ON THE CONCEPT OF VEGETATION CLASS IN PHYTOSOCIOLOGY

The vegetation class is generally accepted as the highest category in vegetation taxonomy. Vegetation classes, following the tradition, are defined mainly on the basis of character species. However, these are s ometimes relatively rare and not always really representative of the e cological conditions of plant communities included in the class. In th e present study the possibilities are discussed for a more comprehensi ve definition of the class, including spatial structure and environmen tal characteristics of the vegetation and the geographical distributio n of character species. These include criteria with practical value, i n particular for the understanding of vegetation in tropical areas. So me cases of well-known vegetation classes are discussed; in most of th em the ranges of single character species and the range of the class a s a whole largely coincide.