LAND CLEARING: Smoke rises from a fire set to clear land for farming or pasture outside Tarapoto, Peru. Roads and fields fragment the forest, drying it faster, changing precipitation patterns and making it more difficult for species to shift their ranges to adapt to climate change.
Image: © BARBARA FRASER
-
The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
Read More »
TARAPOTO, Peru—For tropical ecologist Gregory Asner, flying over the Peruvian Amazon from the town of Tarapoto is like traveling back in time. Modern houses, rice paddies and oil palm plantations give way to steep, forested mountains and then to green, unbroken forest that curves toward the horizon.
Suddenly the tree canopy below the twin-engine plane turns a mottled gray-brown, a sign of drought damage that he estimates may affect as many as half the trees.
In this remote corner of Peru’s Ucayali region, Asner, a tropical ecologist at the Carnegie Institution for Science at Stanford University, is afraid he is seeing the future. In the last few years this patch of forest has been hit by two “once-in-a-century droughts”—one in 2005 and another in 2010. These dry spells may become more frequent as temperatures in the tropical North Atlantic Ocean rise and as humans burn thousands of square kilometers of forest for farming. Although it has seen warmer temperatures in the past, the western Amazon is under siege now from a combination of a warming climate and human population growth that it has never faced before, and scientists are scrambling to determine whether existing protected areas will be enough to buffer against the changes to come.
Behind the plane Asner glimpses smoke rising from fires set to clear land for farming. Migration from the Andean highlands has boosted Peru’s Amazonian states to the top of the population growth chart, and the influx of people is taking a toll on the forest.
Peru’s Ministry of Environment—using satellite images and Carnegie-provided software—calculates that the country lost about 6,475 square kilometers of forest, an area the size of Delaware, between 2005 and 2009, up from some 4,550 square kilometers in the five previous years. Losing forest reduces precipitation, further stressing the remaining trees. “About 50 percent of the rain that falls in the Amazon is generated by the forest itself, through transpiration and evaporation,” Asner says. “Deforestation exacerbates the drought problem, because it removes that internal engine.”
Clearing fields and pastures also leaves more exposed forest edges, drying out the interior and making it more likely to burn if an agricultural fire escapes. Fires during the 2005 and 2010 droughts added 3.8 gigatons of carbon to the atmosphere, according to Simon Lewis, a forest ecologist at University College London. In recent genetic studies Lewis found that Amazonian trees have weathered past climatic warming, but the changes were slower then and were not exacerbated by humans, he says.
Faced with warmer, drier conditions, trees have three options:
“Individuals can acclimate, species can adapt or migrate, or they go extinct,” says Kenneth Feeley, a biologist at Florida International University. A floral species can expand its range into a cooler region, but only as fast as seed dispersal allows. Feeley, who studies trees on the eastern slope of the Peruvian Andes, was surprised to see range changes there in just a few years. “Species are moving upslope about three vertical meters a year—that’s really fast,” he says, although perhaps not fast enough. “Based on the climate change that’s already happening, they need to move nine or 10 vertical meters a years.”
In the lowlands, deforestation reduces the areas to which species can move, and fields, pastures and roads create barriers to dispersal. Peru has some large protected areas, such as Manú National Park, where Feeley does his work, but scientists don’t know if they are big enough—or in the right places—to allow species to migrate in a rapidly changing climate.
Rights & Permissions
See what we're tweeting about
25 Comments
Add CommentNot that I disagree with the whole preservation trend, but is "funny" how the first world destroyed their green, and now that the only real untouched green is outside their borders they want to play nice and fair, pro green.
Reply | Report Abuse | Link to thisWhen in fact, they (the 1st world) are the hungry ones for the now very expensive green and want to have a word in such decisions.
Hey, shut up about this and start naming and finger pointing at the demand, which resides not very far from where this article flourished from.
After all you only "lost" your green because you have a demand for it, otherwise you'd still have it, like they do.
Once again the concept that is not the change that is the problem, but rather the rate of change that is the threat to our biosphere, is at the heart of the issue. The problem is that those with the power to make changes to law that can help mitigate a future disaster just can't do the math. This is the same group of people that want to cut spending for education and research. You can't educate people that can understand the concept of a chain saw much better then the concept of conservation.
Reply | Report Abuse | Link to this"...The problem is that those with the power to make changes to law that can help mitigate a future disaster just can't do the math..."
Reply | Report Abuse | Link to thisOh, they can do the math alright, or have experts do the math for them. THE PROBLEM is Big Carbon, Big Agro, Big Banking stuff so many dollars into the politician's pockets that they could care less about Doing-the-Right-Thing. The modern day mantra for politicians is "What can I do to keep the Cash flowing".
