Trees and their mysteries never cease to amaze. After the “shy” trees that avoid touching each other, the interconnected trees that communicate with each other, or the trees that practice breastfeeding, scientists have now made another incredible discovery on our green friends: trees would also have a “heartbeat”.
On April 20, an article from the New Scientist website detailed the results of a fascinating research: trees would have a sort of “heartbeat” so slow that no scientist had noticed it until now.
Indeed, until recently, biologists were convinced that water circulated through the branches of trees through a phenomenon called osmosis: a diffusion phenomenon that happens when solvent molecules pass through a semi-permeable membrane separating two solutions whose solute concentrations are different. But, that may not be the only way. “We have found that most trees regularly have periodic shape changes, synchronized throughout the plant and shorter than a day-night cycle, which involves periodic changes in water pressure.,” the researchers.
In other words, during the night, the branches of the trees seem to move up and down about a centimeter and a half, contract, dilate and pump essential water from the roots to the leaves, like of our heart responsible for pumping blood and diffusing it into our body.
The difference lies in the fact that, unlike our body with a regular pulse, that of trees is much slower and beats only once every two hours or so. The human pulse regulates the blood pressure, while that of the trees regulates the pressure of the water circulating within them.
These observations took place at night, in greenhouses, in order to ward off the influence of the sun and the wind on the movement of the branches. At present, however, this team of biologists is unable to explain how this pumping mechanism actually works.
One of their theories explains that the trunk could compress the water by pushing it up the tree through the xylem, a plant tissue made up of woody fibers and vessels carrying raw sap, water and nutrients to branches and leaves.