Aquatic and swamp plant communities as indicators of habitat properties of astatic water bodies in north-eastern Poland

Phytosociological and habitat studies were conducted on the water and swamp vegetation of astatic water bodies within north-eastern Poland. The phytocoenoses were selected on the basis of dominance of species forming the particular communities. The analysis of 147 relevés showed the existence of 10 vegetation types: Lemnetum minoris, Spirodeletum polyrrhizae, Riccietum fluitantis, Elodeetum canadensis, Polygonetum natantis, Typhetum latifoliae, Caricetum elatae, Calletum palustris, Potentilletum palustris, Menyanthetum trifoliatae  . Among the properties of water analysed water depth, SO42-, pH, total and carbonate hardness, PO43−, Ca2+, Mg2+ and Na+ were found to be most important in differentiating the habitats of the vegetation types studied. Substrate properties, which best differentiated the habitats of the associations studied were NO3−, Na+, water content, pH and total N. In spite of the wide variability of habitat conditions occurring in astatic water bodies, particular phytocoenoses distinguished on the basis of dominance of one species were associated with specific habitats. The particular phytocoenoses or groups of phytocoenoses could be good indicators of various habitat conditions that occur within astatic water bodies or changes taking place in these habitats.