In the experiment, first of its kind, scientists scanned trees in Austria and Finland with laser beams between sunset and sunrise. From the time it takes beams to bounce back from branches and leaves, they could measure the movements of each tree, in three dimensions and at resolutions of centimetres.
They found that trees have been shown to undergo physical changes at night that can be likened to sleep, or at least to day-night cycles that have been observed experimentally in smaller plants.
Branches of birch trees have now been seen drooping by as much as 10 centimetres at the tips towards the end of the night.
https://www.newscientist.com/articl...ing-branches-while-asleep-for-the-first-time/
They found that trees have been shown to undergo physical changes at night that can be likened to sleep, or at least to day-night cycles that have been observed experimentally in smaller plants.
Branches of birch trees have now been seen drooping by as much as 10 centimetres at the tips towards the end of the night.
https://www.newscientist.com/articl...ing-branches-while-asleep-for-the-first-time/