亚马逊森林遭受毁灭的根源分析报告
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Deforestation in the Amazon
By Rhett A Butler
Between May 2000 and August 2006, Brazillost nearly 150,000 square kilometers offorest—an area larger than Greece—and since 1970, over 600,000 squarekilometers (232,000 square miles) of Amazon rainforest have beendestroyed. Why is Brazil losing so much forest? What can be done toslow deforestation?
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DEFORESTATION IN BRAZIL: 60-70 percent of deforestation in theAmazon results from cattle ranches while the rest mostly results fromsmall-scale subsistence agriculture. Despite the widespread pressattention, large-scale farming (i.e. soybeans) currently contributesrelatively little to total deforestation in the Amazon. Most soybeancultivation takes place outside the rainforest in the neighboringcerrado grassland ecosystem and in areas that have already beencleared. Logging results in forest degradation but rarely directdeforestation. However, studies have showed a close correlation betweenlogging and future clearing for settlement and farming. [Português | Español]
Deforestation by state |
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| Deforestation Figures for Brazil
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Year | Deforestation
[sq mi] | Deforestation
[sq km] | Change
[%] |
|
|
|
| | 1988 | 8,127 | 21,050 |
| | 1989 | 6,861 | 17,770 | -16% | | 1990 | 5,301 | 13,730 | -23% | | 1991 | 4,259 | 11,030 | -20% | | 1992 | 5,323 | 13,786 | 25% | | 1993 | 5,751 | 14,896 | 8% | | 1994 | 5,751 | 14,896 | 0% | | 1995 | 11,220 | 29,059 | 95% | | 1996 | 7,012 | 18,161 | -38% | | 1997 | 5,107 | 13,227 | -27% | | 1998 | 6,712 | 17,383 | 31% | | 1999 | 6,664 | 17,259 | -1% | | 2000 | 7,037 | 18,226 | 6% | | 2001 | 7,014 | 18,165 | 0% | | 2002 | 8,187 | 21,205 | 17% | | 2003 | 9,711 | 25,151 | 19% | | 2004 | 10,590 | 27,429 | 9% | | 2005 | 7,256 | 18,793 | -31% | | 2006 | 5,421 | 14,040 | -49% | | 2007 | 3,865 | 10,010 | -47% |
All figures derived from official National
Institute of Space Research (INPE) data. Individual state figures.
*For the 1978-1988 period the figures represent
the average annual rates of deforestation.
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Causes of deforestation in the Amazon
| Cattle ranches |
| 60-70% | | Small-scale, subsistence agriculture |
| 30-40% | | Large-scale, commercial agriculture |
| 1-2% | | Logging, legal and illegal |
| 2-4% | | Fires, mining, urbanization, road construction, dams |
| 2-4% | | Selective logging and fires that burn under the forestcanopy commonly result in forest degradation, not deforestation.Therefore these factor less in overall deforestation figures. |
The above pie chart showing deforestation in the Amazonby cause is based on the median figures for estimate ranges. Pleasenote the low estimate for large-scale agriculture. Between 2000-2005soybean cultivation reesulted in a small overall percentage of directdeforestation. Nevertheless the role of soy is quite significant in theAmazon. As explained by Dr. Philip Fearnside, "Soybean farms cause someforest clearing directly. But they have a much greater impact ondeforestation by consuming cleared land, savanna, and transitionalforests, thereby pushing ranchers and slash-and-burn farmers everdeeper into the forest frontier. Soybean farming also provides a keyeconomic and political impetus for new highways and infrastructureprojects, which accelerate deforestation by other actors."
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Why is the Brazilian Amazon being Destroyed?Inmany tropical countries, the majority of deforestation results from theactions of poor subsistence cultivators. However, in Brazil only aboutone-third of recent deforestation can be linked to "shifted"cultivators. Historically a large portion of deforestation in Brazilcan be attributed to land clearing for pastureland by commercial andspeculative interests, misguided government policies, inappropriateWorld Bank projects, and commercial exploitation of forest resources.For effective action it is imperative that these issues be addressed.Focusing solely on the promotion of sustainable use by local peoplewould neglect the most important forces behind deforestation in Brazil.
