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Rhett A. Butler / mongabay.com
New evidence challenges the idea that the Amazon Basin was densely inhabited before the arrival of Europeans.
The historical portrayal of the Amazon Basin's residents before 1492 has swung from the stereotype of backward savages to a vision of sophisticated stewards of the land — but a newly reported survey suggests that wide swaths of the Amazon's forests, particularly in the western and central regions, were relatively untouched by humans.
The findings could play into the debate over the Amazon's future as well as its past.
""You can't use an idea of past transformed landscapes to justify modern deforestation," Crystal McMichael, a paleoecologist who analyzed Amazonian soil as part of her research at the Florida Institute of Technology, told me. McMichael is the lead author of a study published in today's issue of the journal Science.
She and her colleagues collected 247 core samples of soil from 55 sites throughout the central and western Amazon, in Brazil and Peru, to check for signs of human disturbance. Their objective was to provide a reality check for what some researchers have called the "1491 hypothesis": the idea that areas of the Amazon Basin were intensely managed centuries ago, but reverted to a more natural state after the arrival of explorer Christopher Columbus and his European brethren, due to the decline of indigenous culture.
One of the foremost critics of that view is Dolores Piperno, a senior scientist at the Smithsonian Institution's National Museum of Natural History and the Smithsonian Tropical Research Institute. Piperno is a co-author of the Science paper.
"Drawing on questionable assumptions, some scholars argue that modern Amazonian biodiversity is more a result of widespread, intensive prehistoric human occupation of the forests than of natural evolutionary and ecological processes," she said in a Smithsonian news release. "Climatologists who accept the manufactured-landscapes idea may incorporate wholesale prehistoric Amazonian deforestation, widespread fires and carbon emissions into their models of what caused past shifts in atmospheric carbon dioxide and methane levels. But we need much more evidence from Amazonia before anything like that can be assumed."
The evidence from the soil samples, including samples taken from sites with previously known human impacts, runs counter to those assumptions. Most of the samples showed little sign of charcoal, which would have been left behind by land-clearing fires. There were few signs of silica deposits known as phytoliths, which are indicators of ancient agriculture. The researchers did pick up the signature of "terra preta" — that is, earth enriched by human waste — but mostly around riverbanks rather than far into the forest.
Crystal McMichael
Researchers Crystal McMichael and Monica Zimmerman collect soil samples in the tropical rainforests of Peru.
"Together, the data suggest that human population densities in the sampled regions were low and highly localized, and were not consistent with major population centers with associated areas of widespread, extensive agriculture," the researchers wrote.
The findings came as no surprise to Michael Heckenberger, an anthropologist at the University of Florida. Heckenberger is perhaps best-known for his study of ancient urban communities in the Upper Xingu region of the Brazilian Amazon, east of the areas surveyed by McMichael and her colleagues. His work was discussed in "The Lost City of Z," a best-selling book by David Grann.
"I was delighted to see the paper, because it does act as a cautionary note," Heckenberger told me.
Heckenberger said the research fits in with the view that the pre-Columbian Amazon Basin had wide areas of forest land that showed relatively little human alteration, as well as areas that supported substantial concentrations of human population.
"This clearly has moved the debate forward," he said. "I hope we don't digress back to [a debate over whether] the Amazon was the setting par excellence for primordial forests and primitive tribes vs. an area that was dominated by large, complex societies. It's neither one nor the other. ... There were patches of dense, complex societies, and then there were other areas that were, if not completely untouched, then something very like untouched forest."
Heckenberger said he was "still of the opinion that as time progresses, we're going to find more and more of the Amazon that did support large populations." But he praised the work published in Science and said he hoped to see more sampling of sites from broader stretches of the Amazon Basin.
"I'd love to grab that team and bring them to my research site, to use that to some degree as a control against what you might expect," he told me. "The flip side of that is to jump into the pickup truck with that team and look for archaeological signatures in the area that they've been studying."
McMichael thought that was a fine idea. "He's done some excellent work," she said of Heckenberger.
