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Original article in National Geographic

BY SARAH GIBBENS

Waste left over from the coffee-making process can jolt destroyed forests back to life.

Just like us, forests move faster with a little coffee in their system.

A recent experiment tested whether coffee pulp, a leftover of the coffee growing process, could help bring Costa Rica’s rainforests back to life. Researchers from the University of Hawai’i at Manoa tested two plots to see how the coffee waste would affect deforested land, covering one parcel of grass with about 20 inches of the pulp and leaving the other untouched.

At each site, land had been exploited for years, either to grow coffee or raise cattle, and was eventually abandoned. It was dominated by invasive grasses, primarily an African species called palisade grass, used to feed grazing livestock. The grass can reach 16 feet tall when not trimmed by grazing animals, preventing native rainforests from easily regrowing.

After two years, the plot of land given a boost from coffee showed a dramatic improvement. Eighty percent of the plot was covered by young tree canopy, some trees already 15 feet—including tropical species that can grow as tall as 60 feet—versus just 20 percent in the untreated plot. In the coffee-fueled plot, trees were also four times taller on average, soil samples were more nutrient-rich, and invasive grasses had been eliminated.

The results were published in the journal Ecological Solutions and Evidence.

Not only does it give coffee producers a sustainable way to dispose of their waste, she says, but it also speeds up the timeline to bring back destroyed forests.

“It’s an amazing win-win situation,” says Rebecca Cole, a study author and ecologist from the University of Hawai’i at Manoa. “It takes tropical forest hundreds of years to grow back. To have [such] tall trees in only two years is really spectacular.”

More research needs to be done, Cole acknowledges, to understand the long-term impacts of coffee pulp and whether it causes any unforeseen pollution.

Still, says Cole, “This really was like a forest on caffeine. I think it’s really promising.”

LOOKING FOR A WIN-WIN

Coffee beans are the seeds of a fruit called a coffee cherry that, when picked, looks like a bright red or yellow cherry. To get coffee beans, producers remove the fruit’s skin, pulp, and other filmy bits. They then dry and roast the remains to make the grounds that end up in your morning cup. Approximately half the weight of a coffee harvest will end up as waste.

In Costa Rica, says Rakan Zahawi, a study author and director of the Lyon Arboretum at the University of Hawai’i at Manoa, coffee producers typically take all that leftover coffee residue to storage lots where it’s left to decompose.

In the early 2000s, Zahawi visited a similar restoration project using orange peels.

“The difference was night and day,” he says of forests treated with oranges and those left untouched, “There was a huge difference.”

The idea stuck with him when he began working in Costa Rica and took notice of the waste generated by the country’s large coffee industry. If the excess coffee pulp could be put to good use somehow, Cole and Zahawi thought, everyone involved—the coffee producers, land owners, and environmentalists—could benefit.

“Essentially it’s a major waste product that’s expensive to process, and they give it away for free,” says Cole. Rather than paying for the waste to be composted and stored, the only cost to the researchers was renting dump trucks to shuttle the pulp.

HOW AND WHY IT WORKS

The idea works like this: spread a foot and a half of the coffee pulp on an area covered in pasture grasses and the foliage underneath will smother and cook until it’s asphyxiated, dies, and decomposes.

“You essentially kill all the roots and rhizomes of the grasses,” says Zahawi.

Zahawi and Cole found that as the decomposed remains of the grasses mix with the coffee’s nutrient-rich layer, it creates a fertile soil. That, in turn, attracts insects, which attracts birds, who then drop seeds into the plot, as does the wind.

Then comes the rebirth.

“It looks like a mess for the first two or three years, and then there’s this explosion of new plants coming in,” says Zahawi. “It’s so nutrient rich they’re sort of growing on steroids.”

The key, they found, was to pile on the pulp—using a thick enough layer of pulp in an area flat enough for it not to wash away, and in a climate with a dry period that allowed the coffee to really bake. Essentially, it became like a very successful compost heap.

“If you stick your hand in this gook, it’s really hot—not scalding but hot enough to smother [the grass],” says Zahawi.

A plastic tarp spread across a field and pinned down by weights would also kill the grasses. But “then you have all this plastic waste,” says Zahawi. And new, fertile soil would still need  to be brought in to attract new plants.

Cole says the most common way to restore forests is to plant trees. But compared to just dumping coffee byproduct and letting nature do the planting, it’s labor intensive and expensive.

“I was kind of skeptical it was going to work. I thought we would just have a greener patch of grass,” she says. Instead, they got the beginnings of a new rainforest.

ROADBLOCKS AND NEEDED RESEARCH

While Cole and Zahawi’s experiment with coffee pulp successfully jump-started forest growth, there are downsides.

“Coffee pulp is really stinky,” says Cole, who was raised on a Costa Rican coffee farm. “I grew up with the smell but a lot of people find it pretty offensive.”

