Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Amazon carbon sink threatened by drought

06.03.2009
The Amazon is surprisingly sensitive to drought, according to new research conducted throughout the world's largest tropical forest. The 30-year study, published today in Science, provides the first solid evidence that drought causes massive carbon loss in tropical forests, mainly through killing trees.

"For years the Amazon forest has been helping to slow down climate change. But relying on this subsidy from nature is extremely dangerous", said Professor Oliver Phillips, from the University of Leeds and the lead author of the research.

"If the earth's carbon sinks slow or go into reverse, as our results show is possible, carbon dioxide levels will rise even faster. Deeper cuts in emissions will be required to stabilise our climate."

The study, a global collaboration between more than 40 institutions, was based on the unusual 2005 drought in the Amazon. This gave scientists a glimpse into the region's future climate, in which a warming tropical North Atlantic may cause hotter and more intense dry seasons.

The 2005 drought sharply reversed decades of carbon absorption, in which Amazonia helped slow climate change.

In normal years the forest absorbs nearly 2 billion tonnes of carbon dioxide. The drought caused a loss of more than 3 billion tonnes. The total impact of the drought - 5 billion extra tonnes of carbon dioxide in the atmosphere - exceeds the annual emissions of Europe and Japan combined.

"Visually, most of the forest appeared little affected, but our records prove tree death rates accelerated. Because the region is so vast, even small ecological effects can scale-up to a large impact on the planet's carbon cycle," explained Professor Phillips.

Some species, including some important palm trees, were especially vulnerable", said Peruvian botanist and co-author Abel Monteagudo, "showing that drought threatens biodiversity too."

The Amazon accounts for more than half of the world's rainforest, covering an area 25 times as great as the United Kingdom. No other ecosystem on Earth is home to so many species nor exerts such control on the carbon cycle.

The study involved 68 scientists from 13 countries working in RAINFOR, a unique research network dedicated to monitoring the Amazonian forests.

To calculate changes in carbon storage they examined more than 100 forest plots across the Amazon's 600 million hectares, identified and measured over 100,000 trees, and recorded tree deaths as well as new trees. Weather patterns were also carefully measured and mapped.

In the wake of the 2005 drought the RAINFOR team took advantage of this huge natural experiment, and focused their measurements to assess how the drought had affected the forest.

The study found that for at least 25 years the Amazon forest acted as a vast carbon sink. A similar process has also been occurring in Africa.

In fact, over recent decades the tropical forests have absorbed one fifth of global fossil fuel emissions.

But in 2005 this process was reversed. Tree death accelerated most where drought was strongest, and locations subject even to mild drying were affected. Because of the study, we now know the precise sensitivity of the Amazon to warming and drought.

If repeated, Amazon droughts will accelerate climate warming and make future droughts even more damaging.

Clare Ryan | EurekAlert!
Further information:
http://www.leeds.ac.uk

More articles from Studies and Analyses:

nachricht Physics of bubbles could explain language patterns
25.07.2017 | University of Portsmouth

nachricht Obstructing the ‘inner eye’
07.07.2017 | Friedrich-Schiller-Universität Jena

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

Serious children’s infections also spreading in Switzerland

26.07.2017 | Health and Medicine

Biomarkers for identifying Tumor Aggressiveness

26.07.2017 | Life Sciences

NASA mission surfs through waves in space to understand space weather

25.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>