Brazil nut journey under future climate change in Amazon

traits, as well as the network of interactions of communities, impacting on interspecific rela- tionships and their structure [3]. In response to the changes, species move into geographic space, seeking adequate climatic conditions for their survival, growth, and reproduction [2, 4], changing their distribution pat- terns over generations [5, 6]. In this way, it can lead to population declines, or even species extinction [7, 8]. As consequence of these cascading events, changes in the climate pattern can promote the loss of biodiversity and ecosystem functions, such as seed dispersal, the germina- tive success of these seeds, and therefore the process of forest regeneration [9], affecting the integrity of biomes on a wide scale [10]. In the Amazon, the consequences of climate change can range from extreme weather events such as droughts and floods, changes in rainfall regime, increased fire risk associated with impacts on climate, health, and biodiversity [11, 12]. Furthermore, extreme droughts and floods cause additional stress on Amazonian forests, increasing the risk of tree mortality [13]. Thus, if changes reach a critical threshold because of increases in temperature, generating lon- ger drought periods in the near future, major changes would be triggered in Amazonia, such as large-scale "savannization" events [11, 12, 14]. According to [15], continuous deforestation in the Amazon severely affected about 36 to 57% of all common and rare tree species. Inasmuch, some species are the merger of losing

over 30% of their original population. This is the case of the Brazilian Nut tree (Bertholletia excelsa), an iconic species of the Amazon region that is among the vulnerable species, under the criteria of the International Union for Conservation of Nature (IUCN) Red List [16]. The Brazil nut tree is a long-lived species that is demanding in terms of favorable light for its survival and ascent in the canopy. In the seedling stage it is demanding for light, especially in open areas such as clearings and grazing, favoring its vertical growth, besides having a high capacity for regrowth and performance recovery after traumatic episodes of physiological nature, being considered indicators of past disturbances. Therefore, its life cycle is associated with natural events and disturbances such as extreme floods, droughts, tree fall gaps and fires [17–20]. B. excelsa is one of the most important non-timber products producing trees in the Amazon bioeconomy. Its fruits are predominantly harvested from natural forests. The species is an emergent tree, reaching heights up to 50 m, and is a long-lived and pioneer. It usually grows in areas above sea level (> 400 m) with an annual mean temperature of 23.5 to 27.6˚C and annual rainfall ranging from 1,445 to 3,399 mm [21]. In this study, to analyze suitability conditions for the Brazil nut distribution by the end of the current century, we used species distribution modeling under future climatic conditions not analogous to the current ones. We also quantify over continuous geographical space and

time in the Amazon landscape, under different climatic scenarios, the extinction patterns, per- sistence places, and colonization of potential distribution areas. Since the species at hand has a strong dependence on human consumption and traditional cultivation activities, this historical distribution pattern must be an issue to be addressed in the conservation strategies. Material and methods Area of study The area of study comprises the Amazon biome in its biogeographic domains defined by the Amazon Network of Georeferenced Socio-Environmental Information (RAISG) polygon (http://raisg.socioambiental.org/ - accessed on the November 2023). The study area covers approximately 7 million km2. It is the world’s largest watershed, encompassing tropical PLOS ONE Effects of climate change on Brazil nut PLOS ONE | https://doi.org/10.1371/journal.pone.0312308 November 13, 2024 2 / 13 Graduac¸ão, Universidade Federal do Para´ https:// www.propesp.ufpa.br/ The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist.