Paradigm change (organismic-continuum) in Soviet phytocoenology occurred in the 1960s, though the idea of a continuum is well known in the Soviet Union since L. G. Ramensky's works, written at the beginning of our century. This change has been influenced by American continuum-ecologists from the Schools of J. T. Curtis and R. H. Whittaker. The organismic approach in Soviet phytocoenology has never had an extreme character, and for this reason paradigm change appeared gradually. The impact of vegetation classification on the paradigm succession is emphasized: whether an investigator admits 'real', discontinuous communities or considers them part of a continuum, in either case he must reduce continuity to discontinuity to achieve a classification.
Nevertheless, the dominant classification systems typical of the organismic period in Soviet phytocoenology were mostly of an organismic character, because they were based on the idea of the organizing role of edificators-dominants in the community, rather than on environmental conditions. The classification system based on the Braun-Blanquet approach which is widely spreading now in the USSR corresponds better to the idea of a continuum, because the floristic-sociological classification criteria reflect habitat conditions, rather than coenotic interrelations.
Organismic and continuum paradigms are compared according to ten principal aspects, the most important of which are: the nature of the plant community, estimation of population differences within a community, synmorphology, syndynamics and relation to the classification problem. * The author acknowledges the comments and suggestions by Profs. R. P. Mclntosh and E. van der Maarel.