Some trees seem to be adapting to climate change by using less water, according to a study by a team of researchers from several universities, including Indiana University, that was recently published in the journal Nature.
Using atmospheric devices on a 150-foot tower in the Morgan-Monroe State Forest, IU researchers measured how much water vapor and gases were being absorbed and released by the forest.
That information, combined with similar data from forests around the world, has led researchers to the conclusion that with more carbon dioxide in the air, trees are using less water.
Two former IU researchers, HaPe Schmidt and Danilo Dragnoi, were authors on the report.
Schmidt, who is now the director of the Institute of Meteorology and Climate Research at the Karlsruhe Institute of Technology in Germany, headed IU’s part of the project while he was a professor there up until 2007. He says scientists knew this kind of thing could happen, but had never actually seen it in nature.
“The really surprising finding, that is really puzzling in a way is that this saving of water was stronger than what was previously found in lab studies,” he says.
The findings could be a good thing because it means trees are likely better able to withstand droughts.
But if trees are using less water, trees are also releasing less water into the atmosphere, which could mean less rain.
In addition, if there is less water being absorbed in the evaporation process, the sun’s energy will just be going into the atmosphere, instead of being absorbed, and that could exacerbate global warming.
Several IU researchers, including Assistant Biology Professor Rich Phillips, are continuing the research Schmidt began. Phillips says recent, drier conditions since 2009, including last year’s drought could provide new data to work with.
“One of the things that we need to test now is to say whether under these new conditions where it’s getting even drier this increased efficient use of water is offset by when it gets really dry and the trees can’t continue to grow,” he says.
More research also needs to be done to find out how individual forests are likely to react to climate change.
“There are different species in the forests, and they might behave slightly differently with respect to carbon update and water loss in different environmental conditions,” says Dragoni, who is now an environmental scientists with the Nevada Division of Environmental Protection.
That is something IU researchers are studying. Phillips says in Indiana forests, oaks and hickories tend to be more drought resistant, while the sugar maple, tulip poplar and sassafras are more drought susceptible.
Both Dragoni and Schmidt also retain titles as adjunct professors at IU because of their continued research in the Morgan-Monroe State Forest.