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Root and fungal biomass production on low, medium and high productivity second-growth douglas-fir stands… Coopersmith, David J. 1986

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ROOT AND FUNGAL BIOMASS PRODUCTION ON LOW, MEDIUM AND HIGH PRODUCTIVITY SECOND-GROWTH DOUGLAS-FIR STANDS ON VANCOUVER ISLAND by DAVID J . COOPERSMITH B . S c , U.B.C. , 1981 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE i n THE FACULTY OF GRADUATE STUDIES FACULTY OF FORESTRY We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o the r e q u i r e d s t a n d a r d UNIVERSITY OF BRITISH COLUMBIA October 15, 1986 © DAVID J . COOPERSMITH, 1986 In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t of the r e q u i r e m e n t s f o r an advanced degree a t the UNIVERSITY OF BRITISH COLUMBIA, I agree t h a t the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and s t u d y . I f u r t h e r agree t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g of t h i s t h e s i s f o r s c h o l a r l y purposes may be g r a n t e d by the Head of my Department or by h i s or her r e p r e s e n t a t i v e s . I t i s u n d e r s t o o d t h a t c o p y i n g or p u b l i c a t i o n of t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l not be a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . FACULTY OF FORESTRY UNIVERSITY OF BRITISH COLUMBIA 2075 Wesbrook P l a c e V a n couver, Canada V6T 1W5 Date: O c t o b e r 15, 1986 A b s t r a c t T h i s s t u d y compared and c o n t r a s t e d f i n e r o o t and f u n g a l biomass p r o d u c t i o n e s t i m a t e s u s i n g s a n d - f i l l e d i n - g r o w t h bags, n a t i v e - s o i l - f i l l e d i n - g r o w t h bags, and s e q u e n t i a l s o i l c o r e s i n x e r i c , m e s i c , and h y g r i c s t a n d s of 5 0 - y e a r - o l d D o u g l a s - f i r on Vancouver I s l a n d . A l t h o u g h no s i g n i f i c a n t d i f f e r e n c e s i n o v e r s t o r e y f i n e - p l u s - s m a l l (^5 mm) r o o t p r o d u c t i o n c o u l d be found between the t h r e e s i t e s , p r o p o r t i o n a l a l l o c a t i o n s of net p r i m a r y p r o d u c t i o n t o the belowground ecosystem d e c r e a s e d w i t h i n c r e a s i n g s i t e p r o d u c t i v i t y . The t o t a l a n n u a l o v e r s t o r e y biomass p r o d u c t i o n on t h e l o w - p r o d u c t i v i t y x e r i c s i t e was 15.7 t h a " 1 y r " 1 . Of t h i s t o t a l , 26.5 p e r c e n t was a l l o c a t e d t o belowground components. On the m i d - s l o p e mesic s i t e , t o t a l o v e r s t o r e y biomass p r o d u c t i o n i n c r e a s e d t o 22.9 t h a " 1 y r " 1 , w h i l e a l l o c a t i o n t o the belowground d e c r e a s e d t o 24.5 p e r c e n t . On the h i g h - p r o d u c t i v i t y h y g r i c s i t e , t o t a l o v e r s t o r e y p r o d u c t i o n i n c r e a s e d t o 25.0 t h a " 1 y r " 1 , of which the belowground component r e p r e s e n t e d 20.0 p e r c e n t . L a r g e d i f f e r e n c e s were found i n the e s t i m a t e s of s t a n d i n g c r o p of r o o t s between i n - g r o w t h bags and s e q u e n t i a l s o i l c o r e s . E s t i m a t e s of a n n u a l f i n e r o o t p r o d u c t i o n , however, were much more s i m i l a r f o r n a t i v e - s o i l - f i l l e d i n - g r o w t h bags and s e q u e n t i a l s o i l c o r e s . The q u a l i t y of growth medium w i t h i n the i n - g r o w t h bags was a l s o found t o have a s i g n i f i c a n t e f f e c t on e s t i m a t e s of s t a n d i n g c r o p and a n n u a l p r o d u c t i o n of r o o t s . G r e a t e r i i amounts of r o o t biomass were found i n the i n - g r o w t h bags which c o n t a i n e d n u t r i e n t - r i c h growth media. Table of C o n t e n t s A b s t r a c t i i L i s t of T a b l e s v i i i L i s t of F i g u r e s x i Acknowledgments x v i i 1 . INTRODUCTION 1 2. LITERATURE REVIEW 5 2.1 Sam p l i n g s t r a t e g i e s i n f i n e r o o t s t u d i e s .'...6 2.2 Methods of s t u d y i n g f i n e r o o t s 6 2.3 Biomass and p r o d u c t i o n e s t i m a t e s of f i n e r o o t s 8 2.4 E s t i m a t e s of the biomass of f u n g a l components 12 3 . THE STUDY AREA 18 3.1 L o c a t i o n , h i s t o r y , and s i t e d e s c r i p t i o n ....18 3.2 Geo l o g y , s o i l s , and humus form 37 3.3 C l i m a t e of the st u d y a r e a 40 4. MATERIALS AND METHODS 43 4.1 F i e l d ...43 4.1.1 Root i n - g r o w t h bag c o n s t r u c t i o n 43 4.1.2 Growth medium 43 4.1.3 I n s t a l l a t i o n of t h e i n - g r o w t h bags ...46 4.1.4 T e s t of two a d d i t i o n a l growth media ..51 4.1.5 Root s a m p l i n g w i t h s e q u e n t i a l s o i l c o r e s 51 4.1.6 C o l l e c t i o n of s o i l f o r s o i l m o i s t u r e d e t e r m i n a t i o n s 52 4.1.7 S o i l t e mperature measurement 52 4.1.8 L i t t e r c o l l e c t i o n s 53 4.1.9 M e n s u r a t i o n a l d a t a 53 i v 4.2 L a b o r a t o r y 55 4.2.1 Root washing and c l a s s i f i c a t i o n 55 4.2.2 Root and f u n g a l biomass e s t i m a t e s ....59 4.2.3 F i n e r o o t and f u n g a l p r o d u c t i o n and t u r n o v e r e s t i m a t e s 59 4.2.4 D e t e r m i n a t i o n of p h y s i c a l s o i l p a r ameters 62 4.3 Data a n a l y s i s 62 4.3.1 The a n a l y s i s of v a r i a n c e model 62 4.3.2 I n t e r p r e t a t i o n of the a n a l y s i s of v a r i a n c e r e s u l t s 67 5. RESULTS AND DISCUSSION 73 5.1 A s h - f r e e d e t e r m i n a t i o n s 73 5.2 Root and f u n g a l dynamics i n t h e i n - g r o w t h bags 74 5.2.1 C o n i f e r o u s l i v e f i n e - p l u s - s m a l l (^5 mm) r o o t component ..74 5.2.1.1 Temporal p a t t e r n s i n r o o t biomass 74 5.2.1.2 The e f f e c t of growth medium on c o n i f e r o u s biomass e s t i m a t e s 79 5.2.2 N o n - c o n i f e r o u s l i v e f i n e - p l u s - s m a l l (<5 mm) r o o t component 84 5.2.2.1 Temporal p a t t e r n s i n r o o t biomass 84 5.2.2.2 The e f f e c t of growth medium on n o n - c o n i f e r o u s biomass e s t i m a t e s 88 5.2.3 Dead f i n e - p l u s - s m a l l (<5 mm) r o o t component 92 5.2.3.1 Temporal p a t t e r n s i n dead r o o t biomass 92 5.2.3.2 The e f f e c t of growth medium on dead biomass e s t i m a t e s ....98 v 5.2.4 F u n g a l component 102 5.2.4.1 Temporal p a t t e r n s i n f u n g a l biomass 102 5.2.4.2 The e f f e c t of growth medium on f u n g a l biomass e s t i m a t e s .106 5.3 P o s s i b l e s o u r c e s of e r r o r i n the p r o c e s s i n g of i n - g r o w t h bags 111 5.4 C o n i f e r o u s r o o t dynamics w i t h s e q u e n t i a l s o i l c o r e s 112 5.4.1 P a t t e r n of l i v e and dead f i n e r o o t dynamics on the x e r i c and h y g r i c s i t e 112 5.4.2 Comparison of e s t i m a t e s of r o o t dynamics from s e q u e n t i a l s o i l c o r e s w i t h t h o s e of i n - g r o w t h bags ..118 5.5 P o s s i b l e e f f e c t s of o n - s i t e a c t i v i t i e s on r o o t and f u n g a l dynamics 123 5.6 Comparison of the e f f e c t s on r o o t and f u n g a l biomass of two a d d i t i o n a l growth media 127 5.7 E s t i m a t e s of aboveground biomass and a n n u a l p r o d u c t i o n 134 5.7.1 P a t t e r n s i n f o l i a r and n o n - f o l i a r l i t t e r p r o d u c t i o n 134 5.7.2 Annual aboveground c o n i f e r o u s biomass p r o d u c t i o n 137 5.7.3 Annual belowground c o n i f e r o u s biomass p r o d u c t i o n 143 5.7.4 Comparison of t o t a l net p r i m a r y p r o d u c t i o n and a l l o c a t i o n p a t t e r n s between the t h r e e s t u d y s i t e s 145 5.8 P a t t e r n s i n s o i l t e m p e r a t u r e and p e r c e n t m o i s t u r e c o n t e n t over time 153 5.8.1 P a t t e r n s i n s o i l t e m p e r a t u r e on the x e r i c and h y g r i c s i t e s 153 5.8.2 P a t t e r n s of p e r c e n t s o i l m o i s t u r e i n m i n e r a l s o i l and o r g a n i c f o r e s t f l o o r h o r i z o n s 155 v i 5.9 C o r r e l a t i o n of belowground p r o d u c t i o n w i t h s o i l p r o p e r t i e s and f o l i a r l i t t e r p r o d u c t i o n 158 5.9.1 The X e r i c s i t e ..159 5.9.2 The Mesic s i t e 162 5.9.3 The H y g r i c s i t e 164 5.9.4 O v e r a l l t r e n d s i n t h e c o r r e l a t i o n d a t a 165 6. Summary and c o n c l u s i o n s 167 , 6.1 Summary of t h e t h e s i s 167 6.2 Summary of the t h e s i s 167 6.3 C o n c l u s i o n s 171 REFERENCES 175 7 . App e n d i c e s 190 7.1 Appendix 1 190 7.2 Appendix 2 216 7.3 Appendix 3 220 7.4 Appendix 4 238 7.4.1 Treatment of h i g h e r - o r d e r f a c t o r i n t e r a c t i o n s w i t h i n an ANOVA 239 v i i L i s t of T a b l e s T a b l e Page I . Summary of t h e mean c l i m a t i c v a l u e s f o r the E a s t Vancouver I s l a n d D r i e r M a r i t i m e subzone of the C o a s t a l Western Hemlock zone (CWHa2) 24 I I . Summary of t h e s o i l , t o p o g r a p h i c a l , and s i l v i c u l t u r a l c h a r a c t e r i s t i c s of the t h r e e s t u d y s i t e s 25 I I I . Summary o f t h e m e n s u r a t i o n a l d a t a of the o v e r s t o r e y components of the 3 study s i t e s 26 IV. Summary of t h e measured s o i l p a rameters of the t h r e e s t u d y s i t e s 39 V. T r a n s f o r m a t i o n s performed on the o r i g i n a l biomass d a t a t o s a t i s f y the ass u m p t i o n s of the a n a l y s i s of v a r i a n c e 68 V I . P r o b a b i l i t i e s of s i g n i f i c a n t F - v a l u e s f o r the f u l l model ANOVA 70 V I I . P r o b a b i l i t i e s of s i g n i f i c a n t F - v a l u e s e x c l u d i n g growth medium as a term i n the ANOVA 71 v i i i V I I I . O v e r a l l mean a s h - f r e e r o o t and f u n g a l w e i g h t s , and c a l c u l a t e d t - v a l u e s f o r p a i r - w i s e t - t e s t c o m p a r i s o n s from n a t i v e - s o i l - and s a n d - f i l l e d i n - g r o w t h bags 82 IX. A n a l y s i s of v a r i a n c e of t h e e f f e c t of t h e f o u r growth media on r o o t and f u n g a l biomass components. ' 132 X. E s t i m a t e s of aboveground s t a n d i n g c r o p of c o n i f e r o u s s p e c i e s f o r the x e r i c , m e s i c , and h y g r i c s i t e s . 138 X I . Comparison of t o t a l c o n i f e r o u s biomass p r o d u c t i o n e s t i m a t e s u s i n g n a t i v e - s o i l - and s a n d - f i l l e d i n - g r o w t h bags and s e q u e n t i a l c o r e s f o r belowground e s t i m a t e s on the x e r i c s i t e . 140 X I I . Comparison of t o t a l c o n i f e r o u s biomass p r o d u c t i o n e s t i m a t e s u s i n g n a t i v e - s o i l - and s a n d - f i l l e d i n - g r o w t h bags and s e q u e n t i a l c o r e s f o r belowground e s t i m a t e s on the mesic s i t e . 141 ix X I I I . Comparison of t o t a l . c o n i f e r o u s biomass p r o d u c t i o n e s t i m a t e s u s i n g s o i l - and s a n d - f i l l e d i n - g r o w t h bags and s e q u e n t i a l c o r e s f o r belowground e s t i m a t e s on t h e h y g r i c s i t e . 142 X I V . S i m p l e c o r r e l a t i o n s between monthly e s t i m a t e s of a s h - f r e e r o o t and f u n g a l biomass, and b i o t i c and a b i o t i c s i t e c h a r a c t e r i s t i c s 160 X L i s t of F i g u r e s F i g u r e Page 3.1. L o c a t i o n of the stu d y a r e a w i t h i n B r i t i s h Columbia 19 3.2. L o c a t i o n of the study a r e a i n r e l a t i o n t o P o r t A l b e r n i 20 3.3. L o c a t i o n of the stu d y s i t e s a l o n g the t o p o g r a p h i c sequence of the study a r e a 21 3.4. T o p o g r a p h i c sequence of ecosystem a s s o c i a t i o n s w i t h i n the d r i e r CWHa2 23 3.5. A view of t h e x e r i c s i t e w i t h i n t h e Gault heri a shall on a s s o c i a t i o n 27 3.6. A view of the mesic s i t e w i t h i n the Moss a s s o c i a t i o n , Hylocomium splendens v a r i a n t 33 x i 3 . 7 . A v i e w of the h y g r i c s i t e w i t h i n the Achlys -Polystichum a s s o c i a t i o n , Polystichum muni turn v a r i a n t . 35 3 . 8 . C o m p a r i s o n o f m o n t h l y p r e c i p i t a t i o n t o t a l s and mean m o n t h l y t e m p e r a t u r e s d u r i n g the s t u d y p e r i o d w i t h t h e 3 0 - y e a r a v e r a g e s f o r t h e P o r t A l b e r n i wea the r s t a t i o n 42 4 . 1 . C o n s t r u c t i o n of the r o o t i n - g r o w t h bags 44 4 . 2 . The f i n i s h e d r o o t i n - g r o w t h b a g . 45 4 . 3 . I n s t a l l a t i o n of t he r o o t i n - g r o w t h bags 47 4 . 4 . An i n s t a l l e d and t a g g e d i n - g r o w t h bag 49 4 . 5 . An example o f t he amounts o f r o o t and f u n g a l b iomass from one i n - g r o w t h bag 60 4 . 6 . P h o t o m i c r o g r a p h of b a s i d i o m y c e t e hyphae e x t r a c t e d from the i n - g r o w t h bags 61 X I X 4.7. D e c i s i o n m a t r i x i l l u s t r a t i n g t h e e q u a t i o n s used f o r f i n e r o o t and f u n g a l p r o d u c t i o n e s t i m a t e s 63 5.1. P a t t e r n s i n a s h - f r e e c o n i f e r o u s l i v e f i n e - p l u s - s m a l l (^5 mm) r o o t biomass from n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags 75 5.2. Comparison of the p a t t e r n s of mean a s h - f r e e c o n i f e r o u s f i n e - p l u s - s m a l l (^5 mm) r o o t biomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags 77 5.3. Comparison of the p a t t e r n s of a s h - f r e e c o n i f e r o u s f i n e - p l u s - s m a l l (^5 mm) r o o t biomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags 80 5.4. Comparison of the p a t t e r n s i n a s h - f r e e n o n - c o n i f e r o u s l i v e f i n e - p l u s - s m a l l (^5 mm) r o o t biomass from n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags 85 x i i i 5.5. Comparison of the p a t t e r n s of a s h - f r e e n o n - c o n i f e r o u s f i n e - p l u s - s m a l l (^5 mm) r o o t biomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags 89 5.6. Comparison of the p a t t e r n s of mean a s h - f r e e ' n o n - c o n i f e r o u s f i n e - p l u s - s m a l l (^5 mm) r o o t biomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags 91 5.7. Comparison of t h e p a t t e r n s i n a s h - f r e e dead f i n e - p l u s - s m a l l (<5 mm) r o o t biomass from n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags 94 5.8. Comparison of the p a t t e r n s of a s h - f r e e dead f i n e - p l u s - s m a l l (<5 mm) r o o t biomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags 99 5.9. Comparison of t h e p a t t e r n s of mean a s h - f r e e dead f i n e - p l u s - s m a l l (£5 mm) r o o t biomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags 101 x i v 5.10. Comparison of t h e p a t t e r n s i n a s h - f r e e f u n g a l biomass from n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags 104 5.11. Comparison of the p a t t e r n s of a s h - f r e e f u n g a l biomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags 107 5.12. Comparison of the p a t t e r n s of mean a s h - f r e e f u n g a l biomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags 109 5.13. Comparison of the p a t t e r n s i n a s h - f r e e v e r y f i n e l i v e and dead (^ 1 mm) c o n i f e r o u s r o o t biomass f o r the x e r i c and h y g r i c s i t e s from s e q u e n t i a l s o i l c o r e s 114 5.14. R e d u c t i o n i n u n d e r s t o r e y v e g e t a t i o n w i t h s a m p l i n g a c t i v i t y on the x e r i c s i t e 125 5.15. Comparison of the s t a n d i n g c r o p s of r o o t and f u n g a l biomass w i t h f o u r growth media on the mesic s i t e 1 28 X V 16. Comparison of t h e p a t t e r n s of f o l i a r and n o n - f o l i a r l i t t e r p r o d u c t i o n on t h e x e r i c , m e s i c , and h y g r i c s i t e s . 136 17. P a t t e r n s i n s o i l t e m p e r a t u r e on the mesic and h y g r i c s i t e s 154 18. P a t t e r n s i n s o i l m o i s t u r e ( p e r c e n t of d r y w e i g h t ) i n m i n e r a l and o r g a n i c f r a c t i o n s of the t h r e e s t u d y s i t e s 157 x v i Acknowledgments T h i s work was c a r r i e d out w i t h the f i n a n c i a l s u p p o r t of the CFS B l o c k g r a n t t o t h e F a c u l t y of F o r e s t r y , and CFS ENFOR c o n t r a c t s t o Dr. J.P. Kimmins. T h i s s u p p o r t i s g r a t e f u l l y acknowledged. A l a r g e number of p e o p l e have c o n t r i b u t e d t o the c o m p l e t i o n of the s t u d y . W i t h o u t naming them a l l , t h e i r a s s i s t a n c e i s acknowledged w i t h t h a n k s . Dr. Hannes Hase i n i t i a t e d t h i s s t u d y , chose the s t u d y s i t e s , and was e x t r e m e l y h e l p f u l i n s e t t i n g up the p r o c e s s i n g r o u t i n e f o r the l a b o r a t o r y work. B a r r y Wong spent many l o n g hours on the computer a n a l y s i s of the s t u d y d a t a . S p e c i a l thanks a l s o go t o Werner Kurz and Dr. J.P. Kimmins f o r t h e i r s u p p o r t and a d v i c e . And a s y m p a t h e t i c thank you i s a l s o g i v e n t o the l a r g e number of summer s t u d e n t s who spent l o n g hours hunched over d i r t y p e t r i d i s h e s s o r t i n g r o o t s . M a c M i l l a n - B l o e d e l Company L t d . a l l o w e d me t o u t i l i z e l a n d w i t h i n t h e i r TFL f o r the s t u d y , and p r o v i d e d me w i t h l a y o u t maps of the a r e a . L a s t , but c e r t a i n l y not l e a s t , I would l i k e t o thank my w i f e V a l e r i e and daug h t e r K a t h e r i n e , f o r p u t t i n g up w i t h me and making a l l the work w o r t h w h i l e . x v i i Slow me down, Lord! Ease the poundi ng of my heart by the quieting of my mind. Steady my harried pace With a vision of the eternal reach of time. Give me, amidst the confusion of my day, The calmness of the everlasting hills. Break the tensions of my nerves With the soothing music of the singing streams That live in my memory. Help me to know the magical restoring power of sleep. Teach me the art of taking minute vacations of slowing down To look at a flower; To chat with an old friend or make a new one; To pat a stray dog; To watch a spider build a web; To smile at a child; Or to read a few lines from a good book. Remind me each day That the race is not always to the swift; That there is more to life than increasing its speed. Slow me down, Lord, And inspire me to send my roots deep Into the soil of life's enduring values That I may grow toward the stars of my greater destiny. Anonymous In memory o f my f a t h e r x v i i i 1. INTRODUCTION A r e v i e w of the f o r e s t r y l i t e r a t u r e r e v e a l s t h a t , u n t i l v e r y r e c e n t l y , belowground p r o c e s s e s have r e c e i v e d s c a n t a t t e n t i o n from f o r e s t s c i e n t i s t s . However, a r a p i d i n c r e a s e i n the number of r e s e a r c h p r o j e c t s c o n d u c t e d i n v a r i o u s f o r e s t ecosystems around the w o r l d over the p a s t decade has f o c u s e d new a t t e n t i o n on the r o l e of f i n e 1 r o o t s and m y c o r r h i z a e i n f o r e s t n u t r i e n t and energy budgets ( e . g . Kimmins and Hawkes 1978, P e r s s o n 1978, 1979, 1980, Vogt et al. 1980, 1981, Keyes and G r i e r 1981, Vogt, G r i e r et al. 1983, Vogt, Moore et al. 1983, F o g e l and Hunt 1983, S a n t a n t o n i o and Hermann 1985). As a r e s u l t of t h e s e and o t h e r s t u d i e s , i t i s now known t h a t e a r l i e r e s t i m a t e s of f i n e r o o t biomass and p r o d u c t i o n g r e a t l y u n d e r e s t i m a t e d the p e r c e n t a g e of net p r i m a r y p r o d u c t i o n (NPP) a l l o c a t e d t o the belowground ecosystem. We a l s o know t h a t v e r y l a r g e s e a s o n a l and s i t e t o s i t e v a r i a t i o n e x i s t s i n t h e a l l o c a t i o n t o the belowground ecosystem ( e . g . Keyes and G r i e r 1981). The major r e a s o n f o r the u n d e r e s t i m a t i o n of r o o t p r o d u c t i o n has been the v e r y s h o r t l i f e span and q u i c k t u r n o v e r of ephemeral f i n e r o o t s and t h e i r a s s o c i a t e d f u n g a l s y m b i o n t s . Even though the s t a n d i n g biomass of t h e s e components i s u s u a l l y q u i t e s m a l l i n comparison t o t h e aboveground biomass, t h e i r p r o d u c t i o n over an e n t i r e year can account f o r a v e r y l a r g e p r o p o r t i o n of the t o t a l biomass 1 F o r the purposes of t h i s s t u d y " f i n e " r o o t s were d e f i n e d as h a v i n g d i a m e t e r s ^2 mm. Roots w i t h d i a m e t e r s between 2mm and 5 mm were d e f i n e d as " s m a l l " . 1 2 p r o d u c t i o n f o r an e n t i r e f o r e s t ecosystem (Bowen 1984). The major d i f f i c u l t y i n q u a n t i f y i n g the a l l o c a t i o n of NPP t o f i n e r o o t s a r i s e s from the d i f f i c u l t y of documenting t e m p o r a l changes i n l i v e and dead s t a n d i n g biomass, and r e l a t i n g t h e s e t e m p o r a l p a t t e r n s t o f i n e r o o t p r o d u c t i o n and t u r n o v e r . T h i s s t u d y was c o n d u c t e d w i t h i n an age c l a s s of s t a n d s t h a t w i l l be of major i n t e r e s t t o s i l v i c u l t u r a l i s t s i n the near f u t u r e as B r i t i s h Columbia moves toward t h e h a r v e s t of more of i t s ' second r o t a t i o n f o r e s t . Our a b i l i t y t o p r e d i c t how such s t a n d s w i l l respond t o s i l v i c u l t u r a l m a n i p u l a t i o n , i n the absence of l o n g - t e r m e m p i r i c a l f i e l d t r i a l d a t a , i s dependent upon a t h o r o u g h knowledge of the n u t r i e n t and energy a l l o c a t i o n p a t t e r n s w i t h i n them. The p a t t e r n s of p h o t o s y n t h a t e a l l o c a t i o n w i t h i n f o r e s t e d ecosystems have a l r e a d y been shown t o be q u i t e p l a s t i c ( L i n d e r and A x e l s s o n 1982). I n c r e a s i n g t h e commercial t i m b e r y i e l d of a f o r e s t c r o p can be a c c o m p l i s h e d by e i t h e r i n c r e a s i n g the r a t e of p h o t o s y n t h e s i s w i t h i n a s t a n d , or by i n c r e a s i n g the p r o p o r t i o n of p h o t o s y n t h a t e s t h a t a r e a l l o c a t e d t o aboveground biomass components (Shepherd 1985), assuming t h a t s u f f i c i e n t l i v e r o o t would remain t o s a t i s f y the the r e q u i r e m e n t s of t r e e growth ( L i n d e r and Rook 1984). Of t h e s e two p o s s i b l e pathways t o i n c r e a s e p h o t o s y n t h e s i s , the second i s i n f l u e n c e d t o a much g r e a t e r e x t e n t by the more common s i l v i c u l t u r a l p r a c t i c e s employed t o d a y , such as f e r t i l i z a t i o n , p l o w i n g , and 3 i r r i g a t i o n ( L i n d e r and A x e l s s o n 1982). The l o n g - t e r m consequences of s h i f t i n g the carbon b a l a n c e away from r o o t s a r e , as of y e t , unknown. We do not y e t have s u f f i c i e n t knowledge about f i n e r o o t dynamics, or about the r o l e p l a y e d by f u n g a l s y m b i o n t s , t o p r e d i c t w i t h c o n f i d e n c e the consequences of c h a n g i n g growth a l l o c a t i o n p a t t e r n s . To d a t e , net f i n e r o o t p r o d u c t i o n v a l u e s o b t a i n e d u s i n g t r a d i t i o n a l s e q u e n t i a l s o i l c o r i n g have been d e r i v e d f o r fewer than 20 s t a n d s throughout the w o r l d (Gholz et al. 1986). I n c r e a s i n g our knowledge about the belowground ecosystem i n many d i f f e r e n t f o r e s t e n v i r o n m e n t s i s the f i r s t , b a s i c s t e p a l o n g t h i s p a t h t o u n d e r s t a n d i n g . F i n e r o o t and m y c o r r h i z a l r e s e a r c h i s g e n e r a l l y t e d i o u s , l a b o u r i n t e n s i v e , and e x p e n s i v e . In f a c t , the l a c k of d a t a on f i n e r o o t p r o d u c t i o n up t o 1975, stems d i r e c t l y from the g r e a t amount of work a s s o c i a t e d w i t h p r o d u c i n g good biomass e s t i m a t e s . Any t e c h n i q u e which would reduce the e f f o r t r e q u i r e d f o r such work would be a v a l u a b l e r e s e a r c h t o o l . R e c e n t l y , Hans Pe r s s o n and h i s c o l l e a g u e s w o r k i n g i n Sweden have a d a p t e d a t e c h n i q u e of Lund et al . (1970) f o r use i n f o r e s t e cosystem s t u d i e s . T h i s t e c h n i q u e , known a l t e r n a t i v e l y as the r o o t i n - g r o w t h bag t e c h n i q u e ( P e r s s o n 1978, 1980), or t h e net s t o c k i n g t e c h n i q u e ( S t e e n 1983), g r e a t l y r e d u c e s the time requirement of r o o t s o r t i n g . The amount of time r e q u i r e d t o s o r t r o o t s can be v e r y g r e a t w i t h more t r a d i t i o n a l work u s i n g s e q u e n t i a l s o i l c o r i n g ( S a n t a n t o n i o 1978). 4 Because of the c o n s t r a i n t s on s t u d y d e s i g n t h a t these more t r a d i t i o n a l t e c h n i q u e s impose, and because of l i m i t a t i o n s i n money and manpower t o u n d e r t a k e t h i s work, i t was d e c i d e d t o i n v e s t i g a t e the u s e f u l n e s s of t h e i n - g r o w t h bag t e c h n i q u e f o r s t u d i e s of ephemeral r o o t s i n second-growth s t a n d s of D o u g l a s - f i r (Pseudotsuga m e n z i e s i i ( M i r b . ) F r a n c o ) on Vancouver I s l a n d , and t o compare the biomass e s t i m a t e s produced u s i n g the i n - g r o w t h bag t e c h n i q u e w i t h t h o s e u s i n g s e q u e n t i a l s o i l c o r i n g (Hase, u n p u b l i s h e d d a t a ) on the same s i t e s . The s p e c i f i c o b j e c t i v e s of t h i s t h e s i s were as f o l l o w s ; 1. t o q u a n t i f y and compare the biomass and s e a s o n a l dynamics of f i n e - p l u s - s m a l l (<5 mm) r o o t s and f u n g a l mycelium i n x e r i c 2 r i d g e t o p , mesic m i d d l e - s l o p e , and h y g r i c l o w e r - s l o p e f o r e s t ecosystems u s i n g the i n - g r o w t h bag t e c h n i q u e ; 2. t o compare the e f f e c t of v a r y i n g t h e m a t e r i a l w i t h i n the i n - g r o w t h bags (from n u t r i e n t - r i c h t o n u t r i e n t - p o o r ) on the r o o t and f u n g a l mycelium p r o d u c t i o n e s t i m a t e s ; . 3. t o compare the i n - g r o w t h bag r o o t e s t i m a t e s w i t h those o b t a i n e d u s i n g c o n v e n t i o n a l s o i l c o r i n g ; . 4 . t o d e t e r m i n e i f the o b s e r v e d s e a s o n a l dynamics were c o r r e l a t e d w i t h the b i o t i c and a b i o t i c s i t e f a c t o r s of s o i l t e m p e r a t u r e , s o i l m o i s t u r e , o r f o l i a r l i t t e r p r o d u c t i o n . 2 The use of the terms x e r i c , mesic and h y g r i c i n t h i s t h e s i s a r e e x p l a i n e d i n Chapter 2. 2. LITERATURE REVIEW U n t i l r e c e n t l y , most i n v e s t i g a t i o n s i n t o the r o l e of f i n e r o o t s have been p h y s i o l o g i c a l i n n a t u r e . S t u d i e s of the r esponse of f i n e r o o t s t o changes i n e n v i r o n m e n t a l f a c t o r s such as t e m p e r a t u r e , s o i l oxygen l e v e l s , m o i s t u r e , and n u t r i e n t a v a i l a b i l i t y have u s u a l l y emphasized the s h o r t term a b i l i t y of r o o t s t o respond t o s t r e s s . W h i l e such q u e s t i o n s a r e i m p o r t a n t , t h e i r i n v e s t i g a t i o n i s more a p p l i c a b l e t o the s h o r t e r t i m e s c a l e s of a g r i c u l t u r a l c r o p s than they a r e t o f o r e s t r y . S e v e r a l t e x t b o o k s d e a l w i t h the p h y s i o l o g i c a l a s p e c t s of f i n e r o o t s i n g r e a t d e t a i l ( K o s t l e r et al. 1968, Carson 1974, T o r r e y and C l a r k s o n 1975, S c o t t - R u s s e l l 1977, H a r l e y and S c o t t - R u s s e l l 1979, Brouwer et al. 1981). The c u r r e n t emphasis of r o o t r e s e a r c h i n f o r e s t ecosystems i s the q u a n t i f i c a t i o n of s t a n d i n g 3 l i v e and dead biomass, a n n u a l p r o d u c t i o n , and t u r n o v e r of ephemeral f i n e r o o t s . To d a t e , d a t a i s l i m i t e d t o c e r t a i n t r e e s p e c i e s growing i n s p e c i f i c h a b i t a t s . Hermann (1977) has r e v i e w e d much of the p u b l i s h e d l i t e r a t u r e up t o 1976, and s e v e r a l r e c e n t symposia have been h e l d on the r o l e of f i n e r o o t s i n f o r e s t ecosystems ( M a r s h a l l 1977, Bohm et al. 1983, A t k i n s o n et al. 1983, Bowen and Nambiar 1984). There i s a r a p i d l y i n c r e a s i n g body of l i t e r a t u r e on f i n e r o o t dynamics. 3The common p r a c t i c e t h r o u g h o u t much of the r o o t l i t e r a t u r e i s t o r e f e r t o an e s t i m a t e of c u r r e n t l i v e biomass as " s t a n d i n g c r o p " . I w i l l make use of the same term, but w i l l d i f f e r e n t i a t e between e s t i m a t e s of l i v e and dead r o o t s by use of t h e terms " s t a n d i n g c r o p , l i v e " and " s t a n d i n g c r o p , dead". 5 6 2.1 SAMPLING STRATEGIES IN FINE ROOT STUDIES There i s c o n f l i c t i n g e v i d e n c e as t o the a p p r o p r i a t e n e s s of random v e r s u s s t r a t i f i e d random samples i n r o o t s t u d i e s . A number of a u t h o r s have found t h a t f i n e r o o t s tend t o be randomly d i s t r i b u t e d w i t h i n s t a n d s ( M o i r and B a c h e l a r d 1969, S a f f o r d and B e l l 1972, McQueen 1973, R e y n o l d s 1974, S a n t a n t o n i o et al . 1977, N u s z d o r f e r 1982). However Nnyama et al. (1978) found t h a t the d e n s i t y of f i n e r o o t s of D o u g l a s - f i r d e c r e a s e d w i t h i n c r e a s i n g d i s t a n c e from the b o l e s of sample t r e e s . More r e c e n t l y , S t . John (1982) and S t . John et al. (1983) found t h a t the m a j o r i t y of f i n e r o o t growth i n t r o p i c a l f o r e s t ecosystems was l o c a l i z e d around c o n c e n t r a t i o n s of n u t r i e n t - r i c h o r g a n i c m a t t e r . T h i s can r e s u l t i n the f i n e r o o t " p o p u l a t i o n " h a v i n g a n e g a t i v e b i n o m i a l r a t h e r than a normal d i s t r i b u t i o n . A n e g a t i v e - b i n o m i a l l y d i s t r i b u t e d p o p u l a t i o n produces clumps of " i n d i v i d u a l s " s u r r o u n d e d by l a r g e amounts of uno c c u p i e d space. I f one i s a b l e t o d i f f e r e n t i a t e between o c c u p i e d and un o c c u p i e d a r e a s , then a s t r a t i f i e d random sample w i l l be the most e f f i c i e n t form of s a m p l i n g . However, i n a n o r m a l l y d i s t r i b u t e d " p o p u l a t i o n " , s t r a t i f i e d random sampl i n g i s no more e f f i c i e n t than random s a m p l i n g ( S t e e l and T o r r i e 1980). 2.2 METHODS OF STUDYING FINE ROOTS The b e s t method by which t o s t u d y r o o t s in situ has been a t o p i c of i n t e n s e debate f o r w e l l over 50 y e a r s . A g r e a t d e a l of m a t e r i a l has been p u b l i s h e d on thes e 7 t e c h n i q u e s (Kinman 1932, L o t t et al . 1950, Hough et al. 1965, M i t c h e l l and Woods 1966, S a f f o r d 1976, Brown and T h i l e n i u s 1977, P e r s s o n 1978, Bohm 1979, Dunsworth and Kumi 1982, F o g e l 1983, P e r s s o n 1983, S i n g h et al. 1984, Aber et al. 1985, Vogt et al . 1985, N a d e l h o f f e r et al. 1 986). N a d e l h o f f e r et al. 1986). However, t h e r e i s s t i l l i n s u f f i c i e n t e v i d e n c e t o p e r m i t an a p r i o r i c h o i c e between t r a d i t i o n a l s e q u e n t i a l s o i l c o r i n g and one of the a l t e r n a t i v e t e c h n i q u e s . The r e s u l t s produced by the former method a r e s t i l l thought by many t o produce the most r e l i a b l e e s t i m a t e s of f i n e r o o t biomass, p r o d u c t i o n , and t u r n o v e r ( S a n t a n t o n i o and Hermann 1985). However, the s e e s t i m a t e s are a c h i e v e d a t a v e r y g r e a t c o s t i n terms of money and manpower. For example, S a n t a n t o n i o (1978) has e s t i m a t e d t h a t t o p r o c e s s a s i n g l e " n a t i v e " s e q u e n t i a l s o i l c o r e from a mature s t a n d of D o u g l a s - f i r i n c e n t r a l Oregon r e q u i r e d 15 p erson-hours of work, and t h a t h i s l a b o r a t o r y ' s y e a r l y p r o c e s s i n g of 324 c o r e s consumed 5000 p e r s o n - h o u r s of e f f o r t ! A l t e r n a t i v e t e c h n i q u e s such as r o o t i n - g r o w t h bags or r o o t o b s e r v a t i o n windows r e q u i r e l e s s l a b o u r t o produce biomass e s t i m a t e s . However, t h e s e a l t e r n a t i v e t e c h n i q u e s may i n t r o d u c e e r r o r s i n t o s t a n d i n g c r o p and p r o d u c t i o n e s t i m a t e s w h i c h a r e i n h e r e n t i n the t e c h n i q u e s t h e m s e l v e s , or may be a s s o c i a t e d w i t h s o i l d i s t u r b a n c e d u r i n g t h e i r i n s t a l l a t i o n . To d a t e , t h e r e a r e v e r y few s t u d i e s which compare biomass and p r o d u c t i o n e s t i m a t e s u s i n g two or more t e c h n i q u e s ( e x c e p t i o n s t o t h i s a r e the works of Kummerow and L a n t z 8 1983, V a v o u l i d o u - T h e o d o r o u 1983, Steen 1985, and Vogt et al. 1985, and o t h e r s i n T a b l e X I , Appendix 1). 2.3 BIOMASS AND PRODUCTION ESTIMATES OF FINE ROOTS Comparisons of r o o t biomass and p r o d u c t i o n e s t i m a t e s of between s t u d i e s i s o f t e n v e r y d i f f i c u l t f o r t h r e e p r i m a r y r e a s o n s : 1. There i s l i t t l e c o n s i s t e n c y i n the time p e r i o d between s u c c e s s i v e samples. Time between samples v a r i e d from as l i t t l e as one week ( A t k i n s o n 1985) t o as much as s i x months (Steen 1983, 1984, L a r s s o n and Steen 1984, Steen and P e r s s o n et al. 1984). 2. There i s no c o n v e n t i o n f o r the d e s i g n a t i o n of an upper s i z e l i m i t t o f i n e r o o t s . Upper s i z e l i m i t s have v a r i e d between one mm and ten mm ( T a b l e X I I , Appendix 1 ) . 3. Many d i f f e r e n t methods have been employed i n the • c a l c u l a t i o n of f i n e r o o t p r o d u c t i o n and t u r n o v e r e s t i m a t e s . The most commonly used t e c h n i q u e i n the e s t i m a t i o n of a n n u a l r o o t p r o d u c t i o n i s t o s u b t r a c t the minimum from the maximum e s t i m a t e of s t a n d i n g c r o p over an e n t i r e year (e.g. Aber et al. 1985, and o t h e r s i n T a b l e X I I , Appendix 1 ) . Such e s t i m a t e s must be c o n s i d e r e d h i g h l y c o n s e r v a t i v e s i n c e they do not t a k e i n t o account month-to-month f l u c t u a t i o n s of l i v e and dead r o o t biomass, or the p o s s i b i l i t y of c o n c u r r e n t p r o d u c t i o n and senescence of r o o t s w h i c h , i f brought i n t o t h e p r o d u c t i o n e q u a t i o n , would g r e a t l y i n c r e a s e the s i z e of 9 th e s e e s t i m a t e ( F a i r l e y and A l e x a n d e r 1985). Other a u t h o r s have u t i l i z e d the sum of d i f f e r e n c e s between monthly e s t i m a t e s of l i v e r o o t biomass, w i t h or w i t h o u t t e s t i n g the s t a t i s t i c a l s i g n i f i c a n c e of such d i f f e r e n c e s . P e r s s o n (1978) and S i n g h et al . (1984) have p o i n t e d out t h a t not t e s t i n g f o r s i g n i f i c a n c e l e a d s t o o v e r e s t i m a t i o n of f i n e r o o t p r o d u c t i o n . P e r s s o n (1978) has produced a c o r r e c t i o n f a c t o r t o be a p p l i e d t o f i n e r o o t p r o d u c t i o n e s t i m a t e s u s i n g u n t e s t e d d i f f e r e n c e s , w h i l e S i n g h et al. (1984) recommended u t i l i z i n g o n l y s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e s . F a i r l e y and A l e x a n d e r (1985) have d i s c u s s e d the advantages and d i s a d v a n t a g e s of the v a r i o u s e s t i m a t i o n t e c h n i q u e s . In a d d i t i o n t o the problems d i s c u s s e d above, d i f f e r e n c e s i n the de p t h of s o i l sampled, p h e n o l o g i c a l s t a t u s of the s t u d i e d s t a n d , s t a n d age, t r e e d e n s i t y , f u n c t i o n a l c l a s s i f i c a t i o n of r o o t s ( l i v e v e r s u s d e a d ) , and u n c e r t a i n t y about t h e e f f i c i e n c y of d i f f e r e n t s a m p l i n g and p r o c e s s i n g methods f u r t h e r c o m p l i c a t e between-study comparisons ( F o g e l 1983). The maximum s t a n d i n g c r o p of r o o t s r e p o r t e d t o dat e has been 103.6 t h a " 1 i n a m i d - s l o p e , semi-deciduous r a i n f o r e s t i n Ghana (Lawson et al. 1970, i n K l i n g e 1973). By com p a r i s o n , the maximum r e p o r t e d r o o t biomass f o r Ps eudot suga menziesii i s 24.1 t h a - 1 f o r a 5 0 - y e a r - o l d s t a n d i n c e n t r a l Oregon ( F o g e l and Hunt 1979). In g e n e r a l , t h e l i t e r a t u r e shows t h a t the s t a n d i n g c r o p of f i n e r o o t s i s g r e a t e r f o r t r o p i c a l than f o r temperate f o r e s t e c o systems. 10 P r o d u c t i o n e s t i m a t e s of f i n e r o o t s as a p e r c e n t a g e of the t o t a l t r e e p r o d u c t i o n ranged from a low of 3.7 p e r c e n t f o r a 1 2 5 - y e a r - o l d Quercus rubra v a r . boreal is ( M i c h x . f.) Farw. s t a n d u s i n g the maximum-minus-minimum e s t i m a t i o n t e c h n i q u e (Aber et al. 1985) t o h i g h s of 73.7 p e r c e n t f o r a mixed Li ri odendron s t a n d i n Tennessee ( H a r r i s et al. 1977) and 73 p e r c e n t f o r Pseudotsuga menziesii i n M i c h i g a n ( F o g e l and Hunt 1979, F o g e l 1983). R e c e n t l y , Vogt, Moore et al . (1983) have e s t i m a t e d t h a t c o n i f e r f i n e r o o t s p l u s m y c o r r h i z a l f u n g i a c c o u n t e d f o r 45 p e r c e n t of NPP i n a 2 3 - y e a r - o l d Abies amabiIi s (Dougl.) Forbes s t a n d , and 75 p e r c e n t i n a 1 8 0 - y e a r - o l d s t a n d . Such e s t i m a t e s must a l s o be c o n s i d e r e d c o n s e r v a t i v e , however, s i n c e no e s t i m a t e s of the p r o d u c t i o n of f u n g a l hyphae i n the s u r r o u n d i n g s o i l were made. An i n c r e a s i n g p r o p o r t i o n of the r e c e n t l i t e r a t u r e has emphasized the v a r i a t i o n i n belowground p r o d u c t i o n w i t h changes i n m o i s t u r e and n u t r i e n t a v a i l a b i l i t y ( u s u a l l y , but not a l w a y s , a s s o c i a t e d w i t h s m a l l changes i n t o p o g r a p h i c p o s i t i o n ) . K a r i z u m i (1976) r e p o r t e d t h a t s t a n d i n g c r o p of l i v e r o o t s i n a Cryptomeria japonica p l a n t a t i o n i n c r e a s e d from wet t o mo i s t t o d r y s i t e s . Keyes and G r i e r (1981) compared 4 0 - y e a r - o l d low p r o d u c t i v i t y and h i g h p r o d u c t i v i t y s t a n d s of Pseudotsuga menziesii i n Washington s t a t e . They found t h a t on the low p r o d u c t i v i t y s i t e , f i n e and s m a l l (^5 mm) r o o t p r o d u c t i o n e q u a l e d 8.1 t h a " 1 y r " 1 , and t h a t t h i s r e p r e s e n t e d 36 p e r c e n t of the t o t a l y e a r l y d r y ma t t e r 11 p r o d u c t i o n of the s i t e . On the h i g h p r o d u c t i v i t y s i t e , y e a r l y f i n e and s m a l l r o o t p r o d u c t i o n amounted t o o n l y 4.1 t ha " 1 y r " 1 , which r e p r e s e n t e d o n l y 8 p e r c e n t of the t o t a l s t a n d d r y m a t t e r p r o d u c t i o n . S a n t a n t o n i o and Hermann (1985) have found s i m i l a r r e s u l t s f o r 70- t o 1 7 0 - y e a r - o l d s t a n d s of Pseudotsuga menziesii growing on d r y , moderate, and wet s i t e s i n Oregon. Root p r o d u c t i o n (<5 mm) was 6.5 t h a " 1 y r " 1 on the d r y s i t e , 6.3 t h a " 1 y r " 1 on the moderate s i t e , and 4.8 t h a " 1 y r " 1 on the wet s i t e . Other a u t h o r s have found t h a t the r o o t s t h e m s e l v e s a r e a b l e t o respond t o h i g h l y l o c a l i z e d changes i n n u t r i e n t a v a i l a b i l i t y w i t h i n the s o i l volume. S t . John (1983) and S t . John et al . (1983) have found t h a t the r o o t s of t r o p i c a l f o r e s t t r e e s p e c i e s i n c r e a s e d t h e i r degree of b r a n c h i n g and t o t a l l e n g t h upon e n c o u n t e r i n g p o c k e t s of n u t r i e n t - r i c h o r g a n i c m a t t e r i n an o t h e r w i s e n u t r i e n t - p o o r s o i l . S i m i l a r p a t t e r n s have been seen i n t h e r o o t f o r m a t i o n s of Betula pendula Roth i n sandy s o i l s w i t h a r t i f i c i a l humus p o c k e t s (L y r and Hoffmann 1974). Indeed, as e a r l y as 1903, s c i e n t i s t s had ob s e r v e d s t i m u l a t e d r o o t growth i n s o i l l a y e r s r i c h i n humus ( M o l l e r 1903, i n L y r and Hoffmann 1974). An a s s o c i a t i o n of f i n e r o o t s w i t h decomposing o r g a n i c m a tter has been noted f o r b o t h temperate (Damman 1971, Kimmins and Hawkes 1978) and t r o p i c a l f o r e s t ecosystems ( K l i n g e 1973, S t a r k and S p r a t t 1977, K l i n g e and H e r r e r a 1978, J o r d a n and H e r r e r a 1981, J o r d a n 1982). 1 2 The h e t e r o g e n e o u s n a t u r e of most f o r e s t s o i l s and the a b i l i t y o f t r e e s p e c i e s t o s e l e c t i v e l y e x p l o i t t he s o i l r e s o u r c e i n c r e a s e s t h e c o m p l e x i t y o f ephemera l r o o t s t u d i e s . I t s h o u l d a l s o a l e r t us t o the p o s s i b i l i t y t h a t t h o s e a l t e r n a t i v e t e c h n i q u e s t o t r a d i t i o n a l s e q u e n t i a l s o i l c o r i n g w h i c h change the n a t u r e o f the s o i l s u b s t r a t e may i n t r o d u c e a r t i f a c t e f f e c t s i n t o any b iomass or p r o d u c t i o n e s t i m a t e . 2 . 