The floristic composition and the phytosociological structure of 1 ha of riparian forest along the Iapó river (Tibagi river basin) in the municipality of Tibagi, Paraná State, Southern Brazil (24º31’S and 50º25’W), were analysed. One hundred contiguous 10 x 10 m quadrats were used to sample trees with DBH <FONT FACE="Symbol">³</FONT> 5 cm. Frequency, density and dominance parameters were calculated for each species. At this locality 1594 individuals, 127 species, 81 genera and 43 families were recorded on the quadrats. Eugenia blastantha, Faramea porophylla, Casearia obliqua, Nectandra grandiflora, Sebastiania commersoniana, Casearia sylvestris and Actinostemon concolor were the most important species in terms of IVI and IVC. Myrtaceae, Lauraceae and Euphorbiaceae were the families with the largest IVI values. Lauraceae presented 15 species and 142 individuals; Myrtaceae, 14 species and 280 individuals and Euphobiaceae, five species and 274 individuals. The value of the Shannon’s diversity index was 3.67.
Phytosociology; riparian forest; Tibagi river basin; Southern Brazil