@brainguy- reducing demand in the West (actually China is the big source for commodities demand now) is absolutely tilting at windmills, unless there is some market signal (carbon tax, etc) that internalizes the externality represented by environmental degradation. And ultimately that requires cooperation between many countries, including China. While a carbon tax could fund forest buyouts, it's unlikely to be signed up to by anyone else than Western Europe and maybe the US (stretching it). Whereas if you try to achieve preservation at the supply side, there is only one country that has to be convinced. Moreover, actually the US has grown back a lot of forests recently. Environmental preservation isn't and shouldn't be a morality play about who's to blame, it should be about doing whatever it takes to preserve and sustain humanity and the planet.
Reply | Report Abuse | Link to thisI would just like to add a few observations.
Reply | Report Abuse | Link to thisThe US and many other countries have already destroyed most of their forest. Having lived 7 years on the Olympic Peninsula, I have seen first hand that the destruction of forests continues unabated in the United States. There is almost zero original (old-growth) forest left at all.
So advice from the USA as an entity in itself is pretty worthless. Even valuable recommendations from the scientific community are taken with a grain of salt, since usually and change in attitude is suggested while in their own countries such a change has never occurred.
David Schneider, Los Organos, Peru - Dual Citzenship - Inside-Peru
@Metridia
Reply | Report Abuse | Link to thisNot for the kind of commodities we are talking about it. OUR rainforest most valuable vs easy product is wood. High quality wood.
Of course, after you got "rid" of the wood (and the "land" is basically destroyed) comes farming and cropping. But the valuable asset here is wood. And China holds no 2nd or 3rd place in it's demand. The US and the EU are the biggest consumers.
That said my friend, carbon taxes are the most inhumane tax one EVER could come up with, after all, WE A CARBON BEIGNS! Taxing carbon would be the same as taxing life. God can... we can't, and should't.
The truth is, corps world finances the green orgs for their own purposes. And the carbon ordeal... well suffice to say it comes from Al Gore. And like Icke's said once, if comes from Mr Gore, it's a scam. I agree 100% with him!! Al Gore should be beaten, crucified and killed and buried in some unmarked grave somewhere nasty.
Hmmm, some strong opinions here. That's okay, though!
Reply | Report Abuse | Link to thisThe 3rd world is cutting down their forests for their own reasons, some of which are exports. North America is not where all that Palm Oil goes. There are environmentalists world wide. You lack what your handle claims.
Reply | Report Abuse | Link to thisPeople here in the U.S. fight hard to stop clear cut logging. If not it would already be all gone. It is a world-wide fight between those who would put short-term proffits before preservation.
Reply | Report Abuse | Link to thisThe problem goes deeper than just who's cutting and who's not. Increasing population demands land, demands cutting trees and burning land off the land. These are subsistence farmers living on the edge of starvation.
Reply | Report Abuse | Link to thisLikely, more land is stripped this way then by logging companies. It's a question of do I feed my family or not cut the trees and just let my family starve?
This happened in the US and is happening around the world and will not stop until the population diminishes or God steps in... as he will do soon :-)
It does come down to population. Too many people and limited space and availability of resources.
Reply | Report Abuse | Link to thisEXCEllENt!! I WAS GOING TO SAY ALMOST THE SAME THING...
Reply | Report Abuse | Link to thisWhy do you confuse education with government? The more government is involved with education the worse it gets.
Reply | Report Abuse | Link to thisThere is more bio diversity now than at any time in human history. This is especially true in the US where the plains were covered with grass and the resultant animal life and is now fertile with pasture, cattle and corn and wheat farms. Short sighted people see this and long for the past of horses and cows. It ain't going to happen.
Reply | Report Abuse | Link to thisTheres no bloody God to step in . WHEN ANY life form exceeds its equilibrium with other life form s on earth than natural balancers begin to take effect.
Reply | Report Abuse | Link to thisproof is all around in the natural world and ALSO in past civilizations where they destroyed their immediate enviroment and the culture died, A note here is the cultural behaviour died out BUT the human species continued.
cattle corn and wheat etc arent biodiversity they are mono cultural only held in place by chemical agents of all forms, we have many people here in Australia who look at the harsh interior of semi arid australia and say theres nothing there , in the same way you look at the grasses of the USA and say it was covered with grasses as if to suggest it was a mono cultural environment
Reply | Report Abuse | Link to thisThere will be a tipping event that humans experience that will rebalance the world s life forms , with our intelligence the destruction(progress for us) will continue and species will be lost( in time new species will evolve ) BUT there will be a tipping point where our numbers WILL be dramatically reduced. I have no idea what a sustainable number is but I bet its probably below our current number (perhaps way below) AND I think it could go multiples higher (20billion) before the cold the earth has, develops into pneunomia and the earth either dies with us or survives with a remnant of our species. I back the second case scenario.