It also attracts a lot of flies and other insects that, despite attracting seed-dispersing birds, are pests for nearby humans.

“There’s also some concern that it will have negative effects on watersheds. There can be some contamination,” says Cole. Coffee pulp contains nutrients like nitrogen and phosphorus that can negatively impact streams and lakes, causing excess algae growth, for example. The pulp may also contain traces of pesticides used during production.

While this experiment was carried out away from water sources, Cole says their future research will look at the potential impact on surrounding areas.

Previous work using orange peels to regrow forests in Costa Rica was met with some backlash. When orange juice maker Del Oro began a partnership with a local protected area to spread truckloads of peels on former cattle pasture, its local competitor, TicoFrut, alleged the program was simply a way to dump waste. The program was stopped by Costa Rican authorities, who sided with the competing juice company.

A PROMISING FUTURE FOR FORESTS?

Dan Janzen and Winnie Hallwachs, a married team of tropical ecologists at the University of Pennsylvania, weren’t surprised by the ecological success of Cole and Zahawi’s reforestation experiment; Janzen forged the relationship between Del Oro and the protected area in 1996 for the same purpose and introduced Zahawi to the concept.

Two decades ago, he saw similar success.

Six months after the orange peels were distributed, Janzen said the small one-hectare plot “looked and smelled horrible.”

“[One and a half] years later it was all gone, and in its place were no invasive African pasture grasses, but a marvelous species-rich patch of broadleaf plants growing from deep black loam soil. Basically, we had fertilized the place very intensively. We were sold,” Janzen writes over email.

He thinks coffee pulp may escape the same fate as the failed orange peel project, saying it’s “less tangled in thorny political issues,” and grown by more small producers rather than two large competing companies.

In addition to researching the long-term impacts, Cole is interested in testing other agricultural by-products. As long as the crop waste is nutrient-rich and not harmful to human health, she would expect similar results.

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Credit Dr Edmar Almeida de Oliveira

Exeter.ac.uk

Innovation by ancient farmers to improve soil fertility continues to have an impact on the biodiversity of the Amazon, a major new study shows.

Early inhabitants fertilized the soil with charcoal from fire remains and food waste. Areas with this “dark earth” have a different set of species than the surrounding landscape, contributing to a more diverse ecosystem with a richer collection of plant species, researchers from the State University of Mato Grosso in Brazil and the University of Exeter have found.

The legacy of this land management thousands of years ago means there are thousands of these patches of dark earth dotted around the region, most around the size of a small field. This is the first study to measure the difference in vegetation in dark and non-dark earth areas in mature forests across a region spanning a thousand kilometers.

The team of ecologists and archaeologists studied abandoned areas along the main stem of the Amazon River near Tapajós and in the headwaters of the Xingu River Basin in southern Amazonia.

Lead author Dr Edmar Almeida de Oliveira  said: “This is an area where dark earth lush forests grow, with colossal trees of different species from the surrounding forest, with more edible fruit trees, such as taperebá and jatobá.”

The number of indigenous communities living in the Amazon collapsed following European colonization of the region, meaning many dark earth areas were abandoned.

The study, published in the journal Global Ecology and Biogeography, reveals for the first time the extent to which pre-Columbian Amerindians influenced the current structure and diversity of the Amazon forest of the areas they once farmed.

Researchers sampled around 4,000 trees in southern and eastern Amazonia. Areas with dark earth had a significantly higher pH and more nutrients that improved soil fertility. Pottery shards and other artefacts were also found in the rich dark soils.

Professor Ben Hur Marimon Junior, from the State University of Mato Grosso, said: “Pre-Columbian indigenous people, who fertilized the poor soils of the Amazon for at least 5,000 years, have left an impressive legacy, creating the dark earth, or Terras Pretas de Índio

Professor José Iriarte, an archaeologist from the University of Exeter, said: “By creating dark earth early inhabitants of the Amazon were able to successfully cultivate the soil for thousands of years in an agroforestry system

“We think ancient communities used dark earth areas to grow crops to eat, and adjacent forests without dark earth for agroforestry.”

Dr Ted Feldpausch, from the University of Exeter, who co-authored the study with Dr Luiz Aragão from the National Institute for Space Research (INPE) in Brazil, said: “After being abandoned for hundreds of years, we still find a fingerprint of the ancient land-use in the forests today as a legacy of the pre-Colombian Amazonian population estimated in millions of inhabitants.

“We are currently expanding this research across the whole Amazon Basin under a project funded by the UK Natural Environment Research Council(NERC) to evaluate whether historical fire also affected the forest areas distant from the anthropogenic dark earths”.

