pa:?ryi Engelm^' Leptarrhena py r o l i f o l i a (D. Don*) R.- Br. Lupinus arcticus S. Watsi Luzula wahlenbergii Rupr«; Mimulus l e w i s i i Pursh. Oxyria digyna (L«) H i l l Parna s s'ia, fimbriata Konig i Pedicularis br'acteosa Benth. Pedicularis ornithorhyncha Benth. Phleum alpinum L. Poa arctica R. Br. Potentilla f l a b e l l i f o l i a Hook. Ranunculus verecundus Robinson Saxifraga arguta D, Don Saxifraga ferruginea Grah, Saxifraga l y a l l i i Engler Trisetum spicatum (L.) Richt. Valeriana sitchensis Bong. Veronica wormskjoldii R. & S; GEOPHYTES (G) Epilobium alpinuii L, Checklist of Lichens from the Subalpine Zone (Nomenclature and authorities taken from the second checklist of lichens of Continental United States and Canada, by Hale and Culberson, I 9 6 0 . ) Alectoria ochroleuca (Ehrh.) Nyl. Alectoria pubescens (Li) Howe Alectoria sarrnentosa Ach. Caloplaca sp. Cetraria glauca (L.) Ach. Cetraria hepatizon (Ach.) Vain Cetraria islandica (L.) Ach, Cetraria stenophylla (Tuck.) Merr. Cladonia b e l l i d i f l o r a (Ach,) Schaer. Cladonia carneola Fr, Cladonia chlorophaea (Florke) Spreng* Cladonia coniocraea (Florke) Sandst. Cladonia deformis (L.) Hoffm. Cladonia ecmocyna (Ach,) Nyl, Cladonia gr a c i l i s (L.) Willd. Cladonia pacifica Ahti Cladonia pleurota (Florke) Schaer. Cladonia rangiferina (L.) Web. Cladonia squamosa (Scop.) Hoffm. Cornicularia californica (Tuck.) Du Rietz Cornicularia divergens Ach. Crocynia membranacea (Dicks,) Zahlbr. Dermatocarpon miniatum (L,) Mann. Icmadophila ericetorum (L.) Zahlbr. Lecanora sp,> Lecidea sp, Lecidea granulosa (Ehrh.) Ach. Letharia vulpins (L.) Hue Lobaria linata (Ach„) Rabenh. Lobaria oregana (Tuck.) Mull. Arg. Mycoblastus sanguinarius (L.) Norm. Parmelia enteromorpha Ach. Parmeliopsis hyperopta (Ach.) Vain. Peltigera aphthosa (L.) Willd. Peltigera canina (L.) Willd. Pilophoron h a l l i i (Tuck,) Vain. Rhizocarpon geographicum (L.) DC. Solorina crocea (L.) Ach. Sphaerophorus globosus (Huds.) Vain. Stereocaulon tomentosum Fr. Umbilicaria phaea Tuck. Umbilicaria torrefacta (Lightf.) Schrad. 139 Checklist of Bryophytes from the Subalpine Zone Nomenclature and. authorities taken from Grout (194O), Andrews (1940) and Evans (1940). Species grouped by growth-forms ac-cording to Gimingham and Birse (1957). (1) Cushions (c): Andreaea b l y t t i i Schimp. Andreaea ni v a l i s Hook. Andreaea rupestris Hedw, Grimnia alpestris Nees Grimmia apocarpa Hedw. (2) T a l l turfs, branches erect (Te); Bryum sandbergii Holz. Dicranum bonjeani De Not. Dicranum fuscescens Turn. Dicranum muhlenbeckii Bry. Eur. Dicranum scoparium Hedw. Drepanocladus ad.uncus (Hedw.) Warnst. Drepanocladus exannulatus (Gumb.) Warnst. Drepanocladus fluitans (Hedw.) Warnst. Hygrohypnum ochraceum (Turn.) Loeske Mnium affine Bland. Mniun nudum Williams Mnium punctatum Hedw. Mnium spinulosum Bry. Eur. Oligotrichum aligerum Mitt. Oligotrichum parallelum (Mitt.) Kindb. Plagiochila asplenioides (L.) Dumort. Pogonatum alpinum (Hedw.) Rohl. Pogonatum contortum (Schwaegr.) Sul l . Pogonatum urnigerum (Hedw.) Beauv. Polytrichum commune Hedw. Rhacomitrium aciculare Brid. Rhacomitrium canescens Brid, Rhacomitrium heterostichum (Hedw.) Brid. Rhacomitrium patens (Hedw.) Huben. Rhacomitrium varium Lesq. & James Scouleria aquatica Hook. ( 3 ) T a l l turfs, short divergent branches (Td): Campylium stellatum (Hedw.) Lange „ C. Jens. Philonotis fontana (Hedw.) Brid. Sphsgnum compactum DC. Sphagnum girgensohnii Russow Sphagnum magellanicum Brid, Sphagnum mendocinum Sull , & Lesq. Sphagnum robustum (Russow) Roll Sphagnum squarrosum Pers. Sphagnum teres (Schimp.) Angstr. (4) Short turfs (t): Aulacoraniura androgynum Schwaegr. Aulacomnium palustre (Web. & Mohr) Schwaegr. Bryum spp. Buxbaumia indusiata Brid. Dichodontium olympicum Ren. & Card. Dicranella heteromalla (Hedw.) Schimp. Dicranella squarrosa (Schrad.) Schimp, Dicr&noweisia crispula (Hedw.) Lindb. Dicranum strictum Schleich. Diplophyllum albicans (L.) Dumort. Diplophyllum obtusifolium (Hook.) Dumort. Diplophyllum plicaturn Lindb. Diplophyllum taxifolium (Wahlenb.) Dumort. Ditrichum montanum Leiberg Kiaeria b l u t t i i (Schimp.) Broth. Kiaeria falcata (Hedw.) Hagen Kiaeria starkei (Web. & Mohr) Hagen Marsupella sparsifolia (Lindb.) Dumort. Marsupella ustulata (Ruben;) Spruce Oligotrichum hercynicum (Hedw.) Lam. & De Cand. Pohlia drummondii (C. Mull.) Andrews Pohlia nutans (Hedw.) Lindb. Polytrichum juniperinum Hedw, Polytrichum norvegicurn Hedw. Polytrichum piliferum Hedw. (5) Mats (M): Bazzania ambigua (Lindenb.) Trevis. Bazzania tricrenata (Wahl.) Trevis. Brachythecium asperrimum Mitt. 'Brachythecium plumosum (Sw.) Bry. Eur. Brachythecium washingtonianum (Eaton) Grout Cratoneuron commutatum (Hedw,) Roth Hookeria lucens (Brid,) Smith Hypnum circinale Hook, Hypnum dieck i i Ren. & Card. Hypnum subimponens Lesq. Plagiothecium denticulatum (Hedw,) Bry. Eur. Plagiothecium elegans (Hook,) S u l l . Plagiothecium piliferum (Sw.) Bry. Eur. Plagiothecium pulchellum (Hedw.) Bry. Eur. Plagiothecium sylvaticum (Brid.) Bry. Eur. Plagiothecium undulatum (Hedw.) Bry, Eur. Porella r o e l l i i Steph, Scapania americana Kc Mull, Scapania bolanderi Aust. Scapania uliginosa (Sw.) Dumort. Scapania umbrosa (Schrad,) Dumort. Scapania undulata (L.) Dumort. H I (6) Thread-like forms (Mb): Barbilophozia barbata (Schmid.) Loeske Barbilophozia lycopodioides ("Wallr.) Loeske Blepharostoma trichophyllura (L.) Dumort. Calypogeia neesiana (Massal. _ Carest.) K. Mull. Calypogeia trichomanis (L.) Corda Cephalozia lammersiana (Hueb.) Spruce Cephalozia leucantha Spruce Cephalozia media Lindb. Eurhynchium stokesii (Turn.) Bry. Eur. Gymnomitrium varians (Lindb.) Schiffn. Harpanthus scutatus (Web. & Mohr.) Spruoe Heterocladium heteropteroides Best Heterocladium procurrens (Mitt.) Rau & Hervey Isopaches bicrenatus (Schmid.) Buch Leiocolea obtusa (Lindb.) Buch Lepidozia reptans (L.) Dumort. Lescuraea baileyi (Best & Grout) Lawton Lescuraea patens (Lindb.) Arn. & Jens. Lescuraea radicosa (Mitt.) Moenken. Lophocolea heterophylla (Schrad.) Dumort. Lophozia alpestris (Schleich.) Evans Lophozia incisa (Schrad.) Dumort. Lophozia porphyroleuoa (Nees) Schiffn. Nardia scalar!s (Schrad.) S. F. Gray Orthocaulis binsteadii (iCaal.) Buch Orthocaulis f l o e r k i i (Web. & Mohr.) Buch Orthocaulis kunzeanus (Huben) Buch Plectocolea obovata (Nees) Mitt. Pleuroclada albescens (Hook.) Spruce Pseudisothecium (= Isothecium) stoloniferum (Hook.) Grout Pterigynandrum filiforrae Hedw. Ptilidium californicun (Aust.) Underw. & Cook Ptilidium c i l i a r e (L.) Nees Ptilidium pulcherrimum (Weber) Hampe Radula complanata (L.) Dumort. (7) Thalloid mats (Th): Conocephalum conicum (L.) Dumort. Moerckia b l y t t i i (Moerck) Brockm. Pellia epiphylla (L.) Corda Pe l l i a neesiana (Gottsche) Limpr. Riccardia multifida (L.) S. F. Gray (8) Wefts (W): Antitrichia curtipendula (Hedw.) Brid. Calliergonella cuspidata (Brid.) Loeske Hylocomium splendens (Hedw.) Bry. Eur. Pleurozium schreberi (Brid.) Mitt. Rhytidiadelphus loreus (Hedw.) Warnst. Rhytidiadelphus sqliflrrosus (Hedw.) Warnst. Rhytidiopsis robusta (Hook.) Broth. APPENDIX II Multiple regression analyses of the incidence of basal snow-crook on amabilis f i r , mountain hemlock and yellow cedar 143 Multiple Regression Analyses of the Incidence of Basal Snow-crook on Amabilis F i r , Mountain Hemlock and Yellow Cedar'. The following variables were considered? %2. - steepest slope on sample plot, in degrees X2 - elevation, in hundreds of feet - length of slope above, coded; 1 - no slope above 2 - 1 chain or less 3 - 1 to 2 chains 4 - 3 to 4 chains 5 - 4 to 10 chains 6 - over 10 chains - basal area per acre, i n square feet X5 - crown closure of A layer, i n percent - aspect, coded according to amount of heat received. Chapter 21 and Figure 99 (Geiger 1957) were used for this purpose. The divisions shown for a clear day in Figure 99 were coded so that the coldest north slope had a value of 10 and the warmest southwest slope a value of 95. X7 - duration of snow, in weeks Y - percentage of trees, i n the 10-inch diameter class or less, with bar.al snow-crook. Only sample plots that had at least 10 trees in the 10-inch class or less and which had uniform slope were used. Thirty-three sample plots f u l f i l l e d these requirements for amabilis f i r , and the same number was used i n the analysis for mountain hemlock and yellow cedar. This allowed use of the same programmed computer instructions for both analyses. For amabilis f i r , the regression equation i s : Y = ,5728XX - ,6168X2 + .3492X3 + .0337X4 - . 3 5 5 6 X 5 + .0255X6 + 1.5401X7 - 24.189 Correlation coefficients show that steepness of slope (X^) i s correlated with the percentage of snow-crook at the .01 level of probability, and basal area (X4) at the .05 level. The regression equation for the most important variable, steepness of slope, i s Y = 5.465 + .689 6X-]_. 144 The table below summarizes the correlation matrix for amabilis f i r ; Independent Variables 1 2 3 4 5 6 7 X 1 .. N N N N N N 2 _ N N N N 3 — N N 4 — N N 5 . N N 6 — N 7 -' Y •,<-,< N N N N N N - not significantly correlated * - significantly correlated (.05 level) ** - highly significant (.01 level) Amongst the independent variables, elevation shows a high correlation with duration of snow, as one would expect i n the Subalpine Zone, Length of slope above a sample plot i s positively correlated v/ith basal area and crown closure, since the most productive stands usually occur on lower or mid-portions of seepage slopes. For mountain hemlock and yellow cedar the regression equation and correlation matrix are as follows; .8770X! -- 2.5326X2 + .2310X3 - .02811^ + „0122X5 + .1748X6 + 5.0545XJ, - 59.150 Independent Variables 1 2 3 4 .5 6 7 X 1 N N N N N N 2 _ N N N N ** 3 ** N N 4 — *r**r- N N 5 — N N 6 _ N 7 _ Y N N N N N For these species, only steepness of slope was significantly cor-related v/ith snow-crook. The regression equation for this variable alone i s Y = 20.491 + .7906X!. 145 APPENDIX III Table XIII Table XIV Explanation and Legend for Synthesis Tables Synthesis Tables I to IX TH5LK XIII Life-form distributions by number of species and by t o t a l cover degree for each association (oolunns 1 to 8). Columns 9 to IS show a further breakdown of hujnicolous bryophytes (column 8) into growth*foros ^ 10 11 1? 13 li» IS I RH Pud Pn6 Ch Subalpine Lyalohltna assooiationi 8 No. species Tot. cor. deg. 7-6.1 7.7 900 185 -37.3 7.6 -6 1? 33 5.3 10.5 26.9 53 388 2U6 2.2 16.1 10.2 2 1.8 •«6 6U6 26.8 Sua llli 2Ul8 Te Kt Td 10 8.8 5 13 2 10 U.U l l . l t 1.6 8.8 30U 18U 13 12.6 7.5 0.5 71 2.9 ll 3.5 5U 2.2 Th 2 1.8 20 0.8 Subalpine Oplopanax assooiationi No. speolea % Tot. cov. deg. % 6 7.7 3U8 30.1 10 12.8 -252 -a . 8 -6 io 15 7.7 12.8 19.2 37 132 122 3.2 l l . ' * 10.6 2 2.6 29 37.2 265 22.9 78 1156 7 9.0 3 3.8 169 77 1U.6 6.7 7 U 7 1 9.0 5.1 9.0 - -1* 1 13 - 1 0.3 - 1.1 - -Streptopus association! No. species % Tot. cov. deg. % 6 5.9 2I105 755 1(7.9. 15.0 1 1.0 7 6.9 9 8.9 19 18.8 1 1.0 29l» 125 1(30 5.9 2.5 8.6 U9 1(8.5 1011 20.2 101 5020 10 3 16 5 11 2 2 3.0 15.8 »*.9 10.9 2.0 2.0 kO? 1(70 Ii3 1 8.0 9.3 0.9 - 52 10 33 1.0 0.2 0,7 Vaccinium alaskaense assooiationi No. species U . % Tot. cov. deg. % 8 1 I4 I* 6 13.1 1.6 6.6 6.6 9.8 1(25 - 35 12 2 19.1 - 1.6 0.6 0.1 2 3.3 2 0.1 3? 52.5 591 26.6 61 2226 7 3 11 2 9 -11.5 U.9 13.0 3.3 1U.7 -308 227 U5 2 9 1U.5 10.2 2.0 - 0.1* -Cladothamnus assooiationi No. species % Tot. cov. deg. t 5 6.1. 10.2 2.6 6 7.7 3 9 3.8 11.5 1625 1659 253 33.3 3U.0 5.2 103 2 2.1 -15 0.3 9 11.5 53 1.1 36 1.6.2 1173 2U.1 78 1*883 9 3 11.5 3.8 68U 382 lU.O 7.8 13 6 16.7 7.7 U 5.1 1 1.3 91 1.9 1!( 0.3 Vaccinium menbranaoeum - Rhododendron association! c~ ~B 5 U 3 1 11.3 15.1 3.8 7.6 5.7 1.9 No, speoisst % Tot. cov. deg. 1127 835 73 18 U8.3 35.8 3.1 0.8 8 15.1 6 0.2 21 39.6 277 11.9 53 2336 6 2 6 3 1. 11.3 3.8 11.3 5.7 7.6 193 8.3 51 2.2 33 1.5 Dwarf Tmga association No. species * Tot. cov. deg. 3 U.6 5 7.7 9 3.1 U 1 6.3 1.5 766 95 615 200 1 32.0 U.O 25.6 8.3 -11 16.9 112 U.7 10 15.U 32 1.3 29 UU.7 579 2U.1 65 21.00 8 2 9 8 1 - 1 12.3 3.1 13.8 12.3 1.5 - 1.5 290 9 191 79 - ID 12.1 0.!* 8.0 3.3 - - 0.'* Vaccinium deliciosum assooiationi ffoT species I3 3 2 ? 1 * 7.9 7.9 5.3 5.3 2.6 Tot. cov. deg. 5 13.2 66 368 261. 22 6.0 33.2 23.9 2.0 -7 18.U 2U 2.2 15 39.5 362 32.8 38 1106 5 1 5 3 1 13.2 2.6 13.2 7.9 2.6 2 * 59 71. 