When is a forest a forest

Prévia do material em texto

TEXTO 1 Para ler e elaborar glossário dos termos destacados em vermelho. 
Radical transparency: tracking deforestation through satellite imagery 
Julian Moll-Rocek, mongabay.com correspondent 
January 28, 2015 
This is the first in a two-part series about advances in mapping technology and how they're 
being used to keep a closer eye on the world's forests. Read the second part here. 
Floating softly through the vacuum of space, the Landsat 7 satellite has faithfully provided 
imaging of the entirety of earth’s surface, every 16 days, since 1999. Now a series of 
technological developments has made this silent spectator a dominant force in tracking forests 
worldwide. From his personal computer in Redwood City, California, Rhett Butler, founder and 
director of mongabay.com, identified an area of recent deforestation on the island of Sumatra. 
In less than 72 hours, he was bumping along a freshly cut logging road in a 4x4 Jeep, following 
his GPS to the coordinates of the identified forest loss. Rounding a hill, Butler came face to face 
with a massive clearing, oil palm seedlings already planted amidst the ruins of the freshly cut 
forest. 
Global Forest Watch (GFW), launched in February of 2014, is an online forest monitoring and 
alert system pioneered by the World Resources Institute in partnership with over 40 other 
organizations, including Google, Esri and the United Nations Environment Program. This 
platform allows for innovative transparency in tracking forest loss and re-growth, providing 
yearly tree cover change data from 2001-2012, available to anyone, at no cost, anywhere in the 
world. 
 
Global Forest Watch provides interactive maps of tree cover extent, loss and gain throughout 
the world. In total, 1.5 million square kilometers (580,000 square miles) of net tree cover were 
lost between 2001 and 2012, responsible for roughly 12 percent of global carbon greenhouse 
gas emissions. Image courtesy of Global Forest Watch. Click to enlarge. 
One of the main datasets mapped by GFW comes from the 2013 study “High-Resolution Global 
Maps of 21st-Century Forest Cover Change,” published by Matthew Hansen and colleagues in 
the journal Science. This massive dataset consists of over 600,000 individual images provided 
by the Landsat 7 satellite, and involved monumental computations made possible by a 
partnership with the Google Earth Engine team. The current GFW platform allows users to 
analyze user-defined areas for changes in forest extent using cloud-based servers, allowing for 
easy access to and customizability of this enormous dataset. 
Still, criticisms have been raised, largely focused around how forests were defined. Hansen and 
his team used an algorithm to distinguish forest cover from other surface types that defines 
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“forest” as vegetation over five meters (16 feet) in height. This definition does not differentiate 
between old growth forests and monoculture timber plantations, which provide vastly divergent 
biodiversity levels and ecosystem services. The area mapped as “tree cover” on the GFW 
platform includes eucalyptus plantations and even oil palm plantations, the expansion of which 
is driving deforestation in Indonesia. According to some critics, this conflation of forests with 
plantations has the potential for abuse by local policy makers, who stand to gain from getting 
credited with pro-forest policies while expanding lucrative oil palm plantations. 
 
