Taxonomic Diversity and Threat Levels of the Arboreal Flora of the Brazilian Amazon

Abstract

The Brazilian Amazon has one of the highest diversities of tree species in the world; however, knowledge of its flora is limited by significant taxonomic and geographic gaps. This study aimed to analyze the taxonomic diversity and conservation status of the arboreal flora in the Legal Amazon using official databases (Flora e Funga do Brasil). A total of 4249 tree species were recorded, with Fabaceae, Melastomataceae, and Apocynaceae showing the greatest species diversity. The states of Amazonas and Pará contained the largest datasets, indicating a sampling bias toward areas with stronger institutional infrastructure. A crucial finding was the high proportion of species classified as "Not Evaluated" or "Data Deficient," indicating a dangerous level of conservation invisibility. Nevertheless, species in high-risk categories (“Critically Endangered,” “Endangered” and “Vulnerable”) were found in all states, reflecting widespread human pressure across the biome. We conclude that conserving Amazonian flora requires urgent attention to gaps in risk assessment and to the integration of taxonomic data into territorial planning and environmental licensing policies.