5 20.2 5.3 6.7 o.U -Phyllodoce - Cassiope association! No. species TT 6 3 1. % 6.1 9.1 U.5 6.1 Tot. cov. deg. i 1 1.5 l U l 265 1500 219 U.7 8.6 1.9.0 7.1 11 16.7 9 0.3 10 15.1 1(8 1.5 27 1(1.0 880 28.7 66 3065 6 2 9 7 3 9.1 3.0 13.6 10.6 d.S UU6 38 231 165 -lU.S 1.2 7.5 5.U -Carex nigricans association! No. species $ Tot. cov, deg. % 1 U.o 1 U.O 2 8.0 ll 16.0 11 1.2 6 2U.0 SOU 56.7 1 U.O in U0.0 372 U2.0 25 888 2 8.0 26 2.9 10 1.1 Leptarrhena - Caltha leptosepala association! No. species % Tot. cov, deg. 3 U.O 3 2 U 6.6 2.6 5.3 6 7.9 10 10 0.5 0.5 5 131 0.2 6.7 29 38.2 1012 51.8 27 35.6 789 U0.3 76 1957 9 2 3 11.8 2.6 U.o 335 251 3 17.1 12.8 0.1 3 _ 1 12.0 - U.O -286 So _ 32.3 - 5.6 • e 2 U 2 6.6 2.6 5.3 2.6 52 8 13? 8 2.7 O.U 6.7 0.U Briorhorum - Sphagna assooiationi No. species - - - 2 U * 5.3 10.5 Tot. cov. deg. 1 10 * . . . 0.1 1.1 15 39.5 SUS 58.3 17 UU.8 379 U0.5 38 935 3 7.9 85 9.1 2 U 2 5.3 10.S 5.3 7 1 1 0.8 -3 7.9 25 2.7 U 10.S 260 27.8 By rock Avge. cover, In A layer B layer C layer D^ layer H --3 ON vn ON to 0 H 0 LYSICHITUM I ON vn ~ J vn vn vo o H OPLOPANAX H 4>~ 4>- vn c> Co o ro Ri STREPTOPUS H vn H 0^ 0N vo o -P- Degraded STREPTOPUS 4>- vn QN W > CQ- 00 NO <£> VACCINIUM ALASKAENSE fO ON H vO f -4s ON o Co Hygric CLADOTHAMNUS H to Lithic CLADOTHAMNUS to Vo M CO vn H vo 4>- NO VACC. MEuBR.-RHODODENDRON H to vn O \_n QN vn 1 Dwarf TSUGA O 4>~ oo vo CO oo vn 1 Dwarf TSUGA -LUETKEA H O vn oo ro so o oo ro VACCINIUM DELICIOSUM vn oo H 0^ vn O 1 PHYLLODOCE -CASSIOPE H vn -0 NO vO 1 1 CAREX NIGRICANS 1 00 00 vn -a ro i LEPTARRHENA 1 ON 00 <3 NO 1 1 ERIOPHORUM -SPHAGNUM j s ro vo l 1 SAXIPRAGA <! CD hi P Crq O M p O <<J to CD c+ 4 ^ P P P ct-fL CD o 4 < o a a hi >r P - TO CD O CD hi P o o O f §•« CD CD £ cr H-O 3 tr1 t=d ATI 1L8 Explanation and Legend for Synthesis Tables 1, In some cases more than one association appears on a synthesis table, mainly for typographical convenience. In the case of the Polytrichum norvegicum association and the Saxifraga t o l a i e i association, which were not studied by sufficient plots, a grouping i s made with the Carex nig-ricans association because of f l o r i s t i c similarities. 2. Plot locations are designated by the following abbreviations: R. M« Round Mountain (Paul Ridge), Garibaldi Park G. - Grouse Mountain H. - Hollyburn Ridge S.M. - Seymour Mountain Dia. H. - Diamond Head area, Garibaldi Park 3. Landforms are numerically coded: 1 - concave 2 - uniform slope 3 - convex (ridge) 4 - f l a t to undulating (rock outcrop) 5 - complex 4. Wind exposure was estimated on the basis of topographic position. An exposed ridge was given a high value on a scale of 10, whereas a protected ravine would have a rating of 5 or 6. Three values appear in the Synthesis Tables: A, exposure of the tree layer to the wind.; B, exposure of the shrub layer; and C, exposure of the herbaceous and low woody layer. 5. Estimated coverage, in per cent, i s given for each layer and each sub-layer i n the vegetation and for decayed wood and rock. Average coverage by each layer i s summarized for each association in Table XIV. 6. A quadrat l/2m. x l/2m. was located in each corner of the rectangular sample plots. A l l coniferous seedlings were t a l l i e d on these, to give an estimate of regeneration per square meter. 7. Species are grouped by layer and sub-layer, usually in decreasing order of presence and decreasing order of total cover degree. In some cases, differentiating species are grouped to indicate subassociation differences,, 8. Species ratings are given by three figures (e.g. 4«+.2 or 6.7.2.) which represent species significance., sociability and vigour. The species significance scale end i t s appropriate cover degree ratings are standard-ized with those of Orloci ( l 9 6 l ) to allow direct f l o r i s t i c comparisons between the two bioclimatic zones. U9 The following scales were used for f l o r i s t i c evaluation: Species Significance Corresponding cover degree i n % + Very sparsely present, dominance very small 0 1 Sparsely present, dominance small 0 2 Very scattered, dominance small 1 3 Scattered to plentiful 5 4 Often, dominance 1/20 to l/lO of plot 10 5 Often, dominance 1/5 to 1/4 of plot 25 6 Any no. of individuals, dominance l / 4 to l / 3 33 7 ti 11 ii 11 11 1/3 to 1/2 50 8 » " » " •' 1/2 to 3/4 75 9 11 I' 11 11 11 over 3/4 95 10 " I' » " " 100% of plot 100 Sociability + Growing singly 1 Grouped or tufted, groups up to 2 Group larger, up to l / l 6 sq. m. 3 Group, l/8 to 1/4 sq. m. 4 " 1/3 to 2/3 " " 5 " 1 to 2 Sq. m. 6 " 5 to 20 » " 11 7 •• 25 to 50 i' -» 8 11 100 11 't 9 11 200 to 250" '' 10 At least 500 sq. m. 9 . Five presence classes are used: 5 - species which occur in 81-100$ of the plots (constants) 4 - species which occur in 61-80$ of the plots 3 - species which occur in 41-60% of the plots 2 - species which occur in 21-40% of the plots 1 - species which occur i n 20% or less of the plots (sporadics) Sporadic species are l i s t e d separately, by vegetation layer at the end of each table with a notation of their f l o r i s t i c rating end the plot on which they occurred. 10. F i d e l i t y i s given only for the layer in which a species shows the highest total cover degree. For example, Abies amabilis i s normally rated only in the A layer. 11 . Total cover degree was calculated for each species on an association by totaling the cover degree values of the species significance ratings on each plot. 16 sq. cm. Vigour 0 - none •+ - poor 1 - f a i r 2 - good 3 - excellent 12. Life-forms (and growth forms for bryophytes) are abbreviated according to the descriptions in Chapter V. SYNTHESIS TAkLE I Cladothamnus association ( Teugoto - Cladothamna Kygrlo Bobaeaoolatlon Plot number 01 03 20 26 U2 Plot sise (acre) VS 1/5 1/5 1/5 1/5 Date 22/6 3/9 20/8 9/9 27/7 1959 1959 1959 1959 I960 Locality (see legend) SM SM SM SM SM Latitude 1»9 2? U9 22 U9 22 1*9 23 U9 22 Longitude 122 57 122 57 122 57 122 57 122 57 Londform (see legend) 2 2 2 2 2 Slope above (est* ft.) IiOO 60 Uoo 50 3D0 Area of assoc. (acre) 1 1 1 1/S 1 Altitude (ft.) 3380 3510 3380 3525 3200 Asp»ct S25S N80B s?w S10W S80W Slope (degrees) 25 22 10 30 8 Wind exposure (A-B-C) 6-5-2 7-5-2 6-3-1 8-6-U 8-6-U ' Snow cover (months) 7 7 7 7 7} % c overage i 15 )35 ). By vegetation layer A^  17 5 A2 35 20 ) 3 5 30 )8 IS 15 15 30 20 50 Uo Uo 60 25 Bl 20 50 17 50 20 B„ 90 65 65 75 90 B 95 95 80 85 95 C 10 7 20 10 35 &H 70 75 60 Uo 75 DL J I 7 2 5 5 1 1 1 _ D 78 76 68 U2 80 By decayed wood 5 1 10 u 5 By rock 7 2 2 1 -Tallest tree on plot (ft.)i Western hemlock — — 73 - -Mountain hemlock 92 72 81 102 7U Amabilis fir 87 70 77 72 7U Tellow cedar 83 77 66 61 70 Regeneration (no./sq. meter) Mountain hemlock — — _ 7 _ Amabilis fir — - - 7 13 Tellow cedar - - - 7 1 Total soil depth (cm.) 82 39 59 79 33 Depth to bottom of An (cm.) 33 13 ZL 9 12 Depth to seepage, If present 80 - - - -A layer** Tsuga mertensiana No. trees over 3 ln./acre Basal area, sq. ft ./acre Gross volume, cu. ft./acre Abies amabilis Sub-layer Bo. trees over 3 ln./acre Basal area, sq. ft./acre dress volume, on. ft •/acre 5.*.2 5.*.? U.6.? 125 156 38UU •.2 *.i 1.*.? 90 Ul 936 U.7.1 ) 5.6.1 ) 5.7.2 3.+.1 U.6.1 195 120 185 111 3975 1?U6 •.2 •.1 U.6.1 180 Uo 558 7.? 3.*.1 80 56 1317 5.7.2 ) 3 ' + ' J U.7.1 U.7.2 135 105 15U 116 356U 2191 K.7.1 l . * . l 165 70 73 23 1590 3U8 Lithic subassociation 101 10U U3 19 ZL 08 2U 26 09 12U 1? 27 20/9 i960 VS 22/7 1961 V5 11/10 1961 28/7 1959 X'f 2/9 1959 10/8 1959 1/5 27/8 1959 1/5 1/9 1959 1/5 11/8 1959 1/5 9/7 1961 M5 29/7 1959 X'? 30/8 1959 0 U9 2U 123 05 2 60 1 H S M S M S M S M S M S M S M S M S M S M U9 23 U9 22 U9 22 U9 22 U9 22 U9 23 U9 23 U9 22 U9 23 U9 23 U9 23 123 11 122 57 1 2? 57 122 57 12? 56 12? 57 1 22 57 1?2 56 1 2? 57 1?2 56 1?? 57 3 3 ? 3 2 U U U U U 3 ( 5 ) 3A 1/3 1/t 1/3 2 1 1/3 2 1/5 1/2 1/U U220 S 15 9-6-2 74 3220 w 3 8-U-l 7 3ieo S20W 21 8-5-2 7 3360 SISE 7-6-1 7 3U00 S20W 7-U-2 7 3130 N20E 7 6-6-2 7 3600 7 15 7-6J» 7 3730 SlUW 10 8-7-3 7 3200 SOSE 8 6-6-3 7 U07S s5ow 20 9-8-5 6 3860 sUov 8 7-7-3 7 3650 ? 8-7-U 7 j» Uo 5o So 70 85 5 So U 2 S5 J65 Uo 75 UO 85 90 5 60 1 1 62 12 35 35 80 90 30 85 2 1 88 3 1? 10 20 30 80 90 5 90 2 U 96 5 23 20 88 92 20 SO 1 u 55 10 12 20 US 60 60 So 1 1 So ) 1 ? 3 12 10 60 60 80 75 1 1 76 ,10 2 10 7 60 65 70 50 1 IS 65 10 35 50 75 55 60 1 1 61 ) )1S ) IS Uo 60 90 30 Uo 1 1? S2 7 10 Uo Uo 25 Uo 1 35 75 ) )15 ) 15 8 55 60 65 65 1 U 70 6 3 u. 3 1 1 1 1 1 2 1 1 U 2 1 5 6 1 30 7 2 2S SO 6 _ SU 70 78 72 72 78 90 73 7U 77 5U 53 59 61 63 56 50 2U 67 60 3U 3U 15 26 SU 25 72 81 60 66 56 U9 26 U6 15 15 19 _ 3 16 7 1 - - - - -_ 1 - -- 13 2 - - - - - - - - -92 7 26 2S U2 37 U7 35 U3 7 U? 33 18 7 ? 7 13 15 2U 6 29 7 10 5 - 7 7 - Uo - UO - - 7 - 30 )U.*.l )«.8.2 )S.7.2 U.7.1 5.7.2 U.7.2 HO 115 170 152 130 1U3 2586 2607 273U U.6.2 165 118 215U 3.6.1 105 115 2359 3.*. 2 65 8U 2 0 * .+.2 •.2 JU.7.2 •.1 U.+.2 jl.*.? ) )$.•.* ) *.2 j3.6.1 ) )S.7.1 ) 70 65 90 60 75 70 99 101 65 102 66 65 ZL36 19U0 1278 IU 22 83U 986 }U.*.l ju.*.2 S.7.1 U.7.1 UUo 125 126 Uo 1U9U 636 J 3 . * . l 2 . * . 1 1 U 0 36 5 U 6 •.1 l.+.l w 2.+.1 80 * . 2 1.+.1 U5 >• 2 - jz.*.i ) r . l 85 110 6 0 6 0 20 70 75 19 13 37 12 12 IU 3 3U 12 188 S7 6 0 6 138 9 8 82 19 296 137 Pres. Fid. Tot. cd. Life-form 2 USU Pm 122 Pm o eontlnued SYNTHESIS TABLE 1 Cladothamnus association, continued Plot number Hygric subassociation 01 03 20 ?6 U; 1(3. 10U U3 1° Lithic subassociation a 08 Th 28 1* rr A layer, continued: Sub- j layer ' Pres. Fid. Tot. Life-c.d. form Chamaecyparis nootkatensis 1 2 6.7.2 U.+.l )2.+.l +.2 )l.+.2 - )5.8.2 )?.+.l ?.+.l - - : - - - U 80 Pm 3 1.+.2 •.1 •.1 2.+.1 2.+.? _ - • .+ _ l.+.l U.6.1 •.? _ U..+.2 - - -No. trees over 3 ln./acre 11? 120 110 160 100 70 75 95 120 75 65 50 35 30 25 Uo 15 Basal area. so. ft./acre 136 75 57 66 75 9 66 36 53 29 U8 8 5 7 5 6 2 Gross volume, ca. ft./acre 30U1 _JLU59 920 800 1076 U6 1?7U 730 650 393 760 76 a 92 U9 26 8 Totals, lncliding sporadics 650 160 No. trees over 3 ln./acre 335 U9S 315 I160 275 3U0 U05 380 290 210 180 1U5, 130 105 135 Basal area. sq. ft./acre 335 300 230 293 ziU 567 2UU 215 190 157 170 119 118 86 110 106 79 Oroas volume, cu. ft./acre 78U2 589? U327 5651* 3615 1,916 U010 2992 2809 3390 ?3S0 20S9 1U5? 1U90 1156 1131 B layer* Tsuga mertensiana 1 (j.6.? 5.6.1 U.6.1 5.6.1 3.7.2 U.6.1 3.*.? 3.+.1 3.6.1 3.6.1 5.6.2 2.6.2 2.6.1 5.6.1 U.6.+ ?.5.i 3.6.1 5 399 Pm 2 1.6.1 2.+.1 2.6.1 U.6.1 1.6.2 ?.*.» 1.+.+ ?.•.! ?.•.? 3.6.1 7.8.2 6.7.? 7.8.1 6.7.1 3.S.+ U.6.1 5.7.1 Vaccinium membranaceum 2 6.7.3 3.5.2 U.6.2 5.7.2 U.5.2 5.6.3 3.5.2 U.6.? 6.7.3 U.7.2 5.7.2 5.7.2 5.7.? 5.7.2 5.6.3 5.7.2 5.7.2 5 ? 3U1 Pnd Cladothamnus pyrolaeflorus 1 - l.U. 3 _ - • - - - - 1.5.3 - - -— - - - 5 u 329 Pnd 2 5.6.? 7.7.3 5.7.3 5.7. ? 5.7.3 7.^ .3 U.6.? U.6.3 ?.5.3 7.7.3 1.6.2 - U.7.2 1.6.1 6.6.1 3.U.2 U.7.2 Chamaecyparis nootkatensis 1 U.6.1 5.6.1 U.6.1 6.7.1 3.7.2 5.6.1 U.+.l U.6.1 U.7.+ U.6.1 3.6.1 ?.6.1 2.6.1 5.6.1 S.6.+ 2.5.+ 1.6.+ 5 ? 301 Pm 2 2.6.1 1.6.1 3.6.1 U.6.1 2.6.2 l.+.l 3.+.1 5.5.1 2.+ .1 3.6.1 U.7.1 U.6.? 2.6.1 3.6.1 U.6.+ 3.6.+ 2.6.+ Vauclni.un alaskaense 2 6.7.? 6.6.2 5.6.? 3.7.2 7.8.3 2.5.1 6.7.3 6.6.? 6.7.2 U.6.2 1.6.2 - 2.6.1 3.6.2 1.+.+ 1.5.2 6.7.2 5 2 295 Pnd Abies amabilis 1 U.6.2 7.7.1 2.6.1 5.6.1 3.7.2 6.7.1 6.7.1 5.6.1 2.6.1 U.6.1 2.6.? 2.6.? 2.6.1 2.6.2 3.6.+ 2.5.1 U.6.1 5 2 ?a Pm 2 2.6.2 3.6.1 3.6.1 U.6.1 2.6.2 3.+.1 ?.+.l 3.+.1 3.5.1 U.6.1 3.6.2 3;6.2 2.6.1 3.6.2 1.+.+ 3.6.1 2.6.1 Menaiesia ferruginea 1 - l.li.3 _ - +.3 _ 1.+.3 _ — 1.6.3 - - - -_ . • 5 3 105 Pnd 2 2.6.2 3.6.? 3.6.2 2.6.2 U.6.3 3.5.2 5.6.3 ?.5.? 3.5.2 6.7.3 3.6.2 2.5.2 2.6.2 3.6.? 2.U.1 1.6.1 2.6.1 Vaocinlum ovalifolium 2 ?.6.1 ?.5.1 1.1.2 U.7.? 1.5.1 •.1 3.5.? ?.5.1 2.U.1 2.5.1 3.6.? l.U.l 2.6.1 3.6.2 - - l.U.l 5 2 31 Pnd Sorbus occidentalis 1 - - •.2 •.2 +.3 2.+.3 +.? - - - - - - - +.2 - - 5 3 8 Pod 2 *.2 •.1 2.+. 2 ?.5.? +.2 l.+.l +.? • 2.5.2 2.5.1 1.+.2 1.+.2 2.+. 2 1.+ .2 1.+.2 2.5.1 +.1 Vaocinium deliciosum 2 - - - - 2.6.? 2.5.? -_ - _ U.6.? U.8.3 3.6.? 3.6.? U.5.3 U.7.2 2.6.2 3 2 53 Pnd Rhododendron albiflorum 1 - - - 2.5.3 - ?.6.3 - - - - - - - - - - - 2 2 119 Pnd 2 2.6.2 - • 6.7.3 - 6.7.3 7.7.3 - - 1.6.2 - - - - - - -Pinus monticola 2 - - - - +.1 - ••• - - - - - - - - - - 1 1 - Pa C layer; ! Vacciniun membranaceum ?.+.? ?,+.l U.S. 2 3.U.? 2.3.2 3.+.2 +.1 I.+.? 2.+.3 3.6.? 5.7.2 5.6.? U.7.2 U.6.2 ?.+.l m U.6.1 5 113 Pnd Rubus pedatus 2.3.? 2.3.? U.3.2 ?.•.? U.3.3 3.+ .1 3.+. 2 U.3.? 2.+.1 2.+.? 3.5.2 l.U. 2 3.3.1 2.5.2 •.• 1.2.2 l.+.l 5 2 56 Ch | Abies amabilis + .+ 2.+.1 2.+.1 ?.+.! 2.+.1 3.+.1 l.+.l 3.+.1 l.+.l l.+ . l 2.+.1 1.+.2 l.+.l 1.+.2 • . • - 2.+.1 5 16 Pm j Cladothamnus pyrolaeflorus +.1 1.+.2 2.3.2 2.+.1 2.+.2 - l.+.l ?.•.? 1.3.2 ?.+.2 1.2.2 - 1.3.? 1.+.2 1.+ .+ +.2 2.3.2 5 6 Pnd j Sorbus occidentalis - +.1 2.+.+ 1.+.2 + .+ l.+.l - • . • - l.+.l l.+.l +.1 l.+.l 1.+.2 1.+ .+ +.• 1.2.1 5 1 Pnd i Vaccinium alaskaense ?.+.l 2.+.1 U.5.2 2.U.2 U.U.2 l.+.l l.+.l 1.+.2 1.+.2 2.5.1 - - - - - - 3.6.1 U 29 Pnd Tsuga mertensiana - - 2.+.? l.+.l - 1.+.+ - ••• - l.+.l 3.+. 2 2.U.2 U.5.3 2.