Harvesting Bertholletia excelsa Bonpl. in a western Amazon rural community: local ecological knowledge and meaning to "nut-crackers".

INTRODUCTION: The collection of Bertholletia excelsa Bonpl. (castanha-da-Amazônia; Brazil nuts) seeds make up part of the everyday activities of the traditional populations that have inhabited all of the Amazon basin since remote times. Nonetheless, knowledge about these harvesting activities in native forest areas has not been well documented. The present study was designed to better understand the significance of this harvesting activity as well as the traditional ecological knowledge of the harvesters. METHODS: Utilizamos entrevistas semiestruturadas para a coleta de dados com extrativistas de castanha, moradores de Caroebe, Roraima (n = 18) durante o período de março de 2021 a março de 2022. The data analysis was based on the frequency of responses to socio-economic questions and their knowledge about that plant species as well as why those interviewees chose that line of work. We also adopted the Spearman and Mann-Whitney non-parametric tests to correlate variables identified in the study, and selected sections of their depositions to highlight the traditional knowledge of the interviewees and their experiences as harvesters. RESULTS: Constatamos que as razões para a escolha do trabalho com o extrativismo para todos os entrevistados é a necessidade de renda complementar, tradição familiar (55%), the sense of well-being provided by contact with the natural environment (25%), and a favorable disposition toward that type of work (11%). Harvesting involves collective work, and many of the interviewees had engaged in those efforts to help their families since their childhood or adolescence. The older harvesters cited more animal species that consumed the Brazil nuts (ρ = 0.60; p = 0.009) and perceived more and greater changes in the environment that were prejudicial to the Brazil nut trees (U = 9.50; p = 0.022). The interviewees who reported lower incomes cited more significant cultural changes and more suggestions concerning conservation activities. According to their statements, deforestation, and the burning and illegal cutting of native trees, including Brazil nut trees, have contributed to environmental change in the region and raised significant concerns about the future of harvesting activities. CONCLUSION: The activities of the "nut-crackers" represent to them more than just a simple source of income, as harvesting provides them with a connection to nature that promotes their well-being and cultural heritage. The nut harvesters have gained specific knowledge concerning both environmental and cultural changes. Those changes have mainly come about through the expansion of agricultural activities and the felling of native forests-which are the main threats to the future of Brazil nut extraction. Attributing value to the folk knowledge of those harvesters would strengthen the local economy, promote forest conservation, and help to better understand the impacts of anthropic activities on the forest and the harvesting of natural products.

Local ecological knowledge concerning the invasion of Amerindian lands in the northern Brazilian Amazon by Acacia mangium (Willd.).

INTRODUCTION: Invasive plants can impact biodiversity as well as the lives of native human populations. Natural ecosystems represent sources of natural resources essential for the subsistence and socio-cultural continuity of these social groups. Approximately 30,000 ha of Acacia mangium were planted for commercial purposes in savanna areas surrounding indigenous lands in Roraima State, Brazil, at the end of the 1990s. We examined the local ecological knowledge of indigenous Wapichana and Macuxi Amerindians, members of the Arawak and Carib linguistic families, respectively, concerning A. mangium Willdenow (Fabaceae) in a savanna ecosystem ("Lavrado") to attempt to understand its propagation beyond the limits of the commercial plantations and contribute to mitigating its impacts on socio-ecological systems. METHODS: The present study was undertaken in the Moskow, São Domingos, and Malacacheta communities in the Moskow and Malacacheta Indigenous Lands (ILs) in the Serra da Lua region of Roraima State, in the northern Brazilian Amazon region. Interviews were conducted with a total of 94 indigenous individuals of both sexes, with ages between 18 and 76, and low levels of formal schooling, with an average time of permanence in the area of 21 years; some still spoke only their native languages. The interviews focused on their ecological knowledge of the invasive, non-native A. mangium and their uses of it. RESULTS: The informants affirmed that A. mangium negatively impacted the local fauna and flora, making their subsistence more difficult and altering their daily routines. Among the problems cited were alterations of water quality (71.3%), negative impacts on crops (60.6%), negative impacts on the equilibrium of the local fauna (52.1%), increased farm labor requirements (41.5%), and restriction of access to indigenous lands (23.4%). There were no significant differences between the opinions of men and women, nor between community leaders and nonleaders. Most of the interviewees (89%) felt that A. mangium had no positive importance for the local economy and saw no future prospects of beneficial use. CONCLUSIONS: The Wapichana and Macuxi informants felt that the invasion by A. mangium had caused negative effects on the natural environment and on community subsistence in the indigenous lands due to its rapid and unwanted propagation. The similarity between the opinions of men and women and between community leaders and nonleaders demonstrates the existence of knowledge that is well distributed among these communities and transmitted within their communities through social-cultural interactions.