Indigenous societies' 'first contact' typically brings collapse, but rebounds are possible

A press release from the Santa Fe Institute: It was disastrous when Europeans first arrived in what would become Brazil -- 95 percent of its population, the majority of its tribes, and essentially all of its urban and agricultural infrastructure vanished. The experiences of Brazil's indigenous societies mirror those of other indigenous peoples following "first contact."

A new study of Brazil's indigenous societies led by SFI researcher Marcus Hamilton paints a grim picture of their experiences, but also offers a glimmer of hope to those seeking ways to preserve indigenous societies.

Even among the indigenous societies contacted in just the last 50 years, says Hamilton, “all of them went through a collapse, and for the majority of them it was disastrous,” with disease and violence responsible in most cases, and with lasting detrimental effects. “That’s going on today -- right now.”

Brazil is “a tragic natural experiment,” Hamilton says: several hundred native tribes contacted by outsiders remain, according to Instituto Socioambiental, a non-governmental organization that reports census data on 238 of those societies going back a half-century or more. That volume of data makes possible a detailed analysis of the health and prospects of the surviving contacted -- and uncontacted -- societies, an analysis that wouldn’t be possible any where else in the world.

Using a method called population viability analysis, the researchers found that contact by outsiders is typically catastrophic, yet survivable. While first contacts in Brazil led to population declines of 43 percent on average, that decline bottomed out an average of eight or nine years after contact, following which population numbers grew as much as four percent a year -- about as much as possible. Projecting those results into the future suggests that contacted and as-yet uncontacted populations could recover from a low of just 100 individuals....

A 1779 engraving by John Webber of riests traveling across Kealakekua bay for first contact rituals. Each helmet is a gourd, with foliage and tapa strip decoration. A feather surrounded akua is in the arms of the priest at the center of the engraving. 

Scientists pioneer method to predict environmental collapse

Terra Daily via SPX: Scientists at the University of Southampton are pioneering a technique to predict when an ecosystem is likely to collapse, which may also have potential for foretelling crises in agriculture, fisheries or even social systems.

The researchers have applied a mathematical model to a real world situation, the environmental collapse of a lake in China, to help prove a theory which suggests an ecosystem 'flickers', or fluctuates dramatically between healthy and unhealthy states, shortly before its eventual collapse.

Head of Geography at Southampton, Professor John Dearing explains: "We wanted to prove that this 'flickering' occurs just ahead of a dramatic change in a system - be it a social, ecological or climatic one - and that this method could potentially be used to predict future critical changes in other impacted systems in the world around us."

A team led by Dr Rong Wang extracted core samples from sediment at the bottom of Lake Erhai in Yunnan province, China and charted the levels and variation of fossilised algae (diatoms) over a 125-year period. Analysis of the core sample data showed the algae communities remained relatively stable up until about 30 years before the lake's collapse into a turbid or polluted state.

However, the core samples for these last three decades showed much fluctuation, indicating there had been numerous dramatic changes in the types and concentrations of algae present in the water - evidence of the 'flickering' before the lake's final definitive change of state. Rong Wang comments: "By using the algae as a measure of the lake's health, we have shown that its eco-system 'wobbled' before making a critical transition - in this instance, to a turbid state....

Géza Maróti's plan of Atlantis mock-up, around 1941 -- public domain

Seal cull will not revive Canada's cod stocks, say scientists

Stephen Leahy in the Guardian (UK): Canada's multimillion dollar proposal to cull grey seals will not bring back the ravaged stocks of Atlantic cod it is intended to help, scientists have said. In October, the Canadian Senate approved a controversial plan to kill 70,000 grey seals in the Gulf of St Lawrence under a bounty system next year, ostensibly to revive the cod stocks that the seals were eating.

But a group of marine scientists at Dalhousie University in Halifax, Nova Scotia, have said in a recent open letter: "There is no credible scientific evidence to suggest a cull of grey seals in Atlantic Canada would help depleted fish stocks recover.

"Seals are being used as a scapegoat, just like whales were once blamed for fishery declines," said Hal Whitehead, marine biologist at Dalhousie, told the Guardian. He called the proposed cull an abuse of the science. "I don't like the idea of slaughtering all these animals for no reason."

Canada's Atlantic cod stocks, once estimated at 1.5-2.5 billion fish of reproductive age, collapsed in the early 1990s from overfishing. Despite a nearly total ban on cod fishing for the past 20 years, stocks have not recovered.

That's not the case for grey seals. Similarly depleted by hunting, numbers stood at just a few thousand in the 1970s. Following the collapse of markets for seal fur, mainly due to bans by European countries, their numbers increased dramatically. Grey seals are now estimated at 300,000 to 400,000....

A grey seal photographed by Andreas Trepte, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 2.5 Generic license

Climate change led to collapse of ancient Indus civilization

Woods Hole Oceanographic Institution: A new study combining the latest archaeological evidence with state-of-the-art geoscience technologies provides evidence that climate change was a key ingredient in the collapse of the great Indus or Harappan Civilization almost 4000 years ago. The study also resolves a long-standing debate over the source and fate of the Sarasvati, the sacred river of Hindu mythology.

Once extending more than 1 million square kilometers across the plains of the Indus River from the Arabian Sea to the Ganges, over what is now Pakistan, northwest India and eastern Afghanistan, the Indus civilization was the largest—but least known—of the first great urban cultures that also included Egypt and Mesopotamia. Like their contemporaries, the Harappans, named for one of their largest cities, lived next to rivers owing their livelihoods to the fertility of annually watered lands.