+. 2 1.+ .+ - U.5.1 U 18 Pm Gaultheria' humifusa +.1 1.1.2 l.+ . l 2.2.2 i .3.2 1.2.2 U.U.3 - 2.3.2 - l.+.l - 3.3.2 l.+.l - - - U 3 18 Ch Vaccinium ovalifolium - 1.+.2 - 3.U.2 - - •.+ -— 1.2.1 - +.1 1.+.+ - — - 1.2.1 3 5 Pnd Chamaecyparis nootkatensis - - l.+.l - l.+.l - 2.+ .1 - l.+.l +.+ l.+.l 2.+.1 l.+.l - - l.+.l 3 2 Pa Menzlesla ferruginea +•1 1.+.2 - - 2.+ . 2 - - - 1.3.2 1.+.2 l.+.l - - 1.+.2 - - - 3 1 Fad BVecnnum spicant • .+ 1.+.2 - - +•+ - +.+ - +•+ - + .+ +•+ ••+ - - - 3 1 1 H Cornus canadensis - - 1.+ .2 - l.+.l — +.+ 3.+. 2 -— - - - 2.5.2 - - - 2 2 6 Ch Veratrim eschscholtaii +.1 - 2.5.? +.• + .• l.+.l -• • - - - - - +.1 - - - 2 1 I 0 Ooodyera oblongifolia - +.1 - - - -— +.2 +.2 - - - - - - 1.2.1 - 2 2 - H Phyllodoce empetriformis l.+ . l 1.+.2 2.3.2 l.+.l 1.2.1 1.+.+ 4.4 1.3.2 1.2.2 3.6.1 U.3.1 6.7.2 6.8.3 2.3.2 5.5. ? 5.8.3 6.7.2 5 2 166 Pas Vaccinium dellclosum - - - 2.6.2 2.5.2 l.+.l - - - U.6.2 7.3.3 7.9.3 6.8.3 7.7.3 U.6.2 U.3.2 U.6.2 U 2 226 Pad Cassiope mertensiana - - - +.1 - - - 2.U.+ U.3.2 5.6.2 5.7.2 2.3.1 3.3.2 U.7.3 U.6.2 3 2 87 Pas Luetkea pectinata - - - +.2 - 1.+.2 - - - - 3.U.2 3.5.2 3.5.1 3.6.2 ?.•.? 1.2.1 2.2.2 3 2 2? Ch Ca*ex nigricans - - - - - - -• - - 2.6.1 2.6.1 3.6.1 •.? l.U.l - 2.6.1 2 1 8 H Lycopodium sitchense - - - - - l.+.l - - 1.2.1 - 2.+. 2 - 1.2.2 1.+.2 - - •.• 2 2 1 Ch D layer (humicolau): j Dicranum fuscescens j 5.6.? 5.6.2 5.6.? 2.5.2 7.6.3 6.6.3 6.6.3 7.6.3 7.6.3 1.2.1 6.U.? 2.5.2 _ 6.6.? 5.U.3 2.3.2 U.U.2 S 2 395 Te Rhytidiopsis robusta • 6.6.3 6.7.2 5.6.? 5.7.2 U.5.2 3.3.2 7.7.3 5.6.3 U.U.? 5.5.2 U.U.2 3.6.2 U.3.2 U.S. 2 3.2.2 S.3.2 U.6.2 s 2 316 W vn continued SYNTHESIS TABLE I, con t inued Cladothamnis a s s o c i a t i o n Hygr i c s u b a s s o c i a t i o n L i t h i c s u b a s s o c i a t i o n P l o t numbe r D l a y e r ( humico lou s ) , c o n t i n u e d ! Dicranum scopar ium O r t h o c a u l i s f l o e r k i i Lophoco lea h e t e r o p h y l l a D i p l o p h y l l u m t a x i f o l i u m A b i e s a m a b i l i s C l a d o n i a b e l l i d i f l o r a R h y t i d i a d e l p h u s l o r e u s Lescuraea b a i l e y i C e p h a l o z i a media B lepharostoma t r i c h o p h y l l u m Chamaecypar is n o o t k a t e n s i s P l a g i o c h i l a a s p l e n i o i d e s P t i l i d i u m c a l i f o r n i c u m P l a g i o t h e c i u m e legans H e t e r o c l a d i u m p rocur rens Mnium sp inu losum C l a d o n i a squamosa C l a d o n i a r a n g i f e r i n a Rhacomitr ium he te ro s t i chum P l eu roz ium s c h r e b e r i K i a * r i a b l y t t i i Rhacomitr ium canescens L e p i d o z i a rep tans B rachy thec ium s p . Bryuir. s p . V a c c i n i u m s p . C r o c y n i a membranacea C l a d o n i a p l e u r o t a 03 20 26 U2 101 10U U3 1? 21 08 2U 28 09 12b 12 27 P r e s . F i d . T o t . L i f e -c d . form U.6.2 U.6.2 6.7 .2 1.1.1 _ 1.1.2 _ 7 .6 .3 U.6.1 7.7 .3 7 .8 .2 1.3.2 _ U.3.2 6.7 .3 U 2 256 Te +.2 2.1.2 1.2 .2 2 .3.2 2.5.2 •3.2.2 - U.3.2 2.2.2 2. 2.2 U.?.2 U.2.2 U.2.2 1.+.2 U.U.3 1.2.2 U.3.2 5 2 70 Mt 1 .3.2 1.1.2 1.2.2 1.1.2 _ 1.1.2 - 1.2.2 1.2.2 1.1 .2 - - - - - - - 3 2 -Mt 1.3.2 1.1.2 1.2.2 1.2.2 1 .3 .2 1.1.2 - 1.1.1 - 1.1.2 - 1.2.1 - 1.1.2 - - 1.1.2 U 2 -t l . + . l _ l . + . l l . + . l l . + . l 1.+.+ l.+ . l 2.+.1 l.+ . l +.1 - l . + . l - - - — 2.+.1 U 1 Pm +.1 l . + . l +.1 1 .1.2 _ 1.+.+ • 2 .2.2 1.1.2 1.1.2 U.U.2 2.3.2 2.+. 2 1.1.? 1.+.2 3.2.2 5 2 19 L 3.3.2 3.5.2 twS.3 U.S.2 3.3.2 . 1.2.1 U.3.2 - 3.U.2 2.3.? - - 2.U.? 1.1.2 - - U 2 52 W 1.3.2 _ 1 .1 .2 2.2.2 l . + . l + .1 3.3.2 - ?. ?.? 1.1.? 1.1.2 1.1.? 1.1.2 1.1.? - - U 3 7 Mt 2.U.2 1.2.2 1.1.2 2.1.2 - - - 1.2.2 1.1.? - 1.1.2 - - - - 3 2 2 Kt 1.2.2 1.1.2 1.2.2 1.1.2 - - - 1.2 .2 1.?.? - - - - - - - 2 2 - Mt +.+ _ +.1 _ l . + . l - l.+ . l - 2.+ .1 - - - +.1 - — — - 2 1 Pm 1 .3 .2 1.3.2 3.6.2 +.1 - - - - - - - - - - - - 2 2 5 Te 1.3.2 _ _ 1.1 .2 _ 1.1.2 - - — 1.1.? 1.2 .2 - — - - 1.1.? 3 2 - Mt 1.1.2 1.2 .2 2.5.2 2.2.2 1.?.2 - - - 1.1.1 1.?.? 1.?.? - - - 1 .2 .2 3 2 1 M 1.2.2 _ 1.2.2 _ - — 1.+.2 1.2 .2 1.?.? - - - - - - 1.2 .2 9 2 • Mt 1.3.2 1.1.2 _ 1.1.2 - - 1.3.3 1.?.? - 1.1 .2 - - - 1.1.2 1.2 .2 3 2 - Te _ _ _ • • 1.1.? • 1.1.? I i .?.? - - 1.1.? 2.?.? 1.3.7 3 2 11 L _ _ 1.1.1 _ 1.?.? _ 1.1.2 +.1 1.3.1 3.3.1 +.1 1.1.3 3.3.? 1.3.1 - 1.3.? U 3 10 L _ _ _ - - 1.1.? _ _ 3.U.2 1.3.? - 1.3.? 3.3.2 2.3.? 2 2 11 Te _ 1.1.2 - 2.1.1 - + .+ 1.?.? 1.?.? _ 3.U.2 - - 2.1.? 2.3.? 1.U.2 u 3 IU M - - - - - _ - 2.5.1 U.5.2 - - - 2.U.? •> i 1? t _ - _ - - — 3.5.2 2.3.? - 3.U.3 - 3.U.? - 2.?.? - 2 2 17 Te _ 2.3.2 1.1 .2 - - - - - 1.1.? - - - 1.1 .2 - - - 2 2 1 Mt 1.1.2 - - - - - - 1.2.2 - 1.1 .2 - 1.2.2 - — — - 2 2 - M _ - 1.2.2 - 1.1.2 - - - - 1.1.1 1.1.? - - 1.1.2 3 2 - t 1. + .1 • - — +.1 - l . + . l — - l . + . l — l . + . l * 1.+.+ — l . + . l 3 - Pnd _ - - 1.1.2 - - — - - - - ?.].? 1.1.2 1.1.2 - 1.1.2 1.1 .2 2 2 1 L - 1.1 .2 - - - - - - - - 1.1.? 3.U.2 - 3.+.? 1.1.1 - 2.?.? 2 2 11 L S p o r a d i c s p e c i e s ! Pm Tsuga h e t e r o p h y l l a 20(+.2); 10l|(U+.l) B l a y e r ! Tm Tsuga h e t e r o p h y l l a 01(+. l ) C l a y e r ! H A g r o s t i s a e q u i v a l v i s 09(+. l ) K Carex l a e v i c u l m i s 20(1.1.1) 0 C l i n t o n i a u n i f l o r a 01(2.+.l)! U3(l.+.2) H Cryptogramma c r i s p a 12(1.1.3.) H Deschampsia a t r o p u r p a r e a 2U(+.l); 28(+.l); 15(+.+) H W p p u r i s montana 2U(3.6.2); 28(2.5.2) 0 L i s t e r a cacurina 0J.(+.l); 20(+.+); 10li(l.+. + ) C l a y e r , con t inued ! Ch Penstemon d a v i d s o n l i 12(+.2) Pm Pinus m o n t i c o l a 08(+.+) Pnd Rhododendron a l b i f l c r u m 1 0 l i ( l . + . l ) H S a x i f r a g a f e r r u g i n e a 12 i i (+ . l ) ; 12(+.?) D l a y e r (humico lous ) ! Mt Anas t rep ta o rcadens i s 01(1.+.2) M Baazan la t r l c r e n a t a 0 1 ( 1 . ? . ? ) ; 20(2 .5.2)-- 1 9 ( l J i . ? ) Mt Ca l ypoge ia nee s i ana 26(1.1.?) L C l a d o n i a g r a c i l i s 08 (1 .1 . 2 ) ; 0 9 ( 2 . 1 . 2 ) ; 12(1.3.2); L C . c o n i o c r a e a 1? (1 .1 . 2 ) ; 21(1.2 .2) 27 (1 . ? . ? ) Ch G a u l t h e r i a humlfusa 01(1.+.2) Te Bryum s a n d b e r g i i 26(1.3.2) M Hypnum e d r c i n a l e 20(1.3.2); 26 (1.1.2); 21(1.1.+) L L o b a r i a l i n a t a 26(+ . l ) ; U31+.1); 21(1 . 2 .2) D l a y e r ( h u m i c o l o u s ) , c o n t i n u e d ! Mt Lophoz i a a l p e s t r l s 21(1.1.2) Mt Lophoz i a i n c i s a 26(1.1.2) t K a r s u p s l l a s p a r s i f o l l a 21(2.2.2); 2U(1.U.2); 27(2.3.2) Te Mnlun punctatum 03(1.+.1); 20(1.+.+); 2 6 ( l .+. l ) « P l a g i o t h e e . undulatum 01(1.3.?); 03(1.1.2); ZL(+. + ) Mt P l e e t o c o l e a obotrata 03(2 .1 .2); 27(U.3.?) Te Pogonatum a lp inum 26(1.1.2); 19(1.1 .2); 21(1.1.2) t P o h l i a s p . 12U(1.1.2) t P o l y t r i c h u m +unlperlnum 09(+ . l ) Ch Rubus pedatus 01(1.+.1) Pnd Sorbus o c c i d e n t a l i s l ? (+ .+) T d Sphagnum plumulosum U? ( l . l . ? ) Pm Tsuga m e r t e n s i a n a U3(+.+); 10U(+.+) L P e l t i g e r a c a n i n a 27(1.1.) 10 SYNTHESIS TABLE II Plot number Plot sise (aore) Date Locality (see legend) Ltt lt-ide Longitude Landforn (see legend) Slops above (est. ft.) Area of ssaoc. (aore) Altitude (ft.) Aspsot Slope (degrees) Wind exposure (A-B-C) Snow cover (months) % coverage! By vegetation layer A A Bl C I D By decayed wood By rook Tallest tree on plot (ft.) Western hemlock Mountain hemlock Amabilis fir Yellow cedar Regeneration (nc/sq. meter)! Mountain hemlock Amabilis fir Yellow cedar Total soil depth (om.) Depth to bottom of An (cn.) Depth to seepage, if present Vaccinium alaskaense association (Abieteto - Tsugetum mertenslanae) 123 106 IS 16 SO 25 29 3 3 3? 155 VS VS VS 1/5 VS VS 1/5 1/5 Vf lVlO 29/7 21/8 16/7 26/7 8/9 U/9 22/8 22/8 1961 1961 1959 1959 I960 1?59 1959 1?°0 i960 SK H SM SM SM SM SM RH RM li9 22 U9 2& h9 22 1>9 22 h9 22 h9 23 1»9 23 U9 U6 1*9 l»6 122 57 1 23 11 122 57 1 22 57 1 22 57 1 22 S7 1 22 57 1 23 02 123 02 2 2 2 2 2 2 2(3) 3(5) 3(5) 1)00 500 1)00 150 SOO 200 100 -1 U 1 1 3/U 1/3 1/2 V? 1/2 3150 S60E' 17 6-l)-2 7 3li30 S30W 20 6-3-3 7* 3200 S17V 5 6-5-2 7 3275 N80W 2? S-J)-l 7* 3050 S5CE 1SV 7-6-h 6| 3625 W 29 7-5-2 7f 3700 I1SU0 S60W S70W 35 1» 7-6-2 8-3-2 7| 8 1)530 9 l»-20 8-3-2 20 70 26 IS 8 35 25 ao ao 50 1)0 22 1? 60 25 20 30 is 1)0 5 26 1)0 1)0 10 20 - 10 95 95 65 So 8S 60 50 60 60 U5 !i 12 20 ao 30 ao 3 2 80 8 U5 So 20 30 U5 as as 95 12 50 95 50 55 60 a« a7 15 12 6 8 6 5 10 2 a 80 5 60 65 70 So 25 35 ao 8 > IS 25 20 8 5 IS 15 • 1 _ 1 . 1) 1 a 2 8 65 oc 90 62 30 50 57 10 15 25 25 25 10 10 30 20 1 1 - 1 - 6 1 3 — 128 id) _ _ . _ _ _ 00 138 102 99 115 9U 128 119 23 121 88 82 70 76 9? 126 10a 77 - - 89 101 90 32 - -— — 7 ? 60 1 7 _ _ 2 118 7 7 2 7 7 3a 9 1 - 7 *> 11 7 7 - -7 7 61 1)2 102 100 3U 55 67 ? 7 20 10 35 20 13 13 10 7 7 - - - 80 - - -A layer! Sub-layer Tsuga mertensiana 1 2 3 No. trees ever 3 in ./acre Basal area, sq. ft./acre Oross volume, cu. ft./acre U.+.l a.+.i 5.+.1 130 92 2178 Abies amabilis No. trees over 3 ln./acre Basal area, sq. ft./acre Oross volume, cu. ft.?aere Tsuga heterophylla No. trees over 3 in./acre Basal area, sq. ft./acre Gross volume, cu. ft./acre Chamaecyparis nootkatensis 1 2 3 No. trees over 3 in./acre Basal area, sq. ft./acre Oross volume, cu. ft./acre +.1 5.7.1 a.+.i 35 66 1292 a.+.2 5.7.2 3.+.1 115 156 2726 5.+.2 +.2 " l 5 128 a380 •.1 7.8.2 U.8.2 105 161 7U69 7.9.1 •a "25 2U0 8802 5.+. 3 a.+.2 a.7.2 90 163 asso +.? +.1 a.+.i -95 ao 9aa 2.+. 2 a.7.2 +.2 75 111 2620 a.7.2 • . 2 a.7.2 130 151 as2a + .2 .7.2 100 ao sa 2 a.7.2 +.+ 60 39 1023 6.8.2 5.7.2 i.+.i 100 30a 1C218 + .1 1. + .l 20 38 i?as 2. +.1 l.+.l ~35 131 3a98 1. +.+ 2. +.+ 105 23 376 3. +.2 a.7.1 5.7.1 139 38 22 2.+.? 7.7.3 a.+.2 75 ??s a872 a.+.i a.6.1 185 91 179a 5.7.2 5.7.2 5.7.2 195 3U6 8720 a.+.2 + .2 a.6.1 aio ns 2050 5.7.3 1.+.2 30 ia? 5790 6.7.2 6.7.2 "70 2sa 106U0 7.7.3 5.7.2 a.+.2 85 273 11005 l.+.l 1.+.+ 1.+ .+ 25 ao iaja +.1 •.1 ao 56 115a +.1 20 2 12 Pres. Fid. Tot. Life-e.d. form S 2 388 Pm 2 187 Pm 2 136 Pm 2 102 Pn Totals, including sporadical No. trees over 3 in./acre Basal area, sq. ft./acre Oross volume, cu. ft./acre 380 ia5 250 265 335 325 625 100 110 321 529 311) ^  359 U25 USl a63 ad 313 62a8 21150 86li) 10109 10093 13166 10782 l6a30 1?J)39 B layeri Vaccinium alaskaense Abies amabilis Tsuga mertensiana Vaccinium, membranaceum Menzlesla ferruginea Vacoinlum! ovalifolium 7.7.3 U.+.l 3.+.1 5.6.1 l.+.l 1.+.1 6.6.3 a.6.2 3.+.1 a.6.1 1.+.2 5.6.3 a.6.2 3.6.2 3.6.2 2.+. 2 +.1 + .1 1.5.1 8.9.2 3.6.1 a.6.2 3.6.1 3.+.1 2.5.2 3.6.1 1.5.1 a.6.3 5.6.1 1.6.2 a.6.2 l.+ .l 2.6.3 3.5.2 5.7.1 a.6.2 a.7.1 a.6.2 a.6.2 a.6.2 1.5.1 a.7.2 6.7.1 a.6.1 a.6.2 3.+.1 5.7.2 a.7.2 a.6.2 5.6.2 a.6.2 5 2 220 Pnd 3.+. 2 1.+.+ 5 188 Pm a.5.2 a.5.2 2.+ .1 - 5 88 Pm 2.5.1 1.+.+ 5.7.3 5.7.3 S 2 86 Pnd +.1 - a 2 59 Pnd 1.U.1 a 2 10 Pnd continued 154 SYNTHESIS TABLE I I , con t inued V a c c i n i u m a laskaense a s s o c i a t i o n P l o t number 123 106 15 16 50 25 29 83 82 P r e s . F i d . T o t . L i f e -Sub- c d . form 3 l a y e r , con t i nued : l a y e r Tsuga h e t e r o p h y l l a 1 3.+.1 • .• U.6.2 +.1 U.6.1 - - - - 3 26 Pm 2 + .+ +.+ 2.2.2 +.1 1.+.1 — -— -17 Pm Chamaecyparis n o o t k a t e n s i s 1 U.6.1 - - l . + . l 2.+.1 2.7.1 l.+ . l - -3 2 3.+.1 - - l.+ . l 1.+.2 l . + . l l.+ . l - Pnd Sorbus o c c i d e n t a l i s 1 - - - - +.3 - +.3 - 3 2 -2 - +.+ - +.1 - l . + . l 1.+.2 - - Pnd Cladothamnus p y r o l a e f l o r u s 2 - - - 1.5.1 1.5.2 U.7.2 - 2 2 10 Rhododendron a l b i f l o r u m 2 - - - - - U.6.2 1.+.2 - - 2 2 10 Pnd C l a y e r -Rubus pedatus U.3.2 U.3.2 2.2.2 3.3.2 2.+.2 2.3.2 3.3.2 l . + . l - 5 2 33 Ch Vacc in ium a laskaense 2.+ .1 2.+.2 3.+.2 3.2.2 2.+. 2 2.U.1 2.3.2 2.3.2- 1.3.2 5 16 Pnd Ab ie s a m a b i l i s l . + . l 3.+.2 3.+.2 2.+. 2 1.+.2 2.+.1 2.+.1 l . + . l 2.5.1 5 IU Pm Vacc in ium membranaceum l . + . l +.1 - 2.1.2 3.U.2 3.3.2 2.3.2 2.3.2 U 13 Pnd C l i n t o n i a u n i f l o r a U.6.3 +.• 2.3.2 1.1.2. 2.+.2 - 2.+. 2 - - U 2 13 0 Blechnum s p i c a n t +.1 - - +.1 2.+.1 2.+ .+ +.1 - - 3 1 2 H M e n z l e s i a f e r r u g i n e a - +.1 2.+.2 l . + . l l.+ . l - 3 1 Pnd Cornus canadens i s 2.+.1 - - + .1 1.+.2 - - - - 2 2 1 Ch Tsuga mer tens iana - - l . + . l - + .1 1.+.2 l . + . l 3 - Pm Goodyera o b l o n g i f o l i a 1.+.3 - - -l . + . l + .2 - — - 2 2 - H P y r o l a secunda +.2 - - + .1 l . + . l - - - -2 2 - Ch S t rep topus s t r e p t o p o i d e s - +.1 +.1 - +.2 - - -2 2 -H Tsuga h e t e r e o p h y l l a - l . + . l 2.+ . 2 - 1.+.2 - - -2 Pm C o r a l l o r h i z a mertens iana - - -+.2 + .1 - - - -2 2 0 L i s t e r a c a u r i n a • - • + .1 + • + - - - -2 2 - 0 Sorbus o c c i d e n t a l i s - - +.1 - +.1 l . + . l - -2 - Pnd Phy l l odoce e m p e t r l f o r m l s - - l . + . l - 1.2.1 1.3.2 +.