The size of the Amazon basin is amazing, and so is the dynamic of how how its incredible rainfall is produced. Did you know that 50 percent of Amazon rainfall is produced by the forest itself, by the transpiration from its trees. The intact forest is a huge moisture pump. The water of my region (Acre) actually recycles up and down 15 times before arriving from the far-away Atlantic. I have posted about this fascinating water cycle at http://lougold.blogspot.com/2010/05/bag-of-water-drops-far-from-atlantic.html

Since deforestation and fragmentation in the East and South can strongly influence this moisture cycle, forest scientists and climate modelers are warning that the effects can ripple across the whole system. There is a range of opinion concerning an imminent Amazon forest die-off and some disagreement as to whether transforming feedback loops are triggered at 20, 30 or 40 percent deforestation. But broad consensus is that we should not be sanguine about the future.

The latest science on the Amazonian rain forests and drought has just been published online in a special report from the New Phytologist which concludes that, although mass die-off is not inevitable, “… when expected feedbacks between vegetation and climate are combined with fire incidence and land-use change scenarios, we conclude that Amazon rain forests are highly vulnerable to loss during the coming decades.”

http://www3.interscience.wiley.com/journal/118538954/home?CRETRY=1&SRETRY=0

\”Highly vulnerable to loss\” does not make me \”cautiously upbeat.\” It makes me \”seriously concerned\” about what might happen as climate changes spreads across this largest rainforest on earth.