4 ' E S T I M A T E S OF THE BIOMASS OF FUNGAL COMPONENTS I f t he l i t e r a t u r e on s t a n d i n g c r o p s , p r o d u c t i o n , and t u r n o v e r o f r o o t s i n f o r e s t e d ecosys t ems i s i n c o m p l e t e , t h a t p e r t a i n i n g t o the b iomass components o f m y c o r r h i z a l and s a p r o p h y t i c f u n g i i s a l m o s t n o n - e x i s t e n t . There a r e v e r y few s t u d i e s o f t he t e m p o r a l b iomass dynamics o f the f u n g a l a s s o c i a t e s o f f o r e s t t r e e s or t h e i r r o l e i n the f u n c t i o n a l e c o l o g y of f o r e s t e c o s y s t e m s , even though the f u n g i may be as i m p o r t a n t a c a r b o n s i n k as the f i n e r o o t s w i t h w h i c h t h e y a r e a s s o c i a t e d ( F o g e l 1 9 8 3 ) . The re i s no d e n y i n g the i m p o r t a n c e of f u n g a l s y m b i o n t s t o the c o n t i n u e d g r o w t h o f most f o r e s t s p e c i e s and t o the f u n c t i o n i n g o f a l l f o r e s t e c o s y s t e m s . K e n d r i c k and B e r c h (1985) s t a t e t h a t o v e r 90 p e r c e n t o f a l l h i g h e r p l a n t s a r e n o r m a l l y m y c o r r h i z a l , and t h a t l a n d p l a n t s and t h e i r a s s o c i a t e d f u n g i p r o b a b l y e v o l v e d t o g e t h e r . There i s s t r o n g e v i d e n c e o f v e s i c u l a r - a r b u s c u l a r m y c o r r h i z a e i n f o s s i l i z e d r o o t s t h a t d i f f e r l i t t l e from t h o s e we see today ( K e n d r i c k and B e r c h 1 9 8 5 ) . I t has a l s o been commonly o b s e r v e d t h a t t he 13 i n t r o d u c t i o n of a n o r m a l l y m y c o r r h i z a l t r e e s p e c i e s i n t o a r e a s of the w o r l d where t h e i r s y m b i o t i c f u n g i do not oc c u r u s u a l l y r e s u l t s i n t h e complete f a i l u r e of the f o r e s t a t i o n attempt (Marx and Krupa 1978). In p a r t i c u l a r , p l a n t a t i o n s w i t h many s p e c i e s of the genus Pi nus cannot grow w i t h o u t m y c o r r h i z a e . M i k o l a (1969) has s t a t e d t h a t s u c c e s s f u l f o r e s t a t i o n w i t h Pi nus i n p r e v i o u s l y n o n - f o r e s t e d a r e a s r e q u i r e s the p a r a l l e l i n t r o d u c t i o n of the e s s e n t i a l e c t o m y c o r r h i z a l f u n g i . M y c o r r h i z a l i n f e c t i o n c o n f e r s a l a r g e number of b e n e f i t s on the h o s t p l a n t . Some of th e s e i n c l u d e i n c r e a s e d l o n g e v i t y of f e e d e r r o o t s , i n c r e a s e d r a t e s of n u t r i e n t a d s o r p t i o n from the s o i l , s e l e c t i v e a d s o r p t i o n of c e r t a i n i o n s (phosphorous i n p a r t i c u l a r ) , an i n c r e a s e d t o l e r a n c e of s o i l t o x i n s , extremes of t e m p e r a t u r e , and a d v e r s e c a t i o n i c and a n i o n i c s o i l c o n d i t i o n s , and p r o t e c t i o n from many r o o t pathogens (Marx and Krupa 1978). The fungus b e n e f i t s as w e l l i n t h a t i t i s p r o v i d e d w i t h a f u n c t i o n a l n i c h e i n which t o l i v e and a p l e n t i f u l s u p p l y of c a r b o h y d r a t e from t h e h o s t p l a n t . These b e n e f i t s t o the h o s t p l a n t come a t a v e r y h i g h c o s t i n terms of expended p h o t o s y n t h a t e . H a r l e y (1975) has e s t i m a t e d t h a t the c a r b o h y d r a t e c o n t a i n e d i n the s h e a t h i n g s t r u c t u r e s and f r u i t i n g b o d i e s of e c t o m y c o r r h i z a l fungus i n a temperate f o r e s t ecosystem was e q u i v a l e n t t o 500 kg h a " 1 , or some t e n p e r c e n t of a n n u a l t i m b e r p r o d u c t i o n . Vogt et al. (1982) have e s t i m a t e d t h a t w h i l e the m y c o r r h i z a l component 1 4 of an Abies amabilis s t a n d i n western Washington amounted t o o n l y one p e r c e n t of the t o t a l ecosystem biomass, t h e i r h i g h r a t e s of r e s p i r a t i o n and c o n t i n u o u s t u r n o v e r consumed f i f t e e n p e r c e n t of NPP, or some 3000 kg h a " 1 y r " 1 . Such l a r g e i n v e s t m e n t s by the t r e e s i n t o s y m b i o t i c r e l a t i o n s h i p s a r e more u n d e r s t a n d a b l e i f we examine the f u n g i ' s "economy of growth" ( K e n d r i c k and B e r c h 1985). An e x t e n s i v e network of minute f u n g a l mycelium r e q u i r e s much l e s s c a r b o h y d r a t e i n v e s t m e n t than an e q u i v a l e n t l e n g t h of f i n e r o o t s and r o o t h a i r s (Sanders and T i n k e r 1973). One cm of r o o t i s e q u i v a l e n t i n biomass t o a p p r o x i m a t e l y 1000 cm of f u n g a l hyphae (Bowen 1985). Hanssen et al. (1974) have e s t i m a t e d t h a t a s i n g l e gram d r y weight of hyphae w i l l have a t o t a l l e n g t h of some 230,000 m, or a p p r o x i m a t e l y the d i s t a n c e from Vancouver t o S e a t t l e . Because of t h e i r v e r y s m a l l d i a m e t e r , t h e f u n g a l hyphae can p e n e t r a t e t he c e l l m a t r i c e s of the a v a i l a b l e o r g a n i c l i t t e r m a t e r i a l , e x t r a c t i n g n u t r i e n t s i n an environment t h a t i s f r e e from competing s o i l b i o t a ( H a r l e y 1971). F u n g a l hyphae i n c o n t a c t w i t h s o i l p a r t i c l e s a l s o e x c r e t e o x a l i c a c i d s which i n c r e a s e the s o l u b i l i t y of p h o s p h o r i c s a l t s w i t h i n the s o i l ( G r a u s t e i n and S o l l i n s 1977). These e s s e n t i a l p r o c e s s e s a r e c a r r i e d out i n p o r t i o n s of the s o i l and o r g a n i c m a t r i x from which even the s m a l l e s t r o o t h a i r s c o u l d not e n t e r . I f t he s m a l l d i a m e t e r of the hypha, which i s r e s p o n s i b l e f o r t h e i n t i m a t e a s s o c i a t i o n of r o o t w i t h s o i l , has,been a boon t o the m y c o r r h i z a l p a r t n e r s h i p , i t has been 1 5 t h e bane of the ecosystem e c o l o g i s t . Few r e s e a r c h e r s have a t t e m p t e d t o q u a n t i f y the biomass of f u n g a l hyphae which r a m i f y t h r o u g h o u t the s o i l m a t r i x . The m a j o r i t y of the l i t e r a t u r e on f u n g a l biomass can be d i v i d e d i n t o two c a t e g o r i e s : 1. papers which e s t i m a t e the l e n g t h of f u n g a l hyphae per gram of f o r e s t s o i l , u s u a l l y w i t h o u t any e s t i m a t i o n of e q u i v a l e n t biomass; 2. p a p e r s which u t i l i z e t he p e r c e n t a g e of f i n e r o o t t i p s w h ich a r e i n f e c t e d by endo- or e c t o m y c o r r h i z a l s t r u c t u r e s as a measure of f u n g a l dynamics i n the s u r r o u n d i n g s o i l . I n the f i r s t c a s e , b o t h d i r e c t ( w e i g h i n g , measuring l e n g t h s ; e.g. F r a n k l a n d 1975, Hedley and S t e w a r t 1982, F o g e l and Hunt 1983) and i n d i r e c t ( c h i t i n a s s a y s , w e i g h i n g s o i l a d h e r i n g t o r o o t s ; e.g. Graham et al. 1982, A b b o t t et al. 1984) methods have been used t o ass a y the amount of e x t e r n a l hyphae formed by m y c o r r h i z a l f u n g i . L e ngth d e t e r m i n a t i o n s have u s u a l l y been made u s i n g m o d i f i c a t i o n s of t h e a g a r - f i l m p l a t i n g t e c h n i q u e s of Jones and M o l l i s o n ( 1 9 4 8 ) . Some a u t h o r s have found a s t r o n g l i n e a r r e l a t i o n s h i p between the l e n g t h of r o o t c o n v e r t e d t o m y c o r r h i z a e and t h e weight of hyphae i n the s o i l ( e . g . Sanders et al. 1977, A b b o t t and Robson 1985). However, o t h e r a u t h o r s have found t h a t d i f f e r e n t f u n g a l i s o l a t e s d i f f e r i n t h e i r a b i l i t y t o form e x t e r n a l hyphae, d e s p i t e s i m i l a r p a t t e r n s of r o o t i n f e c t i o n . So q u a n t i f i c a t i o n of m y c o r r h i z a e a l o n e , w i t h o u t e s t i m a t e s of 16 e x t e r n a l hyphae, may not be a good i n d i c a t o r o f , t h e e x t e n t , or s i z e of the f u n g a l biomass (Graham et al. 1982, Kucey and P a u l 1982, Bowen 1985). R e c e n t l y some a u t h o r s have d e v e l o p e d t e c h n i q u e s t o e s t i m a t e h y p h a l biomass based on volume and d e n s i t y c o n v e r s i o n s of t o t a l h y p h a l l e n g t h s (Hanssen et al . 1974, F r a n k l a n d 1975, Kucey and P a u l 1982). F r a n k l a n d (1975) a l s o a t t e m p t e d t o c o r r e c t f o r the p e r c e n t a g e of dead or "ghost" hyphae i n a sample t o get a more a c c u r a t e e s t i m a t e of the " a c t i v e " f u n g a l biomass. However, such biomass e s t i m a t e s , w h i l e v a l u a b l e , a r e u s u a l l y based on v e r y s m a l l samples ( u s u a l l y two t o f i v e grams of f o r e s t f l o o r or s o i l i s a l l the m a t e r i a l t h a t i s used i n the d i l u t i o n p l a t i n g t e c h n i q u e s t o e s t i m a t e t o t a l h y p h a l l e n g t h s , from which the biomass e s t i m a t e s a r e p r o d u c e d ) . Such a s m a l l sample cannot g i v e an a c c u r a t e e s t i m a t e of the o v e r a l l s i t e f u n g a l biomass because of the h e t e r o g e n e o u s n a t u r e of most f o r e s t s o i l s and t h e i r f u n g a l c o l o n i s t s . T h i s t e c h n i q u e a l s o f a i l s t o d i s t i n g u i s h between f u n g i p r e s e n t in situ as hyphae and th o s e p r e s e n t o n l y as dormant s p o r e s , but whose dormancy ( m y c o s t a s i s ) i s broken by the p l a t i n g t e c h n i q u e s employed ( H a r l e y 1971). Warcup (1967) has found t h a t 87 p e r c e n t of the c o l o n i e s produced on d i l u t i o n p l a t e s were not found as a c t i v e hyphae i n the n a t i v e s o i l . The development of a q u i c k and a c c u r a t e t e c h n i q u e t o e s t i m a t e f u n g a l hyphae in situ remains one of the key problems f o r f u t u r e s t u d i e s i n t o f i n e r o o t and f u n g a l 17 e c o l o g y ( F o g e l 1985). I t was l a r g e l y s e r e n d i p i t o u s t h a t I d i s c o v e r e d t h a t the i n - g r o w t h bag t e c h n i q u e c o u l d be u t i l i z e d t o q u a n t i f y f u n g a l biomass dynamics. What l i m i t e d l i t e r a t u r e t h e r e i s c o n c e r n i n g t h i s t e c h n i q u e makes no mention of f u n g a l s t r u c t u r e s o t h e r than m y c o r r h i z a e ( P e r s s o n 1979). The f a c t t h a t t h i s d i s c o v e r y was made p u r e l y by a c c i d e n t does not l e s s e n i t s ' impact. I t may now be p o s s i b l e , u s i n g a d a p t a t i o n s of the r o o t i n - g r o w t h bag t e c h n i q u e , t o study the f u n g u s - r o o t s y m b i o s i s in situ w i t h much l e s s e f f o r t than had p r e v i o u s l y been r e q u i r e d . 3. THE STUDY AREA 3.1 LOCATION, HISTORY, AND SITE DESCRIPTION The s t u d y a r e a i s l o c a t e d on the south-west f a c i n g s l o p e s of t h e B e a u f o r t range on c e n t r a l Vancouver I s l a n d between P o r t A l b e r n i and P a r k s v i l l e (49° 16' N l a t i t u d e and 128° 48' W l o n g i t u d e ) ( F i g u r e 3.1 and 3.2). The a r e a i s s i t u a t e d w i t h i n the E a s t Vancouver I s l a n d D r i e r M a r i t i m e subzone of the C o a s t a l Western Hemlock zone (CWHa2, N u s z d o r f e r et al. 1985). Mean e l e v a t i o n s of the s t u d y p l o t s v a r y between 319 m and 366 m. T a b l e I summarizes the g e n e r a l c l i m a t i c c h a r a c t e r i s t i c s of the subzone ( K l i n k a et al. 1979). A l t h o u g h found w i t h i n the C o a s t a l Western Hemlock zone, the s t u d y a r e a and the m a j o r i t y of the s u r r o u n d i n g f o r e s t s u p p o r t n e a r l y pure s t a n d s of 50 t o 80 y e a r - o l d D o u g l a s - f i r . The a r e a was log g e d i n the l a t e 1920's and s e v e r e l y burned i n t h e summer of 1931. S e v e r a l v e t e r a n D o u g l a s - f i r , a d j a c e n t t o t h e uppermost p l o t , s u r v i v e d b o t h the l o g g i n g and the f i r e , and p r o b a b l y s e r v e d as a seed s o u r c e f o r the p r e s e n t s t a n d s . Three s i t e s a l o n g a s h o r t t o p o g r a p h i c sequence ( r i d g e - t o p t o l o w e r - s l o p e seepage s i t e ) were chosen w i t h i n t h e s t u d y a r e a . Two p l o t s were e s t a b l i s h e d w i t h i n each s i t e ( F i g u r e 3.3). Sampled s t a n d s were s e l e c t e d t o c h a r a c t e r i z e each of t h r e e edatopes [which a r e c o m b i n a t i o n s of hygrotope ( s o i l m o i s t u r e regimes) and t r o p h o t o p e ( p o t e n t i a l s o i l 18 19 F i g u r e 3.1. C L o c a t i o n of the s t u d y a r e a i n B r i t i s h C o lumbia. T h i s f i g u r e shows the r e l a t i o n s h i p of the study a r e a t o Vancouver I s l a n d and t h e m a i n l a n d of B r i t i s h C olumbia. 20 F i g u r e 3.2. L o c a t i o n of the study a r e a i n r e l a t i o n s h i p t o P o r t A l b e r n i . The a r e a shown i n F i g u r e 3.2 c o r r e s p o n d s t o the i n s e t a r e a of F i g u r e 3.1. 21 F i g u r e 3.3. L o c a t i o n of the st u d y s i t e s a l o n g the t o p o g r a p h i c sequence of the st u d y a r e a . The area shown i n F i g u r e 3.3 co r r e s p o n d s t o the i n s e t a r e a of F i g u r e 3.2. Contour l i n e ( s o l i d l i n e s ) g i v e e l e v a t i o n s i n f t ( m ) . Dashed l i n e s r e p r e s e n t main and secondary roads ( M a c M i l l a n B l o e d e l Co. L t d . , Cameron D i v i s i o n ) . • = The Gault heri a shall on a s s o c i a t i o n ; A = The Moss a s s o c i a t i o n ; = The Achl ys - Pol ysti chum a s s o c i a t i o n . 22 n u t r i e n t r e g i m e s ) ] ; The x e r i c - p o o r Gaultheria shall on a s s o c i a t i o n , the mesic-medium Moss a s s o c i a t i o n , and the h y g r i c - r i c h Ac hi ys-Pol yst i chum a s s o c i a t i o n . These edatopes c h a r a c t e r i z e t h r e e ecosystem a s s o c i a t i o n s ( F i g u r e 3.4) as d e f i n e d by Koj i m a and K r a j i n a (1975). Hygrotopes and tr o p h o t o p e s were i n f e r r e d l a r g e l y from s i t e c h a r a c t e r i s t i c s and t o p o g r a p h i c p o s i t i o n i n the f i e l d as o u t l i n e d by Walmsley et al. (1980). The ob s e r v e d v e g e t a t i v e , s o i l , and s i t e c h a r a c t e r i s t i c s of the st u d y s i t e s a r e summarized i n Tabl e I I . A d d i t i o n a l s o i l c h a r a c t e r i s t i c s , d e s c r i b e d by Kojima and K r a j i n a as t y p i c a l f o r the s e a s s o c i a t i o n s , a r e g i v e n i n T a b l e X V I I , Appendix 2. A b r i e f d e s c r i p t i o n of each of the t h r e e s i t e s f o l l o w s . 1. The X e r i c s i t e , w i t h i n t he G a u l t h e r i o ( s h a l l o n i s ) - P s e u d o t s u g e t u m m e n z i e s i i a s s o c i a t i o n (= the Gaultheria shall on a s s o c i a t i o n ) (Kojima and K r a j i n a 1975). F i g u r e 3.5. T h i s s i t e was l o c a t e d on the upper s l o p e s of the e l e v a t i o n a l t r a n s e c t a t an a l t i t u d e of 366 m. The moss and herb l a y e r of t h e s e s t a n d s was p o o r l y d e v e l o p e d . The most common mosses, Kindbergia oregana ( S u l l . ) Ochyra and Dicranum fuscescens T u r n . , were u s u a l l y l i m i t e d t o r o t t i n g wood. Goodyera obi ongi folia Raf. and Chimaphila umbel I at a (L.) B a r t , c h a r a c t e r i z e d t he s p a r s e herb l a y e r . In c o n t r a s t t o the h e r b s , t h e r e was a v e r y v i g o r o u s shrub l a y e r composed of Gaultheria shall on P u r s h and Mahonia •\ M ( h ) ' PSEUOOTSUGA MEN2IES!I mesic 4 TSUCA HETEROPHYLIA THUJA PLICATA F i g u r e 3.4. Topographic sequence of ecosystem a s s o c i a t i o n s w i t h i n the d r i e r subzone of the CWHa2 (Kojima and K r a j i n a 1975); 1. J = t h e Juniperus communis v a r . montana a s s o c i a t i o n ; 2. G = t h e Gault her i a shall on a s s o c i a t i o n ; 3. M(m) = the moss a s s o c i a t i o n - Mahonia nervosa v a r i a n t 4. M(h) = the moss a s s o c i a t i o n - Hylocomium splendens var i a n t ; 5. A-P(a) = the Ac hiys-Pol ysti chum a s s o c i a t i o n Achlys triphylI a v a r i a n t ; 6. A-P(p) = the Achl ys-Pol yst i chum a s s o c i a t i o n -Pol ystichum munitum v a r i a n t ; 7. O-A = the Oplopanax-Adi ant um a s s o c i a t i o n . 24 Tab l e I . Summary of the mean c l i m a t i c v a l u e s f o r the E a s t Vancouver I s l a n d D r i e r M a r i t i m e subzone of the C o a s t a l Western Hemlock zone (CWHa2) ( K l i n k a et al. 1979). C l i m a t i c parameter Mean v a l u e C l i m a t e (Koppen/Trewartha); d r i e r C f b Mean a n n u a l p r e c i p i t a t i o n (mm); 2060 Mean p r e c i p i t a t i o n , w e t t e s t month 347 (December) (mm); Mean p r e c i p i t a t i o n , d r i e s t month ( J u l y ) 36 (mm); Mean p r e c i p i t a t i o n , A p r i l - Sept. (mm); 464 Mean a n n u a l t e m p e r a t u r e (°C); 8.7 Mean t e m p e r a t u r e , warmest month (August) 16.8 (°C); Mean t e m p e r a t u r e , c o l d e s t month 0.9 (January) (°C); Number of months w i t h mean t e m p e r a t u r e s 5 g r e a t e r than 10°C; Number of months w i t h mean t e m p e r a t u r e s 0 l e s s than 0°C; R a t i o a c t u a l t o p o t e n t i a l 0.87 e v a p o t r a n s p i r a t i o n ; Maximum snow de p t h (cm); 19 Number of months w i t h water d e f i c i t s ; 1.8 25 T a b l e I I . Summary of the s o i l , t o p o g r a p h i c a l , and s i l v i c u l t u r a l • c h a r a c t e r i s t i c s of the t h r e e s t u d y s i t e s . Study S i t e s C h a r a c t e r i s t i c X e r i c S i t e M e s i c S i t e H y g r i c S i t e E l e v a t i o n (m) 366 S i t e p o s i t i o n upper s l o p e R e l i e f shape 1 concave Slope (%) Aspec t Seepage 1 D r a i n a g e c l a s s 1 P a r e n t m a t e r i a l 1 A v r g . t r e e h t . (m) 2 a v r g . t r e e age ( y r ) 2 Rep. SI 1o o 3 C a l c . S I ^ Q Q 3 40 southwest absent w e l l d r a i n e d m o r a i n a l veneer .17.0 54 33 21.8 327 lower m i d - s l o p e s t r a i g h t 1 5 southwest s e a s o n a l l y p r e s e n t m o d e r a t e l y w e l l d r a i n e d c o l l u v i a l veneer over a m o r a i n a l b l a n k e t 36.7 52 37 48. 1 319 v a l l e y f l o o r s t r a i g h t 3 west p r e s e n t i m p e r f e c t l y d r a i n e d c o l l u v i a l veneer over a m o r a i n a l b l a n k e t 37.7 52 54 49.8 1 a f t e r Walmsley et al. 1980. 2 Data c o u r t e s y of P. P o l a n d ( u n p u b l i s h e d ) . 3 R e p o r t e d s i t e i n d i c e s a r e from Kojima and K r a j i n a (1975). C a l c u l a t e d s i t e i n d i c e s a r e from s i t e index e q u a t i o n s (Omule 1983) f o r c o a s t a l D o u g l a s - f i r and u t i l i z e mean h e i g h t and age e s t i m a t e s f o r each s t a n d . Table III. Summary of the mensurationa1 data of the overstory components of the 3 s i t e s . Data for 1983 courtesy of P. Poland (unpublished). Values given are for means and, where calculated, 1 SE of mean (1n parentheses). Study Sites the Character 1st 1 c Xeric s i t e Mesic s i t e Hygric s i t e Species' 1. duly 1983 density (trees/ha) Mean tree DBH (cm) Basal area (m'/ha) % of total basal area July 1985 Density (trees/ha) Mean tree DBH (cm) Basal area (m* /ha) % of total basal area DF 6467 8.55 6190 8 .94 (0.45) 45.51 (5.15) 85 . 12 HEM CED 277 18.40 (0.42) (1.21) 43.29 7.43 (4.82) (0.94) 85.35 14.65 277 19 .03 (1.11) 7.94 (0.90) 14 .88 1 Abbreviations; DF = Pseudotsuga menziesii; HEM = Tsuga heterophyl1 a; CED = Thuja p i i c a t a ; TOT = total for a l l trees. TOT 6744 8.96 (0.97) 50. 72 (5.82) 6467 9.37 (0.50) 53 . 35 (6.19) DF 1151 24.35 (1.28) 61 .90 (6.86) 91.13 1090 25.61 (1.33) 64.23 (7.07) 91 .07 HEM 81 20. 35 (4.48) 3.01 (1.38) 4.43 81 2 1 .03 (4.67) 3.22 ( 1 .50) 4.57 CED 222 1 1 .78 ( 1 85) 3 .02 (1.10) 4.44 222 1 1 .93 1 .85 3 .08 (1.11) 4.36 TOT 1454 22. 21 (1.20) 67.93 (7.47) 1393 23 . 17 ( 1 .26) 70. 53 (7.78) DF 605 34 .55 (1.79) 62.84 (5.55) 94.94 575 36.43 (1.77) 65.36 (5.51 ) 94 .89 HEM 44 26.80 (2.78) 2.55 (0.53) 3 .86 44 27 . 33 (2.85) 2.65 (0.55) 3.85 CED 59 12.88 (1.43) 0.80 (0.17) 1 . 20 59 13.38 ( 1 .54) 0.86 (0.19) 1 . 25 TOT 708 32.26 (1.78) 66. 19 (6.20) 678 33.84 (1.81) 66. 19 (6.20) 27 F i g u r e 3 . 5 . A view of the x e r i c s i t e w i t h i n t h e Gaultheria shallon assoc i a t i o n . 28 nervosa (Pursh) N u t t . w i t h minor components of Vacci ni um p a r v i f o l i u m Smith and Rosa gymnocarpa N u t t . The main components of the s p a r s e t a l l shrub l a y e r were Tsuga het e r o p h y l I a (Raf.) S a r g . and Thuja p l i c a t a (Donn.). The t r e e l a y e r was dominated by s m a l l d i a m e t e r Pseudotsuga m e n z i e s i i which made up 83.3 p e r c e n t of the t o t a l b a s a l a r e a f o r t h i s s t a n d ( T a b l e I I I , F i g u r e 3.5). Average stem d i a m e t e r a t b r e a s t h e i g h t (dbh = 1.3 m) i n c r e a s e d from 8.96 cm t o 9.37 cm between J u l y 1983 and J u l y 1985, w h i l e the s t a n d d e n s i t y d e c r e a s e d from 6467 l i v e stems per h e c t a r e t o 6190 l i v e stems per h e c t a r e d u r i n g the same p e r i o d . K o jima and K r a j i n a (1975) s t a t e t h a t the p r o d u c t i v i t y of t h i s ecosystem i s q u i t e low, w i t h a s i t e i ndex of 33 m per 100 y e a r s f o r Pseudotsuga m e n z i e s i i and 26 m per 100 y e a r s f o r Tsuga het e r o p h y l I a. However, u s i n g s t a n d a r d s i t e index e q u a t i o n s f o r c o a s t a l D o u g l a s - f i r (Omule 1983), and the e s t i m a t e s of mean s t a n d age and t r e e h e i g h t , the c a l c u l a t e d s i t e index a t 100 y e a r s of 21.8 m was even l e s s than the f i g u r e s g i v e n by the above a u t h o r s (Table I I ) . The d i f f e r e n c e between the two e s t i m a t e s of s i t e index a t 100 y e a r s can p r o b a b l y be e x p l a i n e d by t h e d i f f e r e n t ages a t which the r e s p e c t i v e s i t e i n d i c e s were c a l c u l a t e d . Kurz ( u n p u b l i s h e d ) has r e - c a l c u l a t e d the s i t e i n d i c e s f o r a number of s t a n d s of Vancouver I s l a n d D o u g l a s - f i r growing on a v a r i e t y of s i t e s w i t h a range of s i t e q u a l i t i e s . Even though t h e s e s t a n d s were measured as r e c e n t l y as 20 y e a r s ago, he found as much as a 5 m d i f f e r e n c e between the 29 c a l c u l a t e d s i t e i n d i c e s a t 50 y e a r s f o r the same s i t e . K o j i m a and K r a j i n a (1975) worked i n mature s t a n d s of t r e e s , w h i l e t h i s s tudy was c o n d u c t e d i n a r e l a t i v e l y young s t a n d , w i t h an average s t a n d age of o n l y 54 y e a r s ( T a b l e I I ) . The h i g h d e n s i t y of t r e e s on the " x e r i c s i t e would a l s o have a f f e c t e d the s i t e i n d e x . H i g h p l a n t i n g d e n s i t i e s have been shown t o decrease the mean p l a n t weight f o r a l a r g e number of a n n u a l and p e r e n n i a l p l a n t s p e c i e s , as w e l l as f o r many f o r e s t t r e e s p e c i e s (Harper 1977). C u r t i s and Reukema (1970) found t h a t d e c r e a s i n g the i n i t i a l s p a c i n g of p l a n t e d D o u g l a s - f i r from 3.0 m t o 1.5 m caused a d e c r e a s e of a p p r o x i m a t e l y 35 p e r c e n t i n t h e t o t a l h e i g h t a t 40 y e a r s of age i n dominant and co-dominant i n d i v i d u a l s of the h i g h e r d e n s i t y s t a n d . The c a l c u l a t e d s t a n d d e n s i t y of g r e a t e r than 6000 stems per ha on the x e r i c s i t e i s e x t r e m e l y h i g h f o r D o u g l a s - f i r on the c o a s t . Normal p l a n t i n g d e n s i t i e s f o r D o u g l a s - f i r on a good t o mesic s i t e i n t h i s a r e a range between 700 and 1800 stems per ha. 2. The M e s i c s i t e , w i t h i n the Hyloco m i o ( s p l e n d e n t i s ) - K i n d b e r g i o ( o r e g a n i ) Mahonio ( n e r v o s a e ) - Pseudotsugo-Tsugetum h e t e r o p h y l l a e a s s o c i a t i o n , hylocomiosum s p l e n d e n t i s v a r i a n t (= the Moss a s s o c i a t i o n , Hylocomium splendens v a r i a n t ) (Kojima and K r a j i n a 1975). F i g u r e 3.6. 30 U n l i k e the x e r i c Gaultheria shall on a s s o c i a t i o n , the Moss a s s o c i a t i o n , Hylocomium splendens v a r i a n t on the lower s l o p e mesic s i t e i s t y p i f i e d by fewer, l a r g e r t r e e s and a v e r y w e l l d e v e l o p e d moss l a y e r . The o v e r s t o r e y canopy c l o s u r e was g r e a t e r than 80 p e r c e n t , r e s u l t i n g i n lower l i g h t l e v e l s i n the u n d e r s t o r e y here than i n the x e r i c s i t e . C o n s e q u e n t l y , t h e r e i s p o o r e r shrub development w i t h i n the mesic s i t e than i n the Gaultheria shall on a s s o c i a t i o n , where canopy c l o s u r e i s not as g r e a t . The f o r e s t f l o o r was c a r p e t e d w i t h a t h i c k c o v e r i n g of v a r i o u s moss s p e c i e s . The t h r e e most abundant s p e c i e s found were Hylocomium splendens (Hedw.) B.S.G., Kindbergia oreganum, and Rhytidi adelphus loreus (Hedw.) Warnst. The herb l a y e r , a l t h o u g h s p a r s e , c o n t a i n e d a number of im p o r t a n t i n d i c a t o r s p e c i e s . Achlys triphylla (Smith) DC. was p r e s e n t , but not abundant, as was Linnaea boreal is L. T h i s s i t e a l s o c o n t a i n e d the i n t e r e s t i n g (and q u i t e b e a u t i f u l ) s a p r o p h y t i c s p e c i e s Allotropa virgata T. & G. K r a j i n a and S p i l s b u r y (1953, i n Ko j i m a and K r a j i n a 1975) s t a t e t h a t a c o n c e n t r a t i o n of s a p r o p h y t i c s p e c i e s i s c h a r a c t e r i s t i c of t h i s a s s o c i a t i o n . Both Mahonia nervosa and Gaultheria shall on were p r e s e n t , but were much l e s s abundant than on the x e r i c s i t e . Vaccinium parvifolium and Rosa gymnocarpa were a l s o found growing on o l d stumps. The o v e r s t o r e y l a y e r was a g a i n dominated by Pseudotsuga menziesii, which a c c o u n t e d f o r 91.1 p e r c e n t of the t o t a l 31 b a s a l a r e a f o r the s t a n d ( T a b l e I I I , p. 26, and F i g u r e 3.6, p. 3 3 ) . The u n d e r s t o r e y c o n t a i n e d e q u a l amounts of Tsuga het er ophylI a and Thuja pi i cat a, t h e l a t t e r b e i n g absent c o m p l e t e l y from the x e r i c s i t e . P r o d u c t i v i t y of t h i s s i t e was h i g h e r than t h a t of the x e r i c s i t e . The average stem dbh i n c r e a s e d from 22.2 cm t o 23.2 cm between J u l y 1983 and J u l y 1985, w h i l e the number of l i v e stems per h e c t a r e d e c r e a s e d from 1454 t o 1393 d u r i n g the same p e r i o d . A l t h o u g h the x e r i c and mesic s i t e s t h i n n e d a t the same r e l a t i v e r a t e s between 1983 and 1985 (Table I I I ) , t h e r e were much g r e a t e r amounts of s t a n d i n g dead and downed wood on the mesic s i t e ( F i g u r e 3.6). S i t e index f o r t h i s p l a n t a s s o c i a t i o n was r e p o r t e d t o be 40 m per 100 y e a r s f o r Pseudotsuga menziesii, 37 m per 100 y e a r s f o r Tsuga het erophylI a, and 32 m per 100 y e a r s f o r Thuja pi i cat a (Kojima and K r a j i n a 1975). However s i t e index a t 100 y e a r s f o r D o u g l a s - f i r on t h i s s i t e , u s i n g the mean e s t i m a t e s of t r e e h e i g h t and s t a n d age, was c a l c u l a t e d a t 48.1 m (T a b l e I I , p. 2 5 ) . The d i f f e r e n c e between my c a l c u l a t e d s i t e index a t 100 y e a r s and t h a t g i v e n by Kojima and K r a j i n a (1975) i n d i c a t e s t h a t my mesic s i t e i s a t the w e t t e r end of hygro t o p e s c a l e f o r t h i s a s s o c i a t i o n . The pr e s e n c e of a l a r g e number of r i c h e r - s i t e i n d i c a t o r s p e c i e s more commonly a s s o c i a t e d w i t h h y g r i c s i t e s would a l s o s u p p o r t t h i s . The d e s i g n a t i o n of t h i s s i t e as b e l o n g i n g t o the Moss a s s o c i a t i o n was based p r i n c i p a l l y on the abundance of Hylocomium splendens and Kindbergia oreganum t h r o u g h o u t the st u d y p l o t s . The 32 abundance of the moss on t h i s s i t e c o u l d have been i n f l u e n c e d , however, by the v e r y dense n a t u r e of the o v e r s t o r e y s t a n d and the r e s u l t a n t low l i g h t l e v e l s . These lower l i g h t l e v e l s may not have a l l o w e d f o r the development of a more abundant herb l a y e r c h a r a c t e r i s t i c of more p r o d u c t i v e a s s o c i a t i o n s . Both t h e g r e a t e r measured s i t e i ndex of t h i s s i t e , and i t s ' c l o s e p r o x i m i t y t o h y g r i c s i t e ( F i g u r e 3.3, p. 21) suggest t h a t i t may a c t u a l l y be c l o s e r t o s u b - h y g r i c i n i t s ' h y g r o t o p e . 3. The H y g r i c s i t e , w i t h i n t h e K i n d b e r g i o ( o r e g a n i ) - T i a r e l l o ( t r i f o l i a t a e P o l y s t i c h o ( m u n i t i ) - A c h l y d o ( t r i p h y l l a e ) - T h u j e t u m p l i c a t a e a s s o c i a t i o n , p o l y s t i c h o s u m m u n i t i v a r i a n t (= the Achi ys - Pol ystichum a s s o c i a t i o n , Pol ysti chum muni t um v a r i a n t ) (Kojima and K r a j i n a 1975). F i g u r e 3.7. The h y g r i c seepage s i t e w i t h i n the Achi ys - Pol ysti chum a s s o c i a t i o n , Pol ysti chum muni turn v a r i a n t was a h i g h l y d i v e r s e and p r o d u c t i v e s i t e . I n d i v i d u a l l y , the t r e e s on t h i s s i t e were the l a r g e s t of a l l t h r e e s i t e s ( T a b l e s I I and I I I ) . These t r e e s grew i n p a t c h e s , however, p r i n c i p a l l y on o l d stumps, so canopy c l o s u r e h e r e was l e s s than f o r the Moss a s s o c i a t i o n . The r e s u l t a n t h i g h e r l i g h t l e v e l s a t the f o r e s t f l o o r , and the i n c r e a s e i n m o i s t u r e a v a i l a b i l i t y from down s l o p e seepage, a l l o w e d f o r a much g r e a t e r abundance and v a r i e t y i n herbs and shrubs than i n the o t h e r two s i t e s . The h i g h n u t r i e n t c o n t e n t of the seepage water i n f l u e n c i n g t h i s F i g u r e 3 . 6 . A view of the mesic s i t e w i t h i n t h e Moss a s s o c i a t i o n , Hylocomium splendens v a r i a n t . 34 s i t e can be i n f e r r e d by the pr e s e n c e of many n i t r i p h y t i c s p e c i e s such as Streptopus ampl e xi f ol i us (L.) D C , and by the c o a r s e t e x t u r e of the u n d e r l y i n g s o i l h o r i z o n s which would have c o n t a i n e d o n l y s m a l l amounts of n u t r i e n t - r i c h s i l t and c l a y . The moss l a y e r on t h i s s i t e was much l e s s abundant than on mesic s i t e . Kindbergia oreganum, Rhyt i di adeI phus loreus, and Hylocomium splendens were p r e s e n t , but not i n the c o n t i n u o u s c a r p e t s seen i n t h e Moss a s s o c i a t i o n on the mesic s i t e . One i m p o r t a n t s p e c i e s found i n t h i s l a y e r and not seen e l s e w h e r e was Leucolepis menziesii (Hook.) S t e e r e ex L. Koch. T h i s b e a u t i f u l moss i s a c a l c i p h y t e , i n d i c a t i v e of h i g h l e v e l s of a v a i l a b l e c a l c i u m i n the s o i l s o l u t i o n , and u s u a l l y a s s o c i a t e d w i t h h i g h l y p r o d u c t i v e ecosystems. I t formed dense mats on the w e t t e s t p o r t i o n s of the h y g r i c p l o t s . The s p a r s e t a l l s h rub l a y e r was composed p r i n c i p a l l y of j u v e n i l e Thuja plicata and Tsuga het er ophyl I a . Vacci ni um parvifolium and Mahonia nervosa were s c a t t e r e d w i t h i n the p l o t s . The herb l a y e r was dominated by v e r y v i g o r o u s Polystichum munitum ( K a u l f . ) P r e s l . , many of which were 2 m a c r o s s and 1.5 m h i g h . Achlys triphylla was the most abundant s p e c i e s over c e r t a i n p o r t i o n s of the p l o t s . Tiarella trifoliata v a r . trifoliata L., Tiarella trifoliata v a r . laciniata (Hook.) Wheel., Trientalis latifolia Hook., and Streptopus amplexifoli us a l s o c h a r a c t e r i z e the herb l a y e r of t h i s h y g r i c s i t e . Galium triflorum M i c h x . was 35 F i g u r e 3 . 7 . A view of the h y g r i c s i t e w i t h i n the Achi ys Pol yst i chum a s s o c i a t i o n , Pol ysti chum muni turn v a r i a n t . 36 s c a t t e r e d t h r o u g h o u t t h e p l o t s . The o v e r s t o r e y was dominated by Pseudotsuga m e n z i e s i i [94.9 p e r c e n t of the t o t a l b a s a l a r e a ( T a b l e I I , p. 2 5 ) ] . The average stem d i a m e t e r was the g r e a t e s t of any of the t h r e e s i t e s , i n c r e a s i n g from 32.3 cm i n J u l y of 1983 t o 33.8 cm i n J u l y of 1985. Stan d d e n s i t y was the l o w e s t of a l l t h r e e s i t e s , d e c r e a s i n g from 708 l i v e stems per h e c t a r e t o 678 l i v e stems per h e c t a r e d u r i n g the s t u d y p e r i o d . Kojima and K r a j i n a (1975) s t a t e t h a t some of the h i g h e s t p r o d u c t i v i t i e s i n the e n t i r e p r o v i n c e have been r e c o r d e d f o r t r e e s i n t h i s a s s o c i a t i o n . T h e i r r e p o r t e d s i t e i n d e x f o r Ps eudot suga menziesii i n t h i s a s s o c i a t i o n i s 54 m per 100 y e a r s , w h i l e t h a t of Tsuga het er ophylI a and Thuja p i i c a t a a r e 41 m per 100 y e a r s . The s i t e index which I c a l c u l a t e d showed l i t t l e d i f f e r e n c e from t h e s e r e p o r t e d f i g u r e s , w i t h an e s t i m a t e d s i t e i n d e x of 49.8 m a t 100 y e a r s f o r D o u g l a s - f i r ( T a b l e I I ) . However, i t i s c l e a r from the dbh measurements i n T a b l e I I I (p. 26) t h a t the average t r e e on the h y g r i c i s much b i g g e r than the average t r e e on the mesic s i t e , and i s p u t t i n g on d i a m e t e r growth much f a s t e r . I t seems u n l i k e l y t h a t t h e s e two s i t e s s h o u l d have such s i m i l a r s i t e i n d i c e s . I f , however, t h e r e were s e v e r e b r u s h problems on the h y g r i c s i t e a f t e r t h e o l d growth s t a n d was removed (as t h e c u r r e n t c o n d i t i o n of the s i t e i n d i c a t e s t h e r e would be i f the o v e r s t o r e y s t a n d now p r e s e n t were removed) then c o m p e t i t i o n between s e e d l i n g s and b r u s h s p e c i e s c o u l d have g r e a t l y reduced the i n i t i a l h e i g h t growth of t h e s e t r e e s . 37 The p r e s e n t s t a n d , h a v i n g o v e r t o p p e d the br u s h s p e c i e s , i s c u r r e n t l y growing a t a much f a s t e r r a t e than the mesic s i t e , and w i l l p r o b a b l y a t t a i n a h e i g h t of over 60 m by the age of 1 00. 3.2 GEOLOGY, SOILS, AND HUMUS FORM The g e o l o g y of s o u t h e r n Vancouver I s l a n d has been g r e a t l y i n f l u e n c e d by r e c u r r e n t v o l c a n i c and more r e c e n t g l a c i a l e v e n t s . The u n d e r l y i n g bedrock of t h e s t u d y a r e a i s unus u a l i n t h a t i t c o n s i s t s p r i m a r i l y of f o l d e d sandstone and c o n g l o m e r a t e s e d i m e n t a r y m a t e r i a l , u n l i k e most of the mountainous s p i n e of Vancouver I s l a n d which i s u n d e r l a i d by v o l c a n i c b a s a l t , i n t r u s i v e g r a n i t e , and g r a n o d i o r i t e (Anonymous 1981). These g e o l o g i c a l m a t e r i a l s a r e o v e r l a i n by g l a c i a l t i l l , g l a c i o - f l u v i a l , a l l u v i a l and c o l l u v i a l m a t e r i a l , p r i n c i p a l l y of v o l c a n i c g e n e s i s . The s o i l s on a l l t h r e e s i t e s were c o a r s e t o v e r y c o a r s e t e x t u r a l l y , had moderate t o h i g h c o a r s e fragment c o n t e n t s , and ranged from sandy loams t o loamy sands ( T a b l e I V ) . On the upper s l o p e s of the stu d y a r e a , w i t h i n the Gaultheria shall on a s s o c i a t i o n , the m o r a i n a l m a t e r i a l i s l e s s than one m t h i c k , f o r m i n g a veneer over bedrock. On the mid- and lower s l o p e s , w i t h i n the mesic and h y g r i c a s s o c i a t i o n s , c o l l u v i u m and g l a c i o - f l u v i a l m a t e r i a l over g l a c i a l t i l l a r e over one m t h i c k , b l a n k e t i n g the u n d e r l y i n g bedrock c o m p l e t e l y . A d d i t i o n a l s o i l , c h a r a c t e r i s t i c s u s u a l l y a s s o c i a t e d w i t h t h e s e p l a n t a s s o c i a t i o n s a r e g i v e n i n T a b l e 38 X V I I , Appendix 2. The x e r i c Gaultheria shall on a s s o c i a t i o n l o s e s m o i s t u r e r a p i d l y t o down s l o p e seepage. In th e s e r e l a t i v e l y d r y c o n d i t i o n s , a t h i n o r t h i v e r o m o r humus form ( K l i n k a et al. 1981) over an e l u v i a t e d d y s t r i c b r u n i s o l (Anonymous 1978) have d e v e l o p e d ( T a b l e I V ) . On t h e mesic Moss a s s o c i a t i o n , the f o r e s t f l o o r showed e v i d e n c e of b o t h s o i l a n i m a l a c t i v i t y , and the pre s e n c e of f u n g i . However, t h e r e was not s u f f i c i e n t m i x i n g of the o r g a n i c and m i n e r a l h o r i z o n s t o produce a t r u e mor humus form. The humus on t h i s s i t e was c l a s s i f i e d as a Humimormoder ( K l i n k a et al. 1981), w h i l e the s o i l s were c l a s s i f i e d as d u r i c d y s t r i c b r u n i s o l s (Anonymous 1978). On t h e h y g r i c Ac hiys-Polysti chum a s s o c i a t i o n , t h e r e was g r e a t l y i n c r e a s e d s o i l a n i m a l a c t i v i t y . T h i s s i t e d e v e l o p e d a l o o s e , w e l l mixed Ah h o r i z o n which c o n t a i n e d l a r g e numbers of earthworms, s p i d e r s , and c e n t i p e d e s . The humus form on t h i s s i t e was c l a s s i f i e d as an o r t h i v e r m i m u l l ( K l i n k a et al. 1981). The s o i l s on the h y g r i c s i t e showed e v i d e n c e ( g l e y i n g ) of a f l u c t u a t i n g water t a b l e , and were c l a s s i f i e d as g l e y e d d y s t r i c b r u n i s o l s (Anonymous 1978). A l l t h r e e a s s o c i a t i o n s showed i n c r e a s i n g c o a r s e fragment c o n t e n t w i t h d e p t h i n the s o i l p r o f i l e ( T a b l e I V ) . 39 T a b l e IV. Summary of the measured s o i l p a r a m e t e r s of the t h r e e s t u d y s i t e s . D e s c r i p t i o n s a r e based on two s o i l p i t s f o r each a s s o c i a t i o n . S o i l sub-group d e s i g n a t i o n s were based on m o r p h o l o g i c a l f e a t u r e s o n l y . C h e m i c a l a n a l y s e s f o r i r o n and aluminum c o n t e n t were not done. F i g u r e s i n pa r e n t h e s e s a r e one s t a n d a r d e r r o r (where c a l c u l a t e d ) . P l a n t A s s o c i a t i o n Parameter Gaul theri a shalI on assoc i a t i o n Moss a s s o c i a t i o n Ac hi ys -Pol ystichum a s s o c i a t i o n S o i l sub-group T e x t u r e Humus form Hor. t h i c k , (cm); F.F. A B BC Coarse f r a g , c o n t . >2 mm (% by v o l . ) A B B u l k d e n s i t y (g per cm 3) F.F. M i n e r a l (A+B) E l u v i a t e d d y s t r i c b r u n i s o l Loamy sand O r t h i v e r o m o r 5.7 (0.51) 2 53 20 + 90.90 (1.33) .0938 (.0096) .7188 ( . 1105) D u r i c d y s t r i c b r u n i s o l Loamy Sand Humimormoder 3.2 (0.41) 1 60 20 + 85.39 (3.81) 91.08 (1.96) .0978 ( .0127) .4980 (.0423) G l e y e d d y s t r i c b r u n i s o l Sandy Loam O r t h i v e r m i m u l l 2.4 (0.27) 8.5 37 25 + 63.27 (5.78) 86.41 (3.47) .0586 ( .0079) . 1 749 (.0541) Methods a. b. as f o l l o w s ; B u l k d e n s i t y - sample of known volume ( d e t e r m i n e d u s i n g water poured i n t o a p l a s t i c - l i n e d e x c a v a t i o n ) i s d r i e d a t 105°C t o c o n s t a n t w e i g h t . Coarse fragments - volume of m i n e r a l m a t e r i a l >2 mm, measured by water d i s p l a c e m e n t . S o i l s u b - g r o u p i n g s a r e a f t e r Anonymous (1978), Humus form c l a s s i f i c a t i o n i s a f t e r K l i n k a et al. (1981). 40 3.3 CLIMATE OF THE STUDY AREA The Koppen c l i m a t i c d e s i g n a t i o n f o r the study a r e a i s Cfb ( T a b l e I , K l i n k a et al. 1979, p. 24) which i s i n d i c a t i v e of a m i l d , t e m p e r a t e , r a i n y c l i m a t e w i t h no d i s t i n c t d r y season and c o o l summers. K l i n k a et al. (1979) s t a t e t h a t t h i s a r e a i s d r i e r than the u s u a l C f b c l i m a t e , and t h a t summer water d e f i c i t s do e x i s t . The 1.8 month f i g u r e g i v e n by K l i n k a et al. (1979) r e p r e s e n t s an average summer m o i s t u r e d e f i c i t o v e r s e v e r a l y e a r s . S e v e n t y - s e v e n p e r c e n t of the mean a n n u a l p r e c i p i t a t i o n f a l l s between October 1st and March 3 1 s t . A l t h o u g h mean monthly t e m p e r a t u r e s never go below 0°C, p e r i o d i c t e m p e r a t u r e s as low as -22°C were r e c o r d e d i n the p l o t s . A c c u m u l a t i o n s of as much as 20 cm of snow f o r p e r i o d s as l o n g as two months were r e c o r d e d d u r i n g the c o u r s e of the s t u d y . F i g u r e 3.8 shows the p a t t e r n of mean monthly and 30-year a v e r a g e temperature and p r e c i p i t a t i o n d a t a f o r the P o r t A l b e r n i weather s t a t i o n (49° 14' N, 128° 48' W, a t 59m mean e l e v a t i o n ) which i s l o c a t e d a p p r o x i m a t e l y t h r e e km from our s t u d y s i t e s (Anonymous 1982). A l t h o u g h the p a t t e r n shown by the monthly mean te m p e r a t u r e d a t a f o l l o w e d the 30-year a v e r a g e s q u i t e c l o s e l y over t h e c o u r s e of the s t u d y , t h e r e was a wide d e p a r t u r e of the monthly p r e c i p i t a t i o n t o t a l s f o r 1984 and 1985 as compared t o the 30-year average f i g u r e s . In p a r t i c u l a r the summers of 1984 and 1985 and the w i n t e r and s p r i n g of 1985 41. were much d r i e r t han the 3 0 - y e a r a v e r a g e d a t a wou ld i n d i c a t e t h e y s h o u l d have been . D u r i n g t h e s e t i m e s , w h i c h c o r r e s p o n d e d t o the m a j o r i t y o f my o n - s i t e s a m p l i n g , m o i s t u r e d e f i c i t s w o u l d p r o b a b l y have been more s e v e r e t han the f i g u r e o f 1.8 months r e p o r t e d by K l i n k a et al . ( 1 9 7 9 ) . By c o m p a r i s o n , the summer of 1983 a p p e a r s t o have been much c l o s e r t o t h e 3 0 - y e a r a v e r a g e i n t e rms o f measured p r e c i p i t a t i o n . 10-I A J F M A M J J A 8 O N D J F M A M J J A 8 0 N 0 J F M A M J J A 8 O 1983 1984 _ . 1985 F i g u r e 3.8. Comparison of the 30-year averages of monthly p r e c i p i t a t i o n and mean temperature t o the monthly means of p r e c i p i t a t i o n (A) and temperature (B) r e c o r d e d f o r the P o r t A l b e r n i weather s t a t i o n (49° 14' N, 124° 48' W, 59m mean e l e v a t i o n ) f o r the c o r r e s p o n d i n g p e r i o d of t h i s s t udy (Anonymous 1982). 4. MATERIALS AND METHODS 4.1 FIELD 4.1.1 ROOT IN-GROWTH BAG CONSTRUCTION Root i n - g r o w t h bags were c o n s t r u c t e d from c l e a r p o l y u r e t h a n e p l a s t i c mesh w i t h a t h r e e mm pore s i z e u s i n g a 5.0 cm ( o u t s i d e d i a m e t e r ) s t e e l p i p e as a t e m p l a t e . The p l a s t i c mesh was s t r e t c h e d around the p i p e , then hand sewn u s i n g 20 l b n y l o n f i s h i n g l i n e . One end of the bag was sewn s h u t , c r e a t i n g a porous tube 35 cm l o n g by f i v e cm wide ( F i g u r e s 4.1 and 4.2). 4.1.2 GROWTH MEDIUM For the major p o r t i o n s of t h i s s t u d y , two d i f f e r e n t m a t e r i a l s were used as growth medium i n the i n - g r o w t h bags: 1. m i n e r a l s o i l from the t o p 50 cm of the s o i l p r o f i l e from each of the t h r e e s i t e s was brought t o the l a b o r a t o r y , a i r d r i e d , and s i e v e d t o l e s s than .833 mm i n o r d e r t o remove e x i s t i n g l i v e and dead r o o t s . F o r e s t f l o o r m a t e r i a l s ( p r i n c i p a l l y n e e d l e and s m a l l branch l i t t e r ) from a l l s i t e s were a l s o c o l l e c t e d , a i r d r i e d and ground t o l e s s than .1 mm u s i n g a W i l e y m i l l . 