+ 3 1 - Pne D l a y e r (humicolous)t R h y t i d i o p s i s r o b u s t a 7.7.3 2.3.2 5.6.3 5.6.2 7.6.3 3.6.2 U.U.2 3.2.2 2.3.2 5 2 172 w A b i e s a m a b i l i s l . + . l 2.+.1 l . + . l 1.+.2 2.+.1 +.1 l . + . l l . + . l — 5 2 Pm Dicranum fu scescens 1.1.2 3.3.2 - 8 .9 .2 6.6.3 - 2.2.2 5.5.3 6.7.3 U 2 172 Te Rhy t i d i ade lphus l o r e u s 5.U.2 - . 5.6.2 1.2.1 3.U.2 + .2 1.1.2 - - U 2 55 W B le pharostoraa t r i c h o p h y l l u m 1.1.2 + .2 - 2.6.2 + .2 1.1.2 3.3.2 1.1.2 — U 2 6 Mt C e p h a l o z i a media 1.1.2 1.1.2 - 1.1.2 1.1.2 1.1.2 3.3.2 1.1.2 - U 2 5 Mt Ca l ypoge i a nee s i ana - 1.3.2 +.2 1.1.2 2.3.2 1.1.2 2.2.2 1.2.2 - U 2 2 Mt Lophoco lea h e t e r o p h y l l a 1.1.2 - 1.1.2 1.1.2 1.1.2 - 2.2.2 - 1.1.2 U 2 1 Mt L e p i d o z i a r e p t ana 1.1.2 1.2.2 1.1.2 — 1.1.2 1.2.2 - - 1.1.2 U 2 -Mt Dicranum seoparium 5.U.3 - 5.6.2 - 1.1.3 6.7.3 7.6.2 - - 3 2 133 Te O r t h o c a u l i s f l o e r k i i — - - - - 1.1.2 1.3.2 U.3.2 U.U.2 3 2 20 Mt P l a g i o thec ium e legans - - 1.2.2 - 1.1.2 2. 2.2 2.2.2 - 2.2.2 3 2 3 M Hypnum c i r c i n a l e — - 2.3.2 - 1.3.2 1.3.2 2.3.2 1.1.2 - 3 2 2 M C l a d o n i a b e l l i d i f l o r a - - - +.+ 1.+.2 + .1 2.1.2 2.2.2 3 2 2 L Mnium sp inulosum 2.3.2 1.2.2 1.3.2 1.3.2 - - - 3 2 1 Te P t i l i d i u m pulcherr imum - - - - 1.1.2 1.1.2 1.+ .2 - 1.1.2 3 2 - Mt V a c c i n i u m spp* - + .+ + .2 1.1.2 - + .1 -— - 3 — Pnd Lophoz i a i n c l s a - - - - - + .2 • U.6.2 2 2 10 Mt P l a g i o thec ium undulatum 2.3.2 - - - 2.5.2 - - - - 2 2 2 M Bazzan i a t r i c r e n a t a 2.2.3 - 2.2.2 - 1.2.2 - - - 2 2 2 M K i a e r i a b l y t t i i - - - - 2. 2.2 2.3.2 - 2 1 2 t Mnium punctatum - - 2.3.2 1.2.1 1.1.2 - - - - 2 2 1 Te P l e c t o c o l e a obovata - - - - - 2.1.2 1.1.2 - - 2 2 2 Mt Bryum s p . - - - - + .2 2.3.2 - - 2 2 1 Te Chamaecyparis noo tka tens i s l . + . l - - - + .1 - - - - 2 — Pm C l a d o n i a c o n i o c r a e a • - - - - - 1.1.2 1.+.2 - 2 2 L Bryum s a n d b e r g i i - - - - - 1.5.2 - l . + . l 2 2 Te S capan i a b o l a n d e r i 1.1.+ - - - - - - 1.1.2 2 2 _ M Brachythec ium s p . 1.3.2 - - - 1.3.2 - 1.2.2 2 2 _ M P leuroz ium s c h r e b e r i 1.1.+ - - + .2 -— _ _ + .+ 2 2 W Lescuraea b a i l e y i . - - - + .+ 1.2.2 1.1.2 _ 2 2 _ Mt P l ag i o thec ium den t i cu l a tum 1.1.2 - + .2 _ _ 1.2.2 2 2 M Tsuga mertens iana 1.+.1 l . + . l l . + . l • _ * • 8 _ Pm D ip l ophy l l um t a x i f o l i u m 1.3.2 - - - - + .2 1.1.2 - - 2 2 - t Sporad i c s p e c i e s : A l a y e r , none B l a y e r , none C l a y e r : H Carex n i g r l o a n s 82(1.6.+); 29(1.5.+) Pm Chamaecyparis n o o t k a t e n s i s 50(1.+.+) Pnd Cladothamnus p y r o l a e f l o r u s l 6 ( l , + . l ) ; 29(l.+.l) Ch Luetkea p e c t i n a t a 29(2.U.2) Pnd Rhododendron a l b i f l o r u m 25(+.2) Pnd Rubus s p e c t a b i l i s 25(+.+) H S t rep topus a m p l e x i f o l i u s 29(+,l) H T i a r e l l a u n f f o l i * * * 29(+.1) Pnd Vacc in ium o v a l i f o l i u m 25(1.3.1); 29(2.+.2) 0 Veratrum e s c h s c h o l t z i i 29(+.l) D l a y e r , humicolous M B a z z a n i a ambigua 83(1.1.2) Mt Eurhynchium s t o k e s i l 50(1.1.2) M P l a g i o c h i l a a s p l e n i o i d e s 123(1.5. 2) Te Rhacomitr ium he te ro s t i chum 82(1.1.2) Pm Tsuga h e t e r o p h y l l a 50(1.+ .+ ) SYNTHESIS TABLE III Streptopus association (Abieteto - Streptopetum) Typical subassociation (subassoc. abletetoso - streptopetosum) Degraded subassociation (subassoc. chamaecyparetosum) Plot number Plot slse (acre) Date Locality (see legend) Latitude Longitude Landfcrm (eee legend) Slope above (est. ft.) Area of assoc. (acre) Altitude (ft.) Aspect Slops (degrees) Wind exposure (A-B-C) Snov cover (months) % coveragei By vegetation layer A^  A, L22 S7 1 22 57 122 57 1 22 58 123 03 1 23 03 1 22 57 1 23 11 122 58 123 05 1 23 05 1 23 03 1 23 03 C DH fe D* By decayed wood By rock Tallest tree on plot (ft.)t Western hemlock Mountain hemlock Amabilis f i r fellow cedar Regeneration (no./sq. meter) West, or mtn. hemlock Amabilis f i r Yellow cedar Total soil depth (em.) Depth to bottom of An (cm.) Depth to seepage, i f present Remarks 13 Hi OI 51 85 _2L UU 107 _ _. ._ , —, Ji 102 103 36 66 175 175 575 575" 571 575 575 575 57? 57? 575 575 57J" 16/7 31/8 22/7 8/9 29/8 9/8 19/7 29/7 23/7 20/9 20/9 9/8 8/8 1 959 1959 1959 i960 i960 i960 1961 1961 i960 i960 i960 i960 i960 07 T7T 02 10 11 125 TT? 57? 175 57T 06 "T7T SM U9 22 SM 1*9 22 SM 1*9 22 SM 1*9 22 RM 1*9 1*6 RM 1.9 1*6 SM 1*9 22 H 1*9 si* SM 1*9 22 0 1*9 23 G 1*9 23 RM 1*9 1*6 RH U9 1*6 2 250 2/3 3070 H70W 19 5-2-1 6* 15 >60 70 5 75 75 75 55 2 57 10 2 300 2 3025 S80W 20 7-1.-2 «* 20 60 1 70 10 70 75 50 25 10 35 25 128 170 156 170 7 ? 7 50 3U 35 ? ? 7 78 Hi 70 2 1500 1 3050 N75W Uo 6-U-l 7 20 20 25 50 7 60 65 UO 55 30 1 85 35 1 116 125 120 122 1 7 7 7U 10 72 l-(2) 500 1/U 2 ISO 1 3280 U360 sisw NUOH o-S 10 7-5-2 6-3-1 % 8 l-(2) 250 1/2 U120 35 15 20 60 IO 10 15 55 70 8 1 78 15 1 30 15 20 55 Uo 55 -85 30 60 18 2 80 35 3 119 11 131 15U 127 151 60 US 70 36 25 1 19 105 32 21 15 7-6-3 6| 35 30 8 65 20 50 60 25 50 5 55 15 1 16 131 157 68 10U 20 2 2 2 2 2 2 2 300 Uoo UOO 300 UOO 200 600 1/2 1 3A 1/2 1 1/2 3/U 3330 3500 3330 3725 3710 U300 3780 N80H N80W S10W w W N80W w 20 33 17 3U 3U 25 10 7-5-2 6-3-1 7-5-2 8-5-3 8-5-3 8-6-U 8-U-2 7 7 7 7 7 6| 7 25 55 12 20 50 35 30 25 15 Uo 20 30 20 U5 20 20 30 UO 30 15 20 55 80 75 65 85 65 85 Uo U 20 8 5 10 -50 Uo Uo 20 20 25 35 80 UU 55 28 25 35 35 50 Uo Uo UO US 18 10 80 5 35 25 10 UO 55 7 1 20 9 5 6 8 „ 5 1 1 - - -87 6 55 35 IS U6 63 15 2 25 10 10 15 25 1 1 6 2 1 - -_ _ nU _ _ _ 1U2 132 171 112 lUl lUl 116 -138 121 112 13U 168 1U6 1U8 92 - 130 - - - 129* 1U2 18 U8 1 u 3 18 82 36 23 19 33 59 - 9 - - - - 2» 7 1 85 92 93 72 100 7 1 29 1? 11 21 9 1 ? - - - - -red-12/8 8/8 1U/8 20/7 11/9 13/8 1959 1959 1959 I960 1961 1959 SM SM SM SM H SM U9 22 U9 22 U9 22 U9 22 U9 2U U9 22 122 57 122 57 122 56 122 56 123 11 122 57 2 2(5) 2 2 2 2 200 300 200 300 300 1 20 2 2/3 3/5 3A 1 3A 3260 S10B 30 6-3-1 7 20 12 UO 60 UO 50 80 25 75 7 1 82 10 2 110 101 100 86 25 3U0O S10W 20 7-U-3 6i 30 US 25 75 12 Uo U5 7 30 U 1 35 6 2 110 125 ? 7 7 90 UU 65 3150 S80E 5 6-5-1 7 20 25 30 65 20 US 60 12 65 10 1 75 15 2 106 1U2 129 ? 7 ? 72 10 3220 S70B 22 6-3-2 «* 12 25 20 So 20 35 US 15 US 3 2 50 S 2 llU 129 122 152 31*80 S60E 3U 6-5-3 6* So 35 20 70 20 75 85 10 US 2 U7 78 109 110 117 23 2 7U 1 8 ? 59 1 3330 S70E 10 6-1.-1 7 35 15 25 65 30 50 70 25 60 5 1 65 10 1 117 93 llU 7 1 7 61 15 A layer* Abies amabilis Sub-layer No. trees over 3 in./acre Basal area, sq. ft./acre Gross volume, cu. ft./acre 5.*.3 ll..*. 3 5.*.3 6.8.3 +.1 U.+.3 U.7.2 6.7.2 2.*. 2 3.7.2 6.8.3 +.2 5.8.3 6.8, 6.8. U.*.2 U.*.2 3.7.2 5.7.2 5.8.3 5.8.2 3.*. 2 3.*. 2 5.7.2 5.8.3 5.8.3 6.7.2 7.8. 6.8. 6.7. 6.8.3 5.8.3 U.8.2 Scbassoc Char. P c d . 5.7.1 5 r~*.3 5.7.31 S'i +.2 5.7.1 US 50 100 50 135 135 180 135 70 185 150 lUo 50 12U 239 96 128 286 U21 20U 163 73 31U U81 25U 135 6573 13011. 3502 6 220 13537 16U26 7653 U62U 2516 11369 20890 1316U 9235 5.7.2 6.7.2 3.+. 2 U.7.3 5.7.2 1.+.1 U.+.3 U.7.2 2.+.1 •.1 3.+.1 5.7.1 +.3 2. *. 2 3. +. 2 170 ISO 120 80 51 H5 65 276 170 182 83 35 IU26 9953 68U2 UU96 186U 820 Subassoc. Pres. Char, e.d. 30 Sntire association Pres. Fid. Tot. Life-c«d» foro 2 918 Fm continued - y i VJI SYNTHESIS TABLE III, continued Streptopus association Typical subassociation Degraded subassociation Plot number 13 l'l 17 51 85 37 UU 107 3U 10? 103 36 66 Subassoc. 07 02 10 11 125 06 Subassoc. Entire association Pres. Char Pres. Char Prea. Fid. TOt. lAle-Sub- cd. cd. cd. f orm A layer, continued: layer Tsuga mertensiana 1 _ _ +.3 3.+ .2 + .3 1.+.+ 5.+.3 8.9.3 3.+.2 U.+.3 +.3 1.+.2 U 25 U.7.2 U.+.2 - _ 5.+.3 5.7.3 5 30 5 2 U32 Pm 2 3.+.1 3.+.? 5.+.3 1.+.2 5.7.3 _ 5.7.2 + .2 _ _ - U.+.2 3.+. 2 3.7.2 3.+.1 U.+.2 2.+.2 3 - - 3.*.2 3.7.2 - 2.+ . 2 - 3.+. 2 U.7.2 u.7.2 - - U.7.2 5.7.1 U.7.1 U.7.2 U.7.1 U.7.2 No* trees over 3 in./acre _ 55 60 50 15 60 35 50 85 70 25 _ 105 110 85 115 70 115 Basal area, sq. ft./acre _ - 92 8U 96 56 2U6 335 97 330 136 38 _ 208 183 87 SU 1U0 206 Gross volume, cu.ft./acre - - 2719 3172 UU02 2U69 8991 15090 3236 8153 U10U 1316 - 6088 5111 3U89 256U 3776 5873 Chamaecyparis nootkatensis 1 _ 3.*. 2 _ _ +.1 _ 2.+. 3 _ _ _ 2 9 ?.+.? _ U.7.3 U.+.3 5.8.3 U.7.2 5 17 3 ? 113 Pm 2 - - U.7.2 _ -_ + •+ _ U.7.2 - - - - - - 3.+.1 U.7.2 U.+.2 +.2 - - •.2 2.+.1 - - - - l.+.l - - - ?.+.l - 3.6.1 l.+.l - +.2 NOo trees over 3 in./acre U5 s _ 10 _ 25 _ _ 70 _ 60 U0 U5 30 Basal area, sq. ft./acre _ 232 U8 _ 96 208 _ -_ 202 - 238 29U 520 18 Gross volume, cu. ft./acre - - 696O 500 - - 1336 - U925 - - - - U17U - 7U60 8138 10732 S53U Tsuga heterophylla 1 •.2 +.3 •.2 2.+. 2 _ • _ _ 3.+. 3 - - U.+.2 3 27 - - - - - - 2 2 3 ? 165 Pm 2 ) 6 7 1 7.8.3 3.7.2 3.+ .2 - - - - 3.+.2 - - - U.7.1 - - - - 3.+.+ -3 ) - 3.6.2 2.+. 2 - - - - - - - 5.7.1 +.2 - - -No. trees over 3 in./acre 50 50 65 Uo 5 _ _ _ 25 _ _ 65 5 - - 10 -Basal area, sq. ft./acre 31? 16U 65 8? _ - _ _ 76 - - - 120 U - - - 92 -Gross volume, cu. ft./acre 1U190 82UU 201U 236? 1 _ _ - 2637 - -_ Wl05 56 - - - 1680 -Totals, including sporadics: 165 1U0 350 265 265 235 380 260 No, trees over 3 in./acre 95 100 265 155 190 155 250 170 170 270 Basal area, sq. ft./acre UU3 U03 U35 3U2 38? U78 5U6 U98 U5U 6hh 617 ?92 337 U79 U60 5U5 U70 835 259 Gross volume, cu, ft./acre 20763 21258 1519U 1275U 179UO 18899 17960 1971U 13U1U 19fli2 2U988 1UU80 16515 117U5 15072 17791 15198 18052 12227 B layer: Vaccinium alaskaense 2 8.7.3 7.8.2 6.8.? U.6.1 U.6.? 5.7.2 6.7.2 6.7.2 5.7.2 S.6.1 5.6.1 U.6.1 5.7.2 5 29 5.7.2 5.6.2 U.6.2 5.6.3 7.7.3 5.6.2 5 27 5 ? 539 Pnd Abies amabilis 1 2.+.1 2.+. 2 3.6.2 2.6.1 5.7.2 U.7.2 5.6.2 U.6.2 U.7.1 U.6.2 2.+.1 U.+.l - 5 19 5.7.1 U.6.2 U.6.1 U.6.1 5.6.1 3.6.1 5 35 5 U26 Pm 2 5.6.1 5.7.2 U.6.? U.6.1 U.6.1 U.6.1 U.+.l 2.6.2 2.+.1 3.+ .1 2.+.1 U.+.2 U.6.1 5.7.1 U.+.l 6.7.1 U.6.1 2.+.1 U.6.1 176 Tsuga mertensiana 1 _ 2.+.1 U.7.2 5.7.2 2.+. 2 U.6.2 2.+.1 3.+.1 2.6.1 3.6.2 U.5.1 - U 11 2.6.1 3.6.2 2.5.1 3.6.1 2.+.1 2.6.1 5 11 5 Pm 2 -_ 3.6.? l.+.l U.6.1 U.6.2 U.+.l 2.+.1 2.+.1 1.+ .+ 3.+.2 - U.6.1 2.+.1 5.7.1 3.5.1 1.+.+ U.6.1 2U Henziesia ferruginea 2 1.+.2 1.5.2 2.6.? l.+.l - l.+.l 1.5.2 +.1 3.6.3 2.5.1 - - 2.+.1 U 1 2.5.2 1.5.1 l.+ . l 3.6.2 U.5.2 1.+.1 5 2 5 2 Pod Vaccinium membranaceum 2 - - 2.6.? - 5.6.3 2.+.1 1.+.2 3.5.1 +.1 2.+.+ 3.U.1 2.5.1 - U u 3.6.2 l.+.l 2.5.2 3.5.2 3.5.1 2.6.2 5 3 U ? 56 Pnd Tsuga heterophylla 1 3.+.1 U.7.2 2.+.1 3.+ .1 l.+.l - - l.+.l - - 2.+.1 - U u - +.1 - - - - 1 - 3 3U Pm 2 2.5.1 U.7.2 l.+.l - - l.+.l - - l.+.l - - 2.+. 2 - - - - - - -Vaccinium ovalifolium 2 3.5.2 2.5.2 +.1 l.+.l 1. + .+ l.+.l - 1.5.2 - - - - 1.5.1 U - - - l.+.l +.1 - - 2 - 3 2 6 Pnd Sorbus occidentalis 1 - - - +.2 -_ - +.2 +.3 - - - - u - - - - - - - 3 - 3 ? 1 Pnd 2 1.+.2 - l.+.l +.1 + .1 _ _ 1.+.2 2.5.2 + .1 - - l.+.l - +.+ +.+ +.1 - -Rubus spectabilis 2 U.7.2 1.5.2 - _ _ l.+.l _ +.1 - 2.5.1 ?.5.2 - - 3 2 - - - - - - 0 - 2 2 12 Pnd Cham, nootkatensis 1 _ _ - - _ - l.+ . l + .+ _ - -_ - 2 1 3.6.1 - +.1 +.1 l.+.l +.1 5 1 2 11 Pm 2 - - - - - - l.+.l + .+ 3.5.2 - - - - 2.6.1 - 1.5.1 l.+.l 1.+.+ Cladothamnus pyrolaeflorv.s 2 - - - - - - - - - - - - - 0 - 1.5.2 l.+.l +.1 +.2 2.6.3 - 5 - 2 ? 1 Pnd Rhododendron albiflorum 2 - - - _ - - - - - - - -_ 0 - - - •.1 - U.6.2 _ 2 5 1 1 10 Pnd Oplopanax horridus 2 - - - - - - - - - + .+ - 1.+.+ 2 - - - - - - - 0 - 1 1 - Pnd C layer: Rubus pedatus 8.8.3 5.7.2 6.7.3 2.3.2 5.3.2 U.U.2 5.6.3 U.6.2 2.2.2 u.3.2 U.3.2 U.2.2 l . U . l 5 18 U.5.2 3.5.2 U.5.2 U.6.3 U.U.3 3.6.2 5 8 5 2 235 Ch Blechnum spicant U.5.2 2.6.2 U.6.2 (".8.2 +.+ _ U.6.1 l.+.l 5.6.2 2.U.1 l.+.l 2.5.1 5 9 U.5.2 3.U.1 +.+ 2.5.1 U.5.1 U.7.2 5 7 5 3 1U8 H Streptopus roseus 1.+.2 l.+.l 3.U.2 2.+.1 2.+.2 U.5.3 1.+.2 6.6.2 l.+.l 5.3.2 5.3.2 1.5.1 3.5.3 5 8 2.+.1 - 2.+ . 2 2.U.3 2.U.2 2.+. 2 5 1 5 3 110 H Vaccinium alaskaense + .2 3.6.2 U.2.2 1. + .+ 2.3.2 l.+.l 3.3.2 3.+.2 3.3.2 3.*.2 3.+. 2 3.+.1 1.1.2 5 U 3.5.2 2.+. 2 U.5.2 3.5.2 l.+.l 3.5.2 5 U 5 72 Pnd SYNTHESIS TABLE III, continued Streptopus association Typical subassociation Degraded subassociation Plot number 13 Ill 17 51 85 37 Itli 107 3L 10? 103 36 66 Subassoc. 07 0? 10 11 125 06 Subassoc. Entire association Pres. Char 1*1-83 Char. Pres. Fid. Tot. Life-C layer, continued. c d . c d . c d . form Abies aaabilla 3.*.1 2.*.? 2.+.1 3.*.? L.+.l 2...1 lu+.l 1.+.2 l .+.l 2.+ .1 2.+ . 2 3.+.1 2.+.1 5 3 3.+.1 3.+.1 3.+.1 3.'. 7 2.+.1 2.+.1 5 3 5 63 Rn Veratrum eschscholtzii - - 1.+.2 3.*.? +.1 2.ij.? 2.+ . 2 l . + . l l .+.l + .• + .+ l .+.l +.1 5 - l .+.l l .+.l +.1 '.1 + .+ 1.+.3 5 - 5 2 7 0 Clintonia uniflora 2.3.3 3.5.2 I1.6.3 b.5.3 _ - 2.2.2 3.5.2 ll.ll. 2 1.+.2 1.+.2 _ 3.5.2 li 5 I1.6.3 3.U.2 - - b.3.3 5.7.3 li 12 U 2 97 0 Streptopus streptopoides 7.6.3 U.5.2 _ l .+.l 1.+.2 2.+.1 + .1 3.1*.? 2.+ .+ 3. 2.2 3.3.2 2.+.1 1.3.? 