Arboriculture and silvopastoralism during the formative period (1,400 bC-500 aD) of the salar de Atacama basin

Abstract

Several hypotheses and models have been put forward about the role played by agriculture, horticulture, gathering, hunting and herding of camels during the Formative period (1,400 BC-500 AD) in the oases of the Salar de Atacama and the Middle Loa. This article re-assessed these proposals in light of new data obtained mainly from the analysis of microfossils attached to lithic hoes, grinding instruments and, to a lesser extent, from different isotopes (d13Ccol, d13Cap, d15N, d18O, Sr87/Sr86). The data is interpreted from a theoretical perspective that emphasizes risk and nonlinear evolution in human-plant interaction. I discuss the functionality of the instruments analyzed and the management of wild resources such as cacti and sedges, as well as unidentified tubers. From an archaeobotanical perspective I suggest that algarrobo (Prosopis) forests are not native to the area, but were the product of a formative arboriculture possibly linked to a silvopastoralist economy in the oases. Both proposals reconsider the cultural and ecological history of the area, and enrich the discussion of the Formative and of the biogeography of Prosopis in the Americas.