UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

The ecology of genus Typha in wetland communities of the eastern Ontario-western Quebec region of Canada Bayly, Isabel 1974

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1974_A1 B39.pdf [ 18.47MB ]
Metadata
JSON: 831-1.0093148.json
JSON-LD: 831-1.0093148-ld.json
RDF/XML (Pretty): 831-1.0093148-rdf.xml
RDF/JSON: 831-1.0093148-rdf.json
Turtle: 831-1.0093148-turtle.txt
N-Triples: 831-1.0093148-rdf-ntriples.txt
Original Record: 831-1.0093148-source.json
Full Text
831-1.0093148-fulltext.txt
Citation
831-1.0093148.ris

Full Text

THE ECOLOGY OF GENUS TYPHA IN WETLAND COMMUNITIES OF THE EASTERN ONTARIO - WESTERN QUEBEC REGION OF CANADA by ISABEL LAW BAYLY B.S c , Carleton U n i v e r s i t y , 1953 M.A., Un i v e r s i t y of Toronto, 1956 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY i n the Department of Botany We accept t h i s thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA In presenting t h i s t h e s i s i n p a r t i a l f u l f i l m e n t of the requirements f o r an advanced degree at the U n i v e r s i t y of B r i t i s h Columbia, I agree that the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r reference and study. I f u r t h e r agree that permission f o r extensive copying of t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by the Head of my Department or by h i s r e p r e s e n t a t i v e s . I t i s understood that copying or p u b l i c a t i o n of t h i s t h e s i s f o r f i n a n c i a l gain s h a l l not be allowed without my w r i t t e n permission. Department of Botany The U n i v e r s i t y of B r i t i s h Columbia Vancouver 8 , Canada D a t e A p r i l 18, 1974 i ABSTRACT BAYLY, I.L. (Department of Biology, Carleton U n i v e r s i t y , Ottawa, Ontario, Canada) 1973. The ecology of the genus Typha i n wetland communities of the eastern Ontario - western Quebec region of Canada. Ph.D. Thesis, Department of Botany, U n i v e r s i t y of B r i t i s h Columbia. The study was designed to determine the nature of Typha communities i n the area and c o r r e l a t e the c h a r a c t e r i s t i c s of these communities with differences i n c l i m a t i c , edaphic and aquatic environment. A seasonal comparison of plant - s o i l - water r e l a t i o n s h i p s was made between Typha glauca and Phragmites communis, the two major competitors f o r marsh habi t a t s . Phragmites i s seen to make high demands on the substrate for calcium, magnesium and phosphorus, requirements which may l i m i t i t s c o l o n i z a t i o n of nutrient-poor ha b i t a t s . Except for potassium, Typha i s shown to make only moderate demands on the substrate, and also shows the a b i l i t y to accumulate high concentrations of sodium without tox i c e f f e c t s . Pattern of uptake and r e c y c l i n g of macronutrients i s s i m i l a r i n both species, but the graphs of seasonal uptake d i f f e r i n shape. Onset of seasonal senescence i n Typha coincides with achievement of maximum growth, but i n Phragmites, a plant of indeterminate seasonal growth, seasonal senescence i s not corr e l a t e d with maximum height. Pattern of uptake and u t i l i z a t i o n of ions d i f f e r s , and the ions may be c l a s s i f i e d into three categories. F i r s t are those ions which are u t i l i z e d early i n the growing season, and are then cycled between plant and substrate, e.g., calcium and magnesium. Second are the ions which are u t i l i z e d early i n the growing season and are then cycled to the rhizome f o r overwinter storage, e.g., potassium and phosphorus. Third are ions which flu c t u a t e passively i n response to external concentrations, e.g., sodium and i r o n . Seasonal studies of uptake and growth of f l o a t i n g mat communities of Typha confirm that (a) the pattern of uptake, and amount of uptake of ions i s s i m i l a r i n f l o a t i n g mats, despite lower concentrations of nutrients i i i n the mat matrix, (b) the f l o a t i n g mat matrix contributes to the growth of Typha i n the same manner that normal s o i l contributes to growth i n s o i l rooted communities. Introgressive h y b r i d i z a t i o n i n Typha i n eastern Canada has been investigated. With h y b r i d i z a t i o n and introgression, T_. a n g u s t i f o l i a and T_. l a t i f o l i a produce v a r i a b l e s e r i e s of character recombinations, in c l u d i n g T_. glauca. Such intr o g r e s s i o n makes p o s i t i v e i d e n t i f i c a t i o n s to species d i f f i c u l t . Within the study, v a r i a b i l i t y i s found to be greater on new habitats, p a r t i c u l a r l y those bordering bodies of shallow water. Older more stable communities are represented by fewer v a r i a n t s , the environment apparently s e l e c t i n g p a r t i c u l a r genotypes. Sample material was taken both from Typha stands and from stands dominated by other major species, in c l u d i n g the following: Acorus calamus, Alisma plantago-aquatica, Calamagrostis canadensis, Agrostis s t o l o n i f e r a , Butomus umbellatus, Decodon v e r t i c i l l a t u s , Dulichium arundinaceum, Epilobium  hirsutum, Eupatorium maculatum, G l y c e r i a canadensis, Impatiens b i f l o r a , Juncus effusus, Nuphar advena, Onoclea s e n s i b i l i s , P h alaris arundinacea, Phragmites communis, S a g i t t a r i a l a t i f o l i a , ,S. r i g i d a , Scirpus americanus, cyperinus, S_. f l u v i a t i l i s , j3. rubrotinctus , _S. v a l i d u s , Sparganium  androcladum, S^. eurycarpum, Spiraea alba and Zizania aquatica. Three d i s t i n c t community types were recognized and described: (a) Typha communities of the deeper waters of open marshes, where nutrients are low i n the substrate, but water c i r c u l a t e s f r e e l y presenting a constant i f d i l u t e supply of nu t r i e n t s ; (b) Typha-Sagittaria communities of open marshes, i n the shallower water, they are two-layered, with the lower story composed of S a g i t t a r i a l a t i f o l i a or Pontederia cordata; nutrient l e v e l s are higher, as the r e s u l t of accumulation of organic matter i n the substrate; (c) Typha- Galium communities, found i n the shallow and moist portions of open marshes i i i as w e l l as i n closed marshes where water may subside to ground l e v e l i n the l a t e summer months. Here the mature s o i l s are high i n organic matter and n u t r i e n t s . T y p i c a l species i n addition to Typha, are Galium palustre, Cicuta  b u l b i f e r a , Lysimachia t e r r e s t r i s and•Glyceria canadensis. F l o a t i n g mat communities of Typha, derived from land-based communities are also described. They consist of buoyant, leached organic mats. Mature marsh s o i l s are found to be modified by the p a r t i c u l a r dominant so that unique s o i l s emerge. T y p i c a l marsh s o i l as a c o l o n i z i n g substrate of Typha communities i s the Rego Gleysol. Recycling and accumula-t i o n of organic matter develops the s o i l s into Humisols. F l o a t i n g mat s o i l s have been c l a s s i f i e d as Hydric F i b r i s o l s , according to the Canadian c l a s s i -f i c a t i o n . Competition from other marsh species i s l i m i t e d . Most species, regardless of n u t r i e n t requirements, can be overtopped by Typha. Scirpus  validus can occupy deeper waters. Phragmites communis, possibly the strongest competitor, i s probably eliminated from c o l o n i z a t i o n of low nutrient s o i l s because of i t s high requirement for calcium and magnesium. i v TABLE OF CONTENTS Abstract i Table of contents i v L i s t of tables . . v L i s t of figures v i Acknowledgment x Introduction 1 Methods 8 Section I. General climate of marsh communities 12 General d e s c r i p t i o n . . . . 13 S i t e exposure 22 Section I I . Plants and plant communities 24 L i f e form spectrum of marshes . . . . 25 Hyb r i d i z a t i o n and int r o g r e s s i o n i n Typha 27 Categories of Typha communities 39 Adventives i n the marsh community 49 Provenances and height at maturity 50 Ionic composition of leaves of marsh species 61 Moisture content of plants 68 Section I I I . P h y s i c a l factors of the marsh 79 Light 80 Water 102 S o i l 114 Section IV. Plant - s o i l - water r e l a t i o n s h i p s 159 Seasonal v a r i a t i o n i n Typha glauca 160 Seasonal v a r i a t i o n i n Phragmites communis 176 Comparison of Typha glauca and Phragmites communis . . . 187 Seasonal v a r i a t i o n of a f l o a t i n g mat community of Typha glauca on Sanctuary Pond . . 192 Seasonal v a r i a t i o n of a f l o a t i n g mat community of Typha glauca on Big Pond, Point Pelee 198 Discussion 207 Conclusions 231 Bibliography 236 Appendix I. L i s t of vascular plants 243 Appendix I I . Statistical analyses 249 Appendix III. Soil corer equipment 257 V LIST OF TABLES Table I Life-form spectrum of a marsh 26 Table I I Hybrid index c h a r a c t e r i s t i c s . . . . . . 28 Table I I I Factors concerned with height i n Typha 53 Table IV Maximum height i n m, of mature plants 54 Table V Average nutri e n t and sodium content of leaves 66 Table VI Percent moisture content, based on fresh weight of species which occur on self-dominated plots and with Typha 69 Table VII Percent moisture content, based on fresh weight, of selected species, i n communities dominated by various species 70 Table VIII Light i n t e n s i t i e s within plant communities 85 Table IX Light r e l a t i o n s h i p s of subordinate species . 87 Table X Water analysis of marsh plo t s f o r a s i n g l e season . . . 96 Table XI Water analysis of selected dominants 101 Table XII Average a i r , water and s o i l temperatures f o r vegetation dominants . 127 Table XIII S o i l c h a r a c t e r i s t i c s by d i s t r i c t 136 Table XIV S o i l c h a r a c t e r i s t i c s for vegetation dominants Parts I and II 140 v i LIST OF FIGURES Figure 1 Map of sampling areas 15 Figure 2 Temperature - p r e c i p i t a t i o n , Chelsea . . . 17 Figure 3 Temperature•- p r e c i p i t a t i o n , Norway Bay 17 Figure 4 Temperature - p r e c i p i t a t i o n , Ottawa . . . 19 Figure 5 Temperature - p r e c i p i t a t i o n , North Bay . . . . 19 Figure 6 Temperature - p r e c i p i t a t i o n , Port Dover . 20 Figure 7 Temperature - p r e c i p i t a t i o n , Leamington 20 Figure 8 T o t a l population d i s t r i b u t i o n . „. . . . . 29 Figure 9 Hybrid index, non-peripheral samples 31 Figure 10 Hybrid index, peripheral samples 32 Figure 11 Hybrid index, i n d i v i d u a l ponds 34 Figure 12 Map of Point Pelee Marsh 36 Figure 13 Hybrid index, non-peripheral areas 37 Figure 14 Typha community, deep water 42 Figure 15 Two-layered Typha community . . . 42 Figure 16 Two-layered Typha community 43 Figure 17 S a g i t t a r i a l a t i f o l i a 43 Figure 18 Typha - Galium community . . . . . . . . 44 Figure 19 F l o a t i n g mat community 46 Figure 20 Phragmites communis 46 Figure 21 Scirpus americanus 47 Figure 22 Zi z a n i a aquatica 47 Figure 23 Scirpus validus 48 Figure 24 Eupatorium maculatum 48 Figure 25 European adventives 51 Figure 26 Typha provenances 52 Figure 27 Herbarium specimens of Typha 57 v i i Figure 28 Typha spp. , Scirpus f l u v i a t i l i s 58 Figure 29 Herbarium sheets of marsh dominants 59 Figure 30 Herbarium sheets of marsh dominants . . . 60 Figure 31 Seasonal moisture content of leaves, Nuphar advena and Typha glauca 74 Figure 32 Seasonal moisture content of leaves, Typha glauca and Phragmites communis 76 Figure 33 Open sky l i g h t readings, 1967 season . . . 81 Figure 34 Growth of Typha i n closed marsh 83 Figure 35 Typha - Galium community 83 Figure 36 Open marsh Typha community 84 Figure 37 Open marsh community 84 Figure 38 F l o a t i n g mat, l i g h t r e l a t i o n s h i p s 89 Figure 39 Phragmites communis, l i g h t r e l a t i o n s h i p s 90 Figure 40 Nuphar advena, l i g h t r e l a t i o n s h i p s 90 Figure 41 Plot l i g h t r e l a t i o n s h i p s 92 Figure 42 Plot l i g h t r e l a t i o n s h i p s 93 Figure 43 Plot l i g h t r e l a t i o n s h i p s 94 Figure 44 Plot l i g h t r e l a t i o n s h i p s 95 Figure 45 Calcium-magnesium r e l a t i o n s h i p s i n water 107 Figure 46 Dulichium arundinaceum I l l Figure 47 Typha l a t i f o l i a , sparse growth I l l Figure 48 Sagittate form, S a g i t t a r i a l a t i f o l i a 112 Figure 49 Ensiform form, S a g i t t a r i a l a t i f o l i a 112 Figure 50 F r e e - f l o a t i n g aquatics 113 Figure 51 P a r t i c l e s i z e , Tay River 118 Figure 52 P a r t i c l e s i z e , Gatineau River 118 Figure 53 P a r t i c l e s i z e , Gatineau River 119 Figure 54 P a r t i c l e s i z e , Gatineau River 119 v i i i Figure 55 P a r t i c l e s i z e , Norway Bay 120 Figure 56 P a r t i c l e s i z e , Rideau River . . 120 Figure 57 P a r t i c l e s i z e , Ramsayville Marsh 121 Figure 58 Typha - S a g i t t a r i a , seasonal s o i l temperatures 125 Figure 59 Typha glauca, seasonal mat temperatures 126 Figure 60 S o i l temperatures, adjacent pl o t s 131 Figure 61 S o i l temperatures, adjacent plots 132 Figure 62 S o i l temperatures, adjacent plots 133 Figure 63 Typha glauca, seasonal s o i l temperatures 162 Figure 64 Typha glauca, seasonal moisture content 164 Figure 65 Typha glauca, growth patterns of leaves 166 Figure 66 Typha glauca, seasonal calcium 167 Figure 67 Typha glauca, seasonal magnesium 168 Figure 68 Typha glauca, seasonal sodium 170 Figure 69 Typha glauca, seasonal i r o n 171 Figure 70 Typha glauca, seasonal potassium 173 Figure 71 Typha glauca, seasonal phosphorus 174 Figure 72 Phragmites communis, seasonal s o i l temperatures 178 Figure 73 Phragmites communis, growth and moisture 179 Figure 74 Phragmites communis, seasonal calcium 181 Figure 75 Phragmites communis, seasonal magnesium . . 182 Figure 76 Phragmites communis, seasonal sodium 183 Figure 77 Phragmites communis, seasonal potassium 185 Figure 78 Phragmites communis, seasonal phosphorus 186 Figure 79 F l o a t i n g mat, Sanctuary Pond, calcium 193 Figure 80 F l o a t i n g mat, Sanctuary Pond, magnesium 195 Figure 81 F l o a t i n g mat, Sanctuary Pond, potassium 196 Figure 82 F l o a t i n g mat, Sanctuary Pond, sodium 197 i x Figure 83 F l o a t i n g mat, Big Pond, calcium 200 Figure 84 Fl o a t i n g mat, Big Pond, magnesium 201 Figure 85 Fl o a t i n g mat, Big Pond, potassium . 202 Figure. 86 F l o a t i n g mat, Big Pond, sodium 203 X ACKNOWLEDGEMENT I acknowledge the counsel of Dr. V.J. Kra j i n a and h i s associates at the U n i v e r s i t y of B r i t i s h Columbia, a l l of whom have, at i n t e r v a l s throughout the study, offered valuable advice. P a r t i c u l a r mention should be made of the following: Dr. C A . Rowles, Dr. G.H.N. Towers, Dr. R.F. Scagel, Dr. T.M.C. Taylor, Dr. W.B. Schofield, Dr. Janet Stein and Dr. C.J. Marchant. In Ottawa, Dr. W.G. Dore, whose i n t e r e s t i n plants of the Ottawa d i s t r i c t and wetland species i n p a r t i c u l a r i s profound, has encouraged me during the study. I thank Mr. G.C Bayly f o r h i s assistance with photography, Mr. B. von Spindler f o r h i s analysis of s o i l samples for the summer of 1966, and my summer as s i s t a n t s , Mr. Peter Meggs (1966), Mr. Donald Moxley (1967), Mr. Tom O'Neill (1968 and 1970) and Miss Antoinette Hartgerink (1969). I am indebted to the B r i t i s h American O i l Company and to the National Research Council of Canada, the former for a supporting fellowship, the l a t t e r for a grant, without which the study would not have been poss i b l e . 1 INTRODUCTION In the shallow waters of many parts of the world, marsh vegetation forms extensive communities. These provide cover for w i l d l i f e , conserve water, r e t a i n and b u i l d s o i l . In the environmental sense, they are disturbed communities, affected strongly by t h e i r aquatic surroundings, but nevertheless, they form important communities i n the natural environment. A d i s t i n c t i o n should be made between the four major wetland ecosystems, marsh, fen, swamp and bog (Dansereau 1957, Polunin 1960,-Sculthorpe 1967). A marsh i s a herb-dominated ecosystem i n which the rooting medium i s submerged f o r long periods, and i s composed c h i e f l y of mineral materials which may be high i n humus content. Marshes may be freshwater, s a l i n e or brackish. A swamp i s s i m i l a r to a marsh, except that the dominant vegetation i s composed of woody plants (Penfound 1952). Both fen and bog belong to the general e c o l o g i c a l c l a s s i f i c a t i o n of mire and moor, which includes a l l wetlands based upon wet peat as the rooting medium. A fen i s distinguished from a bog i n that i t s water i s supplied both by p r e c i p i t a t i o n and by water which has been i n contact with mineral s o i l s , thus a fen i s r i c h e r i n minerals than would be expected from p r e c i p i t a t i o n alone. A bog depends on water supply which contains l i t t l e more nutrient than does rainwater. Occasionally bogs can revert to marshes, although such occurrences are r a re, but marshes can become bogs, and often do (Dansereau and Segadas-Vianna 1952). The most common habitat f o r Typha i s the freshwater marsh. Taxonomically, the genus Typha i s eastern North America presents some d i f f i c u l t y . It i s a cosmopolitan genus, and many forms and v a r i a t i o n s have been described. The species i n the present study are Typha a n g u s t i f o l i a L. , T_. l a t i f o l i a L. and T_. glauca Godr. Both T_. angustif o l i a and T_. l a t i f o l i a are r e a d i l y distinguished. J_. angustif o l i a has a slender inflorescence and 2 the male portion of the spike is separated from the female portion by a naked stalk. The leaves are narrow and dark green. J_. l a t i f o l i a has a short thick female inflorescence, and the male portion of the spike is continuous with the female portion. The leaves are wide (greater than 2 cm) and light green. Both species have 2n=30, and are f u l l y s e l f - f e r t i l e (East 1940). The species are wind-pollinated, but bees also v i s i t Typha to gather the copious pollen. Between T. angustif o l i a and T_. l a t i f o l i a hybridization is strong and where the two species have grown in proximity, there are no barriers to cross-fertilization (Marsh 1963). One of the many introgressive combinations is the plant described as T_. glauca Godron (Fassett and Calhoun 1952). Under f i e l d conditions in eastern North America, hybrid vigour of this plant distinguishes i t from the other two species. The female inflorescence is separated from the male inflorescence, is thicker than in T_. angustif o l i a , but thinner than the female inflorescence of T_. l a t i f o l i a . The vegetative parts of T_. glauca often surpass 3 metres in height, while leaves of T_. l a t i f o l i a and T_. angustif o l i a usually grow to a height of 2 metres or less. The leaves of T_. glauca are noticeably glaucous. A l l three species can occur together, and exhibit a degree of v a r i a b i l i t y which makes recognition of individual species d i f f i c u l t . Lacking better terminology, I have retained the species name T_. glauca, using i t where i t best applies. I have also dealt with the problem of va r i a b i l i t y in a study which is included i n the thesis. Formal classification of wetland communities has received considerable attention. Braun-Blanquet (1932, 1964) shows part of such a classification in his discussion of the plant communities of Bas Languedoc, France. Koch (1926) indicates that a l l wetland communities belong to the order Phragmitetalia, although segregated into several alliances. Alliance Phragmition contains Koch's Scirpo-Phragmitetum, of which one of the 3 c h a r a c t e r i s t i c species i s Typha l a t i f o l i a . C h a r a c t e r i s t i c species of the a l l i a n c e include S a g i t t a r i a s a g i t t i f o l i a , G l y c e r i a aquatica, Phalaris  arundinacea, Acorus calamus and Typha a n g u s t i f o l i a . Also within the order i s the a l l i a n c e Magnocaricion elatae, into which are grouped the t a l l sedge communities of stagnant waters. Within t h i s a l l i a n c e , two associations Caricetum elatae typhosum l a t i f o l i a e and Caricetum rostratae typhosum l a t i f o l i a e are recognized. Both have Typha l a t i f o l i a as a c h a r a c t e r i s t i c species. Other workers i n Europe have made strong contributions to the c l a s s i f i c a t i o n and understanding of aquatic communities. The major contributions have come from Tiixen and Pr e i s i n g (1942), Ellenberg (1963), Neuhausl et a l . (1965) and Hejny (1960). In North America, Conard (1952) has described the vegetation of Iowa using Zurich-Montpellier methodology. In his Phragmition he places f i v e d i s t i n c t a ssociations: Phragmitetum; Scirpetum v a l i d i ; Typhetum; Phalaridetum arundinaceae; Spartinetum pectinatae. On a less formal basis, many phytosociological r e l a t i o n s h i p s have been recognized, both i n North America and elsewhere. Penfound (1952) has recognized three major marsh categories i n Louisiana. These are: Zlzaniopsis m i l i a c e a (Giant Cutgrass), Mariscus jamaicensis (Saw-grass) and Typha - Scirpus - Panicum. The r e l a t i o n s h i p of S a g i t t a r i a l a t i f o l i a and _S. l a n c i f o l i a to stands of Typha i n Louisiana has also been described. Davis (1937) ind i c a t e s the close r e l a t i o n s h i p of Typha, Scirpus and Panicum i n southern wetland communities, p a r t i c u l a r l y i n the F l o r i d a everglades communities. Other authors have noted the close r e l a t i o n s h i p between Scirpus and Typha (Tallon 1958, Kadlec 1958). Associated with a study of the s u i t a b i l i t y of the region of A r i e s , France, f o r r i c e growing,"Tallon has described the 4 wetland a s s o c i a t i o n there as aTyphetum-Scirpetum. Kadlec has suggested that the r e l a t i o n s h i p s between Scirpus and Typha communities r e s u l t from i n t e r s p e c i f i c competition combined with f l u c t u a t i o n s i n water l e v e l . F l o a t i n g mats of Typha have been studied by Getz (1961) i n southern Michigan, and by Reichle and Doyle (1965) i n I l l i n o i s . Both authors describe the mats as bog mats, on the basis that they support Sphagnum and Chamaedaphne  ca l y c u l a t a i n addition to Typha. Considerable information concerning Typha marshes i s i n the l i t e r a t u r e . The following paragraphs present some of the r e l a t i o n s h i p s which have been reported. These serve as background to the study. In wetlands, both q u a l i t y and quantity of water influence f l o r i s t i c s t r u c t u r e . Changes i n water depth may allow competitive opportunity for more x e r i c species (Brenner 1966, Rpbel 1962, Uhler 1944), sedges being more tolerant of d r i e r conditions than i s Typha. One of the r e s u l t s of a continued draw-down i s the development i n Typha marshes of a multilayered understory, and a succession to more mesic plants (Harris and Marshall 1963). Resumption of o r i g i n a l water depth following a period of continued draw-down has been reported to increase both Phalaris arundinacea and Typha, although of the two, Typha i s more tolerant of extremes of water l e v e l (Bedish 1967, Laing 1941). Phragmites communis, a major species of wetlands, does not appear to grow w e l l i n areas of extreme water f l u c t u a t i o n , and makes best growth i n continuously deep water (Luther 1951). The impact of 0 2 content of water has been v a r i o u s l y reported, and for Typha a n g u s t i f o l i a , i t appears that low 0 2 content i n the water of marshes i s one of the factors which favours i t s continued growth (Damas 1959). A c i d i t y and a l k a l i n i t y have received l i t t l e more than general a t t e n t i o n , but Frost (1939) a t t r i b u t e s d i s t r i b u t i o n of marsh f l o r a to amplitude of tolerance to'pH, which i n h i s study of trout streams was 5 alkaline. Genera which he l i s t s as having a tolerance to the widest range in his study, pH 7.4 - 8.4, are Scirpus, Phragmites, Sparganium and Glyceria, a l l potential competitors of Typha. An interesting report on strontium-calcium relationships in marsh plants has been made by Ophel and Fraser (1970) in which they claim marsh plants can discriminate against strontium in favour of calcium, so that in any food chain in which aquatic plants take part, they are l i k e l y to introduce strontium enrichment to the environment. Only one seasonal study of substrate u t i l i z a t i o n in marsh plants has been reported. This was done by Boyd (1970) and concerns Typha l a t i f o l i a and Scirpus americanus. He reports that rapid uptake of nutrients occurs earlier than the period of maximum growth, and that as the plant ages, amounts of macronutrients decrease in the leaves. The present study gives a pair of seasonal studies of uptake in both Typha glauca and Phragmites communis, the two major competitors for marsh habitats. Several studies of primary productivity in Typha marshes have been made. Bray (1962) has studied a marsh in Minnesota, Matveeva and Znamenskaya (1959) a marsh near Leningrad, while Jervis (1964) has studied primary productivity in a marsh ecosystem in Michigan. Primary productivity in Typha marshes i s very high: 1904 gm/m2 (Jervis 1964), 16000 to 17070 kg/ha/yr (Bray 1962). Typha marshes out-produce a l l other wetlands in the studies by more than 300 gm/m2/yr., and 99% of the material is from Typha alone. In comparison, xeric habitats have only 60% of their primary productivity produced by their codominants (Pearson 1966). F i r s t estimates of energy budgets for a Typha marsh are reported by Bray (1962) in which he shows that during the growing season (in Minnesota) about 3% of visible radiation is spent on reflection, 2.2% on photosynthesis, and the remainder on evapotranspiration and conduction-convection. Estimates of annual radiation expenditure were 0.6% in photosynthesis, 34.0% in 6 r e f l e c t i o n , 32.0% on evapotranspiration and 33.4% on conduction-convection. Incoming v i s i b l e r a d i a t i o n for a clear summer sky (maximum) i s estimated at 110,870 lux. Several s o i l studies of wetlands have shown that Typha tolerates extreme f l u c t u a t i o n s of both s a l i n i t y and pH. McMillan (1959) notes that both Typha l a t i f o l i a and T_. a n g u s t i f o l i a t o l e r a t e s a l t concentrations of up to 3% for periods up to four months, with no apparent damage. McMillan uses t h i s tolerance to explain the a b i l i t y of Typha to compete so s u c c e s s f u l l y with other marsh species. Fleming and Alexander (1961) show that Typha also t o l e r a t e s lowering of pH (below pH 2.0), produced during the drying of s a l i n e marshes. Howard (1965) notes that a l l u v i a l s o i l s i n which Typha grows can be low i n carbon content (5.71 - 7.85%), with comparative f i g u r e s for fen s o i l s 13.3 - 24.2%. Growth c h a r a c t e r i s t i c s of Typha have prompted studies concerning i t s physiology, biology and ecotypic v a r i a b i l i t y . Yeo (1964) reports that i n s i x months a s i n g l e plant produces a rhizome network 10 feet i n diameter, and Smith (1967) reports that a s i n g l e seed can produce up to 98 shoots i n the second year from i t s rhizome system. The female spike of T. l a t i f o l i a , which i s only about 15 cm long i s capable of producing 222,000 v i a b l e f r u i t s i n one season, and 100% germination i s common. E f f i c i e n t d i s p e r s a l by such diverse b i o t i c agents as carp (White 1966), k i l l d e e r and mallard ducks (Vlaming and Proctor 1968) i s quite p o s s i b l e , together with d i s p e r s a l by wind and water. The extraordinary a b i l i t y to completely colonize new habitats i s furthered by high rates of germination i n white l i g h t and low 0 2 concentrations (Sifton 1959). The many p h y s i o l o g i c a l v a r i a t i o n s of enzyme systems of Typha have been demonstrated by McNaughton (1966 a-d, 1967, 1969, 1970) who suggests that these ecotypic v a r i a t i o n s contribute to the a b i l i t y of Typha to colonize such a wide range of habitats. 7 The problem of rapid growth rate and aggressive c o l o n i z a t i o n of disturbed habitats by Typha has led to an ever-expanding l i s t of papers concerned with i t s eradication by herbicides. E f f e c t s of various growth deterrents have been reported by many authors (Levi 1960, Robson et a l . 1966, Timmons 1963, Heath and Ruch 1958, B a l l 1958). A l l methods (Dalapon, Radapon etc.) are expensive, but e f f e c t i v e . Environmental "catastrophes" produce vegetational changes i n Typha marshes. S h i f t s i n vegetation have been a t t r i b u t e d to high water l e v e l s (Yeager 1949, McDonald 1955), boring insects (Pancoast 1937), n u t r i a damage (Swank and Petrides 1954), t h r i p s (Hood 1955), aphids (Hayden 1939), carp damage ( G i l t z and Myser 1954), drought (Brenner 1966), p o l l u t i o n (Errington 1957) and storms (Harris and Chabreck 1958). Economic uses f o r Typha marshes are l i m i t e d . Primary uses, as protection f o r w i l d l i f e , are well-known. Many animals use marshes f or food and nesting, among those the meadow vole, Microtus pennsylvanicus (Getz 1970); n u t r i a , Myocastor coypu; muskrat, Ondatra zibethicus; coot, F u l i c a  americana, discussed by K i e l (1955); the redhead duck, Aythya americana, discussed by Lokemoen (1966); and redwinged blackbirds, Agelaius phoeniceus (Godfrey 1966). Use of Typha marshes for ensilage i s suggested by Matveeva and Znamenskaya (1959). This use might prove b e n e f i c i a l to drought areas, but as yet remains untried. Any study of wetlands contributes to knowledge of a habitat too often ignored by e c o l o g i s t s . While i t i s impossible to consider a l l factors together, comparative information on water, s o i l , environment and vegetation have been c o l l e c t e d from p l o t s of Typha as well as other marsh dominants. Information gained w i l l o f f e r i n s i g h t into the r o l e of Typha within marsh communities, at the same time demonstrating that marshes are s p e c i f i c e n t i t i e s , and that within wetlands, Typha forms i t s own unique communities. 8 METHODS SELECTION AND TREATMENT OF VEGETATION Strands of many wetland plants, when growing vigorously, contain few species. A r b i t r a r y s e l e c t i o n of sampling areas was based p r i n c i p a l l y on s i z e of stand. Stands of Typha which were smaller than 500 sq. m. were considered too small f o r sampling. Samples of each species of vegetation, usually l e a f m a t erial (in Typha, inflorescence st a l k s and rhizomes), were c o l l e c t e d d i r e c t l y i n t o a i r - t i g h t weighing t i n s . Samples were weighed on a r r i v a l at the laboratory, a i r - d r i e d f o r at l e a s t 24 hours, and then oven-dried f o r 48 hours at 103 ± 2°C, at which time the samples were reweighed for moisture content determinations. Subsequent chemical analyses f o r calcium, magnesium, potassium, sodium, phosphorus and nitrogen were made, using a 5 g. oven-dry sample of the plant material which remained from the moisture content determination. Quantitative chemical methods were those of Jackson (1958), with the exception of phosphorus determinations for the seasonal studies of Typha and Phragmites, where the method followed was the method of Daniel and Neal (1967). Although the major dominant of the eastern Canadian marshes i s Typha  sp. , large stands of vegetation dominated by other species also occur. When present, such stands were also sampled. In smaller marshes, only one sample was taken, but very large marshes might have up to 20 samples taken through the marsh. In addition, a number of plots were selected f o r seasonal studies, and on these, sampling was continued throughout the growing season, with sampling occurring at regular i n t e r v a l s , usually twice a week. T o t a l number of samples studied was 590. Since marshes are one-, r a r e l y two-layered (herb and shrub l a y e r ) , a sub-layer designation of the herb layer was adopted, i n which the t a l l e s t l a y e r i s referred to as the Typha sub-layer (L-3), which at maturity, usually exceeds 150 cm and may reach 3m. Sub-layer 2 (L-2) contains those plants 9 which are growing i n the 50 - 149 cm height range, e.g., Scirpus validus and Impatiens b i f l o r a . Sub-layer 1 (L-l) contained erect, creeping or repent plants with mature heights of 49 cm or l e s s , e.g., Galium palustre. Where necessary a ground layer (G) was distinguished. Also delineated were f l o a t i n g -leaved hydrophytes, submerged hydrophytes such as Myriophyllum, Elodea and Ceratophyllum, as w e l l as f r e e - f l o a t i n g hydrophytes such as Lemna minor. ENVIRONMENTAL MEASUREMENTS (a) CLIMATOLOGICAL MEASUREMENTS TEMPERATURE. For each sample p l o t , a record of weather conditions was made, and where relevant, these are mentioned i n the discussion of data. Temperature was measured f o r the a i r above the p l o t , as w e l l as f o r the Typha sub-layer. LIGHT. Quantitative measurement of l i g h t was made i n each p l o t , using a Lange Mark III Luxmeter, which, with a lens cap change, sensed a range of 0 - 100,000 lux. A luxmeter i s s e n s i t i v e , so that most accurate readings are obtained on e i t h e r a cloudless or a completely overcast day. The following method of measurements was adopted. A l l readings were taken as close to mid-day as possible, beginning with an open sky measurement. Readings were then made within the vegetation sub-layers, at the 150, 100 and 50 cm l e v e l , as well as ground, water l e v e l and r e f l e c t e d l i g h t from water, where ap p l i c a b l e . This s e r i e s was followed by a further open sky reading. Each seri e s of vegetation readings was regarded as acceptable only when the two open sky readings checked within an a r b i t r a r y f i g u r e of 5 percent. Sub-layer readings were then expressed as a percentage of open sky readings, and averaged to obtain a f i g u r e of r e l a t i v e l i g h t r e l a t i o n s h i p s as expressed i n the tables. (b) WATER Where the sample pl o t was o v e r l a i n with a water lay e r , e i t h e r 10 standing or running, duplicate 500 ml water samples were c o l l e c t e d . One sample was used i n the f i e l d f o r determination of oxygen content using the Winkler method (Farber 1960). In studies l a t e r than the f i r s t season, a YSI Oxygen meter, c a l i b r a t e d against Winkler readings, was used for oxygen content determinations. The second sample was used i n the f i e l d f o r a pH determination, then immediately c h i l l e d and placed i n a portable freezer chest and removed to the laboratory. Analyses f o r magnesium, calcium, potassium, sodium, phosphorus and nitrogen were made, usually within 48 hours of c o l l e c t i o n , using methods described by Jackson (1958). Water temperatures were also recorded for each sample p l o t , (c) SOIL For each sample p l o t , s o i l temperatures were recorded, s t a r t i n g with a surface l e v e l measurement, and proceeding at 20 cm i n t e r v a l s to a depth of 80 cm, where s o i l and water permitted. The measuring device was a YSI Thermistor probe, a t h i n s t a i n l e s s s t e e l rod i n which was embedded a s e n s i t i v e thermocouple. The handle of the probe was not waterproof, so that where the s o i l was o v e r l a i n with water, usually only shallow s o i l depth readings could be made. Data were averaged by l e v e l s , for presentation i n the tables. A minimum of two s o i l cores was taken f o r each sample p l o t , where possible to a depth of 90 cm (far i n excess of the rooting depth of marsh species). Cores f o r the f i r s t sampling season were made with a s o i l tube, which with extensions, cored to a depth of 75 cm, and had an i n s i d e diameter of 2 cm. This corer proved u n s a t i s f a c t o r y , and a s p l i t - c o r e s o i l corer was designed, which would core a maximum of 100 cm (without extensions). I t had an i n s i d e diameter of 3.5 cm, and delivered not only an undisturbed sample of s o i l , but also a sample of water which overlay the s o i l . A l l subsequent sampling was made with t h i s instrument. Sample cores were placed i n clean p l a s t i c trays, stored i n a portable freezer chest and removed to the laboratory 11 for study. There the following records were made on the undisturbed cores: horizon depth, colour matching using Munsell colour chart for s o i l s (Munsell 1954), pH for each horizon, and an estimate of root penetration of the s o i l . In the f i e l d , samples were taken from each horizon, placed i n a i r - t i g h t weighing t i n s , and taken to the laboratory where moisture content determina-tions for the various horizons were made (sample weighed, then a i r - d r i e d , f i n a l l y reweighed a f t e r oven-drying for 48 hours at 103 ± 2°C). The sample cores from the f i e l d were placed i n a dark air-conditioned room to air^-dry, after which the samples were sieved with a 1 mm sieve, and prepared for further a n a l y s i s . Analyses for samples of the f i r s t f i e l d season were made by Mr. B. von Spindler of the S o i l Department of the Univ e r s i t y of B r i t i s h Columbia. A l l other samples were analysed at Carleton U n i v e r s i t y . Methods used for s o i l analyses were: organic matter, Walkley-Black method (Jackson 1958); nitrogen, micro-Kjeldahl (Jackson 1958); phosphorus (expressed as a v a i l a b l e phosphorus), a modified method of Bray and Kurtz (1945); magnesium, calcium, sodium and potassium, ammonium acetate extraction (Jackson 1958) , followed by analysis using the J a r r e l l - A s h atomic absorption spectrophotometer. P a r t i c l e s i z e was analyzed using the hydrometer method of Bouyoucos (1927, 1936). S o i l pH was measured with a Corning pH meter, using a s o i l s o l u t i o n (5:1) of d i s t i l l e d water and s o i l . A n a l y t i c a l r e s u l t s were averaged by horizons, provided that the horizons were comparable. If not, data were arranged as to s o i l type, and the s o i l c h a r a c t e r i s t i c s then expressed i n the tables. GENERAL CLIMATE OF MARSH COMMUNITIES AND ENVIRONS 13 GENERAL DESCRIPTION OF SAMPLING AREAS Sampling areas for the study consisted of selected marshy lands i n western Quebec and eastern Ontario, together with s i t e s near North Bay, and the large marshes at Long Point and Point Pelee National Park. Locations of the sampling areas are indicated i n Figure 1.* Quebec s i t e s . P l ots i n Quebec were a l l s i t e d i n the counties of Pontiac and Gatineau, which border the Ottawa River. P r i o r to settlement, natural vegetation of t e r r e s t r i a l communities was f o r e s t , and much forest p e r s i s t s . Major f o r e s t species of well-drained s i t e s are Acer saccharum Marsh., Fagus  g r a n d i f o l i a Ehrh., T i l i a americana L., Fraxinus americana L., Betula  papyrifera Marsh., Quercus b o r e a l i s Michx. f. and Populus tremuloides Michx. On d r i e r s o i l s , p r i n c i p a l f orest trees are gymnospermous, Pinus strobus L., Abies balsamea (L.) M i l l . , Pinus resinosa A i t . , P_. banks iana Lamb. and Picea glauca (Moench) Voss. On poorly drained s i t e s p r i n c i p a l gymnosperms are Picea glauca (Moench) Voss, P_. mar iana ( M i l l . ) BSP, L a r i x l a r i c i n a M i l l , and Thuja o c c i d e n t a l i s L., and the angiospermous trees are Fraxinus nigra Marsh, and the genera Ulmus, S a l i x and Populus. Most of the area l i e s i n the Laurentian Upland physiographic region and a narrow band i n the south l i e s i n the Ottawa Valley lowland. The r i v e r v a l l e y s and l a c u s t r i n e basins are 400 to 800 f t . above sea l e v e l . The Ottawa River v a l l e y r i s e s from 200 f t . above sea l e v e l at H u l l , Quebec, to 400 f t . above sea l e v e l at Chapeau. * Note: general d e s c r i p t i o n s , including l i s t of trees and temperature-p r e c i p i t a t i o n data have been compiled from the following references; H i l l s eit a l . 1944, Hoffman et a l . 1964, Hogarth 1962, Lajoie 1962, Canada Dept. of Transport 1967, Richards et a l . 1949. 14 The study area i s part of tke Ottawa River hydrographic basin, with r i v e r s flowing from west to east. In Gatineau and Pontiac counties, a l l r i v e r s entering the system flow from the north. In Gatineau county, the most important t r i b u t a r y i s the Gatineau River, s i t e of many of the Quebec sampling areas. Parent materials of s o i l s are underlain by Precambrian rocks, except i n the west and southwest where the shoreline i s underlain by Paleozoic formations. The Middle Ordovician Ottawa formation, c o n s i s t i n g mainly of limestone, i s prevalent west of H u l l , Quebec. In the v i c i n i t y of Norway Bay, another sampling area, the Lower Ordovician Beekmantown s e r i e s , mainly of limestone and dolomite, i s found i n small pockets. Surface deposits, which are the s o i l parent materials of much of the area, f a l l i nto several groups; g l a c i a l , f l u v i a l , marine and l a c u s t r i n e , a l l u v i a l and organic. Continental g l a c i e r s l e f t g l a c i a l t i l l of varying thickness, the t i l l c o n s i s t i n g of rock fragments and rock f l o u r . These t i l l s cover nearly a l l of the Laurentian Uplands. Deep t i l l s , derived from a c i d i c Precambrian rocks, are the basis of most of the upland s o i l s . G l a c i a l t i l l s have been washed and transported, and f l u v i o - g l a c i a l material has been deposited along the r i v e r v a l l e y s and the shores of the lakes and the sea that existed i n the Ottawa Valley at the close of the g l a c i a l period. Most of the o r i g i n a l deposits are buried under f i n e alluvium from 1 ^ 4 f t . t h i c k . Three main types of marine and l a c u s t r i n e clay may be recognized. In the d i s t r i c t , the thickest clays are marine, and these form the parent material for the Ottawa and Rideau s o i l s e r i e s . More recently, f i n e s i l t y alluvium i s s t i l l being deposited, and forms the basis of parent material for the shore communities of the study area. Temperature and p r e c i p i t a t i o n figures for lower Gatineau s i t e s have been obtained from the Chelsea, Quebec s t a t i o n , which i s close to the Figure 1. Map of eastern Ontario and part of western Quebec, showing locations of sampling areas. S p e c i f i c areas are numbered: 1 North Bay, 2 Taylor Lake, Quebec, 3 Cascades-Chelsea, Quebec, 4 Norway Bay, Quebec, 5 Ottawa d i s t r i c t , 6 P e r t h . d i s t r i c t , 7 Long Point, 8 Point Pelee. 16 sampling areas (note; a l l temperature^precipitation f i g u r e s , except where s p e c i f i c a l l y noted, are based on an average of 30 years data). They show the e s s e n t i a l cool (microthermal) climate of the d i s t r i c t and are shown i n Figure 2. Mean annual temperature i s 5.0°C, with average f r o s t - f r e e period (based on 22 years) of 154 days. Latest spring f r o s t has occurred on May 21 (heavy snow has occurred as l a t e as May 27) with average l a s t f r o s t May 7. Annual p r e c i p i t a t i o n i s 87.6 cm, with approximate equal d i s t r i b u t i o n between the periods May to October and November to A p r i l . The Norway Bay s i t e s l i e i n Pontiac county, Quebec, but the nearest meteorological s t a t i o n i s Renfrew-Sand Point, Ontario, about one mile distant on the shore of the Ottawa River opposite Norway Bay. Mean annual temperature i s 5.4°C, with mean annual p r e c i p i t a t i o n of 59.7 cm. D i s t r i b u t i o n of temper-ature and p r e c i p i t a t i o n by month for Norway Bay, i s shown i n Figure 3. Ontario s i t e s . Carleton county i s located on the south shore of the Ottawa River i n eastern Ontario. Here major r i v e r systems flow north into the Ottawa River. Most of the sampling areas l i e w i t h i n 100 miles of Ottawa, comprising the counties of Nepean, Gloucester, Carleton and Lanark. Under^ l y i n g bedrock i s c h i e f l y limestone and shale of Paleozoic age, with l o c a l outcroppings of Precambrian limestone. Bedrock, except for some l o c a l i z e d areas, i s covered with consolidated materials, mostly d r i f t . Comparatively small areas of the floodland along present stream and r i v e r courses, and l a r g e r areas of peat and muck formation, are of recent o r i g i n . The study area generally possesses waterlaid sediments, and within the area are p l a i n s of grey-brown clays and s i l t s , low i n lime, and d e l t a i c sand p l a i n s . Materials which make up the grey-brown clay plains were probably deposited by estuarian waters or i n channels of the Pre-Ottawa River and are mainly the s i l t s and clay which have been c a r r i e d down from the north. In the area, clay deposits are nearly 100 f t . t h i c k . D e l t a i c sand p l a i n s formed when the Pre-Ottawa River and other streams u, j l — — i ^ . . . . . . 1 , . 1 5 . 