She speculated that pre-Columbian tribes preferred to live near rivers rather than in the forest interior "so they could connect with other communities" more easily. She also suspected that the eastern side of the Amazon Basin was settled more intensely than the western side because it was drier and more amenable to forest-clearing. However, even if large settlements existed in some parts of the Amazon before Columbus, that shouldn't be used as a defense for 21st-century deforestation, McMichael said.
"The amazing biodiversity of the Amazon is not a byproduct of past human disturbance," she said in a news release. "We also can't assume that these forests will be resilient to disturbance, because many have never been disturbed, or have only been lightly disturbed in the past. Certainly 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."
More about Amazonian culture:
- Pre-1492 Amazon farmers didn't use controlled burns
- How the Amazon's lost cities worked
- Another 'Stonehenge' discovered in Amazon
- Gallery: A tale of seven cities, lost and found
In addition to McMichael and Piperno, authors of "Sparse Pre-Columbian Human Habitation in Western Amazonia" include M.B. Bush, M.R. Silman, A.R. Zimmerman, M.F. Raczka and L.C. Lobato.
Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.
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The past tense of tread is trod.
1tread
verb \ˈtred\
trod\ˈträd\ also tread·ed trod·den\ˈträ-dən\ or trodtread·ing
Definition of TREAD
transitive verb
1
a : to step or walk on or over b : to walk or proceed along : follow <treading a fine line between tradition and innovation>
2
a : to beat or press with the feet : trample b : to subdue or repress as if by trampling : crush
3
: to copulate with —used of a male bird
4
a : to form by treading : beat <tread a path> b : to execute by stepping or dancing <tread a measure>
intransitive verb
1
: to move or proceed on or as if on foot <must tread lightly>
2
a : to set foot <has gone where others fear to tread> b : to put one's foot : step <carelessly treading on the flowers>
Another example of where English is going these days. Just like on the news no one 'Pled' innocent anymore, now it's 'pleaded'
I had some nice brod fishsticks last night
William, you're right about "trod" vs. "treaded." Webster's prefers "trod"; nevertheless, the phrase just doesn't click for me, so I'm trying a more general approach for the headline. The point, I think, is that this research adjusts the picture that some folks have. In the western Amazon, there's much less evidence of development than in the eastern Amazon - but as Heckenberger says, it's neither all one way or all the other. So I guess it's better to have a headline that emphasizes the adjustment. But I'm not yet completely satisfied. If anyone has a better idea for a headline, I'm all ears.
Even Pre-Columbus Amazonian's Preferred Location Location Location
The best I could come up with Alan ....
Since they preferred to live near the river or on waterfront property ....
Or where the land flooded less frequently ....
Thanks for the article Alan ....
The Amazon basin recovered "due to the decline of the indigenous population." Really? Is that anything like the wholesale slaughter of every native who was not worked to death as slaves?
Articles like this really make me wonder....
Just because the people that lived there did not alter (disturb) the landscape does not mean that they were not there and living off of the land. The number of core samples taken is a moot point when you consider how big that forest actually is. You could drill a core into the ground and miss what is just a few yards away. Go to any park, pull 250 cores out of it, and let me know how much you can really tell about the park. Will the cores show you the person that just walked thru it? Nope. Will it show you the people eating in the pavilion? Only if they leave something there that is not biodegradable or burn the pavilion down.
If you drill a hole in the middle of the street, chances are really good that there will not be any cement in the core, but the sidewalk that is right next to, is cement.
People today assume that every pocket of humanity leaves a path of destruction everywhere they go. But that does not mean that was always the case.
The speculation parts of the article are just that. Speculations with no proof or reasoning. We really do not know much at all about what the history of the Amazon Basin is. All of the history there is, is completely one sided. Anything that was written down by the natives was considered to be demonic in some way and destroyed. They did that to every book/scroll they could find. There are only about 3 books that survived from the Mayans. More than a few of the explorers wrote that the Mayans had the biggest library the had ever seen. And you can bet that the Mayans were a lot smarter than people give them credit for today. Their calendar is still more accurate than any one conceived since.
