Abstract <p>The article presents the results of our study of the dynamics of a forest ecosystem type typical of the central part of the Volga Upland, namely, a wet sudubrava (C₃). The studies were conducted on the territory of the Upper Sura section of the Privolzhskaya Lesostep Nature Reserve. The course of the process was studied in an age row identified in homogeneous forest growth conditions based on the principles of dynamic classification of forest types. As a result of processing of forest taxation data, the average values for some taxation characteristics of tree stands were obtained for each age class. At the same time, changes in all components of the stands were analyzed. Based on this analysis, the age row was divided into separate periods and phases. Trends in the change in the proportion of each forest-forming species in the composition of the tree stand at several age stages are described by nonlinear equations. The study had shown that the resultant age row is that of forest community transformations. Disruption of the forest formation process has led to a large-scale replacement of native stands by their derivatives. After the start of clear-cutting, the area occupied by deciduous trees has been constantly growing. The formation of sparse pine stands was a consequence of large-scale intermediate felling, sanitation and voluntary selective cutting. At the same time, transformation of the lower tiers of the communities occurred. These factors have caused deterioration in the conditions for the natural regeneration of pine (<i>Pinus sylvestris</i> L.). As a result, the possibility of forming pine stands by natural regeneration is now almost completely excluded.</p>