THE GENESIS OF THREE PODZOL-LIKE SOILS OCCURRING OVER A CLIMATIC GRADIANT ON VANCOUVER ISLAND by DAVID E. MOON A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE STUDIES (Department of Soil Science) We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA David E. Moon October 1981. In presenting t h i s thesis i n p a r t i a l f u l f i l m e n t of the requirements for an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y a v a i l a b l e f o r reference and study. I further agree that permission for extensive copying of t h i s thesis for s c h o l a r l y purposes may be granted by the head of my department or by h i s or her representatives. I t i s understood that copying or p u b l i c a t i o n of t h i s thesis for f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of £ot<- Sc//?x>c£ The University of B r i t i s h Columbia 2075 Wesbrook Place Vancouver, Canada V6T 1W5 Date ZC OCT. nF-fi 12/19) ABSTRACT Three s o i l s occurring on a climosequence were studied to c l a r i f y c e r t a i n aspects of Podzol genesis and Podzol c l a s s i f i c a t i o n . Data on p h y s i c a l , chemical, and s o i l s o l u t i o n c h a r a c t e r i s t i c s of the three s o i l s were c o l l e c t e d and analysed. A l l measures of i r o n and aluminum were analysed and presented as mass per horizon. Rates of movement f o r calcium, magnesium, sodium, potassium, i r o n and aluminum between the canopy, forest f l o o r , B^ and B2 horizons were also measured. The interpretations of d i f f e r e n t measures of i r o n and aluminum as an index of Podzol expression were shown to be inconsistent. A simple l i n e a r model was developed and applied to data from the three s o i l s . The model defined the balance of additions, losses, transformations, and translocations within and between horizons f o r each s i t e . The model r e s u l t s supported the following hypotheses: 1) The balance of additions, l o s s e s , translocations, and transformations vary across the climosequence. 2) The three s o i l s studied can be i d e n t i f i e d by the balance of processes acting to produce sesquioxide r i c h B horizons. 3) Current Podzol c l a s s i f i c a t i o n c r i t e r i a do not r e f l e c t differences i n the balance of these processes. The model did not support the hypothesis that rates of biochemical c y c l i n g would be r e f l e c t e d i n Podzol B horizon expression. i i i Two d i s t i n c t balances of processes.forming i r o n and aluminum r i c h B horizons were shown to occur. In one s i t e i r o n and aluminum accumulate p r i m a r i l y as a r e s u l t of p r e f e r e n t i a l l o s s of other s o i l constituents; i n the other s i t e s i r o n and aluminum are dominantly the product of e l u v i a t i o n from the Ae horizon and deposition i n the B horizons. Current c l a s s i f i c a t i o n c r i t e r i a grouped the two s o i l s showing the most strongly contrasting genetic processes together as Brunisols while the intermediate balance was c l a s s i f i e d as a Podzol. The reasons f o r t h i s inconsistency are discussed. i v ACKNOWLEDGEMENTS I wish to express my gratitude to a number of people. I am indebted to Dr. V.J. K r a j i n a who shared h i s respect f o r nature, to Dr. T.M. B a l l a r d who by example and c r i t i c i s m set a high standard of s c i e n t i f i c r igour, and to Dr. L.M. Lavkulich whose respect f o r students i n s t i l l e d i n me the s e l f confidence necessary to attempt t h i s p r o j ect. To them I owe both respect and thanks. I am further indebted to Dr. Lavkulich f o r his moral support and h i s seemingly endless patience i n waiting f o r t h i s t h e s i s . I would also l i k e to thank Beverley and B i l l Herman and Ms. Kathy L i for t h e i r assistance with f i e l d sampling and laboratory a n a l y s i s . The number of friends and colleagues who helped i n one way or another i s too large to l i s t but none the less they are g r a t e f u l l y acknowledged. To my wife Barbara, whose help with everything from digging holes to proof reading was the l e a s t of the support she gave, I owe the most. V CONTENTS CHAPTER I INTRODUCTION 1 Approaches to Genetic Studies 1 The Development of Canadian Concepts of Podzol Genesis 4 Rationale for the Study 9 Hypotheses 11 CHAPTER II MORPHOLOGY AND CHEMISTRY 13 INTRODUCTION 13 MATERIALS AND METHODS 14 Study Area 14 Sampling Design 15 A n a l y t i c a l Methods 21 SITE CHARACTERISTICS 23 Climate 23 Parent Material 28 Re l i e f 28 Vegetation 30 Time 31 SOIL MORPHOLOGY 31 P r o f i l e Descriptions 31 Results 37 Discussion 39 SOIL ANALYSIS 42 S t a t i s t i c a l Model 42 Results 43 Discussion 50 SOIL WATER 54 S t a t i s t i c a l Models 54 Results 56 Discussion 60 v i CHAPTER III A SIMPLE LINEAR MODEL 65 INTRODUCTION 65 THE MODEL 66 RATES AND PATTERNS OF REDISTRIBUTION 76 The Solum 76 The E l u v i a l A Horizon 80 The I l l u v i a l B Horizon 81 The B 2 Horizon 82 PARTITIONING FORMS OF IRON PLUS ALUMINUM 84 Forms of Iron Plus Aluminum Pa r t i t i o n e d 85 Results of P a r t i t i o n i n g 88 CORRELATION OF PREDICTED WITH MEASURED VALUES 91 The Ae Horizon 91 The B 1 Horizon 94 The B 2 Horizon 94 DISCUSSION 95 The Solum 95 The Ae Horizon 95 The B 1 Horizon 99 The B 2 Horizon 102 GENETIC RELATIONSHIPS 105 Ae HORIZON FORMATION 105 B 1 HORIZON FORMATION 108 B 2 HORIZON FORMATION 110 CONCLUSIONS 111 LITERATURE CITED 115 APPENDICES Appendix 1 Design, Construction and I n s t a l l a t i o n of Water Collectors 121 Appendix 2 S o i l Chemical Analyses 129 Appendix 3 Water Chemistry Analysis 133 Appendix 4 Vegetation Species L i s t s 147 v i i TABLES Table 2-1 Summary Climatic C h a r a c t e r i s t i c s for the Biogeoclimatic Units Represented by the Study Sites 16 2-2 Model f or Analysis of Variance of S o i l Properties 43 2-3 Mean S i t e Values for S o i l A n a l y t i c a l Data by Horizon 44 2-4 Forms of Extractable Iron as a Percentage of the Fine Earth Fraction 52 2-5 Comparison by S i t e of Selected Measures of Podzol Development 54 2-6 Models for Analysis of Variance of S o i l Water Chemistry 55 2-7 Mean S i t e Values f o r S o i l Water Chemistry by C o l l e c t i o n Level 57 2-8 Retention Values of Fe, A l , and Fe+Al as a Proportion of Input Values for the Surface Mineral S o i l 60 2- 9 Ranges of Iron and Aluminum Concentrations (ppm); Measured i n Lysimeter C o l l e c t i o n s and Soluble i n Water 61 3- 1 Model Results of Input-Output for Horizons 77 „ „ _ n Fe+Al Lost Fe+Al i n P.M. n o 3-2 Loss Rations — ; — ^ „ — 78 Mass Lost Mass of P.M. 3-3 C o r r e l a t i o n Table of Model Output 79 3-4 Mean Site Values f o r Model Predicted Forms of Iron plus Aluminum 89 3-5 Mean S i t e Values for Values of Extractable Iron plus Aluminum 89 3-6 Predicted Non-Primary Fe+Al and Acid Ammonium Oxalate Extractable Fe+Al 90 3-7 Cor r e l a t i o n Table of Model Predicted with Measured Values 92 3-8 Fe/Al Ratio f o r Acid Ammonium Oxalate Extractable, C i t r a t e Bicarbonate D i t h i o n i t e Extractable, and To t a l Values 98 3-9 Selected C h a r a c t e r i s t i c s of Ae Horizons 106 v i i i FIGURES Figure 2-1 Sampling Design 20 2-2 Mean Monthly P r e c i p i t a t i o n by S i t e 24 2-3 Mean Monthly Maximum, Minimum and Mean A i r Temperatures 25 2-4 S o i l Matrix P o t e n t i a l ( i n Bars), Weekly Mean Si t e Values by Horizon 27 2-5 Cummulative P a r t i c l e Size (Means and Standard Deviations) f o r the B^ and B 2 Horizons 29 3-1 Diagramatic Representation of the Horizon Model 68 3-2 Diagramatic Representation of the Solum Model Showing Linkage of Horizon Models 69 3-3 Stages of Model Construction 71 CHAPTER I INTRODUCTION Podzols i n the Canadian System of S o i l C l a s s i f i c a t i o n (1978) occur over a broad range of climates and landscapes (Clayton et^ a l . , 1977) and show a l i m i t e d range of morphological, p h y s i c a l and chemical properties. This range of properties has generally been interpreted as r e s u l t i n g from the e l u v i a t i o n of i r o n and aluminum from the surface (Ae) horizons and i l l u v i a t i o n of i r o n , aluminum, and organic compounds i n the subsurface (B) horizons (McKeague et a l . , 1978; Stobbe and Wright, 1959; Valentine et a l . , 1978). In Chapter I I , morphology, chemistry, and biochemical c y c l i n g of three s o i l s showing varying degrees of Podzol expression are examined as a means of characterizing Podzol forming processes. Results are discussed i n terms of current and h i s t o r i a l concepts of Podzol expression. Data from the three s o i l s are evaluated using a simple l i n e a r model, presented i n Chapter I I I , to explain inconsistencies between morphological and a n a l y t i c a l measures of Podzolic s o i l expression. APPROACHES TO GENETIC STUDIES Present day concepts of Podzol genesis are the product of pedological studies begun i n the l a t e 1800's, by Russian pedologists, and continued by numerous inve s t i g a t o r s to the present. Some ea r l y pedologists thought that the Podzolic"'' Ae horizon, was remnant ash from major forest f i r e s . A p plication In t h i s paper the term Podzolic r e f e r s to s o i l s or s o i l a t t r i b u t e s which are c h a r a c t e r i s t i c of but not exclusive to the Podzolic Order i n the Canadian System of S o i l C l a s s i f i c a t i o n . - 2 -of the s c i e n t i f i c method to the problem of s o i l genesis quickly d i s c r e d i t e d t h i s e a r l y theory and has made s i g n i f i c a n t progress toward explaining Podzolic s o i l formation. Quantitative approaches to the problem of Podzol genesis have taken two approaches; the experimental approach, where a r t i f i c i a l systems over which the i n v e s t i g a t o r has considerable control are studied, and the observational approach, i n which natural systems over which the i n v e s t i g a t o r has very l i t t l e c ontrol are studied. The work of Pedro i n 1964, on rock weathering i n Soxhlet apparatus, exemplifies the experimental approach (Henin and Pedro, 1965), while that of Jenny (1941), o u t l i n i n g the factors of s o i l formation, exemplifies the observational approach. Experimental pedology i s generally laboratory based and e i t h e r explores s p e c i f i c p h y s i c a l chemical r e l a t i o n s h i p s to test portions of hypotheses of s o i l development, or attempts to evaluate more h o l i s t i c theories of s o i l formation by speeding up processes which are analagous to those processes presumed to be operating i n n a t u r a l conditions. "Studies i n the a r t i f i c i a l weathering of mica" (Rausell-Colom et_ a l . , 1965) and "Interaction of i r o n with r a i n f a l l leachates" (Schnitzer, 1959) are examples of the former while "The laboratory weathering of rocks" (Henin and Pedro, 1965)provides ? examples of the l a t t e r . Experimental pedology allows for greater control over the system under study but cannot duplicate natural systems and therefore r e s u l t s must be viewed with some caution. Observational pedology, i n contrast to experimental pedology, i s f i e l d based and i s much less amenable to experimental c o n t r o l . I t i s known to r e f l e c t n atural processes. Observational pedology takes two forms. In one, - 3 -l i t t l e or no attempt i s made to standardize factors known to influence s o i l formation and i n the other,the pedologist attempts to study s o i l s which vary i n . a s i n g l e or l i m i t e d number of factors which are known to influence s o i l formation. Two c l a s s i c a l studies exemplify these approaches. "Russian Chernozem," written by Dokuchaev i n 1883, i s an example of observational pedology which did not attempt to standardize s o i l factors and yet provided the foundation of modern s o i l science by recognizing s o i l s as n a t u r a l l y occuring bodies varying geographically i n a definable manner. "Factors of s o i l formation" (Jenny, 1941) provided the basis for the independent v a r i a b l e approach to observational pedology and has given r i s e to a number of "sequence" studies i n which the influence of environmental gradients or time sequences on s o i l development are studied. " V e r t i c a l s o i l z o n a l i t y i n North Vietnam" (Fridland, 1959), and "A chronosequence of s o i l s and vegetation near Mt. Shasta, C a l i f o r n i a " (Dickson and Crocker, 1953) are only two examples of such studies. The experimental and observational approaches when applied i n t h e i r extreme forms are of l i m i t e d value since experimental r e s u l t s may not r e f l e c t n a t u r a l systems and observational r e s u l t s can provide only hypotheses which are based i n empiricism and are d i f f i c u l t to t e s t . When combined, the two approaches represent an a p p l i c a t i o n of the s c i e n t i f i c method to the problem of s o i l genesis. Observational pedology generates hypotheses of s o i l formation. Experimental pedology can then test these hypotheses under co n t r o l l e d conditions to ensure that they are consistent with p h y s i c a l , chemical, and b i o l o g i c a l processes, and can propose mechanisms or processes to elaborate on the observational hypotheses. The r e s u l t i n g theory can then be evaluated and applied to or tested against observational pedology. — 4 -Unfortunately t h i s a p p l i c a t i o n of the s c i e n t i f i c method i s beyond the scope of a s i n g l e study. The d i s c i p l i n e of pedology must gain i t s s c i e n t i f i c c r e d i b i l i t y from the sum of work done by a number of contributors. The importance of organic acids i n the e l u v i a t i o n of podzol Ae horizons was hypothesized from observational pedology but the experimental work of Bloomfield (1953a,1953b, 1954a, 1954b, 1954c, 1955), Martin and Reeve (1957a, 1957b), 1960), Schnitzer (1969), Schnitzer and Delong (1952, 1955), Schnitzer and Skinner (1963), and others was necessary to demonstrate the a b i l i t y of organic substances from l e a f l i t t e r and canopy drip to mobilize i r o n and aluminum. These and other workers are attempting to define the s p e c i f i c substances and mechanisms involved i n t h i s m o b i l i z a t i o n but such mechanisms should be shown to operate i n natural systems before r e c e i v i n g widespread acceptance. THE DEVELOPMENT OF CANADIAN CONCEPTS OF PODZOL GENESIS The evolution of concepts of Podzolic s o i l genesis i n Canada can give some i n s i g h t i n t o the a p p l i c a t i o n of experimental and observational pedology. I n i t i a l l y Canada i n h e r i t e d the concept of Podzolic s o i l s from Russian and European pedologists. The bleached e l u v i a l (Ae or A2) horizons of such s o i l s was viewed as the e s s e n t i a l c h a r a c t e r i s t i c of Podzolic s o i l s . Subsequent studies gradually led to a process-based theory of Podzol genesis. Stobbe and Wright 0-959) i n t h e i r paper "Modern concepts of the genesis of Podzols" apply the s c i e n t i f i c method to the question of Podzol genesis. They out l i n e the d i s c r e d i t i n g of a number of mechanisms of i r o n m o b i l i z a t i o n and - 5 -deposition by reference to experimental and observational data. For example, the mechanism of simple acid s o l u t i o n weathering producing c h a r a c t e r i s t i c Podzol morphology was discounted when experimental r e s u l t s showed that the 3+ s o l u b i l i t y of Fe at pH above 3.5 was n e g l i g i b l e and observational r e s u l t s demonstrated that most Podzols do not reach such low values. The humus protected s o l theory of Aarnio (1913) , although supported i n part by the experimental work of Deb (1949), had to be rejected because p r e c i p i t a t i o n i n the B horizon depended on high l e v e l s of divalent cations i n the B horizon. Many Podzols show very low concentrations of divalent cations i n the B horizon and the experimental work by Deb could not demonstrate p r e c i p i t a t i o n by calcium saturation (Stobbe and Wright,1959). Stobbe and Wright (1959) r e f l e c t e d p r e v a i l i n g Canadian concepts of Podzols i n which the Ae horizon was of major importance. The e l u v i a t i o n of clay was viewed as a r e q u i s i t e conditioning process f o r the mobili z a t i o n of i r o n and aluminum sesquioxides and not as a s o i l forming process leading to i l l u v i a t i o n and the formation of clay enriched horizons. Stobbe and Wright concluded that, "...the p r e v a i l i n g concepts of the genesis of Podzols are that the per c o l a t i n g decomposition products of organic matter, p a r t i c u l a r l y the organic acids and other complexing substances, bring about the so l u t i o n of sesquioxides, the reduction of Fe and the formation of soluble metal-organic complexes, some of which may be chelates. The complexes move to the lower horizons and are p r e c i p i t a t e d under o x i d i z i n g conditions probably by the destruction of the ligands by microorganisms and/or by sorption." - 6 -They further noted i n t h e i r conclusions, "While the theories i n v o l v i n g complex, formation and possibly chelation appear to be reasonable, more f a c t u a l information i s required before i t can be d e f i n i t e l y concluded that these processes play a major r o l e i n Podzol formation. More information i s needed on the c o n s t i t u t i o n , p a r t i c u l a r l y the number and kinds of periphery groups, of the organic material(s) moving through the A2 and the B horizon. Also, the mechanisms advanced f o r the p r e c i p i t a t i o n of sesquioxides to form the B horizon are based on inconclusive • evidence and require further research." From 1955 to 1965 the concept of the Podzol and Podzolic s o i l s des-cribed by Stobbe and Wright was r e f l e c t e d i n the d e f i n i t i o n of Podzolic s o i l s presented i n 1955 at the Third Conference of the National S o i l Survey Committee (Canada). Podzolic s o i l s were defined as " S o i l s with (A2) bleached e l u v i a l horizons and (B2) i l l u v i a l horizons having accumulations of Pw,^ 3 a n d / o r organic matter or clay (not Solonetzic B)". These s o i l s are subdivided at the next lowest category using, as one of the c r i t e r i a , the nature of the i l l u v i a l products and Podzols are now r e s t r i c t e d to s o i l s whose B2 horizons show i l l u v i a l ^2^3 and/or organic matter. I t i s of note that while sesquioxide, organic matter, and clay enrichment were considered diagnostic, no chemical l i m i t s or extraction techniques were s p e c i f i e d . In 1965, at the meetings of the National S o i l Survey Committee, the c i t r a t e - b i c a r b o n a t e - d i t h i o n i t e e x t r a c t i o n of Mehra and Jackson (1960) i n general use as a means of evaluating i r o n oxide contents of s o i l s was replaced by the acid ammonium oxalate extraction of Tamm (1922), as modified by Schwertmann (1964) (NSSC, 1965). A combination of - 7 -observational and experimental work by McKeague and Day (1966) had demonstrated that oxalate extracted much l e s s primary i r o n from s o i l s than did d i t h i o n i t e and was able to i n d i c a t e Bf development even i n i r o n r i c h materials. D e f i n i t e l i m i t s of i r o n plus aluminum increases i n the B horizon over the C horizon were adopted but the morphological concepts remained e s s e n t i a l l y the same. With d e f i n i t e chemical c r i t e r i a for the i d e n t i f i c a t i o n of Podzols established, emphasis s h i f t e d away from the Ae horizon to the B horizon u n t i l by 1968, the Ae horizon was no longer a requirement for Podzolic s o i l s (NSSC, 1968). This s h i f t i n emphasis represented a dramatic break with the " c l a s s i c a l " concept of the Podzol prevalent i n Europe and the Soviet Union. Podzol s o i l s i n Canada were now, by d e f i n i t i o n , s o i l s with accumulations of oxalate extractable i r o n plus aluminum i n the B horizon greater than some s p e c i f i e d value r e l a t i v e to the C horizon. There i s no requirement that t h i s i r o n plus aluminum be i l l u v i a l and, i n f a c t , many s o i l s c l a s s i f i e d as o x i s o l s and u l t i s o l s i n the S o i l Taxonomy of the United States would meet those chemical requirements fo r a Podzol. Much of the pedological work being done i n Canada during the period 1955 to 1973 was directed towards defining chemical c r i t e r i a which would allow the d i f f e r e n t i a t i o n of major s o i l types on the basis of w e l l defined procedures. This work, despite i t s reference to laboratory methods, was p r i m a r i l y observational rather than experimental. Various extraction procedures were evaluated f o r t h e i r a b i l i t y to d i s t i n g u i s h already established classes of s o i l s (McKeague and Day, 1965; McKeague et a l . , 1971). Large - 8 -numbers of s o i l s showing c h a r a c t e r i s t i c Podzol morphology were analysed and class l i m i t s set on the basis of empiricism. The rigorous a p p l i c a t i o n of these class l i m i t s l e d to the recognition of Podzols lacking Ae horizons even though the ce n t r a l concept of the Podzol (the Orthic subgroups) required Ae horizons to be present. Despite adoption of the a c i d ammonium oxalate extraction as diagnostic i n 1968, work continued on forms of extractable i r o n and aluminum. Experimental work (Aleksandrova, 1960; Bascomb, 1968; McKeague, 1968; McKeague et a l . , 1971) demonstrated a high degree of s p e c i f i c i t y of pyrophosphate extractions for o r g a n i c a l l y bound i r o n and, to a l e s s e r extent, aluminum. The c l a s s i c a l concept of Podzol genesis being the r e s u l t of organic m o b i l i z a t i o n and deposition of i r o n and aluminum made the value of sodium pyrophosphate extractable i r o n plus aluminum an a t t r a c t i v e possible c r i t e r i o n for Podzol c l a s s i f i c a t i o n . Problems with d i s t i n g u i s h i n g amorphous i r o n plus aluminum derived from v o l c a n i c ash and o r g a n i c a l l y mobilized i r o n and aluminum, and the s u s c e p t i b i l i t y of some iron-bearing primary minerals to attack by acid ammonium oxalate led the Canada S o i l Survey Committee to adopt sodium pyrosphosphate extractable i r o n plus aluminum as the major chemical c r i t e r i a f o r Podzols i n 1973 (McKeague, personal communication). At the same time the requirement for an Ae horizon i n the Orthic subgroups was dropped, thereby completing the s p l i t with the t r a d i t i o n a l concept of Podzols. The Canadian Podzol now requires only a minimum l e v e l of organic matter and/or pyrophosphate extractable i r o n plus aluminum i n a morphological B horizon at l e a s t 10 cm t h i c k . - 9 -This change i n c r i t e r i a , i f viewed i n the context of experimental work, may i n f a c t more l e g i t i m a t e l y measure the amount of o r g a n i c a l l y bound ir o n and aluminum i n a B horizon but leaves some serious questions unanswered. For example, i f we s t i l l view Podzol B horizons as o r g a n i c a l l y mobilized (rather than complexed) i r o n and aluminum, why i s the Ae horizon no longer diagnostic? What i s the mean residence time of o r g a n i c a l l y complexed i r o n and aluminum i n a s o i l and does i t r e f l e c t more than a short term balance of accretion and degradation through b i o l o g i c a l a c t i v i t y ? RATIONALE FOR THE STUDY This study was designed to c l a r i f y and test the concepts of Podzol formation i m p l i c i t i n "The Canadian System of S o i l C l a s s i f i c a t i o n " . The current c l a s s i f i c a t i o n c r i t e r i a of Podzolic s o i l s are: S o i l s of the Podzolic order are defined on the basis of a combination of morphological and chemical c r i t e r i a of the B horizons. S o i l s of the order must meet the following l i m i t s . Morphological 1. The podzolic B horizon i s at l e a s t 10 cm t h i c k and has moist, crushed colors as follows: a. The color i s black or the hue i s e i t h e r 7.5YR or redder or 10YR near the upper boundary and becomes yellower with depth. b. The chroma i s higher than 3 or the value i s -3 or l e s s . 2. The accumulation of amorphous material i n the podzolic B horizon i s ind i c a t e d by: a. Brown to black coatings on some mineral grains or brown to black microaggregates. b. A s i l t y f e e l when rubbed wet unless the material i s cemented. 3. The texture of the podzolic B horizon i s coarser than clay. 4. The s o i l e i t h e r has no Bt horizon or the upper boundary of the Bt horizon i s at a depth greater than 50 cm from the mineral s o i l surface. - 10 -Chemical 1. The s o i l s have a B.subhorizon (Bh) at le a s t 10 cm thick that contains more than 1% organic C, les s than 0.3% pyrophosphate-extractable Fe, and has a r a t i o of organic C to pyrophosphate-extractable Fe of 20 or more. 2. A l t e r n a t i v e l y , the s o i l s have a B subhorizon (Bf or Bhf) at least 10 cm thick with the following c h a r a c t e r i s t i c s : a. An organic C content of more than 0.5%. b. A pyrophosphate-extractable Al+Fe content of 0.6% or more i n textures f i n e r than sand and of 0.4% or more i n sands (coarse sand, sand, fine sand, and very f i n e sand). c. A r a t i o of pyrophosphate-extractable Al+Fe to clay (<2um) of more than 0.05. d. A r a t i o of organic C to pyrophosphate-extractable Fe of l e s s than 20, or pyro-phosphate-extractable Fe at le a s t 0.3%, or both. A Bf contains 0.5-5% organic C, and a Bhf contains more than 5% organic C. McKeague et a l . (1978) summarize the genesis of Podzolic s o i l s as follows, "The genesis of Podzolic s o i l s involves leaching, depletion of bases, the i n t e r a c t i o n of soluble organic matter with s o i l minerals and the tra n s l o c a t i o n of materials." It i s i n t e r e s t i n g to note that e l u v i a t i o n and i l l u v i a t i o n of organic matter and/or sesquioxides are not mentioned, nor i s the nature or d i s t r i b u t i o n of the translocated material s p e c i f i e d . The paper o u t l i n e s a concept of Podzols and Podzol genesis that i s f a r more d e t a i l e d than that quoted above but, with the exception of b r i e f reference to Podzolic s o i l s lacking Ae horizons, the processes discussed are remarkably s i m i l a r to the European and Soviet concepts of Podzolic processes. These processes centre on the e l u v i a t i o n of i r o n and aluminum from the Ae horizon and i l l u v i a t i o n of organic matter and i r o n and aluminum i n the B horizon. A l l examples used i n McKeague et^ a l . (1978) were s o i l s with Ae and/or Ahe horizons. - 11 -The p r e v a i l i n g c e n t r a l concept of Podzolic s o i l s i n Canada seems to be at odds with the morphological and chemical c r i t e r i a used to define them. I t i s possible that undue emphasis was placed on empirical r e s u l t s without adequate reference being made to observational anomalies during the formulation of Podzolic s o i l c l a s s i f i c a t i o n c r i t e r i a . HYPOTHESES This study described three s o i l s occuring over a climosequence as a means of cha r a c t e r i z i n g Podzol forming processes. Inconsistencies i n measures of Podzol expression (presented i n Chapter II) led to the following hypotheses: 1) The balance of additions, losses, transformations, and translocations within and between horizons w i l l vary across the climosequence. 2) The three s o i l s studied can be distinguished by the balance of processes acting to produce sesquioxide. r i c h B horizons at each s i t e . 3) Differences i n the rate of biochemical c y c l i n g of i r o n and aluminum w i l l influence the i n t e n s i t y of Podzolic B horizon expression. 