In this warm and humid environment characterized by poor preservation of macrobotanical remains (e.g., charred seeds, roots), the application of state-of-the-art phytolith, starch grain, and pollen analyses are crucial to reconstruct the agricultural history of the region.

The project has evidenced that the coastal Guianan landscapes are neither purely natural nor purely man-made, but rather are hybrid landscapes resulting from the interactions of pre-Hispanic farmers and natural processes (PNAS, Journal of Archaeological Science, 2010).

More significantly, it has revealed a unique perspective on land use before and after Europeans arrived to the Americas in 1492. It showed that, in contrast to tropical forest contexts where the collapse of indigenous populations after 1492 led to decrease forest clearance for agriculture, fires in these Amazonian savannas are a post-Columbian phenomenon. By also revealing that pre-Columbian raised-field farmers limited fire, this research has offered a fresh perspective on an emerging alternative approach to savannah land use and conservation that can help reduce carbon emissions (PNAS 2012). 

Publications:

Iriarte, J., M. J. Power, S. Rostain, F. E. Mayle, H. Jones, J. Watling, B. S. Whitney and D. B. McKey. 2012. Fire-free land use in pre-1492 Amazonian savannas. Proceedings of the National Academy of Sciences USA 109: 6473-6478. [Open Access]

Iriarte, J., B. Glaser, J. Watling, A. Wainwright, J. J. Birk, D. Renard, S. Rostain and D. McKey. 2010.Late Holocene Neotropical agricultural landscapes: phytolith and stable carbon isotope analysis of raised fields from French Guianan coastal savannahs. Journal of Archaeological Science 37: 2984-94. [Abstract]

McKey, D., S. Rostain, J. Iriarte, B. Glaser, J. J. Birk, I. Holst and D. Renard. 2010. Pre-Columbian agricultural landscapes, ecosystem engineers, and self-organized patchiness in Amazonia. Proceedings of the National Academy of Sciences USA 107:7823-7828. [Open Access]

Iriarte, J. and R. Dickau. 2012. As culturas do milho? Arqueobotânica de las sociedades hidráulicas das terras baixas sul-americanas. Amazônica 4:30-58. [Open Access]

Renard, D., J. J. Birk, B. Glaser, J. Iriarte, G. Grisard, J. Karl and D. McKey. 2012. Origin of mound-field landscapes: a multi-proxy approach combining contemporary vegetation, carbon stable isotopes and phytoliths. Plant and Soil 351:1-17. [Abstract]

Renard, D., J. Iriarte, J. Birk, S. Rostain, B. Glaser and D. McKey. 2011. Ecological engineers ahead of their time: The functioning of pre-Columbian raised-field agriculture and its potential contributions to sustainability today. Ecological Engineering 45:30-44. [Abstract]

Partners:

Prof. Doyle McKey, University of Montpellier, France.

Dr. Stephen Rostain, Archéologie des Amériques, CNRS-Université Paris 1 Panthéon-Sorbonne, France.

Prof. Bruno Glaser, Martin-Luther-Universität Halle-Wittenberg, Germany.

Dr. Francis Mayle, Institute of Geosciences, University of Edinburgh, UK.

Dr. Mitchell Power, Department of Geography, University of Utah.

Dr. Bronwen Whitney, Institute of Geosciences, University of Edinburgh.