2. beach sand from J e r i c h o Beach, a d j a c e n t t o the U. B. C. campus, was c o l l e c t e d from below the h i g h water mark. T h i s sand o r i g i n a t e d i n the F r a s e r R i v e r w a t e r s h e d , and was d e p o s i t e d on the beach by the combined a c t i o n s of 43 F i g u r e 4.1. C o n s t r u c t i o n of the i n - g r o w t h bags. S t a r t i n g m a t e r i a l s c o n s i s t e d of c l e a r p l a s t i c mesh w i t h a t h r e e mm pore s i z e and 20 l b n y l o n f i s h i n g l i n e . The s t a i n l e s s s t e e l p i p e used as a t e m p l a t e f o r the i n - g r o w t h bags i s a l s o shown. F i g u r e 4.2. The f i n i s h e d i n - g r o w t h bags. In-growth bags were u s u a l l y 35 cm l o n g . As many as t e n bags per hour c o u l d be hand sewn. 46 r i v e r and t i d e . The sand was composed p r i m a r i l y of q u a r t z and f e l d s p a r g r a n u l e s , but d i d have a n o t i c e a b l e c o n t e n t of w h i t e and b l a c k micas as w e l l . T h i s sand was t h o r o u g h l y washed u s i n g r u n n i n g t a p water, a i r d r i e d , then s i e v e d t o l e s s than .833 mm. 4.1.3 INSTALLATION OF THE IN-GROWTH BAGS I n s t a l l a t i o n p o i n t s w i t h i n the study p l o t s were chosen u s i n g a random number t a b l e t o d e t e r m i n e random c o - o r d i n a t e s . H o l e s 30 cm deep were made u s i n g a c o r i n g tube (5.1 cm i n s i d e d i a m e t e r , F i g u r e 4.3). One end of t h i s tube was sharpened w h i l e the o t h e r end was r e i n f o r c e d t o accommodate a s t e e l cap. T h i s s a m p l i n g d e v i c e was d r i v e n i n t o the ground u s i n g a l a r g e m a l l e t , and e x t r a c t e d by hand. I f a stone was e n c o u n t e r e d , i t was e x t r a c t e d (as l o n g as t h e e x t r a c t i o n d i d not g r e a t l y d i s t u r b the s i z e or shape of t h e h o l e ) and the h o l e was then r e - c o r e d . Where a l a r g e r r o c k was e n c o u n t e r e d , which made s a m p l i n g t o a f u l l 30 cm i m p o s s i b l e , the c l o s e s t a d j a c e n t spot t h a t c o u l d be s u c c e s s f u l l y c o r e d was u t i l i z e d . In g e n e r a l , the s o i l s on a l l t h r e e s i t e s had low p e r c e n t a g e s of l a r g e s t o n e s i n t h e i r upper 50 cm, so c o r i n g was not d i f f i c u l t . The i n - g r o w t h bag was p l a c e d i n the h o l e , and s o i l o r sand was poured i n t o the bag. The s o i l or sand was tapped down i n t e r m i t t e n t l y t o ensure good c o n t a c t between the s i d e s of the h o l e and the i m p l a n t e d i n - g r o w t h bags, and t o e l i m i n a t e a i r p o c k e t s i n the bags t h e m s e l v e s . S i n c e b o t h 47 F i g u r e 4 . 3 . I n s t a l l a t i o n of the r o o t i n - g r o w t h bags. The n a t i v e s o i l c o r e was e x t r a c t e d u s i n g a s t e e l p i p e auger. 48 sand and s o i l m a t e r i a l were v e r y d r y , the bags f i l l e d e a s i l y . V e r y l i t t l e p r e s s u r e was needed d u r i n g t h e t a p p i n g o p e r a t i o n , so a b n o r m a l l y h i g h b u l k d e n s i t i e s of m a t e r i a l w i t h i n t h e bags (which c o u l d have e x c l u d e d p e n e t r a t i o n by some r o o t s ) were p r o b a b l y a v o i d e d . The n a t i v e - s o i l - f i l l e d i n - g r o w t h bags were topped o f f w i t h 2 t o 5 cm of ground f o r e s t f l o o r m a t e r i a l . A minimum of f i v e cm of i n - g r o w t h bag mesh p r o t r u d e d from th e ground t o a l l o w f o r t a g g i n g and f o r ease of e x t r a c t i o n a t the time of s a m p l i n g ( F i g u r e 4.4). The p l a s t i c n e t t i n g m a t e r i a l was s t r o n g enough t o a l l o w e x t r a c t i o n by s i m p l y p u l l i n g s t r a i g h t up on the exposed p o r t i o n s of the bags. Other a u t h o r s , w o r k i n g i n h e a v i e r a g r i c u l t u r a l s o i l s , have found t h a t e x c a v a t i o n of the s u r r o u n d i n g s o i l volume was n e c e s s a r y f o r r e t r i e v a l of the bags (Steen 1984, 1985, Steen and A l - W i n d i 1984). However, because t h i s method would have e n t a i l e d s e v e r e s i t e d i s t u r b a n c e t h a t c o u l d have a f f e c t e d ongoing r o o t growth i n t o the r e m a i n i n g bags, t h i s r e t r i e v a l method was r e j e c t e d . For the most p a r t , because of t h e c o a r s e t e x t u r e of t h e s o i l s on t h e t h r e e s i t e s , e x c a v a t i o n was a l s o u n n e c e s s a r y . R e t r i e v a l of the i n - g r o w t h bags prove d t o be most d i f f i c u l t d u r i n g the w i n t e r . The s t u d y s i t e s were c o v e r e d w i t h snow f o r a t l e a s t p a r t of the w i n t e r , when even f i n d i n g the bags was sometimes d i f f i c u l t and i n v o l v e d sweeping the snow away t o expose t h e i r t o p s . Moreover, v e r y low morning t e m p e r a t u r e s would o f t e n f r e e z e the f o r e s t f l o o r s u r r o u n d i n g F i g u r e 4 . 4 . An i n s t a l l e d and tagged i n - g r o w t h bag. In t h i s example the growth medium w i t h i n the i n - g r o w t h bag i s s i l i c a sand. A f t e r i n s t a l l a t i o n , i n - g r o w t h bags were l e f t i n the f i e l d f o r n i n e months b e f o r e b e i n g r e - c o l l e c t e d . 50 t h e b a g s . On some m o r n i n g s t h e b a g s h a d t o l i t e r a l l y be " c h i p p e d " f r o m t h e s u r r o u n d i n g o r g a n i c l a y e r . The h o l e s l e f t b e h i n d a f t e r e x t r a c t i n g a b a g were c h e c k e d f o r r o o t s w h i c h m i g h t h a v e p u l l e d o u t o f t h e bags an d r e m a i n e d b e h i n d . Few were e v e r f o u n d . The l i v e f i n e r o o t s t h a t h a d grown i n t o t h e bag s n a p p e d o f f q u i t e r e a d i l y a n d r e m a i n e d w i t h i n t h e b a g s . Any r o o t s p r o t r u d i n g o u t o f t h e b a g s a f t e r e x t r a c t i o n were s n i p p e d o f f t o k e e p t h e s a m p l i n g v o l u m e c o n s t a n t ' . E x t r a c t e d i n - g r o w t h b a g s were p l a c e d i n p l a s t i c b a g s , b o x e d , a n d s t o r e d a t 4°C u n t i l p r o c e s s e d . P r e l i m i n a r y work w i t h i n - g r o w t h b a g s on t h e x e r i c a n d h y g r i c s i t e showed l i t t l e r o o t g r o w t h i n t o t h e b a g s a f t e r t h r e e a n d s i x m o n t h s . I d e c i d e d on a n i n e month i n t e r v a l b e t w e e n i n s t a l l a t i o n a n d r e t r i e v a l o f t h e i n - g r o w t h b a g s t o a l l o w a s much t i m e a s p o s s i b l e f o r new r o o t g r o w t h t o o c c u r . W i t h t h e n i n e month p e r i o d , I was s t i l l a b l e t o d i f f e r e n t i a t e b e t w e e n r o o t s p r o d u c e d d u r i n g r e c u r r i n g a n n u a l c y c l e s o f p r o d u c t i o n . S e t s o f f i v e b a g s p e r m a t e r i a l p e r p l o t w e r e i n s t a l l e d on e a c h s i t e a t m o n t h l y i n t e r v a l s . The f i r s t s e t s o f i n - g r o w t h b a g s were i n s t a l l e d on t h e 1 2 t h o f J u n e , 1983, and t h e l a s t on t h e 3 0 t h o f S e p t e m b e r 1984. The f i r s t s e t o f b a g s were r e - c o l l e c t e d on M a r c h 1 s t 1984, a n d t h e l a s t on t h e 2 9 t h o f J u n e , 1985. 51 4.1.4 TEST OF TWO ADDITIONAL GROWTH MEDIA For one i n s t a l l a t i o n d a t e , a d d i t i o n a l s e t s of bags u s i n g two d i f f e r e n t growth media were i n s t a l l e d on one s i t e ; the mesic s i t e . Pure s i l i c a s a n d - b l a s t i n g sand s e r v e d as the " n u t r i e n t - p o o r e s t " of a l l the growth media t e s t e d . The second a d d i t i o n a l medium was f e r t i l i z e d n a t i v e s o i l , u s i n g 400 kg/ha e q u i v a l e n t of 14:14:14 (N:P:K) Osmocote® slow r e l e a s e f e r t i l i z e r as the enrichment m a t e r i a l . T h i s s e r v e d as our " n u t r i e n t - r i c h e s t " growth medium. Ten i n - g r o w t h bags of each of the two r e g u l a r growth media p l u s t e n bags of each of the two a d d i t i o n a l m a t e r i a l s were i n s t a l l e d on the mesic s i t e on October 1 s t , 1984, and were r e - c o l l e c t e d on June 2 9 t h , 1985. 4.1.5 ROOT SAMPLING WITH SEQUENTIAL SOIL CORES T r a d i t i o n a l s e q u e n t i a l s o i l c o r i n g was c a r r i e d out a t b i m o n t h l y i n t e r v a l s on the x e r i c and h y g r i c s i t e s , between F e b r u a r y 23 1983 and May 10 1984 ( n i n e s a m p l i n g d a t e s i n t o t a l ) . The s a m p l i n g and subsequent p r o c e s s i n g were done by Dr. Hannes Hase as p a r t of h i s p o s t - d o c t o r a l f e l l o w s h i p r e s e a r c h ; t o d a t e the work i s u n p u b l i s h e d . S a m p l i n g was done u s i n g the same 30 cm s t a i n l e s s s t e e l c o r e r as was used i n c r e a t i n g h o l e s f o r the i n - g r o w t h bag i n s t a l l a t i o n . At each s a m p l i n g e v e n t , n i n e t o e i g h t e e n sample c o r e s were taken from s i x s u b - p l o t s as a s t r a t i f i e d random sample from randomly s e l e c t e d 1 m x 1 m g r i d p o i n t s . Because of t h e r e l a t i v e l y s m a l l a r e a of the sample p l o t s and 52 the l a r g e number of samples per s a m p l i n g e v e n t , s a m p l i n g was done w i t h replacement (sample p o i n t s c o u l d be s e l e c t e d more than o n c e ) . However, new c o r e s were t a k e n a t l e a s t 25 cm from p r e v i o u s c o r e s . A f t e r e x t r a c t i n g the sample from the s o i l c o r e r , the depth of f o r e s t f l o o r was r e c o r d e d . The sample was then s e p a r a t e d i n t o m i n e r a l s o i l and o r g a n i c l a y e r s , bagged, and t r a n s p o r t e d back t o t h e l a b o r a t o r y a t 0°C. • The v a r i a t i o n i n the number of c o r e s t a k e n a t each s a m p l i n g event was caused by the l a r g e amount of work a s s o c i a t e d w i t h p r o c e s s i n g t h e s e s e q u e n t i a l c o r e s . I n i t i a l s a m p l i n g e v e n t s took 18 c o r e s per s i t e . However, i t was not p o s s i b l e t o p r o c e s s a l l t h e s e c o r e s i n o n l y two months t i m e . Sample s i z e was s u b s e q u e n t l y reduced t o n i n e c o r e s per s a m p l i n g e v e n t . 4.1.6 COLLECTION OF SOIL FOR SOIL MOISTURE DETERMINATIONS S o i l e x t r a c t e d from each s i t e d u r i n g t h e monthly i n s t a l l a t i o n of the i n - g r o w t h bags was s e p a r a t e d i n t o m i n e r a l and o r g a n i c l a y e r s , b u l k e d , s i e v e d on s i t e t o l e s s than two mm, and bagged. T h i s m i n e r a l and o r g a n i c m a t e r i a l was then packed i n i c e and t r a n s p o r t e d back t o the l a b o r a t o r y . 4.1.7 SOIL TEMPERATURE MEASUREMENT S o i l t e m p e r a t u r e s a t 15 cm s o i l d e p t h were m o n i t o r e d over the c o u r s e of the s t u d y on the x e r i c and h y g r i c s i t e s 53 u s i n g OMNIDATA® Model TA51 remote t e m p e r a t u r e probes (Anonymous 1980). Readings from each probe were taken i n the e a r l y mornings and l a t e a f t e r n o o n s on each day t h a t I v i s i t e d t he st u d y s i t e s . Lack of a t h i r d probe p r e v e n t e d me from measuring s o i l t e m p e r a t u r e s on the mesic s i t e . 4.1.8 LITTER COLLECTIONS Aboveground l i t t e r f a l l was measured a t monthly i n t e r v a l s u s i n g t en .133 m2 p l a s t i c c o l l e c t i o n t r a y s per s i t e . The t r a y s were p l a c e d randomly around the s i t e s and c l e a r e d of any o v e r t o p p i n g s h r u b s . The bottoms of the t r a y s were p e r f o r a t e d t o a l l o w r a i n w a t e r t o escape, and c o v e r e d w i t h f i h e - m e s h , p l a s t i c m osquito n e t t i n g t o p r e v e n t the l o s s of l i t t e r t h r o u g h the d r a i n a g e h o l e s . L i t t e r c o l l e c t e d from each t r a p was bagged and t r a n s p o r t e d t o t h e l a b o r a t o r y where i t was d r i e d t o c o n s t a n t weight a t 70°C, s e p a r a t e d i n t o f o l i a r ( p r i n c i p a l l y c o n i f e r o u s n e e d l e s ) and n o n - f o l i a r ( b r a n c h e s , b a r k , bud s c a l e s , and p o l l e n cones) components and weighed. 4.1.9 MENSURATIONAL DATA F i x e d - a r e a p l o t s were e s t a b l i s h e d on each of the s i t e s i n J u l y of 1983 and remeasured i n J u l y of 1985. P l o t b o u n d a r i e s were s e t by c h o o s i n g f o u r c o r n e r t r e e s c o n s i d e r e d t o be i n s i d e the p l o t s . A c t u a l p l o t c o r n e r s were then l o c a t e d h a l f w a y between t h e s e c o r n e r t r e e s and t h e i r n e a r e s t l i v i n g n e i g h b o r s o u t s i d e the p l o t s . A l l t r e e s w i t h i n the 54 p l o t s were i n v e n t o r i e d f o r dbh, s p e c i e s , and crown c l a s s . The t r e e s on the p l o t s were then d i v i d e d i n t o f i v e dbh c l a s s e s . The mean d i a m e t e r of t r e e s w i t h i n each dbh c l a s s was d e t e r m i n e d and th e two t r e e s c l o s e s t t o t h i s mean di a m e t e r were c o r e d f o r age a t b r e a s t h e i g h t . The s t a n d a r d age c o r r e c t i o n f o r Pseudotsuga menziesii taken a t 1.2 meters i s s i x , n i n e , and 12 y e a r s f o r good, medium, and poor s i t e s r e s p e c t i v e l y (Omule 1983). However, t h r e e young D o u g l a s - f i r s a p l i n g s , 1.3 m i n h e i g h t and gro w i n g on a mi d - s l o p e c l e a r - c u t d i r e c t l y a d j a c e n t t o the s t u d y a r e a were found t o be 13 y e a r s of age a t b r e a s t h e i g h t . E x t r a p o l a t e d age c o r r e c t i o n f a c t o r s of ten y e a r s f o r the h y g r i c s i t e and 16 y e a r s f o r the x e r i c s i t e were used t o c o r r e c t the mean age a t b r e a s t h e i g h t f o r each s i t e . The h e i g h t of seven dominant and co-dominant t r e e s per s i t e were measured, and t h i s mean h e i g h t used f o r s i t e index d e t e r m i n a t i o n u s i n g s t a n d a r d h e i g h t over age c u r v e s f o r D o u g l a s - f i r (Omule 1983). A l l t r e e s w i t h i n the p l o t s were marked a t the p o i n t of measurement u s i n g p l a s t i c f l a g g i n g t a p e . T h i s a l l o w e d f o r the subsequent remeasurement of t h e s e t r e e s a t the same p o i n t and d e c r e a s e d the chances of b i a s due t o d i f f e r e n t measurement s t a n d a r d s . Aboveground and c o a r s e r o o t biomass components were then c a l c u l a t e d u s i n g the r e g r e s s i o n e q u a t i o n s of F e l l e r et al. ( 1 9 8 3 ) , and Gholz et al. (1979) f o r good (mesic and h y g r i c ) and poor ( x e r i c ) s i t e s . 55 4.2 LABORATORY 4.2.1 ROOT WASHING AND CLASSIFICATION Each sampled i n - g r o w t h bag was measured t o d e t e r m i n e the e x a c t l e n g t h of bag t h a t was f i l l e d w i t h growth medium. The c o n t e n t s of the i n - g r o w t h bag were then washed g e n t l y onto two s t a c k e d s o i l s i e v e s . The uppermost s i e v e (a #10 s i e v e , mesh s i z e = 2.0 mm) r e t a i n e d most of the l a r g e r and l o n g e r r o o t and m y c e l i a l s e c t i o n s , and any l a r g e p i e c e s of c o n t a m i n a t i o n which adhered t o t h e bag a t the time of e x t r a c t i o n from the s o i l . The f i n e r bottom s i e v e (a #20 s i e v e , mesh s i z e = 0.833 mm) r e t a i n e d t h e f i n e r r o o t f r a g m e n t s , f u n g a l hyphae, and a s m a l l amount of c o n t a m i n a t i n g m i n e r a l and o r g a n i c m a t e r i a l . S i n c e i t had p r e v i o u s l y been s i f t e d t h r o u g h the same s e t of s i e v e s , n e a r l y a l l of t h e growth medium i n the bags washed e a s i l y t h r ough b o t h of the s i e v e s . A l i g h t washing f o r o n l y 30 t o 60 seconds was a l l t h a t was n e c e s s a r y t o produce a r e l a t i v e l y c l e a n , m i n e r a l - s o i l - f r e e sample of r o o t and f u n g a l m a t e r i a l . M a t e r i a l and wash water which passed t h r o u g h the s i e v e s was c o l l e c t e d , c h e c k e d f o r r o o t and f u n g a l f r a g m e n t s , and d i s c a r d e d . A s m a l l component of decomposed o r g a n i c m a t e r i a l was r o u t i n e l y r i n s e d t h r o u g h the s i e v e s , but few l i v e f i n e r o o t t i p s were found i n t h i s d i s c a r d e d m a t e r i a l . One b i g advantage of u s i n g p r e v i o u s l y s i e v e d m a t e r i a l was t h a t i t p e r m i t t e d the use of t h e v e r y f i n e #20 s i e v e 56 w i t h o u t a huge i n c r e a s e i n t h e amount of s o r t i n g t o be done. W i t h r o o t s t u d i e s u s i n g n a t i v e c o r e s , i t i s r a r e f o r s i e v e s f i n e r than two mm t o be u t i l i z e d i n r o o t w a s h i n g . 4 Many m y c o r r h i z a l r o o t t i p s and s m a l l r o o t f ragments, not t o mention most of the f u n g a l biomass, a r e l o s t when u s i n g a two mm s i e v e , e s p e c i a l l y where v i g o r o u s s o i l washing i s a l s o r e q u i r e d . S a f f o r d (1974) e s t i m a t e d t h a t l o s s e s i n f i n e r o o t fragments due t o v i g o r o u s washing c o u l d amount t o as much as 10 p e r c e n t of the t o t a l r o o t biomass <.5 mm i n d i a m e t e r , e s p e c i a l l y from o r g a n i c h o r i z o n s . M a t e r i a l r e t a i n e d by t h e s i e v e s and w i t h i n the mesh of the i n - g r o w t h bags was p l a c e d i n t o p l a s t i c p e t r i d i s h e s f i l l e d w i t h d i s t i l l e d w a t e r , c l e a n e d of c o n t a m i n a t i n g m i n e r a l and o r g a n i c s o i l m a t e r i a l , and s e p a r a t e d i n t o r o o t and f u n g a l components u s i n g t w e e z e r s ( F i g u r e 4.5). Roots were s e p a r a t e d i n t o c o n i f e r o u s and n o n - c o n i f e r o u s c l a s s e s based on t h e i r m o r p h o l o g i c a l c h a r a c t e r i s t i c s . C o n i f e r o u s r o o t s were u s u a l l y l a r g e r than one mm i n d i a m e t e r , l i g h t brown t o b l a c k i n c o l o u r d e p ending on t h e i r age (the newest r o o t s a r e u n s u b e r i z e d a t t h e i r t i p s , so they a r e the l i g h t e s t i n c o l o u r ) , and u s u a l l y p o s s e s s e d one t o many m u l t i - b r a n c h e d m y c o r r h i z a l r o o t t i p s . These m y c o r r h i z a e were v e r y d i s t i n c t i v e . N o n - c o n i f e r o u s r o o t s were u s u a l l y l e s s than one mm i n d i a m e t e r , were e i t h e r b l a c k or t r a n s l u c e n t i n "An e x c e p t i o n t o t h i s a r e t h e s t u d i e s of S a n t a n t o n i o et al. ( 1 9 7 7 ) , S a n t a n t o n i o and Hermann ( 1 9 8 5 ) , and Gholz et al. 1986, who u t i l i z e d s i e v e s w i t h a mesh s i z e as s m a l l as 0.2 mm i n t h e i r r o o t s o r t i n g . However, where s i e v e s of l e s s than two mm were u t i l i z e d , s u b s a m p l i n g of the m a t e r i a l r e t a i n e d by t h e s e v e r y f i n e s i e v e s was a l s o common. 57 c o l o u r , and i f they were l a r g e r than one mm i n d i a m e t e r , they were never e c t o m y c o r r h i z a l . F u n g a l mycelium appeared as a mass of brown or b l a c k j e l l y - l i k e m a t e r i a l r e t a i n e d w i t h i n the mesh of the i n - g r o w t h bag or on the mesh s c r e e n of t h e s i e v e s . I n d i v i d u a l hyphae c o u l d o n l y be seen under the m i c r o s c o p e ( F i g u r e 4.6). I t i s p o s s i b l e t h a t s e v e r a l d i f f e r e n t s p e c i e s of fungus c o u l d have grown w i t h i n the i n - g r o w t h bags over the c o u r s e of the s t u d y . S e v e r a l a u t h o r s have noted t h a t f u n g a l s p e c i e s change r e l a t i v e l y q u i c k l y over time on any g i v e n s i t e (Mason et al . 1983). I made no attempt t o i d e n t i f y the f u n g a l components t o the s p e c i e s l e v e l . However, r e g u l a r c h e c k s of f u n g a l mycelium under the m i c r o s c o p e c o n s i s t e n t l y showed the p r e s e nce of clamp c o n n e c t i o n s between n e i g h b o u r i n g c e l l s i n the hyphae, i n d i c a t i n g t h a t a l l s p e c i e s were B a s i d i o m y c e t e s , a phylum of f u n g i whose members a r e o f t e n m y c o r r h i z a l ( K e n d r i c k and B e r c h 1985). The clumps of f u n g a l mycelium were u s u a l l y wrapped around new e c t o m y c o r r h i z a e . The f u n g a l hyphae and r o o t t i p s c o u l d be p u l l e d a p a r t u s i n g t w e e z e r s . The d i s t i n c t i o n between l i v e and dead r o o t s was based on m o r p h o l o g i c a l c h a r a c t e r i s t i c s . Roots which were t u r g i d , had a smooth e p i d e r m i s , and showed no s e p a r a t i o n between c o r t e x and endodermis, or o t h e r s i g n s of i n t e r n a l decay when viewed under the d i s s e c t i n g m i c r o s c o p e , were c l a s s i f i e d as a l i v e . S e v e r a l a u t h o r s have used n u c l e a r s t a i n i n g t o d i f f e r e n t i a t e between l i v e and dead c e l l s w i t h i n r o o t s 58 (Holden 1975). Kurz ( u n p u b l i s h e d ) has used i o d i n e t o s t a i n s t a r c h g r a n u l e s w i t h i n r o o t s t o d i f f e r e n t i a t e between l i v e and dead r o o t s . Because of i n c o n s i s t e n t s t o r a g e time f o r samples, and l i m i t a t i o n s i n time and manpower, n e i t h e r of thes e t e c h n i q u e s were used. However, our r o o t p r o c e s s i n g and c l a s s i f i c a t i o n t e c h n i q u e s were c o n s i s t e n t w i t h those used i n many r e c e n t r o o t s t u d i e s ( P e r s s o n 1980, Vogt et al. 1981, S a n t a n t o n i o and Hermann 1985). No attempt was made t o d i f f e r e n t i a t e between l i v e and dead f u n g a l mycelium, or between the v e r y f i n e s t l i v e and dead n o n - c o n i f e r o u s r o o t s ( t h o s e l e s s than .5 mm i n d i a m e t e r ) . Other a u t h o r s ( F r a n k l a n d 1975, and Nagel-De B o o i s and Jansen 1971) have used v i t a l s t a i n s such as p h e n o l i c a n i l i n e b l u e , or p h a s e - c o n t r a s t m i c r o s c o p y t o s e p a r a t e " a c t i v e " and " i n a c t i v e " f r a c t i o n s of t h e s o i l f u n g a l biomass. S i n c e I d i d not s e p a r a t e l i v e and dead f u n g a l m a t e r i a l , my e s t i m a t e s f o r hyphae s h o u l d be c o n s i d e r e d as t o t a l , r a t h e r than l i v e biomass. S t o r a g e , washing, and s o r t i n g t e c h n i q u e s f o r the s e q u e n t i a l s o i l c o r e samples were s i m i l a r t o tho s e used f o r the i n - g r o w t h bags, e x c e p t t h a t samples from the s e q u e n t i a l c o r e s were soaked f o r 24 hours i n a m i l d d e t e r g e n t s o l u t i o n p r i o r t o washing t o d i s s i p a t e o r g a n i c f i l m s . A d d i t i o n a l l y , i n s t e a d of 2 mm and .833 mm s t a c k e d s i e v e s b e i n g used i n the washing o p e r a t i o n , f i v e mm and two mm s i e v e s were u t i l i z e d . The use of the l a r g e r s i e v e s was n e c e s s i t a t e d by the heterogeneous n a t u r e of t h e s e q u e n t i a l c o r e samples. A 59 g r e a t e r degree of a g i t a t i o n was a l s o r e q u i r e d t o p r o p e r l y c l e a n t h e s e r o o t samples as compared t o th o s e t a k e n from the in - g r o w t h bags. 4.2.2 ROOT AND FUNGAL BIOMASS ESTIMATES P e t r i d i s h e s c o n t a i n i n g r o o t and f u n g a l components were d r i e d a t 70°C i n a f o r c e d draught oven t o c o n s t a n t w e i g h t , c o o l e d i n a d e s i c c a t o r , then weighed. Each month's samples were b u l k e d by type of biomass component, i n - g r o w t h m a t e r i a l , and s i t e . The ash c o n t e n t of thes e b u l k e d samples was then d e t e r m i n e d a f t e r h e a t i n g i n a m u f f l e f u r n a c e a t 475°C f o r f o u r hours (samples from i n d i v i d u a l i n - g r o w t h bags c o n t a i n e d i n s u f f i c i e n t amounts of biomass t o a l l o w d r y a s h d e t e r m i n a t i o n s w i t h o u t b u l k i n g ) . The biomass e s t i m a t e s r e p o r t e d i n t h i s s t u d y a r e t h e r e f o r e i n a s h - f r e e d r y we i g h t s . 4.2.3 FINE ROOT AND FUNGAL PRODUCTION AND TURNOVER ESTIMATES F i n e r o o t and f u n g a l p r o d u c t i o n and t u r n o v e r were c a l c u l a t e d u s i n g the d e c i s i o n m a t r i x of F a i r l e y and Al e x a n d e r (1985, F i g u r e 4.7), which was adapte d from a s i m i l a r d e c i s i o n m a t r i x of M c C l a u g e r t y et al . (1982). P r o d u c t i o n and t u r n o v e r c a l c u l a t i o n s a r e based on s t a t i s t i c a l l y s i g n i f i c a n t d i f f e r e n c e s between maxima and minima of l i v e and dead r o o t , and of f u n g a l biomass. S t a t i s t i c a l s i g n i f i c a n c e between maxima and minima were c a l c u l a t e d u s i n g Duncan's m u l t i p l e range (a=0.05) f o r r o o t 60 gure 4.5. An example of the amounts of root and fungal biomass from one in-growth bag after processing and c l a s s i f i c a t i o n . The o r i g i n a l 7 root categories shown were subsequently grouped into 4 classes for weighing and ashing. The extra p e t r i dish to the l e f t of the CLFS NEW and F dishes (The F of the fungal p e t r i dish i s hidden by hyphae. It i s , however, the dish d i r e c t l y above and to the l e f t of the CLS NEW p e t r i dish) i s a processing dish containing uncleaned fugal mycelium. The subsequent biomass groupings were as follows; 1. CLSN [coniferous l i v e fine (<2 mm) new] + CLS [coniferous l i v e fine (<2 mm)] + CLB [coniferous l i v e small (2-5 mm)] = CLFS [coniferous l i v e fine-plus-small (0-5 mm)] 2. NCLS [non-coniferous l i v e fine (<2 mm)] + NCLB [non-coniferous l i v e small (2-5 mm] = NCLFS [non-coniferous l i v e fine-plus-small (0-5 mm)] 3. DS [dead fine (0-2 mm)] 4. F (fungal) 6 1 gure 4 . 6 . P h o t o m i c r o g r a p h of b a s i d i o m y c e t e hyphae e x t r a c t e d from the i n - g r o w t h bags. Clamp c o n n e c t i o n s can be seen i n the s w e l l i n g s between c e l l s a l o n g the m y c e l i a l s t r a n d ( m a g n i f i c a t i o n 220X a c t u a l s i z e ) . 62 and f u n g a l biomass from i n - g r o w t h bags, and Duncan's l e a s t s i g n i f i c a n t d i f f e r e n c e (LSD, a=.05) f o r r o o t biomass from s e q u e n t i a l s o i l c o r e s ( S t e e l and T o r r i e 1980). 4.2.4 DETERMINATION OF PHYSICAL SOIL PARAMETERS M i n e r a l and o r g a n i c s o i l m a t e r i a l e x t r a c t e d from each s i t e d u r i n g t h e i n s t a l l a t i o n of the i n - g r o w t h bags was t r a n s p o r t e d back t o the l a b o r a t o r y f o r d e t e r m i n a t i o n of s o i l m o i s t u r e c o n t e n t and b u l k d e n s i t y . G r a v i m e t r i c s o i l m o i s t u r e was d e t e r m i n e d by d r y i n g the samples a t 105°C t o c o n s t a n t weight (minimum d r y i n g time was 24 hour s ) f o l l o w e d by c o o l i n g i n a d e s i c c a t o r and w e i g h i n g . Dry w e i ght d e t e r m i n a t i o n s f o r t h e b u l k d e n s i t y measurements were made u s i n g the same p r o c e d u r e as f o r the g r a v i m e t r i c s o i l m o i s t u r e measurements. V a l u e s a r e r e p o r t e d f o r b o t h c o a r s e (^2 mm) and f i n e (0-2 mm) m i n e r a l and o r g a n i c f r a c t i o n s . T h e i r volume was d e t e r m i n e d by measuring the amount of water t h e y d i s p l a c e d i n a g r a d u a t e d c y l i n d e r . 4.3 DATA ANALYSIS 4.3.1 THE ANALYSIS OF VARIANCE MODEL I n i t i a l e x a m i n a t i o n of the r o o t and f u n g a l biomass d a t a r e v e a l e d a l a r g e v a r i a t i o n between sample t i m e s , s i t e s , and growth media. An a n a l y s i s of v a r i a n c e (ANOVA, a=.05) was employed t o t e s t f o r s i g n i f i c a n t d i f f e r e n c e s i n f i n e r o o t and f u n g a l biomass e s t i m a t e s between p l a n t a s s o c i a t i o n s , 63 LIVE increase decrease A f l l i v e > A f l d e a d increase P = A f l l l v e + A f l d e a d M = A » d e j J D = 0 P = A B I , V C + A f l d , : a d M = A 0 d " d D = 0 /> = 0 M = - A f l , i v e D = - A f l l i v e - A f i d e a d decrease f = A B l l v e Af = 0 D = - A B d c a d /* = 0 A* = - A f l l i v e = - A f l l , v e - Atf l k i" 1 F i g u r e 4.7. D e c i s i o n m a t r i x i l l u s t r a t i n g the e q u a t i o n s used f o r f i n e r o o t and f u n g a l p r o d u c t i o n . The d i r e c t i o n of change i n the l i v e and dead biomass (B) components d i c t a t e s the a p p r o p r i a t e q u a d r a n t . P r o d u c t i o n ( P ) , m o r t a l i t y (M), and d i s a p p e a r a n c e (D) a r e then c a l c u l a t e d by summing the e s t i m a t e s f o r a l l sampling i n t e r v a l s w i t h i n the year ( F a i r l e y and Al e x a n d e r 1985). 64 between p l o t s w i t h i n a s s o c i a t i o n s , and between growth media ( n a t i v e s o i l v e r s u s beach sand) over t i m e . Because t h e r e was some v a r i a t i o n i n the depth t o which the i n - g r o w t h bags were f i l l e d ( t h e o v e r a l l mean depth of m a t e r i a l i n the i n - g r o w t h bags, was 26.7 cm, w i t h a s t a n d a r d d e v i a t i o n of 5.0 cm), depth of growth medium w i t h i n the i n - g r o w t h bags was t e s t e d as a c o - v a r i a t e w i t h i n the model. Because of t h e v e r y l a r g e numbers of z e r o s i n some of t h e r o o t and f u n g a l components, e s p e c i a l l y f o r the l a r g e r d i a m e t e r r o o t c l a s s e s , i t was d e c i d e d t o amalgamate the o r i g i n a l seven r o o t c a t e g o r i e s i n t o f o u r c a t e g o r i e s f o r the purposes of the a n a l y s i s of v a r i a n c e ( F i g u r e 4.5, p. 6 0 ) . Over th e c o u r s e of the s t u d y , a t o t a l of 16 i n - g r o w t h bags were p r e m a t u r e l y p u l l e d out of the ground (presumably by deer or b l a c k b e a r , both of which were f r e q u e n t l y seen on the s i t e s ) , were d e s t r o y e d upon e x t r a c t i o n ( e . g . where a bag caught on a l a r g e s t r u c t u r a l r o o t and r i p p e d open when p u l l e d u p ) , or were s i m p l y never r e c o v e r e d . T h i s r e s u l t e d i n an u n b a l a n c e d e x p e r i m e n t a l d e s i g n which n e c e s s i t a t e d the use of UBC GENLIN ( G r e i g and B j e r r i n g 1980), a l e a s t s quares a n a l y s i s of v a r i a n c e program f o r u n b a l a n c e d d e s i g n s . T h i s program a l l o w s f o r m i s s i n g d a t a w i t h i n f a c t o r s , c o - v a r i a t e s , or dependent v a r i a b l e s . The two major assumptions of the ANOVA a r e t h a t the e x p e r i m e n t a l e r r o r s a r e random, i n d e p e n d e n t l y and n o r m a l l y d i s t r i b u t e d about a z e r o mean, and have a homogeneous v a r i a n c e , and t h a t t r e a t m e n t e f f e c t s a r e a d d i t i v e ( S t e e l and 6 5 T o r r i e 1980). F - t e s t s on the u n m o d i f i e d d a t a showed t h a t the f i r s t of t h e s e two assumptions was not met. The v a r i a n c e s of the e x p e r i m e n t a l e r r o r of the u n m o d i f i e d d a t a were not n o r m a l l y d i s t r i b u t e d . There were l a r g e numbers of means which had v e r y l a r g e or v e r y s m a l l e x p e r i m e n t a l e r r o r s . Because of the l a c k of homogeneity of the v a r i a n c e s of the d a t a , a l o g a r i t h m i c t r a n s f o r m a t i o n was pe r f o r m e d on each r o o t and f u n g a l component, and the d a t a were then r e t e s t e d ( T a b l e V ) . D e s p i t e a l l e f f o r t s , no s u c c e s s f u l t r a n s f o r m a t i o n c o u l d be found f o r the "dead s m a l l (^5 mm) from n a t i v e s o i l " or " f u n g a l mycelium from beach sand" components ( T a b l e V I ) . The a p p l i e d t r a n s f o r m a t i o n s g r e a t l y r e d u c e d the c a l c u l a t e d F - v a l u e (which t e s t s the homogeneity of t h e d a t a v a r i a n c e ) i n c o m parison t o the u n t r a n s f o r m e d d a t a , but not enough t o produce a n o n - s i g n i f i c a n t r e s u l t . Such a r e s u l t i s not uncommon i n b i o l o g i c a l d a t a . The f a i l u r e t o f u l l y s a t i s f y the a s s u m p t i o n s of the a n a l y s i s of v a r i a n c e u s u a l l y r e s u l t s i n t he t r u e l e v e l of s i g n i f i c a n c e b e i n g g r e a t e r than the appa r e n t l e v e l ( S t e e l and T o r r i e 1980). In o t h e r words, r a t h e r than t e s t i n g the n u l l h y p o t h e s i s a t the f i v e p e r c e n t l e v e l , t h e a c t u a l t e s t l e v e l may be s l i g h t l y h i g h e r . For t h i s r e a s o n , i t was d e c i d e d t o t e s t a l l biomass component and growth media c o m b i n a t i o n s u s i n g the t r a n s f o r m e d d a t a . The a n a l y s i s of v a r i a n c e was c a r r i e d out u s i n g the f o l l o w i n g s t a t i s t i c a l model: Y i j k l u + T + S + b, (d - d ) + T x S + T x P/S i j i j k l i j i ( j ) k + T x M + p/S x M + • T x S x M i l ( j ) k l i j l + T x P/S x M + 1 i ( j ) k l ( i j k l ) m where; Y = v a r i a t e , t r a n s f o r m e d r o o t and i j k l f u n g a l w e i g h t s u = mean e f f e c t T = e f f e c t of the i l e v e l of f i x e d t i m e , i i = 1 t o 17 S = e f f e c t of j l e v e l of f i x e d p l a n t j a s s o c i a t i o n , j = 1 t o 3 P/S = e f f e c t of k l e v e l of random p l o t s n e s t e d ( j ) k w i t h i n the i l e v e l of p l a n t a s s o c i a t i o n , k = 1 ,2 M = e f f e c t of 1 l e v e l of f i x e d i n - g r o w t h bag 1 medium, 1 = 1 , 2 b, = c o v a r i a t e f o r d depth of growth i j k l medium w i t h i n the i n - g r o w t h bags Z = e r r o r term ( i j k l ) m 67 The o r i g i n a l model a l s o i n c l u d e d r o o t and f u n g a l components as an a d d i t i o n a l t e s t term. However, the i n c l u s i o n of t h i s term caused t h e model t o exceed the maximum a l l o w a b l e number of de g r e e s of freedom w i t h i n UBC GENLIN. The p r e s e n t model r e q u i r e d s e p a r a t e GENLIN runs f o r each component. 4.3.2 INTERPRETATION OF THE ANALYSIS OF VARIANCE RESULTS • I n t e r p r e t a t i o n s of the f i r s t - o r d e r r e s u l t s of the ANOVA [whi c h t e s t the e f f e c t of the m u l t i p l e t r e a t m e n t s (e . g . t i m e , s i t e , growth medium) on t h e dependent v a r i a b l e ( e . g . r o o t or f u n g a l b i o m a s s ) ] a r e dependent on n o n - s i g n i f i c a n t i n t e r a c t i o n s of t h e t r e a t m e n t s a t second-order and g r e a t e r l e v e l s w i t h i n the ANOVA. S i g n i f i c a n t i n t e r a c t i o n u s u a l l y o c c u r s where the t r e a t m e n t s do not have the same e f f e c t from one b l o c k t o an o t h e r ( i n my c a s e , where the p a t t e r n of r o o t and f u n g a l growth between p l o t s w i t h i n s i t e s , or w i t h d i f f e r e n t growth media, a r e not s i m i l a r between s i t e s ) . U n l e s s we can e x p l a i n t h e s e s i g n i f i c a n t i n t e r a c t i o n s , i n t e r p r e t a t i o n of the f i r s t - o r d e r r e s u l t s of an ANOVA which c o n t a i n s them may l e a d us t o c o n c l u d e t h a t a g i v e n t r e a t m e n t has a s i g n i f i c a n t e f f e c t on the dependent v a r i a b l e when i n f a c t i t may have no e f f e c t a t a l l (Kozak, p e r s o n a l c o m m u n i c a t i o n ) . T h i r d o r d e r i n t e r a c t i o n s between t i m e , p l o t s w i t h i n a s s o c i a t i o n s , and growth medium (TxP/SxM) were not s i g n i f i c a n t f o r any of the "four biomass components ( T a b l e 68 T a b l e V. T r a n s f o r m a t i o n s performed on o r i g i n a l d a t a t o s a t i s f y the assumptions of the a n a l y s i s of v a r i a n c e . F - v a l u e s which a r e s i g n i f i c a n t a t p^0.05 a r e u n d e r l i n e d . r o o t t r a n s f o r m a t i o n 1 F - v a l u e s i g n i f i c a n c e 2 component 1 CLFS.sa TRW = RW**.2463 0.7250 0. 9733 CLFS.so TRW = RW**.2719 1.0643 0. 3201 NCLFS.sa TRW = RW**.1999 0. 1892 1 . 0 NCLFS.so TRW = RW**.2267 0.9127 0. 6925 DS. sa TRW = RW**.4800 0.4568 0. 9998 DS. so TRW = RW**.3383 2.7537 0. 0000 F. sa TRW = RW**.1779 1.5917 0. 0006 F. so TRW = RW**.2261 1.1202 0. 2319 A b b r e v i a t i o n s ; 1. CLFS = c o n i f e r o u s l i v e f i n e - p l u s - s m a l l (<5 mm) r o o t s 2. NCLFS = n o n - c o n i f e r o u s l i v e f i n e - p l u s - s m a l l (^5 mm) r o o t s 3. DS = dead f i n e - p l u s - s m a l l (<5 mm) r o o t s 4. F = f u n g a l mycelium 5. sa = biomass e s t i m a t e s from s a n d - f i l l e d i n - g r o w t h bags 6. so = biomass e s t i m a t e s from n a t i v e - s o i l - f i l l e d i n - g r o w t h bags 7. TRW = t r a n s f o r m e d r o o t weight 8. RW = u n t r a n s f o r m e d r o o t weight 9. ** denotes e x p o n e n t i a l power t r a n s f o r m a t i o n 2 t e s t f o r s i g n i f i c a n c e was made u s i n g B a r t l e t t ' s t e s t f o r homogeneity of v a r i a n c e s . S i g n i f i c a n c e l e v e l s g r e a t e r than 0.05 i n d i c a t e t h a t the t e s t e d v a r i a n c e s a r e not s i g n i f i c a n t l y d i f f e r e n t . 69 V I ) . However, s i g n i f i c a n t t h i r d o r d e r i n t e r a c t i o n s between t i m e , s i t e and growth medium (TxSxM) d i d o ccur i n the dead s m a l l and f u n g a l components, and a second o r d e r t i m e - b y - s i t e (TxS) i n t e r a c t i o n was s i g n i f i c a n t f o r a l l f o u r r o o t components. R e r u n n i n g the ANOVA model f o r each r o o t component and growth medium c o m b i n a t i o n ( e f f e c t i v e l y s i m p l i f y i n g the model by removing growth medium as an i n c l u d e d component) g r e a t l y r e d u c e d the number of s i g n i f i c a n t second o r d e r i n t e r a c t i o n s (Table V I I ) . S i g n i f i c a n t t i m e - b y - s i t e i n t e r a c t i o n s were p r e s e n t i n f i v e of the e i g h t r o o t component - growth medium c o m b i n a t i o n s , but were h i g h l y s i g n i f i c a n t ( h a v i n g a p r o b a b i l i t y <.001) i n o n l y two of t h e s e f i v e . Because the d i s c u s s i o n of s i g n i f i c a n t h i g h e r - o r d e r t r e a t m e n t i n t e r a c t i o n s i s s p e c u l a t i v e and q u i t e ponderous, where l e s s than c l e a r - c u t ANOVA r e s u l t s o c c u r , no attempt w i l l be made t o e x p l a i n them i n t h i s s e c t i o n . D i s c u s s i o n of some of these i n t e r a c t i o n s a p p e a r s i n Appendix 4. W h i l e s i g n i f i c a n t t r e a t m e n t i n t e r a c t i o n s may negate the r e s u l t s of the ANOVA, th e y do not p r e c l u d e the use of o t h e r s t a t i s t i c a l t e s t s on the d a t a . An ANOVA i s i n f a c t a m u l t i p l e means t e s t ( S t e e l and T o r r i e 1980). T e s t s of p a i r e d means, w h i l e not a l l o w i n g us as broad an o v e r v i e w of the e n t i r e d a t a s e t , s t i l l a l l o w us t o d i f f e r e n t i a t e between t r e a t m e n t means w i t h i n a s i n g l e b l o c k (e.g. between mean r o o t and f u n g a l biomass e s t i m a t e s from d i f f e r e n t g r o w t h - m e d i a - f i l l e d i n - g r o w t h bags from the same s i t e ) . In T a b l e VI. P r o b a b i l i t y of s i g n i f i c a n t F -values (a<.05) from the ANOVA of r o o t and fungal biomass. " S i t e " r e f e r s t o st u d y s i t e and " p l o t " r e f e r s to r e p l i c a t e s w i t h i n each study s i t e . " M a t e r i a l " r e f e r s to the m-growth medium (sand v e r s u s n a t i v e s o i l ) used In the bags. P r o b a b i l i t i e s not s i g n i f i c a n t a t a<.05 l e v e l a r e under 11ned. Root Component 7 Source of V a r i a t i o n 1 df 1 T e s t 1ng Term CLFS NCLFS DS F Time 16 TxP/S 0 .000 0. 000 0. .000 0. .000 S i t e 2 P/S 0. .255 0. 030 0. .007 0, .007 P l o t / S i t e 3 e r r o r 0. . 130 0. 000 0. . 385 0. .039 Mater i a l 1 P/SxM 0. .027 0. 007 0. .000 0, .002 Mat. depth 1 e r r o r 0. . 237 0. 655 0. .874 0. ,743 T x S 29 TxP/S 0. .043 0. 004 0. OOO 0. .000 T x P/S 45 e r r o r 0. , 387 0. 967 0. ,970 0. ,578 T x M 15 TxP/SxM 0. .064 0. 725 0. .000 0. .000 S x M 2 e r r o r 0. . 173 0. 005 0. OOO 0. ,000 P/S x M 3 e r r o r 0. 858 0. 228 0. 035 0. ,498 T x S x M 27 e r r o r 0. .634 0. 074 0. 000 0. .002 T x P/S x M 42 e r r o r 0. 376 0. 010 0. 945 0. ,859 E r r o r 719 T o t a l 905 1 A b b r e v l a t i o n s a. T = 11 me b. S = s i t e c. M = m a t e r i a l d. F ' = p l o t s e. P/S = p l o t s w i t h i n s 1 tes f . df = degrees of freedom ' A b b r e v i a t i o n s f o r r o o t components ar e the same as f o r T a b l e 5.1. T a b l e V I I . P r o b a b i l i t y of s i g n i f i c a n t F - v a l u e s (a<.05) from the ANOVA of r o o t and f u n g a l biomass f o r each r o o t component by growth medium combination. " S i t e " r e f e r s to study s i t e and " p l o t " r e f e r s t o r e p l i c a t e s w i t h i n each study s i t e . " M a t e r i a l " r e f e r s to the growth medium (sand v e r s u s n a t i v e s o i l ) used i n the bags. P r o b a b i l i t i e s not s i g n i f i c a n t at a<.05 l e v e l a re u n d e r l i n e d . Root Component 1 Source d f 1 Test CLFS CLFS NCLFS NCLFS OS DS F F of V a r . 1 Term sand s o i l sand s o i l sand s o i l sand s o i l T 16 TxP/S 0. .000 o .000 S 2 T 0. 873 0 .692 P/S 3 E 0. 395 0. . 355 M D 1 E 0. 582 0. ,280 TxS 29 TxP/S 0. 501 0. ,077 TxP/S 45 E 0. 537 0. ,253 E 374 Tot . 470 0 .000 0, .000 0 .000 0 .000 0 .000 0, .000 0 .013 0. 000 0, . 243 0. .304 0, ,003 0, .022 0, ,083 0. .001 0, , 164 0, ,076 0. ,047 0. , 720 0. . 124 0. 648 0. ,920 0. 706 0. 016 0. 121 0, 020 0. 186 0. 045 0. ,000 0. ,039 0. 000 0. ,913 0. ,218 0. ,670 0. ,989 0. ,867 0. ,534 1 Abbrev1 at 1ons; a . T = 11 me b. S = s i t e P/S p l o t s w i t h i n s i t e s c. M D = m a t e r i a l depth df = degrees of freedom d. P = p l o t s g. E = e r r o r T o t . t o t a l ' A b b r e v i a t i o n s f o r r o o t components are the same as f o r T a b l e 5.1 72 t h i s way, s t a t i s t i c a l i n t e r p r e t a t i o n s of the d a t a a r e s t i l l p o s s i b l e . 5. RESULTS AND DISCUSSION 5.1 ASH-FREE DETERMINATIONS A s h - f r e e d r y w e i g h t s v a r i e d between 51.1 p e r c e n t and 86.2 p e r c e n t of d r y w e i g h t s f o r r o o t and f u n g a l components i n s a n d - f i l l e d i n - g r o w t h bags, and 65.3 p e r c e n t t o 85.3 p e r c e n t of d r y w e i g h t s f o r the same components i n s o i l - f i l l e d i n - g r o w t h bags. The a s h - f r e e d e t e r m i n a t i o n method used here produces a c o n s e r v a t i v e biomass e s t i m a t e . N u s z d o r f e r (1982) has used the d i f f e r e n c e between p e r c e n t ash c o n t e n t of r o o t s growing i n m i n e r a l and o r g a n i c h o r i z o n s f o r c a l c u l a t i o n of h i s a s h - f r e e c o r r e c t i o n f a c t o r s . Such an e s t i m a t e assumes t h a t o n l y those r o o t s g r o w i n g i n m i n e r a l h o r i z o n s c o n t a i n m i n e r a l c o n t a m i n a n t s . The a s h c o n t e n t of r o o t s found i n o r g a n i c h o r i z o n s would be assumed t o o r i g i n a t e as n o n - c o m b u s t i b l e s t r u c t u r a l m a t e r i a l s produced by the r o o t s t h e m s e l v e s . S i n c e no s e p a r a t i o n of m i n e r a l - and o r g a n i c - f r a c t i o n r o o t s was made i n t h i s s t u d y , the a s h - f r e e p e r c e n t a g e c a l c u l a t i o n s r e p r e s e n t s l i g h t o v e r e s t i m a t e s of a c t u a l m i n e r a l c o n t a m i n a t i o n , and t h e r e s u l t a n t biomass e s t i m a t e s u s i n g t h e s e p e r c e n t a g e s a r e t h e r e f o r e u n d e r e s t i m a t e s of the t r u e biomass. 