Advancing Amazonian botanical knowledge: a detailed ecological characterization of an open ombrophile forest, southwest Amazonian Brazil

Bruno Umbelino , Juliana Stropp, Ingrid Mendes-Silva, Ricardo Aleixo Correia, Antônio Silveira, Ana C. M. Malhado

Biodiversity inventories present excellent opportunities for ecological investigations and the classification of different threats to the community, nonetheless these applications are not frequently employed. Our main objective was to determine the tree and palm community within a one-hectare areas, also exploring the association between functional attributes and the projected threat of category for the future (by 2050) in a conservation unit situated within the Brazilian Amazon Deforestation Arc. We established a rectangular plot (10x1000m) to assess the community structure. Information on seed and fruit size attributes was obtained from the literature, along with data on the projected threat category. Overall, two taxa (Rubiaceae sp.and Rhizophoraceae sp.) were characterized only at the family level, 106 at the genera level (morpho-species) and 124 until binomial name. We found information about seed size for 55 genera. Medium-sized seeds were the most frequent, occurring in 22 genera, followed by large seeds (16), small seeds (6), and very small seeds (5). As for the projected threat status for 2050, we found that 28 species were classified as vulnerable and 16 species as endangered. In our plot we founded a few numbers of species with many individuals. We conclude that floristic studies associated with ecological approach carried out in the southwestern region of the Brazilian Amazon are rare and our study, provides a significant contribution to biodiversity knowledge.