Reconstructing the Early Living Collections of the Rio de Janeiro Botanical Garden (1808–1822): Historical Documents, Surviving Trees and Spatial Evidence

Botanical gardens function as living historical collections and essential germplasm banks for ex situ conservation. Despite the global importance of the Rio de Janeiro Botanical Garden (JBRJ), founded in 1808 by the King of Portugal, its early floristic composition and initial spatial development lacked systematic records, which complicates modern curatorial efforts. This study reconstructed the garden’s foundational spatial and floristic organization (1808–1822) using phytochronological analysis integrated with Geographic Information Systems (GIS) and the Jabot database, the institution’s internal botanical collection management system. By georeferencing primary historical sources and cartography from 1809 and 1844, the research established a foundational inventory of 70 taxa. Results identified 94 georeferenced specimens representing 28 of these original taxa, signifying that 40% of the original floristic composition remains in the current arboretum. Spatial analysis further revealed a two-phase territorial expansion, transitioning from an initial 4.5-hectare triangular plot to an 8-hectare quadrangular landscape after 1815. The convergence of historical spatial patterns and species underscores the institution’s role as a ‘living monument’. These findings provide fundamental technical criteria for the management of historical cultural heritage, highlighting the need to incorporate the management of collections and significant landscapes into institutional plans.