Ancient Maya Left Lasting Impact.

• Position: THE ENVIRONMENT

Evidence from the tropical lowlands of Central America reveals how Maya activity more than 2,000 years ago not only contributed to the decline of their surroundings, but continues to influence today's environmental conditions, according to researchers at the University of Texas, Austin.

Synthesizing old and new data, researchers were the first to show the full extent of the "Mayacene" as a microcosm of the early anthropocene --a period when human activity began greatly affecting environmental conditions.

"Most popular sources talk about the anthropocene and human impacts on climate since the Industrial Revolution, but we are looking at a deeper history," says Tim Beach, professor of geography and the environment. "Though it has no doubt accelerated in the last century, humans' impact on the environment has been going on a lot longer."

By looking at Maya impacts on climate, vegetation, hydrology, and lithosphere from 3,000 to 1,000 years ago, researchers propose that the Maya's advanced urban and rural infrastructure altered ecosystems within globally important tropical forests.

The researchers identified six stratigraphic markers (or "golden spikes") that indicate a time of large-scale change: "Maya clay" rocks; unique soil sequences; carbon isotope ratios; widespread chemical enrichment; building remains and landscape modifications; and signs of Maya-induced climate change.

"These spikes give us insight into how and why Mayas interacted with their environment, as well as the scope of their activity," relates Sheryl Luzzadder-Beach, chair of the Department of Geography and the Environment.

Maya clay and soil sequences indicated erosion, human land-use changes, and periods of instability. Soil profiles...