73 74 5.2 ROOT,AND FUNGAL DYNAMICS IN THE IN-GROWTH BAGS 5.2.1 CONIFEROUS LIVE FINE-PLUS-SMALL (<5 MM) ROOT COMPONENT 5.2.1.1 Temporal p a t t e r n s i n r o o t biomass S t a n d i n g c r o p s of c o n i f e r o u s r o o t s i n b o t h n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h were a t t h e i r maximum l e v e l s i n March or A p r i l 1984. C o n i f e r o u s l i v e r o o t biomass i n the s a n d - f i l l e d bags may have peaked a t an e a r l i e r d a t e than t h i s , however, s i n c e a t the time of the f i r s t sample i t was a l r e a d y d e c r e a s i n g . There was no way t o a s c e r t a i n when peak s t a n d i n g c r o p of l i v e r o o t s would have o c c u r r e d a t t h i s t i m e , s i n c e the March sample was the f i r s t s e t of bags sampled. Biomass l e v e l s of l i v e r o o t s on a l l t h r e e s i t e s s u b s e q u e n t l y f e l l t o v e r y low l e v e l s from May th r o u g h .August 1984, then peaked a g a i n i n l a t e f a l l . The s t a n d i n g c r o p s of r o o t s i n b o t h g r o w t h - m e d i a - f i l l e d bags g e n e r a l l y h e l d s t e a d y or d e c l i n e d s l i g h t l y f o l l o w i n g t h e s e second f a l l p e aks. The peak s t a n d i n g c r o p e s t i m a t e s seen i n the s p r i n g of 1984 were always g r e a t e r than t h e biomass e s t i m a t e s of the f o l l o w i n g y e a r . P a t t e r n s of o v e r s t o r e y s p e c i e s f i n e r o o t p r o d u c t i o n were s i m i l a r f o r x e r i c , m e s i c , and h y g r i c s i t e s ( F i g u r e 5.1). Other a u t h o r s have found s i m i l a r p a t t e r n s of f l u c t u a t i o n s i n f i n e r o o t s t a n d i n g biomass. S a n t a n t o n i o and Hermann (1985) found r e l a t i v e l y h i g h l e v e l s of s t a n d i n g c r o p i n the s p r i n g and f a l l , and low l e v e l s i n 75 2000-1 D J F 1985 < CO in <n O E o co "o o or 6 0 0 -4 0 0 -200 Site O Low (L) site A Medium (M) site O High (H)_ site _ F M A M J J A S O N D J F M A M J J 1984 1985 _ , Date F i g u r e 5.1. P a t t e r n s i n a s h - f r e e c o n i f e r o u s l i v e f i n e - p l u s - s m a l l ( £ 5 mm) r o o t b i o m a s s f o r x e r i c ( l o w ) , m e s i c ( m e d i u m ) , a n d h y g r i c ( h i g h ) s i t e s f r o m n a t i v e - s o i l - f i l l e d ( A ) a n d s a n d - f i l l e d ( B ) i n - g r o w t h b a g s . B a r s on e s t i m a t e s r e p r e s e n t one s t a n d a r d e r r o r o f t h e m e a n . 76 summer and w i n t e r over t h r e e c o n s e c u t i v e y e a r s of s a m p l i n g i n wet, moderate and d r y s t a n d s of l o w - e l e v a t i o n D o u g l a s - f i r . Peak biomass l e v e l s were u s u a l l y seen i n A p r i l , May, or June i n a l l t h r e e s i t e s . A l t h o u g h l a r g e month-to-month v a r i a t i o n was common, t h e s e a u t h o r s found t h a t t h e i r moderate s i t e had the g r e a t e s t s t a n d i n g c r o p s of c o n i f e r o u s f i n e r o o t biomass, f o l l o w e d by the wet and d r y s i t e s r e s p e c t i v e l y . T h i s c o n t r a s t s w i t h my d a t a where the x e r i c s i t e had the g r e a t e s t and the mesic s i t e had t h e l o w e s t mean e s t i m a t e d s t a n d i n g c r o p s of l i v e r o o t s ( F i g u r e 5.2). P e r s s o n (1978, 1979, 1980) found a s i m i l a r p a t t e r n of s p r i n g and f a l l growth f l u s h e s of ^2 mm r o o t s i n young and mature s t a n d s of S c o t s p i n e i n Sweden. However, the summer lows of s t a n d i n g c r o p were much l e s s pronounced as compared t o o t h e r s t u d i e s ( c f . S a n t a n t o n i o and Hermann 1985, C o o p e r s m i t h , t h i s s t u d y ) , and a t h i r d peak of growth i n the e a r l y summer was seen i n both young and mature s t a n d s . T h i s d i s s i m i l a r i t y between s t u d i e s can p r o b a b l y be a t t r i b u t e d t o the d i f f e r e n t n a t u r e of t h e c l i m a t e s between Sweden and the west c o a s t of N o r t h A m e r i c a . Keyes and G r i e r (1981) found peak s t a n d i n g c r o p s of <2 mm l i v e r o o t biomass i n June i n a l o w - p r o d u c t i v i t y s t a n d of 4 0 - y e a r - o l d D o u g l a s - f i r i n we s t e r n Washington S t a t e . S t a n d i n g c r o p s of l i v e r o o t s then f e l l c o n t i n u o u s l y t o t h e i r l o w e s t l e v e l s by mid-December, but 250 D 2 50 _j , _ "i 1 Xeric Mesic Hygric Siie In-growth Material O S a n d - f i l l e d Bogs  * So i l - f i l l ed Bags F i g u r e 5.2. Comparison of the p a t t e r n s of mean a s h - f r e e c o n i f e r o u s f i n e - p l u s - s m a l l (<5 mm) r o o t biomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags f o r x e r i c ( l o w ) , mesic (medium), and h y g r i c ( h i g h ) s i t e s . B a rs on e s t i m a t e s r e p r e s e n t one s t a n d a r d e r r o r of the mean. 78 began i n c r e a s i n g a g a i n by March of the f o l l o w i n g y e a r . The s t a n d i n g c r o p s of f i n e r o o t s on a n e i g h b o u r i n g h i g h - p r o d u c t i v i t y s i t e f l u c t u a t e d v e r y l i t t l e over t h e c o u r s e of s a m p l i n g . However, t h e a u t h o r s sampled o n l y e v e r y t h i r d month, so i t i s p o s s i b l e t h a t a g r e a t d e a l of the s h o r t term (month-to-month) f l u c t u a t i o n i n f i n e r o o t biomass c o u l d have been m i s s e d . The ANOVA showed t h a t time had a h i g h l y s i g n i f i c a n t e f f e c t on s t a n d i n g c o n i f e r o u s f i n e r o o t biomass ( p < . 0 0 l ) , but t h a t no s i g n i f i c a n t e f f e c t of s i t e (p=0.255) or p l o t s w i t h i n s i t e s (p=0.130) c o u l d be found ( T a b l e V I , p. 7 0 ) . The n o n - s i g n i f i c a n t e f f e c t of s i t e i s not r e a l l y s u r p r i s i n g . A l t h o u g h s t a n d i n g c r o p v a l u e s f o r x e r i c and mesic s i t e s were g e n e r a l l y g r e a t e r than t h o s e f o r the h y g r i c s i t e f o r b o t h n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags, t h e r e were r a r e l y any monthly e s t i m a t e s i n which t h e s t a n d a r d e r r o r b a r s between the t h r e e s i t e s d i d not o v e r l a p . The n o n - s i g n i f i c a n t e f f e c t of p l o t s - w i t h i n - s i t e s p r o b a b l y r e f l e c t s the even d i s t r i b u t i o n of the o v e r s t o r e y s p e c i e s w i t h i n the s t u d y p l o t s . The s i g n i f i c a n t t i m e - b y - s i t e i n t e r a c t i o n of the f u l l model ANOVA tempers t h e s i g n i f i c a n t e f f e c t of time mentioned above. However, s p l i t t i n g the c o n i f e r o u s l i v e r o o t d a t a i n t o s e p a r a t e s e t s f o r each growth media e l i m i n a t e d t h i s s i g n i f i c a n t i n t e r a c t i o n (Table V I I , p . 7 1 ) . The ANOVA f o r t h e s e s e p a r a t e d a t a s e t s showed 79 t h a t time was h i g h l y s i g n i f i c a n t f o r c o n i f e r o u s l i v e r o o t p r o d u c t i o n from b o t h g r o w t h - m e d i a - f i l l e d i n - g r o w t h bags ( p < . 0 0 l ) . These r e s u l t s s u p p o r t s the t h e o r y of a s e a s o n a l p a t t e r n of r o o t p r o d u c t i o n i n temperate c o n i f e r o u s f o r e s t s . 5.2.1.2 The e f f e c t of growth medium on c o n i f e r o u s biomass e s t i m a t e s The f u l l - m o d e l ANOVA showed t h a t growth medium d i d have a s i g n i f i c a n t e f f e c t on the e s t i m a t e d c o n i f e r o u s l i v e biomass (p=.027, T a b l e V I ) . A l t h o u g h the p a t t e r n s f o r s t a n d i n g c r o p were s i m i l a r f o r n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags, the biomass e s t i m a t e s f o r t h e n a t i v e - s o i l - f i l l e d bags were u s u a l l y g r e a t e r than those from the s a n d - f i l l e d bags, and a t t i m e s they c o u l d be two t o t h r e e t i m e s as g r e a t ( F i g u r e 5 . 3 ) . Combining the s t a n d i n g biomass e s t i m a t e s f o r a l l months t o produce a mean s t a n d i n g c r o p e s t i m a t e f o r each s i t e and growth medium demo n s t r a t e d the d i f f e r e n c e s between e s t i m a t e s f o r the two growth media even more c l e a r l y ( F i g u r e 5 . 2 ) . Mean s t a n d i n g c r o p e s t i m a t e s f o r n a t i v e - s o i l - f i l l e d i n - g r o w t h bags were always g r e a t e r than those produced from s a n d - f i l l e d i n - g r o w t h bags. The d i f f e r e n c e s between the means w i t h i n each p l a n t a s s o c i a t i o n were a l l h i g h l y s i g n i f i c a n t ( p a i r e d t - t e s t , a^.01, performed on u n t r a n s f o r m e d d a t a , T a b l e V I I I ) . 80 1200-, D J F 1985 Material O Sond-f i l led Bogs $ Soi l - f i l led Bags F i g u r e 5 . 3 . U a t e C o m p a r i s o n of t he p a t t e r n s o f a s h - f r e e c o n i f e r o u s f i n e - p l u s - s m a l l ( £ 5 mm) r o o t b iomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h b a g s . B a r s on e s t i m a t e s r e p r e s e n t one s t a n d a r d e r r o r o f the mean. A . the x e r i c ( low) s i t e B . the mes i c (medium) s i t e C . t he h y g r i c ( h i g h ) s i t e 81 F i g u r e 5 . 3 . c o n t ' d . 82 T a b l e V I I I . O v e r a l l mean a s h - f r e e r o o t and f u n g a l biomass (kg/ha) and t h e c a l c u l a t e d t - v a l u e s f o r p a i r - w i s e c omparisons from n a t i v e - s o i l - f i l l e d ( s o i l ) and s a n d - f i l l e d (sand) i n - g r o w t h bags. P a i r e d t - t e s t s were done on un t r a n s f o r m e d d a t a f o r each p l a n t a s s o c i a t i o n - biomass component c o m b i n a t i o n . Study s i t e s 1 Biomass X e r i c M e s i c H y g r i c Component 2 C L F S sand 112.7 80.8 99.4 s o i l 215.0 154.1 180.1 c a l c . t 21.21" 14.32* 26.21" N C L F S sand 32.2 8.0 5.6 s o i l 112.1 31.2 15.6 c a l c . t 51.07" 41 .76" 30.40" DS sand 13.6 6.1 16.0 s o i l 178.5 141.4 220.5 c a l c . t 72.02" 664.56" 90.27" sand 57.4 80.1 17.7 s o i l 55.2 94.6 13.6 c a l c . t 2.103 3 18.44" 10.03" 1 S t u d y s i t e s ; x e r i c = the Gaultheria shallon a s s o c i a t i o n , mesic = the Moss a s s o c i a t i o n . h y g r i c = the Achi ys - Pol i sti chum a s s o c i a t i o n . 83 Table V I I I c o n t ' d 2 A b b r e v i a t i o n s f o r biomass components; 1. CLFS = c o n i f e r o u s l i v e - f i n e - p l u s s m a l l (^5 mm) r o o t s 2. NCLFS = n o n - c o n i f e r o u s l i v e f i n e - p l u s - s m a l l (<5 mm) r o o t s 3. DS = dead f i n e - p l u s - s m a l l (<5 mm) r o o t s 4. F = f u n g a l mycelium 3The c a l c u l a t e d t - v a l u e i s s i g n i f i c a n t a t t h e 0.05^p^0.0l l e v e l . The c r i t i c a l v a l u e of t a t a=0.025 ( t w o - t a i l e d ) w i t h >120 degrees of freedom i s 1.960. "The c a l c u l a t e d t - v a l u e i s s i g n i f i c a n t a t the p^0.01 l e v e l . The c r i t i c a l v a l u e of t a t a=0.005 ( t w o - t a i l e d ) w i t h >120 degrees of freedom i s 2.576. 84 5.2.2 NON-CONIFEROUS LIVE FINE-PLUS-SMALL (<5 MM) ROOT  COMPONENT 5.2.2.1 Temporal p a t t e r n s i n r o o t biomass Temporal f l u c t u a t i o n s i n the s t a n d i n g c r o p of n o n - c o n i f e r o u s f i n e - p l u s - s m a l l (<5 mm) r o o t biomass showed a modal p a t t e r n which was somewhat s i m i l a r t o t h a t seen w i t h the c o n i f e r o u s l i v e r o o t component ( F i g u r e 5.4). The low p r o d u c t i v i t y , x e r i c s i t e had t h e g r e a t e s t e s t i m a t e d s t a n d i n g c r o p of n o n - c o n i f e r o u s r o o t s i n b o t h the n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags. The s o i l - f i l l e d bags seemed t o show a s t r o n g e r modal p a t t e r n of growth than d i d the s a n d - f i l l e d bags, a t l e a s t on the x e r i c s i t e . T h i s was u n l i k e the p a t t e r n s of p r o d u c t i o n seen f o r the c o n i f e r o u s r o o t component, where a l l t h r e e s i t e s showed modal p a t t e r n s of belowground p r o d u c t i o n ( F i g u r e 5.1, p. 7 5 ) . There was a l a r g e d i f f e r e n c e i n the amounts of n o n - c o n i f e r o u s r o o t s found i n i n - g r o w t h bags w i t h d i f f e r i n g growth medium. T h i s w i l l be d i s c u s s e d f u r t h e r i n a l a t e r s e c t i o n (see s e c t i o n 5.2.2.2, p. 8 8 ) . However, i t i s i m p o r t a n t t o r e a l i z e here t h a t the s c a l e s of the two graphs i n F i g u r e 5.4, comparing the r o o t dynamics w i t h the two growth media, a r e not the same. From i t s ' h i g h p o i n t i n March 1984, the s t a n d i n g c r o p of n o n - c o n i f e r o u s r o o t s on the x e r i c s i t e i n n a t i v e - s o i l - f i l l e d i n - g r o w t h bags, f e l l i n i r r e g u l a r 85 1000-1 A Date F i g u r e 5.4. Comparison of the p a t t e r n s i n a s h - f r e e n o n - c o n i f e r o u s l i v e f i n e - p l u s - s m a l l (<5 mm) r o o t biomass f o r x e r i c ( l o w ) , mesic (medium), and h y g r i c ( h i g h ) s i t e s from n a t i v e - s o i l - f i l l e d (A) and s a n d - f i l l e d (B) i n - g r o w t h bags. Bars on e s t i m a t e s r e p r e s e n t one s t a n d a r d e r r o r of the mean. 86 s t e p s t o a low between J u l y and September 1984, a f t e r which i t began t o i n c r e a s e a g a i n . The second peak ( i n Jan u a r y 1985) on the x e r i c s i t e was a g a i n l e s s than the March 1984 peak, r e p e a t i n g the p a t t e r n seen i n the c o n i f e r o u s l i v e r o o t component. However, t h e r e was a complete o v e r l a p of the s t a n d a r d e r r o r b a r s a s s o c i a t e d w i t h the March 1984 and Ja n u a r y 1985 peaks, so i t i s d i f f i c u l t t o say whether they would have been s i g n i f i c a n t l y d i f f e r e n t . S t a n d i n g c r o p e s t i m a t e s f o r the mesic and h y g r i c s i t e s from n a t i v e - s o i l - f i l l e d bags f l u c t u a t e d much l e s s d r a m a t i c a l l y than they d i d on the x e r i c s i t e . Peaks i n s t a n d i n g c r o p were seen i n June 1984 and F e b r u a r y 1985 on t h e mesic s i t e , and i n A p r i l and October 1984 on the h y g r i c s i t e . S t a n d i n g c r o p e s t i m a t e s produced from s a n d - f i l l e d bags showed some i n t e r e s t i n g d i f f e r e n c e s compared t o those from n a t i v e - s o i l - f i l l e d bags. The g e n e r a l p a t t e r n of x e r i c ^ mesic >. h y g r i c s i t e s f o r s t a n d i n g c r o p was r e p e a t e d , however, t h e r e was a g r e a t e r degree of o v e r l a p between t h e s t a n d a r d e r r o r b a r s between s i t e s , and the l a r g e t e m p o r a l f l u c t u a t i o n s t h a t were seen i n the biomass e s t i m a t e s from n a t i v e - s o i l - f i l l e d bags were d e c r e a s e d . The f u l l - m o d e l ANOVA showed t h a t t i m e , s i t e , p l o t s w i t h i n s i t e s , and growth m a t e r i a l a l l had a s i g n i f i c a n t e f f e c t on n o n - c o n i f e r o u s r o o t biomass (p<.01, T a b l e V I , 87 p. 7 0 ) . S i g n i f i c a n t i n t e r a c t i o n s a t h i g h e r l e v e l s i n the model negate th e s e r e s u l t s , however. Running the d a t a f o r each growth medium i n a s e p a r a t e ANOVA d i d reduce the problem of s i g n i f i c a n t i n t e r a c t i o n s . A l t h o u g h the d a t a from s a n d - f i l l e d bags s t i l l showed s i g n i f i c a n t s e c ond-order i n t e r a c t i o n s , t h o s e from n a t i v e - s o i l - f i l l e d i n - g r o w t h bags d i d n o t . I n the l a t t e r , t i m e , s i t e , and p l o t s - w i t h i n - s i t e s a l l p r o v e d t o have a h i g h l y • s i g n i f i c a n t e f f e c t on s t a n d i n g c r o p of n o n - c o n i f e r o u s r o o t biomass (p<.001, T a b l e V I I , p. 7 1 ) . The i n t e r p r e t a t i o n of the s i g n i f i c a n t t r e a t m e n t e f f e c t s f o r the n a t i v e - s o i l - f i l l e d i n - g r o w t h i s s t r a i g h t f o r w a r d . At the s t a r t of t h i s s t u d y t h e r e were much g r e a t e r amounts of n o n - c o n i f e r o u s b r u s h on the x e r i c s i t e than on the o t h e r two s i t e s . I t s h o u l d not be s u r p r i s i n g t h a t s i t e , would prove t o have a s i g n i f i c a n t e f f e c t . However, the s i g n i f i c a n t p l o t - w i t h i n - s i t e s e f f e c t c r e a t e s some problems f o r t h i s s i m p l e e x p l a n a t i o n . The s i g n i f i c a n t e f f e c t of p l o t s - w i t h i n - s i t e s p r o b a b l y r e f l e c t s t h e uneven d i s t r i b u t i o n of the u n d e r s t o r e y v e g e t a t i o n t h r o u g h o u t the t h r e e s i t e s . Even the mesic Moss a s s o c i a t i o n , which had the p o o r e s t u n d e r s t o r e y development of the t h r e e s i t e s , had p o c k e t s of h u c k l e b e r r y and sword f e r n a s s o c i a t e d w i t h s m a l l b r e a k s i n the o v e r s t o r e y canopy. T h i s p a t t e r n was a c c e n t u a t e d even more on the x e r i c Gaultheria shall on and h y g r i c Achlys - Pol isti chum 88 s i t e s , where t h i c k clumps of u n d e r s t o r e y v e g e t a t i o n would a l t e r n a t e w i t h moss-covered open spaces under denser canopy c o v e r . S i n c e p l o t s - w i t h i n - s i t e s i s a n e s t e d v a r i a b l e w i t h i n s i t e s i n the ANOVA model, a s i g n i f i c a n t e f f e c t of p l o t s means t h a t the v a r i a b i l i t y w i t h i n the model b l o c k s ( t h e p l o t s w i t h i n the t h r e e s t u d y s i t e s ) i s g r e a t e r than the v a r i a t i o n between the b l o c k s ( the t h r e e s t u d y s i t e s t h e m s e l v e s ) . The s i g n i f i c a n t e f f e c t of s i t e , w h i l e i n t e r e s t i n g , i s once more confounded. 5.2.2.2 The e f f e c t of growth medium on n o n - c o n i f e r o u s biomass e s t i m a t e s The d i f f e r e n c e s between s t a n d i n g c r o p e s t i m a t e s p r o d u c e d from n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags are even c l e a r e r f o r the n o n - c o n i f e r o u s r o o t s ( F i g u r e s 5.5 and 5.6) than they were f o r the c o n i f e r o u s r o o t component ( F i g u r e 5.2, p. 77, and F i g u r e 5.3, p. 8 0 ) . P a t t e r n s of change i n s t a n d i n g c r o p were s i m i l a r f o r both growth media, but i n 41 of 46 p a i r e d monthly o b s e r v a t i o n s , e s t i m a t e d s t a n d i n g biomass from n a t i v e - s o i l - f i l l e d bags were g r e a t e r than t h e i r c o u n t e r p a r t s from s a n d - f i l l e d bags. The e f f e c t of growth medium on e s t i m a t e d biomass was emphasized by c a l c u l a t i n g the mean s t a n d i n g c r o p f o r a l l sample times f o r each s i t e and growth medium. The p a t t e r n of mean e s t i m a t e d s t a n d i n g biomass f o r the two media i s s i m i l a r t o t h a t seen i n t h e c o n i f e r o u s l i v e 89 1000-1 D J F 1985 F i g u r e 5 . 5 . C o m p a r i s o n o f the p a t t e r n s o f a s h - f r e e n o n - c o n i f e r o u s f i n e - p l u s - s m a l l (^5 mm) r o o t b iomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h b a g s . B a r s on e s t i m a t e s r e p r e s e n t one s t a n d a r d e r r o r o f the mean. A . the x e r i c ( l ow) s i t e B . t he mes i c (medium) s i t e C . the h y g r i c ( h i g h ) s i t e 200 c 1984 1 9 8 5 O Sond-f i l led Bogs • Soi l - f i l led Bags F i g u r e 5 . 5 . c o n t ' d . 91 140 120-100-80 60-40-20-Xeric Mesic Site Hygric O S o n d - f i l l e d Bags • So i l - f i l l ed Bags F i g u r e 5.6. Comparison of the p a t t e r n s of mean a s h - f r e e n o n - c o n i f e r o u s f i n e - p l u s - s m a l l (^ 5 mm) r o o t biomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags f o r x e r i c ( l o w ) , mesic (medium), and h y g r i c ( h i g h ) s i t e s . Bars on e s t i m a t e s r e p r e s e n t one s t a n d a r d e r r o r of the mean. 92 component. The x e r i c s i t e had the g r e a t e s t mean s t a n d i n g c r o p l e v e l s f o r b o t h growth media, but the mesic s i t e v a l u e s were s l i g h t l y g r e a t e r than the h y g r i c s i t e v a l u e s . The d i f f e r e n c e s between the p a i r e d o b s e r v a t i o n s f o r the two growth media on each s i t e were a l l h i g h l y s i g n i f i c a n t ( p a i r e d t - t e s t , a^.01, on u n t r a n s f o r m e d d a t a , T a b l e V I I I , p. 8 2 ) . D e s p i t e the poor r e s u l t s of the ANOVA, growth medium c l e a r l y had a s i g n i f i c a n t • e f f e c t on t h i s biomass component i n the i n - g r o w t h bags. Much g r e a t e r e s t i m a t e s of n o n - c o n i f e r o u s r o o t s were produced u s i n g n a t i v e s o i l i n the i n - g r o w t h bags than were produced u s i n g beach sand. 5.2.3 DEAD FINE-PLUS-SMALL (<5 MM) ROOT COMPONENT 5.2.3.1 Temporal p a t t e r n s i n dead r o o t biomass D i s c u s s i o n of the t e m p o r a l v a r i a t i o n i n s t a n d i n g c r o p and the ANOVA r e s u l t s f o r the dead r o o t component i s d i f f i c u l t f o r two r e a s o n s . Not o n l y was one of t h e assumptions of the ANOVA v i o l a t e d f o r the "dead f i n e - p l u s - s m a l l from n a t i v e s o i l " r o o t component, but the f u l l - m o d e l ANOVA a l s o showed s i g n i f i c a n t s e cond-order and t h i r d - o r d e r i n t e r a c t i o n i n alm o s t e v e r y c a s e ( T a b l e V I , p. 7 1 ) . U t i l i z i n g the s m a l l e r ANOVA model d i d not improve t h i s s i t u a t i o n v e r y much. The o n l y unconfounded o b s e r v a t i o n which I c o u l d make f o r the dead s m a l l component from e i t h e r growth media was t h a t p l o t s - w i t h i n - s i t e s , and m a t e r i a l d e pth w i t h i n the 93 i n - g r o w t h bags showed no s i g n i f i c a n t e f f e c t ( T a b l e V I I , p. 71 ) . The h i g h l y confounded r e s u l t s of the ANOVA a r e not s u r p r i s i n g i f I l o o k a t t h e p l o t t e d d a t a p a t t e r n s f o r t h i s component. Few, i f any c l e a r p a t t e r n s e x i s t i n the d a t a ( F i g u r e 5.7). The most s t r i k i n g f e a t u r e of t h e s e graphs a r e the l a r g e d i f f e r e n c e s between the biomass l e v e l s f o r the two growth media; the n a t i v e - s o i l - f i l l e d i n - g r o w t h bags had much g r e a t e r l e v e l s of dead r o o t s than d i d the s a n d - f i l l e d bags. Peaks i n dead r o o t biomass i n s a n d - f i l l e d bags were seen i n J u l y 1984 on a l l t h r e e s i t e s , i n December 1984 on the h y g r i c s i t e , and i n Ja n u a r y 1985 on the mesic and x e r i c s i t e s . S t a n d i n g c r o p l e v e l s d e c r e a s e d d u r i n g F e b r u a r y and March 1985 and i n c r e a s e d a g a i n t o t h e i r h i g h e s t l e v e l s f o r b o t h t h e x e r i c and h y g r i c s i t e s i n A p r i l 1985. The i n c r e a s e s which o c c u r r e d on the mesic s i t e i n the s p r i n g of 1985 were not as d r a m a t i c as t h o s e seen on the o t h e r two s i t e s . The f l u c t u a t i o n s i n dead r o o t biomass from n a t i v e - s o i l - f i l l e d i n - g r o w t h bags were much more e r r a t i c than t h o s e o b s e r v e d i n the s a n d - f i l l e d bags. The x e r i c s i t e s t a r t e d from a maximum i n March 1984 ( a l t h o u g h t h i s mean i n c l u d e d a v e r y l a r g e s t a n d a r d e r r o r ) , d e c r e a s e d t o low l e v e l s between A p r i l and September 1984, then i n c r e a s e d i n i r r e g u l a r s t e p s t h r o u g h the s p r i n g of 1985. The mesic s i t e showed v e r y low dead biomass l e v e l s 9 4 F i g u r e 5 . 7 . Date Compar i son of t he p a t t e r n s i n a s h - f r e e dead f i n e - p l u s - s m a l l ( £ 5 mm) r o o t b iomass f o r x e r i c ( l o w ) , m e s i c (medium), and h y g r i c ( h i g h ) s i t e s from n a t i v e - s o i l - f i l l e d (A) and s a n d - f i l l e d (B) i n - g r o w t h b a g s . B a r s on e s t i m a t e s r e p r e s e n t one s t a n d a r d e r r o r of t he mean. 95 t h r o u g h December 1984, then i n c r e a s e d i n i r r e g u l a r s t e p s - t h r o u g h J u l y 1985. The h y g r i c s i t e r e c o r d e d the h i g h e s t peak l e v e l of dead r o o t biomass of a l l t h r e e s i t e s . E s t i m a t e s f o r t h i s s i t e i n c r e a s e d from a low i n March 1984 t o a peak i n August 1984. Most of t h i s peak was gone by September, but dead biomass l e v e l s then i n c r e a s e d t o a second peak i n December 1984. Both the August and December peaks on the h y g r i c s i t e were much g r e a t e r than t h e peak s t a n d i n g c r o p s o b s e r v e d f o r the o t h e r two s i t e s . A f t e r the peak i n December, v a l u e s on the h y g r i c s i t e f e l l t o a m i d - w i n t e r low i n F e b r u a r y 1985, then i n c r e a s e d and d e c r e a s e d i n i r r e g u l a r s t e p s a t a p p r o x i m a t e l y the same l e v e l s as the x e r i c and mesic s i t e s . I t i s i n t e r e s t i n g t o note t h a t the J u l y 1984, December 1984, and May 1985 peaks i n t h e s t a n d i n g c r o p of dead r o o t s on t h e h y g r i c s i t e w i t h the s a n d - f i l l e d i n - g r o w t h bags c o r r e s p o n e d t o ti m e s when the c o n i f e r o u s l i v e r o o t biomass was e i t h e r a t a minium, or d e c r e a s i n g toward a minimum ( F i g u r e 5.1, p. 7 5 ) . S i m i l a r o b s e r v a t i o n s can be made f o r the l i v e and dead r o o t components on the x e r i c and mesic s i t e s as w e l l . D e creases i n t h e l i v e c o n i f e r o u s r o o t component seem t o be c l o s e l y c o - o r d i n a t e d w i t h i n c r e a s e s i n the dead r o o t component i n the s a n d - f i l l e d i n - g r o w t h bags. S i m i l a r c o r r e l a t i o n s between the t e m p o r a l p a t t e r n s of l i v e and dead biomass components has been r e p o r t e d by o t h e r 96 a u t h o r s ( c f . S a n t a n t o n i o and Hermann 1985). A s i m i l a r r e l a t i o n s h i p between l i v e and dead r o o t s does not h o l d t r u e , however, f o r the n a t i v e - s o i l - f i l l e d i n - g r o w t h bags. Of the two d r a m a t i c i n c r e a s e s i n dead biomass seen on the h y g r i c s i t e i n August and December 1984, o n l y the August peak c o r r e s p o n d s t o a minima f o r c o n i f e r o u s r o o t biomass ( F i g u r e 5.1). In f a c t , t h e December peak i n s t a n d i n g c r o p f o r the dead component o c c u r r e d a t a time when the c o n i f e r o u s l i v e r o o t biomass was i n c r e a s i n g . I t i s u n l i k e l y t h a t I would see s i m u l t a n e o u s p r o d u c t i o n and m o r t a l i t y of r o o t s on the w e t t e r h y g r i c s i t e when t h e r e was l i t t l e e v i d e n c e of t h i s phenomenon on the d r i e r two s i t e s . Both Kurz and Kimmins ( i n p r e s s ) and S a n t a n t o n i o and Grace ( i n p r e s s ) have d e m o n s t r a t e d t h a t s u b s t a n t i a l amounts of f i n e r o o t p r o d u c t i o n a r e p o s s i b l e even when l i t t l e or no change i n the s t a n d i n g c r o p of f i n e r o o t s i s e v i d e n t . I f p r o d u c t i o n and senescence of f i n e r o o t s occur a t e q u a l r a t e s , t h e n t h e r e w i l l be l i t t l e a p p a rent change i n the monthly e s t i m a t e s of f i n e r o o t s ( t h e " s t a t e " v a r i a b l e of biomass) even though the amount of i n p u t of NPP t h r o u g h th e belowground ecosystem c o u l d be s u b s t a n t i a l ( t h e " r a t e " v a r i a b l e s of p r o d u c t i o n , senescence and d e c o m p o s i t i o n would be v e r y h i g h ) . A good a n a l o g y t o t h i s s i t u a t i o n would be the case where water i s f l o w i n g a t a v e r y h i g h r a t e i n t o a b a t h t u b which has a l a r g e 97 h o l e i n i t s s i d e . W h i l e water moves i n t o and out of the b a t h t u b a t v e r y h i g h r a t e s , t h e r e i s l i t t l e a p p a rent change i n t h e l e v e l of water i n the t u b . However, such a s i t u a t i o n i s much more l i k e l y t o o c c u r on a w a t e r - l i m i t e d s i t e where f i n e r o o t s senesce and d i e much f a s t e r than t h e y would on a w e t t e r s i t e ( S a n t a n t o n i o and Hermann 1985). There a r e s e v e r a l p o s s i b l e e x p l a n a t i o n s f o r t h i s • d i s c r e p a n c y i n t h e p a t t e r n of dead r o o t biomass f o r the two growth media. F i r s t l y , the peaks i n dead r o o t biomass seen on the h y g r i c s i t e w i t h s o i l - f i l l e d i n - g r o w t h bags might be due t o s a m p l i n g ( S i n g h et al. 1984). T h i s i s p o s s i b l e i n the December peak, because of i t s ' v e r y l a r g e e s t i m a t e of s t a n d a r d e r r o r , but i t i s much l e s s l i k e l y f o r the J u l y peak which had a much s m a l l e r s t a n d a r d e r r o r . S e c o n d l y , the peaks c o u l d r e p r e s e n t d i f f e r e n c e s i n s a m p l i n g methods between s e t s of samples. T h i s , u n f o r t u n a t e l y , i s the more p r o b a b l e cause of t h e l a r g e r amounts of dead r o o t biomass, and the g r e a t e r f l u c t u a t i o n s over t i m e , o b s e r v e d on the h y g r i c s i t e w i t h s o i l - f i l l e d bags. I was u n a b l e t o keep the same t e c h n i c a l s t a f f over the e n t i r e s t u d y p e r i o d . Even w i t h q u a l i t y c o n t r o l checks t o keep c o n s i s t e n t e v a l u a t i o n and s o r t i n g s t a n d a r d s , the l a r g e amount of dead r o o t fragments i n the n a t i v e - s o i l - f i l l e d bags ( e s p e c i a l l y i n the s o i l m a t e r i a l from the h y g r i c s i t e ) c r e a t e d a c o n s t a n t e v a l u a t i o n problem i n t r y i n g t o 98 d e c i d e which r o o t t i p s had grown i n t o t h e bags and s u b s e q u e n t l y d i e d , and which had been p l a c e d i n the bags w i t h .the growth medium. There was no such problem i n the s a n d - f i l l e d i n - g r o w t h bags, and the p a t t e r n s of l i v e and dead r o o t s f o r t h e s e samples make much more sense. 5 . 2 . 3 . 2 The e f f e c t of growth medium on dead biomass e s t i m a t e s A l t h o u g h the ANOVA r e s u l t s were i n c o n c l u s i v e due t o the h i g h degree of p o s i t i v e second- and t h i r d - o r d e r i n t e r a c t i o n , F i g u r e s 5 .8 and 5 .9 c l e a r l y show the e f f e c t of growth medium on e s t i m a t e s of dead r o o t biomass. The p a i r e d graphs of biomass e s t i m a t e s from n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags f o r each s i t e show t h a t dead r o o t biomass e s t i m a t e s from s o i l - f i l l e d bags were always g r e a t e r than t h o s e from s a n d - f i l l e d bags, and were sometimes an o r d e r of magnitude g r e a t e r ( F i g u r e 5 . 8 ) . P o o l i n g a l l the d a t a f o r each growth medium t o produce a mean s t a n d i n g dead r o o t biomass e s t i m a t e showed t h i s e f f e c t as w e l l . For a l l t h r e e s i t e s , the e s t i m a t e d mean s t a n d i n g c r o p of dead r o o t s from s o i l - f i l l e d i n - g r o w t h bags was g r e a t e r than t h a t f o r s a n d - f i l l e d bags ( F i g u r e 5 . 9 ) . P a i r e d c o m p a r i s o n s of t h e means f o r the two growth media w i t h i n each p l a n t a s s o c i a t i o n showed t h a t t h e i r d i f f e r e n c e s were a l l h i g h l y s i g n i f i c a n t ( p a i r e d t - t e s t , a ^ . 0 1 , performed on u n t r a n s f o r m e d d a t a , T a b l e V I I I , p. 8 2 ) . 99 800-_ 600-Material O Sond-f i l led Bog <$> Soil-f i l led Bog M A 1984 Date F i g u r e 5 . 8 . Compar i son of the p a t t e r n s of a s h - f r e e dead f i n e - p l u s - s m a l l (^5 mm) r o o t b iomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h b a g s . B a r s on e s t i m a t e s r e p r e s e n t one s t a n d a r d e r r o r o f the mean. A . t he x e r i c ( l ow) s i t e B . t he mes ic (medium) s i t e C . t he h y g r i c ( h i g h ) s i t e Material O Sond-fi l led Bogs * Soil-f i l led Bags Date F i g u r e 5 . 8 . c o n t ' d . 101 250 JC V) (/) o E o CD o o i_ Q) 0) H— I _c V) D c o CD 200 150-100-50-Xeric Mesic Site Hygric In-growth Material O Sand- f i l led Bags  Soi l - f i l led Bags F i g u r e 5.9. Comparison of t h e p a t t e r n s of mean a s h - f r e e dead f i n e - p l u s - s m a l l (^5 mm) r o o t biomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags f o r x e r i c ( l o w ) , mesic (medium), and h y g r i c ( h i g h ) s i t e s . B a rs on e s t i m a t e s r e p r e s e n t one s t a n d a r d e r r o r of the mean. 1 02 The g r e a t e r s t a n d i n g c r o p of dead r o o t s i n the s o i l - f i l l e d i n - g r o w t h bags i s not v e r y s u r p r i s i n g . S i n c e t h e s e i n - g r o w t h bags c o n t a i n e d g r e a t e r mean l e v e l s of l i v e c o n i f e r o u s and n o n - c o n i f e r o u s r o o t s , I would e x p e c t them t o have g r e a t e r amounts of dead biomass. However, u n l i k e the s a n d - f i l l e d i n - g r o w t h bags, the n a t i v e - s o i l - f i l l e d bags were topped o f f w i t h two t o f i v e cm of ground f o r e s t f l o o r m i x t u r e . The o r i g i n a l f o r e s t • f l o o r m a t e r i a l s g a t h e r e d from a l l t h r e e s i t e s c o n t a i n e d l a r g e amounts of l i v e and dead r o o t s . A l t h o u g h t h i s m a t e r i a l was re-g r o u n d s e v e r a l t i m e s i n the W i l e y m i l l , i t i s s t i l l p o s s i b l e t h a t i t c o n t a i n e d r e c o g n i z a b l e dead r o o t fragments which would have i n c r e a s e d the e s t i m a t e of dead r o o t biomass. 5.2.4 FUNGAL COMPONENT 5.2.4.1 Temporal p a t t e r n s i n f u n g a l biomass S t a n d i n g c r o p e s t i m a t e s f o r f u n g a l biomass on some s i t e s ( F i g u r e 5.10) showed a marked s e a s o n a l i t y s i m i l a r t o t h a t seen i n the c o n i f e r o u s l i v e component. S t a n d i n g c r o p s on the x e r i c and mesic s i t e s were h i g h e s t i n the s p r i n g of 1984 f o r both n a t i v e - s o i l and sand growth media. These i n i t i a l h i g h l e v e l s f e l l q u i c k l y t o summer lows i n J u l y and August. There was some subsequent r e c o v e r y i n the f a l l of 1984 and e a r l y w i n t e r of 1985, e s p e c i a l l y by the mesic s i t e . However, the peaks i n f u n g a l biomass seen i n March and A p r i l 1984 were t h r e e 103 t o f i v e t i m e s t h o s e seen i n the w i n t e r and e a r l y s p r i n g of the f o l l o w i n g y e a r . The i n - g r o w t h bags from the h y g r i c s i t e c o n t a i n e d v e r y low l e v e l s of f u n g a l biomass thr o u g h o u t the e n t i r e y e a r . There were s m a l l and i n c o n s i s t e n t i n c r e a s e s from base l e v e l s of s t a n d i n g biomass w i t h each growth medium, but no pronounced peak or marked s e a s o n a l i t y t o t h e i r appearance as was seen i n the i n - g r o w t h bags from the o t h e r two s i t e s . D i s c u s s i o n of the r e s u l t s of the ANOVA f o r the f u n g a l biomass component i s a g a i n d i f f i c u l t . As was the case f o r p o r t i o n s of the dead r o o t biomass d a t a , no t r a n s f o r m a t i o n c o u l d be found which s a t i s f i e d the homogeneity of v a r i a n c e r e q u i r e m e n t of the ANOVA f o r t h e d a t a from s a n d - f i l l e d i n - g r o w t h bags. S i g n i f i c a n t second- and t h i r d - o r d e r i n t e r a c t i o n i n both ANOVA models a l s o made i n t e r p r e t a t i o n s of t h e s e r e s u l t s d i f f i c u l t ( T a b l e V I , p. 7 0 , and V I I , p. 7 1 ) . The ANOVA f o r the s e p a r a t e d a t a s e t s f o r each growth media d i d show one i n t e r e s t i n g e f f e c t . Depth of growth medium i n the s a n d - f i l l e d i n - g r o w t h bags had a s i g n i f i c a n t e f f e c t on f u n g a l biomass ( p = . 0 l 6 , T a b l e V I I , p. 7 1 ) . The s o i l - f i l l e d i n - g r o w t h bags showed no such e f f e c t . There were a l s o s i g n i f i c a n t d i f f e r e n c e s between the s t u d y p l o t s w i t h i n t h e s i t e s f o r the s a n d - f i l l e d bags (p= .047 , T a b l e V I I ) , w h i l e no d i f f e r e n c e s w i t h p l o t s c o u l d be d e t e c t e d f o r the n a t i v e - s o i l - f i l l e d 104 2000-1 1500-1000-5 0 0 -1200 1000-8 0 0 -6 0 0 -4 0 0 -2 0 0 -Date Site O Low (L) site A Medium (M) site o High (H) site F i g u r e 5.10. D o t e Comparison of the p a t t e r n s i n a s h - f r e e f u n g a l biomass f o r x e r i c ( l o w ) , mesic (medium), and h y g r i c ( h i g h ) s i t e s from n a t i v e - s o i l - f i l l e d (A) and s a n d - f i l l e d (B) i n - g r o w t h bags. Bars on e s t i m a t e s r e p r e s e n t one s t a n d a r d e r r o r of the mean. 1 05 i n - g r o w t h bags. I t i s p o s s i b l e t h a t t h e s e d i f f e r e n c e s i n t h e e f f e c t of depth of m a t e r i a l and p l o t f o r the two growth media are i n d i c a t i o n s t h a t more than a s i n g l e s p e c i e s of f u n g i were p r e s e n t on the s t u d y s i t e s . F ungi e x h i b i t the same range i n a d a p t i v e a b i l i t i e s t h a t o t h e r s p e c i e s do. M y c o l o g i s t s and f o r e s t e r s have o f t e n s e l e c t e d a m y c o r r h i z a l symbiont t h a t was not o n l y c o m p a t i b l e w i t h t h e i r t r e e s p e c i e s , but had the a b i l i t y t o grow under extreme c o n d i t i o n s as w e l l . Work w i t h e c t o m y c o r r h i z a l f u n g i on mine t a i l i n g s , which have v e r y h i g h l e v e l s of heavy m e t a l s , has shown t h a t c e r t a i n s p e c i e s of f u n g i have g r e a t e r t o l e r a n c e t o t o x i c s u b s t a n c e s than o t h e r s ( K e n d r i c k and B e r c h 1985). I t s h o u l d not be s u r p r i s i n g t h e n , t h a t o n l y c e r t a i n members of f u n g a l community on my p l o t s would have been a b l e t o e x p l o i t the sand medium i n h a l f of the i n - g r o w t h bags. A l t h o u g h the growth environment w i t h i n t h e s e bags would not have been t o x i c , i t would have d r i e r and n u t r i e n t - p o o r e r than t h a t i n t h e n a t i v e - s o i l - f i l l e d i n - g r o w t h bags. I f a l a r g e a r e a of a g i v e n s t u d y s i t e were dominated by s p e c i e s which d i d not have the a b i l i t y t o grow s u c c e s s f u l l y i n the sand medium, t h e r e would be low l e v e l s of f u n g a l biomass i n the s a n d - f i l l e d i n - g r o w t h bags of t h e s e a r e a s . T h i s c o u l d have r e s u l t e d i n t h e s i g n i f i c a n t d i f f e r e n c e s between the s t u d y p l o t s which the ANOVA showed. S i n c e the n a t i v e - s o i l - f i l l e d i n - g r o w t h bags c o n t a i n e d s o i l 1 06 m a t e r i a l which had a c t u a l l y come from t h e t h r e e s i t e s , t h e s e bags p r o b a b l y r e p r e s e n t e d a much more s u i t a b l e growth environment f o r the v a r i o u s s p e c i e s of f u n g i on the p l o t s . P a i r i n g the graphs f o r the two growth media by s i t e ( F i g u r e 5.11), and c a l c u l a t i o n of an o v e r a l l mean f u n g a l biomass e s t i m a t e f o r each growth medium and s i t e c o m b i n a t i o n ( F i g u r e 5.12) showed t h a t the Mes i c s i t e had the g r e a t e s t mean f u n g a l biomass of a l l t h r e e s i t e s . A u t h o r s of o t h e r belowground s t u d i e s have o f t e n bypassed the m e s i c , m i d - s l o p e s i t e s t o c o n c e n t r a t e on l o w - p r o d u c t i v i t y , x e r i c s i t e s , and h i g h - p r o d u c t i v i t y , h y g r i c s i t e s ( e . g . Hase, u n p u b l i s h e d , t h i s s t u d y ) as b e i n g r e p r e s e n t a t i v e of two extremes a l o n g a c o n t i n u o u s spectrum of p r o d u c t i v i t y . The l a c k of a s t r a i g h t l i n e r e l a t i o n s h i p between t o p o g r a p h i c p o s i t i o n and s t a n d i n g c r o p , a t l e a s t f o r f u n g a l mycelium, makes i n t e r p o l a t i o n between x e r i c and h y g r i c s i t e v a l u e s v e r y q u e s t i o n a b l e . 5.2.4.2 The e f f e c t of growth medium on f u n g a l biomass e s t i m a t e s In c omparison t o the o t h e r t h r e e biomass components, the f u n g a l component showed the s m a l l e s t e f f e c t of growth medium on e s t i m a t e d biomass ( F i g u r e 5.11). A l t h o u g h the l a r g e s t s i n g l e measure of s t a n d i n g f u n g a l biomass was o b t a i n e d u s i n g s o i l - f i l l e d i n - g r o w t h bags ( i n A p r i l 1984 on the mesic s i t e , F i g u r e 5.10), the graphs of s t a n d i n g c r o p f o r the two growth media for. 107 1200 -i Material O Sond-fi l led Bogs $ Soil-f i l led Bags M A M 1984 D a t e F i g u r e 5.11. Comparison of the p a t t e r n s of a s h - f r e e f u n g a l biomass between n a t i v e - s o i l - f i l l e d and s a n d - f i l l e d i n - g r o w t h bags. Bars on e s t i m a t e s r e p r e s e n t one s t a n d a r d e r r o r of the mean. A. the x e r i c (low) s i t e B. the mesic (medium) s i t e C. the h y g r i c ( h i g h ) s i t e 109 120n CD o» 100-SSOLUOI 8 0 -CD Fungal . 6 0 -free ash- 4 0 -Mean 2 0 -Xeric Mesic Site Hygric In-growth Material O Sand- f i l led Bags  * Soi l - f i l led Bags F i g u r e 5.12. C o m p a r i s o n o f t h e p a t t e r n s o f mean a s h - f r e e f u n g a l b i o m a s s b e t w e e n n a t i v e - s o i l - f i l l e d a n d s a n d - f i l l e d i n - g r o w t h b a g s f o r x e r i c ( l o w ) , m e s i c ( m e d i u m ) , a n d h y g r i c ( h i g h ) s i t e s . B a r s on e s t i m a t e s r e p r e s e n t one s t a n d a r d e r r o r o f t h e mean. 1 10 each s i t e p a r a l l e l e d each o t h e r c l o s e l y , and t r a n s e c t e d r e g u l a r l y . The most i n c o n s i s t e n t r e l a t i o n s h i p between e s t i m a t e d biomass and growth medium was shown by the h y g r i c s i t e . However, the apparent d i f f e r e n c e s i n monthly e s t i m a t e s of f u n g a l biomass between growth media here were m a g n i f i e d by the d i f f e r e n t s c a l e of the y - a x i s f o r t h i s g raph as compared t o the graphs f o r the x e r i c and mesic s i t e s . The s m a l l e r degree of d i f f e r e n c e between growth media f o r t h e f u n g a l component as compared t o o t h e r biomass components, can be seen even more c l e a r l y i n F i g u r e 5.12. The o v e r a l l mean s t a n d i n g c r o p from t h e p o o l e d monthly e s t i m a t e s showed how l i t t l e d i f f e r e n c e t h e r e was between the two growth media. Indeed, on the x e r i c and h y g r i c s i t e s , the o v e r a l l mean biomass e s t i m a t e s from s a n d - f i l l e d i n - g r o w t h bags were g r e a t e r than t h o s e from s o i l - f i l l e d i n - g r o w t h bags, a s i t u a t i o n not seen i n any o t h e r biomass component. On the mesic s i t e however, the s o i l - f i l l e d i n - g r o w t h bags a g a i n produced the l a r g e r o v e r a l l mean. D e s p i t e the r e l a t i v e l y s m a l l d i f f e r e n c e between the mean biomass e s t i m a t e s of the two growth media compared w i t h e a r l i e r e s t i m a t e s f o r the o t h e r t h r e e biomass components, p a i r e d t e s t s of t h e s e means on each s i t e showed t h a t a l l d i f f e r e n c e s between growth media were s i g n i f i c a n t t o a t l e a s t the .05 l e v e l ( p a i r e d t - t e s t , p e r f o r med on u n t r a n s f o r m e d d a t a , T a b l e V I I I , p. 82 ). 