Model shows ‘waves of forest degradation’


An international team of researchers has developed a model that suggests degradation of tropical forests occurs in a series of “waves”, reports the BBC News website’s Mark Kinver.

High-value trees were felled in the first “wave”, followed by a wave that removed mid-value timber before the remaining wood was felled for charcoal.

The team hopes the model will help manage forests as vital carbon sinks and limit the loss of biodiversity.

The findings appear in the Proceedings of the National Academy of Sciences.

The researchers said an economic theory was used to provide a general model to predict patterns of tree loss.

This translates to a prediction that waves of forest degradation will emanate from major demand centres and expand into nearby forested areas, targeting resources in sequence, starting with those of highest value,” they wrote in their PNAS paper.

“Such a sequence of demand, linked to resource utilisation, has been demonstrated for unmanaged fisheries… but has not been shown for the exploitation of differently valued tropical forest products.”

The team used data collected in the area surrounding Tanzania’s largest city, Dar es Salaam, to see how far the degradation “waves” had travelled between 1991 and 2005.

“The first wave that emanates is high-value timber, and that is mostly used for export,” explained co-author Antje Ahrends, an ecologist at the Royal Botanical Garden, Edinburgh.

“There has been a massive demand for this in China, and this is where most of the timber ends up.”

Dr Ahrends said the first wave moved out from Dar es Salaam rapidly, averaging about nine kilometres each year, because the “timber companies had lorries and loads of people working for them”.

“For the firms, it is only worthwhile to stay in a forest when timber can be accessed relatively easily,” she told BBC News.

“So once it becomes not so easy to get hold of the rest, the companies generally move on.”

The first wave had already moved outside of the team’s study area, and Dr Ahrends estimated that it was already more than 200km from Dar es Salaam.

The second wave saw trees being felled for medium-valued timber, which was generally used in the city for construction and furniture.

“This is expanding very rapidly, in line with urban migration,” she explained. “The town has an average growth rate of about 7% each year, so there is – again – a rapidly growing demand for this material.”

The timber is harvested by local companies, again with lorries, allowing large volumes to be collected in a relatively short space of time. This resulted in this degradation wave to also cover about nine kilometres each year.

The third and final wave involved local people collecting wood to make charcoal for cooking.

“It’s the most destructive of all of the waves because charcoal burners would collect everything,” observed Dr Ahrends, who was based at the York Institute for Tropical Ecosystem Dynamics when she carried out this research.

“It is only worthwhile moving on once there are no sizeable trees left in the forest.”

As a result, the charcoal wave had moved relatively slowly – from 20km outside Dar es Salaam in 1991 to 50km away in 2005.

“It is the most difficult of the waves to tackle because it is very poor people who burn charcoal and their livelihoods depend upon it.”

“Targeting that wave would mean trying to provide alternative resources for cooking, and alternative incomes for people who burn charcoal.

Species loss

The team also developed their model to gauge what impact forest degradation had on “public good” services, such as carbon storage and biodiversity.

They did this by recording what species of trees were in a particular area of the study, and what size the individual trees were.

“This later enabled us to calculate species richness and also the amount of carbon those trees were storing,” Dr Ahrends said.

“We found that there was a very strong linear impacts; for example, tree species richness dropped to only 14 species-per-sample-unit close to Dar es Salaam, whereas it is more than 40 species in areas 200km away.”

Dr Ahrends suggested that the model could be used to understand the impact of forest degradation in other sub-Sarahan nations in Africa.

“This is because conditions are very similar: high levels of corruption, weak law enforcement and very rapid rates of urbanisation.”

She added that the team’s model could help policymakers who were looking at ways to limit deforestation rates.

“What is really important is to understand the pattern of degradation and the way it spreads,” she suggested.

“While we have a good understanding of deforestation – which is the complete clearance of a forest – it is much more difficult to measure degradation.

“So if you have this simple model, then you have a basic understanding of how degradation might spread… which may help you develop some prediction of where it might spread from and how far it might spread.”

Source: BBC News website

Date: 03/08/2010

Indonesia ‘failing on pledge to reduce forest fires’


The Indonesian government failed to live up to its promises to reduce fires across the tropical nation last year, reports Mongabay.com.Take Cover library picture

It quotes The Jakarta Post as saying that the nation’s 2009 State Environment Report revealed a 59% increase in the number of fire hotspots from 19,192 in 2008 to 32,416 last year.

Officials are reported as saying that land clearing was the primary cause because, unlike temperature forests, intact rainforests rarely burn naturally.

“Illegal land clearing with fires by local people in Kalimantan and Sumatra is still rampant,” Heddy Mukna, deputy assistant for forest and land management at the Environment Ministry told the Post.

