Breakthrough discovery reveals how thirsty trees pull water to their canopies

January 20, 2016
Credit: Wikipedia.

A scientific mystery about how trees pull water from the ground to their top branches has been solved by an international team of researchers from the University of Leicester and the Queensland University of Technology, Australia.

The team, led by Dr Adrian Boatwright, who conducted the research while at the University of Leicester's Department of Chemistry, has examined the phenomenon of water being pulled to the top of tree branches, when says that the maximum height water can be pulled up is 33 feet due to gravity – known as the barometric limit.

The researchers have discovered that water can in fact be held in a vacuum for almost indefinite periods of time and even under significant tension without forming bubbles or breaking apart, which helps to explain how trees siphon water to their highest points.

The team also found that water can be pulled up to as much as 45 feet - well above the barometric limit, overturning the theory proposed by seventeenth century Italian physicist and mathematician Evangelista Torricelli which has stood for the last 400 years.

Dr Boatwright said: "How is it that trees can pull water up to the top most branches? This question has troubled both botanists and physicists for many years with various mechanisms used to describe this process - ranging from capillary action to osmotic pressure.

"By siphoning water up to as much as 45 feet we have managed to 'break' the barometric limit and show that the maximum height is limited only by the strength of bonds in the ."

While the widespread view has been that siphons work because of , recent research has shown that cohesion and gravity, and not atmospheric pressure is the driving principle.

Dr Stephen Hughes, Senior Lecturer in the Science and Engineering Faculty at Queensland University of Technology added: "The first recorded use of siphons was in ancient Egypt circa 1430 BC. Our experiment, conducted over 3,400 years later, is the first report published in the scientific literature of a siphon operating over the barometric limit. How siphons work has been quite controversial. This experiment is a clear demonstration that siphons work through gravity and not atmospheric pressure as is commonly supposed."

Explore further: Physicist demonstrates dictionary definition was dodgy

More information: A. Boatwright et al. The height limit of a siphon, Scientific Reports (2015). DOI: 10.1038/srep16790

Related Stories

New seafloor map helps scientists find new features

January 14, 2016

An international scientific team recently published a new map of the ocean floor based on Earth's gravity field, and it is a particularly useful tool. Such seafloor maps can aid submariners and ship captains with navigation, ...

Treetop leaves of tall trees store extra water

November 2, 2015

A research team led by Associate Professor Ishii Roaki and Doctoral Student Azuma Wakana from the Kobe University Graduate School of Agricultural Science has discovered that the water storage tissue that they recently found ...

Bat species found to have tongue pump to pull in nectar

September 28, 2015

(—A trio of researchers affiliated with the University of Ulm in Germany and the Smithsonian Tropical Research Institute in Panama has found that one species of bat has a method of collecting nectar that has never ...

Recommended for you

How the Earth stops high-energy neutrinos in their tracks

November 22, 2017

Neutrinos are abundant subatomic particles that are famous for passing through anything and everything, only very rarely interacting with matter. About 100 trillion neutrinos pass through your body every second. Now, scientists ...

Quantum internet goes hybrid

November 22, 2017

In a recent study published in Nature, ICFO researchers led by ICREA Prof. Hugues de Riedmatten report an elementary "hybrid" quantum network link and demonstrate photonic quantum communication between two distinct quantum ...

Lightning, with a chance of antimatter

November 22, 2017

A storm system approaches: the sky darkens, and the low rumble of thunder echoes from the horizon. Then without warning... Flash! Crash!—lightning has struck.

Enhancing the quantum sensing capabilities of diamond

November 22, 2017

Researchers have discovered that dense ensembles of quantum spins can be created in diamond with high resolution using an electron microscopes, paving the way for enhanced sensors and resources for quantum technologies.

Study shows how to get sprayed metal coatings to stick

November 21, 2017

When bonding two pieces of metal, either the metals must melt a bit where they meet or some molten metal must be introduced between the pieces. A solid bond then forms when the metal solidifies again. But researchers at MIT ...


Adjust slider to filter visible comments by rank

Display comments: newest first

5 / 5 (1) Jan 20, 2016
This does not seem to be news.
It has been known that water can exist under tension in a metastable state instead of turning to vapor.
Jan 20, 2016
This comment has been removed by a moderator.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.