111 The s i m i l a r i t y between the e s t i m a t e s of mean f u n g a l biomass f o r the two growth media i s somewhat s u r p r i s i n g . The n a t i v e s o i l growth medium would have had l a r g e numbers of f u n g a l s p o r e s common t o the t h r e e s i t e s a t the time t h a t the i n - g r o w t h bags were i n s t a l l e d . The sand growth medium would have had few s p o r e s , and those t h a t i t d i d c o n t a i n would p r o b a b l y not have been adapted to t h e growth c o n d i t i o n s of the s t u d y s i t e s as were the s p o r e s which the s o i l medium c o n t a i n e d . The s m a l l degree of d i f f e r e n c e between the mean e s t i m a t e s of f u n g a l biomass f o r the two growth media i s p r o b a b l y a good i n d i c a t i o n t h a t the m a t e r i a l w i t h i n the i n - g r o w t h bags was i n v a d e d v e r y q u i c k l y by hyphae from the s u r r o u n d i n g s o i l volume. 5.3 POSSIBLE SOURCES OF ERROR IN THE PROCESSING OF IN-GROWTH  BAGS Because of manpower l i m i t a t i o n s , i t was n e c e s s a r y t o keep r o o t i n - g r o w t h bags i n s t o r a g e ( a t 4°C) f o r p e r i o d s of up t o s i x months. N u s z d o r f e r (1982) has s u g g e s t e d t h a t the unequal s t o r a g e time of samples c o u l d i n t r o d u c e a s y s t e m a t i c e r r o r due t o the d e a t h and decay of r o o t s w i t h i n the bags, and t h e i r subsequent i n c o r r e c t c l a s s i f i c a t i o n upon p r o c e s s i n g . However, F e r r i e r and A l e x a n d e r (1985) found t h a t f i n e r o o t t i p s and m y c o r r h i z a e p e r s i s t i n a r e c o g n i z a b l e " l i v i n g " c o n d i t i o n ( i n t a c t , t u r g i d apex; l i g h t e r i n c o l o u r than "dead" f i n e r o o t s ) f o r a t l e a s t n i n e months a f t e r were 1 1 2 s e v e r e d from the pa r e n t t r e e , but were l e f t in situ. Biomass e s t i m a t e s from those i n - g r o w t h bags s t o r e d f o r the l o n g e s t p e r i o d d i d not show sudden i n c r e a s e s i n dead r o o t biomass when compared t o biomass e s t i m a t e s from bags sampled one month p r e v i o u s or one month l a t e r , but s t o r e d f o r s h o r t e r p e r i o d s . A l l samples c o n t a i n i n g the same i n - g r o w t h m a t e r i a l from t h e same s i t e and s a m p l i n g p e r i o d were p r o c e s s e d a t one t i m e . 5.4 CONIFEROUS ROOT DYNAMICS WITH SEQUENTIAL SOIL CORES 5.4.1 PATTERN OF LIVE AND DEAD FINE ROOT DYNAMICS ON THE  XERIC AND HYGRIC SITE F i g u r e 5.13 shows the s e a s o n a l f l u c t u a t i o n s i n the s t a n d i n g c r o p of ve r y f i n e 5 (<1 mm) c o n i f e r o u s r o o t biomass on t h e x e r i c and h y g r i c s i t e s sampled w i t h s e q u e n t i a l s o i l c o r e s . A l t h o u g h t h e r e was a l a r g e degree of o v e r l a p between the s t a n d a r d e r r o r b a r s on monthly s t a n d i n g c r o p e s t i m a t e s of l i v e c o n i f e r o u s r o o t s , a s e a s o n a l p a t t e r n of belowground p r o d u c t i o n i n both s i t e s was a p p a r e n t . However, the r e l a t i v e d i f f e r e n c e s between s e a s o n a l maxima and minima i n the s e q u e n t i a l c o r e e s t i m a t e s were not as g r e a t as thos e from 5 F o r t h i s p o r t i o n of the d i s c u s s i o n , v e r y f i n e r o o t s w i l l be c l a s s i f i e d as h a v i n g d i a m e t e r s ^1 mm. A l t h o u g h Dr. Hase sampled f o r , and s e p a r a t e d , r o o t s w i t h d i a m e t e r s as l a r g e as 10 mm, a t t h e time of t h i s w r i t e - u p , t h e o n l y d a t a which were ready f o r a n a l y s i s were tho s e c o n c e r n i n g t h e s e v e r y f i n e r o o t s . However, t h i s biomass component d i d make up, on av e r a g e , over 80 p e r c e n t of t h e monthly s t a n d i n g c r o p e s t i m a t e s f o r b o t h the x e r i c and h y g r i c s i t e s , and were r e s p o n s i b l e f o r most of biomass i n t h e p r o d u c t i o n e s t i m a t e s . 1 1 3 the i n - g r o w t h bags ( F i g u r e 5 . 1 , p. 7 5 ) . On the h y g r i c s i t e , peaks i n t h e s t a n d i n g c r o p s of l i v e r o o t s i n A p r i l of 1983 were f o l l o w e d by summer lows, when the m a j o r i t y of new p r o d u c t i o n would have been c o n c e n t r a t e d i n t he aboveground biomass p o r t i o n s . Most of the f i n e r o o t biomass l o s t d u r i n g the summer was r e g a i n e d q u i c k l y by the f a l l and e a r l y w i n t e r of 1984. The x e r i c s i t e showed a much s m a l l e r drop i n l i v e r o o t s from i t s ' s p r i n g peak i n A p r i l t o t h e summer low i n June. Because s i t e c o n d i t i o n s would have been much more se v e r e on the x e r i c s i t e than on the h y g r i c s i t e , t h i s s m a l l d e c r e a s e i n l i v e r o o t biomass i s p r o b a b l y i n d i c a t i v e of a c o n t i n u o u s replacement of the v e r y f i n e r o o t biomass d u r i n g the d r i e s t p a r t of the y e a r . Both the x e r i c and h y g r i c s i t e s showed v e r y l a r g e i n c r e a s e s i n l i v e r o o t biomass between F e b r u a r y and A p r i l 1984. S t a n d i n g c r o p s of l i v e r o o t s i n March of 1984 were 1500 kg h a - 1 t o 2000 kg h a " 1 g r e a t e r than they were i n A p r i l 1983. Whether t h e s e i n c r e a s e s r e f l e c t e d e x c e p t i o n a l l y good growth c o n d i t i o n s of t h a t s p r i n g , of t h e p r e v i o u s summer and f a l l , or perhaps m i l d w i n t e r c o n d i t i o n s I do not know. What i s i n t e r e s t i n g , however, i s t h a t t h e s e v e r y h i g h biomass l e v e l s appear t o be u n s u s t a i n a b l e on t h e x e r i c s i t e . U n l i k e the s p r i n g and summer of 1983, t h a t of 1984 saw a d r a m a t i c d e c r e a s e i n the s t a n d i n g c r o p of l i v e r o o t s on the x e r i c s i t e . C o n i f e r o u s r o o t biomass on t h e h y g r i c s i t e f e l l as w e l l , but t h i s d e c r e a s e was not as d r a m a t i c a d e p a r t u r e of 1 14 8000 08 JZ 3 eooo CO 0) 03 E o CD 4000 o o oc CD © £ 2000 i JC CO < 0 - I 1 — — i 1 1 ' 1 1 T f — 1 1 r ~ F M A M J J A S O N D J F M A M J 1983 Date 1984 B 1000 ± , 800 0) CO CO E o CD o o oc CD CD t_ i JC CO < 600 400 200 Site o Xeric site * Hygric site Date F i g u r e 5.13. P a t t e r n s i n a s h - f r e e v e r y f i n e (^1 mm) l i v e and dead c o n i f e r o u s r o o t biomass f o r the x e r i c (low) and h y g r i c ( h i g h ) s i t e s from s e q u e n t i a l s o i l c o r e s . B a r s on e s t i m a t e s r e p r e s e n t one s t a n d a r d e r r o r of the mean. A. p a t t e r n s i n l i v e s t a n d i n g c r o p B. p a t t e r n s i n dead s t a n d i n g c r o p 1 1 5 the b e h a v i o u r of t h i s s i t e i n 1983, as was the c a s e f o r t h e x e r i c s i t e . There would t h e r e f o r e seem t o be upper l i m i t s on the amount of l i v e r o o t biomass t h a t can be s u s t a i n e d by t h e s e poor, x e r i c s i t e s d u r i n g t i m e s of drought s t r e s s . The x e r i c s i t e c l e a r l y had g r e a t e r s t a n d i n g c r o p s of l i v e f i n e r o o t s than d i d the h y g r i c s i t e , w i t h an o v e r a l l mean s t a n d i n g biomass of 4820 kg h a - 1 ± 616 kg h a - 1 (mean ± 1 SE) as compared t o 3478 kg h a " 1 ± 270 kg h a " 1 f o r the h y g r i c s i t e . However, the magnitude of f l u c t u a t i o n s ( i n terms of the a b s o l u t e amounts of g a i n or l o s s i n biomass) and the t i m i n g of t h e s e changes were almost i d e n t i c a l between the two s i t e s , e x c e p t d u r i n g the f i r s t d e c r e a s e i n c o n i f e r o u s r o o t biomass between A p r i l and June of 1983, when the d e c r e a s e on the h y g r i c s i t e was much g r e a t e r than t h a t on the x e r i c s i t e . T h i s might seem s u r p r i s i n g s i n c e the x e r i c s i t e , which would have l o s t water t o down s l o p e d r a i n a g e much f a s t e r than any o t h e r s i t e , would have had the more s e v e r e and l i m i t i n g growth c o n d i t i o n s . Because of t h i s I would have e x p e c t e d t o see a more s e v e r e drop i n l i v e biomass on the x e r i c s i t e . The l a c k of such a d r o p a g a i n demonstrates the p o w e r f u l p h o t o s y n t h a t e s i n k t h a t the belowground component r e p r e s e n t s on t h e s e p o o r e r s i t e s . D e s p i t e s i t e c o n d i t i o n s t h a t would have been becoming p r o g r e s s i v e l y d r i e r , r o o t p r o d u c t i o n c o n t i n u e d t hroughout the summer of 1983 on the x e r i c s i t e . On the h y g r i c s i t e , w i t h i t s ' c o n t i n u o u s f l o w of seepage w a t e r , t h e r e would have been a lower r e q u i r e m e n t f o r a l a r g e 1 1 6 f i n e r o o t biomass t o s u p p l y adequate water and n u t r i e n t s t o the t r e e s . On such a s i t e , the aboveground biomass p r o b a b l y becomes a more p o w e r f u l p h o t o s y n t h a t e s i n k f o l l o w i n g bud b u r s t i n the s p r i n g , and new r o o t growth c e a s e s (Vogt et al. 1980). F u r t h e r e v i d e n c e t o s u p p o r t t h i s t h e o r y can be seen i n the graph of dead r o o t biomass dynamics over the same p e r i o d . There were l a r g e i n c r e a s e s i n the amount of dead f i n e r o o t biomass between A p r i l and August 1983 on the x e r i c s i t e and much s m a l l e r i n c r e a s e s d u r i n g the same p e r i o d on the h y g r i c s i t e . D e s p i t e the l a c k of a l a r g e - s c a l e d e c r e a s e i n the l i v e f i n e r o o t biomass on the x e r i c s i t e , l a r g e amounts of t h i s component must have been d y i n g o f f . These r o o t s must have been r e p l a c e d q u i c k l y and c o n t i n u o u s l y t o m a i n t a i n the s t a n d i n g c r o p of l i v e r o o t s a t adequate l e v e l s f o r t h i s s i t e . I have no e x p l a n a t i o n as t o why dead r o o t biomass f e l l t o such low l e v e l s i n October 1983. I t i s u n r e a s o n a b l e t o b e l i e v e t h a t d e c o m p o s i t i o n would remove al m o s t the e n t i r e dead r o o t component from b o t h s i t e s . I am l e f t t o c o n c l u d e t h a t t h i s v e r y l a r g e drop i n dead biomass must r e p r e s e n t some s o r t of s a m p l i n g e r r o r f o r t h i s month's samples. One of the most s t r i k i n g a s p e c t s of F i g u r e 5.13 a r e t h e l a r g e d i f f e r e n c e s between l i v e and dead s t a n d i n g c r o p s o b s e r v e d on both s i t e s . D e s p i t e f l u c t u a t i o n s of as much as 2000 kg h a " 1 between s u c c e s s i v e e s t i m a t e s of l i v e s t a n d i n g c r o p , t h e r e were never i n c r e a s e s or d e c r e a s e s g r e a t e r than 1 17 700 kg h a " 1 i n the dead s t a n d i n g c r o p component. Such a l a r g e d i s c r e p a n c y i s d i f f i c u l t t o account f o r . I t i s p o s s i b l e t h a t most of the dead f i n e r o o t s decomposed q u i c k l y enough so as t o be u n r e c o g n i z a b l e as r o o t m a t e r i a l upon c o r i n g on the subsequent sample d a t e . However, Berg and Ekbohm (1983) found t h a t l e s s than twenty p e r c e n t of the o r i g i n a l mass of one t o two mm dead f i n e r o o t s i n a 1 2 0 - y e a r - o l d Pi nus sylvestris s t a n d i n c e n t r a l Sweden had decomposed a f t e r 140 d a y s . I t seems u n l i k e l y , then t o f i n d such complete d e c o m p o s i t i o n a f t e r o n l y s i x t y days. Another p o s s i b l e e x p l a n a t i o n f o r the d i s a p p e a r a n c e of the f i n e r o o t biomass i s t h a t s o i l m i c r o i n v e r t e b r a t e s c o u l d have consumed i t . S e a s t e d t (1984) s t a t e s t h a t m i c r o a r t h o p o d s can account f o r as much as 69 p e r c e n t of the a n n u a l decay r a t e of f o r e s t l i t t e r . E s t i m a t e s of d i r e c t r o o t h e r b i v o r y by s o i l m i c r o f a u n a a r e much l o w e r , however. H a r r i s et al. (1980) s t a t e t h a t consumption r a t e s of t e n p e r c e n t of s t a n d i n g f i n e r o o t biomass per y e a r p r o b a b l y r e p r e s e n t an upper l i m i t f o r temperate f o r e s t s , and t h a t r a t e s of two p e r c e n t per y e a r a r e g e n e r a l l y more r e a l i s t i c . F u r t h e r t o t h i s argument, the l a r g e d e c r e a s e i n s t a n d i n g l i v e r o o t biomass between A p r i l and June 1984 o c c u r r e d w i t h a p p r o x i m a t e l y e q u a l magnitude on b o t h the x e r i c and h y g r i c s i t e s . W h i l e r o o t h e r b i v o r y may have been a p o s s i b l e cause of such a l a r g e d i s a p p e a r a n c e on the h y g r i c s i t e , w i t h i t s ' m u l l f o r e s t f l o o r and p r o b a b l e l a r g e s o i l i n s e c t p o p u l a t i o n , i t i s u n l i k e l y t o have c a u s e d a s i m i l a r drop on the x e r i c 1 18 s i t e , which had a mor f o r e s t f l o o r . T h i s s i t e would have had a reduced amount of s o i l a n i m a l a c t i v i t y i n comparison t o the h y g r i c s i t e , e s p e c i a l l y of the l a r g e r s o i l a n i m a l s such as nematodes, which consume l a r g e amounts of r o o t biomass. How then do I account f o r t h i s m i s s i n g biomass? Most p r o b a b l y , much of t h i s fragmented dead r o o t component was r i n s e d t h r o u g h the two mm s i e v e and l o s t d u r i n g sample washing. T h i s would e x p l a i n why t h e f l u c t u a t i o n s i n dead r o o t biomass were s i m i l a r on bo t h the x e r i c and h y g r i c p l a n t a s s o c i a t i o n s . 5.4.2 COMPARISON OF ESTIMATES OF ROOT DYNAMICS FROM SEQUENTIAL SOIL CORES WITH THOSE OF IN-GROWTH BAGS A l t h o u g h the e x t e n t of o v e r l a p between s e q u e n t i a l c o r e s a m p l i n g and the r e t r i e v a l of the i n - g r o w t h bags was l i m i t e d t o the p e r i o d between F e b r u a r y and June 1984, e x a m i n a t i o n of the s t a n d i n g c r o p e s t i m a t e s produced w i t h the s e q u e n t i a l s o i l c o r e s h e l p e d g r e a t l y i n a s s e s s i n g the u s e f u l n e s s and l i m i t a t i o n s of the i n - g r o w t h bag t e c h n i q u e . However, because they c o v e r d i f f e r e n t p e r i o d s of s t u d y , and were t h e r e f o r e produced under d i f f e r i n g c l i m a t i c c o n d i t i o n s , i t i s d i f f i c u l t t o compare the s e a s o n a l r o o t dynamics of t h e two t e c h n i q u e s . S e v e r a l p o i n t s of F i g u r e s 5.1 (p. 7 5 ) , 5.7 (p. 94) and 5.13 do, however, i n v i t e c o m p a r i s o n s . The most o b v i o u s d i f f e r e n c e between t h e s e graphs a r e the l a r g e d i f f e r e n c e s between the e s t i m a t e s of s t a n d i n g l i v e c o n i f e r o u s r o o t 1 19 biomass produced w i t h s e q u e n t i a l c o r e s and i n - g r o w t h bags. The l a r g e s t s i n g l e monthly e s t i m a t e of a s h - f r e e c o n i f e r o u s <5 mm r o o t biomass f o r t h e i n - g r o w t h bags was 536 kg h a " 1 made on March 1 1984 on the x e r i c s i t e w i t h n a t i v e s o i l as the growth medium. The c o r r e s p o n d i n g e s t i m a t e f o r s e q u e n t i a l c o r e s , produced on March 14 1984 on t h e same s i t e f o r t h e <1 mm component, was 6914 kg h a " 1 , more than an o r d e r of magnitude g r e a t e r . The l a t t e r biomass e s t i m a t e was a l s o the s i n g l e l a r g e s t e s t i m a t e produced f o r the s e q u e n t i a l s o i l c o r e s a m p l i n g . There a r e , t h e r e f o r e , c l e a r d i f f e r e n c e s between the two t e c h n i q u e s as f a r as e s t i m a t e s of c o n i f e r o u s l i v e s t a n d i n g c r o p a r e c o n c e r n e d . Are t h e r e reasons f o r t h e s e d i f f e r e n c e s ? The m a j o r i t y of the c o n i f e r o u s r o o t s which appeared i n t h e i n - g r o w t h bags tended t o be v e r y l o n g and s l e n d e r . M y c o r r h i z a l t i p s , when they o c c u r r e d , were s m a l l , s i n g l e or p a i r e d , and were w i d e l y spaced a l o n g the l e n g t h of the r o o t . These t y p e s of r o o t s have been r e f e r r e d t o as " s e e k e r " or " p i o n e e r " r o o t s by L y r and Hoffmann (1974), who d e s c r i b e d the phenomenon f o r t r e e r o o t s growing t h r o u g h n u t r i e n t d e f i c i e n t m a t e r i a l . By c o m p a r i s o n , the m y c o r r h i z a e were much denser i n the r o o t samples from the s e q u e n t i a l s o i l c o r e s , and tended t o be c o r a l l o i d i n a ppearance, w i t h a g r e a t many m y c o r r h i z a l r o o t t i p s packed t o g e t h e r . Indeed, th e s e v e r y l a r g e numbers of m y c o r r h i z a e a c c o u n t e d f o r most of the v e r y f i n e r o o t biomass i n the s e q u e n t i a l c o r e s . S t . John (1983) has 1 20 d e s c r i b e d a s i m i l a r p a t t e r n of r o o t growth i n t o r o o t - f r e e s o i l volumes i n the t r o p i c a l r a i n f o r e s t s of the Amazon. I n i t i a l e x p l o r a t o r y r o o t s i n t h e s e t r o p i c a l f o r e s t ecosystems tended t o be l o n g and unbranched. However, upon e n c o u n t e r i n g a n u t r i e n t - r i c h pocket of o r g a n i c m a t t e r they branched p r o f u s e l y . A l t h o u g h t h i s o b s e r v a t i o n was more a f u n c t i o n of s i t e f e r t i l i t y than of age, i t i s p o s s i b l e t h a t , i n temperate c o n i f e r o u s f o r e s t , the h i g h e r d e n s i t i e s of m y c o r r h i z a l r o o t t i p s a r e o n l y produced by o l d e r f i n e r o o t s ; t h o s e t h a t a r e perhaps a y e a r or more o l d and have, by t h e i r growth i n t o a n u t r i e n t - r i c h or m o i s t m i c r o s i t e w i t h i n the s o i l volume, s u r v i v e d f o r more than one s e a s o n a l growth c y c l e . Such a mechanism would be advantageous because c a r b o h y d r a t e e x p e n d i t u r e s on d e v e l o p i n g l a r g e m y c o r r h i z a l s t r u c t u r e s i n m i c r o s i t e s where the f i n e r o o t s c o u l d not s u r v i v e would be a v o i d e d . Because no r o o t s w i t h i n the i n - g r o w t h bags c o u l d have been o l d e r than n i n e months (t h e maximum l e n g t h of time t h a t the i n - g r o w t h bags were l e f t on s i t e ) , t h e r e may not have been s u f f i c i e n t time f o r c o r r a l o i d m y c o r r h i z a e t o form. V a r t a n i a n (1981) noted t h a t not a l l r o o t t i p s d i e when growth c o n d i t i o n s i n the s o i l volume become u n f a v o u r a b l e . P r o g r e s s i v e drought s t r e s s on the a n n u a l d i c o t y l e d o n Sinapi s alba L. i n d u c e d h a r d e n i n g o f f of some of i t s ' s h o r t r o o t t i p s v i a d e p o s i t i o n of c a r b o h y d r a t e as g l u c o s e and s t a r c h . Because t h e s e r o o t s were u n s u b e r i z e d , they were a b l e t o expand r a p i d l y and form new r o o t h a i r s w i t h i n h o u r s of 121 r e - w e t t i n g . The p o r t i o n s of my study a r e a sampled by the s e q u e n t i a l s o i l c o r e s c o n t a i n e d g r e a t e r amounts of two mm t o t e n mm i n dia m e t e r r o o t s t h a n d i d the i n - g r o w t h bags (Hase, u n p u b l i s h e d ) . These r o o t s , which c o u l d have been one t o s e v e r a l y e a r s o l d , c o u l d have s e r v e d as a base f o r a b u r s t of new r o o t growth as d e s c r i b e d by V a r t a n i a n (1981). I t i s , t h e r e f o r e , not s u r p r i s i n g t h a t the r o o t biomass e s t i m a s t e s from the s e q u e n t i a l s o i l c o r e s were g r e a t e r than e s t i m a t e s from the i n - g r o w t h bags. E r i c s s o n and P e r s s o n (1980) a l s o found v e r y few r o o t s of o v e r s t o r e y p l a n t s l a r g e r than two mm i n t h e i r i n - g r o w t h bags i m p l a n t e d f o r two y e a r s i n t o 2 0 - y e a r - o l d Pi nus sylvestris s t a n d s i n c e n t r a l Sweden. F a b i a o et al. ( 1 9 8 4 ) , w o r k i n g i n s t a n d s of b l u e gum {Eucalyptus globulus L a b i l l . ) i n P o r t u g a l found t h a t the amount of <2 mm r o o t s i n t h e i r i n - g r o w t h bags r e a c h e d a maximum a f t e r s i x months i n sandy s o i l a r e a s , whereas i t took t w e l v e months f o r t h e s t a n d i n g c r o p t o peak i n s t u d y a r e a s w i t h a c l a y e y s o i l . However, n e i t h e r E r i c s s o n and P e r s s o n (1980) or F a b i a o et al. (1984) made co m p a r i s o n s of biomass e s t i m a t e s u s i n g i n - g r o w t h bags and s e q u e n t i a l s o i l c o r i n g . By way of c o n t r a s t , Steen (1985), w o r k i n g i n t h i r d y e a r f a l l o w g r a s s f i e l d s i n Sweden, found t h a t r o o t biomass i n her i n - g r o w t h bags reached comparable l e v e l s t o th o s e found i n s e q u e n t i a l s o i l c o r e s a f t e r o n l y two months. However, the s i z e , p e r s i s t e n c e , and growth r a t e of the r o o t systems of 1 22 g r a s s e s d i f f e r g r e a t l y from t h o s e of t r e e s p e c i e s , making com p a r i s o n s d i f f i c u l t . Kummerow and L a n t z (1983) found comparable amounts of v e r y f i n e r o o t s i n r e d shank c h a p a r r a l (Adenostoma fasciculatum H. & A.) communities sampled w i t h s e q u e n t i a l s o i l c o r e s and i n - g r o w t h bags. S t a n d i n g c r o p of the <1 mm r o o t s w i t h i n t he i n - g r o w t h bags peaked a f t e r o n l y f i v e months i n the s o i l , but a g a i n v e r y few l a r g e r s t r u c t u r a l r o o t s two t o f i v e mm i n di a m e t e r were found. E x t e n d i n g the time p e r i o d t h a t the i n - g r o w t h bags a r e l e f t i n t h e f i e l d would p r o b a b l y reduce t h e d i s c r e p a n c i e s i n s t a n d i n g c r o p e s t i m a t e s between t h e s e two t e c h n i q u e s . However, I e x p e r i e n c e d a r e l a t i v e l y l a r g e amount of d e s t r u c t i o n of i n - g r o w t h bags a f t e r o n l y n i n e months. E x p e r i m e n t s i n v o l v i n g v e r y l o n g p e r i o d s of r e s i d e n c e on a g i v e n s t u d y s i t e (say perhaps as l o n g as t e n y e a r s ) would p r o b a b l y be p r a c t i c a l o n l y where a n i m a l s ( d e e r , b e a r , and s q u i r r e l s ) c o u l d be e x c l u d e d ( e x t r e m e l y d i f f i c u l t ) , and i n st a n d s where the chances of n a t u r a l d i s t u r b a n c e such as wind throw, which c o u l d uproot or bury i m p l a n t e d bags, was q u i t e low. Even t h e n , such an experiment would p r o b a b l y have t o i n c o r p o r a t e i n t o i t s ' d e s i g n the p r o b a b i l i t y of l o o s i n g a l a r g e p e r c e n t a g e of the i n i t i a l s t o c k of bags. I a l s o found t h a t , a f t e r o n l y n i n e months, the mesh m a t e r i a l of my i n - g r o w t h bags had become somewhat b r i t t l e . The mesh m a t e r i a l f o r a study w i t h t en y e a r i n - g r o w t h bag r e s i d e n c e t i m e s would have t o be much s t u r d i e r than the 1 23 m a t e r i a l t h a t I u t i l i z e d , and would p r o b a b l y use a t h i c k e r mesh w i t h s m a l l e r o p e n i n g s . T h i s might e x c l u d e some r o o t growth or s o i l a n i m a l a c t i v i t y , which c o u l d a f f e c t the dynamics of the l i v e and dead r o o t s w i t h i n t h e bags. 5.5 POSSIBLE EFFECTS OF ON-SITE ACTIVITIES ON ROOT AND  FUNGAL DYNAMICS I have a l r e a d y noted t h a t the graphs of the l i v e r o o t dynamics from i n - g r o w t h bags showed l a r g e d e c r e a s e s from the s p r i n g of 1984 t o the s p r i n g of 1985. In some c a s e s , as i n the c o n i f e r o u s l i v e and f u n g a l biomass components, the 1985 e s t i m a t e s were as much as an o r d e r of magnitude l e s s than the c o r r e s p o n d i n g e s t i m a t e s from 1984. Was t h i s the r e s u l t of c l i m a t i c d i f f e r e n c e s between 1984 and 1985, or d i d such y e a r - t o - y e a r d e c l i n e s i n s t a n d i n g c r o p s of l i v e r o o t s and f u n g i r e f l e c t s i t e d i s t u r b a n c e caused by sampling? The weather c o n d i t i o n s between November 1984 and J u l y 1985 were u n u s u a l f o r Vancouver I s l a n d , based on l o n g term t e m p e r a t u r e and p r e c i p i t a t i o n a v e r a g e s ( F i g u r e 3.8, p. 4 2 ) . The f a l l of 1984 was e x t r e m e l y wet and q u i t e c o l d , w h i l e the f o l l o w i n g s p r i n g and summer were u n u s u a l l y d r y . The summer of 1985 was so d r y i n f a c t , t h a t i t produced some of the worst f o r e s t f i r e s i n l i v i n g memory th r o u g h o u t the p r o v i n c e . By c o m p a r i s o n , the s p r i n g and summer of 1984 were r e l a t i v e l y m i l d and m o i s t . Data from s e q u e n t i a l s o i l c o r e s has a l r e a d y shown t h a t c o n i f e r o u s l i v e biomass peaked i n F e b r u a r y and March of 1984 1 24 a t l e v e l s s u b s t a n t i a l l y above those of 1983. Thus, i t i s p o s s i b l e t h a t the l a r g e d e c r e a s e i n l i v e biomass components from 1984 t o 1985 s i m p l y r e f l e c t e d some of the n a t u r a l v a r i a t i o n i n p r o d u c t i v i t y c o u p l e d w i t h changes i n growth c o n d i t i o n s which v a r y g r e a t l y from year t o y e a r . Perhaps t h e lower l e v e l s of l i v e biomass seen i n t h e i n - g r o w t h bags i n the s p r i n g of 1985 a r e more r e p r e s e n t a t i v e of the l o n g - t e r m base l e v e l s of biomass than were the peaks of biomass seen i n the s p r i n g of 1984. A l t e r n a t i v e l y , s i t e d i s t u r b a n c e from monthly s a m p l i n g a c t i v i t i e s may have r e s u l t e d i n the d e c l i n e i n l i v e r o o t and f u n g a l biomass. F i g u r e 5.14 shows two v i e w s of the x e r i c p l a n t a s s o c i a t i o n t a k e n on the l a s t s a m p l i n g d a t e i n J u l y 1985. P i c t u r e A shows the dense u n d e r s t o r e y development on an u n d i s t u r b e d a r e a d i r e c t l y a d j a c e n t t o the x e r i c s i t e s t u d y p l o t s . P i c t u r e B was t a k e n a t the same l o c a t i o n , but shows the view i n t o the s t u d y p l o t s . The r e d u c t i o n i n u n d e r s t o r e y v e g e t a t i o n i n the s t u d y p l o t i s o b v i o u s , and i n some a r e a s t h e r e was complete l o s s of f o r e s t f l o o r and exposure of m i n e r a l s o i l . I t i s p r o b a b l e t h a t my a c t i v i t i e s on the s i t e s broke l a r g e numbers of r o o t s i n the upper o r g a n i c l a y e r s and caused some s o i l c o m p a c t i o n . S c o t t - R u s s e l l (1977) has n o t e d t h a t s o i l c ompaction can l e a d t o a n a e r o b i c s o i l c o n d i t i o n s which can e x c l u d e new r o o t growth t h r o u g h much of the s o i l volume. The same e f f e c t has been shown t o be t r u e f o r the growth of f u n g a l mycelium ( S k i n n e r and Bowen 1974). S a n t a n t o n i o and Hermann (1985) 125 F i g u r e 5.14. R e d u c t i o n i n u n d e r s t o r e y v e g e t a t i o n w i t h s a m p l i n g a c t i v i t y on t h e x e r i c s i t e . Photos show view i n t o the sampled p l o t of the x e r i c Gaultheria shall on a s s o c i a t i o n ( A ) , and an unsampled a r e a d i r e c t l y a d j a c e n t t o the sampled p l o t ( B ) . 126 a l s o n o t e d a st e a d y d e c l i n e i n l i v e f i n e r o o t biomass over t h r e e y e a r s on a l l t h r e e of t h e i r s t u d y s i t e s which were a l s o sampled a t monthly i n t e r v a l s . However, they a t t r i b u t e d t h e s e d e c l i n e s t o n a t u r a l v a r i a t i o n i n belowground p r o d u c t i v i t y w i t h v a r i a t i o n i n c l i m a t i c c o n d i t i o n s and not t o t h e i r o n - s i t e a c t i v i t i e s . Which of t h e s e two f a c t o r s , n a t u r a l system v a r i a t i o n or d i s t u r b a n c e - i n d u c e d change, was t h e cause of the drop i n l i v e r o o t s t a n d i n g c r o p t h a t I o b s e r v e d ? I t i s p r o b a b l e t h a t b o t h f a c t o r s were i m p o r t a n t , one more than the o t h e r depending on the s p e c i f i c s i t e . I have c l e a r , a l t h o u g h i n d i r e c t e v i d e n c e i n F i g u r e 5.14 t h a t my a c t i v i t i e s had a se v e r e impact on the x e r i c s i t e . Whether the obser v e d changes i n the aboveground u n d e r s t o r e y v e g e t a t i o n c o r r e s p o n d t o s i m i l a r changes i n the belowground r o o t and f u n g a l components, I can o n l y s p e c u l a t e on. What I do know, however, i s t h a t n e i t h e r the mesic nor the h y g r i c s i t e s showed the same degree of d i s t u r b a n c e i n t h e i r u n d e r s t o r e y v e g e t a t i o n as d i d the x e r i c s i t e . T h i s may r e f l e c t the r e s i l i e n c e of the former two s i t e s i n terms of t h e i r . a b i l i t y t o produce new u n d e r s t o r e y v e g e t a t i o n a f t e r d i s t u r b a n c e . C e r t a i n l y the u n d e r s t o r e y s p e c i e s common t o the mesic and h y g r i c p l a n t a s s o c i a t i o n s were much f a s t e r growing than the s a l a l w hich dominated the x e r i c s i t e . The f a c t t h a t a l l t h r e e s i t e s showed the same d e c r e a s e i n l i v e r o o t and f u n g a l biomass from 1984 t o 1985, whereas t h e r e was a marked d i f f e r e n c e i n v i s u a l e v i d e n c e of s i t e 1 27 d i s t u r b a n c e between s i t e s s u g g e s t s a c l i m a t i c mechanism c o n t r o l l i n g r o o t and f u n g a l p r o d u c t i o n . I f I su s p e c t a d i s t u r b a n c e - r e l a t e d e f f e c t , I must a l s o ask why I d i d not see t h i s drop i n l i v e biomass e a r l i e r ? The l a r g e s t l i v e f i n e r o o t e s t i m a t e s from the i n - g r o w t h bags were produced i n March and A p r i l of 1984. By t h a t t i m e , however, o n - s i t e a c t i v i t y f o r t h i s s t u d y had been underway f o r more than a y e a r , a f a c t t h a t i s not r e f l e c t e d i n the l i v e r o o t biomass e s t i m a t e s from the s e q u e n t i a l s o i l c o r e s . 5.6 COMPARISON OF THE EFFECTS ON ROOT AND FUNGAL BIOMASS OF  TWO ADDITIONAL GROWTH MEDIA In an e a r l i e r s e c t i o n of t h i s c h a p t e r I d i s c u s s e d the e f f e c t t h a t growth medium had on e s t i m a t e s of l i v e and dead f i n e r o o t biomass. F i g u r e 5.15 shows the s t a n d i n g c r o p s of the f o u r r o o t and f u n g a l components u s i n g the two r e g u l a r and two a d d i t i o n a l growth media. I t appears t h a t the f e r t i l i z e r t r e a t m e n t enhanced r o o t growth w i t h i n the i n - g r o w t h bags i n comparison w i t h the n a t i v e s o i l medium. Mean s t a n d i n g c r o p of the c o n i f e r o u s l i v e component i n t h e s e f e r t i l i z e d bags was n e a r l y t h r e e t i m e s t h a t of the u n f e r t i l i z e d n a t i v e - s o i l - f i l l e d bags, w i t h p r o g r e s s i v e l y lower v a l u e s i n the beach sand and s i l i c a sand bags. In a d d i t i o n t o the q u a n t i t a t i v e e f f e c t of enhanced r o o t g rowth, t h e r e were a l s o q u a l i t a t i v e changes t o the c o n i f e r o u s r o o t s i n the f e r t i l i z e r t r e a t m e n t . The new c o n i f e r o u s r o o t s found w i t h i n the f e r t i l i z e d bags had 1 28 800 600-cn 400 200 sil. sand bea. sand nat. soil fert. soil In-growth Material LEGEND EZ1 CLf+s NCLf+s CD D f + s F i g u r e 5.15. Comparison of the s t a n d i n g c r o p s of r o o t and f u n g a l biomass w i t h the two r e g u l a r (beach sand and n a t i v e s o i l ) and two a d d i t i o n a l (pure s i l i c a sand and f e r t i l i z e d n a t i v e s o i l ) growth media. S e t s of ten i n - g r o w t h bags were i m p l a n t e d of the mesic Moss a s s o c i a t i o n , and were the l a s t bags r e t r i e v e d i n J u l y of 1985. Those b a r s i n c l u d i n g d i f f e r e n t l e t t e r s a r e s i g n i f i c a n t l y d i f f e r e n t from e s t i m a t e s of s i m i l a r biomass components from i n - g r o w t h bags f i l l e d w i t h a l t e r n a t e growth media (Duncan's m u l t i p l e range t e s t , a = .05). 1 29 d i a m e t e r s t h a t were as l a r g e as f i v e mm, l a r g e r than any o t h e r new r o o t s found over the c o u r s e of t h i s s t u d y . These r o o t s were o f t e n found wrapped around the y e l l o w p e l l e t s of Osmocote f e r t i l i z e r . The enhancement of r o o t growth by t h e f e r t i l i z e r t r e a t m e n t was most d r a m a t i c f o r the n o n - c o n i f e r o u s l i v e r o o t component. V a l u e s f o r t h i s component were more than an o r d e r of magnitude g r e a t e r than the e s t i m a t e d l e v e l s f o r any o t h e r growth medium. By f a r the l a r g e s t p r o p o r t i o n of t h i s i n c r e a s e i n n o n - c o n i f e r o u s r o o t biomass was from sword f e r n r o o t s , which were r e a d i l y i d e n t i f i a b l e because of t h e i r l a r g e s i z e , unbranched h a b i t , and d i s t i n c t i v e r e d c o l o u r . In some i n s t a n c e s , the i n - g r o w t h bags w i t h the f e r t i l i z e d n a t i v e s o i l had so much growth of new sword f e r n r o o t s t h a t i t was n e c e s s a r y t o e x c a v a t e them a t the time of s a m p l i n g . E x c a v a t i o n was r a r e l y n e c e s s a r y w i t h o t h e r growth media. In a d d i t i o n t o enhanced r o o t growth, i t appears t h a t the f e r t i l i z e r t r e a t m e n t i n c r e a s e d the l o n g e v i t y of the r o o t s w i t h i n the i n - g r o w t h bags as compared t o the u n f e r t i l i z e d n a t i v e s o i l t r e a t m e n t . D e s p i t e h a v i n g much g r e a t e r amounts of l i v e r o o t s , the f e r t i l i z e d i n - g r o w t h bags had l e s s e r amounts of dead r o o t s than d i d the u n f e r t i l i z e d n a t i v e - s o i l - f i l l e d bags. A l e x a n d e r and F a i r l e y (1983) have d e s c r i b e d a s i m i l a r response i n a 3 5 - y e a r - o l d S i t k a s p r u c e p l a n t a t i o n i n S c o t l a n d f o l l o w i n g n i t r o g e n f e r t i l i z a t i o n . P r o d u c t i o n of new m y c o r r h i z a e and 0 t o 5 mm r o o t s was d e c r e a s e d by an average of 22 p e r c e n t i n the f e r t i l i z e d 130 s t a n d s as compared t o t h e a d j a c e n t u n f e r t i l i z e d s t a n d s . However, l o n g e v i t y of t h e s e r o o t components was i n c r e a s e d by even g r e a t e r amounts, over 30 p e r c e n t , r e s u l t i n g i n a net i n c r e a s e i n the s t a n d i n g c r o p of t h e s e s t r u c t u r e s compared t o the l e v e l s seen i n t h e u n f e r t i l i z e d p l o t s . I t i s i n t e r e s t i n g t o compare the f u n g a l biomass l e v e l s f o r a l l f o u r growth media. A l t h o u g h the e s t i m a t e d f u n g a l biomass i n the f e r t i l i z e d n a t i v e s o i l t r e a t m e n t was g r e a t e r than t h a t f o r the u n f e r t i l i z e d n a t i v e s o i l , i t was l e s s than t h a t seen i n the beach s a n d - f i l l e d i n - g r o w t h bags. I t i s a l s o i n t e r e s t i n g t o remember t h a t the mesic s i t e on w h i c h t h i s a d d i t i o n a l e x p e r i m e n t was performed was the one s i t e on which the n a t i v e - s o i l - f i l l e d i n - g r o w t h bags produced the g r e a t e r o v e r a l l mean f u n g a l biomass e s t i m a t e ( F i g u r e 5.12, p. 109). The enhanced growth due t o the f e r t i l i z e r t r e a t m e n t t h a t was seen i n the c o n i f e r o u s and n o n - c o n i f e r o u s components i s not e v i d e n t i n the f u n g a l component. By way of c o n t r a s t t o the enhanced r o o t growth produced by the f e r t i l i z e r t r e a t m e n t , the s i l i c a sand growth medium produced low e s t i m a t e s of l i v e and dead r o o t biomass; v a l u e s which were v e r y c l o s e t o t h o s e seen i n the beach s a n d - f i l l e d i n - g r o w t h bags. F u n g a l biomass e s t i m a t e s were, however, much lower f o r the s i l i c a sand t r e a t m e n t than f o r the beach sand t r e a t m e n t . I f t h e s e d i f f e r e n c e s i n f u n g a l biomass between growth media a r e s i g n i f i c a n t , t h i s might suggest t h a t some component of the beach sand (perhaps the p o t a s s i u m - r i c h mica g r a n u l e s ) c o u l d have s t i m u l a t e d the p r o d u c t i o n of f u n g a l 131 mycelium w i t h i n t h e s e i n - g r o w t h bags. An a n a l y s i s of v a r i a n c e of t h e s e d a t a c o n f i r m e d t h a t growth medium w i t h i n the i n - g r o w t h bags had a s i g n i f i c a n t e f f e c t on t h r e e of the f o u r biomass components (p<.05, T a b l e I X ) . The o n l y component t h a t was not s i g n i f i c a n t l y a f f e c t e d by the d i f f e r e n t growth media was the f u n g a l component. The a n a l y s i s c o n f i r m s some of the r e s u l t s I found e a r l i e r i n the l o n g e r term i n - g r o w t h bag s t u d y ; r e s u l t s which a l s o showed t h a t growth medium had the l e a s t e f f e c t on f u n g a l biomass. There i s c o n f l i c t i n g e v i d e n c e i n the l i t e r a t u r e as t o whether i n c r e a s i n g the n u t r i e n t s t a t u s of a s i t e t h r o u g h f e r t i l i z a t i o n i n c r e a s e s or d e c r e a s e s f i n e r o o t p r o d u c t i o n . L y r and Hoffmann (1974), c i t i n g work performed by O t t o , found t h a t a l t h o u g h t h e " r o o t i n g q u o t i e n t " ( t o t a l r o o t length/number of r o o t t i p s ) was g r e a t l y reduced by f e r t i l i z a t i o n i n a number of o r c h a r d t r e e s p e c i e s , the s i z e of the r o o t system changed v e r y l i t t l e . Tamm (1979) found s i m i l a r r e s u l t s i n optimum n u t r i t i o n s t u d i e s of S c o t s p i n e , w i t h l i t t l e d i f f e r e n c e i n f i n e r o o t p r o d u c t i o n between f e r t i l i z e d and u n f e r t i l i z e d s t a n d s d e s p i t e l a r g e , and s i g n i f i c a n t i n c r e a s e s i n a l l o t h e r biomass f r a c t i o n s i n the f e r t i l i z e d p l o t s . In c o n t r a s t , E r i c s s o n and P e r s s o n (1980) found t h a t w h i l e t h e r e was no d i f f e r e n c e i n the f i n e s t r o o t f r a c t i o n (<1 mm) between f e r t i l i z e d - i r r i g a t e d and c o n t r o l p l o t s of S c o t s p i n e , t h e r e were s i g n i f i c a n t i n c r e a s e s i n b o t h the t o t a l l e n g t h and biomass of the 1 t o 2 mm f r a c t i o n of r o o t s 1 32 Tab l e IX. A n a l y s i s of v a r i a n c e (a=.05) of the e f f e c t of the f o u r growth media on the s t a n d i n g c r o p [kg h a " 1 (±1 SE)] of the f o u r r o o t and f u n g a l components. Growth media w i t h F - v a l u e s h a v i n g p r o b a b i l i t i e s g r e a t e r than .05 d i d not s i g n i f i c a n t l y e f f e c t the biomass l e v e l s i n the i n - g r o w t h bags and were not t e s t e d f u r t h e r . Means f o l l o w e d by a d i f f e r e n t l e t t e r were s i g n i f i c a n t l y d i f f e r e n t from o t h e r means of the same biomass component (Duncan's m u l t i p l e range t e s t , a=.05). B i o m a s s C o m p o n e n t 1 c o n . none. dead fun g . l i v e l i v e mean D mean D mean D mean D F - v a l u e 12.4135 3. 1545 38 .031 6 1 .4046 p r o b a b i l i t y <.0001 • 0360 < .0001 0.2565 G r o w t h M e d i a 1 . S i l i c a sand 6.90 b 3. 00 b 7 .10 c 20.30 (2.61) (1 . 41 ) (1 .22) (4.76) 2. Beach sand 4.50 b 1 . 70 b 7 .80 c 74. 1 0 (2.00) (0. 70) (1 .74) (48.20) 3. N a t i v e s o i l 1 7.60 b 9. 50 b 1 04 .9 b 6.70 (3.79) (2. 21 ) (14 . 13) (3.18) 4. F e r t i l i z e d 70.70 a 1 65. 70 a 63 .7 a 33.20 s o i l (16.86) (90. 67) (5 .72) (10.50) 1 A b b r e v i a t i o n s f o r t h e biomass component a r e as f o l l o w s ; con. = c o n i f e r o u s l i v e , none. = n o n - c o n i f e r o u s l i v e , dead = dead, and fu n g . = f u n g a l . D r e f e r s t o the g r o u p i n g as per the Duncan's m u l t i p l e range t e s t . 1 33 i n the t r e a t e d p l o t s . S i m i l a r l y , S a f f o r d (1974) found more than t w i c e the s t a n d i n g c r o p of <3 mm r o o t s i n f e r t i l i z e d 9 0 - y e a r - o l d mixed b e e c h - b i r c h - m a p l e s t a n d s as compared t o u n f e r t i l i z e d s t a n d s . I t s h o u l d not be s u r p r i s i n g t h a t e x p e r i m e n t a l work i n v o l v i n g b r o a d c a s t f e r t i l i z a t i o n s s h o u l d show such v a r i a b l e r e s u l t s , s i n c e any response by the t r e e s would be dependent on the g i v e n s o i l and c l i m a t i c c o n d i t i o n s of t h e s i t e , which i n t h e m s e l v e s would be h i g h l y v a r i a b l e . There a r e much more c o n s i s t e n t r e s u l t s i n the l i t e r a t u r e on the r e s ponse of r o o t systems t o h i g h l y l o c a l i z e d e n r i c h m e n t s of t h e s o i l volume, e x p e r i m e n t a l work which i s more r e l e v a n t t o my work w i t h the i n - g r o w t h bags. Most a u t h o r s have found l a r g e i n c r e a s e s i n f i n e r o o t s where l o c a l i z e d c o n c e n t r a t i o n s of n u t r i e n t s were found. I have a l r e a d y mentioned the work of S t . John (1983), S t . John et al. (1983) and L y r and Hoffmann (1974) on t h i s s u b j e c t . C o u t t s and P h i l i p s o n (1976, 1977) d i v i d e d the r o o t systems of i n d i v i d u a l s i t k a s p r u c e and l o d g e p o l e p i n e s e e d l i n g s i n t o growth p o t s s u p p l i e d w i t h e i t h e r h i g h - n u t r i e n t or l o w - n u t r i e n t s o l u t i o n s . For b o t h , s p e c i e s the h i g h - n u t r i e n t regime s t i m u l a t e d r o o t g r o w t h , p r o d u c i n g a l a r g e r and l o n g e r r o o t system than t h a t found i n the l o w - n u t r i e n t e n v i r o n m e n t . Such a response has a l s o been shown f o r a number of c e r e a l c r o p s as w e l l , and has been termed "compensatory growth" by C r o s s e t t et al. (1975). Cuevas and Medina (1983), w o r k i n g i n the Tierra Fi rme r a i n f o r e s t s of the R i o Negro r i v e r b a s i n , p e r f o r m e d an 1 34 experiment t h a t was remarkably s i m i l a r t o the my four-growth-media e x p e r i m e n t . The a u t h o r s found g r e a t l y enhanced r o o t growth i n t o i n - g r o w t h bags c o n t a i n i n g v e r m i c u l i t e w h i c h had p r e v i o u s l y been soaked f o r 48 hours i n 0.1 M s a l t s o l u t i o n s of c a l c i u m , phosphorous, or n i t r o g e n , as compared t o c o n t r o l bags which were soaked i n water from the R i o Negro r i v e r . The g r e a t e s t growth enhancements were i n f a c t found w i t h the phosphorous and c a l c i u m t r e a t m e n t s , i n d i c a t i n g t h e importance and l i m i t i n g abundance of t h e s e two n u t r i e n t s t o the n u t r i e n t c y c l e s of t r o p i c a l f o r e s t s . The a b i l i t y t o e x p l o i t a heterogeneous s o i l environment seems t o be u n i v e r s a l t o temperate and t r o p i c a l f o r e s t t r e e s p e c i e s , as w e l l as t o many a g r i c u l t u r a l c r o p s p e c i e s . Such an a b i l i t y , t h e a n t a g o n i s t i c r e l a t i o n s h i p between the l e n g t h growth of t h e p r i m a r y r o o t and the development of l a t e r a l r o o t s , i s an e c o l o g i c a l l y u s e f u l a d a p t a t i o n i n t h a t i t a l l o w s t h e m o d i f i c a t i o n of p o r t i o n s of the r o o t system under the i n f l u e n c e of h i g h l y l o c a l i z e d s i t e f a c t o r s ( L y r and Hoffmann 1974). 