- Rodrigues, L., Lombardo, U., Canal Beeby, E. & Veit, H. Linking soil properties and pre-
Columbian agricultural strategies in the Bolivian lowlands: the case of raised fields in
Exaltación. Quat. Int. 437 , 143–155 (2017).
- Boixadera, J., Poch, R. M., García-González, M. T. & Vizcayno, C. Hydromorphic and clay-
related processes in soils from the Llanos de Moxos (northern Bolivia). Catena 54 ,
403–424 (2003).
- Hanagarth, W. Acerca de la Geoecología de las Sabanas del Beni en el Noreste de
Bolivia (Instituto de Ecología, 1993).
- Lombardo, U., Ruiz-Pérez, J. & Madella, M. Sonication improves the efficiency, efficacy
and safety of phytolith extraction. Rev. Palaeobot. Palynol. 235 , 1–5 (2016).
- Piperno, D. R. Identifying crop plants with phytoliths (and starch grains) in Central and
South America: a review and an update of the evidence. Quat. Int. 193 , 146–159 (2009).
- Iriarte, J. Assessing the feasibility of identifying maize through the analysis of cross-
shaped size and three-dimensional morphology of phytoliths in the grasslands of
southeastern South America. J. Archaeol. Sci. 30 , 1085–1094 (2003).
- Watling, J. et al. Differentiation of Neotropical ecosystems by modern soil phytolith
assemblages and its implications for palaeoenvironmental and archaeological
reconstructions II: southwestern Amazonian forests. Rev. Palaeobot. Palynol. 226 , 30–43
(2016).
- Dickau, R. et al. Differentiation of Neotropical ecosystems by modern soil phytolith
assemblages and its implications for palaeoenvironmental and archaeological
reconstructions. Rev. Palaeobot. Palynol. 193 , 15–37 (2013).
- Hogg, A. G. et al. SHCal13 Southern Hemisphere calibration, 0–50,000 years cal BP.
Radiocarbon 55 , 1889–1903 (2013).
- Bronk Ramsey, C. Bayesian analysis of radiocarbon dates. Radiocarbon 51 , 337–360 (2009).
- Piperno, D. R. et al. Phytoliths in Cucurbita and other Neotropical Cucurbitaceae and their
occurrence in early Archaeological sites from the lowland American tropics. J. Arch. Sci.
27 , 193–208 (2000).
Acknowledgements We acknowledge the support of the Bolivian Ministerio de Culturas y
Turismo, the Gobierno Autónomo Departamental del Beni and the owners of the properties on
which the study sites are located: J. P. Llapiz, F. Boheme, J. Rivero, O. Sikuajara, F. Velasco and
T. Boorsma from the Barba Azul Natural Reserve. We thank L. Rodrigues, N. Zihlmann,
G. P. Fernández and L. M. Ortega for participation during fieldwork, as well as E. Canal-Beeby,
M. Madella, D. Mckey, J. Carson, M. González and S. Tin for their support at different stages of
this work. This work was supported by Swiss National Science Foundation grant numbers
200020-141277/1 and P300P2_158459/1; Marie Skłodowska-Curie Actions EU Project 703045;
PAST project funded by the European Research Council (ERC), grant agreement number
ERC_Cog 616179; National Geographic Society grant HJ-074ER-17; TerraSAR-X/TanDEM-X
mission, grant number DEM_OTHER1040; and AHRC-FAPESP MoU research grant HERCA,
reference AH/S001662/1.
Author contributions U.L. designed the research. U.L., J.M.C., J.R.-P. and H.V. conducted the
fieldwork. J.M.C. and J.R.-P. conducted the archaeological excavations, U.L. conducted the GIS
mapping and analyses. U.L., L.H., J.R.-P. and J.I. carried out the phytolith analyses. U.L. and J.I.
wrote the paper with the help of all authors.
Competing interests The authors declare no competing interests.
Additional information
Supplementary information is available for this paper at https://doi.org/10.1038/s41586-020-
2162-7.
Correspondence and requests for materials should be addressed to U.L.
Peer review information Nature thanks Maarten Blaauw, Francis Mayle and Deborah M.
Pearsall for their contribution to the peer review of this work.
Reprints and permissions information is available at http://www.nature.com/reprints.
