Page:Plant indicators the relation of plant communities to process and practice.djvu/12

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VI CONTENTS.

PAGE.


Growth-Forms

Nature 68
Kinds 69
Indicator relations 69
Standard plants for growth correlations 70
Competition-forms 71

Communities as Indicators

Value 72
Kinds of communities 72
Community structures 73
Alternes 73
Layers 74
Aspects 75

Kinds of Indicators

Basis of distinction 76

Factor Indicators

Basis and kinds 76
Quantitative sequences 77
Climatic and edaphic indicators 77
Water indicators 78
Light indicators 79
Temperature indicators 81
Indicators of solutes 83
Saline indicators 83
Lime indicators 84
Aeration indicators 85
Indicators of factor-complexes 88
Soil indicators 88
Slope-exposure indicators 88
Altitude indicators 89
Organism indicators 90

Process Indicators

Nature 91
Kinds 91
Fire indicators 92
Lumbering indicators 93
Cultivation indicators 93
Grazing indicators 94
Indicators of irrigation and drainage 95
Construction indicators 96
Physiographic indicators 97
Climatic indicators 97

Practice Indicators

Nature and kinds 98

Paleic Indicators

Paleo-ecology 99
Nature of paleic indicators 100
Kinds 101
Paleic indicators of climates and cycles 103
Paleic indicators of succession 103
Plant indicators of animals 104
Animal indicators of plants 104

Climax Formations Of Western North America

Nature 105
Tests of a climax 105
Structure and development 106
Societies 107
Names of climax communities 109
Seral communities 109
Indicator significance of climax formations 111
Significance of succession 111
Indicator value of disturbed areas 112
Summary of the climax formations 113

The Grassland Climax

Stipa-Bouteloua Formation

General relations 114
Unity of the grassland 116
Correlation with climate 116
Use of weather records 116
Relationship of associations 118
Floristic relations 119
Ecological relations 120
Subdominants 120
Developmental relations 121

The True Prairie

Stipa-Koeleria Association

Extent 121
Factor relations 123
Sequence of dominants 123

Societies

Nature 125
Control of dominants 125
Relation to consociation 126
Origin 126
Mixed societies 127
Aspects 127
Zones and alternes 128
Studies of prairie societies 129

Clans

Vernal clans 131
Estival clans 131
Serotinal clans 131

The Subclimax Prairie

Andropogon Associes

Nature 131
Range 132
Factor relations 133
Sequence 133
Grouping 134

Societies and Clans

The Mixed Prairie

Stipa-Borteloua Association

Nature 135
Effect of grazing and climatic cycles 135
Range 136
Grouping 137
Sequence of dominants 138

Societies of the Mixed Prairie

Prevernal societies 139
Vernal societies 139
Estival societies 139
Serotinal societies 139