Estimation of Cypripedium calceolus L. coenopopulations on limestone deposits along the valley slopes of the Vyatka River

A comprehensive research of rare and endangered species plays an important role in the conservation of biological diversity. Cypripedium calceolus L. (fam. Orchidaceae Juss.) is a rare species included in the Red Data Book of Kirov region. It needs biological control in its territory. The aim of this study was to investigate the ontogenetic structure and morphometric parameters, and to identify the vital structure of C. calceolus cenopopulations in Kirov region. In 2014, we examined the state of five C. calceolus cenopopulations (CP) on limestone deposits along the Vyatka river valley slopes (southern taiga subzone, Kirov region, Russia) (See Table 1). To study the conditions of coenopopulations, we used approaches and methods of plant population biology (Uranov, 1975; Coenopopulations ..., 1976, 1977, 1988; Zaugol'nova et al. 1993; Zhukova, 1995). Ontogenetic spectra were typifed according to the “delta-omega” classification (Zhivotovsky, 2001), determining age (Δ) and efficiency (ω) indices. In each habitat, we laid transects which were then divided into plots where individuals at different onthogenetic state were registered. The coenopopulation vitality structure was investigated using the method of calculating the IVC index (Ishbirdin and Ishmuratova, 2004) and the method of calculating the Q index (Zlobin, 1989, 2009). The variability and correlation structure of C. calceolus populations was studied according to classification of NS Rostova (2001). To study morphometric characteristics of plants we considered their height, the number of leaves and flowers, the size of the leaf (length and width), the number of leaf veins, the size of the lip (length and width), the length of the blade lip. We analyzed up to 30 generative individuals in each CP. It was defined that ontogenetic structure of all 5 coenopopulations was normal, incomplete, right-side type with maximum on generative plants. The proportion of generative plants varies from 47 to 72%. Virginile individuals dominate in pregenerative group, 26 to 46%. Immature plants take 0.34 to 8.44% (See Fig. 1). Seedlings and juvenile plants of seed origin were not marked, which proves that population quantity of the studied CPs is promoted vegetatively. We marked insignificant fluctuations of quantitative proportions of different ontogenetic states. Based on the ratio of age index (∆) and efficiency (ω), all studied C. calceolus coenopopulations, excluding CP4, are defined as ripening. CP4 is characterized as mature (See Fig. 2). Based on the analyses of morphological parameters of variability structure it was determined that the least variable parameters of C. calceolus are the number of leaves, the size of the lip (length and width), and the length of the blade lip; generative sprout height varies the most. The number of flowers can serve as an ecological indicator (See Fig. 3). Analyses of vitality structure allowed revealing that the most favorable conditions for C. calceolus form in spruce herbaceous forests with fir and pine (CP 4), where maximum vitality index (IVC=1.14) and quality parameter (Q=28.0) were marked, as well as the largest number of individuals with high vitality, up to 60.98% (See Table 2). The least favorable conditions form on an anthropogenically transformed substrate of an old limestone open-cut overgrowing with pine, spruce, aspen and mixed herbs (CP5), where IVC and Q reach minimum values of 0.83 and 15.5, correspondingly. CP vitality type estimated by Q-criteria showed that almost all CPs are prosperous (excluding CP5, which is defined as depressed). The studied species has a narrow set of ontogenetic tactics: convergent, divergent, and divergent-convergent (See Fig. 4-6). The type of coherence in morphological structure of the plant revealed a stress-protective ontogenetic strategy (See Fig. 7). Complex estimation of organismic and populational characteristics of C. calceolus showed that most of the studied CPs are “Near Threatened” and need habitat protection measures (See Table 3). CP 1 depends on conservation. The paper contains 7 Figures, 3 Tables and 36 References.

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