5 6 _ - - - + .1 - 1 - 1 U 3 78 H Vacciniun iwjfibranaceuin - _ - 3.3.? ?.+.? l .+.l I.+.? _ 2.+ .+ 2.+.+ 2.?.? l .+.l li 1 b.5.2 + .1 3.5.7 l . ' . l l .+. l 5 3 29 Pnd Tiarella unifoliata i.+.j * . l - 2.+.? 2.5.2 - 3.+ .? - 5.3.2 5.7.2 1.1.7 1.+ .7 h 6 - - l.+.l- - - / - 1 - 3 2 57 U Tsuga mertensiana - -_ 1.+ .7 3.+.1 - U.+.l _ 1.+.+ + .1 l .+.l _ 3 2 3.+.1 2.+.1 - 2.3.1 5 2 3 23 Pn Tiarella trifoliata U i . ? 3.5.2 *.? - l .+.l - - 1.+.? 2. + .? 1.+.2 2. + .? li 2 _ - l . + . l - - 1 - 3 2 16 H Athyrium filix-femina 2.5.1 1.5.? +.• - + .1 - 3.b.? 2.1i.2 - - h 1 - -_ - - + .+ 1 - 3 •y 7 H Meniiesia ferruginea - - l.+ . l - - - - - - l . ' . l 2 - l .+. l 1.+ .+ 3.+.1 l . ' . l - 1.+.7 5 1 3 5 Pnd Streptopus amplexifolius 1...* 1.*.? + .+ - l .+.l - l.+ . l - - >l - +.1 - - •.1 - - ? - 3 7 1 H Listera caurina - - 1.*.? - +.1 • - - - - - - 1.+.3 2 - 1.+.7 - l.+.l *.] + .2 +.1 5 - 3 ? - G Sorbus occidentalis - •.1 l.+ . l - 1.+ .+ + .1 - ... 1.+ .+ — - - l.+.l 3 - - l.+.l - +.1 - l .+.l 3 - 3 - Pnd Gymnocarpiuri dryopteris 3.3.? - - - - 3.6.3 - l . l i .? - b.6.2 1.6.2 - 3 3 - - - - - - 0 - 2 ? 20 0 Cornus canadensis '.? 2.3.2 l.+.l - - - - ?.?.? - - - 2.+.1 3 - 3.+.2 - - - - - 1 5 2 ? 3 Ch Tsuga heterophylla 2.'.1 2.5.? 7.+.1 - - - - - - - - l .+.l - 2 1 - - - - - - 0 - 2 3 Pm Lysichitum americanum 2.5.1 * . l 1JJ.1 1.+.+ - - - - - - - 7 - - - - + .+ - - 1 - 2 2 1 0 Carex laevictilmis * . l - - - _ - - - 1 _ _ 1.6.1 •.+ _ _ 7 _ 2 2 H Rubus spectabilis - '.1 -_ 1.+ .+ - - - ».l _ - 2 - - - _ - - 0 - 2 - Pnd Chamaecyparis nootkatensis - - - - - - I.+.? - l.+.l - - - - 1 - - - - '.• •.1 3 - . 2 - Pm Cladothamnus pyrolaefloras - - - - - - - - - - - - 1 - l .+.l - +.+ - + .1 *.+ li - 2 - Pnd D layer (humlcolous)j Rhytidiopsis robusta 3.2.2 U.5.2 3.5.? 5.5.? 5A3 5.1:. 2 3.U.? L.b.7 1.?.? _ 5.5.3 6.7.3 5 Ill fl.6.7 U.5.2 7.6.7 I1.6.? 5.5.3 6.6.3 5 31i 5 2 372 W Abies amabilis — 2.+ .1 - 2.+.1 2.+.1 2.+.1 2.+.1 ?.•.? - l.+.l l.+.l l.+.l 2.+.1 L 1 +.2 l.+.l 2.+.1 2.'.1 2.+.1 1.+.1 5 1 5 10 Fm Dicranum fuscescens 1.7.1 - 7.5.7 5.6.? _ 7.6.3 3.3.? li.3.? U.3.? 2.7.2 L.S.3 li.6.2 5 12 6.5.? 2.?.? _ 2.3.7 5.5.3 - li 15 l> 2 192 Te Mnium nudum b.5.2 5.6.? 5.6.? 5.5.2 2.3.? _ 1.?.? 2.2.2 l.b.7 U.b.2 _ 1.1.1 li 10 1.1.3 - 2.b.2 1.?.? 1.2.2 2.3.7 5 - li 2 99 Te Rhytidiadelphus loreus 2.2.2 U.S.? 1. ?.? 5.6.? _ 5.6.? _ 5.ll.2 1.1.? 1.1.2 1.2.7 1, 8 li.S.? U.S.? 2.5.1 1.?.] 3.3.1 2.2.2 5 5 U 2 96 V Plagiothecium elegans 2.?.? 3.3.? 1.5.? ?.?.? - 1.1.? 2.?.? 2.1.? ?.2.? - - - b 1 1.?.? 2.3.2 1.3.2 1.1.1 1.2.7 2.b.2 5 - li 7 1? M Hypnum clrclnale X.?.? - - 1.?.? ?.l.? - 2.1.? 1.1.? 1.1.? 1.1.? 1.1.7 b 1 1.2.2 1.?.? - - - - 7 - li 2 12 H Calypogeia neesiana J.?.? 1.3.? 1.1.? ?.5.3 1.3.? - 1.1.1. 1.1.? 1.?.? I. 7.? - h - 2.3.2 1.1.2 - 1.?.? - 1.1.2 ll - U 2 8 Ht Cephalozia media 1.1.? - 1.1.? 1.1.? 1.1.? 2. 2.2 - _ 1.1.? - - 1.1.1 1.1.1 ti - 1.2.2 1.7.2 2.3.2 1.1.1 1.1.7 3.3.2 5 1 u 2 7 Mt Diplophyllum taxifolium 1.3.? - 1.?.? 1.3.? 1.1.? - 1.?.? -_ _ 1.?.? 1.?. ? 3 - 1.1.? 1.1.? 1.7.7 - 1.?.? 1.1.? 5 - u 2 - Ht Plagiothecium denticulatum 2. 2.2 - - 1.1.? 1.1.2 3.+.? _ - 1.1.1 _ k 3 _ l.li.? _ _ 1.1.7 - 2 - 3 3 21 M. Mnium spinulosum - - 1.1.1 - ?.3. ? - - - 1.?.? _ - 1.1.1 - 2 - 1.?.? - 3.1i.? - 1.2.? 1.3.? ll 1 3 2 6 Te Lophocolea heterophylla - 1.3.? - 1.1.2 - - 1.1.? - - 1.1.? 1.1.? 3 - - 1.7.2 3.?.? 1.1.1 1.1.2 2.1.? 5 1 3 2 6 Mt Dicranum scoparium - b.5.3 - - 6.6.2 - - X -_ - - 2 Ill - 5.6.7 b.5.2 - 5.6.? 3 20 2 2 101, Te Blepharostoma trlchophyllum - - - ?.l.? - - - - -_ 1.1.1 1.1.7 2 - 1.1.? 1.?.2. 7.3.7 _ - 3.3.? li 1 2 2 7 Mt Baszania amblgua - + .+ - 3.3.? _ - - _ 1.1.2 _ _ 1.1.7 2 1 1.?.? _ - _ _ 1.1.? 2 _ 2 3 5 Mt Lepidozia reptans 1.?.? 2.?. 2 1.1.? - - - - - -_ -_ 2 _ 1.1.7 2.3.2 1.1.7 _ - 2.1.2 ll - 2 2 3 Mt Plagiothecium undulatum 2.3.? 2.2.? 1.3.? 1.3.3 _ - _ 1.1.+ _ _ - _ 2 _ _ _ _ 1.1.1 1.3.1 - 2 - 2 2 2 M Chamaecyparis nootkatensis - - - - - - l.+.l + .+ _ _ _ _ _ 1 _ + .1 - _ + .+ 2.+.1 - 3 - 2 1 Pn Tsuga mertensiana - - - - 1.+ .+ l.+.l 2.+.1 I.+.? _ - - - - 7 - +.1 l . ' . l - +.+ — 3 - 2 1 Pn Bryum sandbergll - - - ia. i - - 2.5.2 _ - 1.?.? 1.2.2 1.2.2 1.1.1 3 _ - - - - - 0 - 2 2 - To Plagiochila asplenioides - - - 1.1.2 - -_ . _ - _ _ _ 1 1.1.? _ 1.3.2 _ 1.1.? 1.1.? li - 2 2 - Te Bazzania trierenata - - - - 1.2.2 - 1.1.? _ _ - 2 _ 1.7.7 - - 1.7.2 1.1.? 3 - 2 2 - M Scapania bolanderi - - - 1.1.? - - - - - 1.1. • 1.1.1 - 1.1.+ 2 - 1.1.? - - - - 1.1.2 2 - 2 2 - M ? ? 9 9 =9="= = a p. j f v n a N <• a er o 0 t» o. p. ro i » p ^ jj n X B c i . i a o o a + < o 1 M 0-? II O I M - t + Q - P 1^  1 C C O "o* + o r*-OOBV>i*-'CO*-"»t— • ++> l\3 .—. O V>! • J >-' H~ 3 0-4- CM ^+ f 1? £* EF « » n a to M- O 1 g s: 3 r' " 8 ! % >i ** S P \j4 ro 4 ro STNTrGSIS TABLE IV Leptarrhena - Caltha leptosepala association (Lcptarrheneto - Calthetum leptosepalae) Eriophorum - Sphagnum association (Eriophoreto - Sphagnetum) Plot number 87 52 70 73 79 ?5 88 81 73 8U 86 105 Plot size (acre) 1/60 3/30 1/90 1A0 1/20 l A O 1/60 1A0 1/20 1/20 1/20 l/*0 Date 31/8 6/9 2U/3 30/8 11/3 21/9 31/8 23/8 25/8 29/8 29/3 21/7 I960 i960 I960 i960 i960 i960 I960 I960 I960 i960 I960 1961 Locality (see legend) RM RM RM RM RM 0 RM RM RM RM RM H Latitude U9 U6 U9 U3 U9 U6 U9 U6 U9 U6 U9 2U U9 U6 U9 U6 U9 U6 U9 U6 U9 U6 U9 2U Longitude 1?3 03 123 0? 123 02 123 02 123 0? 123 05 123 03 123 02 123 02 1 23 03 123 03 123 11 Landform (see legend) 2 1 1 1 1 1 (2) 2 1 1 1 2 2 Slope above (est* ft.) 300 along along along ISO along 300 - - - 180 300 stream stream stream stream Area of assoc. (acre) 1/25 1/10 1/60 1/25 1/20 1/30 VUo 1/7 1A0 i A 1/3 1/20 Altitude ( f t . ) I1O60 1*735 U800 U68O U550 U200 U060 U600 U600 U350 U310 3U50 Aspect W N80W NljOW SUOW S6CW SUOE S30E flat flat flat N w Slope (degrees) 9 6 u 9 10 l l * 2 0 0 0 U 10 Wind exposure (A-B-C) 0-0-6 0-0-6 0-0-5 0-0-5 0-0-7 0-0-5 0-0-6 0-0-5 0-0-5 0-0-6 0-0-6 0-0-6 Snow cover (months) 8 9 9 9 8* 8 8 8 8 7* % coverage: By vegetation layer Bi - - - - 8 - -— - - - -B 2 - 1 - - 10 1 — — — - — — B . 1 - - 15 1 - - _ - - -C 95 60 85 85 98 95 90 75 90. 90 90 98 I>H 80 95 90 90 70 85 85 50 95 80 20 90 By decayed wood - - - 3 - - - 3 - 3 - -By rock - -— - - - - 1 - - -— By open water - 5 - - - - - 25 5 • - - -D W t / * \ Regeneration ino./sq. meter J n n o Total soil depth (cm.) 67 7 7U 36 Uo 55 80 ? . 85 7 8U 7 Depth to bottom of An (cm.) 66 ? 18 25 Uo 28 6U 85 7 83 7 Depth to seepage, i f present 20 ? 32 2 7 22 68 7 36 ? 83 ? Pres. Fid. Tot. Life- Pres. Fida Tot* Life-B layer: c d . form C layer: c d . form Salix commutata + . • - - 1.5.2 - - 2 U - Pnd Carex aquatil is 8.7.3 _ 2.3.2 7.6.2 8.7.3 U 5 201 H Eriophcrun angustifolium - U.3.2 8.6. ? 7.7.1 2.2.1 U 5 136 H C layer: Deschampsia atropurpurea - l . + . l 3.3.2 2.3.2 - 3 2 6 H 6.5.3 6.U.2 7.6.3 6.U.3 Veratrum eschscholtzll - + .+ 1.+.1 - +.+ 3 1 - G Leptarrhena pyrolifolia 2.+.3 7.6.2 5.+.3 5 U 225 H Carex nigricans - 8.5.2 - 1.5.2 - 2 2 75 H Erigeron peregrinus 2.*. 2 U.3.2 7.U.2 U.2.2 6.6.? 5.U.3 3.3.2 5 u 13U H Carex spectabilis - 5.3.2 5.5.2 - — 2 2 50 H Caltha leptosepala 6.U.2 3.2.2 5.3.3 6.U.2 U.U.2 5.3.3 6.5.2 5 5 16U H Equisetum palustre - l.+.l - 3.+.1 - 2 2 5 0 Parnassia fimbriata 5.3.3 5.U.2 - 5.3.2 3.U.2 3.3.2 5.U.2 5 U 110 H Tof i - l d i a glntinosa - - 1.+.2 3.+.2 - 2 2 5 0 Carex spectabilis 3.3.2 1.1.2 - +.+ U.U.2 3.2.2 U.3.2 5 3 30 H Calamagrostis canadensis - 1.+.2 - 2.2.2 2 2 1 H Carex nigricans - - 5.5.2 5.6.2 2.3.2 7.7.3 2.3.2 U 2 102 H Agrostis aequivalvis - - - 1.+.2 2.2.2 2 2 1 H Epilobium alpdnum - 3.2.1 l.+.l 2.2.2 l.+.l 3.2.2 - I* U 11 0 Luetkea pectinata - 2.+. 2 - - +.1 2 2 1 Ch Deschampsia atropurpurea - 2.+.1 1.+ .2 + .2 l.+ . l 2.+.? U 2 2 H Hippuris montana l.+.l - - 1. 2. 2 2 1 - H Phyllodoce empetriformis - l.+.l 1.2.2 1.3.2 +•+ - U 1 - Pne Scirpus caespitosus 1.+.2 - 1.+.2 - 2 3 - H hitella pentondra — 1.+.2 1.+.2 l.+.l 1.+.2 1.+.2 — U 3 — H Equisetum palustre U.U.2 U.3.2 - 3.+.2 7.7.3 - S.U.2 U U 100 0 D layer (humicolous): Agrostis aequlvalvls - 2.1.2 - 1.+.2 - S.U.3 1.+.2 3 2 26 H Veratrum eschscholtzll - - +.+ +.+ 5.5.2 +.+ • 3 2 25 0 Drepanocladus aduncus 7.6.2 3.3.2 - U.2.2 2.3.2 U 2 66 Te Luetkea pectinata 1.2.2 3.2.2 1.+.2 - •.? — 3 2 5 Ch Sphagnum plumulosum 2.6.2 6.6.3 6.6.'? - - 3 3 67 Td Juncus mertenelanus - 1.1.2 - 2.2.2 - 1.+.2 2.2.2 3 3 2 H Scapania ullginosa • U.3.2 3.2.2 U.2.2 — 3 3 25 M Valeriana sitchenals - - — 2.3.2 2.+.2 +.2 1.2.2 3 2 2 - H Polytrichum commune - U.5.3 2.2.2 - 3.U.2 3 3 16 Te Vaccinium deliciosum - - • . • +.• 1.5.2 + .+ - 3 1 • Pnd Mnium nudum _ 2.3.2 2.2.2 2.2.2 - 3 2 3 Te Petasites f rlgidus 5.6.2 + . • 3.2.2 - - 3 u 30 H Calliergonella euspldata 2.2.2 • - 2.2.2 - 1.3.2 3 3 2 W Arnica latifolia - U.3.2 1.3.2 - 1.+.2 - - 3 3 IP H Sphagnum mendocinum - - 7.6.2 - 8.7.3 2 3 125 Td Hippuris montana - 3.3.2 2.2.2 • - - 1.1.2 - 3 2 6 H Sphagnum squarrosum - 6.6.3 - 5.3.2 - 2 2 58 Td continued continued SYNTHESIS TABLE IV, continued Leptarrhena - Caltha leptcseiala association Plot number 87 52 70 73 79 95 88 Pres. Fid. Tot. Life-c.d. form C layer, continued: Juncus drummondii _ 2.1.? 1.1.2 1.3.2 _ _ 3 2 1 H Habenarla saccata +.2 + .+ - 1.2.2 _ - 1.+.3 3 2 - 0 Viola paluatris • - - - 2. 2.2 - 5.3.2 2 2 26 H Senecio triangularis - - 3.U.2 U.3.3 -— 2 2 15 H Tofieldia glutinosa 2.+.? - - - 1.+ .2 - 3.+.2 3 i 6 G Carex 11 lota - - +.1 2.+.1 - - ? 2 1 K Agrostis thurberiana - _ • 1.+.2 - — 2 2 - K Veronica serpylllfolia - - l.+.l - - 1.+.2 - ? 3 - H Cassiope mertensiana - + .+ — — — 2 1 - Pne Chamaecyparis nootkatensis +.+ * • +.+ - - 3 1 - Pm Carex ablata 1.+.? - - - +.1 - - 2 2 - H D layer (humicolous): Rhytidiadelphus squarrosus 7.5.3 5.3.? 6.L.3 U.6.2 6.3.2 5.3-2 8.7.2 5 U 251 W Drepanocladus aduncus 6.5.3 6.3.? 7.U.3 6.6.2 1.2.2 7.6.2 U.U.2 5 l i 209 Te Philonotis fontana U.3.2 6.6.? U.3.2 6.6.2 6.U.2 1.2.2 - 5 l l 119 Td Mnium nudum 2. 2.2 U.3.2 1.2.2 - 5.2.2 - - 3 2 36 Te Sphagnum plumulosum - - - 1.3.2 1.U.2 U.U.2 - 3 2 10 Td Moerckia blyttii - 2.1.? - 2»+.2 3.+.2 - - 3 ? 7 Th Bryum sp. 2. 2.2 5.U.2 - - 2. 2.2 - - 3 ? 27 Te Bryum sandbergii 2. 2.2 ?.2.2 - - - - 5.7.2 3 ? 27 Te Cratoneuron commutatum 1.2.2 3.2.? 2. 2.2 - - - 3 3 6 M Dicranum fuscescens - 2.3.2 2. 2.2 - - - ? ? 2 Te Campylliuro stellatum 2. 2.2 - - 2. 2.2 - 2.2.2 - 3 3 3 Td Scapania ullginosa - 2.2.2 2. 2.2 - - - - 2 ? 2 M Marsupella sparsifolia - 1.3.2 2.2.2 - - - - ? 2 2 t Abies amabilis - - - - - +.+ ? 1 - Pm Eriophorum - Sphagnum association Sporadic species: C layer: H Agrostis thurberlana 78(1.+.1) H Agrostis idahoensls 8U(l.+.2) H Caltha, leptosepala 86(5.+.?) Ch Gaultheria humifusa 105(1.U.2) 0 Streptopus roseus 105(l.+.2) H Trientalis arctica 105(S.ll.2) H Viola glabella 8!i(2.+.?) H Viola palustris 105(5.5.?) D layer (humicolous): Mt Anastrepta orcadensls 8U(1.1.2) Mt Calypogeia trichcmanis 86(1.1.?) M Cratoneuron commutatum 86(1.1.?) M Hypnum circinale 86(1.1.?) Ht Leiocolea obtusa 81(1.1.?) Mt Orthocaulis floerkii 78(2.2.2) t Pohlia sp. 105(2.3.2) t Polytriehun Juniperinum 8U(1.1.2) W Rhytidiopsis robusta 78(3.3 . 2 ) Td Sphagnum megallanlcum 8 1 i ( l i . l i . ? ) Sporadic species: B layer: Pm Chamaecyparis nootkatensis 79(U.6.1) Pnd Rhododendron albiflorum 79(1.6.?) Pm Tsuga mertensiana 95(+.+ ) Pnd Vaccinium deliciosum 79(1.+.?) C layer: H Agrostis idahoensls 87(1.+.?) H Calamagrostis canadensis 88(5.6.3) H Eriophorum ai gustifolium 87(1.?.?) Ch Oaultheria humifusa 88(+.l) 0 Habenarla dilatata 88(1.+.3); 87(+.?) H Hordeum brachyantherum 95(3.3.?) Ch Lycopodium selago 5?(+.l) G Lysichitum americanum 87(+.+) H Mimulus lewisii 5?(3Jl.?) Ch Rubus pedatus 79(+.+) Pnd Salic commutata 79(1.5.?) H Saxifraga arguta 52(3.3.2) H Scirpus caespitosus 87(8.7.31 Pnd Sorbus occidentalis 95(+.+) Pnd Vaccinium membranaceum 95(1.3.+ ) D layer (humicolous): Pm Abies amabilis 88(+.+) Mt Anastrepta orcadensls 70(2.2.2) t Aulacomnium palustre 75(5-6.2) W Calliergonella cuspldata 70(1.?.?) Mt Cephalozia leucantha 52(2.1.2) Pm Chamaecyparis nootkatensis 87(+.+ ) Th Conocephalum conicum 73(2.?.?) t Dicranella squarrosa 95(1.2.2) Te Drepanocladus exannulatus 73(1.2.2) t Kiaeria falcata 70(1.1.1) Mt Lophozia porphyroleuca 52(2.1.2) t PoHia sp. 5?(5.U.3) Te Polytrichum commune 95(2.3.2) Te Rhacomitrium canescens 95(6.U.2) Te Rhacomitrium heterostichum 52(l.2.2) Td Sphagnum squarrosum 73(1.2.2) SYNTHESIS TABLE V Subalpine Lysichitum association (Chamaecypareto - I.yslchltetum) Subalpine Oplopanax association (Thu.leto - Oplopanacetum abietetosum amabilis) Plot number 18 126 127 U9 128 Ul 89 Plot size (acre) VS 1/5 V? 1/5 V5 1/5 3Ao Date 27/7 12/9 13/9 25/7 13/9 29/7 31/8 1959 1961 1961 i960 1961 i960 i960 Sporadic spp.. Lysichitum assoc. Locality (see legend) SM H H SM H SM RM A layer: Pm Pinus monticola U9(+.3) Latitude U9 22 U9 23 U9 23 U9 22 U9 23 U9 22 U9 U6 Pm Thuia plicata 128(5.7.