Ancient Mayan Clearcutting Still Impacts Carbon in Soil

Posted By: Marty

Ancient Mayan Clearcutting Still Impacts Carbon in Soil - 08/22/18 05:26 PM

Even 1,000 years after a forest regrows, the soil beneath still wonít hold as much carbon as it once could, a new study suggests

Thereís a popular notion that the ancient Maya lived in total harmony with the land, leading a sustainable lifestyle that took only what they needed from the vast tropical forests surrounding them. But thatís not really the case. The Maya deforested large swathes of land, cutting down trees in order to plant fields of corn, for firewood and for building their monumental temples. When a massive drought struck around 900 A.D., itís believed the society did not have the forests and other resources to fall back on, leading to the end of an empire. But it turns out in the intervening 1,100 years, the impact of that resource depletion can still be felt. Maddie Stone at Earther reports that a new study shows that clearcutting has impacted the soilís ability to store carbon, a finding that has big implications for modern societies.

Today, much of the land cleared by the Maya has been reclaimed by the rainforest, and one would think the area has completely recovered from the exploitation. But in a new study in the journal Nature Geosciences, geochemist Peter Douglas of McGill University and his colleagues examined soils from the area. According to a press release, they extracted sediment cores from three lakes in the Maya lowlands of Mexico and Guatemala. They then used radio-carbon dating to get the ages of plant waxes, molecules produced by vegetation that bind with minerals and last a very long time. The waxes wash out of the soil into the lakes. When the age of the plant waxes is compared to the age of fossils in the sediment cores, it can tell researchers how long those plant waxes, and presumably soil carbon, has been in the ground. The larger the age gap between the waxes and the fossils, the longer the carbon has been sequestered in the ground.

What the study shows is that once the Maya began deforestation, the soil began to lose its ability to store carbon long term. Over the past 3,500 years, which includes the time the Maya were active in the region, the age of the plant waxes decreased from 70 to 90 percent, a sign that the soil is simply not holding as much carbon as in pre-Maya times, instead releasing it into the atmosphere.

Click here to read the rest of the article in Smithsonian Magazine

Posted By: Mike Campbell

Re: Ancient Mayan Clearcutting Still Impacts Carbon in Soil - 08/23/18 02:55 AM

I have a lot of problems with believing the hype about the Maya cut all their forests and so caused the ruin of their civilization. 1. If right now you cut out a parcel to plant a milpa within 30 years it will again have mature trees of all species. 2. Maya were stone age people, no iron tools. By what method did they cut down and haul away all the trees? Not with stone axes that is for sure. I challenge the guy that wrote this to take down even one hardwood tree with a good steel machete much less a stone axe. A big hardwood tree weighs thousands of pounds and no record of the Maya using wheels either and certainly they had no horses or other domesticated work animals. Deforestation is a product of our mechanized society. 3. To the best of my knowledge there is no archeological record of any kind that would suggest this theory, no paintings or glyphs. 4. The Maya civilization existed for 3,000- 4,000 years and still exists. How did it take 4,000 years for the environmental impacts to kick in? I simply do not think there is enough evidence to suggest this as a real possibility and I do not believe it.
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