Brazilian deforestation is strongly correlated to the economichealth of the country: the decline in deforestation from 1988-1991nicely matched the economic slowdown during the same period, while therocketing rate of deforestation from 1993-1998 paralleled Brazil'speriod of rapid economic growth. During lean times, ranchers anddevelopers do not have the cash to rapidly expand their pasturelandsand operations, while the government lacks funds to sponsor highwaysand colonization programs and grant tax breaks and subsidies to forestexploiters.
A relatively small percentage of large landowners clear vastsections of the Amazon for cattle pastureland. Large tracts of forestare cleared and sometimes planted with African savanna grasses forcattle feeding. In many cases, especially during periods of highinflation, land is simply cleared for investment purposes. Whenpastureland prices exceed forest land prices (a condition made possibleby tax incentives that favor pastureland over natural forest), forestclearing is a good hedge against inflation.
Such favorable taxation policies, combined with governmentsubsidized agriculture and colonization programs, encourage thedestruction of the Amazon. The practice of low taxes on income derivedfrom agriculture and tax rates that favor pasture over forestovervalues agriculture and pastureland and makes it profitable toconvert natural forest for these purposes when it normally would not beso.
A Closer Look at Brazilian Deforestation
Today deforestation in the Amazon is the result of several activities, the foremost of which include:
Clearing for Cattle Pasture
Cattleranching is the leading cause of deforestation in the Brazilian Amazon.This has been the case since at least the 1970s: government figuresattributed 38 percent of deforestation from 1966-1975 to large-scalecattle ranching. However, today the situation may be even worse.According to the Center for International Forestry Research(CIFOR), "between 1990 and 2001 the percentage of Europe's processedmeat imports that came from Brazil rose from 40 to 74 percent" and by2003 "for the first time ever, the growth in Brazilian cattleproduction—80 percent of which was in the Amazon—was largely exportdriven."
Several factors have spurred recent Brazil's growth as a producer of beef:- CURRENCYDEVALUATION—The devaluation of the Brazilian real against the dollareffectively doubled the price of beef in reals and created an incentivefor ranchers to expand their pasture areas at the expense of therainforest. The weakness of the real also made Brazilian beef morecompetitive on the world market [CIFOR].
- CONTROL OVER FOOT-AND-MOUTH DISEASE—The eradication offoot-and-mouth disease in much of Brazil has increased price and demandfor Brazilian beef.
- INFRASTRUCTURE—Road construction gives developers andranchers access to previously inaccessible forest lands in the Amazon.Infrastructure improvements can reduce the costs of shipping andpacking beef.
- INTEREST RATES—Rainforest lands are often used for landspeculation purposes. When real pasture land prices exceed real forestland prices, land clearing is a good hedge against inflation. At timesof high inflation, the appreciation of cattle prices and the stream ofservices (milk) they provide may outpace the interest rate earned onmoney left in the bank.
- LAND TENURE LAWS—In Brazil, colonists and developers can gaintitle to Amazon lands by simply clearing forest and placing a few headof cattle on the land. As an additional benefit, cattle are a low-riskinvestment relative to cash crops which are subject to wild priceswings and pest infestations. Essentially cattle are a vehicle for landownership in the Amazon.
Some have suggested that agricultural certification could help reduce destructive clearing for cattle pasture.
Colonization and subsequent subsistence agriculture
Asignificant amount of deforestation is caused by the subsistenceactivities of poor farmers who are encouraged to settle on forest landsby government land policies. In Brazil, each squatter acquires theright (known as a usufruct right) to continue using a piece of land byliving on a plot of unclaimed public land (no matter how marginal theland) and "using" it for at least one year and a day. After five yearsthe squatter acquires ownership and hence the right to sell the land.Up until at least the mid-1990s this system was worsened by thegovernment policy that allowed each claimant to gain title for anamount of land up to three times the amount of forest cleared.
