Holocene Environmental Change in the Maya Lowlands of Petén, Guatemala:

My doctoral investigations explored Holocene environmental change in the Maya lowlands of Petén, Guatemala.  I used stratigraphic variations in the oxygen isotopic composition and trace element composition of biogenic carbonate from Petén lake sediment cores to infer past environmental changes in the region.  These sediment variables indicated that pronounced changes in watershed hydrologic balance were caused by human-induced deforestation and natural climate change.  Strictly climatic interpretation of the isotopic and trace metal record suggests higher precipitation during the period of Maya settlement expansion between 400 B.C. and 150 A.D.  Alternatively, this period of minimum oxygen isotope values may have been a consequence of increased surface runoff and groundwater inflow to the lakes related to watershed deforestation by the Maya.  When the Maya population declined ~850 A.D., oxygen isotope values increased as a consequence of reduced hydrologic input to the lakes caused by decreased precipitation or forest recovery.  Paleolimnological results from Petén suggest that human-induced changes in watershed vegetation cover can alter lake hydrologic budgets, thereby confounding paleoclimatic inferences based on the oxygen isotopic composition of biogenic carbonate.  More recent work extending from my Ph.D. research has focused on modeling the influence of vegetation changes and natural climate variability on the hydrologic and isotopic evolution of Petén lakes as well as late Holocene environmental change and volcanic hazards in Nicaragua.

Related Programs:

Swiss Federal Institute of Aquatic Science and Technology (EAWAG) - Department of Surface Waters (Dr. Flavio Anselmetti)
University of Cambridge - Department of Earth Sciences  (Dr. David Hodell)
University of Florida - Department of Geological Sciences (Drs. Mark Brenner and Jason Curtis)