Mysterious Earthen Rings Predate Amazon Rainforest

[Judi Lynn]

Mysterious Earthen Rings Predate Amazon Rainforest

Jul 7, 2014 05:00 PM ET // by Stephanie Pappas, LiveScience


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Shown here, a ring ditch next to Laguna Granja in the Amazon of northeastern Bolivia.
Heiko Prumers [/font]

A series of square, straight and ringlike ditches scattered throughout the Bolivian and Brazilian Amazon were there before the rainforest existed, a new study finds.

These human-made structures remain a mystery: They may have been used for defense, drainage, or perhaps ceremonial or religious reasons. But the new research addresses another burning question: whether and how much prehistoric people altered the landscape in the Amazon before the arrival of Europeans.

"People have been affecting the global climate system through land use for not just the past 200 to 300 years, but for thousands of years," said study author John Francis Carson, a postdoctoral researcher at the University of Reading in the United Kingdom. (See Images of the Ancient Amazonian Earthworks)

For many years, archaeologists thought that the indigenous people who lived in the Amazon before Christopher Columbus arrived in the Americas in 1492 moved across the area while making barely a dent in the landscape. Since the 1980s, however, deforestation has revealed massive earthworks in the form of ditches up to 16 feet (5 meters) deep, and often just as wide.

These discoveries have caused a controversy between those who believe Amazonians were still mostly gentle on the landscape, altering very little of the rainforest, and those who believe these pre-Columbian people conducted major slash-and-burn operations, which were later swallowed by the forest after the European invasion caused the population to collapse.

More:
http://news.discovery.com/history/archaeology/mysterious-earthen-rings-predate-amazon-rainforest-140707.htm#mkcpgn=rssnws1

[Benton D Struckcheon]

1. Ancient history is largely misunderstood.

Agriculture was originally an urban pursuit. Nomads were folks who were dispossessed and so started wandering. Most hunter/gatherers who are still "uncontacted" today are very likely to be descendants of people who were much more advanced and who either voluntarily or involuntarily got isolated.
Original Americans mostly wound up dying from disease when the Europeans arrived. A plurality died from war with the Europeans. Populations were undoubtedly far far higher than most people believe now.

[Scootaloo]

2. The first Spanish explorers into the Amazon reported extensive agriculture and civilization

It was apparently a populous place, according to them.

Not too many decades later, the next bunch of explorers found next to nothing, and those initial claims were dismissed as fantasy.

Now though, structures like this are being found, and at least point towards vindication of those initial reports.

What happened? Disease. Introduced diseases wiped out 90% of the population in the Americas - in both continents. When 90% of a population just dies, that society crumbles to nothing. What we think of as "Indians," the buckskin-gclad subsistence hunter who's at one with nature... Is largely a product of this apocalypse. Those were the survivors of a Columbian doomsday event, scraping at the edges of what they once had.

In the Amazon basin, there is next to no stone. The structures the inhabitants build would have been made of earth and wood. Which rotted and washed out quickly enough, were replaced by tropical scrub quickly enough that they could have seemed to have never existed in three decades.

But what is the difference between those inhabitants of the basin, and modern intrusions into the forest? well, that's simple - the lack of advanced tools meant that the amazon Indians couldn't remove large trees, except by burning them away - and even then there's a definite size limit. They stripped brush, burned out smaller trees, and left the bigger ones standing. Their agriculture revolved around species domesticated from either the Andes (such as the potato)or the basin itself (manioc, peanuts), rather than imported plainsland plants like oh i dunno, wheat. it was small-scale, rather than industrial. The only domestic animals were dogs, cavies, and perhaps turkeys.

By contrast current agriculture in the Amazon removes everything to create big open flatland for non-native crops and cattle grazing.

[dipsydoodle]

3. Amazon rainforest grew after climate change 2,000 years ago -study

Swathes of the Amazon may have been grassland until a natural shift to a wetter climate about 2,000 years ago let the rainforests form, according to a study that challenges common belief that the world's biggest tropical forest is far older.

The arrival of European diseases after Columbus crossed the Atlantic in 1492 may also have hastened the growth of forests by killing indigenous people farming the region, the scientists wrote in the U.S. journal Proceedings of the National Academy of Sciences (PNAS).

"The dominant ecosystem was more like a savannah than the rainforest we see today," John Carson, lead author at the University of Reading in England, said of the findings about the southern Amazon.

The scientists said that a shift toward wetter conditions, perhaps caused by natural shifts in the Earth's orbit around the sun, led to growth of more trees starting about 2,000 years ago.

http://uk.reuters.com/article/2014/07/07/environment-amazon-idUKL6N0PI5L320140707