The study of vegetation requires the fullest possible knowledge of 

 the basic units — the plant communities. In an effort to promote 

 this knowledge and to advance the science of vegetation, the 

 authors have adopted as the central theme of this book the 

 formation and nature of the plant community. The development 

 of the theme begins with a discussion of the properties of species 

 and populations, i.e., of the relations of plants and animals to their 

 physical environment and to one another. It is then demonstrated 

 how these properties lead to the formation of various kinds of 

 groupings and communities. This discussion is followed by an 

 analysis of community characteristics and their use in description 

 and classification, and of the changes, or dynamics, that occur in 

 plant communities. Numerous illustrative examples are provided 

 in order to clarify concepts and to assist in the solution of specific 

 problems, particularly as they are encountered in the field. 



This book is intended as a text for semester or quarter courses 

 in plant ecology; as a supplement to textbooks in general ecology 

 which usually do not deal adequately with the formation and 

 nature of the plant community; or as an adjunctive text for 

 courses in animal ecology, forestry, range management, wildlife 

 management, conservation, and agriculture. It is also intended 

 to serve the general reader who desires to be better informed about 

 the nature of vegetation and its potentialities. 



The background for the ideas expressed in the following pages 

 is a mosaic of varied kinds of experience. Contributions to this 

 mosaic have been drawn from the fertile field of ecological litera- 



ax 



