The object of our research was one of the most common orchids in the world – Cypripedium calceolus L. As a rare species, it is listed in the Red book of the Russian Federation (3 category of rarity) [8], the Kirov region (3 category of rarity) [9], as well as in the Red books of 59 regions of the Russian Federation [2]. Limiting factors in the Kirov region are the violation of habitats as a result of anthropogenic impacts – deforestation, recreation, collection for bouquets, digging, reducing the number of species. Studies on the study of C. calceolus in the Kirov region are isolated [10–12]. The purpose of this work is to identify phytocenotic parameters and environmental conditions of C. calceolus habitats within the southern taiga fragment of the range.
Studies of ecological and cenotic conditions of C. calceolus habitats were conducted in southern taiga forest ecosystems within the Kirov region (Slobodskaya, Afanasyevsky districts) (See table 1) in the period from 2012 to 2019.
The studied habitats of C. calceolus are confined to non-morally-boreal-small-grass and grass spruce forests (Melico nutantis-Piceetum abietis subass. typicum, Maianthemo-Piceetum subass. typicum var. typical) (See fig. 1), pine trees with fir and spruce of various grasses (Melico nutantis-Pinetum sylvestris var. Lathyrus vernus). The growth of C. calceolus on the technogenically disturbed substrate of an old spent limestone quarry overgrown with coniferous rocks and various grasses was also noted. All the studied biotopes are characterized by a large constancy of non-moral species with not significant coverage of mosses.
The stand of spruce forest types is dominated by Picea abies, pine-Pinus sylvestris. Abies sibirica occurs as an impurity. The undergrowth layer has a diverse species composition: Sorbus aucuparia, Frangula alnus, Lonicera xylosteum, Yuniperus communis, Daphne mezereum. In this tier of most studied phytocenoses there is a Atragene sibirica. The grass-shrub layer is also very diverse, which determines the high specificity of these communities. In addition to species of boreal small grass (Maianthemum bifolium, Orthilia secunda, Luzula pilosa, Rubus saxatilis), the presence of non – morals is characteristic-Lathyrus vernus, Melica nutans, Stellaria holostea, Asarum europaeum. Moss-lichen layer is fragmentary (covering up to 45 %), Pleurozium schreberi and Hylocomium splendens act as sodominants.
Phyto-indication of the studied C. calceolus habitats according to ten ecological scales of D. N. Tsyganov (See table 2, Fig. 2) showed that in relation to the complex of all environmental factors, the studied species is mesovalent (MV) (It total = 0.54) and has an average level of lability in relation to the studied environmental factors.
In relation to the complex of all environmental factors, C. calceolus is a mesobiont species. On a scale of soil acidity, the species is semistarvation at termokhimicheskie and apolitically scale and dial illumination-shading – metavalent on the scale of the wealth of the soil nitrogen – hemimillennial at createmotions scale and the scale of continentality of the climate avivamento. Only on the scale of soil moisture and the scale of soil salt regime, C. calceolus is stenovalent, which indicates a very limited range of possible habitats for this factor.
The species, in the studied habitats, realizes from 4.61 to 23.84 % of its potential according to the studied factors. For C. calceolus, the results obtained allow us to extend the scale of soil acidity by 0.75 degrees to the right. According to the other scales, the values of the ecological space of the studied CP are placed in the ranges given by D. N. Tsyganov for this type
Edaphic conditions of C. calceolus on the scale of soil moisture correspond to regimes from dry-saline to wet-forest-saline; on the factor of soil salt regime-poor soils; soil acidity – acidic-slightly acidic soils; soil richness in nitrogen – nitrogen – poor soils; moisture variability-soils with relatively stable and poorly variable moisture.
Forest history, peatland development and mid- to late Holocene environmental change in the southern taiga forest of central European Russia