102 



The Plant World. 



THE POIXT OF VIEW IX VEGETATION PROBLEMS 

 INVOLVING CLIMATE. * 

 By Edgar N. Traxseau. 

 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 as- 

 suredly true that it has only recently gained recognition. To 

 a certain extent the movement has involved the substitution 

 of the ecological for the floristic method in geographic problems 

 involving climate. It has resulted in a general dissatisfaction 

 with the older descriptive methods and has tended toward a 

 better appreciati3n of the value of exactness both in the delinea- 

 tion of vegetation and the quantitative analysis of environmental 

 complexes. 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 con- 

 ception of plant distribution. 



Fourteen years ago it was possible for one of the most 

 prominent students of the North American biota to say: f "It 

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

 geographic distribution of life in North America is completed. 

 The primary regions and their principal subdivisions have been 

 mapped, the problems involved in the control of distribution 

 have been solved, and the laws themselves have been formulated." 

 Such a claim could have been made only for a static system, 

 since a genetic conception of the problem necessarily involves 

 the indefinite postponement of the approach toward a final 

 solution. 



The appearance of the classics of Warming and Schimper 

 served to impress all with the inherent complexity of the problem. 

 We are no longer deeply concerned with the discussion as to 

 whether temperature or moisture is the more important geo- 

 graphic factor. Neither do we hope to erect a stable system 



*Frotn a paper read before the Botanical Society of America at the Baltimore meeting, 



December, 1903. 

 t Yearbook U. S. Dept. Agri. 1394, p. 214. 



