Impacto das mudanças climáticas na distribuição de Bertholletia excelsa

Abstract

Bertholletia excelsa, also known as the Brazil nut tree, stands out as a dominant and safeguarded species within the ecosystem, serving a pivotal function in the cycling of nutrients and the delivery of essential ecosystem services in the Amazon rainforest. This study aimed to model the suitable habitat distribution of this species, by comparing different ensemble models constructed using various spatial filtering resolutions. Additionally, we aimed to include an evaluation of the influence of human activities in promoting or dispersing B. excelsa seeds and/or stands. The results highlight the impact of model selection on the present and future projections, with a significant difference between the projections for the 2050s. We emphasise the importance of considering multiple models for different climatic conditions to better assess the uncertainty of future projections when making climate change policies. The best model (AUC = 0.94) was achieved with geographic plus environmental filtering and a resolution of 2.5 arcminutes. The model predicted a contraction of the suitable habitat area for Brazil nut trees in the present and an even more severe scenario in the future, with precipitation seasonality being the most impactful variable in the species distribution. Future studies should also examine the expected impacts of climate change on the seed production of Brazil nut trees, including indirect effects such as changes in pest and disease incidence.