Evaluation of coenopopulations of some nemoral species in pine types of communities

The authors of the article have evaluated the stat and structure of coenopopulations of nemoral species using the ex ample of Convallaria majalis L. and Polygonatum odoratum (Mill.) Druce. Three cenopopulations of P. odoratum (CPP.1 – CPP.3) and f our of C. majalis (CPC.4 CPC.7) have been described while studying thr ee quarters of the Medvedsky Bor nature sanctuary. The authors have com e t the conclusion that all the studied coenopopulations of P. odoratu m and C. majalis were normal juvenile incomplete. Due to the high demand of C. majalis and P. odoratum in soil moisture, their existence in the p ine communities of the Medvedsky Bor nature sanctuary is ensured by the pre sence of green mosses that retain moisture on the substrate surfac e.


Introduction
Pine forests represent special communities: they do not form their own natural zone. They are formed on the territory of the northeastern European part of Russia by plants Pinus sylvestris L. from different migration waves. On the territory of the natural sanctuary "Medvedsky Bor" they are relict communities of the postglacial xerothermal epoch on the continental sand dunes. Due to the prevailing biotope conditions, pine forests often contain pine forests, boreal species, and plants from other ecological-coenotic groups, for example, nemoral ones. In particular, representatives of the latter include May lily of the valley (Convallaria majalis L.) and fragrant bush (Polygonatum odoratum (Mill.) Druce), which are the objects of our study. Previously, the features of biomorphology were studied and the parameters of the counting units of their coenopopulations were identified [1]. The aim of this research is to assess the state and structure of coenopopulations (CP) of C. majalis and P. odoratum in pine types of communities.
were carried out according to generally accepted geobotanical methods [2]. To study the age spectrum and the number of coenopopulations of vegetatively mobile species, partial formations were taken as counting units [3]. Therefore, we took into account individual partial shoots of C. majalis and P. odoratum (individuals). Their assignment to specific ontogenetic states was carried out according to the data of a number of studies [4][5][6][7][8][9]. During office processing, the age spectra of CP were calculated based on the ratio of different age groups, which were expressed as a percentage of the total number of individuals and their types were estimated [10]. The indices of age and energy efficiency [11], recovery (J В ) and replacement (J З ) [12] were used as integral characteristics of the ontogenetic structure of coenopopulations of species. The type of CP of the studied species was determined according to the classification (∆-ω) [11]. In CPP.2, the recovery and replacement indices are 2.18. Indicators of the indices of age and energy efficiency (0.11 and 0.36, respectively) make it possible to classify this CP as a young one. Among ontogenetic states, immature ones prevail. All of the above gives grounds to characterize CPP.2 as normal juvenile incomplete.

Results and their discussion
The recovery index in CPP.3 is also equal to the replacement index (3.29), and the indicators of age (0.09) and energy efficiency (0.31) indicate that the coenopopulation is young. The coenopopulation is dominated by immature individuals. It can be concluded that CPP.3 is normal juvenile incomplete.
The state of C. majalis coenopopulations is the following. In CPC.4, the indices of recovery and replacement are 0.65 and 0.63, respectively. Based on the values of the indices of age (0.21) and energy efficiency (0.61), the coenopopulation is maturing with a predominance of generative individuals. Thus, CPC.4 is normal maturing incomplete.
Among the ontogenetic states of individuals in CPC.5, generative individuals predominate. The replacement and recovery indices are 0.8 and 0.94, respectively. Based on the values of the indices of age (0.25) and energy efficiency (0.58), the coenopopulation is young according to the delta-omega classification. Thus, CPC.5 is normal juvenile incomplete.
In CPC.6, values of the replacement and recovery indices are 2.56 and 4.6, respectively, and according to the age (0.23) and energy efficiency (0.44) indices, the coenopopulation belongs to the "young" type. The coenopopulation is dominated by virginal individuals. It can be concluded that CPC.6 is normal juvenile incomplete.
The replacement and recovery indices in CPC.7 are 1.37 and 1.48, respectively. The indices of age and energy efficiency indices (0.20 and 0.54, respectively) make it possible to classify this coenopopulation as a young one. Among ontogenetic states, virginal ones predominate. Thus, the CPC.7 of C. majalis can be characterized as normal juvenile incomplete.
Based on the ratio of individuals of different ontogenetic states in the studied coenopopulations, the authors compiled their ontogenetic spectra (Fig.). For CPP.1, the spectrum resembles a bimodal one with peaks in immature and generative individuals. The ontogenetic spectra of CPP.

Conclusion
Thus, in the course of the study, the authors evaluated the coenopopulations of C. majalis and P. odoratum, confined to forest pine communities. For the coenopopulations of P. odoratum, the following was stated: individuals of the generative period predominate in CPP.1, while CPP.2 and CPP.3 have significantly more representatives of the pregenerative period. It indicates a fairly stable position of the species in these communities; indices of recovery and replacement indices indicate a fairly successful self-maintenance of all three coenopopulations. For the studied coenopopulations of C. majalis, it was noted that generative individuals predominate in CPC.4 and CPC.5, while virginal individuals prevail in CPC.6 and CPC.7. As a result of the rejuvenation of generative individuals of C. majalis, immature and virginal ontogenetic states were noted in the studied CPs. Due to the high demand of C. majalis and P. odoratum in soil moisture, their existence in pine communities of the Medvedsky Bor nature sanctuary is ensured by the presence of green mosses that retain moisture on the surface of the substrate.