CONCLUSION 



It may be concluded that while all the various kinds of classi- 

 fication of vegetation have value, the kind to employ is deter- 

 mined by the purpose or need of the investigator, the extensive- 

 ness of the area, and the available time and facilities. When one 

 starts with a large area, the geographic, physiognomic, and eco- 

 logic criteria are the most useful. The resulting units may be 

 subdivided by the same criteria, but final classification of the 

 fundamental units, based on their own intrinsic properties, re- 

 quires the use of floristic composition, particularly the kinds and 

 numbers of species, as well as dominant, constant, and charac- 

 teristic species. Classification based on the kind of succession and 

 the stage in the sere, in order to be adequate, must be accom- 

 panied by floristic analysis and description of all the com- 

 munities making up the various stages. Classification, however, 

 when analytic data on intrinsic properties and descriptions are 

 available, may begin with the basic units, which are usually 

 small in area and homogeneous. In any case, whether one is 

 primarily concerned with geographic distribution, physiognomy, 

 habitat conditions, successional sequences, or plant sociological 

 analysis, a comprehensive and satisfying classification must in- 

 clude consideration of the properties of the stands, and these 

 properties can only be revealed by detailed analysis. 



GENERAL REFERENCES 



Becking, R. W., "The Zurich-Montpellier School of Phytosociology," Botan. Rev., 

 23,411-488 (1957). 



Braun-Blanquet, J., "Plant Sociology," McGraw-Hill Book Co., New York, 

 N.Y., 1932. 



Conard, H. S., "The Vegetation of Iowa," Unw. Iowa Stud. Ser., 19, No. 424, 

 1-166 (1952). 



Knapp, R., "Arbeitsmethoden der Pflanzensoziologie und Eigenschaften der 

 Pflanzengesellschaften, I. Einfiihrung in die Pflanzensoziologie," Eugen 

 Ulmer, Stuttgart, Germany, 1958. 



Poore, M.E.D., "The Use of Phytosociological Methods in Ecological Investi- 

 gations, I. The Braun-Blanquet System," Jour. EcoL, 43, 226-244 (1955); 

 "II. Practical Issues Involved in an Attempt to Apply the Braun-Blanquet 

 System," Ibid., 43, 245-269 (1955); "III. Practical Application," Ibid., 43, 

 606-651 (1955); "IV. General Discussion of Phytosociological Problems," 

 Ibid., 44, 28-50 (1956). 



188 • Classification of ConrnMimunities 



