Floristic and phytocenotic diversity of waterlands of the Shatsk national natural park as a basis for monitoring its condition

The floral and phyto-assessment characteristics of wetlands are an important indicator for their monitoring. The territory of the Shatsky National Natural Park is a natural nucleus of the Polesia Ecology Corridor and a storing part of the All-European Environmental Network. The preservation of the unique wetland complexes of the park requires constant monitoring of the most significant indicators that reflect their condition. The purpose of the studies was to generalize and analyse the flora of the higher vascular plants and vegetation of the park, justifying their use as monitoring indicators. The authors' field research on flora and vegetation was carried out during 2006-2020 on the whole territory of Shatsk NNP. Sixteen test sites were laid for detailed studies. Based on research and analysis of literature sources, 318 species of upper vascular plants belonging to 6 classes and 74 families were found in the flora of the park's wetlands. Among the numerous families are represented typical for the natural floodplains of the wetlands of the Shatsk Lake: Cyperaceae, Poaceae, Asteraceae, Ranunculaceae, Lamiaceae, Potamogenaceae, Salicaaceae, Fabaceae, Polygonaceae. Species from «The Red Book of Ukraine» (Aldrovanda vesiculosa L., Betula humilis Schrank, Dactylorhiza maculata (L.) Soо, D. majalis (Rchb.) P.F. Hunt & Summerhayes, D. incarnata (L.) Soó, Epipactis palustris (L.) Crantz, Platanthera bifolia (L.) Rich., Carex chordorhiza Ehrh., Cladium mariscus (L.) Pohl s.l..) and species subject to regional protection in Volyn region are represented in the flora at the investigated sites (for example, Salix myrsinifolia Salisb., Batrachium aquatile (L.) Dumort., Hypericum tetrapterum Fr., Sparganium natans L., Nymphaea candida С. Presl, Carex limosa L., C. paniculata L., C. flacca Schreb., Eriophorum gracile W.D.J. Koch, Potamogeton praelongus Wulf., P. obtusifolius Mertens & W.D.J. Koch., Rhynchospora alba (L.) Vahl, Drosera rotundifolia L., Senecio paludosus L., Ptarmica salicifolia (Besser) Serg.). The vegetation cover of the studied territory is naturally dominated by cenoses, primarily of marsh and forest vegetation types, in particular eutrophic sedge swamps, black alder, alder pine, and on hilltops - pine forests of blueberry green moss. Coastal-aquatic, aquatic and wetland groups of grasslands are well represented. In wetlands in studied areas, eutrophic swamps are primarily represented, which are dominated by grass, sometimes there are sparse forests. Among the forest groups, associations of alder, alder-birch and pine forests are well represented. In the elevated areas of relief, vegetation was formed with the participation of xerophytes, semixerophythics, submesophytes and mesophytes. In monitoring the status of the park's wetlands at the population and species level, it is first necessary to monitor the development of the most rare species of flora from "The Red Book" and from the regional protection list. However, attention needs to be paid to population dynamics of adventive species, especially invasive species (Bidens frondosa L., Echinocystis lobata (Michx.) Torr. et Gray, Impatiens parviflora DC., Parthenocissus quinquefolia (L.) Planch., Acer negundo L., Quercus rubra L., Prunus cerasifera Ehrh., Prunus serotina Ehrh., Salix fragilis L., Conyza canadensis (L.) Cronquist, Erigeron annuus (L.) Pers., Oenothera biennis L., Heracleum sosnowskyi Manden., Ambrosia artemisiifolia L.). At the coenotic level, priority should be given to the development of wetland, coastal-aquatic and grassland (marsh and wet) groupings, which have limited spread in the region. In parallel, there is a need to control the growth of such groupings, which are highly competitive and capable of displacing less competitive groups. It is very important to link this dynamic with the changing abiotic conditions of ecotopes. Indicators for monitoring should be the dynamics of individual flora species and plant communities.