Palaeoenvironmental Evidence of Wetland Domestication in the Llanos De Mojos, Bolivian Amazon

Abstract

Past societies in Amazonia have actively shaped their landscapes over millennia through practices such as earthwork construction, agroforestry, crop production, and fire-use. While previous research has largely focused on terrestrial environments, recent studies reveal that humans also played a significant role in transforming aquatic systems - traditionally viewed as inaccessible or non-useful spaces. The Llanos de Mojos is a seasonally flooded savannah characterised by its strong flood pulse and flat topography in the Bolivian Amazon that offers the opportunity to investigate human-environment interactions due to extensive Pre-Columbian earthworks within the mosaic of ecosystems (savannahs, gallery forests, permanent and seasonal wetlands). These earthworks have been interpreted as forms of landscape domestication but are also hypothesised methods of hydrological management.
This study utilised a multiproxy approach of macrocharcoal, diatoms, pollen, non-pollen palynomorphs (NPPs), lipid biomarkers, and stable isotopes on four sediment cores from a permanent wetland in the Mojos, with basal dates between approximately 12,410 and 5150 cal yr BP. The research aimed to reconstruct human-environment interactions across spatial and temporal scales and assess how management strategies influenced both ecology and hydrology. Findings revealed similar occurrences across the region but at different times, with differences of approx. 1200 years in the establishment of wetland conditions and vegetation and approx. 1500 years in fire-activity, which occur earlier than previously reported in the region. If driven solely by climate, such as rising precipitation, these instances would have occurred simultaneously across sites. Instead, the spatial and temporal differences indicate local communities were continuously and independently modifying their terrestrial and aquatic environments concurrently over long periods. Overall, this study highlights the critical role of humans in shaping tropical aquatic ecosystems in addition to their terrestrial ecosystems. It also emphasises the value of multi-proxy and multi-core approaches for revealing finer-scale variations in past environmental management.

Date of Award	19 Feb 2026
Original language	English
Awarding Institution	Northumbria University
Supervisor	Bronwen Whitney (Supervisor), Mike Jeffries (Supervisor), Maarten van Hardenbroek van Ammerstol (Supervisor) & Emma J. Pearson (Supervisor)