Poor farmers use fire for clearing land and every year satellite images pick up tens of thousands of fires burning across the Amazon.Typically understory shrubbery is cleared and then forest trees arecut. The area is left to dry for a few months and then burned. The landis planted with crops like bananas, palms, manioc, maize, or rice.After a year or two, the productivity of the soil declines, and thetransient farmers press a little deeper and clear new forest for moreshort-term agricultural land. The old, now infertile fields are usedfor small-scale cattle grazing or left for waste.
Between 1995 and 1998, the government granted land in theAmazon to roughly 150,000 families. Forty-eight percent of forest lossin 1995 was in areas under 125 acres (50 hectares) in size, suggestingthat both loggers and peasants are significant contributors todeforestation.
Infrastructure Improvements
Roadconstruction in the Amazon leads to deforestation. Roads provide accessto logging and mining sites while opening forest frontier land toexploitation by poor landless farmers.
Brazil's Trans-Amazonian Highway was one of the most ambitiouseconomic development programs ever devised, and one of the mostspectacular failures. In the 1970s, Brazil planned a 2,000-mile highwaythat would bisect the massive Amazon forest, opening rainforest landsto (1) settlement by poor farmers from the crowded, drought-plaguednorth and (2) development of timber and mineral resources. Colonistswould be granted a 250-acre lot, six-months' salary, and easy access toagricultural loans in exchange for settling along the highway andconverting the surrounding rainforest into agricultural land. The planwould grow to cost Brazil US$65,000 (1980 dollars) to settle eachfamily, a staggering amount for Brazil, a developing country at thetime.
The project was plagued from the start. The sediments of theAmazon Basin rendered the highway unstable and subject to inundationduring heavy rains, blocking traffic and leaving crops to rot. Harvestyields for peasants were dismal since the forest soils were quicklyexhausted, and new forest had to be cleared annually. Logging wasdifficult due to the widespread distribution of commercially valuabletrees. Rampant erosion, up to 40 tons of soil per acre (100 tons/ha)occurred after clearing. Many colonists, unfamiliar with banking andlured by easy credit, went deep into debt.
Adding to the economic and social failures of the project, arethe long-term environmental costs. After the construction of theTrans-Amazonian Highway, Brazilian deforestation accelerated to levelsnever before seen and vast swaths of forest were cleared forsubsistence farmers and cattle-ranching schemes. The Trans-AmazonianHighway is a prime example of the environmental havoc that is caused byroad construction in the rainforest.
Road construction and improvement continues in the Amazon today: Paving of roads brings change in the Amazon rainforest and the Chinese economy drives road-building and deforestation in the Amazon
Commercial agriculture
Recently,soybeans have become one of the most important contributors todeforestation in the Brazilian Amazon. Thanks to a new variety ofsoybean developed by Brazilian scientists to flourish in rainforestclimate, Brazil is on the verge of supplanting the United States as theworld's leading exporter of soybeans. High soybean prices have also served as an impetus to expanding soybean cultivation.
Philip Fearnside, co-author of a report in Science[21-May-04] and member of Brazil's National Institute for AmazonianResearch in Manaus, explains,"Soybean farms cause some forest clearing directly. But they have amuch greater impact on deforestation by consuming cleared land,savanna, and transitional forests, thereby pushing ranchers andslash-and-burn farmers ever deeper into the forest frontier. Soybeanfarming also provides a key economic and political impetus for newhighways and infrastructure projects, which accelerate deforestation byother actors."
Satellite data from 2004 shows a marked increase in deforestation along the BR-163 road,a highway the government has been paving in an effort to help soyfarmers from Mato Grosso get their crops to export markets. Typically,roads encourage settlement by rural poor who look to the rainforest asfree land for subsistence agriculture.