+ ) Longitude 122 57 1 23 11 123 11 122 57 1 23 11 122 57 1 23 03 3 layer: Lsndform (see legend) It 2) 2 2 2 2 l-<2) 2 Pnd Rhododendron alMflonwi 39(i.+) Slope above (est* ft.) 1500 1000 500 500 1000 1000 350 Pm Taxus brevlfolia 1?3(?.6.+) Area of assoc. (acre) i A V5 l A 1/3 1/2 1/5 1/20 Pm Thuja plicata 128(+.+) U060 C layer: Altitude (ft.) 3000 2900 2930 2900 2970 3050 H Agrostis alba 128(+.l) Aspect N70W s6ov SU0W SUOE W s8ow N30W H Arnica latifolia UMl.U.2) Slope (degrees) 27 8 7 15 20 25 10 H Bcykinia elata 128(+.2) Wind exposure (A-B-C) 6-14-1 5-2-1 5-2-2 7-5-3 6-2-1 7-5-2 8-6-U H Caltha leptosepala 89(5.6.3) Snow cover (months) 7 6 6 % 6 6| 8 H Carex physocarpa 12fl(+.2) % coverage: 65 Uo Uo i» Pnd Cladoth. pyrolaeflorus Ul(+.l) By vegetation layer A^  10 5 ]* G Equisetum palustre 89(5.U.3) A? 8 JUO 30 U5 Uo K Galium triflorum 128(1.1.2) A3 35 20 U5 30 30 15 G Habenarla dllatata 89(+.J) A li5 75 60 80 80 55 30 H Hippiris montana 89(l.+.l) Bl 10 25 20 28 35 18 25 H Juncus mertensianus 89(5.7.3) B 2 65 Uo 20 30 30 25 30 H Polystichum munitum 127( + .+) B 65 6< 35 50 55 us Uo Pnd Sorbus occidentalis 128(+.2) C 65 65 65 60 65 75 70 H Tiarella laciniata 123(+.l) DH 65 80 80 75 70 60 85 H Trientalis arctica 128(l.+ .?) DL 20 8 15 20 3 U 3 D layer (humicolous): "R 1 2 - - - 1 - Mt Cephalozia leucantha 126(1.1.2) D 85 90 95 95 73 .65 88 t Diplophyllum taxifollum 18(1.1.2) 5 Mt Lophozia porphyroleuca 41(1.1.2) By decayed wood 35 10 20 25 6 6 Mt Ptilidium oalifornieum U9(1.2.2) By rock 1 2 - - - 1 - L Cladonia coniocraea 18(1.1.2) Tallest tree on plot (ft.): M Cratoneuron coromutatum 89( 2. 2.2) Western hemlock 128 Ul 9U - 113 - - Mt Blephar. trichophylluir U9(1.1.2) Mountain hemlock I2il 97 89 100 10B 97 91 Pm Thuja plicata 128(1.+ .2) Amabilis fir 10U 107 U8 75 7U 92 23 L Cladonia belUdlflora 89(1.+.2) Yellow cedar 107 111 86 87 - 92 59 Pm Tsuga mertensiana Ul(l.+.l) Western red cedar - - - - 99 - - Mt Orthocaulis floerkii 89(2.+.?) Douglas fir - - - - - - - K Scapania uliginosa 89(U.5»?) Sitka spruce - - - - - - - W Rhytldiad. squarrosus 89(5.U.2) Regeneration (no./sq. meter): 672 6U 56 Td Philonotis fontana 89(U.6.?) West, or mtn. hemlock 7 66 101 - Mt Heterocladium procurrens 128(1.2.2) Amabilis fir 7 30' 107 10 2 10 - Te Drepanocladus aduncus 89(3.U.2) Yellow cedar 7 9 55 1 2 5 - t Dicranella squarrosa 89(1.?.?) Total soil depth (cm.) 9U W Hylocomium splendens U9 ( + .+ ) •ino ? 7 72 ? 100 Te Hygrohypnum ochraceum 89(3.2.2) Depth to bottom of A^  (cm.) 28 ? 0 U5 ? 6U 65 M Hookeria lucens 126(1.1.1) Depth to seepage, if present 5° ? 50 •> 66 10 A layer: Sub-layer Chamaecyparis nootkatensis 1 2 3 No. trees over 3 in./acre Basal area, sq. ft./acre Gross volume, cu. ft./acre Tsuga heterophylla 1 2 . 1 1.6.2 -+.2 -25 25 5!. 56 1531 3160 5.7.2 5.7.2 U.6.2 5.7.2 120 136 2620 2379 2 6.+.1 5.7.+ - 1 •.+ 5.7.2 1.+.2 V' • 1 +.+ 3.6.2 ]U.7.3 j 5 . + . ? 3.7.2 5.6.2 50 110 65 113 28U2 213 139 2333 U.+ .+ + •+ 5.+ .+ 92 91 35 33 Pres. Fid. Tot. Lif< c.d. form ? 161 Pm 12U 1/5 1/5 1/5 1/5 8/3 12/3 28/8 12/3 i960 I960 i960 I960 RM RM RM RM U9 U6 U9 U6 U9 U6 U9 US 123 03 123 03 123 03 123 03 l-(2) l-(20 l-(2) l-(2) 500 600 1500 Uoo 1/3 1/5 1/2 5 3770 3365 U030 3575 N80W N6OW N50W S10E 17 19 20 13 8-6-2 7-6-3 7-5-3 7-2-1 6 7 6 ) „ 20 30 >* 35 ) 3 5 60 10 10 8 3 U5 Uo Uo 80. 20 2 10 2 7S 70 70 Uo 85 7? 80 U2 60 Uo 50 60 60 80 70 So 10 3 10 6 70 83 80 56 20 15 20 25 135 102 112 160 - 1U3 136 -1SU 1U2 1?1 136 su _ 128 - - - 170 158 - - -31 11 8 1 72 18 37 12 67 5S 72 102 10 15 27 9 - 25 56 -Tsuga heterophylla Abies amabilis Sub-layer (U.+ .2 2.+. 2 30 6U 2UU8 U.7.1 U.7.1 UO 68 19 3U )5.7.2 3. + .2 5.7.2 8.3.2 UO 113 13}. 358 UU28 1?15U J5-7-* 11:1 's.™ +.1 2.+. 2 3.+.2 Pres. Fid. Tot. Life-c.d. form 2 l6l Pm 31 Pm o SYNTHESIS TABLS 7, continued Subalpine Lysichitum association Plot number Tsuga heterophylla, continued Ho. trees over 3 ln./acre Basal area, sq. f t . / aore Gross volume, cu, ft./acre Abies amabilis 1 2 3 No. trees over 3 ln./acre Basal area, sq. ft./acre Oross volume, cu. ft./acre Tsuga mertensiana 1 2 3 Ro. trees over 3 in./acre Basal area, sq. ft./acre Gross volume, cu. ft./acre Totals, Including 8 po radios: Ho. trees over 3 in./acre Basal area, sq. ft./acre Oross volume, oo. ft./acre B layers Vaccinium alaskaense Abies amabilis Cham, nootkatensis Tsuga mertensiana Menslesla ferruginea Tsuga heterophylla Vaccinium ovalifolium Cladothamnus pyrolaeflorus Vaccinium membranaceum Rubus spectabilis Sorbus occidentalis C layer: Lysichittm americanum Rubus psdatus Clintonia uniflora Carex laevloulmls Veratrum eschscboltili Bleehnua spieant Athyrium filix-femina Streptopus roseus Streptopus amplexifolius Vaccinium alaskaense Abies amabilis Cornus canadensis Tsuga heterophylla Menslesla ferruginea L i s t e n cordata Coptis asplenlfoils 18 126 127 J i 2 _ 128 Jj l 8?_ 35 65 77 2876 29U8 35 80 95 20 97 9U 100 23 261:0 279b 2223 156 +.1 6.7-1 55 125 21 52 U82 1526 U.+ .2 +.1 b . o l l fa* 85 25 172 25 585b 770 5.*.+ 90 l i 1SU +.2 5 26 692 +.1 3.+.1 llO U2 872 2.+.3 2.+. 2 2.*. 2 60 52 1325 5.7.1 U.7.2 90 36 770 +.2 V 35 25 850 jU.7.1 3.7.1 100 60 1535 JU.7.2 U.7.1 115 68 11:30 1.0 126 3121 200. 230 200 305 275 300 295 32u 217 2US 381 boo 2°U 270 10?ll3 8U08&06 9869 9296 5963 5530 7.8.2 3.6.2 3.6.2 1. +.1 +.1 2. +. 2 2.6.2 1.5.2 2.+.2 1.6.2 1.5.1 +.•.1 1.5.1 1 5.6.1 U.6.2 J.+.+ 1.+.+ 1. +.2 +•+ U.U.2 2. +. 2 5.6.2 5.6.1 3.6.1 1.+.+ 1. +.+ 2. + .* 2.6.2 1.+.+ 1.+.+ U.7.2 2.+.1 U.6.2 U.6.2 1. +.1 U.6.2 2. +.2 2.5.1 U.6.2 3.6.2 1.5.1 1.6.3 U.7.3 b.+.l 2. +.+ 1.+.+ l . + . l U.6.2 •.1 3.6.3 U.7.3 3. *.+ 1.+.+ 1.5.2 +.3 1.+.2 2.6.2 •.3 U.6.2 U.7.2 2.+.1 1.+.2 1. +.l U.7.2 2. *. 2 3.6.2 l . + . l 1. +.l 2.5.1 +.3 3.6.2 2.5.2 1.6.2 +.3 2. *.3 1.3.2 3.+.1 1. + 5,6.2 5.6.2 2. +.1 2.U.1 3Ji . l 2.U.2 6.8.2 U.3.2 3.5.3 +.1 3.3.2 U.6.2 •.1 3.3.3 3.?a 1.2.2 1.3.2 1.2.2 1JU.3 •a •.2 2.5.2 5.6.2 li.3.3 U.U.3 1.+.+ 3.5.2 +.• 1.+.2 • . • 1. +.2 2. *.* 1. +.2 2. *.* 1.+.2 • . • b.5.3 7 . 8 . 2 U . 6 .2 3 . S . 3 • . 1 1 . +.l 2 . U.1 2.+.Z 2 . * . 2 • . • 1 . + . 1 2 . + . 1 1 . * . ? 2 . * . 1 •a U . 6 .3 6.6.2 U.3.3 U.3.? 1.2.1 2.*a 2.5a 1 . *a 3.U.2 2. + . 1 2.*. 2 •a 7.8.2 2.2.2 2.3.2 +.+ 1 . +.2 2. U.2 2.5.1 2.2.2 1.+.2 1 . + . + 1.+.2 1.+.2 1.+.2 •.+ +.2 3. *.2 7.7.2 3.U.2 3Jl.2 +.+ U.5.2 l.U.2 b.6.2 3.3.2 1 . + . 1 2. +.2 1. +.l 2. +.2 1 . +.l 2. +.2 +.2 2.3.2 5.6.2 1 . +.2 6.7.2 3J4.2 3.6.2 2.3.2 2. +.2 1 . +.2 2. +.1 Fid . Tot. Life, c d . form 2 113 Pm 2 U5 Pm 5 2 130 Pnd 5 93 Pa 5 61 Pm 5 36 Pm 5 2 33 Pnd 5 22 Pm 3 2 6 Pnd 3 2 5 Pnd 3 2 2 Pnd 3 2 1 Pnd 3 2 1 Pod 266 0 U6 Ch 36 0 33 H 21 18 17 H 6 b 2 2 1 27 0 R H 0 0 Pnd Pm Ch Pa a B Snbalpine Oplopanax association 92 91 35 38 Abies amabilis, continued Thuja plicata Tsuga mertensiana 1 2 Totals, including sporadiosi No. trees over 3 in./acre 90 90 90 155 Basal area, sq. ft./acre 251 263 327 579 Oross volume, ou. ft . /ae. 11U50 11559 U-U56 28259 Picea sitchensis 50 35 US 5 129 13U 65 11 6398 6816 2t«? 5UO +.1 5 5 lOl'i 3.+.1 l . + . l 20 36 1190 1.+.3 )+ -15 5 61 131 2809 U590 )2.+.2 5 S3 2500 2.+.0 Pres. F id . Tot. Life-e.d. form 3 3 5 Pm 3 2 5 Bn 3 U 1 Pm B layer: Oplopanax horridus Vaccinium alaskaense Abies amabilis Vaccinium ovalifolium Vaccinium nerobranacsura Lonioera utahensis Ribes bracteosum Sorbus occidentalis Hensiesla ferruginea Tsuga mertensiana Rubus smotabllls C layer: Athyrium filix-femina Oymnooarpium dryopteris Streptopus roseus Tiarel la unifoliata Clintonia uniflora Viola glabella AM.es amabilis Oplopanax horridus Streptopus amplexifolius Bubo.0 podatus Veratran esohsoboltsli Pyrola secunda Osmorhisa purpurea Tiarel la t r i fo l i a t a 2.6.3 6.7.2 U.6.2 3.6.1 3.6.1 2.U.2 l .U . l (+.2) 3*6.2 1. +.3 2.5.3 2. +.3 2.6.3 2.+.1 2.+.1 U.6.2 +.3 7.9.1 5.6.2 +.• 3.+.1 3.S.2 I.+.? 1.+.2 1. + . 1 2 . * . 2 7.7.2 5.6.2 U.7.2 3.+.1 l . + . l l.U.2 +.1 2.5.1 2.5.2 U.6.2 3.6.1 5.7.1 • . • 1.+.2 1.+.1 1.+.+ 2 . + . 1 2 . + . 1 5.7.3 b.5.2 5.U.1 3.3.2 b.5.2 3.3.2 2. +.1 3.S.2 3Ju3 3.3.2 3. +.2 2.3.2 2.+.1 1.+.2 b.6.2 S.6.2 3.U.2 U.U.2 1.+.2 3.5.3 1. +.1 2. +.1 2.*.3 1.5.2 i.+a 1.+.2 1.+.2 S.+.2 5.7.2 U.U.2 b.5.2 3.3.2 1.+.2 3.3.3 3 . * a i . + . i 1 . +.2 1.2.2 2. + . 1 1.3.2 2.3.2 2a. 2 1.5.2 3.U.2 3.6.3 3.2.2 bJt.2 •.2 %+.l 1.+.2 1 . * . ? 2. +.2 • . 1 2.2.2 •.2 1.+.2 135 Pnd 7 0 6 0 6 1 3 3 11 60 50 U5 25 20 IS 1 1 6 6 6 5 2 2 2 Pnd Pa Pad Pnd Pnd Pnd Pnd Pm Pnd H 0 0 B 0 B Pm Pnd 0 Ch a Ch B B ON eoatlmtad SYNTHESIS TABLE V, continued Subalpine Lysichitum association Plot number 18 126 127 U9 128 Ul 89 C layer, continued: Oymnocarpium dryopteris 2.?. 2 2.5.2 - - 3.U.2 U.5.2 1.2. Tiarella unifoliata +.2 — 1.+ .2 +.2 3.5.? 2.2.2 -Tiarella trifoliata 1.5-? _ 1.+.2 1.3.2 3.5.2 +.2 -Streptopus streptopoides - l.+.l 2.+ . 2 2.+. 2 2.3.2 -Habenaria saccata +.1 +.1 - +.2 1.+.3 2.+ . Cham* nootkatensis - - 1.+.2 1.+ .+ l.+.l 2.+ . Valeriana sitchensis - - - _ U.5.2 U.5.2 2.3. Viola glabella - - - - U.6.3 2.5.2 3.U. Parnassia fimbriate - - - - 1.2.2 1.2.3 U.U. Senecio triangularis - - - - l.+.l 1.+.2 3.3. Rubus sjctabilis - •.+ - - + .+ + .2 -Maianthemum dilatatum - + .1 l.+.l - 1.+.2 - -Mitella pentandra - - - 1.+.3 + .1 1.+. I«ptarrhena pyrolifolia - - - - 1.+.2 5.3. Epilobium alpinum - - - - - +.1 3.2. Linnaea borealis - - _ 3.U.2 - +.2 -Erigeron peregrinus - - - - - l.+.l 3.3. Nephrophyllidiun crista-galli - - 2.5.2 - 2.3.2 - -Agrostis aequlvalvis - - - - - + •+ 2.+. Goodyera oblongifolia. - - - +.1 + .1 - -Osjijorhiza purpurea - - - - + .+ l.+.l -Saacifraga arguta - - - - 1.+ .2 - I. + . Lycoporiiuiti cl3vatum - - - + •+ + .2 - -Carer spectabilis - - - - - +.+ !.+. Oault.heria ovali folia - - - - 3.2. Pyrola secunda - - - l.+.l +.1 - -Melica smithil - - - - - + .+ 1| + . D layer (humicolous): Mniiun nuduu 5.6.3 5.5.3 6.7.3 e. - . 1 7.7.3 6.6.3 _ Rhytidiadelphus loreus 3.?.? 5.6.3 U.6.3 5.3.7 5.6.3 3.U.2 2.3. Rhytidiopsis robusta 2.3.2 U.5.2 2.3.1 6.6.2 U.5.2 3.U.2 -Plagiothecium undulatum 2.3.2 U.U.2 5.6.2 2.2.+ U.3.2 -Sphagnum squarrosiim - 5.6.2 3.6.3 2.5.3 3.6.3 3.5.2 1.2. Dicranum fuscescens 3.3.2 3.3.2 2.3.1 U.U.2 3.3.2 3.3.2 3.3. Pellia epiphylla 3.2.2 1.2.2 1.2.2 2.5.2 2.2.2 U.5.2 2.+. Abies amabilis 2.+.1 2.+.1 2.+.1 2.+.1 l.+.l l.+.l -Plagiothecium elegans 3.3.2 1.3.2 2.2.2 - 2.2.2 +.+ -Mnium spinulosum - 3.3.2 2.2.2 1.2.2 1.3.2 • 1,2. Tsuga heterophylla 1.+ .+ l.+.l 3.1.+ +.1 - -Brachythecium as nerrlmum - — 2.?. 2 7.2.2 2.2.2 - -Lophocolea heterophylla +.2 - - 2.1.2 - 1.1.2 -Cephalozia media 1.1.2 2.1.2 - 1.1.2 — 1.1.2 -Chamaecyparis nootkatensis - +.• + .+ + .+ + .+ - -Plagiochila asplenioides - 1.1.2 - 1.1.2 - 1.1.2 -Lepidozia reptans 1.2.2 1.2.1 - - - 1.2.2 -Scwpania bolanderi - 1.1.1 - 1.1.2 - + .+ -Calypogeia trichoraaiis — 1.1.2 1.1.2 - - 1.1.2 1.2. KnJ.um punctatum - - - - - l.+.l 7.6. Drepanocladus fluitans - - - - - 1.1.2 U.3. Eurhynchium stokesii - - - 3.5.2 3.3.2 - -Campy Ilium stellatum - - - - - 2.2.2 2. 2. Conocephalum conicum - - - - 2.3.2 • ?. 2. Hypnum circir.ale - - - - - 2.2.2 ?. 2. Dicranum scoparium - - 2.2.2 1.3.2 - - -Pleurozium schreberi - -_ +.+ - 2. 2.2 -Baazania arnbigua - 2.2.3 - 1.1.2 - - -Sphagnum girgensohnii 2.6.2 - - 1.2.2 - - -Cerphalo«ia lammersiana 1.2.2 - - - - 1.2.2 -Plagiothecium denticulatum - +.2 - 1.1.2 - -Hypmin dieckii - 1.2.2 - - - -Bryum sandbergii - - - - - 1.3.2 1.1. Calypogeia neesiana 1.1.2 - - - - 1.1.2 -Prss 17 a 6 H 5 H 3 H 1 a 1 Pm 21 H 16 ri 10 H 5 H - Pnd _ 0 _ H 25 H 5 0 5 Ch t H 2 H 1 H H _ H H Ch _ H - Ch - Ch _ H 191 Te 96 w 60 w U7 M Ul Td 36 Te 18 Th U Pm 7 M 6 Te 5 Pm 3 K 1 Mt l Mt - Pm _ Te - Mt M Mt 50 Te Subalpine Oplopanax association 92 91 35 38 ?res. Fid. Tot. Life-f com CO. C layer, continued: Vaccinium alaskaense l.+.l 1.+.2 2.+.2 5 2 Pnd Strepttipus streptopoides 2.+ . 2 l.+.l 1.+ .+ 1.+.3 5 2 1 0 Vaccinium msmbranaceiim l . + . l 1.+.2 l.+.l l.+.l 5 - Pnd Listera isn.rrina + .1 +.1 + .+ + .1 5 2 - 0 Cornus canadensis 2.+*2 2.2.2 - 5.U.3 U 2 27 Ch Valeriana sitchensis 2.U.1 3.3.2 U.5.3 - U 2 16 H Habenaria saccata 3.+.3 - + .3 +.2 u 2 5 0 Sorbus occidentalis 2.*.2 +.1 - l.+.l u 1 Pnd Lycopodium clavatum + .+ 1.+.2 - 1.+ .5 u 3 - Oh Ribes lacustre 3.+ .2 - - + .+ 3 3 5 Pnd Linnaea borealis 2.3.3 - - 2.3.3 3 2 2 Ch Tsuga heterophylla - l.+.l l.+.l 3 - fro Clayt.onia sibirica 1.+.3 - 2.+.1 - 3 2 1 H Rubus spectabilis - 1.+ .2 +.2 - 3 - Pnd Ribes bracteosum - _ +.2 1.+.2 3 - Pnd D lqyer (humicolous): Rhytidiopsis robusta U.6.2 U.5.2 U.U.2 6.6.2 5 2 66 V Dicranum fuscescens 3.S.2 3.5.2 3.U.2 U.3.2 5 2 25 Te Abies amabilis 2.+.1 l.+.l 3.+.1 3.+.1 5 11 Pm HypmiTri eirclnelfl 2.3.2 2.U.2 2.3.2 3.2.2 5 2 8 M Scapania bolanderi 2.1.2 2.1.2 1.1.2 2.1.1 5 3 3 M Tsuga heterophylla + .1 l.+.l l.+.l l.