The state of Kalimantan on the island of Borneo saw fires triple in some areas from 2008 to 2009.

Haze blanketed much of the island last year during the “burning season”.

In 2007, the Indonesian government announced plan to cut forest fires in half to mitigate climate change from 35,279 fires in 2006.

The government has since revised that reduction from 50% to just 20%.

Indonesia is the third largest emitter of greenhouse gases in the world behind China and the US.

An estimated 80% of the nation’s 2.3 billion tonnes of greenhouse gas emissions is from rainforest and peatland destruction.

Source: Mongabay.com

Date: 13/06/2010

Key role of forests ‘may be lost’


Forests’ role as massive carbon sinks is “at risk of being lost entirely”, the BBC’s Mark Kinver has reported top forestry scientists as warning.

The International Union of Forest Research Organizations (IUFRO) says forests are under increasing degrees of stress as a result of climate change.

Forests could release vast amounts of carbon if temperatures rise 2.5C (4.5F) above pre-industrial levels, it adds.

The findings will be presented at the UN Forum on Forests, which begins on Monday in New York.

Compiled by 35 leading forestry scientists, the report provides what is described as the first global assessment of the ability of forests to adapt to climate change.

“We normally think of forests as putting the brakes on global warming,” observed Professor Risto Seppala from the Finnish Forest Research Institute, who chaired the report’s expert panel.

“But over the next few decades, damage induced by climate change could cause forests to release huge quantities of carbon and create a situation in which they do more to accelerate warming than to slow it down.”

The scientists hope that the report, called Adaption of Forests and People to Climate Change – A Global Assessment, will help inform climate negotiators.

The international climate debate has focused primarily on emissions from deforestation, but the researchers say their analysis shows that attention must also be paid to the impacts of climate change on forests.

While deforestation is responsible for about 20% of greenhouse gas emissions from human activities, forests currently absorb more carbon than they emit.

But the problem is that the balance could shift as the planet warms, the report concludes, and the sequestration service provided by the forest biomes “could be lost entirely if the Earth heats up by 2.5C or more”.

The assessment says higher temperatures – along with prolonged droughts, more pest invasions, and other environmental stresses – would trigger considerable forest destruction and degradation.

This could create a dangerous feedback loop, it adds, in which damage to forests from climate change would increase global carbon emissions that then exacerbate global warming.

The report’s key findings include:

  • Droughts are projected to become more intense and frequent in subtropical and southern temperate forests
  • Commercial timber plantations are set to become unviable in some areas, but more productive in others
  • Climate change could result in “deepening poverty, deteriorating public health, and social conflict” among African forest-dependent communities

The IUFRO assessment will be considered by delegates at the eighth session of the UN Forum on Forests, which has the objective of promoting the “management, conservation and sustainable development of all types of forest”.

Co-author Professor Andreas Fischlin from the Swiss Federal Institute of Technology commented: “Even if adaption measures are fully implemented, unmitigated climate change would – during the course of the current century – exceed the adaptive capacity of many forests.

“The fact remains that the only way to ensure that forests do not suffer unprecedented harm is to achieve large reductions in greenhouse gas emissions.”

Source: BBC News website

Date: 18/04/2009

Amazon deforestation trend ‘on the increase’


Deforestation in Brazil’s Amazon forests has flipped from a decreasing to an increasing trend, ScienceDaily reports.

Commenting on the figures released by the country’s space agency INPE, Brazilian environment minister Carlos Minc confirmed that the government was set to announce forest related carbon emission reduction targets.

He added that he hoped that the scheme would link halting deforestation to the national climate change campaign.

From August 2007 to July 2008, Brazil deforested 11,968 square kilometers of forests in the area designated as the Legal Amazon.

This was a 3.8% increase over the previous year and an unwelcome surprise following declines of 18% over the previous period.

From 2003-2004 to 2006-2007, annual deforestation totals from the agency fell from 27,423 sq-km to 11,532 sq-km.

There were fears that the current trend could have been worse but for new measures introduced part way through the year when it became apparent that annual deforestation was accelerating towards a possible 15,000 hectare level.

Source: ScienceDaily

Date: 04/01/2009

Canopy penetrating system boosts forest carbon monitoring


A tool for monitoring tropical deforestation has gotten a boost from the one of the world’s largest supporters of Amazon conservation, reports Mongabay.com.

The Gordon and Betty Moore Foundation has awarded a $1.6m grant to the Carnegie Institution’s Department of Global Ecology to expand and improve its tropical forest monitoring tool known as the Carnegie Landsat Analysis System Lite (CLASLite).