4) Current Podzol c l a s s i f i c a t i o n c r i t e r i a do not r e f l e c t differences i n the balances of these processes. Chapter II describes the study area, sampling design and a n a l y t i c a l methods used. I t establishes the existence of a climosequence, the uniformity of s o i l forming v a r i a b l e s other than climate; and i t tes t s f o r differences i n morphological and chemical measures of Podzol expression along the defined climosequence. In ad d i t i o n , Chapter I I presents rates of movement of calcium, magnesium, sodium, potassium, i r o n and aluminum between the canopy, forest f l o o r , B l and B2 horizons of the s i t e s . S i t e differences are tested - 12 -and the values of i r o n and aluminum measured are discussed i n terms of current theories on i r o n and aluminum mob i l i z a t i o n . Chapter I I I develops a simple l i n e a r model, based on observational pedology, to provide a means of evaluating the data presented i n Chapter II and uses the model as a means of t e s t i n g the above hypotheses. - 13 -CHAPTER I I MORPHOLOGY AND CHEMISTRY INTRODUCTION S o i l s of the Podzolic order i n the System of S o i l C l a s s i f i c a t i o n f o r Canada (1978) must meet both morphological and chemical requirements. Three s o i l s occurring on a climosequence across what are considered to be B r u n i s o l i c and Podzolic s o i l forming environments (Valentine eT a l . , 1978) provided a means of evaluating morphological and chemical changes i n response to a presumed in c r e a s i n g l y Podzolic environment. Changes i n morphological expression, s o i l chemistry, and rates of biochemical c y c l i n g can be interpreted as a response to c l i m a t i c changes; The various measures of Podzol expression, both h i s t o r i c a l and current, can be compared to the c l i m a t i c gradiant. The mountainous t e r r a i n and P a c i f i c Maritime climate of coastal B r i t i s h Columbia combine to produce a broad range of s o i l climates within r e l a t i v e l y short distances. The remaining undisturbed forest cover and r e l a t i v e l y uniform age of Pleistocene g l a c i a l deposits makes the lo c a t i o n of r e a d i l y accessible climosequences possible. The r e l a t i v e l y low f l o r i s t i c d i v e r s i t y of the area r e s u l t s i n plant communities of very s i m i l a r f l o r i s t i c character which occur across s i g n i f i c a n t c l i m a t i c ranges. This f l o r i s t i c s i m i l a r i t y allows f o r the s e l e c t i o n of a climosequence on which the f l o r i s t i c composition and structure are not s i g n i f i c a n t v a r i a b l e s . I t i s possible then, with the standardization of r e l i e f and parent m a t e r i a l , to f i n d a true climosequence. S t r a t i f i e d random sampling using segments of a climosequence as the basis f o r s t r a t i f i c a t i o n provided the means of ensuring that s o i l differences - 14 -would be found but that actual s i t e s e l e c t i o n would not be biased by s t r a t i f i c a t i o n on actual pedogenic properties. The use of a climate-based s t r a t i f i c a t i o n also f a c i l i t a t e d the i n t e r p r e t a t i o n of the r e s u l t s since differences would be a t t r i b u t a b l e to c l i m a t i c d i f f e r e n c e s . MATERIALS AND METHODS STUDY AREA The study area i s located approximately 25 km south west of Nanaimo City at 49°02' north l a t i t u d e and 124°12' west longitude. I t l i e s on the eastern side of Vancouver Island Mountains and adjacent to the Nanaimo lowland (Holland, 197;4) . Climate of the area i s strongly influenced by three f a c t o r s . Lying on the eastern side of the Vancouver Island Mountains, where the highest peaks are i n excess of 2135 m, the area i s influenced by a pronounced r a i n shadow. In addition to the r a i n shadow e f f e c t , a summer high pressure ridge centred on the Coastal C o r d i l l e r a causes a northward d e f l e c t i o n of P a c i f i c Ocean a i r masses r e s u l t i n g i n a pronounced drought. Thus of the 66 to 300 cm of annual p r e c i p i t a t i o n recorded on the south east of Vancouver Island only about 10% of t h i s comes during the summer months. Within t h i s general c l i m a t i c regime large elevation changes over short distances produce marked vegetation zonation along e l e v a t i o n a l sequences, presumably i n response to c l i m a t i c gradients. In addition, the moderating marine influence at lower elevations and high snow pack at higher elevations combine to produce a s o i l c l i m a t i c regime i n which the mineral s o i l seldom, i f ever, freezes. Within t h i s general c l i m a t i c regime three s i t e s were chosen to represent - 15 -a climosequence of s o i l s . S i t e s e l e c t i o n was based on c l i m a t i c inferences from vegetation-climate r e l a t i o n s h i p s outlined by K r a j i n a (1969). Climatic inferences were supported by two years monitoring of meteorological data at each s i t e . Within t h i s i n f e r r e d climosequence the other s o i l forming factors of Jenny (1941) were held as constant as p o s s i b l e . S i t e 1, at e l e v a t i o n 365 m and sloping approximately 8.5 degrees south, represents the Coastal Douglas f i r wet subzone ( a f t e r K r a j i n a , 1969) or the Nanaimo & Georgia variant of the Wetter Maritime Coastal Douglas f i r subzone (a f t e r K l i n k a et a l . , 1979). Table 2-1 gives summary data f o r the three Biogeoclimatic subzone variants represented by S i t e s 1, 2 and 3. S i t e 2, at elevation 550 m and sloping approximately 8.5 degrees south east, represents the dry subzone of the Coastal Western Hemlock Zone ( a f t e r K r a j i n a , 1969) or the East Vancouver Island variant of Drier Maritime Coastal Western Hemlock subzone ( a f t e r K l i n k a et_ a l . , 1979) . S i t e 3, at 730 m and sloping approximately 7 degrees east, represents Coastal Western Hemlock wet subzone ( a f t e r K r a j i n a , 1969) or the East Vancouver Island Montane variant of the Wetter Maritime Coastal Western Hemlock subzone ( a f t e r K l i n k a et a l . , 1979). Sit e s 1 and 3 represent the wetter and d r i e r ends of t h e i r respective subzones. SAMPLING DESIGN Sampling was conducted using a two stage s t r a t i f i e d sampling design. Three s i t e s , each representing a d i f f e r e n t c l i m a t i c range but sharing common ranges of r e l i e f , parent material, and vegetation, were chosen. Within each s i t e three .04 ha p l o t s were chosen at random and within each Table 2-1. Summary Climat i c C h a r a c t e r i s t i c s f o r the Biogeoclimatic Units Represented by the Study S i t e s * S i t e 3 West S i t e 1 S i t e 2 Vancouver Island Nanaimo & Georgia East Vancouver Island Montane Wetter Maritime CWH Climatic C h a r a c t e r i s t i c s Wetter Maritime CDF Drier Maritime CWH Number of c l i m a t i c data 11 6 11 sets Mean annual p r e c i p i t a t i o n (mm) 1217 (257.7)** 2060 (267.3) 3941 (411.9) Mean temperature of the coldest month (°C) 1.5 (0.82) 0.9 (1.12) 0.1 (0.99) Index of c o n t i n e n t a l i t y 14 (2.6) 15 (5.5) 2 (3.7) Mean r a d i a t i o n during growing season (Ly) 42600 (1240) 42200 (2130) 39600 (1570) Mean p r e c i p i t a t i o n April-September (mm) 260 (44.3) 404 (38.5) 967 (135.8) Mean temperature of the warmest month (°C) 16.7 (1.14) 16.8 (1.53) 10.2 (0.98) Accumulated degree days over 5.6°C 1534 (196.8) 1540 (213.9) 502 (118.4) Fr o s t - f r e e period (days over 0°C) 207 (18.3) 196 (16.4) 170 (13.9) Mean p r e c i p i t a t i o n of the d r i e s t month (mm) 27 (7.7) 36 (4.1) 102 (20.3) Mean p r e c i p i t a t i o n of the wettest month (mm) 207 (46.9) 347 (40.6) 597 (55.1) Data i s taken from Klinka jet a l . , 1979 Standard deviations - 17 -Mean annual temperature (°C) Number of months w i t h mean temperature over 10°C Number of months w i t h mean temperature below 0°C Water s u r p l u s (mm) Water d e f i c i t (mm) Number of months w i t h water d e f i c i t Maximum snow depth (cm) Number of months w i t h s n o w f a l l P o t e n t i a l e v a p o t r a n s p i r a t i o n (mm) A c t u a l e v a p o t r a n s p i r a t i o n (mm) R a t i o a c t u a l to p o t e n t i a l e v a p o t r a n s p i r a t i o n (%) A c t u a l e v a p o t r a n s p i r a t i o n : A p r i l - S e p t e m b e r (mm) A c t u a l e v a p o t r a n s p i r a t i o n February (mm) A c t u a l e v a p o t r a n s p i r a t i o n : March (mm) A c t u a l e v a p o t r a n s p i r a t i o n : A p r i l (mm) 8.8 8.7 5.0 (0.74) (0.61) (0.48 4.8 5.0 0.6 (0.60) (0.0) (1.03) 0.0 0.0 0.4 (0.0) (0.0) (0.92) 826 1626 3516 (249.7) (263.0) (421.3) 192 133 3 (26.2) (17.3) (8.7) 3.8 2.2 0.2 (0.40) (0.41) (0.60) 15 35 139 (10.8) (19.7) (38.3) 1.5 2.2 6.0 (0.93) (1.17) (0.77) 581 567 436 (12.4) (19.4) (15.0) 390 432 433 (28.8) (13.0) (8.1) 67 76 99 (4.4) (2.4) (1.8) 344 396 419 (33.0) (16.3) (9.2) 4 1 0 (3.2) (1.8) (0.0) 24 21 0 (2.3) (0.9) (0.0) 53 50 23 (1.3) (1.9) (0.9) - 18 -Actual evapotranspiration: 94 93 80 May (mm) (4.7) (4.8) (3.3) Actual evapotranspiration: 87 106 93 June (mm) (10.5) (6.1) (4.6) Actual evapotranspiration: 27 47 103 July (mm) (7.7) (8.1) (5.1) Actual evapotranspiration: 36 45 75 August (mm) (10.9) (8.1) (4.1) Actual evapotranspiration: 48 55 45 September (mm) (4.6) (7.6) (1.4) Actual evapotranspiration 17 14 14 October (mm) (3.3) (2.1) (2.4) Actual evapotranspiration: 1 0 0 November (mm) (1.8) (0.0) (0.0) - 19 -p l o t a number of sampling locations were chosen at random (see Figure 2-1). S i t e s and p l o t s used were the same for a l l parameters measured but sampling locations and numbers within plots varied between parameters. Daily maximum and minimum temperatures were recorded using 30 day recording hygrothermographs, located i n immediately adjacent c l e a r cuts. For forested p l o t temperatures 30 day recording remote probe thermographs were used; at 160 cm above ground, at the surface of the mineral s o i l below the forest f l o o r , and at 20 cm depth i n the mineral s o i l . Only one observation point was monitored for each s i t e . Incident p r e c i p i t a t i o n was measured using three c o l l e c t o r s per s i t e i n adjacent c l e a r cuts. Water volumes were measured and sampled f o r chemical analysis as soon as p r a c t i c a b l e following r a i n during the summer months and monthly during the winter. Throughfall or canopy drip was measured using a t o t a l of four c o l l e c t o r s per p i t , or twenty four per s i t e . Volume measurement followed the same regime as incident p r e c i p i t a t i o n but sampling for chemical analysis was done by combining the contents of four c o l l e c t o r s and then subsampling to provide two samples per pl o t f o r chemical a n a l y s i s . Solution moving from the forest f l o o r into the mineral s o i l , from the upper diagnostic B horizon into the lower horizons, and f i n a l l y out of the rooting zone was c o l l e c t e d f o r analysis using 6 inch diameter Alundum lysimeter plates attached to hanging water columns to provide tension (Cole, 1958). Two lysimeter plates per sampling depth were i n s t a l l e d at each p l o t providing a t o t a l of s i x sampling stations per s i t e for each depth. S o i l matrix p o t e n t i a l was monitored using nests of f i v e gypsum FIG.2-I SAMPLING DESIGN SITE PLOT I PLOT 2 PLOT 3 A * SITE CLIMATE PLOT X = THROUGHFALL COLLECTORS ASSOCIATED WITH PIT I Y = THROUGHFALL COLLECTORS ASSOCIATED WITH PIT 2 Z = NEST OF GYPSUM B L O C K S PIT 1 " L F H LEACHATE 2 = B| LEACHATE 3 =B 2 LEACHATE C* COLLECTION CONTAINERS S3 o - 21 -resistance blocks i n s t a l l e d at 15 cm depth increments from the forest f l o o r down. Two nests per plot were monitored weekly during the summer. Two s o i l p i t s with a minimum longest dimension of 1 meter and a minimum depth of 1.2 meters each were located at random i n each plot. Morphological descriptions and sampling were done on the upslope p i t face and one side. Total cross sectional sampling area was 11.60 m x 1.20 m for Site 1, 10.75 m x 1.50 m for S i t e 2, and 10.40 m x 1.50 m for Site 3. Bulk density and coarse fragments were determined at successive depths during excavation of the p i t . The technique used and the volume of sample necessary precluded bulk density determination on a horizon by horizon basis. Following excavation of the p i t , each morphologically d i s t i n c t area was delineated, diagramed to scale, and sampled. Samples were taken from the entire delineated area of each horizon pocket, or layer. Instrumentation and coll e c t o r design are described i n Appendix 1. ANALYTICAL METHODS A l l water samples were treated and analysed i n the same way. Two hundred and f i f t y m i l l i l i t r e subsamples were taken from each c o l l e c t o r , a c i d i f i e d with HC1 and stored at 4°Centigrade u n t i l analysed. P r e c i p i t a t i o n and throughfall were f i l t e r e d through Whatman #42 f i l t e r paper p r i o r to storage. Samples allowed to warm to room temperature were analysed for calcium, magnesium, sodium, and potassium on a Perkin Elmer 303 Atomic Absorption Spectrotophotometer and 200 ml of solution were concentrated by evaporation i n a hot water bath to 20 ml for analysis of iron and aluminum on the same instrument. - 22 -S o i l p h y s i c a l properties were determined i n the following manner. Bulk density was determined using the.excavation technique outlined i n Lavkulich (1977). Sampling depths and volumes were v a r i a b l e but at least three determinations of three l i t r e volumes or greater were made at successive depths to the high density material underlying the solum. S o i l material excavated for the determination was screened to 1.27 cm and each s i z e f r a c t i o n weighed i n the f i e l d . The l e s s than 1.27 cm s i z e f r a c t i o n was subsampled to 225 ml volumes for oven drying to convert f i e l d weights to oven dry weights. A f t e r drying, the subsamples were screened to 2 mm and each s i z e f r a c t i o n weighed. The 2 mm to 1.27 cm s i z e f r a c t i o n s and the greater than 1.27 cm inch s i z e f r a c t i o n s were added to provide an estimate of coarse fragment contents. Cumulative p a r t i c l e s i z e using the hydrometer techniques outlined i n H a r r i s and Lavkulich (1972) was determined for the <2 mm s i z e a i r dried samples of each major horizon or pocket described i n the f i e l d . A l l chemical analyses were conducted on a i r dried m a t e r i a l , crushed with a wooden r o l l e r and sieved to l e s s than 2 mm. The following chemical analyses were performed: pH (0.01 M C a C l 2 ) , % carbon (Leco induction furnace), % nitrogen (Macro-Kjeldahl), cation exchange capacity (Na 0 Ac at pH 7.0) and exchangeable bases, sodium pyrophosphate (pH 10.0) extractable i r o n and aluminum, acid ammonium-oxalate extractable i r o n and aluminum, c i t r a t e -b icarbonate-dithionite extractable i r o n and aluminum, and t o t a l Ca, Mg, Na, K, Fe, A l , and S i (Rantala and Loring, 1973). T o t a l elemental analysis was done on only 2 of the 3 p l o t s at each s i t e . A l l analyses except Macro-Kj e l d a h l and t o t a l elemental analysis were done following Lavkulich and Harris (1972). - 23 -Macro-Kjeldahl followed McKeague C1976) and total elemental analysis followed Lavkulich (1977). SITE CHARACTERISTICS CLIMATE Figures 2-2 and 2-3 represent mean monthly precipitation and ambient air temperature for the period May 1975 to A p r i l 1976. The period was considered representative of the three years monitored. It was also, fortuitously, the only continuous f u l l year period during which either l o g i s t i c problems or w i l d l i f e vandalism did not cause significant data gaps. Figure 2-2 shows precipitation with consecutive bars representing Sites 1, 2 and 3 respectively. The pronounced summer dry period is characteristic of the area, as i s the marked period of high precipitation from October to May. Although not distinguished here the months of January and February had snow accumulations ranging from 30 cm at Site 1 to 100 cm at Site 3. F ield observations and lysimeter collections indicate that v i r t u a l l y a l l of this snow cover entered the solum during snow melt. No significant differences i n incident precipitation were recorded between sites and total annual precipitation was nearly identical at a l l s i tes . Figure 2-3, presenting mean monthly maximum and minimum air temperatures by s i te , shows a typical pattern for the area. Unlike precipitat ion, Sites 1, 2 and 3 show a relat ively consistent decrease in mean air temperature along the inferred climosequence. Missing data precludes a similar presentation of s o i l temperature but the same pattern was evident, although damped, with s o i l temperatures being consistently lower along the climosequence. PRECIPITATION (cm) - 25 -FIG. 2-3 MEAN MONTHLY MAXIMUM, MINIMUM, AND MEAN TEMPERATURES 30T I - 26 -At no time during the 3 year monitoring period did the s o i l freeze, although the forest f l o o r would occasionally freeze f o r short periods during December and May. During these periods, generally overnight, the forest f l o o r was s t i l l highly porous and had thawed p r i o r to any incident p r e c i p i t a t i o n . Figure 2-4 presents s o i l matrix p o t e n t i a l f o r the period June to October 1974, the d r i e s t year monitored. Bars represent mean s i t e values for the forest f l o o r , diagnostic (B^) horizon and second major (B2) horizon re s p e c t i v e l y . Readings were taken weekly. Figure 2-4a presents data from S i t e 1, Figure 2-4b data from S i t e 2, and Figure 2-4c data from S i t e 3. Despite comparable p r e c i p i t a t i o n inputs, decreasing temperature and aspect differences(south to southeast to east) combine to produce a strong gradient along the i n f e r r e d climosequence. S i t e 1, shows a three week period during which the forest f l o o r and the B^ horizon approach or exceed permanent w i l t i n g point (15 bars) and a one week period during which the B 2 horizon exceeds 10 bars. S i t e 2 shows a one week period during which the forest f l o o r exceeds 15 bars and both the B^ and B 2 exceed 5 bars, although at no time did e i t h e r exceed 10 bars. S i t e 3 remained moist for the whole summer, at no time did any portion of the s o i l exceed 5 bars. I t should be pointed out that despite the l i m i t a t i o n s of gypsum resistance blocks, gravimetric samples confirmed water contents lower than hygroscopic moisture content f o r those s o i l s monitored at greater than 30 bars matrix p o t e n t i a l . / S i t e s 1 and 3 represent the wetter and d r i e r ends of t h e i r respective subzones. The change from south to east aspect compresses both the elevation - 27 -FIG. 2-4 (A) 8ITE I 4 0 T 30 H 20 H I0H SOIL MATRIX POTENTIAL (IN BARS) WEEKLY MEAN SITE VALUES BY HORIZON 0 LBD u n _ _ i n a _ d h _ _ u n _ J U N E I J U L Y JUL (B) SITE 2 30-1 20 10 AUGUST SEPTEMBER' OCTOBER -jib dL JUNE ( C ) 3ITE 3 30 T JULY AUGUST SEPTEMBER 1OCTOBER 20 ° JUNE " ' " m I " n A „ ^ , , C T m i • l i n ™ tfh nn , nn im tm JULY AUGUST S E P T E M B E R 1 OCTOBER - 28 -and p r e c i p i t a t i o n range necessary to produce f l o r i s t i c d i f f e r e n c e s . Three years of p r e c i p i t a t i o n monitoring shows no s i g n i f i c a n t p r e c i p i t a t i o n differences between s i t e s . Monitoring of s o i l water matrix p o t e n t i a l and s o i l temperature does support a sequence of warm summer dry period to cool summer wet period along the sequence outlined. PARENT MATERIAL A l l three s i t e s have deep morainal deposits co n s i s t i n g of r e l a t i v e l y 3 dense (bulk density 1.45 - 1.56 g/cm ) t i l l o v e r l a i n by a r e l a t i v e l y low 3 density (bulk density .95 - 1.35 g/cm ) g l a c i a l t i l l layer approximately 85 cms i n depth. Pebble counts showed approximately 20% b a s a l t i c and 80% g r a n i t i c rock types f o r S i t e s 1 and 2 and approximately 30% b a s a l t i c and 70% g r a n i t i c rock types for S i t e 3. Clay free p a r t i c l e s i z e d i s t r i b u t i o n i ndicates uniform solum texture for S i t e s 1 and 3, while Si t e s 2 shows a la y e r of coarse material (sand vs loamy sand) below 40 cms at S i t e 2. Textures of the surface 40 cms are consistent at a l l three s i t e s (Figure 2-5) while texture below 80 cms at S i t e 3 shows a s l i g h t clay increase. RELIEF A l l s i t e s were chosen so as to minimize possible catchment for water moving downslope above the higher density t i l l s below the solum. S i t e 1 i s located approximately 150 m slope distance from the crest of an east west oriented ridge on an 8.5 degree slope and microtopography i s r e l a t i v e l y smooth. S i t e 2 occupies the convex shoulder of a northwest-southeast ridge and consists of a seri e s of 8.5 degree sloping terrace l i k e units on an over a l l 20° slope. S i t e 3 located at higher elevation on the same ridge Figure 2-5 Cumulative P a r t i c l e Size (Means and standard deviations) for the B. and B 2 Horizons x SITE I • SITE 2 A SITE 3 to VO I Ji 4 4 f!{ V 1 1.4 2.8 3.9 4.7 6.6 9.4 16.3 22.8 29.3 35.8 50.1 EQUIVALENT SPHERICAL DIAMETER OF PARTICLES (pm) 90.4 - 30 -also occupies a convex shoulder p o s i t i o n and has a 7 degree slope. Microtopography on a l l three s i t e s i s r e l a t i v e l y smooth but i s somewhat more i r r e g u l a r on Site 2. Saturation of the solum for more than a few centimeters above the dense su b s o i l was infrequent even during heavy winter rains but saturation depths of a few centimeters were common and excavations i n the more dense s u b s o i l were frequently f i l l e d with water at Sites 2 and 3. VEGETATION A l l s i t e s supported l a t e s e r a i forest stands i n excess of 200 yrs of age. F l o r i s t i c d i v e r s i t y i n the area i s low but differences between s i t e s are pr i m a r i l y i n the presence or d i s t r i b u t i o n of species with low cover values i n the berh layer and tree species present i n the understory. Stand physiognomy i s s i m i l a r on a l l s i t e s . Tsuga heterophylla (Rafinesque) Sargent and Pseudotsuga menziesii (Mirbel) Franco var. menziesii, comprise the dominant canopy on a l l s i t e s , with Tsuga heterophylla forming 60-80% of the t o t a l tree cover on a l l s i t e s . Intermediate and suppressed trees are nearly pure Tsuga heterophylla, however minor occurences of Pseutotsuga menziesii and Pinus monticola D. Douglas ex Don ( i n Lambert)at Site 1, Thuja p l i c a t a Donn ex D. Don i n Lambert at S i t e 2, and Abies amabilis (D. Douglas ex Loudon) J . Forbes Chamaecyparis nootkatensis (D. Don) Spach, and Thuja p l i c a t a at Site 3 are c h a r a c t e r i s t i c of t h e i r respective Biogeoclimatic subzone. While d i s t i n c t differences occur i n the herb and moss layers the contribution to biomass of d i f f e r i n g species i s so s l i g h t as to have l i t t l e impact on s o i l development. The shrub layer while dominated by Gaultheria shallon Pursh does have a minor component of Vaccinium parvifolium - 31 -J.E. Smith and Vaccinium alaskaense T.J. Howell with V.. alaskaense absent from S i t e 1. In addition G^. shallon shows a peak i n both cover and vigour at S i t e 2. A l l plant names are from Taylor and MacBride (1977). Stand structure consists p r i m a r i l y of mature dominant and codominant trees with only scattered intermediate siz e d trees and a moderate number (15% cover) of strongly suppressed trees. Although seedlings one to two years o l d are abundant, few seem to survive. Crown closure was 30% at S i t e 1 and 70% at Sit e s 2 and 3. Basal area and tree height were greatest at S i t e 2 while S i t e 1 showed the lowest basal area but t a l l e r trees than S i t e 3. S i t e 1 was also characterized by large openings. A complete vegetation species l i s t for each s i t e i s presented i n Appendix 4. , TIME G l a c i a l deposits are from the Fraser g l a c i a t i o n which receded approximately 10,000 years ago. The precise age of the s o i l s cannot be determined. However, no evidence could be found which would i n d i c a t e that the morainal deposits i n the v a l l e y system were not the product of the same advance. While i t i s u n l i k e l y that s o i l s were exposed at p r e c i s e l y the same time, the Fraser retreat was fast enough to ensure approximately equal ages for the deposits i n the study area. SOIL MORPHOLOGY PROFILE DESCRIPTIONS Presented below are p r o f i l e descriptions which represent the modal p r o f i l e f o r each s i t e . They are generalizations of the s i x p r o f i l e des-c r i p t i o n s done at each s i t e and present the modal value and ranges for each parameter discussed. SITE 1 ELUVIATED DYSTRIC BRUNISOL HORIZON DEPTH THICKNESS cm LFH 5.0-0 1.5-15 Ae 0-3 1-15 Bmccl 3^ -5 0-5 Bmcc2 3-34 11-34 Bm 34-66 19-50 Black 2.5YR 2/1 (10R 2/1 - 5YR 2/2) m granular-conifero- humimor underlain . by discontinuous areas of grey (5YR 5/1 m) mycelial mats; abundant f i n e and medium roots; extremely acid. Abrupt wavy to smooth boundary to Grey 10YR 5/1 (10YR 5/1 - 10YR 5/2) m gr a v e l l y loamy sand, massive, very f r i a b l e ; few f i n e and common medium roots, extremely acid. Abrupt wavy to occas i o n a l l y i r r e g u l a r boundary to Brown 7.5YR 5/6 (5YR 5/8 - 7.5YR 5/6) m gr a v e l l y loamy sand; massive, very f r i a b l e with few to common fi n e oblong concretions; few f i n e and medium roots; very strongly a c i d . Abrupt discontinuous boundary to, or Yellowish brown 10YR 5/4 (7.5YR 4/4 -10YR 5/6) m gr a v e l l y loamy sand, very weak medium subangular blocky; very f r i a b l e -f r i a b l e with few fine oblong concretions; few to common f i n e and common medium roots; very strongly a c i d . Clear, to gradual i n places, wavy boundary to Light yellowish brown 2.5Y 6/4 (5Y 5/3 -10YR 5/7) m matrix with common prominent yellowish red (10YR 4/4 - 5YR 5/8) mottles; g r a v e l l y loamy sand, very weak subangular blocky grading to moderate medium subangular blocky at depth, moist consistence grades from very f r i a b l e to firm; few f i n e and few to common medium roots are present. Fragments of underlying material showing higher bulk density bleached faces over a t h i n reddish brown layer and yellowish brown to o l i v e grey i n t e r i o r s are frequently present. Horizon i s very strongly acid and has a cl e a r wavy boundary to - 33 -BCcj 66-80 1-40 C 80+ Olive grey 5Y 5/2 (5Y 5/2 - 5Y 6/3) m matrix; g r a v e l l y sandy loam. Horizon has moderate f i n e subangular blocky to strong medium pl a t y or pseudoplaty structure. Red faces show bleached o l i v e (5Y 5/3) faces underlain by a t h i n yellowish red (5YR 5/8) band). I n t e r i o r of peds (matrix) may show common prominent f i n e (7.5YR 6/8) mottles. Consistence ranges from fi r m to extremely firm and shows a degree of b r i t t l e n e s s which may in d i c a t e weak cementation. Roots are few and r e s t r i c t e d to areas between peds, reaction i s strongly to very strongly a c i d and the horizon has an abrupt wavy boundary to Olive 5Y 5/2 (5Y 4/2 - 5Y 5/3) m; gravelly sandy loam. Massive to very coarse pl a t y , f i r m to very firm. Shows few medium to coarse prominant 5YR 5/8 mottles. Roots are rare and the upper portion of the horizon may show weak cementation. The immediate surface also shows a bleached layer s i m i l a r to the ped surfaces i n the BC horizon. - 34 -SITE 2 ELTJVIATED DYSTRIC BRUNISOL HORIZON DEPTH THICKNESS cm LFH 5^0 Ae 0-8 Bmcl Bmc2 2,5-10 2.5-30 8-38 15-60 38-63 5-45 BCc 63-88 0-60 88+ Reddish black 10 R 2.5/1 to very dusky red 2.5YR 2.5/2 granulo-conifero Humimor; abundant f i n e and medium roots; extremely acid. Abrupt wavy to smooth boundary to Grey 10YR 5/1 (5YR 5/1 - 10YR 6/1) m gra v e l l y sandy loam; massive, very f r i a b l e ; few f i n e and common medium roots, extremely a c i d . Abrupt to i r r e g u l a r boundary to Strong brown 7.5YR 5/6 (10YR 5/3 - 5YR 4/6) tending to yellow with depth, g r a v e l l y loamy sand; very weak medium subangular blocky; very f r i a b l e with pockets of weak cementation, colours tend to 5YR 4/6 i n cemented areas; few to common f i n e and common to p l e n t i f u l medium roots; very strongly acid. Clear wavy boundary to Light yellowish brown 2.5Y 6/4 (5Y 5/3 -2.5Y 6/4) m g r a v e l l y sand with common fi n e to medium yellowish red to strong brown mottles; massive very f r i a b l e with pockets of weak cementation; few f i n e and few to common medium roots, strongly a c i d . Clear to abrupt wavy boundary to Olive 5Y 5/3 (2.5Y 5/2 - 5Y 6/3) m gr a v e l l y sand to gr a v e l l y loamy sand; with common fi n e to medium prominent mottles; massive fi r m to very f i r m and somewhat b r i t t l e ; very few f i n e and medium roots; strongly acid. Abrupt to clear wavy boundary to Olive grey 5Y 4/2 (5Y 4/2 - 5Y 5/2) m gr a v e l l y loamy sand with few to common medium to f i n e prominent yellowish red mottles; massive firm consistence, very few roots; strongly acid. - 35 -SITE 3 ORTHIC HUMO-FERRIC PODZOL Reddish black 10R 2.5/1 (10R 2.5/1 -10R 3/2) granulo-conifero. Humimor underlain by discontinuous areas of grey mycelial mats. Abundant f i n e and medium roots; extremely acid. Abrupt wavy boundary to Ae 0-7 2-27 Grey to greyish brown 10YR 5/1 (10YR 5/1 - 5/1) m gr a v e l l y sandy loam; massive f r i a b l e to very f r i a b l e ; few f i n e and common medium roots; extremely a c i d . Abrupt wavy to i r r e g u l a r boundary to Bfcc 7-42 10-45 Strong brown 7.5YR 5/6 m dominant s o i l colour but with v a r i a b l e admixtures of yellowish red (5YR 4/6 - 5YR 5/8), yellowish brown (10YR 5/4 - 10YR 5/8) and l i g h t o l i v e brown (2.5Y 5/4) as pockets and mottle'" l i k e d i s t r i b u t i o n ; g r a v e l l y loamy sand with few to common fin e charcoal centred concretions; very weak to moderate medium subangular blocky very f r i a b l e to f r i a b l e with small pockets of very weak cementation; few f i n e common to p l e n t i f u l medium roots; very strongly a c i d . Clear to gradual wavy boundary to Bm 42-68 10-40 Light yellowish brown 2.5Y 6/4 (5Y 5/2 -2.5Y 5/4) m g r a v e l l y loamy sand; moderate subangular blocky to platy f i r m to very firm peds with common to many, inped and exped, f i n e to medium, prominent red to strong brown mottles, moderate peds are embedded i n a loose to very f r i a b l e near s t r u c t u r e l e s s matrix. Roots are few to common and r e s t r i c t e d to the very f r i a b l e matrix and exped areas; very strongly a c i d . Abrupt wavy to smooth boundary to HORIZON DEPTH THICKNESS cm LFH 5-0 2-9 - 36 -Bccj 68-87 9-40 C 87+ Olive 5Y 5/3 (5Y 5/3 - 5Y 5/2) m gr a v e l l y loamy sand to sandy loam; massive, very firm and s l i g h t l y b r i t t l e ; shows evidence of very coarse pseudo-p l a t y structure with occasional bleached grey (5Y 6/1) faces, upper boundary shows s i m i l a r bleaching; common to many, f i n e medium and coarse, prominent, red to yellowish red mottles occur; roots are few to absent; very strongly acid. Gradual boundary to Olive grey 5Y 5/2 (5Y 5/2 - 2.5Y 6/4) gr a v e l l y loamy sand to sandy loam; massive firm; with few f i n e medium and coarse prominent yellowish brown to strong brown mottles; roots few to absent; strongly a c i d . - 37 -RESULTS Forest f l o o r s are s i m i l a r on a l l three s i t e s and average around 5 cm thick. They are classed as granulo-conifero Humimor and the only morphological difference i s the lack of a discontinuous mycelial mat at S i t e 2. The e l u v i a t e d A horizon, considered diagnostic of Podzols i n some s o i l c l a s s i f i c a t i o n s , i s present on a l l three s i t e s but i s poorly developed at S i t e 1 and well developed at Sites 2 and 3. The Ae i s morphologically s i m i l a r at a l l s i t e s i n a l l parameters except depth which i s t h i n (^3 cm) at S i t e 1 and r e l a t i v e l y t hick (7-8 cm) on Site s 2 and 3. Upper B horizon colour development shows the following pattern. At S i t e 1, a 3 cm, strong brown (7.5YR 5/6 m) discontinuous Bmccl horizon o v e r l i e s a 31 cm, yellowish brown (10YR 5/4 m) Bmcc2 horizon. The Bmcc2 horizon tends to yellow with depth and meets the minimum morphological require-ments f o r a Podzol B horizon but i s more t y p i c a l of B r u n i s o l i c B horizons i n the area (Keser and St. P i e r r e , 1973). S i t e 2 has a 30 cm, strong brown (7.5YR 5/6 m) Bmcjl horizon which tends to yellow with depth. I t i s t y p i c a l of Podzol B horizons but f a i l s to meet current chemical requirements f o r the Podzolic Order. S i t e 3 shows s i m i l a r development to S i t e 2 with a strong brown 7.5 5/6 Bfcc horizon ^35 cm thick. The Bfcc tends to yellow with depth but shows a strong admixture of yellowish brown and l i g h t o l i v e brown pockets and mottle l i k e d i s t r i b u t i o n s . 