ABORIGINAL AGRICULTURE AND LAND USAGE IN THE AMAZON BASIN, ECUADOR

This paper presents a record of aboriginal agriculture and land usage in the Amazon Basin derived from phytolith studies of a sediment core from Lake Ayauch', located at an elevation of 500 m in southeastern Ecuadorian Amazonia. This first phytolith study of Amazonian lake sediments indicates the initiation of maize cultivation at c. 5300 BP. Greatly increased frequencies of maize between 2400 BP and 800 BP suggest a period of agricultural intensification, but even during this time phytolith spectra hold significant frequencies of plants of forests. The phytolith sequence indicates an ancient pattern of seed cropping in Amazonian terra firme forests, associated with cultivation of riparian "wetlands" of lake margins. Presence of particulate carbon in agricultural horizons attests to use of fire in plot preparation and suggests that a reconsideration of the source of prehistoric carbon found underneath mature terra firme forests in other regions of the Amazon Basin is needed. © 1990.