16 



THE DEVELOPMENT OF ASSOCIATION 

 AND CLIMAX CONCEPTS 



Their Use in Interpretation of the Deciduous 



Forest ^ 



E. Lucy Braun 



Ecology is defined as the study of life in relation to environment. It is con- 

 cerned with what is and why. The ecological study of a single organism fre- 

 quently meets with almost insurmountable obstacles because environment, if 

 broken down into its component parts, is no longer environment. The ecologi- 

 cal study of a complex piece of vegetation — a forest for example — presents 

 innumerable problems, for the complexity of the environment — with its inter- 

 acting factors — is multiplied by the complexity of the community; it does 

 not yield to laboratory analysis. The methods of the physiologist fail. 



Attempts at mathematical interpretation are for the most part static, and 

 they often obscure rather than reveal the true picture of vegetation. Vegeta- 

 tion is dynamic — an ever-changing complex now appearing quiescent and in 

 complete equilibrium with the habitat, now displaying obvious evidence of 

 change. I believe that failure to recognize the dynamic aspects of vegetation 

 is a primary cause of differing concepts. A dynamic approach is essential to 

 interpretation of our eastern forests. 



Observation of natural changes in vegetation long ago resulted in the con- 

 cept of succession; recognition of quiescent phases led to the climax con- 

 cept. The association concept arose from the need for designating so-called 

 units of vegetation. 



Concepts have changed through the years; they should change. As Cooper 



1 A paper delivered at Storrs, Conn., August 28, 1956, as part of the Ecological 

 Society's symposium, "Approaches to Interpretation of the Eastern Forests of 

 North America." 



329 



