Stable carbon isotope ratios in lake and swamp sediments as a proxy for prehistoric forest clearance and crop cultivation in the Neotropics

Close correspondence between stable carbon isotope ratios (δ ^sup 13^ C), pollen, and charcoal profiles in sediment cores from Laguna Zoncho and Machita swamp, Costa Rica, shows that prehistoric forest clearance and crop cultivation can be detected in the stable carbon isotope ratios of total organic carbon (δ ^sup 1^3C^sub TOC^). Analyses of δ 13C^sub TOC^ complement evidence from pollen, charcoal, and phytoliths and provide a proxy that is sensitive to the intensity and/or proximity to core sites of prehistoric forest clearance and agriculture in watersheds. Stable carbon isotope analyses are particularly useful in situations in which other evidence of forest clearance and agriculture is limited.[PUBLICATION ABSTRACT]