Henryk Tomaszewicz

Habitat conditions of the phytocoenoses of myriophylletum alterniflori lemée 1937 em. Siss. 1943, myriophylletum verticillati soó 1927 and myriophylletum spicati soó 1927 in Poland

Abstract A comparative analysis of the habitats of 28 Myriophylletum alterniflori, 23 Myriophylletum verticillati and 29 Myriophylletum spicati phytocoenoses from 50 lakes within northern and south-eastern Poland was conducted. On the basis of phytosociological data, and the physical and chemical properties of water and substrate in the analysed phytocoenoses, it is demonstrated that the phytosociological distinction of the associations studied, based on floristic dominance, is confirmed in the distinction of their habitats, both with respect to water and substrate chemistry. Myriophylletum alterniflori phytocoenoses in Poland are restricted to soft, oligotrophic-mesotrophic waters, poor in calcium and magnesium, and to substrates also poor in these elements. Myriophylletum verticillati phytocoenoses occur in mesotrophic or slightly eutrophic waters, poor in NO 3 N, PO 4 P and K on hydrated, organic and organic-mineral substrates, mostly rich in calcium. The phytocoenoses of Myriophylletum spicati grow in waters with a wide trophic amplitude, although their optimum development occurs in typical eutrophic waters. They may be indicators of substrates poor in organic matter.