Rio de Janeiro Botanical Garden: Biodiversity Conservation in a Tropical Arboretum

In light of increasing human impacts on natural areas and climate change, urgent action is required to accelerate species conservation efforts. Ex situ conservation has gained importance, yet the increasing endangered species challenge is magnified in botanic gardens, notably tropical ones, insufficient to safeguard such diverse flora. This study focused on the living collection of the arboretum at the Rio de Janeiro Botanical Garden, examining all cultivated specimens and institutional database records between January and July 2023. It cross-referenced the collection’s composition with the Flora e Funga do Brasil list, as well as Red Lists, to reveal that the collection includes 6960 specimens representing 1420 species, with 60.6% of these species native to Brazil, belonging to 134 botanical families. The collection encompasses all Brazilian phytogeographic domains, with the Atlantic Forest and the Amazon having the highest number of species in cultivation. In terms of conservation efforts, the collection includes 83 species from the Brazilian Red List and 106 species from the IUCN Red List, contributing to the Global Strategy for Plant Conservation, Target 8. This evaluation is the first step toward identifying collection gaps, future planning, and targeting species for acquisition to enhance the effectiveness of our conservation efforts.