Floristic and phytosociological composition of ecotone between mixed ombrophile forest and seasonal semideciduous forest

Abstract

Floristics, structure and succession stage of a 38-year-old secondary forest remnant, ecotone between FOM and FES, adjacent to the Bituruna PR Brazil hydroelectric reservoir are characterized. Sixty 200 m2 splits for the tree extract and sixty 10m2splits for the sub-forest were established. Tree extract had a density of 1,035 trees.ha-1, basal area basal of 38.98 m2.ha-1, 108 native species and Shannon's diversity at 4.01. Sub-forest was characterized by density at 11,000 trees.ha-1, basal area of 8.65 m2.ha-1, 96 native species and Shannon's diversity at 3.67. Richness and diversity were great in both. Non-pioneering species were underscored in the sub-forest. Typical species of FES were slightly more representative than those of FOM, with a smaller difference in the tree extract. There was a significant dissimilarity in the floristic composition between the tree extract and the sub-forest. The forest was well preserved, with characteristics between the intermediate and advanced successional stages. Percentage of species typical of each phytophysionomy was according to expected for height and topographic conditions of the ecotone under analysis.