1 Structure and consistence do not vary from s i t e to s i t e but cementation of the upper B horizons v a r i e s . S i t e 1 shows no evidence of cementation, S i t e 2 shows approximately 20% weak cementation (orterde) and S i t e 3 approximately 5% very weak cementation. Colours i n the cemented areas tend to - 38 -redder hues and lower values and chromas. Charcoal centred concretions and nodules were found at Si t e s 1 and 3 but were absent at S i t e 2. Lower B horizons, excluding the BCc horizon of S i t e 2, show the following properties. Matrix colour at a l l three s i t e s i s l i g h t yellowish brown with common prominent mottles grading from yellowish red at S i t e 1, to yellowish red and strong brown at S i t e 2, to strong brown and red at S i t e 3. In addition the percentage of mottles tends to increase as w e l l . I t should be noted here that although described as mottles these "blotches" of colour are probably not the product of p e r i o d i c saturation, since saturated conditions were r a r e l y found at t h i s depth during the coarse of the study. Structure of the Bm horizon at S i t e 1 probably represents degradation of the massive structure at depth since maximum expression of pedogenic structure would be expected i n the upper B horizons rather than at lower depths. There appears to be a gradual progression from the obvious fragments of underlying material (the i n t e r i o r s of which show the same morphological features as the C horizon and also show bleached faces) to the very weak medium subangular peds which dominate the horizon. The Bmc2 horizon of S i t e 2 shows no s t r u c t u r a l development; i t shows neither pedogenic structure nor degradation of a massive state. The horizon does show pockets of weak cementation and i s s l i g h t l y coarser textured than the overlying B horizon and the comparable horizons of S i t e s 1 and 3. The S i t e 3 Bm horizons show s i m i l a r structure to S i t e 1 but the apparent degradation of the massive structure i s not as marked. The peds, or perhaps more c o r r e c t l y i n h e r i t e d fragments, are imbedded i n a nearly s t r u c t u r e l e s s matrix i n d i c a t i n g that the weak medium subangular blocky matrix of S i t e 1 may be pedogenic. Also - 39 -the p l a t y form o f many of the former peds i s s i m i l a r to the u n d e r l y i n g s t r u c t u r a l form. The BC h o r i z o n s show s i m i l a r c o l o u r s and m o t t l e d i s t r i b u t i o n s between s i t e s . S i t e 1 shows moderate f i n e subangular b l o c k y to s t r o n g medium p l a t y o r p s e u d o p l a t y , f i r m to v e r y f i r m peds. The h o r i z o n s t r u c t u r e i s s i m i l a r to the Bm h o r i z o n of S i t e 3 but a l t e r a t i o n from the C h o r i z o n i s not as marked. I n a d d i t i o n , the p l a t y peds show a degree of b r i t t l e n e s s o r weak cementation not e v i d e n t i n the Bm of S i t e 3. The BCc h o r i z o n of S i t e 2, w h i l e showing s l i g h t l y c o a r s e r t e x t u r e and s l i g h t l y more angular coarse fragments than the u n d e r l y i n g C h o r i z o n , seems t o p r e s e n t a t r a n s i t i o n a l weather ing and pedogenic stage to the C i n t h a t the o n l y apparent d i f f e r e n c e i s i n a degree o f cementation i n d i c a t e d by b r i t t l e n e s s and f i r m e r c o n s i s t e n c e i n the BCc. S i t e 3 shows massive to v e r y coarse p l a t y s t r u c t u r e w i t h o c c a s i o n a l l y b leached faces i n d i c a t i n g g r a d u a l d e g r a d a t i o n of the massive C h o r i z o n not as advanced as at S i t e 1. H e r e , as w e l l , peds show a s l i g h t b r i t t l e n e s s i n d i c a t i n g v e r y weak cementation l a c k i n g i n the C h o r i z o n . DISCUSSION S o i l morphology i n d i c a t e s two p o s s i b l e modes o f g l a c i a l d e p o s i t i o n and subsequent s o i l development. The f i r s t mode, which i s e v i d e n t at S i t e s 1 and 2, i n d i c a t e s an i n i t i a l d e p o s i t i o n o f a compact r e l a t i v e l y h i g h b u l k d e n s i t y m a t e r i a l beneath a warm g l a c i e r . T i l l d e p o s i t i o n as wet (non-frozen) m a t e r i a l a l l o w s f o r compaction under the p r e s s u r e of o v e r l y i n g i c e . The frequent occurrence o f a r a t h e r abrupt t r a n s i t i o n from - 40 -r e l a t i v e l y low bulk density non-compact material to the higher bulk density compact material has a l t e r n a t e l y been explained as the pedogenic weathering front (primarily by geomorphologists) and as ablation t i l l overlying basal t i l l ( p r i m a r i l y by pedologists). The progression of structure from massive to very coarse p l a t y structure i n the C horizon, to subangular blocky and pseudoplaty structure i n the BC and Bm horizons, and the unweathered appearance of many ped i n t e r i o r s would tend to support the theory of a pedogenic weathering front. Colour and cementation pattern on the other hand do not conform to the d i s t r i b u t i o n pattern of structure. Depth l i m i t s for the major horizons are approximately equal, colour changes occur at approximately the same depths and cementation occurs to approximately the same depth at each s i t e . This indicates comparable depths of weathering at a l l s i t e s . Depths to s i g n i f i c a n t p l a t y peds with unweathered i n t e r i o r s and depths to massive or coarse p l a t y structure r e s p e c t i v e l y are 66 cm and 80 cm f o r Si t e 1 and 42 cm and 68 cm for S i t e 3. This would i n d i c a t e that although the massive compacted nature of the o r i g i n a l t i l l material i s gradually being degraded i t ' does not correspond to the weathering front and the occurence of non-compact material i s probably the r e s u l t of i n h e r i t e d properties as w e l l as pedogenic development. No inferences as to whether the non-compacted material i s derived at le a s t p a r t i a l l y from ablation t i l l or simply l e s s compacted basal t i l l can be made, except to note that no evidence of water-worked textures or s t r a t i f i c a t i o n was found at Sites 1 or 3. Si t e 2 i n contrast shows no evidence of t h i s progressive s t r u c t u r a l change. Bulk d e n s i t i e s are s i g n i f i c a n t l y lower and there i s no evidence of p l a t y or pseudoplaty structure. While materials are s t i l l classed as - 41 -g l a c i a l t i l l they lack the coherence and matrix c h a r a c t e r i s t i c s of the basal or compacted t i l l at S i t e s 1 and 3. As noted e a r l i e r s o i l s at t h i s s i t e show s l i g h t l y coarser textures and more angular coarse fragments at depth than e i t h e r the overlying material or the materials found' at S i t e s 1 and 3. A p l a u s i b l e explanation of t h i s deposition pattern l i e s i n the presence of a rock promontory extending i n t o the v a l l e y at r i g h t angles to the presumed flow of i c e . S i t e 2 l i e s i n the immediate lee of t h i s promontory and the coarser textured more angular materials may have been sheared o f f the promontory and deposited beneath the entrained material. The angularity of material argues f o r a short distance of transport and the low bulk density and non-compact nature of the deposits can be explained by deposition i n the lee of the promontory where i c e loading would be lower. Morphological expression of Podzol formation i s weak at S i t e 1. The th i n Ae horizon and yellowish brown Bmcc2 horizon are t y p i c a l of E l u v i a t e d D y s t r i c Brunisols rather than Podzols. S i t e s 2 and 3, on the other hand, show w e l l developed Podzol morphology, the 7-8 cm Ae horizon and 30-35 cm strong brown upper B horizons with pockets of weak cementation (orterde) are t y p i c a l of Humo F e r r i c Podzols i n the area (Keser and St. P i e r r e , 1973). If anything, the s l i g h t l y deeper Ae horizon, stronger and more extensive cementation, and more consistent Podzol B colours would suggest S i t e 2 as marginally the most strongly expressed Podzol. As noted on the p r o f i l e d e s c r i p t i o n s , however, only S i t e 3 meets both morphological and chemical c r i t e r i a of a Podzol. - 42 -SOIL ANALYSIS For the purpose of discussion horizons, pockets, and layers were grouped into the f i v e major horizons l i s t e d f o r each s i t e . The horizons designated were based on an evaluation of the morphological and chemical data of each sample. This was done for each s o i l p i t and the values for each horizon calculated as the sum of the values of each horizon or pocket m u l t i p l i e d by i t s c r o s s - s e c t i o n a l sampling area and divided by the cross-s e c t i o n a l area of the horizon. I t should be noted here that the Bmccl and Bmcc2 horizons described i n the p r o f i l e d e s c r i p t i o n of S i t e 1 were grouped into the Bmcc (using the same method) for purposes of comparison between s i t e s . STATISTICAL MODEL The s t a t i s t i c a l model presented i n Table 2-2 was used to test the n u l l hypothesis that no s i g n i f i c a n t s i t e differences e x i s t . Analysis of variance was done using the s t a t i s t i c a l program UBC MFAV (Chinh D.Le 1980). Table 2-3 presents some of the standard s o i l analyses giving mean s i t e values, analysis of variance, and Duncan's New Mu l t i p l e Range Test based on the weighted mean horizon values for each p i t . - 43 -Table 2-2. Model f o r Analysis of Variance of S o i l Properties. Source of Variance Degrees of Freedom Test Sit e s 2 Plots e Site s Plots c S i t e s 6 P i t s c P l o t s c S i t e s P i t s c P l o t s c S i t e s (Error) 9 Total 17 RESULTS Bulk Density, pH, Carbon, Nitrogen, and Bases Bulk density measurements are presented as grams of f i n e earth per cubic centimeter of t o t a l s o i l so that c a l c u l a t i o n s of value x bulk density w i l l y i e l d unit volume horizon values corrected for bulk density and coarse fragment content. As noted e a r l i e r , the method used for bulk density determination precluded horizon s p e c i f i c determinations so the values presented are interpolated f o r each p i t from determinations made by depth. The figures represent the s i t e mean and standard deviations of these i n t e r -polations. As would be expected from the p r o f i l e descriptions bulk density shows a general increase with depth on a l l s i t e s . S i t e 1 shows s l i g h t l y higher bulk de n s i t i e s i n the surface three horizons and S i t e 2 i s notable for the lower values i n the BCc and C horizons. This i s consistent with the proposed modes of deposition. Also of note i s the high bulk density of the BCcj horizons of S i t e 3, which s t i l l r e t a i n much of the massive character of the underlying compacted t i l l . S t a t i s t i c a l analysis of the Table 2-3. Mean Site Values for Soil Analytical Data Presented by Horizon Horizon Site Depth cms Thickness cms B.D. g/cm3 PH % C 1 % N 1 Ca 2 Mg2 Na2 K 2 2 C.E.C. NaP Fe 1 NaP A l 1 AMOX Fe1 AMOX A l 1 CBD Fe 1 CBD Al' 1.14 1.96 .02 .94 .16 .04 .10 10.3 .08 .08 .25 .10 .39 .07 1.07 3.8 1.32 .02 .66 .14 .04 .16 7.1 .03 .04 .29 .08 .31 .05 1.08 3.7 1.55 .02 .76 .16 .04 .15 6.2 .04 .04 .14 .06 .40 .04 N.S. N.S. N.S. N.S. N.S. N.S. * ** ** ** * * ** * N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. 231 123 231 213 123 132 123 231 321 312. 221 213 321 — —'— — ~"— ~ 1.27 4.6 1.30 .02 .15 .04 .04 .20 8.6 .11 .39 .70 1.21 .98 .63 1.20 4.7 1.36 .02 .19 .04 .03 .12 11.4 .09 .41 1.21 1.82 1.19 .78 1.16 4.7 1.76 .04 .29 .06 .04 .15 12.7 .18 .50 .64 1.30 1.10 .78 N.S. N.S. N.S. ** N.S. N.S. N.S. N.S. N.S. ** N.S. ** N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. ** ** 123 123 123 123 123 231 231 123 213 123 312 132 132 123 1.33 4.9 .72 .01 .15 .02 .02 .09 5.5 .04 .26 .35 1.22 .54 .42 1.28 5.1 .53 .01 .17 .02 .02 .06 5.9 .04 .29 .41 1.25 .64 .55 1.28 5.0 .97 .02 .26 .04 .04 .12 10.2 .10 .36 .58 1.07 .81 .60 N.S. N.S. * N.S. ** * N.S. ** * ** * * N.S. * N.S. N.S. N.S. * N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. * N.S. N.S. 132 213 213 123 123 213 213 123 123 123 123 312 123 123 1.35 5.0 .49 .01 .17 .01 .03 .09 5.1 .03 .23 .30 1.02 .41 .36 1.29 5.2 .28 .01 .27 .02 .03 .06 5.0 .03 .29 .53 1.23 .54 .39 1.56 5.0 .61 .01 .33 .04 .05 .08 7.1 .06 .31 .62 .92 .70 .46 ** N.S. * N.S. N.S. N.S. N.S. N.S. N.S. * N.S. N.S. N.S. * N.S. N.S. N.S. N.S. * * N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. N.S. 213 132 213 123 123 123 123 231 213 213 123 123 312 123 123 — — — — — 1.60 5.2 .15 0 .15 .02 .03 .07 2.9 .02 .17 .30 .74 .29 .22 1.56 5.2 .14 0 .50 .05 .06 .09 3.4 .02 .14 .66 .74 .33 .19 1.60 5.1 .24 0 .26 .01 .04 .07 3.4 .06 .23 .58 .69 .53 .33 Ae BC 1 2 3 Sites 3 Plots w S . D.N. M. R.T. 1 2 3 Sites Plots w S D.N.M.R.T. 1 2 3 Sites Plots w S D.N.M.R.T. 1 2 3 Sites Plots w S D.N.M.R.T. 1 2 3 Sites Plots w S D.N.M.R.T. 0-3 0-8 0-7 3-34 8-38 7-42 34-66 38-63 42-68 66-80 63-88 68-87 80+ 88+ 87+ 2.9 8.3 7.2 31.2 30.0 34.9 32.2 25.1 19.7 14.1 24.7 19.7 N.S. N.S. 312 N.S. N.S. 213 N.S. N.S. 123 N.S. N.S. 132 N.S. N.S. 132 N.S. N.S. 132 N.S. * 132 N.S. N.S. 231 * N.S. 123 N.S. N.S. 213 N.S. N.S. 132 312 ** N.S. 123 * N.S. 213 4> -P-values as % oven dry weight values as milliequlvalents per 100 grams * = significance at the .05 probability level ** » significance at the .01 probability level homogeneous subsets at the .10 probability level are underlined - 45 -interpolated values was considered inappropriate but analysis of variance, at the 10% l e v e l of confidence, of actual measurements showed, for horizons not r e t a i n i n g the massive character of compacted t i l l , no s t a t i s t i c a l l y s i g n i f i c a n t differences between s i t e s . S o i l pH measured i n 0.01 molar C a C l 2 > w h i l e showing an expected increase with depth,shows no s i g n i f i c a n t s i t e d i f f e r e n c e s . Even at the .10 p r o b a b i l i t y l e v e l , Duncan's New M u l t i p l e Range Test cannot d i s t i n g u i s h differences between s i t e means for any horizon. Percent s o i l carbon also shows the expected decrease with depth but i n t e r e s t i n g l y does not show s i g n i f i c a n t s i t e differences i n the b i o l o g i c a l l y more active surface horizons. The B 2 and BC horizons show s i t e differences s i g n i f i c a n t at the .05 p r o b a b i l i t y l e v e l p r i m a r i l y because of the low l e v e l s at S i t e 2. As noted previously, the B 2 and BC horizons have coarser textures i n four of the s i x p i t s at S i t e 2. The low carbon values are more l i k e l y the r e s u l t of texture differences than s i t e d i f f e r e n c e s . This hypothesis i s supported by a s i g n i f i c a n t p l o t within s i t e difference where the coarse textures show lower % C. Percent nitrogen, despite very low values, shows s i g n i f i c a n t s i t e differences i n the B^ and B 2 horizons. Ranked mean values correspond to the ranked means of % carbon as would be expected and % N of the B 2 shows a marginally s i g n i f i c a n t p l o t within s i t e difference a t t r i b u t a b l e again to S i t e 2. Soil bases Ccalcium, magnesium, sodium, potassium) show no consistent s i t e differences except i n the B 2 horizon where a l l bases show s i g n i f i c a n t s i t e d i f f e r e n c e s . Duncan's New M u l t i p l e Range Test suggests co n s i s t e n t l y - 46 -highest values at S i t e 3 but S i t e s 1 and 2 are demonstratably d i f f e r e n t only f o r potassium. Cation exchange capacity and potassium both show s i g n i f i c a n t s i t e differences i n the Ae and B 2 horizons. Ranked means and Duncan's New M u l t i p l e Range Test show no consistent trends e i t h e r when calculated at the 5% p r o b a b i l i t y or 10% p r o b a b i l i t y l e v e l s . S i t e 3 generally shows the highest values for bases and cation exchange capacity while S i t e 1 generally shows the lowest. Extractions f o r Iron and Aluminum • Extractable s o i l i r o n provides by f a r the most consistent means of d i s t i n g u i s h i n g s i t e differences and some discussion of the extraction techniques used i s i n order. The evaluation of s o i l i r o n and aluminum has,in the past, mainly been done using three extraction techniques and t o t a l elemental analysis. The analyses used are; t o t a l i r o n and aluminum, and sodium pyrophosphate at pH 10 a c i d ammonium oxalate, and c i t r a t e - b i c a r b o n a t e - d i t h i o n i t e extractions of i r o n and aluminum. Sodium pyrophosphate i s considered to extract p r i m a r i l y o r g a n i c a l l y complexed i r o n and aluminum compounds (McKeague et a l . , 1971). Acid ammonium oxalate extracts primarily.: acid soluble " F u l v i c " organic complexed plus amorphous inorganic i r o n and aluminum (McKeague and Day, 1966; McKeague, 1967; and Bascomb, 1968 [Fe only]) and sodium c i t r a t e - b i c a r b o n a t e - d i t h i o n i t e extracts a wide range of c r y s t a l l i n e to a c i d i n s o l u b l e (Humic) organic complexes. The pressure bomb technique of Rantala and Loring (1973) i s a measure of t o t a l i r o n - 47 -p l u s aluminum i n the sample s i n c e i t rep resents a complete d i g e s t of a l l l e s s than 2 mm s i z e s o i l m a t e r i a l . I n t e r p r e t a t i o n of the v a r i o u s e x t r a c t i o n techn iques can be q u a l i t a t i v e at b e s t , s i n c e there i s a s i g n i f i c a n t over lap i n the forms of i r o n and aluminum e x t r a c t e d by each t e c h n i q u e . In a d d i t i o n e f f i c i e n c y of e x t r a c t i o n of each form of i r o n and aluminum i n areas of over lap v a r i e s from e x t r a c t i o n to e x t r a c t i o n . T h i s i s p a r t i c u l a r l y obvious when o x a l a t e e x t r a c t i o n s o f t e n exceed d i t h i o n i t e e x t r a c t i o n s even though d i t h i o n i t e e x t r a c t s a w ider range of i r o n and aluminum forms. F o l l o w i n g i s a d i s c u s s i o n of the p o s s i b l e sources of i r o n and aluminum i n a s o i l h o r i z o n and t h e i r p robable r e l a t i o n s h i p s as sources of i r o n and aluminum a v a i l a b l e f o r e x t r a c t i o n by the v a r i o u s techniques used. Sodium Pyrophosphate : Sodium pyrophosphate e x t r a c t s p r i m a r i l y o r g a n i c a l l y complexed i r o n and aluminum. In the Ae h o r i z o n s i t i s assumed that t h i s Fe + A l i s the product of b i o t i c c y c l i n g . The i l l u v i a l B h o r i z o n s have three p o s s i b l e sources of pyrophosphate e x t r a c t a b l e i r o n and aluminum: 1) r e s i d e n t c y c l e d Fe + A l , assumed i n the model to be near z e r o ; 2) t r a n s l o c a t e d Fe + A l , c a l c u l a t e d as a product of 10,000 years accumulat ion at p resent r a t e s but p robab ly hav ing a much s m a l l e r mean res idence va lue as the o r g a n i c a l l y complexed form; and 3) i n s i t u accumulat ion as a r e s u l t of root up take , root exudate weather ing and root decompos i t ion . A c i d Ammonium O x a l a t e : A c i d ammonium o x a l a t e e x t r a c t s p r i m a r i l y a c i d s o l u b l e ( J u l v i c ) . o r g a n i c a l l y complexed and amorphous hydrous ox ides of i r o n and aluminum (Bascomb, 1968) . I t shows the same p o s s i b l e sources as sodium - 48 -pyrophosphate extractable Iron and aluminum but would presumably extract, i n addition to these sources, amorphous i r o n and aluminum present as a res u l t of jln s i t u weathering or the amorphous component of primary i r o n plus aluminum. I f we assume that o r g a n i c a l l y complexed i r o n and aluminum are subject to release as amorphous materials on decomposition, then acid ammonium oxalate should provide a more e f f i c i e n t e x traction of the t o t a l b i o t i c cycled and translocated i r o n and aluminum present i n the s o i l . This would be e s p e c i a l l y true for the B^ horizon f o r the following reasons. Humic acid i s less soluble than f u l v i c acid i n ne u t r a l to acid solutions and w i l l therefore accumulate i n the A horizon with a consequently higher proportion of f u l v i c a c i d i n the B horizons (McKeague, 1968). Since i r o n and aluminum i n organic complex i s p r i m a r i l y associated with the f u l v i c f r a c t i o n (Schnitzer and Desjardins, 1962) acid ammonium oxalate should provide a reasonably e f f i c i e n t e x t r a c t i o n of the or g a n i c a l l y complexed ir o n and aluminum s t i l l present. Citrate-Bicarbonate-Dithionite: Since c i t r a t e - b i c a r b o n a t e - d i t h i o n i t e has been shown to extract a l l forms of i r o n and aluminum, except s i l i c a t e s (Bascomb, 1968), i t can be expected to r e f l e c t a l l forms of i r o n and aluminum including some c r y s t a l l i n e and might, therefore, be l o g i c a l l y expected to show the highest extractable values i n a l l horizons. As w i l l be discussed l a t e r , t h i s was i n fact true only f o r i r o n plus aluminum i n the Ae horizons of S i t e s 1 and 3. Unlike the pressure bomb digest used, citrate-bicarbonate-d i t h i o n i t e does not measure t o t a l i r o n and aluminum since, i n the l a t t e r e x t r a c t i o n , most of the w e l l c r y s t a l l i n e primary i r o n and aluminum s i l i c a t e s are unaffected and extraction of the w e l l c r y s t a l l i n e oxides i s incomplete. - 49 -Forms of i r o n : An approximate p a r t i t i o n i n g of i r o n into o r g a n i c a l l y complexed, inorganic amorphous, and weakly c r y s t a l l i n e can be accomplished i n the following manner. Organically complexed i r o n i s measured d i r e c t l y by sodium pyrophosphate extraction. Acid ammonium oxalate extracts both amorphous inorganic and f u l v i c acid complexed i r o n , therefore subtraction of sodium pyrophosphate values from acid ammonium oxalate values w i l l give an approximate value for inorganic amorphous i r o n . Citrate-bicarbonate-d i t h i o n i t e extracts over the f u l l range of i r o n forms including i r o n compounds more strongly c r y s t a l l i n e than acid ammonium oxalate can extract. Acid ammonium oxalate overlaps the extraction range of organic forms since most organic matter translocated w i l l be i n the f u l v i c f r a c t i o n and therefore the oxalate value substracted from the d i t h i o n i t e value w i l l give an estimate of weakly c r y s t a l l i n e i r o n i n the horizon. The r e s u l t s of i r o n and aluminum analysis for the three s i t e s are as follows: Sodium pyrophosphate i r o n shows s i g n i f i c a n t s i t e differences i n a l l horizons, while aluminum by the same extraction shows s i g n i f i c a n t s i t e differences only i n the Ae and B 2 horizons. Duncan's New M u l t i p l e Range Test applied at the 5% p r o b a b i l i t y l e v e l c o n s i s t e n t l y defines two homogenous subsets for i r o n and ranked means between i r o n and aluminum within horizons are i n general agreement. The Ae horizon shows highest l e v e l s i n S i t e 1 as a subset, with S i t e s 2 and 3 showing lower values and s t a t i s t i c a l l y not separable as the second subset. The diagnostic horizon shows a r e v e r s a l of t h i s pattern with S i t e 3 showing the highest values. While i r o n has two homogenous subsets with S i t e 3 c l e a r l y distinguished, aluminum shows overlapping ranges for S i t e 2 even with a 10% p r o b a b i l i t y range t e s t . - 50 -Acid ammonium oxalate extraction f o r i r o n and aluminum provides an i n t e r e s t i n g contrast with sodium pyrophosphate extraction. Iron values are s i g n i f i c a n t l y d i f f e r e n t for the Ae, B^, and B 2 horizons, while aluminum i s s i g n i f i c a n t only for the Ae. Duncan's New Mult i p l e Range Test at the 5% p r o b a b i l i t y l e v e l shows a clear r e v e r s a l i n ranking of mean s i t e i r o n values f o r the B^, with S i t e 2 having the highest values and S i t e 3 having the lowest but being s t a t i s t i c a l l y inseparable from S i t e 1. Citr a t e - b i c a r b o n a t e - d i t h i o n i t e extractables follow the pattern of sodium pyrophosphate except that the diagnostic B^ horizons show no s i g n i f i c a n t s i t e e f f e c t s , while showing