5.7 ESTIMATES OF ABOVEGROUND BIOMASS AND ANNUAL PRODUCTION 5.7.1 PATTERNS IN FOLIAR AND NON-FOLIAR LITTER PRODUCTION F i g u r e 5.16 shows the a n n u a l p a t t e r n of f o l i a r and n o n - f o l i a r l i t t e r p r o d u c t i o n on t h e x e r i c , mesic and h y g r i c s t u d y s i t e s . W i t h the e x c e p t i o n of one or two anomalous months d a t a , t h e r e i s s u r p r i s i n g l y l i t t l e d i f f e r e n c e i n the 135 amounts of l i t t e r , b o t h f o l i a r and n o n - f o l i a r , produced by the t h r e e s i t e s , or i n t h e i r r a t e s of p r o d u c t i o n from month-to-month. There was a l a r g e i n c r e a s e i n the r a t e of f o l i a r l i t t e r p r o d u c t i o n from September t h r o u g h November 1984 on a l l t h r e e s i t e s . F o l i a r l i t t e r p r o d u c t i o n then f e l l t o low l e v e l s between December and A p r i l , a f t e r w hich i t began t o i n c r e a s e a g a i n on t h e mesic and h y g r i c s i t e s . The x e r i c s i t e showed no i n c r e a s e i n f o l i a r l i t t e r p r o d u c t i o n u n t i l June. The p a t t e r n s of n o n - f o l i a r l i t t e r p r o d u c t i o n f o r the t h r e e s i t e s were s l i g h t l y more i r r e g u l a r than t h o s e f o r f o l i a r l i t t e r . There was a s t r o n g peak i n n o n - f o l i a r l i t t e r p r o d u c t i o n i n A p r i l of 1985 on a l l t h r e e s i t e s . T h i s peak c o r r e s p o n d e d t o bud b u r s t and the onset of aboveground growth of t h a t s p r i n g . By f a r the l a r g e s t p r o p o r t i o n of the l i t t e r biomass f o r t h i s month was p o l l e n cones and bud s c a l e s . T h i s was u n l i k e a l l o t h e r months' samples i n w h i c h the m a j o r i t y of the n o n - f o l i a r l i t t e r biomass was composed of s m a l l t w i g s and b r a n c h e s . The g r e a t e s t amounts of n o n - f o l i a r l i t t e r p r o d u c t i o n f o r any one month were found on the h y g r i c s i t e . T h i s might seem s u r p r i s i n g a t f i r s t . However, summer wind st o r m s , which o c c u r r e g u l a r l y on the west c o a s t of Vancouver I s l a n d , a f f e c t e d the h y g r i c p l a n t a s s o c i a t i o n much more than they d i d the o t h e r two a s s o c i a t i o n s . The more open n a t u r e of the s t a n d on the h y g r i c s i t e a l l o w e d t h e s e storms t o move th r o u g h the t r e e s on t h i s s i t e much more v i o l e n t l y , c a u s i n g 136 o < to to < g CD DC < lOOO-i 8 0 0 -6 0 0 -4 0 0 -2 0 0 -1 ' V V %) cD — i 1 1 1 1 1 1 1 1 1 1 1 1 1 JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG 1984 1985 5 0 0 4 0 0 -3 0 0 -B \ to to < o CD or Z J 2 0 0 -< I z o z Site O Low (L) site A Medium (M) site O Hig.h(H)si»e "T—' 1 1 1 1 1-JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG 1984 1985 F i g u r e 5.16. Comparison of the l i t t e r p r o d u c t i o n and h y g r i c ( h i g h ) s t a n d a r d e r r o r of A. B. Date p a t t e r n s of f o l i a r and n o n - f o l i a r on the x e r i c ( l o w ) , mesic (medium), s i t e s . Bars on e s t i m a t e s r e p r e s e n t one the mean. f o l i a r l i t t e r p r o d u c t i o n n o n - f o l i a r l i t t e r p r o d u c t i o n 1 37 a l a r g e amount of branch and t w i g breakage. The c l o s e l y spaced t r e e s of the x e r i c and mesic s i t e s p r e v e n t e d the wind from p e n e t r a t i n g the canopy, t h e r e b y r e d u c i n g the amount of wind damage c o n s i d e r a b l y . D e s p i t e the l a r g e d i f f e r e n c e s i n the q u a n t i t y of aboveground biomass ( T a b l e I I I , p.26 and T a b l e X, p. 138) between the t h r e e s i t e s , t h e r e was v e r y l i t t l e d i f f e r e n c e i n the t o t a l amount of f o l i a r and n o n - f o l i a r l i t t e r produced between J u l y of 1984 and June of 1985. T o t a l l i t t e r p r o d u c t i o n was 3464 kg h a - 1 on the x e r i c s i t e , 3250 kg h a " 1 on the mesic s i t e and 3680 kg h a - 1 on the h y g r i c s i t e . Of t h e s e t o t a l s , f o l i a r l i t t e r composed 2653 kg h a " 1 , 2395 kg h a " 1 , and 2765 kg ha"' f o r the x e r i c , m e s i c , and h y g r i c s i t e s r e s p e c t i v e l y ( T a b l e s X, X I , X I I , and X I I I ) . 5.7.2 ANNUAL ABOVEGROUND CONIFEROUS BIOMASS PRODUCTION E s t i m a t e s of a n n u a l aboveground o v e r s t o r e y p r o d u c t i o n were made by t a k i n g the d i f f e r e n c e between the r e g r e s s i o n e s t i m a t e s of biomass f o r the m e n s u r a t i o n a l p l o t measurements of 1983 and 1985, then a v e r a g i n g them over two y e a r s . These e s t i m a t e s showed t h a t the h y g r i c s i t e w i t h i n the Achlys -Pol i st i chum a s s o c i a t i o n was t h e most p r o d u c t i v e of the t r e e s i t e s , f o l l o w e d by the mesic and then the x e r i c s i t e r e s p e c t i v e l y . Annual aboveground p r o d u c t i o n a veraged 16282 kg h a " 1 y r " 1 on the h y g r i c s i t e , 14047 kg h a " 1 y r " 1 on the mesic s i t e , and o n l y 8069 kg h a " 1 y r " 1 on the x e r i c s i t e ( T a b l e s X I , X I I , and X I I I ) . I n c l u s i o n of the f o l i a r and 138 T a b l e X. E s t i m a t e s of s t a n d i n g c r o p f o r aboveground components and t o t a l s [kg ha"' (±1 SE)] of c o n i f e r o u s s p e c i e s f o r the x e r i c , m e s ic, and h y g r i c s i t e s . Biomass e s t i m a t e s "were produced from r e g r e s s i o n e s t i m a t e s r e l a t i n g biomass of each component t o a f u n c t i o n of t r e e d i a m e t e r s measured i n J u l y of 1983, and a g a i n i n J u l y of 1985. (Gholz et al. 1979, F e l l e r et al. 1983). Study S i t e • ^ „ _ _ _ _ B i o m a s s x e r i c mesic h y g r i c C o m p o n e n t kg h a - 1 % kg h a - 1 % kg h a " 1 Stemwood b i o m a s s 1 983 1985 s t e m b a r k b i o m a s s 1983 1985 n e e d l e b i o m a s s 1 1983 1985 l i v e b r a n c h b i o m a s s 1 983 1985 126267 56.2 334957 62.8 408418 66.2 (22326) (65895) (49385) 138360 56.8 358861 63.3 436265 66.5 (24018) (70201) (51182) 26345. 11.7 (4524) 28788 11.8 (4857) 6275 2.8 (1938) 6368 2.6 (1965) 31779 14.2 (3415) 33283 13.7 (3574) 41090 7.7 (7299) 43921 7.7 (8480) 24080 4.5 (2145) 24344 4.3 (2166) 48980 9.2 (5328) 50072 8.8 (5439) 49637 8.0 (5944) 52958. 8.1 (6151) 18824 (1269) 19104 (1442) 4201 9 (3284) 431 28 (3292) 3.0 2.9 6.8 6.6 139 T a b l e X . c o n t ' d . S t u d y S i t e B i o m a s s C o m p o n e n t kg ha x e r i c - 1 ( m e s i c h y g r i c kg h a - 1 % kg h a " 1 % c o a r s e r o o t b i o m a s s 1 983 1985 t o t a l a b o v e g r o u n d b i o m a s s 1 983 33809 15.1 (5439) 36680 15.1 (5894) 84598 15.8 (15508) (16422) 98501 16.0 (7020) 89949 15.9 104612 15 .9 (11670) 224475 100.0 533705 100.0 617399 100.0 1 985 243479 100.0 567147 100.0 656067 100.0 f o l i a r l i t t e r 2653 p r o d u c t i o n 2 r a t i o f o l i a g e 2 .37 b i o m a s s t o f o l i a r l i t t e r 3 2395 10 .16 2765 6 .94 b e c a u s e of a l a c k o f a s u i t a b l e r e g r e s s i o n e q u a t i o n f o r a D o u g l a s - f i r s t a n d w i t h £ 6000 s tems h a - 1 , f o l i a g e b iomass was e s t i m a t e d from t h e r a t i o o f f o l i a g e b iomass between good an poor 4 8 - y e a r - o l d s t a n d s i n F e l l e r et al . (198.3). 2 E s t i m a t e s o f f o l i a r l i t t e r b iomass were measured d i r e c t l y , no t e s t i m a t e d . 3 F o l i a g e b iomass used f o r t h i s r a t i o e s t i m a t e a r e from the 1985 b iomass e s t i m a t e s . 1 40 T a b l e X I . Comparison of t o t a l c o n i f e r o u s biomass p r o d u c t i o n e s t i m a t e s f o r the x e r i c s i t e u s i n g n a t i v e - s o i l - and s a n d - f i l l e d i n - g r o w t h bags, and s e q u e n t i a l s o i l c o r e s f o r f i n e r o o t biomass p r o d u c t i o n e s t i m a t e s . In-growth Bags S e q u e n t i a l Cores s a n d - f i l l e d n a t i v e -s o i l - f i l l e d Biomass Component • kg h a ' 1 y r " 1 % kg h a ' 1 y r ' 1 % kg h a ' 1 y r " 1 % Aboveground 1 stemwood 6047 43. 5 6047 38. 5 6047 36. 3 bark 1 222 8. 8 1222 7. 8 1 222 7. 3 l i v e n e e d l e 2 47 0. 3 47 0. 3 47 0. 3 l i v e b ranch 753 5. 4 753 4. 8 753 4. 5 T o t a l s t a n d i n g 8069 58. 0 8069 51 . 4 8069 48. 4 L i t t e r f a l l f o l i a r 2653 19. 1 2653 16. 9 2653 15. 9 n o n - f o l i a r 81 1 5. 8 811 5. 2 81 1 4. 9 T o t a l 3464 24. 9 3464 22. 1 3464 20. 8 l i t t e r f a l l T o t a l 11533 • 83. 0 1 1533 73. 5 1 1 533 69. 2 aboveground Belowground c o a r s e r o o t s 1 1436 10. 3 1436 9. 1 1 436 8. 6 f i n e r o o t s 478 3. 5 2090 13. 3 3690 22. 2 f u n g a l hyphae 445 3. 2 638 4. 1 — — T o t a l 2359 16. 9 41 64 26. 5 51 26 30. 8 belowground TOTAL 1 3892 100. 0 1 5697 100. 0 1 6659 100. 0 1 E s t i m a t e s of aboveground and c o a r s e r o o t components of t h e p r o d u c t i o n e s t i m a t e s were made u s i n g the e q u a t i o n s of F e l l e r et al. (1983) and Gholz et al. (1979). 2 Because of l a c k of a s u i t a b l e r e g r e s s i o n e q u a t i o n f o r v e r y dense st a n d s of D o u g l a s - f i r , e s t i m a t e s of n e e d l e biomass f o r the x e r i c s i t e were made by t a k i n g the r a t i o of ne e d l e biomass between good and poor 4 8 - y e a r - o l d s t a n d s from F e l l e r et al. (1983) and a p p l y i n g i t t o the f o l i a g e biomass e s t i m a t e on the h y g r i c s i t e . 141 T a b l e X I I . Comparison of t o t a l c o n i f e r o u s biomass p r o d u c t i o n e s t i m a t e s f o r the mesic s i t e u s i n g n a t i v e - s o i l - and s a n d - f i l l e d i n - g r o w t h bags, and s e q u e n t i a l s o i l c o r e s f o r f i n e r o o t biomass p r o d u c t i o n e s t i m a t e s . I n - g r o w t h Bags S e q u e n t i a l Cores s a n d - f i l l e d n a t i v e -s o i l - f i l l e d Biomass Component • kg h a " 1 y r " 1 % kg h a " 1 y r ' 1 % kg h a " 1 y r " 1 % Aboveground 1 stemwood 1 1952 56. 7 1 1952 52. 1 1 1 952 59. 8 bark 1416 6. 7 1416 6. 2 1416 7. 1 l i v e n e e d l e 133 0. 6 1 33 0. 6 1 33 0. 7 l i v e b r a n c h 546 2. 6 546 2. 4 546 2. 7 T o t a l s t a n d i n g 1 4047 66. 6 1 4047 61 . 3 1 4047 70. 3 L i t t e r f a l l f o l i a r 2395 1 1 . 4 2395 10. 5 2395 12. 0 n o n - f o l i a r 855 4. 1 855 3. 7 855 4. 3 T o t a l 3250 15. 5 3250 14. 2 3250 16. 3 l i t t e r f a l l T o t a l 1 7297 82. 1 1 7297 75. 5 1 7297 86. 6 aboveground Belowground c o a r s e r o o t s 1 2676 12. 7 2676 1 1 . 7 2676 13. 4 f i n e r o o t s 330 1 . 6 1 677 7. 3 -- --f u n g a l hyphae 762 3. 6 1 258 .5. 5 — — T o t a l 3768 17. 9 561 1 24. 5 2676 13. 4 belowground TOTAL 21065 1 00. 0 22908 1 00. 0 1 9973 1 00. 0 1 E s t i m a t e s of aboveground and c o a r s e r o o t components of the p r o d u c t i o n e s t i m a t e s were made u s i n g the e q u a t i o n s of F e l l e r et al. (1983) and Gholz et al. (1979). 1 42 T a b l e X I I I . Comparison of t o t a l c o n i f e r o u s biomass p r o d u c t i o n e s t i m a t e s f o r the h y g r i c s i t e u s i n g n a t i v e - s o i l - and s a n d - f i l l e d i n - g r o w t h bags, and s e q u e n t i a l s o i l c o r e s f o r f i n e r o o t biomass p r o d u c t i o n e s t i m a t e s . i n - g r o w t h Bags S e q u e n t i a l Cores s a n d - f i l l e d n a t i v e -s o i l - f i l l e d Biomass Component • kg h a " 1 y r " 1 % kg h a " 1 y r " 1 % kg h a " 1 y r " 1 % Aboveground 1 stemwood 1 3925 59. 5 1 3925 55. 8 13925 52. 6 bark 1661 7. 1 1661 6. 6 1661 6. 3 l i v e n e e d l e 141 0. 6 141 0. 6 141 0. 5 l i v e b r a n c h 555 2. 4 555 2. 2 555 2. 1 T o t a l s t a n d i n g 1 6282 69. 6 1 6282 65. 2 1 6282 61 . 5 L i t t e r f a l l f o l i a r 2765 1 1 . 8 2765 1 1 . 1 2765 10. 4 n o n - f o l i a r 915 3. 9 915 3. 7 915 3. 5 T o t a l 3680 15. 7 3680 14. 8 3680 13. 9 l i t t e r f a l l T o t a l 1 9962 85. 3 19962 80. 0 19962 75. 4 aboveground Belowground c o a r s e r o o t s 1 3056 13. 0 3056 12. 2 3056 1 1 . 5 f i n e r o o t s 297 1 . 3 1843 7. 4 3456 13. 1 f u n g a l hyphae 94 0. 4 100 0. 4 — — T o t a l 3447 14. 7 4999 20. 0 651 2 24. 6 belowground TOTAL 23409 100. 0 24961 100. 0 26474 100. 0 ' E s t i m a t e s of aboveground and c o a r s e r o o t components of the p r o d u c t i o n e s t i m a t e s were made u s i n g the e q u a t i o n s of F e l l e r et al. (1983) and Gholz et al. (1979). 143 n o n - f o l i a r l i t t e r p r o d u c t i o n f i g u r e s i n c r e a s e d t h e s e aboveground p r o d u c t i o n e s t i m a t e s t o 19962 kg h a " 1 y r " 1 f o r the h y g r i c s i t e , 17297 kg h a ' 1 y r - 1 f o r t h e mesic s i t e and 11533 kg h a - 1 y r - 1 f o r t h e x e r i c s i t e . There were l a r g e d i f f e r e n c e s i n the p r o p o r t i o n a l a l l o c a t i o n of NPP t o the f o l i a r l i t t e r component between the x e r i c s i t e and the o t h e r two study s i t e s . On the x e r i c s i t e , t h i s component r e p r e s e n t e d 23.0 p e r c e n t of aboveground p r o d u c t i o n , but o n l y 13.8 and 13.9 p e r c e n t on the mesic and h y g r i c s i t e s . P r o p o r t i o n a l a l l o c a t i o n s t o b a r k , l i v e b r a n c h and n o n - f o l i a r l i t t e r f a l l were a l s o s l i g h t l y lower on t h e s e l a t t e r two s i t e s than they were on the x e r i c s i t e . The r e d u c t i o n i n a l l o c a t i o n s t o bar k , b r a n c h , and n o n - f o l i a r l i t t e r biomass components on t h e mesic and h y g r i c s i t e s i s b a l a n c e d by i n c r e a s e d a l l o c a t i o n s t o stemwood biomass. T h i s component acc o u n t e d f o r 69.8 p e r c e n t of the ann u a l aboveground p r o d u c t i o n on the h y g r i c s i t e , 69.1 p e r c e n t on the mesic s i t e , but o n l y 52.4 p e r c e n t on the x e r i c s i t e . 5.7.3 ANNUAL BELOWGROUND CONIFEROUS BIOMASS PRODUCTION The e s t i m a t e s of a n n u a l belowground p r o d u c t i o n showed a s u b s t a n t i a l l y d i f f e r e n t p a t t e r n from t h a t seen i n the aboveground components. Coarse r o o t s : The e s t i m a t e s of a n n u a l p r o d u c t i o n of c o a r s e r o o t s (produced from r e g r e s s i o n e s t i m a t e s , as were the aboveground components) were n e a r l y e q u a l on the mesic 1 44 and h y g r i c s i t e s , a v e r a g i n g 2676 kg h a " 1 y r - 1 and 3056 kg h a - 1 y r - 1 f o r each, r e s p e c t i v e l y . Both of t h e s e e s t i m a t e s were a p p r o x i m a t e l y t w i c e t h a t f o r t h e x e r i c s i t e , w h i c h averaged 1436 kg h a " 1 y r " 1 over the two y e a r s . F i n e - p l u s - s m a l l r o o t and f u n g a l p r o d u c t i o n : F i n e - p l u s - s m a l l and f u n g a l p r o d u c t i o n e s t i m a t e s , based on s t a t i s t i c a l l y s i g n i f i c a n t changes i n the monthly e s t i m a t e s of s t a n d i n g c r o p ( T a b l e s X V I I I t o XXV, Appendix 3, p. 220), showed t h a t a n n u a l r o o t p r o d u c t i o n i n the n a t i v e - s o i l - f i l l e d i n - g r o w t h bags was g r e a t e s t on the mesic s i t e w i t h , 2935 kg h a - 1 y r - 1 , f o l l o w e d by the x e r i c s i t e a t 2728 kg h a - 1 y r " 1 , and the h y g r i c s i t e a t 1943 kg h a - 1 y r " 1 . By c o m p a r i s o n , belowground p r o d u c t i o n e s t i m a t e s from s a n d - f i l l e d i n - g r o w t h bags were between o n e - t h i r d and o n e - f i f t h as l a r g e . The g r e a t e s t amount of p r o d u c t i o n i n t h i s growth medium was found f o r t h e mesic s i t e , w i t h 1092 kg h a " 1 y r " 1 , f o l l o w e d by the x e r i c s i t e a t 923 kg h a " 1 y r " 1 , and the h y g r i c s i t e a t o n l y 391 kg h a " 1 y r " 1 . The d i f f e r e n c e s between a n n u a l r o o t p r o d u c t i o n e s t i m a t e s from s e q u e n t i a l s o i l c o r e s and s o i l - f i l l e d i n - g r o w t h bags were s m a l l e r than the d i f f e r e n c e s i n s t a n d i n g c r o p e s t i m a t e s between the two growth media f o r b o t h the x e r i c and h y g r i c s i t e s . On the x e r i c s i t e , a n n u a l f i n e - p l u s - s m a l l r o o t p r o d u c t i o n was e s t i m a t e d a t 2090 kg h a " 1 y r " 1 w i t h n a t i v e - s o i l - f i l l e d i n - g r o w t h bags, and 3690 kg h a " 1 y r " 1 u s i n g s e q u e n t i a l s o i l c o r e s ( T a b l e X I , p. 140), a d i f f e r e n c e of 56.6 %. On the h y g r i c s i t e , t h e comparable 1 45 v a l u e s were 1843 kg h a - 1 y r " 1 , 3456 kg h a " 1 y r - 1 , and 53.3 % r e s p e c t i v e l y ( T a b l e X I I I , p. 142). On t h e s e s i t e s , the e s t i m a t e s u s i n g t h e i n - g r o w t h bags were p r o p o r t i o n a t e l y s i m i l a r t o t h o s e from the s e q u e n t i a l c o r e s . By c o m p a r i s o n , the e s t i m a t e s of a n n u a l a n n u a l f i n e - p l u s - s m a l l r o o t p r o d u c t i o n u s i n g s a n d - f i l l e d i n - g r o w t h bags r e p r e s e n t e d o n l y 12.7 % and 8.6 % of the annual s e q u e n t i a l c o r e p r o d u c t i o n e s t i m a t e s f o r t h e x e r i c and h y g r i c s i t e s . From t h e s e d a t a I can c o n c l u d e t h a t the d i f f e r e n c e i n e s t i m a t e s between the i n - g r o w t h bags and s e q u e n t i a l s o i l c o r e s i s much l e s s f o r p r o d u c t i o n e s t i m a t e s than f o r the s t a d i n g c r o p e s t i m a t e s . One of t h e most i n t e r e s t i n g a s p e c t s of the belowground p r o d u c t i o n e s t i m a t e s was the low l e v e l s of f u n g a l biomass produced on t h e h y g r i c s i t e . F u n g a l hyphae from n a t i v e - s o i l - f i l l e d i n - g r o w t h bags r e p r e s e n t e d 15.3 p e r c e n t of the t o t a l a n n u a l belowground biomass p r o d u c t i o n on the x e r i c s i t e , 22.4 p e r c e n t on the mesic s i t e , but o n l y 2.0 p e r c e n t on the h y g r i c s i t e . 5.7.4 COMPARISON OF TOTAL NET PRIMARY PRODUCTION AND ALLOCATION PATTERNS BETWEEN THE THREE STUDY SITES Comparisons of t o t a l o v e r s t o r e y NPP f o r the t h r e e s i t e s showed v e r y l a r g e p r o d u c t i v i t y d i f f e r e n c e s between the stu d y s i t e s . T o t a l o v e r s t o r e y biomass p r o d u c t i o n e s t i m a t e s f o r the x e r i c s i t e ranged from a low of a p p r o x i m a t e l y 13.9 t h a " 1 1 46 u s i n g s a n d - f i l l e d i n - g r o w t h bags t o e s t i m a t e r o o t and f u n g a l biomass p r o d u c t i o n , t o a p p r o x i m a t e l y 15.7 t h a ' 1 w i t h n a t i v e - s o i l - f i l l e d i n - g r o w t h bags, and 16.7 t h a ' 1 w i t h s e q u e n t i a l s o i l c o r e s ( T a b l e X I , p. 140). On t h e mesic s i t e , e s t i m a t e s of t o t a l o v e r s t o r e y NPP i n c r e a s e d from a p p r o x i m a t e l y 21.1 t h a " 1 f o r s a n d - f i l l e d i n - g r o w t h bags, t o 22.9 t h a ' 1 f o r n a t i v e - s o i l - f i l l e d i n - g r o w t h bags ( T a b l e X I I , p. 141). S i n c e no s e q u e n t i a l s o i l c o r i n g was done on t h i s s i t e , the t h i r d e s t i m a t e of t o t a l NPP f o r t h i s s i t e i s i n c o m p l e t e . The h y g r i c s i t e produced the g r e a t e s t e s t i m a t e s of t o t a l o v e r s t o r e y NPP. These e s t i m a t e s ranged from a low v a l u e of a p p r o x i m a t e l y 23.4 t h a - 1 u s i n g s a n d - f i l l e d i n - g r o w t h bags, t o 24.9 t h a - 1 f o r n a t i v e - s o i l - f i l l e d i n - g r o w t h bags, and 26.5 t h a - 1 f o r s e q u e n t i a l s o i l c o r i n g ( T a b l e X I I I , p. 142). R e g a r d l e s s of the t e c h n i q u e u t i l i z e d t o e s t i m a t e belowground p r o d u c t i o n , the e s t i m a t e s of t o t a l o v e r s t o r e y NPP produced f o r the h i g h p r o d u c t i v i t y , h y g r i c s i t e were always a t l e a s t 50 p e r c e n t g r e a t e r than the c o r r e s p o n d i n g e s t i m a t e s f o r the x e r i c , low p r o d u c t i v i t y s i t e . A l t h o u g h t h e r e were l a r g e d i f f e r e n c e s i n t o t a l a n n u a l net p r i m a r y p r o d u c t i o n between the t h r e e s i t e s , the p r o p o r t i o n a l a l l o c a t i o n s t o aboveground and belowground components d i d not v a r y g r e a t l y . F i n e - p l u s - s m a l l r o o t and f u n g a l biomass e s t i m a t e s produced w i t h n a t i v e - s o i l - f i l l e d i n - g r o w t h bags, p l u s e s t i m a t e s of c o a r s e r o o t s , a c c o u n t e d f o r 26.5 p e r c e n t 147 of t o t a l net p r i m a r y p r o d u c t i o n on the x e r i c s i t e , 24.5 p e r c e n t f o r the mesic s i t e , and 20.0 p e r c e n t f o r the h y g r i c s i t e ( T a b l e s X I , X I I , and X I I I ) . The e s t i m a t e s produced from s a n d - f i l l e d i n - g r o w t h bags showed s l i g h t l y d i f f e r e n t r e s u l t s . The t o t a l amounts of f i n e r o o t and f u n g a l biomass i n t h e s e bags were l e s s than f o r the n a t i v e - s o i l - f i l l e d i n - g r o w t h bags. As a r e s u l t , the c a l c u l a t i o n s of the p e r c e n t a g e s of NPP a l l o c a t e d t o t h e belowground ecosystem were a l s o s m a l l e r . In t h i s c a s e , the mesic s i t e had the g r e a t e s t p r o p o r t i o n a t e amount of belowground p r o d u c t i o n , a c c o u n t i n g f o r 17.9 p e r c e n t of the t o t a l net p r i m a r y p r o d u c t i o n f o r t h i s s i t e . T h i s e s t i m a t e was f o l l o w e d c l o s e l y by t h a t f o r the x e r i c s i t e , a t 16.7 p e r c e n t , and the h y g r i c s i t e a t 14.7 p e r c e n t r e s p e c t i v e l y . E s t i m a t e s of belowground p r o d u c t i o n produced w i t h s e q u e n t i a l s o i l c o r i n g showed r e l a t i v e l y s m a l l d i f f e r e n c e s i n belowground p r o d u c t i o n between x e r i c and h y g r i c s i t e s . U s i n g t h i s t e c h n i q u e , belowground p r o d u c t i o n a c c o u n t e d f o r 30.3 p e r c e n t on the t o t a l NPP on t h e x e r i c s i t e , and 24.6 p e r c e n t on t h e h y g r i c s i t e . By c o m p a r i s o n t o most of the more r e c e n t f i g u r e s i n the l i t e r a t u r e f o r comparable s t a n d s , my e s t i m a t e s of f i n e r o o t and f u n g a l p r o d u c t i o n , and p r o p o r t i o n a l a l l o c a t i o n of NPP t o the belowground ecosystem a r e q u i t e low. Keyes and G r i e r (1981) found s i m i l a r amounts of aboveground s t a n d i n g c r o p , and s i m i l a r l e v e l s of aboveground a n n u a l p r o d u c t i o n i n h i g h and low p r o d u c t i v i t y , 4 0 - y e a r - o l d 1 48 s t a n d s of D o u g l a s - f i r as compared t o my s t u d y . Aboveground net p r o d u c t i o n was 13.7 t h a - 1 y r - 1 on t h e i r h i g h p r o d u c t i v i t y s i t e , and 7.3 t h a " 1 y r - 1 on t h e low p r o d u c t i v i t y s i t e . These f i g u r e s compare w i t h 11.8, 17.3, and 20.0 t h a " 1 y r " 1 f o r my x e r i c , m e s i c , and h y g r i c s i t e s r e s p e c t i v e l y ( T a b l e s XI t o X I I I , pp. 139 t o 141). However, u n l i k e my r e s u l t s , Keyes and G r i e r (1981) found much g r e a t e r amounts of r o o t p r o d u c t i o n on t h e i r low p r o d u c t i v i t y s i t e . T o t a l belowground p r o d u c t i o n was 8.1 t h a " 1 y r - 1 , r e p r e s e n t i n g 52.6 p e r c e n t of the t o t a l net p r i m a r y p r o d u c t i o n , on t h e i r low p r o d u c t i v i t y s i t e . Of the 8.1 t h a " 1 y r " 1 t o t a l f o r t h i s s i t e , t h e <1 mm r o o t s r e p r e s e n t e d 5.6 t h a " 1 y r " 1 . On the h y g r i c s i t e , t o t a l belowground p r o d u c t i o n was e s t i m a t e d a t 4.1 t h a " 1 y r " 1 , which a c c o u n t e d f o r o n l y 23.1 p e r c e n t of t h e t o t a l net p r i m a r y p r o d u c t i o n on t h i s s i t e , and the <1 mm r o o t s composed o n l y 1.4 t h a " 1 y r " 1 of the belowground component f o r t h i s s i t e . My e s t i m a t e s of the p r o p o r t i o n a l a l l o c a t i o n of NPP t o belowground p r o d u c t i o n on my h y g r i c s i t e a g r e e d c l o s e l y w i t h the e s t i m a t e s of Keyes and G r i e r (1981) f o r t h e i r "good" s i t e However, the c o r r e s p o n d i n g e s t i m a t e s f o r my x e r i c s i t e were a p p r o x i m a t e l y one h a l f the s i z e of the e s t i m a t e of belowground a l l o c a t i o n f o r t h e "poor" s i t e from the Keyes and G r i e r (1981) s t u d y . The g r e a t e r p r o d u c t i v i t y of t h e belowground ecosystem on the p o o r e r s i t e i n the study by Keyes and G r i e r (1981) r e s u l t e d i n r e l a t i v e l y s m a l l d i f f e r e n c e s between the 1 49 e s t i m a t e s of t o t a l net p r i m a r y p r o d u c t i o n f o r t h e i r two s i t e s . These a u t h o r s found t h a t t o t a l net p r i m a r y p r o d u c t i o n was 15.4 t h a " 1 y r " 1 on t h e i r low p r o d u c t i v i t y s i t e , and 17.8 t h a " 1 y r " 1 on the h i g h p r o d u c t i v i t y s i t e . T h i s i s i n d i r e c t c o n t r a s t t o my f i n d i n g s of more than a 50 p e r c e n t d i f f e r e n c e i n t o t a l NPP between my x e r i c and h y g r i c s i t e s . S a n t a n t o n i o and Hermann (1985) found much s m a l l e r d i f f e r e n c e s i n <1 mm r o o t p r o d u c t i o n between d r y , moderated and wet s t a n d s of D o u g l a s - f i r i n Oregon than d i d Keyes and G r i e r (1981) i n t h e i r s t u d y . O v e r a l l s t a n d i n g c r o p s of f i n e r o o t s d i d not d i f f e r s i g n i f i c a n t l y between the t h r e e s i t e s u t i l i z e d by S a n t a n t o n i o and Hermann (1985). However, f i n e r o o t p r o d u c t i o n , based on monthly changes i n s t a n d i n g c r o p s of l i v e and dead f i n e r o o t s , v a r i e d from a h i g h of 6.5 t h a " 1 y r " 1 on t h e i r d r i e s t s i t e , t o 6.3 t h a " 1 y r " 1 on t h e moderate s i t e , t o the l o w e s t v a l u e of 4.8 t h a " 1 y r " 1 on t h e i r wet s i t e . I t i s d i f f i c u l t t o draw any c o n c l u s i o n from comparisons of t h e r e s u l t s of t h e s e two s t u d i e s w i t h t h o s e of my s t u d y . A l t h o u g h i t would appear t h a t a l l t h r e e s t u d i e s were p e r f o r m e d i n s i m i l a r ecosystems, t h e r e were c l e a r d i f f e r e n c e s between the r e s p e c t i v e s t u d y a r e a s . Of t h e s e t h r e e s t u d i e s , o n l y my s t u d y was conducted i n a s i n g l e , c o n t i n u o u s , even-aged t o p o g r a p h i c sequence. Low and h i g h p r o d u c t i v i t y s t a n d s i n the Keyes and G r i e r (1981) s t u d y d i f f e r e d from each o t h e r p r i n c i p a l l y i n t h e i r s o i l t y p e s . Mean dbh of dominant and codominant t r e e s i n t h e i r 150 s t a n d s d i f f e r e d by o n l y f o u r cm, as compared t o a d i f f e r e n c e of over 20 cm between x e r i c and h y g r i c s t a n d s i n t h i s s t u d y ( T a b l e I I I , p. 2 6 ) . U s i n g the mean h e i g h t and age e s t i m a t e s of Keyes and G r i e r (1981), and t h e e q u a t i o n s of Omule (1983) f o r c o a s t a l D o u g l a s - f i r , the s i t e i n d i c e s of the two s t a n d s used by t h e s e a u t h o r s i n t h e i r s t u d y were c a l c u l a t e d a t 36.3 m and 52.0 m f o r the poor and good s i t e r e s p e c t i v e l y . A l t h o u g h t h e r e i s a c l o s e s i m i l a r i t y between my h y g r i c s i t e (SI,oo = 49.8 m, Ta b l e I I , p. 25) and the h i g h p r o d u c t i v i t y s t a n d of Keyes and G r i e r (1981), i t i s o b v i o u s t h a t my x e r i c s i t e ( S I 1 0 o = 21.8 m, T a b l e I I , p. 25) i s a l o t p o o r e r than t h e i r "poor" s i t e . The s t u d y s i t e s u t i l i z e d by S a n t a n t o n i o and Hermann (1985) ranged i n age from 70- t o 1 7 0 - y e a r s - o l d , and w h i l e the a u t h o r s s t a t e d t h a t l a r g e d i f f e r e n c e s i n p r o d u c t i v i t y e x i s t e d i n them, t h e i r c a l c u l a t e d b a s a l a r e a s , mean h e i g h t of dominant and codominant t r e e s , and t o t a l aboveground biomass e s t i m a t e s f o r each s t a n d v a r i e d l i t t l e . The s t a n d d e n s i t i e s i n t h e s e unmanaged s t a n d s were a l s o s u r p r i s i n g l y s i m i l a r f o r s t a n d s t h a t were supposed t o be so d i f f e r e n t . D e n s i t i e s ranged from a h i g h of 648 stems h a - 1 f o r the w e t t e s t s i t e , t o 602 stems h a ' 1 f o r the d r i e s t s i t e , t o 556 stems h a ' 1 on the moderate s i t e . T h i s , a g a i n , i s i n d i r e c t c o n t r a s t t o what was seen i n my s t a n d s . Stand d e n s i t y d e c r e a s e d from a maximum d e n s i t y of 6744 stems h a - 1 on the x e r i c s i t e , t o 1454 stems h a - 1 on the mesic s i t e , t o a minimum of 708 stems h a - 1 on the h y g r i c s i t e ( T a b l e I I I , p. 151 26) S a n t a n t o n i o and Hermann (1985) do s t a t e , however, t h a t t h e i r d r i e s t s i t e was not t y p i c a l of the low p r o d u c t i v i t y , r i d g e - t o p s i t e s of the western Cascades. T h e i r study s i t e had h i g h e r s t o c k i n g and lower amounts of b r u s h than a more t y p i c a l x e r i c s i t e , and, i n f a c t the S I 1 0 o f o r t h i s s i t e , c a l c u l a t e d i n the same manner as was done above f o r the Keyes and G r i e r (1981) s i t e s , t u r n s out t o be 39.2 m. The l a r g e d i f f e r e n c e s i n the e s t i m a t e s of belowground p r o d u c t i o n between th e s e t h r e e s t u d i e s may t h e r e f o r e r e f l e c t more on the d i f f e r e n c e s between t h e i r r e s p e c t i v e s t u d y a r e a s and s t a n d c o n d i t i o n s than a n y t h i n g e l s e . The e s t i m a t e s of the p e r c e n t a l l o c a t i o n of net p r i m a r y p r o d u c t i o n t o belowground s t r u c t u r e s from my s t u d y , as w e l l as o t h e r s , must be c o n s i d e r e d t o be c o n s e r v a t i v e . No attempt was made t o q u a n t i f y the c a r b o h y d r a t e s i n k s r e p r e s e n t e d by r o o t r e s p i r a t i o n or r o o t e x u d a t i o n , or t o q u a n t i f y the amount of f i n e r o o t s t aken by r o o t g r a z e r s . I have a l r e a d y d i s c u s s e d the p o t e n t i a l l o s s e s i n f i n e r o o t biomass t h a t can be e x p e c t e d from consumption of r o o t s by s o i l a n i m a l s ( s e c t i o n 5.4.1, p. 112). Such l o s s e s can account f o r s m a l l , but l o c a l l y s i g n i f i c a n t d r a i n s on the carbon budgets of f o r e s t ecosystems. E s t i m a t e s of c a r b o h y d r a t e e x p e n d i t u r e s i n r o o t exudates a r e even more d i f f i c u l t t o get than a r e e s t i m a t e s of r o o t g r a z i n g . H a l e et al. (1978) s t a t e t h a t a l t h o u g h q u a n t i t a t i v e , in situ e s t i m a t e s of t h e amount of m a t e r i a l s e c r e t e d as m u c i l a g e by f i n e r o o t s a r e l a c k i n g , the 1 52 b i o l o g i c a l a c t i v i t y g e n e r a t e d i n the r h i z o s p h e r e around t h e r o o t s by t h e s e exudates would l e a d us t o c o n c l u d e t h a t v e r y s u b s t a n t i a l amounts of c a r b o n and n i t r o g e n a r e i n v o l v e d . C o l l e c t i o n of exudates from the r o o t s of b a r l e y i n s o l u t i o n c u l t u r e s have i n d i c a t e d t h a t t h i s m a t e r i a l r e p r e s e n t s up t o t e n p e r c e n t of the shoot d r y weight ( F o g e l 1985). Smith (1977) has c a l c u l a t e d t h a t t h e r o o t exudates from t h r e e hardwood s p e c i e s growing i n t h e Hubbard Brook e x p e r i m e n t a l f o r e s t v a r i e d between 0.51 p e r c e n t and 1.43 p e r c e n t of the d r y weight of <3 mm r o o t s e v e r y two weeks. R e s p i r a t i o n a l e x p e n d i t u r e s f o r f i n e r o o t s , m y c o r r h i z a e , and t h e i r a s s o c i a t e d s o i l mycelium can a l s o be v e r y h i g h . Bowen (1985) s t a t e s t h a t the amount of net p r i m a r y p r o d u c t i o n g o i n g t o f i n e r o o t s and m y c o r r h i z a l f u n g i i s f a r i n e x c e s s of the amounts needed t o account f o r the p r o d u c t i o n of r o o t biomass a l o n e . M y c o r r h i z a l - i n f e c t e d f i n e r o o t s , i n p a r t i c u l a r , a r e i n t e n s i v e s i n k s f o r c a r b o h y d r a t e s , w i t h r e s p i r a t i o n r a t e s 1.5 t o 2 t i m e s those of u n i n f e c t e d r o o t s ( H a r l e y and S m i t h 1 983, i n Bowen 1985) Vogt et al . (1980) have found t h a t , even though m y c o r r h i z a e a c c o u n t e d f o r o n l y one p e r c e n t of t h e t o t a l system biomass i n a h i g h e l e v a t i o n P a c i f i c s i l v e r f i r s t a n d , t h e i r r e s p i r a t i o n a l c o s t s a l o n e a c c o u n t e d f o r 15 p e r c e n t of t o t a l NPP f o r t h i s system. In a l l , c a r b o h y d r a t e e x p e n d i t u r e s f o r r e s p i r a t i o n a l c o s t s and exudate l o s s e s p r o b a b l y r e p r e s e n t a t l e a s t 20 p e r c e n t of t o t a l net p r i m a r y p r o d u c t i o n (Bowen 1985). Such 153 f i g u r e s would i n d i c a t e t h a t most, i f not a l l , f i n e r o o t s t u d i e s have s e r i o u s l y u n d e r e s t i m a t e d the importance of f i n e r o o t p r o d u c t i o n t o f o r e s t ecosystems. 5.8 PATTERNS IN SOIL TEMPERATURE AND PERCENT MOISTURE  CONTENT OVER TIME 5.8.1 PATTERNS IN SOIL TEMPERATURE ON THE XERIC AND HYGRIC  SITES F i g u r e 5.17 shows the p a t t e r n s i n s o i l t e m p e r a t u r e a t 15 cm depth between May 1984 and J u l y 1985 f o r the x e r i c and h y g r i c s i t e s . A l t h o u g h the i n d i v i d u a l measurements i n t h i s f i g u r e do not r e p r e s e n t means f o r the e n t i r e month, t h e p a t t e r n s of v a r i a t i o n seen here c l o s e l y resemble the g e n e r a l p a t t e r n of mean d a i l y a i r t e m p e r a t u r e r e c o r d e d f o r t h e P o r t A l b e r n i weather s t a t i o n ( F i g u r e 3.8, p. 4 2 ) . However, s o i l t e m p e r a t u r e s i n the two s i t e s were not as extreme as the summer h i g h and w i n t e r low t e m p e r a t u r e s r e c o r d e d f o r t h i s weather s t a t i o n . There were no l a r g e d i f f e r e n c e s between the s o i l t e m p e r a t u r e s of the two s t u d y s i t e s . There was o n l y one month (October 1984) i n whi c h t h e d i f f e r e n c e between t h e s e two measurements was g r e a t e r than 2°C. In a l l but one monthly measurement, however, the s o i l t e m p e r a t u r e on the h y g r i c s i t e was l e s s than t h e s o i l t e m p e r a t u r e on t h e x e r i c s i t e [ t h i s one e x c e p t i o n a l measurement o c c u r r e d i n December 1984, an e x t r e m e l y c o l d and d r y p e r i o d which saw mean d a i l y 154 14-| 0 -I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 i APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL 1984 1985 Date Plot O Low Productivity Plot 4> High Productivity Plot F i g u r e 5 . 1 7 . P a t t e r n s i n s o i l t e m p e r a t u r e ( ° C ) a t 15 cm d e p t h on the x e r i c ( l ow) and h y g r i c ( h i g h ) s i t e s . E s t i m a t e d t e m p e r a t u r e s a r e means of a t l e a s t two r e a d i n g s o f remote t e m p e r a t u r e p r o b e s f o r a s i n g l e mon th ly v i s i t t o each s i t e . 1 55 temperature and monthly mean p r e c i p i t a t i o n l e v e l s f a l l w e l l below t h e i r r e s p e c t i v e 30-year averages ( F i g u r e 3.8, p . 4 2 ) ] . What i s i n t e r e s t i n g about F i g u r e 5.17 i s the c o m p a r a t i v e l y narrow range of measured s o i l t e m p e r a t u r e s f o r thes e two s i t e s . D e s p i t e the e x t r e m e l y c o l d weather of December 1984, when minimum te m p e r a t u r e s as low as -22°C were r e - c o r e d d u r i n g v i s i t s t o the study s i t e s , s o i l t e mperature a t 15 cm never went below 1.5°C. At the o p p o s i t e extreme, d u r i n g the p r o l o n g e d d r y summer of 1985, w i t h d a i l y maximum t e m p e r a t u r e s w e l l i n t o the m i d d l e 30's°C, s o i l t e m p e r a t u r e s on b o t h s i t e s remained a t or near 10°C. In such a range of a i r t e m p e r a t u r e s , the l e t h a l or l i m i t i n g e f f e c t s of h i g h s o i l t e m p e r a t u r e s , which o t h e r a u t h o r s ( L y r and Hoffman 1974, Deans 1979, Tryon and Chapin 1983, M a r s h a l l and Waring 1985) have shown t o be i m p o r t a n t , p r o b a b l y had l i t t l e impact on f i n e r o o t dynamics. Temperature may s t i l l e x e r t a g r e a t d e a l of c o n t r o l on the annual c y c l e s of belowground p r o d u c t i o n , t h r o u g h i t s ' e f f e c t on s o i l m o i s t u r e . However, t e m p e r a t u r e - r e l a t e d m o r t a l i t y of f i n e r o o t s on my s i t e s was u n l i k e l y below the f i r s t few cm of the f o r e s t f l o o r . 5.8.2 PATTERNS OF PERCENT SOIL MOISTURE IN MINERAL SOIL AND  ORGANIC FOREST FLOOR HORIZONS F i g u r e 5.18 shows t h e s e a s o n a l p a t t e r n i n the m o i s t u r e c o n t e n t of o r g a n i c f o r e s t f l o o r and m i n e r a l s o i l <2 mm f r a c t i o n s f o r the x e r i c , m e s i c , and h y g r i c s i t e s . U n l i k e the 156 p a t t e r n of s o i l t e m p e r a t u r e s ( F i g u r e 5.17), t h e r e were c l e a r s e a s o n a l d i f f e r e n c e s between s i t e s f o r the m o i s t u r e c o n t e n t of b o t h o r g a n i c and m i n e r a l m a t e r i a l s . In a l l t h r e e s i t e s , the s o i l m o i s t u r e of the o r g a n i c f o r e s t f l o o r m a t e r i a l was always g r e a t e r than t h a t of the m i n e r a l s o i l . The o r g a n i c f o r e s t f l o o r f r a c t i o n s showed the g r e a t e s t v a r i a b i l i t y on a s e a s o n a l b a s i s , i n c r e a s i n g t h e i r s o i l m o i s t u r e from lows of between 25 t o 30 % of d r y weight i n the d r i e s t p a r t s of t h e summer (August or September), t o between 130 and 150 % m o i s t u r e c o n t e n t i n l a t e f a l l and e a r l y w i n t e r . For t h e o r g a n i c f o r e s t f l o o r m a t e r i a l , t h e r e was a p a t t e r n of i n c r e a s i n g s o i l m o i s t u r e w i t h i n c r e a s i n g s i t e p r o d u c t i v i t y , a t l e a s t f o r p a r t of the y e a r . T h i s p a t t e r n was seen most s t r o n g l y d u r i n g the l a t e s p r i n g and e a r l y summer months (June t o A u g u s t ) , and a g a i n i n the l a t e f a l l and e a r l y w i n t e r months (November t o J a n u a r y ) . However, d u r i n g the i n t e r i m p e r i o d s , t h e r e was v i r t u a l l y no d i f f e r e n c e between t h e p e r c e n t m o i s t u r e c o n t e n t s of the o r g a n i c m a t e r i a l s of the t h r e e s i t e s . U n l i k e the o r g a n i c f o r e s t f l o o r m a t e r i a l , the m i n e r a l s o i l m a t e r i a l from each s i t e showed d i s t i n c t d i f f e r e n c e s i n t h e i r s o i l m o i s t u r e over the e n t i r e y e a r , and a c o n s i s t e n t i n c r e a s e i n m o i s t u r e c o n t e n t w i t h i n c r e a s i n g s i t e p r o d u c t i v i t y . The a m p l i t u d e of the s e a s o n a l changes i n p e r c e n t m o i s t u r e c o n t e n t was much s m a l l e r as compared t o the changes seen i n the f o r e s t f l o o r m a t e r i a l . P e r c e n t m o i s t u r e c o n t e n t f o r the m i n e r a l s o i l f r a c t i o n , on any g i v e n s i t e , 1 57 200- i v. CD • 'o o 150-100 5 0 -1 1 1 1 1 1 1 1 1 1 i i i JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL 1984 1985 Date Horizon O Low Site Forest Floor <fc Low Site Mineral Soil O Medium Site Forest Floor # Medium Site Mineral Soil O High Site Forest Floor # High Site Mineral Soil F i g u r e 5 . 1 8 . P a t t e r n s i n s o i l m o i s t u r e ( p e r c e n t of d r y w e i g h t ) i n m i n e r a l and o r g a n i c f r a c t i o n s of the x e r i c ( l o w ) , mesic (medium), and h y g r i c ( h i g h ) s i t e s . E s t i m a t e s a r e based on the p e r c e n t s o i l m o i s t u r e (% d r y weight) of t h r e e subsamples from a l a r g e r c omposite sample (<2 mm f r a c t i o n ) f o r each m a t e r i a l . 1 5 8 v a r i e d by a f a c t o r of two t o t h r e e between the w e t t e s t and d r i e s t t i m e s of the y e a r . For the o r g a n i c f o r e s t f l o o r m a t e r i a l , t he m o i s t u r e c o n t e n t v a r i e d by a f a c t o r of f i v e and s i x over t h e same time p e r i o d . The x e r i c s i t e showed the g r e a t e s t l a g between the time t h a t the o r g a n i c m a t e r i a l s a t t h e ground s u r f a c e showed i n c r e a s e s i n t h e i r p e r c e n t m o i s t u r e c o n t e n t ( w i t h the onset of wet f a l l w e a t h e r ) , and the time t h a t the m i n e r a l s o i l i n lower h o r i z o n s began t o wet up. M o i s t u r e c o n t e n t of the o r g a n i c m a t e r i a l s on t h i s s i t e began t o i n c r e a s e by October 1984, but c o n t i n u e d t o d e c r e a s e i n the m i n e r a l s o i l u n t i l November 1984. Comparisons f o r the mesic and h y g r i c s i t e s showed t h a t b o t h m i n e r a l and o r g a n i c m a t e r i a l s t a r t e d t o i n c r e a s e t h e i r m o i s t u r e c o n t e n t s by October 1984, e x h i b i t i n g no l a g time a t a l l between h o r i z o n s . 5.9 CORRELATION OF BELOWGROUND PRODUCTION WITH SOIL  PROPERTIES AND FOLIAR LITTER PRODUCTION Simple c o r r e l a t i o n s were made between the monthly e s t i m a t e s of t h e f o u r belowground components from n a t i v e - s o i l - f i l l e d i n - g r o w t h bags, s o i l t e m p e r a t u r e , p e r c e n t m o i s t u r e c o n t e n t of m i n e r a l s o i l and o r g a n i c f o r e s t f l o o r s , and f o l i a r l i t t e r p r o d u c t i o n f o r each s i t e . An a d d i t i o n a l biomass component was c r e a t e d by summing the e s t i m a t e s of c o n i f e r o u s l i v e r o o t s and f u n g a l hyphae. E s t i m a t e s of s o i l t e m p e r a t u r e on t h e mesic s i t e were made by a v e r a g i n g the e s t i m a t e s of t h e x e r i c and h y g r i c s i t e s . S i n c e l i t t e r 1 5 9 c o l l e c t i o n s were made o n l y between June 16th 1984 and June 1st 1985, the c o r r e l a t i o n s were l i m i t e d t o the b i o t i c and a b i o t i c d a t a c o l l e c t e d between these d a t e s . F o l i a r l i t t e r p r o d u c t i o n was a l s o t e s t e d a g a i n s t the a b i o t i c f a c t o r s t o compare the c o r r e l a t i o n s of aboveground and belowground biomass components w i t h a b i o t i c s i t e measurements. 