Page:Plant succession; an analysis of the development of vegetation.pdf/11

VII

CONTENTS. VI. Stabilization and Climax—Cont.

V

The Climax

 * Concept 105


 * Nature 106


 * Relation to succession 106


 * Kinds of climaxes 107


 * Subclimaxes 107


 * Potential climaxes 108


 * Changes of climate 109


 * Preclimax and postclimax 109


 * Changes of climax 110

Development and Structure

 * Relation 111


 * Kinds of structure 111


 * Zonation 111


 * Relations of climax zones 113


 * Significance of alternation 115


 * Developmental relation of layers 115


 * Relation of seasonal aspects 116

Historical Summary:

 * The formation concept 116


 * Grisebach's concept of the formation 116


 * Drude's concept 117


 * Clements's concept 118


 * Moss's concept 118


 * Schröter's concept 119


 * Gradmann's concept 119


 * Warming's concept 120


 * Negri's concept 122


 * Correlation of divergent views 122


 * Significance of development 123


 * Earlier suggestions of developmental view 123

The Formation:

 * Developmental concept of the formation 124


 * Analysis of the formation 125


 * Formation units 125


 * Formation 126


 * Names of formations 127

Climax Units:

 * Association 128


 * Consociation 129


 * Society 130


 * Bases 131


 * Kinds of societies 132


 * Aspect societies 132


 * Layer societies 133


 * Cryptogamic societies 133


 * Terminology 133


 * Changes of rank or dominance 134


 * Clan 134

Seral Units:

 * Nature and significance 135


 * Associes 136


 * Consocies 137


 * Socies 138


 * Colony 138


 * Family 139


 * Summary of units 139


 * Mixed communities 139


 * Nomenclature of units 140


 * Formation groups 142


 * Bases 143


 * Developmental groups 143

Direction of Development

 * Development always progressive 145


 * Nature of regression 145


 * Course of development 146


 * Regression and retrogression 146


 * Nilsson's view 146


 * Cowles's view 147


 * Cajander's view 149


 * Sernander's view 149


 * Moss's view 150


 * Hole's view 154


 * Conversion of forest 155


 * Status of forest in Britain 156


 * Artificial conversion 157


 * Graebner's studies: Conversion of forest to heath 157


 * Conversion of forest into moor 159


 * Causes of conversion 161


 * Possibility of backward development 162


 * Degeneration 163


 * Regeneration 163


 * Correlation of progressive developments 164


 * Convergence 165


 * Normal movement 166


 * Divergence 167

Classification of Seres

 * Historical 168


 * Clements's system 168


 * Normal and anomalous succession 169


 * Primary and secondary succession 169


 * Cowles's system 171


 * Possible bases of classification 175


 * Developmental basis of classification 175


 * Initial areas and causes 176


 * Relative importance of bases 177


 * The climax as a basis 177


 * Recognition of climax areas 177


 * Climaxes of North American vegetation 179


 * Subclimaxes 180


 * Relationship of climaxes 180


 * Names of climaxes 181


 * Priseres and subseres 182


 * Hydroseres and xeroseres 182


 * Phylogenetic system 183

Climax Formations of North America

 * Classification 184

The Deciduous Forest Climax

 * Prisere 184


 * Hydrosere 184


 * Xerosere 203


 * Subsere 212

The Prairie-Plains Climax

 * Prisere 214


 * Xerosere 214


 * Hydrosere 220


 * Subsere 221

The Cordilleran Climaxes

 * Priseres 225


 * Subseres 226