Central America is still reeling over the deforestation that is believed to have contributed to the collapse of Mayan civilization a thousand years ago.
According to a new study, even after the forest has grown back, the soil of the Yucatan peninsula region still cannot hold as much carbon as it used to.
Mayan Deforestation
The ancient civilization of the Maya has always been depicted to be in harmony with the environment. However, experts have debunked the idea and said that like any other culture, the Maya ended up clearing the land for firewood, fields, and their temples.
When drought struck, the Mayans had no forest to turn back to when their resources had run out. Experts believe that this caused the fall of the empire.
It turned out that the massive swaths of deforestation by the Maya continues to be a problem where the empire once proudly stood. While most of the land cleared by the ancient civilization has been reclaimed by rainforests, the soil has not completely recovered.
"When you go to this area today, much of it looks like dense, old-growth rainforest," said Peter Douglas, a geochemist from McGill University and the co-author of the study. "But when you look at soil carbon storage, it seems the ecosystem was fundamentally changed and never returned to its original state."
The researchers extracted sediment core samples from three lakes in the Maya Lowlands of Mexico and Guatemala. They then used carbon dating to measure the age of plant waxes in the soil and compare it to the plant fossils found in the same layer of sediment.
The study has found that, after the ancient civilization deforested their land a thousand years ago, the age between the plant fossils and the waxes significantly decreased. This means that the carbon stored in the soil is moving in and out at an accelerated rate.
Even after the trees have grown back, carbon storage in the soil became less stable. The soil remains to be the largest storehouses of carbon on the planet.
Mayan Deforestation And Climate Change
Douglas said that the findings from the study published in Nature should encourage people to protect the remaining old-growth rainforests around the world. It could also help researchers understand the implications of carbon offsets which often involve reforestation. Susan Crow, a soil ecologist at the University of Hawaii, agreed with Douglas.
"We are counting on reforestation as a critical climate change mitigation action in [the] near future," Crow stated. "[T]his paper seems to question the effectiveness of this strategy."
Douglas, however, warned that the results of the study are not necessarily true to all the other rainforests cleared for various reasons across the world. The next step, he said, should be to analyze tropical forests in other regions of the world and see if there is a pattern.
He also wants to apply the same technique he and his team used in the lands of Central America to studying permafrost and how the changes in climate in the long history of the world impacted carbon storage.
