Tasmanian Blue Gum Trees Show Signs of Circadian Rhythm

Aw, that sweet circadian rhythm. Our little 24-hour biological clock that signals when it's time to go get up with the light and time to go to sleep with the darkness.

Well, turns out, trees also have their own internal clocks that help coordinate the activities of their cells with the cycles of the day and night.

According to a recent study, scientists knew of circadian rhythms in leaves, but not in whole trees. Thus, researchers looked at the Tasmanian blue gum tree and found that it appears to use its internal clock to regulate water intake. Because of this, scientists actually believe that these cycles could affect models of climate change.

"It had never been shown that the circadian rhythm of the leaf affected the whole tree," said study researcher Ruben Diaz Sierra, a physicist at the National University of Distance Education in Spain, via Live Science. "If it works for the tree, it works for the whole forest."

As researchers note, via the study's abstract, that the role of the circadian clock in controlling the mebaolism of entire trees has seldom been considered, they tested whether this idea would affect nocturnal whole-tree water use. 

Thus, researchers monitered trees in "whole-tre chambers" as part of the Hawkersbury Forest Experiment near Sydney, Australia. Following, they mesasured hwo much water vapor each lost through the small openings in the leaves' stomata. Researchers then compared the results to what was seen during overcast nights, which shows drastic changes in temperatures and humidity. 

Findings showed that in the six hours after dusk, water loss declined, but noticeably increased during the six hours before dawn, even on nights when temperature and humidity remained constant, according to the study. Researchers, thus believe these changes are caused by a biological clock within the trees.

The researchers believe the study carries important implications for models of climate change. "Right now, the models don't take into account the time of day," Sierra said, via Live Science. He believes that if a tree's carbon monoxide consumption is more or less based on the time of day, this could potentially affect how climate change will affect ecosystems. 

More information regarding the study can be found in the New Phytologist.