Friday, September 21, 2007

Drought Makes Rainforest Greener

Research by Scott Saleska of the University of Arizona found that tropical rainforests actually become greener and more lush during a drought. The research was done during a drought that coincided with the natural dry season in the Amazon in 2005 and results are being published in the September 21 issue of the journal Science.

An abstract of an article published in Geophysical Research Letters, March 2006, contains the following:

MODIS Enhanced Vegetation Index (EVI, an index of canopy photosynthetic capacity) increased by 25% with sunlight during the dry season across Amazon forests, opposite to ecosystem model predictions that water limitation should cause dry season declines in forest canopy photosynthesis.

In other words, global warming models predict that the rainforest will be hit by drought and indicate that the rainforest will suffer from decreased rainfall but actual measurements show an increase in green vegetation during a dry period. The researchers believe that less rain allows the trees to receive more sunlight and to dig their roots further into the earth to get water.

Other articles on this subject:
Times Online
Fox News

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