4 J f M A M J J A S O N Dj, J M O N T H S Figure 2. Graph of temperature-precipitation figures for Chelsea, Quebec (based on 30 years data). I J ' F M A M . J J A S O N D J -1 M O N T H S I Figure 3. Graph of temperature-precipitation figures for Norway Bay, Quebec (based on 30 years data). 18 emptied into the sea. The r i v e r , lengthening as the sea lowered, cut down one delta to b u i l d another at a lower l e v e l . Such a d e l t a formed and was p a r t i a l l y destroyed near Ottawa. When the Champlain Sea again receded, the Pre-Ottawa River cut a channel through these areas, leaving the clay p r a c t i c a l l y bare. Some of these old channels can be c l e a r l y seen on a e r i a l photographs of the Mer Bleue area which now supports enormous acreages of marsh and bog vegetation. The counties to the south and west of Ottawa have a cool humid climate, generally colder than that common to other lowlands i n Ontario. In Ottawa, mean annual temperature i s 5.3°C, and annual mean p r e c i p i t a t i o n i s 87.0 cm. An average of 228.6 cm of snow f a l l s annually. R a i n f a l l from the period of May to September (approximate growing season for t e r r e s t r i a l communities) i s 39.98 cm. Climate of the d i s t r i c t i s one of cold winters and warm summers. Temperature-precipitation figures appear i n the graphs of Figure 4. In the North Bay d i s t r i c t , climate i s more severe than at other s i t e s . Mean annual temperature i s 4.6°C, and mean annual p r e c i p i t a t i o n i s 86.3 cm. Water systems flow into Lake N i p i s s i n g to the west, and the Mattawa River, which flows east into the Ottawa River. Lakes are deep and the r i v e r s s w i f t . In numerous small lakes of the area, marsh vegetation merges with acid bog vegetation. T e r r e s t r i a l s o i l s o v e r l i e granite, and are'.mainly clay-loams and sandy-textured s o i l s , w e ll to poorly drained. Very acid conditions are common, and the land i s often stony. Temperature-precipitation figures for the d i s t r i c t appear i n Figure 5. Long Point Marsh i s contained i n the large peninsula which projects into the eastern part of Lake E r i e . Climate i s mild, with wet winters and moist, warm summers, the climate tempered by the lake environment. Mean annual temperature i s 8.2°C and mean annual p r e c i p i t a t i o n i s 81.4 cm. T e r r e s t r i a l s o i l s of Long Point belong to grey-brown podzolic and humic •• T E M P . ° C Figure 4. Graph of temperature - p r e c i p i t a t i o n figures for Ottawa, Ontario (based on average of 30 years data). T E M P . °C F M A M J J A S O N D J * " M O N T H S Figure 5. Graph of temperature - p r e c i p i t a t i o n figures for North Bay, Ontario (based on 30 years data). 20 T E M R ° C J F M A M J J A S O N D J M O N T H S Figure 6. Graph of temperature - p r e c i p i t a t i o n figures for Port Dover, Ontario, the s t a t i o n closest to Long Point Marsh (based on average, of 30 years data). - . Q I 1 1 1 1 1 1 1 1 » 1 J lt.4 I M O N T H S j 1 ; ( Figure 7. Graph of temperature - p r e c i p i t a t i o n figures for Leamington, Ontario, the s t a t i o n closest to Point Pelee Marsh (based on average of 30 years data). 21 g l e y s o l groups, and the s p e c i f i c s o i l series for Long Point, Brady, i s described as outwash sand with a limestone base. P r e c i p i t a t i o n and tempera-ture figures for Long Point are taken from the meteorological s t a t i o n at Port Dover, about one mile d i s t a n t from the marsh (Figure 6). Point Pelee marsh i s found i n Essex county, and projects into Lake E r i e at i t s western end. Essex county has the mildest climate i n Ontario, and the marsh represents the southernmost part of Canada. In recent times, the l e v e l of water of the Great Lakes has r i s e n , and the marsh has become a marsh of f l o a t i n g mats of Typha, with a l l other vegetation subordinate to the mat vegetation. O r i g i n a l l y Essex county was forested by a t y p i c a l C a r o l i n i a n f l o r a , but many species have become rare, although they s t i l l f l o u r i s h i n Point Pelee National Park, where the marsh i s situa t e d . Areas north of the park have had the marshland muck s o i l s drained, and the area has been given over to a g r i c u l t u r e . The growing season i n the area i s long, averaging 160 f r o s t - f r e e days. Mean annual temperature i s high for Ontario, 8.9°C, and mean annual p r e c i p i t a t i o n i s 73.2 cm. The area often has drought conditions during the summer months, although t h i s does not a f f e c t the marshes, which draw t h e i r water supply from Lake E r i e . Figure 7 presents temperature-precipitation figures for the Leamington meteorological s t a t i o n , the s t a t i o n closest to the marsh. 22 SITE EXPOSURE Wetlands a l l occupy lowlands, i n which accumulation of water (semi-stagnant, or even stagnant when eutrophic) i n moderate quantities i s one of the most important environmental parameters. Surrounding the marshes south of Ottawa, the crowns of the low h i l l s are covered with Populus tremuloides Michx., and the long slopes to the marsh are grass dominated to the border of the marsh, where hydric conditions allow the growth of alder, (Alnus rugosa). There i s l i t t l e wind protection, and maximum exposure to l i g h t (Typha species are shade i n t o l e r a n t ) . Along the Rideau River, s i t e s are protected by twenty-foot banks of a previous f l o o d - p l a i n , so that the marshes are shaded i n early morning or l a t e afternoon. Mid-stream a l l u v i a l bars, on which emergent vegetation grows abundantly, are f u l l y exposed. In the Perth area, s i t e s are protected by mixed deciduous forest to the water edge, so that a l l s i t e s receive p a r t i a l protection from wind damage. In the Norway Bay area, one marsh borders a clay-laden stream ( s i t e of extensive stands of S a g i t t a r i a l a t i f o l i a ) while the other i s i n the back-waters of a large bay, protected from d i r e c t storm damage by a seri e s of granite outcrops at the entrance to the bay. The three main s i t e s along the Gatineau River are from north to south: Cascades, Ramsay's Crossing and Blackburn's Creek. At Cascades, the marsh i s protected from the main current of the Gatineau River by a forested (Alnus rugosa) area on the north and east margins, and by r e s t r a i n t logs on the south and west margins. At Ramsay's Crossing, the north marsh i s protected on three sides by steep forested h i l l s . The south marsh i s s i m i l a r l y protected. Sites at Blackburn's Creek have forested slope a l s o , between which the small marsh-bordered creek flows into a sheltered bay.' 23 At Long Point, the marsh i s protected only by a sandy ridge, and by a s e r i e s of former beach ridges which penetrate the marsh. Here vegetation receives the force of storms which approach from an e a s t e r l y d i r e c t i o n o f f Lake E r i e . This i s the l a r g e s t freshwater marsh i n Ontario, and the only large one i n which Phragmites communis i s of any importance. The marsh at Point Pelee i s protected from Lake E r i e storms by a p a i r of sandy ridges on the west and.east margins, the two ridges coverging to a long sandy point (see Figure 12). Floating mats are common, but they are so extensive, and the vegetation so dense, that even during severe storms, there i s l i t t l e movement of the mats. Elevations are a l l l e s s than 400 f t . (121.9 m) above sea l e v e l . Latitude v a r i e s , from 42° at Point Pelee to more than 46° at North Bay. Longitude also v a r i e s , from 83° at Point Pelee to 76° at Ottawa. PLANTS AND PLANT COMMUNITIES 25 LIFE FORM SPECTRUM OF MARSHES A l l plants found on a l l quadrats are l i s t e d i n Appendix I. A table of the l i f e forms present may be seen i n Table I. Plants are c l a s s i f i e d according to the l i f e forms of Raunkier (Braun-Blanquet 1964). However, although the forms of Raunkier are we l l - s u i t e d to t e r r e s t r i a l h a b i t a t s , to be r e a l l y worthwhile for wetland habitats they have been expanded. The expansion of the terms i s outlined i n the next few sentences. Therophyta hydrophytica - annual plants with an aquatic h a b i t a t , e.g., Bidens cernua, Bidens frondosa. Hydrophyta natantia submersa - water plants which are f r e e - f l o a t i n g , but which f l o a t below the surface of the water, e.g., Ceratophyllum demersum. Geophyta rhizomatosa hydrophytica - aquatic geophyta rhizomatosa, e.g., Butomus umbellatus. Geophyta radicigemmata hydrophytica - aquatic geophyta radicigemmata, e.g., Cicuta b u l b i f e r a . Chamaephyta s u f f r u t i c o s a hydrophytica - aquatic chamaephyta s u f f r u t i c o s a , e.g., Solanum dulcamara. Chamaephyta equisetacea - aquatic equisetoid chamaephytes, e.g., Equisetum  hiemale. Nano-phanerophyta hydrophytica - aquatic nano-phanerophytes, e.g., Rosa  p a l u s t r i s . The table shows that the marshes are best characterized by hydrophyt rhizome-bearing geophytes (geophyta rhizomatosa hydrophytica), nearly 35 percent of the species found there belonging to t h i s group of plants. Q u a n t i t a t i v e l y , t h i s category includes those species (Phragmites, Typha and Scirpus) which form the major dominants of wetland h a b i t a t s , and further r e i n f o r c e s the p o s i t i o n i n marshes of geophyta rhizomatosa hydrophytica. TABLE I. LIFE FORM SPECTRUM - PERCENTAGE OF SPECIES Th 5.2 Th hy 10.2 Hy n 0.9 Hy n s 3.5 Hy ra 9.5 G rh 8.6 G rh hy 34.5 G r a 2.6 G r a hy 0.9 H 4.2 He 8.6 Hr 2.6 Ch s hy 1.6 Ch f 0.9 Ch e 0.9 NP 3.5 NP hy 0.9 MP 0.9 Legend: Th, therophyta; Th hy, therophyta hydrophytica; Hy n, hydrophyta natantia; Hy n s, hydrophyta natantia submersa; Hy r a , hydrophyta r a d i c a n t i a ; G rh, geophyta rhizomatosa; G rh hy, geophyta rhizomatosa hydrophytica; G r a , geophyta radicigemmata; G r a hy, geophyta radicigemmata hydrophytica; H, hemicryptophyta; He, hemicryptophyta caespitosa; Hr, hemicryptophyta rosulata; H r e , hemicryptophyta reptantia; Ch s hy, chamaephyta s u f f r u t i c o s a hydrophytica; Ch f, chamaephyta f r u t i c o s a ; NP, nano-phanerophyta NP hy, nano-phanerophyta hydrophytica; MP, macro-phanerophyta. 27 EVIDENCE OF HYBRIDIZATION AND INTROGRESSION IN TYPHA Eastern Canada possesses two species of Typha, T_. l a t i f o l i a and T_. a n g u s t i f o l i a . Wherever the two species overlap, the p o t e n t i a l i t y f or h y b r i d i z a t i o n i s strong, and many authors (Hotchkiss and Dozier 1949, Fernald 1950, Munz 1959) have considered the apparent f e r t i l e hybrid as a d i s t i n c t species, r e f e r r e d to as T_. glauca Godron. Indeed, most of the material which i s found i n eastern Canada can be more c l o s e l y r e l a t e d to plants with a series of characteristies.which l i e somewhere between the descriptions of 2L* l a t i f o l i a and T_. angustif olia.. Although any large marsh would have been equally s u i t a b l e for a study of the degree of i n t r o g r e s s i o n , a ser i e s of c o l l e c t i o n s was made i n the marsh at Point Pelee National Park, during the summer of 1970. This amounted to 614 samples of Typha, consisting of f l o r a l s t a l k and leaves, from 22 separate areas i n the large (2568 acres) marsh. A scoring system was designed, based on standard d e s c r i p t i v e c h a r a c t e r i s t i c s of the two "parent" species (Table I I ) . F l o r a l c h a r a c t e r i s t i c s were weighted so that t h e i r values were of equal weight with vegetative c h a r a c t e r i s t i c s i n the scoring of the hybrid index. T o t a l Population D i s t r i b u t i o n Figure 8 shows the hybrid index values for the t o t a l marsh sampling. The d i s t r i b u t i o n i s t y p i c a l of a population which i s introgressing following h y b r i d i z a t i o n , although the parental species are now poorly represented. Of the 614 i n d i v i d u a l scores, only seven were t y p i c a l of T_. l a t i f o l i a (Score 14 - 15). Thus the population i n the marsh represents a strongly i n t r o g r e s s i v e group, the majority of which may be placed i n the category of T_. glauca. There appear to be two and possibly three p r i n c i p a l scores i n the marsh as a whole. The main one, consisting of i n d i v i d u a l s of score 5, i s most common, followed by a second population containing i n d i v i d u a l s of score 8 and a t h i r d population containing i n d i v i d u a l s of score 10. The marsh then I I . CHARACTER EVALUATION FOR TYPHA SPP. HYBRID INDEX Character V a r i a t i o n Score Leaf Width 16 - 20 mm 0 12 - 15 mm 1 8 - 11 mm 2 4 - 7 mm 3 0 - 3 mm 4 Inflorescence Gap 0 mm 0 1 - 20 mm 1 21 - 40 mm 2 41 - 60 mm 3 61 - 80 mm 4 81 -100 mm 5 Bract of Female Flower Absent 0 Present 3 Pappus of Female Unclubbed 0 Clubbed 3 Stigmas Spatulate 0 Linear 3 Maximum index value -Minimum index value -18. T y p i c a l Typha a n g u s t i f o l i a 14 0. T y p i c a l Typha l a t i f o l i a 1 - 2 . 29 Figure 8. Frequency of hybrid index values for combined samples taken at Point Pelee. 30 contains few i n d i v i d u a l s of T_. l a t i f o l i a or T_. angustif o l i a , but i s instead t y p i f i e d by a group of i n d i v i d u a l s which show segregation of characters of the two parental populations. I t may be speculated that changing conditions of the environment are now s e l e c t i n g these i n d i v i d u a l s i n preference to the parental species, so that eventually new ecotypes may emerge. This preference f o r plants having c h a r a c t e r i s t i c s other than those of the parental species i s widespread. Peripheral vs. Non-peripheral D i s t r i b u t i o n of Individuals To t e s t whether the v a r i a b i l i t y of scores was of greater frequency i n the p e r i p h e r a l samples than i n the more established i n t e r i o r samples which did not border on open water, samples were grouped and plotted as peripheral and non-peripheral data. Here d i s t r i b u t i o n of the segregating types i n the non-peripheral graph (Figure 9) shows that the d i s t r i b u t i o n i n the established areas of the marsh i s l i m i t e d p r i n c i p a l l y to i n d i v i d u a l s of scores 5 and to a l e s s e r extent 8. By contrast, d i s t r i b u t i o n of the peripheral samples (Figure 10) shows two nearly equal peaks of i n d i v i d u a l s of scores 5 and 10, with a secondary peak con s i s t i n g of i n d i v i d u a l s of score 7. At l e a s t three scores predominate i n the p e r i p h e r a l d i s t r i b u t i o n , and other scores are w e l l -represented. Thus the populations of the i n t r o g r e s s i v e types are more l i m i t e d i n the non-peripheral habitats than i n the peripheral ones. The suggestion here i s that the p e r i p h e r a l h a b i t a t s , as newer ha b i t a t s , allow the expression of a wider v a r i e t y of types, whereas the non-peripheral habitats have, with t h e i r more stable environmental pressures, tended to se l e c t f or c e r t a i n i n d i v i d u a l s of p a r t i c u l a r scores. Area D i s t r i b u t i o n of Peripheral Samples The sample data include f i v e d i f f e r e n t bodies of open water within the marsh, and to determine whether the peripheral samples were behaving s i m i l a r l y for each body of water, the peripheral data were regrouped 31 SCORE NUMBER Figure 9. Frequency of hybrid index scores i n non-peripheral samples of Typha. TOTAL PERIPHERAL SAMPLES SCORE NUMBER Figure 10. Frequency of hybrid index scores among peripheral populations of Typha. 33 according to ponds. Figure 11 i l l u s t r a t e s the pond data. Although numbers of samples were small, comparison of the hybrid frequency d i s t r i b u t i o n suggests that the peripheral samples behave d i f f e r e n t l y along the borders of at l e a s t some of the ponds. A l l of the areas of the marsh have shown some r e a c t i o n to the recent high water l e v e l s on the Great Lakes, but shallow, r a p i d l y prograding ponds such as East and West Cranberry Ponds have continued to maintain a rapid growth. Here a l l scores are equally represented, as the populations move rap i d l y out into new open water hab i t a t s . The other ponds, p a r t i c u l a r l y Sanctuary and Redhead Ponds, have regressed under the high water conditions, so that the peripheral populations of previous years are missing e n t i r e l y , and the present peripheral populations are i n essence a part of the more stable non-peripheral communities of previous years. Big Pond, which has undergone some regression due to the high water, has again begun to prograde, and the graph shows the two d i s t i n c t segregants (5 and 8) of the stable non-p e r i p h e r a l h a b i t a t s , plus a s e r i e s of small numbers of i n d i v i d u a l s with other scores. Here there are two trends operating, the f i r s t ( s t a b i l i z a t i o n ) indicated by the two major scores, over which i s superimposed a second trend of a new s e r i e s of progression and competition ( c o l o n i z a t i o n ) , represented by the wide d i s t r i b u t i o n of other scores. Area D i s t r i b u t i o n of Non-peripheral Samples After a l l of the o r i g i n a l 22 sample areas were graphed, data s i m i l a r i t i e s allowed the marsh to be condensed into 8 "geographic" areas. In each, behaviour of the scores serves as an i n d i c a t o r of the d i f f e r e n t environmental pressures acting upon the segregants (Figures 12, 13a, 13b). Area I, with i t s two main scores plus a weaker representation of others indicates an area of rapid ecesis, which has only recently become non-peri p h e r a l . Area II has s i m i l a r i t i e s to Area I, but i s of more recent o r i g i n , since the many scores are more equal i n d i s t r i b u t i o n , so that Figure 11. D i s t r i b u t i o n of scored i n d i v i d u a l s of peripheral Typha around i n d i v i d u a l ponds at Point Pelee. 35 competition among diff e r e n t - s c o r e d i n d i v i d u a l s i s s t i l l strong. In Area I I I , competition has been among different-scored i n d i v i d u a l s i n the past, and some are s t i l l represented, but the population i s beginning to s t a b i l i z e , with i n d i v i d u a l s of score 5 predominating. Area IV i s more or l e s s s t a b i l i z e d with i n d i v i d u a l s of score 5, and i t i s an area where succession to plant communities of Decodon v e r t i c i l l a t u s i s taking place. Area V indicates a trend toward s t a b i l i z a t i o n , although sorting of the i n d i v i d u a l s of d i f f e r e n t scores i s s t i l l occurring. In Area VI, s t a b i l i z a t i o n i n v o l v i n g i n d i v i d u a l s of scores 5 - 6 i s occurring, with i n d i v i d u a l s of other scores reduced i n numbers. Area VII, unlike most of the other areas, i s becoming s t a b i l i z e d with i n d i v i d u a l s of score 3, a plant type which most c l o s e l y resembles Typha  l a t i f o l i a . T_. l a t i f o l i a tends to occupy the shallower more t r a n s i t i o n a l marshy areas, and indeed Area VII i s i n t h i s state of swamp-forest t r a n s i t i o n . Area VIII, though shallow, continues to show the e n t i r e range of scores, suggesting that for Typha, i t i s one of the more recent habitats i n the marsh. Thus we have i n t h i s large marsh, as i n most of the eastern marshes, a complex of segregating i n d i v i d u a l s of the genus Typha, with i n t r o g r e s s i o n allowing a s e r i e s of continuous v a r i a t i o n s i n between the two parental species, T_. l a t i f o l i a and T_. angustif o l i a . In time, with habitat s e l e c t i o n operating, populations of some i n d i v i d u a l types may develop and maintain themselves. However, since the marsh habitat i s always unstable, a l l segregants i n the population are usually represented i n close proximity. Introgression i n Point Pelee Marsh i s by no means a unique phenomenon, wherever these two species are d i s t r i b u t e d together, and f r e e l y interbreed to form f e r t i l e hybrids, i t becomes d i f f i c u l t to separate species. A c t u a l l y , the populations are behaving together as though the two species were only the opposing extremes of a si n g l e large population, which thus can be considered l o c a l l y simply.as the genus Typha. 36 Figure 12. Map of Point Pelee Marsh, showing d i s t r i b u t i o n of non-peripheral areas. The marsh i s bordered on the north by a dike, which separates the marsh from a g r i c u l t u r a l lands. I t i s bordered on the west, east and south by Lake E r i e , from which i t i s separated by a serie s of beach ridges. Shaded areas indicate bodies of open water within the marsh. Figure 13b. D i s t r i b u t i o n of hybrid index scores i n d i f f e r e n t non-peripheral areas of Point Pelee Marsh. 39 CATEGORIES OF TYPHA COMMUNITIES In eastern Canada, Typha forms stands which extend over large portions of wetland areas. However, species other than Typha can also form large stands, and wherever large communities based on other species were found, samples from these communities were also taken. This procedure was followed so that the r e l a t i o n s h i p between Typha and other communities might be kept r e l a t i v e . A plot s i z e of 36 sq. m. has proved useful f o r autecological information concerning Typha and other species of the wetlands. I f the Typha communities were to be formally c l a s s i f i e d , they would belong (according to Zurich-Montpellier methodology) to the order Phragmitetalia (Koch 1926), which includes a l l reedswamp associations. These groups a l l develop i n shallow waters, which range from 0 - .1.5 m i n depth. Thus, they tend to range from the shorelines of open waters and the water-saturated zones around ponds to the aquatic associations with which they intermingle. They are best developed i n eutrophic waters, and imperfectly i n o l i g o t r o p h i c waters. The c h a r a c t e r i s t i c species of the order i n Europe, as described by Koch, are the following: Equisetum f l u v i a t i l e , Ranunculus lingua, Rorippa amphibia, Oenanthe aquatica, Alisma plantago- aquatica and I r i s pseudacorus. Of these, only Alisma plantago^-aquatica and Eguisetum f l u v i a t i l e are found i n the study area, the other species being l i m i t e d e s s e n t i a l l y to Europe. The a l l i a n c e to which the Typha communities would belong i s the Phragmition. In Europe, c h a r a c t e r i s t i c plants of the a l l i a n c e are S a g i t t a r i a s a g i t t i f o l i a , G l y c e r i a aquatica, Phalaris arundinacea, Acorus  calamus and Typha a n g u s t i f o l i a . Of these, only the l a s t three are common to the marsh habitats of eastern Canada. In European c l a s s i f i c a t i o n , the closest a s s o c i a t i o n to which Typha communities would belong i s the Scirpo-Phragmitetum. For t h i s a s s o c i a t i o n , 40 c h a r a c t e r i s t i c species are Scirpus l a c u s t e r , Typha l a t i f o l i a , Sparganium  ramosum, Rumex hydrolapathum, Sium l a t i f o l i u m and Butomus umbellatus. Of these, only Typha l a t i f o l i a and Scirpus v a l i d u s , which i s considered by some taxonomists to be a subspecies of S_. la c u s t e r , are native to Canada. Butomus  umbellatus i s , however, present, and i s becoming r e l a t i v e l y common to wetland habitats of eastern Canada, although i t i s a native of Europe. For North America, Conard (1952) has c l a s s i f i e d a Typhetum, together with a Scirpetum v a l i d i , a Phragmitetum communis, a Zizanietum aquaticae and a Spartinetum pectinatae, suggesting that i n North America the associations involving these dominants are probably more d i s t i n c t than they are i n Europe. Within the Typha communities of t h i s study, while not formally recognized as a subassociation of a Typhetum, three d i s t i n c t groups or types emerge, which because of t h e i r d i s t i n c t n e s s , are used as sub-categories within the framework of the study. They are: the Typha communities which form nearly pure stands; the Typha-Sagittaria communities; the Typha-Galium communities. The f i r s t group (Figure 14), where nearly pure stands of Typha occur, i s found on the margins of bodies of running water, extending to a depth of a metre or more, and i s usually rooted i n a compacted substrate of mineral s o i l (alluvium). Here only Typha grows, and i t i s eit h e r T_. angustif o l i a or T_. glauca, since T_. l a t i f o l i a was not found i n any of the samples. pH le v e l s of s o i l substrate tend to a l k a l i n i t y , and the s o i l substrate i s possibly of l e s s importance than i s the f a c t that the continuous passage of water, always laden with a small but s i g n i f i c a n t amount of nutrie n t material, passes through the communities. The stands are often rather open, and l i g h t conditions approximate those of the open sky. Where the waters are slow^-moving, one finds species such as Lemna minor, L_. t r i s u l c a and Hydrocharis  morsus-ranae, which are f a i r l y evenly d i s t r i b u t e d among a l l emergent aquatic communities i n the study area. 41 The second group (Figure 15, 16) i s represented by the Typha- S a g i t t a r i a community. It occupies a shallower portion of the aqueous habitat, where the waters are slow-moving, but where the s o i l substrate i s ov e r l a i n by water at a l l times of the year. Major species here are Typha  a n g u s t i f o l i a , T_. glauca and S a g i t t a r i a l a t i f o l i a . Other species which are f a i r l y t y p i c a l but of les s common occurrence are Pontederia cordata, Butomus  umbellatus and Sparganium eurycarpum. B a s i c a l l y t h i s community i s two-layered, with the Typha growing i n close association with shade-adapted forms of species which may also form t h e i r own communities outside the Typha community (Figure 17). Here the communities are formed where pH i s s l i g h t l y a l k a l i n e to ne u t r a l , and water oxygen content i s lower than that found i n the previous group. The s o i l s are a l l of deposited materials, sometimes o v e r l a i n with a thin layer of organic material. Nutrients are supplied by t h i s substrate, and are also contributed by the waters which continue to c i r c u l a t e , though slowly, through the communities. The t h i r d group i s t y p i f i e d by communities of Typha-Galium (Figure 18). Here the communities are found on the shallow waters, and p a r t i c u l a r l y i n areas where the s o i l becomes s e m i - t e r r e s t r i a l , although the s o i l s remain water saturated at a l l times. The communities therefore can be found on the margins of running streams and large lakes, or on the margins of ponds and i n shallow depressions where run-off provides continuous moisture. T y p i c a l species present are Typha l a t i f o l i a , T_. a n g u s t j f o l i a , T_. glauca, Galium  palustre, Cicuta b u l b i f e r a , Sium suave, Lysimachia t e r r e s t r i s , G l y c e r i a  canadensis, Impatiens b i f l o r a , Triadenum virginicum and Rorippa i s l a n d i c a . Since the waters over the s o i l of these communities can become very shallow or even lacking at c e r t a i n times of the year, the opportunity occurs for more species to invade, adapted to s e m i - t e r r e s t r i a l habitats; Thus one finds that the communities tend to be more mixed, and plants of a more t e r r e s t r i a l type may often be found. Such communities are i n a p o s i t i o n to receive seeds Figure 14. Hydric portion of the Typha community. T. glauca stand, Long Point, July, 1969. Figure 15. Two-layered portion of Typha community with T_. glauca and S a g i t t a r i a l a t i f o l i a . Tay River, September 7, 1967. Figure 17. S a g i t t a r i a l a t i f o l i a community. Norway Bay, August 29, 1967. 44 Figure 18. I n t e r i o r view of a s e m i - t e r r e s t r i a l Typha community. Ramsayville, September 15, 1967. 45 of one or more successional species, and i t i s from such communities that succession to a more t e r r e s t r i a l community type occurs. Here the s o i l i s the all-important supplier of n u t r i e n t s , since the water simply r i s e s above the s o i l surface, or subsides below i t , and as such i t functions mainly as an extension of the s o i l s o l u t i o n . pH v a r i e s widely, but tends to become acid toward the end of the growing season. The s o i l s vary from Rego Humic Gleysols to Organic s o i l s , but they always have some overlay of organic material. Floating mats (Figure 19) represent a variant of the s e m i - t e r r e s t r i a l category of Typha community. They are formed under high water l e v e l s when ent i r e mature Typha communities, together with a part of the organic horizon, r i s e to the water surface. They are water-saturated and maintained by the buoyancy provided by the aerenchyma systems of the plants. Such communities must depend heavily upon nutrient supplies a v a i l a b l e from the water i n which they f l o a t . The aqueous substrate may be acid or a l k a l i n e . When a c i d , these communities may support bog f l o r a i n addition to Typha, however usually the f l o r a i s s i m i l a r to s e m i - t e r r e s t r i a l Typha communities, but l i m i t e d i n numbers and depauperate. Floating mats have been discussed separately i n the study. One point regarding marsh communities must be stressed, and t h i s point i s strongly emphasized by most wetland researchers (Hejny 1961, Hartog and Segal 1964, Sculthorpe 1967, Haslam 1971). Rate of growth of i n d i v i d u a l species i n wetlands i s quite phenomenal, and huge monodominant (Haslam 1971) stands are to be expected wherever a species secures a point of c o l o n i z a t i o n . There are probably no r e a l p a r a l l e l s to t h i s s i t u a t i o n anywhere i n t e r r e s t r i a l communities. Thus, vigorously growing marsh communities may have few species other than the actual dominant. Examples of some major stands are i l l u s t r a t e d by Figures 20 - 24. They are Phragmites communis (Figure 20), Scirpus 46 Figure 19. Floating mat community of Typha l a t i f o l i a . Bog f l o r a i s also present. Taylor Lake, September 5, 1967. Figure 2 0 . Phragmites communis community. Point Pelee, August, 1969. 47 Figure 22. Zizania aquatica community. Long Point, July, 1969. Figure 23. Scirpus validus community. Long Point, J u l y , 1969. Figure 24. Eupatorium maculaturn community. Blackburn's Creek, August 20, 1967. 49 americanus (Figure 21), Zizania aquatica (Figure 22), Scirpus validus (Figure 23) and Eupatorium maculatum (Figure 24). Other examples include stands of Nuphar advena, Calamagrostis canadensis, Carex l a c u s t r i s , Decodon  v e r t i c i l l a t u s , J u s t i c i a americana, Pontederia cordata, S a g i t t a r i a l a t i f o l i a , S_. r i g i d a , Sparganium eurycarpum. ADVENTIVES IN THE MARSH COMMUNITY Special mention should be made of four species, which though present i n low numbers or even absent from most parts of Canada, are becoming common i n eastern Canada i n wetland areas. A l l are adventives from Europe. Of these, Lythrum s a l i c a r i a (Figure 25a), long established, was not found on plots with Typha, although i t i s to be expected. It i s found commonly i n ditches and disturbed wetlands, but as yet has not infr i n g e d upon n a t u r a l l y occurring Typha communities. I t i s very abundant i n both the Ottawa and Montreal d i s t r i c t s , and i s now present as far west as Toronto, having spread from Montreal along our inland waterways. Butomus umbellatus (Figure 25b), the second species, was recorded for the f i r s t time i n Canada i n 1905 (Marie-Victorin 1964), and i s found i n Typha stands. It i s also found i n communities which i t dominates. Epilobium hirsutum (Figure 25c) i s found l o c a l l y i n mixed communities on moist substrates. I t has not been found i n Typha stands, but. one large community of Epilobium hirsutum, found on a moist slope above a Typha stand, was sampled. L a s t l y the aquatic Hydrocharis  morsus-ranae (Figure 25d) was introduced only i n 1943 (Dore 1968) , but has maintained such rapid growth along the Rideau and Ottawa River waterways that i t i s ra p i d l y changing the appearance of the aquatic communities i n the area. Like a l l f l o a t i n g aquatics, i t finds i t s way into purely aquatic stands of Typha. A l l four of these species are spreading so r a p i d l y that there i s l i t t l e doubt that a l l w i l l eventually change the nature of parts of the 50 wetland communities i n eastern Canada. PROVENANCES, AND HEIGHT AT MATURITY Importance of l o c a l i t y and other factors on growth of Typha i s i l l u s t r a t e d by the bar graph i n Figure 26, while the factors are presented as a summary i n Table I I I . Considerable v a r i a t i o n i n growth pattern i s seen, and height appears to be governed by l a t i t u d e , as well as other s i t e c h a r a c t e r i s t i c s . Heights are based on measurements taken a f t e r J u l y 1 of any study year, since Typha growth has slowed by that time. Rideau River plants have been grouped with those of Ramsayville, because they are both from the immediate v i c i n i t y of Ottawa, and are of the same l a t i t u d e and roughly the same i o n i c content i n substrates. Excepting Point Pelee provenance, we see that height i s correlated d i r e c t l y with the following f a c t o r s : l a t i t u d e (shortest plants at the most northerly l a t i t u d e s , t a l l e s t plants at the most southerly l a t i t u d e s ) ; pH (a c i d i c provenances have shorter plants than the a l k a l i n e ones); nutrient content (lower concentrations of nutri e n t ions show the smaller growth response); species d i s t r i b u t i o n (neither Typha glauca nor T_. a n g u s t i f o l i a extends to the more northerly s i t e s ) . No d i r e c t c o r r e l a t i o n appears between height and longitude, nor degree of exposure and longitude, although the height of the Long Point plants may be reduced s l i g h t l y because of open marsh exposure to Lake E r i e storms. Considering Point Pelee provenance with the others, one sees c l e a r l y the s i g n i f i c a n c e of the rooting medium of Typha. Heights of the Gatineau provenance include a few s i t e s which were on f l o a t i n g mats, together with many plants which were rooted on water-saturated s o i l substrates. A l l other provenances except Point Pelee have the plants rooted i n s o i l . Point Pelee, which ought to have very t a l l Typha, a l l factors other than rooting medium considered, has stands which are based e x c l u s i v e l y on f l o a t i n g mats. Not 51 Figure 25a. Lythrum s a l i c a r i a . Figure 25b. Butomus umbellatus. Figure 25c. Epilobium hirsutum. Figure 25d. Hydrocharis morsus-ranae. Figure 25. European adventives. A l l four have been introduced into eastern Canada. 4 0 0 Figure 26. Bar graph of average heights of Typha measured i n the d i f f e r e n t d i s t r i c t s of the study. Upper and lower bars indi c a t e maximum and minimum heights. TABLE I I I . FACTORS CONCERNED WITH HEIGHT IN TYPHA Provenance Comparative Height pH Rooting Condition Nutrient Content Latitude Order N-S Longitude Order E-W Extreme* Exposure Species North Bay + shortest 3-7 s o i l **medium 1 4 no l a t i f o l i a Gatineau 3-7 s o i l low 2 1 no a l l species Point Pelee 7-9 f l o a t i n g high 7 7 no a l l species Ramsayville 7-9 s o i l high 4 2 no a n g u s t i f o l i a & glauca Norway Bay 7-9 s o i l high 3 3 no glauca Long Point 7-9 s o i l high 6 6 yes glauca & l a t i f o l i a Tay River t a l l e s t 7-9 s o i l high 5 5 no glauca * i n the sense presented i n the discussion of s i t e exposure. + see Figure 26 for heights. p a r t i c u l a r l y low i n calcium (see Table X I I ) . 54 TABLE IV. MAXIMUM HEIGHT IN M. OF MATURE PLANTS Sit e Species cn CO a CU cd •u •u •H CD CO es CD ctf •u M •H •H 3 CD CO ft ct) 4J e •u 4-> 3 •H rH •H •H CO rJ M rH cd Cd cd CO cu W J3 c P i 1 1 p-. H Cfl cd cd 1 ,G x; p. P- a o i> >i Z H H CO 4-1 cd 60 c •H 4-) cd o cd I Acorus calamus 1.05* - 1.05 1.00 — Alisma plantago-aquatica 0.70* - 0.70 0.64 -Butomus umbellatus 1.00* - 0.98 - -Dulichium arundinaceum 0,69* - 0.40 -Eupatorium maculatum 1.40* - - 1.50 -G l y c e r i a canadensis 1.10* - - 1.15 -Impatiens b i f l o r a 0.78* 0 .80 - 0.45 -Juncus effusus 1.13* - - 0.89 -Onoclea s e n s i b i l i s 1.00* - - 0.47 -Phalaris arundinacea 1.50* - 1.05 1.07 -Phragmites communis 2.81* 1 .82 - -S a g i t t a r i a l a t i f o l i a 0.72* - 0.76 0.40 -Scirpus cyperinus 1.50* - - 1.08 Scirpus f l u v i a t i l i s 1.49* 1 .60 - 1.35 -Scirpus validus 2.38* 2 .31 - 1.20 Typha a n g u s t i f o l i a 1.65 1 .80* 2.45* 2.38* -Typha glauca 1.91 3 .00* 2.60* 2.90* 3.00* Typha l a t i f o l i a 2.80 2 .30* 2.30* 1.93* 1.81* Scirpus atrovirens 0.92 - - 1.00 -Bidens cernua 0.68 - - 0.50 -Lysimachia t e r r e s t r i s 0.47 - - 0.77 -Sium suave • 1.00 - - 0.64 -. Cicuta b u l b i f e r a 0.60 - 0.55 0.38 Pontederia cordata 1.63 - 0.95 - -Triadenum virginicum 0.25 - - 0.30 0.38 Galium palustre 0.37 - - 0.36 -* indicates s i t e s dominated by the species. 55 only are the mats i n constant motion, but also instead of r e c e i v i n g nutrients from a r e l a t i v e l y r i c h s o i l s o l u t i o n , the plants are receiving nutrients through the f l o a t i n g mat, e s s e n t i a l l y from a very d i l u t e nutrient medium. Reduction i n height of t h i s provenance provides a demonstration of the value of a stable rooting medium, other than for simple anchorage. A table of heights at maturity based on Typha-dominated and other s i t e s i s presented i n Table IV (see also Figures 27, 28). Maximum heights are expressed here, the r e s u l t of measuring the height of each species each time that i t occurred i n the p l o t s . The table shows that marsh dominants make t h e i r t a l l e s t growth on the s i t e s which they themselves dominate. A l l forms of Typha have poorer growth i n the Typha-Galium communities, where water and nutrient conditions are most v a r i a b l e , although T_. glauca communities appear to have greater adaptation for a wider range of conditions than do i t s parent species. T_. l a t i f o l i a appears to be the only species of Typha which i s able to grow with other species as dominants, but even then growth i s poorer, and the plants are sparse. Also reproduction on such s i t e s i s only vegetative. It becomes obvious from Table IV that i n terms of height alone, Typha has few competitors among marsh species, with the exception of Phragmites  communis, and t h i s species i s so uncommon i n the area as to o f f e r few problems i n terms of competition for h a b i t a t . The other species nearest i n height at maturity are Scirpus f l u v i a t i l i s (Figure 28a) , S_. cyperinus (Figure 29b), _S_. validus (Figure 29c) and Phalaris arundinacea, a l l of which may be overtopped by Typha (Table III) should competition occur for a new habitat. Yet with the exception of Phragmites, a l l of these species are abundant i n eastern marshes. Growing uniformly on a l l s i t e s on which they are found are Acorus  calamus (Figure 30a), Butomus umbellatus, Typha glauca and G l y c e r i a canadensis (Figure 29d). Species which grow better when they dominate a s i t e and less well when they are subordinate to other species are Phalaris arundinacea, Dulichium arundinaceum (Figure 30d), Impatiens b i f l o r a , Onoclea  s e n s i b i l i s , Phragmites communis, Scirpus f l u v i a t i l i s , S^  validus , Typha  l a t i f o l i a and T_. angustif o l i a . The minor species, which do not dominate any s i t e , show some v a r i a b i l i t y i n height, r e s u l t i n g from l i g h t conditions and the modification of substrate imposed upon them by the dominant members of the communities i n which they grow. These are Bidens cernua, Lysimachia  t e r r e s t r i s , Sium suave, Cicuta b u l b i f e r a , Triadenum virginicum and Galium  palustre. S a g i t t a r i a l a t i f o l i a , a sturdy species of the open marshes, appears to have s u f f i c i e n t e c o l o g i c a l amplitude to grow equally well both as a dominant and as a subordinate species i n Typha communities. It appears to t o l e r a t e reduced l i g h t conditions so w e l l that growth i s l i t t l e changed i n f u l l sunlight or under conditions of p a r t i a l shade (Figures 16, 17). I l l u s t r a t i o n s of some of the p r i n c i p a l species of the marshes, many of which dominate s i t e s i n the marsh, appear as Figures 27 - 30. 57 Figure 27a. Typha l a t i f o l i a . Figure 27b. Typha glauca. Figure 27c. Typha a n g u s t i f o l i a Figure 27d. Typha glauca. Figure 27. Herbarium specimens of Typha taken from plots on which i t was dominant. 58 Figure 28a. Scirpus f l u v i a t i l i s . Figure 28b. Typha glauca, Figure 28d. Typha a n g u s t i f o l i a . Figure 28c. Typha l a t i f o l i a , f l o a t i n g mat population. Figure 28. Herbarium specimens of species from plo t s on which they were dominant. 59 Figure 29a. Juncus effusus. Figure 29b. Scirpus cyperinus. Figure 29c. Scirpus v a l i d u s . Figure 29d. G l y c e r i a canadensis. Figure 29. Herbarium specimens of species taken from plots which they dominated. Figure 30a. Acorus calamus. Figure 30b. S a g i t t a r i a r i g i d a . Figure 30c. Scirpus americanus. Figure 30d. Dulichium arundinaceum. Figure 30. Herbarium specimens of species taken from plot on which they were dominant. 61 IONIC COMPOSITION OF LEAVES OF MARSH SPECIES Seasonal uptake studies of both Typha and Phragmites (Section IV) show that v a r i a t i o n i n i o n i c content over seasonal growth i s to be expected i n marsh species. These changes i n uptake and accumulation coincide with demand made by the species during periods of slow as well as accelerated growth. As such, Typha and Phragmites are the only two species which were studied i n a complete spectrum of uptake over a season. However, i n the random plo t sampling, l e a f material was sampled f o r species occurring on each p l o t , so that a representative spectrum (though not so complete), was a v a i l a b l e for most of the species found i n the study. They provide compar-at i v e information regarding the requirements of i n d i v i d u a l species, as compared with Typha and Phragmites. In a l l species l i s t e d , the average i s backed by at least ten readings. Ranges and standard deviations are not useful here, since the seasonal v a r i a b i l i t y of such measurements are already understood. Thus, the measurements t e l l the reader simply what the compar-ativ e values are of one species compared with another. Also when such numbers are a v a i l a b l e , the basic requirements of the species for substrate nutrients becomes s i g n i f i c a n t . There are few studies on which to base accumulation of ions by marsh species. Standards here are based on the seasonal performances of Typha  glauca as compared with Phragmites communis. For instance, with calcium content, r e l a t i v e to a l l species tested, Typha ( a l l species) i s a "moderate accumulator" while Phragmites i s a "high accumulator". Given s i m i l a r environments, d i f f e r e n t species probably react d i f f e r e n t l y i n th e i r patterns of i o n i c accumulation. Such differences are inherent i n the species. Data of nutrient accumulation of d i f f e r e n t species are shown i n Table V. Compared with other genera, Typha glauca and T_. l a t i f o l i a contain 62 calcium i n the medium range of values, while T_. a n g u s t i f o l i a has a much lower (only about ha l f as much) quantity of calcium i n the l e a f m aterial. High accumulations of calcium occur i n true aquatics, such as Lemna minor, L. t r i s u l c a and Potamogeton p e r f o l i a t u s , together with Decodon v e r t i c i l l a t u s , Nuphar advena and one species found i n the Typha-Galium communities, Cicuta  b u l b i f e r a . Many species that form dominant stands appear to be low accumulators of calcium, i n p a r t i c u l a r Dulichium arundinaceum, Phalaris  arundinacea, Agrostis s t o l o n i f e r a , Lysimachia t e r r e s t r i s , Onoclea s e n s i b i l i s , Z i z a n i a aquatica, Juncus effusus and most species of Scirpus.. Only Scirpus  validus and S_. americanus appear to be moderate accumulators of calcium. This low or moderate calcium requirement may operate as a factor i n successful competition with Typha for substrates i n many parts of eastern Canada, substrates which are b a s i c a l l y low i n calcium, mainly because of t h e i r pre-Cambrian o r i g i n s . A notable exception for calcium requirment i s the high requirement of Phragmites communis. This may be one of the reasons why Phragmites i s r e l a t i v e l y uncommon i n many of the study areas. In magnesium accumulation, again Typha has r e l a t i v e l y moderate accumulation. T_. a n g u s t i f o l i a has the highest percentage, T_. l a t i f o l i a the lowest, and T_. glauca the intermediate. Many marsh species take up le s s magnesium than Typha, p a r t i c u l a r l y Calamagrostis canadensis, Scirpus  cyperinus, Carex l a c u s t r i s and Zizania aquatica. Some aquatics, Lemna minor and L_. t r i s u l c a , accumulate large amounts of magnesium r e l a t i v e to Typha, while R i c c i a f l u i t a n s , also a f l o a t i n g aquatic, contains only 0.08%. P o t e n t i l l a p a l u s t r i s , Pontederia cordata and Nymphaea odorata, together with Chamaedaphne calyculata and Myrica gale accumulate small amounts of magnesium. Re l a t i v e l y large amounts of magnesium are accumulated by both Scirpus  f l u v i a t i l i s and Phragmites communis, so again, these species probably have some d i f f i c u l t y competing with Typha on magnesium-poor s i t e s . 