Tropical tree offers mosquito repellent hope


Isolongifolenone, a natural compound found in the Tauroniro tree (Humiria balsamifera) of South America, has been identified as an effective deterrent of mosquitoes and ticks, reports Mongabay.com

It quotes researchers writing in the Journal of Medical Entomology, who said that derivatives of the compound have long been used as fragrances in cosmetics, perfumes, deodorants, and paper products.

However, they added, new processing methods could make it as inexpensive to produce as DEET – a potent and widely available synthetic insect repellent that works by blocking the aroma of human sweat.

The authors, led by Aijun Zhang of the US Department of Agriculture’s Invasive Insect Biocontrol and Behavior Laboratory, found that isolongifolenone deters the biting of the mosquitoes Aedes aegypti and Anopheles stephensi “more effectively than the widely used synthetic chemical repellent N,N-diethyl-3-methyl benzamide (DEET) in laboratory bioassays”, and repels blacklegged ticks and lone star ticks “as effectively as DEET”.

“Isolongifolenone is easily synthesized from inexpensive turpentine oil feedstock,” the authors wrote.

“We are therefore confident that the compound has significant potential as an inexpensive and safe repellent for protection of large human populations against blood-feeding arthropods.”

Tauroniro, whose common names include Bastard bulletwood, Oloroso, Couramira, or Turanira, is found in marshy forests in the Guianas, Colombia, Venezuela, and the Brazilian Amazon, according to the US Forest Service.

Source: Mongabay.com

Date: 05/02/2009

Disagreement over rainforest recovery


Will rainforests survive? That was the topic of a debate at the Smithsonian Institution’s National Museum of Natural History.

Satellite data and other research has revealed that huge tracts of abandoned tropical forests, which were once logged or farmed, are regrowing.

This evidence has prompted a contentious exchange of views and theories among scientists around the world.

One camp suggests that the regrowth of rainforests has been overlooked, resulting in the current “biodiversity crisis” argument, which fears that half of the world’s species could be lost in the coming decades, is too pesimistic.

However, another school of thought contends that only about half of the plants species originally found in rainforests will return to the areas, and that many animals will not survive the transition.

Others warn that the continuing expansion of netoworks of access roads into rainforests will make it easier for poachers and loggers, threatening the existence of tropical species even further.

Cristian Samper, director of the National Museum of Natural History, who presided over the debate, said: “By bringing together the world’s most foremost authorities on different aspects of rainforest sicence, we hope to achieve new insights into a situation with potentially profound implications for all species, including ours.”

Using a combination of satellite data and field research, estimates suggest that:

  • ten million square kilometres have been cleared of at least half of their wood cover for human uses, includingtimber and agriculture
  • five million square kilometres have been selectively logged, often with high-impact methods that leave forests degraded
  • Of the intact forests remaining, about 275,000 square kilometres – an area bigger than the UK – were felled in five years (between 2000 and 2005)
  • approximately 350,000 square kilometres  (about 2% of original forested areas) are in some stage of regrowth, primarily in South Asia and Latin America.

According to Greg Asner from the Carnegie Institution, deforestation was the most profound change underway in tropical rainforests.

However, he added, land abandonment was the second most important trend, with the majority of the abandonment occurring in upland areas that offered marginal farming opportunities.

Often, the inhabitants departed to pursue better income opportunities in lowlands and cities.

He added that regrowth was relatively quick:  the forest canopy closed after just 15 years; after 20 years, about half of the original biomass weight had grown back.

Joseph Wright, from the Smithsonian Tropical Research Institute, noted that more than 20% of all land within 10 degrees of the equator had acquired protected status, and that the tropics had a percentage of protected land greater than North America, Europe or Japan.

He and colleague Helene Muller-Landau asserted in a 2006 study: “Large areas of tropical forest cover will remain in 2030 and beyond.

“We believe that the area covered by tropical forest will never fall to the exceedingly low levels that are often predicted.”

They added: “Extinction will threaten a smaller proportion of tropical forest species than previously predicted.”

Their position was partly based on UN predictions of growing urbanisation and slower population growth.  As a result, the abandoned areas will recover and tropical species spared, they contend.

But William Laurance, also from the Smithsonian Tropical Research Institute, argued that secondary and degraded forests would sustain only a fraction of existing animal species.

He added that birds and mammals were more vulnerable to the altered habitat than insects and other small organisms.

Forest destruction in years past was largely the result of land being cleared for small-scale farming, he observed.

However, trade globalisation was fostering large-scale industrial agriculture, logging and mining; all of which was accelerating forest destruction.

The world was now losing the equivalent of 50 football fields of old-growth forest every minute, he warned.

“Rainforest regrowth is indeed occurring in regions but most old growth is destroyed,” he said.  “In biodiversity terms, this is akin to a barn door closing after the horses have escaped.”

The findings from the debate, and the evidence presented by the speakers, will be published as papers in a special edition of the journal Conservation Biology.