The Stanford University-based group says CLASLite “will rapidly advance deforestation and degradation mapping in Latin America, and will help rainforest nations better monitor their changing carbon budgets.”

The technology will also prove to be useful when the REDD (Reducing Emissions from Deforestation and Degradation) mechanism, currently under negotiation at international climate talks, comes online.

“About 20% of global greenhouse gas emissions come from deforestation and degradation of tropical forests,” said Greg Asner, project leader for CLASLite.

“Much of it occurs in developing nations, where monitoring capabilities are often unavailable to governments and NGOs.

“This grant allows us to improve and expand CLASLite, and to train many people from tropical forest nations so that they can determine where and when forest losses are occurring.

“Perhaps most importantly,” he added, “rainforest nations will be able to better determine how much CO2 comes from deforestation and degradation. (This) information has been very scarce in the past.

CLASLite is capable of penetrating the upper levels of the rainforest canopy and detecting small differences in vegetation patterns at a scale of about 100 feet (30 metres), producing forest maps from old and new data from Landsat satellites, as well as several other Nasa sensors in Earth orbit.

“The technology can sense changes resulting from selective logging and small surface fires that burn below the forest canopy.

Source: Mongabay.com

Date: 04/12/2008

Prince calls for rainforest bills


Prince Charles has called for rich countries to pay an annual “utility bill” for the benefits given to the world by its rainforests, the BBC News website reports.

Speaking in the Indonesian capital, Jakarta, the prince called rainforests the “world’s greatest public utility”.

They act as an air conditioner, store fresh water and provide work, he said.

The proposal by the Prince’s Rainforest Project would generate funds allowing rainforest countries to change their practices and halt deforestation.

The Prince of Wales outlined the plan in a speech to the Indonesian President, Dr Susilo Bambang Yudhoyono, and his cabinet in Jakarta.

He told the audience at the Merdeka Palace: “Indonesia and the other rainforest nations are stewards of the world’s greatest public utility.

“The rest of us have to start paying for it, just as we do for water, gas and electricity.”

He added: “Payments should have the characteristics of a commercial transaction, in the same way we pay for our water, gas and electricity.

“In return the rainforest nations would provide eco-services such as carbon storage, fresh water and the protection of biodiversity.”

The prince said the forests provided a livelihood for more than a billion people.

As developed nations were the driving force behind their destruction, through a demand for products like beef, palm oil, soya and logs, they should be billed for their protection, he said.

It is hoped that a large part of the funds raised from the “utility bills” would come from bonds issued by an international body.

Describing the form the annual billing could take, the prince said: “These emergency funds could be provided directly by developed world governments, perhaps from expanded development aid budgets, from surcharges on activities which cause climate change or from the auction of carbon market emission allowances.

“However, I hope that even in the short term the large part of the required funding could be provided by the private sector by subscribing to long-term bonds issued by an international agency.

“The issuing entity would pay the proceeds from the bonds to the rainforest nations. They in turn would use the money to re-orientate their economies to halt or refrain from deforestation.”

Earlier on his Indonesian visit, the Prince visited the Harapan Rainforest conservation project on the island of Sumatra as part of his 10-day tour of Asia.

Indonesia is the final leg of his tour. Prince Charles and the Duchess of Cornwall also visited Japan and Brunei, but he travelled to Indonesia alone as his wife has returned to Britain for other engagements.

Source: BBC News website

Date: 03/11/2008

CO2 ‘delays autumnal leaf fall’


Increasing levels of carbon dioxide in the atmosphere is extending trees’ growing season, say scientists.

However, as reported in the blog Science Centric, the news had been welcomed by the forestry sector.

Writing in the journal Global Change Biology, Professor David Karnosky from Michigan Technological University, US, led an international team of researchers that suggested that the lengthening of the growing season would make forests more productive because they would absorb more carbon before shedding their leaves.

The researchers from the US and Europe collected and analysed two years’ data of what they called “autumnal senescence“, or the changing of colours and falling of leaves, which was triggered by declining photosynthesis.

They found that the forests on both continents stayed greener longer as CO2 levels rose, independent of temperature changes.

However, they added that the experiments were too brief to indicate how mature forests may be impacted over time. Professor Karnosky also said that other factors, such as increasing levels of low-level ozone, could limit the beneficial effects of elevated carbon dioxide levels.

The blog said the research was another example of an expanding body of scientific evidence that global climate change was affecting the world’s forests.

Science Centric added that the effects of increased atmospheric CO2 on tree growth had been documented before, however, this report had challenged the prevailing view among scientists that other factors, such as temperature and length of day, were the primary elements influencing autumnal senescence.

Source: Science Centric blog

Date: 16/08/2008

Source: Michigan Technological University

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