63 Only four species take up sodium i n larger amounts than Typha, namely Lemna t r i s u l c a , Nymphaea odorata, Onocles s e n s i b i l i s and Galium palustre. Of these, the f i r s t two are t y p i c a l l y aquatic, while the other pair inhabit shaded acid s o i l s . Of the three species of Typha, only T_. angustif o l i a shows a high sodium content i n l e a f material, about equal with Scirpus f l u v i a t i l i s and S a g i t t a r i a r i g i d a . In the main, sodium values are low i n the substrates, and i t i s u n l i k e l y that many marsh species can accumulate large amounts of sodium without harm to the t i s s u e s . Typha, however, appears to accommodate considerable amounts of sodium within i t s t i s s u e s , a possible reason why i t tolerates r e l a t i v e l y s a l t y s o i l s so s u c c e s s f u l l y (McMillan 1959) . Potassium i s not present i n large amounts i n any of the marsh s o i l s , but many marsh species appear to take up and accumulate large amounts. A l l three species of Typha contain potassium i n moderate amounts, about 1.3%, as do the majority of other species. Some plants which tend to occupy acid substrates, Alnus rugosa, Myrica gale and Thelypteris p a l u s t r i s , appear to accumulate le s s potassium. However, many species accumulate potassium far i n excess of the Typha requirement. These are S a g i t t a r i a l a t i f o l i a , P o t e n t i l l a p a l u s t r i s , Sparganium eurycarpum, Pontederia cordata, Impatiens b i f l o r a , R i c c i a f l u i t a n s , Scirpus rubrotinctus, Sium suave and Nuphar advena. Each can be found i n and near the Typha communities. Nitrogen l e v e l s vary greatly i n plant material. In Typha, highest content (1.13%) i s found i n T_. angustif o l i a , followed i n order of decreasing content by T_. l a t i f o l i a and T_. glauca (0.62%). Very low accumulations of nitrogen are found i n Chamaedaphne cal y c u l a t a (0.06%), a marginal marsh species, occurring mainly i n bogs, Galium palustre (0.19%), R i c c i a f l u i t a n s (0.32%) and Thelypteris p a l u s t r i s (0.06%). Nitrogen content r e l a t i v e l y higher than that found i n Typha occurs i n Impatiens b i f l o r a , I r i s v e r s i c o l o r , Lemna t r i s u l c a , Lysimachia t e r r e s t r i s , P h a l a r i s arundinacea, S a g i t t a r i a 64 l a t i f o l i a , S_. r i g i d a , Scirpus v a l i d u s , EL rubrotinctus, S^. americanus, Sparganium eurycarpum, Phragmites communis and Juncus effusus. The r a t i o of nitrogen to phosphorus i n commercial crops has been l i s t e d as approximately 5:1 (Fried and Broeshart 1967), although there i s a degree of v a r i a b i l i t y i n the f i g u r e s . This r a t i o does not seem to apply to marsh species, many of which show r a t i o s of the two nutrients which more nearly approximate a r a t i o of 1:1 (water a n a l y s i s , though v a r i a b l e through the season, shows N/P r a t i o s between 20:1 and 10:1, except for the Rideau River and Point Pelee s i t e s , where the r a t i o approaches 1:1). Of i n t e r e s t i s the content of Typha, which i n T_. glauca approaches a r a t i o of 1:1, while T_. l a t i f o l i a has a s l i g h t l y wider r a t i o and T_. a n g u s t i f o l i a approaches the conventional 5:1 r a t i o reported by F r i e d and Broeshart (1967). Only Chamaedaphne c a l y c u l a t a , Myrica gale, R i c c i a f l u i t a n s and Scirpus cyperinus have N/P r a t i o s i n favour of phosphorus. Since most marsh species grow r a p i d l y , flower and become senescent i n a very short period, i t seems probable that the narrower N/P r a t i o s of marsh species may o f f e r them some metabolic advantage, which may p a r t i a l l y account for the rapid growth. Several trends appear i n these data. In general, i t appears that the true ( f l o a t i n g and submerged) aquatics tend to be greater accumulators of nutrients than are the emergent aquatics, which as a group are only moderate accumulators. Plants of acid communities tend to be low accumulators of n u t r i e n t s . Within Typha communities, most subordinate plants are also no more than moderate accumulators of n u t r i e n t s . However, t h e i r p r o d u c t i v i t y , when combined with that of Typha, i s probably one of the major factors which leads to rapid build-up of n u t r i e n t - r i c h horizons i n marshes. In the l i s t , nearly a l l of the competitors of Typha accumulate one or more ions i n excess of the accumulation by. Typha. Scirpus cyperinus accumulates lower amounts of a l l nutrients except phosphorus, Scirpus 65 f l u v i a t i l i s accumulates more magnesium, sodium and potassium, but less phosphorus than Typha. S^  v a l i d u s contains more potassium and nitrogen, but less of other ions. Juncus effusus contains very low amounts of calcium and potassium. Decodon v e r t i c i l l a t u s , which i n Point Pelee appears to succeed Typha when there i s a die-back due to high water or excessive grazing by muskrat, i s high i n i t s requirement for both calcium and potassium. Phragmites i s high i n i t s requirement of calcium, magnesium and nitrogen, however, i t s sodium i s very low. Species d i f f e r i n t h e i r nutrient requirements, and thus i n the amounts of nutrients which they take from the s o i l . A nutrient-poor mineral s o i l , such as often i s the f i r s t wetland substrate a v a i l a b l e for c o l o n i z a t i o n , might be depleted of nutrients by a "high accumulator". Typha, with only moderate accumulation of nutrients probably has some advantage competitively on such substrates. 66 TABLE V. AVERAGE NUTRIENT AND SODIUM CONTENT IN LEAVES OF WETLAND SPECIES Percent based on oven dry weight Species i Ca Mg Na K N p Acorus calamus 0 .48 0 .23 0 .23 2 .0 0 .82 +0 .68 Agrostis s t o l o n i f e r a 0 .17 0 .26 0 .19 2 .1 0 .98 0 .41 Alnus rugosa 0 .59 0 .24 0 .16 0 .1 0 .98 0 .32 Calamagrostis canadensis 0 .65 0 .13 0 .04 2 .2 - -Carex l a c u s t r i s 0 .26 0 .06 0 .03 1 .0 0 .87 0 .35 Chamaedaphne cal y c u l a t a 0 .25 0 .09 0 .13 0 .6 0 .21 0 .45 Cicuta b u l b i f e r a 1 .30 0 .24 0 .16 2 .4 0 .55 0 .14 Decodon v e r t i c i l l a t u s 1 .32 0 .44 0 .15 2 .4 - -Dulichium arundinaceum 0 .15 0 .22 0 .32 0 .6 0 .90 0 .54 Equisetum arvense 0 .57 0 .80 0 .16 2 .4 0 .43 0 .37 Eupatorium maculatum 0 .45 0 .65 0 .24 1 .2 ' 0 .53 0 .05 Galium palustre 0 .63 0 .60 0 .56 2 .0 0 .19 0 .19 Impatiens b i f l o r a 0 .62 0 .88 0 .24 4 .0 2 .45 0 .21 I r i s v e r s i c o l o r 0 .49 0 .28 0 .24 1 .6 1 .71 0 .08 Juncus effusus 0 .10 0 .36 0 .16 1 .7 1 .26 0 .28 Lemna minor 1 .17 0 .54 0 .29 2 .5 1 .05 0 .28 Lemna t r i s u l c a 3 .15 0 .54 0 .92 2 .2 1 .56 0 .98 Lysimachia t e r r e s t r i s 0 .19 0 .70 0 .18 2 .2 1 .29 0 .23 Myrica gale 0 .45 0 .16 0 .16 0 .4 0 .58 0 .76 Nuphar advena 1 .51 0 .27 0 .06 3 .2 -Nymphaea odorata 0 .46 0 .14 0 .80 1 .3 0 .86 0 .59 Onoclea s e n s i b i l i s 0 .24 0 .52 0 .72 1 .6 1 .00 0 .42 Ph a l a r i s arundinacea 0 .13 0 .36 0 .24 1 .6 1 .34 0 .18 Phragmites communis 1 .12 0 .72 0 .04 0 .8 1 .90 0 .49 Pontederia cordata 0 .52 0 .11 0 .20 3 .0 1 .07 0 .62 Potamogeton p e r f o l i a t u s 5 .12 0 .74 0 .16 1 .6 0 .84 0 .31 P o t e n t i l l a p a l u s t r i s 0 .44 0 .09 0 .03 3 .2 0 .74 0 .63 R i c c i a f l u i t a n s 0 .44 0 .08 0 .09 3 .2 0 .32 +1 .00 S a g i t t a r i a l a t i f o l i a 0 .38 0 .42 0 .22 3 .7 1 .78 +0 .40 S a g i t t a r i a r i g i d a 0 .54 0 .39 0 .48 0 .4 1 .95 0 .71 S a l i x p e t i o l a r i s 0 .35 0 .26 0 .18 0 .8 0 .78 0 .39 Scirpus americanus 0 .35 0 .15 0 .12 1 .6 1 .24 0 .28 Scirpus atrovirens 0 .20 0 .15 0 .14 1 .4 0 .60 0 .24 67 Percent based on oven dry weight Species Ca Mg Na K N P Scirpus cyperinus 0 .16 0 .04 0 .20 0 .8 0 .29 0, .56 Scirpus f l u v i a t i l i s 0 .15 0 .84 0 .48 2 .0 1 .05 0. .24 Scirpus rubrotinctus 0 .22 0 .48 0 .24 3 .2 1 .40 0, .33 Scirpus validus 0 .33 0 .38 0 .28 1 .8 1 .71 0. .27 Sium suave 0 .47 0 .36 0 .03 3 .2 0 .41 0. .48 Solidago gigantea 0 .33 0 .40 0 .24 2 .8 0 .87 0, .43 Sparganium eurycarpum 0 .41 0 .64 0 .04 3 .2 2 .04 0. .49 Spiraea alba 0 .34 0 .22 0 .16 0 .6 0 .92 0, .13 Thelypteris p a l u s t r i s 0 .44 0 .25 0 .04 0 .4 0 .06 0, .03 Triadenum virginicum 0 .49 0 .32 0 .28 0 .9 0 .55 0, .40 Typha a n g u s t i f o l i a 0 .27 0 .39 0 .41 1 .4 1 .13 0, .31 Typha glauca 0 .46 0 .23 0 .27 1 .2 0 .62 0, .52 Typha l a t i f o l i a 0 .46 0 .16 0 .17 1 .3 0 .94 +0, .53 Z i z a n i a aquatica 0 .23 0 .06 0 .12 1 .2 0 .76 0, .29 N.B. In the P column, a + sign indicates an average i n which at l e a s t one reading i s greater than 1 percent. 68 MOISTURE CONTENT OF PLANTS Moisture content i n l i v i n g vegetation can be useful as an i n t e r p r e -t a t i v e t o o l i n ecology of marsh plants. The average percent moisture content may o f f e r an i n d i c a t i o n of the e c o l o g i c a l categories to which a p a r t i c u l a r species belongs from the point of view of i t s hygrotopes. In the main, percent moisture content provides a simple i n d i c a t i o n of metabolic performance of a plant, as shown i n the seasonal studies of Typha and Phragmites i n Section IV. A s h i f t i n percent moisture content can show c l e a r l y a s h i f t i n metabolic a c t i v i t y of the species, and can be useful i n comparisons of the growth c h a r a c t e r i s t i c s of a s e r i e s of dominants. On a l l sample p l o t s , plant samples were taken for species which were of common occurrence i n the p l o t s , and t h e i r moisture content was measured. Except for the seasonal studies of the two major dominants, these r e s u l t s were averaged and presented as s i n g l e figures i n Tables VI and VII, figures expressed as percent moisture, based on fresh weight. Some moisture contents not l i s t e d i n tables are also quoted for comparison, since these species are l i s t e d at l e a s t for i o n i c content tables. The percent moisture content of the various species which may dominate communities i n marshes, as opposed to the same species when found with Typha communities, i s shown i n Table VI. When these species occur i n Typha communities, the major e c o l o g i c a l change i s one of l i g h t r e l a t i o n s h i p s , since they must occupy a sub-layer lower than Typha, and hence receive less l i g h t than when dominants i n t h e i r own communities. Factors of the substrate, such as moisture a v a i l a b i l i t y and pH, may also be changed. The species of marsh plants f a l l into a ser i e s of categories when considered on the basis of average percent moisture content. F i r s t are the f r e e - f l o a t i n g hydrophytes (Raunkier's hydrophyta natantia) with c o n s i s t e n t l y high percent moisture contents. Examples are Lemna minor 89.9, L. t r i s u l c a 69 TABLE VI. AVERAGE PERCENT MOISTURE CONTENTS, BASED ON FRESH WEIGHT OF SPECIES WHICH OCCUR ON SELF-DOMINATED PLOTS AND WITH TYPHA. Community Species CO CD id c cfl CC •w 4J CO CO CO C CD 4J CD Cd cd cd •H 4J !-i CO ft cfl T3 4-1 c CD !^ +J •H 4-> iH •H • r l 4J cd U M .-1 cd C cd cd cd o •H CD c« o iH 6 C 1 in O 1 T3 .* 1 cd cd cd cd in J3 a ft a ft a> >- >> CO H H H Acorus calamus 75.6 - 79.8 - -Alisma plantago-aquatica 89.0 - - 89.0 -Butomus umbellatus 82.0 - 85.4 - -Decodon v e r t i c i l l a t u s 83.0 - - - 77.2 Eupatorium maculatum 78.0 - - 74.8 -G l y c e r i a canadensis 64.0 - - 85.6 -Impatiens b i f l o r a 91.0 - 92.0 - -Juncus effusus 62.3 - - 68.4 -Onoclea s e n s i b i l i s 78.0 - - 76.7 -Phalaris arundinacea 75.7 - 67.5 74.4 -S a g i t t a r i a l a t i f o l i a 82.9 - 81.9 - 84.0 -S a g i t t a r i a r i g i d a 85.1 - 81.0 - -Scirpus cyperinus 62.5 - 63.0 -Scirpus f l u v i a t i l i s 75.3 - 67.0 73.8 — Scirpus validus 75.2 - 78.0 -Sparganium eurycarpum 77.5 - 79.6 — Typha a n g u s t i f o l i a 72.9 77.5 66.1 73.9 70.7 Typha glauca 73.0 68.2 75.9 71.3 72.4 Typha l a t i f o l i a 72.3 78.0 72.5 73.9 70.4 TABLE VII. PERCENT MOISTURE CONTENT, BASED ON FRESH WEIGHT, OF SELECTED SPECIES, IN COMMUNITIES DOMINATED BY VARIOUS SPECIES.  Community Species CO cfl o 3 • r l cfl 4-1 4 J CO Cfl e cfl Cfl 3 CO CO 3 3 CD cu • r l CD ft cfl a 4-1 W 4 J • r l o r H • H tH cfl Cfl cfl Cfl CD Cfl cfl Cfl o CO r H cfl • r l 4 J 0 r H C U 3 X) <4H 3 • r l o CD 60 o 3 CU O • r l • r l • r l (3 4-) >> Cfl g 60 O T) r H CD 60 4 J • r l Cfl r l 4-1 B cfl cfl Cfl MH 3 C • r l Cfl r l • H 3 4-1 3 • r l 4-1 s • r l CO 3 SH r H cu > (U • r l • r l 4 J Cfl X» 3 M ft 3 60 r H Cfl cfl U MH cfl Cfl Cfl r H Cfl Cfl o r H 3 CO <4H • r l • r l o MH CO O r H ca- • H Cfl d cu CD r l U • r l UH • r l cu • r l Cfl Cfl CO CO C 1 1 cfl o U • r l CD SH 4-1 4-> 3 3 Cfl Cfl Cfl ** 0 4 J CU 4 J 3 Cfl 4-1 4 J ft ft 60 Cfl cn Cfl O pa O r H • r l • r l Sh r l u X! X! XS • H ft pa Cfl 60 60 • r l • r l cfl ft ft ft r H 3 r H 3 Si Cfl Cfl O O ft >1 ! ^ < W O H i-j FM CO CO CO CO co H H H Alisma plantago-aquatica Butomus umbellatus G l y c e r i a canadensis Impatiens b i f l o r a S a g i t t a r i a l a t i f o l i a Scirpus atrovirens Carex c r i n i t a Bidens cernua Carex r e t r o r s a Lysimachia t e r r e s t r i s Lycopus u n i f l o r u s Sium suave P o t e n t i l l a p a l u s t r i s Cicuta b u l b i f e r a 89.0 78.0 - 84.6 74.0 64.0 67.5 - 91.0 90.9 83.0 68.0 72.0 83.0 84.0 74.0 81.0 90.5 75.5 79.3 78.5 77.0 83.0 78.5 86.0 93.5 82.9 83.3 81.0 - 69.1 91.0 86.0 85.4 92.0 81.9 89.3 85.6 90.0 87.9 80.4 64.0 87.2 85.3 85.5 79.5 77.0 77.0 86.5 88.6 Community Species Triadenum virginicum Galium palustre Lemna minor Lemna t r i s u l c a Ceratophyllum demersum Hydrocharis morsus-ranae Pontederia cordata CD 13 a cd 0 4-1 CD cd cd 3 CO "d CD CD •rl CO ft 3 4-1 O rH •rl M cd cd cd cd cd O CO rH cd •rl 4-1 0 C . 13 MH 3 •rl o U CO •rl . •rl •rl C 4-1 cd 60 cn 60 4 J •rl cd 4-1 e C 3 3 •rl cd U •rl 3 4-1 3 •rl CO u rH CD > CD •rl •H 4 J 3 S-i P. 3 60 rH Cd 4-1 ca cd cd >N rH cd cd o <4H •rl •rl o 14H 3 C/2 o rH CD CD U u •rl MH •rl cd cd CO CO C 1 1 CD 4-1 4-) 3 3 cd 3 cd 4-1 4-1 ft ft 60 cd cd cd o r-l •rl •rl u U u xi Xi .£ c cd 60 60 •H •rl cd & ft ft 3 Xi cd cd o o ft >N CO CO CO C/l H H H - - - - - 89.5 - 80. 8 77. 76.0 78.6 - - 83.1 89.5 - 84. 9 - - 91.5 - - - 92.0 80. 3 96. - - 91.5 - - -- - - - - 94.5 - 96. 0 - - - - - - 94.0 94. 7 96. - - - - - - - 84. 3 72 91.5 and Ceratophyllum demersum 95.3. Also with high moisture content are the hydrophyta adnata, such as Hydrocharis morsus-ranae 94.9, Myriophyllum 88.8 and U t r i c u l a r i a 94.5. The only two exceptions of higher moisture content i n the study, other than those j u s t mentioned, were Impatiens  b i f l o r a , which has almost a "succulent" habit, and a s p e c i a l l y selected Typha s i t e , where a f l o a t i n g mat had sunk, and the Typha was s t i l l growing, but very poorly (Figure 31). A l l of the rooted aquatics have moisture contents which are c o n s i s t e n t l y i n the 80 - 90 percent category. Examples are Nuphar advena 80.0, Potamogeton nodosus 87 .2, P_. amplifolius 87 .3 and Elodea canadensis 86.5. Also many of the subordinate plants of the marsh, plus a few of the major dominants share t h i s high moisture content. Examples are Rorippa i s l a n d i c a 81.9, P i l e a fontana 81-. 7 and Sparganium  androcladum 80.0. Highest moisture contents of species which may form large stands were found i n Impatiens b i f l o r a , which on a l l s i t e s has a moisture content of greater than 90 percent. Lowest moisture contents for the plant averages was found i n Scirpus cyperinus and Juncus effusus. Percentage moisture content for Juncus effusus was highly v a r i a b l e , and was higher within the Typha communities than on s i t e s which i t dominated. Plants with percent moisture contents lower than Juncus effusus were encountered, but while some of these form communities of which they are dominants they are not found within the Typha communities. An example i s Spiraea alba, with a moisture content of 61.7 percent. I t i s found i n sandy s o i l adjacent to, but not within the Typha communities. F a i r l y uniform percent moisture contents, regardless of the community where the species grow, are found i n Alisma plantago-aquatica, Butomus umbellatus, Eupatorium maculatum, Impatiens b i f l o r a , Onoclea  s e n s i b i l i s , S a g i t t a r i a l a t i f o l i a and Sparganium eurycarpum. A l l occupy 73 several kinds of s i t e s , yet the water content of the plants remain v i r t u a l l y unchanged over a l l of them. The genus Typha also exhibits few v a r i a t i o n s on the average from a moisture content close to 70 percent. Few marsh dominants have percent moisture contents s i m i l a r to Typha, but some of the important species close to the moisture content category of Typha are Decodon v e r t i c i l l a t u s 76.7 , J u s t i c i a americana 79 .5, Scirpus  americanus 77.0 and Z i z a n i a aquatica 74.7. The remainder of the dominant marsh species, mostly of the reed or grass type, have percent moisture contents which are considerably lower than the other species. Average percent moisture contents for those not l i s t e d i n the tables are Calamagrostis  canadensis 59.1, Carex l a c u s t r i s 63.4, Dulichium arundinaceum 68.7, Spiraea  alba 61.7 and Phragmites communis 67.9. In terms of moisture content, i n d i v i d u a l species vary over the growing season, and the v a r i a t i o n appears to depend on the species, as well as the conditions of the h a b i t a t . To i l l u s t r a t e t h i s statement f i v e examples are presented. In Nuphar advena, growing vigorously on an open s i t e at Point Pelee marsh, percent moisture content (based on leaf samples) begins as high as 86 percent and continues slowly to decline throughout the en t i r e sampling period (Figure 31). The i m p l i c a t i o n of t h i s moisture pattern for t h i s rooted hydrophyte i s that there are no rapid metabolic s h i f t s involved i n the growth of the plant, and that metabolic preparation for overwintering and production of shoots for the following year i s accomplished by a steady and continuing process u n t i l the approaching cold weather of the f a l l season ends ac t i v e metabolism. Figure 31 also i l l u s t r a t e s the percent moisture content of a healthy f l o a t i n g mat of Typha glauca. Here the sampling period commences with a moisture content of 77.9 percent (about normal for the s t a r t of a growing season for Typha), flowering occurs i r r e g u l a r l y through the period June 19 -o Typha - sunken mat - • Nuphar advena -m Typha - f l oa t ing mat 3 0 MAY 16 J U N E 24 IO 18 JULY 26 11 19 AUGUST 27 Figure 31. Seasonal v a r i a t i o n i n moisture content of leaves, i n Nuphar advena, f l o a t i n g mat of Typha glauca and a sunken mat of Typha glauca. Point Pelee Marsh, 1969. ^ •P-75 to 30 (1969) and slowly the moisture content declines to the end of the sampling period. So for the f l o a t i n g mat, at l e a s t i n terms of moisture content, i t appears that Typha i s following a moisture regime s i m i l a r to that of Nuphar. This pattern should be compared with the percent moisture content pattern for Typha which i s rooted i n the s o i l (Figure 32). The t h i r d example i n Figure 31 represents a f l o a t i n g mat which has l o s t i t s buoyancy and has sunken to the f l o o r of the pond. In height, none of the Typha ever were t a l l e r than 76 cm, and they s t a r t the season with such a high percent moisture content that they approximate the percent moisture content of f r e e - f l o a t i n g hydrophytes. These plants d i d not flower, and they maintained the same type of percent moisture content to the end of the sampling period. I t i s clear that such a high percent moisture content, appearing i n t h i s p a r t i c u l a r community, i s far out of l i n e with the normal moisture content of Typha, and that t h i s community was subjected to very adverse conditions. The sunken mat community did not survive the winter. Figure 32 i l l u s t r a t e s the behaviour of rooted communities of Typha  glauca and Phragmites communis with respect to seasonal v a r i a t i o n of percent moisture content. In Typha, the samples show a high and constant percent moisture content u n t i l about July 21, considerably l a t e r than the flowering date which i s i n early J u l y . A f t e r July 21, percent moisture content s t e a d i l y declines to the end of the sampling period. Thus i t appears that some s h i f t i n metabolic a c t i v i t y , possibly seasonal senescence of the leaves and subsequent tr a n s l o c a t i o n of nutrients to the rhizome for overwintering, i s w e l l under way i n the early summer, and continues to the end of the growing season, although on a reduced scale. Moisture content for- the rhizome, discussed i n Section IV, remains constant for the en t i r e sampling period. The second part of Figure 32 shows the behaviour of a stand of Phragmites communis, with respect to moisture content. In Phragmites, 76 , ( , | , t i • i — IO 30 19 9 29 18 7 27 17 6 MAY JUNE JULY AUGUST SEPTEMBER OCTOBER Figure 32. Seasonal v a r i a t i o n i n percent moisture content i n l e a f material f o r rooted communities of Typha glauca and Phragmites communis. 77 percent moisture content, which i s i n i t i a l l y l e s s than i n Typha, declines s t e a d i l y from a peak at the beginning of sampling to the end of the sampling period. I t also continues growth f o r the en t i r e time, even though there i s a continuously lowering moisture regime. Apparently, Phragmites can maintain a continuing increase i n height, produce flowers and f r u i t and presumably c a r r i e s on the necessary t r a n s l o c a t i o n processes, a l l simultaneously and on a d e c l i n i n g percent moisture content as w e l l . The patterns of Typha and Phragmites are thus quite d i f f e r e n t . When comparing the behaviour of the two Typha stands, the one based on a f l o a t i n g mat, and the other rooted i n the s o i l , we f i n d that the behaviour of each d i f f e r s . I f we accept the idea that the Typha stand which i s rooted i n the s o i l i s the normal condition f o r the plants, then some i n t e r p r e t a t i o n becomes necessary of the reduced height (maximum 250 cm i n the f l o a t i n g mat, 300 cm i n rooted Typha) i n the f l o a t i n g mat stands, together with the slow rather than r e l a t i v e l y sharp reduction i n moisture content. One i n t e r p r e t a t i o n , i n view of the prevalence of f l o a t i n g mat communities, i s that Typha has s u f f i c i e n t metabolic f l e x i b i l i t y to allow i t to adapt to d i f f e r e n t substrate conditions, and that i t adapts so e f f i c i e n t l y that, except for a measureable height d i f f e r e n c e , f l o a t i n g mats are both v i a b l e and vigorous. SUMMARY OF SECTION II (a) A table of l i f e - f o r m s , based on a modified Raunkierian system, shows that marsh vegetation i s characterized by hydrpphytic rhizome-bearing geophytes (geophyta rhizomatosa hydrophytica), with nearly 30 percent of a l l species found there belonging to th i s newly proposed group. (b) To demonstrate the depth of the i d e n t i f i c a t i o n problem f o r Typha i n eastern Canada, a study was made of 614 samples of Typha at Point Pelee marsh. A hybrid index was constructed, using standard c h a r a c t e r i s t i c s of 78 T_. l a t i f o l i a and T_. a n g u s t i f o l i a . Of the samples only seven showed character-i s t i c s of t y p i c a l T_. l a t i f o l i a and only four of T_. a n g u s t i f o l i a . A l l others occupied the range of v a r i a b i l i t y between the two, although many could be categorized as T_. glauca. Further inspection showed that plants with p a r t i c u l a r combinations of characters could be found i n e c o l o g i c a l l y d i f f e r e n t parts of the marsh. (c) Three types of Typha communities are recognized. They are the nearly-pure stands of Typha growing i n open water, the two-layered Typha -S a g i t t a r i a communities and the Typha - Galium communities. A va r i a n t of the t h i r d community, the f l o a t i n g mat, i s also described. P o t e n t i a l impact of the four European adventives, Lythrum s a l i c a r i a , Butomus umbellatus, Epilobium hirsutum and Hydrocharis morsus-ranae, on wetland communities i s also discussed. (d) Comparison of height of Typha i n the regions where sampling occurred shows that c o r r e l a t i o n s are l i k e l y between height and l a t i t u d e , pH, nutrient content of s o i l and species. Typha emerges as one of the t a l l e s t species of the marsh, and thus i s not e a s i l y overtopped. (e) In terms of i o n i c content, Typha appears to be only a moderate accumulator of n u t r i e n t s , a l l other p o t e n t i a l competitors, including Phragmites, having higher requirements for at l e a s t one of the ions tested, so that i n nutrient-poor s o i l s , Typha would probably have a d i s t i n c t advantage i n c o l o n i z a t i o n . The a b i l i t y of Typha to t o l e r a t e considerable amounts of sodium i s noted, and i t i s suggested that t h i s a b i l i t y may give the genus an advantage i n brackish h a b i t a t s . (e) Moisture content i n marsh plants operates to show basic differences i n plant categories, and a l s o , i f followed seasonally on selected stands to show s h i f t s i n metabolic a c t i v i t y during the growing season. I I I . PHYSICAL FACTORS OF THE MARSH - LIGHT, WATER, SOIL 80 STRUCTURE OF MARSH COMMUNITIES IN TERMS OF LIGHT RELATIONSHIPS The l i g h t f a c t o r i n marsh communities can be very useful i n the i n t e r p r e t a t i o n of s t r a t i f i c a t i o n and community structure. Although considerable f l u c t u a t i o n i s to be expected, even i n open sky readings taken on successive days, nevertheless the comparative r e l a t i o n s h i p s of the s t r a t a of each community remains unimpaired by such f l u c t u a t i o n s . Through the study period, open sky readings show considerable f l u c t u a t i o n . The highest readings taken were 100,000 lux, the maximum reading possible on the luxmeter (the maximum occurred only twice i n a l l the readings taken). The lowest open sky reading was 10,000 lux, recorded during a d u l l overcast day with thundershowers. Usual readings for open sky v a r i e d between 50,000 and 80,000 lux for a normal day reading for open sky. As an example of the sort of f l u c t u a t i o n s which occur with open sky readings, a plot of average and maximum open sky readings for the 1967 f i e l d season i s given i n Figure 33. Despite the considerable v a r i a b i l i t y of the readings, the graphs show a peak of l i g h t i n t e n s i t y which i s approached towards the t h i r d week i n J u l y , a time at which many of the marsh species are flowering. Following the peak, there i s a s l i g h t decline to the end of the sampling period. A table of l i g h t r e l a t i o n s h i p s i s given i n Table VIII. Intensity of l i g h t within the layers (measured at 150 cm height for L-3, 100 cm for L-2 and 50 cm for L - l ) has been calculated as a percentage of open sky readings (which would be 100 percent), and i s so expressed i n the table. Communities which have L-3 dominants (very few i n the marshes) are l i s t e d i n a l l columns. Communities with L-2 height dominants are f i r s t recorded i n the L-2 column (layer 3 for such communities would be open sky, ergo a 100% reading). There are no dominants i n the L - l , but the l i g h t percentages there are s i g n i f i c a n t . Once reduced to percentages, samples taken on d i f f e r e n t days Figure 33. Plot of average and maximum open sky readings taken during the f i e l d season of 1967. 82 and under d i f f e r i n g open sky conditions, may be compared. The comparative l i g h t r e l a t i o n s h i p s of the communities may then be compared with those found i n the Typha communities. Naturally i t i s expected that l i g h t r e l a t i o n s h i p s within the stand are strongly influenced by the form of the dominant species. For instance, the l e a f y bushy form of Spiraea alba reduces L-2 readings to only 15.4 percent of open sky readings, while the slender gladiate form of Typha reduces l i g h t i n the L-2 to an average of 33.1 percent of open sky i n t e n s i t i e s . For L-2 height dominants, Decodon v e r t i c i l l a t u s (counted as an L-2 because i t only s l i g h t l y exceeds the one metre height) has dense and l e a f y growth, and reduces the l i g h t r e l a t i o n s h i p to only 33 percent of the open sky reading i n a matter of only a few centimetres. In contrast, the spreading slender growth form of Carex c r i n i t a , allows open sky readings at the 100 cm l e v e l . Such basic differences i n form n a t u r a l l y exert a profound e f f e c t on l i g h t r e l a t i o n s h i p s and plant growth i n lower s t r a t a of marsh communities. The communities i n which Typha i s represented as a nearly pure stand, and the Typha - S a g i t t a r i a communities both have stronger l i g h t i n t e n s i t i e s w ithin the stands than have the Typha - Galium communities. Although t h i s d i f f e r e n c e may appear s l i g h t , s l i g h t differences i n growth habit of Typha may account for i t . The Typha - Galium communities'are t y p i c a l of closed marshes and ponds, and there the growth of the Typha i s dense and erect. The nearly pure stands of Typha and Typha - S a g i t t a r i a communities are more t y p i c a l of open marshes and moving waters, and there growth i s not only l e s s dense, but also the leaves are usually deflexed as w e l l . These factors make the Typha - Galium communities darker i n the lower (L-l) l e v e l s than are the nearly pure stands of Typha and the Typha - S a g i t t a r i a communities. Differences are i l l u s t r a t e d i n Figures 34-37. The majority of species which are l i s t e d i n Table VIII have as t h e i r 83 Figure 35. Galium palustre on the dry f l o o r of a closed marsh. Low l i g h t i n t e n s i t y of Typha-Galium community, Ramsayville marsh, September 15, 1967. Figure 36. Growth habit of Typha i n an open marsh. Tay River, September 11, 1967. Figure 37. Bright l i g h t conditions at bases of Typha i n an open marsh. Dots on water are Nostoc caeruleum. Tay River, September 11, 1967. 85 TABLE VIII. LIGHT INTENSITIES WITHIN PLANT COMMUNITIES, EXPRESSED , AS A PERCENTAGE OF OPEN SKY READINGS Community Dominant L-3 L-2 L-l Water R Surface (Ground) Acorus calamus - 75.0 Agrostis s t o l o n i f e r a - 33.7 Calamagrostis canadensis - 21.1 Carex l a c u s t r i s - 63.3 Carex c r i n i t a - 100.0 Decodonn v e r t i c i l l a t u s - 7.5 -Dulichium arundinaceum - 33.2 Eupatorium maculatum - 77.0 15.8 Juncus effusus - 64.0 60.0 Nuphar advena - - 16.1 Phalaris arundinacea - 44.1 -Phragmites communis 30.6 - -S a g i t t a r i a l a t i f o l i a S. l a t i f o l i a (ensiform) -S a g i t t a r i a r i g i d a Scirpus americanus -Scirpus cyperinus Scirpus f l u v i a t i l i s -Scirpus rubrotinctus Scirpus validus -Sparganium eurycarpum Spiraea alba 71.0 Spirogyra sp. -Polygonum sagittatum - 58.0 Potamogeton p e r f o l i a t u s - - 40.0 Zizania aquatica - 81.8 Typha, nearly pure 73.3 Typha - S a g i t t a r i a 76.5 33.1 Typha - Galium 66.9 41.5 7.1 Typha, f l o a t i n g mat 66.0 35.6 15.5 81.7 77.9 90.3 75.2 73.5 68.5 56.0 73.5 73.4 15.4 57.8 22.8 3.2 4.2 15.4 49.1 99.0 87 .0 71.5 26.3 16.2 23.6 20.8 5.1 11.3 8.1 8.6 7.6 8.4 66/0.24* 5.9 68.0 9.1 10.5 5.8 21.0 16.0 2.6 10.7 11.7 2.2 10.2 19.0 2.8 8.8 7.4 20.0 4.5 20.8 53.6 18.3 9.4 8.2 2.0 12.5 9.5 0.1 0.2 0.0 11.0. 9.4 10.7 Legend. Water ref e r s to l i g h t reading at the water surface, not r e f l e c t e d . It i s the amount of r e f l e c t e d l i g h t from a water surface. Surface (Ground) i s the amount of l i g h t reaching ground, whether above or below water l a y e r . * Readings above/below the Spirogyra mat. 86 upper l i m i t of l i g h t i n t e n s i t y the l i g h t i n t e n s i t y of the open sky, which can approach 100,000 lux, and most grow with no protection from f u l l i n s o l a t i o n . Many l i k e Typha, are stenophotic species, growing poorly or not at a l l i f overtopped. Further examples are Acorus calamus, Carex l a c u s t r i s , Scirpus americanus, Phragmites communis and Zizania aquatica. Euryphotic species, which t o l e r a t e both conditions of f u l l i n s o l a t i o n as w e l l as habitats where they are overtopped by another dominant are S a g i t t a r i a  l a t i f o l i a and Sparganium eurycarpum. Some of the other species need further mention. Carex c r i n i t a i s not common i n Typha communities, but i t does form a d e f i n i t e part of marshy ha b i t a t s . Usually i t grows with Juncus effusus, or may sometimes be found as a weak sub-layer of Alnus rugosa t h i c k e t s , where i t t o l e r a t e s considerable shading. Eupatorium maculatum, a common plant of the margins of wetlands, appears to have l i g h t r e l a t i o n s h i p s very s i m i l a r to Typha. It grows best where i t i s the dominant, and i s found r a r e l y with Typha. When the two occur together, Eupatorium grows vigorously between Typha which i s widely spaced, and usually s t e r i l e . Both Scirpus cyperinus and :S_. val i d u s can and do grow with Typha. When t h i s occurs, S^ . cyperinus i s found under conditions s i m i l a r to those described for Eupatorium, while S^ . v a l i d u s and Typha occur together when the nearly pure stands of Typha extend into the deeper water where jS. validus i s growing. The two species can coexist for long periods. Table IX shows examples of minimum l i g h t i n t e n s i t i e s under which subordinate species of Typha communities have been found. Under these conditions they a l l grow w e l l , flower and complete t h e i r l i f e cycles, as many of them are annuals. A l l t o l e r a t e l i g h t conditions f a r below those of open sky conditions. A l l can also make good growth i n f u l l i n s o l a t i o n , and many occur i n more open communities where f u l l sunlight s t r i k e s them i n the daylight hours. In contrast to these euryphotic species, the e x t i n c t i o n TABLE IX. LIGHT RELATIONSHIPS OF SUBORDINATE SPECIES (Intensity i n layers below dominants, % open sky readings) Species % Open Sky Min. Reading, Lux Asclepias incarnata 28.2 4,500 Bidens cernua 20.3 16,000 Bidens frondosa 6.9 6,900 Cicuta b u l b i f e r a 21.8 3,300 Cyperus s t r i g o s a 11.1 1,900 Galium palustre 13.1 6,000 Hibiscus p a l u s t r i s 11.4 7,500 Impatiens b i f l o r a 25.0 7,500 Lycopus u n i f l o r u s 10.8 4,500 P i l e a fontana 9.6 1,500 Rorippa i s l a n d i c a 12.4 7,000 S c u t e l l a r i a g a l e r i c u l a t a 9.5 4,300 Thelypteris p a l u s t r i s 7.2 6,000 Triadenum virginicum 7.4 6,900 Species are a l l found i n Typha communities. These are L-2 and L - l members of three-layered communities. 88 point of Typha under natural conditions appears to be very high i n terms of l i g h t i n t e n s i t y . In a l l the sampling, I have never found young Typha seedlings on the f l o o r of a vigorously growing Typha community. The only Typha seedlings noted during that time occurred on a mat which had been chewed down to the surface by muskrats. There the t i n y seedlings f l o u r i s h e d . Thus for seedlings under natural conditions, i t would appear that l i g h t conditions short of f u l l open sky are probably l i m i t i n g . So f a r as flowering i s concerned, I have found i n the laboratory, where the highest lux attained i s 10,000, that while good growth of Typha from dormant shoots occurs, and seedlings w i l l germinate, the plants do not flower (light-dark periods i n the growth room are programmed to simulate natural growing seasons). Consequently f o r flowering conditions, a l i g h t i n t e n s i t y greater than 10,000 lux i s c l e a r l y required. A s e r i e s of graphs, showing changing l i g h t r e l a t i o n s h i p s over s i n g l e growing seasons, for three d i f f e r e n t marsh species, are shown i n Figures 38 -40. Figure 38 shows l i g h t conditions within the stand, for a close-growing Typha glauca f l o a t i n g mat. The mats at Point Pelee marsh grow i n a manner s i m i l a r to those i n Ramsayville marsh, and the l i g h t r e l a t i o n s h i p s are s i m i l a r to those of the Typha - Galium communities of closed marshes. In May, when the young shoots stand erect, l i g h t i s s i m i l a r . t o that found for open sky conditions. As the plants grow, and the leaves expand, l i g h t r e l a t i o n s h i p s change, so that by the end of the sampling period, they are only about o n e - f i f t h of what they are at the beginning of the season. In contrast, the pattern i n Phragmites communis (Figure 39) begins with the young shoot, unexpanded leaves and high l i g h t i n t e n s i t y , lowers i n mid-season as the leaves expand and increase i n number, and then increases again toward the end of the sampling period as the leaves begin to lose moisture content and become i n r o l l e d , thus increasing the l i g h t i n s i d e the stand. The pattern Figure 38. Seasonal l i g h t r e l a t i o n s h i p s within a f l o a t i n g mat community of Typha glauca. Point Pelee, 1969. Readings taken at 100 cm l e v e l . Figure 39. Seasonal l i g h t r e l a t i o n s h i p s i n a Phragmites  cummunis community. Point Pelee, 1969. Readings taken at the 100 cm l e v e l . j 31 8 16 24 2 10 18 26 3 II 19 27 M A V JUNE JULY AUGUST I , . • Figure 40. Seasonal l i g h t r e l a t i o n s h i p s within a Nuphar  advena community. Point Pelee, 1969. Readings taken 30 cm above water surface. 91 of l i g h t i n the Nuphar advena community (Figure 40) i s s i m i l a r to that of the Typha mat (Figure 38), except that l e a f expansion i n the early part of the growth period produces a broad f l a t t e n e d blade, which lowers l i g h t i n t e n s i t i e s i n the Nuphar community considerably below those found i n the Typha communities. Figures 41 - 44 show sample l i g h t r e l a t i o n s h i p s i n a serie s of communities. Each set was taken on the same day and under i d e n t i c a l l i g h t conditions. They i l l u s t r a t e the basic differences i n i n t e n s i t i e s which e x i s t between communities which have d i f f e r e n t dominants, while at the same time emphasizing the s i m i l a r i t y of r e l a t i o n s h i p s which are found within the various stands of Typha. 92 3 2 W . G L A Y E R S Figure 41. Comparison of l i g h t r e l a t i o n s h i p s i n d i f f e r e n t communities. Readings taken the same day under i d e n t i c a l l i g h t conditions. Dominants are named i n the legend. Readings taken for open sky, L-3, L-2, L - l (water surface, W) and ground G. 3 2 W G L A Y E RS Figure 42. Comparison of l i g h t r e l a t i o n s h i p s i n d i f f e r e n t communities. Readings taken the same day under i d e n t i c a l l i g h t conditions. Dominants are named i n the legend. Readings taken for open sky, L-3, L-2, water surface W and ground G. JULY 25. 1969 3 2 W w L A Y E R S Figure 43. Comparison of l i g h t r e l a t i o n s h i p s i n d i f f e r e n t communities. Readings taken the same day under i d e n t i c a l conditions. Dominants are named i n the legend. Readings taken for open sky, L-3, L-2, water surface and 10 cm below water surface. Figure 44. Comparisons of l i g h t r e l a t i o n s h i p s i n d i f f e r e n t communities. Readings taken the same day under i d e n t i c a l conditions. Dominants are named i n the legend. Readings taken for L-3, L-2 and ground, G. TABLE XX. WATER ANALYSIS FROM MARSH SAMPLES TAKEN OVER A SINGLE SEASON Sample Elements i n ppm Depth Temp. Date 1 Dominant (cm) (°C) pH 0 2 Mg Ca Na K P N 774.1 Typha a n g u s t i f o l i a G 2 - 18.1 8.0 - 8.6 15.2 106 3.5 0 2.3 75.1 Scirpus f l u v i a t i l i s - 16.5 7.5 - 10.0 12.5 140 6.4 0 2.3 75.2 Typha a n g u s t i f o l i a G 15 17.5 8.0 - 13.2 17.3 382 7.1 0 5.1 76.1 Typha a n g u s t i f o l i a G 10 14.5 8.0 - 9.7 14.8 70 2.1 1.1 4.0 77.1 Typha a n g u s t i f o l i a G 0 17.5 8.0 - 8.3 10.8 96 2.6 0 2.3 77..2 Juncus effusus 10 21.5 8.0 - 9.3 17.3 64 2.6 0.2 3.4 711.1 Typha a n g u s t i f o l i a 28 19.5 8.0 - 7.8 11.2 27 3.5 0 1.7 711.2 Scirpus validus 15 23.5 8.0 - 9.7 11.6 132 2.1 0.2 1.7 712.1 Typha a n g u s t i f o l i a G 7 22.5 8.0 5.5 10.0 16.8 148 4.6 0 1.7 712.2 Phalaris arundinacea 4 22.5 8.0 3.3 12.6 28.0 148 2.6 0.6 3.4 714.1 Typha a n g u s t i f o l i a G 26 16.5 8.0 1.1 6.0 26.4 112 12.6 0.6 1.1 714.2 Typha a n g u s t i f o l i a G 37 17.5 - 11.0 21.3 190 11.6 0 1.7 718.1 Typha a n g u s t i f o l i a G 30 19.5 8.0 1.2 9.8 16.0 5 4.6 0 1.7 718.2 Typha a n g u s t i f o l i a G 35 17.0 8.0 2.7 9.8 16.0 42 2.6 0.6 4.0 718.3 Typha a n g u s t i f o l i a G 20 18.9 8.0 4.1 8.3 16.0 78 4.6 0 1.7 719.1 Typha a n g u s t i f o l i a G 5 15.5 8.0 0.2 12.2 14.5 132 2.6 0.2 2.8 719.2 Typha a n g u s t i f o l i a G 5 19.5 8.0 2.0 10.0 14.5 112 3.5 0 2.8 724.3 H 20 3 59 18.1 7.8 5.9 12.9 15.2 58 4.0 0.4 3.4 726.1 Potamogeton p e r f o l i a t u s 15 25.5 8.0 4.3 7.8 17.3 3.2 2.1 0.2 1.7 728.3 Typha glauca G 22 19.5 8.0 5.0 10.0 20.9 70 12.6 0.9 2.3 81.1 Acorus calamus 0 24.5 7.8 13.0 5.5 5.2 2 1.3 0.6 1.7 Sample Depth Temp. Date 1 Dominant (cm) (°c) 81.2 Typha l a t i f o l i a G 10 22.5 81.4 H 20 - 23.5 81.5 H 20 - 21.2 81.6 H 20 - 21.2 81.7 H 20 - 21.2 81.8 H 20 - 21.2 88.1 Scirpus americanus 12 24.0 88.2 Dulichium arundinaceum 1 24.0 88.3 Typha l a t i f o l i a FM 4 0 24.0 88.5 Scirpus americanus 4 24.0 810.1 Typha l a t i f o l i a G 0 18.1 810.4 Typha l a t i f o l i a FM 0 21.1 810.5 Scirpus cyperinus 4 20.5 810.6 Carex l a c u s t r i s 5 18.9 815.1 Typha glauca T 5 75 24.0 815.2 Typha glauca T 50 23.5 815.3 Typha glauca T 46 24.0 815.4 Typha glauca T 46 23.5 815.6 Zizania aquatica 31 21.2 818.1 S a g i t t a r i a r i g i d a 62 23.5 pH 0 2 Elements i n ppm Mg Ca Na K P N 7.0 9.1 6.0 6.8 - 17.0 - -- 14.3 - -- 14.0 - -- 13.0 - -- 13.6 - -8.1 12.7 5.5 6.8 8.2 11.5 5.7 6.4 6.5 2.7 5.4 4.0 8.3 10.0 6.0 5.2 8.2 7.3 6.3 7.6 6.3 4.3 5.2 2.2 6.5 1.2 5.8 4.8 7.0 4.6 5.3 0.8 8.0 5.5 8.6 14.1 8.0 5.9 8.3 13.6 8.1 6.1 8.3 14.1 8.3 6.3 8.3 12.5 8.2 5.5 8.3 12.8 7.4 7.2 10.0 18.5 3 2.1 0.6 2.3 1.6 1.0 0 4.0 1.5 1.0 0.2 2.8 2.2 1.4 0.2 2.3 2.1 0.4 0 1.1 1.8 1.0 0 1.7 2.2 1.0 0 1.7 1.9 1.4 0 1.1 1.8 1.0 0 0.6 2.4 1.4 0.6 1.7 2.2 2.1 0 1.7 1.9 1.4 0.6 1.7 2.6 1.4 0 1.7 2.0 2.1 0 2.8 3.8 3.5 0.2 2.8 Sample Depth Temp. Date 1 Dominant (cm) (°C) 818.2 S a g i t t a r i a r i g i d a 57 22.5 818.3 S a g i t t a r i a r i g i d a 80 21.5 823.1 Typha glauca S 6 50 17.5 823.2 S a g i t t a r i a l a t i f o l i a 40 16.5 823.3 Typha a n g u s t i f o l i a S 35 16.5 823.4 Typha glauca S 42 16.5 823.5 Typha a n g u s t i f o l i a S 44 15.5 825.2 Typha l a t i f o l i a FM 7 20.5 825.3 Typha l a t i f o l i a FM 11 21.5 825.3A H 20 - 21.5 825.4 Typha l a t i f o l i a FM 4 22.5 825.5 Typha l a t i f o l i a FM 7 21.5 825.6 Typha l a t i f o l i a FM 11 21.2 825.7 Scirpus americanus 26 25.4 825.9 Dulichium arundinaceum 8 25.0 825.10 Acorus calamus 27 24.3 829.1 Typha l a t i f o l i a S 21 24.0 829.2 Typha l a t i f o l i a S 38 22.5 829.3 Typha glauca FM 9 20.5 91.1 Typha l a t i f o l i a FM - 18.9 Elements i n ppm pH 0 2 Mg Ca Na K P N 7.4 8.3 9.3 16.4 7.6 6.5 9.1 18.9 8.2 5.7 9.5 21.3 7.6 6.1 9.5 23.3 8.0 8.1 9.5 20.0 8.1 7.4 9.3 21.7 7.7 5.6 8.5 19.3 6.7 6.4 5.1 4.0 6.3 6.1 4.9 5.7 7.0 6.8 4.8 2.8 6.7 6.5 3.9 3.2 7.1 9.5 4.0 4.0 7.0 5.7 4.0 4.4 6.8 8.1 3.8 2.4 6.5 9.1 5.2 4.4 6.9 9.9 5.2 5.7 6.8 5.9 6.0 5.2 7 .0 5.1 5.6 5.2 7.1 6.9 5.8 3.6 6.5 4.9 6.1 7.6 3.5 2.1 + 1.7 4.0 1.4 0 2.3 14.0 2.6 0 1.7 8.4 4.0 0.2 1.1 10.2 4.0 1.1 0.6 13.4 4.0 0.1 3.4 12.6 7.1 0 2.8 3.3 1.0 0.7 1.1 3.0 2.1 0.4 0.6 3.5 1.0 0 2.8 2.0 2.1 0 2.3 2.0 1.4 0 2.8 1.4 1.4 0 -1.0 1.0 0 1.7 1.8 1.0 0.5 1.7 1.5 0.9 0 1.7 2.6 2.6 0.2 1.1 2.1 1.3 0 1.7 1.6 1.0 0 1.7 1.5 1.3 0.2 2.8 Date 1 Dominant Sample Depth (cm) Temp. (°c) pH 0 2 Elements Mg Ca i n ppm Na K P N 91.1A H 20 100 18.9 6.9 6.8 6.8 8.0 2.2 1.0 0.1 2.3 91.2 Typha l a t i f o l i a FM 0 16.5 6.6 2.2 6.6 6.4 2.5 1.0 0.6 2.3 91.3 Typha l a t i f o l i a FM 0 17.5 7.0 7.1 6.6 7.6 1.9 1.0 0 -95.1 Typha l a t i f o l i a FM 0 18.9 7.0 6.9 6.4 7.6 2.0 1.0 0 0.6 95.2 Typha l a t i f o l i a FM 0 22.5 - 4.2 - - - - - -95.3 Typha l a t i f o l i a FM 0 19.3 6.7 5.7 5.8 7.6 4.0 2.1 0 1.7 97.1 Typha l a t i f o l i a FM 0 19.5 7.1 7.5 7.8 10.4 1.7 .4 0 3.4 97.2 Typha l a t i f o l i a FM 29 18.9 7.2 6.0 7.8 10.8 2.6 1.4 0 2.8 97.3 Typha glauca FM 52 20.0 7.2 9.6 7.8 13.6 2.9 1.3 0 1.7 97.4 Typha glauca FM - 20.0 7.4 5.8 7.8 10.8 1.8 1.4 0 2.3 911.1 Typha glauca FM 0 18.1 7 .2 6.9 7.8 9.6 2.6 1.4 0 1.7 911.2 Typha glauca FM 42 17.5 7.5 7.0 7.8 10.4 2.1 1.4 0.2 3.4 911.3 Typha glauca FM 42 19.5 7.2 8.4 8.1 12.8 3.2 1.3 0 2.8 911.4 Typha glauca FM 51 15.5 7.2 5.2 8.1 7.6 2.0 2.1 0.1 1.1 926.1 Typha glauca S 36 12.5 7.0 2.4 9.7 20.5 9.6 9.2 3.3 1.7 926.2 Typha glauca S 42 12.5 7.3 3.4 10.0 18.1 5.0 4.6 1.3 0.6 Legend: 1 data and plot number l i s t e d as a single number; f i r s t d i g i t i s the month, second and t h i r d d i g i t s the day of the month; following the period the number appears. G i s a Typha - Galium community, open water. FM i s a f l o a t i n g mat community. T i s a nearly pure community of Typha. S i s a Typha - S a g i t t a r i a community. Geographical locations of samples. Samples 74.1 to 728.3, Ramsayville marsh. Samples 81.1 to 810.6, Gatineau River. Samples 815.1 to 815.6, Tay River. 