a s i g n i f i c a n t p l o t within s i t e v a r i a t i o n . The estimation of c r y s t a l l i n e i r o n yielded s i g n i f i c a n t negative values f o r four of the twenty-four samples used and was therefore considered suspect and not analysed. Table 2-4 presents estimates of o r g a n i c a l l y complexed i r o n , inorganic amorphous i r o n , and the r a t i o of organic to inorganic forms of i r o n . The inorganic amorphous f r a c t i o n dominates both Ae and B^ horizons at a l l s i t e s and because of t h i s , analysis of variance and Duncan's New Mult i p l e Range Test on o r g a n i c a l l y complexed and amorphous inorganic i r o n produce r e s u l t s comparable to the same tests on sodium pyrophosphate and acid ammonium oxalate extractable values of i r o n . DISCUSSION I f , despite the greater e f f i c i e n c y of extraction by acid ammonium oxalate over c i t r a t e - b i c a r b o n a t e - d i t h i o n i t e f o r some horizons, we accept that the c i t r a t e - b i c a r b o n a t e - d i t h i o n i t e value r e f l e c t s both forms of - 51 -ir o n we can make the following inferences. horizon values f o r t o t a l organic and inorganic amorphous i r o n are comparable, only the r a t i o of one to the other changes from s i t e to s i t e . Organically complexed i r o n i s highest at S i t e 3 and lowest at S i t e 2, whereas inorganic amorphous ir o n i s highest at S i t e 2 and lowest at S i t e 3. The decomposition product of o r g a n i c a l l y complexed i r o n w i l l be acid ammonium oxalate extractable and thus high values of o r g a n i c a l l y complexed i r o n inputs would y i e l d high values of inorganic amorphous i r o n a f t e r decomposition. The change i n r a t i o s of o r g a n i c a l l y complexed amorphous i r o n i s probably due to differences i n mean residence time of the o r g a n i c a l l y complexed form. As noted e a r l i e r , S i t e 1 shows a pronounced summer drought with matrix p o t e n t i a l s i n excess of -30 bars. This water stress i s severe enough to i n h i b i t decomposition; whereas S i t e 2, although somewhat cooler, seldom exceeds matrix potentials of -10 bars and may have more rapid decomposition during the warm summers. Sit e 3, while never showing s i g n i f i c a n t moisture s t r e s s , does have cooler temperatures and thus may show slower rates of decomposition. The s o i l c l i m a t i c v a r i a b l e s are most strongly expressed i n the Ae horizon and i f the r a t i o of organic to inorganic i r o n i s re l a t e d to decomposition rate d i f f e r e n c e s , these differences should be most strongly expressed i n the Ae horizon. S i t e 1, where decomposition i n the Ae should be much slower than the B^ due to summer moisture s t r e s s , shows the expected increase of the organic to inorganic r a t i o from .16 i n the B^ horizon to .47 i n the Ae horizon (Table 2-4). S i t e 2, where moisture stress i s not serious, shows l i t t l e change from the B^ to the Ae horizon, the s l i g h t l y more serious moisture stress i n the Ae may be o f f s e t by warmer temperatures. At S i t e 3, - 52 -Table 2-4. Forms of Extractable Iron as a % of Fine Earth Fra c t i o n for Ae and horizons* S i t e 1 S i t e 2 S i t e 3 Sig DNMRT Ae horizon org. Fe amor. Fe org. Fe/ amor. Fe .08 .17 .47 .03 .30 .10 .04 .11 .36 .032 .004 2 3 1 3 1 2 B^ horizon org. Fe amor. Fe org. Fe/ amor. Fe .10 .09 .62 1.10 .16 .08 .19 .42 .45 .008 .016 2 1 3_ 3 1 2 based on the 12 p r o f i l e s used i n Chapter 2 - 53 -where no moisture stress was recorded, the r a t i o decreases from .45 i n the horizon to .36 i n the Ae horizons. Warmer surface temperatures may be promoting increased decomposition. Sodium pyrophosphate extractable i r o n then would seem to have a highly v a r i a b l e mean residence time between s i t e s and not r e a l i s t i c a l l y r e f l e c t t o t a l i r o n movement or enrichment. Acid ammonium oxalate which extracts both organic and inorganic amorphous forms more c l o s e l y r e f l e c t s i r o n r e d i s t r i b u t i o n . C i t r a t e - b i c a r b o n a t e - d i t h i o n i t e while supposedly extracting a l l forms of i r o n was not able to d i s t i n g u i s h between s i t e s . An evaluation of s o i l development based on morphology i s at odds with the supporting a n a l y t i c a l data (Table 2-5). As discussed e a r l i e r morphological c h a r a c t e r i s t i c s of Podzols are most strongly expressed at S i t e 2, followed c l o s e l y by S i t e 3 and very weakly expressed at S i t e 1. According to the Canadian System of S o i l C l a s s i f i c a t i o n (1978) only Site 3 meets the chemical c r i t e r i a f o r a Podzol, while Si t e s 1 and 2 are c l a s s i f i e d as Brunisols. Duncan's New Mu l t i p l e Range Test on sodium pyrophosphate extractable i r o n ranks means as two homogeneous subsets with Si t e s 1 and 2 grouped together despite t h e i r contrasting morphological c h a r a c t e r i s t i c s . Acid ammonium oxalate, used from 1955 to 1973 as the extraction agent for chemical Podzol c r i t e r i a , groups S i t e s 1 and 3 i n one subset and S i t e 2 as another. Despite the ranking of S i t e 2 with the highest extractable i r o n , acid ammonium oxalate values s t i l l group the two contrasting morphological types. Using the pre-1974 c r i t e r i a , a l l s i t e s were c l a s s i f i e d as Podzols and a l l s i t e s show an increase i n c i t r a t e - b i c a r b o n a t e - d i t h i o n i t e extractable i r o n and aluminum and could have been c l a s s i f i e d as Podzols p r i o r to 1955. - 54 -Table 2-5. Comparison by Si t e of Selected Measures of Podzol Development Na Pyrophosphate A.A. Oxalate C B . D i t h i o n i t e Horizon Morphology F e M F e A l Fe A l Ae (1)(3,2) (2,3)(1) (3,2)(1) (3)(1,2) (3)(2)(1) (2)(1,3) (3,2)(1) B 1 (D(3,2) (2,1)(3) (1,2)(2,3) (3,1)(2) (1,3)(2) (1,3,2) (1,3,2) Duncan's New Multiple Range Test at 10% P r o b a b i l i t y Levels brackets enclose homogenous subsets and s i t e s are ranked by increasing value. SOIL WATER STATISTICAL MODEL Analysis of the s o i l water data used the following s t a t i s t i c a l models. Analysis of concentration data and water volume used f u l l y nested analysis of variance following the model shown i n Table 2-6a. An evaluation of mean square values for p l o t s w i t h i n s i t e s and p i t s within pl o t s indicated that the design could be treated as 6 plots within s i t e s , since mean square values were approximately equal. This allows f o r 15 degrees of freedom i n the denominator of the F test rather than 6 and modifies the model to that used i n Table 2-6b. Due to l i m i t a t i o n s of tension lysimeters as quantitative c o l l e c t o r s when influenced by water tables, volumes of lysimeter c o l l e c t i o n s were not analysed. When compared to thro u g h f a l l volumes, lysimeter c o l l e c t i o n s - 55 -Table 2-6. a) Analysis of Variance Source Degrees of Freedom Test Sites 2 P l o t s _ 9 Sites P l o t s _ c S i t e s 6 P i t s Q Plots P i t s c Plots 9 Times 7 Times x Plots c S i t e s S i t e s x Times 14 Times x P l o t s c Sit e s Times x Plots 9 S i t e s 42 Er r o r Error 63 T o t a l 143 b) Analysis of Variance Source Degrees of Freedom Test Sites 2 P i t s w S i t e s (Error 1) 15 Times 7 Si t e s x Times_ 14 Times ;x, P i t s c- S i t e s 105 (Error 2) Tot a l 143 Times x P i t s c S i t e s Times x P i t s c S i t e s - 56 -showed an approximate 20% undercollection below LFH and a highly v a r i a b l e o v e r c o l l e c t i o n increasing from the B^ to the ~S>^. This would be expected due to the proximity of a temporary, shallow perched water table during rainstorms. RESULTS Table 2-7 presents mean monthly s i t e values f o r throughfall volume and concentrations, i n parts per m i l l i o n , f o r calcium, magnesium, sodium, potassium, iron,and aluminum. Values are presented for t h r o u g h f a l l , water leaving the LFH, water leaving the B^ horizon, and water leaving the B 2 horizon. Also presented are mean monthly estimates of the t o t a l mass of the sum of bases (Ca, Mg, Na, and K), the mass of i r o n , aluminum, and i r o n , ., ,, i i ^ j concentration x volume , .. plus aluminum. Masses were calculated as — r - ; — — : and values X-sec. c o l l e c t i o n area 4 presented are times 10 . Values f o r mass f l u x are the t o t a l mass i n grams 2 crossing a i m c r o s s - s e c t i o n a l area of the s o i l . Volumes: Volumes showed no s i g n i f i c a n t s i t e d i f f e r e n c e s , as would be expected since incident p r e c i p i t a t i o n did not, and Duncan's New M u l t i p l e Range Test (D.N.M.R.T.) applied at the .10 p r o b a b i l i t y l e v e l , defined only one homogeneous subset. With the exception of mass fl u x of s i l i c a a l l other parameters showed s i g n i f i c a n t s i t e differences at the 5% confidence l e v e l or better. Duncan's New Multiple Range Test (D.N.M.R.T.) cons i s t e n t l y separates at l e a s t two homogeneous subsets, three for concentrations of Ca, Fe, and A l and for mass f l u x of A l . Over a l l , S i t e s 1, 2 and 3 show a s t a t i s t i c a l l y s i g n i f i c a n t reduction corresponding to the i n f e r r e d vegetation climosequence, i n both concentration and mass f l u x f or a l l elements analysed. Table 2-7. Mean Site Values for Soil Water Chemistry Presented by Collection Level Level Site Volume ml. Calcium Magnesium Sodium Potassium ppm-1 ppm ppm ppm Iron ppm Aluminum ppm Sil i c a ppm/10 Bases 2 gms' Iron gms Aluminum gms Fe+Al gms Si gms/io Throughfall 1 2 3 1954 1840 1919 .65 .33 .23 .34 .16 .11 1.02 .40 .37 1.38 .67 .43 .07 .05 .03 .13 .08 .05 .20 .18 .09 Sites 3 . D.N.M.R.T. N.S. 2 3 1 ** 3 2 1 ** 3 2 1 ** 3 2 1 ** 3 2 1 ** 3 2 1 ** 3 2 1 * 2 2 1 LFH 1 2 3 .83 1.13 1.05 .26 .35 .28 .80 .81 .62 .58 .50 .50 .36 .38 .17 1.00 1.23 .39 1.63 2.06 1.12 Sites D.N.M.R.T. N.S. 1 3 2 N.S. 1 3 2 ** 3 12 N.S. 3 2 1 N.S, 1 1 2 * 1 1 2 ** 2 12 1 2 3 Sites D.N.M. R.T. 1 2 3 Sites D.N.M.R.T. .71 .21 .66 .28 .14 .34 1.19 .76 .32 .94 .22 .13 .27 1.33 .60 .21 .76 .24 .09 .18 1.49 N.S. * ** N.S. N.S. * N.S. 3 1 2 3 1 2 1 3 2 2 3 1 3 2 1 3 2 1 1 2 3 .61 .22 .72 .14 .09 .23 1.20 .71 .30 .98 .22 .09 .18 1.30 .68 .26 .84 .22 .07 .15 1.39 N.S. * ** N.S. N.S. N.S. N.S. 13 2 1 3 2 1 3 2 2 3 1 3 1 2 3 2 1 1 2 3 .35 .02 .04 .06 .05 .29 .02 .03 .05 .05 .28 .01 .01 .02 .02 ** ** ** N.S. 3 2 1 2 2 1 3 2 1 2 2 1 3 2 1 .62 .13 .33 .46 .52 .70 .12 .40 .53 .59 .65 .06 .13 .19 .34 N.S. N.S. N.S. N.S. * 1 3 2 3 2 1 3 1 2 3 1 2 2 12 .43 .04 .11 .15 .34 .53 .03 .08 .11 .34 .48 .04 .07 .11 .44 N.S. N.S. N.S. N.S. N.S. 1 3 2 2 3 1 3 2 1 2 1 3 3 2 1 .46 .03 .08 .11 .41 .51 .03 .05 .08 .35 .49 .02 .05 .08 .46 N.S. N.S. N.S. N.S. N.S. 1 3 2 3 2 1 2 3 1 2 3 1 2 1 3 Ln Values in ppm are concentrations Values in gms are values crossing a 1 m^ area in one year , * = significant at the .05 probability level ** = significant of the lines underline homogeneous subsets at the .10 probability level ,01 probability level - 58 -Forest Floor: Water emerging from the forest f l o o r shows a consistent increase i n concentration of Ca, Fe, and A l over throughfall values f o r a l l s i t e s . Mg, Na, and K show no consistent r e l a t i o n s h i p , Mg and Na show a decrease at S i t e 1 and increases at Sites 2 and 3, while K shows a decrease at Sites 1 and 2 while increasing at S i t e 3. The increase was s t a t i s t i c a l l y s i g n i f i c a n t f or Ca, Fe, and A l , but s i t e differences i n the amount of the increase could not be demonstrated. Analysis of variance demonstrated s i g n i f i c a n t s i t e differences f o r concentrations of sodium, and aluminum only, although D.N.M.R.T. (10%) demonstrated some mean differences where analysis of variance did not. Ranked means, where demonstrably d i f f e r e n t , showed a reduction i n concentration from S i t e 2 to S i t e 3. S i t e 1 was generally intermediate, but lowest f o r calcium. Despite a general increase i n s o l u t i o n concentration f o r most elements, s i t e differences are not as pronounced as for t h r o u g h f a l l nor are mean rankings the same, S i t e 2 shows the highest s o l u t i o n concentrations and mass f l u x . Horizon: Water leaving the B^ horizon shows a marked reduction i n concentrations from the forest f l o o r at a l l s i t e s and for a l l elements except sodium which shows an increase over forest f l o o r values at S i t e 3. Sit e differences are not s i g n i f i c a n t at the 5% confidence l e v e l except f o r magnesium, sodium, and aluminum where D.N.M.R.T. separates S i t e 2 with highest base concentrations from S i t e s 1 and 3 with lower base concentrations. Aluminum shows ranked means with concentrations decreasing from Sit e s 1 through S i t e 3. ~&2 Horizon: Concentrations and mass of bases leaving the B 2 horizon show no s i g n i f i c a n t differences from water leaving the B-, horizon. Iron - 59 -and aluminum show s i g n i f i c a n t reductions from the horizon but no s i g n i f i c a n t s i t e d i f f e r e n c e s . While th r o u g h f a l l chemistry shows s i g n i f i c a n t s i t e differences with concentration decreases corresponding to the i n f e r r e d climosequence, t h i s pattern i s not r e f l e c t e d i n water emerging from the forest f l o o r . Calcium (a constituent of c e l l w a l l s ) , i r o n and aluminum show marked and consistent increases i n concentration on leaving the forest f l o o r . This release from the forest f l o o r has obscured the s i t e differences for calcium and i r o n , arid reduced the l e v e l of s i g n i f i c a n c e at which s i t e differences f o r aluminum are demonstratable. D.N.M.R.T. on i r o n and aluminum concentrations, i r o n plus aluminum, and aluminum mass f l u x separate and rank means increasing i n the order 3, 1, 2 for s i t e s . This r e v e r s a l of p o s i t i o n f o r Sites 1 and 2 may be interpreted as the r e s u l t of higher rates of decomposition at S i t e 2 i n response to a much more favorable summer moisture regime. Concentrations of calcium, i r o n , and aluminum leaving the B^ show marked and consistent decreases from those leaving the forest f l o o r . The surface mineral horizons are acting as f i l t e r s for calcium, i r o n , and aluminum. S i t e differences f o r aluminum concentrations can s t i l l be demonstrated at the 5% s i g n i f i c a n c e l e v e l and are the r e s u l t of a progressive decrease i n concentration from S i t e 1 to Site 2 to S i t e 3. S i t e differences for Ca, Fe, and A l have been e f f e c t i v e l y masked by the time water emerges from the B 2 horizon although D.N.M.R.T. s t i l l shows the progressive decrease i n aluminum concentration evident below the B^ horizon. Calculations of i r o n , aluminum, and iro n plus aluminum retained i n the surface mineral s o i l , based on mean s i t e values, are presented i n - 60 -Table 2-8. Although not s t a t i s t i c a l l y d i f f e r e n t S i t e s 1 and 2 show comparable values while S i t e 3 i s markedly lower. Table 2-8. Retention Values of Fe, A l , and Fe + A l as a Proportion of Input Values f o r the Surface Mineral S o i l . Iron, Aluminum, and Iron + Aluminum Retained by Surface S o i l AFe AA1 AFe + A l S i t e 1 .09 .22 .31 S i t e 2 .09 .32 .42 S i t e 3 .02 .09 .08 DISCUSSION The concentrations of i r o n and aluminum i n the lysimeter c o l l e c t i o n s are greater than can be explained by simple water s o l u b i l i t i e s . Table 2-9 presents measured ranges of i r o n and aluminum concentration i n the lysimeter 3+ 3+ c o l l e c t i o n s and s o l u b i l i t i e s of i r o n (Fe ) and aluminum (Al ) i n water. - 61 -Table 2-9. Ranges of Iron and Aluminum Concentration i n PPM; Lysimeter C o l l e c t i o n s and Soluble i n Water. Measured Soluble i n H 20* mean high mean low pH 5.0 pH 5.5 -4 Iron ( F e 3 + ) 3.80 x 1 0 _ 1 0.70 x 1 0 _ 1 0.96 x 1 0 _ 3 2 , 3 6 X 1 0 Aluminum ( A l 3 + 1.23 1.50 x 1 0 _ 1 1.03 x 1 0 _ 1 5.67 x 10" 4 *Van Schuylenborgh and Bruggenwert (1965) As can be seen even the lowest concentration i n the leachate exceeds the highest s o l u b i l i t y l e v e l i n water. I t should be emphasized that concentrations as high as those l i s t e d above for soluble i n water are u n l i k e l y for the following reasons: 1) the nature of the d i f f u s e double layer at the s o l i d - l i q u i d contact causes higher concentrations i n s o i l s o l u t i o n immediately adjacent to the s o i l p a r t i c l e s than i n solutions occupying s o i l voids. Lysimeter extractions at tensions of approximately 100 cm are u n l i k e l y to include the higher concentration solutions. Samoylova and Demkin (1976) report s i g n i f i c a n t l y higher l e v e l s of cation concentration i n s o i l solutions c o l l e c t e d by d i s -placement than i n solutions c o l l e c t e d by lysimeter. 2) i n the coarse textured highly pervious s o i l s of the research s i t e s i t i s u n l i k e l y that water would remain i n contact with the mineral s o i l s long enough to reach equilibrium. - 62 -3) much of the water moving through the s o i l system may in. f a c t bypass the s o i l matrix (de V r i e s , 1979). The reduction i n concentration with depth however would argue that at least the major portion of s o i l water does i n fact move through the matrix. The l e v e l s reported here are i n f a c t i n reasonable agreement with the l e v e l s reported elsewhere. Schnitzer and Desjardin (1969) report l e v e l s of .23 ppm Fe i n leachates from a Humic Podzol and U g o l i n i e_t al. (1977.) report l e v e l s of .11 ppm Fe i n lysimeter leachates c o l l e c t e d from the 02 of a Podzol (Cryandept). A number of organic c a r r i e r mechanisms have been invoked to explain the anomalously high values of translocated i r o n measured i n Podzols. The most popular of these i s transport as organo-m e t a l l i c complexes. The a b i l i t y of organic acids to complex with and carry i r o n and aluminum i n s o l u t i o n has been w e l l documented. Bloomfield (1953) demonstrated the a b i l i t y of l e a f extracts from Kauri and Scots Pine to extract i r o n and a t t r i b u t e d t h i s a b i l i t y to an i n i t i a l reduction of 3+ 2+ Fe to Fe by phenol groups, followed by complexing with the carbox.yl groups of the l e a f extract. Schnitzer and Skinner working with organic matter from a Podzol Bh horizon characterized a number of organic-cation 3+ 3+ complexes. They demonstrated 2:1 molar complexes of Fe and A l at pH 5.0 and some evidence f o r 6:1 molar complexes which were water i n s o l u b l e . From t h i s they concluded that a range of complexes from 1:1 to 6:1 could form and that the complexes would become les s soluble as the r a t i o increased. They further presented evidence for electrovalent bonding between p a r t i a l l y hydroxylated i r o n and aluminum and COOH fu n c t i o n a l groups (Schnitzer and - 63 -Skinner, 1963a). Support for the involvement of COOH groups was provided by demonstrating a reduction i n Fe uptake by blocking the COOH groups with methylation (Schnitzer and Skinner, 1963b). Iron and aluminum carboxyl bonds were demonstrated (Schnitzer and Skinner, 1964) and support for the importance ef phenolic groups was provided when blocking of e i t h e r COOH or phenolic groups reduced uptake (Schnitzer and Skinner, 1965). The a p p l i c a b i l i t y of t h i s work to f i e l d systems was supported when the extracts of the Bh horizons used were shown to be very s i m i l a r to natural leachates c o l l e c t e d from the same s o i l (Schnitzer and Desjardins, 1969). McKeague et a l . (1978) used the following assumptions: 1) The concentration of organic matter i n s o l u t i o n i s 0.1 gm/litre. 2) The organic matter i n so l u t i o n i s s i m i l a r to the f u l v i c a c i d described by Gamble and Schnitzer (1973) with 8 mmol of carboxyl and 3 mmol of phenolic hydroxyl groups per gram of f u l v i c a c i d . 3) F u l v i c acid p r e c i p i t a t e s when 50% of the carboxyl s i t e s are occupied by metal ions, or 4 mmol of carboxyl s i t e s are ava i l a b l e to mobilize i r o n and aluminum. 4) 3 mmol of carboxyl groups w i l l complex 2 mmol of i r o n or aluminum. According to the above assumptions, the s o i l s o l u t i o n can have concentrations as high as 2.4 x 10 m o l e s / l i t r e . In view of those c a l c u l a t i o n s the highest measured values of 5.24 x 10 moles per l i t r e i r o n plus aluminum are c e r t a i n l y within reason. The marked reduction i n i r o n and aluminum concentrations below the B^ horizon i s also consistent with reported data. Similar patterns were reported by Belousova (1974), Din'Sham (1977), and U g o l i n i et a l . (1977). - 64 -Obviously b i o l o g i c a l c y c l i n g plays a major r o l e i n the annual movement of ir o n and aluminum but the influence of t h i s c y c l i n g on e l u v i a l A or i l l u v i a l B horizon formation has yet to be elucidated or demonstrated. S o i l water chemistry shows the greatest s i m i l a r i t y between the two most strongly contrasting morphological types and i s consistent only with sodium pyrophosphate extractable i r o n . I t i s also consistent with current theories on organic c a r r i e r s . The three measures of s o i l i r o n and aluminum, s o i l morphology, and s o i l water chemistry provide no consistent agreement e i t h e r i n ranking of s i t e s or i n t h e i r a b i l i t y to separate s i t e s . While an analysis of s o i l morphology, s o i l chemical p r o p e rties, and s o i l water chemistry can c l e a r l y demonstrate s i g n i f i c a n t s i t e differences for a l l s i t e s , i t does l i t t l e to elucidate the causes of these d i f f e r e n c e s , unless t i e d to at le a s t a conceptual model of s o i l formation. The following chapter constructs a simple l i n e a r model of s o i l formation as a means of in t e g r a t i n g the s t a t i c analysis of t r a d i t i o n a l s o i l chemistry with the dynamic analysis of s o i l water chemistry. The r e s u l t i n g model i s used to explain the s i t e differences demonstrated i n chapter two and to re c o n c i l e them with s o i l morphology i n the framework of a conceptual model of s o i l genesis. - 65 -CHAPTER I I I A LINEAR MODEL INTRODUCTION In 1959, R. Simonson presented "Outline of a generalized theory of s o i l genesis". This paper viewed s o i l as the product of four general processes; additions, losses, transformations, and transfers ( t r a n s l o c a t i o n s ) . Applied on an i n d i v i d u a l horizon basis t h i s model provides a framework within which lysimeter data and more conventional s o i l analysis can be evaluated. Inputs to and outputs from a horizon are monitored using lysimeters, outputs from one horizon which are input to and remain i n another horizon may be considered transfers or translocations, and transformations are evaluated using various extractions of material resident i n the horizon. Like most approaches to pedogenetic weathering studies an index mineral or mineral s u i t e i s necessary to provide a basis f o r horizon comparisons. In t r a d i t i o n a l approaches t h i s index mineral i s considered immobile, but using the input-output model developed i n t h i s chapter the reference or index material need not be considered immobile since i t s rate of movement i s being monitored. The Canadian System of S o i l C l a s s i f i c a t i o n uses the value of extractable i r o n plus aluminum i n the c l a s s i f i c a t i o n c r i t e r i a f o r Podzols and f o r t h i s reason i r o n plus aluminum was chosen as the index value for horizon and p r o f i l e comparisons. Differences i n p h y s i c a l , chemical, and b i o l o g i c a l behaviour of i r o n and aluminum have been demonstrated by numerous workers and e l u c i d a t i o n of the s p e c i f i c reactions and compounds involved i n Podzol - 66 -genesis would require independent treatment of the two elements, The purpose of this study however, is to evaluate only the general processes of addition, loss, translocation and transformation with reference to Podzol formation. The model developed in the following pages was applied to iron, aluminum, and iron plus aluminum index values. Since comparable results were obtained in a l l three cases and since iron plus aluminum values are used as chemical criteria in the Canadian System of Soil Classification only the model results based on iron plus aluminum will be discussed. THE MODEL The following model was constructed to help identify the mechanisms and patterns of the pedogenic redistribution of Fe and Al during podzolic soil development. It will be developed in stages and then applied to data on three separate soils. It is based on the following four assumptions, which will be discussed with reference to the soils used to test the model: 1) Biological cycling is in steady state, that is patterns of uptake and return are not changing and more specifically rate of uptake equals rate of return. A further assumption is that this is true for specific horizons within the soil. 2) The system has been changing at a constant rate for a l l but insignificant periods of time since soil development began and as a corollary of this, the soil is of monogenetic development. 