Forest change in the northern Yucatan lowlands (Mexico) during Maya cultural periods: insights from a paired lake reconstruction

Palaeoecological records from the Maya lowlands indicate that there is an emerging pattern of complex vegetation change across the Terminal Classic Period, a time that was characterised by frequent droughts and collapse of major Maya centres. To fully understand the extent of anthropogenic influences on Yucatan forest composition in space and time, more palaeoecological records are needed, as well as a better understanding of the relationship between forest cover and modern pollen deposition in lakes. Here, we investigate pollen-landscape relationships from lakes in the northern central Yucatan (19° 50’N, 88° 44’W) through comparison of forest cover data with arboreal pollen in recently deposited sediments. Twelve pollen assemblages from across two lakes, Lagunas Esmeralda (ca. 0.6 km by 0.1 km) and Chichancanab (ca. 14.5 km by 0.7 km), indicate that the lakes capture local and regional pollen signals, respectively. This spatial understanding was applied to the interpretation of a new 386-cm palaeoecological record dating to 4200 BCE from Esmeralda and an existing record from Chichancanab dating from ca. 200 CE until present. The data show that fire use and maize cultivation occurred at Esmeralda as early as 3500 BCE, but impact on forest cover and composition was minimal throughout. The Chichancanab record shows maize cultivation through the Classic period and relatively stable forest cover. In contrast, high variability of forest pollen values from Laguna Esmeralda during the Late and Terminal Classic periods shows localised changes in forest composition, likely driven by human activity in response to cultural change and climate stress.