Abstract

Atacama Desert is pictured by salt flats and plantless environments. Late Pleistocene (< 26-15 ka BP) subfossil diatom stratigraphic records and geomorphological evidence, however, show that shallow lakes existed. Here we describe 18 different diatom taxa from laminated lake sediments (13 samples from ~15cm profile) in the salt-encrusted Salar de Bellavista (section BV-01). Most of taxa are cal yr BP in order to document the prior-to, during, and after ecological responses of the 8.2 ka event. Pollen analysis suggests a decrease in Picea pollen, and increase in Pinus pollen beginning around the 8,500 cal yr BP with a minimum of Picea pollen occurring around 8,200 cal yr BP. By using a multi-proxy approach using elemental XRF data, macroscopic charcoal and macrofossil analyses, preliminary results suggest disturbances may have helped facilitate vegetation change between 8000 and 9000 cal yr BP. For example, identification of several bark beetle remains suggests the presence of host specific Picea disturbance agents, which could have also helped facilitate the decline in Picea pollen. This study aims to investigate the main driver(s) associated with the change in vegetation composition at Prasilske Lake in order to understand both the local-scale and regional-scale drivers of vegetation change associated with the 8.2 ka event.