DEMODRIVERS relies heavily on the success of its bold field-work component and intensive laboratory analyses. These are the two most critical aspects of the research program.
Fieldwork (relating to WP1, WP2, WP5 and tasks 2,4,6,7 and 8) The first two fieldwork seasons have been successfully completed.
*WP1-Survey and mapping of forest islands.
We have produced 120 Digital Elevation Models from 120 forest islands across the two seasons(Task 6). These will be essential to calculate the volume of forest islands, which, together with the elemental analysis and the radiocarbon program, will allow us to quantify the total amount of phosphorus accumulated in the totality of the archaeological sites per unit of time. Phosphorus can then be used as a proxy for the number of people, providing a quantitative reconstruction of the demographic curve, which is one of the main goals of DEMODRIVERS.
*WP2-Coring of forest islands.
We have modified the sampling strategy from what was planned in the original proposal. The original idea was to core and sample clusters of 5 forest islands and survey 10 more islands in the surrounding locality. However, when we started working in the field, obtaining the permits from the surrounding properties proved to be very time consuming, slowing down the entire campaign. On the other hand, once we had the permit to core in a property, we were able to take cores from more than 5 forest islands relatively easily and rapidly. So, the final strategy we decided to use, was to work with small clusters, but coring all the forest islands within each cluster (task 7), not only 5. Eventually, this will provide us with a larger number of samples and a more robust database. A total of 279 plastic liners with sediments have been retrieved from 117 forest islands belonging to 14 clusters and shipped to Barcelona. These correspond to 146 cored locations, as for some forest island we performed a transect rather that a single core in the centre.
*WP5-Archaeological excavations
Archaeological excavations (task 8) are needed to unveil the changes in cultural practices and technological innovations that can then be linked to changes in palaeo-demographics. We performed excavations in three sites along a east-west transect. Two forest islands were excavated in 2023 and one in 2024. Isla Encanto, in the proxtorimity of Trinidad and Isla Chuchíos in the eastern
extreme of the Llanos de Moxos, were excavated in 2023, while Isla Curupaú, on the western side of the Llanos de Moxos was excavated in 2024. All the artefacts will be analysed in situ during the 2025 field campaign, mostly by local experts.
*Unplanned activity–Building a phytolith reference collection.
A phytolith reference collection is a key element in AI training (WP6). In the original proposal we planned to use already existing reference collections stored by project collaborators J.Iriarte andF.Mayle.In collaboration with Bolivian botanist M.Moraes we have collected 170 plant specimens from forest islands and plants with local economic value in order to improve our reference collection.
* Laboratory analyses and AI
We have implemented a complete workflow to process all the samples from Bolivia.We are currently in the process of digitizing the reference collection gathered last field season to train the AI and perform the initial large-scale classifications.
