Nature & Environment

Trees may actually 'sleep' during the night

By T.K. Randall
May 19, 2016

Image: Leaf Forest
Credit: Den Vish / CC BY-SA 4.0 (adapted) Andras Zlinszky and his colleages from the Center for Ecological Research in Tihany, Hungary, made the discovery after using lasers to measure trees in Austria and Finland during the night.

They found that the branches of birch trees actually droop by as much as ten centimeters as part of a subtle day-night cycle that had only ever been observed before in small plants.

"It was a very clear effect, and applied to the whole tree," said Zlinszky. "No one has observed this effect before at the scale of whole trees, and I was surprised by the extent of the changes."During the day the trees angle their branches higher up to help them catch more sunlight, but at night, when there is no sunlight, letting the branches droop is a good way to conserve energy.

"There have been some studies on circadian rhythms in trees, mostly studying gene expression, but this latest research is a beautiful way to watch it happen in individual trees," said C. Robertson McClung of Dartmouth College in Hanover, New Hampshire.

"It shows things are happening in the real world."

Source: New Scientist

Tags: Trees, Sleep