Threats and Sustainability of Brazil Nut (Bertholletia excelsa Bonpl.) Pre-Industrialization in the Amazon Region

Abstract

Brazil nut (Bertholletia excelsa) is an important species in the Amazon, but the relationships between seed production and climate change are still poorly understood. Seed production data were obtained for the entire Brazilian Amazon, while data on precipitation, relative humidity, vapor pressure deficit, and temperature (mean and maximum) were collected to test their relationship with seed production in the Baixo Amazonas. Annual seed production in the Baixo Amazonas varied between 2156 and 10,235 tons per year from 1990 to 2021, with an average of 5192 tons per year. Linear regression analyses did not identify significant relationships between seed production and climatic variables during the same year (p > 0.05). However, significant relationships were found between the volume of seeds in the base year and climatic variables from 1 year before seed collection (p < 0.05), except for total precipitation (p = 0.15). Temperature was the main climatic variable affecting Brazil nut production, indicating that each 1°C increase in temperature is associated with an average decrease in seed volume ranging from 2595 to 2673 tons. Temperature measures explain between 38% and 42% of the variability in seed volume in the Baixo Amazonas. Therefore, it is crucial to mitigate global warming, invest in technological processes to add value to the remaining seeds, and adopt B. excelsa varieties more adapted to climate change.