Friday 29 August 2008

Amazon rainforest was giant garden city

By Roger Highfield, Science Editor
Last Updated: 7:01pm BST 28/08/2008

The "pristine" Amazon rainforest was covered by a vast sprawl of interconnected villages between 1,500 and 500 years ago, according to a study that shows how nature has felt the impact of man for much longer than realised.

Explorers have long sought lost cities of the Amazon, now almost entirely obscured by forest. Today it turns out that the "garden cities", which date back 1500 years, were too spread out to make sense of on foot.

Aerial shot of an Amazon village showing central plaza and the roads radiating from the centre
Assisted by satellite imagery, researchers have spent more than a decade uncovering and mapping the lost and obscured communities to show they held more than 1000 people each and were once large and complex enough to be considered "urban" as the term is commonly applied to medieval European and ancient Greek communities.
In the Xingu region of the Brazilian Amazon, these garden cities radiated out over a diameter of 150 miles, covering an area of 18,000 square miles that exceeds the sprawl of Los Angeles by 35 fold.
However, they only held around 50,000 people, compared with the 13 million in LA.
The extraordinary conclusion is reached by anthropologists from the University of Florida and Brazil, and a member of the Kuikuro, an indigenous people who are the descendants of the settlements' original inhabitants.

"If we look at your average medieval town or your average Greek polis, most are about the scale of those we find in this part of the Amazon," said Prof Mike Heckenberger of the University of Florida, lead author of the paper published today in the journal Science.
"Only the ones we find are much more complicated in terms of their planning."
The paper also argues that the size and scale of the settlements in the southern Amazon in North Central Brazil means that what many scientists consider virgin tropical forests were shaped by human activity hundreds of years ago.
Not only that, but the settlements - consisting of networks of walled towns and smaller villages, each organised around a central plaza - suggest future solutions for supporting the indigenous population in Brazil's state of Mato Grosso and other regions of the Amazon, the paper says.
Around the communities the scientists found dams and artificial ponds that indicate the then inhabitants farmed fish, which today could be a valuable new food resource.
Prof Heckenberger and his colleagues first announced the discovery of the first settlements in 2003, revealing the largest date from around 1250 to 1650, when European colonists and the diseases they brought likely killed most of their inhabitants.
The communities are now almost entirely overgrown. But Prof Heckenberger said that members of the Kuikuro, a Xinguano tribe that calls the region home, are adept at identifying tell-tale signs of old settlements, from "dark earth" that indicate past human waste dumps or farming, concentrations of pottery shards and earthworks.
The new paper reports that the settlements consisted of clusters of 150-acre towns and smaller villages organised in spread out "galactic" patterns.
None of the large towns was as large as the largest medieval or Greek towns. But as with those towns, the Amazonian ones were surrounded by large walls - in their case, composed of earthworks still extant today.
Each settlement had an identical formal road, always oriented northeast to southwest in keeping with the mid-year summer solstice, connected to a central plaza.
The findings are important because they contradict long-held stereotypes about early Western versus early New World settlements that rest on the idea that "if you find it in Europe, it's a city.
If you find it somewhere else, it has to be something else," Prof Heckenberger said. "They have quite remarkable planning."
Because it means at least one area of "pristine" Amazon has a long history of human activity, the find could change not only how scientists assess the flora and fauna, but also how conservationists preserve the remains of forest so heavily cleared it is the world's largest soybean producing area.