Staggering tree loss from 2005 Amazon storm

Science Daily: A single, huge, violent storm that swept across the whole Amazon forest in 2005 killed half a billion trees, a new study shows While storms have long been recognized as a cause of Amazon tree loss, this study is the first to produce an actual body count. And, the losses are much greater than previously suspected, the study's authors say. This suggests that storms may play a larger role in the dynamics of Amazon forests than previously recognized, they add.

Previous research had attributed a peak in tree mortality in 2005 solely to a severe drought that affected parts of the forest. The new study says that a single squall line (a long line of severe thunderstorms, the kind associated with lightening and heavy rainfall) had an important role in the tree demise. This type of storm might become more frequent in the future in the Amazon due to climate change, killing a higher number of trees and releasing more carbon to the atmosphere.

Tropical thunderstorms have long been suspected to wreak havoc in the Amazon, but this is the first time researchers have calculated how many trees a single thunderstorm can kill, says Jeffrey Chambers, a forest ecologist at Tulane University, in New Orleans, and one of the authors of the paper, which has been accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union (AGU).

In 2005, there was a spike in tree mortality in the Amazon. Previous studies by a coauthor of this new paper, Niro Higuchi of Brazil's National Institute for Amazon Research (INPA), showed the second largest upsurge recorded since 1989 for the Manaus region. Also in 2005, large parts of the Amazon forest experienced one of the harshest droughts in the last century. A study published in the journal Science in 2009 pointed at the drought as the single agent for a basin-wide increase in tree mortality. But a very large area with major tree loss (the region near Manaus, in the Central Amazon) was not affected by the drought.

"We can't attribute [the increased] mortality to just drought in certain parts of the basin -- we have solid evidence that there was a strong storm that killed a lot of trees over a large part of the Amazon," Chambers says….

From 1853,a sepia painting of the Brazilian forest by Manuel de Araújo Porto-Alegre