Rising demand for palm oil has been driving deforestation as forests are replaced by oil palm 
plantations. These scenes from Indonesia show the stark contrast between these landscapes, 
which have huge implications for biodiversity levels and ecosystem services. As of now, the 
GFW dataset does not distinguish between plantations and forest, as long as vegetation 
surpasses the minimum threshold of five meters in height. Images by Rhett Butler. 
The existing confusion in forest definitions may have serious implications for governments and 
decision makers. “In Indonesia there has been a real political debate on what the real numbers 
are,” said Dr. Fred Stolle of WRI in an interview with mongabay.com. A recent study in Nature 
Climate Change published by researchers at the University of Maryland and the World 
Resources Institute (two leading partners in GFW) had found increasing levels of deforestation 
in primary forests, which conflict with the Indonesian National Forestry Ministry’s reports of a 
decreasing trend in forest loss. Three high-level roundtables were convened to debate the 
matter, with representatives from the Indonesian government, University of Maryland, WRI and 
others present. The debate remains unresolved. 
The delicate nature of this forest definition game was made evident in 2000 when the Food and 
Agriculture Organization, an agency of the United Nations, changed its forest definition to a 
uniform definition across developing and developed nations in anticipation of the global Forest 
Resource Assessment. This change resulted in an additional 300 million hectares, or an 
increase in global forest levels of about 10 percent. 
Instead of aligning itself with any specific forest definition, GFW has decided to provide open 
access to these data while clearly stating how each dataset is defined. “We aim to provide a 
platform that can host a wide variety of information on forests, and make all that information 
transparent and accessible to everybody,” said WRI’s communications officer James Anderson. 
This flexible approach allows GFW to provide data while leaving its interpretation open to local 
perceptions. Anderson explained, “Maybe the solution is not always a single global definition, 
because values differ from place to place, and forests are just so different across the world. So 
the way in which we measure and monitor them needs to be different in different places.” 
Anderson emphasized how important it is for users to understand just what is shown on the 
maps they are looking at. “Reading the fine print is important! Misinterpretation is definitely a 
danger, but it’s always been a danger, even before GFW,” he said. “GFW has put this data out 
there in a way that’s never been seen before. I think it’s good and healthy for us to have a 
dialogue about that.” 
These are critical times for the world’s forests, highlighted by the recent UN climate summit in 
New York. One of its components, the New York Declaration on Forests, included a call to cut 
deforestation in half by 2020, and altogether by 2030, as well as restore an area larger than 
India by 2030. 
As the world awakens to the importance of its forests, the need for a clear understanding of 
those forests becomes more pertinent. “We’ve made a lot of changes in just the past few 
http://www.sciencemag.org/content/344/6187/981.4.full
months,” Anderson said. “We now have access to more and more high-resolution imagery. 
Meeting these commitments means forest change needs to be measured clearly.” 
Citations: 
Hansen, M. C., Potapov, P., Moore, R., Hancher, M., Turubanova, S. A., Tyukavina, A., … 
Townshend, J. R. G. (2013). High-Resolution Global Maps of 21st-Century Forest Cover 
Change. Science, 850(342), 850–853. 
Hansen, M. (2014). Response to Comment on “High-resolution global maps of 21st-century 
forest cover change.” Science, 981(344). 
Putz, F. E., & Romero, C. (2014). Futures of Tropical Forests ( sensu lato ). Biotropica, 46(4), 
495–505. 
Sasaki, N., & Putz, F. E. (2009). Critical need for new definitions of “forest” and “forest 
degradation” in global climate change agreements. Conservation Letters, 2(5), 226–232. 
Margono, B. A., Potapov,P. V, Turubanova, S., Stolle, F., & Hansen, M. C. (2014). Primary 
forest cover loss in Indonesia over 2000-2012. Nature Clim. Change, 4(8), 730–735. Retrieved 
from http://dx.doi.org/10.1038/nclimate2277 
Martin Persson, Sabine Henders, and Thomas Kastner. 2014. "Trading Forests: Quantifying the 
Contribution of Global Commodity Markets to Emissions from Tropical Deforestation." CGD 
Working Paper 384. Washington, DC: Center for Global Development. 
http://www.cgdev.org/publication/trading-forests-quantifying-contribution-global- commodity-
markets-emissions-tropical 
Tropek, R., Sedláček, O., Beck, J., Keil, P., Musilová, Z., Símová, I., & Storch, D. (2014). 
Comment on “High-resolution global maps of 21st-century forest cover change”. Science (New 
York, N.Y.), 344(6187), 981. 
http://news.mongabay.com/2015/0128-gfrn-moll-rocek-tracking-deforestation-through-satellite-
imagery.html 
 
Ver http://www.redd-monitor.org/wp-content/uploads/2009/09/2009-Putz-Conservation-Letters-
on-REDD.pdf 
http://www.sciencemag.org/content/344/6187/981.4.full 
 
TEXTO 2 – Tradução dos trechos destacados em vermelho 
When is a forest a forest? How definitions affect monitoring 
Julian Moll-Rocek, mongabay.com correspondent 
January 29, 2015 
This is the second in a two-part series about advances in mapping technology and how they're 
being used to keep a closer eye on the world's forests. Read the first part here. 
 
This acacia timber plantation in Colombia may be defined as forest by satellite data. Photo by 
Rhett A. Butler. 
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http://www.redd-monitor.org/wp-content/uploads/2009/09/2009-Putz-Conservation-Letters-on-REDD.pdf
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http://www.sciencemag.org/content/344/6187/981.4.full
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“We live in a world of constant beta,” explains James Anderson, communications officer for the 
World Resources Institute’s (WRI) Forests program. Nearly every week features are tweaked on 
the Global Forest Watch (GFW) platform, an innovative mapping system that allows users to 
track changes in global forest extent, among other features. Constant innovation in 
technological capability as well as broad social engagement, allowing for more on the ground 
verification, keep GFW on the cutting edge of forest monitoring. 
However, one fundamental thing remains elusive: what exactly is a forest? With forest 
definitions differing from country to country, and primary forests, secondary forests, and even 
tree plantations all perceived collectively as "tree cover" by satellite data, how does one 
accurately keep tabs on land changes? 
To confront this issue, GFW has implemented a number of new features in recent months. One 
of these allows the user to adjust the density of tree cover to suit their own definition of “forest.” 
Ranging from 10 to 75 percent canopy cover, this reflects the flexible definition put forth by the 
Kyoto Protocol, which required countries to define a national canopy cover between 10 and 30 
percent. 
 