Logging
Intheory, logging in the Amazon is controlled by strict licensing whichallows timber to be harvested only in designated areas. However, thereis significant evidence that illegal logging is quite widespread inBrazil. In recent years, Ibama—Brazil's environmental enforcementagency—has made several large seizures of illegally harvested timberincluding one in September 2003 when 17 people were arrested forallegedly cutting 10,000 hectares worth of timber.
Logging in the Amazon is closely linked with road building.Studies by the Environmental Defense Fund show that areas that havebeen selectively loggedare eight times more likely to be settled and cleared by shiftingcultivators than untouched rainforests because of access granted bylogging roads. Logging roads give colonists access to rainforest, whichthey exploit for fuelwood, game, building material, and temporaryagricultural lands.
Other causes of forest loss in Brazil
Historically,hydroelectric projects have flooded vast areas of Amazon rainforest.The Balbina dam flooded some 2,400 square kilometers (920 square miles)of rainforest when it was completed. Phillip Fearnside, a leadingexpert on the Amazon, calculated that in the first three years of itsexistence, the Balbina Reservoir emitted 23,750,000 tons of carbondioxide and 140,000 tons of methane, both potent greenhouse gases whichcontribute to global climate change.
Mining has impacted some parts of the Amazon Basin. During the1980s, over 100,000 prospectors invaded the state of Para when a largegold deposit was discovered, while wildcat miners are still active inthe state of Roraima near the Venezuelan border. Typically, minersclear forest for building material, fuelwood collection, andsubsistence agriculture.
Fires
Virtuallyall forest clearing, by small farmer and plantation owner alike, isdone by fire. Though these fires are intended to burn only limitedareas, they frequently escape agricultural plots and pastures and charpristine rainforest, especially in dry years like 2005.Many of the fires set for clearing forest for these purposes are setduring the three-month burning season and the smoke produced createswidespread problems across the region, including airport closings andhospitalizations from smoke inhalation. These fires cover a vast areaof forest. In 1987 during a four-month period (July-October), about19,300 square miles (50,000 sq. km) of Brazilian Amazon were burned inthe states of Parà, Rondonia, Mato Grosso, and Acre. The burningproduced carbon dioxide containing more than 500 million tons ofcarbon, 44 million tons of carbon monoxide, and millions of tons ofother particles and nitrogen oxides. An estimated 20 percent of firesthat burn between June and October cause new deforestation, whileanother 10 percent is the burning of ground cover in virgin forests.
Fires and climate change are having a dramatic impact on the Amazon. Recent studiessuggest that the Amazon rainforest may be losing its ability to staygreen all year long as forest degradation and drought make it dangerously flammable.Scientists say that as much as 50 percent of the Amazon could go up insmoke should fires continue. Humidity levels were the lowest everrecorded in the Amazon in 2005.
Slavery and Violence in the Amazon
TheAmazon has been a place of violence since at least the arrival ofEuropean explorers, and the present is no exception. Violent conflictsbetween large landowners, poor colonists, and indigenous groups overland are not unusual in the Amazon and may be worsening.
The Pastoral Land Commission, a nongovernmental group workingin the region, found that land battles in Brazil's countryside reachedthe highest level in at least 20 years in 2004. According to the annualreport by the organization, documented conflicts over land amongpeasants, farmers, and land speculators rose to 1,801 in 2004 from1,690 conflicts in 2003 and 925 recorded in 2002. Tensions reachedtheir peak earlier this year with the high-profile slaying of DorothyStang, an American nun who worked with rural poor, by gunmen associatedwith plantation owners. In response to the murder, the Braziliangovernment sent in the army to quell violence in the region andpromised to step up environmental monitoring efforts.
The government has also stepped up efforts to end slavery inthe Amazon. While Brazil officially abolished slavery in 1888, thegovernment acknowledges that at least 25,000 Brazilians work under"conditions analogous to slavery," clearing land and working for cattleranches, soy farms, and other labor-intensive industries. Some groupssay the true figure could be ten times that amount. In 2005, 4,133slaves were freed after Brazilian Swat-style teams raided 183 farms.