The only things we know for sure is that we basically destroyed their civilization, and now people are cutting the forests down at a rate that is plain scary. It is a shame, we could have learned a lot from the people that lived there in the past. They knew how to farm in the forest and make topsoil, something that they can not even do today without resorting to harsh chemicals, etc.
And the slave thing is not what killed most of them off, small pox did. There are more than a few writings left by explorers that said they found natives, but they died off long before they got there. Diseases can travel far faster than a horse. One of the Spanish explorers wrote "God has cleansed the land of native and opened the door for other people." Others wrote about the small pox outbreak that killed most of the natives on both the North and South Americas. Which is proof that diseases spread far faster than the explorers could explore it. You can't enslave someone that is dead, and most of the population died without ever seeing another race of people.
"terra preta", from the article. Even biodegradables leave obvious evidence. Finding measurable proof that more many people pooped along the river banks than in the interior pretty much clinches it for me. More people lived along the river than in the interior. Just like now, and for the same reasons.
Not that that is any excuse to stop people from farming hitherto unused jungle land, now. I mean, you don't want to wipe out the last half acre of a plant which, every seven years, produces berries that give lifetime immunity to cancer and arteriosclerosis. On the other hand people have to eat. Tough call.
As to the "1491 hypothesis"; The work of Dr. Dull demonstrates from lake sediment cores the abrupt land-use changes. The BC, charcoal and pollen evidence is very hard to ignore;
The Columbian encounter led to terrestrial biospheric carbon sequestration on the order of 2 to 5 GtC Climate Forcing.
smpp/content~db=all?content=10.1080/00045608.2010.50243
The Paleoclimate Record shows agricultural-geo-engineering is responsible for 2/3rds of our excess greenhouse gases. The unintended consequence, the flowering of our civilization. Our science has now fully realized the consequences of additional fossil emissions and has developed a more encompassing wisdom.
Wise land management, afforestation and the thermal conversion of biomass can build back our soil carbon. Pyrolysis, Gasification and Hydro-Thermal Carbonization are known biofuel technologies,
What is new are the concomitant benefits of biochars for Soil Carbon Sequestration; building soil biodiversity & nitrogen efficiency,
for in situ remediation of toxic agents, as a feed supplement cutting the carbon foot print of livestock.
Modern systems are closed-loop with no significant emissions. The general life cycle analysis is: every 1 ton of biomass yields 1/3 ton Biochar equal to 1 ton CO2e, plus biofuels equal to 1MWh exported electricity, so each energy cycle is 1/3 carbon negative.
What we can do now with "off the shelf" technology, what I proposed at the Commission for Environmental Cooperation, to the EPA chiefs of North America.
The most cited soil scientist in the world, Dr. Rattan Lal at OSU, was impressed with this talk, commending me on conceptualizing & articulating the concept.
A Report on my talk at CEC, and complete text & links are here:
group/biochar-policy/message/3233
The Establishment of Soil Carbon as the Universal Measure of Sustainability
The combination of off-the-shelf hyperspectral remote sensing data with the understanding that Terra Preta soils inpart higher phosphorus content in the forest canopy will allow a very exact assay of the true extent of these anthropogenic soils.
NASA’s Space Archaeology; $364K Terra Preta Program
blogspot.com/2010/08/time-traveling-via-satellite.html
Cheers,
Erich
Erich J. Knight
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540-289-9750
Skype; Erichj11 (under my shengar@aol.com address)
Technology Adviser;
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2010 US Biochar Conference, at Iowa State University
iastate.edu/events/biochar2010/conference-agenda/agenda-overview.html
All my Headline Char News can be reviewed at;
group/se-biochar
Poor Columbus, blamed for everything even though he died 35 years before the first European saw the Amazon.
