From a recent JPL press release:

A single, huge, violent storm that swept across the whole Amazon forest in 2005 killed half a billion trees, according to a new study funded by NASA and Tulane University, New Orleans.

While storms have long been recognized as a cause of Amazon tree loss, this study is the first to actually quantify losses from a storm. …

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 lightning and heavy rainfall) had an important role in the tree demise. Research suggests 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.

Wow!