Lidar assessment of ancient wetland farming on the coasts of Tabasco and Campeche, Mexico and their links to Holocene Global Change

Abstract:

Humans started manipulating wetlands for farming in the Early Holocene. Early examples were rice paddies facilitated by surplus monsoon rain induced flooding in Asia and canalized systems in the Americas. Studies have linked these wetlands with increased greenhouse gases—and the possible Early Anthropocene—from deforestation to create plots and changing environments from oxidizing to reducing soils. Several recent lidar studies have shown that Wetland farming in the Americas was also widespread and may also have contributed to global change, carbon sequestration, and certainly created landesque capital and ecosystem change. This paper presents a new assessment of publicly available and restricted access lidar imagery from the coastal plains of Tabasco and Campeche, Mexico to estimate the aerial extent of ancient wetland agriculture. In this region, the Usumacinta, Mexico’s largest river and other large rivers converge, creating a vast area of wetlands at the heartland of Maya and Olmec civilizations. Recent work shows a high density of ancient habitation sites and wetland field complexes, and scholars have long reported ancient canals in this region. First, we review where and how wetland complexes have been verified by coupled lidar and multiproxy evidence through excavation and coring in Histosol and other soil types. Second, we present the new areas of wetland field complexes in Campeche and Tabasco. Third, we discuss new case studies of canal systems. Finally, we present a model for how to verify such systems through remote sensing and field verification and begin to answer questions of human impacts through wetland farming on the Early Anthropocene.