15 March 2010
Source: Journal Watch
A report that the Amazon rainforest became greener during a 2005 drought cannot be confirmed, according to a study in Geophysical Research Letters.
Scientists don’t yet know exactly how droughts will affect the Amazon. In the worst-case scenario, climate change would cause the forests to die off and turn into savanna, resulting in the release of carbon. But in a 2007 study, scientists reported that a drought in 2005 actually caused the Amazon canopy to ‘green-up’.
Now, another team claims that the study doesn’t stand up to scrutiny. The researchers analyzed a new version of satellite data and found greening in only 11-12% of undisturbed forest area that experienced drought. Another 28-29% became browner or stayed the same, and the remaining data were too corrupted to evaluate accurately.
The amount of greening and browning didn’t appear to differ much in years when there was no drought, the team says. Therefore, the canopy changes observed during the 2005 drought “are not unique,” they write. – Roberta Kwok