+.l 5 - Pm Mnium nudum _ 7.6.2 7.7.3 2.3.2 U 2 101 Te Bryum sandbergii U.5.2 1.1.2 1.3.2 - U 3 10 Te Eurhynchium stokesii 2. 2.2 2. 2.2 1.1.2 - U 2 2 Mt Mnium punctatum 6.6.3 - 1.1.2 - 3 2 33 Te Rhytidiadelphus loreus U.3.2 2.3.2 - - 3 2 11 W Cephalozia media - - 1.1.2 2.2.2 3 2 1 Mt Calypogeia neesiana - 1.1.2 1.1.2 - 3 2 - Ht Moerclcia blyttii - 2.2.2 1.2.2 - 3 2 1 Th Cladonia coniocraea _ 1.+ .+ - 1. + .+ 3 2 - L Thuja plicata +.1 - - +.+ 3 Pm Ptilidium californicum 1.1.2 - 1.1.2 - 3 2 - Mt Hplophyllum taxifolium 1.1.2 - +.2 - 3 2 _ t Plagiothecium undulatum 1.2.2 - +.2 - 3 2 - M Sporadic species: A layer: Pm Pseudotsuga menziesii 33(U.+.l) B layer: Pnd Ribes lacustre 92(3.6.2) 1 C layer: H Adenocaulon bicolor 38(+.l) H Agrostis alba 92(l.+.l) H Carex laevicuTmis 92(l.+.l) G Corallorhlza mertensiana 38(+.+) H Lusula parviflora 91(+.l) G Lysichitum americanum 92(1.+ .+ ) H Mitella pentandra 92(1.+.l) Ch Mooeses uniflora 38(1.+.2) H Polystichum munj+.um 38( + .+ ) Pm Pseudotsuga menziesii 3fl(+.+) Pm Sambucus pubens ?2(+.l) H Senecio triangularis 35(2.U.2) C layer, continued: H Stellarla crispa 92(+.l) Pm Thuja plicata 38C+.1) Pnd Vaccinium ovalifolium 91(+.2) layer (humicolous): Mt Lophocolea heterophylla 92(1.1.2) M Plagiothecium elegans 91(2.2.2) L Cladonia bellldiflora 92(+.+) M Plagiothecium denticulatum 35(+.2) M Brachythecium asperrimum 35(1.1.2) V Rhytidiadelphus squarrosus 35(+.2) Mt Lophozia porphyroleuca 35(1.1.2) Mt Heterocladium irocurrens 91(2.2.2) t Dicranella heteromalla 91(2.2.2) M Baszania arnbigua 35(1.1.2) t Pohlia nutans 35(+.2) t Polytrichum +uniporinum 91(1.1.2) Te Pogonatun urnigerum 35(1.3.2) M Hookerla lucens 91(2.1.2) Te Pogonatum contcrtum 91(1.2.2) Te Pogonatum alpinum 92 (+.2) SYNTHESIS TABLE VI Plot number Vaccinium membranaceum - Rhododendron association (Taugeto - Vaocinletum meabranacel) 165 80 110 120 67 57 60 6U 119 Plot size (acre) Date Locality (see legend) Latitude Longitude Landform (see legend) Slope above (est. ft.) Area of assoc. (acre) Altitude (ft.) Aspect Slope (degrees) Wind exposure (A-B-C) Snow cover (months) % coverage: By vegetation layer By decayed wood By rock Tallest tree on plot (ft.) Western hemlock Mountain hemlock Amabilis f i r Yellow cedar Regeneration (no./sq. meter)1 Mountain hemlock Amabilis f i r Yellow cedar Total soil depth (cm.) Depth to bottom of An (cm.) Depth to seepage, i f present Remarks 39 • 1/5 VS 1/5 1/5 1/5 1/20 1/10 1/10 1/10 23/8 25/8 5/8 22/8 2U/8 12/8 12/8 11/8 21/8 I960 I960 1961 1961 I960 1961 I96I 1961 1961 RM RM Lions Dla. H RM RM RM RM Dla. H 1»9 U6 U9 1»6 U9 27 U9 U8 U9 U6 U9 U8 U8 U7 U9 li7 U9 I»9 123 02 1 23 02 1 23 1 2 1 22 59 1 23 02 1 22 59 1 23 00 1 23 00 1 22 59 2 75 1 2 75 1 I1600 I1600 w w 27 25 8-5-3 8-6-U A layer: Tsuga mertensiana Sub-layer 1 2 3 No. trees over 3 in./acre Basal area, sq. ft./acre Gross volume, cu. ft./acre 8 ) 3 0 35 U5 5 90 92 8 Uo U 1 UU 82 57 62 1 2 76 15 15 20 22 So 20 85 90 8 25 3 1 29 6 2 88 70 ? 38 21 3 2 75 1 2 3880 U700 flat S60E UU 8-5-2 8-6-3 H 8* 1/5 2 100 1/20 3 1/2 U8U0 U850 5000 flat W flat 25 8-3-1 9-8-7 9-7-3 8 8 8 75 135 20 80 7 80 85 U 70 1 2 72 3 U 57 75 60 58 28 19 9 ? ? ? Abies amabilis No. trees over 3 in./acre Basal area, sq. ft./acre Gross volume, cu. ft./acre )6.7.2 5.7.2 155 188 j 3153 j J -! U.+ . l 1 85 i U3 ! 5U7 | 8 .8 .? u.7.2 3.+.1 120 22U 5023 +.1 3.+.1 U.7.1 100 53 997 Chamaecyparis nootkatensis No. trees over 3 in./acre Basal area, sq. ft./acre Gross volume, cu. ft./acre ;u.+.+ U.+ .+ uo 709 30 58 988 180 26U 5192 3.+.1 70 26 360 1~ U.+.l us 20 331 Uo 50 25 80 95 3 8 1 1 10 3 12 103 101 75 10 )U.+.2 5.7.2 105 lit? 3003 )5.+.2 5.7.1 105 181 UU51 25 25 30 65 30 80 90 2 UO U 1 UU 10 1 81 67 Uo lit Uo J60 70 3 75 75 20 65 1 66 10 82 80 61 6 5.7.2 7.8.1 5.7.2 ) , a . 255 55 23U ? 5060 7 50 80 8 70 70 U 8 2 10 20 72 62 UU 35 7.8.1 )7.8.1 120 7 7 3 1/5 1 5060 5600 5 SUOE 6 10 9-7-3 9-8-7 8i 9 U5 J60 80 25 80 90 6 5 2 10 63 60 57 30 ) no ) 10 55 25 70 60 20 1 a 10 22* 50 10 Alpine f i r 6.8.1 ) 7.8.1 105 7 7 )U.7.1 ) 170 ? ? 3.+.1 +.1 +.1 3.+.1 5.'?:2 W'1 J 5 ' * ' 1 )5.*.l 180 35 35 70 10U ? 2 1 17U1 ? ? 7 Pres. Fid. Tot. Llfe-o.d. form J 2 601 Pm 2U0 Pm 31 Pm Totals, Including sporadics: No. trees over 3 in./acre Basal area, sq. ft./acre Gross volume, cu. ft./acre B layer: Vaccinium membranaceum Tsuga mertensiana 280 250 310 269 335 3U7 UU09 7008 6581 210 U35 323 338 7U5U 6901 90 155 175 230 Abies amabilis Rhododendron albiflorum Vaccinium deliciosum Vaccinium ovalifolium Sorbus occidentalis 5.6.1 2.6.2 3.6.1 7.8.3 5.6.3 U.5.1 5.6.3 U.+.l 2.6.1 U.6.1 l.+.l 2.6.3 6.7.3 2.6.3 3.+.1 1. +.+ 2. + .+ U.+.+ 2.+ .1 8.7.2 +.1 1.5.2 1.+ .2 7.7.3 7.7.3 8.8.2 5.7.3 8.7.3 U.6.1 5 3 335 Pnd U.6.1 5.7.2 • . • U.7.1 U.6.1 7.6.+ 5 1UU Pm U.+.l 3.+.1 l.+.l 2.+.1 l.+.l U.6.1 U.6.+ U.6.1 U.7.2 + . • + •+ - 5 68 Pm U.+.l 1.+.+ 2.+.1 1.+.+ 2.+.1 -2.6.? - - - - - U U 298 Pnd 6.7.3 7.7.3 - 7.8.3 - 3.6.2 - 2.6.2 5.5.2 2.5.2 U.6.3 1.3.3 U 2 63 Pnd - +.+ - - - - 3 2 15 Pnd Pnd 2.+.1 continued 164 SYNTHESIS TABLE V I , c o n t i n u e d V a c c i n i u m membranaceum - Rhododendron a s s o c i a t i o n P l o t number 39 80 110 120 67 57 60 6U 119 P r e s . F i d . T o t . c d . L i f e -f o r m S u b -IS l a y e r , c o n t i n u e d : l a y e r V a c c i n i u n a l a s k a e n s e 2 C h a m a e c y p a r i s n o o t k a t e n s i s 1 2 H a n z i s s i a f e r r u g i n e a 2 1.+.+ U.+.? 5.6.? 3.+.1 3.6.1 5.7.? +.+ 1.+ .+ +.+ - - - - - 2 2 2 1 1 50 20 Pnd Pm Pnd C l a y e r t P h y l l o d o c e e m p e t r i f o r m i s 1.2.1 1.+.+ l . ? . l +.+ 1.3.2 U.5.? 1.3.? 3.5.? 6.6.? 5 ? U8 Pne V a c c i n i u m d e l i c i o s u m U.+.l U.5.2 - 1.+ .+ 1.+ . ? U.6.? 2. ? . ? 2.6.2 3.3.? 5 37 Pnd V a c c i n i u m membranaceum 3.2.2 3.3.? ?.+.+ 2.+ . ? 2.+.? 3.+.? 3.+.? 2.3.2 U.U.l 5 3U Pnd C a s s i o p e m e r t e n s i a n a 1.+ .+ +.+ -— 1.+.+ 1.+.+ 1.3.1 +.+ 5.5.? U 2 25 Pne l u e t k e a p e c t i n a t a 2.+.1 . - - l . + . l 1.+.1 1.3.? l . + . l 3.?. 3 U 2 11 Ch A b i e s a m a b i l i s 1.+.+ 2.+.1 2.+.1 1.+.+ — 1.+ .+ + .+ - U 3 Pm RubUB peda tu s 2.+.1 3.2.2 + .+ - - l .+ . l - -2.+.1 3 2 7 C h T s u g a m e r t e n s i a n a + .+ — + . • - -+ .+ - 3 -Pm Rhododendron a l b i f l o r u m - 2.+.1 1.+.+ - - - -— -2 1 Pnd C h a m a e c y p a r i s n o o t k a t e n s i s l .+ . l l . + . l +.1 - - - - -2 -Pm S o r b u s o c c i d e n t a l i s + .+ 1.+ .+ - - - - - - -2 -Pnd D l a y e r ( h u m i c o l o u s ) : R h y t i d i o p s i s r o b u s t a U.3.? 3.U.? 6.6.3 ?.?.+ 2 . 2 . ? 1.2.1 ?.U.l 1.3.+ - 5 2 51 W O r t h o c a u l i s f l o e r k i i 3.U.? 2 . 1 . 2 1 . 1 . • U.3.2 2.+.1 1 . 2 . 2 2.1.1 3.?.? 5 2 33 Mt D i c r a n u m f u s c e s c e n s _ _ 6.6.3 U.3.2 - 7.6.2 U.5.2 3.5.? U.U.l U 2 118 T e C l a d o n i a b e l l i d i f l o r a - 2 . 1 . ? 1.+.+ 2 . 2 . 2 -— 1 . 1 . 2 2 . 1 . 2 3 2 3 L C r o c y n l a membranacea l . + . l l . + . l - — + . 2 - +.? - 2 . 2 . 2 3 ? 1 L C l a d o n i a c a r n e o l a l . + . l — — - l . + . l - +.? 2 . ? . ? — 3 ? 1 L C l a d o n i a p l e u r o t a l . + . l l . + . l - l . + . l - • . ? 2 . 1 . 2 — 3 ? 1 L D i c r a n u m s c o p a r i u m 5.5.3 S.5.3 - - 5.6.2 -— - -2 ? 75 Te A b i e s a m a b i l i s +.+ — 2.+.1 - - 1.+ .+ - - -2 - Pm C h a m a e c y p a r i s n o o t k a t e n s i s l . + . l - l . + . l - - - - - -2 -Pm P t i l i d i u m p u l c h e r r i m u m 1 . 1 . 2 l . l . ? +.+ - - - - - -2 1 -Mt Hnium s p i n u l o s u m + .+ +.? - - - - - - -2 1 -T e P l a g i o t h e c i u m e l e g a n s - - -2.1.1 — 1 . 2 . ? — - -2 2 -M Hypnum c i r c i n a l e 1 . 1 . ? l . l . ? - - - - - - -? 1 -M P l a g i o t h e c i u m d e n t i c u l a t u m - • . ? - 1 . 1 . ? - - - -2 1 -M L e s c u r a e a b a i l e y i - l . l . ? — — 1.3.2 - - - -? 2 -Mt R h a c o m i t r i u m h e t e r o s t i c h u m - - 1.3.? 1.1.1 - - - - - 2 2 - Te C e t r a r i a i s l a n d i c a - 1 . ? . ? - - 3 . 2 . 2 3.1.2 - - - ? 2 -L B r a c h y t h e c i u m s p . - +.? -— - - • . ? - 2 2 -M Bryum s p . - — — — - 1.1 .1 U i . 2 - -? 2 -T e P o h l i a n u t a n s - l . l . ? - - - - 1 . 1 . 2 -— 2 2 -t B a r b i l o p h o z l a l y c o p o d i o l d e s 1 . 2 . 2 1 . 2 . 2 — - - - -— - 2 2 - Mt C l a d o n i a squamosa 1.1.1 1.+.? — - — — — 1 . ? . ? -? 2 -L S p o r a d i c s p e c i e s : A l a y e r t Pm A b i e s l a s i o c a r p a 119(U.6.+) Pm P i n u s m o n t i c o l a 110(+.+) Pm T s u g a h e t e r o p h y l l a 110(+.+) B l a y e r : Pm A b i e s l a s i o c a r p a 119 (U .6 .+ ) C l a y e r t 0 C l i n t o n i a u n i f l o r a 3 9 ( i . + . l ) 0 C o r a l l o r h i z a m e r t e n s i a n a 1 1 0 ( + . l ) C h Q a u l t h e r i a h u m i f u s a 1 1 0 ( 1 . 3 . 2 ) C h Lyaopod ium s i t c h e n s e 1 1 9 ( 1 . 2 . 2 ) H S t r e p t o p u s r o s e u s 1 2 0 ( 1 . + . 1 ) Pnd V a c c i n i u m a l a s k a e n s e 110(2.+.+) 0 V e r a t r u m e s c h s c h o l t z l l 39(+.+) D l a r y e r , h u a d c o l o a s : Mt B l e p h a r o s t c a s a t r i c h o p h y l l u m 67(1.+ .+) L C l a d o n i a r a n g i f e r i n a 39(+.+) t D i p l o p h y l l u m p l i c a t u m 8 0 ( 1 . 1 . 2 ) Mt L o p h o s l a p o r p h y r o l e u c a 8 0 ( 1 . 1 . ? ) T e P l a g l o c M l a a s p l e n i o i d e s 39(+.+) W P l e u r o s i u m s c h r e b e r i 1 1 0 ( 1 . 1 . 2 ) T e Pbgonatum a l p i m i m 8 0 ( 1 . 2 . ? ) t P o l y t r i c h u m p i l i f e r u m 1 1 9 ( 1 . 1 . ? ) L S t e r e o c a u l o n tomentosum 67 ( 1 . 1 . 2 ) Pm T s u g a m e r t e n s i a n a 110(+.+) 165 SYNTHESIS TABLE VII Dwarf Tsuga association (Han o-Tgug«tuJo martansianae) typical subassociation (subassoc. nano-tsuRstoaum mertensianae) : number 30 113 m 97 Luetkea subassociation (subassoc. luetkeetosum paotlnatae) UO 6l "~09 W 100 Plot size (acre) Date Locality (see legend) Latitude Longitude Landforra (see legend) Slop* above (est. ft.) Area of assoc. (acre) Altitude (ft.) Aspect Slops (degrees) Wind exposure (A-3-C) Snow cover (months) % coveragei By vegettt ion layer By decayed wood By rock Regeneration (no./sq. meter). Total soil depth (cm.) Oepth to bottom of A^  (cm.) 1/5 2U/8 1959 SH U9 23 122 57 h 3A lioij S80E 10 0-3-6 7 65 80 35 50 1 10 6o 1 20 1/50 16/8 1961 Oar. U9 U8 123 00 2 500 l/20 5000 E 15 0-8-5 « 15 60 70 85 70 1 70 i/M> 1A0 22/8 20/9 1961 I960 Oar. 0 ii9 U9 U9 2li 122 56 1 23 05 2 2 300 1/10 1/30 5100 UUoo S20W N60W 23 16 0-3-2 0-3-5 70 80 US 15 2 17 S 85 95 80 70 10 80 1/20 17/8 1961 RM Ii9 U7 122 59 2 500 1A0 14750 S15W 7 0-3-6 8* 1 60 60 85 70 1A0 8/9 i960 SM ll9 22 l?2 57 2 90 1/5 3310 N30E 13 0-6-U 7 55 55 90 60 U8 6 2b 3 51 5 Uo 5 1/20 1A0 7/9 2U/8 i960 I960 RH KM U9 U7 U9 U6 123 00 123 02 2 70 1 2 200 1 5050 I182O V N 26 7 0-6-S 0-6-5 H 8J 50 50 90 50 1A0 30/8 i960 RM U9 U6 123 02 2 200 VS U725 N50V 22 0-7-5 « 1A0 20/9 I960 0 U9 2U 123 05 2 250 1/5 !i230 H50E 30 0-6-U 8i 1 60 60 10 1.6 55 5 _ _ 2 UO 20 8 Uo 20 10 95 70 95 60 70 1 _ 5 1 60 75 2 - 30 1 non. . . . 36 60 82 12 2 8 - 5 7 Sporadic species layer! Pnd Cladoth. pyrolaeflorus 30(3*6.1) Pnd Vacciniun ovalifoliua 30(+.l) C layert H Blechnum spicant U0(+.+) H Carex pyrenaica 30(+.l) Pnd Cladoth. pyrolaeflorus 30(1.+.1) H Juncus drunmondil 30(+.l) Pnd Henaiesla ferruginea 30(+.+) H Pedic. ornithoiyacha 121(+.l) H Saxifraga ferruginea 30(+,l) Ch Rubus pedatus 30(1.+.1) D layer (humicolous). Pm Abies amabilla 97(+.+) Mt Calypogeia sp. 69(2.1,2), 100(+. Ht Cephalozia leucantha 69(1.+.+) L Cladonia coniocraea 69(3.+.?) L Cladonia rangiferina 40(2.5.1) L Cetraria islandioa 69(J.f.l) t Diohodontium olymploum 6l(j.4.2) Te Dicramim scbparium 30(2.3.2) L Lecidia granulosa 61(1,1,?) Ht Lophozia inciea 7U(U.?.?) Ht Gyimcfnltriiim varians ll6(l. ?,?) Te Mnium nudum 100(1.1."?) Mt Nardia scalaris 6l(l,}.?) Te Ollgotrlchum parallelum 100(1.1. W Pleurozium schreberi U0(1,1,?) Te Pogonatuin'alpinum 1.0(1, ?»?) t Polytrichum Juniperinum 30(+.2) t Polytrlchon norvegicom 69(1.?. 2) Subassociation Subassociation Entire association Sub- Pres. Char. Pres. Char. Pres. fid. Tot. Life. B layen layer cd. cd. cd. form Tauga raertenaiana 1 5.6.1 5.6.1 5.6.1 U.+.+ 5 91 _ _ 1.5.+ 5 37 5 2 6U0 Pm 2 7.7.1 8.3.1 8.7.1 9.3.+ 8.7.+ 7.«.+ 7.7.+ 7.6.1 5.5.1 U.U.+ Vaccinium deliciosum 2 2.6.2 2.U.2 U.5.3 - - 3 u - - - 2. + .1 +.1 2 - 2 15 Pnd 7acclniura membranaceum 2 3.5.2 - - - - 1 5 - - 1.+ .+ - + ,+ 2 - 2 5 Pnd Sorbus occidentalis 2 2.*. 2 _ l.+.l - - 2 1 - - - 2.».+ 1 1 2 2 2 Pnd Chamaecyparis nootkatensis 1 2.*.1 - - - - 2 1 - - - - - ] 1 2 1 2 Pm 2 1.5.1 + .+ - - - 2.+.+ - - - - -Abies amabilis 1 1.*.* - - - - 1 - - - - - - 2 - 2 1 - Pm 2 + .+ - _ _ _ _ _ _ Pinus monticola 2 •.0 - - - - 1 - + .+ - - - - 1 - 2 1 - Fta C layen Phyllodoce empetriformis 5.6.2 5.7.3 5.5.2 6.6.3 6.5.2 5 28 8.7.3 7.7.3 7.6.3 1.2.1 U U3 5 2 316 Pne Cassiope mertensiana 2.U.2 6.7.3 U.U.2 7.6.3 7.7.3 5 29 7.6.3 7.7.3 7.6.3 3.U.3 - u 39 5 2 299 Pne Luatkaa pectinata 3.5.2 3.U.2 2.