A MULTI-PROXY STUDY OF HOLOCENE ENVIRONMENTAL-CHANGE IN THE MAYA LOWLANDS OF PETEN, GUATEMALA

We used multiple variables in a sediment core from Lake Peten-Itza, Pe ten, Guatemala, to infer Holocene climate change and human influence o n the regional environment. Multiple proxies including pollen, stable isotope geochemistry, elemental composition, and magnetic susceptibili ty in samples from the same core allow differentiation of natural vers us anthropogenic environmental changes. Core chronology is based on AM S C-14 measurement of terrestrial wood and charcoal and thus avoids th e vagaries of hard-water-lake error. During the earliest Holocene, pri or to similar to 9000 C-14 yr BP, the coring site was not covered by w ater and all proxies suggest that climatic conditions were relatively dry. Water covered the coring site by similar to 9000 C-14 yr BP, coin ciding with filling of other lakes in Peten and farther north on the Y ucatan Peninsula. During the early Holocene (similar to 9000 to simila r to 6800 C-14 yr BP), pollen data suggest moist conditions, but high delta(18)O values are indicative of relatively high E/P. This apparent discrepancy may be due to a greater fractional loss of the lake's wat er budget to evaporation during the early stages of lake filling. None theless, conditions were moist enough to support semi-deciduous lowlan d forest. Decrease in delta(18)O values and associated change in ostra cod species at similar to 6800 C-14 yr BP suggest a transition to even moister conditions. Decline in lowland forest taxa beginning similar to 5780 C-14 yr BP may indicate early human disturbance. By similar to 2800 C-14 yr BP, Maya impact on the environment is documented by acce lerated forest clearance and associated soil erosion. Multiple proxies indicate forest recovery and soil stabilization beginning similar to 1100 to 1000 C-14 yr BP, following the collapse of Classic Maya civili zation.