| This dissertation addresses two uncertain issues in Mesoamerican paleoecology: the nature of mid Holocene climate change in central Mexico and whether or not climate change was a factor in the population displacement that characterized Mesoamerica during the late Classic. We explore the first question with a 6,400-year pollen record from Hoya La Alberca, the Bajío, central Mexico. We conclude that the mid Holocene (ca. 5,500–4,000) was warm and dry based on the increased importance of oaks relative to pines. We address the second question with a network of surface samples and pollen records from Hoya La Alberca, Guanajuato, and Laguna Atezca, Hidalgo. Based on these studies, we find evidence of climate change in central Mexico during the late Classic. An increase of pine relative to oak indicates cooler or wetter conditions. We also reinterpret the paleoecological record of R. B. Brown who carried out a study in the Bajío in 1984 and found no evidence of climate change during the Classic period. |
