20 THE STUDY OF PLANT COMMUNITIES • Chapter I 



velopment of the dynamic point of view. Undoubtedly each 

 method has its place and usefulness. In fact, each has profited from 

 the other, but, since the dynamic point of view has the broadest 

 usefulness in both pure and applied ecology, it will be emphasized 

 here. 



BACKGROUND FOR COMMUNITY STUDY 



Systems of description of vegetation that are based upon appear- 

 ance or general nature of the plants have been used with some suc- 

 cess, particularly by plant geographers. Such systems indicate size 

 and form of plants; whether they are evergreen or deciduous, 

 herbaceous or woody; 210 position of buds in the dormant season, 202 

 and various other characters classified under the general headings 

 of growth forms or life forms. This makes possible the visualization 

 and superficial comparison of otherwise unfamiliar vegetation and 

 likewise may serve to bring out certain characteristics of com- 

 munities that otherwise might not be apparent. Such systems are 

 either based upon previous detailed studies of the species, or they 

 may be a means of superficially characterizing vegetation of which 

 the taxonomy is still inadequately known. They can only supple- 

 ment studies based upon taxonomy since description of a commu- 

 nity, to be adequate for all purposes, must be based upon species. 

 The field ecologist must, therefore, have a thorough working 

 knowledge of taxonomy and, preferably, some experience with 

 the flora of the region of his studies 



Just as the study of vegetation must remain more or less super- 

 ficial without a solid taxonomic foundation, so will interpretations 

 and explanations be limited by the amount of autecological infor- 

 mation available about the species and their environments. Physi- 

 ological-ecological investigations, in the field and under natural 

 conditions, constantly modify synecological conclusions that have 

 been made deductively, or they suggest new interpretations and 

 investigations. The quality of community studies, therefore, de- 

 pends upon certain fundamentals, which include a knowledge of 

 the individual species and their requirements and responses. 