3) The present macro-climate adequately reflects the period of soil development. - 67 -4) The parent material was uniform throughout the solum. The model stratifies the total Fe and Al present in a given horizon into that which is present in unweathered material (crystalline), that which has been left behind as a result of preferential loss of other material (residual), that which has been biologically extracted and returned (cycled), and that which has been transferred from overlying horizons (translocated). The model consists of three input-output horizon models linked to form an input-output model for the solum. Each horizon is the same (Figure 3-1) .consisting of inputs of solution or suspension, outputs of solution or suspension, movement of material into solution and movement of material out of solution from the beginning of soil development to time of analysis. In addition, the model accounts for standing capital of materials at time i n i t i a l and time present, and biological uptake. Figure 3-1 represents the horizon diagramatically. Linkage of the horizon models is accomplished in the following manner (see Figure 3-2) : Input to the surface horizon equals the sum of biotic uptake from the three submodels, output from the surface horizon equals input to the middle horizon, output from the middle horizon equals input to the lower horizon, and output from the lower horizon equals loss from the solum. Field monitoring and laboratory analysis provided data on the following variables (Figure 3-2): A horizon VX2 = Fe and Al input to surface of the solum TXl = total standing capital of Fe and Al MASS1 = total soil constituents - 68 -(VX) Fet Al INPUT TIME 0 Fe + Al BIOTIC UPTAKE (XU) TIME PRESENT TOTAL Fe+AI (XO) 1 TOTAL Fe + AI (TX) TOTAL SOIL MASS (TO) 1 TOTAL SOIL MASS , RESIDUAL Fe+ Al (RS) , CYCLED Fe+AI (CY) Fe+AI RELEASED > TRANSLOCATED (RL) Fe + AI ( TR) TOTAL MASS LOST > (TL) 1 *Fe+ Al ENRICHMENT OUTPUT Fe+-Al (VX) FIG.3-I DIAGRAMATIC REPRESENTATION OF HORIZON SUBMODEL - 69 -• x u s TIME 0 1 INPUT (VX2) X TIME PRESENT BKJTIC "UPTAKE Ae HORIZON OUTPUT BIOTIC_ "UPTAKE (XU2 ) INPUT 1 (VXA) I TX 2 MASS 2 •RS2 + TR2 T B, HORIZON OUTPUT (VX3) INPUT LBIOTIC UPTAKE-1 (XU3) 1 RL 3 TL 3 -4 TX3 MASS 3 -+R83+TR3 I B 2 HORIZON OUTPUT LOSS (VX4) FIG.3 "2 DIAGRAMATIC REPRESENTATION OF SOLUM MODEL SHOWING LINKAGE OF HORIZONS - 70 -horizon TX2 = t o t a l standing c a p i t a l of Fe and A l MASS2 = t o t a l s o i l constituents VX3 = Fe and A l output from B^ horizon B 2 horizon VX3 = Fe and A l input to B 2 = Xout B 1 TX3 = t o t a l Fe and A l MASS3 = t o t a l s o i l constituents VX4 = Fe and A l output from B 2 = loss from solum C horizon TX5 = i r o n plus aluminum i n the C horizon Using the above v a r i a b l e s , the model w i l l be constructed i n the three stages represented i n Figure 3-3. Stage 1: T o t a l i r o n plus aluminum at the beginning of s o i l development CXOS) i s calculated as XOS = TX1 + TX2 + TX3 + VX4 (1) where TX1 = t o t a l i r o n plus aluminum present i n the Ae horizon TX2 = t o t a l i r o n plus aluminum present i n the B^ horizon TX3 = t o t a l i r o n plus aluminum present i n the B 2 horizon VX4 = annual loss of i r o n plus aluminum at base of solum times 10,000 years T o t a l s o i l mass at time zero (TOS) i s calculated as TOS = XOS v (% X C v 100) (2) where XOS i s defined i n equation 1 % X C - percentage of Fe+Al i n the C horizon FIG. 3-3 STAGES OF MODEL CONSTRUCTION kwXUAH XOA TOA l*_xus—I X09 TO 3 vxe TXA I MA8S A VXS _1_ I TX3 , MASS 3 VX4 3 - 3 0 STAGE I 3 - 3 b 8TA9E 2 1 vxe 1 P-xue <-XU3 XOI TXI TOI 1 MA88I 1 VXA 1 xoe 1 TX2 TOE , MA38S M tl 1 » 1 1 1 VX3 i X03 I TX3 T03 1 MASS S M * 1 1 VX4 3 - 3 c 8TA8E 3 - 72 -To t a l s o i l l o s s f o r the solum (TLS) i s calculated as TLS = TOS - CMASS1 + MASS2 + MASS3) (3) where TOS i s defined by equation 2 MASS1 = bulk density times thickness of Ae MASS2 = bulk density times thickness of B MASS3 = bulk density times thickness of B 2 and t o t a l b i o t i c uptake from the solum (XUS) i s assumed equal to i r o n plus aluminum leaving the LFH (VX2) XUS = VX2 (4) Stage 2: Monitoring s o i l water chemistry below the Ae horizon was imp r a c t i c a l , therefore, i n order to calculate mass f l u x across the Ae-B^ boundary»an intermediate set of c a l c u l a t i o n s t r e a t i n g the Ae and B^ horizons as a sing l e horizon (the A horizon)was performed. Assuming that the biochemical cycle i s i n steady state, proportional uptake from a s p e c i f i c horizon i s equal to the proportional return to the horizon. For the A horizon b i o t i c uptake (XUA) can be determined using B i o t i c uptake A = Return to A or XUA = VX2-VX3 B i o t i c uptake Solum Return to Solum XUS VX2-VX4 where XUS = VX2 as defined by equation 4 VX2 = i r o n plus aluminum entering mineral s o i l surface VX3 = i r o n plus aluminum leaving the B^ horizon VX4 = i r o n plus aluminum leaving the solum i t follows then that XUA = CCVX2 - VX3) T (VX2 - VX4)) x VX2 (5) - 73 -s i m i l a r l y uptake from the horizon (XU3) i s calculated as XU3 = (VX3 - VX4) v (VX2 - VX4) x VX2 (6) Iron plus aluminum l o s t from the A horizon (XLA) i s calculated as XLA = VX3 - (VX2 - XUA) (7) and i r o n plus aluminum l o s t from the B 2 horizon (XL3) as XL3 = VX4 - XU3 (8) Stage 3: In order to calculate l o s s values s p e c i f i c to the Ae and horizons i n i t i a l values must be determined. The model accomplishes t h i s i n the following manner: I n i t i a l i r o n plus aluminum values (XOA) are calculated as XOA = TX1 + TX2 + XLA (9) where TX1 = i r o n plus aluminum present i n Ae horizon TX2 = i r o n plus aluminum present i n B^ horizon XLA i s defined by equation 7 and i n i t i a l mass (TOA) i s calculated as TOA = XOA v (%. X C v 100) (10) where XOA i s defined by equation 9 % X C = % i r o n plus aluminum i n the C horizon Bulk density of the A horizon (BDA) can now be calculated as BDA = TOA i (DEPTH 1 + DEPTH 2) (11) where DEPTH 1 = thickness of the Ae horizon DEPTH 2 = thickness of the B 1 horizon - 74 -I n i t i a l values f o r the Ae and horizons can now be c a l c u l a t e d , T o t a l i n i t i a l s o i l mass i n the Ae h o r i z o n (T01) i s c a l c u l a t e d as T01 = BDA x DEPTH 1 (12) s i m i l a r l y t o t a l i n i t i a l s o i l mass i n the B^ h o r i z o n (T02) as T02 = BDA x DEPTH 2 (13) and t o t a l i n i t i a l values of i r o n p l u s aluminum f o r the Ae and B^ horizons as X01 = T01 x '(% X C v 100) (14) and X02 = T02 x (% X C v 100) (15) r e s p e c t i v e l y Losses f o r the Ae and B^ horizons can now be c a l c u l a t e d T o t a l i r o n plus aluminum l o s t from the Ae (XL1) as XL1 = X01 - TX1 (16) T o t a l s o i l mass l o s t from the Ae (TL1) as TL1 = TOl - MASS1 (17) S i m i l a r l y f o r the B^ h o r i z o n , i r o n p l u s aluminum l o s s (XL2) XL2 = X02 - TX2 (18) and t o t a l s o i l mass l o s t (TL2) i s TL2 = T02 - MASS2 (19) where TX1 = present t o t a l of i r o n p l u s aluminum i n the Ae TX2 = present t o t a l of i r o n p l u s aluminum i n the B.^ MASS1 = BDA times thickness of the Ae MASS2 = BDA times thickness of the B 1 - 75 -In c a l c u l a t i n g output from the Ae horizon b i o l o g i c a l uptake from the Ae horizon was assumed to be zero. The following observations support t h i s assumption. The Ae horizon shows a p r e f e r e n t i a l loss of i r o n plus aluminum, percentage extractable and percentage t o t a l l e v e l s of i r o n and aluminum are very low and show higher proportional l e v e l s of c r y s t a l l i n e forms than other horizons, t h i s would indi c a t e lower l e v e l s of a v a i l a b l e i r o n and aluminum than the underlying B^ horizon. Root d i s t r i b u t i o n i s much lower i n the Ae horizon than i n the B^, there i s a near absence of f i n e roots and a much smaller volume of Ae material (8-20% of the B^ values) from which to extract i r o n and aluminum. Although some uptake and return must occur i t i s f o r the purposes of calculation,considered zero and output from the Ae (VXA) i s calculated as VXA = VX2 + XL1 (20) Since p a r t i t i o n i n g of horizon i r o n and aluminum i s dependent on a number of assumptions i t may be useful to discuss the model r e s u l t s with respect to rates and patterns of r e d i s t r i b u t i o n before attempting to p a r t i t i o n the forms of i r o n and aluminum i n each horizon. I t should be noted here that experimental error i s r e l a t i v e l y large since the model i s applied to p l o t estimates of each l e v e l and there i s no d i r e c t r e l a t i o n s h i p between water c o l l e c t i o n s at each l e v e l . C o l l e c t o r s which sampled s p e c i f i c l e v e l s for each p i t were s p a t i a l l y separated by as much as 10 meters. For t h i s reason p r o b a b i l i t y l e v e l s of .10 f o r an F test i n analysis of variance are considered s i g n i f i c a n t and p r o b a b i l i t y l e v e l s of .05 h i g h l y s i g n i f i c a n t . - 76 -RATES AND PATTERNS OF REDISTRIBUTION The model was a p p l i e d to f o u r of the s i x p i t s monitored at each s i t e and used va lues of i r o n p l u s aluminum. C a l c u l a t i o n s were based on a 10,000 year weather ing p e r i o d at the annual r a t e mon i to red . Model r e s u l t s were submit ted to the s t a t i s t i c a l model used f o r s t a t i c s o i l parameters . The model used d i f f e r s o n l y i n the number of r e p l i c a t e s f o r a n a l y s i s and t h e r e f o r e has fewer degrees of freedom. Table 3 - 1 presents mean s i t e . r e s u l t s Fe + A l / TL of the model o u t p u t . Table 3 - 2 p resents Loss R a t i o s of ^ + ^—]~ro ' o o • Table 3 - 3 p resents a c o r r e l a t i o n m a t r i x of model o u t p u t s . Some of the v a r i a b l e s are d i r e c t l y dependent , fo r example VXA i s c a l c u l a t e d as the sum of VX2 + XL1 and s i g n i f i c a n t c o r r e l a t i o n s are expec ted , o thers are more or l e s s independent and s i g n i f i c a n t c o r r e l a t i o n s may r e f l e c t r e a l system p r o c e s s e s . Table 3 - 3 d i s t i n g u i s h e s v a r i a b l e s used i n the c a l c u l a t i o n of another v a r i a b l e by u n d e r l i n i n g the r v a l u e o p p o s i t e the model dependent v a r i a b l e . The Solum A n a l y s i s of v a r i a n c e shows s i g n i f i c a n t s i t e d i f f e r e n c e s i n l o s s of t o t a l s o i l c o n s t i t u e n t s but not f o r l o s s of i r o n p l u s aluminum. D .N .M.R.T . ranks s i t e s as 2 , 3 , 1 i n ascending o rder of l o s s f o r both t o t a l s o i l and i r o n p l u s aluminum and was ab le to separate S i t e 1 from S i t e s 2 and 3 f o r t o t a l l o s s . As would be expected the r a t i o s of i r o n p l u s aluminum to t o t a l s o i l c o n s t i t u e n t s i n d i c a t e a n e g a t i v e enrichment of i r o n p l u s aluminum ( p r e f e r e n t i a l l o s s of s o i l c o n s t i t u e n t s o ther than Fe and A l ) , D .N .M.R.T , was unable to separate S i t e 1 w i t h the h i g h e s t r a t e of i r o n p l u s aluminum - 77 -Table 3-1. S i t e 1 S i t e 2 S i t e 3 Sig. D.N.M.R.T. VX2 4.4 3.9 1.9 .42 3 2 1 NS XL1 .24 .59 .41 .02 1 3 2 ** TL1 1.2 2.2 1.1 .09 3 1 2 * VXA 4.6 4.5 2.3 .44 3 2 1 NS XU2 3.7 3.5 1.4 .43 3 2 1 NS XL2 .39 -.18 .13 .08 2 3 1 * TL2 7.5 3.2 4.4 .10 2 3 1 * RL2 .87 .39 .54 .11 2 3 1 NS VX3 1.3 .8 1.1 .05 2 3 1 ** XU3 .64 .39 .54 .52 2 3 1 NS XL3 .23 .07 .17 .41 2 3 1 NS TL3 5.3 1.4 2.8 .07 2 3 1 * RL3 .62 .17 .34 .06 2 3 1 * VX4 .87 .47 .71 .22 2 3 1 NS T l o s t S 14.0 6.7 8.3 .08 2 3 1 * - 78 -m , -• ~ o T „ . Fe+AL Lost , Fe+Al i n P.M. „ . Table .3-2. Loss Ratios „ „ , T / w 5 "T7— Values greater than To t a l Lost Moss P.M. 1 Indiate P r e f e r e n t i a l Loss of Fe+Al S i t e 1 S i t e 2 S i t e 3 Mean Ae 1.75 2.24 3.07 2.49 B 1 .44 .04 .29 .26 B 2 .37 .34 .50 .44 Solum .53 .57 .71 .60 Table 3-3. Correlation Table of Model Output Pearson Correlation C o e f f i c i e n t s VX2 XLl T L l VXA XL2 TL2 VX3 XL3 TL3 VX4 VX2 1,0000 0.1398 0.1922 0.9976** 0.1817 0.1898 0.2206 -0.4613 -0.2067 0.0577 XLl 0.1398 1.0000 0.8061** 0.2081 -0.6267+ -0.3976 -0.2466 -0.3473 -0.2944 -0.3276 T L l 0.1922 0.8061** 1.0000 0.2463 -0.5414+ TO.1042 -0.1129 -0.3461 -0.0252 -0.3421 VXA 0.9976** 0.2081 0.2463 1.0000 0.1356 0.1597 0.2006 -0.4800 -0.2248 0.0341 XL2 0.1817 -0.6267+ -0.5414+ 0.1356 1.0000 0.8416** 0.5066+ 0.0473 0.3639 0.8393** TL2 0.1898 -0.3976 -0.1042 0.1597 0.8416** 1.0000 0.5030+ -0.1216 0.6180+ 0.6995* VX3 0.2206 -0.2466 -0.1129 0.2006 0.5066+ 0.5030+ 1.0000 0.3672 0.4127 0.6487+ XL 3 -0.4613 -0.3473 -0.3461 -0.4800 0.0473 -0.1216 0.3672 1.0000 0.2725 0.3740 TL3 -0.2067 -0.2944 -0.0252 -0.2248 0.3639 0.6180+ 0.4127 0.2725 1.0000 0.3999 VX4 0.0577 *0.3276 -0.3421 0.0341 0.8393** 0.6995* 0.6487+ 0.3740 0.3999 1.0000 + - SIG LE 0.05 - SIG LE 0.01 - SIG LE 0.001 - 80 -return to mineral s o i l from Si t e s 2 and 3 even though the throughfall data, with two more r e p l i c a t e s per s i t e was able to do so. No c o r r e l a t i o n between rates of nutri e n t c y c l i n g (VX2) and t o t a l rates of weathering (TLS) could be demonstrated. Iron plus aluminum losses from the solum (VX4) show the strongest c o r r e l a t i o n with B-^ horizon processes. An r of .84 f o r ir o n plus aluminum l o s t from the B^ horizon (XL2) with VX4 shows a highly s i g n i f i c a n t and strong p o s i t i v e c o r r e l a t i o n . A l l other parameters associated with the B^ are s i g n i f i c a n t l y correlated with VX4 but to a le s s e r extent. Solum losses would appear to be con t r o l l e d by processes i n the B^ horizon rather than biochemical c y c l i n g , since no other s i g n i f i c a n t c o r r e l a t i o n s could be demonstrated. The E l u v i a l A Horizon Losses from the Ae horizon do not conform to t o t a l solum losses. Analysis of variance shows s t a t i s t i c a l l y s i g n i f i c a n t (P = .05) s i t e differences f o r i r o n plus aluminum and (P = .10) for mass l o s s . D.N.M.R.T. segregates S i t e 2 with highest losses of both i r o n plus aluminum and mass but does not d i s t i n g u i s h between S i t e s 1 and 3 f o r e i t h e r . Inspection of loss r a t i o s shows p r e f e r e n t i a l loss of i r o n plus aluminum from the Ae horizon f o r a l l s i t e s . Although proportional l o s s of i r o n plus aluminum increases from Si t e s 1 to 2 to 3, and appears i n v e r s e l y r e l a t e d to t o t a l i r o n plus aluminum entering the horizon, no s i g n i f i c a n t c o r r e l a t i o n could be demonstrated between e i t h e r t o t a l mass or concentration entering the horizon (VX2) and proportional l o s s (LR1). As with solum losses, Ae losses do not appear to be co n t r o l l e d by biochemical c y c l i n g and i n fac t Ae horizon losses show the reverse s i t e ranking to solum losses. 8{ - 81 -The I l l u v i a l B Horizon The t o t a l i r o n plus aluminum entering the B^ horizon (VXA) i s p r i m a r i l y a function of b i o t i c c y c l i n g although the proportion contributed by the Ae horizon increases from 8% at S i t e 1 to 25% and 22% r e s p e c t i v e l y at S i t e s 2 and 3. The s t a t i s t i c a l l y s i g n i f i c a n t s i t e d ifferences i n Ae horizon losses (XL1) have been masked by the over-whelming influence of b i o l o g i c a l l y cycled i r o n plus aluminum (VX2). Iron plus aluminum l o s t from the B^ horizon (XL2) show s i g n i f i c a n t s i t e differences at the 10% p r o b a b i l i t y l e v e l and Duncan's New Mul t i p l e Range Test separates two homogeneous subsets ranked i n increasing order from S i t e 2 to S i t e 3, to S i t e 1. S i t e 2, shows an. absolute gain i n i r o n 2 plus aluminum of .18 grams per 1 cm cross s e c t i o n a l column of the B^ horizon. T o t a l s o i l l o s s from the B^ horizon (TL2) follows a s i m i l a r pattern to XL2 but shows net losses at a l l s i t e s . Loss r a t i o s show a c l e a r p r e f e r e n t i a l l o s s of i r o n plus aluminum, i n the B^ horizon. There i s a net negative enrichment of i r o n plus aluminum or p r e f e r e n t i a l loss of s o i l constituents other than i r o n plus aluminum. There i s a s i g n i f i c a n t negative c o r r e l a t i o n between i r o n plus aluminum l o s t from the B^ horizon and i r o n plus aluminum l o s t from the Ae horizon (XL2 with XLl) as w e l l as between XL2 and t o t a l mass l o s t from the Ae horizon (TL1). Values f o r r were .63 and .54 r e s p e c t i v e l y . T o t a l losses from the B^ show a strong p o s i t i v e c o r r e l a t i o n (r = .84) with B^ horizon losses of i r o n plus aluminum (XL2), but show a much weaker non-significant negative c o r r e l a t i o n Cr = .40) with XLl and no c o r r e l a t i o n (r = .10) with t o t a l mass l o s t from the Ae ( T L l ) . This would suggest a causal r e l a t i o n s h i p - 82 -between i r o n plus aluminum l o s t from the Ae (XLl) and i r o n plus aluminum l o s t from the horizon (XL2). The accumulation of weathering products of i r o n plus aluminum from the Ae horizon i n the B^ horizon tends to i n h i b i t weathering i n the B^ horizon. This i s due to an accumulation of equilibrium weathering products and as a r e s u l t of a protective amorphous coating on the primary minerals. The lower c o r r e l a t i o n of t o t a l mass l o s t from the B^ horizon (TL2) with i r o n plus aluminum losses from the Ae (XL l ) , and lack of c o r r e l a t i o n with t o t a l mass l o s t from the Ae (TLl) suggests that t o t a l mass loss from the B^ horizon (TL2) i s at least p a r t l y a function of weathering of ferro-magnesium minerals i n the B^ horizon. Total mass l o s t from the B^ i s retarded by the accumulation of i r o n plus aluminum weathering products from the Ae. The r e l a t i o n s h i p between B^ horizon mass losses (TL2) and the Ae horizon i s l a r g e l y i n d i r e c t and a function of the ir o n plus aluminum r e l a t i o n s h i p . The high c o r r e l a t i o n between the loss r a t i o of the B^ (LR2) and i r o n plus aluminum l o s t from the B^ (XL2) and the low c o r r e l a t i o n between LR2 and i r o n plus aluminum l o s t from the Ae (XLl) would tend to support t h i s i n t e r p r e t a t i o n . I t i s of i n t e r e s t to note that, despite the much larger values of b i o l o g i c a l l y cycled i r o n plus aluminum (VXA) than i r o n plus aluminum l o s t from the Ae (XLl) no c o r r e l a t i o n with e i t h e r i r o n plus aluminum or t o t a l mass losses could be demonstrated. This suggests that despite r e l a t i v e l y large masses of i r o n and aluminum involved i n b i o t i c c y c l i n g , b i o t i c c y c l i n g has l i t t l e apparent e f f e c t on e i t h e r losses from the Ae horizon or r e d i s t r i b u t i o n i n the B^ horizon. I t was noted e a r l i e r that solum losses are r e l a t e d to B-, horizon losses but that B., horizon losses are apparently - 83 -related to i r o n plus aluminum losses from the Ae horizon. Presumably then iron plus aluminum losses from the solum may be inversely r e l a t e d to i r o n plus aluminum losses from the Ae horizon. The B 2 Horizon Iron plus aluminum entering the B 2 horizon (VX3) shows a highly s i g n i f i c a n t p o s i t i v e c o r r e l a t i o n with i r o n plus aluminum l o s s , t o t a l mass loss and loss r a t i o of the B.^ horizon (VX2, TL2, and LR2). The cor r e l a t i o n s of VX3 with XL2 and TL2 (r = .51 and r = .50 respectively) are r e l a t i v e l y weak while the c o r r e l a t i o n with LR2 (r = .67) i s r e l a t i v e l y strong. The higher c o r r e l a t i o n of i r o n plus aluminum leaving the B^ horizon with the loss r a t i o of the B^ (VX3 with LR2) may be r e l a t e d to the i n t e n s i t y of weathering, since there i s a hig h l y s i g n i f i c a n t c o r r e l a t i o n between loss r a t i o and proportion of t o t a l horizon mass l o s t as a r e s u l t of weathering. The overwhelming influence of b i o l o g i c a l c y c l i n g on s o i l water chemistry has been l o s t , there i s no c o r r e l a t i o n between i r o n plus aluminum entering the Ae horizon (VX2) and i r o n plus aluminum leaving the B^ horizon (VX3). Iron and aluminum values i n the s o i l water entering the B 2 horizon (VX3) are at le a s t p a r t l y r e l a t e d to processes occuring i n the B^ horizon. Iron plus aluminum losses show no c o r r e l a t i o n with losses from the overlying horizon. T o t a l mass loss from the B 2 horizons (TL3) shows a highly s i g n i f i c a n t p o s i t i v e c o r r e l a t i o n (r = .62) with t o t a l mass loss from the B^ horizon (TL2). This indicates that TL2 and TL3 are probably responding to the same processes. Loss r a t i o of the B 2 (LR3) shows the same r e l a t i o n -ship to VX2 as did i r o n plus aluminum loss (XL3) and a strong highly s i g n i f i c a n t p o s i t i v e c o r r e l a t i o n with i r o n plus aluminum loss (XL3). - 84 -Also of Interest Is the lack of correlation between the mass of chemical cycling, which averages 2.5 times the total iron plus aluminum released by weathering (32% of total solum iron plus aluminum), and either the release or loss of iron and aluminum from the horizons. The B 2 horizon appears to represent a different system than the horizon. Losses of iron plus aluminum and total horizon mass as well as loss ratio appear unrelated to processes occuring in the overlying horizons. A l l estimates of soil weathering used for the B^ horizon, B 2 horizon and solum are in general agreement. Duncan's New Multiple Range Test ranks and separates means in the order of increasing loss; Site 2, Site 3, Site 1 . Iron plus aluminum losses from the Ae horizons are the reverse of this order and although no strong negative correlation between iron plus aluminum loss from the Ae and iron plus aluminum loss from the solum could be demonstrated the link was established indirectly through the B^ horizon. PARTITIONING FORMS OF IRON PLUS ALUMINUM Two models were used in partitioning the forms of iron plus aluminum. The first model assumes that a l l iron plus aluminum lost from the overlying horizon is deposited in the immediate underlying horizon and therefore that a l l iron plus aluminum lost from the horizon is derived from primary minerals in the horizon. The second model presumes that primary iron and aluminum will not be mobilized unless inputs from the overlying horizon cannot account for total outputs. Therefore only that iron plus aluminum lost from the overlying horizon which is in excess of the horizon loss will be deposited. - 85 -Forms of Iron plus Aluminum P a r t i t i o n e d Cycled: Two l e v e l s of cycled i r o n plus aluminum have to be recognized. The f i r s t i s the t o t a l mass of i r o n plus aluminum c i r c u l a t e d by b i o l o g i c a l c y c l i n g and i s assumed to be equal to t o t a l uptake rate from the horizon. This i r o n plus aluminum cannot be further p a r t i t i o n e d since there i s no way of knowing what proportion of t h i s i r o n and aluminum has been previously cycled, translocated, released from primary weathering, or taken d i r e c t l y from primary minerals. The second l e v e l i s the t o t a l mass of i r o n and aluminum resident i n the horizon. For the purposes of the model, resident i r o n plus aluminum i s assumed to be n e g l i b l e . Although there i s c e r t a i n to be at l e a s t a portion of resident i r o n plus aluminum a t t r i b u t a b l e to b i o t i c c y c l i n g the exact amount cannot be determined. For the purposes of comparison a non-additive value of 0.06 times b i o t i c uptake i s used as a value against which c o r r e l a t i o n s with extractable forms can be tested, i t does not constitute a portion of the i r o n plus aluminum claculated by the model. The value 0.06 i s the mean proportion of i r o n plus aluminum entering the Ae horizon which was extractable from the Ae horizon by a c i d ammonium oxalate. Released: Released r e f e r s to the i r o n and aluminum component of the calculated t o t a l horizon l o s s and i s calculated for the B 1 horizon as: RL2 = TL2 x (% Fe+Al i n parent material) and s i m i l a r l y f or the horizon as RL3 = TL3 x (% Fe+Al i n parent material) - 86 -where RL equals released, TL equals t o t a l horizon mass l o s s , and 2 and 3 r e f e r to the B^ and B 2 horizons. No assumptions about the form of t h i s i r o n plus aluminum are made. Residual: Released i r o n and aluminum not l o s t from the horizon i s re f e r r e d to as r e s i d u a l i r o n plus aluminum. In model A horizon outputs are presumed to come f i r s t from released i r o n and aluminum and then, i f output exceeds t h i s value, to come from translocated i r o n plus aluminum. Residual i r o n plus aluminum i s calculated as: RS2 = RL2 - XL2 and RS3 = RL3 - XL3 for the B^ and B 2 horizons r e s p e c t i v e l y . In model B,horizon outputs are assumed to be derived f i r s t l y from already mobilized inputs and then, i f the outputs are i n excess of inputs, from released i r o n and aluminum. The remaining released i r o n plus aluminum i s then referred to as r e s i d u a l and i s calculated as follows: IF (XL2 > XLl) then RS2 = RL2 - (XL2 - XLl) and IF (XL2 < XLl) then RS2 = RL2 where XLl = Fe+AI l o s t from the Ae, XL2 = Fe+AI l o s t from the B^ horizon, RL2 = released Fe+AI from the B^, and RS2 = Residual Fe+AI i n the B^ horizon RS3, r e s i d u a l Fe+AI i n the B 2 horizon i s calculated i n the same way: IF (XL3 > XL2) then RS3 = RL3 - (XL3 - XL2) and IF (XL3 , RL2) then TR2 = XLl - (XL2 - RL2) and IF (XL2 < RL2) then TR2 = XLl s i m i l a r l y , for the B 2 horizon IF (XL3 > RL3) then TR3 = XL2 - (XL3 - RL3) and IF (XL3 < RL3) then TR3 = XL2 where XL = Fe+Al l o s t , RL = Fe+Al released, TR = Fe+Al translocated, and 2 and 3 r e f e r to horizons B^ and B 2 r e s p e c t i v e l y . In model B, output from the horizon i s presumed to come f i r s t l y from i r o n and aluminum already mobilized i n the overlying horizon and then from released icon plus aluminum. Only i f input exceeds output can there be a value f o r translocated i r o n plus aluminum. In t h i s model the translocated i r o n plus aluminum i s calculated as: TR2 = XLl -XL2 and TR3 = XL2 - XL3 where TR = translocated i r o n plus aluminum, XL = i r o n plus aluminum l o s t , and 1, 2 and 3 r e f e r to the Ae, B^ and B 9 horizons r e s p e c t i v e l y . - 88 -Results of P a r t i t i o n i n g Results of the model are presented i n Table 3-4. Mean s i t e values f o r model predicted forms of i r o n plus aluminum and mean s i t e values f o r forms of extractable i r o n plus aluminum are presented i n Table 3-5. Amorphous i r o n plus aluminum i s calculated as the acid ammonium oxalate value l e s s the sodium pyrophosphate value. From the discussion on extraction techniques i t i s presumed that t h i s represents non-organically complexed amorphous material. Cycled: Following the assumption that resident cycled i r o n plus aluminum i s a f i x e d proportion of the t o t a l cycled, neither the nor the B 2 horizons show s i g n i f i c a n t s i t e differences, i n f a c t the p r o b a b i l i t y associated with the F value makes the p o s s i b i l i t y of e i t h e r Type 1 or Type 2 errors h i g h l y u n l i k e l y . Released: The value f o r released i r o n plus aluminum,while used i n the c a l c u l a t i o n of translocated and r e s i d u a l sesquioxide forms, i s r e a l l y a measure of t o t a l s o i l l o s s from the horizon. Duncan's New Mul t i p l e Range Test at the 10% p r o b a b i l i t y l e v e l separates and ranks means i n the order S i t e 2, S i t e 3, S i t e 1. Analysis of variance shows marginally s i g n i f i c a n t s i t e d ifferences f o r the B^ horizon and s i g n i f i c a n t s i t e differences f o r the horizons Translocated: Model A and model B while producing d i f f e r e n t estimates of translocated i r o n plus aluminum show the same s i t e r e l a t i o n s h i p s . Analysis of variance f o r the B^ horizon shows highly s i g n i f i c a n t s i t e differences but Duncan's New Mul t i p l e Range Test only separates S i t e 2 from S i t e s 1 and 3. In the B 2 horizon, model A produces s i g n i f i c a n t s i t e differences when - 89 -Table 3-4. Mean Si t e Values f o r Model Predicted forms of Iron plus Aluminum S i t e 1 S i t e 2 S i t e 3 Prob. D.N.M.R.T. Sig. Cy2 .22 .21 .08 .43 3 2 1 NS., TR2a .25 .59 .41 .02 1_3 2 ** TR2b .00 .58 .22 .03 1_3 2 ** RL2 .87 .39 .54 .11 2 3 1 NS Rs2a .48 .37 .30 .49 3 2 T NS RS2b .72 .39 .49 .19 2 3 1 NS NP2 .73 .96 .71 .14 3JL 2 NS Cy3 .04 .02 .03 .52 2 3 1 NS TR3a .38 .01 .24 .07 2 3 1 * TR3b .25 .01 .15 .14 2 3 1 NS RL3 .62 .17 .34 .06 2 3 1 * RS3a .40 .11 .18 .27 2 3 1 NS RS3b .52 .11 .26 .11 2 3 1 NS NP3 .78 .12 .41. .08 2 3 1 * Table 3-5. Mean S i t e Values f o r Forms of Extractable Iron plus Aluminum S i t e 1 S i t e 2 Sit e 3 Prob. D.N.M.R.T. Sig. NaPXl A0X1 CBDX1 AM0R1 NaPX2 A0X2 CBDX2 AMOR2 .003 .01 .02 .007-.17 .69 .57 .52 .007 .03 .03 .02 .20 1.15 .79 .95 .008 .02 .03 .01 .27 .79 .75 .52 .18 .04 .02 .01 .07 .01 .25 .00 1 3 2 NS * * * NS * NS NaPX3 A0X3 CB0X3 AM0R3 ,13 ,68 .44 .55 .09 .55 .34 .45 ,11 .40 ,33 .29 .33 .10 .26 .08 2 3 1 3 2 1 3 2 1 3 2 1 NS NS NS NS - 90 -analysis i s performed and Duncan's New M u l t i p l e Range Test at the 10% pro-b a b i l i t y l e v e l separates overlapping means increasing from S i t e 2 to 3 to 1. Residual: Unlike translocated i r o n plus aluminum, estimates of r e s i d u a l i r o n plus aluminum show d i f f e r e n t s i t e responses depending upon the model applied. Model A produces no s i g n i f i c a n t s i t e differences for e i t h e r the or B 2 horizons while model B shows s i g n i f i c a n t s i t e differences i n the B 2 horizon. Duncan's New M u l t i p l e Range Test ranks and separates overlapping means i n the increasing order S i t e 2 to S i t e 3 to S i t e 1 f o r both B^ and B 2 horizons. Non-Primary: Non-primary i r o n plus aluminum i s calculated as the sum of translocated and r e s i d u a l forms and i s uninfluenced by the d i f f e r e n c e i n the models used. S i g n i f i c a n t s i t e differences are demonstrable only for the B 2 horizon where Duncan's New M u l t i p l e Range Test ranks overlapping means i n the increasing order S i t e 2, S i t e 3, S i t e 1. A comparison of model calculated mean s i t e values for i r o n plus aluminum with mean measured extractable forms l i s t e d i n Table 3-5 shows the best agree-ment between non-primary i r o n plus aluminum and acid ammonium oxalate (Table 3-6). Table 3-6. Predicted Non-primary Fe+Al and Acid ammonium oxalate extractable Fe+Al S i t e 1 S i t e 2 S i t e 3 NP2 .73 .96 .71 AOX2 .69 1.15 .79 NP3 .78 .12 .41 A0X3 .68 .55 .40 - 91 -Despite the rather remarkable agreement when s i t e means are compared, p i t by p i t comparisons showed great v a r i a b i l i t y and a highly s i g n i f i c a n t but r e l a t i v e l y small c o r r e l a t i o n c o e f f i c i e n t of 0.55. CORRELATION OF PREDICTED TO MEASURED FORMS OF IRON PLUS ALUMINUM In an attempt to evaluate the model r e s u l t s a c o r r e l a t i o n table of model r e s u l t s and measured extractable forms was constructed. I t i s presented as Table 3-7. Following the