818.1 to 818.3, Rideau River, 823.1 to 823.5, Norway Bay. 825.2 to 825.10, Gatineau River. 829.1 to 829.3, Norway Bay. 91.1 to 95.3, Taylor Lake. 97.1 to 911.4, Tay River. 926.1, 2, Norway Bay. TABLE XI. WATER ANALYSIS OF SELECTED DOMINANTS* Temp. Elements i n ppm Dominant Depth (i cm) (°C) pH 0 2 Mg Ca Na K P N Typha, nearly pure 46 (54) 130 21.8 6.2 (8.2) 8.3 6.0 8.4 13.5 2.3 1.5 0.1 1.7 Typha - S a g i t t a r i a 21 (39) 50 17.3 6.8 (7.5) 8.2 5.5 8.5 16.4 8.7 4.4 0-3.3 1.7 Typha - Galium 0 (8) 32 18.3 6.2 (8.0) 8.1 3.1 9.6 16.6 112 5.6 0-0.9 2.3 Typha, f l o a t i n g mat 28 19.3 4.0 (7.0) 9.2 6.4 6.4 7.8 2.3 1.4 0-0.7 2.3 Carex l a c u s t r i s 0 (5) 45 19.3 6.6 (7.0) 7.0 4.6 5.3 0.8 1.8 1.0 0 0.6 Calamagrostis canadensis 24 (36) 67 24.7 3.2 (6.9) 8.1 8.0 8.2 28.0 5.1 2.2 - -Decodon v e r t i c i l l a t u s 49 (53) 60 27.0 6.7 (7.1) 7.3 3.8 10.7 48.6 6.8 4.8 - -Juncus effusus 0 (10) 26 .21.5 7.2 (8.0) 3.5 9.3 17.3 64 2.6 0.2 3.4 Nuphar advena 81 (99) 122 24.9 5.9 (7.0) 9.1 9.3 9.0 30.0 6.1 3.1 - -Phragmites communis 0 (51) 121 19.2 6.0 (7.5) 8.5 1.2 12.7 61.6 3.8 7.3 1.9 2.0 S a g i t t a r i a l a t i f o l i a 0 (40) 95 16.5 6.8 (7.6) 6.1 9.5 23.3 8.4 4.0 0.2 1.1 S a g i t t a r i a r i g i d a 57 (85) 110 23.6 6.5 (7.2) 7.6 7.1 5.8 15.9 2.9 1.2 0.4 2.3 Scirpus americanus 12 (20) 115 24.6 7.4 (7.5) 7.6 9.9 4.7 4.6 1.8 1.0 0-0.5 2.6 Scirpus f l u v i a t i l i s 5 (89) 110 20.3 7.0 (7.4) 8.1 5.8 3.4 14.9 25.2 1.2 0.2 2.3 Scirpus validus 15 (92) 148 20.0 6.1 (7.4) 8.0 5.7 4.2 15.5 15.4 0.8 0.2 1.7 Ziz a n i a aquatica 31 (100) 140 19.7 7.0 (7.4) 8.2 6.3 2.6 15.6 1.7 0.4 - 2.8 * for the seasons of 1967 to 1971. Ranges are given for water depth and pH, other figures are averages. Figures i n parentheses are averages. 102 WATER AS AN EDAPHIC FACTOR IN MARSH COMMUNITIES The studies of water as an edaphic factor began i n 1967. Water samples were taken on a l l p l o t s which were ove r l a i n with water. Water which o v e r l i e s wetlands may contribute nutrients to the marsh system, and i n some instances, may be as important to marsh plants as the s o i l s which underlie the marshes. To i l l u s t r a t e the v a r i a b i l i t y of r e s u l t s , water samples for 1967 are l i s t e d i n Table X. Add i t i o n a l samples have been taken i n a l l years of the study except the f i r s t one. Po s i t i o n of water over the s o i l (or below the surface) (Kubiena 1953) c l a s s i f i e s s o i l as subaqueous and even at other times s e m i t e r r e s t r i a l . For instance, the nearly pure stands of Typha which inhabit the deeper waters up to one metre, are continuously subaqueous, while the Typha - Galium communities can be s e m i t e r r e s t r i a l to t e r r e s t r i a l . Several general trends which run through a l l the data are i l l u s t r a t e d i n Table X. F i r s t i s the s l i g h t lowering of pH which occurs toward the end of the growing season. This change i n pH values over the season r e f l e c t s the turnover of organic material i n the marshes, with i t s subsequent decay and release of organic acids, phosphates and n i t r a t e s into the water. Although i n d i v i d u a l species and populations may decay at d i f f e r e n t rates and release may be at d i f f e r e n t times of the season, there appear to be s u f f i c i e n t numbers of species involved i n the l a t e season turnover of organic material, so that pH values are affe c t e d . Oxygen contents of water vary considerably with temperature of water, amount of turbulence, amount of l i g h t and numbers of organisms present. Conspicuous d i u r n a l rhythms can be detected i n water systems where plant material i s present and abundant (Sculthorpe 1967) . In order to sample oxygen content so that near-maximum figures could be determined, a l l samples were taken between 11 a.m. and 1 p.m.. From these data i t appears that i n 103 general the oxygen content of marshes i s low, lowest readings occurring i n the shallow s t i l l waters of the closed marshes, and higher readings occurring where the waters are moving, turbulent and becoming supersaturated with oxygen (Reid 1961) from continuous motion (compare i n Table X the Typha T communities and the S communities with the Typha G, the Typha-Galium communities of the s t i l l waters). Analysis of major elements shows that the s t i l l waters of the closed marshes are r i c h e r i n nutrients than the moving waters of the open marsh systems. In the closed marshes runoff i s received into the low-lying basins, and slowly evaporates, concentrating the nutrients i n the aqueous systems. In Typha, vigorous growth i s accomplished i n the closed marshes under higher nutrient content than i s usually encountered i n the systems with moving waters. However, the t a l l e s t Typha i n the samples i l l u s t r a t e d by Table X are those from p l o t s 911.1-4 from the Tay River, where, with the exception of the calcium content, the nutrients tested are low i n comparison with the closed marshes. Water Analyses by Dominant Species A summary of water analyses, grouped on the basis of selected dominants i s presented i n Table XI. It i s based, not only on the r e s u l t s i n Table XI, but also on the l a t e r work done i n subsequent years at Long Point and Point Pelee. With the increase of i n d i v i d u a l species and numbers of samples, the r e s u l t s are more r e l i a b l e . F i r s t point of i n t e r e s t i s the l i m i t a t i o n s of growth which are placed on i n d i v i d u a l dominants by water depth. In the Typha communities, the range of depth i s between ground l e v e l and 132 cm, and plants grow equally w e l l over the e n t i r e range. The only species which was found i n a greater depth of water was Scirpus v a l i d u s , at 148 cm and here i t was growing w e l l , but was widely spaced out, as opposed to i t s • u s u a l l y dense 104 growth i n shallower waters. Phragmites communis, the most obvious competitor for Typha, occupies approximately the same range of water depths as does Typha, and one would expect to f i n d i t i n s i m i l a r h a b i t a t s . At l e a s t one author (McMillan 1959) has suggested that the competitiveness of Typha i s based on i t s tolerance for high s a l t concentra-tions; While the table reveals that Typha can t o l e r a t e high s a l t concentra-t i o n s , p a r t i c u l a r l y sodium, i t i s also apparent that the same i s possible for Phragmites communis, Scirpus f l u v i a t i l i s , S_. v a l i d u s , Phalaris arundinacea and Juncus effusus, some of the other major competitors for wetlands h a b i t a t s . Nor does pH n e c e s s a r i l y appear to be a greatly l i m i t i n g f a c t o r , since Typha stands grow through a pH range of 4.0 to 9.2 which contains almost a l l water pH conditions of wetlands with the possible exception of a l k a l i n e sloughs and acid bogs. The highest and lowest pH values for Typha both occur i n samples taken at Point Pelee, where values of 4.0 and 9.2 have both been found associated with f l o a t i n g mats (although not at the same times of the growing season). Of the other dominants, none appear to t o l e r a t e such a wide range of pH values, and the majority are found where pH values are circumneutral to a l k a l i n e . An example of a narrow tolerance i n pH i s Scirpus  americanus, which shows a range of only 7.4-7.6. The only examples of tolerances to a wide range of pH values, other than Typha, are Calamagrostis  canadensis (3.2-8.1) and Nuphar advena (5.9-9.1). Oxygen content i n water varies widely, but r e s u l t s show conclusively that waters i n marshes have lower oxygen content than open waters of the same system. At the water temperatures involved the amount of oxygen present i n the system ranges at saturation, from 8.0 to 8.7 ppm. Above t h i s f i g u r e the water i s spoken of as being supersaturated., probably as the r e s u l t of phytoplankton, algae and water plants, which during photosynthesis release oxygen. Readings below 8.0 ppm represent oxygen d e f i c i t s , which may a f f e c t 105 the a c t i v i t i e s of f i s h and microorganisms, but which appear to have l i t t l e e f f e c t upon the emergent vascular plants. Tolerance for low oxygen content of waters i s c h a r a c t e r i s t i c of Typha (Laing 1941) as i t probably i s for a l l hydrophytes which have the adaptation of aerenchyma systems. The range of oxygen content found i n waters i n which Typha grows i s from 0-13.4 ppm, a range exceeded by few dominant species. Many including Phragmites communis, can t o l e r a t e low oxygen content i n the water, so that f o r most dominants, i t appears that oxygen content i s not a l i m i t i n g factor to t h e i r growth. As expected, the plants of more open water, such as Nuphar advena, S a g i t t a r i a  r i g i d a and the f l o a t i n g mats of Typha a l l inhabit waters which have ranges of oxygen content which extend well into the category of at l e a s t temporarily supersaturated s i t e s . For magnesium content of the water samples, the range for Typha communities was 5.2-13.2 ppm, and strong t a l l plants have been found on a l l plot s which exceeded 6 ppm. Other readings s i m i l a r to the lowest readings fo r Typha, were obtained from waters with such dominants as Scirpus  americanus, and Carex l a c u s t r i s , but most of the competing species grow i n waters which f a l l w e l l within the range for the Typha communities. On the average, dominants such as Phalaris arundinacea and Phragmites communis, show considerably higher values than Typha, while dominants such as Zizania  aquatica, Scirpus validus and S_. f l u v i a t i l i s have much lower ranges of magnesium values i n the waters i n which they grow. The range of calcium i n water samples for Typha i s wide, from 3.2 to 26.4 ppm, with good growth occurring on a l l s i t e s i n both the open and closed marshes and on the f l o a t i n g mats, throughout, the highest part of the range. Poor growth was made i n the lower parts of the range (below 6 ppm). A few of the other dominants c l e a r l y t o l e r a t e low ranges of calcium content of waters, one being Scirpus americanus. A number of dominants show a 106 preference f o r calcium-rich waters, among these being Calamagrostis  canadensis, Nuphar advena, Phragmites communis, S a g i t t a r i a l a t i f o l i a and Decodon v e r t i c i l l a t u s . In the waters of open marshes found along the Ottawa and Rideau Rivers as well as i n the Perth d i s t r i c t , a strongly correlated r e l a t i o n s h i p (r = 0.92) was obtained between amounts of magnesium and calcium present i n the water. This r e l a t i o n s h i p i s i l l u s t r a t e d i n Figure 45. Ranges of sodium i n water samples for Typha communities show v a r i a t i o n from a high of 382 ppm (next highest 140 ppm) to a low of 1.4 ppm. A l l readings for other dominants f a l l within t h i s range. High sodium contents of water occur i n Ramsayville marsh, a closed marsh system. Typha obviously t o l e r a t e s these high sodium contents, and grows w e l l under these "brackish" conditions. Other competing species, such as Juncus effusus, Scirpus validus and S^  f l u v i a t i l i s also grow well under these conditions, although a l l the samples of S_. f l u v i a t i l i s taken under the higher sodium conditions i n the water, were vegetative. Although figures taken i n the Phragmites communis samples i n t h i s study do not reveal much concerning sodium tolerance, Phragmites also t o l e r a t e s high sodium conditions, since i t grows w e l l i n brackish water (Bjork 1967) , and should be expected to occupy habitats s i m i l a r to Typha, at l e a s t i n terms of sodium tolerance. Potassium ranges i n water samples are from 1.0 to 12.6 ppm for Typha-dominated s i t e s . A l l s i t e s have good growth except where potassium content i s as low as 1 ppm. Most of the other dominants, excepting Phragmites communis and Decodon v e r t i c i l l a t u s , t o l e r a t e values within the potassium range of the Typha s i t e s . Rather low potassium contents of waters were recorded for Carex l a c u s t r i s , Scirpus americanus, S_. f l u v i a t i l i s , S_. v a l i d u s , S a g i t t a r i a r i g i d a and Zizania aquatica s i t e s . Amounts of phosphorus i n water samples were often so low that the Figure 45. Relationship of calcium and magnesium i n water samples. N.B. Samples from Ottawa, Rideau and Tay River systems. 1967. 108 s e n s i t i v e c o l o r i m e t r i c tests could detect no phosphorus at a l l . Where they were detectable the range of phosphates i n the water did not appear to strongly influence the growth of Typha, or of any of the other dominants. Phosphates can be useful i n d i c a t o r s of p o l l u t i o n , but more often i n wetlands they represent phosphates which have been released i n the marshes through the death and decay of plant and animal material indigenous to the marsh system (Welch 1952, Hynes 1970, Sculthorpe 1967). Nitrogen (as determined by Kj e l d a h l methods) represents the t o t a l of a l l nitrogen present, whether organic or inorganic. Nitrogen was very low, the range f o r Typha being 0.6-5.1 ppm. No c o r r e l a t i o n i s apparent between nitrogen content of water and growth of Typha, or of any of the other dominants l i s t e d i n the ta b l e . Water Depth One of the most obvious l i m i t a t i o n s i n the growth of wetland species i s water depth, and most wetland species respond i n some way to water l e v e l , i n c l u d i n g f l u c t u a t i o n s of water l e v e l . Typha l a t i f o l i a does not appear to t o l e r a t e water deeper than one metre for sustained periods, but can and does t o l e r a t e some temporary f l u c t u a t i o n s i n water l e v e l such as those which r e s u l t from c o n t r o l dams. T_. l a t i f o l i a also grows w e l l i n rather weedy communities of moist higher ground, so that the range of t h i s species i s one gradient from strongly hydric to hy g r i c . Neither T_. a n g u s t i f o l i a nor T_. glauca appears to t o l e r a t e habitats which are always hygric only, although both have been found i n communities where the water subsides to ground l e v e l near the end of the growing season. Tolerance of other dominants to water f l u c t u a t i o n i s also strong. Both Dulichium arundinaceum and Scirpus  americanus form extensive communities along the muddy shores and wetlands of the Gatineau River, which shows considerable f l u c t u a t i o n due to a control dam at Chelsea, Quebec. Both grow w e l l even though e n t i r e communities may 109 be submerged f o r days at a time, followed by lowering of water l e v e l s which may leave them growing on cracking mud f l a t s . Both Scirpus validus and . cyperinus have also been found under s i m i l a r conditions. This a b i l i t y to withstand temporary drying conditions, and also to survive inundation o f f e r s these species a wider range of hab i t a t s , and the p o s s i b i l i t y of successful c o l o n i z a t i o n of habitats where water fl u c t u a t i o n s of t h i s sort e x i s t . Figure 21 of Scirpus americanus and Figure 46 of Dulichium arundinaceum, together with Figure 47 of Typha l a t i f o l i a , a l l i l l u s t r a t e communities which grow under conditions of f l u c t u a t i n g water l e v e l s . S a g i t t a r i a l a t i f o l i a responds to conditions of water depth and water f l u c t u a t i o n . Plants which grow on substrates which are constantly immersed respond with the production of r i g i d ensiform leaves which contain more aerenchyma than emergent leaves. Figure 48 and 49 i l l u s t r a t e the two lea f forms of S a g i t t a r i a l a t i f o l i a . The scape of the immersed plants usually r i s e s above the water l e v e l so that flowering i s a e r i a l , although the flowers are smaller than i n emergent plants of the same species. A second i n t e r p r e -t a t i o n of the production of ensiform leaves bears on nutrient supply and new habitat c o l o n i z a t i o n , and t h i s i s discussed i n the s o i l s section. 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 formation i s based on a response to water depth (Arber 1920, Sculthorpe 1967). There seems l i t t l e doubt that where water i s present i n any reasonable depth, i t has a d i r e c t influence on the growth of c e r t a i n plant communities. C l e a r l y f r e e - f l o a t i n g hydrophytes must derive nutrients from the water alone, and these would also respond d i r e c t l y to l i g h t and temperature of the water i n which they grow. In wetlands, the free - r-floating vegetation i s often s t r a t i f i e d , so that some hydrophytes f l o a t d i r e c t l y on the surface, while others form subsurface l a y e r s . The two most common species with Typha, are Lemna minor and Hydrocharis morsus-ranae. Common 1.10 species of the subsurface layers are Lemna t r i s u l c a , R i c c i a f l u i t a n s , Ceratophyllum demersum, Myriophyllum v e r t i c i l l u m and U t r i c u l a r i a v u l g a r i s . Some of these species are i l l u s t r a t e d i n Figure 50. I l l Figure 46. Dulichium arundinaceum community. Fluctuation of water l e v e l does not i n h i b i t growth of t h i s species. Cascades, P.Q., August 25, 1967. Figure 47. Typha l a t i f o l i a community. Sparse growth appears to be associated with extreme f l u c t u a t i o n of water l e v e l s . Cascades, P.O., August 25, 1967. 112 Figure 49. Ensiform-leaved S a g i t t a r i a l a t i f o l i a . Gatineau River, .P.Q. 113 Figure 50c. Lemna t r i s u l c a . F i g ure 50d. Lemna minor. Figure 50. Members of f r e e - f l o a t i n g aquatic communities. 114 SOILS OF MARSH COMMUNITIES General Of a l l n a t u r a l l y occurring material at the earth's surface, s o i l s are c e r t a i n l y one of the most complex. S o i l has been studied from many aspects, but the one most often used as an approach i s that of f e r t i l i t y , or the a b i l i t y of the s o i l to support v i a b l e communities, whether natural or a g r i c u l t u r a l . There i s p o s i t i v e i n t e r a c t i o n between the s o i l and the plants which i t supports. Some forms of vegetation cannot be supported by c e r t a i n s o i l s , and n a t u r a l l y occurring communities must occupy substrates s u i t a b l e for co l o n i z a t i o n . Following germination of seeds on the substrates for which they are s u i t a b l e , s o i l - p l a n t i n t e r a c t i o n s begin. The vegetation acts upon the s o i l to modify i t , and i t becomes so modified by the p a r t i c u l a r type of vegetation which i t now supports, that i n turn, the s o i l becomes unique. To investigate t h i s concept, among others, s o i l samples i n the form of undisturbed cores where possib l e , were taken from a l l sample p l o t s , both of Typha and of other marsh dominants. S o i l C l a s s i f i c a t i o n The Canadian System of S o i l C l a s s i f i c a t i o n (National S o i l Survey of Canada, 1965, 1970) i s based on the d e f i n i t i o n of s o i l as "any unconsolidated mineral or organic layer thicker than 4 inches (10 cm), occurring n a t u r a l l y on the earth's surface". Surface layers which do not meet these requirements are not s o i l and are designated as rockland, i c e or water. This system allows f o r layers developed under wet conditions, e i t h e r organic or mineral, and as such the c l a s s i f i c a t i o n i s the most suited to the d e s c r i p t i o n of these wetland s o i l s . A l l c l a s s i f i c a t i o n s have t h e i r drawbacks. There are always a r t i f i c i a l boundaries to a c l a s s i f i c a t i o n , so that sequences of s o i l s , which 115 may a c t u a l l y be continuous i n t h e i r developmental s e r i e s , must be divided to f i t the c l a s s i f i c a t i o n . The s o i l s i n t h i s study do appear to follow a d e f i n i t e developmental sequence from minimal mineral s o i l s to deep organic s o i l s . Within the bounds of the c l a s s i f i c a t i o n however, they are described i n the paragraphs which follow. G l e y s o l i c Order. These s o i l s are saturated with water and are under reducing conditions continuously or at some period of the year, unless they have been a r t i f i c i a l l y drained. Within 50 cm of the mineral surface they have matrix colours of low chroma as a r e s u l t of reducing conditions, and they may show mottles of high chroma, as the r e s u l t of l o c a l i z e d oxidation of ferrous i r o n and deposition of hydrated ferrous oxides. These s o i l s are developed under hydrophytic vegetation. Humic Gleysol Great Group. This great group contain gleysols which when v i r g i n have an Ah horizon more than 8 cm t h i c k . Rego Humic Gleysol (subgroup). These are Humic Gleysols with p r o f i l e types (L-H), Ah, Cg, Ckg or Ccag. They are Humic Gleysols with a non-effervescent Ah horizon and without a B horizon. These s o i l s support by far the l a r g e s t number of vegetation dominants i n the study, having been found beneath communities of many dominants i n addition to Typha. Such dominants are Acorus calamus, Agrostis s t o l o n i f e r a , Dulichium arundinaceum, G l y c e r i a  canadensis, Impatiens b i f l o r a , Onoclea s e n s i b i l i s , P h a l a r i s arundinacea, Phragmites communis, S a g i t t a r i a l a t i f o l i a , S_. r i g i d a , Scirpus americanus, !S_. cyperinus, S_. f l u v i a t i l i s , S_. v a l i d u s and Spiraea alba. It i s t y p i c a l of temporary s t i l l waters, where considerable build-up of humus i s po s s i b l e . Gleysol Great Group. This great group contains gleysols which when v i r g i n , have either no Ah horizon or an Ah horizon up to 8 cm. Rego Gleysol (subgroup). These are the Gleysols which have a shallow Ah horizon or lack an Ah horizon e n t i r e l y , and also lack a B horizon. 116 The C horizon i s gleyed or under reducing conditions. These s o i l s are t y p i c a l of continuously moving waters, where there i s l i t t l e opportunity to form a d e f i n i t e humus l a y e r , or of s o i l where there i s a successive deposit of alluvium, so that buried horizons become common. Rego Gleysols occur beneath communities of the following dominants: Butomus umbellatus, G l y c e r i a canadensis, S a g i t t a r i a l a t i f o l i a (ensiform-leaved), Scirpus  cyperinus, J3. rubrotinctus, Sparganium eurycarpum, and i n many plots of Typha which occurs as nearly pure stands. Organic Order. These s o i l s are developed p r i m a r i l y from organic deposits that are saturated for most times of the year. An organic layer must contain 30% organic matter. Depths of layers vary according to the contact of the lay e r . F i b r i s o l Great Group. These are organic s o i l s with a dominantly f i b r i c middle l a y e r , or middle or surface t i e r s , i f a l i t h i c , t e r r i c , hydric or c r y i c contact occurs i n the middle t i e r . In the present study, the s o i l s i n t h i s group are represented by the Hydric F i b r i s o l subgroup, which has a hydric contact with the organic l a y e r . These are the f l o a t i n g mats of Typha. A l l represent a condition which i s derived from a normal soil-based Typha community. They are t y p i c a l of deep water areas, or areas where there i s considerable change i n water depth from one season to another. They may also develop where run-off may r a i s e or lower the water depths for b r i e f periods. Humisol Great Group. These are organic s o i l s with dominantly humic middle l a y e r s , or middle or surface t i e r s , i f a t e r r i c , l i t h i c , hydric or c r y i c contact occurs i n the middle l a y e r . A l l the study s o i l s of t h i s category f a l l into the T e r r i c Humisol subgroup, representing a heavy accumulation of decomposed organic material underlain by the o r i g i n a l C horizon. They are found i n areas where the waters, when present, are 117 r e l a t i v e l y s t i l l , allowing for deposition and retention of organic matter, and where for some part of the season, the water l i e s close to the l e v e l of the s o i l surface, allowing reasonable oxidation and decay of the accumulated organic material. The following dominants were found to be supported by T e r r i c Humisols: Juncus effusus, Scirpus cyperinus, Spiraea alba, some Typha - S a g i t t a r i a communities, and some Typha - Galium communities. Within the Typha communities, i t i s possible to observe populations of s o i l s which include a l l those j u s t described. No doubt i f one were to concentrate more strongly on another wetland dominant, the same would also hold true, since from the time of c o l o n i z a t i o n , each dominant continues to modify and b u i l d s o i l , so that from a bare mineral substrate, the usual condition f o r c o l o n i z a t i o n , s o i l s would continue to b u i l d horizons, and deepen the surface organic l a y e r s . So far as Typha communities are concerned, c e r t a i n s o i l s are more appropriate partners f o r the various community types. The nearly pure stands of Typha i n the deeper moving waters, are characterized by the Rego Gle y s o l . The S a g i t t a r i a - Typha communities are best character-ized by the Rego Humic Gleysol, while the Typha - Galium communities are supported p r i n c i p a l l y on Hydric F i b r i s o l s . Approximate Analysis and Cumulative P a r t i c l e Size D i s t r i b u t i o n Figures 51-57 show a s e r i e s of cumulative p a r t i c l e s i z e d i s t r i b u t i o n s and approximate analyses of mineral horizons of s o i l i n the various d i s t r i c t s where the marshes are located. They represent mineral horizons of the dominants of the marshes, most of which are formed from the same l o c a l mineral horizons, although eventually modified by i n d i v i d u a l dominants. They have been selected to show s i m i l a r i t i e s and differences of parent horizons i n the d i f f e r e n t d i s t r i c t s . In the graphs, the basic reading, which represents.the 100% marsh of the sample, has been omitted. The hydrometer method of Bouyoucos (Bouyoucos, 1927, 1936) was used to make the determinations. 118 L4J < H Z 111 o UJ a z o U o < 70 60 50 40 30j -20 IO APPROX. ANALYSIS SAND 86 3 % SILT 7 8 % CLAY 5 6 % MAXIMUM PARTICLE ANALYSIS cm Figure 51. P a r t i c l e s i z e d i s t r i b u t i o n , mineral horizon, Tay River. Sample from mid-stream Typha community. UJ < H z UJ <J a. UJ a z o 70 60 50 4 0 3 2 o u < 30 20 IOl APPROX. ANALYSIS SAND 6 8 - 9 % SILT 2 1 - 4 % CLAY 9 7 % m O O TJ- in o O O O o o q co O 8 o CM O O O O O O MAXIMUM PARTICLE DIAMETER cm Figure 52. P a r t i c l e s i z e d i s t r i b u t i o n , mineral horizon, Gatineau River. Sample from marginal Typha community. 119 70 60 50 4 0 30J-20 IOI APPROX. ANALYSIS SAND 46 8 % SILT 3 6 - 7 % CLAY 1 6 5 % CM o o CO O O O o in <o O O O O co o 8 5 CM o co O o in •o O O MAXIMUM PARTICLE DIAMETER cm Figure 53. P a r t i c l e s i z e d i s t r i b u t i o n , mineral horizon, Gatineau River, area beside Scirpus validus community. 70| UJ < 60| z UJ O CC UJ a z o St _i 3 u u < 50 40 30 20 l O APPROX. ANALYSIS (M O O to O o-SAND 32 1 % SILT 50 9 % CLAY I 7 0 % O O O O co o 8 6 CM o to O in O O MAXIMUM PARTICLE DIAMETER cm Figure 54. P a r t i c l e s i z e d i s t r i b u t i o n , mineral horizon, Gatineau River, area beside a Scirpus cyperinus community. 120 Figure 55. P a r t i c l e s i z e d i s t r i b u t i o n , mineral horizon, Norway Bay, P.Q. River alluvium sample beside S a g i t t a r i a  l a t i f o l i a community. APPROX. ANALYSIS SAND 2 9 - 6 % MAXIMUM PARTICLE DIAMETER cm Figure 56. P a r t i c l e s i z e d i s t r i b u t i o n , mineral horizon, Rideau River. Sample from beside Typha glauca community. 121 Figure 57. P a r t i c l e s i z e d i s t r i b u t i o n , mineral horizon, Ramsayville marsh. Sample from open water beside Typha  glauca community. 122 Figure 51 shows data for one of the three sands encountered i n the study. Sand content i s very high, and s e t t l i n g so rapid, that the sand p a r t i c l e s have mainly s e t t l e d by the second reading, which appears i n the graph. The horizon i l l u s t r a t e d i s from a mid-river sample, where a vigorous Typha community was growing. Around i t samples taken from the r i v e r margin show patterns s i m i l a r to Figures 55 and 56, a pattern of clay and s i l t , t y p i c a l of r i v e r alluvium. Figures 52-54 are a l l derived from mineral horizons from Gatineau River s i t e s . Here sandy and clay farmlands have been flooded by waters which rose when a dam was constructed at Chelsea, Quebec i n 1926. Continuous deposition of clay and s i l t has proceeded from that time. The graphs show high to moderate sand contents, with low clay and r e l a t i v e l y high s i l t content. Figures 55 and 56 are derived from s o i l s from a l l u v i a l r i v e r s i t e s , where s i l t deposition i s continuous, and the waters are i n constant motion. Here clay and s i l t f r a c t i o n s are high, and the sand f r a c t i o n r e l a t i v e l y low. These s o i l s remain long i n suspension, and under natural conditions, the waters remain turbid for long periods a f t e r storms and run-off. Both Norway Bay and the Rideau River samples show s i m i l a r curves, which are t y p i c a l of s o i l s along the r i v e r margins. Figure 57 shows the p a r t i c l e s i z e d i s t r i b u t i o n for the mineral horizon of the large closed marsh at Ramsayville. Here sand content i s low, and the clay f r a c t i o n very high. Materials under n a t u r a l conditions remain long i n suspension a f t e r storms, so that the waters of the marsh are often t u r b i d . Mineral horizons at Ramsayville marsh are very compact and s t i c k y . No p a r t i c l e s i z e d i s t r i b u t i o n s have been made f o r e i t h e r Point Pelee or Long Point marsh. The underlying horizons however show very high sand content i n each marsh, and appear to have s i m i l a r c h a r a c t e r i s t i c s for parent 123 horizons. Approximate analysis for Point Pelee i s cl a y 3.0%, s i l t 1.0% and sand 96.0%. Approximate Mineralogy of C Horizons The mineral horizons on which the approximate analyses and p a r t i c l e s i z e d i s t r i b u t i o n s were performed were separated for the clay f r a c t i o n and these were given to Dr. G. Chao of the Geology Department of Carleton University f or mineralogical i d e n t i f i c a t i o n by X-ray a n a l y s i s . P h y l l o s i l i c a t e clay minerals were not detected i n any of the samples. Dr. Chao reported that only primary minerals were present and that quartz and pl a g i o c l a s e constituted 96% of the minerals i n a l l samples. He found that amphibole was present i n small quantities i n the samples from the Gatineau and Rideau River and suggested the possible presence of dolomite i n samples from Blackburn's Creek (a small t r i b u t a r y of the Gatineau Ri v e r ) , i n some from the Gatineau River, the Rideau River and Norway Bay, P.Q.. The absence of p h y l l o s i l i c a t e minerals suggests that e i t h e r these minerals have been c a r r i e d away i n suspension with the running water, or else no k a o l i n i z a t i o n has occurred. A d d i t i o n a l studies would be required to determine p r e c i s e l y the nature and o r i g i n of the minerals present. S o i l Temperatures S o i l temperatures i n wetlands can vary greatly over the growing season because of dif f e r e n c e s i n texture, moisture content, depth of over-l y i n g water and amounts of vegetation present. Within the closed marsh, of the Typha - Galium communities, records of s o i l temperatures were made through the growing season of 1968, from May 7 to the f i r s t week i n November (Figure 63). Temperatures were a l l taken from the same plo t i n Ramsayville marsh. Probably only temperatures from the zero down to 20 cm depth are of d i r e c t importance to the growth of the community, since no root systems penetrate below the 20 cm l e v e l . 124 However i t may be seen that f l u c t u a t i o n s i n temperature occur as deep as the 60 cm depth. The two-layered Typha - S a g i t t a r i a communities of the open marshes r e t a i n water cover through the en t i r e growing season. A graph of s o i l temperature data (Figure 58), derived from random p l o t s , indicates that i n the rooting layer r e l a t i v e l y high temperatures are maintained u n t i l mid-August, a f t e r which temperature declines to the steady temperature of the 60 cm depth. In such deep-water communities the s o i l approaches an equilibrium of temperature at an e a r l i e r time than i n the shallower communities (compare with Figure 63 Page 162), the overlying waters probably exerting some influence on t h i s condition. Figure 59 shows the mat temperatures of a si n g l e f l o a t i n g mat community, measured over the summer of 1969 at Point Pelee. Mat temperatures reached t h e i r highest i n Ju l y , at the time when the Typha was i n flower. Surface temperatures were s l i g h t l y ^ l e s s than i n the adjacent water, and were lower at the bottom part of the mat than at the surface. In general, temperatures were l e s s i n the mat than i n the water, and there was a gradual decline i n temperature from the top to the bottom of the mat. Some v a r i a t i o n i n s o i l temperature i n d i f f e r e n t s i t e s i s probably a t t r i b u t a b l e to vegetation type, although s o i l s i n wetlands are usually s i m i l a r . Table XII i l l u s t r a t e s t h i s concept. There, several kinds of s o i l c h a r a c t e r i s t i c s may be seen. A l l s o i l temperatures used were taken near mid-day, so that a i r and water temperatures would be maximum, and s o i l s would show fl u c t u a t i o n s a r i s i n g from r i s i n g a i r and water temperatures. Temperatures have been taken through the growing season as w e l l , and the r e s u l t s f o r the s o i l beneath each dominant have been arranged as averaged for each s o i l l e v e l . On the moist s i t e s , the trend i s toward temperatures which are higher at the surface and low i n the lower l e v e l s of the s o i l , with the lowest Figure 58. Seasonal s o i l temperatures, taken i n 1966-67 on random plots of Typha - S a g i t t a r i a communities. Figure 59. Seasonal v a r i a t i o n of water and mat temperatures of a f l o a t i n g mat community of Typha glauca. Point Pelee marsh, 1969. TABLE XII. AVERAGE AIR, WATER AND SOIL TEMPERATURES FOR VEGETATION DOMINANTS Temp. °C Temp. °C Depth cm Temperature S o i l °C  Dominant ( a i r ) (water) (water) 0 cm 20 cm 40 cm 60 cm 80 cm Acorus calamus 22 .9 23. 3 23.8 26 .7 20 .9 19 .6 18 .3 17. ,8 Agrostis s t o l o n i f e r a 27 .5 ss ss 21 .7 17 .8 15 .3 13 .3 10. .6 Alisma plantago-aquatica 23 .8 s s 17 .2 17 .2 16 .8 16 .1 Butomus umbellatus 28 .9 23. 8 40.0 22 .5 21 .3 20 .0 Carex l a c u s t r i s 23 .8 22. 5 6 21 .3 18 .6 17 .1 17. .1 Dulichium arundinaceum 25 .0 24. 5 3 24 .1 21 .1 19 .4 Epilobium hirsutum 28 .9 s s 18 .3 16 .8 Eupatorium maculatum 23 .8 ss ss 17 .2 16 .1 Gl y c e r i a canadensis 26 .2 s s 17 .8 16 .1 15 .3 Impatiens b i f l o r a 26 .2 s s 18 .3 16 .0 15 .0 13 .3 Juncus effusus 26 .5 s s 18 .3 15 .6 13 .9 12 .9 Onoclea s e n s i b i l i s ss ss 14 .4 12 .8 11 .8 10 .6 Phalaris arundinacea 28 .5 22. 8 2 22 .5 20 .0 18 .7 Phragmites communis 26 .0 19. 2 50.7 15 .0 13 .2 11 .6 Polygonum p e r s i c a r i a 23 .8 ss ss 18 .3 17 .8 18 .3 S a g i t t a r i a l a t i f o l i a 24 .1 19. 6 14.0 22 .0 20 .8 19 .4 19 .0 17. .6 S. l a t i f o l i a (ensiform) 21 .9 20. 6 0* 24 .7 21 .7 20 .3 19 .0 17. ,8 S a g i t t a r i a r i g i d a 22 .2 22. 4 66.0 20 .6 Scirpus americanus 24 .5 24. 4 16.0 23 .4 21 .8 19 .7 19 .7 Scirpus cyperinus 23 .5 15. 6 5 20 .7 20 .6 19 .2 18 .1 17, .8 Scirpus rubrotinctus s s 17 .8 16 .1 15 .6 Dominant Temp. °C Temp. °C Depth cm Temperature S o i l °C  (air) (water) (water) 0 cm 20 cm 40 cm 60 cm 80 cm Scirpus f l u v i a t i l i s 26.4 18.9 17.0 18.9 16.9 16.1 14.9 13.9 Scirpus validus 26.2 21.5 15.0 23.1 23.2 19.7 18.9 17.8 Sparganium androcladum 23.5 19.4 43.0 18.6 18.3 - - -Sparganium eurycarpum 26.5 26.4 - 26.4 23.5 - - -Spiraea alba 26.5 ss ss 23.1 16.8 14.6 12.3 11.1 Ziz a n i a aquatica 26.5 24.5 31 22.2 21.7 - - -Typha deeper water 27.4 22.8 51.0 20.3 19.1 - - -Typha - S a g i t t a r i a 23.2 17.7 36.0 16.9 16.1 15.0 - -Typha - Galium 23.6 22.8 12.0 17.2 15.3 13.9 13.6 12.5 Typha f l o a t i n g mat 22.1 19.4 56.0** 18.6 17.9 17.4 - -N.B. * usually submerged, but sampled during a period of low water. ** depth of water below f l o a t i n g mat, depth above i s one cm. s indicates water at surface of s o i l only, ss indicates water table i s below surface of s o i l . 129 average temperatures approximately 10°C at the 80 cm l e v e l . Dominants which show t h i s pattern of s o i l temperatures are Agrostis s t o l o n i f e r a , Juneus effusus, Impatiens b i f l o r a , Onoclea s e n s i b i l i s , Spiraea alba and the Typha - Galium communities. A l l have water tables close to or s l i g h t l y above the s o i l surface toward the end of the growing season. The Typha communities of deeper flowing water share s o i l character-i s t i c s with few other communities. Here roots and rhizomes are never exposed d i r e c t l y to a i r . Water covering the s o i l i s at a lower temperature than the a i r , unlike communities where, with prolonged warm weather, the temperature of the s t i l l water approaches that of the a i r above i t . Dulichium arundinaceum, Scirpus americanus and S^. validus have s o i l c h a r a c t e r i s t i c s which show that they grow i n water which r i s e s i n temperature i n response to a i r temperatures and the heat of the sun. Decrease i n temperature from surface to lower s o i l s i s gradual. The Typha - S a g i t t a r i a communities share s o i l c h a r a c t e r i s t i c s with no other communities. The dense growth of the stand, coupled with the continuously shaded water which o v e r l i e s the s o i l , allows s o i l temperatures to remain low throughout the growing season. The fibrous nature of the f l o a t i n g mats of Typha renders them porous, and subjects them to temperatures which approximate those of the water i n which they f l o a t . In the study area, t h i s category of Typha has no counterpart i n the other dominants. Within the mat, temperatures decline s l i g h t l y from the surface to the lower side of the mat u n t i l the lower side of the mat i s pierced by the probe, whereupon temperature again becomes the temperature of the water. On land-based s i t e s , the only s o i l with s i m i l a r c h a r a c t e r i s t i c s belongs to the fibrous-rooted Phalaris arundinacea, a species which also forms f l o a t i n g mats, although none have been found i n t h i s study. 130 Comparison of S o i l Temperatures made on D i f f e r e n t Plots and Depths on the  Same Day Comparative s o i l temperatures, actual and not averages, can reveal s i m i l a r i t i e s and differences between plant communities which grow close together. Examples are given of such measurement i n Figures 60 - 62. They d i f f e r i n the dominant vegetation of the s i t e , and the legend of each set of graphs names the dominants which are represented. The s i m i l a r i t i e s of the Typha a n g u s t i f o l i a , T_. l a t i f o l i a and Scirpus f l u v i a t i l i s curves on the graphs i n the upper and lower parts of Figure 60 are very obvious. The Typha a n g u s t i f o l i a - Scirpus validus comparison of the same fi g u r e shows an almost i d e n t i c a l curve for both s i t e s , but s o i l temperatures for Typha  a n g u s t i f o l i a are markedly lower than those for Scirpus v a l i d u s . In Figure 61, graphs of Typha glauca - Agrostis s t o l o n i f e r a -Spiraea alba s o i l temperatures demonstrate that even though the macroclimate may be i d e n t i c a l , s o i l s below the s i t e s vary s i g n i f i c a n t l y i n temperature c h a r a c t e r i s t i c s . The three closed marsh s i t e s , temperatures of which are depicted i n Figure 62, are adjacent to each other. The s i t e s d i f f e r i n temperature but not i n temperature pattern. Loss of the l a s t reading i n the Typha l a t i f o l i a measurements r e s u l t s from a pan-like structure i n the s o i l . The lower part of Figure 62 i s another closed marsh s i t e . Although the upper and lower parts of Figure 62 represent r e s u l t s from s i t e s which are more than 60 miles apart, temperature patterns for each of the Typha s i t e s are nearly i d e n t i c a l . To i l l u s t r a t e the v a r i a t i o n i n temperature encountered from t e r r e s t r i a l to wetland conditions, a transect 100 feet long (30.7 m) was established along a gradient from a f i e l d of S e t a r i a , down a gentle slope into the dense almost pure stands of Typha (centre, Figure 62). Only two temperatures are a v a i l a b l e from the f i e l d (hard c l a y ) , but these show a JULY 5 1967 AIR TEMP. 19 4 ° C T. angustifolia • Sc. fluviatilis • JULY II 1967 AIR T E M P 31 l ° C T angustifolia • Sc.validus x AUGUST 22 1967 AIR T E M P 18 3 ° C T. latifolia O Sc. fluviatilis • 2 0 ao 6 0 SOIL DEPTH C M 8 0 Figure 60. Comparisons of s o i l temperatures from adjacent p l o t s taken on the same day. Figure 61. S o i l temperatures taken from adjacent p l o t s on the same day. o ui a < a a. 2 IS lO AIR TEMPERATURE 2l.7t TRANSECT TEMPERATURES AUG.23 1966 Typha latifolia Agrosti J Onoclea AUG. 26 1966 Setaria Mentha Onoclea Typha - Scutellaria Typha O x S IO 30 SO 70 SOIL DEPTH CM JULY 29 1966 Typha latifolia Glyceria grandis Carcx hystericlna Impatient biflora 90 ® Figure 62. S o i l temperatures taken from adjacent pl o t s on the same day. 134 high surface temperature, d e c l i n i n g r a p i d l y to the lower reading below the s o i l surface. Temperature declines as the Typha i s approached and i s lowest i n the Typha communities. Slopes for the Typha graphs show that wet s i t e s are lower i n temperature than dry s i t e s , and that the changes i n temperatures i n the Typha s i t e s are much l e s s d r a s t i c than i n the d r i e r s i t e s . In summary of s o i l temperature studies, s o i l s of the wetlands and the mature vegetation dominants which they support contribute mutually to t h e i r temperature patterns. S o i l temperatures vary over the growing season, with flowering of many marsh dominants occurring when the s o i l s are warmest. Temperature regimes of s o i l s seem to vary depending on the mature communities which cover them. L a s t l y , probably the r e s u l t of high moisture content, s o i l s of wetlands are r e l a t i v e l y cold s o i l s , with temperature differences lower than on comparative t e r r e s t r i a l s i t e s . S o i l Analysis General. The s o i l s of wetlands, although e x h i b i t i n g l e s s v a r i a t i o n than t e r r e s t r i a l s o i l s , are nonetheless v a r i a b l e . Each shares the feature of high moisture content i n the upper horizons, and progressively lower moisture content i n lower more f i n e l y and densely sorted horizons. In wet condition, the most common colour i n upper horizons i n 10YR/2/1 and i n lower horizons 5Y/2/1 (Munsell 1954). Colours of low chroma and value i n mineral horizons are c h a r a c t e r i s t i c of the G l e y s o l i c Order, since the horizon i s gleyed. Some Norway Bay samples had most colours i n the lower horizons of 5GY/2/1. When exposed to a i r , many of the s o i l s show mottles of hydrated f e r r i c oxides, but sub-aqueous s o i l s , under natural conditions of saturation, do not display v i s u a l rusty mottling, and are made weakly b l u i s h by ferrous compounds. At Long Point and Point Pelee, lower horizons are sandy, and do not show mottling of any so r t . Texture. Many of the s o i l s have wide C/N r a t i o s . pH ranges are 135 also wide, from 3.0 to 8.9, although the great majority are circumneutral. T e x t u r a l l y , most s o i l s i n the study have f i n e l y sorted a l l u v i a l parent material, although on some of the Tay River s i t e s , at Long Point and Point Pelee, sand i s the common substrate. Because flooding and seasonal deposition of alluvium i s common i n marshes, i t i s not unusual to f i n d C horizons of clay interspersed with buried organic horizons. Vegetation - S o i l . Rooting i s very shallow i n wetland s o i l s , so that most roots are found only i n the loose organic horizons, with l i t t l e or no penetration of the underlying c l a y . Even where organic layers are shallow or l a c k i n g , seedlings and mature plants tend to spread t h e i r root systems across the surface of the f i n e l y textured clay l a y e r , so that with minimal penetration of the clay, a thick absorptive mat o v e r l i e s the surface. This may be due to the density of the clay layers of the substrate. Such mats once formed, have only a tenuous hold on the clay substrate, and may be displaced e a s i l y by an increase i n current or water depth. F l o a t i n g mats of Typha are common i n the study areas ( f l o a t i n g mats of Calamagrostis and Carex l a c u s t r i s were found at Long Point, but were not sampled) and are present on the Tay River, at Norway Bay, Taylor Lake, some Gatineau River s i t e s , Long Point and Point Pelee. These mats appear to form when masses of vegetation f l o a t free from the supporting mineral base material and become independent. Organic mats, with t h e i r hydric contact are considered Hydric F i b r i s o l s of the Canadian C l a s s i f i c a t i o n , the actual mat being the organic horizon. S o i l s by D i s t r i c t s Table XI11 shows a summary of analyses of s o i l s arranged by d i s t r i c t s . I t serves as a general i n d i c a t i o n of the conditions found on widely separated s i t e s . Amounts of organic matter (OM) and nitrogen vary considerably and TABLE XIII. SOIL CHARACTERISTICS BY DISTRICT P Exch. Cations, m.e. per 100 g of S o i l D i s t r i c t Horizon OM N% (ppm) Na K Ca Mg CEC Rideau River Ah 2 .6 0 .29 8 0 .64 0 .47 2 .3 1. .1 20 .3 Cg 5 .2 0 .32 6 0 .59 0 .42 2 .4 0, .6 12 .8 Ramsayville Ah 24 .3 1 .05 13 8 .27 0 .86 4 .3 2 .4 39 .3 Cg 1 .2 0 .30 8 4 .51 0 .60 1 .8 0, .9 13 .2 Lucerne, P.Q. Ah 0 .8 0 .24 10 0 .72 0 .36 2 .7 0. .8 22 .3 Cg 0 .1 0 .05 8 0 .63 0 .29 2 .1 0. .6 12 .2 Gatineau River, P.Q. Ah 5 .2 1 .20 7 0 .77 0 .58 4 .0 1, .3 22 .3 Cg 3 .7 0 .43 9 0 .66 0 .47 1 .9 0, ,7 10 .1 Taylor Lake, P.Q. Oh 26 .0 8 .04 28 1 .43 1 .14 3 .1 1, .0 13 .2 Masham, P.Q. Ah 12 .3 0 .59 13 1 .03 0 .47 8 .2 3. .7 36 .6 Cg 43 .2 0 .96 14 1 .31 0 .46 12 .7 4. .7 72 .5 North Bay Ah 51 .8 0 .60 11 1 .03 1 .19 9 .1 3, .4 57 .2 Cg 23 .3 0 .43 11 1 .09 1 .12 9 .2 3. .7 63 .8 Tay River Ah 7 .9 3 .42 11 1 .06 0 .93 3 .1 1. .0 15 .6 Cg 3 .2 1 .16 8 0 .65 0 .65 2 .8 1. ,0 17 .9 Norway Bay, P.Q. Ah 18 .9 4 .46 11 1 .37 1 .02. 