Global Forest Watch allows users to adjust the density of tree cover to suit their own definition 
of “forest.” The intention is to allow users to use a definition of forest that is most appropriate for 
their local ecosystem. It is important to be aware of how this can be used to manipulate tree 
cover, as in this example of Uganda, where different thresholds result in a more than 25-fold 
difference in tree cover percentage. Image courtesy of Global Forest Watch. Click to enlarge. 
However, the function is not without its caveats; namely, it can only be applied to forest extent 
and loss, but not to forest gains. As Dr. Fred Stolle, manager of WRI's Forest Landscape 
Objective explained, “a signal of a tree falling is very easily recognized, but of course regrowing 
from a seedling to a bigger seedling to a tree takes a couple years before you see it. How we 
deal with that, we don’t know yet.” In particular, the difficulty in using remote sensing techniques 
in classifying the re-growth of forests means serious challenges for monitoring forest restoration 
goals set by the UN. 
One of the group’s biggest priorities is integrating an extensive global land use/land cover map. 
“Tree cover extent is just tree cover extent," Stolle said. "It doesn’t say if its primary forest, 
secondary forest, agroforest or whatever. So that is one of the problems that we have. We 
would like to get much deeper into distinguishing different forest types." 
Their ongoing work into tree cover differentiation may help resolve the main criticism leveled at 
GFW and similar remote sensing-based forest-monitoring tools: the lack of distinction between 
natural forests and plantations. In partnership with Transparent World, a non-profit specialized 
in remote sensing and mapping projects, WRI is using highly skilled experts to visually 
distinguish plantations from natural forests in satellite images. The process relies on a set of 
indirect indicators such as road networks, landscape dynamics and fire frequency to narrow 
down areas that are then checked by humans. 
As Dmitry Aksenov of Transparent World explained, “many countries report plantations as forest 
to make the picture look nicer internationally. Nowadays it is also a carbon sink issue. Also it 
may be a way for hiding real deforestation if plantation development is presented as successful 
reforestation. On the other hand, some tree cover loss detected may not be deforestation but 
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the rotation of plantations after periodic harvest.” To date, the organization has completed the 
mapping of plantations for Malaysia, Liberia and Colombia, and is hoping to finish a first draft of 
Brazil, Indonesia, Peru and Cambodia by March 2015. This would represent over 50 percent of 
existing tropical plantations globally. 
 
An acacia timber plantation abuts rainforest in Sabah, Indonesia. Monoculture tree plantations 
don't house the biodiversity of natural forest, but can look deceptively similar from the air. Photo 
by Rhett A. Butler. 
Through these new forms of forest data representation, GFW has made policy impacts across 
the globe. In Central America, a group of countries is cracking down on illegal logging, and will 
begin using GFW's forest extent as a baseline for monitoring logging activity, according to 
Anderson. Pressure is mounting to increase transparency regarding forest data as this becomes 
the new global standard. Equatorial Guinea, a small African nation that has been notorious for 
corruption surrounding its lucrative forestry sector recently released its land use information 
publicly. Improving technologies and information accessibility means corrupt exploitation of 
natural resources is increasingly difficult to hide. 
The continuous evolution of GFW has been more than just technological, according to 
Anderson. “We started off with a simpler vision, using the best technology available to monitor 
and map forests," he said. "But the process itself has been just as eye-opening as the results. 
We’ve heard a lot more perspectives, and we’ve been able to encourage other people to talk to 
each other. We are still at the early stages in our global discussion about these things. We are 
starting to coordinate better, across countries, across organizations, and this is part of that 
process.” 
Citations: 
Hansen, M. C., Potapov, P., Moore, R., Hancher, M., Turubanova, S. A., Tyukavina,A., … 
Townshend, J. R. G. (2013). High-Resolution Global Maps of 21st-Century Forest Cover 
Change. Science, 850(342), 850–853. 
Tropek, R., Sedláček, O., Beck, J., Keil, P., Musilová, Z., Símová, I., & Storch, D. (2014). 
Comment on “High-resolution global maps of 21st-century forest cover change.” Science (New 
York, N.Y.), 344(6187), 981. 
Hansen, M. (2014). Response to Comment on “High-resolution global maps of 21st-century 
forest cover change.” Science, 981(344). 
Putz, F. E., & Romero, C. (2014). Futures of Tropical Forests (sensu lato). Biotropica, 46(4), 
495–505. 
Sasaki, N., & Putz, F. E. (2009). Critical need for new definitions of “forest” and “forest 
degradation” in global climate change agreements. Conservation Letters, 2(5), 226–232. 
http://www.theguardian.com/global-development/2013/jun/13/transparency-equatorial-guinea-tutu-alicante
http://www.theguardian.com/global-development/2013/jun/13/transparency-equatorial-guinea-tutu-alicante
http://www.wri.org/resources/maps/forest-atlas-equatorial-guinea