Source: Smithsonian press release

Date: 12/01/2009

Hackers ‘aid’ Amazon logging scam


Hackers have helped logging firms in Brazil evade limits on tree felling, says a Greenpeace report.

The hi-tech criminals penetrated a computer system designed to monitor logging in the Brazilian state of Para, according to a report on the BBC News website.

Once inside the system, hackers issued fake permits so loggers could cut down far more timber than environmental officials were prepared to allow.

Greenpeace estimates that 1.7m cubic metres of illegal timber may have been removed with the aid of the hackers.

Drawing on information released by Brazilian federal prosecutor Daniel Avelino, Greenpeace believes hackers were employed by 107 logging and charcoal companies.

“Almost half of the companies involved in this scam have other law suits pending for environmental crimes or the use of slave labour,” said Mr Avelino in a statement issued by Greenpeace.

Mr Avelino is suing the companies behind the mass hack attack for two billion reals (£564m) – the estimated value of the timber illegally sold.

The Brazilian investigation of the hackers began in April 2007 and more than 30 ring leaders were arrested during the summer of that year. The ongoing investigation means that now 202 people face charges for their involvement in the subversion of the logging system.

The hack was made possible by a decision in 2006 to do away with paper forms to help monitor whether logging and charcoal firms were keeping to the quotas they were set.

Instead, the Amazon state of Para turned to a fully-computerised system that issued travel permits for the timber logging firms were removing. The intent was that travel permits would stop being issuedonce logging companies had reached their annual quota.

With the help of the hackers, Brazilian logging firms were able to issue fake permits allowing them to bust through these caps.

“We’ve pointed out before that this method of controlling the transport of timber was subject to fraud,” said Andre Muggiati, Greenpeace campaigner in Manaus. “And this is only the tip of the iceberg, because the same computer system is also used in two other Brazilian states.”

Source: BBC News website

Date: 15/12/2008

Forest diversity ‘stems from specialisation’


The rich diversity of trees in tropical forests may be “the result of subtle strategies that allow each species to occupy its own ecological niche” rather than random dispersal, Mongabay.com reports.

Studying the traits of trees in Yasuni forest in Ecuador, Nathan Kraft and colleagues, writing in the journal Science, found evidence to support the theory that “niche separation” – subtle habitat specialisations among species – drives tree diversity in the rainforest.

The researchers’ findings challenge the recent hypothesis of “neutral theory”, which attributes community composition to chance.

“If the neutral theory is correct, we would expect these traits to be distributed at random throughout the forest, but that was not the case,” said Renato Valencia, professor at Pontificia Universidad Catolica del Ecuador and lead investigator at the Yasuni forest plot, which is associated with the Center for Tropical Forest Science/Smithsonian Institution Global Earth Observatory network.

“The traits we measured give us important clues about the strategy of each species in the forest – how they make a living – if you will.

“One exciting thing that we found is that trees growing near each other tend to make a living in different ways from their neighbors,” explained Dr Kraft, from UC Berkeley.

“This is a common pattern in less diverse communities, but it is hard to imagine in a hyper-diverse forest like Yasuni.”

The scientists plan to continue their research at Yasuni and other sites to better understand the patterns of biodiversity around the world.

The Center for Tropical Forest Science/Smithsonian Institution Global Earth Observatory network includes more than 30 forest dynamics plots in 17 countries.

Source: Mongabay.com

Date: 24/10/2008

‘Historic deal’ to save Sumatran forests


The Indonesian government and conservation group WWF have announced a commitment to protect the remaining forests and critical ecosystems of Sumatra, the world’s sixth-largest island, which holds some of the most diverse and endangered forests, a press release by the green group anounced.

They wrote:

Sumatra is the only place on Earth where tigers, elephants, orangutans and rhinos co-exist but since 1985 the island has lost 48 percent of its natural forest cover. This historic agreement represents the first-ever island-wide commitment to protect Sumatra’s stunning biodiversity. It has been endorsed by governors of all the provinces across Sumatra and also by four Ministers.

“This agreement commits all the Governors of Sumatra’s ten provinces, along with the Indonesian Ministries of Forestry, Environment, Interior and Public Works, to restore critical ecosystems in Sumatra and protect areas with high conservation values,” said Hermien Roosita, Deputy Minister of Environment. “The Governors will now work together to develop ecosystem-based spatial plans that will serve as the basis for future development on the island.”

WWF, Conservation International (CI), Fauna and Flora International (FFI), Wildlife Conservation Society (WCS), and other conservation groups working in Sumatra have agreed to help implement the political commitment to protect what remains of the island’s species-rich forests and critical areas.

“WWF is eager to help make this commitment a reality to protect the magnificent tropical forests across Sumatra. These forests shelter some of the world’s rarest species and provide livelihoods for millions of people,” said Mubariq Ahmad, CEO of WWF-Indonesia.

Today’s announcement follows commitments made at the Convention on Biological Diversity’s Conference of Parties in Bonn in May to achieve zero net deforestation by 2020 – that means that global forest coverage must remain the same, taking into account deforestation and reforestation.

Source: WWF press release

Date: 08/10/2008

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