Amazonian Historical Ecology

This project evaluates how past and current human management activities may influence useful species distribution and dominance in Amazonian forests.

Amazonian forests have a large number of useful species recognized by local people, most of which are considered Non-Timber Forest Products (NTFPs). Although Amazonian forests contain a high number of species, forests are dominated by relatively few tree species, many of which are used by traditional peoples. Native peoples may have contributed to this pattern of dominance of Amazonian useful species. Studies indicate that the long process of cultivation and domestication of useful plants and forest management by pre-Columbian human populations have transformed primary forests into anthropogenic forests. Anthropogenic forests are recognized by the concentration of useful and/or domesticated species and they are usually associated with anthropogenic soils, known as Amazonian Dark Earths (ADEs) or Terra Preta de Índio (TPI). William Balée estimated that 11.8% of Amazonian forests are anthropogenic; however, when we consider the complexity and size of some pre-Columbian societies and their extensive knowledge of landscapes and plant domestication combined with a range of forest management practices, the extension of anthropogenic forests is probably underestimated. Traditional peoples have inherited part of native knowledge and also manipulate species and forests to make them more productive and useful.

For my PhD, I am interested in (1) identifying the historical human influences and environmental factors that explain the dominance of useful species across different Amazonian geographical regions; and (2) detecting the evidences of landscape domestication and its extension around pre-Columbian settlements. I investigate evidence of forest domestication in: (1) the forest soils and arboreal compositions; and (2) in traditional management practices today. I expect to find footprints of past human management on the current arboreal composition in different geographical regions of the Amazon basin. Moreover, I expect to document forest management practices of Amazonian societies that enhanced usefulness of forest landscapes.

This thesis is planned to investigate forest domestication in different spatial and temporal scales. First, I analyze the effect of past forest domestication at regional scales with forest inventory data across different Amazonian geographical regions. Second, I reduce the scale of analysis to understand landscape domestication in different Brazilian river basins, quantifying the extent of anthropogenic soils and forests in riverside villages. Then, I document practices of forest management at some villages, and I do forest inventories to understand how current people domesticate Amazonian forests.

Societal Importance
Anthropogenic forests are of paramount importance to traditional human populations, since these forests concentrate useful plants for subsistence and marketing. Understanding how current people have managed and transformed anthropogenic forests will contribute to recommending best practices for management and conservation.