discussion on extraction techniques the series sodium pyrophosphate (NAP), acid ammonium oxalate (AOX), c i t r a t e -bicarbonate-dithionite (CBD), and amorphous (AMOR) may be viewed as de-creasing degrees of organic complexing with NAP representing exclusive o r g a n i c a l l y complexed forms and AMOR representing nearly e x c l u s i v e l y inorganic amorphous forms of i r o n plus aluminum. The Ae Horizon As noted e a r l i e r the t o t a l mass of i r o n plus aluminum entering at the s o i l surface as a r e s u l t of biochemical c y c l i n g (VX2) seems to have l i t t l e i nfluence on s o i l weathering, t h i s despite comprising >75% of the t o t a l f l u x across the Ae-B^ boundary. This pattern indicated by the model r e s u l t s i s r e f l e c t e d i n the extractable forms of i r o n plus aluminum and no s i g n i f i c a n t c o r r e l a t i o n between biochemical c y c l i n g (VX2) and any extractable form of i r o n plus aluminum i n any horizon was demonstrated. A l l measures of extractable i r o n plus aluminum show highly s i g n i f i c a n t p o s i t i v e c o r r e l a t i o n s with t o t a l s o i l loss (TL1) and ir o n plus aluminum loss (XLl) i n the Ae horizon. - 92 -Table 3-7. Corr e l a t i o n Table of Model Predicted with Measured Values Pearson Co r r e l a t i o n C o e f f i c i e n t s Ae horizon VX2 XLl T L l NAPX1 0.1954 0.7223* 0.5775+ A0X1 0.4379 0.8231** 0.7019* CBDX1 0.2292 0.8359** 0.5753+ AM0R1 0.1407 0.8481** 0.7121* AE with horizon VX2 XLl T L l NAPX2 -0.3239 0.2025 -0.1166 A0X2 0.3170 0.8239** 0.6103+ CBDX2 -0.3352 0.6069+ 0.4482 AM0R2 0.4089 0.8061** 0.6712* B^ horizon VXA CY2 RL2 RS2a RS2b TR2a TR2b NP2 NAPX2 -0.3058 -0.2873 0.0854 -0.0936 0.0650 0.2025 0.0186 0.0962 A0X2 0.3708 0.3490 -0.2603 -0.0469 -0.2211 0.8239** 0.6826* 0.6211+ CBDX2 -0.2887 -0.3082 -0.0895 0.0443 -0.0350 0.6069+ 0.4331 0.5117+ AM0R2 0.4603 0.4325 -0.3024 -0.0257 -0.2550 0.8061** 0.7127* 0.6216* B 2 horizon VX3 CY3 RL3 RS3a RS3b TR3a TR3b NP3 NAPX3 -0.0960 -0.0845 0.4826 0.4455 0.4119 0.0431 0.0579 0.2993 A0X3 -0.1576 -0.1194 0.1296 0.0671 0.0396 -0.1027 -0.0975 -0.0148 CBDX3 -0.0762 -0.2231 0.6332+ 0.6210+ 0.5851+ 0.1306 0.1550 0.4560 AM0R3 -0.1608 -0.1058 0.0676 -0.0016 -0.0287 -0.1271 -0.1219 -0.0708 Inputs and Outputs VX2 VX2 VXA VX3 VX4 + a = b = -SIG. output output 1.0000 0.9976** 0.2206 0.0577 LE 0.05 * -SIG. from model A from model B VXA 0.9976** 1.0000 0.2006 0.0341 LE 0.01 ** -SIG. VX3 0.2206 0.2006 1.0000 0.6487+ LE 0.001 VX4 0.0577 0.0341 0.6487+ 1.0000 - 93 -This i s due to the d i r e c t c o r r e l a t i o n of TL1 and XLl with the t o t a l mass of the Ae from which the extractions were taken. Correlation c o e f f i c i e n t s of r = 0.72, r = 0.82, r = 0.84 and r = 0.85 for sodium'pyrophosphate, ammonium oxalate, c i t r a t e - b i c a r b o n a t e - d i t h i o n i t e and calculated inorganic amorphous r e s p e c t i v e l y with XLl would indi c a t e that the c o r r e l a t i o n i s strongest between i r o n plus aluminum weathering and r e s i d u a l inorganic forms of amorphous material. The highly s i g n i f i c a n t c o r r e l a t i o n s of i r o n plus aluminum extractable from the Ae horizon with XL2, TR2A, TR2B, and NP2 are l i k e l y i n d i r e c t through the influence of XLl since the model produced a highly s i g n i f i c a n t negative c o r r e l a t i o n between XLl and XL2. Model r e s u l t s do not support or confirm the negative c o r r e l a t i o n between A0X1, AM0R1 and TR3A, TR3B. Nor do they support or confirm the negative c o r r e l a t i o n between AM0R1 and RS3B, NP3 although the model l i n k s X Ll to XL2 and XL2 to XL3 and the r e l a t i o n s h i p would be expected to be negative. As with the c o r r e l a t i o n of extractable forms with X L l , the c o r r e l a t i o n i s strongest with inorganic forms of amorphous i r o n plus aluminum. A0X2, CBD2, and AM0R2 show highly s i g n i f i c a n t p o s i t i v e c o r r e l a t i o n s with t o t a l loss (TL1) and i r o n plus aluminum loss (XLl) from the Ae. The much higher c o r r e l a t i o n between XLl and extractable forms indicates that the r e l a t i o n s h i p between TL1 and extractable i r o n plus aluminum i s i n d i r e c t through XLl. The r e l a t i v e l y high c o r r e l a t i o n c o e f f i c i e n t (r = .82) between A0X2 and X L l , and lack of c o r r e l a t i o n between eit h e r i r o n plus aluminun entering (VX2) or leaving (VXA) the Ae horizon supports the model p r e d i c t i o n of biochemical c y c l i n g being r e l a t i v e l y unimportant i n the development of the i l l u v i a l B horizon. - 94 -The Horizon Model-predicted forms of i r o n plus aluminum when tested against extractable forms i n the B^ horizon showed s i g n i f i c a n t c o r r e l a t i o n s only for translocated (TR2) and non primary (NP2) with A0X2, CBD2, and AM0R2. Model A showed consistently higher c o r r e l a t i o n c o e f f i c i e n t s than model B and acid ammonium oxalate showed the highest c o r r e l a t i o n of the three extractable forms. Of s p e c i a l i n t e r e s t i s the near zero c o r r e l a t i o n of NAP2 with any predicted form of i r o n plus aluminum i n the B^ horizon. Extractable forms of i r o n plus aluminum show co n s i s t e n t l y lower c o r r e l a t i o n c o e f f i c i e n t s with t o t a l non primary i r o n plus aluminum i n the B^ horizon CNP2) than with TR2A. The s i g n i f i c a n t c o r r e l a t i o n i s probably due to the translocated component of NP2. The B 2 Horizon Ci t r a t e - b i c a r b o n a t e - d i t h i o n i t e i s the only extractable form of i r o n plus aluminum to show a s i g n i f i c a n t c o r r e l a t i o n with any of the predicted forms. Model A and model B do not produce s i g n i f i c a n t l y d i f f e r e n t c o r r e l a t i o n s although model A shows s l i g h t l y higher r values. The s i g n i f i c a n t c o r r e l a t i o n of t o t a l loss from the B 2 (TL3) and i r o n plus aluminum released by weathering (RL3) with CBD3 i s expected, since the model predicts these as the major source of r e s i d u a l i r o n plus aluminum. The c o r r e l a t i o n between CBD3 and NP3 i s s i g n i f i c a n t l y lower than CBD3 with RS3. Model A then produces the closest agreement with actual measured values of i r o n and aluminum both for t o t a l and p a r t i t i o n e d forms of ir o n plus aluminum - 95 -i n the horizon and w i l l be used as the basis f o r the discussion which follows. DISCUSSION The Solum Evaluation of t o t a l biochemical c y c l i n g and solum loss of i r o n plus aluminum show no s i g n i f i c a n t s i t e differences f o r eit h e r v a r i a b l e despite s i g n i f i c a n t l y d i f f e r e n t r e l o c a t i o n patterns and morphology. The s o i l climosequence of warm dry to cool moist cannot be shown to have influenced biochemical c y c l i n g or t o t a l i r o n plus aluminum l o s s , nor can a c o r r e l a t i o n between rates of biochemical c y c l i n g and s o i l weathering be demonstrated f o r t h i s study. Loss r a t i o s demonstrate a net negative enrichment of i r o n plus aluminum f o r the solum as a whole. S i t e s 1, 2 and 3 show proportional increases of 7.6%, 3.3%, and 3.3% re s p e c t i v e l y . No t o t a l solum measurements can be shown to follow e i t h e r the chemical or morphological pattern of Podzol development and i n fact net negative enrichment i s the reverse of that expected on the basis of morphology. Total solum acid ammonium oxalate extractable i r o n plus aluminum does, however, correspond to the morphological i n t e r p r e t a t i o n of strength of s o i l development. The Ae Horizon Within the model of s o i l genesis being used i n t h i s study the Ae horizon i s a horizon dominated by losses of mineral s o i l constituents and additions of organic material. Both measured and model predicted values demonstrated a highly active weathering regime. Model r e s u l t s i n d i c a t e t o t a l s o i l losses - 96 -from the Ae horizon of 27%, 20%, and 12% i n i t i a l values for Sites 1 through 3, and i r o n plus aluminum losses of 47%, 48%, and 52% i n i t i a l values i n the same s i t e order. Ae horizons are dominated by quartz and feldspar minerals i n the s i l t to f i n e sand p a r t i c l e s i z e range and present a much smaller surface area for weathering than the smaller c r y s t a l s i z e s of the clay minerals. The Goldich s t a b i l i t y series f o r s i l t and sand sized p a r t i c l e s l i s t s the ferro magnesium minerals as being much more weatherable than potassium feldspars or quartz and conforms to strength of c r y s t a l structure. Ferro magnesium minerals then would be expected to weather r a p i d l y , as would the feldspars containing higher numbers of alumina tetrahedra i n the c r y s t a l structure (Barshad, 1964). This would tend to leave r e l a t i v e l y coarse textured materials dominated by quartz and potassium feldspars strongly r e s i s t e n t to further weathering. Clay s i z e minerals with a much larger surface area would be expected to weather much more quickly and show the same pattern of weatherability with degree of linkage and number of alumina tetrahedra. This may i n part explain the marked p r e f e r e n t i a l loss of i r o n plus aluminum r e l a t i v e to t o t a l Ae losses but does require that i r o n and aluminum weathering products be removed from the horizon. Since secondary i r o n and aluminum compounds are among the most stable of s o i l constituents and since i r o n and aluminum s o l u b i l i t i e s are so low (Van Schuylenborgh and Bruggenwert, 1965) one or several organic c a r r i e r mechanisms must be invoked to f u l l y explain the phenomenon. This study sheds l i t t l e l i g h t on the mechanism of i r o n and aluminum mo b i l i z a t i o n i n the Ae horizon except that t o t a l horizon organic carbon shows no c o r r e l a t i o n (r = .16) with measured o r g a n i c a l l y complexed sodium pyrophosphate i r o n plus aluminum. - 97 -Since no c o r r e l a t i o n of i r o n plus aluminum input to the horizon with any extractable forms could be demonstrated, and since there i s no source for translocated i r o n plus aluminum, i t seems reasonable to assume that the i r o n plus aluminum extractable from the Ae horizon i s p r i m a r i l y r e s i d u a l . This i s supported by greater e f f i c i e n c y of c i t r a t e - b i c a r b o n a t e - d i t h i o n i t e extraction r e l a t i v e to the other extractions i n the Ae horizon, which indicates a greater proportion of weakly c r y s t a l i n e i r o n and aluminum minerals. Ratios for acid ammonium oxalate and citrate-bicarbonate-d i t h i o n i t e extractable i r o n to aluminum (Table 3-8) show much higher values i n the Ae horizon than i n a l l other horizons. The greater ease of 3+ 3+ hydroxylation of the Fe over A l w i l l tend to produce more complete 3+ p r e c i p i t a t i o n as Fe(OH).j of released i r o n , whereas A l w i l l undergo varying degrees of hydroxylation and polymerization and act as polyvalent cations (Barshad 1964), which can be more e a s i l y mobilized. This would then tend to cause a net negative enrichment of i r o n r e l a t i v e to aluminum i n the strong weathering environment of the Ae and i s again consistent with the i n t e r p r e t a t i o n of extractable i r o n plus aluminum i n the Ae being l a r g e l y r e s i d u a l and are most l i k e l y i n the Fe(OH) 3 (or F^O^ - 3H20) and A1(0H) 3 (or A 1 2 0 3 - 3H20) forms. Calculations on a percentage by weight b a s i s , y i e l d mean oxalate extractable i r o n plus aluminum values by horizon of Ae = .31, B^ = 2.29, B 2 = 1.63, BC = 1.54, and C = 1.24 supporting a rather e f f i c i e n t removal or i r o n and aluminum from the Ae horizon. I f t o t a l i r o n plus aluminum l o s t from the Ae horizon i s used as a measure of "Podzolization", S i t e 2 shows s i g n i f i c a n t l y greater Podzol expression than Si t e s 1 and 3 which are s t a t i s t i c a l l y inseparable. I f morphology of the Ae i s used then, based on thickness S i t e s 2 and 3 represent stronger Podzol expression than S i t e 1. - 98 -Table 3-8. Iron/Aluminum Ratio f or Sodium pyrophosphate (NAP), acid ammonium oxalate (AAO) c i t r a t e bicarbonate d i t h i o n i t e extractable (CBD) , and t o t a l horizon values Horizon S i t e NAP AAO CBD Tota l Ae 1 1.0 2.5 5.6 .6 2 .8 3.6 6.2 .7 3 1.0 2.3 10.0 .6 mean (.9) (2.8) (7.3) (.6) B 1 1 .3 .6 1 . 6 .5 j. 2 .2 .7 1.6 .6 3 .4 .5 1.4 .6 mean (.3) (.6) (1.5) (.6) B 9 1 .2 .3 1.3 Z 2 .1 .3 1.2 3 .3 .5 1.4 (.2) (.4) (1.3) BC 1 .1 .3 1.1 2 .1 .4 1.4 3 .2 .7 1.8 (.1) (.5) (1.4) C 1 .1 .4 1.3 2 .1 .9 1.7 3 .3 .4 1.6 (.1) (.6) (1.5) - 99 -The B 1 Horizon The horizon, which for these s o i l s i s diagnostic f o r c l a s s i f i c a t i o n , shows net enrichment of i r o n plus aluminum at a l l s i t e s . A l l forms of measured i r o n plus aluminum including t o t a l digest, as w e l l as model r e s u l t s show a maximum f o r i r o n plus aluminum i n the B^, S i t e 2 i n fac t shows an average net gain i n i r o n plus aluminum over the i n i t i a l content. Two general mechanisms are generally invoked to explain t h i s net or r e l a t i v e gain i n i r o n plus aluminum. The f i r s t conforms to the c l a s s i c a l concept of Podzols and requires the mob i l i z a t i o n of i r o n plus aluminum i n the Ae horizon, t r a n s l o c a t i o n to and deposition i n the B^ horizon. In the context of the model, the horizon i s one dominated by transfers of i r o n plus aluminum from the Ae to the B^ i n excess of losses from the B^. The second mechanism, referred to as f e r r a l i t z a t i o n by Pedro (1961) requires the p r e f e r e n t i a l loss of s o i l constituents other than i r o n and aluminum, r e s u l t i n g i n a net negative enrichment of i r o n plus aluminum r e l a t i v e to other s o i l constituents. This mechanism implies a horizon forming process dominated by losses of materials other than i r o n and aluminum and trans-formations of i r o n and aluminum compounds. A t h i r d possible mechanism, not often invoked, i s biochemical r e d i s t r i b u t i o n through b i o t i c c y c l i n g . Iron and aluminum are extracted by roots from the t o t a l solum and returned to the surface where they are c a r r i e d by water flow to the B^ horizon and pr e c i p i t a t e d . Biochemical c y c l i n g , although very dramatic i n terms of t o t a l mass of i r o n and aluminum transferred (6.4, 3.4, and 2.4 times acid ammonium oxalate - 100 -extractable i n the B^ horizon as estimated for 10,000 yrs. for Si t e s 1, 2, and 3 r e s p e c t i v e l y ) , seems to have l i t t l e influence on either Ae or B^ horizon development. No c o r r e l a t i o n of i r o n plus aluminum cycled, with e i t h e r model estimated losses or any of the extractable forms of i r o n plus aluminum, could be demonstrated. I t would appear that biochemical c y c l i n g of i r o n and aluminum represents a f a i r l y closed system and that once i n the c y c l e , i r o n and aluminum tend to remain. Since the exact forms or mechanism of i r o n uptake are not known i t can only be assumed that s o i l i r o n and aluminum derived from biochemical c y c l i n g i s i n a much more r e a d i l y a v a i l a b l e form than other sources. On the basis of t h i s study i t i s d i f f i c u l t to support biochemical c y c l i n g of i r o n and aluminum as a s i g n i f i c a n t mechanism i n the development of these s o i l s . The model used predicts two d i s t i n c t balances of mechanism involved i n forming the B^ horizon. At S i t e 1 calculated values of non-primary i r o n are p a r t i t i o n e d into 34% translocated and 66% r e s i d u a l i r o n plus aluminum i n d i c a t i n g a horizon dominated by f e r r a l i t i z a t i o n or negative enrichment. Sit e s 2 and 3 are p a r t i t i o n e d into 60% and 58% translocated versus 40% and 42% r e s i d u a l i n d i c a t i n g a dominance of i l l u v i a t i o n over f e r r a l i t i z a t i o n . S i t e 1 would correspond to the concepts expressed i n Brown earths and highly weathered Brunisols whereas S i t e s 2 and 3 more c l o s e l y r e f l e c t the concept embodied i n the c l a s s i c a l Podzol. A number of c o r r e l a t i o n s both with model r e s u l t s and measured extractable values i n d i c a t e a strong process linkage between the Ae horizon and both rates of t r a n s l o c a t i o n and net negative enrichment. A highly - 101 -s i g n i f i c a n t negative c o r r e l a t i o n (r* - = 0.63) of i r o n plus aluminum l o s t from the Ae horizon CXLl) with i r o n plus aluminum l o s t from the (XL2), and a highly s i g n i f i c a n t p o s i t i v e c o r r e l a t i o n (r = 0.72, 0.72, and 0.84 fo r NAP, AOX, and CBD respectively) of predicted translocated values with Ae horizon extractable values may be interpreted i n the following manner. I f , as model A assumes, nearly a l l i r o n plus aluminum l o s t from the Ae i s deposited i n the B^ horizon the negative r e l a t i o n s h i p between XLl and XL2 can be viewed as the accumulation of i r o n and aluminum weathering products i n f l u e n c i n g equilibrium values and thus retarding weathering rates of B^ primary minerals. The dominance of acid ammonium oxalate extractable over the more c r y s t a l l i n e c i t r a t e - b i c a r b o n a t e - d i t h i o n i t e extractable form possibly indicates incomplete hydroxylation and some polymerization of i r o n and more probably aluminum. This would cause a slower-weathering rate than immediate conversion to F^O^ or A^O-j. The strong p o s i t i v e c o r r e l a t i o n between model predicted translocated values and Ae horizon extractable values are i n fact due to the c o r r e l a t i o n between l e v e l s of extractable i r o n and aluminum and rate of weathering i n the Ae. Evaluation of percentage values indicates that t h i s i s l a r g e l y a function of t o t a l horizon mass and that indeed a highly s i g n i f i c a n t negative c o r r e l a t i o n of percent X L l with % NAP1 (r = 0.84) and % CBD1 (r = 0.59) occurs. This indicates that as weathering i n t e n s i t y increases r e s i d u a l i r o n plus aluminum as a proportion of t o t a l horizon values decreases. Further support for a process linkage between the Ae and B^ horizons comes from the strong c o r r e l a t i o n (r = 0.82) of acid ammonium oxalate extractable i r o n plus aluminum from the B^ (A0X2) and XLl. - 102 -The two processes of development, negative enrichment and i l l u v i a t i o n , seem in v e r s e l y r e l a t e d . Increasing l e v e l s of i l l u v i a l i r o n plus aluminum i n h i b i t release of primary i r o n and aluminum i n the B^ horizon. This further emphasizes the d i s t i n c t i o n of the balance of processes between S i t e 1 and Sit e s 2 and 3 and groups the two morphological Podzols together. The strong c o r r e l a t i o n A0X2 with predicted translocated i r o n plus aluminum provides strong support f o r the i l l u v i a l process but predicted r e s i d u a l values show no c o r r e l a t i o n with measured values of i r o n plus aluminum. Table 3-6 shows a remarkable agreement between predicted non primary i r o n plus aluminum and measured acid ammonium oxalate values. However approximately 50% of the predicted value i s p a r t i t i o n e d to r e s i d u a l material and, as noted, r e s i d u a l i r o n plus aluminum shows no c o r r e l a t i o n with A0X2 values or for that matter any extractable values. I t must be stated then that measured values do not support the contribution of r e s i d u a l i r o n and aluminum presented by the model. The Horizon The B 2 horizon shows some d i s t i n c t contrasts to the B^ horizon which suggest a d i f f e r e n t mode of genesis. C o r r e l a t i o n values of predicted with measured values of i r o n plus aluminum give no s p e c i a l credence to either model A or model B. However where the B^ horizon showed a strong c o r r e l a t i o n only between acid ammonium oxalate extractable i r o n plus aluminum and predicted translocated values, the B ? horizon shows a strong c o r r e l a t i o n - 103 -only between c i t r a t e - b i c a r b o n a t e - d i t h i o n i t e extractable values and pre-dicted r e s i d u a l i r o n plus aluminum. This would suggest a horizon dominated by negative enrichment rather than i l l u v i a t i o n as the mechanism of i r o n plus aluminum enrichment. The f a c t that citrate-bicarbonate-d i t h i o n i t e i s assumed to extract more c r y s t a l l i n e i r o n and aluminum sesquioxides than acid ammonium oxalate i s supportive of t h i s i n t e r p r e t a t i o n , since r e s i d u a l i r o n and aluminum are more l i k e l y to be c r y s t a l l i n e than translocated i r o n and aluminum. Model A indicates three d i f f e r e n t balances of mechanism for the three s i t e s ; nearly equal at S i t e 1, nearly complete f e r r a l i t i z a t i o n at S i t e 2 and dominant i l l u v i a t i o n at S i t e 3. Model B consi s t e n t l y predicts horizon development p r i m a r i l y as a r e s u l t of negative enrichment which i s more consistent with the data. The f a i l u r e of c o r r e l a t i o n analysis to demonstrate a c l e a r preference may be due to the r e l a t i v e l y small difference i n predicted r e s i d u a l values produced by models A and B, which none the les s strongly influence the proportion of translocated to r e s i d u a l values. In summary, four d i s t i n c t processes are acting to produce horizon development i n the s o i l s studied and the r e s u l t i n g s o i l s are the product of not only the balance of processes but also the o v e r a l l rates of process. Ae horizons are dominated by losses of a l l mineral s o i l constituents i n the clay s i z e f r a c t i o n and a net negative enrichment of coarser s i z e f r a c t i o n s , which are dominated by quartz and feldspars. S i t e differences are caused by rate of loss not a s h i f t i n process balance. The B-^ horizons are the product of the balance between t r a n s l o c a t i o n , transformation, and losses. Translocation from the horizon perspective may be viewed as addition. - 104 -P r e f e r e n t i a l losses of s o i l material other than i r o n and aluminum cause a net negative enrichment of i r o n and aluminum and a transformation of these materials to t h e i r respective hydrous oxides. Translocation of i r o n and aluminum from the Ae horizon causes p o s i t i v e enrichment and also tends to depress the rate of loss or negative enrichment. S i t e differences are at t r i b u t a b l e to both differences i n the balance of processes and the over a l l rates of process. S i t e 1, B^ horizons are dominated by negative enrichment or p r e f e r e n t i a l losses with a subdominant contribution from translocations. S i t e s 2 and 3, on the other hand, show the reverse balance with dominant translocations and subdominant negative enrichment. S i t e 2 and 3, while showing the same balance of process, are i n f a c t separable on the rate of process with S i t e 3 showing much slower rates. The net r e s u l t i s that i n terms of t o t a l extractable i r o n and aluminum S i t e 3 i s more s i m i l a r to Si t e 1 than S i t e 2 despite S i t e s 2 and 3 showing the same process balance. Mor-p h o l o g i c a l l y S i t e 1 represents a Bru n i s o l , while S i t e s 2 and 3 represent Podzols. This i s consistent with process balances and ranked means for ammonium oxalate extractable i r o n and aluminum. The B 2 horizons of a l l s i t e s are dominated by the process of negative enrichment and show s i t e differences due p r i m a r i l y to rate of process. Model r e s u l t s and morphology rank the three s i t e s i n the order 1,3,2 of increasing Podzol expression. Measured solum i r o n plus aluminum loss and calculated solum mass loss are ranked i n the reverse order. This pattern would argue against any p o s i t i v e c o r r e l a t i o n between i n t e n s i t y of s o i l weathering and degree of Podzol development. In fac t c o r r e l a t i o n s - 105 -between i r o n plus aluminum l o s t from the Ae horizon, extractable from the horizon, or calculated as translocated were eit h e r near zero or negative and not s i g n i f i c a n t . S i t e differences i n Podzol development then are obviously not p r i m a r i l y the r e s u l t of o v e r a l l weathering i n t e n s i t y but rather of process balance. P r e c i p i t a t i o n , r e l i e f , parent material, vegetation composition, and time have been held r e l a t i v e l y constant between s i t e s with standing crop biomass, s o i l temperature and summer s o i l water regime being the only obvious v a r i a b l e s . GENETIC RELATIONSHIPS The pattern of s o i l development recorded i n t h i s study can be interpreted as a response to the s o i l climate differences recorded. The i n t e r p r e t a t i o n i s consitent with current theories of Podzol formation. Ae HORIZON FORMATION As discussed i n Chapter 2 the Ae horizons are chemically and morphologically very s i m i l a r . The only s i g n i f i c a n t differences recorded are i n thickness and percent carbon content. Table 3-9 presents a summary of mean s i t e c h a r a c t e r i s t i c s of the Ae horizons. Neither i r o n plus aluminum entering the horizon (VX1) nor the calculated i r o n plus aluminum leaving the horizon (VXA) are s i g n i f i -cantly d i f f e r e n t nor are there any s i g n i f i c a n t c o r r e l a t i o n s between VX1 or VXA and any parameters associated with the Ae horizon (Tables 3-3 and 3-7). The major diffe r e n c e l i e s i n the mass of the Ae horizons (thickness x bulk density) and the t o t a l i r o n plus aluminum l o s t from the horizon ( X L l ) . As shown - 106 -Table 3-9. Selected Characteristics of the Ae horizons Site 1 Site 2 Site 3 Sig. D.N.M.R.T. Mass 3.3 8.8 7.7 .01 1 3_2 % C 1.96 1.32 1.55 .11 2 _ A J L XLl .24 .59 .41 .02 ±J_ 2 VX1 4.4 3.9 1.9 .42 3 2 1 VXA 4.6 4.5 2.3 .44 3 2 1 - 107 -e a r l i e r the Ae i s characterized by the p r e f e r e n t i a l loss of i r o n and aluminum. I t i s reasonable to assume that the factors c o n t r o l l i n g i r o n and aluminum mob i l i z a t i o n are the factors c o n t r o l l i n g Ae formation. As documented i n Chapter 2 mobile f u l v i c a c i d i s the major agent implicated i n the transport of i r o n and aluminum. The mass of f u l v i c acid moving through the Ae horizon as w e l l as the degree of saturation of carboxyl and phenolic functional groups with cations should influence the degree of Ae horizon development. Evidence that the slower decomposition rate at S i t e 1 i s due to moisture stress and that at Site 3 i t i s due to lower temperatures was discussed i n Chapter 2. A d d i t i o n a l support for t h i s contention comes from the marked s i m i l a r i t y i n forest f l o o r s between s i t e s . A l l systems were assumed to be i n steady state, therefore, for S i t e 1 with presumably lower l e v e l s of l i t t e r return ( s i t e one had only 30% crown closure versus s i t e s 2 and 3 with 70%) to show comparable l e v e l s of forest f l o o r accumulation would require slower decomposition rates. S i t e 3 with intermediate biomass production l e v e l s and comparable forest f l o o r accumulations has, presumably, intermediate decomposition rates. Release of organic acids, then, would be expected to be greatest at S i t e 2, with highest l i t t e r production and most rapid decomposition, and lowest at S i t e 1, with lowest l i t t e r ' , production and slowest decomposition rates. The d i f f e r e n c e i n a v a i l a b l e s i t e s for complex formation (-C00H, OH groups) between Site s 1 and 3 i s enhanced by higher concentrations of i r o n and aluminum i n water leaving the forest f l o o r . Iron and aluminum i n s o l u t i o n are already occupying the s i t e s a v a i l a b l e for mobilizing i r o n and aluminum i n the Ae horizon. - 108 -S i m i l a r l y the higher concentrations of i r o n and aluminum i n water leaving the f o r e s t f l o o r at S i t e 2 w i l l tend to reduce the influence of lower organic a c i d production at S i t e 3. Differences