REBIRTH

The rainforests of southern Mexico and Central America are a biodiversity hotspot severely threatened by modern agriculture, urban expansion and climate change. In the past, these forests were already impacted by human activities, with the expansion of Classic Maya cities between AD 250 and 1000 causing unprecedented deforestation in the lowlands of the Yucatan Peninsula. Available paleoecological data (fossil pollen) indicate that forest regeneration was relatively rapid, in the region of 80 to 260 years, after the Maya deserted the region following the collapse of their government during the Terminal Classic period (AD 800-1000). However, while pollen archives provide information on the relative extent of forests, we still have a poor understanding of how their floristic composition and physiognomy changed as a result of anthropogenic modifications. Besides, these forests were probably also affected by a generally drier climate and severe drought episodes during the Late Holocene that are confirmed by paleoclimatic studies.

In this context, the Rebirth project aims to understand the impact of human activities on the dynamics and reforestation processes of tropical rainforests in the past. Several Maya sites in the Department of Alta Verapaz, Guatemala, have been excavated since 2016 as part of the Raxruhá-Cancuén Regional Archaeological Project. This region straddles the southern Maya lowlands and the highlands, where data are rare on the paleoenvironment during the pre-Columbian period, unlike the central and northern lowlands, which are much better documented. The Alta Verapaz sites offer archaeological contexts, both in urban centers and in caves, that cover a long period of occupation, from the foundation of the cities to their political demise and abandonment by the Maya. The anthracological study of these contexts – the study of archaeological wood charcoal – will allow us to reconstruct the evolution of the forest cover during the Classic period and beyond. Anthracology has proved its worth in other parts of the world for reconstructing paleoenvironments. However, this approach has never been used systematically in the southern Maya lowlands. The research questions this project will address are the following: What was the impact of regional droughts and human activities on local forests during the Classic period? To what extent were forests cleared and disturbed at the end of the first millennium AD? How did the forests recover after the Maya abandoned the region? In the global context of climate change and adaptation of human societies, this project will provide new data for anticipating the long-term effects of climate and human modifications on the biodiversity of neotropical rainforests.