Interspecies coenotic communications of the bracken (Pteridium pinetorum subsp. sibiricum) on a mountain gradient in the Western Sayan

On the basis of Bravais correlation coefficient, coenotic communication of Pteridium pinetorum subsp. sibiricum was estimated with species of vascular plants, mosses and lichens of forests of the perhumid sector in the Western Sayan. Among significant coefficients, we found 2 groups of positive correlation of different extent of communication and a group of negative correlation. We recorded 360 species of the highest vascular plants and also mosses and lichens during field researches. Pteridium was recorded in 51 descriptions, in which 257 species were taken as a whole. In communities of Pteridium species cycle with domination or considerable participation of the bracken, 23 descriptions were made, in which 203 species were noted. For 198 species of Pteridium, we received Bravais correlation coefficient and criterion χ², characterizing a degree of its correlation to other species. Among them, 113 reliable with a 5-% significance value coefficients were chosen. Among statistically significant depending on narrowness and a communication orientation of P. pinetorum subsp. sibiricum with other species 3 groups of correlation were allocated. We used descriptions of forests of full mountain gradient (from subtaiga to subalpine sparse forests) in this investigation. We explored regional specifics of the mountain territory through the eco-coenotic relations of P. pinetorum subsp. sibiricumas one of the most important dominant of subtaiga forests with types of forest communities of a full high-rise range. An important feature of forests of the perhumid sector in the Western Sayan is a great share of nemoral and large herb elements. These elements have a strong connection with P. pinetorum subsp. sibiricum. P. pinetorum subsp. sibiricum has a high activity in subtaiga forests where communities of Pteridium species cycle with its domination or considerable participation are formed. Species that are strongly connected with P. pinetorum subsp. sibiricumare widespread, mainly, in the south of the boreal zone, and also in the nemoral zone. Such types have continuous or disjunctive Euro-Asian type of distribution. Some of them are in mountains of the perhumid sector of the Western Sayan Mountains on the eastern border of distribution. Under conditions of reducing heat availability at the top part of the subbelt of black forests, an ecotope range of P. pinetorum subsp. sibiricum is wedged. It is reflected that P. pinetorum subsp. sibiricum has negative correlation with typical boreal and subalpine elements. The analysis of correlation of P. pinetorum ssp. sibiricum with constant species of forest communities of the humid sector of the Western Sayan allows specifying the state of an ecological niche of this fern in the region with perhumid climate. This research is important for comparison with other regions of the Altai-Sayan mountain region where Pteridium pinetorum subsp. sibiricumis also dominant in the herb layer of subtaiga light coniferous and small-leaved forests.

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