Post-Conquest vegetation and fire dynamics at Laguna Carse, Costa Rica: A pollen and microscopic charcoal record

The study of lake sediment-derived proxy records from southern Costa Rica has shown that changes in vegetation and fire activity over the late Holocene are linked to population declines associated with Spanish Conquest, changes in precipitation, and human impacts on the landscape. We present a high-temporal resolution palaeoenvironmental record of vegetation and fire from Laguna Carse, a lake in southern Pacific Costa Rica that formed shortly following Spanish Conquest in the region. We analyse pollen and microscopic charcoal to assess changes in vegetation and fire activity and to interpret the temporal variability of landscape modification and anthropogenic land use over the past 400 years. Our pollen and microscopic charcoal records show evidence of anthropogenic land clearance and the onset of agricultural activity at ca. 250 to 225 cal bp, coincident with the colonial resettlement of members of the Térraba indigenous community into the Diquís Valley in southern Pacific Costa Rica. Our proxy records also indicate drought conditions during the onset of the Little Ice Age and Spanish Conquest in southern Costa Rica.