Pureo ........ Blame the P.C. indoctrination in public schools. The first time my children came home with "Columbus was a mass murderer" we sat down and had a long talk about the clash of two civilizations at different levels of developement, the difference between social norms 600 years can make and the difference between exploration and murder ... to name a few topics. The Spanish were a brutal and hard hearted system that did result in tragedy whereever they set foot, but taken outside the context of the time place and people while trying to define it by todays social standards is not realistic. The aboriginal at the advanced stone age level of developement were people like any other with the usual wars killings and brutality just like every other on earth. there just were not enough Spanish to personally destroy multitudes of aboriginals. The usual blame on firearms and armor does not hold water. The guns of the period were extremely inaccurate and the armor could not stand up to even the stone tipped atlatl.
The Aztecs, Mayans and Incas were well beyond the 'aboriginal advanced stone age development'.
Well it was probably a lot more savage with more gold lying around.
I don't think most people are getting the point of this article. the indigenous populations of the Americas collapsed after Europeans arrived, that is just a fact, and no one is hating on Columbus. I think the article is about the impact the indigenous cultures had, or did not have, on the forest. This is a very interesting and well written article, especially for those of you who have read the 1491 book by Charles Mann. Thanks for a great Saturday morning read, Alan!
Pueo,
My point is unintended consequences, Charles Mann in 1491 maintains that the Columbian exchange was the reuniting of life on the planet after hundreds of millions of years divided by plate tectonics. The genetic evidence now shows a 50% depopulation of the New World, that is a lot of fields untended for the forest to regrow. Those gigatons of carbon added insult to injury for the Europeans suffering the Little Ice Age. However those who embraced the potato suffered way less than the bread eaters in France.
The research by Julia Pongratz of the Carnegie Institute, in an article on Genghis Khan's CO2 Sainthood.
0120-hance_mongols.html, The Unintended, Heavy-handed, forest conservation ties in with the research I have been following. I venture to say, that Dr. Dull's work also nominates Christopher Columbus for Sainthood. His nomination is weighted with 2 to 5 billion tons versus Mr Khan's 700 million tons of CO2. The relevance of afforestation as a climate tool should please Dr. Hansen with his latest plans for 100 GtC of Forest;
"The Case for Young People and Nature: A Path to a Healthy, Natural, Prosperous Future".
jeh1/mailings/2011/20110505_CaseForYoungPeople.pdf
• Centuries before the shape of the earth was indicated by Columbus and Magellan, the Bible stated that this planet is not flat but spherical?—Isaiah 40:22.
22 There is One who is dwelling above the circle of the earth, the dwellers in which are as grasshoppers, the One who is stretching out the heavens just as a fine gauze, who spreads them out like a tent in which to dwell.- If they would have only read the BIBLE.
Why would anyone have given more merit to one passage than any of the rest of the fairytales? that particular book starts out with an unworkable premise and continues from that beginning. does not get more believable as it progresses. As a collection of tribal myths and traditions fine, as a guide to scientific believable text it fails.
According to a non-academic source, the Amazon region has the best biodiversity in the world, because that is the oldest, unchanged region in the world. So various organisms have had the time to diversify in large numbers.
Buddy Levy's fascinating book River of Darkness chronicles conquistador Francisco Orellana's 1541 trip down the complete length of the Amazon from Peru, the first by any Westerner. During that nearly 2 year trip, Orellana and his band ran into many tribes, some more sophisticated (and hostile) than others. His story seems to contradict what McMichael is contending. Granted, Orellana's story (largely recorded by a monk travelling with them) could have been embellished, but still, it makes one realize that all viewpoints should be considered.
The Spaniards didn't kill off the indigenous people directly, the diseases they brought did it. People who, years later, tried to find the large native settlements described by DeSoto couldn't. Many called him a liar who was just trying to attract people to be colonists. Again, it wasn't the first Florida land hoax, the diseases his party carried decimated those they came in contact with. (Measles and other "childhood" diseases were often fatal to the natives.)
quite interesting!! please visit the university of nigeria for your academic norishments.