i n the nature of decom-p o s i t i o n products are possible but u n l i k e l y to be large since the vegetative source material i s nearly i d e n t i c a l . Probable production of f u n c t i o n a l groups capable of m o b i l i z i n g i r o n and aluminum correspond to i r o n and aluminum losses from the Ae horizons. '&1 HORIZON FORMATION An explanation of the horizon development requires a mechanism of i r o n and aluminum enrichment rather than one of i r o n and aluminum removal. The two mechanisms proposed are i l l u v i a t i o n (translocation) and negative enrichment ( f e r r a l i t i z a t i o n ) . Negative enrichment i s r e l a t i v e l y e a s i l y explained by the very low s o l u b i l i t i e s of i r o n and aluminum i n simple aqueous systems. The higher s o l u b i l i t i e s of the other s o i l constituents w i l l cause them to be l o s t p r e f e r e n t i a l l y , t h u s causing a net negative enrichment or proportional increase of i r o n and aluminum. Model r e s u l t s i n d i c a t e that t h i s mechanism i s important at a l l s i t e s , however some means of i n a c t i v a t i n g organic acid m o b i l i z a t i o n must be proposed since i t has caused p r e f e r e n t i a l losses i n the Ae horizons. The i n a c t i v a t i o n of organic m o b i l i z a t i o n and the deposition ( p r e c i p i t a t i o n ) of o r g a n i c a l l y mobilized i r o n and aluminum translocated from the Ae horizon may be explained by the same mechanism. Increased loadings of i r o n and aluminum on the carboxyl groups of f u l v i c acids have been shown to cause p r e c i p i t a t i o n of the acids (Schnitzer and Skinner, 1963a). The generally weakly expressed Ae horizons on i r o n - 109 -r i c h parent materials i n Podzolic environments (Lewis, 1976), the demonstration that i r o n movement decreases as i r o n concentrations a v a i l a b l e f or complexing increase (Bloomfield, 1953, Deb, 1950), and the general occurrence of Podzolic s o i l s on coarse textured quartz r i c h s o i l s (McKeague et a l . , 1978) would tend to support the experimental r e s u l t s of Schnitzer and Skinner (1963a). McKeague ^ t a l . (1978) estimated p r e c i p i t a t i o n of f u l v i c acids at 50% saturation of the carboxyl groups. Dawson et a l . (1978) demonstrated the p r e c i p i t a t i o n of mobile f u l v i c acids, c o l l e c t e d using tension lysimeters, by B i r horizon material sampled from the same s i t e as the lysimeter c o l l e c t i o n s . This supported f i e l d measurements, i n d i c a t i n g reductions i n i r o n and mobile f u l v i c acids below the B^htr - B 2 i r horizons monitored. The formation of the B^ horizons studied can be viewed as follows: P r e c i p i t a t i o n of the mobile f u l v i c acids i s caused by overloading the s i t e s a v a i l a b l e f o r complexing. The point at which t h i s occurs i s a function of i n i t i a l loading as the s o l u t i o n enters the s o i l and the amount of i r o n plus aluminum a v a i l a b l e f o r complexing i n the s o i l . Iron and aluminum released by weathering i n the B^ horizon, as w e l l as i r o n and aluminum released by decomposition of previously complexed materials becomes a v a i l a b l e to cause overloading and p r e c i p i t a t i o n . Dawson et^ a l . (1978) showed o r g a n i c a l l y complexed i r o n i n a Bhir to be i n e f f e c t i v e i n p r e c i p i t a t i n g f u l v i c a c i d , inorganic amorphous i r o n i n a B i r highly e f f e c t i v e and amorphous Fe(0H) 3 completely e f f e c t i v e i n removing mobile f u l v i c acids from leachates c o l l e c t e d below the Ae horizon. Organic complexes of i r o n and aluminum deposited as a r e s u l t of p r e c i p i t a t i o n of f u l v i c acids are most ra p i d l y decomposed at S i t e 2 and i r o n and aluminum are released to cause pre-- 110 -c i p i t a t i o n of incoming organo-metalic complexes. Therefore, not only does S i t e 2 produce the most mobile i r o n and aluminum, but i t has the greatest capacity to f i x incoming organo-metalic complexes due to i t s high values of inorganic amorphous i r o n and aluminum. S i t e s 1 and 3 show comparably lower l e v e l s of inorganic amorphous i r o n and aluminum, but S i t e 3 because of i t s higher organic matter production and slower decomposition rates i n the horizon shows the highest l e v e l of o r g a n i c a l l y complexed i r o n and aluminum. B 2 HORIZON FORMATION The B 2 horizons show few s i t e d i f f e r e n c e s . Organically complexed i r o n plus aluminum increases from S i t e s 1 to 3, presumably i n response to slower decomposition rates and higher p r o d u c t i v i t y but beyond t h i s the s o i l c l i m a t i c differences appear to have been damped out. C e r t a i n l y temperatures and s o i l matrix p o t e n t i a l measurements in d i c a t e far more homogeneity than for the B^ or Ae horizons. Processes i n the B 2 horizon appear to be p r i m a r i l y p h y s i c a l l y based. However, concentrations of i r o n and aluminum i n s o i l s o l u t i o n leaving the solum are s t i l l i n excess of those possible i n simple aqueous so l u t i o n . I f organic c a r r i e r s are involved they could e a s i l y have by passed the s o i l matrix v i a macrochannels during heavy r a i n f a l l . Results of t h i s study are consistent with currently proposed mechanisms of Podzol formation (DeConinck 1980, McKeague et a l . 1978, Peterson 1976). - I l l -CONCLUSIONS HYPOTHESIS 1. The balance of processes which control s o i l formation can be demonstrated to vary across a climosequence. Process balances were shown to change from one dominated by losses and transformations i n the horizons of S i t e 1 to ones dominated by translocations and transformations i n the B^ horizons of S i t e s 2 and 3. S i t e s 2 and 3 while showing comparable balances of processes also showed s i g n i f i c a n t l y d i f f e r e n t rates at which the processes were acting. A strong negative c o r r e l a t i o n of i r o n plus aluminum l o s t from the Ae horizon with losses of both i r o n plus aluminum and t o t a l s o i l mass i n the horizon indicates that the processes of t r a n s l o c a t i o n to, i n h i b i t s loss from B horizons. HYPOTHESIS 2: Podzolic s o i l s can be distinguished by the balance of processes which i s acting to produce sesquioxide r i c h B horizons. A p p l i c a t i o n of the model developed i n Chapter 3 demonstrated that the two s i t e s with s o i l s showing strong Podzolic morphology had B^ horizons dominated by translocations and transformations of i r o n plus aluminum. The s i t e with s o i l s showing B r u n i s o l i c morphology had B^ horizons dominated by transformations of i r o n plus aluminum and p r e f e r e n t i a l loss of other s o i l constituents. The model further demonstrated that the strength of Podzolic s o i l morphology was r e l a t e d to the rate at which the processes were acting on the s o i l s . The best expressed Podzol morphology occurred i n those s o i l s showing the highest rates of t r a n s l o c a t i o n . - 112 -HYPOTHESIS 3: Differences i n the rate of biochemical c y c l i n g of i r o n and aluminum w i l l influence the i n t e n s i t y of Podzolic B horizon expression. No s i g n i f i c a n t c o r r e l a t i o n between measures of biochemical c y c l i n g and extractable l e v e l s of i r o n and aluminum could be demonstrated. I f the current theory of i r o n and aluminum movement i n Podzols i s v a l i d , the number of f u n c t i o n a l groups already occupied by i r o n and aluminum should influence the rate of mo b i l i z a t i o n and deposition. The high proportion of i r o n and aluminum moving as a r e s u l t of biochemical c y c l i n g versus the proportion moving as a r e s u l t of e l u v i a t i o n indicates that biochemical c y c l i n g should be important. The f a i l u r e to demonstrate s i g n i f i c a n t c o r r e l a t i o n s may be due to the high sampling e r r o r . HYPOTHESIS 4: Current Podzol c l a s s i f i c a t i o n c r i t e r i a do not r e f l e c t s o i l forming process d i f f e r e n c e s . Analysis of the model output, i r o n plus aluminum extractions, and s o i l morphology demonstrated c l e a r l y that the sodium pyrophosphate extraction technique currently being used f o r Podzol c l a s s i f i c a t i o n grouped together the two most strongly contrasting s o i l morphologies and balances of processes. S i t e s 1 and 2 were c l a s s i f i e d as Orthic D y s t r i c Brunisols while S i t e 3 was c l a s s i f i e d as an Orthic Humo F e r r i c Podzol. S i t e 2 showed both the strongest Podzol morphology and the strongest expression of tr a n s l o c a t i o n i n the B^ horizon while S i t e 1 showed the weakest. Acid ammonium oxalate separated S i t e 2 from S i t e 1 but grouped the only s i t e c l a s s i f i e d as a Podzol (Site 3) - 113 -with the only s i t e showing c h a r a c t e r i s t i c Brunisol morphology (S i t e 1). Citr a t e - b i c a r b o n a t e - d i t h i o n i t e while ranking s o i l s i n the same order as acid ammonium oxalate was i n e f f e c t i v e at demonstrating s i t e d i f f e r e n c e s . Of the f i v e measures of Podzolic development, four (morphology, acid ammonium oxalate extractable i r o n plus aluminum, citrate-bicarbonate extractable i r o n plus aluminum, and the balance of s o i l forming processes acting on the B^ horizon) ranked the s i t e s i n the same order of increasing Podzol development. The one measure which was not i n agreement, sodium pyrophosphate extractable i r o n plus aluminum, i s the current extractant used for the d e f i n i t i v e chemical c r i t e r i a i n c l a s s i f y i n g Canadian Podzols. It i s i n t e r e s t i n g to remember that u n t i l 1965 the Canadian Podzol was recognized p r i m a r i l y on morphological c r i t e r i a and that the presence of an Ae horizon was a required c h a r a c t e r i s t i c . Results of the model used i n th i s d i s s e r t i o n strongly support the old morphological concept. Only the balance and rate of B^ horizon forming processes r e f l e c t s the t r a d i t i o n a l i n t e r p r e t a t i o n of s o i l morphology. None of the t r a d i t i o n a l e xtraction techniques f u l l y r e f l e c t e i t h e r the morphology or the balance of processes acting to produce horizonation. The current system for s o i l c l a s s i f i c a t i o n i n Canada i s showing a new awareness of the importance of morphology by e s t a b l i s h i n g morphological requirements f o r a Podzolic B horizon but i t does not go far enough. I t i s u n r e a l i s t i c to expect that a simple laboratory procedure, or even a se r i e s of simple procedures, can adequately r e f l e c t the balance of s o i l forming processes we view as Podzolic s o i l formation. The reestablishment of more t r a d i t i o n a l morphological requirements, in c l u d i n g - 114 -the Ae horizon f o r at le a s t Orthic subgroups, would remove much of the ambiguity present i n current Canadian concepts of Podzols and Podzol formation. The emphasis on a feature as subject to short term change as org a n i c a l l y complexed i r o n plus aluminum extractable from the B horizon i s inappropriate and should be replaced by either acid ammonium oxalate or some combination of extraction procedures. In addition more rigorous morphological requirements f o r both Ae and B horizons appear to be necessary. - 115 -LITERATURE CITED ALEKSANDROVA, L.N. 1960. The use of sodium pyrophosphate f o r separating free humic substances and t h e i r organo-mineral compounds from the s o i l . Sov. S o i l S c i . 2: 190-197. Transl a t i o n of Pochvovedeniye 1960: 90-96. BARSHAD, I. 1964. Chemistry of s o i l development. In: Bear, F.E. (ed.). Chemistry of the s o i l , Reinhold Publishing Corp., New York, pp 1-70. BASCOMB, C L . 1968. D i s t r i b u t i o n of pyrophosphate-extractable i r o n and organic carbon i n s o i l s of various groups. J . S o i l S c i . 19: 251-268. BELOUSOVA, V.V. 1974. Role of the migration of water-soluble substances i n the formation of Podzolic Al-Fe-Humic s o i l s (based on lysimeter data). Sov. S o i l S c i . 6: 694-708. Translation of Pochvovedeniye (1974) 12: 55-69. BLOOMFIELD, C. 1953a. A study of podzolization. Part I. The mobili z a t i o n of i r o n and aluminium by Scots Pine needles. J . S o i l S c i . 4, 5-16. BLOOMFIELD, C. 1953b. A study of podzolization. Part I I . The mob i l i z a t i o n of i r o n and aluminum by the leaves and bark of Agathis a u s t r a l i s (Kauri). J . S o i l S c i . 4, 17-23. BLOOMFIELD, C. 1954a. A study of podzolization. Part I I I . The mobili z a t i o n of i r o n and aluminum by Rimu (Dacrydium cupressinum). J . S o i l S c i . 5, 39-45. BLOOMFIELD, C. 1954b. A study of podzolization. Part IV. The mobili z a t i o n of i r o n and aluminum by picked and f a l l e n l a r c h needles. J . S o i l S c i . 5, 46-49. BLOOMFIELD, C. 1954c. A study of podzolization. Part V. The mobili z a t i o n of ir o n and aluminum by aspen and ash leaves. J . S o i l S c i . 5, 50-56. BLOOMFIELD, C. 1955. A study of podzolization. Part VI. The immobilization of i r o n and aluminum. J . S o i l S c i . 6, 284-292. BRUHERT, S. 1970a. 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Dept. of Botany, U n i v e r s i t y of B r i t i s h Columbia, Vancouver, B.C., Canada. JENNY, H. 1941. Factors of S o i l Formation; a system of quantitative pedology. McGraw-Hill Book Co., New York, 281 pages. LAVKULICH, L.M. 1977. Methods Manual Pedology Laboratory. Dept. S o i l Science, Uni v e r s i t y of B.C., Vancouver, B.C. V6T 1W5. LEWIS, T. 1976. The t i l l - d e r i v e d Podzols of Vancouver Island. Upubl. PhD. Thesis, U n i v e r s i t y of B r i t i s h Columbia. MARTIN, A.E. and R. REEVE. 1957a. Chemical Studies on Podzolic I l l u v i a l Horizons I. The extraction of organic matter by organic chelating agents. J. S o i l S c i . 8: 268-278. MARTIN, A.E. and R. REEVE. 1957b. Chemical Studies on Podzolic I l l u v i a l Horizons I I . The use of acetylacetone as an extractant of translocated organic matter. J . S o i l S c i . 8: 279-286. MARTIN, A.E. and R. REEVE. 1960. Chemical Studies of Podzolic I l l u v i a l Horizons IV. The f l o c c u l a t i o n of humus by aluminum. J . S o i l S c i . 11: 369-381. - 118 -MARTIN, A.E. 1960. Jour. S o i l S c i . 11(2): 369-381. V. F l o c c u l a t i o n of Humus by F e r r i c and Ferrous i r o n and by N i c k e l . J. S o i l S c i . McKEAGUE, J.A. 1968. Humic-fulvic acid r a t i o , A l , Fe, and C i n pyrophasphate extracts as c r i t e r i a of A and B horizons. Can. J. S o i l S c i . 48: 27-35. McKEAGUE, J.A. (ed.). 1976. Manual on Sampling and Methods of Analysis. S o i l Research I n s t i t u t e , A g r i c u l t u r e Canada, Ottawa. McKEAGUE, J.A., J.E. BRYDON, and N.M. MILES. 1971. D i f f e r e n t i a t i o n of forms of extractable i r o n and aluminum i n s o i l s . S o i l S c i . Soc. Am. Proc. 35: 33-38. McKEAGUE, J.A. and J.H. DAY. 1966. D i t h i o n i t e - and oxalate-extractable Fe and A l as aids i n d i f f e r e n t i a t i n g various classes of s o i l s . Can. J S o i l S c i . 46: 13-22. McKEAGUE, J.A., G.J. ROSS, and D.S. GAMBLE. 1978. "Properties, C r i t e r i a of C l a s s i f i c a t i o n , and Concepts of Genesis of Podzolic S o i l s i n Canada i n Quaternary S o i l s , Third York Quaternary Symposium, 1978, Geo. Abstract Nowich, England. MEHRA, O.P. and M.L. JACKSON. 1960. Iron oxide removal from s o i l s and clays by a d i t h i o n i t e - c i t r a t e system buffered with sodium bicarbonate. Proc. 7th. nat. Conf. Clays. 1959, 5: 317-327. NSSC (National S o i l Survey Committee). 1955. Third Conference of the National S o i l Survey Committee (Canada), A g r i c u l t u r e Canada, Ottawa. NSSC (National S o i l Survey Committee). 1965. Proceedings of National Meetings: Ottawa, A g r i c u l t u r e Canada. NSSC (National S o i l Survey Committee). 1968. Proceedings of National Meetings: Ottawa, A g r i c u l t u r e Canada. RANTALA, R.T.T. and D.H. LORING. 1973. Technical Notes: New low cost Teflon Decomposition Vessel. At. Adsorpt. Newsl. 12(4): 97-99. RAUSELL-COLOM, J . , T.R. SWEATMAN, C B . WELLS, and K. NORRISH. 1965. Studie i n the a r t i f i c i a l weathering of mica. In: Hallsworth, E.G. and D.V. Crawford (eds.). Experimental Pedology, Butterworths, London, pp 40-72. SAM0YL0VA Ye. M. and V.A. DEMKIN. 1976. Composition of d i f f e r e n t f r a c t i o n s of the s o i l s o l u t i o n . Sov. S o i l S c i . 8: 665-668. Transl a t i o n of Pochvovedeniye (1976) 11: 24-27. - 119 -SCHNITZER, M. 1959. Interaction of Iron with R a i n f a l l Leachates. J . S o i l S c i . 10: 300-308. SCHNITZER, M. 1969. Reactions between f u l v i c a c i d , a s o i l humic compound and inorganic s o i l constituents. S o i l S c i . Soc. Am. Proc. 33: 75-81. SCHNITZER, M. and W.A. DE LONG. 1952. A note on the podzolization processes. S c i . Agric. 32: 680-681. SCHNITZER, M. and-W.A; "DE; LONG. 1955. Investigations on the m o b i l i z a t i o n and transport of i r o n i n forested s o i l s . I I . The nature of the reaction of l e a f i n f r a c t s and leachates with i r o n . S o i l S c i . Soc. Am. Proc. 19: 363-368. SCHNITZER, M. and J.G. DESJARDINS. 1962. Molecular and equivalent weights of the organic matter of a Podzol. S o i l S c i . Soc. Am. Proc. 26: 362-365. SCHNITZER, M. and J.G. DESJARDINS. 1969. Chemical c h a r a c t e r i s t i c s of a natu r a l s o i l leachate from a Humic Podzol. Can. J. S o i l S c i . 49: 151-158. SCHNITZER, M. and S.I.M. SKINNER. 1963a. Organo-metallic i n t e r a c t i o n s i n s o i l s : 1. Reactions between a number of metal ions and the organic matter of a podzol B^ horizon. S o i l S c i . 96: 86-93. SCHNITZER, M. and S.I.M. SKINNER. 1963b. Organo-metallic i n t e r a c t i o n s i n s o i l s : 2. Reactions between d i f f e r e n t forms of i r o n and aluminum and the organic matter of a podzol B^ horizon. S o i l S c i . 96: 181-186. SCHNITZER, M. and S.I.M. SKINNER. 1964. Organo-metallic i n t e r a c t i o n s i n s o i l s : 3. Properties of i r o n - and aluminium-organic-matter complexes, prepared i n the laboratory and extracted from a s o i l . S o i l S c i . 98: 197-203. SCHNITZER, M. and S.I.M. SKINNER. 1965a. Organo-metallic i n t e r a c t i o n s i n s o i l s : 4. Carboxyl and hydroxyl groups i n organic matter and metal retention. S o i l S c i . 99: 278-284. SIMONSON, R.W. 1959. Outline of a generalized theory of s o i l genesis. S o i l S c i . Soc. Am. Proc. 23: 152-156. STOBBE, P.C. and J.R. WRIGHT. 1959. Modern concepts of the genesis of Podzols. S o i l S c i . Soc. Am. Proc. 23: 161-164. TAYLOR, R.L. and B. MacBRIDE. 1977. Vascular Plants i n B r i t i s h Columbia: A d e s c r i p t i v e Resource Inventory. Tech. B u l l . No. 4. The Botanical Garden The Un i v e r s i t y of B r i t i s h Columbia, The University of B r i t i s h Columbia Press, Vancouver, 754 pages. - 120 -UGOLINI, F . C , R. MINDEN, H.J. DAWSON, and J. ZACHARA. 1977. An example of s o i l processes i n the Abies amabilis zone of Central Cascades, Washington. S o i l S c i . 124: 291-302. VALENTINE, K.W.G., P.N. SPROUT, T.E. BAKER, and L.M. LAVKULICH. 1978. "The S o i l Landscapes of B r i t i s h Columbia." Publ. The Resource Analysis Branch, M i n i s t r y of the Environment, V i c t o r i a , B r i t i s h Columbia, 197 pages. VAN SCHUYLENBORGH, J . , and M.G.M. BRUGGENWERT. 1965. On S o i l Genesis i n temperate humid climate. V. The formation of " a l b i c " and "spodic" horizon. Neth. J . Agric. S c i . 13: 267-279. - 121 -Appendix 1 Design, Construction and I n s t a l l a t i o n of Water Co l l e c t o r s - 122 -LYSIMETERS Lysimeter design and i n s t a l l a t i o n followed that of Cole (1958) with minor modifications (Figure A l ) . F i f t y - f o u r 12 mm by 15.25 cm diameter alundum disks with a i r entry values of 300 cm tension were obtained from P a c i f i c Lysimeter, S e a t t l e , Washington. Spacer rings 14 cm i n diameter and 3 mm thick were cut from .25 mm w a l l a c r y l i c tubing and fastened to the bottom of the alundum plates with epoxy r e s i n . Backing plates 2.5 mm thick and 14 cm i n diameter were fastened to the spacer rings and the sides and back of the lysimeter sealed with epoxy. Holes 6.5 mm i n diameter were d r i l l e d through the backing p l a t e , one i n the centre and one adjacent to the spacer r i n g . A c r y l i c tubing 6.4 mm i n diameter with 1.6 mm thick walls were sealed i n t o the backing plate with epoxy r e s i n . Tygon tubing 6.4 mm i n s i d e diameter with .32 mm thick walls connected the c o l l e c t i o n b o t tles to the a c r y l i c connector tubes. The assembled lysimeters were leached with 500 ml of 0.1N HC1 followed by 2.0 l i t r e s of water and 500 ml d i s t i l l e d water before i n s t a l l a t i o n . C o l l e c t i o n Bottles C o l l e c t i o n b o t t l e s were f i v e g a l l o n glass water b o t t l e s f i t t e d with water t i g h t rubber stoppers into which two a c r y l i c tubes (dimensions were the same as lysimeter plate connectors) had been f i t t e d . One tube extended from 2.5 cm above the stopper to approximately 25 cm below the stopper and was to be attached to the tension column connector of the lysimeter. The other tube (designed to release displaced a i r ) extended from approximately 25 cm below the stopper-to a l e v e l high enough to ensure clearance of any Fig. Al-1 Lysimeter Design ACRYLIC SPACER RING ALUNDUM PLATE TO COLLECTOR - 124 -temporary perched water table. A l l c o l l e c t o r s , tubes and connectors were acid washed and rinsed i n deionized water p r i o r to i n s t a l l a t i o n . I n s t a l l a t i o n of Instruments Lysimeters were i n s t a l l e d i n the s o i l p i t s used for morphological descriptions and sampling. The p i t s were approximately 1.6 m deep by 1.0 m by 1.2 m. S l i t s were cut into the upslope w a l l and angled upward u n t i l the desired horizon was reached. M a t e r i a l used to i d e n t i f y the horizon was screened to 2 mm and used on top of the plate as packing to ensure contact. The plates were i n s t a l l e d at a s l i g h t angle with the bleeder connector on the high side and the s l i t was b a c k f i l l e d and packed to hold the lysimeter i n place. Following i n s t a l l a t i o n of the plates the p i t walls were l i n e d with 1.27 cm plywood. The c o l l e c t i o n b o t t l e s were then i n s t a l l e d at various depths to provide approximately 60 cm of tension when the water column was established Figure A2. At some p i t s the c o l l e c t i o n b o t t l e had to be set with top below the l e v e l of the compact t i l l . During r a i n storms the top of the b o t t l e would be below water hence the water t i g h t stoppers and long e x i t tubes. Water Columns The pronounced summer drought made the maintenance of water columns impossible, the plates were therefore allowed to dry out during periods of low or no r a i n f a l l . Tension was e a s i l y reestablished by sucking water through the bleeder tube u n t i l a l l a i r was removed, clamping the bleeder tube o f f and allowing plate to saturate from below. When the plate was Fig. Al-2 Lysimeter Installation - 126 -saturated the column was adjusted to the appropriate depth and l e f t . Summer c o l l e c t i o n s were sporadic since much of the incident p r e c i p i t a t i o n moved in t o the s o i l at matrix p o t e n t i a l s far lower than 60 cm. Water columns were often broken before the wetting front from a rainstorm reached the lysimeter p l a t e s . C o l l e c t i o n Samples were taken by pumping out the c o l l e c t i o n b o t t l e s . Small volumes were c o l l e c t e d with a small suction pump while large volumes were c o l l e c t e d with a " b i l g e " pump. As noted i n the text volumes c o l l e c t e d were not considered to be a measure of f l u x and were used to get concentration data only. Sampling those c o l l e c t i o n s with tops below the compacted t i l l required that the p i t be pumped dry frequently and the top removed from the b o t t l e for sampling and then resealed before the p i t f i l l e d with water. Construction of P r e c i p i t a t i o n C o l l e c t o r s (Figure A3) P r e c i p i t a t i o n and throughfall c o l l e c t o r s were constructed from 10.16 cm i n s i d e diameter p o l y v i n y l chloride (P.V.C.) drain t i l e . One meter long pieces were f i t t e d at one end with caps molded from the same material and sealed with s i l i c o n e caulking compound. The open end was bevelled from the outside to the i n s i d e to minimize splash. A p l a s t i c funnel was f i t t e d to the i n s i d e of the tube approximately 10 cm below the top of the tube and plug of glass wool inserted i n the neck of the funnel to reduce evaporation between c o l l e c t i o n s . During December, January, and February, - 127 -F i g . Al-3 P r e c i p i t a t i o n and t h r o u g h f a l l C o l l e c t o r Design GLASS WOOL PLUG POLYETHYLENE FUNNEL 4" DIAMETER P.V.C. DRAIN TILE P.V.C. CAP - 128 -the p l a s t i c funnels were removed to prevent possible snow accumulation on top of the c o l l e c t o r s . The c o l l e c t o r s were attached to wooded stakes protruding v e r t i c a l l y approximately 70 cm above the ground. The one meter length ensured that the c o l l e c t i o n surface was above the understory vegetation and also above any expected snow pack. A l l c o l l e c t e r s were acid washed and rinsed with deionized water p r i o r to i n s t a l l a t i o n . - 129 -Appendix 2 S o i l Chemical Analy - 130 -CJ Q 03 in T- co o i t c n o j c n i o r - • q - f - r - a i P ) n o n i n oi -3- vr *r in co u i n on "» CM in CD t *- CM co CD •» ^ 10 M n o 0) O CM CO CD to in oo oo O CN T CN CN ID co in CN o r> CN co *- co o o o o o CN CO CO CO to CO CO CO CO CO CN vr co vr •>- CM oo CO CO T- CN O ^ CD O O 0 ) < H f O O CM vr co vr CD ••- co in vr cc CM CO O *- CN CO CN vr "-ID CO 00 O O O CM CO CD < CO co o < o < o < < a. CO O 0) ID ^ O VT CO CO CM oo co r- co cc O in co CM -r-c o o o i t i n O cc vr co CN in co in oo o O CD "st VT CN r> co cn in T-O co co CN in ••- in *- oo O oo vr •>-in CD O *- co in tn vr vr CM O O O CO LO vr O) CO CN r> -r- O t~ eo co cn r> co CN in r> r> r- oo CO T- co vr CM 0) CM -r- LO in o vr co co *- CO VT CN CO CM CN CO LO CN O C M C M C N O -r- VT CN CO CO ' - i n c o O O ) »- CN r- CD CN co a) o in cn oo O r> co O co vr O O co cn CN o) a i o n o o o o o in co O vr in *- cc ^- CM vr a> co co co co o cn CN r~ co CO CN co vr CM CM cc CN 1 - CM CO CM *- O vr r> O) CO r~ vr CN CM CN co r> -r- r -*- CC vr CO CO N 0) N O Cl CN CO CM CO vr in co in o oo CN CC CO CO •* cn r-- co vr r- c o c o o c o r ^ CM co cn CM r- co r~ o co o co in oo co co co r~ o in r> O O) CM CM T- O (O CM -r- f ••- CO CM CN — O O CM CM CM O VT CM CN -r- O VT CO CN •>-O CO CO CO CM - O O O O f~ CO CO CN CM o o o o o 00 O CO CN CN O - O O O in CM co in *-O O O O 00 xt CO CO f O - O O O co in co CN CN O - O O O _i < M S CM OO cn r- vr vr vr co co o cn o co r- *- co in oo co co co i n o o c o o o c o i n o o o o o o c o vr co co co r-vr co O O oo vr CD CN vr co c o i n i n c N c o co in r- CM ••-co vr vr vr co co vr vr vr vr co vr vr vr co CM vr vr vr vr in co co O CM co co cc CD oi O CM co O co O CM in vr co O co 01 f o) t O) t co C O C N O ' - O O ••-(•- r> c o t ^ r ^ c o o M » t ON c o o m c n i n oo in t - co in oo oo vr in in cn vr co CM o s ^ co o i ^ in co o o co co vr CM cn oo vr O O i n t t - o o o 0) co CM co O f - O O r» cp in co vr O ^ O O O CO vr vr CN » - O CO ••- O 00 - ^ O C O C D O O ^ C N ^ ^ - T - ^ T - ^ ^ O ••-••- O •>- O t CM CM CO CM ^ in CO CM CM VT CN CO CO VT CO CN CN CO VT LO CN CO VT CO PO CO CO CO Z i O O O O O o o o o o o o o o o o o o o o o o o o o o o o o o O I 10 CM »" »" O COLO CM'O O VT CO T- O r---vf CM CM T- CD CO CN -r- O co vr CM o " - O O O O - " - 0 0 0 0 *- o o o o ••- o o o o -^oooo o o o o CJ z O c o c o r - c c i n c o o o c o c D co r~ co co co ••- vr vr vr r- in o vr r~ CM CO CO - - vr LO 0) -r- -r- -r- C n C N ' - C N ' - - r - - . - - r - . r - T - 3 ) . - . - . - . - Q r r r r - Q 5 ^ - T - - r - - r -C M - r - - r - - r - 0 CN CN -r- -r- O CM CN » - -r- O CN -r- -r- O C M C N - r - - r - 0 CM CM CM O O o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o O 0) 0) O) CM — CN vr vr CM O co co oo vr - r - c o c o c n o 00 CM t co O in vr r- co -- co 0 00 r> LO O -r- cc 00 *- O C D i n C O O ) CD vr 00 r-r ~ - r - o c o - r - 10 m co vr r -I CL CM -r-CD O O CO ^r LO in in CM T-00 CM CM CM vr in in in •r- CM co vr in CM co vr in •r- -r- -r- -r- -r- CM CM CM CM CM VT t> -r- CN •vr in in — CM co in CM CM CM CM CM CM T-LO C- CD *-f ^ v n n in -r- cn co 1 in t i n co cn CM -r-vr vr in in •r- CM co vr m - r - c N c o - r r i n *- CN co vr in CNCNCMCNCM -r- -r- -r- -r- -r- CN CN CN CN CM CN CN CN CN CN CO CO CO CO CO CO CO CO CO CO - 131 -- 132 -Q co rr r- co CD in 01 O CN r~ CN n o i n O O O O O O O co t- O rr O r~ O CD O r-co r- O — *-CN CO CM CM 15 1 O O 00 CN i - CM Tt I S O M I ) ' - o oa n in IT) — — CM ••- * - CO CN CM CD CO CD — t -r r — — CM r r — tn i - t -r r CN i - CN o ID in o O — o ••- in o — r> CN in o in r- co o O o CM co CM O CO CO CD — O * - ••- CN CD CD O) — CO CO CD CN — rr CD CD 1 O CO in CD CD • ^ ' - C N C D C D O O 01 in CD CO C J CO CJ < < < a < CJ L U CJ in oo oo ^ r r CM co O co O o> in co CM O O C D C D C O co i n h - co co O CD i n i n r r co - - o — O O CD CD r r CO r r CN co i n — O ID CD co i n CO CM »- CD O l O oo in f ro r- co in co co CN r - CD co r r i - o in oo n - CD — CO CD M oi in o CD CD CD CD in CN T- 0) CD CO 0) CO CD r r r» in CD i» cn co oo oo r» co CN l ~ - CO — CD t O) CD CD CO CD 00 r r CN r -O in O oo r r t- o in in O m CM co cn r r O O O I O I O I CO O CD CD i n O r- O co CD CD — oo r r r -O — O CD CO CD r- co r~ cn O io r> ip oi 01 r> CM in co r-- cn O cn CD 01 O in ^ CM i n co CM co ' - c o c D c o i n * - r> in i n t- — i n t- r r in — oo CD CD CD ••- r r in r r CO CD co CD r~ cn ••- in r r r - in r r r r in — co O ID CO CN — in r r o cn cn O in r r co — rr co ID i n o O rr co co rr r r r~ i n f - — r r co O CM — O C O C O C N C N o co r r CM co co r r o O CN O co co r r — co r- o in CN O — - o o co T- cn oo in O CM o O O in co co r> O O - - O - r r o O ID i n O CN o O r r T - CN i n cn O - — o o r r CD r- CO CN O CN O O O in r- to cn r - co r - co co ••-in co oo r - r - inoooococo cn r - CD r r r r r r co CD r~ r r cn in r r co in r r co co co oo CM co co co r r 0 ) CD r r O co r r 00 00 00 r -oo i n CN co r r CM r f r r r r r r in oo CN ID CD r> CM r r CD co i n r r r r r r co O rr rr in in N - >- co O CD O — CD O — co r r CN O i - -r- CD co oo O CD — CO r r r r r r r r r r r r co i - o r - CN i n r r co CN r r r r r r r r CN in o oo oo — r - — r r a> C D - ^ c o r r c o CD — oo co co m r r o CD co C D C N O C D C O c o o i n o c o c o m c n i D C M < • ^ r r o c D C D r - CM o co m C N ' - ' - O O O O O CN CN cn co - - - O o rr in co r*- oo - - - o o i n cn i n CM oo T- -r- o r r t> f- oi cn - - — O O r r c N c o r r r r i n r r c o c o c o O O O O O O O O O O r r CD r r in r r O O O O O r r co co i n r r O O O O O i n r r oo t~ i n O O O O O r r r r co r r in O O O O O C5 c n r r c o c o o CD in co CM - -- - O O O O — O O O O O O in r r CM — - o o o r - CD co r r — — o o o o O i n r r O — CN O O *- O CD i n co co CN - O O O O O z C D c o O c n c o i n c o i n o i c N O — C O C N C N CJ> — CM CN i n CD i n oi r r i n CN co CN cn O in o t» CD co CN co CN CM co co in r-O CM co in CM CN CM CD 00 O t - CO CM CM CO CN CO T- — O O O O O O CN CO CN — — O O O O O C N C N C N O O — I"- CN * - O O O O O O O O O O O CO CM CM T- O O O O O O CM in CN o O O O O O — CM CO CD CO — r r o i n CM cn co — CM CD - - c o c n r r c n r~ ••- o co CM i n r ^ o c o r - C M C N O C O O — in 01 CD — c N C o r r — o - " - m c D C M - " -r - — cn r r o i n r r c o c n c M a CM co * -oo r- — — CM CD r- cn — CM r - m o i o c n r~ r- — o O cn cn cn co 10 oo o -c o r r i n i n i n c o r r r r i n . i n co r r r r i n r r co r r m i n i n co r r r r r r i n co r r i n i n i n — CM co r r m ••- CM co r r i n ••- CM co r r i n ••- CM co r r i n ••- CM co r r i n — CM co r r i n •>-••- — C N C N C M C N C M •— T- -r- i - C N C N C M C M C N ^ T- ^ C N C M C M C N C M — T- T- — -r- C M C M C M C M C M C N C N C N C M C M C O C O C O C O C O C O C O C O C O C O C O C O C O C O C O CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO 00 w H M cn - 133 -i Appendix 3 Water Chemistry Analysis - 134 -Coding of i d e n t i f i c a t i o n (ID) for water samples S i t e Period Plot 1 1 1 1 1 -J P i t — Level - 135 -ID VOL CA MG NA K FE AL 1 1 1 1 1 1 60 1 .58 .90 4.81 16.80 21 1 1 1 0637 .67 .71 .75 1 .93 .04 .09 31 1 1 1 531 7 .14 .12 .46 .25 .09 .12 41 1 1 1 281 6 .28 .15 1 .03 .25 .12 .12 51 1 1 1 2258 .18 .08 .41 .16 .06 .12 61 1 1 1 2025 .13 .08 .48 . 1 1 .02 .05 71 1 1 1 2729 .15 .08 .57 .19 .04 .06 81 1 1 1 01 30 .53 .23 .96 1 .46 .19 .20 1 1 1 1 2 160 1.41 .32 .99 .97 .09 .72 21 1 1 2 0637 .94 .21 1.18 1 .63 .05 .18 31 1 1 2 531 7 1 .21 .32 1 .24 .80 .69 2.15 41 1 1 2 281 6 .58 .19 1 .04 .37 5.08 12.10 51 1 1 2 2258 .32 .14 .61 .31 .07 .24 61 1 1 2 2025 .57 .19 .76 .46 .05 .12 71 1 1 2 2729 .87 .19 .53 .29 . 1 4 .49 81 1 1 2 01 30 .68 .29 .68 .26 .06 .48 1 1 1 13 160 1.12 .24 .68 .48 .00 .07 21 1 1 3 0637 .42 .16 .56 .66 .01 .09 31 1 1 3 531 7 .34 .12 .67 . 1 1 .07 .10 41 1 1 3 281 6 .31 .10 .68 . 1 4 .79 ,1 .58 51 1 1 3 2258 .32 .15 .52 .05 .02 .05 61 1 1 3 2025 .35 .13 .48 .07 .13 .39 71 1 1 3 2729 .30 . 1 1 .62 .19 .09 .26 81 1 1 3 01 30 ,30 . 1 3 .56 .06 .04 .08 1 1 1 1 4 160 .97 .20 .73 .22 .00 .00 21 1 1 4 0637 .38 . 1 3 .69 . 1 1 .00 .01 31 1 1 4 5317 1.81 .38 1 .43 .38 .00 .00 41 1 1 4 2816 .32 . 1 3 .57 .08 .30 .55 51 1 1 4 2258 .33 . 1 3 .66 . 1 7 .07 .19 61 1.1 4 2025 .45 .17 .71 .18 .07 .24 71 1 1 4 2729 .34 .12 .47 . 1 3 .03 .08 81 1 1 4 01 30 .60 .21 .91 .04 .04 .05 1 1 121 0040 2.64 1 .38 4.37 6.00 21 121 0607 .81 1 .22 .93 3.75 .03 . 1 2 31 121 4083 .35 .19 .56 .64 .13 . 1 5 41 121 2690 .26 . 1 1 .81 . 1 4 .47 .71 51 121 2050 .22 .10 .44 .20 .03 .05 61 121 2500 .22 .10 .51 .15 .05 .09 71 121 2729 .28 . 12 .72 .27 .01 .04 81 1 2.1 0125 1 .01 .34 1.16 2.30 .07 .14 1 1 123 0040 1 .29 .44 .40 .19 .02 .20 21 123 0607 1 .38 .49 .54 1 .25 .02 .07 31 123 4083 .97 .28 .27 .49 .21 .54 41 1 23 2690 1.13 .32 .84 .17 .26 .51 51 123 2050 .68 .20 .58 .15 .18 .35 61 123 2500 .35 . 1 1 .48 .18 .08 .48 71 123 2729 .83 .23 .42 . 1 1 . 1 3 .42 81 123 0125 1 .26 .48 1.01 .37 .31 .65 - 136 ID VOL CA MG NA K FE AL 1 1 1 24 0040 1 .20 .20 .56 .18 .01 .06 21 1 24 0607 .41 .65 .66 .69 .01 .07 31 1 24 4083 .67 .20 1 .06 .19 .10 .23 41 124 2690 .65 .30 .55 .17 .41 .93 51 1 24 2050 .42 .20 .60 .24 .05 .13 61124 2500 .61 .19 .40 .09 .19 .69 71 124 2729 .38 .12 .46 .19 .01 .09 81 1 24 01 25 .86 .26 1.21 .21 .13 .20 11122 0040 .97 .20 .73 .22 .00 .01 21 122 0607 .35 .48 .58 .32 .00 .03 31 122 4083 .25 . 1 2 1 .00 .19 .04 .12 41 122 2690 .58 .22 .74 .05 .58 1 .38 51 122 2050 .22 . 1 3 1 .23 .23 .08 .20 61 122 2500 .27 .12 .90 .15 . 1 3 .85 71 122 2729 .19 . 1 1 .83 . 1 4 .21 .22 81 122 01 25 .51 .18 1.13 .10 .06 .08 11211 001 5 3.77 2.24 5.97 21211 0686 1 .03 .88 .56 2.68 .02 .01 31211 401 6 .39 .15 .41 .42 .05 .03 41211 2550 .22 .10 .70 . 1 4 .21 .40 51211 2000 .20 .07 .31 . 1 3 .04 .08 61211 2943 .23 .08 .33 .08 .05 .04 71211 2729 .28 .09 .56 .18 .03 .05 81211 0187 1.10 .27 .63 1 .35 .06 .10 11212 001 5 1 .34 .34 .60 1 .06 .19 2.10 21212 0686 1.16 .39 .74 .34 .03 .12 31212 401 6 2.28 .37 .93 .45 .56 1 .59 41212 2550 1 .73 .31 .59 .38 1 .84 3.39 51212 2000 1 .62 .31 1.12 .39 .15 .60 61212 2943 .54 .19 .67 .10 .06 .20 71212 2729 1.18 .21 .57 .15 .12 .54 81212 0187. 1.18 .18 .48 .20 .29 1 .09 11214 001 5 1 .06 .22 .59 .18 .00 .00 21214 0686 .53 .21 .56 .26 .01 .06 31214 401 6 .52 .21 .63 .18 .18 .36 41214 2550 .74 .19 .94 . 1 4 .30 .66 51214 2000 .48 .22 .56 .20 .05 . 1 1 61214 2943 .46 . 1 7 .58 . 1 6 .07 .19 71214 2729 .40 .14 .58 . 1"7 .02 . 15 81214 0187 .73 .21 .65 .15 .09 .22 11213 001 5 .71 .16 .59 .11 .00 .01 21213 0686 .35 .14 .38 .21 .00 .05 31213 401 6 .51 .19 .80 .10 . 1 1 .23 41213 2550 .33 . 1 4 1.11 .19 .78 1 .58 51213 2000 .49 .23 .71 .10 .04 .10 61213 2943 .45 .17 .61 .09 .05 .05 71213 2729 .40 . 1 4 .56 .10 .or .06 81213 0187 .40 .15 .65 .12 .04 .08 - 137 -ID VOL CA MG NA K FE AL 11221 0070 1 .92 1 .09 3 .75 4.80 21 221 0845 .54 .55 .44 1 .89 .03 .07 31 221 4967 .22 .14 .47 .40 .15 .31 41221 2860 .25 .12 1 .16 .21 .13 .18 51221 2094 .21 .08 .43 .18 .04 .10 61221 2730 .23 .08 .44 .09 .03 .00 71 221 2729 .28 .09 .50 .22 .03 .07 81 221 01 77 1 .25 .27 .83 1 .35 .06 .10 1 1223 0070 1 .88 .26 .57 .95 . 1 1 .48 21223 0845 .61 .35 .74 .36 .04 .08 31223 4967 2.08 .31 .63 .49 .15 .85 41223 2860 1 .34 .22 .48 .33 .47 .69 51223 2094 .92 .14 .65 .27 .23 .69 61 223 2730 .75 .12 .60 .15 .10 .26 71 223 2729 .77 . 1 1 .56 .13 .12 .38 81 223 01 77 .90 .30 .72 .67 .38 .89 1 1 222 0070 .68 .22 .62 .67 .01 . 1 3 21222 0845 .50 .21 .65 .29 .01 .06 31 222 4967 .45 .35 1 .08 1 .29 .15 .65 41 222 2860 .77 .28 .87 .10 2.96 6.80 51 222 2094 .32 .20 .53 .63 .10 .24 61 222 2730 .34 . 1 5 .47 .43 .07 .17 71 222 2729 .34 . 1 5 .51 .39 .07 .15 81222 01 77 .36 .16 .60 .45 .07 .25 1 1 224 0070 1 .06 .24 .70 .47 .00 .00 21224 0845 .31 .22 .73 .16 .06 .23 31 224 4967 .57 .35 1 .03 .59 .10 .86 41 224 2860 .64 .28 .72 .64 .35 .72 51224 2094 .43 .21 .62 .58 .04 .09 61224 2730 .43 .17 .62 .48 .05 .13 71 224 2729 .49 .18 .67 .54 .01 .08 81 224 01 77 .53 .18 .76 .60 .06 .27 11311 0080 1 .83 .75 3 .29 3.90 21311 0632 .54 .76 .42 3.08 .02 .09 31311 3987 .23 .15 .48 .64 . 1 4 .25 41311 2943 .60 .24 .80 .17 .33 .66 51311 1 700 .20 .08 .30 .19 .08 .10 61311 2835 .25 .08 .36 .18 .05 .06 71311 2729 .30 .10 .56 .20 .04 .07 81311 01 20 1 .00 .26 .73 2.05 .09 .19 11312 0080 1 .49 .37 1 .95 1 .90 .12 .55 21312 0632 .70 .46 .66 1 .76 .22 .09 31312 3987 1 .89 .64 .91 2.12 .34 1 .35 41312 2943 1 .32 .52 .77 1 .60 .45 1.11 51312 1700 .72 .29 .64 1 .04 .29 .70 61312 2835 .62 .23 .47 .64 .28 .68 71312 2729 .73 .24 .49 .70 .24 .60 81312 0120 .89 .24 .71 .30 .37 .85 - 138 -ID VOL CA MG NA K FE AL 11313 0080 1 .84 .22 .95 .32 .00 .02 21313 0632 .43 .33 .58 .75 .02 .07 31313 3987 .47 .18 .88 .17 .18 .47 41313 2943 .25 .10 1 .09 .29 .24 .20 51313 1700 .42 .19 .67 . 1 5 .05 .12 61313 2835 .44 . 1 5 .69 .1 3 .09 .30 71313 2729 .39 . 1 6 .59 .12 .01 .07 81313 0120 .66 .25 .80 .27 .18 .18 11314 0080 1 .24 .23 .76 .15 .00 .13 21314 0632 .36 .30 .46 .28 .00 .05 31314 3987 .81 .25 .88 . 1 1 .24 .47 41314 2943 .66 .34 .71 .97 .50 1 .20 51314 1700 .55 .24 .73 . 1 2 .04 . 1 2 61314 2835 .54 .21 .68 .07 .06 . 1 1 71314 2729 .61 .20 .66 .10 .01 .09 81314 0120 .39 .16 .70 . 1 4 . 1 3 .29 11321 01 60 2 .04 .52 1 .21 2.90 .02 . 1 4 21 321 0805 .85 .49 1 .44 1 .85 .01 .06 31 321 5162 .23 .13 .43 .41 .15 .27 41 321 2025 .27 .13 1 . 1 2 .24 .16 . 1 7 51 321 2306 .19 .07 .32 . 1 3 .06 .10 61 321 2860 .19 .07 .34 .10 .04 .00 71 321 2729 .34 .09 .52 .29 .02 .07 81 321 0248 .69 .16 .45 1 .02 .08 .19 1 1 322 0160 1 .06 .20 1 .45 .76 .01 .26 21 322 0805 .66 .21 .90 .63 .02 . 1 1 31 322 5162 1 .06 .37 .78 .27 .46 1 .34 41 322 2025 1 .08 .34 .91 .73 .10 .60 51 322 2306 .85 .22 .83 .54 .08 .52 61 322 2860 .76 .18 .67 .39 .21 1 . 1 3 71 322 2729 .82 . 16 .63 .37 .09 .51 81 322 0248 .68 .24 .60 . 1 6. .07 .31 1 1 323 01 60 .83 .32 .68 1 .07 .00 . 1 4 21 323 0805 .50 .18 .66 .21 .06 .23 31 323 5162 .61 .23 .99 .16 .49 •1 .09 41 323 2025 .78 .29 .67 .24 .04 .28 51 323 2306 .56 .23 .71 .17 .03 .15 61 323 2860 .63 .22 .64 . 1 6 .04 . 1 1 71 323 2729 .85 .23 .74 .23 .04 .28 81323 0248 .43 .18 .43 . 1 1 .05 .17 1 1 324 0160 .87 .16 .86 .16 .00 .00 21 324 0805 .42 .16 .76 . 1 1 .00 .09 31324 5162 .26 .21 1 .01 .30 .10 .34 41324 2025 .64 .24 .88 . 1 1 .13 .32 51 324 2306 .49 .21 .85 .13 .04 . 1 1 61 324 2860 .54 .19 .74 .09 .04 .07 71324 2729 .51 .16 .67 .09 .02 .09 81 324 0248 .48 .20 .68 . 1 1 .04 .10 - 13.9 -ID VOL 121 n 0155 221 1 1 0730 321 1 1 371 3 421 1 1 3900 521 1 1 1600 621 1 1 3100 721 1 1 2456 821 1 1 0235 121 12 0155 221 12 0730 321 12 371 3 421 12 3900 521 1 2 1 600 621 1 2 3100 721 12 2456 821 1 2 0235 121 13 0155 221 13 0730 321 13 371 3 421 1 3 3900 521 13 1 600 621 1 3 3100 721 1 3 2456 821 1 3 0235 121 14 01 55 221 1 4 0730 321 14 3713 421 14 3900 521 1 4 1 600 621 1 4 31 00 721 14 2456 821 14 0235 12121 0185 22121 0807 32121 4090 42121 1300 52121 1850 62121 2790 72121 2456 82121 0195 12122 0185 1 22122 0807 32122 4090 2 42122 1300 1 52122 1850 1 62122 2790 72122 2456 1 82122 0195 CA MG NA .76 .73 .66 .29 .21 .33 .13 .04 .31 .20 .08 .41 .13 .07 .41 .25 .10 .73 .55 .26 .93 .28 .26 .58 .13 1.31 1 .39 . 8 1 .46 .68 .53 .28 1 .05 .50 .27 1 .00 .86 .21 .66 .99 .27 .70 .98 .22 .71 .26 . 1 4 .75 .71 .66 1 .09 .76 .31 .67 .65 .31 .87 .49 .29 .76 .50 .30 .61 .53 .27 .64 .57 .30 1 .23 .37 .19 .95 .89 .35 1 .34 .61 .22 1 .22 .75 .28 1.01 .53 .25 .95 .55 .24 .89 .56 .22 .85 .66 .26 1 .24 .47 .57 .37 .16 .13 .20 .06 .04 .22 .16 .06 .28 .10 .06 .34 . 1 7 .09 .52 .49 .24 .74 .04 .39 .58 .89 .47 .65 .33 .55 .87 .45 .36 .82 .03 • .28 1 .20 .75 .22 .78 .03 .22 .63 .65 .21 .91 K FE AL 3.05 .01 .02 .81 .05 .10 .20 .39 .71 .29 .05 .06 .22 .04 .04 .37 .03 .04 1 .35 .03 .01 2.07 .10 .49 .71 .39 .25 1 .35 .45 2.20 .43 4.04 10.01 .25 .10 .23 .27 .12 .60 .70 .12 .64 .62 . 12 .59 .24 .00 .09 .32 .05 .18 .18 .12 .33 .25 .32 .98 .22 .13 .30 .24 .02 .10 .30 .02 .06 .50 .06 . 1 5 .13 .00 .06 .18 .00 .05 .12 .29 . 16 .10 .33 .47 .05 .06 . 1 1 .08 .02 . 1 5 .08 .00 .03 .30 .12 .23 1 .78 .01 .02 .52 .06 .08 .10 .07 . 1 1 .15 .06 .05 .10 .01 .01 .20 .01 .07 1 .40 .06 .07 .84 .10 .53 .48 .04 .32 .69 .33 1 .79 .46 2.09 9.30 .36 .23 .96 .27 .12 .73 .38 '.10 .43 .31 .36 .66 - 140 -ID VOL CA MG NA K FE AL 12123 0185 .29 .15 .76 .18 .00 .03 22123 0807 .48 .46 1 .01 .41 .02 .09 32123 4090 2.23 .48 1 .60 .34 .10 .34 42123 1 300 .48 .23 .87 .28 .27 .78 521 23 1850 .34 .23 .85 .25 .09 .12 621 23 2790 .44 .23 .81 .26 .05 .18 72123 2456 .72 .25 .79 .19 .02 . 1 1 82123 0195 .37 .22 .80 .25 .05 .17 1 21 24 0185 .37 .16 .80 .21 .00 .04 221 24 0807 .46 .42 .91 .29 .00 .03 32124 4090 .65 .27 .59 . 1 1 .13 .16 42124 1300 .72 .25 .99 .21 .28 .89 52124 1850 .46 .22 .76 . 1 2 .07 .10 62124 2790 .46 .22 .73 .12 .02 .08 72124 0 2456 .46 .19 .05 . 1 1 .01 .07 82124 0195 .56 .21 .87 .20 .04 .06 12211 0130 2221 1 0735 .66 .54 .46 2.39 .01 .03 3221 1 461 0 .26 .15 .20 .76 .03 .08 4221 1 3320 . 1 3 .05 .29 . 1 7 . 1 4 .29 5221 1 1350 .38 . 1 2 .49 .44 .06 .09 6221 1 1900 .23 .08 .39 .29 .02 .01 7221 1 2456 .29 .10 .58 .36 .01 .03 8221 1 0195 .85 .23 .66 2.35 .05 .07 12212 0130 .88 .39 .81 .80 .07 .62 22212 0735 .74 .63 1 .20 .57 . . 1 1 .69 32212 461 0 2.1 1 .39 .98 1 .27 .31 1 .42 4221 2 3320 1.13 .35 .72 .37 .45 .33 5221 2 1350 .65 .21 .83 .24 .35 .69 6221 2 1900 .66 .19 .75 .19 .09 .46 7221 2 2456 .88 .18 .69 .21 .10 .43 82212 0195 1.01 .19 .67 .30 .06 .18 1 221 3 0130 .83 .23 1 .02 .37 .00 .02 2221 3 0735 .70 .58 1 .32 . 1 3 .02 .10 3221 3 461 0 .65 .26 1 .00 .32 .05 .20 4221 3 3320 .82 .28 1 .00 .24 .24 .54 5221 3 1350 .69 .24 1 .09 .17 .16 .22 6221 3 1900 ."57 .20 .76 .18 .02 .08 7221 3 2456 .66 . 1 9 .76 . 1 9 .00 .06 8221 3 0195 .66 .33 1 .01 .30 .04 .15 1 221 4 0130 .38 .14 .77 .13 .00 .06 22214 0735 .80 .61 1 .18 .10 .00 .01 3221 4 461 0 .85 .29 1 .12 .44 .04 .13 4221 4 3320 .96 .29 1 .14 .26 .15 .54 52214 1350 .68 .25 1 .07 .16 .20 .24 6221 4 1900 .71 .25 .99 . 1 4 .01 .07 7221 4 2456 .70 .20 .85 .15 .00 .04 82214 0195 .72 .26 1 .03 .16 .08 .15 - 141 -ID VOL 1 2221 01 55 22221 0456 1 32221 4090 42221 1500 52221 1316 62221 1 500 72221 2456 82221 0149 1 1 2222 0155 2 22222 0456 1 32222 4090 2 42222 1500 1 52222 1316 1 62222 1500 72222 2456 82222 0149 12223 01 55 22223 0456 1 32223 4090 42223 1 500 1 52223 1316 62223 1 500 1 72223 2456 1 82223 01 49 1 12224 01 55 22224 0456 1 32224 4090 1 42224 1 500 1 52224 1316 1 62224 1500 72224 2456 82224 01 49 12311 01 55 2231 1 0730 3231 1 431 3 4231 1 2750 5231 1 1918 6231 1 3300 7231 1 2456 8231.1 0197 1 231 2 0155 2231 2 0730 3231 2 431 3 1 4231 2 2750 1 5231 2 1918 6231 2 3300 1 7231 2 2456 1 8231 2 01 97 CA MG NA .02 .90 .74 .60 .24 .27 .18 .07 .29 .35 . 1 1 .40 .31 .10 .52 .35 . 1 3 .71 .27 .35 .86 .08 .65 .70 .25 1.10 1.13 .79 .70 1 .24 .26 .40 1 .20 .01 .34 1.18 .93 .24 .72 .97 .23 .72 .77 .20 .69 .97 .35 .79 .73 .95 1 .79 .90 .57 .83 .36 .43 1.31 .97 .36 1.13 .13 .42 1.31 .10 .36 1.13 .41 .44 1 .41 .67 .28 1.15 .09 1 .05 1 .28 .27 .43 1 .43 .50 .46 1 .47 .04 .38 1 .37 .91 .34 1.16 .95 .31 1 .09 .93 .29 1 .09 .50 .33 .35 .25 . 1 3 .19 .18 .11 .63 .39 . 1 1 .41 . 1 4 .05 .29 .26 .09 .56 .98 .24 .65 .61 .21 .90 .71 .37 .63 .06 .29 .93 .57 .29 .53 .80 .25 .92 . 1 1 .20 .38 .29 .21 .40 .84 .28 1 .51 K FE AL 3.40 .01 .07 1 .07 .13 .21 .22 .06 .06 .28 .09 .10 .22 .05 .05 .35 .00 .05 1 .80 .06 .07 1 .05 .17 .99 .65 .09 .26 .80 .14 .81 .20 .38 .79 . 13 .19 .23 .34 . 1 1 .45 .36 .08 .35 .35 .43 .55 .21 .00 .03 .46 .04 .18 .27 .08 .45 .12 . 14 . 1 6 .12 1 .22 1 .86 . 13 .20 .22 .18 .00 .06 . 12 .24 .27 .05 .00 .06 .39 .01 . 1 1 .10 .05 .08 .10 .09 . 1 1 .05 .19 .34 .04 .04 . 1 1 .06 .00 .08 .04 ..09 . 1 4 1 .50 .00 .02 .59 • .08 . 1 5 .21 .07 . 1 1 .25 .07 . 1 1 .10 .01 .01 .20 .00 .05 1 .20 .08 .13 .15 .03 . 1 4 .49 .05 .16 .61 .33 .89 .52 1 .39 3.56 .24 . 1 4 .38 .28 . 1 4 .77 .24 .08 .29 .33 .20 .44 - 142 -ID VOL CA MG NA K FE AL 1 231 3 01 55 .47 .19 .56 . 1 4 .00 .02 2231 3 0730 .38 .58 .78 .31 .01 .10 3231 3 4313 1 .00 .27 .85 .23 . 1 1 .26 42313 2750 .79 .25 .84 .13 .36 .82 5231 3 1918 .64 .28 .96 .18 .34 .57 6231 3 3300 ) .66 .29 .87 .20 .07 .15 7231 3 2456 .57 .18 .61 .10 .06 .26 8231 3 0197 .69 .31 .94 .21 .07 .21 12314 01 55 .52 .22 .87 .08 .00 .02 2231 4 0730 .37 .36 .52 •.18 .00 .02 3231 4 431 3 .81 .28 1 .15 .14 -.06 .08 4231 4 2750 .84 .28 .95 . 1 1 . 1 1 .35 5231 4 1918 .65 .27 1 .01 .10 .27 .34 6231 4 3300 .68 .25 .89 .10 .08 .31 7231 4 2456 .63 .22 .80 .10 .03 .36 82314 0197 .72 .28 1 .03 .15 .06 .16 1 2321 0150 22321 0840 .43 .26 .32 1 .22 .00 .03 32321 3735 .46 .15 .20 .60 .22 .55 42321 3266 .27 . 14 .68 .24 .09 .18 52321 2262 .21 .07 .37 .14 .05 .04 62321 3700 .19 .08 .41 .12 .02 .03 72321 2456 .23 .09 .45 .20 .04 .10 82321 0222 .70 . 1 6 .37 1 .05 .04 .04 12322 0150 1 .41 .38 .70 .45 .00 .01 22322 0840 1 .55 .30 1 . 1 1 .25 .04 .17 32322 3735 2 .95 .62 .92 1.10 1 .00 5.40 42322 3266 1 .39 .34 .86 .40 1 .67 4.80 52322 2262 .82 . 1 4 .39 .24 .24 .51 62322 3700 .86 .21 .66 .27 . 12 .60 72322 2456 1 .03 .22 .63 .38 .10 .43 82322 0222 .95 .15 .38 .22 .55 1 .78 1 2323 01 50 .51 .21 .84 . 1 3 .00 .00 22323 0840 .65 .29 .89 .18 .00 .01 32323 3735 .82 .26 1 .04 .19 .22 .45 42323 3266 .82 .30 .98 .20 .70 .66 52323 2262 .6.9 .27 .97 .12 .09 .36 62323 3700 .66 .29 .87 .20 .07 . 1 5 72323 2456 .72 .25 .79 . 1 9 .02 . 1 1 82323 0222 .62 .19 .56 .12 . 1 4 .23 12324 0150 .62 .24 .92 .07 .00 .05 22324 0840 .54 .34 .90 .22 .00 .02 32324 3735 1 .00 .35 1 .28 .22 . 1 3 .26 42324 3266 .95 .31 1 . 1 1 .16 .19 .47 52324 2262 .56 .24 .89 . 1 1 .83 .91 62324 3700 .66 .26 .93 .10 .03 .14 72324 2456 .66 .23 .73 .10 .01 .12 82324 0222 .75 .25 .91 .10 .07 .18 ID VOL CA 13111 0180 231 1 1 0987 .38 331 1 1 51 22 . 1 8 431 1 1 2150 .16 531 1 1 2000 .06 631 1 1 2590 .08 731 1 1 2543 .21 831 1 1 0261 .38 13112 0180 .54 231 1 2 0987 1 .02 331 1 2 51 22 1 .62 431 12 2150 1 .30 531 1 2 2000 .39 631 1 2 2590 .76 731 1 2 2543 1 .58 83112 0261 .74 13113 0180 .43 231 1 3 0987 .55 33113 51 22 .76 431 1 3 21 50 .63 531 1 3 2000 .57 631 13 2590 .56 731 1 3 2543 .68 83113 0261 .59 13114 0180 .43 23114 0987 .56 33114 51 22 .79 43114 21 50 .77 531 1 4 2000 .59 631 1 4 2590 .55 73114 2543 .60 83114 0261 .60 13121 0132 23121 1 075 .30 331 21 4847 .21 431 21 3117 .22 53121. 21 12 .12 63121 1 500 . 1 3 731 21 2543 . 17 83121 0320 .34 1 31 22 01 32 .56 23122 1075 .80 33122 4847, 1 .83 431 22 3117 1 .19 53122 21 12 .68 631 22 1500 .75 731 22 2543 .82 83122 0320 1 .29 - 143 -MG NA K FE AL .22 .24 1.10 .00 .03 . 1 1 .25 .51 .05 .04 .05 .70 .40 . 1 1 .16 .05 .29 . 1 1 .06 .08 .05 .31 .08 .00 .00 .10 .70 .28 .01 . 1 1 .15 .53 .60 .08 .06 .15 .29 .74 .03 .22 .29 .62 .80 .05 .17 .31 .39 1 .62 .68 1 .05 .38 .49 1 .38 .27 .51 .21 .84 . 1 4 .08 .18 .18 .52 .60 .06 .16 .28 .68 .68 .06 .23 .15 .55 .14 . 14 .48 .16 .57 .17 .00 .00 .18 .91 .34 .04 .04 .23 .85 .29 .36 .59 .20 .77 .21 .04 .09 .20 .70 .18 .08 . 1 5 .22 .70 .16 .03 .13 .22 .94 .35 .04 .10 .18 .69 . 1 6 .09 .1 4 .19 .59 .10 .00 .04 .24 .92 .38 .01 .06 .28 .86 .27 .18 .26 .29 .86 . 1 5 .07 .18 .27 .73 .08 .09 .11 .24 .71 .10 .02 . 1 2 .22 .77 .20 .01 . 1 1 .26 .68 .20 .25 .25 .19 .19 .87 .01 .04 . 12 .28 .61 .06 .07 .13 .82 .19 .04 .09 .07 .28 . 1 2 .02 .01 .07 .35 .08 .04 .04 .09 .56 .24 .00 ' .03 . 12 » .32 .46 .04 .04 . 1 1 .22 .30 .03 .27 .24 .62 .21 .09 .66 .25 .32 .26 .26 .90 .21 .39 .15 .22 .46 .13 .42 .08 .13 .40 . 17 • .64 . 1 1 .16 .61 . 14 .55 . 1 4 .08 .41 .27 .59 .80 .10 .23 - 144 -ID VOL CA MG NA K FE AL 1 31 23 0132 .30 .12 .53 .15 .00 .00 231 23 1075 .40 .16 .81 .34 .03 .08 331 23 4847 .45 . 1 3 .60 .22 .48 .78 431 23 3117 .53 .15 .63 .19 .16 .21 53123 2112 .40 .17 .61 . 1 1 . 1 1 .09 631 23 1500 .44 .16 .61 .10 .00 .00 731 23 2543 .87 .35 1.10 .25 . 1 0 .20 831 23 0320 .40 .17 .55 .13 .04, .06 1 31 24 0132 .56 .26 .70 .07 .00 .00 231 24 1075 .50 .23 .86 .10 .01 .07 331 24 4847 .78 .30 .98 .15 .09 . 1 6 431 24 3117 .78 .29 .85 . 1 4 .08 .10 53124 21 12 .60 .26 .76 .10 .02 .08 631 24 1500 .56 .24 .77 .10 .01 .07 731 24 2543 .59 .23 .71 .12 .00 .09 831 24 0320 .68 .29 .82 .13 .09 .12 1 321 1 0100 2321 1 0837 .48 .37 .37 1 .80 .02 .06 3321 1 4640 .18 . 1 4 .25 .64 .08 . 1 1 4321 1 2457 .26 . 1 5 .82 .24 .05 .08 5321 1 1 650 . 17 .07 .32 . 1 5 .07 .09 6321 1 2800 . 16 .08 .35 .18 .01 .01 7321 1 2543 .30 . 1 5 .74 .34 .00 .05 8321 1 0262 .38 . 1 7 .51 .70 .10 .10 13212 0100 .50 .25 .62 .28 .00 .06 2321 2 0837 .96 .41 .89 .50 .01 .07 3321 2 4640 .61 .24 .82 .22 .08 . 1 3 4321 2 2457 1 .38 .30 .61 .73 .19 .43 53212 1 650 .45 .35 .69 . 1 1 .08 . 1 1 6321 2 2800 .48 .32 .70 .12 .03 .10 73212 2543 1 .29 .74 .84 .36 .03 .19 83212 0262 1 .09 .55 .65 .55 .79 .33 13213 0100 .44 .23 .77 .07 .00 .02 2321 3 0837 .58 .21 .90 .21 .01 .06 3321 3 4640 .50 .24 .80 .18 .10 .20 4321 3 2457 1 .65 .21 .70 .29 . 1 0 .22 5321 3 1650 .47 .25 .77 .10 . 1 0 .17 6321 3 2800 .52 .25 .80 . 1 3 .01 .07 7321 3 2543 .58 .24 .77 . 1 3 .00 .07 8321 3 0262 .64 .30 1 .02 .17 .08 .17 13214 0100 .47 .24 .80 .08 .00 .01 23214 0837 .74 .26 1.01 .10 .02 .08 3321 4 4640 .54 .23 .78 .13 . 1 3 .25 4321 4 2457 1.81 .30 .91 . 1 4 .06 .17 53214 1650 .50 .26 .80 .10 .09 .16 63214 2800 .54 .25 .79 .12 .04 . 1 4 7321 4 2543 .65 .25 .80 .13 .00 .07 83214 0262 .68 .30 .90 .13 .12 .13 - 145 -ID VOL CA MG NA K FE AL 1 3221 0150 23221 0938 .30 .26 . 1 9 1.17 .01 .05 33221 451 0 .13 . 1 1 . 1 5 .57 .03 .03 43221 2800 .06 .06 .34 . 1 1 .00 .03 53221 1 725 .81 .20 .82 .47 .06 .17 63221 2500 .09 .06 .28 .15 .00 .04 73221 2543 .25 . 1 3 .80 .29 .06 .09 83221 01 42 .33 . 1 6 .44 .70 . 1 1 .10 1 3222 0150 .87 .32 .60 .87 .03 .33 23222 0938 .90 .75 .76 .56 .02 . 1 1 33222 4510 1 .17 .32 .69 1.01 .29 .71 43222 2800 1 .38 .30 .61 .73 .19 .43 53222 1 725 .81 . 1 3 .97 .36 .12 .40 63222 2500 .51 .22 .80 .21 .06 .18 73222 2543 1 .25 .32 .66 .39 .08 .32 83222 0142 .54 .24 .82 .15 .10 .50 1 3223 0150 .44 .21 .76 .09 .00 .05 23223 0938 .42 .21 .89 . 1 4 .06 .09 33223 451 0 .79 .32 1.10 1.01 .13 .20 43223 2800 1 .65 .21 .70 .29 .10 .22 53223 1 725 .37 .27 .82 . 1 4 .09 .24 63223 2500 .38 .19 .73 .12 .04 . 1 1 73223 2543 .84 .33 1 .24 .25 .00 .08 83223 01 42 .41 .21 .75 .14 .06 .06 13224 01 50 .45 .22 .76 . 1 1 .00 .06 23224 0938 .66 .26 1 .07 .21 .01 .08 33224 4510 .65 .26 .96 .20 . 1 4 .24 43224 2800 1 .81 .30 .91 . 14 .06 . 1 7 53224 1725 .08 .04 .24 .18 .05 .06 63224 2500 .46 .21 .75 .13 .03 . 1 3 73224 2543 .49 .20 .74 .15 .03 . 1 3 83224 01 42 .40 .22 .77 .13 .04 .02 1 331 1 01 32 2331 1 0907 .30 .28 .22 1 .20 .01 .05 3331 1 4567 .23 .13 .16 .49 .06 .08 4331 1 1 387 .08 .04 .31 .13 .03 .07 5331 1 1931 .15 .06 .36 .17 .00 .06 6331 1 3000 . 1 5 .06 .31 .10 .01 .01 7331 1 2543 .21 . 1 1 .66 .25 .02 .07 8331 1 0260 .73 .16 .65 1.21 .05 .04 13312 0.1 32 .80 .35 .68 .50 .03 .22 23312 0907 .96 .32 .89 .50 . 1 1 .17 3331 2 4567 2 .08 .43 .73 1.41 1.11 1 .61 43312 1387 1 .12 .34 .85 .55 .13 .32 53312 1 931 .75 .24 .75 .63 . 10 .33 63312 3000 .91 .23 .54 .33 . . 13 .28 7331 2 2543 1 .62 .29 .80 .35 .20 .53 8331 2 0260 .51 .19 .55 .27 .13 .26 - 146 -• ID VOL CA MG NA K FE AL — -13313 01 32 .50 .24 .88 .19 .00 .02 2331 3 0907 .58 .21 .97 .21 .01 .10 3331 3 4567 .86 .28 1 .04 .21 .70 1.14 43313 1387 .84 .29 .94 .18 .08 .19 53313 1931 .70 .26 .87 .15 .06 .13 63313 3000 .58 .22 .80 .13 .12 .18 7331 3 2543 .59 .21 .74 .10 .02 . 1 1 83313 0260 .81 .32 1 .08 .20 .07 .08 13314 0132 .72 .30 .95 . 1 1 .00 .02 23314 0907 .75 .30 1 .13 .08 .01 .06 33314 4567 1 .03 .35 1 .22 . 1 1 .50 1.16 43314 1 387 .85 .31 1 .00 .13 .00 .07 53314 1 931 .70 .28 .88 .10 .10 .17 63314 3000 .69 .29 .96 .10 .05 .07 73314 2543 .72 .26 .90 .10 .00 .06 83314 0260 .69 .25 1 .21 .45 . 1 5 .16 13321 0120 23321 0865 .44 .26 .32 1 .55 .01 .05 33321 4700 .26 . 1 3 .20 .75 .06 .08 43321 2625 .15 .07 .32 .18 .03 .09 53321 1881 .29 .10 .42 .35 .03 .06 63321 2300 .20 .07 .36 .24 .02 .01 73321 2543 .46 .16 1 .00 .65 .01 .06 83321 0261 .32 . 1 1 .43 .35 .05 .03 13322 0120 1 .00 .18 .27 .31 .04 .23 23322 0865 1 .40 .20 .31 .49 .06 .28 33322 4700 1 .83 .23 .31 .84 .96 1 .99 43322 2625 1 .91 .26 .71 .83 . 1 3 .41 53322 1881 1 . 1 4 .30 .84 .44 . 1 1 .21 63322 2300 .68 .22 .64 .27 .08 .25 73322 2543 .96 . 1 3 .41 .44 .04 .26 83322 0261 .50 .08 .41 .37 .14 .19 13323 01 20 .38 . 1 5 .40 .31 .00 .02 23323 0865 .61 .19 .42 .20 .05 . 1 1 33323 4700 .84 .23 .54 .78 .36 .94 43323 2625 .59 .18 .46 .59 . 1 1 .37 53323 1881 .46 .16 .47 .33 .08 .14 63323 2300 .47 . 1 5 .57 .33 .02 . 1 4 73323 2543 .45 . 1 3 .61 .39 .00 .08 83323 0261 .41 . 1 4 .61 .48 .08 .21 13324 0120 .61 .24 .76 .09 .00 .01 23324 0865 .70 .20 .56 .05 .00 .08 33324 4700 .91 .29 1 .01 .18 .36 .67 43324 2625 .82 . .31 .91- . 1 3 .10 .33 53324 1881 .67 .28 .83 .10 .03 .12 63324 2300 .67 .26 .84 .16 .12 .30 73324 2543 .75 .22 .85 .23 .00 .07 83324 0261 .61 .26 .88 .21 .13 .14 - 147 -Appendix 4 Vegetation Species L i s t s - 148 -SITE 1 elevation 365 m l a t i t u d e N 49°01' longitude 124°11' Dominant Trees % Cover Pseudotsuga menziesii (Mirbel) Franco 12 Tsuga heterophylla (Raf.) Sarg. 18 Pinus monticola Dougl. ex D. Don i n Lamb. + Intermediate and Suppressed Trees Tsuga heterophylla 40 * Pseudotsuga menziesii 5 Pinus monticola + Shrubs Gaultheria shallon Peush 50 Vaccinium parvifolium Sm. i n Rees 2 Mahonia newssa (Pursh) Nutt. + Rosa gymnocarpa Nutt i n Torr. x Gray + Herbs Chimaphila umbellata CL.) Barton + Linnaea b o r e a l i s L. ]_ * Pyrola dentata Sm. i n Rees 1 * Festuca o c c i d e n t a l i s Hook. 1 * A l l o t r o p a v i r g a t a Torr. x Gray i n Gray + * Heeracium alb i f l o r u m Hook. + Calypso bulbosa (L.) Oakes i n Thompson + Boshniakia hookeri Walp. 1 Hypopithys lanuginosa Nutt. + Mosses and Lichens * Cladonia g r a c i l i s (L.) W i l l d . 2 S t o k e s i e l l a oregana (S u l l . ) Robins 40 Rhytediadelphus triquetrus (Hedw.) Warnst. 10. Pieranum fuscescens Turn. 1 Polytrichum juniperum Hedw. 1 Hylocomium splendens (Hedw.) B.S.G. 10 - 149 -SITE 2 elevation 550 m l a t i t u d e 49°02'N longitude 124°12' Dominant Trees % Cover Pseudotsuga menziesii 15 Tsuga heterophylla 70 Thuja p l i c a t a Donn. ex D. Don i n Lamb. + Intermediate and Suppressed Trees Tsuga heterophylla 15 Thuja p l i c a t a + Shrubs Gaultheria s h a l l o n 70 Vaccinium parvifolium 1 Vaccinium alaskaense How. + Herbs Linnaea b o r e a l i s 2 Goodyeara o b l o n g i f o l i a Raf. 1 Cornus canadensis L-. 1 L i s t e r a cordata (L.) R. Br. i n A i t + L i s t e r a banksiana L i n d l . + C o r a l l o r h i z a maculata Raf. + Pyrola p i c t a Sm. i n Rees + Hemitomes congestum Gray + Mosses Hylocomium splendens 50 Rhytidiadelphus loreus (Hedw.) Warnst 10 Dicranum feescescens 1 S t o k e s i e l l a oregana + - 150 -SITE 3 elevation 730 m l a t i t u d e 49°03'N longitude 124°12' Dominant Trees % Cover Pseudotsuga menziesii 10 Tsuga heterophylla 70 Abies amabalis (D, Doug, ex Loud) Forbes + Intermediate and Suppressed Trees Tsuga heterophylla 15 Thuja p l i c a t a 2 Chamaecyparis nootkatensis (D. Don) Spach. 2 Abies amabalis 1 Shrubs Gaultheria shallon 30 Vaccinium alaskaense 10 Vaccinium o v a l i f o l i u m Sm. i n Rees + Vaccinium pa r v i f o l i u m 5 Herbs Linnaea b o r e a l i s 3 Cornus canadensis 1 Goodyeara o b l o n g i f o l i a 1 Pyrola p i c t a 1 Pyrola sp. (probably P_. a s a r i f o l i o (Michaux)} 1 L i s t e r a banksiana + L i s t e r a cordata + Hemitomes congestum + Mosses Rhytidiopsis robusta (Hedw.) Brobl. 30 RhytidiadeIphus loreus- 10 Hylocomium splendens 15 Dicranum fuscescens 1