講演情報
[U11-P25]Reconstructing human-environment interactions in the Maya lowlands using lipid biomarkers
*Benjamin Gwinneth1、Kevin Johnston2、Andy Breckenridge3、Peter Douglas4、Isabel Strachan4,1、Alexis Marcoux1、Haydar Martínez Dyrzo5、Priyadarsi Roy5 (1.Département de géographie, Université de Montréal、2.Independent Scholar, Columbus, United States of America、3.Natural Sciences Department, University of Wisconsin-Superior, Superior, United States of America、4.Department of Earth and Planetary Sciences, McGill University, Montréal, Canada、5.Departamento de Dinámica Terrestre Superficial, Universidad Nacional Autónoma de México, Ciudad de México, México)
キーワード：
palaeoclimate、biogeochemistry、lipid biomarkers、human-environment、Maya Lowlands、palaeolimnology
The lowland Maya of Mesoamerica were affected by multiple environmental stresses throughout their history, and in some areas experienced a major demographic and political decline, or collapse, during a period of inferred intense multidecadal drought, approximately 1200- and 1000-years BP. Given regional variation in the timing and character of the collapse, much remains to be discovered about the complex interactions between climate and society in the Maya lowlands. To this end, we combine carbon and hydrogen isotopic analyses of leaf wax n-alkanes with quantification of faecal stanols and polycyclic aromatic hydrocarbons from a lake sediment core from the southwest lowlands to assess whether (1) palaeoecological evidence of land use is related to population change; and (2) whether population and land use are linked to changing precipitation. Our data reveal a transition from generally more intense fire use and C4 plant agriculture during the Preclassic (3500–2000 BP) to dense populations and reduced fire use during the Classic (1600–1000 BP). This is consistent with other evidence for a more urbanised and specialised society in the Classic. We do not find evidence of drought in the hydrogen isotope leafwax record (δDlw), implying that local drought was not a primary driver of observed variability in land use or population change in the Classic-period southwestern lowlands. We present preliminary data from lake sediment cores from the northern lowlands.