Authors: Erik N Johanson*, Florida Atlantic University, Sally P Horn, University of Tennessee, Chad S Lane, University of North Carolina Wilmington, Jacob A Cecil, University of Tennessee
Topics: Paleoenvironmental Change, Biogeography, Latin America
Keywords: paleoenvironment, costa rica, paleoclimate, isotopes, fire
Session Type: Poster
Start / End Time: 8:00 AM / 9:40 AM
Room: Napoleon Foyer/Common St. Corridor, Sheraton, 3rd Floor
Presentation File: No File Uploaded
We present two high-resolution records of Late Holocene fire history from lakes in the lowlands of southern Pacific Costa Rica, and compare them with evidence of prehistoric agriculture in the same cores and with records of regional paleoclimate. Macroscopic charcoal influx in Laguna Danta and Laguna Carse shows several major and minor peaks across the last ca. 800 years, but does not show the decline at the time of the Little Ice Age and Spanish contact evident in other charcoal records from the region. Stable carbon isotope values in sediments indicate that agricultural activity declined at this time at Laguna Danta, but the association between fire and indigenous agriculture at the study sites is not strong. Instead, drought appears to be a primary driver of fire in the lowlands of southern Pacific Costa Rica. Peaks in macroscopic charcoal at Laguna Danta coincide with shifts in the mean latitudinal position of the Intertropical Convergence Zone in the Caribbean as reconstructed from the Cariaco Ti record. We interpret our charcoal records to indicate both human use of fire in agricultural settings and wildfires in intact forests driven by regional changes in climate.