Many areas with dark earth are currently cultivated by local and indigenous populations, who have had great success with their food crops. But most are still hidden in the native forest, contributing to increased tree size, carbon stock and regional biodiversity. For this reason, the lush forests of the “Terra Preta de Índio” and their biological and cultural wealth in the Amazon must be preserved as a legacy for future generations, the researchers have said. Areas with dark earth are under threat due to illegal deforestation and fire.

 “Dark earth increases the richness of species, an important consideration for regional biodiversity conservation. These findings highlight the smallscale longterm legacy of preColumbian inhabitants on the soils and vegetation of Amazonia,” said co-author Prof Beatriz Marimon, from the State University of Mato Grosso.

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Topic: Ancient forest
The discoveries could boost indigenous populations’ claims to ancestral lands long thought to be untouched by human activity

A tropical forest writes much of its history at large scale, producing trees as tall as skyscrapers and flowers the size of carry-on luggage. But by zooming in, scientists are uncovering chapters in forest history that were influenced by human activity far earlier than anyone thought.

A new study of pollen samples extracted from tropical forests in southeast Asia suggests humans have shaped these landscapes for thousands of years. Although scientists previously believed the forests were virtually untouched by people, researchers are now pointing to signs of imported seeds, plants cultivated for food, and land clearing as early as 11,000 years ago—around the end of the last Ice Age.

The study, to be published in the peer-reviewed Journal of Archaeological Science comes from researchers led by paleoecologist Chris Hunt, of Queen’s University, Belfast, who analyzed existing data and examined samples from Borneo, Sumatra, Java, Thailand and Vietnam.

Pollen offers an important key for unlocking the history of human activity in a region where dense tropical forests make traditional excavations slow, arduous work, and thick canopies hinder aerial surveys. Reliance on building materials that perish with the centuries (rather than stone or ceramic) can make it difficult to recognize signs of long-gone inhabitants. Pollen, however, can survive for thousands of years in the right conditions and paint a picture of vegetation over time.

In the Kelabit Highlands of Borneo, for example, pollen samples dated to about 6,500 years ago contain abundant charcoal evidence of fire. That alone doesn’t reveal a human hand. But scientists know that specific weeds and trees that flourish in charred ground would typically emerge in the wake of naturally occurring or accidental blazes. What Hunt’s team found instead was evidence of fruit trees. “This indicates that the people who inhabited the land intentionally cleared it of forest vegetation and planted sources of food in its place,” Hunt explained in a statement about the study.

Hunt’s team also looked at the types of pollen reported in cores extracted from very isolated areas where, in all likelihood, humans did not intervene with the succession of plants that would have come about simply because of changes in temperature, rainfall, and competition among species. The patterns in these cores could then be used as a proxy for what to expect without human intervention. When layers sampled from other, comparable sites in the region failed match up, it raised a flag for the researchers that humans may have disrupted the natural succession through burning, cultivation, or other activities.

“Ever since people had the ability to make stone tools and control fire, they were able to manipulate the environment,” explained biologist David Lentz, who directs the Center for Field Studies at the University of Cincinnati. “In pre-agricultural times, they would burn forest to improve hunting and increase the growth of plants that were edible—often weedy plants with lots of seeds. This is a pattern that we see all over the world.” It’s not surprising, he added, to see it documented in Southeast Asia.

And yet, Hunt said, “It has long been believed that the rainforests of the Far East were virgin wildernesses, where human impact has been minimal.” To the contrary, his team traced signs of vegetation changes resulting from human actions. “While it could be tempting to blame these disturbances on climate change,” he said, “that is not the case as they do not coincide with any known periods of climate change.

This kind of research is about more than glimpsing ancient ways of life. It could also present powerful information for people who live in these forests today. According to Hunt, “Laws in several countries in Southeast Asia do not recognize the rights of indigenous forest dwellers on the grounds that they are nomads who leave no permanent mark on the landscape.” The long history of forest management traced by this study, he says, offers these groups “a new argument in their case against eviction.”

Such tensions have played out beyond Southeast Asia. In Australia, for example, “the impact of humans on the environment is clear stretching back over 40,000 years or so,” says environmental geoscientist Dan Penny, of The University of Sydney. And yet, he says, “the material evidence of human occupation is scarce.” Starting in the 18th century, the British used that fact “to justify their territorial claim” to land inhabited by Aboriginal Australians—declaring it terra nullius (belonging to no-one), establishing a colony, and eventually claiming sovereignty over the entire continent.

This latest study comes as part of a larger discussion about when and how our species began shaping the world around us. “Humans and pre-humans have been present in Asia for a very long time, and there have been a number of studies that point to a very long history of human alteration of the natural environment,” says Penny. Hunt’s work in Southeast Asia, he says, makes a “valuable contribution” to that discussion, and to a broader debate surrounding the timing of what scientists call the Anthropocene—a proposed period in human history when activity began to alter natural processes in a significant way.”

