PRESENT PROBLEMS IN PLANT ECOLOGY 



V. The Relation of the Climatic Factors to 

 Vegetation 



PROFESSOR EDGAR N. TRANSEAD 

 Eastern Illinois State Normal School 



1. The Recent Advance in Point of Fim.-Perhaps 

 the most interesting and important advance that has been 

 made during the last decade in the study of the relation 

 of plants to environment is in regard to the point of view. 

 It is difficult to say just when the movement began, but 

 it is assuredly true that it has only recently gained recog- 

 nition. To a certain extent the movement has involved 

 the substitution of the ecological for the floristic method 

 in geographic problems involving climate. It lias re- 

 sulted in a general dissatisfaction with the older descrip- 

 tive methods and has tended toward a better appreciation 

 of the value of exactness both in the delineation of vegeta- 

 tion and the quantitative analysis of environmental com- 

 plexes. The movement has further brought to our atten- 

 tion the necessity for investigating vegetation processes 

 by experimental methods comparable to those by which 

 plant processes have long been studied. As I see it, 

 however, these are secondary phenomena attending the 

 substitution of dynamic and genetic views of vegetation 

 for the century-old static conception of plant distribution. 



Fourteen years ago it was possible for one of the most 

 prominent students of the North American biota to say: 1 



It appears, therefore, that in its broader aspects the study of the 



