Lasers reveal ancient Maya as well-connected, environmentally conscious.

Science News uses LIDAR mapping to reveal an ancient Maya empire that wasn’t so much slash-and-burn and smash-and-grab as they were smart farmers and wide-ranging communicators:

A small plane carrying light detection and ranging equipment, or lidar, emitted laser pulses that gathered data on the ground’s shape across 2,144 square kilometers of northern Guatemala. Based on the more than 60,000 lidar-identified structures, the researchers estimate that a minimum of 7 million to 11 million people inhabited northern Guatemala near the end of the Classic Maya period.

Lidar views of the ancient Maya’s urban and rural infrastructure are particularly impressive, [Tulane archaeologist Francisco] Estrada-Belli says. Water control was crucial. Much of the unsettled wetlands throughout northern Guatemala contain remnants of crisscrossing drainage channels that form grids within what must have once been agricultural fields. Some channels extend for one kilometer or more. Remains of stone terraces and low walls enclose many cultivation areas.

Evidence of carefully irrigated agricultural fields challenges a popular view that Classic-era centers relied on food from soil-damaging, slash-and-burn farming. That practice eventually contributed to Maya civilization’s downfall, some researchers have argued.

Although sustainable cultivation techniques appear to have been standard for the ancient Maya, farmland near the largest Maya cities would not have provided enough food for local populations, the researchers say. Additional food was imported from distant sites belonging to common political networks, the team suspects.

Strategically placed bridges, ditches, ramparts, stone walls and terraces suggest military conflicts occurred frequently.

That didn’t stop cities from maintaining long-distance contacts and forming networks of politically aligned sites. Raised roads, or causeways, connected the earliest Maya sites, including three dating to a few hundred years before the Classic period, to nearby centers. These 10- to 20-meter-wide causeways run for as many as 22 kilometers.