drastic decreasc of species richness (from 10 to 3 species), disappearance of 3 specics protected by law (Stone loaclı ... river chanelization on the following days: 6 XI 2003, 6 II 2004 and 20 IV 2004. The .... *Årednie oznaczone tymi samymi literami nie różniÄ siç statystycznie przy p
