The following news release was issued by Macquarie University in
Australia. It describes a project incorporating data collected in
ecosystems around the world, including data from the Arctic tundra
acquired by Alistair Rogers, a biologist at the U.S. Department of
Energy's Brookhaven National Laboratory as part of DOE's
Next-Generation Ecosystem Experiments (NGEE Arctic) project. For more
information about Rogers' work, see the accompanying sidebar and
links. Media inquiries about the overall study should be directed to
Amy MacIntyre at Macquarie University: +61 (2) 9850 4051,
Macquarie University News Release
Plants Use Water Wisely - Mostly
March 2, 2015
Plants trade water for carbon - every litre of water that they extract
from the soil allows them to take up a few more grams of carbon from
the atmosphere to use in growth. A new global study, led by Australian
researchers and published this week in Nature Climate Change, shows
that plants trade their water wisely, with different plant species
having different trading strategies depending on how much it costs
them to obtain their water.
"Our study looks at how much extra water it would take for a plant to
gain one more gram of carbon," says Dr Yan-Shih Lin of Macquarie
University, lead author of the study.
"We predicted that individual plants should keep this exchange rate
constant, but that the exchange rate should differ depending on what
type of plant it is and where it grows."
Comparing data from the different ecosystems showed that most of the
researchers' predictions were supported, indicating that plants have
adapted their water-use strategies to their environments. The biggest
surprise was that evergreen savanna trees were among the most
spendthrift plants with water, despite living in hot and arid
The researchers expected that plants with costly water transport
structures, such as conifers and trees with dense stemwood, would be
more conservative with their water, while grassy plants should be more
spendthrift. They also predicted that plants growing in cold or dry
environments should be more miserly with their water than plants
adapted to hot or wet environments.
"We crowd-sourced the data we needed to test these predictions," says
Professor Belinda Medlyn, of the University of Western Sydney.
"We couldn't travel the whole world ourselves, so we contacted other
researchers around the globe and together we put together data from
all kinds of ecosystems, from Arctic tundra to the Amazon rainforest
to the backblocks of Australia."
"This work is important because it provides insights into how plants
have adapted to their environments" says Dr Lin.
"Vegetation plays a really major role in the Earth system, by storing
carbon, moving water around the landscape and cooling the planet's
surface. These results provide us with crucial new information needed
to predict these effects, especially under different climate-change
Yan-Shih Lin et al. "Optimal stomatal behavior around the world"
Nature Climate Change, March 2015, Vol. 5. DOI: 10.1038/NCLIMATE2550
Brookhaven National Laboratory Sidebar: Serendipitous Data Sharing
Alistair Rogers, a Brookhaven Lab biologist with expertise in plant
physiology, has been collecting data in Barrow, Alaska, as part of the
U.S. Department of Energy's Next-Generation Ecosystem Experiments
NGEE-Arctic project. His work is focused on improving how Arctic plant
physiology is represented in Earth system models.
Some of this data has now been incorporated into an international
effort to improve how the behavior of plant structures that regulate
the flow of carbon dioxide (CO2) and water between leaves and the
environment are represented in these models. That project, led by
Yan-Shih Lin of Australia's Macquarie University and Belinda Medlyn of
the University of Western Sydney and published in Nature Climate
Change, aimed to build a new global dataset describing how these
pore-like structures, called stomata, function in different
plant/climate environments, or biomes.
"Stomatal control of the transfer of CO2 into the leaf is an important
process controlling CO2 uptake," said Rogers, "but current Earth
system models represent this process in a way that treats most
vegetation identically. A global dataset incorporating measurements
from multiple biomes around the world will improve our understanding
of the role stomata play in the global carbon cycle."
Rogers was one of many scientists from around the world participating
in this ambitious project.
"Data on Arctic species are particularly rare, so I was excited to
have the opportunity to share data from the NGEE-Arctic project-the
only Arctic data in this synthesis," Rogers said.
NGEE-Arctic is led by DOE's Oak Ridge National Laboratory and is
supported by the DOE Office of Science (BER).
One of ten national laboratories overseen and primarily funded by the
Office of Science of the U.S. Department of Energy (DOE), Brookhaven
National Laboratory conducts research in the physical, biomedical, and
environmental sciences, as well as in energy technologies and national
security. Brookhaven Lab also builds and operates major scientific
facilities available to university, industry and government
researchers. Brookhaven is operated and managed for DOE's Office of
Science by Brookhaven Science Associates, a limited-liability company
founded by the Research Foundation for the State University of New
York on behalf of Stony Brook University, the largest academic user of
Laboratory facilities, and Battelle, a nonprofit applied science and
Scientific Paper: "Optimal stomatal behaviour around the world"
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Brookhaven National Laboratory www.bnl.gov