Peatland vegetation of the Syra Pogonia massif of the Rivneskyi Nature Reserve (Polissia, Ukraine): ecological characteristics

Abstract

Background. Peat bog complexes are self-sufficient ecosystems in which unique microclimatic conditions leading to a significant diversity of valuable plant communities are formed. Such communities are sensitive to the effects of climate change or any anthropogenic intervention. The lack of reliable information on their distribution on the territory of the Syra Pogonia peat-bog massif of the Rivnenskyi Nature Reserve necessitates a detailed study of the bog vegetation. Therefore, the purpose of the work was to classify the community of peatland vegetation of the Syra Pogonia massif and to determine the features of their syntaxonomic and ecological differentiation for further development of environmental management strategies. Materials and Methods. The study of the peculiarities of peatland vegetation was conducted on transects that represent the variety of local conditions of the complex system. A total of 141 relevés were analysed using the Braun–Blanquet method. The material was analysed using TURBOVEG 2.79 and JUICE 7.0.83 software. Vegetation units were separated using the method of two-factor indicator species analysis (TWINSPAN). Diagnostic species of syntaxa were determined by the fidelity coefficient phi, the fidelity threshold for which was > 25 %. The statistical significance of the phi coefficient was determined with the Fisher’s test at P < 0.001. The DCA-ordination method was used to identify an ecological differentiation of units. Results. Peatland vegetation of the Syra Pogonia massif of the Rivnenskyi Nature Reserve was analysed. We identified 7 associations belonging to 6 alliances, 6 orders and 4 classes and compiled a vegetation syntaxonomic scheme. The leading factor of ecological differentiation of community is humidity of the area. The greatest diversity is inherent in mesotrophic areas, rare species are found and grouped according to diffe­rent ecological conditions. The species composition of 7 associations includes 79 plant species, of which 65 are vascular and 14 are bryophytes. Using methods of phytosociological analysis, we established that the distribution of community in multi-dimensional space of ecological factors occurs under the conditions of their complex action. At the same time, changes in the humidity regime are of crucial importance for the selected syntaxa (Andromedo polifoliae-Sphagnetum magellanicі). The results of the phytoindicative analysis proved that the associations identified on the territory of the Syra Pogonia peat-bog complex are acidophilic in terms of acidity, and oligotrophic in terms of the requirements for the content of nutriens. Conclusions. As orders, and result of the analysis of relevés, 7 associations, which belong to 6 alliances, 6 orders and 4 classes were selected. Based on the results of the dataset analysis, a vegetation classification scheme was compiled. As a result of the cluster analysis of 7 associations, a significant difference between communities of watered and wet habitats was revealed. We established that the differentiation of the vegetation on the territory of the peat massif of Syra Pogonia mainly depends on the change in the moisture regime.