Reply | Report Abuse | Link to thisThe population pressure for new land could be met by educating the people in permaculture methods of farming. That way the forest could be changed at the fringes into forest farming plus crop cultivation that does minimal damage. Permaculture in this kind of climate is capable of producing higher total yields than conventional agriculture, and what is more, it is sustainable.
Reply | Report Abuse | Link to thisWe are all so blind.
Reply | Report Abuse | Link to thisNeed makes hungry to life,
Plant wants to fly as kite,
So man want to cut its hand
No need forest, don't it band.
What we think ?
Are we king ?
Why man create like this mind ?
Actually we are all so blind.
---- Nirmalendu Das
Dated: 28-12-2012.
Email: nirmalgopa@gmail.com
Renewable resources are unable,or not given time to renew, so as we clear the earth of its forests future generations face potential disaster and hardships on an unimaginable scale if this trend is not reversed. Scientist estimate that it would take seven planet earths for the population of the world to use the resources that the U.S. does in able to live like we do. A very disturbing estimation.
Reply | Report Abuse | Link to thisIt's overpopulation: That's the problem with us as a species. As obvious as our domination is, it's persistently avoided. There's an innate disrespect for the earth in our irresponsibility, a smallness of future perspective.
Reply | Report Abuse | Link to thisPatrickR - "Seven Earths" ? Your source for this nonsense?
Reply | Report Abuse | Link to thisFew problems have simple solutions. Forestry management is practical on a sustainable basis. Unfortunately too frequently the battle is fought more on ideological grounds than proven scientifically based sustainability grounds. There is room in the middle between the extremes of open slather & lock up.
Reply | Report Abuse | Link to thisUnfortunately in developing countries or countries not having the ability to enforce sensible regulation, rapacious practices often rule.
Some importing countries do have regulations requiring proof that the timber originates from sustainable forestry practicing sources. This is to be encouraged. Unfortunately, in many areas the rapacious model prevails with some countries, Malaysia being one, being the predators in the surrounding region. They need to be continually exposed & condemned. It has to be said, corruption lubricates the bad practices with the local populations inevitably being short-changed as well as losing their resource.
Well said yarberry.
Reply | Report Abuse | Link to thisWe _all_ need to reduce our populations, in rich countries and in poor countries.
Here in Britain, which on a global scale is rich (though our elites are making sure that the rich get richer while the poor get poorer, so it doesn't feel like it for most of us) we're increasing our level of woodland cover, after the terrible woodland destruction of the 1950s, 1960s and 1970s.
But we still don't have absolute protection for all our ancient woods. We're only just starting to discuss population policy. We're still not growing almost all our food - we still import a lot. We still eat too much meat and other animal produce, so we waste land to grow crops for animals. We still haven't protected the habitats around our coastline (some marine conservation zones will be created this year, but most of the proposed sites won't get protected because our government is ecologically ignorant and illiterate). And we're still producing most of our food from annual plants rather than perennial plants.
The crucial point for people in Peru and other poor countries is that they won't just be doing the whole world a favour if they control their population size, grow food in sustainable ways, and protect their forests and other habitats - they'll be doing themselves a favour as well.
The Roman Catholic church needs to grow up and accept that contraception isn't wrong. We'd stand a much better chance of living in a healthy decent civilised world if all religions and philosophies accepted that contraception is a moral necessity.
I was in Tingo Maria in 2007/2008. Tingo Maria is situated in the Peruvian Amazon rainforest. One night it started raining and it did not stop for about 5 hours. The rain was so heavy that I thought the town was going to flood. The swimming pool at the resort we stayed at overflowed, and the lawn was completed flooded the next morning. I observed at least 20 cm of rainfall in the pool at least. You could not sleep due the noise of the rainfall. As I am a forester with a BSc and have a MSc in Environmental Sciences, I cannot recall observing any signs of moisture or heat stress in or around Tingo Maria as it relates to tree condition. One thing though is that soils are very fine textured, highly oxidized, and do not appear to be able to store much moisture. Obviously the existence of dead tree roots allows for increased soil moisture retention. Whereas cleared pasture over time loses those root channels, and results in greater overland flow of heavy rain events, leading to lower evapotranspiration. So in my opinion to conserve the Amazon rainforest it will necessary to halt deforestation and conversion of the more dynamic and diverse native rainforest.
Reply | Report Abuse | Link to this