"Adult Amazon Trees Gain Mass, Puzzle Scientists"

An article by John Roach in National Geographic News http://news.nationalgeographic.com/news/2001/12/1213_carbonsink.html

Explored by Kathy Mertens, December 21, 2001

Research has shown that mature forest trees in the Amazon have grown in size over the last 20 years (1). Scientists don’t know the cause of this phenomenon or the effects it might have on global warming but it is thought to be that the trees are acting as a huge "carbon sink".

Oliver Phillips of the University of Leeds in the United Kingdom has published his results a study showing the growth of the Amazon forest trees over the last 20 years. This study fascinated me since we just finished up talking about global warming. Phillips believes that the trees are acting as a huge "carbon sink", absorbing more carbon from the atmosphere than they release. This is a very enlightening discovery as these trees were thought to be "carbon neutral", giving off as much carbon as they absorb each day (1).

Biomass holds about as much carbon as the atmosphere

Phillips' study has made other researchers eager to find out exactly what is going on with the forests in the Amazon. A specific organization has been established to research this matter, the Amazon Forest Inventory Network or RAINFOR. They are studying the link between carbon sinks and global warming and how long the effect might last. This organization has received funding from the European Union, the United States and the National Geographic Society.

The carbon sink theory is not the only theory being looked at here. Other theories include the forests receiving more nutrients than previously as the result of human activities. Some of those activities are forest fires, which release increased amounts of nitrogen into the atmosphere. The nitrogen is then absorbed by clouds and returns to Earth as rain, thus fertilizing the forests. Another idea is since logging in the Amazon rain forest has diminished in some areas the forests may be starting to recover, thus there is an increase in mass. The principal is the same with our lawns. We cut the grass, the grass goes into a survival mode and grows, it grows we then cut, a vicious cycle but it works the same in areas of forests that are recovering from logging.

Currently the more widely accepted idea for the growth of these trees is that the forests are acting as a carbon sink as a result of the carbon-fertilization effect. Phillips is concerned that the results of the RAINFOR study could lead to complacency and a failure to address the causes of global warming. He believes that if humans want to avoid the worst-case scenario of global warming they must reduce the burning of fossil fuels.

After reading this article I agree with Phillips and his colleagues that another major reason to conserve the Amazon forests, is that they may be acting as a brake against the pace of global warming by absorbing carbon dioxide from the atmosphere (40).