Ethnobotanical information can clarify how dependent a community is on local plant resources and provide evidence about the consequences of resource exploitation. We performed a quantitative analysis on different aspects of knowledge and use of palms by the residents of the surrounding the Tucuruí Hydroelectric Power Station reservoir, eastern Amazonia, and their relationship with socioeconomic factors, adopting the methodology of consensus among informants. We based the study on accidental sampling of the 232 families and data were gathered through semi-structured forms. We evaluated correlations between the effective use and importance of species and the effect of socioeconomic factors on the knowledge and use of palms as cited by the informants. Informants know 27 species of palms and use 20 of these in eight different categories, the main ones being for food, utensils and construction. The species most widely used and cited as most important were Attalea speciosa, Oenocarpus bacaba, Euterpe oleracea, A. maripa and Socratea exorrhiza. For the informants, the value of a palm species is directly related to the different types of uses that it offers. The knowledge about palms is greater among farmers than fishermen and, when considering the medicinal aspect, it is greater among women than among men.

Documenting the ethnobotanical knowledge of populations living in protected areas is important both for science and for the eff ective conservation of these areas, as it can help to clarify the level of dependency that human communities have on local plant resources. Babassu (Attalea speciosa, Arecaceae) is one of the most important non-timber forest resources of rural communities in the Amazon. We explored the ethnobotanical knowledge and uses of babassu by riverine populations inhabiting the Tucuruí Lake Protected Areas Mosaic in the eastern Amazon, by examining the diversity, purposes and descriptions of its uses and aspects of its extraction. Data were collected in 2010 and 2014 from 193 families. A total of 1,226 use records were cited representing 60 diff erent uses. Records were classifi ed into nine use-categories; utensils and tools was the most important category, followed by construction and human food. Th e use with the greatest purpose consensus value among the informants was thatch. Babassu proved to be an important resource for the livelihood of the local communities in providing shelter, food and reliable energy. Most informants lacked knowledge about sustainable practices and management of this resource.