Shhh. Even trees need their zzzzz's, scientists say

Researchers in Finland and Austria have found that trees 'sleep,' responding to changes in light and temperature at night.

|
Amit Dave/Reuters
Men rest under the shade of a tree on a hot summer day in Ahmedabad, India. It turns out trees need their rest to, according to new research from Finland and Austria.

If a tree snores in the forest, does it make a sound?

Ok, trees probably don't snore, but it turns out they might actually sleep, according to recent research.

Most living organisms respond to the variations in temperature and light that come during the nighttime. A team of researchers from Austria, Finland, and Hungary have discovered that trees might also need their shut-eye.

The researchers used laser scans and examined two different silver birch trees, one in Finland and one in Austria, to look for patterns. They used the lasers to monitor specific points on the trees and then created point cloud maps of the organisms’ movements and the surrounding forest canopies. What the researchers found is that the trees’ branches made very subtle but discernible movements at sunset, and again at sunrise.

“Our results show that the whole tree droops during night which can be seen as position change in leaves and branches,” Eetu Puttonen, of the Finnish Geospatial Research Institute, said in a press release. “The changes are not too large... but they were systematic and well within the accuracy of our instruments.”

Both the Finnish and Austrian trees slowly drooped beginning at sundown, and then gradually returned to their original position after sunrise. The researchers haven’t conclusively determined whether this is because they are capitalizing on the availability of sunlight for photosynthesis or the trees are actually following a circadian rhythm.

What is clear to the researchers, though, is that this isn’t a case of unusually high winds tossing the trees around. Both experiments were conducted under calm and clear conditions, where no wind or rain was observed.

The research team plans to use these findings to conduct future studies on the difference between trees’ water use at night and during the day, and whether their sleep patterns play a role.

"Understanding ecophysiological processes of individual trees, including their diurnal water use pattern and how this changes under water stress is becoming increasingly important for climate research," the researchers write in a paper published in the journal Frontiers in Plant Science.

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

You've read  of  free articles. Subscribe to continue.
Real news can be honest, hopeful, credible, constructive.
What is the Monitor difference? Tackling the tough headlines – with humanity. Listening to sources – with respect. Seeing the story that others are missing by reporting what so often gets overlooked: the values that connect us. That’s Monitor reporting – news that changes how you see the world.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

QR Code to Shhh. Even trees need their zzzzz's, scientists say
Read this article in
https://www.csmonitor.com/Science/2016/0520/Shhh.-Even-trees-need-their-zzzzz-s-scientists-say
QR Code to Subscription page
Start your subscription today
https://www.csmonitor.com/subscribe