Stanford study shows dry air drives overlooked changes in how plants drink and breathe

June 01, 2020

Plants drink up much of the water that falls to Earth. They take what they need before releasing it through tiny holes on the underside of their leaves, just as people release water vapor with every exhale.

How much a plant drinks and the rate at which it releases water, or transpires, depends partly on moisture levels in the air and soil. Global warming will shift this process more than previously predicted, according to new research from Stanford University.

Published June 1 in Nature Climate Change, the
"This is good news," said study co-author

"Whether plants will fare better in future droughts is a more complex question," said lead author

For agricultural crops, this means the best available estimates of future water needs, growth and vulnerability are "likely to be incorrect" during periods when the atmosphere is very dry, said another of the study's authors,

Atmospheric dryness going 'through the roof'

The scientists looked specifically at a component of climate models that estimates evapotranspiration, which refers to the rate at which Earth's land surface and plants return water to the atmosphere. "So much of the water balance in any given ecosystem goes to evapotranspiration, it has implications for how much water is left over for water resources for people," Konings said. "It also has big effects on weather and climate."

A common modeling approach treats this dynamic process more or less as a function of soil moisture. "That's not realistic because vegetation responds to drought based on the amount of water inside the leaves," Konings said.

Few climate models try to disentangle the effects of dry soil and dry air when predicting changes in evapotranspiration. "The models in use right now work really well if you're averaging wet and dry conditions over multiple years, but not in times of drought," said Konings, who is also a center fellow, by courtesy, at Stanford

This entanglement becomes increasingly problematic under climate change. In some

Bringing in hydraulics

The researchers modeled the effect of this drying on plants' drinking habits by zooming in on responses in the plant hydraulic system - the pipes and valves inside a plant's roots, stem and leaves. They developed mathematical techniques to derive evapotranspiration rates from a combination of widely available datasets, including records of soil texture, canopy heights, plant types and flows of carbon and water vapor at 40 sites around the world. Then they cross-checked their techniques against limited real-world measurements of evapotranspiration.

The development of a hydraulic model, in itself, is not a first. But the researchers went further, comparing the different model approaches to understand the impact of plant hydraulics under various conditions.

They found the most widely used approaches for estimating evapotranspiration miss about 40 percent of the effect of dry air. This is like a weather forecast that fails to mention wind chill or stifling humidity. The effect is strongest - and current predictions are the most off-base - in places where plants are the least adapted to drought. Konings said, "We were surprised that this had such a big effect."
-end-
Konings is also an Assistant Professor, by courtesy, of Geophysics in Stanford

The research was supported by NASA Terrestrial Ecology, NOAA and the National Science Foundation.

Stanford's School of Earth, Energy & Environmental Sciences

Related Science Articles from Brightsurf:

75 science societies urge the education department to base Title IX sexual harassment regulations on evidence and science
The American Educational Research Association (AERA) and the American Association for the Advancement of Science (AAAS) today led 75 scientific societies in submitting comments on the US Department of Education's proposed changes to Title IX regulations.

Science/Science Careers' survey ranks top biotech, biopharma, and pharma employers
The Science and Science Careers' 2018 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.

Science in the palm of your hand: How citizen science transforms passive learners
Citizen science projects can engage even children who previously were not interested in science.

Applied science may yield more translational research publications than basic science
While translational research can happen at any stage of the research process, a recent investigation of behavioral and social science research awards granted by the NIH between 2008 and 2014 revealed that applied science yielded a higher volume of translational research publications than basic science, according to a study published May 9, 2018 in the open-access journal PLOS ONE by Xueying Han from the Science and Technology Policy Institute, USA, and colleagues.

Prominent academics, including Salk's Thomas Albright, call for more science in forensic science
Six scientists who recently served on the National Commission on Forensic Science are calling on the scientific community at large to advocate for increased research and financial support of forensic science as well as the introduction of empirical testing requirements to ensure the validity of outcomes.

World Science Forum 2017 Jordan issues Science for Peace Declaration
On behalf of the coordinating organizations responsible for delivering the World Science Forum Jordan, the concluding Science for Peace Declaration issued at the Dead Sea represents a global call for action to science and society to build a future that promises greater equality, security and opportunity for all, and in which science plays an increasingly prominent role as an enabler of fair and sustainable development.

PETA science group promotes animal-free science at society of toxicology conference
The PETA International Science Consortium Ltd. is presenting two posters on animal-free methods for testing inhalation toxicity at the 56th annual Society of Toxicology (SOT) meeting March 12 to 16, 2017, in Baltimore, Maryland.

Citizen Science in the Digital Age: Rhetoric, Science and Public Engagement
James Wynn's timely investigation highlights scientific studies grounded in publicly gathered data and probes the rhetoric these studies employ.

Science/Science Careers' survey ranks top biotech, pharma, and biopharma employers
The Science and Science Careers' 2016 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.

Three natural science professors win TJ Park Science Fellowship
Professor Jung-Min Kee (Department of Chemistry, UNIST), Professor Kyudong Choi (Department of Mathematical Sciences, UNIST), and Professor Kwanpyo Kim (Department of Physics, UNIST) are the recipients of the Cheong-Am (TJ Park) Science Fellowship of the year 2016.

Read More: Science News and Science Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.