5.9.1 THE XERIC SITE On the x e r i c s i t e , the o n l y f a c t o r w h i c h d i d not show good c o r r e l a t i o n f o r a t l e a s t one of the belowground biomass components was f o l i a r l i t t e r f a l l . The l a r g e s t c o r r e l a t i o n f o r t h i s f a c t o r had a c a l c u l a t e d r - v a l u e of -.11 f o r the n o n - c o n i f e r o u s r o o t component (T a b l e X I V ) . Thus, a t b e s t , the v a r i a t i o n i n f o l i a r l i t t e r f a l l a c c o u n t e d f o r s l i g h t l y more than one p e r c e n t of the v a r i a t i o n i n t h e r o o t biomass d a t a on t h i s s i t e . A l l t h r e e of the r e m a i n i n g a b i o t i c s i t e f a c t o r s showed s t r o n g e r c o r r e l a t i o n s w i t h a t l e a s t some of the belowground biomass components. M i n e r a l s o i l and o r g a n i c f o r e s t f l o o r m o i s t u r e c o n t e n t s were al w a y s p o s i t i v e l y c o r r e l a t e d w i t h r o o t and f u n g a l biomass. The s t r o n g e s t r e l a t i o n s h i p w i t h f u n g a l hyphae was w i t h f o r e s t f l o o r m o i s t u r e c o n t e n t ( r = .61)., w h i l e f o r c o n i f e r o u s l i v e r o o t s , m i n e r a l s o i l m o i s t u r e c o n t e n t produced the l a r g e s t c o r r e l a t i o n c o e f f i c i e n t ( r = .50). T h i s s t r o n g p o s i t i v e c o r r e l a t i o n of biomass and m o i s t u r e c o n t e n t s u p p o r t s the t h e o r y t h a t m o i s t u r e a v a i l a b i l i t y i s the p r i m a r y l i m i t i n g f a c t o r i n r o o t and 160 T a b l e XIV. Sim p l e c o r r e l a t i o n s between monthly e s t i m a t e s of a s h - f r e e r o o t and f u n g a l biomass from n a t i v e - s o i l - f i l l e d i n - g r o w t h bags, s o i l p r o p e r t i e s , and f o l i a r l i t t e r p r o d u c t i o n f o r the t h r e e s i t e s . Biomass Component P r o p e r t y 1 L I T . % S o i l M % FF M r S o i l T X e r i c S i t e 1. c o n i f . l i v e .06 .50 .48 2. n o n - c o n i f. -.11 .38 .16 l i v e 3. dead -.14 .38 .33 4. f u n g a l -.07 .40 .61 5. t o t . .01 .49 .46 o v e r s t o r e y 2 6. f o l i a r -.62 -.20 l i t t e r -.28 -.60 -.06 -.42 -.23 .46 M e s i c S i t e 1 . c o n i f . 1 i v e -.32 2. n o n - c o n i f . -.41 1 i v e 3. dead . 1 2 4. f u n g a l .07 5. t o t . -.13 o v e r s t o r e y 6. f o l i a r l i t t e r H y g r i c S i t e 1. c o n i f . l i v e .25 2. n o n - c o n i f . -.07 1 i v e 3. dead -.18 4. f u n g a l .53 5. t o t . .22 o v e r s t o r e y 6. f o l i a r l i t t e r .43 .51 -.33 .03 -.22 -.36 .29 .10 -.21 -.04 .23 .18 .47 .40 -.36 .06 .16 .05 .36 .41 -.51 .20 .10 -.10 .17 .12 .23 .25 -.09 .23 .41 .46 -.47 .14 .25 .03 p r o p e r t i e s ; L I T . = f o l i a r l i t t e r f a l l , % S o i l M = p e r c e n t s o i l m o i s t u r e c o n t e n t of the ^ 2 mm m i n e r a l s o i l f r a c t i o n , % FF M = p e r c e n t s o i l m o i s t u r e c o n t e n t of the <2 mm o r g a n i c f o r e s t f l o o r f r a c t i o n , S o i l T = tem p e r a t u r e (°C) a t 15 cm s o i l d e p t h on the x e r i c and h y g r i c a s s o c i a t i o n s , and i t e r a t i v e l y f o r the mesic s i t e . 2 t o t . o v e r s t o r e y = sum of f u n g a l hyphae and c o n i f e r o u s l i v e r o o t components. 161 f u n g a l p r o d u c t i o n on t h e s e x e r i c s i t e s . S o i l t e m p e r a t u r e showed s t r o n g n e g a t i v e c o r r e l a t i o n s f o r the n o n - c o n i f e r o u s and f u n g a l componen t s . The o v e r s t o r e y r o o t components ( b o t h l i v e and dead) showed much weake r , but s t i l l n e g a t i v e c o r r e l a t i o n s . The s t r o n g n e g a t i v e r e l a t i o n s h i p o f s o i l t e m p e r a t u r e w i t h n o n - c o n i f e r o u s r o o t s was p r o b a b l y due t o the l a r g e f l u s h e s o f u n d e r s t o r e y g r o w t h i n the s p r i n g , when t e m p e r a t u r e s were s t i l l r e l a t i v e l y l o w , as compared t o the summer and f a l l , when t e m p e r a t u r e s a r e g r e a t e r and u n d e r s t o r e y g r o w t h i s no t as v i g o r o u s . L i k e w i s e , the l a r g e f l u s h e s o f f u n g a l hyphae p r o d u c t i o n i n the f a l l and w i n t e r on t h i s s i t e wou ld a l s o p r o d u c e a s t r o n g n e g a t i v e c o r r e l a t i o n w i t h t e m p e r a t u r e . By c o n t r a s t w i t h the b e l o w g r o u n d componen t s , f o l i a r l i t t e r f a l l was s t r o n g l y n e g a t i v e l y c o r r e l a t e d t o s o i l m o i s t u r e c o n t e n t ( r = - . 6 2 ) , and p o s i t i v e l y c o r r e l a t e d w i t h s o i l t e m p e r a t u r e ( r = . 4 6 ) . The l a r g e s t amounts o f f o l i a r l i t t e r p r o d u c t i o n o c c u r r e d i n the e a r l y s p r i n g , as m o i s t u r e c o n t e n t i n the s o i l was d e c r e a s i n g and s o i l t e m p e r a t u r e was i n c r e a s i n g . C o m b i n i n g the c o n i f e r o u s l i v e r o o t and f u n g a l hyphae components p r o d u c e d a c o r r e l a t i o n c o e f f i c i e n t a l m o s t as s t r o n g as the c o n i f e r o u s component by i t s e l f , a t l e a s t f o r the two m o i s t u r e c o n t e n t f a c t o r s . C a l c u l a t e d r - v a l u e s f o r t h i s combined v a r i a b l e were .49 w i t h the m i n e r a l s o i l m o i s t u r e c o n t e n t , and .46 f o r t he f o r e s t f l o o r m o i s t u r e c o n t e n t . 1 62 5.9.2 THE MESIC SITE The c o r r e l a t i o n of the b i o t i c and a b i o t i c s i t e f a c t o r s t o belowground p r o d u c t i o n were not as s t r o n g on the mesic s i t e as they were on t h e x e r i c s i t e . There were o n l y f i v e c o r r e l a t i o n c o e f f i c i e n t s w i t h c a l c u l a t e d v a l u e s g r e a t e r than .40, as compared t o ten f o r the x e r i c s i t e . S i m i l a r t o the x e r i c s i t e , t h e c o n i f e r o u s l i v e r o o t component showed a p o s i t i v e c o r r e l a t i o n w i t h m i n e r a l s o i l m o i s t u r e c o n t e n t ( r = .43) and f o r e s t f l o o r m o i s t u r e c o n t e n t ( r = .51), and a n e g a t i v e c o r r e l a t i o n w i t h s o i l t e m p e r a t u r e ( r = - . 3 3 ) . The c o r r e l a t i o n between c o n i f e r o u s and n o n - c o n i f e r o u s r o o t biomass and f o l i a r l i t t e r p r o d u c t i o n was a g a i n n e g a t i v e , and somewhat s t r o n g e r than was seen f o r the x e r i c s i t e . The l a r g e s t r - v a l u e s f o r t h e s e comparisons was -.41 f o r the n o n - c o n i f e r o u s r o o t component. For the r e m a i n i n g biomass components, the l a r g e s t r - v a l u e f o r t h i s s i t e was produced by the c o r r e l a t i o n of f u n g a l hyphae p l u s c o n i f e r o u s r o o t biomass and m i n e r a l s o i l m o i s t u r e c o n t e n t . Of the s i x t e s t e d biomass components and c o m b i n a t i o n s , t h i s one showed the s m a l l e s t drop i n r - v a l u e f o r c o r r e l a t i o n w i t h s o i l m o i s t u r e c o n t e n t compared t o the r - v a l u e s c a l c u l a t e d f o r the x e r i c s i t e . A l l o t h e r t e s t e d f a c t o r s showed v e r y poor c o r r e l a t i o n s between r o o t or f u n g a l biomass p r o d u c t i o n on t h i s s i t e . I t would appear t h a t r o o t and f u n g a l p r o d u c t i o n were l e s s dependent on m i n e r a l s o i l m o i s t u r e c o n t e n t on t h i s s i t e t h a n they were on the x e r i c s t u d y s i t e , but t h a t f o r e s t 1 63 f l o o r m o i s t u r e c o n t e n t and c o n i f e r o u s r o o t p r o d u c t i o n were s t i l l as s t r o n g l y c o r r e l a t e d as on the p r e v i o u s s i t e . The upper o r g a n i c l a y e r s on the mesic s i t e d i d get e x t r e m e l y d r y i n the summer, and p r o b a b l y had m o i s t u r e c o n t e n t s t h a t would have been low enough t o i n h i b i t r o o t growth. The same e f f e c t cannot be s a i d t o have been t r u e f o r t h e f u n g a l hyphae. T h i s biomass component showed a much lower c o r r e l a t i o n w i t h f o r e s t f l o o r m o i s t u r e c o n t e n t ( r = .23) as compared t o the x e r i c s i t e ( r = .61). T h i s was perhaps due t o the g r e a t e r m o i s t u r e c o n t e n t of the o r g a n i c m a t e r i a l on t h i s s i t e , and the f u n g i ' s a b i l i t y t o p e n e t r a t e t h e l i t t e r i t s e l f and t a p a water s o u r c e t h a t would have been u n a v a i l a b l e t o the r o o t s . Another i n t e r e s t i n g c o m p a r i s o n between t h e s e two s i t e s i s t h a t f o l i a r l i t t e r p r o d u c t i o n showed v i r t u a l l y no c o r r e l a t i o n w i t h any of the a b i o t i c s i t e f a c t o r s on the mesic s i t e . T h i s was u n l i k e the s i t u a t i o n on the x e r i c s i t e , where f o l i a r l i t t e r was s t r o n g l y n e g a t i v e l y c o r r e l a t e d w i t h m i n e r a l s o i l m o i s t u r e c o n t e n t , and p o s i t i v e l y c o r r e l a t e d w i t h s o i l t e m p e r a t u r e . The g r e a t e r p r o d u c t i o n of f o l i a r l i t t e r i n J u l y , August, and September of 1984 on the x e r i c s i t e , and the d e l a y i n the l a r g e f a l l i n c r e a s e i n f o l i a r l i t t e r on the mesic s i t e ( t o November as compared t o October on the x e r i c s i t e ) p r o b a b l y a c c o u n t s f o r these lower c o r r e l a t i o n s . The g r e a t e r p r o d u c t i o n of f o l i a r l i t t e r d u r i n g the summer and e a r l y f a l l months on the x e r i c s i t e , when s o i l t e m p e r a t u r e s were h i g h and s o i l m o i s t u r e c o n t e n t s low, would have produced the s t r o n g e r c o r r e l a t i o n s h e r e . 1 64 5.9.3 THE HYGRIC SITE The t r e n d of weaker c o r r e l a t i o n between belowground p r o d u c t i o n and b i o t i c and a b i o t i c s i t e f a c t o r s as s i t e p r o d u c t i v i t y i n c r e a s e s was c o n t i n u e d on the h y g r i c s i t e . F o r t h i s s i t e , s i x of the c a l c u l a t e d c o e f f i c i e n t s had r - v a l u e s g r e a t e r than .40. However, the l a r g e s t of t h e s e was produced by the c o r r e l a t i o n of f u n g a l biomass w i t h f o l i a r l i t t e r ( r = .53). C o n s i d e r i n g the r e l a t i v e unimportance of the f u n g a l hyphae on the h y g r i c s i t e , t h i s s t r o n g c o r r e l a t i o n does not t e l l us a g r e a t d e a l . C o n i f e r o u s l i v e biomass was a g a i n c o m p a r a t i v e l y s t r o n g l y c o r r e l a t e d w i t h s o i l m o i s t u r e c o n t e n t ( r = .36) and f o r e s t f l o o r m o i s t u r e c o n t e n t ( r = .41). However, t h e s e c o r r e l a t i o n s were not as s t r o n g as were t h e i r r e s p e c t i v e c o u n t e r p a r t s f o r the o t h e r two s i t e s . There was a s t r o n g n e g a t i v e c o r r e l a t i o n of c o n i f e r o u s l i v e r o o t s w i t h s o i l t e m p e r a t u r e ( r = - . 5 1 ) . The w i n t e r f l u s h e s of f i n e r o o t growth, and lower amounts of f i n e r o o t p r o d u c t i o n i n the s p r i n g and summer r e l a t i v e t o the o t h e r two s i t e s would p r o b a b l y account f o r t h i s s t r o n g e r n e g a t i v e r e l a t i o n s h i p . The combined component of c o n i f e r o u s f i n e r o o t s p l u s f u n g a l hyphae showed a s l i g h t l y weaker c o r r e l a t i o n w i t h m i n e r a l s o i l m o i s t u r e c o n t e n t ( r = .41) as compared t o the mesic s i t e , but i n c r e a s e d i t s ' r - v a l u e i n t h e comparison w i t h f o r e s t f l o o r m o i s t u r e c o n t e n t ( r = .46). T h i s component a l s o showed a s t r o n g e r n e g a t i v e c o r r e l a t i o n t o s o i l t e m p e r a t u r e ( r = -.47) than d i d the c o r r e s p o n d i n g 1 65 r e l a t i o n s h i p s on the o t h e r two s i t e s . F o l i a r l i t t e r p r o d u c t i o n showed v e r y poor c o r r e l a t i o n t o the a b i o t i c s i t e f a c t o r s , c o n t i n u i n g a t r e n d of lower c o r r e l a t i o n w i t h i n c r e a s i n g s i t e p r o d u c t i v i t y f o r t h i s component. 5.9.4 OVERALL TRENDS IN THE CORRELATION DATA I t appears as i f the p e r c e n t m o i s t u r e c o n t e n t s of the m i n e r a l s o i l and o r g a n i c f o r e s t f l o o r m a t e r i a l s g i v e the be s t c o r r e l a t i o n s w i t h c o n i f e r o u s r o o t biomass and f u n g a l hyphae. S o i l t e m p e r a t u r e was u s u a l l y n e g a t i v e l y c o r r e l a t e d w i t h r o o t and f u n g a l biomass, p r o b a b l y because of the s e a s o n a l n a t u r e of aboveground and belowground p r o d u c t i o n (low amounts of r o o t s p r o d u c e d d u r i n g the summer p e r i o d when aboveground growth i s r a p i d ) , and the e f f e c t of s o i l t e m p e r a t u r e on s o i l m o i s t u r e . There i s a t r e n d f o r weaker c o r r e l a t i o n s of the a b i o t i c f a c t o r s and the biomass d a t a w i t h i n c r e a s i n g s i t e p r o d u c t i v i t y . As we move down the t o p o g r a p h i c sequence from the x e r i c r i d g e - t o p s i t e t o t h e h y g r i c seepage s i t e , the growth c o n d i t i o n s t h a t t h e s i t e s would e x p e r i e n c e d u r i n g the summer growth p e r i o d would become l e s s s e v e r e . I t makes sense t h a t t h e r e would be s t r o n g e r c o r r e l a t i o n s between belowground p r o d u c t i v i t y and a b i o t i c s i t e f a c t o r s on the x e r i c s i t e , where such f a c t o r s would be much more l i m i t i n g . S i n c e t h e r e was so l i t t l e d i f f e r e n c e i n the temp e r a t u r e d a t a between the t h r e e s i t e s (see S e c t i o n 5.8.1, p. 152), thes e 1 6 6 r e s u l t s a l s o suggest t h a t m o i s t u r e i s the p r i n c i p a l l i m i t i n g f a c t o r on r o o t and f u n g a l p r o d u c t i o n . 6. SUMMARY AND CONCLUSIONS 6.1 SUMMARY OF THE THESIS 6.2 SUMMARY OF THE THESIS A l l of the o b j e c t i v e s s e t out f o r t h i s s t u d y have been met. A d e t a i l e d a n a l y s i s of the belowground biomass p r o d u c t i o n dynamics on the x e r i c , m e s i c , and h y g r i c s i t e s r e v e a l e d no s i g n i f i c a n t e f f e c t of s i t e f o r the o v e r s t o r e y <5 mm r o o t component. S i t e d i d prove t o be s i g n i f i c a n t f o r the n o n - c o n i f e r o u s <5 mm r o o t biomass e s t i m a t e s from n a t i v e s o i l - f i l l e d i n - g r o w t h bags. However, r e s u l t s f o r o t h e r biomass components were confounded due t o s i g n i f i c a n t s e cond-order and t h i r d - o r d e r f a c t o r i n t e r a c t i o n s i n the a n a l y s i s of v a r i a n c e . Growth m a t e r i a l (beach sand or n a t i v e s o i l ) w i t h i n the i n - g r o w t h bags had a s i g n i f i c a n t e f f e c t on the biomass e s t i m a t e s f o r a l l f o u r r o o t and f u n g a l components on a l l t h r e e s i t e s . The t e s t i n g of an a d d i t i o n a l two growth media ( s i l i c a sand and f e r t i l i z e d n a t i v e s o i l ) r e v e a l e d t h a t the n u t r i e n t - r i c h growth m a t e r i a l s s t i m u l a t e d the p r o d u c t i o n of c o n i f e r o u s and n o n - c o n i f e r o u s f i n e r o o t s , i n c r e a s e d the s i z e of the c o n i f e r o u s r o o t component, and i n c r e a s e d the l o n g e v i t y of r o o t s w i t h i n the bags. A l t h o u g h t h e r e were s i g n i f i c a n t d i f f e r e n c e s i n the e s t i m a t e s of f u n g a l h y p h a l biomass between the two o r i g i n a l growth media i n t h e i n - g r o w t h bags, the r e l a t i o n s h i p was not 167 168 c o n s i s t e n t between s i t e s . The t e s t of the two a d d i t i o n a l growth media on the mesic s i t e showed t h a t the f u n g a l hyphae were the l e a s t a f f e c t e d of the f o u r biomass components by the q u a l i t a t i v e changes i n the growth media w i t h i n the bags. Comparisons between the e s t i m a t e d s t a n d i n g c r o p s of c o n i f e r o u s r o o t s produced from n a t i v e s o i l - f i l l e d i n - g r o w t h bags and s e q u e n t i a l s o i l c o r e s showed t h a t the i n - g r o w t h bag t e c h n i q u e g r e a t l y u n d e r e s t i m a t e d the c o n i f e r o u s r o o t biomass. In p a r t i c u l a r , the i n - g r o w t h bag t e c h n i q u e gave poor e s t i m a t e s of m y c o r r h i z a l biomass. Compared t o the l a r g e numbers of m y c o r r h i z a e found w i t h s e q u e n t i a l s o i l c o r i n g , the f i n e r o o t s which appeared i n the i n - g r o w t h bags tended t o be l o n g and s l e n d e r , and had v e r y few, s m a l l m y c o r r h i z a e . E s t i m a t e s of the s t a n d i n g c r o p of v e r y f i n e r o o t s produced w i t h s e q u e n t i a l s o i l c o r e s f o r the x e r i c and h y g r i c s i t e s were as much as an o r d e r of magnitude g r e a t e r than the e s t i m a t e s from n a t i v e s o i l - f i l l e d i n - g r o w t h bags f o r the same s i t e s and t i m e s . D e s p i t e t h e s e l a r g e d i f f e r e n c e s i n e s t i m a t e s of s t a n d i n g c r o p , a n n u a l o v e r s t o r e y p r o d u c t i o n e s t i m a t e s (based on s t a t i s t i c a l l y s i g n i f i c a n t changes i n monthly or b i m o n t h l y s t a n d i n g c r o p e s t i m a t e s of l i v e and dead r o o t s ) were much more s i m i l a r f o r the two t e c h n i q u e s . Annual belowground p r o d u c t i o n e s t i m a t e s from n a t i v e s o i l - f i l l e d i n - g r o w t h bags r e p r e s e n t e d 56.6 p e r c e n t and 53.3 p e r c e n t of the comparable e s t i m a t e s from s e q u e n t i a l s o i l c o r e s f o r the x e r i c and h y g r i c s i t e s r e s p e c t i v e l y . S i m i l a r e s t i m a t e s produced from 1 69 s a n d - f i l l e d i n - g r o w t h bags were much s m a l l e r , r e p r e s e n t i n g o n l y 12.7 p e r c e n t and 8.6 p e r c e n t of the s e q u e n t i a l s o i l c o r i n g e s t i m a t e s f o r the two s i t e s . A l t h o u g h t h e r e was no s i g n i f i c a n t e f f e c t of s i t e on the e s t i m a t e s of c o n i f e r o u s f i n e r o o t biomass, t h e r e were l a r g e d i f f e r e n c e s i n the p r o p o r t i o n s of net p r i m a r y p r o d u c t i v i t y which were u t i l i z e d i n belowground p r o d u c t i o n . As s i t e q u a l i t y i n c r e a s e d (as we moved from the r i d g e - t o p x e r i c s i t e , w i t h i n t he FONT 2 > G a u l t h e r i a s h a l l o n a s s o c i a t i o n , t h r o u g h the mesic s i t e , w i t h i n the Moss a s s o c i a t i o n , t o the h y g r i c s i t e , w i t h i n the Ac hiys-Polyst i chum a s s o c i a t i o n ) , t o t a l a n n u a l biomass p r o d u c t i o n i n c r e a s e d by more than 50 p e r c e n t , a l l o c a t i o n s of NPP t o the belowground components d e c r e a s e d , and t h e p r o p o r t i o n a l p r o d u c t i o n of stemwood biomass i n c r e a s e d . U s i n g the belowground p r o d u c t i o n e s t i m a t e s from n a t i v e s o i l - f i l l e d i n - g r o w t h bags, t o t a l a n n u a l biomass p r o d u c t i o n was 15.7 t h a - 1 on the x e r i c s i t e , 22.9 t h a - 1 on the mesic s i t e , and 25.0 t h a - 1 on the h y g r i c s i t e . On the x e r i c s i t e , 26.5 p e r c e n t of a n n u a l biomass p r o d u c t i o n budget was a l l o c a t e d t o r o o t and f u n g a l s t r u c t u r e s , and 38.5 p e r c e n t t o stemwood biomass p r o d u c t i o n . On the mesic s i t e , belowground p r o d u c t i o n d e c r e a s e d p r o p o r t i o n a t e l y t o 24.5 p e r c e n t of t o t a l biomass, w h i l e stemwood biomass p r o d u c t i o n i n c r e a s e d t o 52.1 p e r c e n t . The h y g r i c s i t e a l l o c a t e d o n l y 20 p e r c e n t of i t s ' t o t a l biomass p r o d u c t i o n budget t o belowground s t r u c t u r e s w h i l e consuming 170 55.8 p e r c e n t i n stemwood p r o d u c t i o n . A l a r g e p a r t o f t h e d i f f e r e n c e s i n a n n u a l b e l o w g r o u n d p r o d u c t i o n b e t w e e n t h e h y g r i c s i t e a n d t h e o t h e r two s i t e s i s i n t h e much s m a l l e r a mounts o f f u n g a l h y p h a e p r o d u c e d on t h e h y g r i c s i t e a s c o m p a r e d t o t h e x e r i c a n d m e s i c s i t e s . F u n g a l h y p h a l p r o d u c t i o n r e p r e s e n t e d 4 . 0 p e r c e n t o f t o t a l b i o m a s s p r o d u c t i o n on t h e t h e x e r i c s i t e , 5.5 p e r c e n t on t h e m e s i c s i t e , b u t o n l y 0 . 4 p e r c e n t on t h e h y g r i c s i t e . I t w o u l d a p p e a r t h a t l a r g e p r o d u c t i v i t y d i f f e r e n c e s e x i s t e d b e t w e e n my s t a n d s o f D o u g l a s - f i r , w h i c h d i f f e r e d f r o m e a c h o t h e r p r i n c i p a l l y i n t h e i r t o p o g r a p h i c a l p o s i t i o n s . T h i s f i n d i n g d i r e c t l y c o n t r a d i c t s e a r l i e r work o f K e y e s a n d G r i e r ( 1 9 8 1 ) , who s u g g e s t e d t h a t d i f f e r e n c e s i n a b o v e g r o u n d p r o d u c t i o n b e t w e e n h i g h a n d l o w p r o d u c t i v i t y s t a n d s o f D o u g l a s - f i r ( d i f f e r e n t i a t e d a s s u c h l a r g e l y by d i f f e r e n c e s i n t h e i r u n d e r l y i n g s o i l s ) c o u l d be e x p l a i n e d by an i n c r e a s e d a l l o c a t i o n o f NPP t o t h e b e l o w g r o u n d c o m p o n e n t s on p o o r e r s i t e s , a n d t h a t t o t a l e c o s y s t e m p r o d u c t i o n v a r i e d l i t t l e b e t w e e n g o o d a n d p o o r s t a n d s . Of my t h r e e s t u d y s i t e s , t h e x e r i c s i t e showed t h e s t r o n g e s t c o r r e l a t i o n o f b e l o w g r o u n d p r o d u c t i o n t o t h e t e s t e d b i o t i c a n d a b i o t i c s i t e f a c t o r s . A l t h o u g h t h e s t r e n g t h o f t h e a s s o c i a t i o n s b e t w e e n t h e t e s t e d b i o m a s s c o m p o n e n t s a n d t h e s i t e f a c t o r s was n e v e r v e r y g r e a t ( t h e l a r g e s t c o r r e l a t i o n c o e f f i c i e n t was .62; t h u s n e v e r more t h a n 38 p e r c e n t o f t h e v a r i a t i o n i n t h e b i o m a s s component c o u l d be e x p l a i n e d by v a r i a t i o n o f t h e t e s t e d s i t e f a c t o r ) , 171 t h e r e was a t r e n d of d e c r e a s i n g c o r r e l a t i o n of c o n i f e r o u s l i v e r o o t biomass and m i n e r a l s o i l m o i s t u r e c o n t e n t w i t h i n c r e a s i n g s i t e p r o d u c t i v i t y . Combining c o n i f e r o u s r o o t and f u n g a l biomass components d e c r e a s e d the e x t e n t of d e c l i n e of the r - v a l u e s w i t h i n c r e a s i n g s i t e p r o d u c t i v i t y , a l t h o u g h the i n i t i a l c o r r e l a t i o n c o e f f i c i e n t s of the x e r i c s i t e f o r t h i s component were somewhat s m a l l e r . 6.3 CONCLUSIONS A l t h o u g h the i n - g r o w t h bag t e c h n i q u e i s p o t e n t i a l l y a u s e f u l t o o l f o r the study of belowground p r o d u c t i o n , I have d e m o n s t r a t e d some d e f i n i t e l i m i t a t i o n s i n h e r e n t i n the t e c h n i q u e w h i c h must be t a k e n i n t o c o n s i d e r a t i o n b e f o r e i t i s u t i l i z e d . The advantages of t h i s t e c h n i q u e a r e as f o l l o w s ; 1. The amount of time spent washing and s o r t i n g the r o o t and f u n g a l m a t e r i a l i n the i n - g r o w t h bag samples i s g r e a t l y reduced as compared t o the more t r a d i t i o n a l s e q u e n t i a l s o i l c o r e s . F i v e t o e i g h t i n - g r o w t h bags can be s o r t e d i n the same amount of time t h a t a s i n g l e s e q u e n t i a l s o i l c o r e would r e q u i r e . As a r e s u l t of t h i s , i t would be p o s s i b l e t o i n c r e a s e the number of samples t a k e n from a g i v e n s i t e on a s i n g l e s a m p l i n g d a t e , the t ime between sample e v e n t s might be d e c r e a s e d , or t h e number of s i t e s s t u d i e d c o u l d be i n c r e a s e d . 2. D i r e c t e s t i m a t e s of f u n g a l hyphae i n t h e s o i l a r e p o s s i b l e w i t h the i n - g r o w t h bags, something which i s a l l 1 72 but i m p o s s i b l e t o do w i t h s e q u e n t i a l s o i l c o r e s . The l a c k of f u n g a l biomass e s t i m a t e s i n most o t h e r r o o t s t u d i e s of f o r e s t t r e e s p e c i e s r e p r e s e n t s a s e r i o u s u n d e r e s t i m a t i o n of the importance of the belowground ecosystem t o the t o t a l a n n u a l p r o d u c t i o n budgets of such systems, e s p e c i a l l y i f e s t i m a t e s of the r e s p i r a t i o n c o s t s of t h i s f u n g a l biomass a r e a l s o i g n o r e d . The p r i n c i p l e s h o r t c o m i n g s of t h e i n - g r o w t h bag t e c h n i q u e a r e as f o l l o w s ; 1. M o n thly s t a n d i n g biomass e s t i m a t e s from i n - g r o w t h bags were much s m a l l e r than comparable e s t i m a t e s made from s e q u e n t i a l s o i l c o r e s . 2. There i s a demonstrated a r t i f a c t e f f e c t a s s o c i a t e d w i t h the p r e p a r a t i o n of the growth medium t o be used i n the i n - g r o w t h bags. P r e p a r a t i o n s such as s i e v i n g or f e r t i l i z a t i o n , which i n c r e a s e or c o n c e n t r a t e the n u t r i e n t - r i c h component of the growth medium, s t i m u l a t e d the p r o d u c t i o n and l o n g e v i t y of c o n i f e r o u s and n o n - c o n i f e r o u s r o o t s w i t h i n the i n - g r o w t h bags. I t may be p o s s i b l e t o a v o i d , or a t l e a s t d e c r e a s e the impact of t h e s e two s h o r t c o m i n g s of t h e i n - g r o w t h bag t e c h n i q u e by a l t e r i n g the method s l i g h t l y . 1. I n c r e a s i n g the l e n g t h of time t h a t t h e i n - g r o w t h bags a r e l e f t on s i t e b e f o r e they a r e r e - c o l l e c t e d would g i v e the r o o t s i n the s u r r o u n d i n g s o i l a l o n g e r p e r i o d i n w hich they c o u l d grow i n t o the bags. S e v e r a l y e a r s worth of r o o t and f u n g a l p r o d u c t i o n w i t h i n the bags would more 1 7 3 c l o s e l y r e p r e s e n t the n a t u r a l belowground " p o p u l a t i o n s " i n t he s u r r o u n d i n g s o i l s . The i n c r e a s e d r e s i d e n c e t i m e s would a l s o a l l o w the st u d y s i t e s a chance t o r e c o v e r from any d i s t u r b a n c e - r e l a t e d impact from the i n s t a l l a t i o n of the bags. A l t h o u g h a more d u r a b l e n e t t i n g m a t e r i a l would have t o be u t i l i z e d , and the st u d y d e s i g n would have t o i n c o r p o r a t e the p r o b a b i l i t y of l o s i n g p o s s i b l y l a r g e numbers of bags, e s t i m a t e s of the s t a n d i n g c r o p of c o n i f e r o u s r o o t s would p r o b a b l y be c l o s e r t o tho s e produced w i t h s e q u e n t i a l s o i l c o r i n g . I m p l a n t a t i o n t i m e s of between t h r e e and f i v e y e a r s a r e p r o b a b l y not i m p r a c t i c a l f o r l o n g e r - t e r m e c o l o g i c a l s t u d i e s . However, i n c r e a s i n g the l e n g t h of time t h a t the i n - g r o w t h bags remained on the s i t e s would make the r o o t m a t e r i a l w i t h i n t h e s e i n - g r o w t h bags more het e r o g e n e o u s , and would c e r t a i n l y slow t h e i r p r o c e s s i n g time c o n s i d e r a b l y , t h e r e b y r e d u c i n g the advantage of the i n - g r o w t h bag t e c h n i q u e over more t r a d i t i o n a l s e q u e n t i a l c o r e s a m p l i n g . 2 . The problem of the s t i m u l a t i o n of r o o t p r o d u c t i o n w i t h c o n c e n t r a t i o n of the n u t r i e n t - r i c h p o r t i o n s of the growth medium w i t h i n the i n - g r o w t h bags i s a b i t more d i f f i c u l t t o r e s o l v e . However, i t might be p o s s i b l e t o add an amount of i n e r t m a t e r i a l (such as the c o a r s e s i l i c a sand used i n one p a r t of t h i s s t u d y ) i n p r o p o r t i o n t o the amount of l a r g e r m a t e r i a l s i e v e d and d i s c a r d e d from the n a t i v e s o i l . A l t h o u g h the s t r u c t u r e 1 7 4 of t he m a t e r i a l w i t h i n the i n - g r o w t h bags wou ld not be the same as t h a t i n the s u r r o u n d i n g s o i l vo lume , the s t i m u l a t o r y e f f e c t o f c o n c e n t r a t i n g the n u t r i e n t - r i c h p o r t o n s o f o f t h e s o i l on c o n i f e r o u s and n o n - c o n i f e r o u s r o o t b iomass wou ld be a v o i d e d . L a s t l y , t h e r e appear t o be good r e a s o n s f o r a v o i d i n g the use o f n u t r i e n t - p o o r g r o w t h media ( such as sand) i n the i n - g r o w t h b a g s . The beach sand g r o w t h medium p r o d u c e d e x t r e m e l y poor r o o t s t a n d i n g c r o p and p r o d u c t i o n e s t i m a t e s as compared t o t h o s e p r o d u c e d w i t h s e q u e n t i a l s o i l c o r e s or n a t i v e - s o i l - f i l l e d i n - g r o w t h b a g s . The re was a l s o l i t t l e d i f f e r e n c e between the p r o c e s s i n g t i m e s o f , o r the f u n g a l b iomass e s t i m a t e s f r o m , i n - g r o w t h bags f i l l e d w i t h e i t h e r m a t e r i a l ; two f a c t o r s w h i c h c o u l d have i n f l u e n c e d our c h o i c e o f medium. REFERENCES A b b o t t , L.K., and A.D. Robson. 1985. F o r m a t i o n of e x t e r n a l hyphae i n s o i l by f o u r s p e c i e s of v e s i c u l a r - a r b u s c u l a r m y c o r r h i z a l f u n g i . New P h y t o l o g i s t 99: 245-255. A b b o t t , L.K., A.D. Robson, and G. de Boer. 1984. 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Temperature c o n t r o l over r o o t growth and r o o t biomass i n t a i g a f o r e s t t r e e s . Can. J . F o r . Res. 13: 827-833. V a r t a n i a n , N. 1981. Some a s p e c t s of s t r u c t u r a l and f u n c t i o n a l m o d i f i c a t i o n s i n d u c e d by drought i n r o o t systems. Pp. 309-318 ^n Brouwer, R., 0. G a s p a r i k o v a , J . K o l e k , and B.C. Loughman ( e d s . ) , S t r u c t u r e and F u n c t i o n of P l a n t R o o t s . P r o c e e d i n g s of the Second I n t e r n a t i o n a l Symposium, B r a t i s l a v , C z e c h o s l o v a k i a , S ept. 1-5, 1980. M a r t i n u s N i j h o f f , Junk P u b l i s h e r s , the Hague. V a v o u l i d o u - T h e o d o r o u , E. 1983. { F i n e - r o o t and humus dynamics i n humus p r o f i l e s from d i s t u r b e d p i n e . } - German. Ph.D. T h e s i s , U n i v e r s i t y of Hohenheim, F e d e r a l R e p u b l i c of Germany. D i s s e r t a t i o n . 167 p. Vogt, K.A., R.L. Edmonds, C. C. G r i e r , and S. R. P i p e r . 1980. S e a s o n a l changes i n m y c o r r h i z a l and f i b e r o u s - t e x t u r e d r o o t biomass i n 23- and 1 8 0 - y e a r - o l d P a c i f i c s i l v e r f i r s t a n d s i n w e s t e r n Washington. Can. J . F o r . Res. 11:223-229. Vogt, K.A., R.L. Edmonds, and C. C. G r i e r . 1981. S e a s o n a l changes i n biomass and v e r t i c a l d i s t r i b u t i o n of m y c o r r h i z a l and f i b r o u s - t e x t u r e d c o n i f e r f i n e r o o t i n 23- and 1 8 0 - y e a r - o l d s u b a l p i n e Abies amabilis s t a n d s . Can. J . F o r . Res. 11: 223-229. Vogt, K.A., C.C. G r i e r , and C E . M e i e r . 1982. M y c o r r h i z a l r o l e i n net p r i m a r y p r o d u c t i o n and n u t r i e n t c y c l i n g i n Abies amabilis ecosystems i n w e s t e r n Washington. E c o l o g y 6 3 ( 2 ) : 370-380. Vogt, K.A., C.C. G r i e r , C E . M e i e r , and M.R. Keyes. 1983. O r g a n i c m a t t e r and n u t r i e n t dynamics i n f o r e s t f l o o r s of young and mature Abies amabilis s t a n d s i n w e s t e r n Washington, as a f f e c t e d by f i n e - r o o t i n p u t . E c o l . Monogr. 5 3 ( 2 ) : 139-157. Vogt, K.A., E.A. Moore, D.J. Vogt, M.M. R e d l i n , and R.L. Edmonds. 1983. C o n i f e r f i n e r o o t and m y c o r r h i z a l r o o t biomass w i t h i n the f o r e s t f l o o r s of D o u g l a s - f i r s t a n d s of d i f f e r e n t ages and s i t e p r o d u c t i v i t i e s . Can. J . F o r . Res. 13: 429-437. Vogt, K.A., D.J. V ogt, E.E. Moore, W. L i t t k e , C.C. G r i e r , and L. Leney. 1985. E s t i m a t i n g D o u g l a s - f i r f i n e r o o t biomass and p r o d u c t i o n from l i v i n g bark and s t a r c h . Can. J . F o r . Res. 15: 177-179. 189 Walmsley, M., G. U t z i g , T. V o i d , D. Moon, and J . van B a r n v e l d ( e d s . ) . 1980. D e s c r i b i n g Ecosystems i n the F i e l d . RAB T e c h n i c a l Paper 2, Land Management Report No. 7. P r o v i n c e of B r i t i s h Columbia, M i n i s t r y of Environment, Resource A n a l y s i s Branch; M i n i s t r y of F o r e s t s , R e s e a r c h B r a n c h , V i c t o r i a . 224 p. Warcup, J.H. 1967. F u n g i i n s o i l . Pp. 51-110 in Burges, A., and F. Raw ( e d s . ) , S o i l B i o l o g y . Academic P r e s s , London. Weaver, T. 1977. Root d i s t r i b u t i o n and s o i l water regimes i n n i n e h a b i t a t t y p e s of the n o r t h e r n Rocky M o u n t a i n s . Pp. 239-244 in M a r s h a l l , J.K. ( e d . ) , The Belowground Ecosystem: A S y n t h e s i s of P l a n t - A s s o c i a t e d P r o c e s s e s . Range S c i e n c e Dept. S e r i e s No. 26, C o l o r a d o S t a t e U n i v e r s i t y , F o r t C o l l i n s , C o l o r a d o . 7. APPENDICES 7.1 APPENDIX 1 Ta b l e XV p. i i Summary of the methods used i n f i n e r o o t s t u d i e s . T a b l e XVI p. x i i i Summary of biomass and p r o d u c t i o n e s t i m a t e s i n f i n e r o o t s t u d i e s . 190 Table XV Summary of the methods used In fine root studies. Species (age 1n years), site and/or soil sample core sample # of 11 me H of description. location, source method1 di am. depth samples between sample (cm) (cm) per events events event (months) Temperate Forests Conlferous Abies amabi Iis (23 8> 180) on volcanic ash a 3.6 24 6 2-4 10 soils over glacial t i l l . Cedar River Watershed, 80 km south of Seatle, Wash., U.S.A. 1150 m elevation. Vogt et al . 1980. Abies amabiI is (23 & 180) on volcanic ash a 3.8 40 9 .75-2 30 soils over glacial t i l l . Cedar River Watershed, 80 km south of Seattle, Wash., U.S.A. 1150 m elevation. Grier et al. 1981, Meier et a! . 1985. 4b)es 1 asiocarpa (mature) on coarse soils, a 2.0 70 4 1 1810 m & 2360 m elevation, Bozeman. Montana. Weaver 1977. Picea QIauca sandy 1nfer111e podzols, Prince Hawkes 1978. Abies Iasiocarpa stands on gl ac1o-f1uv1 a 1 humo-ferr 1 c George, B.C. Kimmins and 1 1 Table XV cont'd. Species (age m years), site and/or soil description, location, source sampl1ng method1 core di am. (cm) sample depth (cm) # of samples per event t ime between events (months) # of sample events Picea sftchensis (14 & 16) plantation on peaty gleyed soil, Greskine Forest, Scotland. 355 m elevation. Ford and Deans 1977, Deans 1979, 1981. a 8> e -- 50 20 . 2 5 Picea si tchensi s (35) plantation, Scotland. Alexander and Falrley 1983. a 4.0 10 15 1 24 Pinus radiata (8) plantation, fertilized and unfertilized sites on sandy loam soil near Koetong, Victoria, Australia. Squire et a]. 1978 . a 5 . 7 22.8 1 18 Pinus r a d i a t a (10, 20, 35) plantations on fine-textured podzolic soils, Canberra, Australia. Moir and Bachelard 1969. a d 4.5 25x25 30 15 1 1 --32 5 Pinus resinonsa (125) on alfisols derived from glacial t i l l . Wisconsin. Aber et at. 1985. a 6. 1 20 7 3 5 Pinus restnosa (53) plantation, stonev glacial spodosols, Harvard Research Forest, a a 1 .9 5.0 15 15-120 9 9 1 1 10 10 Massachusetts. McClaugerty et al. 1982, Aber et al. 1985. Table XV cont'd. Species (age in years), site and/or soil description, location, source sampling method1 core di am. (cm) sample depth (cm) # of samples per event time between events (months) # of sample events Pinus strobus (125) on alfisols derived from glacial t i l l , Wisconsin. Aber et a/. 1985. a G . 1 20 7 3 5 Pfnus strobus (35) on sandy qlacial kames, Michigan. Fogel 1983. a -- 30 1 -- --Pinus sylvestris (20) plantation on sandv podzols of glacio-fluvial origin, Jadraas, Sweden. 185 m elevation. Ericsson and Persson 1980. b 6.7 30 22 1 9 Pinus sylvestrfs (20) plantation on sandv sediments of glacial origin, central Sweden. Persson 1978. a 6.7 30 13 .5-.75 16 Pfnus sylvestrfs (18 & 120) plantation on sandy sediments of glacial origin, central Sweden. Persson 1980. a a 6.7 6.7 30 30 13 17 .5-.75 .5-2 16 9 Pinus taeda (15) plantations on tvclc a 10 60 7 .5-1.5 15 paleudults and hapludults near Oak Ridge, Tennessee. Harris et al. 1977. vo 1 i 1 Table XV cont'd. Species (age In years), site and/or soil sampli ng core sample ft of t ime # of descrIpt ion. location, source method1 di am. depth samples between sample (cm) (cm) per events events event (months) Pseudotsupa menziesii (50) plantation on sandy soils in central Oregon. Fogel and 1979. 30 Hunt Pseudotsuga menziesii (30) on sandy glacial kames, Michigan. Fogel 1983. 30 Pseudot supa menziesii (40) on gravelly loamy sand (low productivity) and silt loam (high productlvty) soils of glacil origin near Seattle, Washington. 320 m elevation. Keyes and Gr1er 1981 . 10. 2 100 45 23 4 23 20 4 Pseudotsuga menziesii (45) plantation on a sandy podzols near Oxford, England. Reynolds c 1974. 130 210 Pseudotsuga menziesii (mature) on sandy to clayey loam soils in the western Cascade Mtns. near Eugene, Oregon. 460 m elevation. Santantonio et al. 1977. 5.0 100 243 V£> 4 * Table XV cont'd. Species (age in years), site and/or soil sampling core sample # of t ime H Of descript ion, location, source method1 di am. depth samples between sample (cm) (cm) per events events event (months) Psei/dotsi/ga menz iesi i (70, 120, 170) on a 5.0 75 G 1 9 volcanic soils of the western Cascade Mtns. near Eugene, Oregon. Santantonio 1978, Santantonio and Hermann 1985. Pseudotsuga menziesii (mature) on sandy soils a 2.0 70 4 1 near Bozeman, Montana. Weaver 1977. Tsuga heterophil la (23 & 47), fertilized and unfertilized stands on loamy soils in the Coast and central Cascade Mtn. ranges, between 76 m and 701 m elevation. Gill and Lavender 1983 Mixed coniferous forest ecosystem, Little a -- 15 -- 2 River Watershed, Tifton, Georgia, U.S.A. b 5x20 10 4 3 3 Hamzah et al. 1983. a 4 20 5 1.5-2 2 Broadleaved Evergreen EucIyptus globulus (11 and 16) plantations on b 7.0 40 4-6 2-6 10-15 sandy and clayey soils, Portugal. Fabiao et al. 1984. VO v Table XV cont'd. Species (age in years), site and/or soil sampling core sample # of t ime n of descr i pt1 on, location, source method1 diam. depth samples between sample (cm) (cm) per events events event (months) •Deciduous-deer rubrum (90) on coarse loamy soils of d 10x10 60-110 1 -- 10 the White Mountains, New Hampshire. 300 m elevation. Safford 1974. Acer saccharum (90) on coarse loamy soils of d 10x10 60-110 1 -- 10 the White Mountains, New Hampshire. 300 m elevation. Safford 1974. Acer saccharum (125) on alfisols derived from a 6.1 20 7 3 5 glacial t i l l , Wisconsin. Aber et al. 1985. Fagus prandifolia (90) on coarse loamy soils, d 10x10 60-110 1 -- 10 White Mountains, New Hampshire. 300 m elevation. Safford (1974). Liriodendron mixed forest on typic paleudults a 10 60 7 .5-1.5 15 and hapludults near Oak Ridge, Tennessee. Harris et al. 1977. PopuI us tremuIoides on sandy soils between a 2.0 70 4 1 1450 m and 2330 m elevation near Bozeman. Montana. Weaver 1977. ^ cn v i Table XV cont'd. Species (age in years), site and/or soil description, location, source sampling method1 core d i am. (cm) sample depth (cm) H Of samples per event 11me between events (months) It of sample events Quercus alba (125) on alfisols derived from glacial t i l l , Wisconsin. Aber et a/. 1985. a 6 . 1 20 7 3 5 Quercus boreal is (125) on alfisols derived from glacial t i l l , Wisconsin. Aber et a/. 1985. a 6. 1 20 7 3 5 Quercus velutina (125) on alfisols derived a 6. 1 20 7 3 5 from glacial t i l l , Wisconsin. Aber et al. 1985 . Qi/ercifs/Carya (60) mixed stands on sandy a 30 1 glacial kames, Michigan, U.S.A. Fogel 1983. Tropical Rain Forests Mixed deciduous rain forest (1, 8, 70) on typlc dystrandepts devolped from aged pyroclastlc material, Turrialba, Costa Rica 650 m elevation. Berish 1982. Mixed Tierra Firme rain forest on clay kaollnlte soils, San Carlos de Rio Negro, Venezuela. Cuevas and Medina 1983. a 4.2 85 1 -- 33 d 25x25 45 1 7 . 5 10 18 v i i Table XV cont'd. Species (age in years), site and/or soil description, location, source sampli ng method1 core diam. (cm) sample depth (cm) « of samples per event t ime between events (months) H Of sample events Mixed Tferra Firme rain forest on clay kaolinite soils, San Carlos de Rio Negro, Venezuela. Jordan and Escalante 1980. e 40x40 40 1 30 17 Dry deciduous forest on shallow red-brown sandy soils near Varanasi, India. Singh and Singh 1981. d 25x25 50 3 4 6 Broadleaf evergreen rain forest on sandy oxisols over laterite and heavy clay near San Carlos, Venezuela. Stark and Spratt 1977. d 50x50 50 1 18 Teirra firme and Campina (heath) rain forest on latosols and giant humus podzols, Amazonas, Brazil. K1inge 1973. d 50x50 100 1 Tall Amazon Catinga on spodosols, San Carlos de Rio Negro, Venezuela. Klinge and Herrera 1978. d 50x50 100 1 13 Old-growth lowland evergreen Tierr a firme b 10 20 1 1 15 rain forest on sandy oxisols near Manaus, Brazil. St. John 1983, St. John et al. 1983. KO Grassland and Agricultural Crops 0 0 viii Tabls XV cont'd. Spscies (age in years), site and/or soil description, location, source sampl1ng method 1 core di am. (cm) sample depth (cm) u of samples per event t ime between events (months) # of sample events Adenostoma sparsi foliurn (54) (red shank chaparral), burnt and unburnt, loamy sand above a mica-schist bedrock, Warner Spring, California, U.S.A. Kummerow and Lantz 1983. a b 4 4 40 40 2 2 .5 1 9 12 Aristida stricata (perennial wire grass) savanahs on fine sandy soils in the Bladen Lakes State Forest, North Carolina. U.S.A. Saterson and Vitousek 1984. a 6.2 10 6 2 15 Beta vulgaris (suqar beets) In a clay soil near Vipangen, Sweden. Steen and Al-Windi 1984. b 7.0 30 3 1 9 Coffee arabica (25) plantation on arid mica-schist soils, Miranda, Venezuela. 1400 ro elevation. Cuenca et a/. 1983. a b 7.6 50 10 12 25 1 1 13 4 Gossypium hi rsutum (cotton) on loamy soils near Auburn, Alabama, U.S.A. Lund et a/. 1970. b 10.8 20 2 1-2 4 Glycine max (soybeans) on loamy soils near b 10.8 20 2 1-2 4 Auburn, Alabama, U.S.A. Lund et a/. 1970. ~1 Table XV cont'd. Species (age 1n years), site and/or soil sampli ng core sample H of 11 me H of description. location, source method1 diam. depth samples between sample (cm) (cm) per events events event (months) Mai us pumi1 a (apple) on fertilized and c 75 .25 24 Irrigated plots, Kent. England. Atkinson 1985. Pseudotsuga menziesii seedlings grown 1n pot e ' -- -- 6 .25-2 5 culture with washed river sand, 3 temperature regimes. Marshall and Waring 1985. Mixed grassland prairie on poorly drained a 4.2 91 4 3 60 loess soils with claypan subsoils, Missouri. Dahlman and Kucera 1965. Fertilized and unfertilized barley crop a 7 50 6 .5-2 20 systems on clayey loam soils of glacial origin, central Sweden. Hansson 1983, Hansson and Steen 1984. Fertilized third year perennial grassland on b 7.0 30 3 2 16 loamy, fine-sand soils, central Sweden. Steen 1984 . Third year perennial grassland on loamy, a 7.0 30 8 1-1.5 3 fine-sand soils, central Sweden. Steen 1984. b 7.0 30 8 1-1.5 3 to o o x Table XV cont'd. Species (age in years), site and/or soil sampl1ng core sample # of t Ime H Of description, location, source method1 d i am. depth samples between sample (cm) (cm) per events events event (months) Second year fallow fields sown with grass b 7 30 e 1 4 species on loamy, fine-sand soils, central b 7 30 3 2 4 Sweden. Steen 1983, 1985, Larsson and Steen b 7 30 1 6 4 1984 . Mixed shrub chaparell on decomposing granitic a 4 20 10 1 12 soils, Echo Valley, California, U.S.A. Kummerow et a\. 