‘Bleeding’ Brazil nut trees: Impacts of a local practice on fruit production

ABSTRACT Bertholletia excelsa , commonly known as the Brazil nut tree, is an emblematic species for Amazon forest conservation and a key source of income for many extractivist families. Indigenous Peoples and traditional communities have interacted with this species for millennia, developing local management practices aimed at maintaining or increasing fruit production. Among these practices is “bleeding,” which involves making incisions in the trunk to stimulate resin exudation, traditionally believed to reduce fruit abortion and thus enhance nut yield. Given the socioeconomic importance of Brazil nut production and the ongoing debate regarding the effectiveness of bleeding, this study investigated whether the practice increases fruit production in low- or non-productive trees over time, whether the timing of bleeding (February or October) influences reproductive responses, and how wound closure varies according to cutting intensity and season. A six-year controlled field experiment was conducted in a native forest within the Reserva Extrativista Chico Mendes in the Brazilian Amazon. We compared two cutting intensities (high versus low) and two application periods (February and October). Treated and control trees were monitored for three years before and after treatment. Overall, no evidence was found that bleeding increased fruit production following treatment, regardless of cutting intensity or timing. Adult trees demonstrated the ability to close bark incisions over time, with faster wound closure following October treatments and slower closure in larger-diameter trees.