1 .9 0. ,6 10 .3 Cg 7 .8 1 .34 11 0 .62 0 .55 1 .7 0. .7 10 .0 Long Point Comp. 0 .24 6 2 .00 2 .05 26 .0 4. .4 P Exch. Cations, m.e. per 100 g of S o i l D i s t r i c t Horizon OM N% (ppm) Na K Ca Mg CEC Point Pelee* L-H 32.3 1.02 5 0.17 0.40 33.1 4.3 66.7 Ah 15.3 0.53 6 0.13 0.15 18.9 1.9 28.4 C 10.3 0.22 8 0.11 0.12 14.1 0.9 10.3 * Data for Point Pelee are from a Phragmites s i t e , and probably does not r e f l e c t the marsh as a whole. OM, organic matter, CEC, cation exchange capacity. 138 r e f l e c t the types of s o i l and environmental conditions of the d i s t r i c t s . At North Bay, where most of the s i t e s are humisols, high average amounts of organic material r e f l e c t s t h i s f a c t . At Taylor Lake, where the data are from f l o a t i n g mats, organic matter again i s high. At Ramsayville, figures are for a marsh system where waters are standing, or are below surface l e v e l s of the s o i l s f o r some period i n the summer, and where organic matter can accumulate with l i t t l e chance of i t being swept away. Point Pelee averages, as noted i n the footnote to the table, are based only on Phragmites stands, so that the figures are lower than i f the f l o a t i n g mat communities had been considered. The lower figures for organic matter come from areas where moving water renders accumulation of organic matter d i f f i c u l t . Nitrogen figures show trends s i m i l a r to organic matter, as do the figures for phosphorus. Parent materials i n a l l d i s t r i c t s are low i n phosphates, and higher amounts of phosphorus found i n upper horizons are correlated with the greater amounts of organic matter deposited there by plants. The strong r e l a t i o n s h i p between amounts of organic c o l l o i d s present and cation exchange capacity (CEC) may also be noted. In a l l d i s t r i c t s , base clays and sands have very low cation exchange c a p a c i t i e s , i n the range of 10-14 m.e./lOO g of s o i l . As amounts of organic matter increase, cation exchange capacity also increases i n proportion to the increased numbers of exchange s i t e s provided by organic c o l l o i d s . This increase can also add more a v a i l a b l e cations to the s o i l complex, and t h i s general r u l e i s also apparent i n the figures of TableXIII. Some inconsistencies do occur, however, p a r t i c u l a r l y with figures pertaining to f l o a t i n g mats, which may well be leached of t h e i r c o l l o i d a l properties, so that only fibrous material remains, and exchange s i t e s are therefore low, as are nutrients i n general. Amounts of exchangeable sodium vary, with the s o i l s of Ramsayville marsh, based on marine clays, having much more r e s i d u a l sodium than other 139 d i s t r i c t s . Potassium, again highly v a r i a b l e by d i s t r i c t i s highest at Long Point, but even where i t i s lowest, i t does not appear to l i m i t marsh vegetation. Calcium figures are much higher for Long Point and Point Pelee than they are for any of the marshes on the Canadian Shield. Plots i n the Ottawa d i s t r i c t , the Gatineau and North Bay do not even come near the sort of calcium content of marsh samples for Lake E r i e . For magnesium, parent materials appear to possess basic amounts of magnesium of about 0.6 - 0.9 m.e./lOO g of s o i l , and amounts frequently increase i n the upper horizons. In f a c t i f the table f o r the ions i s inspected, i t i s apparent that the process of r e c y c l i n g through death and decay of vegetation constantly increases nutrients i n the upper horizons of s o i l s , so that a l l nutrients including nitrogen and phosphorus are frequently increased i n the upper horizons of the s o i l system. S o i l Analysis by Vegetation Dominants Table XIV,. presented i n two parts, i s a summary of s o i l character-i s t i c s c l a s s i f i e d by vegetation dominants. The d i f f e r e n t s o i l categories, which occur for each dominant have been averaged separately and have been presented as a resume of each s o i l category for each dominant. In the text, the ranges of the p a r t i c u l a r numbers are given for Typha, and then the other r e s u l t s for other vegetation dominants have been compared. Organic matter of the s o i l s i s highly v a r i a b l e and except f o r s o i l samples dominated by Phragmites, a l l dominants other than Typha have amounts within the range of the Typha samples (0 - 91% i n Ah and 0 - 64.9% i n C horizons). Quite obviously, Typha and many other dominants can grow on a wide range of organic matter content s o i l s . According to Bear (1964) organic matter i n many s o i l s i s les s than 5 percent, so i t may s a f e l y be concluded that s o i l s of wetlands, p a r t i c u l a r l y i n the upper horizons, are higher i n organic matter than the majority of t e r r e s t r i a l s o i l s . Some s o i l s TABLE XIV!. PART I. SOIL CHARACTERISTICS FOR VEGETATION DOMINANTS Depth Mottles Moisture Dominant S o i l Horizon (cm) Colour Texture pH Roots F e r r i c , % % Acorus calamus RHG Ah 13 10YR/3/1 - 5.3 + 0 43.7 Cg 62+ 5Y/4/1 clay 5.4 - 0 31.7 RHG Ah 10 5Y/3.5/1 - 6.3 + 0 30.5 c g i 24 5Y/4.5/1.5 clay 5.8 - 0 23.3 CgH 41+ 5Y/5/1.5 clay 5.4 - 5-10 22.5 Agrostis s t o l o n i f e r a RHG Ah 23 10YR/3/1 - 6.4 2/3+ 0 -Cg 52+ 10YR/4/4.5 clay 5.9 - 0 -Butomus umbellatus RG Cg 20+ 5Y/1/4.5 clay 6.3 1/4+ 0 -Calamagrostis canadensis RHG Ah - 5YR/2/2 - 8.0 + 0 -C - - sand 8.0 - 0 -Dulichium arundinaceum RHG Ah 34 10YR/3.5/1.5 - 6.2 + 0 -CI 21 5Y/4.5/1.5 clay 6.7 - 5 28.8 CII 20+ 5Y/5/2 clay 6.3 - - 30.6 Epilobium hirsutum RG CI 8 5Y/1/3 - 6.4 + 0 -CII 11+ 5B/0.5/5 clay 6.8 + 0 -G l y c e r i a canadensis RG CI 16 5Y/2/3 - 6.7 3/4+ 0 -CII 20+ 5Y/2/3 clay 6.8 - 20-30 -RHG Ah 14 10YR/2.5/1 - 6.3 + • 0 Cg 20+ 5Y/3.5/1 clay 6.3 - 0 -Dominant S o i l Horizon Depth (cm) Colour Texture pH Roots Mottles F e r r i c , % Moisture % Impatiens b i f l o r a RHG Ah 20 10YR/3/1 - 6.6 + 0 -Cg 46+ 5Y/1.5/2 clay 6.4 - 0 -Juncus effusus Humisol Oh 34-90 10YR/2/1 - 5.8 + 0 39.9 Cg 41-0+ 5Y/5/1 clay 5.9 - 1 22.3 Onoclea s e n s i b i l i s RHG Ah 11 5YR/2/1 - 4.2 + 0 30.5 Cgl 10-19 5YR/2/1 clay 3.8 - 0 -CgH 16+ 10YR/4.5/1 clay 3.8 - 0 -P h a l a r i s arundinacea RHG (carb) Cg 8 5Y/2.5/1 clay 8.0 + 0 44.6 RHG Ah 15 2.5YR/2/0 - 7.0 + 0 36.7 Cg 60+ 5Y/4.5/1 sand 6.0 5 19.1 Phragmites communis RHG L-H 2.5 5YR/2.5/2 - 7.1 + 0 -Ah 7 5YR/3/2.5 - 7.1 + 0 78.7 C 9+ 5YR/2/1 sand 7.1 - 0 27.7 S a g i t t a r i a l a t i f o l i a RHG Ah 11 5Y/3/1.5 - 5.5 + 0 32.4 Cg 64+ 5Y/3/1 sand.clay 7.4 + 0 23.8 S a g i t t a r i a l a t i f o l i a (ensiform) RG C (upper) C (lower) 22 53+ 0/3.5/0 5Y/6/2 clay clay 5.5 7.4 1/4+ 0 0 38.1 20.3 Dominant S o i l Horizon Depth (cm) Colour Texture pH Roots Mottles F e r r i c , % Moisture % S a g i t t a r i a r i g i d a RHG Cgl 11 5Y/3/2 clay 7.7 + 0 30.6 CgH 61+ 5Y/2/1 clay 7.7 - 0 -Scirpus americanus RHG Ah 22 5Y/5/2 - 7.0 + 0 33.2 Cg 60+ 5Y/4.5/2 clay 7.0 - 3 28.9 RHG Ah 25 10YR/3/1 - 5.8 + 0 30.5 Cgl 45 5Y/4.5/2 clay 6.3 - 0 27.7 CgH 10+ 5Y/4.5/1.5 clay 6.3 - 50 19.3 Scirpus cyperinus RG Ah 10 10YR/3/1 - 3.9 + 0 -Cg 35+ 5Y/4/1 clay 4.1 - 0 -RHG Ah 5 5Y/2/1 - 3.5 + 0 -Cg 70+ 5Y/4.5/1 clay 3.1 - 0 -RHG Ah 14 5Y/3/2 - 6.0 + 0 31.0 Cgl 35 5Y/4/2.5 clay 6.3 - 0 29.0 CgH 25+ 5Y/5/3 clay 6.4 - 0 19.0 Humisol Oh 61 10YR/2/1 - 5.3 1/4+ 0 25.9 Cg 18+ 5Y/4.5/2.5 clay 6.3 - 0 28.9 Scirpus rubrotinctus RG Ah 4 5Y/2.5/1.5 - 7.0 + 0 -Cgl 36 2.5Y/5/3 sand 7.0 - 0 28.0 C g l l 50+ 5Y/3.5/1 clay 7.0 - 0 28.0 Dominant S o i l Horizon Depth (cm) Colour Texture pH Roots Mottles F e r r i c , % Moisture % Scirpus f l u v i a t i l i s RHG Ah 25 5YR/2.5/1 - 7.2 1/4+ 0 36.7 Cg 50+ 5Y/4.5/1 clay 6.5 - 5 16.9 RHG (Carb) Cg 9+ 5Y/2.5/1 - 8.0 + 0 40.1 Scirpus validus RHG Ah 30 10YR/2.5/1 - 5.9 1/4+ 0 34.2 Cg 45+ 5Y/5/1.5 clay 6.6 - 0 28.3 Sparganium androcladum Humisol Oh 20+ 2.5YR/2/0 - 3.5 1/4+ 0 -Sparganium eurycarpum RG Cg 8+ 5Y/2/3 clay 7.1 + 0 --Spiraea alba RHG Ah 48 10YR/1/0.5 - 6.5 1/4+ 0 42.7 C § 25+ 5Y/5.5/1.5 clay 7.5 - 0 43.6 Humisol Oh (u) Oh (1) 75+ 10YR/1/0.5 - 6.5 7.0 1/8+ 0 0 39.8 43.6 Typha, nearly pure stands RG Ah 4 5Y/3/1 - 7.1 + 0 -Cg 13+ 2.5Y/3/2 clay 6.8 1/4+ 0 -RHG Ah 25 10YR/2.5/1 - 5.9 + 0 44.3 Cg 50+ 5Y/5/2 clay 7.2 - 0 17.9 Dominant Depth Mottles Moisture S o i l Horizon (cm) Colour Texture pH Roots F e r r i c , % % Typha - S a g i t t a r i a communities Typha — Galium communities R (H) G Cg 25 5Y/3.5/1 clay 6.8 1/4+ 0 34.1 RHG Ah 17 10YR/2/1.5 - 6.9 + 0 33.8 Cg 58+ 5GY/4.5/1 clay 6.9 - 0 23.3 RHG Ah 34 10YR/3/1 - 5.3 + 0 34.8 c g i 8 5Y/5.5/1.5 clay 5.5 - 0 15.4 CgH 42+ 5Y/6/4 clay 6.0 - 40 17.6 Humisol Oh 64+ 10YR/2/1 - 5.9 1/4+ 0 -RG Ah 20 10YR/2/1 - 6.7 + 0 41.3 Cg 55+ 5Y/4.5/1 clay 7 .0 - 20 20.8 RG Ah 18 5Y/2/1 - 6.8 + 0 45.0 Cgl 10 5Y/5/1 clay 7.0 - 5-10 44.1 CgH 40+ 5Y/5.5/1.5 clay 8.0 - 0 40.0 RHG Ah 19 10YR/2/1 - 6.2 + 0 40.2 Cg 56+ 5Y/5/1 clay 6.8 - 5 27.7 RHG Ah 18 10YR/2.5/1 - 6.5 + 0 44.2 Cgl 55 5Y/4.5/1 clay 6.0 - 10 29.2 CgH 5+ 5Y/4.5/1 clay 7.0 - 20 -RHG Ah 18 5Y/2/1 - 6.8 + 0 45.0 Cgl 10 5Y/5/2 clay 7.0 - 5-10 44.6 CgH 40+ 5Y/5.5/1.5 clay 8.0 0 40.0 Dominant Depth Mottles Moisture S o i l Horizon (cm) Colour Texture pH Roots F e r r i c , % % Typha - Galium Humisol Oh! 13 10YR/2/0.5 - 6.4 + 0 -communities Oh 2 6-9 10YR/2/1.5 - 6.0 + 0 -Oh 3 6 10YR/2/1 - 7.0 + 0 -Cg 52+ 5YR/5/1.5 clay 7.2 - 0 -Humisol Oh 5 5YR/2/1 - 5-5 + 0 -Cg 5 10YR/4/1 clay 5.9 + 0 -O h l l 15 5YR/2/1 - 5.9 - 0 -C g l l 31 10YR/5/1.5 clay 6.1 - 10 -CgHI 5+ 10YR/5/1.5 sand - 10 -Humisol Oh 2 10YR/2.5/1 - 6.3 + 0 -Cg 14 5YR/4/2 clay 6.3 1/4+ 25 -O h l l 10+ 10YR/2/1 - 6.4 - 0 -Humisol Oh 2-90 10YR/2/1 - 5.7 + 0 43.7 Cg 88-0+ 5Y/4.5/1 clay 5.9 - 0 27.3 Typha, f l o a t i n g mat F i b r i s o l Oh 25-60 10YR/3/1-2 - 6.0 + 0 91.0 Zizania aquatica RG Cg 10+ 5Y/2/1 clay 7.0 + 0 42.3 RHG (comp) clay 7.9 + 0 -Legend. RG, Rego Gleysol; RHG, Rego Humic Gleysol; carb ., a carbonaceous s o i l which shows effervescence with HC1; + i n depth column, horizon extends beyond core, i n root column, rootinc ; i s present. Colours are given as Munsel numbers, matched oh moist s o i l s . Texture, as p a r t i c l e (textural) analysis , and also v i s u a l l y . TABLE ;XIV.o PART I I . SOIL CHARACTERISTICS FOR VEGETATION DOMINANTS m. e. per 100 g of S o i l P Species S o i l Horizon 0M% Ca Mg K Na N% ppm CEC Acorus calamus RHG Ah 17.0 1.93 0.8 0.95 0.99 2.85 10 17.5 Cg 6.7 1.63 1.3 0.65 0.95 0.55 5 17.9 RHG Ah 82.5 1.55 3.3 0.98 0.73 0.85 18 64.8 Cgl 14.7 1.08 2.3 0.70 1.11 0.74 11 26.1 CgH 1.1 0.59 0.2 0.57 0.37 0.25 9 3.4 Agrostis s t o l o n i f e r a RHG Ah 53.7 11.80 6.6 1.17 1.34 0.94 18 69.6 Cg 11.5 8.10 3.6 0.49 0.87 0.42 10 28.0 Butomus umbellatus RG Cg 0.0 0.90 0.4 0.20 0.70 0.10 4 7.4 Calamagrostis canadensis RHG Ah - 20.00 4.2 1.41 2.43 0.37 8 -C - 15.40 2.9 0.77 2.82 0.14 7 -Dulichium arundinaceum RHG Ah 4.2 0.80 0.1 0.38 0.47 0.53 4 5.4 CI 2.9 1.10 0.1 0.45 0.45 0.47 3 6.7 CII 1.4 0.60 1.2 0.58 0.40 0.25 6 4.9 Epilobium hirsutum RHG Cit. 0.0 3.00 1.2 0.30 0.49 0.07 3 12.9 CII 0.4 2.70 1.1 0.21 0.58 0.05 11 7.6 Gl y c e r i a canadensis RG CI - - - - - - - -CII 0.0 2.40 0.6 0.30 0.53 0.04 7 6.8 RHG Ah 6.5 3.20 0.9 0.41 0.93 0.21 9 23.5 Cg 8.2 4.90 1.2 0.79 0.84 0.30 9 28.6 m ,e. per 100 g of S o i l P Species S o i l Horizon 0M% Ca Mg K Na N% ppm CEC Impatiens b i f l o r a RHG Ah 8 .1 3. ,60 1.1 0.43 0 .57 0. ,28 14 20. ,7 Cg - 1. ,50 0.7 0.20 0 .51 0. 40 6 21. ,4 Juncus effusus Humisol Oh 71 .5 9. .33 3.5 0.90 3 .64 0. 57 16 73. 4 Cg 1 .5 1. 33 0.6 0.51 2 .04 0. 02 5 19. ,2 Onoclea s e n s i b i l i s RHG Ah 46 .1 7. 30 2.3 0.79 1 .68 0. 76 24 76. .2 CgH 44 .7 5. 80 2.4 0.68 1 .58 0. 68 17 72. .0 CgH 8 .8 2. 70 2.0 0.53 1 .24 0. 28 11 26. 4 Phalaris arundinacea RHG (carb) Cg 5 .0 2. 60 0.6 0.45 0 .64 0. 55 8 14. 7 RHG Ah 22 .4 2. 90 1.1 0.57 5 .41 1. 77 9 14. 5 Cg 12 .0 0. 70 0.7 0.57 3 .88 0. 13 12 8. 0 Phragmites communis RHG L-H 32 .2 33. 10 4.3 0.40 0 .17 1. 02 5 66. 7 Ah 28 .4 18. 90 1.9 0.15 0 .13 0. 53 6 28. 4 C 10 .3 14. 10 0.9 0.12 0 .11 0. 22 8 10. 3 S a g i t t a r i a l a t i f o l i a RHG Ah 6 .1 2. 20 0.4 0.32 0. .71 0. 52 8 12. 2 Cg 3. .6 1. 50 0.4 0.34 0, .64 0. 39 9 9. 8 S a g i t t a r i a l a t i f o l i a RG C (upper) 0, .0 1. 90 0.9 0.72 0, .63 0. 00 12. 6 (ensiform) .0 1. 50 C (lower) 2. 0.5 0.51 0, .66 0. 63 7 9. 1 S a g i t t a r i a r i g i d a RHG Cgl 4.4 2.70 0.9 0.63 0.39 1.29 5 11.9 C g l l 10.4 2.60 1.0 0.60 0.74 1.17 6 14.7 Species m.e. per 100 g of S o i l P S o i l Horizon 0M% Ca Mg K Na N% ppm CEC Scirpus americanus RHG Ah 6.6 0.70 0.1 0.57 0.45 0.91 - 4.4 Cg 2.4 0.40 0.1 0.33 0.40 0.44 - 2.9 RHG Ah 3.1 0.70 0.1 0.57 0.45 0.51 5 2.6 Cgl 1.3 0.40 0.1 0.44 0.45 0.37 9 2.7 C g l l 0.6 0.60 0.2 0.44 0.47 0.15 2 4.8 Scirpus cyperinus RG Ah 2.8 1.40 0.2 0.20 0.58 0.15 6 12.4 Cg 3.1 1.30 0.2 0.17 0.58 0.12 6 15.4 RHG Ah 17.3 6.90 2.7 0.87 1.06 0.41 9 32.0 Cg 0.0 2.10 1.4 0.36 0.74 0.08 3 6.1 RHG Ah 4.6 0.46 0.1 0.57 0.42 1.01 12 5.9 Cgl 3.9 0.34 + 0.33 0.35 0.40 6 4.0 C g l l 1.8 0.34 + 0.57 0.45 0.38 6 3.0 Humisol Oh - 0.61 0.1 0.44 0.37 1.95 2 3.3 Cg 2.5 0.54 0.1 0.33 0.35 0.39 11 3.0 Scirpus rubrotinctus RG Ah 3.3 1.18 0.6 0.15 0.97 1.38 26 3.3 Cgl 0.9 0.71 0.6 0.15 0.95 0.18 13 4.0 C g l l 4.5 1.20 0.7 0.33 1.16 0.34 12 5.1 Species m.e. per 100 g of S o i l P S o i l Horizon 0M% Ca Mg K Na N% ppm CEC Scirpus f l u v i a t i l i s RHG Ah - 1.60 0.9 0.57 2.47 2.04 33 12.3 Cg 0.9 0.67 0.7 0.44 2.58 0.15 25 2.4 RHG (carb) Cg 4.3 2.45 0.5 0.57 0.48 0.64 6 9.5 Scirpus validus RHG Ah 12.6 1.50 2.0 0.67 5.18 0.96 12 15.8 Cg 2.3 2.00 1.0 0.46 3.88 0.08 6 11.9 Sparganium androcladum Humisol Oh 63.8 26.30 9.8 0.94 1.82 1.23 21 123.0 Sparganium eurycarpum RG Cg - 1.20 0.3 0.18 0.59 0.08 4 6.1 Spriaea alba RHG Ah - 3.40 1.5 1.17 7.11 9.14 6 24.4 Cg 2.7 1.00 1.1 0.82 4.46 0.36 3 11.7 Humisol Oh (upper) - 3.50 0.6 0.72 10.20 12.40 7 29.8 Oh (lower) - 3.80 0.6 0.52 10.40 2.20 3 31.3 Typha, nearly pure stands RG Ah 6.1 0.62 0.1 0.61 0.51 0.66 10 1.6 Cg 0.6 0.92 0.2 0.28 0.50 - 6 3.8 RHG Ah 12.6 6.60 2.4 0.75 0.91 0.75 9 22.3 Cg 2.9 1.95 0.6 0.61 0.67 0.48 9 9.7 Typha - S a g i t t a r i a communities R (H) G Cg 9.2 1.78 0.8 0.81 0.61 1.22 9 8.7 RHG Ah 18.9 1.89 0.5 0.61 0.54 2.14 13 9.4 Cg 5.7 1.43 0.5 0.61 0.54 0.76 9 10.1 m. e. per 100 g of S o i l P Species S o i l Horizon 0M% Ca Mg K Na N% ppm CEC Typha - S a g i t t a r i a RHG Ah 4.4 0.84 0.2 0.33 0.56 1.06 1 7.0 communities Cgl 4.0 0.63 0.1 0.82 0.33 0.59 5 4.8 CgH 0.8 0.80 0.2 0.57 0.35 0.23 3 5.3 Humisol Oh 64.4 7.30 2.8 1.41 1.73 0.87 13 80.9 Typha - Galium RG Ah — 1.93 0.8 0.45 3.27 0.93 5 12.4 communities Cg 1.3 1.06 0.5 0.37 2.13 0.21 7 9.7 RG Ah - 2.41 1.3 0.82 5.65 0.27 - 18.3 Cgl - 1.22 1.0 1.03 4.67 1.22 12 10.5 CgH 1.4 1.14 1.1 1.77 4.19 0.32 6 6.2 RHG Ah 16.3 2.74 1.2 0.78 3.91 3.79 14 19.3 Cg 2.7 1.85 1.3 0.84 3.46 0.37 16 12.6 RHG Ah - 1.22 0.9 0.82 5.00 3.24 46 10.4 Cgl 1.3 0.59 0.7 0.57 2.86 0.13 18 8.2 C g l l 0.4 0.46 0.6 0.57 2.86 0.07 34 4.0 RHG Ah - 2.41 1.3 0.82 5.65 0.27 - 18.3 Cgl - 1.22 1.0 1.03 4.67 1.22 12 10.5 C g l l 1.4 1.14 1.1 1.77 4.19 0.32 6 6.2 m. e. per 100 g of S o i l P Species S o i l Horizon 0M% Ca Mg K Na N% ppm CEC Typha - Galium Humisol Oh! 69.8 12.70 6.3 2.21 1.51 0.74 16 95.5 communities 0h 2 78.0 9.80 4.5 1.52 1.40 0.70 15 73.3 Oh 3 83.6 8.20 9.7 1.43 1.78 0.65 24 81.6 - Cg 3.6 2.70 2.0 0.49 1.06 0.21 17 21.5 Humisol Oh 61.7 3.90 1.2 1.39 0.85 0.87 23 116.3 Cg 4.0 2.60 1.2 0.27 0.72 0.13 10 19.5 O h l l 74.1 7.90 2.3 0.96 1.39 1.-15 27 82.3 C g l l 0.0 1.10 0.7 0.12 0.45 0.06 11 11.1 C g U I 0.0 1.30 0.6 0.10 0.37 0.06 10 13.4 Humisol Oh 37.5 12.40 5.1 1.06 1.39 0.74 22 48.8 Cg 1.8 3.20 1.2 0.34 0.79 0.07 5 12.0 O h l l 40.7 12.70 5.3 0.83 1.21 0.68 16 56.1 Humisol Oh 68.8 6.20 3.4 0.91 2.51 2.06 19 62.9 Cg 9.4 2.05 0.9 0.63 1.56 0.59 12 16.0 Typha, f l o a t i n g mat F i b r i s o l Of 64.8 2.67 0.8 1.09 1.48 7.85 20 12.6 Zizania aquatica RG Cg - 3.20 0.8 1.03 0.42 - - 22.1 RHG comp - 4.20 3.5 0.85 1.70 0.37 6 -Legend: Horizon and w o i l designations as i n Part I of Table XIII. OM, organic matter; N, nitrogen, as determined by micro-Kjeldahl method; CEC, cation exchange capacity. 152 which support Typha and other species contain no detectable amounts of organic matter, but s t i l l growth i s vigorous for a l l , suggesting that marsh plants require only minimal amounts of organic matter and nutrients to produce adequate growth patterns. Accumulation of horizons of organic matter i n wetlands indicates s t a b i l i t y of both s o i l and s i t e , a measure of the time colonized (most c o l o n i z a t i o n i s on bare mineral s o i l ) and the e f f e c t s of leaching (or lack thereof) by moving water. Results of percentage nitrogen analysis follow a pattern-similar to that of organic matter, but values are of course lower. A v a i l a b l e phosphorus p a r a l l e l s nitrogen and organic matter r e s u l t s . Values f o r sodium probably r e f l e c t the s i t e character, rather than the degree of requirement by vegetation. In Ramsayville marsh, the base i s marine clay, and s i t e s are high i n sodium. The e n t i r e range of a v a i l a b l e sodium on Typha-dominated s i t e s i s 0.3 - 27.2 m.e. per 100 g of s o i l i n the Ah horizons and 0.4 - 7.7 m.e. per 100 g of s o i l i n C horizons. Ramsayville has the maximum of sodium, and a l l other s i t e s are low in.the range. Tolerance of Typha to high sodium concentrations has already been substantiated (McMillan 1959). C e r t a i n l y on a l l s i t e s , performance of Typha was not l i m i t e d by amounts of t h i s ion. Tolerance f o r sodium of competing species however has not previously been studied. Considering the species pool of p o t e n t i a l dominants which i s a v a i l a b l e i n the Ottawa area (see Appendix I ) , Ramsayville marsh i s cu r i o u s l y devoid of large dominants other than Typha. Indeed, the only other dominants i n t h i s large marsh, making large enough stands to be worth noting, and which are s u c c e s s f u l l y completing t h e i r reproductive cycles are Juncus effusus, Phalaris arundinacea i n addition to Spiraea alba and Agrostis s t o l o n i f e r a which grow on d r i e r s i t e s above the main l e v e l s of the marsh. Tolerance f o r sodium (or lack thereof) may also a f f e c t some of the minor species as w e l l , such as Acorus calamus, Scirpus 153 americanus and S a g i t t a r i a l a t i f o l i a , none of which were found i n Ramsayville marsh, although they are abundant elsewhere i n the d i s t r i c t . Potassium data for s o i l s dominated by Typha show that Typha can to l e r a t e a range of 0.14 - 3.4 m.e. per 100 g of s o i l f o r the Ah horizon and 0.1 - 1.77 as the base amounts for C horizons. Potassium does not appear to be a l i m i t i n g f a c t o r for Typha i n the range which has been recorded. However some other dominants were found to make better growth on low-potassium s i t e s . These are Impatiens b i f l o r a , Scirpus americanus, Dulichium arundinaceum and Phragmites communis. On Typha-dominated s i t e s , calcium values range from 0.22 - 24.9 m.e. per 100 g of s o i l i n Ah horizons and 0.22 - 14.5 m.e. i n C horizons. Only at the lowest part of the range do the plants make poor growth, and i n the higher parts of the range growth becomes luxuriant. Lower ranges of calcium are probably l i m i t i n g for Typha, but the upper range i s probably open-ended, and Typha w i l l t o l e r a t e habitats with high amounts of a v a i l a b l e calcium. Most plant species respond well to adequate amounts of a v a i l a b l e calcium, however i t should be noted that several other dominants measured have, calcium amounts i n the s o i l s that suggest that t h e i r lower l i m i t s f o r calcium l i e far above the lower l i m i t s for Typha. Some of these are Agrostis s t o l o n i f e r a , Calamagrostis canadensis, Phragmites communis, Sparganium androcladum and Zizania aquatica. Magnesium of s o i l s dominated by Typha ranges from 0.05 - 11.8 m.e. per 100 g of s o i l i n Ah horizons and 0.1 - 4.9 m.e. i n C horizons. Within these l i m i t s , magnesium does not appear to be a l i m i t i n g f a c t o r to the growth of Typha. A l l other dominants have a v a i l a b l e magnesium values which f a l l w ithin the range tolerated by Typha. As expected, amounts of cations a v a i l a b l e to plant systems are higher i n Ah horizons than i n the parent C horizons. This r e f l e c t s the modification 154 of upper horizons by l i v i n g organisms, p a r t i c u l a r l y the vegetation dominants. Rapid and e f f i c i e n t r e c y c l i n g of ions, so that they concentrate i n mineral-organic laye r s , i s t y p i c a l of wetland habitats, and of Typha communities i n p a r t i c u l a r . Moisture content r e f l e c t s the nature of the s o i l , depth of water table, and often i n marshes, the presence of water-impervious layers i n the lower parts of the s o i l system. On Typha s i t e s , moisture contents of s o i l s are high i n the Ah horizons (approximately'43%) and low i n C horizons (approximately 23%). This condition i s not exclusive to Typha-dominated s i t e s , since t h i s s o i l c h a r a c t e r i s t i c i s shared by s o i l s found beneath the following dominants: Acorus calamus, Juncus effusus, Phalaris arundinacea, Phragmites communis, S a g i t t a r i a l a t i f o l i a , Scirpus americanus, and f l u v i a t i l i s . Beneath the marshes, the impervious layer i s usually f i n e l y -sorted alluvium, which has some moisture, but has such f i n e pores that l i t t l e water passes through the horizon. For Phragmites, a s i m i l a r condition obtains even though the C horizon i s sand. Slow drainage here r e s u l t s from the pores between sand grains being plugged with f i n e organic material. For marshes not founded d i r e c t l y on bedrock, these appear to be the two p r i n c i p a l mechanisms of water re t e n t i o n . S o i l s which do not follow the t y p i c a l wetland patterns for moisture content are the Rego Humic Gleysols which are found i n the moist areas of the wetland gradient. A l l of these s o i l s have thick Ah horizons which are both f r i a b l e and porous, and during the summer months, water l i e s w e l l below the surface of the s o i l . Therefore, surface layers are d r i e r than the lower horizons and then become saturated below the l e v e l of the water table. Such s o i l s do not support Typha, since they are too dry at intermittent i n t e r v a l s during the growing season. However i n the wetter parts of the marsh, Rego Humic Gleysols which lack the p o s s i b i l i t y of the surface layers drying out, 155 can and do support Typha. The i n t e r m i t t e n t l y dry s i t e s , j u s t mentioned, support Agrostis s t o l o n i f e r a and Spiraea alba. Very high moisture content f o r a l l times of the growing season have been recorded above for the f l o a t i n g mat communities of Typha. Substrate on these i n t e r e s t i n g s i t e s has excesses of moisture ( i n the mat 91%), rather low n u t r i e n t concentrations and of course high exposure to l i g h t , so that dwarfing of many of the subordinate species i s common. Under these conditions, Typha appears l i t t l e a f f e c t e d , although growth habit i s reduced from that of Typha rooted i n a conventional s o i l substrate. The measure of successful growth of Typha, even under the adverse conditions of a f l o a t i n g mat, suggests that the plants are highly e f f i c i e n t i n t h e i r manner of water uptake as well as t h e i r u t i l i z a t i o n of l i m i t e d n u t r i e n t supplies. Cation exchange capacity (CEC) i s a measure of exchange s i t e s on s o i l p a r t i c l e s . The s o i l f r a c t i o n s which are most a c t i v e i n exchange or retention of cations are humus and clay f r a c t i o n s r e s p e c t i v e l y . This means that CEC var i e s with the amounts of these f r a c t i o n s as w e l l as the nature of the clay f r a c t i o n and the amounts of organic material. In the C horizons tested (see section on Approximate Mineralogy) the so- c a l l e d c l a y f r a c t i o n consists of primary minerals only, so that i t i s e s s e n t i a l l y rock f l o u r , weathered mechanically to p a r t i c l e s of clay s i z e . Thus the number of exchange s i t e s i n such a f r a c t i o n i s low. Only where organic f r a c t i o n s are present does CEC increase, and with the increase, a v a i l a b l e s i t e s f o r ion retention are also increased. This r e l a t i o n s h i p , between CEC and amounts of organic matter, i s apparent i n the r e s u l t s i n the tab l e . Results of CEC are also correlated with amounts of N and P. In the table, horizon depths are expressed i n cm, and maximum depth i s usually expressed as being l e s s than 75 cm, which i s the length of the corer used i n the f i r s t season of sampling. Horizons which continue below 156 t h i s depth are indicated with a plus (+) sign. Rooting depths for marsh plants are much shallower than t h i s f i g u r e . In Ramsayville marsh, clay horizons are several hundred feet t h i c k , according to geological reports. On other s i t e s , the clay layer i s thinner, but nonetheless exceeds the rooting depth of the marsh species. An Oh or Ah i s present wherever shown i n the table, since the s o i l types have been separated into t h e i r various categories by t h e i r s i m i l a r horizons. Results show that Typha and many other marsh species can colonize habitats from bare clay to organic s o i l s (provided adequate moisture content i s present i n the s o i l s ) . Accumulation of organic horizons by Typha can be demonstrated by observing the increase i n Ah horizons through the progression from the pure Typha communities of deeper waters to the Typha - Galium communities. Depth of the Ah horizon does not appear to influence the growth of Typha communities. I t does however appear to a f f e c t the growth c h a r a c t e r i s t i c s of S a g i t t a r i a l a t i f o l i a . A vigorous emergent aquatic, S a g i t t a r i a should be capable of producing mature (sagittate) leaves on a l l shallow wet s i t e s . However the mature form i s found only where there i s a developed Ah horizon, more n u t r i e n t - r i c h than the C horizon, and i t i s the form of S a g i t t a r i a which bears only j u v e n i l e leaves which p e r s i s t s on bare clay substrates. When the organic layer has accumulated, the saturated humus layer allows S a g i t t a r i a to grow with i t s mature l e a f form. The range of pH values i s considerable, i n d i c a t i n g that Typha can grow w e l l on s o i l s which range i n pH from 4.2 - 8.0, although average pH tends to be circumneutral. With the knowledge that pH fluctuates i n both s o i l and water throughout the growing season, i t may be assumed that tolerance for short periods may exceed even the measured range. Tolerance for a pH range of 4.0 - 6.0 i s found i n the following species: Acorus  calamus, Juncus effusus, Onoclea s e n s i b i l i s , S a g i t t a r i a l a t i f o l i a (form with 157 j u v e n i l e leaves), Scirpus cyperinus and Sparganium androcladum. The majority of the dominants are found on a range of 6.0 - 7.0. These are: Agrostis  s t o l o n i f e r a , Butomus umbellatus, Dulichium arundinaceum, G l y c e r i a canadensis, Epilobium hirsutum, Phalaris arundinacea, S a g i t t a r i a l a t i f o l i a , Scirpus  americanus, S_. rubrotinctus, J3. f l u v i a t i l i s and _S. v a l i d u s . Growing i n a more a l k a l i n e range of pH are S a g i t t a r i a r i g i d a (7.7 - 8.5), Phragmites  communis (6.4 - 8.0 and probably higher, though not i n t h i s study) and Z i z a n i a aquatica (7.0 - 8.0). The l i m i t a t i o n of pH ranges suggests that although Typha may have competitors of d i f f e r e n t species over the e n t i r e range of growth, i t i s possibly the only plant which can compete over so wide a range of pH values. A l l plants recycle n u t r i e n t s , which are deposited, on the death and decay of vegetation, i n the s o i l substrate. Concentrations of these nutrients soon appear i n greater amounts near the s o i l surface and i n the rooting layer than they are i n the parent horizons. As accumulation of r i c h surface horizons proceeds from s o i l s of the Rego Gleysol type to the t h i c k Humisols of mature Typha s i t e s , i t suggests that Typha i s highly successful i n s o i l c o nsolidation and even s t r u c t u r i n g , following i t s c o l o n i z a t i o n of bare mineral s o i l substrates. Summary of Section III The factors of l i g h t , s o i l and water are of great importance to aquatic communities. Marsh dominants l i v e under f u l l i n s o l a t i o n , appear to have high e x t i n c t i o n points, and most cannot survive as subordinate species. This renders marsh communities susceptible to overtopping and thus to succession by woody species. In contrast, the subordinate species of marshes not only can complete t h e i r l i f e c y c les under conditions of very low l i g h t i n t e n s i t y , but also grow well under f u l l i n s o l a t i o n . Since these species have a wide tolerance f o r l i g h t , they are l i m i t e d i n t h e i r environment mainly 158 by factors of substrate, such as n u t r i e n t and moisture requirements. Both water and s o i l c o n s t i t u t e the substrate f o r aquatic plants, the water functioning as substrate for the f r e e - f l o a t i n g communities, while s o i l functions as substrate for the rooted emergents. Where water i s very shallow, i t tends to operate as an extension of the s o i l s o l u t i o n , but with frequent changes i n depth and concentration due to run-off from p r e c i p i t a t i o n , d i r e c t c o r r e l a t i o n s are not possible. In s o i l requirements f o r growth, Typha colonizes areas where moisture content i s c o n s i s t e n t l y high, but n u t r i e n t s may be low. As such, i t appears that minimal requirements for growth of Typha can e a s i l y be met by most wetland s o i l s , thus giving Typha a competitive advantage over many p o t e n t i a l competitors with high nutrient requirements. Under the influence of Typha communities, and presumably under the influence of other major dominants as w e l l , s o i l development proceeds from the minimal Rego Gleysol to organic Humisols of mature communities. Deposition of organic matter and r e c y c l i n g of nutrients enriches and consolidates wetland s o i l s , so that i n mature s o i l s , the substrate i s highly organic and ion-enriched. PLANT - SOIL - WATER RELATIONSHIPS 160 SEASONAL BEHAVIOUR OF THE TWO MARSH COMPETITORS, TYPHA CLAUCA AND PHRAGMITES COMMUNIS In eastern Canada, Typha, f o r the most part, i s unopposed as the major dominant. However, i n many parts of the world, i n Canada p a r t i c u l a r l y i n the p r a i r i e provinces, Phragmites communis i s common, and becomes the only major competitor to Typha. To determine whether these two dominant plants grow under the same environmental conditions two studies, done on Typha  glauca i n 1968 (at Ramsayville Marsh, south of Ottawa), and on Phragmites  communis i n 1969 (at Point Pelee Marsh) were undertaken. Both sample stands were rooted i n s o i l , o v e r l a i n by shallow water, a set of conditions which i s assumed to be normal for both species. Relevant environmental and b i o l o g i c a l data were accumulated on a selected stand i n which either of the two species was dominant, beginning i n early spring and ending i n the f a l l of the same year. For Typha, the seri e s of sampling was longer than f o r Phragmites. Data taken are s i m i l a r to those for i n d i v i d u a l p l o t s . Samples were c o l l e c t e d from each stand at regular i n t e r v a l s , usually twice a week, throughout the growing season. SEASONAL VARIATION IN TYPHA GLAUCA General. The study was done i n the Ottawa d i s t r i c t , where perceptible growth of T_. glauca begins i n l a t e A p r i l . Current shoots are derived from buds i n i t i a t e d during the previous f a l l , as Typha i s a perennial. With cooling temperatures, these buds enter a period of winter dormancy. As spring commences, the buds, covered by short l e a f scales, are shorter than 4 cm. During the spring and summer the shoots may reach up to 3 m i n height. The female flowers of the spike begin to emerge i n early J u l y , and p o l l e n i s shed i n l a t e J u l y . The inflorescence i s overtopped by leaves. Sampling and Analysis. Vegetation and s o i l samples were taken a minimum of twice weekly through the growing season, commencing May 7, 1968, 161 and continuing u n t i l November. Plant samples consist of l e a f , rhizome and f l o r a l s t a l k samples. A measure of growth i s obtained by measuring the l e a f length. S o i l samples were drawn using the s p l i t - c o r e s o i l corer which produces a more or less undisturbed core. Light, temperature, r e l a t i v e humidity and oxygen reading were also obtained. S o i l . The s o i l beneath the Typha stand belongs to the G l e y s o l i c Order, Rego Humic Gleysol subgroup (N.S.S.C. 1970). A l l samples show w e l l -defined Ah and Cg horizons. Ah horizons vary from 10 to 30 cm i n depth with the clay Cg extending below. The rhizosphere of Typha i s r e s t r i c t e d to the Ah horizon, and a l l chemical analysis data i n the comparison are based on r e s u l t s from t h i s horizon. Environmental Data for Stand. Light readings above the stand f l u c t u a t e d a i l y , but usual readings on cloudless days are between 50,000 and 90,000 lux. A i r temperature measured at noon hour fluctuates with the season from early May at 14°C to a high of 38°C i n July, f a l l i n g to a low of 7°C i n November at the end of the sampling period. Water temperatures f l u c t u a t e from a low of 14°C i n May to a high of 25°C i n J u l y and a November low near freezing point. Water oxygen values f l u c t u a t e from a high of 19.9 ppm to a low of 1.0 ppm. Relative humidity within the stand fluctuates from a May low of 30% R.H. to a growth period high of 96% a f t e r flowering (July 28) to a September low of 56% R.H. S o i l Temperature Regime. The s o i l shows a marked s t r a t i f i c a t i o n of temperature throughout the growing season, and a temperature inv e r s i o n occurs i n the s o i l i n the f i r s t week of October (Figure 63). Due to the water overlying the s o i l i n the year i n which the study was done, s o i l temperature f l u c t u a t i o n s occurring a f t e r each r a i n f a l l were not observable. However, temperature f l u c t u a t i o n s i n the s o i l under the Typha do occur even to depths of 60 cm, although probably only the temperatures at zero l e v e l 21 MAY IO 3 0 JUNE 2 0 JULY 9 29 AUGUST 18 S E P T E M B E R 8 28 OCTOBEP Figure 63. Seasonal v a r i a t i o n i n water and s o i l temperatures for Typha glauca communities at Ramsayville marsh. Data for 1968. A d d i t i o n a l graph l i n e indicates time of flowering. 163 down to 20 cm depth are of d i r e c t importance to the growth of the community, since no roots penetrate below t h i s l e v e l . Three periods of growth i n Typha coincide with changes i n s o i l temperature. The f i r s t occurs i n early J u l y , when the flowering period begins. This period i s followed by rapid maturation and f r u i t set, corresponding to the f i r s t two weeks of August and the peak of s o i l temperatures. No increase i n growth occurs a f t e r August 20, and by the f i r s t week i n September, Typha i s showing external signs of senescence. The f i r s t period coincides with r a p i d l y warming s o i l temperatures, coupled with high p r e c i p i t a t i o n (Figure 4) and prolongation of day length. The second period i s one of high p r e c i p i t a t i o n and peak s o i l temperatures, although length of day has begun to shorten. The t h i r d period, of senescence i n Typha coincides with decreasing s o i l temperatures, low p r e c i p i t a t i o n , and a time when the water of the Typha marsh i s subsiding, and s a l t s of s o i l and water are becoming more concentrated. Day length i s also shortened. Nutrient uptake i s then l i m i t e d by low a v a i l a b i l i t y due to d e c l i n i n g s o i l and water temperatures. In November, water above the s o i l becomes colder than the s o i l , and upper l e v e l s of the s o i l become colder than lower l e v e l s . Plant Growth and Moisture Content. Leaf t i s s u e shows high moisture content u n t i l the l a s t 10 days of July with continual decrease u n t i l the end of the vegetative season (Figure 64). F l o r a l s t a l k t i s s u e exhibits a continual decline i n moisture content from the i n i t i a l sampling, while rhizome material maintains a continuous r e l a t i v e l y uniform high moisture content. If constancy of moisture content i n plant material may be. interpreted as a measure of r e g u l a r i t y of metabolic a c t i v i t y , then any deviation of moisture content would then suggest a departure from regular a c t i v i t y . In the case of perennials, such deviation probably represents onset of seasonal senescence. From moisture content data f o r Typha glauca, 164 Figure 64. Seasonal v a r i a t i o n of moisture content i i i Typha glauca. Data for 1968. A d d i t i o n a l graph l i n e indicates time of flowering. 165 t h i s occurs i n l a t e July at the time of p o l l i n a t i o n and s h o r t l y before the peak of l e a f extension (Figure 65). F l o r a l stalks show a gradual decline i n moisture content from f i r s t detection, while rhizome tissue maintains a constant moisture content throughout the whole sampling period. Leaf length has been taken as a measure of growth, and t h i s reaches a peak about the middle of August. Then d e s i c c a t i o n and fragmentation of a p i c a l portions of the l e a f reduces actual l e a f length. Thus May 7 to August 18 may be considered the period of active growth. Calcium. In Typha glauca, calcium i s taken up by the l e a f t i s s u e i n such a way that i n May i t contains about 6 mg/g dry weight calcium, reaching a peak of 9.5 mg/g i n J u l y , coincident with the peak of l e a f extension. As seasonal senescence advances, i t declines i n concentration i n the l e a f to about 6 mg/g dry weight of the l e a f . At t h i s stage the amount of calcium i s either a c t u a l l y lower, or else i s being leached from dead t i s s u e . Since the leaves involved were l i v i n g when sampled, the l a t t e r condition of calcium loss i s u n l i k e l y . Upon f i r s t appearance of f l o r a l s t a l k s a f t e r June 23, high concentrations (of up to 10.8 mg/g dry weight) of calcium are detected i n the s t a l k s . F l o r a l s t a l k t i s s u e then shows a marked and continual decline to the end of sampling, at which time i t has a concentration of 4.1 mg/g dry weight. The rhizome tis s u e concentration p a r a l l e l s that of l e a f t i s s u e with a smaller o v e r a l l v a r i a t i o n of minimal and maximal values. The s o i l horizon shows a coincident loss of calcium upon uptake by the plant material. Calcium plots for t i s s u e and s o i l appear i n Figure 66. Magnesium. In a l l plant t i s s u e samples, magnesium (Figure 67) shows a gradual decline from i n i t i a t i o n of sampling i n May u n t i l termination of sampling i n November. In the leaves, the decrease occurs rather sharply, and declines from 2.8 to about 1.6 mg/g dry weight magnesium at the end of the sample period. An apparently coincident, though e r r a t i c change occurs i n 12 26 9 23 7 21 4 18 I. 15 29 13 27 IO 24 M J J A S O N Figure 65. Growth pattern of leaves i n Typha  glauca. Data for .1968. A f t e r August 18, the photosynthetic parts of the blade are reduced through desiccation and f r a y i n g . A d d i t i o n a l graph l i n e indicates time of flowering. 167 3 8 *0 * • 12 3t 9 23 7 31 4 18 I t5 29 O 27 IO M J J A S O N I _ — 1 ; Figure 66. Seasonal V a r i a t i o n of calcium content i n Typha glauca and s o i l . Data from 1968. A d d i t i o n a l graph l i n e indicates time of flowering. '1 )-4 11 l O It 24 14 « • J O l * i l -A e 2 D 5) u z o »6 < 2 34 12 J O 26 2-6 34 a-2 ao i-e F L O W E R S T A L K S I. I t * ' 0 8 • 0 » • • • • S O I L A h L A Y E R 12 26 0 23 7 21 4 18 t 15 29 13 27 tO Figure 67. Seasonal v a r i a t i o n of magnesium i n Typha glauca and s o i l . Data for 1968. Ad d i t i o n a l graph l i n e indicates time of flowering. 169 the s o i l l a y e r . I t appears that the magnesium content of the s o i l lowers s l i g h t l y when the concentrations are highest i n the l e a f , and becomes higher when the concentration i s lowest i n l e a f t i s s u e . Sodium. Sodium concentration of l e a f and f l o r a l s t a l k t i s s u e both peak around July 21, with concentrations at the peak higher i n the f l o r a l s t a l k (10.2 mg/g) than i n the l e a f t i s s u e (8.0 mg/g). In the leaves, concentrations show a continual decline a f t e r July 21 to a low concentration of 1.7 mg/g dry weight at the end of sampling. F l o r a l s t a l k t i s s u e concentration declines to a low sodium concentration of 2.1 mg/g dry weight. High l e v e l s of sodium are coincident both with flowering and with higher l e v e l s of sodium i n the s o i l sample. Although the i n i t i a l gradual increase may be associated with early growth phenomena, the coincident peaks i n the s o i l samples suggest that the concentration increase may be a passive response to the plant environment. Nevertheless, i t becomes evident that i n Typha leaves and other organs, that i n proportion to the concentration i n the s o i l , uptake i s very high, and that Typha i s evidently tolerant of high concentrations of sodium i n i t s tissues (see Figure 68). Iron. Iron concentration i s inversely r e l a t e d to calcium i n a l l tissues (Figure 69). I n i t i a l and terminal peaks are seen i n both l e a f and rhizome t i s s u e while the f l o r a l s t a l k shows a continual s l i g h t increase i n i r o n concentration i n the tissues from the f i r s t sampling. The concentrating e f f e c t of uptake into the tissues i s very great i n the case of i r o n , which i s found i n the gleyed s o i l i n only small amounts (average 0.03 mg/g dry weight of s o i l ) . The concentration e f f e c t i s seen most strongly i n the rhizome t i s s u e where the peak at the beginning of the sampling period i s 3.8 mg/g, d e c l i n i n g to a low of 0.6 mg/g and at the end of the sampling period returning.only to a concentration of 2.1 mg/g. The e f f e c t i s l e a s t i n the f l o r a l s t a l k where the concentration e f f e c t i s something over tenfold 1.8 • 1 4 I O -O S O 2-3 4 3 0 -2 6 2 2 18 14 I O 0-6 O S -0 3 O l • SOIL Ah LAYER 12 26 M 9 23 J 7 21 J 4 18 A 29 13 27 10 O N Figure 69. Seasonal v a r i a t i o n of i r o n i n Typha  glaUca and s o i l . Data from 1968. A d d i t i o n a l graph l i n e indicates time of flowering. 172 i n the process of uptake. Potassium. Leaf concentration of potassium i s inversely r e l a t e d to rhizome tis s u e concentration (Figure 70). Leaf t i s s u e concentration i s high (20 mg/g dry weight) during early meristematic a c t i v i t y showing a continual decline from the week of May 26, which i s p r i o r to completion of l e a f elongation or seasonal senescence of l e a f t i s s u e , to a low (average) of 12.0 mg/g dry weight. In the same i n t e r v a l , the rhizome concentration r i s e s from a low of 8.7 mg/g to a f i n a l high concentration of 20 mg/g dry weight. F l o r a l s t a l k t i s s u e maintains i t s high concentration through the e n t i r e period of sampling, with f l u c t u a t i o n s i n concentration from 17.7 to 20 mg/g dry weight of t i s s u e . The s o i l samples do not show coincident f l u c t u a t i o n with plant material. Potassium i s transferred p r i m a r i l y from l e a f to rhizome t i s s u e f o r storage a f t e r early meristematic a c t i v i t y and i n i t i a l l e a f elongation. No c o r r e l a t e d transfer i s detectable between plant and s o i l m a t erial. However, i t i s quite obvious that Typha i s able to concentrate r e l a t i v e l y large quantities of potassium i n i t s t i s s u e s , f a r beyond concentrations which occur i n the s o i l . Phosphorus. Leaf concentrations of phosphorus are inversely r e l a t e d to rhizome phosphorus concentrations (Figure 71), as they are for potassium. Leaf t i s s u e shows an i n i t i a l peak (3.5 mg/g) i n the months of May and June with a gradual decline a f t e r the week of June 23 u n t i l the end of sampling (1.0 mg/g dry weight). Rhizome t i s s u e shows a coincident and opposite response (from a low of 1.0 mg/g to a high of 3.7 mg/g dry weight). In f l o r a l s t a l k t i s s u e , as f o r other ions analysed, a continual d e c l i n e i n phosphorus i s exhibited from the f i r s t detection of the s t a l k (from 3.7 to 1.0 mg/g dry weight). Variations i n s o i l phosphorus do not correspond to changes i n concentration i n the plant t i s s u e s . Phosphorus i s maintained i n l e a f t i s s u e during the early period of a c t i v e growth (Figure 65), and i s 2 0 ' ' « ... • 19 F L O W E R S T A L K S . . . 1 8 . . " .. . S O I L A h L A Y E R 12 2 6 9 2 3 7 21 i 18 I 15 2 9 13 2 7 I O M J J A S O N Figure 70. Seasonal v a r i a t i o n of potassium i n Typha glauca and s o i l . Data from 1968. A d d i t i o n a l graph l i n e indicates time of flowering. LEAVES O.S 1 1 X u > D E i/l tr O i a. O I O-3 5 2-5 1-5 O S •46| 38 30 22 .14 FLOWER STALKS , , . .1 . • k-SOIL Ah L A Y E R • i i i i 12 26 9 23 7 21 4 18 I 15 29 13 27 IO M J J . A S O N Figure 71. Seasonal v a r i a t i o n of phosphorus i n Typha  glauca and s o i l . Data from 1968. Ad d i t i o n a l graph l i n e indicates time of flowering. 175 then transferred to rhizome tissue for storage, upon seasonal senescence of the l e a f t i s s u e . No t r a n s f e r between s o i l and plant material i s detectable. In r e l a t i o n to concentrations of s o i l phosphorus, accumulation of phosphorus by Typha i s i n high concentrations. Summary. Seasonal ion concentration curves suggest that, i n terms of u t i l i z a t i o n , the ions may be grouped t e n t a t i v e l y into three categories. The f i r s t group includes those which are c l e a r l y cycled annually between s o i l and plant, such as calcium and magnesium (calcium data show a clear response i n the s o i l , i n d i c a t i v e of annual c y c l i n g , while magnesium, though less c l e a r , might be expected to return small amounts to the s o i l substrate as the upper parts of the plant decay). The second category contains those ions of which the major portion i s stored within the plant system, with c y c l i n g occurring between d i f f e r e n t plant organs, dependent upon seasonal requirements. Both potassium and phosphorus belong to t h i s category, with transfer from leaf to rhizome occurring as seasonal senescence begins i n the l e a f t i s s u e . In the t h i r d category are those ions which appear to fluctuate p a s s i v e l y , such as sodium and i r o n . Sodium appears to vary passively with external s o i l concentration, but a case may also be made with t h i s ion for actual accumulation by Typha, since the concentrations i n the tissues are so high. Iron may also f l u c t u a t e passively i n the plant t i s s u e , with v a r i a t i o n i n t o t a l ion concentration of the plant material, but the graphs i n d i c a t e that accumulation increases i n a l l tissues as the season advances. 176 SEASONAL VARIATION IN PHRAGMITES COMMUNIS General. This study was done i n Point Pelee Marsh, during the summer of 1969. At Point Pelee, growth of Phragmites commences towards the end of A p r i l . As i n T_. glauca, the buds of the current year's growth are formed i n the f a l l of the previous year, remaining dormant during the winter, and resume growth i n the spring. At the end of each growing season, the current a e r i a l shoot dies, and a number of second-order shoots are produced from l a t e r a l buds. In d i v i d u a l stools p e r s i s t for several years. Flowering from terminal densely-flowered panicles occurs i n the l a t e part of July ( f i r s t flowering i s t h i s study occurred on July 25, and some plants continued to flower into September). The inflorescence overtops the mature leaves, since the leaves are l a t e r a l to the culm and spreading. Sampling and Analysis. Methods of sampling and analysis are the same as for T_. glauca, except that the sampling period i s shorter (May 19 to August 31). For measurement of oxygen content of water a YSI Oxygen meter, c a l i b r a t e d against standard Winkler t i t r a t i o n s was used. S o i l . Beneath the Phragmites stand, the s o i l belongs to the G l e y s o l i c Order, Rego Humic Gleysol subgroup, with a 7.5 to 15.0 cm saturated L-H and a 24 to 36 cm organic plus s i l t Ah horizon deposited over a sandy C horizon. The water which o v e r l i e s the s o i l f luctuates i n depth from 21 to 62 cm. The rhizosphere of Phragmites extends w e l l i n t o the Ah horizon, but does not penetrate the C horizon, so that analysis of s o i l i s based on r e s u l t s from the L-H and Ah horizons only. Ah r e s u l t s are shown on the graphs. Environmental Data. Light readings above the stand vary during the sampling period from 15,000 to 94,000 lux, readings being taken at mid-day. Within the stand, l i g h t v a r i e s from 1 to 50% of readings made on open sky. Water temperatures f l u c t u a t e from a low i n May of 12.8°C to a high of 25°C on August 29, followed by a s l i g h t temperature decrease. Oxygen 177 content of water decreases s t e a d i l y from a high of only 3.5 ppm at the beginning of the sampling period to a low at the end of the sampling period of only 0.2 ppm, at which time an a l g a l bloom was present on the water surface. S o i l Temperature Regime. S o i l temperatures show s t r a t i f i c a t i o n (Figure 72) with the layers c l o s e s t to the surface showing higher temperatures than the lower l a y e r s . S o i l temperatures do not reach t h e i r maximum u n t i l l a t e J u l y , coincident with the beginning of the flowering period i n Phragmites. These temperatures are maintained u n t i l the end of the sampling period. At the same time growth slows (Figure 73), and moisture content of le a f t i s s u e (Figure 73) continues to dec l i n e . Growth and Moisture Content of Leaves. In Phragmites, l e a f t i s s u e commences with a moisture content of above 80 percent, and declines continuously to a low of 53.5 percent on the l a s t sampling date. Although only l e a f samples have been considered i n Phragmites, los s of water content from the l e a f suggests that early i n the growing period, l e a f tissues begin to lose metabolic e f f i c i e n c y , even p r i o r to flowering, and that f or mature leaves, seasonal senescence c l o s e l y follows the maturation process. In Phragmites, growth of the plant has been measured as increase i n actual height. The curve (Figure 73) indicates that there i s a continuous increase i n actual height occurring up to the end of the sampling period, with r a p i d increase occurring i n l a t e May and the early part of June, and becoming gradually slower as the season progresses. This suggests that the growth pattern of Phragmites i s roughly indeterminate for a sing l e growing season, and that the plant probably continues growth at a reduced rate u n t i l cold and other environmental factors cause growth to cease e n t i r e l y . The growth period f o r t h i s plant involves the en t i r e summer season, and i s not r e s t r i c t e d to the e a r l i e r part of the summer. O l I I I I 1 1— 1 1 U 1 1 1 1_ 23 31 8 16 24 2 IO 18 26 3 II 19 27 MAY J U N E JULY A U G U S T Figure 72. Seasonal v a r i a t i o n i n water and s o i l temperatures f o r a stand of Phragmites communis at Point Pelee marsh. Data f or 1969. Additional graph l i n e indicates time of flowering"! ' 179 Figure 73. Growth and moisture content graphs for Phragmites  communis. Upper, seasonal increase i n height. Lower, seasonal change i n moisture content. Data for 1969. A d d i t i o n a l graph l i n e i ndicates time of flowering. 180 Calcium. In the week of June 15, coincident with the most rapid plant growth, demand f o r calcium increases, and increasing amounts are taken up. Uptake continues to increase and i s s t i l l proceeding at a high l e v e l at the end of the sampling period. Progression i n uptake i s from a low at the beginning of the sampling period of 8 mg/g dry weight to a f i n a l concentration of 16 mg/g dry weight (Figure 74). This information suggests that seasonal senescence i n Phragmites probably does not occur u n t i l external factors of the environment prevent further uptake of ions. Neither the Ah horizon of the s o i l , nor the water above the s o i l show any trend i n calcium concentration throughout the growing season, but i n the L-H horizon of the s o i l , calcium values lower towards the end of the growing season. This suggests that a continuous drain i s being made on the substrate through the en t i r e period of growth. Magnesium. In leaves of Phragmites, magnesium content shows a gradual decline from the beginning of sampling u n t i l the week of June 15, then exhibits a marked d e c l i n e . From i n i t i a l sampling at a concentration of 9 mg/g dry weight, the decline continues to a low of 5.8 mg/g dry weight at the end of the sampling period (Figure 75). The change i n concentration at the week of June 15 coincides with a sharp decline i n moisture content of lea f m a t e r i a l . A s l i g h t trend toward increase i n magnesium content of the L-H horizon occurs i n the l a t e r part of the sampling period, otherwise there are no apparent trends i n e i t h e r s o i l or water. Sodium. Sodium appears to be passively taken up by the plant system (Figure 76). Peaking occurs throughout the season, dis p l a y i n g no d e f i n i t e trends, and the same sort of peaking also appears i n the L-H layer of the s o i l samples. S l i g h t , uncorrelated peaks also appear i n the water samples. It would appear that while sodium i s taken up into the plant system, i t does t h i s not i n response to a n u t r i t i o n a l requirement, but as a passive response 5 I O O eo • E Q. a. • • • • • •• • a UJ 6 0 • • • * 4 0 • 2 0 • 2 0 • • • 16 • • • • • • • • . e • • E _J 12 • • SOI 6 • • • • V M A Y 1 IS J U N E 1 15 J U L Y IS 31 A U G U S T Figure 74. Seasonal v a r i a t i o n of calcium i n Phragmites communis, s o i l and water. Data for 1969. Ad d i t i o n a l graph l i n e indicates time of flowering. 5 2 m ui z o < 2 s - * - i - s * * * - r » -• • • • r o : 9 I 15 M A Y JUNE Figure 75. Seasonal v a r i a t i o n of magnesium i n Phragmites communis, s o i l and water. Data f o r 1969. Ad d i t i o n a l graph l i n e indicates time of flowering. C 0 7 Figure 76. Seasonal v a r i a t i o n of sodium i n Phragmites communis, s o i l and water. Data for 1969. Ad d i t i o n a l graph l i n e indicates time of flowering. 184 to sodium concentrations. Potassium. In l e a f m a t e r i a l , potassium i s maintained at a high l e v e l (about 17.6 mg/g dry weight) u n t i l the t h i r d week i n June, and then decreases sharply and continues to decline u n t i l the end of the sampling period, at which time potassium i s barely detectable i n the samples (Figure 77). No coincident trends appear i n the s o i l data, but i n the water samples, potassium begins to increase slowly as i t declines i n the l e a f material. Phosphorus. Phosphorus content of l e a f material begins at a high l e v e l , about 6.4 percent (Figure 78) and continues a gradual decline throughout the e n t i r e sampling period to a low of 2.5 percent. As t h i s decline occurs i n the l e a f , a marked increase occurs i n both the L-H and Ah s o i l horizons, and a b r i e f sharp peak appears i n the water samples. Summary. Although data for rhizome material are not a v a i l a b l e for Phragmites, trends are s t i l l apparent i n Phragmites f o r l e a f , s o i l and water samples. These suggest that the behaviour of ions i n Phragmites i s s i m i l a r to Typha, and that those categories of ions described for Typha also apply to Phragmites communis. Both calcium and magnesium belong to the category of ions which are cycled annually between s o i l and plant. Potassium and phosphorus l i e within the category of ions which are mainly stored i n the plant system, with c y c l i n g occurring p r i n c i p a l l y between d i f f e r e n t plant organs, dependent on seasonal requirements. In Phragmites however there i s also evidence to suggest that considerable amounts of these ions are also being returned to the substrate. Sodium belongs to the category i n which ions f l u c t u a t e passively i n the plant material. Considering the data, sodium appears to fl u c t u a t e passively perhaps i n response to external concentrations of the ion i n s o i l and water. There are d e f i n i t e differences between Typha and Phragmites, and these w i l l be discussed i n the comparison which follows. 185 Figure 77. Seasonal v a r i a t i o n of potassium i n Phragmites communis, s o i l and water. Data for 1969. Ad d i t i o n a l graph l i n e indicates time of flowering. 186 Z 0-4 i n or O x a IS) O i a. is J U N E 15 A U G U S T Figure 78. Seasonal v a r i a t i o n of phosphorus i n Phragmites communis, s o i l and water. Data for 1969. A d d i t i o n a l graph l i n e indicates time of flowering. 187 COMPARISON OF BEHAVIOUR OF TYPHA GLAUCA AND PHRAGMITES COMMUNIS DURING SEASONAL GROWTH General. Both dominants are perennial, showing vigorous growth and producing stands which are capable of covering large areas, v i r t u a l l y to the exclusion of other species. Both make mat-type growth i n the substrate, and are capable of e x i s t i n g under f l u c t u a t i n g water conditions, since they are shallow-rooted, and the root and rhizome systems contain abundant aerenchyma, which o f f e r s buoyancy to the plants, and f a c i l i t a t e s the formation of f l o a t i n g mats. In each, the buds of any current year are i n i t i a t e d during the f a l l and summer months of the previous year. Flowering f or Typha occurs i n l a t e June and early July, pollen production i s copious and several hundred thousand f r u i t s are produced per spike. For Phragmites, flowering production appears more l i m i t e d , and fewer f e r t i l e f r u i t s are produced from the terminal pa n i c l e . The form of the plants d i f f e r s conspicuously, i n that Typha leaves are p r i n c i p a l l y basal i n appearance, while leaves of Phragmites are borne l a t e r a l l y on a r i g i d culm. S o i l . S o i l s beneath both of the stands are o v e r l a i n with water, although the water can be very shallow, or i n some years a c t u a l l y can subside below the s o i l surface. Both s o i l s belong to the Rego Humic Gleysol subgroup (N.S.S.C. 1970). The L-H horizon of Typha i s minimal on the study p l o t , while that of Phragmites i s t h i c k e r , 7.5 - 15 cm i n depth. Both Ah horizons contain organic matter, but the C horizons d i f f e r , with the Cg horizon of Typha composed of f i n e l y sorted clay, and the C horizon of Phragmites composed of sand. In each rooting i s strong i n the Ah horizon, and neither of the rooting systems penetrates the C horizon. Growth Phenomena and Moisture Content. In Typha, growth i s e s s e n t i a l l y over i n early J u l y , with no increase i n numbers or length of leaves i n the l a t e r months of the summer. This stoppage of growth coincides 188 with decreases i n moisture content, which suggests that, metabolically, a c r i t i c a l change i n a c t i v i t y has occurred. Probably the change indicates that a c t i v i t i e s i n v o l v i n g rhizome storage f o r the next year have commenced, and that t r a n s l o c a t i o n of materials from mature leaves to rhizome has begun. In Phragmites, moisture content, which i s l e s s than i n Typha even at the period of most rapid growth, maintains a slow decline u n t i l the t h i r d week i n June, a f t e r which i t declines more r a p i d l y to the end of the sampling period i n September. Peak metabolic a c t i v i t y thus appears shorter than i n Typha, or at l e a s t l e s s e r r a t i c , but i n contrast, growth i s continuous r i g h t to the end of the sampling period. Obviously Phragmites can continue to function e f f i c i e n t l y , regardless of reduced moisture content, and l i k e l y begins to translocate materials e a r l i e r i n the growing season than does Typha, so that early i n the season, preparation f o r the next year i s under way. Calcium. A comparison of l e a f t i s s u e calcium content shows differences i n calcium demands between the two species (Figures 66 and 74). In Typha, uptake continues at a r e l a t i v e l y steady l e v e l u n t i l June 15, when, coincident with rapid l e a f extension, uptake increases to a peak at July 21. Then the period of so- c a l l e d seasonal senescence commences, moisture content declines and calcium content also declines to the end of the sampling period. In Phragmites, calcium content of leaves remains r e l a t i v e l y low and constant during the period of most r a p i d growth, u n t i l June 15, a f t e r which i t s t e a d i l y increases u n t i l the end of the sampling period. Increase i n growth, however continues, and i s s t i l l doing so at the end of sampling. Thus both growth and moisture content behaviour as well as calcium uptake behaviour d i f f e r i n the two species. A comparison of r e s u l t s i n terms of actual amounts of calcium accumulated, indicates that calcium demands of Phragmites f a r exceed those of Typha, so that Phragmites might more r a p i d l y exhaust a 189 calcium-poor s o i l , or might not even be able to germinate or grow on such a s o i l . Thus i n terms of calcium demands, the two stands behave i n quite d i f f e r e n t ways, and t h i s behaviour may account for the s l i g h t habitat differences from one community to another, as well as for the greater success of Typha i n eastern Canada, an area which i s t y p i c a l l y calcium-poor. Magnesium. In uptake of magnesium, the two stands again show some d i s s i m i l a r i t y (Figures 67 and 75). The Typha stand f l u c t u a t e s around a l e v e l of 2.8 mg/g dry weight u n t i l the f i r s t week of August, when i t begins to d e c l i n e , and continues t h i s decline u n t i l November, the end of the sampling period. In the Phragmites stands, magnesium uptake i s maintained at about 9.0 mg/g dry weight u n t i l June 15, the time at which moisture content begins to decrease at a more rapid rate. I t then decreases s t e a d i l y u n t i l the end of the sampling period. The pattern of demand i s s i m i l a r i n both stands, high i n the e a r l y period of growth and d e c l i n i n g toward the end of the growing season, but the demand for magnesium i n Typha i s maintained for a much longer period than i t i s i n Phragmites. This increased period of magnesium demand i n Typha may simply be a function of a low demand of the plant occurring over a longer period of time. A comparison of the two graphs (Figures 67 and 75). shows c l e a r l y that Phragmites i s making f a r greater demands on the substrate than i s Typha, with Phragmites r e c e i v i n g more than three times the amount of magnesium. A c t u a l l y there i s no overlap at a l l between the figures i n the two graphs. Here i s a second and stronger example of Phragmites as a heavy user of substrate materials. I t i s also a reinforcement of the remarks given for calcium, namely that i f the s o i l substrates are low i n n u t r i e n t s , the high demands made for both calcium and magnesium by Phragmites might ei t h e r r a p i d l y deplete the systems, thus rendering s t a t i c the community through 190 r e s t r i c t i o n s i n growth as a r e s u l t of the ions becoming " f i x e d " i n the already existent plant systems. More probably Phragmites would be simply unable to germinate or grow on such nutrient-poor substrates. Typha however would probably be able to u t i l i z e nutrient-low s o i l s , and thus would gain an advantage where nutri e n t supplies are l i m i t e d . Sodium. Although t h i s ion i s not considered to be a plant n u t r i e n t , i t i s a common constituent of wetland s o i l s , often i n considerable concen-t r a t i o n s . With t h i s ion, uptake appears to be proportional to concentration i n the substrate, although one peak i n Typha (Figure 68) occurs at the time of flowering. However, considering the e r r a t i c behaviour of sodium content during the e n t i r e sampling period, i t i s apparent that the plant i s reacting to the substrate concentration rather than to some metabolic demand. Accumulation of sodium by Typha however i s considerable, and i t thus appears that Typha can accumulate large amounts of sodium without t o x i c e f f e c t s to the plant system. Comparison of sodium concentration i n the substrates of Typha and Phragmites (Figures 68 and 76) reveals that the sodium concentration of the Typha substrate i s approximately 10 times greater than i t i s i n the Phragmites stand, and that accumulations i n the plant material i s also of t h i s order of magnitude. So i t would appear that the ion i s taken up passively by both species, and that t h e i r behaviour with regard to t h i s ion i s probably s i m i l a r . Potassium. Demands for potassium follow s i m i l a r trends i n both species (Figures 70 and 77). In the e a r l y growth period, the demand i s high i n Typha, but i t begins to decline i n the week of May 26, and continues to do so u n t i l the end of the sampling period. This decline i n Typha begins long before the commencement of seasonal senescence, maximum l e a f extension, or flowering. In Phragmites, the demand continues high u n t i l June 15, the time at which moisture content begins to decrease. The decline of the potassium demand 191 then continues to the end of the sampling period, when the demand i s nearly zero. A comparison of the uptake graphs shows that demand for potassium i s higher i n Typha at a l l times of the growing season than i t i s for Phragmites, and t h i s i s not correlated with amounts of potassium found i n the substrate. This higher demand for potassium on the part of Typha may further separate the habitat preferences of Typha and Phragmites. Phosphorus. Uptake graphs (Figures 71 and 78) of the two species are s i m i l a r i n shape, with i n i t i a l high demand i n the early weeks of growth, followed by a slow decline to the end of sampling. The d i f f e r e n c e however i s one of magnitude, i n that Phragmites requires about twenty times the amount of phosphorus required by Typha, with no overlap at a l l showing on the graphs. Again we f i n d Phragmites with a much greater demand than Typha, which may suggest that where phosphates are low, Typha may have a habitat advantage over Phragmites, since probably i t would be able to grow on substrates which are less r i c h i n phosphates. Conclusion. Although Typha and Phragmites may appear to act as competitors for wetland habita t s , uptake and growth c h a r a c t e r i s t i c s appear to d i f f e r i n the two species. Growth behaviour of each d i f f e r s i n that Typha appears to mature early i n the summer, while Phragmites continues growth u n t i l slowed by adverse environmental conditions. Also demands for nutrients and sodium d i f f e r markedly, i n that Phragmites requires greater amounts of calcium, magnesium and phosphorus, while Typha requires greater amounts of potassium during the growing season. Uptake of sodium i n both appears to fl u c t u a t e passively, dependent on concentrations i n the substrate, but Typha can t o l e r a t e large amounts of sodium i n the plant system, possibly more than Phragmites. While such differences i n i o n i c requirement and uptake may f u r n i s h only s l i g h t i n d i c a t i o n of d i f f e r e n t habitat requirement for the two species, i t does o f f e r some in s i g h t into basic behavioural differences i n 192 the two species, which might r e s t r i c t each one to only p a r t i c u l a r wetland ha b i t a t s . FLOATING MATS OF TYPHA GLAUCA AT POINT PELEE, ONTARIO Since f l o a t i n g mat communities of Typha are of common occurrence i n marshes, p a r t i c u l a r l y where water f l u c t u a t i o n i s common, a pair of these communities were investigated at Point Pelee i n the summer of 1970. Water, mat (termed " s o i l " i n the text) and le a f material were sampled weekly, beginning June 1 and ending September 5. They were analysed f o r four cations, calcium, magnesium, potassium and sodium. Results of the study, together with a comparison of the rooted Typha community, follow. FLOATING MAT COMMUNITY OF TYPHA GLAUCA ON SANCTUARY POND, POINT PELEE, ONTARIO General. The mats are peripheral f l o a t i n g mats which occupy the cent r a l east side of Sanctuary Pond, the most westerly pond of Point Pelee Marsh (see Figure 12). Water depths i n Sanctuary Pond vary from 46.5 cm to 83.0 cm. Water temperatures vary from a low of 18.5°C at f i r s t sampling, reaching a peak of 25°C on the week of Ju l y 1, and d e c l i n i n g only s l i g h t l y to 24°C at the end of the sampling period. Oxygen content of the water, measured as close to mid-day as possib l e , varies from 10.3 ppm at the beginning of sampling to a low of 3.5 ppm at the end. pH also declines from an a l k a l i n e high reading of 9.25 to an acid low of 3.5. A i r temperatures, measured as close to mid-day as possib l e , commence at 19.3°C, r i s e s t e a d i l y to a high of 30.0°C i n the week of August 1, and decline to 25°C at the time of l a s t sampling. Maximum height of the stand, 246 cm, i s achieved by July 1, and l i k e normal Typha, f r a y i n g and browning of the le a f apices causes a s l i g h t decrease to the end of sampling (240 cm) i n September. Flowering commences on June 18. Calcium. Figure 79 shows seasonal plant-soil-water r e l a t i o n s h i p s for calcium. Leaf material shows an increase i n uptake roughly coincident , Q I , — . — , , , , ^ I 15 2 9 13 2 7 IO 2 4 J U N E JULY A U G U S T Figure 79. Seasonal v a r i a t i o n of calcium i n a f l o a t i n g mat community of Typha glauca on Sanctuary Pond, Point Pelee. Data for 1970. Additional graph l i n e indicates time of flowering. 194 with flowering, and thereafter shows only a s l i g h t decline to the end of the sampling period. The mat s o i l shows loss of calcium, also coincident with the time of flowering. Later calcium begins to build up i n the mat, the result of seasonal senescence i n the plant, plus possible export by leaching or loss of mobile calcium. Some correlation i n calcium loss and gain i s also apparent i n the water, with a noticeable gain occurring i n the water adjacent to the mat. Magnesium. Data for magnesium uptake (Figure 80) show only a s l i g h t seasonal increase of magnesium i n leaf material, and t h i s i s coincident with the new growth of Typha. Magnesium uptake then remains f a i r l y constant for the remainder of the sampling period. With both water and s o i l , a lowering of magnesium content appears coincident with the period of flowering and of new growth, followed by peaking towards the end of the sampling period. Potassium. Slight trends i n potassium (Figure 81) appear i n the samples. Slight losses i n both s o i l and water i n mid-season are partly made up by the end of the sampling time. During t h i s time, leaf samples show great v a r i a t i o n , with only a s l i g h t lowering to the end of the sampling period. Sodium. Sodium content (Figure 82) appears to fluctuate i n leaf material i n direct response to the content of water and s o i l substrates. Uptake through the season i s not apparently correlated with growth, although most of the sodium taken up by leaves occurs after the leaves have become mature (week of July 1). The main indications however are that sodium i s taken up passively by the plant i n response to concentration i n the substrate. Conclusion. In the ions sampled i n the fl o a t i n g mat community on Sanctuary Pond, some correlations can be made between changes i n plant material and those observed i n the s o i l and the mat. The ions analysed i n the f l o a t i n g mat population behave s i m i l a r l y to those i n the three categories Figure 80. Seasonal v a r i a t i o n of magnesium i n a f l o a t i n g mat community of Typha glauca on Sanctuary Pond, Point Pelee. Data for 1970. Add i t i o n a l graph l i n e indicates time of flowering. 196 1 Figure 81. Seasonal v a r i a t i o n of potassium i n a f l o a t i n g mat community of Typha glauca on Sanctuary Pond, Point Pelee. Data f or 1970. Add i t i o n a l graph l i n e indicates time of flowering. JUNE JULY AUGUST Figure 82. Seasonal v a r i a t i o n of sodium i n a f l o a t i n g mat community of Typha glauca on Sanctuary Pond, Point Pelee. Data for 1970. Ad d i t i o n a l graph l i n e indicates time of flowering. 198 f i r s t described for the rooted stands of Typha (p. 160 et seq.). Calcium and magnesium show strong c o r r e l a t i o n s with content of both s o i l and water, i n d i c a t i n g that they are cycled annually between s o i l and plant. Potassium r e s u l t s suggest that i t may be at l e a s t p a r t i a l l y stored, with c y c l i n g between plant organs, although t h i s may only be i n f e r r e d from the s o i l and water data, and rhizome material i s not being used i n t h i s study. Sodium r e s u l t s i n d i c a t e that concentration of t h i s ion fluctuates passively i n the plant, responding to external concentrations of t h i s ion. Although t h i s f l o a t i n g mat community reaches maximum height e a r l i e r than the rooted stand of Typha described e a r l i e r , nevertheless there i s good agreement between the two stands regarding the v a r i a t i o n s of the four ions analysed. The f l o a t i n g mat community c l e a r l y draws ions from the mat i n the same manner that the normal community draws ions from i t s s o i l , and ion losses can be detected i n the water near the f l o a t i n g mat as w e l l . So the f l o a t i n g community makes use of not only the ions a v a i l a b l e i n the mat, but also i s i n a p o s i t i o n to draw ions from the free water adjacent to the mat i t s e l f . FLOATING MAT COMMUNITY OF TYPHA GLAUCA ON BIG POND, POINT PELEE General. The f l o a t i n g mat sampled i n t h i s study i s located on the north side of Big Pond, the largest pond i n Point Pelee Marsh (see Figure 12). Water depths i n Big Pond vary from 88.0 cm to 120 cm, depth being dependent upon water pile-up and p r e c i p i t a t i o n . Water temperatures vary from a low of 18.0°C at the beginning of the sampling period to a peak of 27.5°C on August 1 and.again d e c l i n i n g by September to 22.5°C. Oxygen content of water varies from 8.2 ppm at the beginning of sampling to a low of 3.2 ppm by the end of sampling. pH also declines s t e a d i l y from 6.9 to 4.0. A i r temperatures during sampling begin at 18.5°C, reach a peak of 28.5°C on August 1, decline s l i g h t l y and on the l a s t sampling day i n September reach 199 29.0°C. Maximum height of the stand i s achieved by August 1, 213.5 cm, with a s l i g h t d e cline thereafter due to loss of the l e a f apices by f r a y i n g and fragmentation, the r e s u l t of seasonal senescence. Flowering occurs on June 19. S o i l of the mat, as a l l f l o a t i n g mats, i s a Hydric F i b r i s o l (N.S.S.C. 1970). Calcium. Calcium content (Figure 83) shows the trend of uptake which gains some impetus near flowering, and continues u n t i l maximum growth i s achieved (August 1). It then drops s l i g h t l y , the r e s u l t of seasonal senescence. A corresponding depression, coincident with flowering, i s evident on the graph for the s o i l of the mat. Water data show some c o r r e l a t i o n with growth phenomena of the plants. Magnesium. Figure 84, a p l o t of seasonal plant-soil-water r e l a t i o n s h i p s , shows a continuous though s l i g h t increase i n uptake from the beginning of the sampling period to the time of maximum height i n August. It then appears to lower again at the end of the sampling period. A lowering of magnesium content i n the mat appears coincident with flowering, but i o n i c replacement i n the mat occurs r a p i d l y . Potassium. The only d e f i n i t e trend i n l e a f material for potassium content occurs at the end of the growing season, when there i s a notable depletion of potassium from the l e a f (Figure 85). A lowering of ions i n the mat and a steady loss or lowering of ions from the water samples also appears i n the data. Continued loss of K from the water may be due i n part to demand made by the f r e e - f l o a t i n g hydrophytes which dominate the open water of Big Pond, and which are s t i l l growing vigorously at the end of the sampling period. Sodium. Figure 86 shows seasonal v a r i a t i o n of sodium content for plant, s o i l and water. The s l i g h t trends again ind i c a t e that uptake of t h i s ion i s dependent on external concentrations of the ion i n the mat and water 200 12-0 13 6 I IS 29 13 27 IO 24 J U N E JULY A U G U S T Figure 83. Seasonal v a r i a t i o n of calcium i n a f l o a t i n g mat community of Typha glauca on Big Pond, Point Pelee. Data for 1970. A d d i t i o n a l graph l i n e indicates time of flowering. , . > , __, . •-15 29 13 27 IO 24 J U N E JULY A U G U S T Figure 84. Seasonal v a r i a t i o n of magnesium i n a f l o a t i n g mat community of Typha glauca on Big Pond, Point Pelee, Data for 1970. Ad d i t i o n a l graph l i n e indicates time of flowering. 33-0 $ 3 0 0 1 E Z 27Q| 240 O 07\ Figure 85. Seasonal v a r i a t i o n of potassium i n a f l o a t i n g mat community of Typha glauca on Big Pond, Point Pelee. Data for 1970. A d d i t i o n a l graph l i n e indicates time of flowering. 203 Figure 86. Seasonal v a r i a t i o n of sodium i n a f l o a t i n g mat community of Typha glauca on Big Pond, Point Pelee. Data for 1970. Ad d i t i o n a l graph l i n e indicates time of flowering. 204 substrates. Conclusion. These data confirm that the s o i l - p l a n t r e l a t i o n s h i p s f i r s t obtained from normal stands of Typha, are v a l i d even when the s o i l i s represented only by a r e l a t i v e l y t h i n f l o a t i n g mat. Trends i n the three categories of behaviour for the ions, f i r s t described f o r the normal stands of Typha.and for i t s competitor, Phragmites, are also indicated by r e s u l t s from the f l o a t i n g mats. Some trends i n water data, which do not f u l l y coincide with ion data of the s o i l or the plant, may be at l e a s t p a r t l y accounted for by the demands made by the f r e e - f l o a t i n g hydrophytes which dominate the open water of Big Pond, and which are s t i l l making vigorous growth at the end of the sampling period. COMPARISON OF SEASONAL VARIATION OF FLOATING MAT COMMUNITIES OF TYPHA GLAUCA Sanctuary Pond, the more eutrophic of the two ponds, o f f e r s more calcium i n both water and s o i l , and the maximum height of the plants i s s l i g h t l y greater on Sanctuary Pond. Although flowering occurs at approximately the same time on each pond, maximumiheight occurs i n the plants of Sanctuary Pond a month e a r l i e r than on Big Pond. Thus i n Sanctuary Pond, peaking of uptake coincident with flowering and growth i s found together as one strong peak i n the plant m a t e r i a l , together with coincident depressions i n the water samples. In Big Pond, the demands are spread over a longer period of time, and i t appears that replacement i n the mat of ions such as calcium and magnesium, i f i t does occur, i s not made u n t i l the l a s t week of August and continues i n t o the autumn months. Patterns of uptake and replacement, however are s i m i l a r for both f l o a t i n g mat communities. COMPARISON OF FLOATING MAT COMMUNITIES AND NORMALLY ROOTED TYPHA GLAUCA In height, the rooted Typha achieves a greater height (310 cm) than the Typha of the mat communities (240 and 213 cm). The greater growth i s 205 thus achieved by the more stable community. Flowering occurs at about the same time (early to mid-July), but maximum growth occurs l a t e r i n the rooted community (mid-August, as opposed to July 1 and August 1 for Sanctuary and Big Pond r e s p e c t i v e l y ) . A b i l i t y to concentrate ions within the plant system occurs i n the same order of magnitude (considering only the four ions of the mat study) for calcium, magnesium and potassium, apparently regardless of the concentrations of the substrate. This trend i s p a r t i c u l a r l y obvious f o r potassium, where uptake i s very high and uniform despite great d i f f e r e n c e s i n potassium concentration i n s o i l and mat. This suggests that i n Typha at l e a s t , i o n i c requirements are e f f e c t i v e l y accumulated even on s o i l s which have low i o n i c concentrations. The three categories of ions, described f i r s t f o r the rooted communities, also apply to the f l o a t i n g mat communities. In both, data reveal that ions are contributed v i a the major substrate, namely s o i l and fibrous mat, i n d i c a t i n g that the water external to mat and s o i l i s of l e s s importance than the concentration within the actual rooting medium. However, the water which o v e r l i e s wetland s o i l s may function to provide continuous replacement ions for the wetland s o i l s . This would allow b a s i c a l l y low-nutr i e n t s o i l (or s o i l s of low cation exchange capacity) to s u c c e s s f u l l y support the dense growth of vegetation usually associated with marshes. Aside from the d i f f e r e n c e s already mentioned, the f l o a t i n g mats of Typha behave l i k e normally rooted Typha and the trends are s i m i l a r i n both. Ionic demands of the three stands are a l l s i m i l a r , with the exception of sodium, which may be seen to be taken up i n proportion to the amounts present i n the substrate, suggesting that uptake of sodium i s not the r e s u l t of an actual p h y s i o l o g i c a l demand. 206 SUMMARY OF SECTION IV A seasonal approach to plant-soil-water r e l a t i o n s h i p s has been undertaken for normal communities of Typha glauca and i t s competitor Phragmites communis, as well as a p a i r of f l o a t i n g mat communities of Typha  glauca. In a l l communities, considerable seasonal f l u c t u a t i o n s of i o n i c concentrations occur i n plants and t h e i r substrates. In the main, fl u c t u a t i o n s coincide with events of the l i f e c ycle, such as early growth, flowering, achievement of maximum height and t r a n s l o c a t i o n of ions to the storage rhizome. Ionic changes and growth phenomena also are coincident with marked changes i n moisture content. Three i o n i c categories are noted. These are (1), ions which are cycled annually between plant and substrate, (2) ions which, once taken up, are cycled between plant organs, and (3) ions which are accumulated passively i n proportion to the concentration i n the substrate. Patterns of uptake are s i m i l a r for a l l Typha p l o t s , whether s o i l or mat-rooted, but the patterns of uptake d i f f e r between Typha and Phragmites, probably the r e s u l t of t h e i r d i f f e r e n t growth patterns. In terms of accumulation, Phragmites far exceeds Typha i n a l l ions except potassium. These basic differences i n accumulation pattern and amounts accumulated suggest reasons why Typha may be more successful than Phragmites, p a r t i c u l a r l y i n eastern Canada, which i s rather calcium-poor. 207 DISCUSSION (A) GENERAL In the wetlands of eastern Canada, Typha marshes are found i n two d i s t i n c t categories - open and closed. Closed marshes generally evolve from and succeed open marshes, through the simple though often lengthy procedure of loss of a system of c i r c u l a t i n g water. Closed Typha marshes occur on areas of high water ta b l e , and receive moisture from run-off. Water l e v e l i s maintained by r u n - o f f , seepage water, or an impermeable layer below the marsh, or from l i m i t e d water supplies such as e f f l u e n t conduits. Most moisture i s received as run-off from low h i l l s which surround the marsh, during periods of p r e c i p i t a t i o n or from snow melt i n spring months. Greater numbers of species grow i n closed marshes than i n open ones, l a r g e l y because s i t e s are more va r i e d , p a r t i c u l a r l y along the moisture gradient. Water i n a closed marsh may l i e many centimetres above the s o i l surface, or i t may l i e as much as 50 cm below. The Ah horizon of the s o i l may be a metre i n depth, or lackin g . Salt concentration may be very high, or i t may be low. The main environmental stress placed on such a system stems from f l u c t u a t i o n s i n s a l t concentration, and only species that can t o l e r a t e the wide ranges of s a l t concentration, which vary from season to season, can a c t i v e l y compete. Both open and closed marshes share the common environmental problems of water supply, varying c l i m a t i c conditions, and substrate s u i t a b i l i t y . The open Typha marsh i s a major marsh category i n eastern Canada. Here water depth i n vegetation s i t e s may be greater than one metre and the water swift-flowing, with pH circumneutral to a l k a l i n e , depending on whether the water received flows from g r a n i t i c or limestone highlands. Water temperature i n summer i s coo l . S o i l s below the water range from water-washed sands to cl a y s . 208 Ecological conditions i n the open Typha marsh d i f f e r from those of the closed marsh. Here succession, competition for s i t e , aggression and a l l factors which eventually lead to a measure of dynamic s t a b i l i t y can be demonstrated. If the factors of constantly added a l l u v i a l material and the equally persistent p o s s i b i l i t y of erosion are included, the open marsh presents a picture of constant dynamic change. The shallow, slower-moving waters of these marshes are probably the most productive of a l l wetland habitats. Shoreline stands of Typha may be damaged by ice movement i n spring and f a l l , and changed r a d i c a l l y by heavy spring flooding, so that i n the environmental sense, there are no undisturbed habitats. Under such conditions, i t i s surprising to find that marsh ecosystems are reasonably stable. There can be considerable consolidation of s o i l parent materials, and the oxygenated waters support many free-floating aquatics such as Myriophyllum, U t r i c u l a r i a and the more constant members of aquatic communities, Lemna minor and L_. t r i s u l c a . Here waters are warmer than the deeper open marshes, and beneath, the s o i l s usually have a s i l t - o r g a n i c horizon which may be as deep as 25 cm, although the disperse condition of t h i s horizon renders i t d i f f i c u l t to demonstrate using conventional coring methods. Buried horizons are common, and except i n very newly-occupied habitats, there are no stony phases. Mature shore-based Typha communities are single or double-^layered, the lower story consisting of S a g i t t a r i a l a t i f o l i a or Pontederia cordata. The tolerance of second-layer species for variations i n the quantity of available l i g h t permits them not only to grow vigorously as part of the Typha community, but also to dominate thei r own large stands, often adjacent to the Typha communities. These pure stands protect the Typha growth from major mechanical damage during flood periods, including ice damage. 209 In the secluded backwaters of bays, even of ra p i d l y moving r i v e r s , there are always areas where, for periods during the summer months, water remains nearly s t i l l . Here the shallow unshaded water approaches the temperature of the a i r , and a l g a l mats ( p r i n c i p a l l y Spirogyra sp.) are common. pH i s often lower than n e u t r a l , and oxygen content i s low. Nitrogen-fixing organisms, such as Nostoc sp., are often present. When l i g h t conditions are not too r e s t r i c t e d by a l g a l mats, bottom-rooted members of submerged communities are usually C a l l i t r i c h e hermaphroditica, Ludwigia  p a l u s t r i s , Isoetes macrospora and the ensiform-leaved S a g i t t a r i a l a t i f o l i a . Here s o i l s are g l e y s o l i c , with minimal organic horizons (Rego G l e y s o l s ) . The small contribution of organic debris, probably from the bodies of organisms which die i n the warm, low-oxygen content waters, may be swept away by high water i n the following spring. In closed Typha marshes, where water covers the s o i l at a l l times of the year, water depths vary, as does the oxygen content, and pH ranges from s l i g h t l y a c i d i c to 8.0. As the summer progresses, the waters evaporate and s a l t concentrations increase. S o i l s vary from Rego Gleysols to Humisols, but the common s o i l i s the Rego Humic Gleysol. Here there i s a disperse to compact Ah horizon, and a deep compact C horizon, often of clay. An L-H horizon, composed of decayed and water-saturated plant fragments may be present. S o i l s remain cool during the summer months. Vegetation i s multilayered, and i n addition to Typha which forms the t a l l e s t l a y e r , the lower layers may be choked with Juncus effusus, Carex spp. , or Scirpus  cyperinus. The s o i l s about the Typha bases sustain heavy growth of Galium  palustre, Lysimachia t e r r e s t r i s and Cicuta b u l b i f e r a . The surface of the shallow water may support Lemna minor, U t r i c u l a r i a v u l g a r i s , R i c c i a f l u i t a n s and Lemna t r i s u l c a . As i n open marshes, the chief permanent mammal ecosystem component i s the muskrat, Ondatra zibethicus , although many other animals 210 frequent the wetland and some birds nest there. A second type of closed Typha marshes occurs where the water subsides below the s o i l surface f or a part of the growing period, and surfaces of these marshes may become dry. The water table however remains high. Since these areas depend s o l e l y on run-off and p r e c i p i t a t i o n f o r water supply, and evapotranspiration can exceed p r e c i p i t a t i o n for part or a l l of the summer months (Bray 1962), i t i s not unusual to f i n d no water on the f l o o r of closed marshes. The shallow water which covers the s o i l for part of the summer months i s s t i l l , and supports abundant m i c r o f l o r a and -fauna, which are deposited on the f l o o r of the marsh when the water subsides. S o i l s are usually Rego Humic Gleysols or even Humisols, with s o i l r e a c t i o n circumneutral to acid. The water table can l i e as low as 50 cm below the s o i l surface. U n t i l the water subsides, f r e e - f l o a t i n g aquatics are supported. Of these, Lemna minor and R i c c i a f l u i t a n s which can survive even water subsidence, are most common. S o i l s usually show mottling i n the C horizon. Typha marshes which belong to the closed dry marsh type are often d i s t i n c t l y 3 or 4-layered, and the sub-layers are more mesic and diverse than i n other areas of the marsh. Below the Typha, the next t a l l e s t layer contains many species, such as Carex r e t r o r s a , C. comosa and Impatiens  b i f l o r a . A lower layer often contains Galium palustre, S t e l l a r i a a l s i n e , Polygonum sagittatum, Bidens cernua, Lysimachia t e r r e s t r i s , Triadenum  virginicum and G l y c e r i a canadensis. On the ground, depending on the time that the water recedes, there may be a layer of Lemna minor and R i c c i a  f l u i t a n s , a heavy layer of Typha l i t t e r , or the young seedlings of weedy annuals which have blown into the marsh. S o i l s are u s u a l l y Humisols. An a d d i t i o n a l s p e c i a l i z e d marsh condition i s the f l o a t i n g mat. This Typha mat may be b u i l t out from the shore, and may remain i n s i t u or become detached and move about with wind and water motion. The mat may also detach 211 and f l o a t to the surface with increase i n water depth. L i t t l e mineral material i s incorporated, so that the r e l a t i o n s h i p between the mat and the water "substrate" probably assumes more importance than i n other Typha communities. Root formation i s extensive, and r a m i f i c a t i o n of root and rhizome systems contributes to buoyancy, allowing mats to remain a f l o a t and i n t a c t . Vegetation exclusive of Typha i s often sparse and depauperate. The s o i l s of f l o a t i n g mats consist of a sing l e deep organic l a y e r , composed of decayed matter, dead roots and the heavy interwoven mass of l i v i n g roots and rhizomes. It represents the organic layer of a F i b r i s o l which has a hydric contact, and thus f l o a t i n g Typha mats may be c l a s s i f i e d as Hydric F i b r i s o l s . Depending on the buoyancy of the mat and the weight of vegetation which i t supports, the mat may f l o a t with the bases of the Typha rhizomes above or below the water surface. When the bases are below the water, vegetation i s r e s t r i c t e d to Typha, but when the rhizome bases are emergent, vegetation may be v a r i a b l e , most c l o s e l y resembling the vegetation of the f i n a l stage of closed Typha marshes. (B) INTROGRESSIVE HYBRIDIZATION Under c o n t r o l l e d conditions, i t has been proven that Typha l a t i f o l i a and T_. a n g u s t i f o l i a may e a s i l y interbreed (Smith 1967) . That t h i s also occurs n a t u r a l l y i s demonstrated by the study undertaken at Point Pelee Marsh i n 1970. O r i g i n a l l y begun because of d i f f i c u l t i e s with determinations i n Typha, i t has shown conclusively that h y b r i z a t i o n i s not only possible under natural conditions, but i t i s of common occurrence. Introgressive h y b r i d i z a t i o n , which follows the o r i g i n a l crosses, produces an i n f i n i t e range of character recombinations. This e s s e n t i a l l y allows Typha to behave as a s i n g l e large population under a curve, which has as i t s two extremes the o r i g i n a l parental species, T_. l a t i f o l i a and T_. a n g u s t i f o l i a . 212 The environmental factors or pressures which have allowed T_. glauca and other segregants to supplant the parental species, remain obscure. C e r t a i n l y hybrid vigour of T_. glauca i s one major contributing factor to the process. T_. glauca i s l a r g e r , has moderate i o n i c requirements, and generally exhibits a wider range of tolerances for substrate, including successful growth as persistent f l o a t i n g mat communities. The man-made factor of pollutants has been suggested, but T_. glauca has been found to supplant the parental species i n both eutrophic and o l i g o t r o p h i c environments, wherever the two parental species have occurred together. It has been suggested, too, that there are no b a r r i e r s to breeding of the parental species, and i n terms of general h a b i t a t , amounts of p o l l e n produced and the mechanism of wind p o l l i n a t i o n , few b a r r i e r s are present. However, once f e r t i l i z a t i o n has occurred, a p a r t i a l b a r r i e r to v i a b l e seed production becomes apparent. Where 100% germination i s possible i n seeds of both T_. l a t i f o l i a and T_. a n g u s t i f o l i a , only about 4% germination occurs with T_. glauca. Even so, with a p o s s i b i l i t y of 222,000 seeds per female inflorescence, t h i s s t i l l gives 8,880 v i a b l e o f f s p r i n g per female inflorescence, quite s u f f i c i e n t on any scale of a c t i v i t y to form new colonies. Once germinated, the success of new colonies, operating with the advantage of hybrid vigour, seems assured. Continued int r o g r e s s i v e h y b r i d i z a t i o n then produces the f u l l range of character recombinations, phenotypic, and presumably p h y s i o l o g i c a l and biochemical as w e l l . The sampling at Point Pelee Marsh serves to demonstrate that following competition f o r new habitats, and establishment of colonies (a c t u a l l y enormous clones) , where many character combinations are i n i t i a l l y represented, a measure of s t a b i l i t y returns to the marsh. The older parts of the marsh have c l e a r l y fewer of the character combinations than the newer perip h e r a l h a b i t a t s , and the populations are represented by larger numbers 213 of i n d i v i d u a l s of only a few character combinations, or sometimes only one major character recombination. The new s t a b i l i t y of the marsh i s not conferred by the parent species, but by new i n d i v i d u a l s , with c h a r a c t e r i s t i c s which combine those of the two parental species. Ecotypic v a r i a t i o n , where i t confers some e c o l o g i c a l advantage, should c l e a r the way for a more complete u t i l i z a t i o n of the wetland habitat. With the parental species, each appears to occupy a more r e s t r i c t e d habitat than does T_. glauca. T_. l a t i f o l i a tends to occupy the moist, but not wet portion of the h a b i t a t , an area usually high i n n u t r i e n t s , with a v a r i e d f l o r a . T_. a n g u s t i f o l i a grows best i n open marsh conditions, rooted i n s o i l , and continuously supplied by moving water with d i l u t e but constant amounts of n u t r i e n t s . T_. glauca can s u c c e s s f u l l y and vigorously occupy a l l of the wetland h a b i t a t s , proving to be the most successful of the three species. This suggests that T_. glauca, together with the other character recombinations, has s u f f i c i e n t e c o l o g i c a l amplitude, including more vigorous growth c h a r a c t e r i s t i c s , that i t can out-compete the parent species for new h a b i t a t s , and may even be capable of d i s p l a c i n g T_. l a t i f o l i a and T_. a n g u s t i f o l i a from old established h a b i t a t s . That t h i s apparent species complex, which of necessity we designate as T_. glauca Godr. i s a strong and vigorous e c o l o g i c a l force, becomes apparent from the study. That i t i s i n the ascendency i n eastern Canada, becomes obvious to anyone but' the most casual observer of wetland hab i t a t s . (C) FACTORS WHICH INFLUENCE GROWTH OF TYPHA COMMUNITIES (a) Provenances The region where Typha i s found influences i t s height, given that the assessment of height i n Typha should be based on i n d i v i d u a l s which are rooted i n s o i l and are not part of f l o a t i n g mat communities. In general, shorter plants grow i n the more northerly l a t i t u d e s , on more a c i d i c 214 substrates, with lower a v a i l a b l e nutrients (apparently at the lower l i m i t s of n utrient requirements). F l o a t i n g mat communities of Typha have shorter plants than plants which are rooted i n s o i l . While i t i s impossible to separate these factors under f i e l d conditions, the general trends are shown by the data. (b) Accumulation of Substrate Components In a l l , 47 wetland species were c o l l e c t e d i n s u f f i c i e n t numbers to allow averages for i o n i c content of l e a f m a t e r i a l . Compared with these, Typha emerges as a low to moderate accumulator of calcium, magnesium, sodium and phosphorus, and a moderate accumulator of nitrogen. Of the three species, T_. glauca makes the l e a s t demands on the substrate, while J_. l a t i f o l i a makes the greatest, although differences are s l i g h t . Such differences however, may account for the presence of T_. l a t i f o l i a i n the shallow-water, n u t r i e n t -r i c h s i t e s , rather than i n Typha communities i n deeper waters, where nutri e n t supply i s more l i m i t e d . In comparison with Phragmites, a major competitor of Typha, Typha appears to make low demands on the substrate for magnesium, calcium, phosphorus and nitrogen, with moderately high demands for potassium. Phragmites, i n contrast, makes high demands, p a r t i c u l a r l y f o r calcium, on the environment. I t i s these demands which may give Typha the advantage over Phragmites i n the t y p i c a l l y calcium-poor regions of eastern Canada. Ce r t a i n l y several authors have pointed out the r e l a t i o n s h i p of Phragmites as a dominant to n u t r i e n t - r i c h s i t e s (Holdgate 1955, Haslam 1965). The general r u l e f o r accumulation of n u t r i e n t s , at l e a s t i n t h i s study, has been that the s t r i c t aquatics, such as the f r e e - f l o a t i n g hydrophytes, make the l a r g e s t demands on the environment, i n t h e i r case water. The emergent aquatics, within the l i m i t s of the various species d i f f e r e n c e s , make much more moderate demands on the substrate. I t i s t h i s r e l a t i v e l y low demand for nutrients which probably allows c o l o n i z a t i o n of nutrient-poor 215 mineral C horizons by emergent aquatics, p a r t i c u l a r l y Typha. Although c a r e f u l random sampling may be of great use, probably the best understanding of the growth of a p a r t i c u l a r species under f i e l d conditions can be acquired only through complete studies of seasonal growth, uptake and substrate v a r i a b i l i t y . (c) Moisture Content It has been c l e a r l y demonstrated that moisture content of plant material v a r i e s seasonally, as well as from organ to organ. However, moisture, content may be used as an i n d i c a t o r of d i f f e r i n g p h y s i o l o g i c a l methods of growth and accumulation of n u t r i e n t s . While i t seems reasonable to assume that aquatics might have a high moisture content, t h i s i s not apparently always the case. In comparisons of average moisture content with those of other wetland species, Typha has been shown to be more or le s s unique i n i t s category of moisture content. The ser i e s of moisture content categories are as follows: above 90%, f r e e - f l o a t i n g aquatics; 80 - 90%, rooted f l o a t i n g aquatics and Potamogeton; above 70% but le s s than 80%, Decodon v e r t i c i l l a t u s , ( a l l are considerably higher i n average moisture content than i s Typha); below 70%, mainly sedges and grasses, plus Spiraea alba. The i m p l i c a t i o n of t h i s , although d i f f i c u l t to support without c l o n a l studies of a l l the other dominants, i s that Typha may have a more e f f i c i e n t mechanism f o r growth and i o n i c u t i l i z a t i o n than have other emergent aquatics. Not only does Typha d i f f e r i n average moisture content from the f r e e - f l o a t i n g aquatics, but i t also d i f f e r s from a l l the other emergent aquatics as w e l l . (d) Light Light r e l a t i o n s h i p s i n the various Typha communities are markedly d i f f e r e n t , and n a t u r a l l y influence the species which grow on the d i f f e r e n t s i t e s . Light i n nearly pure stands of deeper water of Typha with deflexed 216 growth habits and i n the Typha - S a g i t t a r i a communities, both of open marshes, increases toward day maxima following the i n i t i a l stages of le a f expansion, so that by l a t e J uly, species growing below the Typha layer may be r e c e i v i n g up to 70,000 lux. Soon a f t e r , plants of the understory, S a g i t t a r i a l a t i f o l i a and Pontederia cordata, begin to flower and set f r u i t , although they flower e a r l i e r on s i t e s which they dominate. At t h i s time, l i g h t r e l a t i o n s h i p s i n the understory of the open marsh Typha communities approximate those of the Typha lay e r , and thus adequate l i g h t i s a v a i l a b l e i n the understory during c r i t i c a l periods f or flowering and f r u i t set. A l l species of the understory t o l e r a t e both shaded and bright sun conditions, but make t h e i r strongest growth i n f u l l sun. In contrast, the common species of the Typha - Galium communities of the closed marshes are shade-tolerant, generally shunning open s i t e s , and making l i t t l e major growth without the shel t e r of the t a l l e r species. Most of these species flower at the same time as Typha, or s l i g h t l y l a t e r , and continue to flower and set f r u i t throughout the remainder of the growing season. Such species are Galium  palustre, Impatiens b i f l o r a , Lysimachia t e r r e s t r i s and Cicuta b u l b i f e r a . The continuing erect growth of Typha i n the closed marshes becomes denser as the leaves expand and lengthen, and the l i g h t i n the understory decreases. For the remainder of the growing season, l i g h t r e l a t i o n s h i p s i n the understory are minimal. Light r e l a t i o n s h i p s i n the various l e v e l s of other dominants, l i k e Typha, r e f l e c t the growth form of the dominant, and can be of some use i n pr e d i c t i n g possible species of the lower l e v e l s of the communities. Communities of Phragmites communis are darker at the 150 cm l e v e l than are Typha communities. This i s because Phragmites has spreading leaves a l l along the culm, while Typha grows more or les s erect leaves from basal growth. One would expect that the species growing below Phragmites would be more 217 r e s t r i c t e d i n numbers than even Typha, since few species could become established i n the low l i g h t l e v e l s beneath i t . On consulting Table VIII, for instance, one could predict that species such as Asclepias incarnata, Bidens cernua, Impatiens b i f l o r a and Cicuta b u l b i f e r a would not probably receive s u f f i c i e n t minimum l i g h t i n t e n s i t y to become established. This r e l a t i o n s h i p however remains to be proven, and at present i s only circumstan-t i a l evidence. Typha i s notoriously shade-intolerant, as are most of the other species which can form extensive stands i n wetlands (exceptions are S a g i t t a r i a l a t i f o l i a and Pontederia cordata, both of which can form successful colonies beneath Typha). P o t e n t i a l successors, based on l i g h t requirements alone, would be species which could f u l l y overtop i t . Based on observation, both willow and alder can colonize s i t e s adjacent to Typha s i t e s , and may subsequently invade Typha communities. Species of willow are most common on circumneutral to a l k a l i n e s i t e s , while alder colonizes the s l i g h t l y a c i d to circumneutral substrates. Both alder and willow have shade-tolerant seedlings,.and these may be deposited i n the marshes by the action of wind, or c a r r i e d there by animals. The invasion, however, i s probably not successful unless considerable depths of organic or mineral-organic horizons have accumulated. (e) Water Discussing l i m i t s of water depth, i n connection with growth of aquatic plants, Polunin (1960) states "whereas the water i s commonly 1/2 - 3 metres deep i n the f l o a t i n g - l e a f stage, i n the reed - swamp stage i t i s usually l e s s than 1 metre deep. Here the dominants are of such types as the Common Reed (Phragmites communis), Bulrush (Scirpus l a c u s t r i s ) , Reedmaces or C a t t a i l s (Typha spp.) , Water H o r s e t a i l (Equisetum f l u v i a t i l e ) and various Sedges (Carex spp.) or Papyrus (Cyperus papyrus) i n t r o p i c a l waters, one or 218 other of which usually forms a p r a c t i c a l l y pure stand". Although he mis-gauges the depth of the so - c a l l e d reed - swamp by a depth of about h a l f a metre, he i s r i g h t i n pointing out that depth l i m i t s for emergent aquatics l i m i t them to les s than 150 cm. Within Typha stands, the range of depths over which Typha can grow i s quite wide, varying from 132 cm to stands where the water table l i e s 50 cm below the s o i l surface. According to some authors, a drawdown i s necessary for growth of Typha, and that although such a drawdown obviously encourages c o l o n i z a t i o n of more mesic species, i t may also be necessary for oxygenation of the rhizomes (Laing 1941). A counter-statement by Damas (1959) suggests that low oxygen content of water encourages Typha. Both statements, however paradoxical, may be true. I t i s true that some communities of Typha which occupy hygric and shallow hydric positions i n marshes, where oxygen content of water, which temporarily covers the s o i l , i s very low, may be t o t a l l y emergent for some periods of the year. At that time i t would be expected that the rhizomes would receive greater oxygenation than when under water, and these plants make vigorous growth, forming such Typha stands which presumably prompted Laing to make h i s statement concerning oxygenation and the necessary emergence of the rhizome system. No doubt s i m i l a r stands, when shallowly emersed i n standing waters of low oxygen content also prompted Damas to make h i s observation concerning low oxygen content of water favouring Typha growth. However, there remain many Typha communities which occupy the deeper waters of open marshes, and these never have t h e i r rhizomes emergent at any time. They too make vigorous growth (3 m). Such communities grow i n water which i s well-oxygenated, usually supersaturated, since the water i s co n t i n u a l l y i n motion. In view of the v a r i a b i l i t y of water depth which Typha can obviously t o l e r a t e , i t seems reasonable to suggest that ecotypic v a r i a t i o n might account for some Typha apparently r e q u i r i n g exposure of rhizome systems to a i r , while other clones 2 1 9 are capable of continued growth without d i r e c t exposure to the a i r . Tolerance of Typha to high s a l t concentrations becomes obvious from t h i s study. Even i n open marshes, nutrient supplies are adequate though d i l u t e . Calcium i n the water produces a d e f i n i t e e f f e c t on the growth c h a r a c t e r i s t i c s , and where calcium supply i s abundant, growth i s vigorous. Probably the best example of response to increase i n calcium content of water comes from the comparison of the two f l o a t i n g mat communities of Typha at Point Pelee. Although other cations tested were of approximately the same concentration i n each pond, the calcium content of water i n one pond was 23.3 ppm, while the other pond had a calcium content of 41.7. Growth i n height f o r the f i r s t pond was 213.5 cm, while i n the second pond, Typha reached a height of 246.0 cm. Throughout the study area, concentration of cations d i d not appear to exert a l i m i t i n g e f f e c t on Typha populations. Water i s understandably an important feature of vegetation s i t e s i n wetlands. In the closed marshes where the shallow water i s s t i l l , and where i t subsides into the s o i l towards the end of the growing season, water i s almost an i n t e g r a l part of the organic or mineral-organic horizons of the s o i l , functioning as an "auxiliary s o i l horizon, or as an extension of the s o i l s o l u t i o n . In open marshes, water supplies a constant, i f d i l u t e supply of n u t r i e n t s . Here, water becomes the more important member of the s o i l -water combination. This r e l a t i o n s h i p i s probably of much greater s i g n i f i c a n c e to f r e e - f l o a t i n g aquatics, however, than i t i s to Typha. (f) S o i l S o i l s of Typha communities include Rego Gleysols, Rego Humic Gleysols, Humisols and F i b r i s o l s , according to the Canadian c l a s s i f i c a t i o n . Within the communities, according to the s t a b i l i t y of the s i t e , there i s an orderly progression from minimal s o i l s c o n s i s t i n g p r i n c i p a l l y of C horizons, of low cation exchange capacity and generally low n u t r i t i v e value, to s o i l s of high 220 organic content, increased numbers of horizons, and greatly increased n u t r i t i v e value. The Hydric F i b r i s o l however i s r e s t r i c t e d to f l o a t i n g mat communities. S o i l reaction v a r i e s considerably, and vigorous growth i s made on a l l s i t e s except the most a c i d i c , but most common values l i e i n the range from circumneutral to a l k a l i n e . Salt content of the s o i l s , p a r t i c u l a r l y those of closed marshes, may be high, with vigorous growth apparently unaffected by the high concentrations. Based on depths of organic horizons i n Typha communities, as compared with other dominants, i t becomes apparent that Typha can produce and thus deposit more organic material than other species, so that the s o i l i n Typha communities can be r a p i d l y enriched through organic deposition and concomitant n u t r i e n t accumulation. In addition to the continued a b i l i t y of the communities to draw on the nutrients of the lower horizons, subsequent Typha communities, p a r t i c u l a r l y i n closed marshes, have n u t r i e n t - r i c h horizons on which to draw. This consolidation may be hastened, the r e s u l t of e f f i c i e n t c y c l i n g of nutrients by plant communities. In terms of minimal i o n i c content of s o i l , few species i n the study have been found on s o i l s with lower nutrient content than Typha. Of the other dominants, a l l are found on ranges of ions greater than the minimal requirements for Typha, with the exception of the potassium ion. Species found i n lower potassium s i t e s than Typha are Impatiens b i f l o r a , Scirpus  americanus, Dulichium arundinaceum and Phragmites communis. Further, Typha grows s u c c e s s f u l l y on a wide range of pH value, 4.2 - 8.0, a condition not found i n t h i s study with any of the other wetland dominants. This wide range, i n d i c a t i v e of e f f i c i e n t u t i l i z a t i o n of s o i l n u t r i e n t s , even at pH values where c e r t a i n ions are i n short supply, probably contributes to the a b i l i t y of Typha to compete s u c c e s s f u l l y i n wetland communities. Even the pattern of s o i l temperatures i s d i s t i n c t i v e . Here i t appears 221 that while Typha can grow well on s o i l s of considerable v a r i a t i o n i n temperature pattern, few other species occupy s o i l of such d i f f e r i n g temperature c h a r a c t e r i s t i c s . Again, t h i s a b i l i t y of Typha to compete over a wide range of s o i l temperatures, o f f e r s a d i s t i n c t advantage over other wetland species, p a r t i c u l a r l y when new habitats become a v a i l a b l e for c o l o n i z a t i o n . Ellenberg (1958) has stated that "every community has a p r o f i l e of i t s own". I t i s f a i r l y obvious that a plant community i n the concrete sense must have a s o i l p r o f i l e or p r o f i l e s (unless i t i s an a r t i f i c i a l community grown under glass, or the product of a g r i c u l t u r a l monoculture p r a c t i c e s ) . In t h i s study each plant community i n the sense of s o i l content has i t s own s o i l p r o f i l e . Each also exhibits i n d i v i d u a l s o i l c h a r a c t e r i s t i c s of ion accumulation, horizon depth, moisture and temperature which accompany the build-up of the mature and i n d i v i d u a l s o i l p r o f i l e , according to the p a r t i c u l a r dominant. The p r o f i l e v a r i e s according to the stage of development at which one finds the i n d i v i d u a l s o i l . On t e r r e s t r i a l s o i l s , t h i s s i t u a t i o n may be l e s s apparent, but i n wetland s o i l s based on d i f f e r e n t dominant species, i t becomes f a c t , and one which i s e a s i l y demonstrated. The plant communities i n t h i s study, including Typha, c o l l e c t i v e l y show highly i n d i v i d u a l s o i l s which may be regarded as s p e c i f i c . The communities do not however modify s o i l s so that the l a t t e r require s p e c i a l c l a s s i f i c a t i o n s . Rather they simply vary t h e i r own c h a r a c t e r i s t i c s within the l i m i t s of the orders and subgroups to which the s o i l s belong. (g) Competition From Species Other Than Typha Any species which can form large dominant stands i n wetlands must be considered a p o t e n t i a l competitor i n Typha marshes. Of these, willow and alder alone have the a b i l i t y to completely overtop the Typha community, and following s o i l accumulation, can invade and develop another plant community 222 i n the successional sequence. Even here, the denser stands of Typha withstand these invasions with r e l a t i v e success, since during the e n t i r e study period, only one Alnus seedling was found on Typha s i t e s , and no willows at a l l have been recorded, even though some of the marshes had large stands of willow adjacent to them. Of the other species which are found near Typha s i t e s , and which form large dominant stands, a l l may be eliminated as equal competitors with Typha for one or more reasons, which have already been mentioned i n the present study. The majority, despite substrate requirements or vigour, can be e a s i l y overtopped by Typha, and t h i s would eliminate them from a c t i v e competition on new h a b i t a t s . Only one, Scirpus v a l i d u s , can occupy deeper water (148 cm), where presumably i t would remain as the species successful over Typha. Scirpus f l u v i a t i l i s and Phragmites communis, both of which can achieve mature heights s i m i l a r to Typha communities, and which may compete su c c e s s f u l l y f or c o l o n i z a t i o n of n u t r i e n t - r i c h substrates which become a v a i l a b l e , are probably both excluded from active competition for n u t r i e n t -poor s i t e s , by t h e i r heavy requirements for substrate components. (D) SEASONAL ACTIVITY OF TYPHA AND PHRAGMITES At the time these studies were begun, the general method of data accumulation f o r an e c o l o g i c a l study of a species was to s e l e c t as many random p l o t s as p o s s i b l e , sample, and i n t e r p r e t the species i n the l i g h t of data thus assembled. The disadvantages to such a method seem obvious. One can never r e a l l y assess the species except i n a series of broad g e n e r a l i t i e s . At the same time, Typha and many other marsh dominants r e a d i l y a f f o r d the opportunity of seasonal studies of pure stands, since large monodominant stands are the r u l e , not the exception i n wetland hab i t a t s . Such a study provides, from c l o n a l i n d i v i d u a l s , concrete and i r r e f u t a b l e data concerning the seasonal behaviour of species i n terms of macronutrient uptake, u t i l i z a t i o n 223 of substrate, and r e c y c l i n g and transport of nutrient from one part of the plant to another• In terms of i o n i c uptake by Typha, under f i e l d conditions, the unique behaviour of the macronutrients analysed i s e a s i l y demonstrated. Each ion has i t s own pattern of uptake and d i s t r i b u t i o n , which may be seen i n the plant - substrate graphs. For instance, although both calcium and magnesium are e s s e n t i a l l y recycled to the s o i l following use by leaves, at the time of seasonal senescence, t h e i r i n i t i a l uptake patterns d i f f e r . Calcium uptake increases r a p i d l y up to the flowering period and the period of maximum growth, then decreases. Magnesium begins uptake at a high l e v e l which i s maintained to the period of maximum growth, and then amounts taken i n begin to decrease. A lack of concomitant increase of ions i n rhizome t i s s u e , plus an increase of calcium and to a l e s s e r extent magnesium i n the s o i l substrate suggests that.these ions are annually recycled between plant and s o i l substrate. Potassium has a s i m i l a r uptake pattern i n l e a f material to magnesium, but here, at seasonal senescence, the loss of K i n the lea f m a t erial i s cycled to the ti s s u e of the rhizome, presumably for overwintering and r e u t i l i z a t i o n the following spring. Phosphorus also c l e a r l y shows translocatory phenomena, as decrease i n le a f and flowering s t a l k phosphorus coincides with r i s i n g amounts of phosphorus, not i n the substrate, but i n rhizome t i s s u e . Both i r o n and sodium are seen to fl u c t u a t e passively within the plant - substrate systems. Seasonal moisture content of plant material may o f f e r some i n s i g h t into changes i n metabolic behaviour. In Typha, rhizome material holds a r e l a t i v e l y steady moisture content for the en t i r e growing season. Flowering s t a l k s , t h e i r metabolic functions completed once f e r t i l i z a t i o n takes place, show a continuous decline i n moisture content from the time of flowering. Leaf material maintains a steady moisture content u n t i l the time of flowering, 224 then declines to the end of the growing season. Comparisons of i o n i c content and moisture content i n d i c a t e c l e a r l y that the decline i n moisture content i s coincident with translocatory processes i n the l e a f , and thus presumably moisture content may be used as an i n d i c a t o r of seasonal senescence, c e r t a i n l y of a s i g n i f i c a n t metabolic s h i f t , which i s probably the onset of seasonal senescence. If any further proof of the usefulness of such studies seems necessary, i t comes with the a d d i t i o n a l studies of s o i l - water •*- plant r e l a t i o n s h i p s of the f l o a t i n g mats of Typha. I t has been assumed that because the f l o a t i n g mats had such strong hydric contacts, that the water around them would prove more important than the i o n i c supply of the mats themselves. This hypothesis i s disproven by the data. For the four ions analysed, the mat - Typha r e l a t i o n s h i p s are s i m i l a r to the r e l a t i o n s h i p s discovered i n the o r i g i n a l study, which used normally rooted Typha. Although the concentrations of a v a i l a b l e ions are l e s s i n the f l o a t i n g mats than they are i n a normal s o i l substrate, nevertheless uptake i n Typha i s not i n d i r e c t proportion to concentrations, since i t i s s i m i l a r for both hab i t a t s . This f i n d i n g lends support to the idea that plants, i n t h i s case Typha, accumulate required ions i n response to t h e i r genetic make-up, which influences t h e i r p h y s i o l o g i c a l and biochemical a c t i v i t i e s . I f , under natural condition, the substrate cannot supply the requirements of the p a r t i c u l a r species, then the species w i l l u l t i m a t e l y become extinct i n that h a b i t a t , i f i n f a c t i t can even germinate there i n the f i r s t place. Also a species l i k e Typha, which has only comparatively moderate i o n i c requirements, i s more l i k e l y than other genera to succeed i n new low-nutrient mineral s o i l s , which are the usual type of a v a i l a b l e habitats. In considering Phragmites communis, the major competitor of Typha, two points are immediately obvious. F i r s t , the general pattern of i o n i c 225 uptake i s s i m i l a r i n both plants. However, the actual uptake curves d i f f e r i n shape. This i s not s u r p r i s i n g since the pattern of moisture content and plant growth of Phragmites i s e n t i r e l y d i f f e r e n t from Typha, so the expectation i s strong that the curves of uptake would also be d i f f e r e n t . Second, the requirements of Phragmites d i f f e r from Typha. Phragmites shows a much higher i o n i c requirement for calcium, magnesium and phosphorus, while Typha uses more potassium than does Phragmites. Such differences c e r t a i n l y are s i g n i f i c a n t i n terms of substrate u t i l i z a t i o n , which c l e a r l y d i f f e r s between the two plants. It would appear that, where nutrients are generally low, Typha can more e a s i l y gain ascendency on a new habitat. However, i f nutrients were high i n a newly a v a i l a b l e habitat, then neither Phragmites nor Typha would have an advantage for c o l o n i z a t i o n . (E) GENESIS OF WETLAND COiMMUNITIES A l l wetland communities depend on a source of water, ei t h e r continuous or i n t e r m i t t e n t , which maintains the substrate i n a saturated condition. Open marshes are formed on r i v e r margins and the shores of large lake systems, where f i n e l y - s o r t e d alluvium i s deposited. In the eastern provinces, most a l l u v i a l deposits come from r i v e r s which have flowed only since the period of the l a s t g l a c i a t i o n . Some of the closed marshes near Ottawa have been formed on the now s i l t e d beds of the Pre-Ottawa River. Marshes also may be formed where dams have a r t i f i c i a l l y r a i s e d water l e v e l s , as on the St. Lawrence Seaway, or even where e f f l u e n t and s o i l p a r t i c l e s pass through conduits and are deposited over t o p s o i l i n low-lying areas, forming the basis of ruderal marsh communities. Water depth and water current are both factors which l i m i t species which can colonize marsh h a b i t a t s . Such species, other than f r e e - f l o a t i n g hydrophytes, must be capable of surviving i n f l u c t u a t i n g water l e v e l s and changes of current. Here f r u i t s of Typha have a d i s t i n c t advantage over 226 many wetland species. The f r u i t s of Typha are s h o r t - l i v e d , but they require only moisture to germinate, and can f l o a t , supported by the b r i s t l e s of the f r u i t , u n t i l they reach some s o l i d substrate into which the roots may grow. In shallow waters, the seedlings of emergents r a p i d l y take root, and maintain themselves, provided only that the currents do not sweep them away, or d e s i c c a t i o n from summer drought and drawdown does not k i l l them. Following the tenuous existence i n the seedling stage, plants of the open marshes e s t a b l i s h themselves by adaptations to depth of water and a v a i l a b i l i t y of n u t r i e n t s . Colonization of closed marsh habitats i s a much l e s s hazardous process. While i t follows that there are requirements s i m i l a r to those of open marshes, there are l e s s rigorous conditions for adaptation imposed upon the species. Here the only requirements for successful c o l o n i z a t i o n of protected mud f l a t s (Salisbury 1970) are those of adaptation to a water-saturated h a b i t a t , plus a b i l i t y to germinate i n l i g h t , water and low oxygen content. Once germinated, seedlings undergo environmental s e l e c t i o n through the action of d e s i c c a t i o n , tolerances to changes i n s a l t concentration, as w e l l as f l u c t u a t i o n s i n pH, changes i n water depths and i n d i v i d u a l growth rates of each species. Since Typha has a d i s t i n c t advantage i n a l l categories except tolerance for d e s i c c a t i o n , i t possesses a high c a p a b i l i t y f or domination of wetland communities. (F) SUCCESSION IN WETLANDS In open marshes, there i s l i t t l e occasion f o r a l l u v i a l deposits to accumulate, since water i s i n continual motion. Also, one often observes that because of flooding and recession of water, the topography bordering many r i v e r systems exhibits abrupt changes from one of marsh habitat to one supporting purely t e r r e s t r i a l species. Under such circumstances, Typha communities can be long-persistent, and u n t i l movement of water slows, or i s 227 blocked, allowing deposition of s i l t , such communities can remain as azonal climaxes, i n a state of dynamic equilibrium. Communities i n the shallow waters are subject to a l l u v i a l deposition, and slowly s o i l b u i lds up, with the succession proceeding slowly to c o l o n i z a t i o n by willows, alders and ultimately more mesophytic species. Succession i n the closed marshes follows the order of shallow-pond succession. Here, depending p a r t l y on the t e x t u r a l c l a s s of the s o i l , and the height of the land, succession i s to S a l i x (clay s o i l s ) or Spiraea alba (sandy s o i l s ) or to Alnus rugosa, followed by forest vegetation or grassland. Closed marshes, though some may be long-persistent, are nonetheless temporary stages i n a succession to l e s s hygric and more mesic vegetation. Only l i m i t e d succession can take place on the f l o a t i n g mats of Typha. In some, where the water l i e s above the bases no other species colonizes the mat, and i t remains a pure stand, much as does rooted Typha of deeper waters of open marshes. Where the bases of the Typha are above the water surface, and the water i s a l k a l i n e to n e u t r a l , the mats t h e o r e t i c a l l y can support willows, although no mats have so far been found to do so (some mats at Point Pelee support Decodon v e r t i c i l l a t u s and Cephalanthus o c c i d e n t a l i s ) . In acid waters, such as those at Taylor Lake, f l o a t i n g mats support some bog vegetation, and as i n the changing of a c i d i c marshes to bogs, so the f l o a t i n g mats can become f l o a t i n g bog mats. Some of the species found on the f l o a t i n g mats under a c i d i c conditions are Typha l a t i f o l i a , Myrica gale, Chamaedaphne  ca l y c u l a t a , Thelypteris p a l u s t r i s and Sphagnum recurvum. T a l l e s t shrubs on the mats are Alnus rugosa. However i n the case of f l o a t i n g mats, neither the permanently saturated d e l i c a t e substrate nor the l i m i t a t i o n s of buoyancy permit further stages i n the succession to proceed. (G) SUMMARY In general, Typha communities divide into two p h y s i c a l categories, 228 communities of open and closed marshes. The open marshes are marshes of continuous water c i r c u l a t i o n , and low but constant nut r i e n t supply. The closed marshes are marshes of inconstant water supply, and f l u c t u a t i n g concentrations of nutrients i n the water. Within these marshes several d i s t i n c t Typha communities are recognizable. Of these, the Typha communities composed of nearly pure stands, i n deeper waters, and the two-layered Typha -S a g i t t a r i a communities are t y p i c a l of the open marshes, while the Typha -Galium communities are t y p i c a l of the closed marshes, and shallow back bays of open marshes. T y p i c a l s o i l s of these communities are the Rego Gleysol for the nearly pure Typha communities of deeper water and the Typha -S a g i t t a r i a communities, and the Rego Humic Gleysol and the Humisol for the Typha - Galium communities. The f l o a t i n g mat community of Typha, derived from s o i l - r o o t e d communities, has the Hydric F i b r i s o l as the only s o i l represented. In eastern Canada, due to in t r o g r e s s i v e h y b r i d i z a t i o n , the genus Typha presents a taxonomic as well as an e c o l o g i c a l problem. T_. l a t i f o l i a and T_. a n g u s t i f o l i a hybridize r e a d i l y , producing T_. glauca. With further i n t r o g r e s s i v e h y b r i d i z a t i o n , a complete spectrum of character recombinations i s present i n eastern marshes, so that the e n t i r e complex behaves as though i t were a s i n g l e population with T_. l a t i f o l i a and T_. a n g u s t i f o l i a as the two extremes. However the range of ecotypic v a r i a t i o n may i n part explain the successful c o l o n i z a t i o n by Typha of so wide a range of wetland habi t a t s . Seasonal behaviour studies of normally rooted Typha and f l o a t i n g mat communities of Typha, together with a comparative study of Phragmites communis, have shown that (a), the i o n i c requirements of Typha are generally lower than Phragmites, suggesting that on nutrient-poor s i t e s , Phragmites would be unable to compete for new h a b i t a t s , (b) the substrate of Typha, whether normal s o i l , or the organic mat of the f l o a t i n g mat community, i s more 229 important to growth of Typha than i s the water medium which surrounds i t , (c) provided minimal i o n i c requirements are supplied by the substrate, again either normal s o i l or f l o a t i n g mat substrate, Typha responds with s i m i l a r patterns of i o n i c uptake. Although random sampling c e r t a i n l y allows general assessments of the e c o l o g i c a l p o t e n t i a l of a species, continuous seasonal studies of monodominant stands may more c l e a r l y delineate the requirements and competitive p o t e n t i a l of the selected dominants. Generally growth of Typha has been shown to be influenced by l a t i t u d e , as well as nutrient content of the substrate. Water which o v e r l i e s Typha stands has been found to contribute l e s s to growth of Typha than does the i o n i c content of the substrate matrix. Water i s r e s t r i c t i v e to Typha only when moisture content of the substrate become too low to support hydrophytic growth. Nutrient content of s o i l s may be minimal, yet s t i l l support Typha, but Typha i s also capable of accumulation of r i c h organic horizons as the communities become older. From t h i s study, the genus Typha emerges as a strong and successful competitor i n wetlands, a competitor for nearly a l l possible new wetland ha b i t a t s , including some of considerable s a l i n i t y , and a strong b u i l d e r and consolidator of organic horizons. As l e v e l s of water p o l l u t i o n continue to increase i n the eastern provinces, Typha can draw on i t s capacity to t o l e r a t e high s a l t l e v e l s i n water and s o i l , overcoming the problem of existence where there i s heavy p o l l u t i o n from a g r i c u l t u r a l f e r t i l i z e r s . Typha emerges as a genus which, because of reproductive vigour and wide tolerance for changing environmental conditions, can continue to grace the margins of r i v e r s and streams, providing shelter for w i l d l i f e , despite e f f o r t s of man to mar and mutilate the environment. Typha and i t s communities are unique among wetland communities. Studies of t h i s remarkable genus continue to be a rewarding and i l l u m i n a t i n g 230 undertaking. 