Relax, let your branches down.

Researchers in Europe scanned trees and found that their branches had a distinct tendency to droop by a small amount (at most 4 inches) in the evenings, after a long day’s work of photosynthesizing and standing majestically.

The researchers scanned two birch trees using lasers, one in Finland and one in Austria, and observed the drooping in both trees.

The reasons for the drooping have yet to be determined definitively. One of the authors, András Zlinszky told New Scientist that it could be due to a drop in water pressure in the plant cells that occurs when photosynthesis stops after the sun goes down.

They plan on eventually using the laser scanning technology to look at entire orchards or forests instead of individual trees.

“The next step will be collecting tree point clouds repeatedly and comparing the results to water use measurements during day and night,” says Eetu Puttonen, the other co-author. “This will give us a better understanding of the trees’ daily tree water use and their influence on the local or regional climate.”



Trees at night (left), trees during the day (right).