Amazonian forest conservation through sustainable use: evidence based on Brazil nut life histories linked to human occupation

Summary The Brazil nut tree Bertholletia excelsa is an icon of Amazon conservation through sustainable use. Moderate disturbance, such as that caused by swidden agriculture, favours this heliophilic species. Our systematic literature review of Bertholletia studies and historical records addresses the following questions: do slash-and-burn farming systems increase Bertholletia density and growth? What do historical records reveal about the links between Bertholletia life history and human occupation? And what policies and regulations shape the current context for harnessing this synergistic potential for sustainable use? Compared to mature forests, slash-and-burn fallow seedling/sapling densities (11–82 individuals ha –1 , with a mean of 29 individuals ha –1 ) are greater and faster-growing. Extant Bertholletia trees that were cut and burned during swidden preparation resprout as forked individuals and supplement new seeds buried by Dasyprocta spp. The presence of large forked Bertholletia trees and the occurrence of anthropogenic soils, particularly brown soils associated with Brazil nut tree groves, provide evidence that extant Bertholletia groves may be islands of active and passive agroecological management by ancestral Indigenous populations and local communities. This supports the notion that conservation through sustainable use can maintain Amazonian megadiversity. Furthermore, fire has been used in the Amazon since the onset of crop cultivation (including Bertholletia ) c. 4500 years ago, suggesting that a more effective approach than banning fires would be to implement a systematic and methodical fire and fuel management strategy, given the ineffectiveness of command-and-control policies in this regard. The 124 conservation units and Indigenous lands in the Amazon containing Brazil nut trees reinforce the importance of policies to create protected areas. Evidence suggests that the presence of an Amazonian biocultural forest – a phenomenon resulting from the interaction between human activities and natural processes – can be sustainably used to promote what might be termed ‘sociobiodiversity conservation’.