231 CONCLUSIONS (1) . Marshes are by l i f e - f o r m nearly homogeneous systems, v i r t u a l l y unstoried, of lush growth i n the summer aspect, but for a l l v i s u a l purposes, "dead" above ground i n the winter aspect. In the proposed modified system of Raunkier, nearly 35% of the taxa of the marsh may be c l a s s i f i e d as "geophyta rhizomatosa hydrophytica" (hydrophytic rhizome-bearing geophytes) . (2) . In eastern Canada, h y b r i d i z a t i o n and i n t r o g r e s s i o n between Typha  l a t i f o l i a and T_. a n g u s t i f o l i a are extensive, the hybrids and recombinations, mainly J_. glauca, excluding the parental types, through hybrid vigor and successful competition. The number of recombinations i s highest i n the more recent habitats (borders of bodies of open water). In more stable marsh areas, numbers of recombination types are reduced, presumably through competition, with usually one major type predominating. D i f f e r e n t types appear to gain dominance on s l i g h t l y d i f f e r e n t habitat types. (3) . Factors concerned with the height of Typha i n the p l o t s studied are l a t i t u d e (shortest plants at the most northerly l a t i t u d e ) , pH ( a c i d i c provenances have shorter p l a n t s ) , nutrient content (lower concentrations of n u t r i e n t s , p a r t i c u l a r l y calcium, have the lower growth response), species d i s t r i b u t i o n (T_. l a t i f o l i a i s the only species represented i n the most northerly provenance), rooting medium ( f l o a t i n g mat populations are shorter than populations rooted i n a firm s o i l substrate). (4) . General comparisons of Typha with other marsh species, i n terms of ion accumulation, show that Typha i s a low to moderate accumulator of n u t r i e n t s , but that many of the species of the Typha - Galium communities are moderate to high accumulators of n u t r i e n t s . This suggests that the multiple - species stages of Typha marshes may only be possible following enriching of marsh s o i l s by death and decay of previous Typha generations. (5) . Moisture content can be used both to c l a s s i f y marsh plants and to 232 i n t e r p r e t metabolic changes i n marsh species, p a r t i c u l a r l y seasonal senescence of perennials. High moisture contents are t y p i c a l of f r e e -f l o a t i n g hydrophytes, low moisture contents of reed, sedge and grass types. Typha has a moderate (average) moisture content and most other rooted aquatics have moisture contents which l i e between those of Typha and f r e e -f l o a t i n g species. Departures from the normal moisture content of a species indi c a t e severe metabolic changes ( i n the case of Typha which had a seasonal moisture content of over 90 percent, i t meant the e x t i n c t i o n of the population). Usually sharp changes i n moisture content indicate:; a metabolic change such as the onset of seasonal senescence and t r a n s l o c a t i o n of mobile nutrients to the overwintering organs. (6) . Three major community types are recognized. The f i r s t i s the Typha community of open marshes and deeper waters, e x i s t i n g as nearly pure stands. Most commonly encountered species are T_. glauca and T_. a n g u s t i f o l i a . The second community i s the Typha - S a g i t t a r i a community of the margins of open marshes. The t h i r d community i s the Typha - Galium community found on the moist margins of open and closed marshes. Although Typha, usually J_. glauca or T_. l a t i f o l i a , i s s t i l l the dominant, many other species, such as Galium  palustre, Lysimachia t e r r e s t r i s , Cicuta b u l b i f e r a and Impatiens b i f l o r a are present. If undisturbed, t h i s stage precedes succession to woody species. (7) . Special communities are the f l o a t i n g mats of Typha. Water f l u c t u a t i o n contributes to t h e i r formation, when, with r i s i n g water l e v e l s , the upper mineral-organic horizon of the marsh s o i l p r o f i l e f l o a t s f r e e . Buoyancy of the mat i s maintained by the extensive aerenchyma systems of the l i v i n g mat perennials. Mat f l o r a most c l o s e l y resembles that of the Typha - Galium community. (8) . Both s o i l and community types may be seen as a progression or evolutionary sequence, as mineral-organic and organic horizons are 233 accumulated. Minimal Gleysols, or Rego Gleysols, are c o r r e l a t e d with the pure Typha stands of the deeper waters. As currents slow, and organic deposits accumulate, the s o i l s evolve from Rego Gleysols to Rego Humic Gleysols and then to Organic s o i l s , which represent a climax i n hydrophytic s o i l s . Depending on the age of the marsh, a l l types of these s o i l s may be found i n the Typha - Galium communities, with the Organic s o i l representing the culmination of marsh s o i l development, even as the Typha - Galium community represents the culmination of development i n the Typha-dominated marsh vegetation. (9) . The l i m i t s of s o i l moisture content for Typha are probably only s l i g h t l y l e s s than saturated conditions, although water does not have to o v e r l i e the s o i l i n order that Typha vegetation be s u c c e s s f u l . However, the r o l e of water i n Typha marshes i s e s s e n t i a l edaphic. While i t i s true that rooted aquatics derive t h e i r n u t r i e n t s from the s o i l (or mat) substrate, marsh s o i l s are i n i t i a l l y of low cation exchange capacity and low nutrient status. At the early stages of a marsh, the overlying waters function to supply needed n u t r i e n t s , at a constant r a t e , to the s o i l exchange s i t e s which are being r a p i d l y depleted through growth demands of the marsh vegetation. Indeed, the shallow-rooted systems of a l l marsh vegetation give credence to such a r o l e . Only when organic horizons, with the accompanying increase i n exchange s i t e s and n u t r i e n t s , are formed, do Typha marshes function vigorously with water below the surface of the s o i l . (10) . A l l the major dominants i n the marsh are completely shade i n t o l e r a n t , functioning vigorously only under conditions of f u l l i n s o l a t i o n . Provided that no environmental stress operates to bring about a r e v e r s a l of natural succession, the marsh vegetation succeeds to woody species such as Alnus  rugosa or willows (Salix spp.) . This condition, however, was not studied i n d e t a i l . 234 (11) . Comparison of f l o a t i n g mat populations of Typha and populations which are normally rooted, show comparable seasonal patterns of uptake, which appear to be correlated with growth events such as early meristematic a c t i v i t y , flowering, attainment of maximum growth, seasonal senescence and t r a n s l o c a t i o n of nutrients to the overwintering rhizome. Mat heights are l e s s than normally rooted plants, although nutrient l e v e l s were s i m i l a r . A d i f f e r e n c e i n height between the plants of the two mat populations may be a t t r i b u t e d to higher calcium and potassium values i n the substrate. Results show that Typha can accumulate considerable amounts of sodium without toxic e f f e c t s to the plant system. (12) . Seasonal uptake of ions suggests that the ions studied may be grouped in t o three categories (A) those which are cycled annually between plant and substrate, such as calcium and magnesium, (B) those i n which the major portion* once taken up, i s stored i n the plant system, and i s recycled between organs, such as potassium and phosphorus and (C) those which f l u c t u a t e passively depending on concentration i n the substrate. Sodium i s d e f i n i t e l y i n t h i s category, and i r o n may also belong here as w e l l , although there i s some evidence that i t may belong i n category (B). (13) . Although Typha and Phragmites communis may appear to act as competitors for wetland h a b i t a t s , uptake and growth c h a r a c t e r i s t i c s appear to d i f f e r i n the two species. Growth behaviour of each d i f f e r s i n that Typha glauca appears to mature early i n the summer, while Phragmites communis continues growth u n t i l slowed by adverse environmental conditions. Also demands for nutrients and sodium d i f f e r markedly, i n that Phragmites requires much greater amounts of calcium, magnesium and phosphorus, and accumulates l i t t l e sodium, while Typha requires much greater amounts of potassium, and also t o l e r a t e s large amounts of sodium i n the plant system. These d i f f e r e n c e s i n i o n i c requirement and uptake o f f e r some i n s i g h t into basic behavioural 235 differences i n the two species, which might r e s t r i c t either one to only p a r t i c u l a r wetland h a b i t a t s . 236 BIBLIOGRAPHY Arber, A. 1920. Water plants. A study of aquatic angiosperms. Cambridge Un i v e r s i t y Press. 436 p. B a l l , E.W. 1958. Results of applying dalapon by a i r c r a f t to pest plants i n waterfowl areas of the southeast. Down to Earth 14 (1):11—14. Bear, F.E., Ed. 1964. Chemistry of the s o i l . Reinhold Publishing Corporation, New York. 515 p. Bedish, J.W. 1967. C a t t a i l moisture requirements and t h e i r s i g n i f i c a n c e to marsh management. Amer. Mid i . Natur. 78 (2):288-299. Bjork, S. 1967. Ecologic investigations of Phragmites communis. F o l i a Limnologica Scandinavica. No. 14. Einar Munksgaard, Copenhagen. 248 p. Bouyoucos, G.J. 1927. The hydrometer as a method for the mechanical analysis of s o i l s . S o i l S c i . 23:343-353. Bouyoucos, G.J. 1936. Directions f o r making mechanical analyses of s o i l s by the hydrometer method. S o i l S c i . 32:225-228. Boyd, C.E. 1970. Production, mineral accumulation and pigment concentrations i n Typha l a t i f o l i a and Scirpus americanus. Ecology 51 (2):285-290. Boyd, C.E. 1970. Amino a c i d , p r o t e i n , and c a l o r i c content of vascular aquatic macrophytes. Ecology 51 (5):902-906. Braun-Blanquet, J . 1932. Plant sociology. McGraw-Hill, New York. 375 p. Braun-Blanquet, J . 1964. Pflanzensoziologie. D r i t t e , neubearbeitete und wesentlich vermehrte Auflage. Springer-Verlag, Wien-New York. 865 p. Bray, J.R. 1962. Estimates of energy budgets for a Typha ( c a t t a i l ) marsh. Science 136 (3522):1119-1120. Bray, R.H., and L.T. Kurtz. 1945. Determination of t o t a l , organic, and a v a i l a b l e forms of phosphorus i n s o i l s . S o i l S c i . 59:39-45. Brenner, F.J. 1966. The influence of drought on reproduction i n a breeding population of redwinged blackbirds. Amer. Midi. Natur. 76 (1): 201-210. Canada Department of Transport, Meteorological Branch. 1967. Temperature and p r e c i p i t a t i o n tables for Ontario. Queen's P r i n t e r , Ottawa. 43 p. Conard, H.S. 1952. The vegetation of Iowa. Univ. Iowa Studies Nat. H i s t . 19 (4):1-166. Damas, H. 1959. Ecology of a Katanga marsh. (In French). Ann. Soc. Roy. Zool. Belgique 89 (1):93-103. 237 Daniel, L.J., and A.L. Neal. 1967. Laboratory experiments i n biochemistry. Academic Press, New York. 301 p. Dansereau, P. 1957. Biogeography. An ecological perspective. The Ronald Press Company, New York. 394 p. Dansereau, P., and F. Segadas-Vianna. 1952. Ecological study of peat bogs i n eastern North America. I. Structure and evolution of vegetation. Can. J . Bot. 30 (4):490-520. Davis, J.H. 1937. Aquatic plant communities of Reelfoot Lake. J. Tenn. Acad. S c i . 12:96-103. Dore, W.G. 1968. Progress of the European Frogsbit i n Canada. The Canadian F i e l d Naturalist 82 (2):76-83. East, E.M. 1940. The d i s t r i b u t i o n of s e l f - s t e r i l i t y i n the flowering plants. Proc. Amer. P h i l . Soc. 82:449-518. Ellenberg, H. 1958. Liber die beziehungen zwischen Pflanzengesellschaft, Standort, Bodenprofil und Bodentyp. Angew. Pflanzensoziol. 15: 14-18. Ellenberg, H. 1963. Vegetation Mitteleuropas mit den Alpen. Einfiihrung i n die Phytologie, Band IV, T e i l 2. Eugen Ulmer, Stuttgart. 943 p. Errington, P.L. 1957. Of men and marshes. The MacMillan Company, New York. . 150 p. Farber, L. Ed. 1960. Standard methods for the examination of water and waste water. American Public Health Association, Inc., New York. 626 p. Fassett, N.C., and B. Calhoun. 1952. Introgression between Typha l a t i f o l i a and T_. ang u s t i f o l i a . Evolution 6 (4):367-379. Fernald, M.L. 1950. Gray's manual of botany. 8th Ed. American Book Company, New York. 1632 p. Fleming, J.F., and L.T. Alexander. 1961. Sulphur a c i d i t y i n South Carolina t i d a l marsh s o i l s . . S o i l S c i . Soc. Amer. Proc. 25 (2) :94-95. Frie d , M., and H. Broeshart. 1967. The so i l - p l a n t system. Academic Press, New York. 358 p. Frost, W.E. 1939. The food consumed by brown trout i n acid and alkaline waters. Proc. Ichth. Acad. 45:139. Getz, L.L. 1961. Factors influencing the l o c a l d i s t r i b u t i o n of Microtus and Synaptomys i n southern Michigan. Ecology 42 (1):110-119. Getz, L.L. 1970. Habitat of the meadow vole (Microtus pennsylvanicus) during a population "low". Amer. Midi. Natur. 83 (2):455-461. G i l t z , M.L., and W.C. Myser. 1954. A preliminary report on an experiment to prevent c a t t a i l d i e - o f f . Ecology 35 (3):418. 238 Gleason, H.A. 1958. The new B r i t t o n and Brown i l l u s t r a t e d f l o r a of the northeastern United States and adjacent Canada. Vols. 1-3. The New York Botanical Garden, New York. 1732 p. Godfrey, W.E. 1966. The b i r d s of Canada. Queen's P r i n t e r f or Canada, Ottawa. 428 p. H a r r i s , S.W. 1954. An e c o l o g i c a l study of the waterfowl of the Potholes area, Grant County, Washington. Amer. Mid i . Natur. 52 (2) .403-432. H a r r i s , S.W., and W.H. Marshall. 1963. Ecology of water-level manipulations on a northern marsh. Ecology 44 (2) .331-343. H a r r i s , V.T., and R.H. Chabreck. 1958. Some e f f e c t s of Hurricane Audrey at Marsh Island, Louisiana. Proc. Louisiana Acad. S c i . 21:47-50. Hartog, C. Den., and S. Segal. 1964. A new c l a s s i f i c a t i o n of water-plant communities. Acta Bot. Neer. 13 (3):367-393. Haslam, S.M. 1965. E c o l o g i c a l studies i n the Breck Fens. I. Vegetation i n r e l a t i o n to h a b i t a t . J . E c o l . 53 (3):599-619. Haslam, S.M. 1971. Community regulation i n Phragmites communis T r i n . I. Monodominant stands. J . E c o l . 59 (l):65-73. Hayden, A. 1939. Notes on Typha a n g u s t i f o l i a L. i n Iowa. Iowa State C o l l . Jour. S c i . 13:341-351. Heath, R.C, and L.C. Ruch. 1958. A e r i a l control of c a t t a i l with radapon. Weed Abstr. 7 (3):417. Hejny, S. 1960. Okologische C h a r a k t e r i s t i k der Wasser- und Sumpfpflanzen i n den Slowakischen Tiefebenen (Donau- und Theissgebiet). Verlag der Slowakischen Akademie der Wissenschaften, B r a t i s l a v a . 487 p. H i l l s , G.A., N.R. Richards and F.F. Morwick. 1944. S o i l survey of Carleton County. Experimental Farms Service, Dominion Dept. of A g r i c u l t u r e and the Ontario A g r i c u l t u r a l College, Guelph. 103 p. Hoffman, D.W., B.C. Mathews and R.E. Wickland. 1964. S o i l associations of southern Ontario. Canada Dept. of A g r i c u l t u r e and Ontario Dept. of A g r i c u l t u r e , Guelph. 21 p. Hogarth, D.D. 1962. A guide to the geology of the Gatineau - Lievre d i s t r i c t . The Canadian F i e l d N a t u r a l i s t 76 ( l ) : l - 5 5 . Holdgate, M.W. 1955. The vegetation of some B r i t i s h upland fens. J . E c o l . 43 (2): 389-403. Hood, J.D. 1955. F r a n k l i n i e l l a welaka, a new t h r i p s from F l o r i d a . F l o r i d a Ent. 38 (2) :71-75. Hotchkiss, H., and H. Dozier. 1949. Taxonomy and d i s t r i b u t i o n of North American c a t t a i l s . Amer. Mid i . Natur. 41:237-254. Howard, P.J.A. 1965. The carbon-organic matter f a c t o r i n various s o i l types. Oikos 15 (2). 239 Hynes, H.B.N. 1970. The ecology of running waters. Un i v e r s i t y of Toronto Press, Toronto. 555 p. Jackson, M.L. 1958. S o i l chemical a n a l y s i s . P r e n t i c e - H a l l , Englewood C l i f f s , N.J. 498 p. J e r v i s , R.A. 1964. Primary p r o d u c t i v i t y i n freshwater marsh ecosystem. Ph.D. Thesis. Rutgers U n i v e r s i t y . 58 p. Kadlec, J.A. 1958. An analysis of a woolgrass (Scirpus cyperinus) community i n Wisconsin. Ecology 39 (2):327-332. Kadlec, J.A. 1961. A further comment on the ecology of woolgrass (Scirpus  cyperinus). Ecology 42 (3):591-592. K i e l , W.H. J r . 1955. Nesting studies of the coot i n southwestern Manitoba. J . W i l d l i f e Management 19 (2):189-198. Koch, W. 1926. Die Vegetationseinheiten der Linthbene. Jahrb. St. G a l l . Naturw. Ges. 6:Teil I I : 1-146. Kubiena, W.L. 1953. The s o i l s of Europe. Thomas Murby and Company, London. 317 p. Laing, H.E. 1941. E f f e c t of concentration of oxygen and pressure of water upon growth of rhizomes of semi-submerged plants. Bot. Gaz. 102: 712-714. L a j o i e , P. 1962. S o i l survey of Gatineau and Pontiac Counties, Quebec. Research Branch, Canada Dept. of Agr i c u l t u r e and MacDonald College M c G i l l U n i v e r s i t y . 94 p. Le v i , E. 1960. Chemical c o n t r o l of Typha a n g u s t i f o l i a L. var. brownii. Weeds 8 (1):128-138. Lokemoen, J.T. 1966. Breeding ecology of the redhead duck i n western Montana. J . W i l d l i f e Management 30 (4):668-681. Luther, H. 1951. Verbreitung und Okologie der hoheren Wasserpflanzen im Brackwasser der Ekenas-gegend i n Sidfenland. Acta Bot. Fennica 50:1-370. Ma r i e - V i c t o r i n , F r. 1964. Flor e Laurentienne. Ed. 2. Univ e r s i t y of Montre Presses, Montreal. 925 p. Marsh, L.C. 1963. Studies i n the genus Typha. Ph.D. Thesis. Syracuse Un i v e r s i t y . 126 p. Matveeva, E.P., and L.A. Znamenskaya. 1959. Common c a t ' s - t a i l (Typha  l a t i f o l i a ) . (In Russian). Referat. Zhur., B i o l . , No. 79428. McDonald, M.E. 1955. Cause and e f f e c t of d i e - o f f of emergent vegetation. J . W i l d l i f e Management 19 (l):24-35. McMillan, C. 1959. Salt tolerance within a Typha population. Amer. J . Bot. 46 (7):521-526. 240 McNaughton, S.J. 1966a. Ecotype function i n the Typha community-type. Ec o l . Monogr. 36 (4):297-325. McNaughton, S.J. 1966b. Thermal i n a c t i v a t i o n properties of enzymes from Typha l a t i f o l i a L. ecotypes. Plant P h y s i o l . 41 (10):1736-1738. McNaughton, S.J. 1966c. Light-stimulated oxygen uptake and g l y c o l i c acid oxidase i n Typha l a t i f o l i a L. l e a f d i s c s . Nature 211 (5054): 1197-1198. McNaughton, S.J. 1966d. Oxidase a c t i v i t y i n ecotypic populations of Typha  l a t i f o l i a L. Nature 211 (5056):1377-1379. McNaughton, S.J. 1967. Photosynthetic system I I : r a c i a l d i f f e r e n t i a t i o n i n Typha l a t i f o l i a . Science 156 (3780):1363. McNaughton, S.J. 1969. Genetic and environmental co n t r o l of g l y c o l i c acid oxidase a c t i v i t y i n ecotypic populations of Typha l a t i f o l i a . Amer. J . Bot. 56 (1):37-41. McNaughton, S.J. 1970. Fitness sets f or Typha. Amer. Natur. 104 (938): 337-341. Munsell s o i l color charts. Ed. 1954. Munsell Color Company Inc., Baltimore, Maryland. Munz, P.A. 1959. A C a l i f o r n i a f l o r a . Univ. C a l i f o r n i a Press, Berkeley and Los Angeles. 1681 p. National S o i l Survey Committee (Canada). 1965. Report 6th meeting of the National S o i l Survey of Canada, Laval U n i v e r s i t y , Quebec C i t y . Mimeograph. 132 p. National S o i l Survey of Canada. 1970. 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. Canada Department of A g r i c u l t u r e . 249 p. Neuhausl, R., J . Moravec and Z. Neuhauslova-Novotna. 1965. Synokologische Studien iiber Ro'hrichte, Wiesen und Auenwalder. Verlag der Tschechoslowakischen Akademie der Wissenschaften, Prag. 517 p. Ophel, I.L., and CD. Fraser. 1970. Calcium and strontium d i s c r i m i n a t i o n by aquatic plants. Ecology 51 (2):324-327. Pancoast, J.M. 1937. Muskrat industry i n southern New Jersey. Trans. N. Amer. W i l d l . Conf. 2:527-530. Pearson, L.C. 1966. Primary p r o d u c t i v i t y i n a northern desert area. Oikos 15 (2) :211-228. Penfound, W.T. 1952. Southern swamps and marshes. Bot. Rev. 18 (6):413-446. P i a t t , R.B., and J.F. G r i f f i t h s . 1964. Environmental measurement and i n t e r p r e t a t i o n . Reinhold Publishing Corporation, New York. 235 p. Polunin, N. 1960. An introduction to plant geography. McGraw-Hill Book Company, Inc., New York. 394 p. 241 Reichle, D.E., and W.T. Doyle. 1965. Bryophyte succession i n a northern I l l i n o i s bog. The Bryologist 68 (4):463-470. Reid, G.K. 1961. Ecology of inland waters and estu a r i e s . Reinhold Publishing Corporation, New York. 375 p. Richards, N.R., A.G. Caldwell and F.F. Morwick. 1949. S o i l survey of Essex County. Report No. 11 of the Ontario S o i l Survey, Experimental Farms Service, Dominion Department of Ag r i c u l t u r e and the Ontario A g r i c u l t u r a l College, Guelph. 85 p. Robel, R.J. 1962. Changes i n submersed vegetation following a change i n water l e v e l . J . W i l d l i f e Management 26 (2):221-224. Robson, T.O., E.C.S. L i t t l e , D.R. Johnstone and R.F. H i l l . 1966. A new technique for accurate a e r i a l a p p l i c a t i o n of herbicides to drainage channels with n e g l i g i b l e spray d r i f t . Weed Res. 6 (3).254-266. Salisbury, E. 1970. The pioneer vegetation of exposed muds and i t s b i o l o g i c a l features. P h i l . Trans. Roy. Soc. London. Ser. B. B i o l . S c i . 259 (829).207-255. Sculthorpe, CD. 1967. The biology of aquatic vascular plants. Edward Arnold (Publishers) Ltd., London. 610 p. S i f t o n , H.B. 1959. The germination of l i g h t - s e n s i t i v e seeds of Typha  l a t i f o l i a L. Can. J . Bot. 37 (4):719-739. Smith, S.G. 1962. Natural h y b r i d i z a t i o n among three species of c a t t a i l (Typha) i n C a l i f o r n i a . Amer. J . Bot. 49 (6 pt 2):678. Smith, S.G. 1967. Experimental and na t u r a l hybrids i n North American Typha (Typhaceae). Amer. Midi. Natur. 78 (2):257-287. Swank, W.G., and G.A. Petrides. 1954. Establishment and food habitats of the n u t r i a i n Texas. Ecology 35 (2).172-176. T a l l o n , G. 1958. La f l o r e des r i z i e r e s de l a region d'Aries et ses repercussions sur l a culture du r i z . Vegetatio 8 (l):20-42. Timmons, E.T. 1963. Studies on the control of common c a t t a i l i n drainage channels and ditches. U.S. Department of Ag r i c u l t u r e B u l l . 1286. 51 p. Tiixen, R. , and E. P r e i s i n g . 1942. Grundbegriffe and Methoden zum Studium der Wasser- und Sumpfpflanzen-Gesellschaften. Deutsche Wasser-wirtschaft 37:10-17, 57-69. Uhler, F.M. 1944. Control of undesirable plants i n waterfowl h a b i t a t s . Trans. N. Amer. W i l d l . Conf. 9:295-303. Vlaming, V. de, and V.W. Proctor. 1968. Dispersal of aquatic organisms: v i a b i l i t y of seeds recovered from the droppings of captive k i l l d e e r and mallard ducks. Amer. J . Bot. 55 (l):20-26. 242 Welch, P.S. 1952. Limnology. McGraw-Hill Book Company, Inc., New York. 538 p. White, D. 1966. Vegetative spreading of c a t t a i l s (Typha l a t i f o l i a ) through carp (Cyprinus carpio) disturbance. Amer. Midi. Natur. 76 (2): 510. Yeager, L.E. 1949. E f f e c t of permanent flooding i n a river-bottom timber area. 111. Nat. H i s t . Surv. B u l l . 25:33-65. Yeo, R.R. 1964. L i f e h i s t o r y of the common c a t t a i l . Weeds 12 (4):284-288. 243 APPENDIX I 244 LIST OF VASCULAR PLANTS FOUND ON SAMPLE PLOTS L i f e form abbreviations: Ch f, Chamaephyta f r u t i c o s a ; Ch s hy, Chamaephyta s u f f r u t i c o s a hydrophytica; G r a , Geophyta radicigemmata; G r a hy, Geophyta radicigemmata hydrophytica; G rh, Geophyta rhizomatosa; G rh hy, Geophyta rhizomatosa hydrophytica; H, Hemicryptophyta; He, Hemicryptophyta caespitosa; Hr, Hemicryptophyta r o s u l a t a ; Hy n, Hydrophyta natantia; Hy n s, Hydrophyta natantia submersa; Hy r a , Hydrophyta r a d i c a n t i a ; MP, Macro-phanerophyta; NP, Nano-phanerophyta; NP hy, Nano-phanerophyta hydrophytica; Th, Therophyta; Th 9hy, Therophyta hydrophytica. L i f e Form G rh hy Acorus calamus L. H Agropyron repens (L.) Beauv. H Agrostis s t o l o n i f e r a L. G rh hy Alisma plantago-aquatica L. MP Alnus rugosa (DuRoi) Spreng. Th Ambrosia a r t e m i s i i f o l i a L. G rh hy Asclepias incarnata L. G rh Aster ontarionis Wieg. Th hy A t r i p l e x patula L. Th hy Bidens cernua L. Th hy Bidens frondosa L. H Boehmeria c y l i n d r i c a (L.) Sw. G•rh hy Butomus umbellatus L. H Calamagrostis canadensis (Michx.) Beauv. Th hy C a l l i t r i c h e hermaphroditica L. Hr Cardamine pratensis L. He Carex comosa Boott. He Carex c r i s t a t e l l a B r i t t . He Carex h y s t e r i c i n a Muhl. He Carex l a c u s t r i s W i l l d . He Carex l u r i d a Wahl. 245 LIST OF VASCULAR PLANTS (CONTINUED) G rh hy Carex r e t r o r s a Schw. He Carex s t l p a t a Muhl. Hy n s Ceratophyllum demersum L. Ch f Chamaedaphne cal y c u l a t a (L.) Moench. G rh hy Chelone glabra L. Th Chenopodlum album L. G r a hy Cicuta b u l b i f e r a L. G r a Cirsium arvense (L.) Scop. Ch s hy Decodon v e r t i c i l l a t u s (L.) E l l . G rh hy Dulichium arundinaceum (L.) B r i t t . G rh hy Eleocharis a c i c u l a r i s (L.) R. & S. Th hy Eleocharis ovata (Roth.) R. & S. G rh hy Eleocharis p a l u s t r i s (L.) R. & S. Hy r a Elodea canadensis Gray G rh hy Epilobium coloratum Biehler G rh hy Epilobium hirsutum L. G rh Equisetum arvense L. Ch e Equisetum hiemale L. G rh hy Eupatorium maculaturn L. Th Euphorbia serpens HBK H r Frag a r i a v i r g i n i a n a Duchesne. G rh hy Galium palustre L. G rh hy G l y c e r i a b o r e a l i s (Nash) Batchelder G r h hy G l y c e r i a canadensis (Michx.) T r i n . G rh hy G l y c e r i a grand i s . S... Wats. G rh hy Hibiscus p a l u s t r i s L. Hy r a Hydrocharis morsus-ranae L. 246 LIST OF VASCULAR PLANTS (CONTINUED) Th Impatiens b i f l o r a W i l l d . G rh hy I r i s v e r s i c o l o r L. Hy r a Isoetes macrospora Durieu. He Juncus effusus L. G rh hy J u s t i c i a americana (L.) Vahl. G rh hy Lee r s i a oryzoides (L.) Sw. Hy n Lemna minor L. Hy n s Lemna t r i s u l c a L. Hy ra Ludwigia p a l u s t r i s (L.) E l l . G rh hy Lycopus u n i f l o r u s Michx. G rh hy Lycopus v i r g i n i c u s L. G rh Lysimachia t e r r e s t r i s (L.) BSP G rh hy Lythrum s a l i c a r i a L. G rh Mentha arvensis L. NP Myrica gale L. Hy ra Myriophyllum v e r t i c i l l a t u m L. Th hy Na.ias f l e x i l i s (Willd.) Rostk. & Schmidt Hy r a Nuphar advena A i t . Hy r a Nymphaea odorata A i t . G rh Onoclea s e n s i b i l i s L. G rh hy Penthorum sedoides L. G rh Phalaris arundinacea L. G rh hy Phragmites communis T r i n . Th hy P i l e a fontana (Lunell) Rydb. Th hy Polygonum hydropiper L. Th hy Polygonum l a p a t h i f o l i u m L. Th Polygonum p e r s i c a r i a L. LIST OF VASCULAR PLANTS (CONTINUED) Th hy Polygonum sagittatum L. G rh hy Pontederia cordata L. Hy r a Potamogeton amplifolius Tuckerm. Hy ra Potamogeton nodosus P o i r . Hy r a Potamogeton p e r f o l l a t u s L. G rh P o t e n t l l l a p a l u s t r i s (L.) Scop. Th Rorippa i s l a n d i c a (Oeder) Borbas NP hy Rosa p a l u s t r i s Marsh. H Rumex crispus L. G rh hy S a g i t t a r i a l a t i f o l i a W i l l d . G rh hy S a g i t t a r i a r i g i d a Pursh. NP S a l i x p e t i o l a r i s Sm. G rh hy Scirpus americanus Pers. H c Scirpus atrovirens W i l l d . H c Scirpus cyperinus (L.) Kunth. G rh hy Scirpus f l u v i a t i l i s (Torr.) Gray G rh hy Scirpus rubrotinctus Fern. G rh hy Scirpus validus Vahl. G r h hy S c u t e l l a r i a g a l e r i c u l a t a L. H c S e t a r i a glauca (L.) Beauv. G rh hy Sium suave Wait. Ch s hy Solanum dulcamara L. G rh Solidago gigantea A i t . G ra Sonchus arvensis L. G rh hy Sparganium americanum Nutt. G rh hy Sparganium androcladum (Engelm.) Morong G rh hy Sparganium eurycarpum Engelm. LIST OF VASCULAR PLANTS (CONTINUED) NP Spiraea alba Duroi NP Spiraea tomentosa L. Th hy S t e l l a r i a a l s i n e Grimm. G rh Thelypteris p a l u s t r i s Schott. G r a Triadenum virginicum (L.) Raf. G rh hy Typha a n g u s t i f o l i a L. G rh hy Typha glauca Godr. G r h hy Typha l a t i f o l i a L. Hy n s U t r i c u l a r i a minor L. Hy n s U t r i c u l a r i a v u l g a r i s L. Hy r a V a l l i s n e r i a americana Michx. G rh Verbena hastata L. H r V i o l a p a l u s t r i s L. Th hy Ziza n i a aquatica L. 249 APPENDIX II 250 S t a t i s t i c a l Analyses Randomization methods were used to obtain the data presented i n the body of the text. The s t a t i s t i c a l analysis attempted to describe the seasonal v a r i a t i o n i n Typha glauca plus several other marsh species. The majority of the tables i n the text present the sample means as a function of time. The number of observations upon which each mean i s based i s indicated to give some basis for assessing the p r e c i s i o n of the corresponding estimate. The data range i s also s p e c i f i e d i n the water and s o i l sample cases. Figures 64-77, 73-86 display the scat t e r diagrams; e i t h e r s t r a i g h t l i n e s or smooth curves were f i t t e d s u b j e c t i v e l y to the data where the nature of the seasonal v a r i a t i o n was deemed to be apparent. Subsequent to these analyses a more rigorous s t a t i s t i c a l study was conducted on a selected number of c h a r a c t e r i s t i c s to v e r i f y the r e s u l t s of the l e s s time-consuming but admittedly less objective approach a c t u a l l y employed. Thus suppose that Y denotes the observed value of the response v a r i a b l e at time t , e.g., phosphorus mg per gm dry weight f o r flower stocks i n Figure 71. Let t denote the independent time v a r i a b l e , the observations being taken at equi-distant time i n t e r v a l s . A polynomial model was f i t t e d to the k sets of ordered ( t , Y ) observations. A stepwise regression computer programme was u t i l i z e d to f i t the polynomial of lowest degree p, v i z . , Y = a + bt + c t 2 + d t 3 + ... + r t P which adequately r e f l e c t s the true nature of the response-time r e l a t i o n s h i p . Thus i f p = o, there i s no regression, i . e . , no r e l a t i o n s h i p apparent and the s c a t t e r diagram may be considered as s t r i c t l y random i n nature. If p = 1, the regression i s deemed to be pure l i n e a r and a s t r a i g h t l i n e trend with e i t h e r p o s i t i v e or negative slope describes the r e l a t i o n s h i p . With p = 2 the r e l a t i o n s h i p i s quadratic, p = 3 cubic and so on. The 251 stepwise programme s p e c i f i e s the value of p and computes the l e a s t squares estimates of the unknown regression c o e f f i c i e n t s along with the standard errors of the estimates. It also generates the Analysis of Variance (ANOVA) table upon which the s i g n i f i c a n c e of the s p e c i f i e d regression i s based. Seven regression analyses of the above nature were c a r r i e d out on the c h a r a c t e r i s t i c s (i) phosphorus content i n leaves, ( i i ) phosphorus content i n rhizomes, ( i i i ) phosphorus content i n flower s t a l k s and (iv) phosphorus content i n s o i l Ah la y e r (as depicted i n Figure 71), (v) potassium content i n rhizomes, (vi) potassium content i n leaves, ( v i i ) potassium content i n flower st a l k s (as i n Figure 70). In what follows we have summarized the computer printouts r e l a t i n g to the c h a r a c t e r i s t i c s j u s t s p e c i f i e d . The degree of the b e s t - f i t t i n g polynomial i s indicated and the l e a s t squares c o e f f i c i e n t s are presented along with t h e i r respective standard e r r o r s . The ANOVA table corresponding to the f i t t e d polynomial i s given and the value of the F s t a t i s t i c against which the s i g n i f i c a n c e of the regression i s judged i s provided. The c r i t i c a l F value at the 1% s i g n i f i c a n c e l e v e l i s indicated; any observed F exceeding t h i s value i s said to be "highly s i g n i f i c a n t " or " s i g n i f i c a n t at the 1% l e v e l " . F i n a l l y the c o e f f i c i e n t of multiple c o r r e l a t i o n , i . e . , the c o r r e l a t i o n between the observed Y values and the f i t t e d Yfc values obtained from the l e a s t squares f i t i s given. The greater the value of t h i s c o e f f i c i e n t (the maximum being unity) the better i s the f i t a c t u a l l y obtained. 1. Phosphorus Content i n Leaves: F i t t e d polynomial of degree 3 constant c o e f f i c i e n t = 2.285 l i n e a r c o e f f i c i e n t f 0.3901 x 10"k, standard er r o r = 0.1889 x 10~k cubic c o e f f i c i e n t = 0.6436 x 10" 1, standard error = 0.9977 x 10*"2 252 ANOVA 1 Source d. f. Regression 2 Residual 23 To t a l 25 Mu l t i p l e c o r r e l a t i o n c o e f f i c i e n t : R = 0.85 F i t t e d equation: Y - 2.285 + 0.390 x 10 _ l +t - 0.644 x 1 0 ~ 3 t 3 , t ~— ™27 y ™25 y • • • ™™ 1 ^  X ^  • • • y 23 y 27 • • 2. Phosphorus Content In Rhizomes: F i t t e d polynomial of degree one constant c o e f f i c i e n t = 2.481 l i n e a r c o e f f i c i e n t = 0.1328, standard error = 0.1159 x 10 _ 1 ANOVA 2 Source d.f. Regression 1 Residual 22 Tot a l 23 M u l t i p l e c o r r e l a t i o n c o e f f i c i e n t : R = 0.93 F i t t e d equation: Y = 2.481 + 0.133t, t = -13, -12, -1, 0, 1, 11 3. Phosphorus Content i n Flower Sta l k : F i t t e d polynomial of degree two constant c o e f f i c i e n t = 1.5394 l i n e a r term = -0.1561, standard error = 0.1215 x 10 - 1 quadratic term = 0.1215, standard error = 0.2255 x IO" 2 ANOVA 3 d.f. S.S. M.S. F FQ 9 9 2 12.4806 6.2403 102.07 6.70 13 0.7948 0.6114 15 13.2754 S.S. M ^ F F 0 9 9 13.8971 6.9845 65.6185 5.66 2.4355 0.1059 16.3326 S.S. M.S. 22.4439 3.7602 22.4439 0.1709 26.2041 F 131.31 0.99 7.95 Source Regression Residual T o t a l 253 Multi p l e c o r r e l a t i o n c o e f f i c i e n t : R = 0.97 F i t t e d equation: Y = 1.539 - 0.156t + 0.122t 2, t = -9, -8, ...0, 1, 8, 9. 4. Phosphorus Content i n S o i l : No regression. 5. Potassium Content i n Rhizomes: F i t t e d Polynomial of degree one. constant c o e f f i c i e n t = 16.7979 l i n e a r c o e f f i c i e n t = 0.3097, standard error = 0.6652 x 10 _ 1 ANOVA 5 Source d.f. S.S. M.S. F F Q g g Regression 1 122.0948 122.0948 21.68 7.95 Residual 22 123.9176 5.6326 T o t a l 23 246.0124 R = 0.70 13. F i t t e d equation: Y = 16.800 + 0.310t, t = -13, -12, .. 6. Potassium Content i n Leaves: F i t t e d polynomial of degree one. constant c o e f f i c i e n t = 16.0214 l i n e a r c o e f f i c i e n t = -0.1958, standard er r o r = 0.2446 x 10 - 1 ANOVA 6 Source d.f. S.S. M.S. F F. O Q Regression 1 243.5268 243.5268 64.09 7.82 Residual 24 91.1913 3.7996 T o t a l 25 334.7181 Mu l t i p l e c o r r e l a t i o n c o e f f i c i e n t = 0.85 F i t t e d equation: Y = 2.481 + 0.133t, t = -27, -25, 25, 27. It i s noted immediately from the s t a t i s t i c a l analyses that i n 5 of the 6 cases where a s i g n i f i c a n t regression was found, they were a l l highly s i g n i f i c a n t . Thus we have very strong evidence that r e l a t i o n s h i p s 254 of the types indicated do i n fact e x i s t . The smallest value of the mul t i p l e c o r r e l a t i o n c o e f f i c i e n t observed was 0.85 i n d i c a t i n g that there i s an extremely strong tendency for the observed Y values to c l u s t e r about the f i t t e d l i n e or curve. In the case of phosphorus / l e a v e s , flower s t a l k s , s o i l , the sketched curves were i n agreement with the computer f i t . In the case of phosphorus /rhizomes and potassium/leaves and /rhizomes we sketched a curve which was c u r v i l i n e a r as opposed to the computer l i n e a r f i t s . However i t might be argued that even though the non-linear terms are i n d i v i d u a l l y n o n - s i g n i f i c a n t , t h e i r cumulative e f f e c t (which we might c a l l "deviations from l i n e a r regression") i s indeed s i g n i f i c a n t . The l i n e a r component of the subjective l i n e has the same slope as the computer f i t t e d l i n e which i s perhaps most important. At any r a t e , the purpose of the regression analyses was to demonstrate that there are r e l a t i o n s h i p s present and not to e s t a b l i s h the equations of the r e l a t i o n s h i p s per se. Note added by Dr. V.J. Kra j i n a : The s t a t i s t i c a l content of t h i s t h e s i s was supervised by Dr. Jack E. Graham, Associate Professor of Mathematics, Carleton U n i v e r s i t y , whose work i s grate-f u l l y acknowledged here. In a l e t t e r , addressed to Dr. R.F. Scagel on Feb-ruary 27, 1974, he commented as follows: "I should point out that while I have served as an examiner on a number of Masters and Ph.D. boards, i t was i n my capacity as an applied s t a t i s t i c i a n and not as a b i o l o g i s t that I was appointed. Consequently I can make no judgement concerning the "usefulness of the data" for surely t h i s i s f o r a b i o l o g i s t to decide. However, having run a number of rigorous s t a t i s t i c a l analyses on the data, we can d e f i n i t e l y say that there i s strong evidence that e i t h e r l i n e a r or quadratic r e l a t i o n s h i p s do i n f a c t e x i s t and that Mrs. Bayly's free-hand f i t s were not j u s t a figment of her imagination. The F - r a t i o s developed were highly s i g n i f i c a n t - i n f a c t they are among the highest I have ever seen i n a regression s i t u a t i o n . Mrs. Bayly employed randomization techniques i n s e l e c t i n g her sampling elements and by v i r t u e of the b i o l o g i c a l s i t u a t i o n i t s e l f , I do f e e l that the regression techniques employed are indeed v a l i d and that consequently any inferences derived from her analyses are j u s t i f i e d , at l e a s t from a s t a t i s t i c a l point of view. In-sofar as the impact of her findings on the b i o l o g i c a l world i s concerned, I cannot say i n that I have no formal t r a i n i n g i n biology i t s e l f . " Nutrient and Sodium Content i n Leaves  Ranges and Numbers of Samples  Ca .Mg_ Na K Species Number Min. Max. Min. Max. Min. Max. Min. Max. Acorus calamus 4 0. 45 0 .50 0.16 0.36 0.04 0.32 1 .6 2 .4 Agrostis s t o l o n i f e r a 4 0. 10 0 .20 0.06 0.48 0.04 0.32 1 .2 2 .4 Calamagrostis canadensis 13 0. 35 1 .22 0.09 0.14 0.01 0.14 1 .2 3 .9 Carex l a c u s t r i s 2 0. 21 0 .30 0.06 0.06 0.02 0.04 0 .8 1 .2 Chamaedaphne calyculata 2 0. 25 0 .25 0.02 0.16 0.02 0.24 0 .4 0 .8 Decodon v e r t i c i l l a t u s 14 0. 82 2 .00 0.24 0.59 0.06 0.22 1 .6 3 .5 Dulichium arundinaceum 2 0. 15 0 .15 0.16 0.28 0.24 0.40 0 .4 0 .8 Juncus effusus 4 0. 07 0 .13 0.16 0.68 0.02 0.24 1 .6 2 .0 Lemna minor 4 0. 70 1 .76 0.52 0.60 0.24 0.40 2 .0 3 .2 Lemna t r i s u l c a 2 2. 98 3 .32 0.48 0.60 0.64 1.20 2 .0 2 .4 Lysimachia t e r r e s t r i s 2 0. 12 0 .26 0.60 0.80 0.04 0.32 2 .0 2 .4 Myrica gale 6 0. 30 0 .64 0.08 0.24 0.02 0.48 0 .1 0 .4 Nuphar advena 27 0. 69 2 .30 0.18 0.49 0.02 0.23 2 .3 4 .3 Nymphaea odorata 6 0. 36 0 .85 0.02 0.24 0.48 1.20 0 .4 2 .0 Phalaris arundinacea 2 0. 13 0 .22 0.36 0.60 0.16 0.24 1 .6 2 .8 Phragmites communis 27 0. 50 2 .00 0.40 0.98 0.02 0.07 0 .0 1 .7 Pontederia cordata 3 0. 41 0 .59 0.06 0.16 0.16 0.28 1 .6 3 .6 S a g i t t a r i a l a t i f o l i a 14 0. 19 0 .79 0.24 0.80 0.04 0.96 2 .0 4 .8 S a g i t t a r i a r i g i d a 3 0. 45 0 .64 0.36 0.40 0.32 0.80 3 .6 4 .0 Scirpus americanus 2 0. 17 0 .17 0.06 0.60 0.07 0.32 1 .2 1 .6 Scirpus atrovirens 4 0. 18 0 .24 0.06 0.28 0.04 0.24 1 .2 3 .6 N Min. Max. 0.056 0.056 Min. Max. 1.428 0.49 1.680 0.16 1.00 0.60 0.756 0.980 0.19 0.50 0.042 0.588 0.01 0.90 0.742 1.050 0.35 0.73 1.050 1.484 0.04 0.43 0.812 1.260 0.17 0.35 1.428 1.708 0.95 1.00 1.288 1.288 0.09 0.36 0.070 1.386 0.01 0.90 0.238 1.540 0.38 0.80 1.274 1.344 0.18 0.31 0.14 0.80 0.560 1.386 0.58 0.68 0.490 3.738 0.16 1.00 1.554 2.226 0.03 1.00 0.910 1.568 0.26 0.29 0.336 0.868 0.02 0.28 Nutrient and Sodium Content i n Leaves Ranges and Numbers of Samples  Ca Mg Na K Species Number Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Scirpus cyperinus 5 0.11 0.20 0.02 0.06 0.16 0.48 0.8 0.8 0.280 0.602 0.51 1.00 Scirpus f l u v i a t i l i s 2 0.12 0.18 0.80 0.88 0.48 0.48 2.4 2.8 0.028 2.072 0.07 0.40 Scirpus validus 2 0.28 0.38 0.28 0.48 0.24 0.32 1.6 2.0 1.330 1.708 0.18 0.36 Spiraea alba 4 0.21 0.49 0.16 0.28 0.02 0.16 0.4 0.8 0.238 1.834 0.01 0.47 Thelypteris p a l u s t r i s 2 0.44 0.44 0.09 0.40 0.04 0.04 0.4 0.4 0.056 0.070 0.04 0.50 Typha l a t i f o l i a 20 0.20 0.82 0.02 0.40 0.04 0.48 0.4 2.4 0.056 1.834 0.03 1.00 Typha a n g u s t i f o l i a 18 0.21 0.37 0.16 1.08 0.16 0.96 0.8 2.4 0.028 2.898 0.12 1.00 Typha glauca 65 0.19 2.20 0.02 1.56 0.04 0.88 0.4 4.0 0.070 1.904 0.05 1.00 APPENDIX III 258 Equipment The various equipment used i n sampling, and the methods used i n analyses are described on pages 8-11 of the text body. A s i n g l e exception of importance i s the d e s c r i p t i o n of the s p e c i a l l y designed s p l i t - c o r e s o i l corer which was designed to draw undisturbed samples from a l l u v i a l s o i l . The d e s c r i p t i o n and drawings for the corer follow. A Light-weight S o i l Corer for Moist A l l u v i a l S o i l s Commercial s o i l corers have proven too heavy f o r transporting into the marsh or have y i e l d e d inadequate sample s i z e s for chemical and p h y s i c a l a n a l y s i s . Therefore, p r i o r to the f i e l d season of 1967, a new s o i l corer was designed for the marsh substrates which would y i e l d adequate samples and also be more e a s i l y portable. To decrease the corer weight and r e t a i n a sample s i z e of approx-imately 50 grams i n a l l horizons, aluminum was used i n a l l parts of the sampler with the exception of the cutting b i t . This resulted i n an o v e r a l l reduction i n weight over the commercial model of approximately f i f t e e n pounds. S t e e l was retained for the b i t section of the s o i l corer i n order to preserve the cutting edge of the sampler. Also, a 22 cm extension piece was added to f a c i l i t a t e under water sampling. To f a c i l i t a t e sampling of sandy or high organic s o i l s when a clay plug could not be obtained to hold the s o i l core within the b a r r e l of the corer, a sleeve with a plug was included i n the upper section of the corer. Removal of t h i s plug when d r i v i n g the corer i n the s o i l and replacement p r i o r to drawing the core from the substrate, creates a considerable back pressure, maintaining the sample within the b a r r e l . Further, to remove the sample with a minimum of d i s t o r t i o n or damage to the sample, a s p l i t -core b a r r e l was designed. 259 O v e r a l l length of the new corer i s 101 cm. The complete dimensions are given i n the accompanying sketch. The f a c t o r l i m i t i n g the diameter of the corer i s the i n s i d e diameter of the sampling b i t . The diameter i n the new corer, 3.5 cm, i s s u f f i c i e n t to c o l l e c t a large enough sample f o r a l l the semi-micro analysis completed on s o i l samples i n a l l horizons with the exception of the LH horizon which must be sampled by hand. In most horizons, a sample i n excess of 100 grams (dry weight) was obtained. In addition, the length of the s p l i t b a r r e l was doubled over that of the commercial model to 50 cm to f a c i l i t a t e sampling of the parent material of the Cg horizon. 2 6 0 Working diagram f o r s p l i t - c o r e s o i l corer, f o r use with wet a l l u v i a l s o i l s . Dimensions are given i n inches, since machinists i n Canada use these dimensional u n i t s . Appendix III - fig. 1. 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
http://iiif.library.ubc.ca/presentation/dsp.831.1-0093148/manifest

Comment

Related Items