“We reconstructed the dynamic landscape of the plain where the Indus civilization developed 5200 years ago, built its cities, and slowly disintegrated between 3900 and 3000 years ago,” said Liviu Giosan, a geologist with Woods Hole Oceanographic Institution (WHOI) and lead author of the study published the week of May 28 in the Proceedings of the National Academy of Science. “Until now, speculations abounded about the links between this mysterious ancient culture and its life-giving mighty rivers.”

Today, numerous remains of the Harappan settlements are located in a vast desert region far from any flowing river. In contrast to Egypt and Mesopotamia, which have long been part of the Western classical canon, this amazingly complex culture in South Asia with a population that at its peak may have reached 10 percent of the world’s inhabitants, was completely forgotten until 1920’s. Since then, a flurry of archaeological research in Pakistan and India has uncovered a sophisticated urban culture with myriad internal trade routes and well-established sea links with Mesopotamia, standards for building construction, sanitation systems, arts and crafts, and a yet-to-be deciphered writing system...

Once extending more than 1 million square kilometers across the plains of the Indus River from the Arabian Sea to the Himalayas and the Ganges, over what is now Pakistan, northwest India and eastern Afghanistan, the Indus civilization was the largest—but least known—of the first great urban cultures that also included Egypt and Mesopotamia. Named for one of their largest cities, the Harappans relied on river floods to fuel their agricultural surpluses. Today, numerous remains of the Harappan settlements are located in a vast desert region far from any flowing river. (Liviu Giosan, Woods Hole Oceanographic Institution; Stefan Constantinescu, University of Bucharest; James P.M. Syvitski, University of Colorado.)

Mild climate change killed off ancient Mayans

ChannelNewsAsia via AFP: The collapse of the Mayan civilization was likely due to a relatively mild drought, much like the drier conditions expected in the coming years due to climate change, scientists said Thursday. Scholars have long believed that a major drought caused severe dry conditions that killed off the ancient culture known for its mastery of language, math and astronomy.

But researchers from the Yucatan Center for Scientific Research in Mexico and the University of Southampton in Britain said their analysis shows the drought only caused reductions of 25 to 40 percent less annual rain.

The smaller amounts of rain meant that open water sources in pools and lakes evaporated faster than could be replaced by more precipitation, said the study in the journal Science. "The data suggest that the main cause was a decrease in summer storm activity," said co-author Eelco Rohling of the University of Southampton.

The study is the first of its kind to attempt to assess exactly how much rainfall decreased between 800 and 950 AD when Mayan civilization went into decline, and bases its modeling data on records of past rainfall changes from stalagmites and shallow lakes.

The analysis showed that modest dry spells could have sparked major water shortages in an area with no rivers, and no source of water other than rain....

Mayan ruins in Belize, shot by Josh, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

Collapse of Soviet Union equivalent to Chernobyl for land-use change

A new study shows how a political sea-change affects land use. From Nadya Anscombe in Environmental Research Web: The rate at which agricultural land was abandoned after the collapse of the Soviet Union was roughly the same as that immediately after the Chernobyl nuclear disaster five years earlier, according to researchers. While the effects of the Chernobyl disaster on land-use systems were fairly local, the collapse of the Soviet Union affected one sixth of the planet’s land surface.

The research, which is published in Environmental Research Letters (ERL), highlights how institutions such as governments play important roles in mitigating the impact of socio-economic disturbances on land-use change. “While the dismantling of the Soviet Union had drastic effects on land-use systems in both the Ukraine and Belarus, continuing state-support for agriculture and a stronger institutional inertia resulted in substantially lower abandonment rates in Belarus when compared with the Ukraine,” Tobias Kuemmerle from Humboldt University in Berlin, Germany, told environmentalresearchweb.

Agriculture had been heavily subsidized and intensified during the socialist period. The post-socialist period was characterized by a drastically lower profitability of farming, unsecure land tenure, and decreasing agricultural workforces. This resulted in millions of hectares of farmland being abandoned, practically overnight.

While the Ukraine allowed privatization of all farmland, but implemented land reforms slowly, in Belarus farmland was not privatized and government support for agriculture continued after the collapse of the Soviet Union. As a result, land systems in Belarus were more resilient against the effects of the socio-economic disturbance caused by the collapse of the Soviet Union....

Pictogram of discarded communism by Skarabeusz, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

An editorial in the Salt Lake Tribune raises the danger the American west has largely forgotten – erosion and dust: It was called “The worst hard time

An editorial in the Salt Lake Tribune raises the danger the American west has largely forgotten – erosion and dust: It was called “The worst hard time.” The Dust Bowl, when millions of square miles of formerly productive earth literally dried up and blew away, and took the hopes and fortunes of much of America right along with it.

There were many reasons for the disaster, a perfect dust storm of causes natural (eight years of drought) and human (plowing up the Great Plains). The result was a depopulation of large swaths of America’s midsection that have never recovered, mass migrations and social upheavals, and, to our credit, improved farming methods that take some care to keep the soil where it belongs. And it could very well happen all over again. This time, in Utah. And, when it does, it will be even more our fault than it was the last time. Because now, supposedly, we know better.

Experts at the U.S. Geological Survey and the University of California-Los Angeles have released a report showing that the Southwestern United States is on the brink of another kind of dust bowl. Again, it will be a result of many factors, including that the process begins with a climate that is generally pretty darn dry to begin with and is exacerbated by global climate change and local disregard for the sensitivity of our soils…

Farmer and sons walking in the face of a dust storm. Cimarron County, Oklahoma, in 1936