Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists reconstruct pre-Columbian human effects on the Amazon Basin

19.06.2012
Findings overturn idea that the Amazon had large populations of humans that transformed the landscape

Small, shifting human populations existed in the Amazon before the arrival of Europeans, with little long-term effect on the forest.

That's the result of research led by Crystal McMichael and Mark Bush of the Florida Institute of Technology (FIT). The finding overturns the idea the Amazon was a cultural parkland in pre-Columbian times with large human populations that transformed vast tracts of the landscape.

The Amazon Basin is one of the highest biodiversity areas on Earth. Understanding how it was modified by humans in the past is important for conservation and for understanding the ecological processes in tropical rainforests.

McMichael, Bush and a team of researchers looked at how widespread human effects were in Amazonia before Europeans arrived. They published their results in this week's issue of the journal Science.

"The findings have major implications for how we understand the effect of the land-use change now occurring in Amazonia," said Alan Tessier, program director in the National Science Foundation's Division of Environmental Biology, which funded the research.

"Making the assumption that this system is resilient to deforestation, it turns out, isn't a position supported by historical evidence," Tessier said.

If the pre-Columbian Amazon was a highly altered landscape, then most of the Amazon's current biodiversity could have come from human effects.

The team retrieved 247 soil cores from 55 locations throughout the central and western Amazon, sampling sites that were likely disturbed by humans, such as river banks and other areas known from archaeological evidence to have been occupied by people.

They used markers in the cores to track the histories of fire, vegetation and human alterations of the soil.

The scientists conclude that people lived in small groups, with larger populations in the eastern Amazon--and most people lived near rivers.

They did not live in large settlements throughout the basin as was previously thought. Even sites of supposedly large settlements did not show evidence of high population densities and large-scale agriculture.

All the signs point to smaller, mobile populations before Europeans arrived. These small populations did not alter the forests substantially.

"The amazing biodiversity of the Amazon is not a by-product of past human disturbance," said McMichael. "We can't assume that these forests will be resilient to disturbance, because most of them have, at most, been lightly disturbed in the past.

"There is no parallel in western Amazonia for the scale of modern disturbance that accompanies industrial agriculture, road construction and the synergies of those disturbances with climate change."

Other co-authors of the paper are D.R. Piperno of the Smithsonian National Museum of Natural History; M.R. Silman of Wake Forest University; A.R. Zimmerman of the University of Florida; M.F. Raczka of FIT; and L.C. Lobato of the Federal University of Rondônia in Brazil.

Cheryl Dybas | EurekAlert!
Further information:
http://www.nsf.gov

More articles from Earth Sciences:

nachricht Massive impact crater from a kilometer-wide iron meteorite discovered in Greenland
15.11.2018 | Faculty of Science - University of Copenhagen

nachricht The unintended consequences of dams and reservoirs
14.11.2018 | Uppsala University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

 
Latest News

New materials: Growing polymer pelts

19.11.2018 | Materials Sciences

Earthquake researchers finalists for supercomputing prize

19.11.2018 | Information Technology

Controlling organ growth with light

19.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>