1978. Wheat grown in fine textured clay loamy c 75 140 26 . 2 1 soils, southeastern Australia. Meyer and Barrs 1985. 'Sample methods; a. sequential soil cores b. root in-growth bags c. root observation windows d. soil block excavations e. other Table XVI. Summary of biomass and production estimates in fine root studies. Species (age 1n years), site and/or soil estimation root mean root roots as turnover descr1pt ion, location, source method1 s i ze stand i ng prodct ion percentage t ime limit b1omass (kg ha-1 of NPP (yrs) (mm) (kg ha-1) yr- ' ) (%) -Temperate Forests-Con 1ferous Abies amabi Iis (23 & 180) growing on volcanic ash soils over glacial t i l l . Cedar River Watershead, 80 km south of Seattle, Wash. 1150 m elevation. Vogt et a!. 1980. a. 23-yr-old stand b. 180-yr-old stand <2 <2 2890 7390 1310 5350 2.21 1 . 38 Abies amabiIi s (23 & 180) growing on volcanic ash soils over glacial t i l l , Cedar River Watershead, 80 km south of Seattle, Wash. 1150 m elevation. Grier et al. 1981, Meier et a/. 1985. a. 23-yr-old stand b. 180-yr-old stand <5 <5 9240 12790 G560 1 1 140 55 .0 68.7 1.41 1.15 Abies baIsamea (mature) on sandy soils, Newfoundland. Damman 1971. <10 1 1200 Abies firma (20) on moderately moist soil Japan. Karizumi 1976. <2 2-5 >5 1 100 3500 4600 to o to xi i Table XVI cont'd. Species (age 1n years), site and/or soil est imat1on root mean root roots as turnover descr1pt1 on, location, source method1 s i ze stand 1ng product Ion percentage 11 me 1 1m11 b1omass (kg ha-1 of NPP (yrs) (mm) (kg ha-1) yr- 1 (%) Abies I asiocarpa (mature) on coarse soils, 1810 m and 2360 m elevation, Bozeman, Montana. Weaver 1977. a. 1810 m, forested <5 7140 -- -- --b. 1810 m, logged <5 7540 -- -- --c. 2360 m, forested <5 141 10 -- -- --d. 2360 m, logged <5 8470 -- -- --Picea excelsa (25 and 50). Orlov 1955 (in Head 1973). a. 25-yr-old <3 4000 2000 -- 2 . 00 b. 50-yr-old <3 1200 240 -- 5. 00 Picea cjl auca - Abies 1 asiocarpa stands on e <6.4 1870 --sandy infertile glac1o-f1uv1al humo-ferrlc podzols. Prince George, B.C. Kimmlns and Hawkes 1978. Picea si tchensi s (16) plantation on oeatv <2 3534 5244 15 . 4 0. 67 gleyed soil, Greskine Forest, Scotland. 355 m 2-5 1368 38 0. . 1 36 i.O elevation. Ford and Deans 1977, >5 20102 3154 9 . 3 6. 37 Deans 1979, 1981, total 25004 8436 24 . 8 2 . 96 Picea sitchensis (35) plantation. Scotland. Alexander and Falrley 1983. a. fertilized (300 kg/ha N) d <5 901 365 2. 47 Table XVI cont'd. Species (age in years), site and/or soil est 1 mat 1 on root mean root roots as turnover description, location, source method' s 1 ze standing product 1 on percentage t Ime limit b1omass (kg ha-' of NPP (yrs) (mm) (kg ha-') yr - 1 (%) b. unferti1i zed d <5 887 502 1 .77 Pinus radiata (iO, 20, 35) plantations on fine-textured podzolic soils, Canberra, Australia. Moir and Bachelard 1969. a. 10-yr-old -- <3 213 -- -- --b. 20-yr-old -- <3 189 -- -- --c. 35-yr-old <3 14 1 — — — Pinus resinonsa (125) on alfisols derived f <3 4410 2000 22 .0 2 .21 from glacial t i l l , Wisconsin. Aber et al . a <3 4410 690 8.9 6 .39 1985 . Pinus resinosa (53) plantation, stonev f <3 5100 4100 1 . 24 glacial spodosols, Harvard Research Forest. a <3 5100 10900 -- 0 .47 Massachusetts. Aber et al. 1985, McClaugerty et al. 1982. Pinus resinosa (53), on spodosols derived f <3 5100 4200 30.0 1 . 21 from stoney glacial material, mor forest floor, Massachusetts. Aber et al. 1985. Pinus strobus (125) on alfisols derived from f <3 2890 1400 17.9 2. 06 glacial t i l l , Wisconsin. Aber et al. 1985. a <3 2890 1620 35.9 1 . 78 Table XVI cont'd. Species (age 1n years), site and/or soil est i mat 1 on root mean root roots as turnover description, location, source method1 s 1 ze standing product ion percentage t Ime limit biomass (kg ha-1 of NPP (yrs) (mm) (kg ha-1) yr - 1 (%) Pinus strobus (53) plantation, stoney glacial f <3 3720 2500 22.3 2 .49 spodosols. Harvard Research Forest, a <3 3720 970 10.0 3 .84 Massachusetts. Aber et al. 1985, McClaugerty et al. 1982. Pinus strobus (35) on sandy glacial kames. d <2 1 1750 -- -- --Michigan. Fogel 1983. d <2+mycor. 12486 --Pinus strobus (35) on sandy glacial kames, d <2 15815 — -- — Michigan. Fogel and Hunt 1979. d <2+mycor. 16715 -- -- --Pinus sylvestrfs (20) plantation on sandy podzols of glac1al-f1uvial origin, Jadraas, Sweden. 185 m elevation. Linder and Axelsson 1982 . a. control -- <2 -- 2360 37 .6 --b. fertilized, irrigated -- <2 -- 2520 19.6 Pinus sylvestris (20 and 180) plantation on sandy sediments of glacial origin, central Sweden. Persson 1978, 1979, 1980, 1985. a. 20-yr-old, sequential soil cores d <2 940 1830 60.0 O. 5 1 b. 20-yr-old, in-growth bags a <2 940 1390 60.0 0. 67 c. 180-yr-old, sequential soil cores d <2 1230 1880 -- 0. 65 d. 180-yr-old, in-growth bags a <2 1960 2020 -- 0. 97 Table XVI cont'd. Species (age 1n years), site and/or soil estimation root mean root roots as turnover description, location, source method1 s 1 ze standing product i on percentage t ime limit biomass (kg ha-1 of NPP (yrs) (mm) (kg ha->) yr" 1 (%) Pinus taeda (15) plantations on typlc b <10 6500 8600 0 . 76 paleudults and hapludults near Oak Ridge, Tennessee. Harris et a/. 1977. Pseudotsupa menziesii (50) plantation on d <2 24115 15300 -- 1 .58 sandy soils in central Oregon. Fogel and Hunt 1979. Pseudotsuqa menziesii (30) on sandy glacial d <2 2760 — --kames, Michigan. Fogel 1983. d <2+mycorr. 8251 73.0 Pseudotsupa menziesii (40) on qravellv loamy sand (low productivity) and silt loam (high productlvty) soils of glacial origin near Seattle, Washington. 320 m elevation. Keyes and Grier 1981 . a. low productivity stand a+c <2 8300 5600 3G. 4 1. 48 a 2-5 2200 1400 9. 1 1 . .57 b. high productivity stand a+c <2 2700 1400 7.9 1 . .93 a 2-5 1800 1 100 6.2 1 . .64 Pseudotsupa menziesii (mature) on sandy to -- <5 20730 -- --clayey loam soils in the western Cascade Mtns. near Eugene, Oregon. 460 m elevation. Santantonio et al. 1977. xv 1 Table XVI cont'd. Species (age in years), site and/or soil est i mat 1 on root mean root roots as turnover descr1pt1 on, location, source method1 s 1 ze stand 1ng product 1 on percentage t ime limit b1omass (kg ha-1 of NPP (yrs) (mm) (kg ha-') yr - 1 (%) Pseudotsuga menziesi i (70, 120, 170) on volcanic soils of the western Cascade Mtns. near Eugene, Oregon. Santantonio 1978, Santantonio and Hermann 1985. a. dry 70-yr-old stand b. moderate 170-yr-old c. wet 120-yr-old <5 <5 <5 2570 3600 3235 6500 6300 4800 0.39 0. 57 0.67 Pseudotsuga menziesii (mature) on sandy soils near Bozeman, Montana. Weaver 1977. a. 1650m, forested b. 1830m, forested c. 1830m, logged <5 55 <5 5960 18420 12250 Mixed coniferous forest ecosystem. Little River Watershed, Tifton, Georgia. U.S.A. Hamzah et al. 1983. a. 1n-growth blocks b. sequential coring 1550 5470 3920 2540 0.40 1.15 -Broadleaved Evergreen-EucIyptus globulus (11 and 16) plantations on sandy and clayey soils, Portugal. Fabiao et al. 1984. a. sandy so i1s <2 2370 6000 0.40 M O xv 1 i Table XVI cont'd. Species (age in years), site and/or soil estimation root mean root roots as turnover description, location, source method1 size standing product i on percentage t Ime limit b i omass (kg ha-1 of NPP (yrs) (mm) (kg ha-1) yr- 1 (%) b. c1ayey so i1s c <2 3900 6000 0 .65 Dec i duous Acer rubrum, i Faqus qrndifolia, Acer Saccharum (90) on coarse loamy soils, White Mountains, New Hampshire. 300m elevation. Safford 1974. a. control -- <3 12460 -- -- --b. fert. 1120 kg/ha 1ime -- <3 12290 -- -- --c. fert. 6720 kg/ha NPK+1ime -- <3 271 10 -- -- --Acer saccharum (125) on alfisols derived from a <3 4280 1 100 11.3 3 .89 glacial t i l l . Wisconsin. Aber et al. 1985. f <3 4280 5500 39.0 0. 78 Acer saccharum (125) on alfisols on abandoned a <3 3230 6500 40. 1 0. .50 farmland derived from sandy glacial soil, f <3 3230 1060 10.0 3 . ,05 Wisconsin. Aber et al. 1985. Liriodendron mixed forest on typic paleudults b <5 9000 9000 73 . 7 1 . ,00 and hapludults near Oak Ridge, Tennessee. Harr is et al. 1977. PopuI us tremuIoides on sandy soils between 1560 m and 1830 m elevation near Bozeman, Montana. Weaver 1977. a. 1560 m -- <5 4130 'i i i Table XVI cont'd. Species (age in years), site and/or soil est 1 mat 1 on root mean root roots as turnover description, location, source method1 s 1 ze standing product 1 on percentage 11me limit biomass (kg ha-1 of NPP (yrs) (mm) (kg ha-1) yr - 1 (%) b. 1830 m, forested <5 5550 c. 1830 m, logged -- <5 1990 -- --Quercus alba (125) on alfisols derived from f <3 3410 4 100 27 .2 0 .83 glacial t i l l , Wisconsin. Aber et al. 1985. a <3 3410 1 150 9 . 5 2 .97 Quercus alba (125) on alfisols on abandoned f <3 5150 3400 28.8 1 .51 farmland derived from sandy glacial soils. a <3 5150 3050 26 .6 1 .69 Wisconsin. Aber et al. 1985. Quercus boreal is (125) on alfisols derived f <3 2700 5500 28.8 0. .49 from glacial t i l l , Wisconsin. Aber ef al . a S3 2700 520 3.7 5. . 19 1985 . Quercus boreal is (125) on alfisols on f <3 3890 2500 23.6 1 . ,56 abandoned farmland derived from glacial t i l l . a <3 3890 2350 22 . 5 1 . 66 Wisconsin. Aber et al. 1985. Quercus rubra - Acer rubrum (80) mixed a <3 6100 5400 -- 1 . 13 hardwood stands on stoney entic spodosols of d <3 6100 1 1400 -- 0. 54 glacial origin. Petersham, Massachusetts. McClaugerty et al. 1982. to o <x> x i x Table XVI cont'd. Species (age In years), site and/or soil est i mat 1 on root mean root roots as turnover descr1pt i on, location, source method 1 s 1 ze standing product 1 on percentage t ime limit b i omass (kg ha-1 of NPP (yrs) (mm) (kg ha-1) yr - 1 (%) Quercus rubra 2. Acer rubrum (80), spodosols on stoney glacial material, Massachusetts. Mor forest floors. Aber et at. 1985. <3 6100 4000 30.0 1 .53 Quercus veIut i na (125) on alfisols derived from glacial t i l l , Wisconsin. Aber et a/. 1985. <3 <3 2700 2700 6100 1740 35.3 13.4 0.44 1 . 55 -Tropical Rain Forests-Mixed deciduous rain forest (1, 8, 70) on typlc dystrandepts devolped from aged pyroclastic material, Turrialba, Costa Rica. 650 m elevation. Berlsh 1982. a. 1-yr-old b. 8-yr-old c. 70-yr-old <2 0-5 <2 0-5 <2 0-5 104 1 1287 3074 5868 3417 6445 Mixed Tierra FIrme rain forest on clay kaolinlte soils, San Carlos de Rio Negro, Venezuela. Cuevas and Medina 1983. a. control bags <1 O 1590 xx Table XVI cont'd. Species (age In years), site and/or soil est imat1on root mean root roots as turnover description, location, source method' s ize stand i ng product i on percentage 11 me limit b i omass (kg ha-1 of NPP (yrs) (mm) (kg ha-1) yr - 1 (%) b. fert. 0.1 M NHaC1 e <1 2580 c. fert . 0. 1 M KHJPO. e <1 -- 4000 -- --d. fert. 0.1 M CaCl, e < 1 -- 367 -- --Mixed Tierra Firme rain forest on clay -- <6 56000 2100 25. 1 27.86 kaolinite soils, San Carlos de Rio Negro, Venezuela. Jordan and Escalante 1980. Dry deciduous forest on shallow red-brown sandy soils near Varanasi, India. Singh and Singh 1981 . a. fenced a <6 7627 2785 -- 2.70 b. unfenced a <6 6467 2412 -- 2.70 Broadleaf evergreen rain forest on sandy -- <6 31932 -- -- --oxisols over laterite and heavy clay near San Carlos, Venezuela. Stark and Spratt 1977. Teirra firme and Campina (heath) forest on latosols and giant humus podzols, Amazonas, Brazi1. Klinge 1973. a. 'Tierra firme' rain forest e <2 8400 -- -- --b. 'Campina' rain forest e <2 5600 -- --xx i Table XVI cont'd. Species (age in years), site and/or soil est i mat i on root mean root roots as turnover description, location, source method1 s i ze standi ng product i on percentage 11 me limit b i omass (kg ha-1 of NPP (yrs) (mm) (kg ha-') yr - 1 (%) Tall Amazon Catinqa on spodosols, San Carlos de Rio Negro, Venezuela. Klinge and Herrera 1978. <6 92400 Moist, semi-deciduous Ghana. Lawson et a\ . a. upper slope b. middle slope c. lower slope rain forest near Kade, 1970 (in K1inge 1973) . <2 <2 <2 40000 103000 40300 Tropical rain forest near Banco, Ivory Coast. Huttel 1969 (in Klinge 1973). a. plateau b. va11ey <2 <2 6800 5400 -Grassland and Agricultural Crops-Adenostoma sparsifoIium (54), (red shank chaparral), burnt and unburnt on loamy sand above mica-schist bedrock, Warner Springs, California, U.S.A. Kummerow and Lantz 1983. a. sequential coring, burnt b. sequential coring, unburnt c. in-growth bags, burnt d. in-growth bags, unburnt al 1 al 1 al 1 al 1 3310 1300 3310 1300 2010 330 2860 280 1 .65 3.94 1 . 16 4.64 xx 1 1 Table XVI cont'd. Species (age in years), site and/or soil est imat ion root mean root roots as turnover description, location, source method' s i ze stand 1ng product 1 on percentage t ime limit biomass (kg ha-1 of NPP (yrs) (mm) (kg ha-1) yr - 1 (%) Aristida stricata (perennial wire grass) a <2 1 1340 4440 2.56 savanahs on fine-sandy soils in the Bladen Lakes State Forest, North Carolina, U.S.A. Saterson and Vitousek 1983. Beta v.u I par i s (sugar beets) in a clay soil near Vipangen, Sweden. Steen and Al-Windi 1984. a. untreated control b all -- 818 b. herbicide b all -- 579 Coffee arabica (25) plantation on arid b <1 -- 6710 mica-schist soils, Miranda, Venezuela. 1400 m elevation. Cuenca et a). 1983. Mai us pumiI a (apple) on fertilized and d <2 -- 1700 irrigated plots, Kent, England. Atkinson 1985 . Mixed grassland prairie on poorly drained e -- 18600 5100 -- 3.65 loess soils with claypan subsoils, Missouri. Dahlman and Kucera 1965. rO CO xx i i i Table XVI cont'd. Species (age in years), site and/or soil est 1 mat i on root mean root roots as turnover descr1pt1 on, location, source method1 size standing product 1 on percentage t ime limit biomass (kg ha-1 of NPP (yrs) (mm) (kg ha-1) yr - 1 (%) Fertilized and unfertilized barley crop systems on clayey loam soils of glacial origin, central Sweden. Hansson 1983, Hansson and Steen 1984. a. unfer111i zed a 4000 460 5 .9 8 .70 b 4000 670 8 .4 5 .97 c 4000 460 5 .9 8 .70 b. fert. 120 kg/ha N a 4000 580 5 .8 6 .90 b 4000 640 6 .4 6 . 25 c 4000 640 6 .4 6 .25 c. unfert., sown wi th grasses a 4000 360 4. . 3 1 1 . 1 1 b 4000 580 6. .8 6, ,90 c 4000 440 5 . 2 9. .09 d. unfert., sown with 1ucerne a 4000 570 7. 8 7. 02 b 4000 930 12. 2 4 . 30 c 4000 860 1 1 . 3 4 . 65 Fertilized third year perennial grassland on loamy, fine-sand soils, central Sweden. Steen 1984 . a. fert. 50 kg/ha CaNOi b. fert. 150 kg/ha CaN03 c. fert. 300 kg/ha CaN05 al 1 al 1 al 1 10280 9000 5890 to xx 1 v Table XVI cont'd. Species (age in years), site and/or soil est imat1 on root mean root roots as turnover description, location, source method1 s 1 ze stand 1ng product i on percentage 11me limit biomass (kg ha-' of NPP (yrs) (mm) (kg ha-1) yr - ' (%) Third year perennial grassland on loamy, fine-sand soils, central Sweden. Steen 1985. a. In-growth bags b. sequential soil cores al 1 al 1 3700 3500 3700 3500 45.0 45 .0 1 .00 1 .00 Second year fallow fields sown with grass species on loamy sand soils, central Sweden. Steen 1983, 1985, Larsson and Steen 1984. a. fert. 50 kg/ha N b. fert. 150 kg/ha N c. fert. 300 kg/ha N al 1 al 1 al 1 5350 4550 3540 2430 1530 2510 2.20 2.97 1.41 Mixed shrub chaparel1 on decomposing granitic soils. Echo Valley, California. U.S.A. Kummerow et al . 1978. <1 15800 13170 1 .20 'estimation methods; a. maximum biomass - minimum biomass b. sum of all differences c. sum of statistically significant differences d. budget method (changes in both live and dead biomass) e. all roots f. other 216 7.2 APPENDIX 2 F i g u r e A2 .1 i i E d a t o p i c g r i d f o r the E a s t Vancouver I s l a n d D r i e r M a r i t i m e subzone (Green et al . 1984). Table XVII i i i C h e m i c a l c h a r a c t e r i s t i c s u s u a l l y a s s o c i a t e d w i t h t h e s o i l s of t h e t h r e e p l a n t a s s o c i a t i o n s (Kojima and K r a j i n a 1975). 217 Grid No. 8 Recommended tree species for the: CWHa2 PACIFIC RANGES DRIER MARITIME CWH VARIANT TROPHOTOPE (soil nutrient regime) CD E CD CD i» CD L. 3 en O I! "° 3 _to < LU Q. O h-o DC d >-X "O o E c CD •+-» O 0_ A very poor B poor C medium D rich E very rich © |PlFd I © 1.1 Lichen spp. 2.1 Arctostaphylos 1.2 Chimaphila umbellata uva-ursi 1.3 Vaccinium parvifo/ium 1  Fd ~\.2 Chimaphila umbellata 1.3 Vaccinium parvifolium 1.4 Gaultheria shallon 2.2 Kindbergia oregana © Fdc (M) w I 1.3 Vaccinium parvifo/ium 1.4 Hylocomium splendens 1.5 Rhytidiadeiphus loreus 3.3 Pteridium aquiiinum © (M) HwCw 1.4 Hylocomium splendens 1.5 Dry op ten's expanse 1.6 Blechnum spicant © PICw - Q 1.6 Spiraea doug/asii i 1.7 Sphagnum spp. | Fd 2.1 Ho/odiscus discolor 2.2 Mahonia nervosa *• 3.3 Rhytidiadeiphus triquetrus ^ 3.4 Polystichum munitum © Fdcw CM) " 2 . 2 Mahonia nervosa 3.3 Rhytidiadeiphus triquetrus 3.4 Polystichum munitum 3.5 Tiarella trifoliata © FdBgCw © _ 3.4 Polystichum munitum . 3.5 Tiarella trifoliata 3.6 Athyrium ft'fix-femina .©JACBgCw © _ (10) CWHw @ 3.6 Athyrium filix-femina 3.7 Lysichitum americanum F i g u r e A2 .1 E d a t o p i c g r i d f o r t he E a s t Vancouve r I s l a n d D r i e r M a r i t i m e subzone of the C o a s t a l Wes te rn Hemlock zone showing the g e n e r a l p o s i t i o n of each of the E c o s y s t e m A s s o c i a t i o n s ( f rom Green et al. 1 9 8 4 ) . 218 T a b l e X V I I . C h e m i c a l c h a r a c t e r i s t i c s u s u a l l y a s s o c i a t e d w i t h the s o i l s of the 3 p l a n t a s s o c i a t i o n s as measured by Kojima and K r a j i n a (1975). The v a l u e s a r e means f o r s e v e r a l s o i l p i t s . P l a n t A s s o c i a t i o n F a c t o r The The Moss The Achiys-Gaul t her i a a s s o c i a t i o n - pol ysti chum shal I on Hyl ocomi um a s s o c i a t i o n -a s s o c i a t i o n s pie nde ns Pol ysti chum v a r i a n t muni t um v a r i a n t pH v a l u e : 1. F o r e s t 4.8 4.6 4.9 F l o o r 2. A h o r i z o n 5.2 5.2 5.4 3. B h o r i z o n 5.5 5.5 5.7 4. C h o r i z o n 5.7 5.7 5.9 CEC: 1. f o r e s t 99.2 1 00.2 94.4 f l o o r (meq/1OOg) 2. m i n e r a l 15.7 17.8 19. 1 s o i l (meq/1OOg) T o t a l amounts o f : 1 . Ca 9.3 13.4 32.9 (eq/m 3) 2. Mg ( " ) 2.0 2.7 6.0 . 3. Na ( " ) 1.21 1 .38 1 .68 4. K ( " ) 0.72 0.80 0.65 5. o r g a n i c 25.3 25.0 30.3 m a t t e r (kg/m 3) 6. N (kg/ha) 4020 461 0 6270 7. a v a i l a b l e 14.9 23. 1 21 .5 P (kg/ha) 219 T a b l e X V I I . c o n t ' d . P l a n t A s s o c i a t i o n F a c t o r The The Moss The Achi ys -Gaul t her i a a s s o c i a t i o n - pol ys t i chum shalI on Hyl ocomi um a s s o c i a t i o n -a s s o c i a t i o n s pi e ndens v a r i a n t Pol ys t i chum muni t um v a r i a n t Base S a t u r a t i o n : 1 . f o r e s t 26.5 28.8 31.8 f l o o r (%) 2. m i n e r a l 17.3 23.7 39.0 s o i l (%) C/N r a t i o : 1. f o r e s t 37 34 35 f l o o r 2. m i n e r a l 52 34 28 s o i l F i e l d 15.7 15.9 22.3 m o i s t u r e (% by v o l . ) F i e l d 26.4 25.0 23.8 c a p a c i t y (% by v o l . ) Sand (%) 84.0 84.0 83.6 S i l t (%) 12.5 11.9 13.9 C l a y (%) 3.5 4.1 2.4 220 7 .3 APPENDIX 3 T a b l e X V I I I p. i i C o n i f e r o u s l i v e r o o t biomass from s a n d - f i l l e d i n - g r o w t h bags; means, s t a n d a r d e r r o r s , and D u n c a n s ' m u l t i p l e range g r o u p i n g s . T a b l e XIX p. i v C o n i f e r o u s l i v e r o o t biomass from n a t i v e s o i l - f i l l e d i n - g r o w t h bags; means, s t a n d a r d e r r o r s , and Duncans' m u l t i p l e range g r o u p i n g s . T a b l e XX -• p. v i N o n - c o n i f e r o u s l i v e r o o t biomass from s a n d - f i l l e d i n - g r o w t h bags; means, s t a n d a r d e r r o r s , and Duncans' m u l t i p l e range g r o u p i n g s . T a b l e XXI p. v i i i N o n - c o n i f e r o u s l i v e r o o t biomass from n a t i v e s o i l - f i l l e d i n - g r o w t h bags; means, s t a n d a r d e r r o r s , and Duncans' m u l t i p l e range g r o u p i n g s . T a b l e XXII p. x Dead r o o t biomass from s a n d - f i l l e d i n - g r o w t h bags; means, s t a n d a r d e r r o r s , and Duncans' m u l t i p l e range g r o u p i n g s . 2 2 1 T a b l e X X I I I p. x i i Dead r o o t biomass from n a t i v e s o i l - f i l l e d i n - g r o w t h bags; means, s t a n d a r d e r r o r s , and Duncans' m u l t i p l e range g r o u p i n g s . T a b l e XXIV p. x i v F u n g a l biomass from s a n d - f i l l e d i n - g r o w t h bags; means, s t a n d a r d e r r o r s , and Duncans' m u l t i p l e range g r o u p i n g s . T a b l e XXV „- p. x v i F u n g a l biomass from n a t i v e s o i l - f i l l e d i n - g r o w t h bags; means, s t a n d a r d e r r o r s , and Duncans' m u l t i p l e range g r o u p i n g s . 222 T a b l e X V I I I . V a r i a t i o n i n c o n i f e r o u s l i v e f i n e p l u s s m a l l (^5 mm) r o o t biomass w i t h time f o r s a n d - f i l l e d i n - g r o w t h bags. Except where n o t e d , means a r e from 10 sample bags. One s t a n d a r d e r r o r of the mean i s g i v e n i n p a r e n t h e s e s . Means f o l l o w e d by d i f f e r e n t l e t t e r s a r e s i g n i f i c a n t l y d i f f e r e n t (Duncans' m u l t i p l e range t e s t , a<.05 on t r a n s f o r m e d v a l u e s ) from t h o s e of d i f f e r e n t p l a n t a s s o c i a t i o n s and t i m e s . P l a n t A s s o c i a t i o n Date X e r i c M e s i c H y g r i c (M/D/Y) 030184 518.5 5a -- 284.3* ab (158.3) -- (105.2) 040284 418.4 ab 437.3 1 abc 200.8 ab (87.8) (217.7) (44.2) 050784 226.6 ab 172.7 abc 111.1 3 abc (49.7) (63.3) (40.5) 061684 070684 1 l 9 . 3 1 b c d e 109.9 bed 63.7 2bcde (59.7) (28.9) (24.0) 080284 59.1 bede 67.4 bed 112.5 bed (24.2) (18.2) (29.1) 090184 164.9 abc 125.0 abc 133.8 bed (50.9) (38.4) (48.5) 093084 112.5 bede 69.0 bed 236.4 ab (57.2) (15.8) (99.1) 102884 77.8 bede 72.1 bede 230.7 abc (44.3) (24.9) (96.6) 120184 141.6 bede 109.4 bed 168.0 abc (63.1) (38.8) (51.3) 122984 167.5 bed (72.2) 78.3 bede 123.9 bede (31.3) (53.3) 223 T a b l e X V I I I c o n t ' d . P l a n t A s s o c i a t i o n Date X e r i c M e s i c H y g r i c (M/D/Y) 020285 89.7 bcde 150.9 bed 155.6 1 abc (34.0) (63.0) (66.6) 030285 142.1 bed 147.8 abc 126.3 abc (59.7) (37.5) (29.3) 033185 65.3 bcde 45.6 bcde 40.4 1de (27.6) (31.2) (15.9) 042785 97.0 bcde 90.2 bcde 30.5 de (66.0) (76.7) (9.9) 060185 32.1 de 13.5 e 23.3 de (14.0) (4.5) (15.2) 062985 -- 23.3 cde (10.3) * s u p e r s c i p t e d means c o r r e s p o n d t o the f o l l o w i n g number of samples; a. 1 n=9 d. 4 n=6 b. 2 n=8 c. 3 n=7 e. 5 n=5 224 T a b l e XIX. V a r i a t i o n i n c o n i f e r o u s l i v e f i n e p l u s s m a l l (<5 mm) r o o t biomass w i t h time f o r n a t i v e - s o i l - f i l l e d i n - g r o w t h bags. Except where n o t e d , means a r e from 10 sample bags. One s t a n d a r d e r r o r of the mean i s g i v e n i n p a r e n t h e s e s . Means f o l l o w e d by d i f f e r e n t l e t t e r s a r e s i g n i f i c a n t l y d i f f e r e n t (Duncans' m u l t i p l e range t e s t , a<.05 on t r a n s f o r m e d v a l u e s ) from t h o s e of d i f f e r e n t p l a n t a s s o c i a t i o n s and t i m e s . P l a n t A s s o c i a t i o n Date X e r i c M e s i c H y g r i c (M/D/Y) 030184 978.5 3ab (180.7) 711. (162. 5 4 1) abed 040284 1034.9 ab (127.1) 1 304. (222. 34) a 807. (72. 3 1 1 ) abc 050784 258.6 d e f g h (83.2) 108. (48. 3 5) e f g h i j klmn 102. (28. 6 5) e f g h i j klmn 061684 371.5 def (149.5) g h i 199. (69. 1 0) de f g h i j k l 59 (18. .0 5) j klmn 070684 52.3 j k l m n (16.8) 17 (8 .5 .5) mn 68 (15. .4 1) g h i j k lmn 080284 5 8 . 0 1 j k l m n (29.5) 1 20. (49. 9 1 ) e f g h i j klmn 88 (22. .3 8) e f g h i j klmn 090184 8 2 . 6 1 g h i h j (29.0)lmn 184. (81 . 2 1) e f g h i j klm 294. (167. 0 8) d e f g h i j k 093084 104.7 j k l m n (62.4) 81 (25. .6 5) f g h i j klmn 194. (60. 0 4) d e f g h i j k l 102884 482.3 bcde (132.2) 79 (32. .5 2) i j k l mn 312. (107. 5 7) cdef g 120184 136.5 e f g h i ( 4 3 . 4 ) j k l m n 244. (68. 8 7) d e f g h i j 548. (184. 5 1) bedef 122984 200.6 d e f g ( 4 8 . 4 ) h i j 245. ( 1 57. 8 5) g h i j k lmn 180. (56. 2 2 0) d e f g h i j k 225 T a b l e XIX c o n t ' d . P l a n t A s s o c i a t i o n Date (M/D/Y) X e r i c M e s i c H y g r i c 020285 030285 033185 042785 060185 062985 1 5 1 . 1 1 e f g h i (72.8) jklmn 298.6 c d e f g (68.7) 108.8 f g h i j (37.3)klmn 1 2 2 . 1 1 e f g h i (33.9) j k l m 57.0 klmn (30.5) 245.2 e f g h i (120.8) j k l m n 128.3 g h i j k (81.4) lmn 49.3 mn (47.0) 36.4 mn (12.1) 16.9 n (12.7) 89.8 e f g h i (19.4) j k l m n 186.3 d e f g h (48.7) i j k l 259.4 1 d e f g (62.5) h i j 41.6 j k l m n (12.1) 122.6 h i j k l (74.3) mn 38.5 lmn (26.5) * s u p e r s c i p t e d means c o r r e s p o n d t o the f o l l o w i n g number of samples; a. c. 1 n=9 3 n=7 b. 2 n=8 d. • n=6 226 T a b l e XX. V a r i a t i o n i n n o n - c o n i f e r o u s l i v e f i n e p l u s s m a l l (<5 mm) r o o t biomass w i t h time f o r s a n d - f i l l e d i n - g r o w t h bags. E x c e p t where not e d , g i v e n means are f o r 10 samples. One s t a n d a r d e r r o r of the mean i s g i v e n i n p a r e n t h e s e s . Means f o l l o w e d by d i f f e r e n t l e t t e r s a r e s i g n i f i c a n t l y d i f f e r e n t (Duncans' m u l t i p l e range t e s t , a^.05 on t r a n s f o r m e d v a l u e s ) from t h o s e of d i f f e r e n t p l a n t a s s o c i a t i o n s and t i m e s . P l a n t A s s o c i a t i o n Date (M/D/Y) X e r i c M e s i c H y g r i c 030184 040284 79.2 5 abced (57.2) 56.5 (20.2) 050784 100.9 (31.9) 061684 bede abed 60.3 1 (26.8) abede 33.4 de (13.1) 11.0" (6.8) 37.6 (19.6) 14.7 3 (6.3) abede abede de 070684 080284 090184 093084 102884 120184 83.5 1 a (26.2) 84.0 abc (26.7) 80.0 (36.0) 94.3 (21.3) 57.2 (20.6) 70.8 (20.6) abede bede abede 122984 141.2 (56.7) ab 31.9 (9.8) 29.0 (0.4) 26.0 (9.5) 43.6 (18.7) 30.8 (9.2) 25.3 (12.2) 18.3 (8.5) abede cde de abede cde 9.2: (4.6) 16.9 (7.0) 15.8 (3.1 ) 12.8 (3.0) 14.3 (5.7) 40.0 (30. 1) 38.9 (26.6) 227 T a b l e XX c o n t ' d . P l a n t A s s o c i a t i o n Date X e r i c Mesic H y g r i c (M/D/Y) 020285 47.3 abcde 12.1 e 7.7 1 e (29.0) (2.8) (2.5) 030285 18.3 e 10.3 e 15.0 e (5.5) (4.0) (6.2) 033185 71.2 e 2.6 e 3.3 1 e (63.1) (1.3) (1.3) 042785 9.2 e 1.5 e 3.7 e (1.9) (0.8) (1.4) 060185 7.3 e 2.9 e 4.0 e (3.4) (1.8) (2.2) 062985 -- 6.2 e (2.5) * s u p e r s c i p t e d means c o r r e s p o n d t o the f o l l o w i n g number of samples; a. 1 n=9 b. 2 n=8 c. 3 n=7 d. 4 n=6 e. 5 n=5 228 T a b l e X X I . V a r i a t i o n i n n o n - c o n i f e r o u s l i v e f i n e p l u s s m a l l (<5 mm) r o o t biomass w i t h time f o r n a t i v e - s o i l - f i l l e d i n - g r o w t h bags. Except where n o t e d , means a r e from 10 sample bags. One s t a n d a r d e r r o r of t h e mean i s g i v e n i n p a r e n t h e s e s . Means f o l l o w e d by d i f f e r e n t l e t t e r s a r e s i g n i f i c a n t l y d i f f e r e n t (Duncans' m u l t i p l e range t e s t , a^.05 on t r a n s f o r m e d v a l u e s ) from those of d i f f e r e n t p l a n t a s s o c i a t i o n s and t i m e s . P l a n t A s s o c i a t i o n Date X e r i c M e s i c H y g r i c (M/D/Y) 030184 535 .6 3a -- 71 . 7* abed (280. 8) -— . (15. 9) ef gh 040284 228 .9 abc 121. 2 bede 97. O1 abede (52 .0) (44. 2) f g h i (15. 7) 050784 274 . 1 ab 60. 4 ef g 40. 8 i j (66 .8) (21 . 3) h i j (21 . 5) 061684 301 .9 abc 170. 3 abed 69. 1 f g h i j (76 .9) (70. 2) ef g (40. 4) 070684 78 .2 bede 81 . 2 cdef 49. 2 def g (21 . 7 ) f g h (26. 4) g h i j (11. 3) h i j 080284 1 02 .5 1bede 55. 5 cdef 30. 4 h i j (37 . 0 ) f g h i (17. 4) g h i j (7. 1) 090184 1 03 .8 1bede 66. 6 cdef 32. 6 f g h i j (31 . 4 ) f g h i (24. 5) g h i j (12. 5) 093084 205 .5 abed 77. 8 f g h i j 101 . 2 cde f (43 .8) (32. 4) (49. 4) g h i j 102884 204 . 6 abc 56. 5 def g 24. 3 h i j (44 .0) (18. 8) h i j (7. 0) 120184 215 .5 abed 29. 1 g h i j 22. 6 h i j (75 .7 ) e f (10. 2) (5. 9) 122984 395 . 3 abc 44. 2 f g h i j 38. O 2 f g h i j (90 .8) (15. 5) (12. 3) 229 T a b l e XXI c o n t ' d . P l a n t A s s o c i a t i o n Date X e r i c M e s i c H y g r i c (M/D/Y) 020285 1 85 . 4 1 abed 1 58. 8 cdef 16.1 (60 . 5 ) e f g (35. 9) g h i j (5.8) 030285 222 .9 abed 95. 1 f g h i j 1 3 . 5 1(56 .9) (68. 2) (3.9) 033185 1 29 .2 bcde 29. 1 h i j 20.9 (62 . 0 ) f g h (17. 6) (15.1) 042785 74 .3'bcde 34. 3 g h i j 23.0 (14 . 6 ) f g h (8. 8) (5.2) 060185 10 .6 j 49. 1 h i j 4.3 (3 .6) (41. 0) (1.5) 062985 — 41 . 3 h i j — (9. 6) --* s u p e r s c i p t e d means c o r r e s p o n d t o the f o l l o w i n g number of samples; 230 T a b l e X X I I . V a r i a t i o n i n dead s m a l l (<5 mm) r o o t biomass w i t h time f o r s a n d - f i l l e d i n - g r o w t h bags. E x c e p t where n o t e d , means a r e from 10 sample bags. One s t a n d a r d e r r o r of the mean i s g i v e n i n p a r e n t h e s e s . Means f o l l o w e d by d i f f e r e n t l e t t e r s a r e s i g n i f i c a n t l y d i f f e r e n t (Duncans' m u l t i p l e range t e s t , a^.05 on t r a n s f o r m e d v a l u e s ) from t h o s e of d i f f e r e n t p l a n t a s s o c i a t i o n s and t i m e s . P l a n t A s s o c i a t i o n Date (M/D/Y) X e r i c M e s i c H y g r i c 030184 040284 050784 061684 5.6 s c (5.6) 1.4 c (0.7) 14.6 be (7.6) 2.6 (1.8) 26.8 (13.7) abc 0.0" be 17.1 abc (5.9) 10.8 3 be (6.6) 070684 080284 090184 093084 102884 120184 122984 41.8 1 abc (14.7) 35.3 be (16.3) 16.9 c (3.3) 22.6 c (3.8) 34.8 abc (13.5) 40.0 abc (7.7) 46. 1 (7.5) ab 47.0 (11.6) 19.8 (9.7) 7.1 (3.8) 19.3 (7.6) 17.4 (3.9) 22. 1 (6.5) 24.5 (9.4) abc be be 70.0 2 (14.7) 24.9 (9.5) 20.7 (3.9) 34.8 (10.6) 21.2 (4.9) 60.2 (13.1) 36.2 (12.3) ab abc abc ab abc 231 T a b l e XXII c o n t ' d . P l a n t A s s o c i a t i o n Date X e r i c M e s i c H y g r i c (M/D/Y) 020285 27.3 (4.0) c 22.6 (6.8) be 23.5 1 (3.4) c 030285 22.6 (7.1) be 8.5 (2.6) c 28.7 (6.6) abc 033185 32.0 (7.4) abc 28.7 (8.3) " be 34.8 1 (9.2) abc 042785 96.0 (16.0) a 20.7 (10.6) be 95. 1 (22.3) a 060185 87.5 (16.3) ab 29.6 (5.8) be 87.5 (35.2) ab 062985 -- 36.7 (8.2) abc * s u p e r s c i p t e d means c o r r e s p o n d t o the f o l l o w i n g number of samples; a. 1 n=9 b. d. 4 n=6 e. 2 n=8 5 n=5 c. 3 n=7 232 T a b l e X X I I I . V a r i a t i o n i n dead s m a l l (^5 mm) r o o t biomass w i t h time f o r n a t i v e - s o i l - f i l l e d i n - g r o w t h bags. Except where n o t e d , means a r e from 10 sample bags. One s t a n d a r d e r r o r of the mean i s g i v e n i n p a r e n t h e s e s . Means f o l l o w e d by d i f f e r e n t l e t t e r s a r e s i g n i f i c a n t l y d i f f e r e n t (Duncans' m u l t i p l e range t e s t , a^.05 on t r a n s f o r m e d v a l u e s ) from t h o s e of d i f f e r e n t p l a n t a s s o c i a t i o n s and t i m e s . P l a n t A s s o c i a t i o n Date X e r i c M e s i c H y g r i c (M/D/Y) 030184 393.2 opqr (359.0) 44.2 a (24.7) r s t u 040284 127.3 pqrs (63.2) 103.6 (14.1) nopq 36.4 1 (20.0) t u 050784 125.3 opqr (49.0) 31.1 (10.2) t u 60.4 (11.0) r s 061684 128.2 mnop (24.4) 75.7 (28.7) r s t 64. 1 (19.9) r s t u 070684 55.0 s t u (27.2) 84.4 (29.2) p q r s 177.5 i j k (8.2)lmn 080284 129.7 1mnop (19.7) 119.4 (11.8) klmno 750.0 (101 .2) a 090184 162.0'nopq (43.5) 70.2 (18.9) r s t 261 .3 (44.7) f g h i j k l 093084 317.6 e f g h i (104.4) j k 25.6 (5.5) u 318.6 (18.7) cdef g h i j 102884 335.0 e f g h ( 4 8 . 0 ) i j k 88.2 (17.9) p q r s 406.3 ( 107.7) cdef g h i j 120184 152.3 lmno (21.3) 59.3 (9.9) q r s 697.0 (288.3) ab 122984 364.1 f g h i j (135.2) k l 199.8 (43.6) j klmn 261.5 2 (85. 1) h i j k lm 233 T a b l e X X I I I c o n t ' d . P l a n t A s s o c i a t i o n Date X e r i c M e s i c H y g r i c (M/D/Y) 020285 2 7 4 . 7 1 e f g h i ( 4 5 . 8 ) j k l 1 76. (39. 2 8) i j k l mn 225. (14. 1 0) g h i j k l 030285 490.7 abed (107.6) e f g 538. (203. 9 9) bedef gh 402. (74. 2 1 2) cdef gh 033185 239.1 f g h i j ( 2 6 . 5 ) k l 256. (38. 4 6) f g h i j k l 264. (17. 1 8) def g h i j 042785 507.1'abed (58.6) 526. (140. 8 0) abed e f g 544. (69. 7 4) abc 060185 230.3 f g h i ( 1 0 . 2 ) j k l 352. (30. 3 1) cd e f g h i 305. (21 . 6 3) cdef g h i 062985 503. (68. 7 3) abede * s u p e r s c i p t e d means c o r r e s p o n d t o t h e f o l l o w i n g number of samples; a. 1 n=9 c. 3 n=7 2 n=8 4 n=6 b. d. 234 T a b l e XXIV. V a r i a t i o n i n f u n g a l biomass w i t h time f o r s a n d - f i l l e d i n - g r o w t h bags. Except where n o t e d , means a r e from 10 sample bags. One s t a n d a r d e r r o r of the mean i s g i v e n i n p a r e n t h e s e s . Means f o l l o w e d by d i f f e r e n t l e t t e r s a r e s i g n i f i c a n t l y d i f f e r e n t (Duncans' m u l t i p l e range t e s t , a<.05 on t r a n s f o r m e d v a l u e s ) from t h o s e of d i f f e r e n t p l a n t a s s o c i a t i o n s and t i m e s . P l a n t A s s o c i a t i o n Date X e r i c M e s i c H y g r i c (M/D/Y) 030184 593.4 5abcde . 1 .5" bedef (423.4) — (1 . 5) g h i j 040284 330 .0 ab 605. 2 1 ab 1 24. 7 a ( 5 3 . 6 ) (146. 4) (45. 4) 050784 174.1 abed 314. 3 ab 33. 8 3 def g (70 . 0 ) (74. 1) (4. 2) h i j 061684 --070684 87.2 1abede 130. 1 abed 28. 1 2 i j (26.1) (36. 3) (10. 9) 080284 57.2 abede 49 .2 def g 68. 6 g h i j ( 1 5 . 3 ) f g h (18. 9) h i j (38. 8) 090184 106.7 abede 63 .7 abed 18. 2 j (30.0) (15. 9) ef (8. 2) 093084 80.0 abede 1 36. 9 abed 84. 9 c d e f g ( I 7 . 4 ) f g h (33. 3) (36. 2) h i j 102884 71.7 c d e f g 1 40. 0 abede 112. 9 def g ( 2 5 . 4 ) h i j (50. 9) f g h (40. 0) h i j 120184 86.7 abede 185. 5 abc 49. 2 e f g ( 2 8 . 7 ) f g (38. 5) (21 . 1 ) h i j 122984 92 . 0 abede 281 . 1 abc 25. 8 j ( 2 7 . 4 ) f g (153. 9) (11. 1) 235 T a b l e XXIV c o n t ' d . P l a n t A s s o c i a t i o n Date X e r i c M e s i c H y g r i c (M/D/Y) 020285 78. 7 abcde 1 28.0 abcde 16. 9 1 j (16. 6 ) f g (42.0) (4. 8) 030285 110. 4 abed 187.3 abcde 45. 9 h i j (20. 4) (92.9) f g h (22. 1) 033185 45. 2 c d e f g 56.6 f g h i j 18. 2 1 j (13. 4 ) h i j (35.6) (6. 4) 042785 124. 9 abed 49.5 j 14. 4 j (21 . 5) (24.4) (7. 6) 060185 55. 7 d e f g 66. 1 c d e f g 13. 5 j (14. 0 ) h i j (19.5) h i j (4. 7) 062985 — 227.9 abed -— (150.0) * s u p e r s c i p t e d means c o r r e s p o n d t o the f o l l o w i n g number of samples; a. 1 n=9 b. 2 n=8 c. 3 n=7 236 T a b l e XXV. V a r i a t i o n i n f u n g a l biomass w i t h time f o r n a t i v e - s o i l - f i l l e d i n - g r o w t h bags. Except where note d , means a r e from 10 sample bags. One s t a n d a r d e r r o r of the mean i s g i v e n i n p a r e n t h e s e s . Means f o l l o w e d by d i f f e r e n t l e t t e r s a r e s i g n i f i c a n t l y d i f f e r e n t (Duncans' m u l t i p l e range t e s t , a<.05 on t r a n s f o r m e d v a l u e s ) from those of d i f f e r e n t p l a n t a s s o c i a t i o n s and t i m e s . P l a n t A s s o c i a t i o n Date X e r i c M e s i c H y g r i c (M/D/Y) 030184 573.7 3bcd -- 19. 0" h i j k (180.8) — (13. 2) lmn 0.40284 322.6 b 1302.2 a 23. 6 1 i j k l (32. 1 ) (403.2) (13. 6) mn 050784 57.8 e f g h 138.3 c d e f g 29. 9 i j k l (1 8 . 6) i j (43.9) (17. 7) mn 061684 194.5 bed 284.5 bede 1 33. 6 bede (48. 1 ) (94.3) (40. 2) 070684 20.4 j k l m n 59.3 f g h i j 33. 4 j klmn (15.2) (28.9) k l (23. 4) 080284 2.4n 20. 1 j klmn 43. 2 jklmn (1.6) (4.5) (35. 4) 090184 3 5 . 4 1 h i j K 185.6 bed 13. 8 i j k l (15.1)lmn (58.9) (6. 0) mn 093084 14.2 j k l m n 92.7 def gh 12. 2 j klmn (10.0) (31.0) (5. 4) 102884 95.9 c d e f g 222.0 bed 24. 8 i j k l (39.2) (66.5) (7. 8) mn 120184 46.4 h i j k 87.6 e f g h i 25. 2 j klmn (21.2)lmn (36.9) (17. 8) 122984 75.7 e f g h 127.5 cdef 8 i . 4 2 klmn ( 2 5 . 7 ) i j (47.7) (3. 2) 237 T a b l e XXV c o n t ' d . P l a n t A s s o c i a t i o n Date (M/D/Y) • X e r i c Mesic H y g r i c 020285 1 4 (4 .4 1klmn .0) 93.0 ( 18.2) cdef 39. (24. 3 9) i ] k l mn 030285 61 (17 .3 e f g h i .1) 192.5 (100.3) c d e f g 57. (43. 2 1 3) h i j k lmn 033185 1 4 (3 . 9 mn .6) 1 03.0 (27.4) c d e f g 35. (22. 8 9) i j k l mn 042785 68 (25 , 4 1 g h i j .4)klm 261 .3 (76.6) be 59. (24. 3 7) f g h i j k 060185 (1 4.4klmn .9) 9.4 (2.2) klmn 1 (0. .6 7) lmn 062985 -- 26.3 (12.5) h i j k lmn * s u p e r s c i p t e d means c o r r e s p o n d t o the f o l l o w i n g number of samples; 238 7.4 APPENDIX 4 F i g u r e A4. 1 i i i I n t e r a c t i o n of time and s i t e f o r t h e n o n - c o n i f e r o u s l i v e r o o t component. F i g u r e A4.2 i v I n t e r a c t i o n of s i t e and m a t e r i a l f o r the n o n - c o n i f e r o u s l i v e r o o t component. 2 3 9 7.4.1 TREATMENT OF HIGHER-ORDER FACTOR INTERACTIONS  WITHIN AN ANOVA I n t h i s a p p e n d i x I w o u l d l i k e t o d i s c u s s t h e u s u a l p r o c e d u r e s a s s o c i a t e d w i t h i n t e r p r e t i n g s i g n i f i c a n t f a c t o r i n t e r a c t i o n s w i t h i n an a n a l y s i s o f v a r i a n c e (ANOVA). T h i s d i s c u s s i o n i s b a s e d p r i n c i p a l l y on c o n v e r s a t i o n s w i t h D r . A. K o z a k , s t a t i s t i c i a n i n t h e D e p a r t m e n t o f F o r e s t r y a t UBC, a n d on n o t e s t a k e n i n h i s s t a t i s t i c s c o u r s e s . I t i s p r o v i d e d more f o r d i s c u s s i o n t h a n f o r a n y r e l e v a n c e t o t h e r e s u l t s i n t h i s t h e s i s . S i g n i f i c a n t f a c t o r i n t e r a c t i o n s w i t h i n an ANOVA mo d e l a r e c a u s e d by t h e n o n - u n i f o r m b e h a v i o u r o f b l o c k s w i t h a g i v e n t r e a t m e n t . So, t o u s e t h e i n - g r o w t h b a g s a s an e x a m p l e , i f we s e e i n c r e a s i n g a mounts o f r o o t b i o m a s s w i t h i n c r e a s i n g s i t e p r o d u c t i v i t i e s ( h e r e " s i t e " w o u l d be o u r t r e a t m e n t ) i n t h e n a t i v e - s o i l - f i l l e d i n - g r o w t h b a g s , b u t j u s t t h e o p p o s i t e e f f e c t i n t h e s a n d - f i l l e d i n - g r o w t h b a g s ( d e c r e a s i n g a m o u n t s o f r o o t s w i t h i n c r e a s i n g s i t e p r o d u c t i v i t i e s ) , t h e n " s i t e " w o u l d h a v e h a d a s i g n i f i c a n t , b u t o p p o s i t e e f f e c t on o u r b l o c k s . The ANOVA w o u l d p r o b a b l y show no e f f e c t o f t h e . t r e a t m e n t " s i t e " b e c a u s e t h e t r e a t m e n t e f f e c t w o u l d a v e r a g e d , o r " c o n f o u n d e d " w i t h i n t h e m o d e l . S u c h a s i t u a t i o n p r o d u c e s s i g n i f i c a n t i n t e r a c t i o n w i t h i n t h e m o d e l t e r m s . I f h o w e v e r we c a n e x p l a i n t h i s i n t e r a c t i o n , we 240 can s t i l l s a l v a g e the t e s t e d terms. Perhaps the most d i f f i c u l t p o i n t about e x p l a i n i n g s i g n i f i c a n t i n t e r a c t i o n s i s t h a t the e x p l a n a t i o n must be couched i n terms of the ANOVA model. In o t h e r words, i f the a n a l y s i s was c a r r i e d out u s i n g t r a n s f o r m e d d a t a , we must examine the i n t e r a c t i o n s of these d a t a i n the t r a n s f o r m e d s t a t e . T h i s t a k e s away the b i o l o g i c a l r e l e v a n c e and meaning t o the d a t a . However, i f , by p l o t t i n g the p r e d i c t e d d a t a means ( t h e ANOVA t e s t s d i f f e r e n c e s between p r e d i c t e d r a t h e r than t r u e means) we a r e a b l e t o s a l v a g e a t e s t e d term, or a t l e a s t d e c i d e which terms d e s e r v e f u r t h e r a n a l y s i s , the e x t r a e f f o r t may be w o r t h w h i l e . To demonstrate t h i s p o i n t , I w i l l t a k e a l o o k a t two s i t u a t i o n s i n v o l v i n g p o r t i o n s of my d a t a from c h a p t e r 5. F i g u r e s A4.1 and A4.2 show the p r e d i c t e d mean t r a n s f o r m e d r o o t w e i g h t s of the n o n - c o n i f e r o u s r o o t component. The f u l l - m o d e l ANOVA showed t h a t t h e r e was a s i g n i f i c a n t i n t e r a c t i o n of t i m e - b y - s i t e (p=0.004) and s i t e - b y - g r o w t h medium (p=0.005) f o r the l i v e , n o n - c o n i f e r o u s biomass component ( T a b l e V I , p. 7 0 ) . In the case of t i m e - b y - s i t e i n t e r a c t i o n ( F i g u r e A 4 . 1 ) , p l o t t i n g t h e p r e d i c t e d mean t r a n s f o r m e d r o o t w e i g h t s r e v e a l e d t h a t , up t o November 1984 t h e r e appeared t o be have been f a i r l y c l e a r d i f f e r e n c e s between s i t e s . However, sudden i n c r e a s e s i n the mesic and h y g r i c s i t e biomass l e v e l s i n December e l i m i n a t e d t h e s e d i s t i n c t 241 0.4 0.3 1 o Q : TJ CD E £ 0.2 c D CD ~o CD Q_ 0.1-0.0 J I I Time (Months) Legend ° Xeric • Mesic • Hygr ic F i g u r e A4.1 I n t e r a c t i o n between time and s i t e f o r the n o n - c o n i f e r o u s l i v e r o o t component. P l o t t e d d a t a a r e p r e d i c t e d mean t r a n s f o r m e d r o o t w e i g h t s f o r a l l t h r e e s i t e s and both growth media. T r a n s f o r m a t i o n s c o r r e s p o n d t o the e q u a t i o n s f o r NCLFS.sa and NCLFS.so components of T a b l e VI (p. 7 0 ) . 242 0.35 F i g u r e A4.2 I n t e r a c t i o n between s i t e and m a t e r i a l f o r the n o n - c o n i f e r o u s l i v e r o o t component. P l o t t e d d a t a a r e p r e d i c t e d mean t r a n s f o r m e d r o o t w e i g h t s f o r a l l t h r e e p l a n t a s s o c i a t i o n s and both growth media. T r a n s f o r m a t i o n s c o r r e s p o n d t o the e q u a t i o n s f o r NCLFS.sa and NCLFS.so components of T a b l e VI (p. 70) . 243 e a r l y d i f f e r e n c e s . S i n c e we do not have a case of c o n s i s t e n t but c o n t r a d i c t o r y b e h a v i o u r between the b l o c k s ( i n t h i s c a s e , between the t h r e e s i t e s ) , we a r e una b l e t o e x p l a i n or d i s c o u n t the s i g n i f i c a n t t i m e - b y - s i t e i n t e r a c t i o n , or t o d i s c u s s the the f i r s t - o r d e r r e s u l t s of the ANOVA. The c a s e of the p o s i t i v e s i t e - b y - m a t e r i a l i n t e r a c t i o n ( F i g u r e A4.2) i s e a s i e r t o e x p l a i n . The p a t t e r n s of the mean p r e d i c t e d t r a n s f o r m e d r o o t w e i g h t s f o r each growth m a t e r i a l a r e s i m i l a r i n shape, but d i f f e r i n t h e i r s l o p e s and t h e i r y - i n t e r c e p t s ( F i g u r e A 4.2). The p o s i t i v e i n t e r a c t i o n between t h e s e two f a c t o r s i s p r o b a b l y caused by the d i f f e r e n c e s i n s l o p e s between p o i n t s . There i s , however, a c l e a r s e p a r a t i o n between s i t e s , between e s t i m a t e s produced w i t h d i f f e r e n t growth media, and a p r e d i c t a b l e between p r e d i c t e d mean r o o t weight and s i t e (as p r o d u c t i v i t y i n c r e a s e s , p r e d i c t e d t r a n s f o r m e d r o o t weight d e c r e a s e ) . In t h i s c a s e , because we can i d e n t i f y t he cause of the i n t e r a c t i o n , and show t h a t t h e r e i s a r e l a t i o n s h i p between our t r e a t m e n t and b l o c k s , i t would be unwise t o c o m p l e t e l y d i s r e g a r d the f i r s t - o r d e r r e s u l t s of the ANOVA. In such a s i t u a t i o n as t h i s , where we have a t l e a s t some i n d i c a t i o n t h a t a t r e a t m e n t i s s i g n i f i c a n t , but where the r e s u l t s of the ANOVA a r e confounded, we would be w i s e t o c o n t i n u e the a n a l y s i s , perhaps on s m a l l e r p o r t i o n s of the e n t i r e d a t a s e t , r a t h e r than 2 4 4 throw the d a t a away c o m p l e t e l y . T h i s was indeed the c a s e . By s p l i t t i n g the d a t a by growth medium, and r e - a n a l y z i n g on a s i m p l i f i e d model, we were a b l e t o prove t h a t s i t e and p l o t s - w i t h i n - s i t e were s i g n i f i c a n t t r e a t m e n t s i n the n a t i v e - s o i l - f i l l e d i n - g r o w t h bags (T a b l e V I I , p. 7 1 ) . 

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