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PROVO — Researchers from BYU, Utah State and China have figured out how a certain desert plant thrives without much water, and the results are rather gravity-defying.
The results, the researchers believe, might also lead to future ways to manufacture water on desert lands.
“Making water available to people who need water — I think this can have an important impact in that area,” said William Pitt, a BYU professor of chemical engineering.
Pitt, Tadd Truscott, USU assistant professor of mechanical engineering and BYU grad student Zhao Pan — the study's lead author — worked together to finish research compiled by professors at the Xinjiang Institute of Ecology and Geography in China about a certain moss that grows in the desert.
The desert moss, known as syntrichia caninervis, has been known in the botany community when it was first discovered by Linn J. Mitten well more than a century ago, and it has been known for a while that the moss didn’t need roots in the ground like other plants to absorb water.
The moss typically grows in desert areas, which was found in Utah and in China, where the study of the moss took place.
The Chinese researchers discovered that cutting tiny leaf hairs found on the plant noticeably altered the moss' ability to grow.
However, it wasn’t until the joint BYU and USU research team that scientists figured out exactly how the moss maintained water in dry desert conditions.
As it turns out, the microscopic leaf hairs play a major role in trapping moisture, forming it to much-needed water and giving that to the plant to thrive — even while upside down, according to a study by the research group published in a study this week by “Nature Plants.”
“The plant scientists have, for a long time, realized that the water didn’t come from the roots and that it probably comes from fog, dew and rain — things like that, but nobody had known that the hair structure was critical until the Chinese (scientists) said ‘Let’s see what happens when we cut off the hairs and see how they grow,’” Pitt said. “That’s what piqued our curiosity.”
Using microscopes, the trio found even smaller nanogrooves — about one hundredth the size of a human hair strand, Pitt said — that run down the hair to collect moisture, turn it into droplets and shoot it to down to the leaf.
The researchers captured that process using high-resolution cameras.
This absorption, the researchers found, begins with as little as dew or a drop of water.
The researchers also discovered that the force of this absorption is strong enough that the plant can absorb water in any position, including when the plant is upside down, forcing the water to move upward.
“They don’t creep slowly along these plant hairs,” Pitt said. “Once the droplets are big enough to overcome the forces that pin them in place, then they quickly move down the hair toward the leaf.”
After the researchers saw the process in slow motion, Pitt said he hypothesized that the plant hair had a mechanism about it that allowed it to trap water, and sure enough he was correct when they found the nanogrooves along with barbs that stuck out as well.
Pitt said the barbs trapped the droplets onto the hair and that water formed on the nanogrooves before it moved to the leaf to flourish.
The discovery, Pitt added, could have an impact in water availability and conservation — a major issue in the western U.S. and other places across the globe.
With Pitt, Truscott and Pan each having backgrounds in engineering, the goal from the study is to understand the physics of the moss and use it create technology to solve problems for areas with lesser water availability.
Through that, scientists could build fibers, meshes and webs to collect any form of condensation and push it down to water containers.
“One of the biggest pushes in today’s society is to collect water for people who don’t have water,” Pitt said. “If they live in a place that has fog but not streams or rivers, then this is a technology to collect fog and turn that into water — or just collect moisture from condensation.
“Our interest is not in only revealing what nature does, but learning from nature about how we can make a similar collection of water that would benefit people.”
