Estrutura da comunidade arbórea de um fragmento de floresta ribeirinha do rio Taquari, Lajeado, Rio Grande do Sul, Brasil

This study aimed to evaluate the tree-component structure of a riparian forest in Taquari River, Lajeado, Rio Grande do Sul. In 40 sampling units of 100m2, we sampled 549 individual trees from 62 species and 30 botanical families. The families with the greatest species richness were Myrtaceae and Fabaceae. The diversity estimated by the Shannon index and Pielou evenness was 3.39 and 0.82 nats.ind.-1, respectively. Luehea divaricata Mart. & Zucc., Trichilia clausseni C.DC., Allophylus edulis (A.St.-Hil. et al.) Hieron. ex Niederl. and Machaerium paraguariense Hassl. were the most important species. Gymnanthes klotzschiana Müll.Arg. had the highest correlation among the sampling units that were closer to the river. The results indicate high richness as well as differences in species composition in the studied remnant when compared to other riparian forests in Rio Grande do Sul, being that these differences are fewer in closer areas.