12 



INTRODUCTION 



places is greatest when their arrangements are similar to those 

 found in Nature. Thus if we would make the best esthetic use of 

 our plants we must study in the field the ways in which Nature 

 makes use of the same or similar plants. A full appreciation of 

 the beauties of Nature can be realized only by those who under- 

 stand the reasons for the natural groupings of plants that are found. 





GRAVITY 



V V V V V V V 



Fig. 1.— Diagram showing the principal factors in the environment of land 

 plants. (From Transeau's General Botany. Copyright 1923 by World Book 

 Company, Yonkers-on-Hudson, New York.) 



2. What Plant Ecology Is.— Plant ecology is the science of the 

 interrelations of plants and their environments. It is a part of 

 general ecology, sometimes called bio-ecology, which deals with the 

 interrelations of all living things and their environments. It is 

 impossible to entirely separate plant ecology from animal ecology 



