24 



PLANT SOCIOLOGY 



tion, Assoziationsindividuum or Einzelbestand) and in an abstract sense 

 (the association). 



Smaller Units. — The fundamental unit of vegetation, the associa- 

 tion, is not identical with the smallest unit; it stands to the latter rather 

 in the relation of the species to the variety or form. But as in system- 

 atic botany a knowledge of the species must be acquired before the 

 smaller units (varieties, forms) have any meaning, so should the recog- 

 nition and definition of the association, which requires skill, sociological 

 training, and wide experience, precede the simpler, more purely 

 mechanical study of quadrats. A subsequent arrangement of the data 

 of this mechanized "inductive" method under the head of the larger 



5r^iT^ 



Fig. 9. — Association fragment of the Nardetum upon Alp La Schera (2,000 m.), 

 Swiss National Park. Nardus, Nigritdla, Codoglossum viride, Botrychium lunaria. 

 {Photo by Heller and Braun-Blanquet.) 



natural association is indeed in many cases impossible. Moreover, the 

 synthesis of quadrat samples into larger and more convenient units 

 often fails from the lack of tangible social characteristics. Moreover, 

 when using this method there is always danger of stopping with the 

 purely superficial features and losing sight of the more far-reaching 

 "genotypic" features which are the significant marks for characterizing 

 and understanding the association (Wangerin, 1922, p. 10). 



The smallest distinguishable units of vegetation are of course not to 

 be neglected. But they should be classified as sub-associa Lions or 

 facies, subordinate to the association in the larger sense. 



