Ontogenetic Structure of Woody Plant Cenopopulations in Mature Pine Stands of Moscow

The results of studying the ontogenetic structure of woody plant cenopopulations on 16 permanent sample plots in mature pine forests located in Moscow are presented. A cenopopulation approach was for the first time applied in the conditions of Moscow region to estimate a regenerative capacity of tree species in pine dendrocenoses. During the study, the plots of mature pine stands that are representative for Moscow region were considered. Ontogenetic spectra of the following cenopopulations were considered: Pinus sylvestris L., Acer platonoides L., Tilia cordata Mill., Ulmus laevis Pall., and Corulys avellana L. The analysis of the number of trees and shrubs in the lower tiers of stands (undergrowth and understory) and their occurrence on the sample plots was conducted. The P. sylvestris cenopopulation has a right-sided age spectrum with a prevalence of individuals of generative state and is regressive under these conditions, since pregenerative individuals are completely absent. The cenopopulations of A. platonoides, U. laevis, and C. avellana are characterized as efficiently self-sustaining, while T. cordata as moderately self-sustaining. According to the results of the study, it was revealed that the ontogenetic spectra of most populations of the studied species are incomplete due to the absence of some ontogenetic states in plants. A significant part of cenopopulations of the species have a bimodal ontogenetic spectrum. The ontogenetic state and formation of generation cycles of broad-leaved species are explained by the presence of a sufficient number of open regions (“windows”). It is noted that the undergrowth has a fairly high percentage of mortality before it reaches a generative ontogenetic state under the influence of external and intracoenotic factors. The analysis of the species composition of the undergrowth and understory demonstrated that a set of tree and shrub vegetation includes 12 species.