+. 2 U.*.2 2.2.3 5 u U.3.2 3.3.2 3. 2.2 7.7.3 8.3.3 5 29 5 3 168 Ch Tsuga mertensiana 2.5.1 5.U.2 2.».1 U.+ .+ S.5.+ 5 1 2 3.+.+ 5.3.+ U.U.2 6.3-1 1.+.+ 5 15 5 125 Pm Vacciniun delicinsum 5.6.2 3.U.2 U.U.2 1.+ .+ 1.3.1 5 8 U.3.? 2.+.1 U.3.1 l.+.l 3.6.1 5 5 5 2 6 6 Pnd Deschampsia atropurpirea •.1 1.+.2 + .2 l.+.l +.1 5 - l.+ .l 2.+.? l.+.l 2.+. 2 6.6.2 5 7 5 u 35 H Lycopodium sitchense 3.3.2 U.5.3 3.3.2 2.3.2 2.3.2 5 u 3.3.2 3.U.2 - - - 2 5 U 2 32 Ch Vaccinium raembranaceum 2.5.1 l.+.l - 2.+ .+ - 3 - . 1.+ .+ + •+ 1.+ .+ - 3 _ U 2 2 Pnd Hippuris montana - - - - - 0 1 1.2.2 1.3.2 2. + .1 6.7.3 6.6.3 5 1 3 3 3 67 H Chamaecyparis nootkatensis 1.*.* - - - _ 1 _ 1.+ .+ _ 1.+ .+ 2.+ .+ 3 _ 3 1 Pm Sorbus occidentalis l.+.l _ _ _ 2 _ _ _ + • + 1.+ .+ 2 _ 3 _ Pnd Hleracluni gracile l.U.l - - 3 _ _ 1.+.2 -_ 1 - 3 2 _ H Carex nigricans - - - - - 0 - 1.+ .+ - - U.3.? - 2 5 2 1 10 H Veratrum aschscholtsil _ 1.+.+ _ _ 2 _ _ 2.*. 2 1 1 2 1 1 0 Abies amabilis — -_ _ 1 _ _ 1.+ .+ 1.+ .+ 2 _ 2 _ Pa Oaultbarla humifusa l.tl.2 - - 1.3.2 _ 2 _ 1.+.2 -_ 1 _ 2 2 _ Ch i Erigeron peregrinus - - - 2 - - - - - 0 - 2 1 - H D layer (humicolous)l Orthocaulis floerkii 2.3.2 2.2.2 3.2.2 5.3.2 6.3.2 5 1 3 5.2.2 U.3.2 U.3.2 6.5.2 _ U 1 9 5 2 1U3 88 Mt Dicranum fuscescena 1.2.2 1.2.1 U.U.2 6.5.2 U.U.2 5 11 3. 2.2 3.2.2 5.3.2 U.U.2 _ u 11 5 2 Te Rhacomitrium heteroatichum 6.5.2 - - U.U.2 6.6.3 3 25 5.2.2 3.2.2 - 3.2.2 3 12 U 2 111 Te ; Cladonia bellldiflorai 1.1.2 - - 1.1.+ 3.2.2 3 2 2. 2.2 1.1.1 2.+.1 _ 3 1 U 2 7 L Kiaeria falcata - 3.2.2 - U.3.2 - 2 7 6.U.2 3.2.2 2.2.2 _ 3 1 3 3 2 53 t Kiaeria blyttll - 2.2.2 2.1.2 - 2.3.2 3 1 - - -_ U.1.2 1 10 3 2 1 3 t Rhytidiopsis robusta 2.3.1 - - 2.3.1 - 2 1 2. 2.2 2. 2.2 3. 2.2 _ 3 2 3 2 9 W Crocynia membranacea 2.2.2 1.3.2 1.3.2 - 3.U.2 U 1 - 2. 2.2 _ _ 1 1 3 2 7 I Cladonia plaurota - 1.1.2 2. 2.2 -— 2 1 - 1.+ .+ 1.1.2 _ _ 2 _ 3 2 1 L Cladonia squamosa 1.1.2 1.1.2 1.1.+ - 1. 2.2 U - -_ _ _ 0 _ 3 2 _ L Rhacomitrium varium - 7.5.3 - 3.3.2 - 2 27 _ _ _ _ 0 _ 2 2 55 Te i Lophozia porphyroleuca - - - 1.2.2 - 1 - - - U.2.2 5. + .2 - 2 1 7 2 2 35 Mt Rhacomitrium canescens U.U.2 - _ _ 1 1 0 _ 5.U.2 _ _ 1 25 2 2 35 Te Pellia neesiana - - - - - 0 _ _ l.+.l U .*.2 _ 2 5 2 2 10 Th Pohlia drummondi - 1.1.2 - - 3.3.2 2 2 _ _ 1.1.2 1 2 2 5 t Stereocaulon tomentoaum 1.1.2 2.'.2 _ _ _ 2 _ 3.1.2 _ _ 1 5 2 2 6 L Marsupella sparslfolla 2.2.2 2.2.2 _ _ _ 2 1 2.3.2 _ 1 2 2 3 Harpanthus scutatus - 2.2.2 -_ 1 1 _ 2.3.2 _ _ 1 1 2 2 2 Plagiothecium denticulatum 1.1.1 - - -_ 1 _ n . i _ 1.2.2 2 1 If Diplophyllum taxifolium - - - 1.1.2 _ 1 _ 1.2.2 _ _ 1 2 2 Diplophyllum plicatum — — - 1.1.2 _ 1 _ _ _ _ 1.1.2 1 2 2 t Anastrepta orcadensls - - - - 0 _ _ 1.1.2 1.1.2 1.1.2 3 _ 2 2 Mt Cladonia chlorophaea 1.1.2 1.1.2 - - 2 - - 0 - 2 2 - L 166 11 5 u 1 t rt o H 1 en n rt 31 ! 0 ( 0 H n £- CM S H O O . _3 SB o i n UN i I | p C O ^  1 1^ 1 1 4S* «>• c-i m^Cu H C l H • ^ **\ CN • rH • • • • • • • • o t » * « 1 § ci CM CM 4 + + + • • • • • • • -3 ci H -3 rl«"^ CS) H Cs. 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Tl *S S I f i l ! p i l l f-i £ £ £ £ O UN ll •H « n c 1! O W 5 £ 8 « CO i t E 3 rt 167 SYNTHESIS TABLE IX Plot number Phyllodoce - Cassiope association (Phyllodoceto - Cassiopeturn mertenalanas) 75 1 33 Plot else (aore) Date Locality (see legend) Latitude Longitude Landfona (see legend) Slope above (est. f t . ) Area of assoc. (aore) Altitude (ft .) Aspect Slops (degrees) Wind exposure (A-»3-C) Snow cover (months) % coverage! By vegetation layer A B l 2* c By decayed wood By rook flegeneratlon (no./eq. meter) Total s o i l depth (cm.) Depth to bottom of A n (cm.) Depth to seepage, i f present 62 5 3 96 98 1/20 1/10 l A o l A o 7/9 6/9 JO/9 20/9 I960 I960 19«0 19*0 RH BH a a 99 11/9 1959 'U9 23 U9 U7 U9 U8 U9 2U U9 A U9 2U U9 I16 Ii9 U8 U9 23 U9 23 Ii9 22 U9 23 U9 23 U9 2U U9 ?U 122 57 1 23 00 1 23 00 1 23 05 1*3 05 1 23 05 1 23 02 1 23 OO 122 57 122 57 122 57 122 58 122 56 122 57 122 57 129 130 23 1A0 1A0 1/5 3 A o 3 A o 29/7 1961 1961 1959 SB SK SM 31 US U6 1A0 22/7 19<0 1A0 10/9 1959 1A0 2T/7 i960 1A0 21/7 i960 SM SM SM SM 2 2 2 2 U 2 2 2 2 2 u 120 60 200 300 Uo 120 300 500 150 70 none 1/2 2 15 1/5 1/5 1/2 V U o 10 l A " l/20 1/3 3 8 2 5 5100 U7S0 U370 U100 U250 U600 5075 U o o o 3950 3630 S25W w N 5 0 V NliOB r u t N N5CW SBOE sUow s6ou f l a t 10 12 9 I U _ 26 9 I U 11 18 -0-7-5 0-0-6 0-0-7 0-6-5 0-9-8 0-5-5 0-7-5 0-0-6 0-5-3 0-7-5 6-5-2 71 8 1 9 8 1 8 1 9 8 9 8 8 7 1 5 9 1 - 7 u 2 5 -1 20 18 1 25 9 1 • 7 u 2 5 - 21 18 25 90 90 90 90 95 95 98 96 90 90 60 35 U5 70 70 50 80 65 60 8 5 f° 50 U . . 5 _ _ * m - it SU 30 39 U5 70 75 50 80 65 60 8 5 8 0 5 1 1 - 8 - 1 - -nono ? 10 Uo 1 55 32 38 61 U7 8 5 51 Uo ? 53 35 S 8 5 5 3 26 3 7 7 13 T » - - Uo - - 37 - ? ? -1 30 1/50 U none 1/2 none none 1A0 1/5 3760 UU10 MlOB N6CV U60O f la t 1,600 S708 20 81 81 - _ 8 3 5 1 20 20 5 1 25 20 90 65 50 80 75 Uo 30 30 5 15 20 3 80 55 50 33 a 6 26 16 3 layeri Sub-layer Pres. F id . Tot. U f a -Tsuga mertensiana Cham, nootkateruilfi Vaccinium mambranaceuin Vaccinium deliciosum Sorbus occidentalis 3.5.1 U.5.3 C layeri D layer (humicolous)! Dicranum fuscescens Orthocaulis f loerk i i Rhacomitrium heterostichum Crocynia membranacea Kiaeria falcata Rhytidiopsis robusta Bryum ap. Cladonia be l l id i f lora Oymnomitrium varl*ns Harsuptlla sparsifolla Rhacomitrium canescens 2.5.+ ?.+.• 2,3.+ 1.3.+ 1.+.+ 1.+.2 +,+ u.5.1 +.+ _ •.1 U.6.1 _ U.5.+ U.6.* U.S.* - - 1.6.1 — ?.+.+ U.6.1 • + •+ - l . l i . l U.6.3 U.6.3 1.3.2 1.3.3 - - •.1 -U.6.* c d . form U 2 68 Pm 3.5.* 3 2 52 n» 3.5.+ 3 6 Pnd • 2 30 Pnd + .+ 2 2 Pnd Phyllodoce empetrlforrais 3.7.3 8.9.3 7.6.2 9.9.3 9.7.3 9.9 .3 7.6.3 6.5.3 7.6.2 6.6.3 6.6 .1 8.7.3 5.6.2 U.6.2 7.7.3 5 3 8U9 Pne Cassiope mertensiana U.5.3 U.5.2 8.7.3 6.5.? 7.6.2 7.5 .'? 6.6.3 8.9,T U.5.1 U.3.2 7.6.2 9.8.3 8.6.3 5.6.3 7.7.3 5 3 651 Pne Vaccinium deliciosum 7.7.2 • .+ +.1 3.+ .+ 3.3.+ 2.+ .+ U.U.I 2.3.1 7.6.3 6.6.3 U.3.2 3.U.3 2.5.2 3.6.3 6.7.3 £ 2 209 Pnd Luetkea pectinata 2.3.2 U.3.2 U.3.2 5.U.3 U .2 .2 U.+ .2 3.+.2 U .2 .2 U.+ .2 5.+. 2 2.3.2 2.1;. 2 3.3.2 +.1 3.U.1 5 2 1S6 Ch lycopodium sltehense U.3.2 5.5.3 5.U.3 1.+.+ 1.3.2 + - 5.5.3 - 1.+.+ 1.2.1 2.U.3 +.2 - + » + U 3 86 Ch Vaccinium membranaceum 2.3.2 - + • + 2.+.+ 1.+ .+ 2.+ - - 2.+.1 - • • • 1.2.2 3.5.2 2. + .+ U 2 20 Pnd Tsuga mertensiana 3.+.1 2.*.+ - 2.*.+ 3. 3.+ 2.* .+ 1.+.+ - - 3.+.+ +.1 - +•• - - 3 13 Pa Desonampsia atropurpurea l . + . l - +.1 2.+. 2 l . + . l • .1 l . + . l - - - - 2.+.1 - - 3 2 1 H Chamaecyparis nootkatensis - - • - +•+ - 2.+.+ - * 3.+ .+ — • •+ •.+ - 2 6 Ps Carex nigricans - 3.2.2 - • 1.U.+ - 1.5.1 _ 2.U.2 - 1.1.2 1.2.1 - - - 2 1 6 H Rubus pedatus 1.+.2 - - - - - - - 3.+. 2 l . + . l +.1 — - +.1 - 2 1 5 Ch Klppurls montana - - - 2.2.2 l . + . l 2.+ .2 +.2 - - - - - - - - 2 1 2 H Qaultheria humlfuaa - 1.+.2 - +.2 - - 1.+.2 - - - - - - - 2 2 - Ch Carex spectabilis 1.+ .+ - • - - + . • _ _ -_ l . + . l + .1 2 1 H Sorbus occidentalis +.+ - - + • • - - - • • + - - - - - 2 - Pnd 3.3.2 - 6.1,.? 3.U.2 5.5.3 7.5.3 6.5.2 _ 7.6.3 5.6.2 U.3.2 8.7.2 5.U.2 3.6.2 1.2.2 5 2 3U1 Te 3.2.2 - 7.5.1 U.3.2 u.3.3 6.U.3 U.1.2 3.1.1 5.5.3 U.3.2 3.2.2 U.3.1 3.2.2 3.6.2 3.3.2 5 2 1 8 8 Mt 3.2.2 1.1.+ U.3.2 6.5.2 U.3.2 U.3.2 2.1.2 • - - 3.3.2 5.3.2 1.+.2 3.2.2 2.U.1 3.3.2 U 2 100 Te 1.1.2 U.U.2 • 1.2.2 _ 1.1.2 U.3.3 _ 1.1.2 1.1.2 _ 1.3.2 _ 2.1.2 U 3 31 L - 5.3.2 3.2.2 6.5.3 3.3.2 3.1.2 _ 6.U.2 _ _ _ _ 2.6.2 5.U.2 3 3 1 3 2 t 2.3.2 - - - - 3.2.2 5.2.2 - 2.1.2 2.2.2 + .1 1.1.2 _ 3.6.2 _ 3 1 38 w 3.U.2 - - U .2 .2 1.2.2 3.3.2 - - - 2.2.2 • - 1.1.2 3.5.2 1.3.1 3 2 21 t 2.1.2 + •• 3.U.2 1.1.1 - - — 3.+. 2 2.*. 2 _ l . + . l 3.2.2 _ _ 3 2 1 7 L - U.U.2 2.3.2 3.U.2 - * • 5.3.2 - - _ 2.2.2 2.2.2 _ 2 2 U3 t - - - - - - - - - - 3.3.2 2.5.1 1.2.2 - 2.5.2 2 2 12 t - - - - - - - - - 1.2.2 3.2.2 1.1.2 - 1.2.2 2 2 5 Te Sporadic spades! A layeri Pm Tsuga mertensiana 23(+.2) B layeri Pm Abies aaabilis 31(+.+)| 129(+.+) Pnd Clado. pyrolaeflorus U5(+.+)l 96(1.3.+) Pnd Menslesla ferruginea 23(+.l) Pm Pinus monticola 23(+.+ ) Pnd Vaccinium ovalifolium 99(+.+ ) C layeri Pm Abies amabilis 96(1.+.+) H Caltha leptosepala 75(1.*.1) Pnd Clado. pyrolaeflorus U8(+.+)j 96(1.+.*) H Hleraoium graclle 31(2.+.1)1 53(+.l)l 12?(+ H Juncus drummondii 31(+.+)j U6(+.+)| tt5(+.+) H Leptarrhena pyrolifolia 75(*.*) C layer, continued! Pne Phyllodoce glandulirlora 112(1.1,.3) Pm Pinus monticola 3K + . + ) Pnd Rhododendron albiflorum 62(+,+) H Saxifrage ferruginea 31(+.+)l 23(+.2)l U 8 ( + . * ) Pnd Vaoclnlum ovalifolium U8(+.*)i 99(+.+) 0 Veratrum eschscholtsil 23(+.l) D layer, humicolcjst Pm Abies amabilis U6(*.*)i U9(+.+)| o6(*.*)) 130(+.+) Mt Calypogeia neesiana 96(1.1.2)| 99(1.1.2) L Cetraria Islandica 129(2.*.2) L Claionla graolllB 23(1.1.2) L Cladonia plsurota 23(1.1.2)) 53 ( 2.3. 2) 112(1.1.2) L) L Cladonia ranglferlna 23(1.3.2)| U6(3.3.2) L Cladonia squamosa 23(1.*.3) t Dichodontlttm olympioum 53(1.1.2) I layer (humicolous), continued! Te Dicranum scopartum 33(5.U.3)| U3(2.U.2> t Diplophyllum taxl f . 96(1.1.2)j 130(1.2.2) Mt Oymnomit. conclnnatum 23(1.1.2)|96(1.1.2) Mt Harpanthus ecutatue 96(1.1.2) M Hypnum clrclnale 75(2.2.2) Mt Lescuraea belleyl 33(1.1.2); 129(2.1.2);; 130(1.1.1) Mt Lophozia alpestris U5(1.1.2) Ht L. porphyrolwea 96(2.1.2)| 99(2.1.2/ M Plagiothecium elegai a 33(1.1.2) Mt Plectonolea obovata 31(2.2.?) W Plsuroslum schreberi U6(2.1.?)j U8(2.1.2) Te Pogonatum alpinim 23(1.2.2) t Polytrichum norvegicum 62(1.+ .+) t Polytrichum pHiferum 23(*.2) Te Rhacomitrium varium 23(1.?.?) L Stereocaulon tomentcsum 3J.( +.3.)| 62(1.1.2); U2( 3.1.3) APPENDIX IV PLATE I PLATE II PLATE III PLATE I A, Excellent growth of amabilis fir- on a Streptopus association at 4-000 feet} Paul Ridge} Garibaldi Park, Bl Dense cover of Oplopanax horridus along a temporary mountain stream near 3600 feet, Paul Ridge} Garibaldi Park. C, Sparse distribution of mountain hemlock in the upper subzonej 4.000 feot, Mount Seymour, The ridge in the upper right-hand corner i s in the lower subzone at 3300 feet. D„ Typical isolated clump of mountain hemlock in the upper subzone, 4-600 feet, Paul Ridge, Garibaldi Park. The snow-free ring around the clump (June 17) i s occupied by small mountain hemlock, ..yellow cedar, Rhodo- dendron albiflorum, and Vaccinium membranaceum. E„ Near i t s upper li m i t the Vaccinium membranaceum - Rhododendron assoc-iation occurs only on exposed ridges where snow accumulation i s least.-5100 feet,, Paul Ridge, Garibaldi Park. F-, Succession from (l) Phyllodoce - Cassiope to (2) dwarf Tsuga near the crest of a ridge where snow duration i s reduced.. 5000 feet, near Mam-quam Lake, Garibaldi Park.. P L A T E I PLATE II A. Wet edaphic Leptarrhena - Caltha leptosepala association i n the upper subzone, surrounded by stunted yellow cedar. 4500 feet, Paul Ridge, Garibaldi Park, B, Early stage of succession from open water towards Eriophorum - Sphagnum; Drepanocladus exannulatus and Carex aquatilis are main species. 4.600 feet, Paul Ridge, Garibaldi Park. G, Invasion of (2) dwarf mountain hemlock onto a (l) Phyllodoce - Cassiope area, 5100 feet, Garibaldi Park. D» Well developed Phyllodoce empetriformis - Cassiope mertensiana assoc-iation. 5100 feet, Garibaldi Park. E. Primary succession of a Carex nigricans association towards Phyllodoce -Cassiope. 4-800 feet, Paul Ridge, Garibaldi Park. F, High sociability of Gymnomitrium varians on an unstable collu v i a l slope. 4800 feet, near Mamquam Lake, Garibaldi Park. PLATE I I PLATE III A. Mesic habitats at 5000 feet and higher occupied by Phyllodoce - Cass- iope with sporadic clumps of mountain hemlock. On the warmer westerly slope in the centre of the photograph, trees are favoured. Otherwise they are restricted to prominences or ridges. Upper subzone, Gari-baldi Parle Bo Deformation of mountain hemlock by snow-creep. July 7, 1962. 3800 feet, Mount Seymour. C. Mesic Vaccinium membranaceum - Rhododendron association of the upper subzoneo 3900 feet, near The Lions. D. Small stream in the upper subzone occupied by Drepanocladus exannulatus and Scapania uliginosa, and flanked by Philonotis fon.tana and Petasites frigidus. With increased organic accumulations, these stages w i l l de-velop towards a Leptarrhena - Caltha leptosepala association. E. Saxifraga tolmiei established below a rock where there i s greater s o i l s t a b i l i t y on a colluvial slope. 5000 feet, Paul Ridge, Garibaldi Park. F. Secondary succession towards Gymnomitrium varians and Saxifraga tojLmiei, 16 years after the removal of the sod covering in a Carex nigricans association. 4900 feet, Garibaldi Park.* PLATE III 

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