Wednesday, June 22, 2011

Civilization collapsed after cutting key trees



When the Nazca cleared forests to grow crops, fields washed away leaving desert.

The ancient Nazca people, who once flourished in the valleys of south coastal Peru, literally fell with the trees they chopped down, new research has concluded.

The Nazca caused their own collapse when they cleared their forests in order to make way for agriculture, thus exposing the landscape to wind and flood erosion, according to a study published in the journal Latin American Antiquity.

Best known for carving hundreds of geometric lines and images of animals and birds in the Peruvian desert that are fully visible from the air, the Nazca flourished between the first century B.C. and the fifth century A.D.

During these centuries they made sophisticated ceramics and textiles and amassed one of South America's largest collection of human trophy heads. Then, between 500 and 600 A.D., this enigmatic civilization slid into oblivion.

"It was not just that they were hit by a huge mega El Nino in about 500 A.D., but that they had already cleared their forests of huarango, a tree that lives in highly arid zones and stabilizes the soil with some of the deepest roots of any tree known-and can live up to 1000 years," Alex J. Chepstow-Lusty a palaeoecologist from the French Institute for Andean Studies in Lima, Peru, told Discovery News. More