Walk Quietly in the Woods, Trees Might Be Sleeping
Researchers find trees 'droop' at night
By Michael Harthorne,  Newser Staff
Posted May 20, 2016 4:39 PM CDT

(Newser) – Well this gives the phrase "sleeping like a log" a whole new meaning. New research shows trees might sleep like any other living organism, the Christian Science Monitor reports. Scientists used lasers to make models of silver birch trees in Finland and Australia and discovered the trees' branches "droop" up to 10 centimeters at night, according to New Scientist. They published their findings earlier this year in Frontiers in Plant Science. Studies on flowers and other small plants undergoing changes between night and day go back centuries, according to a press release. But it was never clear if large plants like trees did the same thing. “No one has observed this effect before at the scale of whole trees, and I was surprised by the extent of the changes,” one of the researchers tells New Scientist.

Researchers used laser technology that allowed them to monitor the trees' movements without using lights, which would have produced a photosynthetic response in the plants. They found the trees' branches were at their lowest point a few hours before sunrise. So far, it's unclear if the trees were moving due to their own internal clock or because of reactions to photosynthesis during the day. The drooping could be attributed to the loss of water pressure inside plant cells at night or because it takes energy to hold branches up to the sun during the day. Researchers plan to next study the water use of trees during the day and at night to get a better idea of what's going on. (If you're a woman, trees could extend your life.)