VOLUME XLVII 



NUMBER 2 



Botanical Gazette 



FEBRUARY igog 



RELATION OF SOIL AND VEGETATION ON SANDY 



SEA SHORES 



Pehr Olsson- Seffer 



(with TWELVE figures) 



The studies on which the present paper is based were carried on 

 during a number of years on a variety of sandy sea shores on the Baltic 

 coasts, in Denmark, Holland, Scotland, and France, on the Mediter- 

 ranean shores, along the coasts of Australia and New Zealand, in 

 Hawaii, California, Mexico, and Central America. 



h this paper I propose to give some of the observations made by 

 m )self regarding the conditions for plant life on coastal sand forma- 

 tions, and also to compare these investigations with the accumulated 

 fcsulis from studies on this subject obtained by others. 



Although considerable attention has been given to some of the 

 "tost important points, I have as yet not been able to study in detail 

 ers ' dually weighty; and in trying to interpret several of the phe- 

 nomena of the distribution of sand vegetation I have found myself 

 on ronted with many problems, for the solution of which there is 

 * «& definite evidence at hand. 



con^ USsing the factor s that influence plant life, I have found it 

 hvdrod lent ^ Classify them into the following groups: atmospheric, 



™ ynamic, edaphic, topographic, and historical factors. 



influe°n atm ° SPheriC faCt ° rS a11 those are here referred ' which direCtly 

 ture^h* V Ve§etation throu gh the air. The atmospheric tempera- 



inthe ] 1§ht conditions > the variations in air moisture, the movements 

 kind a , mC f phere ' an d the electricity are the principal factors of this 

 With the )drodynamic factors I understand all those connected 



e Water content of the substratum, and edaphic factors are 



85 



