Structure, diversity and phytogeographic contingent of tree species in a riverine forest in the Planalto da Campanha, Pampa biome

The aim of this study was to describe the structure and diversity of tree species of a riverine forest in the Pai Passo stream, Quarai municipality (RS), and evaluate the floristic relationships. Three 0.25 ha plots were delimited and all trees with a perimeter at breast height >= 15 cm were sampled. In 0.75 ha, we sampled 1,050 individuals distributed in 36 native and two exotic species. The structurally most important species were Pouteria salicifolia (Spreng.) Radlk., Gymnanthes klotzschiana Mull.Arg. and Eugenia uniflora L. The Shannon diversity was 12.38 equivalent species, with Shannon index (H') of 2.52 and Pielou index (J') of 0.70. The species with wide distribution correspond to 50%, the paranense contingent species to 25% and the chacoan species to 25%. The species richness is high for the Planalto da Campanha, due to compensation of chacoan species against the dilution of paranense species, but intermediate for the Pampa biome.

Automated summary

The aim of this study was to describe the structure and diversity of tree species in a riverine forest and evaluate the floristic relationships. The study found high species richness, with Pouteria salicifolia, Gymnanthes klotzschiana, and Eugenia uniflora being the most important species. The species composition was characterized by widespread species, paranense contingent species, and chacoan species.