Ontogenetic and vitality structure of Globularia bisnagarica L. cenopopulations in the Middle and Lower Volga regions

The article presents the results of studying the ontogenetic and vitality structure of 13 cenopopulations of Globularia bisnagarica from the Middle and Lower Volga region. The assessment of the ontogenetic structure was carried out by constructing and analyzing the ontogenetic spectra of each of the studied cenopopulations, as well as the basic ontogenetic spectrum, followed by determining the type of cenopopulations according to the “delta-omega” criterion. On the basis of morphometric parameters, the vitality indices of individuals and cenopopulations were determined, followed by the identification of vitality types and the calculation of the dimensional plasticity index. It has been established that the ontogenetic spectra of the majority of cenopopulations are complete, asymmetric, with peaks in several age groups. The basic ontogenetic spectrum is bimodal, asymmetrical, with a maximum on virginal and mature generative individuals. The majority of G. bisnagarica cenopopulations are young, being dominated by individuals of the pregenerative state. The Srg cenopopulation growing on the territory of the Samara region consisted mainly of individuals of the post-generative state. Four cenopopulations (Pch, Grm, Lhv, Bkm) turned out to be transitional, since they are dominated by generative individuals. According to the assessment of the vitality state, individuals of the middle class of vitality predominated in all the studied cenopopulations. At the same time, most of the studied cenopopulations are defined as prosperous. Likewise, only two cenopopulations: Grm and Lhv from the Ulyanovsk region were characterized as depressed. Thus, taking into account the features above, the general condition of the three cenopopulations: Srg, Grm and Lhv is assessed as unsatisfactory, which makes them the most vulnerable in the event of the impact of adverse environmental factors or an increase in anthropogenic pressure on their habitats.