CONTENTS 



Page 



Preface to the German Edition vii 



Preface to the English Edition ix 



Introduction 1 



PART I. THE BASIS OF SOCIAL LIFE AMONG PLANTS 



CHAPTER I 



Social Life among Plants 5 



Dependent Unions 5 



Commensal Unions 9 



Competition 11 



Competition within the Species 11 



Competition between Individuals of Different Species 12 



Aggressiveness of Species 13 



Determination of Aggressiveness 13 



Overestimation of the Factors of Competition 15 



Competition between Plant Communities 16 



PART II. THE ORGANIZATION OF PLANT COMMUNITIES 



CHAPTER II 



The Smaller Social Units 21 



Habitat and Plant Community 21 



Fundamental Unit of Plant Sociology 22 



Individual Association or Stand 23 



Smaller Units 24 



Fragmentary Associations 25 



Settlement 25 



CHAPTER III 



The Structural Characteristics of the Community 2'3 



Analytic Characters 20 



Kind of Sample Plot 27 



Size of Sample Plots 27 



Number of Individuals and the Spacing of the Species 30 



Determination of Abundance 30 



Determination of Spacing and Density 30 



Cover, Space, Weight 31 



Determination of Cover 31 



Determination of Space 33 



Weighing 33 



xi 



'^3607 