What can de done to save the Amazon rainforest in Brazil?Today Brazil faces an enormous challenge: how to balance economic growth with the preservation of the Amazon rainforest.
News on the Amazon Rainforest XMLU.S. corn subsidies drive Amazon destruction
(12/13/2007)U.S. corn subsidies for ethanol production are contributing todeforestation of the Amazon rainforest, reports a tropical forestscientist writing in this week's issue of the journal Science.
Amazon Conservation Team wins "Innovation in Conservation Award" for path-breaking work with Amazon tribes
(12/11/2007) The Amazon Conservation Team (ACT) was today awardedmongabay.com's inaugural "Innovation in Conservation Award" for itspath-breaking efforts to enable indigenous Amazonians to maintain tiesto their history and cultural traditions while protecting theirrainforest home from illegal loggers and miners.
Controversial dam in the Amazon gets Brazilian go-ahead
(12/11/2007) The Brazilian government has awarded rights to build andoperate a controversial R$10bn hydroelectric power plant on the Madeirariver in the Amazon rainforest near the border with Bolivia, accordingto FT.com.
A comprehensive look at the use of animals in Brazilian medicine
(12/10/2007) For millennia animals have been used in medicine asremedies. While this practice has all but disappeared in westerncountries, many cultures still employ traditional medicine thatincludes animal-derived remedies. Probably the most famous of these arethe Chinese, who for example use seahorses for a variety of ailmentsand rhinoceros horn as an aphrodisiac. Lesser known and studied, thoughjust as varied and rich is Brazil's long tradition of animal-remediesfor all kinds of ailments. A recent study set out to document thewide-range of animals used in Brazilian traditional medicine and itspossible consequences on animal populations, the environment, andBrazilian society.
Amazon deforestation rates drop 20% in 2007
(12/8/2007) Deforestation rates in Brazil's Amazon rainforest dropped20 percent since last year, reported the Brazilian National Instituteof Space Research (INPE).
Global warming accelerates destruction of the Amazon
(12/6/2007) Deforestation and climate change could damage or destroy asmuch as 60 percent of the Amazon rainforest by 2030, according to a newreport from environmental group WWF. The report, The Amazon's ViciousCycles: Drought and Fire in the Greenhouse, shows that degradation inthe Amazon could release 55-97 million tons of carbon dioxide by 2030.Forest loss could also dramatically impact water cycles in the region,affecting rainfall that is critical for river flows and agriculture.
Amazon deforestation could be eliminated with carbon priced at $3
(12/4/2007) The Amazon rainforest could play a major part in reducinggreenhouse gas emissions that result from deforestation, reports a newstudy published by scientists at the Woods Hole Research Center, theInstituto de Pesquisa Ambiental da Amazônia, and the UniversidadeFederal de Minas Gerais. At a carbon price of $3 per ton, protectingthe Amazon for its carbon value could outweigh the opportunity costs offorgoing logging, cattle ranching, and soy expansion in the region.2008 certified emission-reduction credits for carbon currently trade atmore than $90 per ton ($25 per ton of CO2).
Could the carbon market save the Amazon rainforest?
(11/29/2007) The global carbon market could play a key role in savingthe Amazon from the effects of climate change and economic development,which could otherwise trigger dramatic ecological changes, reports anew paper published in Science. The authors argue that awell-articulated plan, financed by carbon markets, could prevent theworst outcomes for the Amazon forest while generating economic benefitsfor the region's inhabitants.
Dutch bank arranges carbon-conservation deal in the Amazon rainforest
(11/27/2007) Dutch bank Rabobank will launch the first-ever carboncredits project in the Xingu region of the Brazilian Amazon, reportsThe Financial Times.
Ground-breaking Amazon rainforest imagery will help monitor deforestation
(11/27/2007) Scientists have developed a ground-breaking highresolution snapshot of 400,000 square kilometers of Amazon rainforest.The work will help researchers remotely monitor deforestation,according to the Woods Hole Research Center (WHRC).
