INTRODUCTION 13 



and this book will be found to overlap into the field of animal ecol- 

 ogy in some instances. However, as long as biological science is 

 organized in our colleges and universities as it is at present, with 

 separate departments of botany and zo5logy, it will be necessary 

 to offer separate courses in plant ecology and animal ecology, and 

 text-books will necessarily deal with these two branches of ecology 

 as though they were distinct subjects. 



Plant ecology is essentially a field study and this fact distinguishes 

 it from plant morphology and plant physiology, which are essentially 

 laboratory studies. It is also one of the most practical of the sub- 

 divisions of botany, since ecological principles form the basis of 

 practice in agriculture and forestry as well as in many of the modern 

 phases of conservation. The problems of the practical plant grower, 

 or the wildlife conservationist, and those of the ecologist are similar 

 and often identical. They are concerned always with the relations 

 of the plant or animal to its environment. 



3. The Environment of Plants.— The environment of a plant 

 consists of everything outside of the plant which influences in any 

 way the life of the plant. The environment is partly living and 

 partly non-living. The living part of the environment consists of 

 plants and animals. The non-living part consists of numerous influ- 

 ences such as light, heat, air, soil and water. Each part of the 

 environment which may exert a specific influence upon the life of 

 the plant is spoken of as a factor of the en\ironment or as an eco- 

 logical factor (Fig. 1). 



4. Autecology and Synecology.— In the study of plant ecology 

 we find it necessary to treat not only of the relations of individual 

 plants to the environment but also of comparable relations of com- 

 munities of plants. The ecology of individual plants is called 

 autecology while the ecology of plant communities is designated 

 synecology. 



This book covers the entire field of plant ecology but the earlier 

 chapters deal almost entirely with autecology while the later 

 chapters treat more largely of synecology. 



REFERENCE 



Clements, Frederic E., and Shelford, Victor E.: Bio-ecology, New York, 

 John Wiley & Sons, 1939. 



