An optical illusion may explain why Amazon forests appear greener during dry seasons.
Satellites observing the forests’ canopies have picked up signs that leaf production cranks up when moisture is scarce. But the trick of light means that Amazon forests might be more vulnerable to drought than scientists suspected. The new analysis of satellite data appears February 5 in Nature.
The study also revamps the forests’ role in carbon storage, says Eric Davidson, a forest ecologist at the Woods Hole Research Center in Falmouth, Mass., who was not involved with the work.
Since Amazon forests looked so green in dry seasons, some scientists believed trees might be pulling extra carbon from the air to make more leaves. But, Davidson says, “this paper shoots a hole in that theory.”
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