Original article:
smithsonian magazine

By Josie Garthwaite
smithsonianmag.com
March 5, 2014

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Topic: The need to go green is ageless

For 1200 years, the Maya dominated Central America. At their peak around 900 A.D., Maya cities teemed with more than 2,000 people per square mile — comparable to modern Los Angeles County. Even in rural areas the Maya numbered 200 to 400 people per square mile. But suddenly, all was quiet. And the profound silence testified to one of the greatest demographic disasters in human prehistory — the demise of the once vibrant Maya society.

What happened? Some NASA-funded researchers think they have a pretty good idea.

“They did it to themselves,” says veteran archeologist Tom Sever.

“The Maya are often depicted as people who lived in complete harmony with their environment,’ says PhD student Robert Griffin. “But like many other cultures before and after them, they ended up deforesting and destroying their landscape in efforts to eke out a living in hard times.”

A major drought occurred about the time the Maya began to disappear. And at the time of their collapse, the Maya had cut down most of the trees across large swaths of the land to clear fields for growing corn to feed their burgeoning population. They also cut trees for firewood and for making building materials.

“They had to burn 20 trees to heat the limestone for making just 1 square meter of the lime plaster they used to build their tremendous temples, reservoirs, and monuments,” explains Sever.

He and his team used computer simulations to reconstruct how the deforestation could have played a role in worsening the drought. They isolated the effects of deforestation using a pair of proven computer climate models: the PSU/NCAR mesoscale atmospheric circulation model, known as MM5 (http://www.mmm.ucar.edu/mm5/), and the Community Climate System Model, or CCSM (http://www.ccsm.ucar.edu/).

“We modeled the worst and best case scenarios: 100 percent deforestation in the Maya area and no deforestation,” says Sever. “The results were eye opening. Loss of all the trees caused a 3-5 degree rise in temperature and a 20-30 percent decrease in rainfall.”

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The results are telling, but more research is needed to completely explain the mechanisms of Mayan decline. Archeological records reveal that while some Maya city-states did fall during drought periods, some survived and even thrived.

“We believe that drought was realized differently in different areas,” explains Griffin. “We propose that increases in temperature and decreases in rainfall brought on by localized deforestation caused serious enough problems to push some but not all city-states over the edge.”

The Maya deforested through the use of slash-and-burn agriculture – a method still used in their old stomping grounds today, so the researchers understand how it works.

“We know that for every 1 to 3 years you farm a piece of land, you need to let it lay fallow for 15 years to recover. In that time, trees and vegetation can grow back there while you slash and burn another area to plant in.”

But what if you don’t let the land lay fallow long enough to replenish itself? And what if you clear more and more fields to meet growing demands for food?

“We believe that’s what happened,” says Griffin. “The Maya stripped large areas of their landscape bare by over-farming.”

Not only did drought make it difficult to grow enough food, it also would have been harder for the Maya to store enough water to survive the dry season.

“The cities tried to keep an 18-month supply of water in their reservoirs,” says Sever. “For example, in Tikal there was a system of reservoirs that held millions of gallons of water. Without sufficient rain, the reservoirs ran dry.” Thirst and famine don’t do much for keeping a populace happy. The rest, as the saying goes, is history.

“In some of the Maya city-states, mass graves have been found containing groups of skeletons with jade inlays in their teeth – something they reserved for Maya elites – perhaps in this case murdered aristocracy,” he speculates.

No single factor brings a civilization to its knees, but the deforestation that helped bring on drought could easily have exacerbated other problems such as civil unrest, war, starvation and disease.

Many of these insights are a result of space-based imaging, notes Sever. “By interpreting infrared satellite data, we’ve located hundreds of old and abandoned cities not previously known to exist. The Maya used lime plaster as foundations to build their great cities filled with ornate temples, observatories, and pyramids. Over hundreds of years, the lime seeped into the soil. As a result, the vegetation around the ruins looks distinctive in infrared to this day.”

“Space technology is revolutionizing archeology,” he concludes. “We’re using it to learn about the plight of ancients in order to avoid a similar fate today.”

Contributors to this research: Archeologist Dr. Tom Sever of UAHuntsville in Huntsville, Alabama; archeologist Dr. William Saturno of Boston University, who is a NASA Intergovernmental Personnel Act Assignee; Rob Griffin, a PhD student at Pennsylvania State University in College Park, Pa, and current Visiting Professional at the National Space Science and Technology Center in Huntsville; Dr. Udaysankar Nair, a research scientist in UAHuntsville’s Earth System Science Center; Daniel Irwin, SERVIR Project Director at NASA’s Marshall Space Flight Center; and paleoclimatologist Dr. Bob Oglesby of the University of Nebraska.

Original article:

redorbit.com

Dauna Coulter, Science @ NASA

October, 2009

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