Amazon rainforest children to get medicinal plant training from shamans
(11/21/2007) The Amazon Conservation Team (ACT) -- a group usinginnovative approaches to preserving culture and improving health amongAmazonian rainforest tribes -- has been awarded a $100,000 grant fromNature's Path, an organic cereal manufacturer. The funds will allow ACTto address one of the most pressing social concerns for Amazon forestdwellers by expanding its educational and cultural "Shamans andApprentice" program for indigenous children in the region.
Whale stranded 1,000 miles up the Amazon river
(11/17/2007) An 18-foot minke whale was found beached on a sandbar1,000 miles up a tributary of the Amazon river, reported Globotelevision and the Associated Press.
In the Amazon, primary forest biodiversity tops that of secondary forest, plantations
(11/12/2007) Plantations and secondary forests are no match for primaryAmazon rainforest in terms of biodiversity, reports the largest everassessment of the biodiversity conservation value in the tropics.
Subtle threats could ruin the Amazon rainforest
(11/7/2007) While the mention of Amazon destruction usually conjures upimages of vast stretches of felled and burned rainforest trees, cattleranches, and vast soybean farms, some of the biggest threats to theAmazon rainforest are barely perceptible from above. Selective logging-- which opens up the forest canopy and allows winds and sunlight todry leaf litter on the forest floor -- and 6-inch high "surface" firesare turning parts of the Amazon into a tinderbox, putting the world'slargest rainforest at risk of ever-more severe forest fires. At thesame time, market-driven hunting is impoverishing some areas of seeddispersers and predators, making it more difficult for forests torecover. Climate change -- an its forecast impacts on the Amazon basin-- further looms large over the horizon.
Proposed gold mine proves controversial in French Guiana rainforest
(11/7/2007) Commercial gold mining threatens a key forest reserve andwetland in French Guiana say scientists who warn that exploitationcould pollute rivers with toxic compounds, threaten wildlife, and putindigenous populations at risk.
New peccary species discovered by embattled Amazon scientist
(11/4/2007) A new species of peccary has been discovered in the Amazonrainforest by a scientist recently charged with biopiracy by theBrazilian government.
Amphibian extinction may be worse than thought
(10/31/2007) Amphibian extinction rates may be higher than previouslythought, according to new DNA analysis that found more than 60unrecognized species in the Guiana Shield of South America.
2007 Amazon fires among worst ever
(10/22/2007) By some measures, forest fires in the Amazon are atnear-record levels, according to analysis Brazilian satellite data bymongabay.com. A surge in soy and cattle prices may be contributing toan increase in deforestation since last year. Last yearenvironmentalists and the Brazilian government heralded a sharp fall indeforestation rates, the third consecutive annual decline after a peakin 2004. Forest loss in the 2006-2007 season was the lowest sincerecord-keeping began in the late in 1970s. While the government triedto claim credit for the drop, analysts at the time said that commodityprices were a more likely driver of slow down: both cattle and soyprices had declined significantly over the previous months.
Brazil to search for oil in the Amazon
(10/21/2007) Brazil's plan to seek oil in the Western Amazon has upsetenvironmentalists, reports the Associated Press (AP). The NationalPetroleum Agency, or ANP, plans to put US$36 million toward oil and gasexploration in Acre, a state bordering Bolivia, according to Brazilianstate media Agencia Brasil, but environmental officials say no impactstudy has been done to assess how the plan could affect the Amazon.
Uncontacted Amazon tribe spotted by plane in Peru
(10/21/2007) A group of uncontacted indigenous tribesmen were spottedby plane in a remote part of the Peruvian Amazon last month, accordingto Survival International. The region is threatened by illegal mahoganyloggers.
News on the Amazon Rainforest XML
Causes and Effects of Deforestation
THE AMAZON RAINFOREST
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发表于 2007/12/16 03:29:47
