Phytosociology analysis of two sites in the Dense Alluvial Ombrophilous Forest with hydromorphic soils, Paraná, Brazil

Abstract

In the present study, we characterize the structure in two sites of Dense Alluvial Ombrophilous Forest, Guaraqueçaba, State of Paraná, Brazil. Aspects of the vegetation were associated to environmental conditions such as soils, topography and water table depth. For the phytosociological study, 16 plots of 10 x 10 m were established in each site and all trees with Perimeter at breast height > 15 cm were sampled. Both sites presented a mixture of Haplic Gleisoil and Melanic Gleisoil. A total of 81 species were identified, belonging to 59 genera and 31 families. Myrtaceae was the family of greatest richness in both areas. The Jaccard’s similarity index was 29,6%. The Shannon’s diversity index was lower in the site of greater water saturation (H´=2,86). However, few species are well adapted to environmental constraints associated with excess water in the substrate. Due to geographical proximity and similarities of climate and soil between the communities, the main factor determining the structure and floristic composition seems to be closely related to the condition of drainage of the soil.