THE SUBJECT MATTER OF ECOLOGY 13 



ENVIRONMENT A COMPLEX OF FACTORS 



Environment includes everything that may affect an organism 

 in any way. It is, therefore, a complex of factors, which may be : 

 substances, such as soil and water; forces, such as wind and grav- 

 ity; conditions, such as temperature and light; or other organisms. 

 These factors may be studied or measured individually, but they 

 must always be considered in terms of their interacting effects 

 upon organisms and each other. The resulting complexity of en- 

 vironment and the array of subject matter encompassed suggest 

 the necessity for drawing upon the knowledge of all fields of sci- 

 ence for its understanding. Therein lie a complete justification of 

 and explanation for ecology. Its special function is to consider 

 such subject matter in terms of organisms. Any one field of science 

 is relatively restricted to its own subject matter, whereas ecology 

 brings together the knowledge of various sciences with the object 

 of interpreting the responses of organisms to their environment. 



Since all plants and animals, including man, are organisms, and 

 since environment can at times include almost anything in the uni- 

 verse, the subject matter of ecology is almost unlimited. As a re- 

 sult, it is dependent upon the specialized fields of science for much 

 of the knowledge it uses. It requires an understanding of the funda- 

 mentals of other sciences, an alertness to changes and new discov- 

 eries in various fields, and a constant consideration of the possibili- 

 ties of using such information for interpreting or explaining the 

 peculiarities, responses, and nature of organisms under the con- 

 ditions in which they live. 



SCOPE OF THE FIELD OF ECOLOGY 



Since the subject is concerned with organisms, it must include 

 both plants and animals. Such a broad biological basis presupposes 

 a solid foundation in both botany and zoology, and, if man is to be 

 considered, an additional need for understanding of sociological, 

 psvchological, and economic problems. Although the latter are 

 not ordinarily considered biological subjects, they may become 

 more so in the future. Sociologists are more and more concerned 

 with "human ecology'' and some phases of ecology have come to 

 be known as "plant sociology!' 



It is, unfortunately, unusual to find students, teachers, or inves- 



