Functional traits have gained scientific support as a tool for understanding forests ecosystems and the goods and services they provide to human populations. Investigating how humans use and interact with plants based on their functional traits is crucial to support the long-term provision of plant-based ecosystem services. Here, we have adopted a large-scale approach encompassing nine different Indigenous communities across a latitudinal gradient of 1800 km in western Amazonia. We study the associations between nine different plant functional traits belonging to 1856 species and multiple cultural and provisioning services to support Indigenous communities in tropical ecosystems. We found that provisioning services, such as medicine, construction, and food, depend on multiple traits, and their selection is heterogeneous among communities. Cultural services, however, such as rituals, cosmetics, or recreational, hold more specific and tight relations with fewer traits. Their selection tends to be similar among communities, suggesting a possible functional selection convergence. Preserving traditional ecological knowledge is crucial for preserving biocultural well-being. Plant selection is not random, and functional traits can help us understand the current and past patterns of selection that have influenced the functional composition of Amazonian forests.