Long-term human influence on the demography and genetic diversity of the hyperdominant Bertholletia excelsa in the Amazon Basin.

The Amazon rainforest is characterized by a limited number of hyperdominant trees that play an oversized role in its ecosystems, nutrient cycle, and rainfall production. Some of these, such as the Brazil nut, appear to have been intensively exploited and dispersed by Indigenous populations since their earliest arrival in this part of South America around 13,000 years ago. However, the genetic diversity-and geographic structure-of these species remains poorly understood, as does their exact relationship with past human land use.

Reimagining the relationship between Gondwanan forests and Aboriginal land management in Australia's "Wet Tropics".

The "Wet Tropics" of Australia host a unique variety of plant lineages that trace their origins to the super-continent of Gondwanaland. While these "ancient" evolutionary records are rightly emphasized in current management of the region, multidisciplinary research and lobbying by Rainforest Aboriginal Peoples have also demonstrated the significance of the cultural heritage of the "Wet Tropics." Here, we evaluate the existing archeological, paleoenvironmental, and historical evidence to demonstrate the diverse ways in which these forests are globally significant, not only for their ecological heritage but also for their preservation of traces of millennia of anthropogenic activities, including active burning and food tree manipulation.

Tropical Trees as Time Capsules of Anthropogenic Activity.

After the ice caps, tropical forests are globally the most threatened terrestrial environments. Modern trees are not just witnesses to growing contemporary threats but also legacies of past human activity. Here, we review the use of dendrochronology, radiocarbon analysis, stable isotope analysis, and DNA analysis to examine ancient tree management.

Growth rings of Brazil nut trees (Bertholletia excelsa) as a living record of historical human disturbance in Central Amazonia.

The Brazil nut tree (Bertholletia excelsa) is an iconic and economically valuable species that dominates vast swathes of the Amazon Basin. This species seems to have been an important part of human subsistence strategies in the region from at least the Early Holocene, and its current distribution may be a legacy of past human settlement. Because B.